System for pressurising a mobile mechanism working in an environment with a potentially explosive atmosphere

Abstract

The present invention relates to a system (40) for pressurising a mobile mechanism comprising a body comprising an outer casing (20) defining an internal volume (25), the pressurising system being installed on board the mobile mechanism and configured to keep a pressurising fluid (45) under pressure in the gaseous state in the internal volume, the pressurising system comprising a storage tank (50) for the fluid and a fluid circuit (55) fluidically connecting the storage tank to the internal volume in order to inject a quantity of pressurising fluid into the internal volume. The pressurising fluid (45) is stored in the storage tank (50) in the liquid state, the pressurising fluid (45) passing to the gaseous state when it is injected into the internal volume (25).

Description

[0001] DESCRIPTION

[0002] Pressurization system for a mobile mechanism working in a potentially explosive atmosphere

[0003] The present invention relates to a pressurization system applied to a mobile mechanism such as a robot.

[0004] Many oil installations are intended to become uninhabited for long periods, in particular in order to reduce emissions generated by the presence and / or transport of human operators on the sites and in order to reduce their exposure to the risks inherent in this type of installation.

[0005] In order to ensure the proper functioning of oil installations, mobile mechanisms, for example autonomous and / or remotely operated robots, are installed on the sites.

[0006] For example, robots are responsible for carrying out inspection, maintenance and production tasks such as collecting and / or transmitting information related to the operation of the installations (video recording, taking measurements, detecting the presence of gas, etc.) and / or carrying out manipulations for the operation and / or maintenance of the installations, in order to ensure the proper functioning and safety of the oil site.

[0007] For this purpose, the robots are generally mobile in order to move to the measurement points and / or carry out manipulations in precise locations on the site, and operate on electric batteries.

[0008] On oil installations (or other types of installations, particularly chemical or food industry installations), under certain conditions, explosive atmospheres can form due to the presence of flammable substances and / or dust.

[0009] Thus, the mechanisms to be deployed in these areas with potentially explosive atmospheres must comply, depending on the region, with ATEX and / or ECEx standards for example, in particular to avoid triggering an explosion that could have serious consequences for the installation. In particular, robots, and any other organs located in these areas with explosive atmospheres, must comply with the standards of the IEC 60079 family.

[0010] To ensure the proper functioning of robots in ATEX zones, the selection of the equipment protection mode according to the hazardous areas is carried out, for example, on the basis of the EN 60079-10 standard. One protection method consists of maintaining the internal volume of the robot at an overpressure relative to the surrounding atmosphere. The internal overpressure protection mode is subject in particular to the EN 60079-2 standard.

[0011] To pressurize the robot's interior, a gas is injected into the robot to create an overpressure relative to the external pressure. This prevents the potentially explosive surrounding atmosphere from entering the robot.

[0012] The injection of gas inside the robot is then done on site, for example by connecting the robot, when recharging the battery, to an available pressurized source such as nitrogen or dry air for example, or, in less frequent cases, by a bottle filled with gas on board the robot, or by injecting ambient air directly into the robot.

[0013] However, when the pressurization system uses an on-board cylinder, the on-board gas cylinder must be recharged or replaced when it is empty, which requires the cylinder to be replaced more or less frequently by an operator and / or gas refill systems to be provided distributed throughout the installation.

[0014] Furthermore, when gas injection is done on site by connecting the robot to an available pressurized source, it is necessary to repressurize the robot frequently, and therefore to provide numerous gas loading points on site.

[0015] Finally, when ambient air is injected directly into the robot, it is first necessary to ensure that it is not explosive gas. Furthermore, there is a risk of injecting humid gas if the ambient air contains moisture, which can impair the robot's proper operation.

[0016] One of the aims of the invention is then to propose a pressurization system for a mobile mechanism capable of working in an environment with a potentially explosive atmosphere, the pressurization system having greater autonomy.

[0017] To this end, the subject of the invention is a pressurization system for a mobile mechanism, in particular a robot, the mobile mechanism comprising a body comprising an external casing defining an internal volume, the pressurization system being on board the mobile mechanism and configured to maintain a pressurization fluid under pressure in the gaseous state in the internal volume, the pressurization system comprising a fluid storage tank and a fluid circuit fluidly connecting the storage tank to the internal volume to inject a quantity of pressurization fluid from the storage tank into the internal volume.

[0018] Because the pressurizing fluid is stored in a storage tank in a liquid state, a greater amount of fluid can be stored than if it were stored in a gaseous state, and the moving mechanism can operate for a longer period between refills of pressurizing fluid.

