Robotic device for coating and / or pre-treatment of overhead transmission or distribution line conductors

Abstract

A robotic device (300) for applying a coating and / or treatment to an overhead transmission or distribution line includes a pair of wheels (302), (304) configured to run on top of a conductor of the line. A pair of applicators (322), (323) are provided at leading and trailing ends of the device (300) for applying a coating or pre-treatment to the line. The wheels (302), (304) are mounted to a top bar (312) of a T shaped connector (315) of the chassis. The connector (315) includes a stem (314) suspending a main body (350) of the device (300) below the wheels. First and second tanks are located in first and second portions (354), (356) of the main body (350) for storing fluid for use in the pre-treatment or coating process. Fluid is supplied from the tanks to the applicators (322), (323) via pumps through fluid conduits disposed in a hollow interior of the connector (315).

Description

[0001] ROBOTIC DEVICE FOR COATING AND / OR PRE-TREATMENT OF OVERHEAD TRANSMISSION OR DISTRIBUTION LINE CONDUCTORS

[0002] BACKGROUND

[0003] The present invention relates a robotic device configured to pre-treat and / or coat an overhead transmission or distribution line, an overhead transmission or distribution line system, a method and a retrofit coating system configured to coat an overhead transmission or distribution line with a coating.

[0004] Described herein are methods, systems and a device for in-situ coating of overhead transmission and distribution conductors with a robotic crawler capable of passing mid-span obstacles.

[0005] A confluence of global trends are driving the need for increased transmission and distribution capacity. These include electrification, renewable energy generation development and population growth. World electricity generation is forecast to grow 25-45 trillion kWh between 2020 and 2050 (US EIA, 2020). Currently, the mechanisms to increase transmission and distribution capacity involve reconductoring overhead lines or building new transmission and distribution lines. These approaches involve heavy engineering, right of way disputes / issues of social acceptance, long project lead times and are capital intensive. Accordingly, to meet the growing electricity demand, cost effective methods to increase transmission and distribution capacity are required.

[0006] Spectrally selective coatings have emerged as a novel solution to increase the capacity of overhead transmission and distribution (T+D) conductors. These spectrally selective coatings work to enhance the capacity of overhead transmission and distribution conductors by optimising the surface for passive radiative cooling: maximised solar reflectivity (above 0.8) and maximised thermal emissivity (above 0.9). This passive temperature reduction of overhead transmission and distribution lines permits a higher current carrying capacity for a fixed cross sectional area or low power losses for a fixed operating current. Such coatings have been demonstrated to increase transmission capacity by up to 30% or reduce transmission power losses by up to 15%.

[0007] Examples of such coatings are described in WO 2020 / 053559, WO 2021 / 105673, WO 2021 / 152311 , WO 2021 / 181076 and WO 2022 / 003096.

[0008] The direct application of capacity enhancing coatings to overhead transmission and distribution conductors in situ represents an opportunity for network operators to uprate transmission and distribution assets without reconductoring or building new lines. Such an innovation would obviate heavy engineering, long project times and significantly reduce cost. I be disclosed in more detail below, according to various embodiments of the present invention robotic technology is disclosed which is capable of connecting to overhead lines, moving down the line and pre-treating the line and / or coating the line.

[0009] Various coating robots are known.

[0010] It is desired that a robotic device is provided which is capable of obstacle navigation. Transmission and distribution lines are comprised of various obstacles which include spacers, spacer dampers, suspension clamps, vibration dampers and suspension towers. Any scalable and productive transmission line coating robot needs to be able to effectively navigate at least some of these obstacles, such that operation is not contingent upon removal of these in advance.

[0011] Furthermore, the issue of conductor bundling should be addressed. Each phase of a transmission or distribution line can exist in bundles comprising two, three, four or more conductors. The geometry of these bundles may vary according to the number of conductors in the phase. Transmission line coating robots should ideally be capable of coating multiple conductors of a bundle (which may also be referred to herein as “sub-conductors”) in one pass, for all conductor configurations.

[0012] According to various embodiments of the present invention a robotic device is disclosed which comprises in-situ overhead transmission or distribution line pretreatment and / or coating capability and / or obstacle navigation capability and / or the capability of pre-treating and / or coating multiple conductors per phase.

[0013] Known devices can be categorised into two broad categories: (i) transmission line inspection robots; and (ii) transmission line coating robots.

[0014] Transmission line inspection robots

[0015] Various types of transmission line inspection robots are known. Transmission line inspection is a routine part of maintenance, in which damage and signs of aging are inspected, reported and maintained if required.

[0016] Transmission line inspection may be performed by humans, walking along the lines, but this is an inherently dangerous and labour intensive task. Alternatively, conductors may be inspected aerially by use of a helicopter. However, it will be understood that this incurs a substantial financial cost and requires specialised labour for operation. Drones have also emerged as a means for transmission line inspection with the aim of reducing the cost associated with using helicopters. However, these are limited by inclement weather and are more limited in their ability to place sensors directly on lines, for example, to measure the degree of corrosion by eddy current sensors, so also have limitations.

[0017] Transmission line inspection robots have been designed to offer solutions to the aforementioned problems. Critical to maintaining productivity, is the requirement for in line obstacle navigation. cample, EP-2882575 discloses a power line inspection robot comprising independent end effectors which can sequentially detach and therefore manoeuvre around obstacles. WO2014 / 086087 discloses a robot system for overhead power transmission line inspection and maintenance comprising several structurally identical drive arms, wherein the drive arms are suspended on a bundled conductor via the drive wheels and due to its multiple arms is able to overcome obstacles: “The present invention can plot a route relatively simply when surmounting obstacles, has good operability, and does not require manual control of the device during the process of surmounting obstacles”.

[0018] CN-212648942U discloses a similar design with four points of attachment over two conductors: “When encountering obstacles such as anti-vibration hammers, spacer rods, and pole tower cross arms, the obstacle-crossing inspection can be completed by sequentially controlling the lifting and movement of the mechanical foot, which solves the above-mentioned problems in the background art”.

[0019] Similarly, CN-106887807 and CN-109638718 disclose a design capable of overcoming obstacles on the line by the hybrid use of UAV and line crawlers i.e. the crawler detaches to become a UAV when obstacles are reached. Other arrangements concerned with obstacle crossing designs are disclosed in CN- 112003185, CN-208923721U, CN-212676775U, CN-109494620, CN-110932173, IN-4373CH2015, CN-107482529, CN-103050908, CN-111181067, CN-113328383, CN-209104683U, CN-112873245, CN-208923715U, CN-208923714U and CN- 112621710. Importantly, none of the above discloses relates to the ability to pretreat or coat lines.

[0020] CA-2899329 discloses a transmission line inspection robot to inspect for damage or corrosion. CN-113629640 and CN-210693396U disclose a robot for overhead transmission lines to mechanically remove ice adhered to transmission lines. WO2011 / 100409 and WO2011 / 100404 disclose a robot for inspecting transmission line components and right of way conditions. None of the disclosed arrangements disclose apparatus for pre-treatment or coating of conductors.

[0021] In broader related fields. CN-106312998 discloses a device for assisting power line robots to be winched onto a line. CN-109245326 discloses an overhead line patrol inspection robot pole tower resident charging station. It is noted that reference is made to: “At present, the technologies for charging the inspection robot are mainly divided into two categories: the robot itself carries the charging device; the robot charges the battery by the external device” and each of these are problematic due to increasing weight or reducing mobility respectively. An arrangement is disclosed comprising an overhead line charging station which allows long term inspection and “residence” on the line. Similarly, CN-205753571 U discloses “an automatic charging system for a transmission line patrol robot, which automatically charges the patrol robot, reduces or avoids stopping the charging frequency of the robot, thereby improving the patrol efficiency”. : a number of known inspection robots include a mechanism for obstacle navigation, known inspection robots do not include either overhead transmission and distribution line pre-treatment or coating functionality.

[0022] Known transmission line coating robots

[0023] US-10461512 discloses an aerial cable treatment system having a cable surface preparation assembly and a coating assembly for the application of spectrally selective coatings to overhead conductors. With respect to high voltage transmission lines, an “aerial cable treatment system can attach to a line and traverse the line between two adjacent towers, or other suitable spans, cleaning and / or coating the line as it travels” is disclosed. The core components of the design include a cable cleaning, coating application, optical guidance, on board control and motorised system for propulsion. The components of the system are included in a single enclosed housing unit through the interior of which the conductor extends during coating or cleaning. The conductor is located between upper and lower sets of wheels which are disposed within the housing unit. This does not provide the ability to negotiate obstacles.

[0024] The cable pre-treatment solution includes “mechanisms that prepare, clean, de-ice, or otherwise mechanically interact with the aerial cable, such as brushes, bristles, scrubbers, scrapers, abrasive paper, emery paper, sandpaper, rollers and so forth.”

[0025] The cable pre-treatment system can provide an air delivery system to provide a 360° air wipe to remove any recently generated debris. The pre-treatment system will also have an optical guidance system which can determine if the pretreatment is sufficient, and returning to areas with insufficient cleanliness.

[0026] A cable coating assembly is also described. This includes a nozzle which is in fluid communication with the fluid storage tank, via a liquid supply system, comprising a pump. The storage tank is disclosed as refillable, or single use that can be replaced. A “drip feed coating applicator assembly” is described which is connected to the air compressor to “distribute the dripped-on coating material uniformly around the cable”. The air wipe ensures that the material penetrates all of the grooves of the conductor. Similar to the pre-treatment system, the optical guidance system records the application of the coating and determines if the application has been sufficient. If not, the device will traverse and recoat. A spray gun which links to the compressor is also disclosed. The system is described as a multi-carriage system, where the first and second carriage can traverse together or separately.

[0027] CN-103934139 also discloses an automatic paint spraying robot to apply insulation coatings for overhead transmission lines. This is due to the need to insulate earlier constructed lines which have no insulation, which now pose a safety creased contamination / population in the surrounding area. “It is made up of some modular structures, described modular structure comprises moving body, power module, aircraft mounted control system, stirring module, spray module and hold down gag”. The coating application module involves two spray heads “at 180° to a point articulated structure”. The pump used is a plunger displacement which appears to be connected to the eccentric wheel drive mechanism, which simultaneously stirs and displaces the paint to the liquid transfer pipeline.

[0028] CN-111001542 and CN-203750741U also disclose overhead conductor spraying robots. Similar to CN-103934139 this is due to the need to retrospectively insulate overhead lines for safety purposes. CN-111001542 discloses a housing where “the lead fixing device is arranged on the shell and used for fixedly connecting the overhead lead spraying machine with an overhead lead and guiding the overhead lead spraying robot to walk” and a “gluing device” arranged on the shell, used for “coating glue onto the overhead conductor”. The glue is applied through a glue extruding unit.

[0029] CN-105728239 also disclose an automatic spraying robot for overhead transmission lines for the purposes of spraying insulation.

[0030] CN-103944102 discloses an overhead transmission line cleaning robot. This comprises a movable trolley, a power source module, a cleaning motor, a servo driver, a compressing device and a cleaning device. It is stated: “The overhead transmission line cleaning robot can be independently used and can also be used in cooperation with a spraying robot”. The “described cleaning motor comprises connected high-pressure sprayer motor and membrane pump, membrane pump entrance is connected with the cleaning agent bucket of cleaning device, and membrane pump is for drawing the cleaning agent of cleaning agent bucket be delivered in the cleaning head of cleaning device”. The cleaning agent outlined is dimethylbenzene.

[0031] US-10461512, CN-103934139, CN-111001542, CN-203750741 U, CN- 103934139, CN-111001542, CN-105728239 and CN-103944102 as discussed above disclose arrangement in which coatings application, or conductor cleaning mechanisms are integrated with a base robotic platform.

[0032] However, importantly, none of the above disclosed arrangements disclose the ability to navigate obstacles or coat multiple conductors in one pass. This is because they generally utilise a “clam shell” like design with annular rings which encapsulate a conductor.

[0033] In each transmission phase there can be a single conductor, or a bundle of conductors, for example, two, three, four or more conductors. Transmission phases are typically bundled. Thus there may be one, two, three or four or more conductors per phase. Reference is made to the arrangement shown in Figs. 1A-F.

[0034] In addition to this, transmission lines have multiple obstacles on the line. These include spacers, dampers, suspension towers. Accordingly, a problem remains in the art to be solved for transmission line robots which can pre-treat and 1 transmission and distribution conductors, desirably of multiple conductor configurations and pass in line obstacles.

[0035] CN203140222U disclose a live-line coating robot for power transmission lines, specifically for the application of anti-icing coating. This is comprised of a robot body, control system, power-supply system and finishing system. The finishing system comprises “application brush assembly, holds material pond, gasoline engine and liquid pump”. “Application brush assembly be about the clamp-on structure, include the nozzle of 120° of 3 spaces. The charging aperture of nozzle is connected with gasoline engine by feeding pipe, and gasoline engine expects that with holding the pond is connected”. Further, “The live-line coating robot for power transmission line anti-icing coating can step cover barriers such as spacer”. Whilst this discloses the concept of obstacle navigation, no detailed mechanisms for coating application or coating applicator / pre-treatment module deployment / retraction are outlined. Further, there is no disclosure of pre-treatment (cleaning / surface preparation) ability.

[0036] CN105470901A discloses an overhead power transmission line de-icing robot. They disclose a “sliding groove convenient for an obstacle-crossing travel mechanism and a de-icing structure” and that “the invention also includes an anti- icing coating application device disposed on the obstacle walking mechanism for applying an anti-icing coating to the outdoor overhead transmission line after deicing to prevent the transmission line from freezing again... “In order to ensure the application effect of the anti-icing coating, the anti-icing coating application device is a rotary nozzle or a swinging nozzle, and the nozzle of the nozzle (sic) is facing the transmission line”.

[0037] The reference does not outline the capability to coat multiple conductors and does not discuss pre-treatment mechanisms either.

[0038] PRESENT INVENTION

[0039] According to an aspect of the present invention there is provided a robotic device configured to pre-treat and / or coat an overhead transmission or distribution line, wherein the robotic device comprises a pre-treatment module and / or a coating application module; wherein the robotic device further comprises an obstacle avoidance module.

[0040] The robotic device may comprise only one of a pre-treatment module and a coating application module, or may comprise both pre-treatment and coating application modules. Preferably at least a coating application module is provided. Where the robotic device comprises only one of a pre-treatment module and a coating application module, it is envisaged that a robotic device in accordance with the invention comprising a pre-treatment module may be run along the line to apply a pre-treatment to the line with another robotic device in accordance with the invention comprising a coating application module then being run along the line to Where a robotic device comprises both pre-treatment and coating application modules, the robotic device may be run along the line to provide both pre-treatment and subsequently coating to line i.e. in a single pass, or may be passed along the line to first provide pre-treatment and then subsequently run along the line again to provide coating to the line.

[0041] The overhead transmission or distribution line referred to herein, and which the robotic device of the invention in any of its aspects or embodiments is configured to pre-treat and / or coat, comprises a set of one or more conductors. The set of one or more conductors may be a single conductor or may comprise a bundle of conductors i.e. a plurality of conductors.

[0042] A bundle of conductors may include two, three, four or more conductors, such as from two to four conductors. For example, bundles may include two, three, four or higher numbers of conductors such as six. The bundle may include at least two, at least three or at least four conductors. Exemplary bundle arrangements include dual, triple, quad or hex bundle conductors. A bundle refers to a set of multiple conductors which are grouped together in the overhead transmission or distribution line. The set of conductors e.g. bundle of conductors may be in respect of a given phase of the transmission or distribution line. The line may comprise a plurality of such sets of one or more conductors e.g. bundles of conductors. A set of one or more conductors, optionally a bundle of multiple conductors, may be provided in respect of each phase of the transmission or distribution line.

[0043] The conductors within each bundle where present may be parallel to one another. The position of the conductors within a bundle are maintained relative to one another by features such as spacers. These provide mid-span obstacles to be negotiated as discussed herein.

[0044] The overhead transmission or distribution line may be a single or double circuit line. Each circuit may have three phases. Each phase e.g. arm of the transmission or distribution line, may then have a respective set of one or more conductors e.g. a bundle of multiple conductors.

[0045] As set out below, the present invention extends to an overhead transmission or distribution line system comprising an overhead transmission or distribution line and a robotic device in accordance with any of the aspects or embodiments of the invention. The robotic device may cooperate with e.g. be mounted to the overhead transmission or distribution line in any of the manners herein described. The line may be in accordance with any of the embodiments described.

[0046] In accordance with the invention in any of its aspects or embodiments the pre-treatment and / or coating is applied to one or more of the set of one or more conductors of the line.

[0047] A range of different types of pre-treatment or coating may be applied depending upon the particular context and / or properties to be imparted to the line.

[0048] It will be appreciated that application of a pre-treatment may or may not involve the application of material to the line. The application of a pre-treatment sxample, abrading a conductor of the line, or other processes which do not necessarily involve application of material to the line. An applicator for providing a pre-treatment may therefore not necessarily apply material to the line, but may be configured e.g. to apply a treatment such as abrasion to the line.

[0049] Preferably, the pre-treatment module is configured to clean at least a portion of an overhead transmission or distribution line e.g. to clean one or more conductors of the set of one or more conductors of the line.

[0050] Preferably, the pre-treatment module is configured to prepare the surface of at least a portion of an overhead transmission or distribution line e.g. to prepare the surface one or more conductors of the set of one or more conductors of the line.

[0051] Preferably, the pre-treatment module comprises a mechanical abrasion system and / or a chemical treatment system. The pre-treatment module may be configured to mechanically abrade and / or chemically treat one or more conductors of the set of one or more conductors of the line.

[0052] The robotic device may comprise one or more applicators for performing pretreatment and / or coating operations. Each applicator may be configured to engage with one of the set of one or more conductors of the line to apply a pre-treatment or coating thereto. The pre-treating and / or coating functionality may be provided using suitable end effector(s) of the robotic device. Each applicator for performing pretreatment and / or coating operations may therefore be an end effector of the robotic device. Various optional features relating to the applicator(s) will be discussed herein. Each of the one or more applicators may be of any of the constructions described. Additional applicators of different construction may or may not be provided.

[0053] The applicator(s) e.g. end effector(s) form part of the coating application module and / or pre-treating module as appropriate. The applicator(s) for performing pre-treatment form part of the pre-treatment module and the applicator(s) for performing coating form part of the coating application module. For each of whichever of the coating and / or pre-treating modules is present, a respective set of one or more applicator(s) may be provided.

[0054] The robotic device therefore may comprise a set of one or more applicators for performing pre-treating and / or a set of one or more applicators for performing coating operations. Where the set of one or more conductors of the line comprises a plurality of conductors i.e. a bundle, providing a plurality of the applicators for providing pre-treatment and / or a plurality of applicators for providing cleaning enables different applicators to engage with different respective conductors of the set i.e. bundle to enable pre-treating and / or coating of multiple conductors of the set i.e. bundle in a single pass. The device may therefore comprise a set of a plurality of applicators for performing pre-treating and / or a set of a plurality of applicators for performing coating operations, wherein, when the line comprises a set of multiple conductors (i.e. a bundle of conductors), different applicators of each set of applicators may engage with different respective conductors of the set of conductors -treating and / or coating of multiple conductors of the set of multiple conductors in a single pass.

[0055] It will be appreciated that multiple applicators may alternatively or additionally be provided which engage with the same conductor of the set of one or more conductors (whether or not the set comprises multiple conductors e.g. a bundle) e.g. to provide different types of pre-treatment and / or coating thereto, or to provide more complete application of the pre-treatment and / or coating.

[0056] The applicator(s) in respect of a coating or pre-treating module should be of the appropriate type to apply the intended coating or pre-treatment, and should be located appropriately to provide the coating or pre-treatment. Exemplary positions of applicator(s) for providing coating or pre-treatment are described below.

[0057] Where the robotic device comprises a pre-treatment module, the one or more applicators may comprise a set of one or more applicators configured to apply pre-treatment in the form of one of more of; surface preparation, cleaning, mechanical abrasion, and chemical treatment to one or more conductors of the set of one or more conductors of the line. For example, an applicator e.g. end effector for applying mechanical abrasion may comprise brushes for abrading the line. Different applicators may be provided for providing the mechanical abrasion and chemical treatment.

[0058] Each applicator in respect of a coating application module may be configured to coat its respective conductor by applying a fluid thereto.

[0059] At least some, and optionally each of the one or more applicators may be configured to pre-treat or coat (as appropriate) its respective conductor by applying a fluid thereto by a contact-based method. Preferably where a coating application module is provided, each applicator for providing a coating is configured to coat its respective conductor by applying fluid thereto by a contact-based method. Each applicator (whether of the pre-treatment or coating application module) configured to coat or pre-treat a conductor by applying fluid thereto is preferably configured to do so in this manner e.g. each applicator of the coating application module preferably is configured to coat a conductor in this way. The contact-based method may be selected from; brushing, rolling, dip coating, fluid jetting, flow coating, fluid deposition and doctoring, electrostatic coating, slot die coating (and equivalent practices), annular die coating, extruding and combinations thereof. It has been found that such methods may provide more control to the pre-treatment or coating application process in comparison e.g. to spraying of material onto the conductor.

[0060] The pre-treatment module may be configured to pre-treat one or more conductors of the set of one or more conductors of the overhead transmission or distribution line, such as in a single pass, further optionally wherein the set of one or more conductors comprises multiple conductors and the pre-treatment application module is configured to pre-treat multiple conductors of the set of conductors of the line, such as in a single pass. In some embodiments the pre-treatment module may I to pre-treat each conductor of the set of one or more conductors of the overhead transmission or distribution line in a single pass.

[0061] The coating application module may be configured to coat one or more conductors of the set of one or more conductors of the overhead transmission or distribution line, such as in a single pass, optionally wherein the set of one or more conductors of the line comprises multiple conductors and the coating application module is configured to coat multiple conductors of the set of conductors of the line, such as in a single pass. In some embodiments the coating application module may be configured to coat each conductor present in the set of one or more conductors of the overhead transmission or distribution line in a single pass.

[0062] The ability to pre-treat and / or coat multiple conductors (e.g. of the set of conductors of the line) in a single pass may be achieved by providing multiple applicators for performing each of pre-treatment and / or coating operations, wherein different ones of the applicators are configured to engage with different respective ones of a plurality of conductors (of the set of conductors) of the line to apply a pretreatment or coating thereto. For example, at least one applicator may be provided in respect of each conductor of a plurality of conductors (or of each one) of the set of conductors of the line. A single applicator may be provided for each conductor or multiple applicators may be provided in respect of a given conductor e.g. to impart different types of pre-treatment or coating thereto.

[0063] In general, the pre-treatment module may be configured to pre-treat (e.g. clean) one or more conductors of the overhead transmission or distribution line, such as in a single pass, further optionally wherein the line comprises multiple conductors and the pre-treatment application module is configured to pre-treat (e.g. clean) multiple conductors of the line, such as in a single pass. In some embodiments the pre-treatment module may be configured to pre-treat (e.g. clean) each conductor of one or more conductors present in the overhead transmission or distribution line in a single pass.

[0064] The coating application module may be configured to coat one or more conductors of the overhead transmission or distribution line, such as in a single pass, optionally wherein the line comprises multiple conductors and the coating application module is configured to coat multiple conductors of the line, such as in a single pass. In some embodiments the coating application module may be configured to pre-treat (e.g. clean) each conductor of one or more conductors present in the overhead transmission or distribution line in a single pass.

[0065] In accordance with the invention in any of its embodiments, each of the one or more applicators for performing pre-treatment and / or coating operations is preferably configured to engage with one of the set of one or more conductors of the line to apply the pre-treatment or coating thereto. The applicator engages around the respective conductor. As discussed above, different applicators may engage with different parts of the same conductor or with different ones of the conductors where multiple conductors are present in the set of one or more conductors. 3 present, the pre-treatment module (e.g. the set of one or more applicators for providing pre-treatment) may be configured to provide complete circumferential coverage of the pre-treatment in respect of the conductor(s) to which pre-treatment is provided. Where present, the coating application module (e.g. the set of one or more applicators for providing coating) may be configured to provide complete circumferential coverage of the coating in respect of the conductor(s) to which coating is provided. Any suitable arrangement may be used to provide complete circumferential coverage of the pre-treatment or coating.

[0066] The following (which may refer to “the applicator”) applies to the, at least one, some or each of the one or more applicators for performing pre-treatment and / or coating operations. As stated above additional applicators may or may not be present e.g. in some cases each applicator present may be of the same construction in accordance with the embodiments defined herein.

[0067] The applicator is configured to circumferentially surround the conductor when engaged around the conductor for applying the coating or pre-treatment thereto. At least one, or preferably each applicator of the one or more applicators may be configured in this way.

[0068] Preferably the applicator is configured to fully circumferentially surround the conductor when engaged around the conductor for applying the coating or pretreatment thereto.

[0069] The applicator may define an annular shape when engaged around the conductor to apply the coating or pre-treatment to thereto, defining a central bore for receiving the conductor. Where the applicator is movable between closed and open configurations as discussed below, the configurations discussed in this paragraph apply to the closed configuration in which it is engaged around the conductor for applying the coating or pre-treatment thereto. At least one applicator is configured in the manner described in this paragraph (preferably at least each of the one or more applicators of the coating application module where present).

[0070] The applicator contacts the conductor when engaged therearound for applying the pre-treatment or coating, for example around the entire circumference of the conductor. Each applicator present may be configured in this way.

[0071] The applicator may be configured to transition between a closed configuration for engaging around the conductor of the line to apply a pre-treatment or coating thereto and an open configuration for disengaging from the conductor. In the open configuration the applicator is disengaged from the conductor i.e. it does not contact the conductor. Transitioning to the open configuration to disengage from the conductor may itself enable certain obstacles to be negotiated (i.e. passed), or may form the first stage in enabling the applicator to be retracted from the conductor in order to negotiate (i.e. pass) an obstacle (as occurs in certain preferred embodiments discussed herein). When in a closed configuration, the applicator may extend fully circumferentially around an axis of the bore and hence of a conductor when disposed therein. Where the device comprises a coating application module, least each of a set of one or more applicators configured to apply the coating is configured to transition between open and closed configurations in any of the manners described. More generally, each applicator of the one or more applicators of the pre-treatment or coating application modules may be configured to transition between an engaged configuration e.g. closed configuration for engaging around the conductor of the line to apply a pre-treatment or coating thereto and a disengaged e.g. open configuration for disengaging from the conductor. The applicator contacts the conductor in the engaged e.g. closed configuration and does not contact the applicator in the disengaged e.g. open configuration.

[0072] The applicator may be located in a position corresponding to the “installation” position discussed below when in the open configuration ready for retraction from the conductor in embodiments where this occurs. The applicator is configured to transition from the closed configuration to the open configuration in either direction as required in use. Thus the applicator may transition from the closed configuration to the open configuration for disengaging from the conductor e.g. to pass an obstacle and from the open configuration to the closed configuration to engage or reengage around the conductor for applying a coating or pre-treatment thereto.

[0073] The applicator may comprise first and second parts movable relative to one another to transition the applicator between the open and closed configurations. The first and second parts may be connected to one another in any suitable manner to enable the parts to move so as to transition the applicator between the open and closed configurations. The applicator may comprise additional parts, or may consist of the first and second parts. The first and second parts are preferably configured such that the applicator defines an annular shape when in the closed configuration with a central bore for receiving the conductor.

[0074] In some preferred embodiments the applicator comprises first and second parts connected to one another at a hinge, wherein the first and second parts are rotatable relative to one another about the hinge to transition the applicator between the open and closed configurations. The hinge extends in a longitudinal direction. The first and second parts are configured such that, when in the closed configuration, the applicator defines an annular shape having a central bore for receiving the conductor. This may be referred to as a “clamshell” type structure. The first and second parts may be directly or indirectly connected to one another at the hinge. The first and second parts may comprise first ends joined to one another at the hinge and opposite free ends, wherein the free ends engage one another when the applicator is in the closed configuration and are spaced apart from one another when the applicator is in the open configuration.

[0075] The applicator may be configured to transition from the closed configuration to the open configuration for disengaging from the conductor under the control of the obstacle avoidance module. The obstacle avoidance module may be operable to cause an applicator to transition to its open configuration for disengaging from the conductor. Where the device comprises a plurality of applicators configured to / veen open and closed configurations, the applicators are preferably selectively and independently transitionable between the open and closed configurations. The applicators are selectively and independently transitionable between the open and closed configurations as required in order to negotiate (i.e. pass) obstacles in use. The obstacle avoidance module may initiate transition of a given applicator from the closed configuration to an open configuration or vice versa as required during use in order to negotiate obstacles encountered.

[0076] By “selectively and independently” it is meant that each applicator is independently able to transition between the open and closed configurations as required, in either direction, without necessitating corresponding transitioning of any of the other applicators present between the open and closed configurations. Thus, one applicator may be transitioned to an open configuration to disengage from its conductor to pass an obstacle while other applicator(s) remain engaged with their conductor(s) to continue to apply pre-treatment and / or coating thereto. Of course, in some cases, it may be desired to transition multiple applicators in the same manner at the same time.

[0077] Transitioning of an applicator between open and closed configurations may be achieved using any suitable actuation mechanism. In some embodiments an actuator is provided associated with each applicator configured to transition between open and closed configurations for transitioning the applicator between open and closed configurations. The actuator may transition the applicator between open and closed configurations under the control of the obstacle avoidance module. Each actuator is preferably independently controllable for transitioning its applicator between open and closed configurations.

[0078] Preferably the applicator is selectively retractable from the conductor with which it engages to apply the pre-treatment or coating thereto in order to negotiate (i.e. pass) an obstacle in use. Each applicator of the one or more applicators may be selectively retractable in this way (e.g. each of a set of one or more applicators of the pre-treatment module and each of a set of one or more applicators of the coating application module as present). While transitioning to an open configuration in which it no longer engages the conductor may be sufficient for an applicator to pass certain types of obstacles, (e.g. smaller mid-span obstacles which do not extend far beyond the line in a lateral direction) the ability to retract the applicator from its conductor will enable a greater range of obstacles to be passed. For example, this would enable mid-span obstacles such as spacers, dampers to be passed, as well as other obstacles such as suspension insulators which may effectively form a T- junction with the conductor.

[0079] The applicator e.g. end effector may be retractable from an installation position in proximity to the conductor with which it engages for applying the coating and / or pre-treatment thereto to a retracted position in which it is located away from the conductor. The applicator is disengaged from its conductor in the installation position. The installation position may correspond to the position of the applicator >en configuration described above, disengaged from the conductor, or any other position in which it is disengaged from the conductor (e.g. where the applicator is not configured to transition between open and closed configurations). Preferably, therefore, the applicator is configured to transition from an engaged e.g. closed configuration for engaging around the conductor of the line to apply a pretreatment or coating thereto and a disengaged e.g. an open configuration for disengaging from the conductor, wherein, the applicator in the disengaged e.g. open configuration is located in an installation position, and is (additionally) configured to be retractable from the installation position to a retracted position in which it is located away from the conductor. Similarly, to re-engage with the conductor, the applicator may move from the retracted position to the installation position around the conductor and then transition to the engaged e.g. closed configuration for engagement around the conductor.

[0080] Retraction of an applicator does not simply involve transforming the applicator from an engaged to a disengaged configuration e.g. from a closed to an open configuration (e.g. involving only rotary movement between parts of the applicator) with the applicator still being disposed circumferentially around the conductor, such as may occur with opening of a clam shell type arrangement exemplified above. The retraction moves the applicator to a position away from the conductor to enable an obstacle to be passed. The retraction is to a position in which the applicator is no longer disposed circumferentially around the conductor e.g. instead being located to a side of the conductor. The applicator is no longer disposed around i.e. concentric with an axis of the conductor.

[0081] The applicator defines a central cavity e.g. bore for receiving a conductor when in the closed configuration for engaging around a conductor. The applicator may define a central axis extending through the bore along the direction a conductor will extend when disposed in the cavity e.g. bore. The applicator circumferentially surrounds the axis. Retraction of the applicator involves movement of the central axis of the applicator. A central axis of an internal cavity of the applicator for receiving a conductor may move to a position parallel and spaced from its position when engaging around its conductor.

[0082] However it is configured, retraction of an applicator may move the applicator from a position in which it circumferentially surrounds a conductor to a position in which it no longer extends circumferentially around the conductor.

[0083] In embodiments in which the applicator comprises first and second parts connected to one another along a hinge, retraction of the applicator involves movement of the hinge. The hinge is spaced away from the conductor in the retracted position. A longitudinal axis of the hinge may lie along a first line when the applicator is in its open configuration (the installation position) and along a second line, spaced from the first line, when the applicator is in its retracted position. Movement of the applicator may involve movement of the axis of the hinge out of a it lies in the open configuration (installed position) and into a different plane.

[0084] The retraction may involve rotational and / or linear motion. The retraction includes at least a linear component of motion.

[0085] The robotic device defines a longitudinal direction in the direction of the line, a transverse direction perpendicular thereto. The device also defines a height direction perpendicular to both the longitudinal and transverse directions. The transverse and height directions may extend horizontally and vertically when the device is installed on the line in use. Retraction involves movement having at least a component in the transverse direction to move the applicator to a lateral side of the conductor. This enables obstacles which typically extend in the vertical direction above a conductor to be passed. The retraction may also include a component in the height direction. The retracted position of the applicator is therefore located to a laterally side and optionally above the unretracted position of the applicator (e.g. the installation position thereof). Retraction involves movement in a lateral direction, and, where the set of one or more conductors is a bundle of multiple conductors, will typically be away from a longitudinal centreline of the bundle. The entire applicator e.g. end effector is retracted from the conductor.

[0086] The applicator is preferably retractable to different positions depending upon the obstacle to be traversed e.g. the size and / or location thereof. This may provide greater flexibility in overcoming a wider range of obstacles.

[0087] Where the applicator(s) are retractable, the applicator(s) are selectively retractable from the conductor(s) with which they engage under the control of the obstacle avoidance module.

[0088] The obstacle avoidance module is preferably operable in use to cause the applicator to retract from the conductor in order to negotiate an obstacle. The obstacle avoidance module is preferably operable to enable each applicator of the one or more applicators present to retract in this way. The obstacle avoidance module may be operable in use to cause an applicator to transition from its engaged e.g. closed configuration to its disengaged e.g. open configuration to disengage from its conductor so as to be in an installation position, and to then retract from the conductor in order to negotiate an obstacle. Similarly, to re-engage with the line, the obstacle avoidance module may cause the applicator to move from the retracted position to the installation position around the conductor and then transition to the engaged e.g. closed configuration for engagement around the conductor.

[0089] Any suitable retraction mechanism may be used to enable an applicator to retract as described. At least one applicator may be mounted or coupled to the chassis in any of the following manners to enable retraction.

[0090] The ability of an applicator to retract may be provided by using a suitable coupling of the applicator to a chassis of the robotic device. The coupling may enable the applicator to move relative to the chassis of the device. Such a coupling may be referred to as a dynamic coupling. This is in contrast to a fixed coupling in which the coupled in a fixed position relative to the chassis. The coupling may comprise parts movable relative to one another in use to enable retraction of the applicator. One of the parts of the (dynamic) coupling may be an arm, the applicator being mounted to the arm. The movable parts of the coupling may be configured to slide or rotate relative to one another. For example, the coupling may comprise a revolute joint, swing arm, prismatic joint or a four-bar link mechanism. Couplings of varying degrees of complexity and including various number of components and / or joints may be used, depending upon the range and / or type of movement to be provided to the applicator.

[0091] At least one and optionally each applicator of the one or more applicators may therefore be coupled to a chassis of the robotic device by a coupling enabling retraction of the applicator from the conductor in use; such as wherein each applicator is coupled to a chassis of the robotic device by a coupling enabling the applicator to move relative to the chassis of the device in order to retract from the conductor in use, for example wherein the coupling comprises parts movable relative to one another in use to enable retraction of the applicator; optionally wherein the coupling comprises a revolute joint, swing arm, prismatic joint or a four- bar link mechanism.

[0092] In some embodiments the applicator is mounted to the chassis by a robotic arm, such as a serial manipulator or, preferably a multi-axis robotic arm.

[0093] A robotic arm as referred to herein includes a plurality of links connected by a plurality of joints. A multi-axis robotic arm as referred to herein may have at least two or three axes, optionally at least four axes, or preferably at least 6 axes. Preferably the robotic arm is a multi-axis robotic arm having at least 6 axes, for example being a 6 axis robotic arm.

[0094] At least some and optionally each applicator may be mounted in this manner. The robotic arm is manipulable for selectively retracting the applicator from a conductor in use. The applicator is mounted to a distal end of the arm, with a proximal end thereof being mounted to a chassis of the robotic device. The robotic arm may be a serial manipulator. This allows the applicator to be readily retracted from the line as needed to pass obstacles. A robotic arm, in particular a multi-axis robotic arm may provide flexibility in terms of how the applicator may be retracted e.g. where it may move to in order to negotiate a particular obstacle. This may enable retraction over greater distances to move out of the way of an obstacle e.g. over a distance in the order of meters. Such arrangements may also allow the same applicator to be brought into engagement with different conductors of a set of multiple conductors of the line to pre-treat and / or coat different conductors of the set. For example, providing the applicator on a robotic arm e.g. multi-axis robotic arm may also enable the applicator to reach multiple conductors of the set of conductors.

[0095] In some further embodiments, it is envisaged that a fixed coupling of the applicator to a chassis of the robotic device may be used, with that part of the being movable in order to retract the applicator. Examples of such arrangements are described herein, in which the chassis comprises portions coupled to one another at one or more central coupling, wherein each central coupling is defined between a pair of arms of the chassis, wherein the applicator(s) are mounted e.g. fixed to ones of the arms of the central coupling(s), wherein movement of an arm on opening of a respective central coupling, with an applicator mounted thereto, retracts the applicator (“split chassis” arrangements). The arm may rotate out of a (horizontal) plane of the conductor to retract the applicator.

[0096] In embodiments therefore, a chassis of the robotic device comprises portions coupled to one another at one or more central coupling, wherein each central coupling is defined between a pair of arms movable relative to one another to transition the central coupling from a closed configuration in which the arms connect the chassis portions and an open configuration for passing an obstacle, wherein at least one applicator is mounted e.g. fixedly to one of the chassis arms, whereby movement of the arm upon opening of the respective central coupling retracts the applicator. The chassis portions are longitudinal portions. The portions may be chassis halves.

[0097] Fixed coupling of an applicator to the chassis may be used without this capability of a part of the chassis to move in order to retract the applicator where it is not necessary for the applicator to be retractable (e.g. where it is simply transformable between open and closed configurations for disengaging and engaging the conductor).

[0098] In general, the obstacle avoidance module (e.g. an applicator retraction system thereof) may be operable in use to cause the or each applicator of the one or more applicators (or each applicator present) to be selectively retractable from its respective conductor of the set of one or more conductors of the line in order to negotiate (i.e. pass) an obstacle. Where multiple applicators are present, individual applicators are preferably independently and selectively retractable from their respective conductors as required in order to negotiate (i.e. pass) obstacles. The obstacle avoidance module (e.g. an applicator retraction system thereof) may be configured such that individual applicators may be independently and selectively retracted from their conductors as required in order to negotiate obstacles. By “selectively and independently” it is meant that each applicator is independently able to retract as required, without necessitating corresponding retraction of any of the other applicators. Thus, one applicator may retract from its conductor while other applicator(s) remain engaged with their conductor(s) to continue to apply pretreatment and / or coating thereto. Of course, in some cases, it may be desired to retract multiple applicators in the same manner at the same time.

[0099] The (or each) applicator is selectively disengageable, and preferably retractable, from its conductor. Once an obstacle has been negotiated, the applicator is configured to re-engage with a respective conductor. The obstacle avoidance module may further be configured to cause the or each applicator to i a respective conductor once an obstacle has been negotiated. Reengagement may involve movement of the applicator from a retracted position to the installation position where the applicator had been retracted, and, in any case, involves transitioning of the applicator from its disengaged e.g. open configuration to the engaged e.g. closed configuration in which it is engaged around the conductor. The obstacle avoidance module may operate a retraction system to cause the applicator to move from a retracted position back to an installation position around the conductor for engagement therewith.

[0100] The obstacle avoidance module may comprise an obstacle detection system for detecting when the device is approaching an obstacle, and an applicator retraction system (which may be in accordance with any of the embodiments described herein) operable to selectively disengage and optionally retract the applicator(s) from respective conductor(s) of the set of one or more conductors of the line in order to negotiate (i.e. pass) detected obstacles in use. Thus, the disengagement, and, where applicable, retraction of the applicators is achieved actively e.g. by the obstacle avoidance module appropriately initiating disengagement or retraction of the applicator(s). This occurs pro-actively in advance of the applicator contacting an obstacle.

[0101] However it occurs, retraction of an applicator in accordance with any of the aspects or embodiments of the invention described herein occurs autonomously. Retraction of an applicator (or movement back to an installation position) and / or transitioning of an applicator between engaged and disengaged e.g. closed and open configurations all occur autonomously. These functions are performed automatically, e.g. under the control of the robotic device, without user intervention.

[0102] Preferably, the obstacle avoidance module is configured to cause the pretreatment module and / or the coating application module (or at least an applicator thereof) to decouple from an overhead transmission or distribution line (or at least a portion thereof) and / or to retract upon encountering one or more obstacles.

[0103] The robotic device of the invention of any of its aspects or embodiments is configured to move along the overhead transmission or distribution line in use to apply the pre-treatment and / or coating thereto. The robotic device comprises a plurality of wheels which are driven to move the robotic device along the line.

[0104] Preferably the robotic device comprises a plurality of wheels which run on the line in use to mount the device to the line. The wheels are configured to run on one or more of the set of one or more conductors of the line in use to mount the device to the line.

[0105] By having wheels which run on the top of the line i.e. on top of one or more respective conductors thereof, it is possible to negotiate certain types of obstacle by rolling over the obstacle. The wheels may therefore be configured to roll over obstacles encountered. This may be useful in particular in overcoming mid-span obstacles such as splice connections, spacers, compression fittings and dampers such as spacer dampers and vibration dampers. Driving the robotic device forward JIS moving over an obstacle therefore may provide obstacle negotiation. The obstacle avoidance module may be configured to cause one or more of the wheels to roll over an obstacle, such as a splice connection, damper, spacer or compression fitting when encountered. The obstacle avoidance module is more broadly acting to negotiate (or pass) the obstacle in this case.

[0106] The device may therefore comprise a plurality of wheels which are configured to engage and run on one or more of the set of one or more conductors of the line in use to mount the device to the line, wherein the wheels may roll over obstacles encountered. Exemplary such obstacles include mid-span obstacles, for example splice connections, dampers, spacers or compression fittings.

[0107] The wheels run on respective conductors of the set of one or more conductors of the line. Where the set of conductors of the line comprises multiple conductors e.g. a bundle of conductors, multiple wheels may engage and run on the same conductor, or wheels may engage and run on multiple conductors. Preferably at least two wheels run on the same conductor. This will enable at least one wheel to remain engaged with its conductor when another of the wheels disengages and retracts from the conductor in use as in certain preferred embodiment discussed herein. This may maintain stability of the device. Even if one of the wheels does not retract from the conductor, having first and second wheels in contact with the same conductor may maintain stability as one traverses e.g. runs over an obstacle, which may result in the wheel temporarily disengaging from its conductor.

[0108] By way of example only and not limitation, each wheel may have a diameter of at least 35 cm and / or no greater than 50cm. Each wheel may have a diameter in the range of from 35 cm to 50cm.

[0109] In some embodiments, each wheel may selectively retract from its respective conductor of the line (i.e. the conductor which it engages and on which it runs) in order to pass an obstacle. Thus the wheel retracts from the conductor in order to disengage from the conductor for passing an obstacle. The device may be configured such that when a wheel to retract from the conductor on which it runs to negotiate (i.e. pass) an obstacle at least one other of the wheels remains engaged with the conductor on which it runs to provide stable support to the robotic device in use. The obstacle avoidance module may be configured to enable or cause at least one wheel to retract from the conductor on which it runs to negotiate (i.e. pass) an obstacle while at least one other of the wheels remains engaged with the conductor on which it runs to provide stable support to the robotic device in use. The ability to retract wheels selectively may enable a greater range of obstacles to be negotiated e.g. including suspension insulators which may form a T-junction with the conductor or suspension towers. This may enable the device to traverse greater distances of the line continuously and automatically without needing to be removed and remounted manually to pass an obstacle.

[0110] This may be achieved in a similar manner to the selective retraction of the applicator(s) with the line in use. bstacle avoidance module may comprise a wheel retraction system operable to cause the or each wheel present to be selectively retractable from a respective conductor of the line on which it runs in order to negotiate an obstacle. The wheel retraction system may, for example, comprise retraction mechanisms in respect of each wheel, or a particular retraction mechanism may be operable to retract a plurality of wheels e.g. a pair of wheels.

[0111] A wheel retraction mechanism may be actively actuated e.g. under the control of the obstacle avoidance module to retract a wheel. In other cases, the retraction of the wheel may be achieved through the use of a passive retraction mechanism e.g. activated through interaction with an obstacle. Retraction of the wheels from the conductor(s) of the line, where used, may be carried out by or under the control of the obstacle avoidance module.

[0112] Each wheel may be retractable from a conductor on which it runs in order to negotiate an obstacle. The obstacle avoidance module may be operable in use to enable (or cause) each wheel present to be retractable in this way. This will enable the wheel to decouple from at least a portion of the line e.g. a respective conductor thereof for negotiating an obstacle.

[0113] The obstacle avoidance module (e.g. a retraction system thereof for the wheels) may be operable in use such that individual wheels may be independently and selectively retracted from conductors of the line as required in order to negotiate obstacles.

[0114] By “selectively and independently” it is meant that each wheel is independently able to be retracted as required, without necessitating corresponding retraction of any other wheels present. Thus, one wheel may be retracted while another wheel remains engaged with its conductor to stably connect the device to the line.

[0115] The device (e.g. a wheel retraction system thereof) is configured such that each wheel reengages with its conductor once an obstacle has been negotiated (i.e. passed). This may occur automatically e.g. where a passive retraction mechanism is used, or may involve a positive actuation to move the wheel back into engagement with its conductor. The obstacle avoidance module may further be configured to cause the or each wheel to reengage with the conductor once an obstacle has been negotiated. This may be achieved by a wheel retraction system of the obstacle avoidance module. In some embodiments the obstacle avoidance mechanism may operate the wheel retraction system to cause the wheel to move back into engagement with the conductor.

[0116] Any suitable wheel retraction mechanism may be used to retract a wheel. In some embodiments retractability of a wheel is achieved by suitable coupling of the wheel to a chassis of the robotic device. The coupling may enable the wheel to move relative to the chassis of the device in order to retract. Such a coupling may be referred to as a dynamic coupling. The coupling may comprise parts movable relative to one another in use to enable retraction of the wheel. The movable parts g may be configured to slide or rotate relative to one another. For example, the coupling may comprise a revolute joint, swing arm, prismatic joint, a four-bar link mechanism or robotic arm e.g. a serial manipulator or multi-axis robotic arm. The robotic arm may be of any of the types discussed in relation to retraction of the applicator(s) and may have at least four or preferably at least 6, for example 6, axes. Couplings of varying degrees of complexity and including various number of components and / or joints may be used, depending upon the range and / or type of movement to be provided to the wheel. As set out above, the wheel retraction mechanism of the obstacle avoidance module may be actively actuated e.g. under the control of the obstacle avoidance module, or may be passively actuated. For example, in the latter case, a sprung joint may enable a wheel to retract out of the way of an obstacle when encountered. Retraction of a wheel may be carried out in a similar manner to retraction of an applicator discussed above.

[0117] Each wheel may therefore be coupled to a chassis of the robotic device by a coupling enabling retraction of the wheel from the conductor in use, such as by a coupling enabling the wheel to move relative to the chassis of the device in order to retract from the conductor in use. Each wheel may be coupled to a chassis of the robotic device by a coupling comprising parts movable relative to one another in use to enable retraction of the wheel; and / or each wheel may be coupled to a chassis of the robotic device by a coupling which comprises a sprung joint, revolute joint, swing arm, prismatic joint, robotic arm, levered screw mechanism or a four-bar link mechanism.

[0118] In some further embodiments, it is envisaged that a fixed coupling of the wheel to a chassis of the robotic device may be used, with that part of the chassis itself being movable in order to retract the wheel. Examples of such arrangements are described herein, in which the chassis comprises portions coupled to one another at one or more central coupling, wherein each central coupling is defined between a pair of arms of the chassis, wherein the wheel(s) are mounted e.g. fixed to ones of the arms of the central coupling(s), wherein movement of an arm on opening of a respective central coupling, with a wheel mounted thereto, retracts the wheel (“split chassis” arrangements). The arm may rotate out of a (horizontal) plane (e.g. including the conductor or parallel to a plane including the conductor) to retract the wheel.

[0119] In embodiments therefore, a chassis of the robotic device comprises portions coupled to one another at one or more central coupling, wherein each central coupling is defined between a pair of arms movable relative to one another to transition the central coupling from a closed configuration in which the arms connect the chassis portions and an open configuration for passing an obstacle, wherein at least one wheel is mounted e.g. fixedly to one of the chassis arms, whereby movement of the arm upon opening of the respective central coupling retracts the wheel. The chassis portions are longitudinal portions. The chassis portions may be chassis halves. ction of a wheel involves movement having at least a component in the transverse direction of the device to move the applicator to a lateral side of the conductor. The retraction may also include a component in the height direction. The retracted position of the wheel is therefore located to a lateral side and optionally above the unretracted position of the wheel for engaging its conductor. The retraction of a wheel may be in a direction of, or include a component in the direction of, an axis about which the wheel rotates when travelling along its conductor in use. Retraction of a wheel may move the wheel out of a vertical plane in which it lies when unretracted for engaging its conductor. The retraction involves linear or rotary movement of the wheel. Where the set of one or more conductors is a bundle of multiple conductors, retraction will typically be away from a longitudinal centreline of the bundle.