[0019] According to other advantageous aspects of the invention, the pressurization system comprises one or more of the following optional features, taken individually or in all technically possible combinations:

[0020] - the pressurizing fluid is a dry fluid and is chosen from carbon dioxide, halogenated gases or a mixture thereof;

[0021] - the fluid circuit comprises a calibrated fluid storage space, the fluid circuit being configured to sequentially transfer pressurizing fluid in the liquid state from the storage tank to the calibrated storage space and then transfer the pressurizing fluid from the calibrated storage space to the internal volume;

[0022] - the calibrated storage space is sequentially fluidically isolated from the internal volume of the movable mechanism during the transfer of the pressurizing fluid in the liquid state from the storage tank to the calibrated storage space, and fluidically isolated from the storage tank during the transfer of the pressurizing fluid from the calibrated storage space to the internal volume;

[0023] - the fluid circuit comprises an injection valve fluidically arranged between the calibrated storage space and the internal volume to control the circulation of the pressurization fluid from the calibrated storage space to the internal volume;

[0024] - the injection valve is a three-way valve comprising a first position for fluidly connecting the storage tank to the calibrated storage space to fill the calibrated storage space with pressurizing fluid and a second position for fluidly connecting the calibrated storage space to the internal volume to inject the pressurizing fluid into the internal volume;

[0025] - the injection valve is a simple valve, the calibrated storage space being defined in the fluid circuit upstream of the injection valve, the closing of the injection valve fluidly isolating the calibrated storage space from the internal volume, the opening of the injection valve fluidly connecting the calibrated storage space to the internal volume for the injection of the pressurization fluid into the internal volume;

[0026] - the fluid circuit includes a normally closed isolation valve, located upstream of the normally closed injection valve;

[0027] - the calibrated storage space is defined between the isolation valve and the injection valve;

[0028] - the isolation valve is controlled as a function of a measurement signal from a first pressure sensor representative of the pressure inside the internal volume, in order to secure the internal volume of the mobile mechanism, and the injection valve is controlled as a function of the opening and closing of the isolation valve;

[0029] - a second pressure sensor arranged to measure the pressure inside the storage tank; and

[0030] - the fluid circuit includes a system for slowing down the expansion of the pressurizing fluid injected into the internal volume.

[0031] According to yet another aspect, the invention relates to a method for pressurizing a mobile mechanism, implementing such a pressurization system, comprising the steps of: storing a pressurization fluid in the liquid state in a storage tank on board the mobile mechanism, injecting a quantity of pressurization fluid from the storage tank into the internal volume of the mobile mechanism, the injected pressurization fluid passing from the liquid state to the gaseous state, to maintain pressurization of the internal volume of the mobile mechanism using the pressurization fluid.

[0032] According to other advantageous aspects of the invention, the pressurization method comprises one or more of the following optional features, taken individually or in all technically possible combinations:

[0033] - the pressurizing fluid is dry and is chosen from carbon dioxide, halogenated gases, or a mixture thereof; and

[0034] - the injection step is carried out sequentially by transferring the quantity of pressurizing fluid from the storage tank to a storage space and then injecting the quantity of pressurizing fluid contained in the calibrated storage space into the internal volume.

[0035] The invention will appear more clearly on reading the description which follows, given solely by way of non-limiting example, and made with reference to the drawings in which: Figure 1 is a schematic external representation of a mobile mechanism, in particular a robot, Figure 2 is a schematic internal representation of the mobile mechanism,

[0036] - Figure 3 is a schematic representation of the pressurization fluid storage systems and the pressurization systems of the mobile mechanism according to a first embodiment, and

[0037] - Figure 4 is a schematic representation of the pressurizing fluid storage systems and the pressurizing systems of the mobile mechanism according to a second embodiment. Figure 1 schematically represents a mobile mechanism.

[0038] By "mobile" is meant that the mechanism is capable of moving on a floor or on stairs by translation and / or that the mechanism comprises a part that is mobile relative to at least one other part of the mechanism, such as an arm that is mobile relative to the body of the mechanism for example.

[0039] In particular, the moving mechanism is a robot 10, although the moving mechanism may be any other kind of device capable of moving.

[0040] A robot is defined as a mechatronic device designed to perform specific tasks, imitating or reproducing human actions.

[0041] The robot 10 is for example configured to collect and / or transmit information related to the operation of an industrial installation as a substitute for or in addition to a human presence.

[0042] The robot 10 is for example equipped to take videos, photos, measurements and / or physically interact with the installation by taking samples for example and to transmit a certain amount of information to a remote operator and / or to a remote control center.

[0043] The robot 10 is, for example, autonomous and / or remotely operable (i.e. operable remotely) by an operator. When it is autonomous, the robot 10 is capable of carrying out missions autonomously, without external intervention.

[0044] The robot 10 includes, for example, an electric battery sufficient to ensure the autonomy and proper functioning of the robot.

[0045] The robot 10 is, for example, intended to operate in areas with potential explosion risks, for example on oil installation sites.