[0120] However it occurs, retraction of a wheel in accordance with any of the aspects or embodiment of the invention described herein occurs autonomously. Retraction of wheel (or movement back to a position in which it engages its conductor) occurs autonomously. These functions are performed automatically, whether involving passively actuated movement of the wheels or actively actuated movement of the wheels e.g. under the control of the robotic device, without user intervention.

[0121] Preferably, the obstacle avoidance module comprises one of more of: (i) a levered screw mechanism; (ii) a single revolute joint mechanism; (iii) a revolute joint mechanism with centre coupling; or (iv) a sprung revolute joint; for retracting the wheels. The same or different types of retraction mechanisms may be associated with different wheels.

[0122] The obstacle navigation module may comprise an obstacle detection system for detecting when the device is approaching an obstacle, and a wheel retraction system (in accordance with any of the embodiments described herein) operable to selectively retract wheels from respective conductor(s) of the line in order to negotiate detected obstacles in use. This may enable proactive avoidance of obstacles e.g. using active wheel retraction. However, as mentioned, passive wheel retraction may alternatively be used, providing obstacle negotiation through interaction between the wheel and the obstacle.

[0123] The obstacle avoidance module may be configured to enable wheels to negotiate obstacles by rolling over the obstacle, or by retracting from the line out of the way of an obstacle. The obstacle avoidance module may be configured to detect a particular obstacle, and cause a wheel to either roll over the obstacle or retract the wheel out of the way of the obstacle depending upon the obstacle detected. This may depend on e.g. the type or size of obstacle.

[0124] Alternatively or additionally, in general the obstacle avoidance module may be configured to cause one or more of the wheels (or an engagement mechanism) to roll over an obstacle such as a damper, spacer or compression fitting, and / or is enable the robotic device to clear a suspension tower or clamp encountered along the line.

[0125] In accordance with any of the aspects or embodiments of the invention, whether or not the wheels are retractable, the wheels are in direct contact with their respective conductor of the set of one or more conductors of the line when engaged therewith.

[0126] The wheels may engage their respective conductor(s) in any suitable manner.

[0127] The wheels may include straight wheels and / or pulley wheels and / or conical wheels. Advantageously the wheels are pulley wheels. A pulley wheel defines a groove in its conductor engaging surface for locating the conductor.

[0128] The wheels may form part of a wheel system connected to a chassis of the device.

[0129] Advantageously the device only includes wheels configured to run on top of conductor(s) of the line in use and does not include wheels running below conductors of the line.

[0130] Any suitable number of wheels may be present. In exemplary embodiments two or four wheels are present, although other arrangements may be used.

[0131] The use of wheels running (only) on top of the conductors is advantageous in facilitating negotiation of obstacles. The conductor engaging surface of the wheel engages a top surface of the conductor in use. Wheels located below a conductor may get in the way when attempting to pass an obstacle.

[0132] Thus, the plurality of wheels preferably only includes wheels configured to engage the top of one or more conductors of the line, and located one behind the other along the length of the conductors, and does not include opposed wheels configured to engage a bottom of the conductors. No opposed wheel is provided beneath any wheel of the device. Having no wheels located below conductors of the line facilitates obstacle navigation, enabling wheels to run over obstacles and / or retract out of their way more easily.

[0133] The wheels which run on the conductors in accordance with the invention may comprise portions which extend over at least a portion of the sides of a conductor with which they are engaged e.g. to locate the conductor. For example, a pulley wheel may define a conductor receiving groove with rims on either side of the groove extending in the radial direction. Even with a wheel extending over the sides of a conductor obstacles e.g. spacers may be driven over. In some embodiments, the wheels may be configured such that in use, each wheel contacts no more than a top 180 degrees of the conductor on which it runs. This may facilitate running over obstacles. However, running over of obstacles may still be achieved even with contact over a greater amount of the circumference of the conductor. Where the wheels are pulley wheels, a depth of a conductor receiving groove may, for example, be no greater than a radius of the conductor to be engaged by the wheel. The depth of the groove is measured between a lowermost point of the conductor rface and the highest point of the rim on either side of the groove. The invention extends to a system in which the wheels are engaged with their respective conductors.

[0134] Preferably the wheels of the device are exposed. The wheels are not disposed within any housing of the device. For similar reasons this enables obstacles to be more readily negotiated by wheels simply running over obstacles and / or retracting out of their way. The absence of a housing enclosing the wheels provides greater freedom in the ability of the wheels to move so as to retract out of the way of an obstacle.

[0135] At least some, and optionally all of the wheels present may be drive wheels. The wheels may be coupled to a motor for traversing the robotic device e.g. a platform thereof along the line. An actuator may be coupled to each wheel. An actuator housing may be provided associated with each wheel.

[0136] Some exemplary configurations of the location of the various components of the robotic device will now be described.

[0137] In some embodiments the device comprises a coating application module, the coating application module comprising an applicator disposed at a trailing end of the chassis to the trailing side of a trailing most wheel. This arrangement may prevent the wheels running over an applied coating. Alternatively or additionally the device may comprise a pre-treatment module, the pre-treatment module having an applicator disposed at a leading end of the chassis to the leading side of a leading most wheel (e.g. the first wheel) and / or an applicator at a trailing end of the chassis to the trailing side of a trailing most wheel (e.g. the second wheel).

[0138] In accordance with any of its aspects or embodiments the robotic device preferably further comprises one or more fluid tanks for holding fluid for use in pretreatment and / or coating of the line. Whether a fluid tank is required for pretreatment will depend on the nature of pre-treatment to be provided. Preferably the device comprises a coating application module, and one or more fluid tanks are provided for holding fluid for use in coating of the line. The one or more fluid tanks present are preferably disposed below the wheels, and preferably entirely below the wheels. The tanks are located below each of the wheels present. The one or more fluid tanks may be suspended below the wheels by a chassis of the device.

[0139] In some embodiments the robotic device comprises a main body suspended below the wheels by a chassis of the device. Optionally the main body is located below the wheels by a distance of at least 15cm. For example, this will provide a suitable gap to pass a damper. A gap between the wheels and the main body will provide the ability to more easily pass obstacles. Where the robotic device comprises a main body suspended below the wheels by a chassis of the device, the one or more tanks may be housed in the main body. In such arrangements, the centre of mass of the device lies in a plane located below a plane in which the bottom of the wheels lies by an appreciable distance. 3ver the tanks are located, the device may further comprise a fluid delivery system for supplying fluid from the one or more tanks to one or more applicators of the pre-treatment module and / or coating application module. The fluid delivery system may supply fluid to at least to the one or more applicators of the coating application module where present and may supply fluid to any applicator of the pre-treatment module requiring fluid in its pre-treatment operation. The fluid delivery system may comprise a set of one or more pumps and a set of one or more fluid passageways e.g. conduits for supplying fluid to the applicator(s). In embodiments in which the device comprises a main body suspended below the wheels by a chassis of the device, the one or more pumps may be located in the main body of the device. The one or more fluid conduits may pass through a hollow interior of a part of the chassis suspending the main body of the device below the wheels to reach the one or more applicators.

[0140] Preferably the plurality of wheels comprise first and second wheels configured to run on a first conductor of the set of one or more conductors of the line, the wheels being spaced apart and located one behind the other along a longitudinal direction of the robotic device. The wheels are consecutive wheels along the longitudinal direction. The longitudinal direction of the device corresponds to the direction of the line along which the device will travel in use. The first and second wheels are configured to contact the conductor tangentially at respective first and second points, the first and second points being connected by a line corresponding to the path of the conductor.

[0141] In embodiments the plurality of wheels of the device consists of the first and second wheels i.e. no further wheels are present for engaging the line. The device may therefore include only two wheels for engaging the line. In other embodiments discussed below additional wheels may be located side by side with the first and second wheels.

[0142] The first and second wheels may be spaced apart along the length of the device (and hence conductor) by a distance of at least 20cm, or at least 25cm. Alternatively or additionally the first and second wheels may be spaced apart by a distance of less than 250cm, or less than 200cm. For example, the wheels may be spaced apart by a distance in a range of from 25cm to 200cm. The spacing of the wheels is taken along a line extending along the length of the device and between the axes of each wheel.

[0143] Whatever the spacing of the wheels, preferably the chassis of the device comprises a longitudinally extending support to which the first and second wheels are mounted. The first and second wheels are therefore mounted to a common support. The support extends in the direction of the line. The wheels may be coupled to the support in any suitable manner. Preferably the wheels are coupled to the support in a manner such that the support is disposed laterally outboard of the wheels. This may assist in obtaining an empty space below the wheels to support otiation. In some embodiments the wheels are fixedly coupled to the support. In such arrangements the wheels are not retractable.

[0144] The support may be a tubular support. The tubular support defines an interior cavity. One or more fluid conduit(s) of a fluid delivery system may pass through the hollow interior of the support to reach the one or more applicators for supplying fluid thereto. In some embodiments a main body of the device is suspended by the chassis below the first and second wheels and the support. In some embodiments as discussed below, the support is provided by a top bar of the T-shaped connector, having a stem which suspends the chassis below the wheels and support.

[0145] The first and second wheels may be disposed at leading and trailing ends of the device respectively. In some embodiments the device comprises a coating application module, the coating application module comprising an applicator disposed at a trailing end of the chassis to the trailing side of second wheel. This arrangement may prevent the wheels running over an applied coating. Alternatively or additionally the device may comprise a pre-treatment module, the pre-treatment module having an applicator disposed at a leading end of the chassis to the leading side of the first wheel and / or an applicator at a trailing end of the chassis to the trailing side of the second wheel.

[0146] Preferably the chassis comprises a T-shaped connector defining a stem and a top bar defining arms on either side of the stem, with the first and second wheels mounted to respective one of the arms at the top of the T-shaped connector, and with a main body of the device mounted to a bottom of the stem of the T-shaped connector. The top bar of the T-shaped connector may therefore provide the common longitudinal support for the wheels discussed earlier. The top bar may thus advantageously be tubular. The wheels are advantageously coupled to the arms in a manner such that the top bar is disposed laterally outboard of the wheels.

[0147] The stem of the T-shaped connector may have a length of at least 15cm. This may help to provide a space between the wheels and main body / housing of the device that enables obstacles to be more easily traversed e.g. dampers.

[0148] The main body of the device may be mounted to the bottom of the stem at a longitudinal edge of the main body. The main body and stem of the T-shape connector may define an “L shape” in vertical cross section where the stem is joined to the main body.

[0149] Preferably the one or more fluid tanks are housed in the main body of the chassis suspended below the wheels by the T-shaped connector. Such arrangements may enable the tank(s) to be located at a desired spacing below the wheels. The wheels are mounted in any suitable manner to the arms of the T- shaped connector e.g. depending whether the wheels are to be retractable. In some embodiments a fixed coupling is used.

[0150] The main body of the chassis may house other components of the device e.g. on board computer, power source, electronics, positioning systems etc. evice comprises a fluid delivery system for supplying fluid from the one or more tanks to the pre-treatment module and / or coating application module. The fluid delivery system may comprise a set of one or more pumps and a set of one or more fluid passageways e.g. conduits for supplying fluid to applicator(s) of the pretreatment and / or coating application modules.

[0151] In embodiments the T-shaped connector defines an internal cavity through which a set of one or more fluid conduits pass to deliver fluid from the one or more tanks to one or more applicators of the pre-treatment and / or coating application modules. The fluid delivery system may supply fluid to at least to the one or more applicators of the coating application module where present and may supply fluid to any applicator of the pre-treatment module requiring fluid in its pre-treatment operation. The internal cavity extends through the stem and top bar of the connector. One or more pumps are provided in the main body of the chassis for pumping fluid from the one or more tanks in use through the set of one or more fluid conduits to the one or more applicators.

[0152] The main body of the chassis may comprise (notional) leading, central and trailing portions along the longitudinal direction. Each may occupy 1 / 3 of the length of the main body. The base of the stem of the T-shaped connector may be connected to the central portion, preferably adjacent a longitudinally extending edge thereof. In embodiments first and second fluid tanks are provided within the leading and trailing portions respectively. This may provide a more stable arrangement in use. The central portion may house the one or more pumps of the fluid delivery system. The central portion may house other components of the device e.g. onboard computer, power source, electronics, positioning systems etc.

[0153] In other exemplary embodiments, the plurality of wheels comprise first and second wheels configured to run on a first conductor of the set of one or more conductors of the line, the wheels being spaced apart and located one behind the other along a longitudinal direction of the robotic device, and third and fourth wheels configured to run on a second conductor of the set of one or more conductors of the line, the wheels being spaced apart and located one behind the other along a longitudinal direction of the robotic device. The first and second conductors are parallel conductors. The first and second wheels are therefore configured to run along a line that is parallel to a line along which the third and fourth wheels run.

[0154] The first and third wheels and second and fourth wheels define first and second pairs of wheels located one behind the other and spaced apart along the longitudinal direction of the device. The wheels in each pair are located side by side. The wheels of each pair may be referred to as opposed wheels. The wheels of each pair may rotate about the same axis and are spaced apart laterally along that axis. The wheels in each pair are spaced apart laterally i.e. in a transverse direction of the robotic device. The most appropriate lateral spacing between the wheels in each pair of wheels will depend upon the spacing of the conductors of a line on which they are to run. ■st and second wheels may be spaced apart along the length of the device by a distance of at least 20cm, or at least 25cm and / or by a distance of less than 250cm, or less than 200cm, and optionally by a distance in a range of from 25cm to 200cm. The third and fourth wheels may be spaced apart along the length of the device by a distance of at least 20cm, or at least 25cm and / or by a distance of less than 250cm, or less than 200cm, and optionally by a distance in a range of from 25cm to 200cm.

[0155] The first and third wheels may be located at a leading end of the device and the second and fourth wheels at a trailing end of the device.

[0156] The first, second, third and fourth wheels may be the only wheels present on the device.

[0157] The first and third, and second and fourth wheels may be mirror images of one another about a longitudinal centreline extending in the direction of the line between the first and second sets of wheels.

[0158] The first and second wheels and third and fourth wheels respectively may be associated with respective halves of a chassis of the robotic device.

[0159] The device may comprise a chassis having first and second halves, the first and second wheels are mounted to a first half of the chassis and the third and fourth wheels being mounted to the second half of the chassis. The chassis halves are longitudinal halves. The halves extend along the direction of the line in use. The first and second chassis halves may provide left and right chassis halves in use.

[0160] The chassis may comprise first and second central couplings bridging between the chassis halves respectively at a first end and a second end thereof, wherein each central coupling is selectively and independently transformable between a closed configuration in which it connects the chassis halves and an open, configuration in which the chassis halves are decoupled from one another at the coupling. The first and second central couplings are located at the leading and trailing ends of the device.

[0161] The first central coupling may be defined between first and second rotatable arms of the chassis, and the second central coupling between third and fourth rotatable arms of the chassis. Rotation of either or both of the arms of a respective central coupling transforms the coupling between its open and closed configurations. The first and third wheels may be mounted to the first and second rotatable arms respectively, and the third and fourth wheels are mounted to the third and fourth rotatable arms respectively. In this way, rotation of any one of the first, second, third and fourth arms to open the central coupling of which the arm forms part disengages the wheel mounted thereto from its conductor and moves the wheel to a retracted position for passing an obstacle. The first, second, third and fourth wheels may be fixedly coupled to their respective arms.

[0162] The first and second central couplings preferably provide the only connection between the chassis halves. Thus, no other transversely extending connection is provided. This enables obstacles to be passed by selectively opening the couplings. s first and second central couplings are the only central couplings present.

[0163] The device may be configured that the first and second (or third and fourth) arms both rotate together to open a respective one of the first and second central couplings. However, the first, second, third and fourth arms are preferably selectively and independently rotatable to transform their respective couplings between the closed and open configurations. This provides greater flexibility in passing obstacles, while maintaining stability of the device on the line in use. For example, if an obstacle is present on only one of the first and second conductors, only one of the arms associated with a coupling need be opened on the relevant side of the device. Each arm may rotate about an axis extending in the longitudinal direction. The longitudinal direction is the direction in which the line extends. Each arm may be rotatable about an axis extending parallel to a conductor of the line in use. This will be parallel to a line connecting the conductor engaging surfaces of the first and second wheels. The arm may rotate out of a horizontal plane including the conductor or a plane parallel thereto.

[0164] The first and second central couplings may be selectively transformed from the closed configuration to the open configuration to pass an obstacle under the control of the obstacle avoidance module. The obstacle avoidance module may be configured to selectively transform only one of the first and second central couplings to the open configuration for passing an obstacle at a time while the other of the first and second central couplings remains in its closed, coupled configuration to maintain a stable connection between the chassis halves in use.

[0165] Advantageously the device comprises one or more applicators for performing pre-treatment and / or coating operations, and at least one of the one or more applicators (or optionally each of the one or more applicators) is mounted to one of the first, second, third and fourth arms. Each applicator is mounted to one of the arms. Where multiple applicators are provided each may be mounted to any one of the arms. In this way the applicator is moved together with the wheel to a retracted position on rotation of the arm to open one of the central couplings. The applicators may be mounted to different ones of the arms, depending on their position. Each applicator may be mounted to a different one of the arms. The applicators may be fixedly mounted to their respective arms. The central coupling at a given end of the device may be located between the wheels and any applicator associated with that end of the device when in the closed, coupled configuration.

[0166] Preferably one or more applicator is provided on each chassis half. This may enable treatment of both the first and second conductors simultaneously. Each applicator may be configured to engage around the same conductor as engaged by the wheels on its side of the chassis.

[0167] The applicator may be of any of the constructions described above i.e. being configured to transition between closed and open configurations (or otherwise between engaged and disengaged configurations) for disengagement from the le obstacle avoidance module may be configured to cause an applicator to transition to its open (or disengaged) configuration to disengage from its conductor before initiating rotation of an arm of a central coupling to which the applicator is mounted to move the applicator to its retracted position.

[0168] Rotation of an arm retracts the wheel (and any applicator) mounted thereto such that it is located to a side of the conductor from which it has disengaged. The retraction therefore moves the wheel (and any applicator) to a position laterally outboard of its position when engaging the conductor. The provision of the split chassis with central couplings therefore enables retraction of a wheel or applicator to be achieved without needing to use a dynamic coupling of the wheel or applicator to the chassis, since a part of the chassis itself may move to retract the wheel or applicator.

[0169] After passing an obstacle, the or each arm of a central coupling may be rotated back to its original position to close the respective coupling once more and engage the wheels associated therewith with its conductor once more. Rotation of an arm back to its original position will move an applicator back to its installation position from which it may be caused to return to its closed configuration to engage around the conductor once more for applying the pre-treatment or coating thereto.

[0170] An arm may rotate through any suitable angle to provide appropriate retraction of a wheel. For example, rotation may be through an angle of at least 45 degrees or at least 60 degrees. Alternatively or additionally, rotation may be through an angle of up to 90 degrees.

[0171] A first longitudinally extending tubular support of the first chassis half may extend between or connect the first and second wheels. A second longitudinally extending tubular support of the second chassis half may extend between or connect the third and fourth wheels. The first and third arms may be rotatably mounted to respective ends of the first support, and the second and fourth arms may be rotatably mounted to respective ends of the second support. Each support may be disposed laterally outboard of its respective wheels when the central couplings are in their closed configuration.

[0172] In this further split chassis embodiment one or more fluid tanks may be provided for holding fluid for use in pre-treatment and / or coating of the line.

[0173] The one or more fluid tanks are preferably disposed below the wheels, and preferably entirely below the wheels.

[0174] The first chassis half may comprise a first tank, and the second chassis half a second tank. The tanks may be suspended below the respective longitudinal support of their chassis halves. Preferably the chassis comprises a first housing suspended below the first tubular support and comprising a first fluid tank, and a second housing suspended below the second tubular support and comprising a second fluid tank.

[0175] The first and second wheels may be provided at opposed ends of the first longitudinal support and the third and fourth wheels at opposed ends of the second upport. The first and third arms of the first and second central couplings may be mounted to the respective ends of the first longitudinal support so as to be rotatable about the axis of the support for retracting the wheels (and, where applicable, applicator(s)). The second and fourth arms of the first and second central couplings may be mounted to the respective ends of the second longitudinal support so as to be rotatable about the axis of the support for retracting the wheels (and, where applicable, applicator(s).

[0176] The first and second wheels may be spaced from one another along a length of the device by the first housing and the third and fourth wheels may be spaced from one another along a length of the device by the second housing.

[0177] A fluid delivery system may be provided for supplying fluid from the one or more tanks to one or more applicators of the pre-treatment module and / or coating application module. The fluid delivery system may supply fluid to at least to the one or more applicators of the coating application module where present and may supply fluid to any applicator of the pre-treatment module requiring fluid in its pre-treatment operation. The fluid delivery system may comprise a set of one or more pumps and a set of one or more fluid conduits for supplying fluid to applicator(s) of the device. First and second sets of one or more pumps and one or more fluid conduits may be provided in respect of each chassis half for supplying fluid to one or more applicator(s) associated with that chassis half. The first and second sets of pump(s) may be disposed in the first and second housings respectively. The first and second housings may include other components required for the operation of the device e.g. communications interfaces, controllers, processors, etc.

[0178] One or more fluid conduits may pass through the hollow interior of each of the first and second supports to supply fluid from the respective one of the first and second tanks to one or more applicators of the device. The fluid conduits associated with each chassis half will supply any applicator(s) associated with that half.

[0179] In a split chassis arrangement, the centre of mass of the device may also lie in a plane located below a plane in which the bottom of the wheels lies by an appreciable distance.

[0180] In some exemplary embodiments regardless of its configuration, whether or not it includes a split chassis, the robotic device defines an empty space extending over a distance of at least 15cm below a lowermost conductor contacting point of each wheel. It is desirable that no components of the device are present over a substantial distance below each conductor and hence wheel. Thus, an empty space may be provided extending over a vertical distance of at least 15cm below a line connecting the lowermost conductor contacting surfaces of the first and second wheels. This may assist in being able to negotiate obstacles. For example, this will provide a suitable gap to pass a damper.

[0181] The use of a split chassis arrangement with central couplings to enable negotiation of obstacles is advantageous in its own right. In general, the robotic device may comprise a chassis having first and second halves connected to one st and second central couplings at leading and trailing ends thereof, wherein the first and second central couplings are selectively and independently openable to retract one or more wheels and / or one or more applicators of the device from engagement with their respective conductors for passing an obstacle.

[0182] Each of the first and second central couplings may be selectively and independently transformable between a closed configuration in which it connects the chassis halves and an open configuration in which the chassis halves are decoupled from one another at the coupling. The first central coupling may be defined between first and second rotatable arms of the chassis, and the second central coupling between third and fourth rotatable arms of the chassis. The one or more wheels and / or one or more applicators are mounted to ones of the first, second, third and fourth rotatable arms, wherein rotation of the arm to which a wheel or applicator is mounted moves the wheel or applicator to a retracted position as the respective central coupling of which it forms part opens. The wheels and / or applicators may be fixedly connected to their respective arms.

[0183] The device may be configured so that only one of the first and second central couplings is opened at a time to pass an obstacle while the other central coupling remains closed to maintain a stable connection between the chassis halves. The first and second central couplings may be the only connections between the chassis halves. There may be only the first and second central couplings present.

[0184] It will be appreciated that in any of the embodiments of the invention having a split chassis, the chassis halves (e.g. first and second chassis halves) are spaced apart from one another (in the transverse direction). The chassis halves are spaced from one another by the arms of the central couplings (i.e. by the arms of the first and second central couplings). The chassis halves are spaced from one another such that a longitudinally extending gap is defined extending between the chassis halves between the central couplings i.e. between the first and second central couplings. This enables an obstacle to be traversed by opening the first and second central couplings sequentially, with no components being present between the chassis halves to interfere with passing the obstacle in the region between the first and second central couplings.

[0185] In any of the aspects or embodiments of the invention, the applicator(s) may be associated with the same or different conductors of the line to the wheels. In some embodiments the device comprises one or more applicators for applying pretreatment and / or coating to one or more conductors on which the wheels run. For example, an applicator may be located at a trailing end of the robotic device for applying pre-treatment and / or coating to a portion of a conductor after the wheels have travelled over that portion of the conductor.

[0186] The device may comprise a detection system, for example comprising one or more camera, for detecting when the device is approaching an obstacle. bstacle avoidance module may be configured to selectively cause one or more applicators and / or one or more wheels of the device to retract from the respective conductor of the set of conductors of the line with which they are engaged when an obstacle is detected in order to pass the obstacle. For example, the obstacle avoidance module may control a wheel retraction system and / or applicator retraction system to retract one or more wheels and / or one or more applicator of the device. The detection system may comprise cameras located at various positions to enable upcoming obstacles to be identified of relevance to the different applicators and wheels present.

[0187] In general, the device may comprise a set of one or more cameras e.g. a pair of cameras may be located looking ahead of the leading end of the device, and optionally behind the rear end of the device. The forward looking camera(s) may enable obstacles to be identified and also assess the conductor(s) before pretreatment or coating. Rear looking camera(s) may assess the conductor(s) after pre-treatment or coating. Additional cameras may be present e.g. looking into the interior of the device from either or both ends. The cameras may be mounted in any suitable manner to a chassis of the device.

[0188] The robotic device may comprise a set of mechanisms e.g. wheels, wherein each mechanism may selectively engage and disengage with the transmission or distribution line, wherein at least one mechanism of the set of mechanisms may disengage from the line while at least one, and optionally a plurality, of the other ones of the set of mechanisms remains engaged with the line. In embodiments three or more of the mechanisms are present in the set of mechanisms. The set of mechanisms may be associated with a platform (or chassis) of the robotic device. In use, the at least one mechanism of the set of mechanisms disengages from the line to negotiate an obstacle while at least one, and preferably a plurality, of other ones of the mechanisms remains engaged with the line to provide stable support to the platform. The platform may drive a disengaged mechanism past an obstacle, such as a suspension clamp. Once the disengaged mechanism has passed the obstacle the mechanism may reengage with the line. The set of mechanisms may comprise a subset of mechanisms located one behind the other along the line. The subset of mechanisms may be associated with the same conductor of the line. Once a disengaged mechanism reengages with the line it may provide stable support to the platform to enable the next following mechanism located behind that mechanism to disengage from the line in order to pass the obstacle. The following mechanism may then reengage with the line after passing the obstacle. This process may be repeated until all mechanisms along the line have traversed the obstacle. The mechanisms may be referred to as “engagement mechanisms”. Arrangements using mechanisms which selectively engage and disengage with the line as described above may be useful in enabling suspension tower clamps to be negotiated. Such mechanisms may be wheels of the device. Such mechanisms may alternatively be provided in addition to wheels or other engagement as described herein to allow a full range of obstacles to be traversed. For example, wheels may roll over some obstacles while mechanisms which selectively engage and disengage the line may facilitate negotiation of suspension clamps.

[0189] The set of mechanisms may be configured to be assembled with the platform in a modular manner. An appropriate number of the mechanisms may then be added to the platform to enable negotiation of obstacle(s) associated with the line i.e. such that stability of the platform may be maintained while one or more mechanism is disengaged from the line to permit movement past an obstacle.

[0190] The mechanisms may selectively engage and disengage with conductor(s) of the line where the line comprises multiple conductors. The set of mechanisms may comprise at least one subset of mechanisms located one behind the other and associated with the same conductor.

[0191] The obstacle avoidance module may comprise one of more of: (i) a levered screw mechanism; (ii) a single revolute joint mechanism; (iii) a revolute joint mechanism with centre coupling; or (iv) a sprung revolute joint.

[0192] In embodiments the robotic device may comprise a pair of wheels being associated with respective ones of a pair of links, the links being coupled to one another at a centre coupling, wherein decoupling of the centre coupling allows the links to rotate so as to move the wheels out of the way of an obstacle. Each wheel may be connected to its respective link at a revolute joint. The links may be associated with respective chassis portions (e.g. halves). When the links are coupled at the centre coupling a rigid connection is provided between the links and thus between the chassis portions. The device may comprise one or more (optionally a plurality of) further such pairs of wheels and links coupled at a centre coupling, wherein when the (first) pair of links is decoupled at the centre coupling in order to pass an obstacle, the at least one further pair of wheels and links remain coupled together at their respective central coupling to ensure a rigid connection between the chassis portions is maintained.

[0193] The robotic device in accordance with any of the aspects or embodiments described herein may comprise one or more of; a power system for providing power to the robotic device, an actuation system, a sensing and perception system, a control system and a wireless communication system. The device may comprise an onboard computer.

[0194] In accordance with the invention in any of its aspects or embodiments, the robotic device is configured that it continues to move along the line even when some applicators and / or wheels thereof are disengaged from their respective conductors. The robotic device is therefore configured to provide continuous movement along the line even as obstacles are traversed. The robotic device provides a platform which traverses the line. The wheels of the device are driven forward to drive the device along the line. In embodiments in which at least one wheel is retracted from the line at least one other wheel is maintained engaged with a conductor of the line svice stably connected thereto and drive the device forward. Alternatively or additionally if a wheel disengages from the line e.g. to roll over an obstacle, other wheels remain engaged with conductor(s) of the line.

[0195] The invention extends to the robotic device in accordance with any of the aspects or embodiments in combination with an overhead transmission or distribution line.

[0196] The invention extends to the robotic device in accordance with any of the aspects or embodiments described installed on an overhead transmission or distribution line. Thus the or each applicator and / or the or each wheel as applicable may be engaged with / around a respective conductor of the line in any of the manners described herein.

[0197] According to another aspect there is provided an overhead transmission or distribution line system comprising: an overhead transmission or distribution line; and a robotic device as described in relation to the invention in any of its aspects or embodiments herein.

[0198] The overhead transmission or distribution line in any of these further aspects or embodiments may be of any of the types described. The line includes the set of one or more conductors referred to herein in relation to the configuration of the robotic device. The robotic device may be installed on i.e. mounted to the line. For example, as described herein, the wheels of the device may be mounted on one or more conductors of the line. In aspects or embodiments having one or more applicators for performing pre-treatment and / or coating operations, the or each applicator of a coating and / or pre-treatment module of the device may be engaged around respective conductor(s) of the line. Where multiple applicators are present at least some may be engaged around the same conductor and / or at least some may be engaged around different ones of the conductors where the set of conductors comprises multiple conductors. In any of the aspects or embodiments in which the device comprises a plurality of wheels, the wheels may be engaged with the same or different conductors of the set of conductors to the applicators. It will be appreciated that in any of the embodiments relating to the robotic device described herein, the robotic device may be installed on an overhead transmission or distribution line.

[0199] The system may comprise one or more overhead transmission or distribution line and one or more robotic device as described herein.

[0200] The present invention in these further aspects may include any or all of the features described in relation to the other aspect(s) of the invention.

[0201] According to another aspect there is provided an overhead transmission or distribution line system comprising: one or more overhead transmission or distribution lines; and one or more robotic devices as described above. resent invention in these further aspects may include any or all of the features described in relation to the other aspect(s) of the invention.

[0202] The invention extends to a method of operating a robotic device in accordance with any of the aspects or embodiments described herein.

[0203] According to a further aspect there is provided a method comprising: installing a robotic device as described in accordance with any of the embodiments herein on an overhead transmission or distribution line; and causing the robotic device to traverse the line while applying a coating and / or pre-treatment thereto and passing one or more obstacles.

[0204] The method may involve operating the applicator(s) and / or wheels in any of the manners described to pass obstacles e.g. to retract wheels and / or applicators from or reengage them with respective conductors, and / or to transition an applicator between open and closed configurations for disengaging from the conductor. In accordance with twin chassis arrangements the method may include opening or closing the central couplings as required. The method may comprise the obstacle avoidance module causing any such steps to occur.

[0205] According to a further aspect there is provided a method comprising: locating a robotic device as described in accordance with any of the embodiments herein in proximity to an overhead transmission or distribution line; and causing the robotic device to avoid one or more obstacles.

[0206] Alternatively or additionally the method comprises causing the robotic device to apply a coating and / or pre-treatment to the line.

[0207] The present invention in these further aspects may include any or all of the features described in relation to the other aspect(s) of the invention.

[0208] According to an aspect there is provided a retrofit coating system configured to coat an overhead transmission or distribution line with a coating comprising: a robotic device as described in accordance with any of the embodiments herein; and a coating material to be applied by the robotic device to an overhead transmission or distribution line so as to form a coating on the overhead transmission or distribution line. In this aspect the robotic device comprises a coating application module. The coating material may be located in a fluid tank of the device as described herein.

[0209] Any embodiment of the invention in which a fluid tank for providing fluid for use in pre-treatment or coating of the line is provided may extend to the tank comprising such fluid. In embodiments the device comprises a coating application module, and the fluid is a coating material.

[0210] The present invention in these further aspects may include any or all of the features described in relation to the other aspect(s) of the invention.

[0211] It will be appreciated that the obstacle avoidance module may enable the robotic device to have the capability to pass mid span obstacles. From a further aspect there is provided a robotic device configured to pre-treat and / or coat an ismission or distribution line, wherein the robotic device comprises a pre-treatment module and / or a coating application module; wherein the robotic device is configured such that it may pass mid span obstacles. The robotic device may include any of the features described in relation to the other aspects herein, and may include any of the features described in relation to the obstacle avoidance module.

[0212] Mid-span obstacles which may be passed by the robotic device and / or which the obstacle avoidance module may enable the device to pass in accordance with the various aspects described herein may include (by way of example and not limitation) spacers, spacer dampers, compression fittings, suspension clamps and vibration dampers. Mid-span obstacles may be encountered when traversing the line in a region between consecutive suspension towers.

[0213] The further aspects described herein may include any or all of the features described in relation to the first aspect and vice versa, to the extent that they are not mutually inconsistent. It will also be recognised that the robotic device, or obstacle avoidance module where provided, may include any combination of the features discussed herein which may allow obstacles to be traversed. This may facilitate allowing the robotic device to traverse different types of obstacle.

[0214] For brevity, reference will be made to overhead transmission and distribution lines herein. It will be appreciated that the principles described herein are applicable to overhead transmission and / or distribution lines.

[0215] As set out above, an overhead transmission or distribution line may include a set of one or more conductors. The individual conductors of the line may be referred to as “subconductors”. The conductor(s) or subconductor(s) referred to herein may therefore be conductor(s) or subconductor(s) of a conductor bundle of the line. A (or each) phase of the transmission or distribution line can be in the form of a set of one or more conductors e.g. a bundle of conductors. Thus the set of e.g. bundle of one or more conductors may be of a phase of the transmission or distribution line. The pre-treatment and / or coating application modules described herein may treat or coat multiple conductors of a conductor bundle of the line in a single pass.

[0216] By way of example only, individual conductors of the line may have a diameter in the range of 10-50mm. The applicator(s) of the embodiments described herein may, for example, be configured to engage around e.g. completely circumferentially surround, a conductor of diameter in this range.

[0217] Advantageously the robotic device of the various embodiments described herein comprises a pre-treatment module and a coating application module. However, in embodiments the device comprises a pre-treatment module and / or a coating application module. Thus, unless the context demands otherwise only one of the pre-treatment module and coating application module may be present. It may be desirable in some cases to separate the pre-treatment and coating processes e.g. to reduce risk of coating contamination. jrms “upper”, “lower”, “lowermost”, “horizontal”, “vertical” etc. are defined with respect to the intended in use orientation of the device when located on a transmission and / or distribution line in use.

[0218] The ends of the device and positions of components thereof may be referred to by reference to leading and trailing ends (or front and back ends) of the device. This refers to the ends as oriented in use when installed on a transmission or distribution line. This does not necessarily imply that the device must always be run in the same orientation. It is envisaged that the direction of a device may be reversible. The terms “leading” and “trailing” may be replaced by references to front and back as appropriate, or first and second ends.

[0219] The device or parts thereof are configured to function as described herein in use. References to the various configurations / functions being applicable when “in use” may therefore be introduced as appropriate where not explicitly stated. For example, in those aspects directed to the robotic device rather than a system including the overhead transmission or distribution line and the robotic device, the applicators and / or wheels are configured such that they may interact with the conductor(s) of the line in the described manner when the robotic device is installed on a line in use e.g. with the wheels running thereon, the wheels or applicators engaging and / or retracting from the conductor(s) etc.

[0220] The obstacle avoidance module herein may broadly be understood as enabling obstacles to be negotiated. For example, in some cases a wheel may contact an obstacle as it passes the obstacle. Negotiating an obstacle herein refers to passing the obstacle. Thus any reference to negotiating or to negotiate an obstacle may be understood as passing or to pass the obstacle. Similarly traversing an obstacle refers to the ability to pass the obstacle.

[0221] The robotic device is configured to autonomously move along the line in use and apply the pre-treatment and / or coating thereto in situ. The robotic device is configured to autonomously pass obstacles. Any functions involved in obstacle negotiation herein therefore occur autonomously and may occur while the device is located in situ on a line.

[0222] By “selectively” it is meant that e.g. a given applicator, wheel or coupling may be transitioned as required between its different states e.g. open / closed, retracted / unretracted. This may occur in either direction.

[0223] The robotic devices of the present invention may have a weight of at least 25Kg and / or no greater than 75Kg. The robotic devices of the invention may have a weight in the range of from 25 to 75Kg.

[0224] By way of example only and not by limitation, the robotic devices in accordance with any of the aspects or embodiments of the invention may, in exemplary embodiments, have a length of at least 0.75m. The robotic devices may alternatively or additionally have a length of no greater than 3m. The robotic devices may alternatively or additionally have a width of at least 30cm and / or less than 80cm. The robotic devices may alternatively or additionally have a height of at id / or a height of less than 70cm. In exemplary embodiments, a robotic device having a “split chassis” configuration may have a length of at least 2m and / or a width of at least 50cm.

[0225] BRIEF DESCRIPTION OF THE DRAWINGS

[0226] Various embodiments of the present invention together with other arrangements given for illustrative purposes only will now be described, with reference to the accompanying drawings, in which:

[0227] Figs. 1A-F show various known conductor bundle configurations;

[0228] Figs. 2A-D show; a conductor spacer (Fig. 2A), a stockbridge vibrational damper (Fig. 2B), a suspension insulator (Fig. 2C) and a tension tower (Fig. 2D);

[0229] Figs. 3A and B show a pair of wheels having a levered screw obstacle navigation mechanism according to an embodiment, with Fig. 3A showing the mechanism in a configuration for engaging the wheels with the conductors of the line, and Fig. 3B showing the mechanism in a configuration for disengaging the wheels from the line for clearing obstacles;

[0230] Figs. 4A and B show a wheel having a revolute joint mechanism according to an embodiment, with Fig. 4A showing the mechanism in a configuration for engaging the wheel with a conductor of the line, and Fig. 4B showing the mechanism rotated to a configuration for disengaging the wheel from the line for clearing obstacles;

[0231] Figs. 5A and B show a pair of wheels having revolute joint mechanisms connected by a centre coupling according to an embodiment, with Fig. 5A showing the revolute joint mechanisms and centre coupling in a closed configuration for engaging the wheels with conductors of the line, and Fig. 5B showing the revolute joint mechanisms rotated to open the centre coupling and disengage the wheels from the line for clearing obstacles;

[0232] Figs. 6A and B show a pair of wheels having passive (spring loaded) joints according to an embodiment, with Fig. 6A showing each joint in a configuration for engaging the wheel with a respective conductor of the line, and Fig. 6B showing the each joint in a configuration for disengaging the wheel from the line for clearing obstacles;

[0233] Figs. 7A-C illustrate various exemplary embodiments illustrating the interaction of the wheels of a robotic device with the bundled conductors of a transmission or distribution line;

[0234] Fig. 8 shows a saddle chassis with tanks offset from mounting point according to an embodiment;

[0235] Fig. 9 shows a single chassis with centre of mass below a conductor on to which it is mounted according to an embodiment;

[0236] Fig. 10 shows a hoop chassis with offset tanks according to an embodiment; 1 shows a manipulator arm applicator installed on an upper conductor according to an embodiment;

[0237] Figs. 12A and B show a drop down coating applicator retracted (Fig. 12A) and installed (Fig. 12B), in both cases in its open configuration;

[0238] Fig. 13 shows a detachable contact based applicator style coating applicator;

[0239] Figs. 14A and B show a contact based coating applicator cross-section (Fig. 14A) and close up view (Fig. 14B) showing the internal features including input port, inner filling chamber, contact interface structures, outlet delivery ports to the conductor and in the centre a representation of an ideal cylindrical conductor diameter according to an embodiment;

[0240] Figs. 15A and B show a coating applicator with four-bar mechanism assembly opened (Fig. 15A) and closed (Fig. 15B) according to an embodiment;

[0241] Fig. 16 shows a schematic fluid delivery diagram showing tank reservoir, peristaltic pump, flow rate sensor, pressure sensor and a coating applicator according to an embodiment;

[0242] Fig. 17 shows an overview of an applicator of a mechanical abrasion system module assembled on an ideal conductor cylinder according to an embodiment;

[0243] Fig. 18 shows a wheel of a mechanical abrasion system applicator assembled with bristles, coupler flange and brushless motor according to an embodiment;

[0244] Figs. 19A and B show close up views of one assembled mechanical abrasion housing according to an embodiment;

[0245] Fig. 20A shows a four-bar mechanism for CAM and PTM according to an embodiment;

[0246] Figs. 20B and C shows a four-bar mechanism and pre-treatment module assembly opened (Fig. 20B) and closed (Fig. 20C) according to an embodiment;

[0247] Figure 21 is a perspective view of a robotic device in accordance with one embodiment taken from one side (and toward the left hand or trailing end);

[0248] Figure 22 is a view of the robotic device of Figure 21 taken from one end (to the left hand or trailing end of Figure 21);

[0249] Figure 23 is a top view of the robotic device of Figure 21 ;

[0250] Figure 24 is a view of the robotic device of Figure 21 taken from one side (the same side to which Figure 21 is taken);

[0251] Figure 25 is a perspective view of a robotic device similar to that of Figures 21 to 24 from one end and side, taken from the opposite side to that of Figure 21 ;

[0252] Figure 26 is a view of the device of Figure 25 taken from one side;

[0253] Figure 27 is a view similar to that of Figure 26, but taken from the opposite side of the device and showing a section through the other side of the main body 450;

[0254] Figure 28 is a top view of the device of Figure 25 showing a part of the main body housing cut away to illustrate the interior thereof; J 29 is a vertical cross sectional view taken through the stem of the T- shape connector of the device of Figures 26 to 28;

[0255] Figure 30 illustrates a device in accordance with another embodiment and having a “split chassis” from a trailing end and Figure 31 is a perspective view of the device taken from above and one side;

[0256] Figure 32 illustrates a device similar to that of Figures 30 and 31 showing the central coupling at the leading end open for traversing an obstacle;

[0257] Figure 33 is a side on view taken from the side of the second chassis half 612 of Figure 32 showing the position of the leading wheel 603 when rotated as the central coupling opens to disengage and retract from the line;

[0258] Figure 34 is a view of the device of Figure 32 taken from above further illustrating the opening of the coupling at the leading end;

[0259] Figures 35 and 36 illustrate the stages in the opening of the central coupling 616 at the trailing end of the device of Figure 32 in a scenario where there is a suspension insulator associated with only the left hand conductor; and Figure 37 shows the arrangement of Figure 36 from above.

[0260] DETAILED DESCRIPTION

[0261] According to various embodiments a robotic device (sometimes referred to as “robot” for brevity) is disclosed which is capable of pre-treating (i.e. cleaning / surface preparing) and / or coating overhead transmission and / or distribution lines. The robotic device is preferably capable of pre-treating and / or coating multiple conductors in a conductor bundle and overcoming mid-span obstacles.

[0262] According to various embodiments the robotic device may comprise one or more of the following subsystems; (i) locomotion and obstacle negotiation mechanism; (ii) chassis; (iii) tool deployment mechanism; (iv) coating application module; (v) pre-treatment module; and (vi) electro-mechanical subsystems

[0263] Locomotion and obstacle navigation

[0264] In general, the robotic device according to various embodiments includes a mechanical platform (or chassis) designed to operate on single or multiple bundle conductors (e.g. dual, triple, quad, and hex bundle conductors), and may overcome obstacles such as splice connections, spacers, spacer dampers and vibration dampers (“first set of obstacles”), as well as being able to negotiate suspension tower clamps.

[0265] Examples of bundled conductors are shown in Figs.1A-F, which illustrate duplex (Figs. 1A and D), triplex (Figs. 1 B and E) and quadruplex (Figs. 1C and F) bundled arrangements. Figs. 1A-C show views of such bundled connectors including spacers, while Figs. 1D-F are corresponding schematic representations of each bundle type. pies of obstacles which may be encountered are shown in Figs. 2A-D, which show; a conductor spacer (Fig. 2A), a stockbridge vibrational damper (Fig. 2B), a suspension insulator (Fig. 2C) and a tension tower (Fig. 2D);

[0266] The first set of obstacles (splice connections, spacers, spacer dampers and vibration dampers) may, for example, be rolled over with wheels of appropriate design and diameter. The platform mechanisms presented may, in embodiments, also enable suspension clamp negotiation.

[0267] The pre-treating and / or coating functionality may be provided using suitable applicator(s) (end effector(s)). The robotic device therefore may comprise a set of one or more end effector(s) for performing pre-treating and / or coating operations. The end effector(s) form part of the coating application module and / or pre-treating module. It is envisaged that where both coating and pre-treating modules are provided, the same set of one or more end effectors may be associated with both the coating and pre-treating modules i.e. such that they may be used to perform coating and pre-treating operations, or different sets of one or more end effectors may be provided associated with each of the coating and pre-treating modules i.e. each being configured to perform (only) one of the coating and pre-treating operations.

[0268] Each end effector is arranged to engage and disengage with the line to enable obstacles (e.g. of the type exemplified in the “first set of obstacles” above) to be negotiated.

[0269] The mechanisms presented are intended to be modular. Some multiple (e.g. three or more) of a mechanism may be integrated into a platform to negotiate a clamp. In embodiments mechanisms can engage and disengage with the line, and at least one mechanism can disengage while at least one (and in embodiments more than one) remains engaged with the line so that the platform maintains the stable support of the line. An example of such a mechanism includes the wheels of the robotic device. The robotic device may comprise one or more pair of wheels, and optionally at least two pairs of wheels. At least one wheel, or optionally pair of wheels can disengage with the line while at least one wheel or pair of wheels remains engaged with the line.

[0270] The mechanisms in embodiments may be arranged such that the platform may stably drive a disengaged mechanism past a suspension clamp. Once that mechanism is beyond the clamp, it may be reengaged with the line. The mechanism beyond the clamp provides support to the platform and enables the next mechanism to disengage with the line. Once the next mechanism is disengaged, the platform may stably drive that mechanism past the suspension clamp, and so on, until all mechanisms are beyond the clamp.

[0271] The robotic device according to various embodiments may comprise a wheel system which, in use, is in direct contact with a transmission and / or distribution line and which is connected to a chassis. (References below will be to a “transmission and distribution line” for brevity, but should be understood to apply to a transmission line). The wheels may be coupled with a motor which is preferably capable of traversing a robotic platform of the robotic device along the line.

[0272] In terms of locomotion, rolling on the conductor(s) with wheels can easily be shown to be most efficient. Different wheel types are disclosed with reference to Figs. 3-6.

[0273] In particular, pulley type wheels as shown in Figs. 4A and B and Figs. 5A and B are effective in maintaining track by directly constraining motion. This is also the case for straight type wheels (see Figs. 3A and B). Straight contact patches have an advantage over pulley wheels in that any point within the contact patch is virtually stationary relative to any other point. Pulley wheels, however, have grip advantage.

[0274] Conical wheels as shown in Figs. 6A and B are a form of train wheels which will track straight along the line due to stable force balance (e.g. on a horizontally configured set of two conductors), but there is no way to set this up on a single conductor.

[0275] The wheel system may be comprised of straight wheels and / or pulley wheels and / or conical wheels.

[0276] Obstacle navigation may be achieved as discussed below.

[0277] Top placement

[0278] According to various embodiments the wheel system may be arranged to sit on top of single conductors or conductor bundles (twin, triplex, quad, or higher number, such as hex) thereby permitting the ability to roll over dampers, spacers, and compression fittings.

[0279] Figures 3-6 illustrate different types of obstacle navigation mechanisms which may be associated with the wheel system. These Figures show the mechanism by reference to a pair of wheels, or a single wheel, for ease of illustration. Each wheel or pair of wheels present may optionally be provided with a suitable obstacle navigation mechanism, whether of the same or differing types.

[0280] Levered screw mechanism

[0281] Figs. 3A and B shows a pair of wheels 1 each having an obstacle navigation mechanism 3 in the form of a levered screw obstacle navigation mechanism according to an embodiment, with Figure 3A showing the wheels engaged with conductors of the line, and Fig. 3B showing the wheels retracted using the levered screw obstacle navigation mechanism out of contact with the line in order to traverse an obstacle.

[0282] Figs. 3A and B shows an embodiment comprising a levered mechanism to move the wheel in an arc, up and away from the bundle centreline when approaching an obstacle, such as a suspension insulator. The actuation in this - AA - comprise a linear screw that has mechanical advantages of being non-backdrivable and a force multiplier.

[0283] The mechanism may also be set up in such a way that the wheels remain upright when they are moved. If using a large diameter wheel relative to a pivot arm length, then maintaining the upright orientation stops the bottom portion of the wheel from nearing the obstacle e.g. insulator.

[0284] Single revolute joint mechanism

[0285] Figs. 4A and B show a wheel T having an obstacle navigation mechanism 3’ in the form of a revolute joint mechanism, with Fig. 4A showing the revolute joint mechanism closed in a first position to enable the wheel to engage a conductor of the line and Fig. 4B showing the revolute joint mechanism rotated to a second position to enable the wheel to disengage from the line to clear obstacles according to an embodiment. The rotation of the revolute joint mechanism rotates the wheel through 90 degrees.

[0286] Figs. 4A and B shows an embodiment comprising rotary actuation of the wheel system to move the wheels away from the conductor axis and obstacle e.g. suspension insulator. The rotary actuation system may be independently controlled.