[0046] Of course, such a robot 10 could operate on any other type of industrial installation and is not limited to use in the oil sector.

[0047] The robot 10 comprises a body 15.

[0048] The body 15 of the robot 10 comprises an external envelope 20 defining an internal volume 25.

[0049] The envelope 20 is for example made of a rigid material, such as a metallic or other material.

[0050] The internal volume 25 has a residual volume depending on the volume of the envelope 20 and the components installed inside the robot 10, for example between 0.001 m 3 and 0.1 m 3 .

[0051] In exemplary embodiments, the body 15 of the robot comprises a base 28 and one or more functional members 30 mounted on the base 28. Each functional member 30 is configured to perform one or more functions. Each functional member 30 is fixedly or movably mounted on the base 28.

[0052] Each functional organ 30 contains, for example, electrical components.

[0053] The outer casing 20 of the robot 10 includes the base 28 and each functional member 30.

[0054] As illustrated in Figure 1, the robot 10 comprises for example a functional member 30 which is a turret, which is for example movable relative to the base 28, in particular rotatable relative to the base 28. The functional member 30 accommodates for example a measuring system and / or even an image capture system.

[0055] The measuring system is for example configured, among other things, to measure one or more distances, a pressure, a temperature, the content of one or more chemical compounds in the surrounding atmosphere, or to detect and / or measure a sound signal (frequency, amplitude), etc.

[0056] Alternatively or optionally, a functional member 30 of the robot 10 is an articulated arm, preferably carrying a tool for carrying out operations, such as for example a gripper or a robotic hand.

[0057] In exemplary embodiments, the robot 10 comprises a movement system 35 configured to enable the robot 10 to move. The movement system 35 comprises, for example, tracks as shown in Figure 1.

[0058] Alternatively or additionally, the movement system 35 comprises wheels and / or articulated legs.

[0059] Generally, the robot 10 comprises a movement system 35 allowing movement of the robot 10 in several directions, on floors of various types and having varied levels of inclination or stairs.

[0060] The movement system 35 is for example mounted on the base 28 of the robot 10 and located outside the external casing 20.

[0061] As illustrated in Figure 2, in exemplary embodiments, the robot 10 comprises a pressurization system 40 embedded on the robot 10 and configured to maintain a pressurization fluid 45 in the gaseous state under pressure in the internal volume 25.

[0062] By "onboard" is meant that the pressurization system 40 is mounted on the robot 10 such that it is moved with the robot 10.

[0063] The pressurizing fluid 45 is preferably a dry fluid. By "dry" is meant that the dew point of the fluid (temperature to which the fluid must be cooled so that the water vapor it contains condenses) is for example 20°C lower than the minimum ambient operating temperature of the fluid. Generally, the dew point of the fluid 45 must be sufficiently low compared to the operating temperature of the pressurizing fluid 45, so as not to cause condensation of the water vapor inside the casing 20, which could impair the operation of the robot 10.

[0064] The pressurizing fluid 45 is chosen to ensure the safety and integrity of the electronic equipment, in particular to be non-corrosive to the electronic or other components of the robot 10.

[0065] The pressurizing fluid 45 is preferably chosen from fluids that are stored in the liquid state at room temperature and under moderate pressure.

[0066] For example, the pressurizing fluid 45 is chosen from carbon dioxide, halogenated gases such as, for example, 1,1,1,2,3,3,3-heptafluoropropane, trifluoromethane, perfluorobutane, or a mixture thereof.

[0067] Preferably, the pressurizing fluid 45 is carbon dioxide.

[0068] The pressurization system 40 is intended to maintain the internal volume 25 of the robot 10 under pressure by injecting the pressurization fluid 45 in the gaseous state into the internal volume 25.

[0069] For example, the pressurization system 40 is configured to maintain an overpressure of between 10 mbar and 200 mbar, for example between 40 mbar and 60 mbar in the internal volume 25 of the robot 10 relative to the surrounding atmosphere.

[0070] This then allows the robot 10 to operate in particular in explosion risk zones as described above.

[0071] The internal volume 25 of the robot 10 being pressurized relative to the atmosphere surrounding the robot 10, infiltration of potentially explosive surrounding atmosphere inside the robot 10 is avoided.

[0072] The pressurization system 40 comprises a storage tank 50 for the pressurization fluid 45.

[0073] The storage tank 50 is for example a pressurized bottle, having a capacity depending in particular on the space available on the robot 10, the additional weight that can be carried on the robot 10, or even depending on the desired pressurization duration.

[0074] The storage tank 50 is configured to store the pressurizing fluid 45 in the liquid state, the pressurizing fluid 45 changing to the gaseous state when it is expanded and injected into the internal volume 25.