[0287] Revolute joint mechanism with centre coupling

[0288] Figs. 5A and B show a pair of wheels 1”, each having an obstacle navigation mechanism 3” including a revolute joint mechanism, similar to Figs. 4A and B, but with the revolute joint mechanisms associated with each wheel being connected at a centre coupling 5 according to an embodiment. Fig. 5A shows the centre coupling in a closed configuration as will be the case when the wheels engage conductors of the line, while Fig. 5B shows the revolute joint mechanisms associated with each wheel once rotated to a second position, resulting in the centre coupling opening, for disengaging the wheels from the line for traversing an obstacle.

[0289] Figs. 5A and B shows an embodiment comprising a revolute joint mechanism similar to the embodiment shown in Figs. 4A and B but with a coupling at the end of each extended wheel axle (or more generally at the end of each “link” of the robotic device). When driving normally, the coupling rigidly connects both axles (or links) and therefore rigidly couples the two chassis halves (see Fig. 5A). When encountering an obstacle, the shafts are decoupled to allow the wheels to swing up and out of the way as before (see Fig. 5B). Other rigidly-coupled wheel and axle (or link) sets along the chassis ensure continual and rigid connection between the chassis halves, while one set is decoupled.

[0290] Sprung joint suspension sets 5A and B show a pair of wheels T”, each having an obstacle navigation mechanism 3”’ in the form of a passive (spring loaded) joint. Fig. 6A shows the passive spring loaded joints in a position for engaging the wheels with conductors of the line, while Fig. 6B shows the passive spring loaded joints in a configuration for disengaging the wheels from the line in order to traverse an obstacle according to an embodiment;

[0291] Figs. 6A and B show a combination of wheel angle and sprung joint suspension sets which allow for the wheels to be pushed aside when contacting an obstacle such as a suspension clamp. The wheels may be arranged to drive upwards against the obstacle as they are pushed aside, which in turn may apply a force countering gravity which may help to prevent detachment from the line.

[0292] Figs. 7 A-C illustrate various exemplary embodiments in which multiple pairs of wheels are provided along the length of the line, which may selectively engage or disengage with the line as required to traverse an obstacle while providing support to a platform (or chassis). For example, a leading wheel set of wheels may move out of engagement with the line (i.e. a conductor thereof) to allow movement past an obstacle while the trailing sets remain engaged with the line to retain the platform of the robotic device in a stable position as it moves along the line. The leading set of wheels may then move back into engagement with the line after passing the obstacle and the next set may move out of engagement with the line and so on until all sets of wheels have passed the obstacle.

[0293] Fig. 7A illustrates a robotic device 12 having sets of wheels 10 of a similar type to those shown in Figs. 5A and B, using a revolute joint mechanism with central coupling 16. The wheels in each set are associated with respective platform (or chassis) halves. The wheels are disposed in pairs, with one wheel of each pair being associated with a respective chassis half, and with the wheels of each chassis half riding on a respective conductor 14 of the line. The tanks 18 and applicators 20 (of the pre-treatment and / or coating application module) associated with the chassis halves may also be seen in Figure 7A. The applicator 20 associated with the right hand chassis half is shown in an open configuration and is retracted from the conductor so that it is not disposed about the longitudinal axis of the conductor, while that associated with the left half is in a closed configuration in which it extends 360 degrees around the conductor. In this embodiment the chassis halves are symmetrical about a plane passing through the centre couplings 16.

[0294] Fig. 7B illustrates a robotic device 32 which uses wheels 30 configured in the manner described by reference to Figs. 6A and B. The wheels are again disposed in pairs, and ride on conductors 34 of the line. An applicator 40 for applying a coating or pre-treatment to the conductor may be seen in an open and retracted configuration. A tank 38 of coating or pre-treatment material is shown. The wheel system is connected by respective chassis arms 46 to the tank 38.

[0295] Fig. 7C uses an arrangement of wheels 50 similar to that of Figs. 4A and B. A leading wheel is shown rotated to a position in which it is disengaged with and i a respective conductor 54 of the line for traversing an obstacle, while the remaining wheels remain engaged therewith. The wheel system is connected to a tank 58 by chassis arms 56.

[0296] Figs. 7A-C are examples of how multiple sets of wheels may be assembled in a modular fashion as required to provide stable support of the robot platform / chassis while traversing obstacles.

[0297] Chassis

[0298] A chassis may be provided which mechanically connects subsystems and which primarily allows useful work of the applicator mechanism. According to various embodiments three different types of chassis may be utilised.

[0299] Saddle chassis

[0300] Fig. 8 shows a chassis concept according to an embodiment that splits the mass of the coating to either side of a rigid saddle type layout that rides the top of the conductor bundle. The tanks 60 are connected to rods 62 on which the wheels are mounted by means of rigid chassis arms 64. This is similar to the chassis arrangement used in the embodiment of Figure 7A. The advantage to having the tanks on the side of the bundle is that they can be positioned closer to the wheel centre axes and this reduces load variations when traversing slopes. The layout relies on rigid joints at or near the centreline in the obstacle negotiation mechanism.

[0301] Single chassis

[0302] Fig. 9 shows a chassis concept according to an embodiment in which the centre of mass is directly below the conductor on to which it is mounted. A tank 70 is mounted to a connecting rod 72 (to which wheels are mounted in use) by means of chassis arms 74. This may provide an arrangement of the type shown in Figure 7C. This is advantageous for ease of installation and removal, and is stable on single conductors. However, this may introduce twist to bundled conductors due to the mass of coating and platform that is offset from the vertical centre plane of the bundle. A solution to this is to ride a platform on either side of the bundle to act as a force balance.

[0303] Hoop chassis

[0304] Fig. 10 shows a hoop chassis having chassis arms 84 with offset tanks 80 according to an embodiment. This encircles the conductor bundle for added stability, but is necessarily large in order to have to negotiate dampers on the lowest conductors of the bundle. The advantages of this layout, though, are stable loading, lly enclose over the top of the bundle, and ready access to each conductor of the bundle.

[0305] Tool deployment mechanism

[0306] The coating application module and pre-treatment module will now be described in more detail below. In order to overcome various issues, the applicators of these modules may be arranged to decouple from the line and to retract upon encountering an obstacle. The mechanism(s) for installation and removal of pretreatment and coating tools can be bolted on to a chassis.

[0307] Two different tool deployment mechanisms are disclosed in more detail below.

[0308] End effector on serial manipulator

[0309] Fig. 11 shows an embodiment wherein an end-effector 90 (in this case, providing the applicator of the coating application module or pre-treatment module) is provided on a multi-axis arm of a serial manipulator robot and can reach to multiple conductors, rather than being constrained to one.

[0310] Single revolute joint retraction mechanism

[0311] A single revolute joint retraction mechanism according to various embodiments is shown in Figs. 12A and B. As shown in Figs. 12A and B, there may be provided an applicator 90 of a coating application module and / or pre-treatment module on the end of a retraction mechanism which may utilise a single revolute joint. Fig. 12A shows the applicator in an open configuration adjacent and retracted from a conductor, while Fig. 12B shown the applicator once it has moved into a position around the conductor for installation while still in an open configuration, ready to close and engage around the conductor. The single revolute joint enables the applicator to move between a retracted position in which it is disengaged from a conductor and an installation position in which it is located around the conductor ready to engage therewith for performing coating and / or pre-treatment of the line. The applicator here is of a clamshell type configuration which may move between a closed configuration for engaging with the line and an open configuration in which it may be retracted from the line. According to an embodiment, a four-bar link mechanism may be used to keep the tool aligned with the conductor. According to another embodiment a prismatic joint may be provided, but the revolute joint and swing-arm allows compliance (if it is necessary) may be built in more easily. Coating application module - annular contact based applicator with fluidic optimised internal geometry

[0312] According to various embodiments a coating application module may be provided which comprises a contact-based applicator which is annular in design with an internal geometrical structure which is optimised for fluid delivery. The coating application module may comprise an actuation system, a fluid delivery system, a coating storage container, a coating applicator and a diameter tolerance compensation system.

[0313] Applicator housing

[0314] An applicator module is an important component of a retrofit coating system as disclosed herein and may be designed to apply an even coating onto the irregular (cylindrical) surfaces of conductor(s) of an overhead lines. The coating applicator may be provided as an end effector of the robotic device.

[0315] The applicator of the coating application module may comprise a detachable annular housing, various contact interface structures and various fluidic interfaces. The applicator module may utilise a clamshell concept design which enables it to engage around a conductor securely. An example of such an applicator 100 is shown in Fig. 13. The mechanical housing geometry of the applicator may according to various embodiments be cylindrical with an overall dimension of 50-90 mm in diameter and a minimum length of 90 mm. This enables a wide selection of conductor diameters to be engaged wherein the conductor may have a diameter in the range 10-50 mm and the integration an individual or multiple input liquid sources. These dimensions are by way of example only and not by limitation and the applicator may be configured as appropriate to cooperate with a conductor of given dimensions. As shown in Fig. 13, these dimensions may be carefully selected to accommodate the different components that are required for its assembly and operation.

[0316] The internal features of the applicator ensure the effective and efficient application of the coating material. The specific internal features of the applicator may vary depending on the specific conductor diameter that will be coated. These features include contact interface structures, fluidic outputs, and an internal annular channel reservoir chamber.

[0317] The contact interface structures play an important role in the operation of the applicator. Their primary function is to centre the conductor to have an even opening gap between the conductor surface and the coating applicator, while reducing the contact area between the conductor and the applicator. The reduction in contact area reduces the friction between the components, which in turn, reduces wear and prolongs the life of the module. The contact interface structures within the applicator :o section the annular output, allowing the coating formulation to be dispensed evenly through several outputs created by such features.

[0318] The fluidic interfaces are another important internal feature of the applicator. The number of fluidic outputs 102 varies depending on the desired wet film thickness to be laid down on the conductor surface. The fluidic outputs may be positioned around the circumference of the applicator to ensure even distribution of the coating material. The size of the fluidic outputs will determine the flow rate and the thickness of the coating material. The internal annular channel reservoir chamber may be designed to store and supply the coating material to the fluidic outputs. The size of the reservoir chamber determines the amount of coating material that can be stored and supplied to the fluidic outputs.

[0319] Fig. 14A shows a contact based coating applicator 110 cross-section and Fig. 14B is a close up view showing the internal features including input port 112, inner filling chamber 114, contact interface structures 116, outlet delivery ports 118 to the conductor 120 and in the centre a representation of an ideal cylindrical conductor 120 diameter according to an embodiment.

[0320] Engagement actuation system

[0321] The engagement actuation mechanism is another important component of the coating application system that enables the opening and closing of the applicator for the connection and disconnection from the conductor. This mechanism may be activated and controlled by the base robotic platform, which is connected to the applicator via an articulated arm.

[0322] There are two different types of actuation mechanisms which may be used for the engagement mechanism: (i) active components such as motors; or (ii) passive compliant structures. An example of a four-bar mechanism assembly 140, which is an active mechanism, is shown in Figs. 15A and 15B, with Fig. 15A showing the applicator in an open configuration and Fig. 15B showing the applicator 130 in a closed configuration for engagement with the conductor. Examples of actuation mechanisms include DC motors, stepper motors, servo motors, linear actuators, pneumatic or hydraulic actuators. While both passive and active types of mechanisms can perform the required function, a passive compliant mechanism may be preferred on account of its lower power consumption and simplified structure components.

[0323] A compliant mechanism may be designed with a specific feature that allows the coating applicator to centre on the conductor as it closes, just through the movement and approach of the articulated arm. This design ensures a secure and precise connection between the applicator and the conductor, enabling the uniform application of the coating material.

[0324] Fluid delivery system With reference to Fig. 16, a fluid delivery system 170 may be provided which is responsible for delivering a coating material from a storage container 172 to a coating applicator 174 in a controlled manner in order to ensure an even coating application.

[0325] The fluid delivery system may comprise various elements such as one or more pumps 176, one or more sensors, a fluidic path and an input to the coating applicator 174. The one or more pumps are responsible for delivering the coating material from the storage container to the applicator. The one or more pumps may include a centrifugal pump, a positive displacement pump, diaphragm pump, peristaltic pump, gear pump or a vane pump, or any combination thereof.

[0326] In addition to the pump, the fluid delivery system also includes several sensors that are used to monitor and control the coating application process. The flow meter 178 is one of these sensors, and it measures the flow rate of the coating material as it is delivered to the applicator module. This allows the system to maintain a consistent flow rate and ensure that the coating material is delivered in the right amount.

[0327] Another important sensor in the fluid delivery system is the pressure sensor 180. This sensor monitors the pressure of the coating material as it is delivered to the applicator. This is important because the pressure can affect the flow rate and the thickness of the coating applied. By monitoring the pressure, the system can adjust the flow rate and ensure that the coating is applied evenly and consistently. The fluidic path is another important component of the fluid delivery system. It is responsible for ensuring that the coating material is delivered from the storage container to the applicator in a controlled manner. The fluidic path includes tubing and fittings that are designed to minimize any turbulence or air bubbles in the coating material, which could affect the coating application process. The path is also designed to minimize any dead spaces where the coating material could accumulate, which would lead to inconsistent coating application.

[0328] Finally, the input to the coating applicator is the point at which the coating material is delivered to the applicator. The input may be designed to ensure that the coating material is delivered in a controlled manner, and that it is evenly distributed across the surface of the applicator. This is important to ensure that the coating material is applied evenly to the conductor surface.

[0329] Diameter variation

[0330] According to various embodiments a diameter variation compensation system may be provided which allows the applicator, which encapsulates the conductor, to vary in diameter in response to broken strands or manufacturing tolerance variations. One method of achieving this is that the contact interface structures have compliance and therefore retract or expand in accordance with meter variation. A second method of achieving this is the use of a flexible or compliant material in the mechanical housing of the applicator. This material is able to deform slightly to adjust to the diameter of the conductor, allowing for a more even application of the coating.

[0331] An iris mechanism may be used for diameter compensation in the coating application process. The mechanism may comprise consist of a series of overlapping plates that form a circular aperture which can expand or contract by moving the plates relative to each other. The mechanism can be adjusted to change the diameter of the aperture as needed to accommodate different conductor diameters. To maintain the same output gap between the conductor surface and the distance set by the contact interface structure height, the iris mechanism can be designed to move the coating applicator along with the plates as they adjust the aperture diameter. This way, the distance between the applicator and the conductor surface can be kept constant while the iris mechanism adjusts to the changing diameter.

[0332] The iris mechanism can be integrated into the existing clamshell design by replacing the current fixed diameter cylinder with the iris mechanism. The closing of the clamshell design needs to be designed in a way that ensures the proper closing of the iris mechanism to prevent leakages in the fluidic path.

[0333] The coating application device may utilise dip coating, slot die coating, mechanical doctor blading, spray coating or ink jetting.

[0334] Fluid

[0335] In order to accommodate the coating of conductors spanning lengths of e.g. 1 km, the integration of a fluid reservoir tank with the robotic base platform is an important consideration. The fluid storage system according to various embodiments may be designed as a modular solution within a mechanical housing measuring, for example, 150 mm by 200 mm by 1000 mm. This configuration allows the coating robot to store approximately 30 litres of coating formulation. A series of independent cartridges may be arranged to sit within the mechanical housing. The cartridges may be varied in nature. The modular design facilitates versatility, as the system comprises a shell capable of housing easily replaceable sources of coating fluid. Preferably, the cartridges may be flexible polymeric cartridges containing the coating formulation. These flexible cartridges may easily interface with the fluid delivery system and may be easily replaced with newly filled ones, effectively operating as a cartridge-based system.

[0336] The modular nature of the fluid storage system offers several advantages. Firstly, it simplifies the replenishment process, allowing for quick and efficient exchange of the cartridges. This enables uninterrupted operation and minimizes downtime during the coating process. Secondly, the use of cartridges ensures a sealed and controlled environment for the coating formulation, preventing i and maintaining its integrity over time. Furthermore clean-up is quick and easy reducing the number of labour hours required.

[0337] The design considerations for the fluid storage system also take into account the dimensions of the robotic base platform and the available space for integration. The chosen box dimensions provide an optimal balance between storage capacity and the overall size of the system, ensuring efficient utilization of space while meeting the desired coating volume requirements.

[0338] Pre-treatment module

[0339] The pre-treatment module is responsible for ensuring the conductor surface is in a clean state with appropriate surface preparation for coating. This involves removing grease, oil, pollutants or external contaminants of any source on top of the conductor surface which may adversely affect the coating finish. The pre-treatment may be applied to the conductor by an appropriate applicator e.g. configured to provide mechanical abrasion and / or chemical pre-treatment of a conductor as described below. The pre-treatment applicator may be provided by a suitable end effector.

[0340] According to various embodiments the pre-treatment module may comprise a mechanical housing / structure, an actuation system, a mechanical abrasion system and / or a chemical cleaning system.

[0341] Mechanical abrasion system

[0342] With reference to Fig. 17 and 18, an embodiment of a mechanical abrasion applicator is disclosed consisting of a pair 200 of grooved wheels 202 positioned, in use, on top and bottom of the conductor. The grooves 210 on the wheels run parallel to the conductor and may be fitted with custom abrasion brushes 212 with bristles of varying hardness. Hard bristles such as stainless steel, brass, aluminium and carbon fibre as well as softer bristles such as nylon, polyester, polypropylene, Tynex and animal hair may be used. By way of example only and not by limitation, the wheels may be arranged to clean conductors which have a diameter ranging from 10-50 mm. This system ensures that the conductor is in contact with the circumferential grooves with bristles thereby providing effective mechanical abrasion for improved coating adhesion.

[0343] The circumferential brushes may be arranged to circulate along the conductor in the axis perpendicular to the conductor. The circumferential groove ensures that all 360° of the conductor is covered. Fig. 18 shows a wheel 202 assembled with a motor 214. Each U-groove brush wheel is mated by screws with a flange coupler which is coupled with a 5 mm diameter shaft of a brushless DC motor. The motor is arranged to rotate in the same direction generating equal opposite forces on the conductor which will not affect severely the overall motion of s other face of the wheel has a hollow hole having different diameters as it goes through the wheel to fit the bearing and dowel pin to keep the wheel aligned while rotating at high speeds. This will help in reducing the vibration of the wheel while it is rotating.

[0344] The diameter of the hole for the bearing may according to one embodiment be 19.3 mm (the precise diameter may vary depending on the tolerance of the selected manufacturing process) and its length may be 5 mm as measured from the side of the wheel which will allow a tight fitting of the outer race of the bearing having 19 mm in diameter and 5 mm in length. After that hole, there is a step of 2 mm length, 19.3 mm outer diameter and 16 mm inner diameter may be provided which avoids the contact of the inner race of the bearing with the wheel while rotating (this will reduce the contact friction between the bearing and the wheel). The inner race of the bearing (10 mm diameter) may be fitted with a 10 mm diameter and 28 mm length dowel pin. Thus, a hole is made from the previous step having 13 mm diameter (greater than diameter of dowel pin to avoid any additional friction due to contact between them while rotation) and may have a 20.5 mm depth inside the wheel. In addition, a spacer of 8 mm length may be added between the wall of the cover and the inner race of the bearing attached to the wheel to avoid contact between cover and wheel. The above dimensions are by way of example only, and not by limitation. The most appropriate dimensions will depend upon the particular arrangement involved, and, for example the dimensions of the conductor etc.

[0345] Mechanical housing

[0346] The mechanical housing for the grooved wheels may be comprised of: (i) one or more encapsulation hoods; and / or (ii) one or more connection platforms.

[0347] With reference to Figs. 19A and 19B, an encapsulation hood 202 is disclosed which comprises a shielded semi-circular shaped part which encapsulates one or more circumferential wheels. Each shielded part may have a dowel pin on its end to keep the U-shaped groove wheel aligned. In one exemplary embodiment these shielded parts may have a circular shape of 136 mm diameter trimmed by 35 mm from the bottom and may have a hollow half circle of 100 mm length. However, these dimensions are given by way of example only, and other dimensions and configurations may be used.

[0348] A connection platform may be provided in conjunction with two L-shaped parts. The second end of the shielded parts may be attached with an L-shaped part by three bolts and screws from the top end. The L shaped parts may be designed to hold the motor of the pre-treatment module, which may, by way of example only, have 40 mm x 70 mm rectangular dimensions. In one exemplary embodiment, all these parts may have a thickness of 5 mm. In exemplary embodiments, the L- shaped parts may have a hole in the middle of the side face having a diameter of 17 mm and may be circumscribed by six 4 mm diameter holes at imaginary 22 mm ameter allowing the assembly of the motor with them. In exemplary embodiments, the middle hole may be provided so as to pass the motor’s shaft and the six small holes may be used to attach the screws between the L-shaped holder and internal threaded holes on the face of the motor. This rectangular platform of L- shaped parts may be attached to the base robotic platform tool deployment mechanism as outlined above. Again, the dimensions and specific configurations described in relation to the various features of the mechanical housing above, including, for example, those disclosed in relation to the connection platform, are merely given by way of illustration and not by limitation. Other dimensions and configurations may be used as appropriate.

[0349] Actuation system

[0350] An actuation system may be provided which permits the opening and closing of an applicator of the pre-treatment system (e.g. an end effector thereof) to permit connection and disconnection from the conductor. This may involve a robotic gripper composed of a pair of four bar mechanisms as shown in Fig. 20A.

[0351] The crank link in each four-bar mechanism (1 and 2) may have a gear shape. These two gears may be mated together. A third gear may be attached with a servomotor and may be mated with the gear in mechanism 1 in order to actuate the robotic gripper. When the actuated gear is rotated, the mated gear in mechanism 1 will rotate allowing the rotation of the mated gear in mechanism 2. The rotation of two gears (crank links) will move the other links in the four-bar mechanism allowing the opening and closing of the pre-treatment applicator e.g. end effector as shown in Figs. 20B and C. Fig. 20B shows the applicator in an open configuration while Fig. 20C shows the applicator in a closed configuration. The synthesis of the four-bar mechanism may be done based on the path of the common point between the end of the robotic gripper and the L-shaped part.

[0352] Chemical cleaning system

[0353] The mechanical abrasion system may be further supported by a chemical cleaning system which may comprise one of more of the following: (i) cleaning solution tanks - these tanks may hold the cleaning solution that is used to clean the parts or surfaces wherein the solution is typically a mixture of water, cleaning chemicals, solvents and other additives; (ii) one or more pumps which may be used to transfer a cleaning solution from the tanks to the cleaning equipment, wherein the one or more pumps may be either electric or pneumatic, and their capacity may depend on the size of the system; (iii) outlet nozzles which may comprise spray nozzles or brushes may be used to apply the cleaning solution to the conductor surface, wherein they may be mounted on a robotic arm or on a fixed structure; (iv) rinse tanks which may be used to rinse the conductor surface after they have been rein the rinse water can be either recycled or discharged to a treatment system; (v) wiping equipment, wherein drying equipment may be used to remove the water from the parts or surfaces after they have been rinsed; (vi) a control system which monitors and controls the cleaning process, including the flow rates of the cleaning solution, the temperature of the solution, and the duration of the cleaning cycle wherein the control system can also include sensors to monitor the quality of the cleaning solution and to detect any problems or faults in the system; and (vii) safety systems which may be used to protect the operators and the environment from any potential hazards associated with the cleaning chemicals, wherein these can include ventilation systems, emergency shutdown systems and alarms to detect leaks or spills.

[0354] The cleaning solution may be formulated to preferentially remove pollutants but not substantially alter or affect the underlying metals of the conductor (aluminium, steel, zinc plating and conductor grease). Examples of such cleaning solutions include those disclosed in US-20100180914 or otherwise commercially available products such as CleanWirx 207 of Corrosion Exchange LLC.

[0355] Electro-mechanical subsystems

[0356] The unit also comprises several key electromechanical subsystems. For example, a power system may be provided wherein this subsystem is responsible for providing power to the robotic device, typically in the form of batteries or a power supply. The robotic device may be powered by batteries or inductively powered by live lines.

[0357] An actuation system may be provided wherein the actuation system includes motors, gears, sensors, actuator couplings, housings, shafts and other components that enable the robot to move and perform its tasks. Examples of these include DC motors, stepper motors, servo motors, linear actuators, and pneumatic or hydraulic actuators.

[0358] A sensing and perception system may be provided wherein this subsystem includes sensors that allow the robot to sense its environment. These may include cameras, LIDAR, ultrasonic sensors, inertial measurement units, force / torque sensors, sonar sensors, temperature sensors, pressure sensors or magnetic sensors. It may also include other sensors that provide feedback on the robotic device's position, orientation, or other parameters such as fill level of coating.

[0359] A control system may be provided which manages the operation of the robotic device, including controlling the actuation system and interpreting the sensor data. It may include switching control, a wired communication bus, servo motor drives, applicator drive, surface preparation drive, and sensor interfaces, any of which may have communication chips, microcontroller chips, local regulation and local sensors. ROV-based and ground station computing, ROV<->Ground station communications modules, situational awareness sensors (e.g. feeler switches, hall sensors, cameras etc.) and human interface device (e.g. joystick, touchscreen) enable remote control.