[0075] Since the storage of the pressurizing fluid 45 is carried out in the liquid state, a significant quantity of pressurizing fluid 45 can be stored in the storage tank 50. This characteristic allows the robot 10 to operate for a longer period of time, because the storage tank 50 needs to be recharged with pressurizing fluid 45 less frequently.

[0076] Advantageously, the storage tank 50 for pressurizing fluid 45 is housed inside the external casing 20.

[0077] Thus, the fluid exchanges between the interior of the external envelope 20 and the exterior of the robot 10 are limited to the strictly necessary exchanges as will be described in more detail later.

[0078] The storage tank 50 is provided with a refill valve 52, preferably located on the outer casing 20.

[0079] The refill valve 52 is arranged to fluidically connect the storage tank 50 to a pressurizing fluid refill system 45, not shown, located outside the outer casing 20 of the robot 10, when the robot 10 needs to be refilled with pressurizing fluid 45, and to fluidically isolate the storage tank 50 from the outside of the robot 10 when the robot 10 is in operating mode and does not need to be refilled with pressurizing fluid 45.

[0080] The pressurizing fluid refill system 45 preferably contains the pressurizing fluid 45 in the liquid state. Thus, the pressurizing fluid refill system 45 can more easily contain a quantity of pressurizing fluid 45 greater than the quantity stored, in the same volume, of pressurizing fluid 45 in the gaseous state. Consequently, the pressurizing fluid refill system 45 is able to refill the storage tank 50 on numerous occasions.

[0081] The pressurization system 40 comprises a fluid circuit 55 fluidly connecting the storage tank 50 to the internal volume 25 to inject a quantity of pressurization fluid 45 from the storage tank 50 into the internal volume 25.

[0082] The fluid circuit 55 is preferably configured for a gravity flow of the pressurizing fluid 45 from the storage tank 50 to the internal volume 25.

[0083] Since the pressurizing fluid 45 is stored in the storage tank 50 in the liquid state, it is possible to simplify the fluid circuit 55 by using gravity as the system for moving the pressurizing fluid 45.

[0084] The fluid circuit 55 is notably constituted by a fluid line 57 for circulating the pressurization fluid 45 connecting the storage tank 50 to the internal volume 25.

[0085] The outlet of the storage tank 50 is for example located at the bottom, relative to a vertical axis, of the storage tank 50, and the fluid line 57 extends downwards from the outlet of the storage tank 50. In a variant, not shown, the fluid circuit 55 comprises a withdrawal pipe inside the storage tank 50 in order to recover the pressurization fluid 45 at the bottom of the storage tank 50, for example if gravity flow is not used.

[0086] With reference to Figure 3, a first embodiment of the pressurization system 40 of the robot 10 will now be described in detail.

[0087] In this embodiment, the fluid circuit 55 advantageously comprises a calibrated storage space 60 configured for temporary storage of a volume of pressurization fluid 45 in the liquid state, between the storage tank 50 and the internal volume 25.

[0088] In particular, the fluid circuit 55 is configured for a gravity flow of the pressurization fluid 45 in the liquid state from the storage tank 50 to the temporary calibrated storage space 60 and then for a gravity flow of the pressurization fluid 45 from the temporary calibrated storage space 60 to the internal volume 25.

[0089] The calibrated storage space 60 defines a storage volume adapted, and previously determined, to a quantity of pressurization fluid 45 to be injected into the internal volume 25 of the robot 10.

[0090] The fluid circuit 55 is configured to sequentially transfer pressurizing fluid 45 in the liquid state from the storage tank 50 to the calibrated storage space 60 and then transfer the pressurizing fluid 45 from the calibrated storage space 60 to the internal volume 25.

[0091] Preferably, the calibrated storage space 60 is fluidically isolated from the internal volume 25 of the robot 10 during the transfer of the pressurizing fluid 45 in the liquid state from the storage tank 50 to the calibrated storage space 60, and the calibrated storage space 60 is fluidically isolated from the storage tank 50 during the transfer of the fluid from the calibrated storage space 60 to the internal volume 25.

[0092] The quantity of pressurizing fluid 45 injected into the internal volume 25 is precisely calibrated according to the volume of the calibrated storage space 60.

[0093] It may be chosen to design a relatively small calibrated storage space 60 in order to regularly inject a small quantity of pressurizing fluid 45 into the internal volume 25, or to design a larger calibrated storage space 60 in order to inject a larger quantity of pressurizing fluid 45 into the internal volume 25 less frequently.

[0094] The configuration of the calibrated storage space 60 can be determined in advance by the designer or manufacturer for each type of robot 10 for example. For example, the calibrated storage space 60 defines an intermediate storage volume whose capacity is calibrated and a function of the internal volume 25.

[0095] Since the injection of pressurizing fluid 45 into the internal volume 25 generally involves very small quantities of pressurizing fluid 45, of the order of a few grams, it is advantageous to provide such an intermediate calibrated storage space 60.

[0096] The implementation of a calibrated intermediate calibrated storage space 60 in fact makes it possible to simplify the fluid circuit 55 in that it does not need a system for precise measurement of the quantity of pressurization fluid 45 injected into the internal volume 25, which is automatically determined by the volume of the calibrated storage space 60.

[0097] The fluid circuit 55 comprises for example a set of valves having one or more valves arranged to sequentially transfer pressurization fluid 45 in the liquid state from the storage tank 50 to the calibrated fluid storage space 60 and then transfer the pressurization fluid 45 from the calibrated fluid storage space 60 to the internal volume 25.

[0098] The valve assembly is arranged along the fluid line 57 of the fluid circuit in order to control the circulation of the pressurizing fluid 45 inside the fluid line 57.

[0099] The valve assembly is also arranged to control the amount of pressurizing fluid 45 injected from the storage tank 50 into the internal volume 25.

[0100] The fluid circuit 55 comprises for example an injection valve 65 fluidically arranged between the calibrated storage space 60 and the internal volume 25 to control the circulation of the pressurization fluid 45 from the calibrated storage space 60 to the internal volume 25.

[0101] In the example illustrated in Figure 3, the injection valve 65 is a three-way valve 65A, 65B, 65C.

[0102] The injection valve 65 comprises, for example, a first path 65A fluidly connected to the storage tank 50, a second path 65B fluidly connected to the calibrated storage space 60 and a third path 65C fluidly connected to the internal volume 25.

[0103] In other words, the first position fluidly connects the storage tank 50 to the calibrated storage space 60 to fill the calibrated storage space 60 with pressurizing fluid 45 in the liquid state and the second position fluidly connects the calibrated storage space 60 to the internal volume 25 to inject the pressurizing fluid 45 into the internal volume 25 in the gaseous state. In an exemplary embodiment, notably illustrated in Figure 3, the fluid circuit 55 advantageously comprises an isolation valve 70 located upstream of the injection valve 65.

[0104] The isolation valve 70 is advantageously located under the storage tank 50, so that the fluid 45 contained in the storage tank 50 simply flows by gravity in the fluid line 57 to the isolation valve 70.

[0105] The isolation valve 70 is for example a motorized valve, in the closed position by default.

[0106] The isolation valve 70 is, for example, a simple valve. By “simple”, we mean that the isolation valve 70 comprises an upstream inlet and a downstream outlet.

[0107] The isolation valve 70 isolates the storage tank 50 by preventing the internal volume 25 from building up pressure, which makes the robot 10 safe. For this purpose, the isolation valve 70 controls the circulation of the pressurizing fluid 45 from the storage tank 50 to the injection valve 65.

[0108] The isolation valve 70 and the injection valve 65 are for example controlled by an electronic control system.

[0109] The electronic control system comprises, for example, an electrical control unit 72 and a first pressure sensor 75.

[0110] The first pressure sensor 75 is used to monitor the pressure in the internal volume 25.

[0111] The isolation valve 70 is for example controlled by the electronic control unit 72 as a function of a measurement signal from the first pressure sensor 75 representative of the pressure inside the internal volume 25 of the robot 10.

[0112] The first pressure sensor 75 is connected to the isolation valve 70 and to the electrical control unit 72 which receives the measurement signal and triggers the opening or closing of the isolation valve 70 depending on the pressure measured in the internal volume 25.

[0113] The injection valve 65 is in particular controlled as a function of the opening and closing of the isolation valve 70.

[0114] In this embodiment, the calibrated storage space 60 is linked to the second channel 65B of the injection valve 65.

[0115] During the circulation of the pressurizing fluid 45 from the storage tank 50 to the calibrated storage space 60, the first and second ports 65A, 65B are open in order to allow the pressurizing fluid 45 to circulate from the storage tank 50 to the calibrated storage space 60 and the third port 65C of the injection valve 65 is closed. Thus, the calibrated storage space 60 of fluid 45 is fluidically isolated from the internal volume 25 of the robot 10 during the transfer of the pressurizing fluid 45 in the liquid state from the storage tank 50 to the calibrated intermediate storage space 60.

[0116] Likewise, when injecting the pressurizing fluid 45 from the calibrated storage space 60 to the internal volume 25, the first channel 65A is closed and the second and third channels 65B, 65C are open in order to allow the fluid to circulate from the calibrated storage space 60 to the internal volume 25.

[0117] Thus, the calibrated fluid storage space 60 is fluidically isolated from the fluid storage tank 50 during the transfer of the pressurizing fluid 45 from the calibrated fluid storage space 60 to the internal volume 25.