[0360] A wireless communication system may be provided which enables the robotic device to communicate with other devices, such as a remote control or a central computer system. These may include a transmitter, receiver, antenna, and other networking hardware. Further this may include speech recognition, natural language processing, or gesture recognition systems.

[0361] The robotic device preferably comprises a navigation system which enables the robotic device to move autonomously through its environment. This may include localization, mapping, and path planning subsystems. This may include GPS (Global Positioning System), Inertial Navigation System (INS), LIDAR, visual odometry, beacons / Automated Guided Vehicles (AGVs), Magnetic sensors or RFID.

[0362] Generally the robotic device may include an on board computer.

[0363] A safety system may be provided which may include sensors and other components that ensure the robot operates safely, such as limit switches, emergency stop buttons, and collision avoidance sensors.

[0364] An exemplary embodiment of a robotic device in accordance with the invention will now be described by reference to Figures 21- 24.

[0365] Figure 21 is a perspective view of the robotic device taken from one side (and toward the left hand or trailing end). Figure 22 is a view of the robotic device of Figure 21 taken from one end (to the left hand or trailing end of Figure 21), Figure 23 is a top view of the robotic device of Figure 21 , and Figure 24 is a view of the robotic device of Figure 21 taken from one side (the same side to which Figure 21 is taken).

[0366] The robotic device 300 is in the form of a platform which is mounted to an overhead transmission or distribution line including a set of one or more conductors in use. The set of conductors may be a single conductor or a bundle e.g. twin, triplex or quad conductor bundle, for example, and typically includes a plurality of conductors. The device 300 is configured to provide a pre-treatment and / or coating to one or more conductors of the bundle in use. The device includes a pair of wheels 302, 304. The wheels are located on top of a conductor of the line (not shown) to mount the device thereto. The wheels are located so as to engage with the same conductor of the line, being located one in front of the other along the direction of the line. In the illustrated embodiment the wheels are pulley wheels.

[0367] The device defines a longitudinal direction (indicated as X-X in Figure 23) in the direction that the transmission or distribution line extends in use (and which corresponds to a direction of travel of the device / platform along the line), and a transverse direction perpendicular thereto (indicated as Y-Y in Figure 23). The transverse direction refers to the direction which is generally horizontal in use. The device has a length in the length direction and a width in the transverse direction. rther defines a height direction (marked as Z-Z in Figure 24) perpendicular to the longitudinal and transverse directions. The height direction refers to the direction which is generally vertical in use.

[0368] For ease of illustration, the wheel 302 will be referred to as the leading wheel, and the wheel 304 as the trailing wheel. This refers to the direction of travel of the device when installed in use, which in this example would be to the right as shown in Figure 21. The leading and trailing wheels provide front and rear wheels of the device. This does not imply that the device necessarily can travel only in one direction. It is envisaged that in some cases the same device may be run in both forward or reverse directions, while in other cases the device may be configured to run in a single particular direction. This will depend e.g. on the positions of the applicators for applying a particular pre-treatment and / or coating. The ability to run the device in either direction also enables it to be used with conductors to the left or right side of a bundle of multiple conductors respective, or to left or right hand bundles of a multi bundle line. However, in some cases, dedicated devices may be provided for use with left hand or right hand located conductors e.g. being mirror images of one another.

[0369] The wheels 302, 304 rotate respectively about axes Xi, X2. These axes extend in the transverse direction. The wheels 302, 304 are mounted to first and second ends (i.e. leading and trailing ends) of the top bar 312 of a T shaped connector 316 of a chassis of the device by means of couplings 306, 308. An actuator housing 325, 329 is provided at the distal end of each coupling 306, 308, adjacent the respective wheel, and houses an actuator for driving the respective wheel.

[0370] The couplings 306, 308 may be fixed couplings. In such arrangements, since the wheels are top mounted i.e. the ride on top of the line (i.e. the conductor thereof), the wheels may still ride over mid-span type obstacles, such as splice connections, dampers, spacers or compression fittings. In other embodiments, the couplings 306, 308 may be dynamic couplings which enable either one of the wheels to be selectively retracted out of engagement with the line (i.e. the conductor thereof) and out of the way of an obstacle, while the other of the wheels remains engaged therewith to provide stable support to the robotic device i.e. platform in use. This may enable a wider range of obstacles to be negotiated, including T- shaped obstacles, such as suspension towers, which the wheel cannot ride over. For example, any of the arrangements shown in Figures 3A-6B may be used. This might, for example, involve a revolute joint.

[0371] In general, a dynamic coupling refers to a non-fixed coupling which permits movement of the wheel relative to the top bar 312 other than rotation about the axis of the wheel. The coupling is configured to enable the wheel to move relative to the top bar 312 to which it is attached. For example, the coupling may be configured to rotate about an axis of the top bar 312 to retract the wheel. The coupling may therefore comprise a revolute joint. In some embodiments the coupling may and second parts connected to one another at a joint, wherein movement of the second part relative to the first may result in retraction of the wheel. The first and second parts may be connected at one end to the bar and the wheel respectively and at the other ends to one another. However the parts may not necessarily be directly connected to one another. There may be one or more intermediate joints. Whatever the form of the coupling, the coupling may be actively actuated to cause retraction of the wheel. Thus an actuator may be provided for independently and selectively retracting each wheel. A wheel may then be actively retracted before encountering an obstacle. In other embodiments a passive retraction mechanism may be used. In such cases contact of the wheel with an obstacle may cause the wheel to automatically retract. For example, a passive arrangement may include a sprung revolute joint.

[0372] Retraction of a wheel where required will, when actively initiated, be initiated when it is determined by the robotic device that retraction is required in order to negotiate an upcoming obstacle. This may be determined in any suitable manner based e.g. on the results of a detection system e.g. one or more cameras, or other sensors, positioning information and / or information obtained by a communications interface of the device.

[0373] Once an obstacle has been passed, the wheel may be moved back from the retracted position to the original position in which it is engaged with the conductor. This may be achieved actively e.g. by under the control of an actuator, or passively e.g. by the wheel automatically moving back e.g. under the action of a spring when it no longer contacts the obstacle.

[0374] The device shown in Figure 21-24 includes applicators (which may be referred to as end effectors) 318, 323 at the leading and trailing ends thereof. Each applicator includes first and second curved parts 320, 322 (or 324, 326) together, which are connected to one another by a hinge 327 (or 328). In the illustrated embodiment the first and second parts define upper and lower parts of the applicator respectively. The hinged connection between the first and second parts enables the applicators to transition between the closed configuration shown in Figure 21, in which the first and second parts of each applicator engage the respective conductor of the line for applying a pre-treatment or coating thereto, and an open configuration in which the first and second parts of the applicator are disengaged from the line.

[0375] In the closed configuration the first and second parts fully circumferentially surround the conductor, (i.e. extend around the full circumference thereof). They define an annular shape having closed central bore for receiving the conductor. When in a closed configuration, the applicator may extend fully circumferentially around an axis of the bore and hence of a conductor when disposed therein. In the open configuration the first and second parts rotate apart from one another about the hinge so as to no longer engage i.e. contact the conductor. The first and second parts do not fully circumferentially surround the conductor in the open configuration. Thus they do not define a closed central bore in the open configuration. The first arts of each applicator each define a first edge and a second edge, wherein the first edges are joined to one another along the hinge. Opposite second edges of the parts contact one another in the closed configuration but are spaced from one another in the open configuration. The opposite second edges define free edges of the first and second parts. This arrangement may be referred to as a “clamshell” arrangement.

[0376] In the view of Figures 21-24 the applicators are shown in the closed configuration. Exemplary open and closed configurations using similar applicators are shown, for example, in Figure 7A, with the left hand applicator being in a closed configuration, and the right hand applicator being in an open configuration.

[0377] The applicators 318, 323 are each coupled to the chassis of the device by means of a respective dynamic coupling 330, 332. The couplings 330, 332 associated with the applicators are most clearly seen in Figure 23. The dynamic couplings may be of any of the types described earlier and enable the applicator, once in its open configuration i.e. disengaged from the line i.e. a conductor thereof, to be retracted out of the way of the conductor (and line). In the retracted position the applicator will no longer be concentric with the axis along which the conductor of the line lies and is disposed to one side of the conductor. By retracting the applicator from the line in this way, obstacles may be negotiated, including mid-span obstacles, such as dampers, splice connections, spacers or compression fittings, and also suspension towers or other T-shaped obstacles.

[0378] The dynamic coupling may, for example, be of the type shown with respect to Figures 12A and B, which allows retraction of the applicator to a more limited degree from the conductor so as to no longer extend therearound i.e. moving to a side thereof, or may be of the type shown in Figure 11 involving a multi-axis robotic arm, which permits a greater range of movement of the applicator. This provides greater flexibility in overcoming a range of different obstacles. While a dynamic coupling is illustrated and enables a greater range of obstacles to be more readily traversed, it is envisaged that in some cases a fixed coupling together with the ability of the applicators to transition to the open configuration may be sufficient to traverse some obstacles. As described with respect to the wheels, the dynamic coupling refers to a movable coupling. Typically the coupling is actuated actively e.g. using a respective actuator.

[0379] When it is determined that retraction of an applicator is required to negotiate an obstacle, the applicator will first be caused to transition to an open configuration in which it is disengaged from the conductor, and then the coupling will be actuated to cause retraction of the applicator away from the conductor. This may be carried out, as described with respect to the wheels, when an obstacle is detected and it is determined that retraction is required. When it is determined that the obstacle has been passed, the coupling may be actuated to move the applicator back into position around the conductor (while still in the open, disengaged configuration) and the applicator then caused to transition to the closed configuration engaged around • once more. The applicators are selectively and independently retractable from their conductors.

[0380] Retraction of wheels and / or applicators is achieved while the robotic device continues to move along the line.

[0381] The applicators shown in the embodiment of Figures 21-24 are arranged such that in use both will engage the same conductor of the line, which corresponds to the conductor on which the wheels 302, 304 ride. Thus the device 300 as illustrated will provide a pre-treatment and / or coating to a single conductor of a bundle of the line. However, in other embodiments, the applicators may be configured to engage around different conductors (e.g. of a bundle) to one another and / or to a conductor on which the wheels ride. This may be achieved using certain types of coupling of the applicators to the chassis, e.g. a multi axis robotic arm, which allows a greater degree of freedom in movement of the applicator e.g. as shown in Figure 11. Arrangements in which applicators engage different conductors of the line will also enable multiple conductors to be treated in the same pass e.g. by providing a plurality of applicators each associated with a different conductor. This may be most readily achieved using a multi axis robotic arm type of coupling of the applicator to the chassis.

[0382] As described earlier, the applicators may be arranged to apply a pretreatment and / or coating to the conductor of the line. The application of pretreatment may involve applying material to the line e.g. a chemical pre-treatment, or may involve applying a treatment to the line such as abrasion without the application of material thereto. The applicators may, for example, be of any of the types previously described. When in the closed configuration, the applicators contact their respective conductor. In embodiments each applicator is configured to contact the conductor around which it is engaged around 360 degrees of the conductor circumferential surface. This may provide more complete pre-treatment or coating of the conductor. While the applicators shown in Figures 21-24 are annular in type, including two parts hingedly attached to one another, it is envisaged that other shapes of applicator may be used, with each applicator desirably still providing complete circumferential coverage of the conductor with which it cooperates. Applicators of the type illustrated in Figures 21-24 (and also Figure 12A and 12B) are particularly useful for applying a coating to the conductor(s) e.g. as part of a coating application process. Examples of applicators useful for applying a pretreatment in the form of abrasion to conductor(s) of the line are shown in Figures 17, 18, 19A, 19B, 20B and 20C.

[0383] In the illustrated embodiment of Figures 21-24 there are two applicators, disposed respectively at the leading and trailing ends of the robotic device. The number and position of the applicators may vary depending upon whether pretreatment and / or coating is to be provided, the number of conductors of the bundle to be coated, and the intended direction of travel of the device etc. For example, where coating is to be provided, it is desirable that the applicator for providing the cosed at the trailing end of the conductor i.e. beyond the trailing wheel e.g. in the position of applicator 323 shown. This will avoid the wheel disturbing the coating once applied. An applicator for pre-treatment if also present on the same device may then be located at the leading end, such as ahead of the leading wheel e.g. in the position of applicator 318 shown. If the device is to be used only for pretreatment, a single applicator may be provided e.g. at the trailing end of the device. Multiple applicators may be provided for providing pre-treatment and / or multiple applicators may be provided for providing coating of the line.

[0384] A pair of cameras 344, 346 are provided looking rearward beyond the applicator 323 along the position of the conductor at the trailing end of the device, and a corresponding pair of cameras 340, 342 are provided looking forward along the position of the conductor at the leading end ahead of the applicator 318. The forward looking cameras 340, 342 form part of the obstacle detection system, while those looking rearward may be used to inspect the applied coati ng / pre-treatm ent. Cameras may be provided at additional positions e.g. looking into the interior of the device along the conductor in either the forward or rearward direction (such as to the trailing side of applicator 318 or the leading side of applicator 323. This may enable inspection of coating / pre-treatment applied by the leading applicator and / or inspection of the conductor prior to application of a coating / pre-treatment by the trailing applicator. The position and / or number of cameras may vary from that illustrated. Generally any suitable arrangement of cameras may be used as required to support obstacle detection and / or inspection of the line before and / or after application of a pre-treatment or coating thereto.

[0385] The chassis includes a T- shaped connector 316 including a top bar 312 to which the wheels are mounted (and which extends in the longitudinal direction), and a stem 314 connecting the top bar 312 to a main body 350 of the chassis. The stem 314 divides the top bar 312 into two arms extending on either side thereof, to which the leading and trailing wheels are coupled. The stem 314 extends downwardly from the top bar 312. The stem extends in a direction perpendicular to the direction in which the top bar extends. In use, the stem extends vertically while the top bar extends horizontally. The stem 314 bisects the top bar 312.

[0386] In this way, the T-shaped connector suspends the main body of the device from the line in use so that it hangs below the line. This is advantageous in that a space is provided beneath the intended path of a conductor to be treated / coated over an appreciable distance, facilitating obstacle navigation. For example, the stem 314 of the connector may have a length of at least 15cm. As the main body is suspended below the wheels and applicators in this way, the wheels and applicators are located outside of a main housing of the device. Indeed the wheels and applicators are not located in any housing and are exposed. The centre of mass of the device is located below the level of the conductor. For example, the centre of mass of the device may be located level with a point in the lower half of a length of le T-shaped connector, labelled A in Figure 22. This position is merely exemplary.

[0387] The main body 350 has first and second opposite edges 351 , 353 extending in the longitudinal direction i.e. in the direction of the line in use, and the stem of the T-shape connector is attached to a central portion 352 of the main body 350 of the housing, being offset toward the first edge 351 thereof. This may assist in stable mounting of the device to a line, even when a wheel is selectively retracted from the line to traverse an obstacle. In the illustrated embodiment, the stem of the T-shape connector is attached to the main body at the first longitudinal edge 351 thereof. When viewed in vertical cross section as in Figure 22, the stem of the T-shape connector and the main body of the housing may define an L-shape. The central portion 352 refers to a central portion of the main body along the longitudinal direction. The central portion 352 may be notionally divided into a first and second outer portions and a central portion therebetween along the length thereof i.e. in the direction of the line. Each portion may be of 1 / 3 of the length of the main body.

[0388] As discussed above, while desirably extending around the full circumference of the conductor when in the closed configuration and engaged around the conductor to apply a coating / pre-treatment thereto, when in the open configuration and retracted from the conductor, the applicators no longer extend around the conductor. Together with the wheels being located in a top line position, i.e. being disposed on top of the line, with no wheels being located below the line and the use of the T-shaped connector, this may assist in obstacle negotiation, since the space beneath the conductor is left free over an appreciable distance. It may be seen that no other components of the robotic device are present in the area beneath the wheels or applicators

[0389] The structure of the chassis, main body and fluid delivery system for the applicators will now be described in more detail by reference to Figures 25-29. Figures 25-29 illustrate a robotic device similar to that shown in Figures 21-24, but without including the applicators or cameras for ease of reference. Like components will be numbered by the same references as in the device of Figures 21-24, but incremented by 100. The device 400 of Figures 21-24 is shown from a different side to the device 300 of Figures 21-24.

[0390] Figure 25 is a perspective view of the device from one end and side, taken from the opposite side to that of Figure 21, having leading 402 and trailing 404 wheels assuming a direction of travel to the left in Figure 25, and taking a section through the T-shape connector and main housing. Figure 26 is a view of the device 400 taken from one side, being the side at which the T-shape connector is located, again showing the T-shape connector and one end of the main body in sectional form to illustrate the interior thereof. Figure 27 is a view similar to that of Figure 26, but taken from the opposite side of the device 400 and showing a section through the other side of the main body 450. Figure 28 is a top view of the device 400 showing a part of the main body housing cut away to illustrate the interior thereof. i vertical cross-sectional view taken through the stem of the T-shape connector of the device 400.

[0391] As illustrated in Fig. 27, the distance Li the spacing of the wheels (as measured between the axes of about which the wheels rotate) may be in a range of from 25cm-200cm. This may also apply to the later twin chassis embodiments. In both cases each wheel may, by way of example, have a diameter in the range of from 35 cm to 50cm.

[0392] All features described with respect to the example of Figures 25-29 will also be present in the example of Figures 21-24. As may be seen best in Figure 25, the interior of the T-shaped connector is hollow. The connector thus defines an inner cavity through which fluid pipes may be routed for supplying fluid from the fluid tank(s) of the device 400 to the applicator(s) thereof as required.

[0393] The main body 350, 450 provides a housing for various components of the device 300, 400. As shown most clearly in Figures 25-29, the main body 450 includes a central portion 452 with first and second outer portions 454, 456 on either side thereof. The central portion is disposed in the region to which the T-shape connector is attached (being attached along one of the longitudinal edges of the main body). Each of the central and first and second outer portions extends over the full width of the main body of the device. The first and second outer portions are located to the leading and trailing ends of the device beneath the leading and trailing wheels of the device. Each of the outer portions 454, 456 houses a respective fluid tank. By providing fluid tanks on either side of the base of the T-shape connector and below the wheels of the device in this way, a stable arrangement may be provided. (The corresponding parts of the main body 350 in the example of Figures 21-24 are labelled as 350, 354 and 356 respectively.)

[0394] The central part 352, 452 of the main body 350, 450 of the device 300, 400 houses various components of the device required for its operation, including a controller e.g. computer system, power source, communications systems, and pumps for pumping fluid from the tanks to the applicators as required. The location of pumps 460 and controller 462 are shown schematically, and are most easily seen in Figure 28. Although not shown in Figures 25-29, suitable pipes will be provided to pump fluid from the tanks disclosed in the regions 456, 454 up through the T-shaped connector to the applicators.

[0395] As mentioned above, in the illustrated embodiment of Figures 21-24 and 25- 29, the wheels are pulley wheels. The shape of the wheel may be seen most clearly in Figure 29. A pulley wheel has a circumferentially extending groove in its conductor contacting surface for locating the conductor in use. The groove of the trailing wheel 304 is denoted 331 in Figure 21. Figure 29 shows the groove 431 associated with the trailing wheel 404. However, as discussed above, other types of wheel may be used. While two wheels are shown, it is envisaged that a greater number of wheels may be used. wheel (whatever its type) may, in some examples, in use extend over (only) up to 180 degrees of the circumferential surface of the conductor on which it runs. Thus the wheel may extend over only an upper part of the surface of the conductor. This facilitates obstacle negotiation, allowing the wheels to readily run over obstacles. For a pulley type wheel as illustrated in Figure 29 this may mean that the height h of a rim 433 of the wheel on either side of the groove 431 measured from a bottom of the groove is no greater than a radius of the conductor. However, this is only exemplary, and it is envisaged that the wheel may extend over a greater proportion of the circumferential surface of the conductor without detriment to obstacle navigation.

[0396] A further embodiment of a device 500 in accordance with the invention will now be described by reference to Figures 30-37.

[0397] Figure 30 illustrates the device 500 from a trailing end and Figure 31 is a perspective view of the device 500 taken from above and one side.

[0398] The wheels, applicators and cameras of the device are similar to those described in relation to the earlier embodiment of Figures 21-24 and 25-29. Rather than there being a single leading and a single trailing wheel, in this case there is a pair of leading wheels and a pair of trailing wheels. The chassis includes first and second halves 510, 512 coupled together at a leading end (first) central coupling 514 and a trailing end (second) central coupling 516. Each chassis half extends in the longitudinal direction i.e. along the length of the line, with the couplings 514, 516 connecting the two halves and extending therebetween in the transverse direction. The chassis half 510 includes a first wheel 502 at the leading end and a second wheel 504 at a trailing end. The chassis half 512 has a third wheel 503 at the leading end and a fourth wheel 505 at the trailing end. The leading and trailing wheels of the chassis halves define respective pairs of opposed wheels (i.e. the first and third wheels 502, 503 and second and fourth wheels 504, 505), the pairs being spaced apart along the length of the device.

[0399] Each chassis half 510, 512 includes a respective tubular connector 518, 520 (first and second connectors) extending between the leading and trailing wheels thereof. A respective housing 522, 524 (first and second housings) hangs below i.e. is suspended from each respective one of the connectors 518, 520. Each housing 522, 524 includes a respective fluid tank disposed therein (first and second fluid tanks).

[0400] As described with respect to Figures 21-29, a suitable arrangement of pipes may be used to supply fluid from the tank of a given chassis half to the applicator(s) associated therewith. Other components of the device e.g. pumps, control system etc as described with respect to the main body of the earlier embodiment may similarly be provided within the housings of the two chassis halves as appropriate.

[0401] I n this embodiment, the wheels 502, 504 of the first chassis half 510 will run on top of a first conductor of the line e.g. of a bundle thereof, while the wheels 503, 505 of the second chassis half 512 run along a second, different conductor of the le which is parallel to the first conductor. In the example illustrated, an applicator 523, 525 is provided at the trailing end of each of the first and second chassis halves respectively (to the trailing side of the trailing wheels), and a further applicator 517, 519 is provided at the leading end of each of the first and second chassis halves, to the leading side of the leading wheels. The pairs of applicators at either end of the chassis are offset longitudinally from one another so that they do not interfere with each other upon opening of the central coupling at the respective chassis end. A pair of cameras is provided associated with each applicator in a similar manner to the embodiment of Figures 21-24 and 25-29. The cameras associated with applicator 523 are labelled 544, 546 respectively, while those associated with applicator 525 are labelled 548, 550 respectively. The applicators are of the same configuration as that described with respect to the embodiment of Figures 21-24 and 25-29. The type of applicator, number and position of the cameras and position of the applicators (e.g. whether provided at the leading or trailing end) may similarly vary from the arrangement illustrated as described with respect to Figures 21-24 and 25-29.

[0402] As in the earlier embodiment of Figures 21-24 and 25-29, the wheels are shown as pulley wheels. Again, the wheels ride on top of respective conductors of a line. The wheels associated with each chassis half ride on the same conductor, which is the same conductor around which the applicators associated with that chassis half engage. As described with respect to the embodiment of Figures 21-25 and 26-29, in alternative arrangements, it is envisaged that the applicators may treat a conductor other than that on which the wheels roll (and additional applicators may be provided to permit treatment of multiple conductors in a single pass).

[0403] An actuator is provided in a respective actuator housing associated with each wheel as in the earlier embodiment of Figures 21-29 for driving each wheel. In the embodiment of Figures 30 and 31, the applicators are fixedly coupled to respective arms of the central coupling at the respective end of the chassis. The front central coupling 514 includes first and second arms 550, 552 associated with the first 510 and second 512 chassis halves respectively. The rear central coupling 516 is seen most clearly in Figure 30 and includes third and fourth arms 530, 532 associated with the first 510 and second 512 chassis halves respectively. Each of the first and second (and third and fourth) arms has a proximal end movably coupled to the chassis e.g. rotatably coupled thereto, and a distal end which is coupled to the other of the first and second (or third and fourth) arms at the central coupling 514 (or 516). The central coupling 514 joins the first and second arms 550, 552. The central coupling 516 joins the third and fourth arms 530, 532.

[0404] The applicators 523 and 525 (and associated cameras) are fixedly connected via connectors 560, 562 to the arms 530, 532 respectively. A similar arrangement is provided at the leading end, with the leading central coupling 514 connecting arms 550, 552 associated with the first and second chassis halves 510, 512. The wheels 504, 505 are fixedly coupled via connectors 570, 571 to the arms le trailing end, with a similar arrangement at the leading end connecting wheels 502, 503 via connectors 573, 574 to arms 550, 552.

[0405] Each arm 530, 532 (and corresponding 550, 552) is rotatably mounted at its proximal end to an end of the connector 518, 520 on the applicable side of the chassis so as to be able to rotate about the axis of the connector. Each arm rotates about an axis extending in the longitudinal direction. Each arm at a particular end of the device is selectively and independently rotatable upon opening of the relevant central coupling. Rotation of a given arm will retract the applicator and wheel mounted to that arm away from the line as described below, permitting negotiation of an obstacle. While one of the central coupling is open to permit rotation of one or both of the arms thereof and retraction of the associated wheel(s) and applicator(s), the other central coupling at the other end of the chassis remains closed, ensuring the chassis halves remain stably connected, allowing the device to continue to traverse the line.