[0118] Alternatively, the fluid circuit does not include an isolation valve 70.

[0119] When the pressurizing fluid 45 is injected into the internal volume 25, the pressurizing fluid 45 undergoes a change of state because the pressure inside the internal volume 25 is substantially lower than the pressure at which the pressurizing fluid 45 was stored in the liquid state.

[0120] This pressure difference causes an expansion of the pressurizing fluid 45 which, as a result, tends to cool.

[0121] In order not to disturb the operation of the first pressure sensor 75 during the injection of the pressurization fluid 45 into the internal volume, the fluid circuit 55 comprises for example a system 78 for slowing down the expansion of the pressurization fluid 45 injected into the internal volume 25.

[0122] This system 78 makes it possible to slow down the expansion of the pressurizing fluid 45 which is injected into the internal volume 25 where the pressure is lower than that at which it was stored in liquid form.

[0123] For example, the system 78 is a heat exchanger, intended to moderate the drop in temperature of the pressurizing fluid 45 during its injection into the internal volume 25.

[0124] The system 78 for slowing down the expansion of the pressurizing fluid 45 is, for example, fluidically located between the set of valves and the internal volume 25.

[0125] The slowing down system 78 comprises for example an expansion conduit 79, schematically represented in Figure 3, configured to slow down the expansion of the pressurizing fluid 45. The expansion conduit 79 is for example in the form of a coil to promote thermal exchanges between the pressurizing fluid 45 circulating in the expansion conduit 79 and the internal volume 25. The electronic control system comprises for example a second pressure sensor 80 arranged to measure the pressure inside the storage tank 50.

[0126] Advantageously, the second pressure sensor 80 is connected to the electrical control unit 72.

[0127] The second pressure sensor 80 provides, for example, via the electrical control unit 72, information to an operator and / or a control station on the quantity of pressurizing fluid 45 remaining inside the storage tank 50.

[0128] Alternatively, the second pressure sensor 80 is connected via a control box, not shown, different from the electrical control unit 72.

[0129] For example, the pressure inside the storage tank 50 is between 50 bar and 200 bar between two operations of filling the storage tank 50.

[0130] When the storage tank 50 no longer contains sufficient pressurizing fluid 45 in liquid phase, the pressure inside the storage tank 50 drops rapidly to a low value.

[0131] Such a pressure drop is quickly detected by the second pressure sensor 80 which transfers, for example via the electrical control unit 72, the information to an operator and / or to a control station.

[0132] Thus, the robot operator is quickly informed in the event of a low quantity of pressurizing fluid 45 remaining in the storage tank 50 and can plan for recharging the storage tank 50 with pressurizing fluid 45 in an efficient manner.

[0133] A second example of embodiment of the pressurization system 40 of the robot will now be described, with reference to Figure 4.

[0134] This second embodiment differs from that of Figure 3 in that the injection valve 65 is a simple valve.

[0135] The calibrated storage space 60 is then defined in the fluid circuit 55 upstream of the injection valve 65, and downstream of the isolation valve 70.

[0136] The upstream of the valve 65 is fluidically connected to the calibrated storage space 60.

[0137] The downstream of the valve 65 is fluidically connected to the internal volume 25 of the robot 10.

[0138] This second embodiment also differs from that of Figure 3 in that the storage tank 50 is located outside the outer casing 20, and not inside.

[0139] The storage tank 50 is however still on board the robot 10.

[0140] This configuration makes it possible to replace the empty storage tank 50 with another full storage tank instead of recharging the storage tank 50 with pressurizing fluid 45 when all the pressurizing fluid 45 initially contained in the storage tank 50 has been used.

[0141] For example, if the storage tank 50 is a bottle containing the pressurizing fluid 45, when the bottle is empty, the robot 10 can be connected to a bottle replacement system 99, schematically shown in Figure 4.

[0142] The 99 bottle replacement system, for example, is operated manually by an on-site operator.

[0143] The fluid circuit 55 then tightly connects the storage tank 50 to the internal volume 25, through the external casing 20.

[0144] The configuration of the storage tank 50 (inside or outside the outer casing 20) is independent of the other characteristics of the first and second embodiments, and all technically feasible combinations between the first and second embodiments are conceivable.

[0145] In order to guarantee the safety of the pressurization system 40 as well as its proper functioning, one or more pressure evacuation systems may be provided on the robot 10.

[0146] Examples of pressure relief systems will now be described with reference to Figures 3 and 4.

[0147] The robot 10 preferably comprises fluidic elements providing safety functions of the robot 10.

[0148] The robot 10 comprises for example a first pressure evacuation system 82 comprising a safety valve 83 configured to protect the storage tank 50, that is to say to allow the pressurization fluid 45 contained in the storage tank 50 to escape outside the external casing 20 of the robot 10.

[0149] The safety valve 83 is for example used when the robot 10 is subjected to high temperature rises, for example during a fire or abnormal heating, and / or to high pressure rises.

[0150] For example, when the pressure of the pressurizing fluid 45 in the fluid circuit 55 and / or in the storage tank 50 reaches a value greater than or equal to, for example, 200 bar, the valve 83 opens to allow the pressurizing fluid 45 to escape to the outside in order to control the pressure in the storage tank 50.

[0151] The first pressure relief system 82 also comprises a first valve 84 and a control valve 85. The valves 84 and 85 are used, for example, when the user wishes to carry out voluntary depressurization to carry out, for example, maintenance actions.

[0152] For this purpose, the valves 84 and 85 are manually controlled by an operator who receives information on the pressure measured inside the storage tank 50 by the second pressure sensor 80.

[0153] Advantageously, downstream of the control valve 85, an outlet nozzle 86 is arranged to guide and evacuate the pressurization fluid 45 outside the external casing 20.

[0154] In the same way as previously, the robot 10 comprises for example a second pressure evacuation system 88 from the internal volume 25 of the robot 10.

[0155] The second pressure relief system 88 is an automatic control mode comprising a set of isolation valves.

[0156] In order to have a second robust pressure evacuation system 88 of the internal volume 25, the robot 10 comprises for example a system of nested and / or stacked isolation valves.

[0157] The evacuation of pressure inside the internal volume 25 of the robot 10 may be necessary for example when a variation in atmospheric temperature is measured.

[0158] For this purpose, the robot 10 comprises a first pressure release valve 89.

[0159] This first pressure relief valve 89 is arranged to be open during normal operation and to trap a quantity of fluid 45 in a pressure relief storage space 92.

[0160] The first pressure release valve 89 is for example motorized and controlled by the electrical control unit 72 as a function of a measurement signal from the first pressure sensor 75 representative of the pressure in the internal volume 25.

[0161] When a pressure threshold is measured by the first pressure sensor 75 in the internal volume 25, the pressure release valve 89 is closed by the electrical control unit 72 in order to fluidically isolate the pressure release storage space 92 containing a quantity of pressurizing fluid 45 under pressure from the internal volume 25.

[0162] Then, a second pressure relief valve 95, fluidically connected to the pressure relief storage space 92, opens to release the quantity of pressurizing fluid 45 trapped in the pressure relief storage space 92 out of the outer casing 20 of the robot 10.

[0163] The second pressure release valve 95 is for example also motorized (in the closed position by default) and controlled by the electrical control unit 72 as a function of a measurement signal from the first pressure sensor 75, and / or as a function of the configuration of the first pressure release valve 89.

[0164] The second pressure relief valve 95 is arranged to transfer the quantity of pressurizing fluid 45 trapped in the pressure relief storage space 92 to the outside of the outer casing 20.

[0165] Optionally, a check valve 96 is arranged between the first and second pressure relief valves 89, 95, and in particular between the pressure relief storage space 92 and near the second pressure relief valve 95 as shown in Figures 3 and 4.

[0166] The presence of the valve 96 prevents unwanted air from entering the internal volume 25 from outside the robot 10.

[0167] Optionally, a filter or strainer 97 is added downstream of the second pressure relief valve 95 to prevent the entry of particles, moisture and / or insects into the robot 10.

[0168] Since the outer casing 20 is not perfectly sealed, leaks of pressurization fluid 45 occur continuously. The pressurization system 40 is further configured to compensate for these leaks and maintain the internal volume 25 of the robot 10 under overpressure, in particular as a function of the pressure measurement provided by the first pressure sensor 75.

[0169] Thus, the leaks of pressurizing fluid 45 ensure the renewal of the pressurizing fluid 45 inside the internal volume 25 and also ensure that the entire internal volume 25 is pressurized with the pressurizing fluid 45.

[0170] A method of pressurizing the internal volume 25 of a robot 10 will now be described, with reference to the embodiments described in Figures 1 to 4.

[0171] For the first filling or filling after maintenance of the robot, a preliminary step to be implemented by an operator, consists in particular of purging the robot 10, to replace the surrounding air with the pressurizing fluid 45.

[0172] In a manner common to the different embodiments, the pressurization method comprises a first step of storing the pressurization fluid 45 in the liquid state in a storage tank 50 on board the robot 10, then a step of injecting a quantity of pressurization fluid 45 from the storage tank 50 into the internal volume 25 of the robot 10, the injected pressurization fluid 45 passing into the gaseous state, to maintain pressurization of the internal volume 25 of the robot 10.

[0173] Preferably, the step of injecting the pressurizing fluid 45 is carried out sequentially by transferring the quantity of fluid 45 from the storage tank 50 to the calibrated storage space 60 and then injecting the quantity of pressurizing fluid 45 contained in the calibrated storage space 60 into the internal volume 25.