[0406] Each central coupling is shown in a closed, coupled configuration in Figures 30 and 31, providing a rigid connection between the chassis halves. Each of the central couplings 514, 516 is configured to be independently and selectively movable between this closed, coupled configuration, and an open, decoupled configuration in use so as to enable the wheels and applicators to be moved out of the way of obstacles. This is achieved by opening of the central joint of the coupling and rotation of one or both of the arms e.g. 530, 532. In the embodiment illustrated, opening of one of the central couplings and associated rotation of the arms apart from one another moves both the wheels and the applicators out of the way of the line. It is envisaged that in other embodiments some form of dynamic coupling might be used to connect an applicator to its chassis half to provide greater freedom of movement of the applicator away from an obstacle / into engagement with a given conductor. For example, a coupling of the type described in relation to any of Figures 21-29 might be used. However, as the chassis is configured to split to traverse an obstacle in the Figures 30 and 31 embodiment, retraction of the applicators from the line may still be achieved where they are fixedly coupled to an arm of the coupling.

[0407] The centre of mass of the device again lies in a plane located below a plane in which the conductor, and also a bottom of the wheels lies. The centre of mass is denoted with a dot labelled B in Figure 30 below item 548 and between the applicators.

[0408] Figure 32 illustrates a device similar to that of Figures 30 and 31, with corresponding parts having the same reference numerals incremented by 100. It will be noted that the device shown in Figure 32 differs in some minor details from that of Figures 30 and 31, for example omitting the applicators at the leading end, and not showing cameras, while instead showing actuators 702, 704 used to transition the applicators between open and closed configurations at the trailing end. The operation of the devices 500, 600 is the same. J 32 shows the central coupling 614 at the leading end open, with the arms 650, 652 to which the wheels 602, 603 are mounted rotated out of engagement with the line to permit a T-shaped obstacle 700 (here a suspension insulator) to be negotiated. Here such obstacles are present on both conductors, requiring rotation of both arms 650, 652 about the axis of the connectors 618, 620. The device may traverse mid-span obstacles by the wheels simply rolling over the obstacles as described in the embodiment of Figures 21-24 or 25-29, for example. However, the split chassis configuration of this further embodiment gives the possibility of traversing other types of obstacles, such as suspension towers or dampers. While the central coupling at the leading end of the chassis opens to traverse the obstacle, the coupling at the trailing end remains closed to keep the chassis halves rigidly fixed to one another and allow the device 600 to continue to traverse the line, with the applicators 623, 624 applying treatment or coating to respective conductors of the line.

[0409] Figure 33 is a side on view taken from the side of the second chassis half 612 of Figure 32 showing the position of the leading wheel 603 when rotated as the central coupling 614 opens to disengage and retract from the line. Figure 34 is a view of the device taken from above further illustrating the opening of the coupling at the leading end.

[0410] Opening of the central coupling 614 between arms 650, 652 is carried out under the control of a suitable obstacle avoidance system of the device as with the earlier embodiments e.g. based on the detection of an obstacle and other inputs. Once the coupling 614 at the leading end has opened, the device i.e. platform may be driven stably forward past the suspension insulator 700. Once the front wheels have passed the obstacle, the arms rotate back to their original position and the leading central coupling is closed again, with the wheels being engaged with their conductors. The front of the chassis is now being rigidly connected and provides stability as the trailing end central coupling 616 opens up to pass the insulator 700. The leading and trailing central couplings are therefore selectively and independently openable.

[0411] Figures 35 and 36 illustrate the stages in the opening of the central coupling 616 at the trailing end of the device in a scenario where there is a suspension insulator 703 associated with only the left hand conductor. Here the applicators 623, 624 are initially engaged around their respective conductors. The first step is for the left hand applicator 623 to transition from the closed configuration to an open configuration so as to be disengaged from its conductor. Figure 35 illustrates the left hand applicator 623 in the open configuration with the right hand one 624 still in the closed configuration. This is achieved in a similar manner to that described in respect of Figures 21-24 or 25-29, and is controlled by the actuator 702 associated with the applicator. Once the applicator 623 is in its open configuration, the central coupling 616 may be opened permitting the arm 630 to rotate to the position shown in Figure 36, thereby moving the wheel 604 and the applicator 623 out of the way of • and the obstacle. The right hand applicator 624 and wheel 605 may remain in place engaged with their respective conductor in this example as there is no obstacle on that conductor. The front end central coupling also remains closed, so that the chassis halves are stably connected allowing the robotic device / platform to continue to traverse the line (and apply coating / pre-treatment at least to the right hand conductor). Figure 37 shows the arrangement of Figure 36 from above.

[0412] Once the obstacle has been traversed i.e. the wheel and applicator on the left hand side are beyond the obstacle 703, the arm 630 may rotate back to the position in Figure 35, and the central coupling closed once more. The applicator 623 may move back to its closed configuration engaged around its conductor to resume pre-treatment / coating thereof. If obstacles were associated with both conductors, both arms of the trailing central coupling would open to retract the wheels / applicators associated therewith as in the example of Figures 33 and 34 at the leading end.

[0413] It will be appreciated that the split chassis arrangement of Figures 30-36 therefore provides great flexibility in negotiating a wide range of obstacles associated with either or both conductors.

[0414] It will be appreciated that a module e.g. obstacle avoidance module, pretreatment or coating application module, may include any suitable set of components, including both electronic and mechanical, for providing the described functionality. The functionality may be implemented at least in part using software. While various embodiments of the present invention have been illustrated and described in detail in the drawings and forgoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. It will be understood that various changes in form and detail may be made without departing from the scope of the present invention as defined by the claims.

[0415] List of embodiments A:

[0416] (The dependency of the embodiments in list A is in relation to the specified embodiments within list A.)

[0417] 1. A robotic device configured to pre-treat and / or coat an overhead transmission or distribution line, wherein the robotic device comprises a pretreatment module and / or a coating application module; wherein the robotic device further comprises an obstacle avoidance module.

[0418] 2. A robotic device in accordance with embodiment 1 , wherein the pretreatment module is configured to clean at least a portion of an overhead transmission or distribution line, optionally wherein the pre-treatment module is configured to clean one or more conductors of the overhead transmission or distribution line in a single pass, further optionally wherein the line comprises multiple conductors and the coating application module is configured to clean multiple conductors of the line in a single pass.

[0419] 3. A robotic device in accordance with embodiment 1 or 2, wherein the pretreatment module is configured to prepare the surface of at least a portion of an overhead transmission or distribution line.

[0420] 4. A robotic device in accordance with embodiment 1, 2 or 3, wherein the pretreatment module comprises a mechanical abrasion system and / or a chemical treatment system.

[0421] 5. A robotic device in accordance with any preceding embodiment, wherein the coating application module is configured to coat one or more conductors of the line in a single pass, optionally wherein the line comprises multiple conductors and the coating application module is configured to coat multiple conductors of the line in a single pass.

[0422] 6. A robotic device in accordance with any preceding embodiment, wherein the obstacle avoidance module is configured to cause the pre-treatment module and / or the coating application module to decouple from an overhead transmission or distribution line and / or to retract upon encountering one or more obstacles.

[0423] 7. A robotic device in accordance with any preceding embodiment, wherein the obstacle avoidance module is configured to cause one or more wheels or an engagement mechanism to roll over an obstacle such as a damper, spacer or fitting and / or is configured to enable the device to negotiate a suspension tower or clamp encountered along the line.

[0424] 8. A robotic device in accordance with any preceding embodiment, wherein the obstacle avoidance module comprises one of more of: (i) a levered screw mechanism; (ii) a single revolute joint mechanism; (iii) a revolute joint mechanism with centre coupling; or (iv) a sprung revolute joint.

[0425] 9. A robotic device in accordance with any preceding embodiment, wherein the robotic device comprises a set of mechanisms associated with a platform of the device, wherein each mechanism may selectively engage and disengage with the transmission or distribution line, wherein at least one mechanism of the set of engagement mechanisms may disengage from the line in order to negotiate an obstacle while at least one, and optionally a plurality, of the other ones of the set of mechanisms remains engaged with the line to provide stable support to the platform.

[0426] 10. A robotic device in accordance with any preceding embodiment wherein the robotic device comprises a pair of wheels associated with respective ones of a pair of links, the links being coupled to one another at a centre coupling, wherein decoupling of the centre coupling allows the links to rotate so as to move the wheels out of the way of an obstacle.

[0427] 11. An overhead transmission or distribution line system comprising: one or more overhead transmission or distribution lines; and one or more robotic devices in accordance with any of embodiments 1-10.

[0428] 12. A method comprising: locating a robotic device in accordance with any of embodiments 1-10 in proximity to an overhead transmission or distribution line; and causing the robotic device to avoid one or more obstacles.

[0429] 13. A retrofit coating system configured to coat an overhead transmission or distribution line with a coating comprising: a robotic device as disclosed in any of embodiments 1-10; and a coating material to be applied by the robotic device to an overhead transmission or distribution line so as to form a coating on the overhead transmission or distribution line. List of embodiments B

[0430] (The dependency of the embodiments in list B is in relation to the specified embodiments within list B.)

[0431] 1. A robotic device configured to pre-treat and / or coat an overhead transmission or distribution line, the line comprising a set of one or more conductors; wherein the robotic device comprises a pre-treatment module and / or a coating application module; and wherein the robotic device further comprises an obstacle avoidance module.

[0432] 2. The robotic device of embodiment 1 wherein the robotic device comprises one or more applicators e.g. end effectors for performing pre-treatment and / or coating operations; wherein each applicator is configured to engage with one of the set of one or more conductors of the line to apply a pre-treatment or coating thereto.

[0433] 3. The robotic device of embodiment 2 wherein the device comprises a pretreatment module, and the one or more applicators comprise a set of one or more applicators configured to apply pre-treatment in the form of one of more of; surface preparation, cleaning, mechanical abrasion, and chemical treatment to one or more conductors of the set of one or more conductors of the line.

[0434] 4. The robotic device of embodiment 2 or 3 wherein at least one, and optionally each, of the one or more applicators is configured to pre-treat or coat its respective conductor by applying a fluid thereto by a contact-based method, optionally wherein the method is selected from; brushing, rolling, dip coating, fluid jetting, flow coating, fluid deposition and doctoring, electrostatic coating, slot die coating, annular die coating, extruding and combinations thereof; and / or wherein the device comprises a coating application module and a set of one or more applicators configured to apply the coating, wherein each of the applicators for applying the coating is configured to coat its respective conductor by applying a fluid thereto by a contact-based method, for example selected from brushing, rolling, dip coating, fluid jetting, flow coating, fluid deposition and doctoring, electrostatic coating, slot die coating, annular die coating, extruding and combinations thereof.

[0435] 5. The robotic device of any one of embodiments 2 to 4 comprising a set of a plurality of applicators for performing pre-treating and / or a set of a plurality of applicators for performing coating operations, wherein, when the line comprises a 3 conductors, different applicators of each set of applicators may engage with different respective conductors of the set of conductors to enable pretreating and / or coating of multiple conductors of the set of multiple conductors in a single pass.

[0436] 6. The robotic device of any one of embodiments 2 to 5 wherein at least one, and optionally each applicator of the one or more applicators is configured to circumferentially surround the conductor when engaged around the conductor for applying the coating and / or pre-treatment thereto.

[0437] 7. The robotic device of any one of embodiments 2 to 6 wherein at least one, and optionally each applicator of the one or more applicators defines an annular shape when in a configuration for engaging around the conductor to apply the coating or pre-treatment to thereto, defining a central bore for receiving the conductor; optionally wherein the device comprises a coating application module and a set of one or more applicators configured to apply the coating, wherein each of the one or more applicators for applying the coating is configured in this manner.

[0438] 8. The robotic device of any one of embodiments 2 to 7 wherein at least one, and optionally each applicator of the one or more applicators is configured to transition between a closed configuration for engaging around the conductor of the line to apply a pre-treatment or coating thereto and an open configuration for disengaging from the conductor for passing an obstacle; optionally wherein the device comprises a coating application module and a set of one or more applicators configured to apply the coating, wherein each of the one or more applicators for applying the coating is configured in this manner.

[0439] 9. The robotic device of embodiment 8 wherein the at least one applicator of the one or more applicators comprises first and second parts connected to one another at a hinge, wherein the first and second parts are rotatable relative to one another about the hinge to transition the applicator between the open and closed configurations, for example wherein the applicator defines a clam-shell structure.

[0440] 10. The robotic device of embodiment 8 or 9 wherein the at least one applicator of the one or more applicators is configured to transition from the closed configuration to the open configuration for disengaging from its conductor for passing an obstacle, for example under the control of the obstacle avoidance module.

[0441] 11. The robotic device of any one of embodiments 8 to 10 wherein the device comprises a plurality of the applicators configured to transition between open and closed configurations, and individual applicators are selectively and independently between the open and closed configurations as required in order to pass obstacles, for example under the control of the obstacle avoidance module.

[0442] 12. The robotic device of any one of embodiments 8 to 11 comprising an actuator associated with each applicator configured to transition between open and closed configurations for causing the applicator to transition between its open and closed configurations.

[0443] 13. The robotic device of any one of embodiments 2 to 12 wherein each applicator of the one or more applicators is selectively retractable from the conductor in order to pass an obstacle in use.

[0444] 14. The robotic device of embodiment 13 wherein at least one and optionally each applicator of the one or more applicators is coupled to a chassis of the robotic device by a coupling enabling retraction of the applicator from the conductor in use; such as wherein each applicator is coupled to a chassis of the robotic device by a coupling enabling the applicator to move relative to the chassis of the device in order to retract from the conductor in use, for example wherein the coupling comprises parts movable relative to one another in use to enable retraction of the applicator; optionally wherein the coupling comprises a revolute joint, swing arm, prismatic joint or a four-bar link mechanism; and / or wherein a chassis of the robotic device comprises portions coupled to one another at one or more central coupling, wherein each central coupling is defined between a pair of arms of the chassis movable relative to one another to transition the central coupling from a closed configuration in which the arms connect the chassis portions and an open configuration for passing an obstacle, wherein at least one applicator is mounted to one of the chassis arms, whereby movement of the arm upon opening of the respective central coupling retracts the applicator.

[0445] 15. The robotic device of embodiment 13 or 14 wherein at least one, and optionally each, applicator of the one or more applicators is coupled to a chassis of the robotic device by a robotic arm, preferably a multi-axis robotic arm, for example having at least 6 axes.

[0446] 16. The robotic device of any one of embodiments 13 to 15 wherein each applicator is selectively retractable from the conductor with which it engages under the control of the obstacle avoidance module.

[0447] 17. The robotic device of any one of embodiments 13 to 16 wherein at least one, or optionally each applicator is configured to transition from a closed configuration for engaging around a conductor of the line to apply a pre-treatment or coating thereto to an open configuration for disengaging from the conductor, wherein, the he open configuration is located in an installation position, and is configured to be retractable from the installation position to a retracted position in which it is located away from the conductor for negotiating an obstacle.

[0448] 18. The robotic device of any one of embodiments 13 to 17 wherein the robotic device comprises a plurality of the applicators, and individual applicators are independently and selectively retractable from respective conductors of the line as required in order to pass obstacles.

[0449] 19. The robotic device of any one of embodiments 13 to 18 wherein the obstacle avoidance module is operable in use to cause the or each applicator to reengage with its respective conductor once an obstacle has been passed.

[0450] 20. The robotic device of any one of embodiments 2 to 19 comprising a plurality of the applicators, wherein at least some of the applicators are configured to engage with the same conductor of the set of one or more conductors for applying the pretreatment and / or coating thereto; and / or wherein at least some of the applicators are configured to engage with different conductors of the plurality of conductors where the set of one or more conductors of the line comprises a plurality of conductors for applying the pre-treatment and / or coating thereto.

[0451] 21. The robotic device of any of embodiments 2 to 20 wherein at least some of the one or more applicators are capable of engaging with different ones of the plurality of conductors where the set of one or more conductors of the line comprises a plurality of conductors for applying the pre-treatment and / or coating thereto, for example and wherein these applicator(s) are mounted to a chassis of the device by a robotic arm, such as a multi-axis robotic arm.

[0452] 22. The robotic device of any preceding embodiment wherein the set of one or more conductors are in respect of a phase of the overhead transmission or distribution line, the set of one or more conductors being a single conductor or a bundle of a plurality of conductors, such two, three, four or more conductors; and / or wherein the pre-treatment module is configured to provide complete circumferential coverage of the pre-treatment in respect of the conductor(s) to which pre-treatment is provided and / or the coating application module is configured to provide complete circumferential coverage of the coating in respect of the conductor(s) to which coating is provided; and / or wherein the device comprises a set of one or more applicators for performing pre-treating and / or a set of one or more applicators for performing coating operations, preferably wherein the robotic device comprises both a pre-treatment module and a coating application module and comprises a set of one or more applicators for performing pre-treating operations and a set of one or more applicators for performing coating operations. 23. The robotic device of any preceding embodiment, wherein the device comprises a plurality of wheels which are configured to engage and run on one or more of the set of one or more conductors of the line in use to mount the device to the line; optionally wherein the device comprises an actuator in respect of each wheel for driving the wheel.

[0453] 24. The robotic device of embodiment 23 wherein the wheels are configured to roll over obstacles encountered, such as mid-span obstacles, for example splice connections, dampers, spacers or compression fittings.

[0454] 25. The robotic device of any one of embodiments 23 or 24 wherein each wheel is selectively retractable from a respective one of the set of one or more conductors of the line on which it runs in order to pass an obstacle.

[0455] 26. The robotic device of embodiment 25, wherein the device is configured such that when a wheel retracts from the conductor of the line on which it runs to pass an obstacle at least one other of the wheels remains engaged with the conductor of the line on which it runs to provide stable support to the robotic device in use.

[0456] 27. The robotic device of embodiment 25 or 26 wherein the obstacle avoidance module comprises a wheel retraction system operable in use to enable each wheel to be selectively retractable from a respective conductor of the line on which it runs in order to pass an obstacle.

[0457] 28. The robotic device of any of embodiments 25 to 27 wherein the obstacle avoidance module is operable in use such that individual wheels are independently and selectively retractable from respective conductor(s) of the line in use as required in order to pass obstacles.

[0458] 29. The robotic device of any or embodiments 25 to 28 wherein the device is configured such that a wheel will reengage with its conductor once an obstacle has been negotiated.

[0459] 30. The robotic device of any one of embodiments 23 to 29 wherein the obstacle avoidance module comprises one of more of: (i) a levered screw mechanism; (ii) a single revolute joint mechanism; (iii) a revolute joint mechanism with centre coupling; or (iv) a sprung revolute joint; for retracting the wheels; and / or wherein the device comprises a chassis having first and second portions connected to one another by first and second central couplings at leading and trailing ends thereof, wherein the first and second central couplings are selectively openable to retract one or more wheels and optionally one or more the device from engagement with their respective conductors for passing an obstacle; and / or wherein a chassis of the robotic device comprises portions coupled to one another at one or more central coupling, wherein each central coupling is defined between a pair of arms of the chassis movable relative to one another to transition the central coupling from a closed configuration in which the arms connect the chassis portions and an open configuration for passing an obstacle, wherein at least one wheel and / or applicator is mounted to one of the chassis arms, whereby movement of the arm upon opening of the respective central coupling retracts the wheel and / or applicator; and / or wherein each wheel is coupled to a chassis of the robotic device by a coupling enabling retraction of the wheel from the conductor in use; such as by a coupling enabling the wheel to move relative to the chassis of the device in order to retract from the conductor in use, for example wherein the coupling comprises parts movable relative to one another in use to enable retraction of the wheel; optionally wherein the coupling comprises a sprung joint, revolute joint, swing arm, prismatic joint, robotic arm, levered screw mechanism or a four-bar link mechanism.

[0460] 31. The device of any one of embodiments 23 to 30 wherein the wheels are pulley wheels.

[0461] 32. The device of any of embodiments 23 to 31 wherein the robotic device comprises a main body suspended below the wheels by a chassis of the device; optionally wherein the main body is located below the wheels by a distance of at least 15cm.

[0462] 33. The device of any preceding embodiment further comprising one or more fluid tanks for holding fluid for use in pre-treatment and / or coating of the line.

[0463] 34. The device of embodiment 33 as dependent upon any of embodiments 23 to 32 wherein the one or more fluid tanks are disposed below the wheels, and preferably entirely below the wheels.

[0464] 35. The device of embodiment 34 as dependent upon embodiment 32 wherein the one or more fluid tanks of the device are housed in the main body of the device.

[0465] 36. The device of embodiment 33, 34 or 35 further comprising a fluid delivery system for supplying fluid from the one or more tanks to one or more applicators of the pre-treatment module and / or coating application module. evice of embodiment 36 wherein the fluid delivery system comprises a set of one or more pumps and a set of one or more fluid conduits for supplying fluid to the applicator(s).

[0466] 38. The device of embodiment 37 as dependent directly or indirectly on embodiment 35, wherein the one or more pumps are located in the main body of the device, and the one or more fluid conduits pass through a hollow interior of a part of the chassis suspending the main body of the device below the wheels to reach the one or more applicators.

[0467] 39. The device of any one of embodiments 23 to 38 wherein the plurality of wheels comprise first and second wheels configured to run on a first conductor of the set of one or more conductors of the line, the wheels being spaced apart and located one behind the other along a longitudinal direction of the robotic device.

[0468] 40. The device of embodiment 39 wherein the first and second wheels are spaced apart along the length of the device by a distance of at least 20cm, or at least 25cm and / or by a distance of less than 250cm, or less than 200cm, optionally wherein the wheels are spaced apart by a distance in a range of from 25cm to 200cm; and / or wherein each wheel has a diameter in the range of from 35 cm to 50cm.

[0469] 41. The device of embodiment 39 or 40 wherein the chassis of the device comprises a longitudinally extending tubular support to which the first and second wheels are mounted; preferably wherein the wheels are coupled to the tubular support in a manner such that the support is disposed laterally outboard of the wheels.

[0470] 42. The device of embodiment 41 as dependent directly or indirectly on embodiment 36 wherein one or more fluid conduit(s) of the fluid delivery system pass through the hollow interior of the tubular support to reach the one or more applicators.

[0471] 43. The device of any of embodiments 39 to 42 wherein the first and second wheels are disposed at leading and trailing ends of the device respectively.

[0472] 44. The device of embodiment 43 wherein the device comprises a coating application module, the coating application module comprising an applicator disposed at a trailing end of the chassis to the trailing side of second wheel and / or wherein the device comprises a pre-treatment module, the pre-treatment module having an applicator disposed at a leading end of the chassis to the leading side of I and / or an applicator at a trailing end of the chassis to the trailing side of the second wheel.

[0473] 45. The device of any one of embodiments 39 to 44 wherein the chassis comprises a T-shaped connector defining a stem and a top bar, the top bar defining arms on either side of the stem, wherein the first and second wheels are mounted to respective ones of the arms, and a main body of the device is mounted to a bottom of the stem of the T-shaped connector.

[0474] 46. The device of embodiment 45 wherein one or more fluid tanks for holding fluid for use in pre-treatment and / or coating of the line are housed in the main body of the chassis suspended below the wheels by the T-shaped connector.

[0475] 47. The device of embodiment 46 comprising a fluid delivery system for supplying fluid from the one or more tanks to the pre-treatment module and / or coating application module, wherein the T-shaped connector defines an internal cavity through which a set of one or more fluid conduits pass to deliver fluid from the one or more tanks to one or more applicators of the pre-treatment and / or coating application modules.

[0476] 48. The device of embodiment 47 wherein one or more pumps are provided in the main body of the chassis for pumping fluid from the one or more tanks in use through the set of one or more fluid conduits to the one or more applicators.

[0477] 49. The device of any or embodiments 45 to 48 wherein the main body of the chassis comprises notional leading, central and trailing portions along the longitudinal direction, wherein the base of the stem of the T-shaped connector is connected to the central portion of the main body; and / or wherein the base of the stem of the T-shaped connector is connected to the main body at a longitudinally extending edge thereof.

[0478] 50. The device of embodiment 49 as dependent on embodiment 48 wherein first and second fluid tanks for holding fluid for use in pre-treatment and / or coating of the line are provided within the leading and trailing portions of the main body respectively; optionally wherein the central portion houses the one or more pumps of the fluid delivery system.

[0479] 51. The device of any one of embodiments 23 to 38 wherein the plurality of wheels comprise first and second wheels configured to run on a first conductor of the set of one or more conductors of the line, the wheels being spaced apart and located one behind the other along a longitudinal direction of the robotic device, and third and fourth wheels configured to run on a second conductor of the set of one or :ors of the line, the wheels being spaced apart and located one behind the other along a longitudinal direction of the robotic device, wherein the first and third wheels and second and fourth wheels respectively define first and second pairs of wheels located one behind the other and spaced apart along the longitudinal direction of the device; optionally wherein the device further comprises one or more fluid tanks for holding fluid for use in pre-treatment and / or coating of the line; further optionally wherein the one or more fluid tanks are disposed below the wheels, for example entirely below the wheels; and / or further comprising a fluid delivery system for supplying fluid from the one or more tanks to one or more applicators of the pretreatment module and / or coating application module, for example wherein the fluid delivery system comprises a set of one or more pumps and a set of one or more fluid conduits for supplying fluid to the applicator(s).

[0480] 52. The device of embodiment 51 wherein the device comprises a chassis having first and second halves, the first and second wheels are mounted to a first half of the chassis and the third and fourth wheels are mounted to the second half of the chassis, wherein the chassis comprises first and second central couplings bridging between the chassis halves at a first end and a second end thereof, wherein each central coupling is selectively and independently transformable from a closed, configuration in which it connects the chassis halves and an open, configuration in which the chassis halves are decoupled from one another at the coupling, wherein the first central coupling is defined between first and second rotatable arms of the chassis, and the second central coupling is defined between third and fourth rotatable arms of the chassis, wherein the first and third wheels are mounted to the first and second rotatable arms respectively, and the second and fourth wheels are mounted to the third and fourth rotatable arms respectively, wherein rotation of any one of the first, second, third and fourth arms to open the central coupling of which the arm forms part disengages the wheel mounted thereto from its conductor and moves the wheel to a retracted position for passing an obstacle; optionally wherein both the first and second wheels, and the third and fourth wheels are spaced apart along the length of the device by a distance of at least 20cm, or at least 25cm and / or by a distance of less than 250cm, or less than 200cm; optionally wherein the first and second wheels, and third and fourth wheels, are each spaced apart by a distance in a range of from 25cm to 200cm.

[0481] 53. The device of embodiment 52 wherein the first, second, third and fourth arms are selectively and independently rotatable to transform their respective couplings between the closed and open configurations. evice of embodiment 52 or 53 wherein the obstacle avoidance module is configured to selectively transform only one of the central couplings to the open configuration for passing an obstacle at a time while the other central coupling remains in its closed, coupled configuration to maintain a stable connection between the chassis halves

[0482] 55. The device of any one of embodiments 52 to 54 comprising one or more applicators for performing pre-treatment and / or coating operations, wherein at least one applicator is mounted to one of the first, second, third and fourth arms, wherein the applicator will be moved together with the wheel to a retracted position on rotation of the arm to open one of the central couplings.

[0483] 56. The device of any one of embodiments 52 to 55 wherein the first and second wheels are connected to one another by a first longitudinally extending tubular support of the first chassis half, and the third and fourth wheels are connected to one another by a second longitudinally extending tubular support of the second chassis half; optionally wherein the first and third arms are rotatably mounted to ends of the first tubular support and the second and fourth arms are rotatably mounted to ends of the second tubular support.

[0484] 57. The device of embodiment 56 wherein the chassis comprises a first housing suspended below the first tubular support and comprising a first fluid tank, and a second housing suspended below the second tubular support and comprising a second fluid tank.

[0485] 58. The device of embodiment 57 wherein one or more fluid conduits pass through the hollow interior of each of the first and second supports to supply fluid from the respective one of the first and second tanks to one or more applicators of the device.

[0486] 59. The device of any preceding embodiment wherein the robotic device defines an empty space extending over a distance of at least 15cm below a lowermost conductor contacting point of each wheel of the device.

[0487] 60. The device of any preceding embodiment wherein the device only includes wheels configured to run on top of conductor(s) of the line in use and does not include wheels running below conductors of the line.

[0488] 61. The device of any preceding embodiment wherein the wheels of the device are exposed and are not disposed within any housing. evice of any preceding embodiment wherein the device comprises an obstacle detection system, for example comprising one or more camera, for detecting when the device is approaching an obstacle.

[0489] 63. The device of any preceding embodiment wherein the obstacle avoidance module is configured to cause one or more applicators and / or one or more wheels of the device to retract from the line when an obstacle is detected in order to negotiate the obstacle.

[0490] 64. The device of any preceding embodiment wherein the robotic device comprises a power system for providing power to the robotic device, an actuation system, a sensing and perception system, a control system and and / or a wireless communication system.

[0491] 65. A robotic device in accordance with any preceding embodiment, wherein the pre-treatment module is configured to clean at least a portion of an overhead transmission or distribution line, optionally wherein the pre-treatment module is configured to clean one or more conductors of the overhead transmission or distribution line in a single pass, further optionally wherein the line comprises multiple conductors and the coating application module is configured to clean multiple conductors of the line in a single pass.

[0492] 66. A robotic device in accordance any preceding embodiment, wherein the pretreatment module is configured to prepare the surface of at least a portion of an overhead transmission or distribution line.

[0493] 67. A robotic device in accordance with any preceding embodiment, wherein the pre-treatment module comprises a mechanical abrasion system and / or a chemical treatment system.

[0494] 68. A robotic device in accordance with any preceding embodiment, wherein the coating application module is configured to coat one or more conductors of the line in a single pass, optionally wherein the line comprises multiple conductors and the coating application module is configured to coat multiple conductors of the line in a single pass.

[0495] 69. A robotic device in accordance with any preceding embodiment, wherein the obstacle avoidance module is configured to cause the pre-treatment module and / or the coating application module to decouple from an overhead transmission or distribution line and / or to retract upon encountering one or more obstacles. Dtic device in accordance with any preceding embodiment, wherein the obstacle avoidance module comprises one of more of: (i) a levered screw mechanism; (ii) a single revolute joint mechanism; (iii) a revolute joint mechanism with centre coupling; or (iv) a sprung revolute joint.

[0496] 71. A robotic device in accordance with any preceding embodiment, wherein the robotic device comprises a set of mechanisms associated with a platform of the device, wherein each mechanism may selectively engage and disengage with the transmission or distribution line, wherein at least one mechanism of the set of engagement mechanisms may disengage from the line in order to negotiate an obstacle while at least one, and optionally a plurality, of the other ones of the set of mechanisms remains engaged with the line to provide stable support to the platform.

[0497] 72. A robotic device in accordance with any preceding embodiment wherein the robotic device comprises a pair of wheels associated with respective ones of a pair of links, the links being coupled to one another at a centre coupling, wherein decoupling of the centre coupling allows the links to rotate so as to move the wheels out of the way of an obstacle.

[0498] 73. An overhead transmission or distribution line system comprising: an overhead transmission or distribution line comprising a set of one or more conductors; and one or more robotic devices in accordance with any preceding embodiment.

[0499] 74. The overhead transmission or distribution line system of embodiment 73 wherein the set of one or more conductors are in respect of a given phase of the overhead transmission or distribution line, the set of one or more conductors being a single conductor or a bundle of a plurality of conductors, such two, three, four or more conductors.

[0500] 75. The system of embodiment 73 or 74 wherein at least two wheels of the device are configured to run on the same conductor where the set of one or more conductors of the line comprises a plurality of conductors; optionally wherein one or more applicators are configured to engage around the same conductor.

[0501] 76. The system of any one of embodiments 73 to 75 as dependent directly or indirectly on embodiment 2 wherein at least some of the one or more applicators are capable of engaging with different ones of the plurality of conductors where the set of one or more conductors of the line comprises a plurality of conductors for applying the pre-treatment and / or coating thereto, for example wherein these applicator(s) are mounted to a chassis of the device by a multi-axis robotic arm. / stem of any of embodiments 73 to 76 as dependent directly or indirectly on embodiment 2 comprising a plurality of the applicators, wherein at least some of the applicators are configured to engage with the same conductor of the set of one or more conductors for applying the pre-treatment and / or coating thereto; and / or wherein at least some of the applicators are configured to engage with different conductors of the plurality of conductors where the set of one or more conductors of the line comprises a plurality of conductors for applying the pretreatment and / or coating thereto.

[0502] 78. A method comprising: locating a robotic device as set out in any of embodiments 1-72 in proximity to an overhead transmission or distribution line; and causing the robotic device to traverse the line while applying a coating and / or pre-treatment thereto and passing one or more obstacles.

[0503] 79. A retrofit coating system configured to coat an overhead transmission or distribution line with a coating comprising: a robotic device as disclosed in any of embodiments 1-72; and a coating material to be applied by the robotic device to an overhead transmission or distribution line so as to form a coating on the overhead transmission or distribution line.

[0504] 80. A method comprising: locating a robotic device in accordance with any of embodiments 1-72 in proximity to an overhead transmission or distribution line; and causing the robotic device to avoid one or more obstacles.

[0505] 81. A retrofit coating system configured to coat an overhead transmission or distribution line with a coating comprising: a robotic device as disclosed in any of embodiments 1-72; and a coating material to be applied by the robotic device to an overhead transmission or distribution line so as to form a coating on the overhead transmission or distribution line.

[0506] 82. The device, system or method of any preceding claim wherein the device has a weight in the range of from 25 to 75 Kg; and / or wherein the device has a length of at least 0.75m, and / or no greater than 3m; and / or wherein the device has a width of at least 30cm and / or less than 80cm; and / or where in the device a height of at least 35cm and / or a height of less than 70cm.

Claims

1. A robotic device configured to pre-treat and / or coat an overhead transmission or distribution line, the line comprising a set of one or more conductors; wherein the robotic device comprises a pre-treatment module and / or a coating application module; and wherein the robotic device further comprises an obstacle avoidance module; wherein the robotic device comprises one or more applicators for performing pre-treatment and / or coating operations; wherein each applicator is configured to engage with one of the set of one or more conductors of the line to apply a pre-treatment or coating thereto in use; wherein each applicator of the one or more applicators is selectively retractable from the conductor in order to pass an obstacle in use; wherein the device comprises a plurality of wheels which are configured to engage and run on one or more of the set of one or more conductors of the line in use to mount the device to the line, wherein the wheels are configured to roll over obstacles encountered, such as mid-span obstacles including splice connections, dampers, spacers or compression fittings.

2. The robotic device of claim 1 wherein at least one applicator of the one or more applicators is coupled to a chassis of the robotic device by a coupling enabling retraction of the applicator from the conductor in use, wherein the coupling enables the applicator to move relative to the chassis of the device in order to retract from the conductor in use, for example wherein the coupling comprises parts movable relative to one another in use to enable retraction of the applicator; optionally wherein the coupling comprises a revolute joint, swing arm, prismatic joint or a four- bar link mechanism.

3. The robotic device of claim 1 or claim 2 wherein a chassis of the robotic device comprises portions coupled to one another at one or more central coupling, wherein each central coupling is defined between a pair of arms of the chassis movable relative to one another to transition the central coupling from a closed configuration in which the arms connect the chassis portions and an open configuration for passing an obstacle, wherein at least one applicator is mounted to one of the chassis arms, whereby movement of the arm upon opening of the respective central coupling retracts the applicator.

4. The robotic device of any preceding claim wherein at least one, and optionally each, applicator of the one or more applicators is coupled to a chassis of the robotic device by a multi-axis robotic arm, for example having at least 6 axes.)botic device of any preceding claim wherein each applicator is selectively retractable from the conductor with which it engages under the control of the obstacle avoidance module.

6. The robotic device of any preceding claim wherein the robotic device comprises a plurality of the applicators, and individual applicators are independently and selectively retractable from respective conductors of the line as required in order to pass obstacles.

7. The robotic device of any preceding claim wherein the device comprises a pre-treatment module, and the one or more applicators comprise a set of one or more applicators configured to apply pre-treatment in the form of one of more of; surface preparation, cleaning, mechanical abrasion, and chemical treatment to one or more conductors of the set of one or more conductors of the line.

8. The robotic device of any preceding claim wherein at least one, and optionally each, of the one or more applicators is configured to pre-treat or coat its respective conductor by applying a fluid thereto by a contact-based method, for example wherein the method is selected from; brushing, rolling, dip coating, fluid jetting, flow coating, fluid deposition and doctoring, electrostatic coating, slot die coating, annular die coating, extruding and combinations thereof.

9. The robotic device of any preceding claim wherein the device comprises a coating application module and a set of one or more applicators configured to apply the coating, wherein each of the applicators for applying the coating is configured to coat its respective conductor by applying a fluid thereto by a contact-based method, for example wherein the method is selected from; brushing, rolling, dip coating, fluid jetting, flow coating, fluid deposition and doctoring, electrostatic coating, slot die coating, annular die coating, extruding and combinations thereof.

10. The robotic device of any preceding claim wherein a pre-treatment module is provided, the pre-treatment module being configured to provide complete circumferential coverage of the pre-treatment in respect of the conductor(s) to which pre-treatment is provided, and / or wherein a coating application module is provided, the coating application module being configured to provide complete circumferential coverage of the coating in respect of the conductor(s) to which coating is provided.

11. The robotic device of any preceding claim wherein at least one, and optionally each, applicator of the one or more applicators is configured to circumferentially surround the conductor when engaged around the conductor for applying the coating or pre-treatment thereto.)botic device of any preceding claim wherein at least one applicator of the one or more applicators defines an annular shape when in a configuration for engaging around the conductor to apply the coating or pre-treatment to thereto, defining a central bore for receiving the conductor; optionally wherein the device comprises a coating application module and a set of one or more applicators configured to apply the coating, wherein each of the one or more applicators for applying the coating is configured in this manner.

13. The robotic device of any preceding claim wherein at least one, and optionally each applicator of the one or more applicators is configured to transition between a closed configuration for engaging around the conductor of the line to apply a pre-treatment or coating thereto and an open configuration for disengaging from the conductor for passing an obstacle; optionally wherein the device comprises a coating application module and a set of one or more applicators configured to apply the coating, wherein each of the one or more applicators for applying the coating is configured in this manner.

14. The robotic device of claim 13 wherein the at least one applicator of the one or more applicators comprises first and second parts connected to one another at a hinge, wherein the first and second parts are rotatable relative to one another about the hinge to transition the applicator between the open and closed configurations, for example wherein the applicator defines a clam-shell structure.

15. The robotic device of claim 13 or 14 wherein the at least one applicator of the one or more applicators is configured to transition from the closed configuration to the open configuration for disengaging from its conductor for passing an obstacle, for example under the control of the obstacle avoidance module.

16. The robotic device of any one of claims 13 to 15 wherein the device comprises a plurality of the applicators configured to transition between open and closed configurations, and individual applicators are selectively and independently transitionable between the open and closed configurations as required in order to pass obstacles, for example under the control of the obstacle avoidance module.

17. The robotic device of any one of claims 13 to 16 comprising an actuator associated with each applicator configured to transition between open and closed configurations for causing the applicator to transition between its open and closed configurations.

18. The robotic device of any preceding claim comprising a set of one or more applicators for performing pre-treating and / or a set of one or more applicators for performing coating operations, preferably wherein the robotic device comprises bothnt module and a coating application module and comprises a set of one or more applicators for performing pre-treating operations and a set of one or more applicators for performing coating operations.

19. The robotic device of any preceding claim wherein each wheel is selectively retractable from a respective one of the set of one or more conductors of the line on which it runs in order to pass an obstacle.

20. The robotic device of claim 19, wherein the device is configured such that when a wheel retracts from the conductor of the line on which it runs to pass an obstacle at least one other of the wheels remains engaged with the conductor of the line on which it runs to provide stable support to the robotic device in use.

21. The robotic device of any one of claims 19 or 20 wherein individual wheels are independently and selectively retractable from respective conductor(s) of the line in use as required in order to pass obstacles.

22. The robotic device of any preceding claim wherein each wheel is coupled to a chassis of the robotic device by a coupling enabling the wheel to move relative to the chassis of the device in order to retract from the conductor in use, for example wherein the coupling comprises parts movable relative to one another in use to enable retraction of the wheel; optionally wherein the coupling comprises a sprung joint, revolute joint, swing arm, prismatic joint, robotic arm, levered screw mechanism or a four-bar link mechanism; and / or wherein the device comprises a chassis having first and second longitudinally extending portions connected to one another by first and second central couplings at leading and trailing ends thereof, wherein the first and second central couplings are selectively openable to retract one or more wheels and optionally one or more applicators of the device from engagement with their respective conductors for passing an obstacle.

23. The device of any preceding claim wherein the wheels are pulley wheels.

24. The device of any preceding claim further comprising one or more fluid tanks for holding fluid for use in pre-treatment and / or coating of the line.

25. The device of claim 24 wherein the one or more fluid tanks are disposed entirely below the wheels.

26. The device of claim 24 or claim 25 further comprising a fluid delivery system for supplying fluid from the one or more tanks to one or more of the applicators of the pre-treatment module and / or coating application module, wherein the fluidim comprises a set of one or more pumps and a set of one or more fluid conduits for supplying fluid to the applicator(s).

27. The device of any one of claims 1-26 wherein the robotic device comprises a main body suspended below the wheels by a chassis of the device; optionally wherein the main body is located below the wheels by a distance of at least 15cm.

28. The device of claim 27 as dependent directly or indirectly on any of claims 24 to 26 wherein the one or more fluid tanks of the device are housed in the main body of the device.

29. The device of claim 28 as dependent directly or indirectly on claim 26 wherein the one or more pumps are located in the main body of the device, and the one or more fluid conduits pass through a hollow interior of a part of the chassis suspending the main body of the device below the wheels to reach the one or more applicators.

30. The device of any preceding claim wherein the plurality of wheels comprise first and second wheels configured to run on a first conductor of the set of one or more conductors of the line, the wheels being spaced apart and located one behind the other along a longitudinal direction of the robotic device.

31. The device of claim 30 wherein the first and second wheels are spaced apart along the length of the device by a distance of at least 20cm, or at least 25cm and / or by a distance of less than 250cm, or less than 200cm; optionally wherein the wheels are spaced apart by a distance in a range of from 25cm to 200cm; and / or wherein each wheel has a diameter in the range of from 35 cm to 50cm.

32. The device of claim 30 or 31 wherein the chassis of the device comprises a longitudinally extending tubular support to which the first and second wheels are mounted; optionally wherein the wheels are coupled to the tubular support in a manner such that the support is disposed laterally outboard of the wheels.

33. The device of claim 32 as dependent directly or indirectly on claim 29wherein one or more fluid conduit(s) of the fluid delivery system pass through the hollow interior of the tubular support to reach the one or more applicators.

34. The device of any of claims 30 to 33 wherein the first and second wheels are disposed at leading and trailing ends of the device respectively.

35. The device of claim 34 wherein the device comprises a coating application module, the coating application module comprising an applicator disposed at a:the chassis to the trailing side of second wheel; and / or wherein the device comprises a pre-treatment module, the pre-treatment module having an applicator disposed at a leading end of the chassis to the leading side of the first wheel and / or an applicator at a trailing end of the chassis to the trailing side of the second wheel.

36. The device of any one of claims 30 to 35 wherein the chassis comprises a T- shaped connector defining a stem and a top bar, the top bar defining arms on either side of the stem, wherein the first and second wheels are mounted to respective ones of the arms, and a main body of the device is mounted to a bottom of the stem of the T-shaped connector.

37. The device of claim 36 wherein one or more fluid tanks for holding fluid for use in pre-treatment and / or coating of the line are housed in the main body of the chassis suspended below the wheels by the T-shaped connector.

38. The device of claim 37 comprising a fluid delivery system for supplying fluid from the one or more tanks to the pre-treatment module and / or coating application module, wherein the T-shaped connector defines an internal cavity through which a set of one or more fluid conduits pass to deliver fluid from the one or more tanks to one or more applicators of the pre-treatment and / or coating application modules.

39. The device of claim 38 wherein one or more pumps are provided in the main body of the chassis for pumping fluid from the one or more tanks in use through the set of one or more fluid conduits to the one or more applicators.

40. The device of any of claims 36 to 38 wherein the main body of the chassis comprises notional leading, central and trailing portions along the longitudinal direction, wherein the base of the stem of the T-shaped connector is connected to the central portion of the main body; and / or wherein the base of the stem of the T- shaped connector is connected to the main body at a longitudinally extending edge thereof.

41. The device of claim 40 wherein first and second fluid tanks for holding fluid for use in pre-treatment and / or coating of the line are provided within the leading and trailing portions respectively; optionally wherein the central portion houses the one or more pumps of the fluid delivery system.

42. The device of any one of claims 1-29 wherein the plurality of wheels comprise first and second wheels configured to run on a first conductor of the set of one or more conductors of the line, the wheels being spaced apart and located one behind the other along a longitudinal direction of the robotic device, and third andconfigured to run on a second conductor of the set of one or more conductors of the line, the wheels being spaced apart and located one behind the other along a longitudinal direction of the robotic device, wherein the first and third wheels and second and fourth wheels respectively define first and second pairs of wheels located one behind the other and spaced apart along the longitudinal direction of the device.

43. The device of claim 42 wherein the device comprises a chassis having first and second halves, the first and second wheels are mounted to a the first half of the chassis and the third and fourth wheels are mounted to the second half of the chassis, wherein the chassis comprises first and second central couplings bridging between the chassis halves at a first end and a second end thereof, wherein each central coupling is selectively and independently transformable from a closed, configuration in which it connects the chassis halves and an open, configuration in which the chassis halves are decoupled from one another at the coupling, wherein the first central coupling is defined between first and second rotatable arms of the chassis, and the second central coupling is defined between third and fourth rotatable arms of the chassis, wherein the first and third wheels are mounted to the first and second rotatable arms respectively, and the third and fourth wheels are mounted to the third and fourth rotatable arms respectively, wherein rotation of any one of the first, second, third and fourth arms to open the central coupling of which the arm forms part disengages the wheel mounted thereto from its conductor and moves the wheel to a retracted position for passing an obstacle.

44. The device of claim 43 wherein the first, second, third and fourth arms are selectively and independently rotatable to transform their respective couplings between the closed and open configurations.

45. The device of claim 43 or 44 wherein the obstacle avoidance module is configured to selectively transform only one of the central couplings to the open configuration for passing an obstacle at a time while the other central coupling remains in its closed, coupled configuration to maintain a stable connection between the chassis halves46. The device of any one of claims 43 to 45 wherein at least one applicator of the one or more applicators is mounted to one of the first, second, third and fourth arms, wherein the applicator will be moved together with the wheel to a retracted position on rotation of the arm to open one of the central couplings.

47. The device of claim 46 wherein the first and second wheels are connected to one another by a first longitudinally extending tubular support of the first chassisthird and fourth wheels are connected to one another by a second longitudinally extending tubular support of the second chassis half.

48. The device of claim 47 wherein the chassis comprises a first housing suspended below the first tubular support and comprising a first fluid tank, and a second housing suspended below the second tubular support and comprising a second fluid tank.

49. The device of claim 48 wherein one or more fluid conduits pass through the hollow interior of each of the first and second supports to supply fluid from the respective one of the first and second tanks to one or more of the applicators of the device.

50. The device of any preceding claim wherein the robotic device defines an empty space extending over a distance of at least 15cm below a lowermost conductor contacting point of each wheel of the device.

51. The device of any preceding claim wherein the device only includes wheels configured to run on top of conductor(s) of the line in use and does not include wheels running below conductors of the line.

52. The device of any preceding claim wherein the wheels of the device are exposed and are not disposed within any housing.

53. The robotic device of any preceding claim comprising a set of a plurality of applicators for performing pre-treating and / or a set of a plurality of applicators for performing coating operations, wherein, when the line comprises a set of multiple conductors, different applicators of each set of applicators may engage with different respective conductors of the set of conductors to enable pre-treating and / or coating of multiple conductors of the set of multiple conductors in a single pass.

54. The robotic device of any preceding claim, wherein the device has a weight in the range of from 25 to 75Kg.

55. An overhead transmission or distribution line system comprising: an overhead transmission or distribution line comprising a set of one or more conductors; and one or more robotic devices in accordance with any preceding claim.

56. The overhead transmission or distribution line system of claim 55 wherein the set of one or more conductors are in respect of a given phase of the overhead transmission or distribution line, the set of one or more conductors being a singlea bundle of a plurality of conductors, such two, three, four or more conductors.

57. The system of claim 55 or 56 wherein at least two wheels of the device are configured to run on the same conductor where the set of one or more conductors of the line comprises a plurality of conductors; optionally wherein one or more applicators are configured to engage around the same conductor.

58. The system of any of claims 55 to 57 wherein at least some of the one or more applicators are capable of engaging with different ones of the plurality of conductors where the set of one or more conductors of the line comprises a plurality of conductors for applying the pre-treatment and / or coating thereto, for example wherein these applicator(s) are mounted to a chassis of the device by a multi-axis robotic arm.

59. The system or device of any preceding claim comprising a plurality of the applicators, wherein at least some of the applicators are configured to engage with the same conductor of the set of one or more conductors for applying the pretreatment and / or coating thereto; and / or wherein at least some of the applicators are configured to engage with different conductors of the plurality of conductors where the set of one or more conductors of the line comprises a plurality of conductors for applying the pre-treatment and / or coating thereto.

60. A method comprising: installing a robotic device as set out in any of claims 1-54 on an overhead transmission or distribution line; and causing the robotic device to traverse the line while applying a coating and / or pre-treatment thereto and passing one or more obstacles.

61. A retrofit coating system configured to coat an overhead transmission or distribution line with a coating comprising: a robotic device as disclosed in any of claims 1 to 54; and a coating material to be applied by the robotic device to an overhead transmission or distribution line so as to form a coating on the overhead transmission or distribution line.

Images