[0174] In an example implemented with a robot 10 such as that illustrated in Figure 3, the injection step is divided into two sub-steps.

[0175] A first sub-step comprises opening the isolation valve 70 (normally closed) and the first and second ports 65A, 65B of the injection valve 65, in order to transfer pressurizing fluid 45 from the storage tank 50 until filling the calibrated storage space 60.

[0176] Once the calibrated storage space 60 is filled with pressurizing fluid 45, the isolation valve 70 (normally closed) is closed.

[0177] The second and third ports 65B, 65C of the injection valve 65 are then opened in order to inject the pressurizing fluid 45 from the calibrated storage space 60 into the internal volume 25.

[0178] If necessary, the pressurization fluid 45 at the outlet of the injection valve 65 is guided by a conduit to the slowing system 78 where its change from liquid to gaseous state is slowed down in order to compensate for thermal losses.

[0179] Furthermore, in an example implemented with a robot 10 as illustrated in Figure 4, comprising a simple injection valve 65 and a calibrated storage space 60 defined in the fluid circuit 55 upstream of the injection valve 65, the method of pressurizing the internal volume 25 of the robot 10 differs from that of the first mode implemented by the injection sub-steps.

[0180] A first sub-step comprises opening the isolation valve 70 until the calibrated storage space 60 is filled, then closing the isolation valve 70 once the calibrated storage space 60 is filled with pressurizing fluid 45.

[0181] A second sub-step comprises opening the injection valve 65 in order to inject the pressurization fluid 45 from the calibrated storage space 60 into the internal volume 25.

[0182] The pressurization system according to the invention has numerous advantages.

[0183] First of all, the storage tank 50 of the pressurizing fluid 45 being configured to store the pressurizing fluid 45 in the liquid state, the autonomy of the robot can be greater and adapted.

[0184] Indeed, the quantity of pressurizing fluid 45 stored in the liquid state is greater, for a given volume, than the quantity of pressurizing fluid 45 stored in the gaseous state. Thus, the robot 10 needs to be recharged with pressurizing fluid 45 for the pressurization of the internal volume 25 less frequently and can operate for longer periods autonomously while being able to operate in explosion risk zones.

[0185] Furthermore, when the pressurizing fluid 45 is carbon dioxide, it is easy to obtain, on any industrial site, carbon dioxide in order to recharge the storage tank 50 of the robot 10.

[0186] Furthermore, at room temperature carbon dioxide is in the liquid phase at a lower pressure than other fluids, and therefore more easily accessible.

[0187] Indeed, carbon dioxide is a gas easily found in industry, particularly in carbon dioxide fire extinguishers, which are widely used for firefighting purposes.

[0188] The presence of a calibrated intermediate storage space 60 for the pressurizing fluid 45 in the fluid circuit makes it possible to simplify the fluid circuit 55 which does not need to provide a system for measuring the quantity of pressurizing fluid 45 injected into the internal volume 25 in order to control the pressure in the internal volume 25 of the robot 10.

[0189] The injection valve 65 and isolation valve 70 are advantageously combined in order to regulate the circulation of the pressurization fluid 45 in the fluid circuit 55 and to inject, sequentially, the pressurization fluid 45 into the internal volume 25.

[0190] The presence of two valves makes it possible in particular to decouple the functions of regulation and injection of the pressurization fluid 45 and in particular limits incidents linked to a human handling error or to a control fault originating from the electrical control unit 72.

[0191] Another advantage of the invention is the simplification of the design of the recharging stations (electric recharging and recharging with pressurizing fluid). Indeed, by implementing fewer recharging points with pressurizing fluid, a majority of recharging stations can be equipped with electricity only, they then need to be less regularly distributed on the site than when they were combined with the gas recharging points.

[0192] This advantage allows in particular the use of induction electric charging stations (without physical contact), which simplifies the design and operation of electric charging of the robot, in particular because there is no precise physical contact to ensure between the electric charging station and the robot.

[0193] It could then be possible to converge towards a universal electric charging station, whereas today, each robot has a personalized charging station depending in particular on its singular geometric shape. More generally, the pressurization system is capable of maintaining the internal volume of a mobile mechanism under overpressure, in order to ensure the proper functioning of the mobile mechanism in areas with potentially explosive atmospheres.

[0194] In other words, the pressurization system is not limited to the internal volume of a robot, but can be used for any other conceivable mobile mechanism.

Claims

CLAIMS 1. Pressurization system (40) of a mobile mechanism, in particular a robot (10), the mobile mechanism comprising a body (15) comprising an outer casing (20) defining an internal volume (25), the pressurization system (40) being on board the mobile mechanism and configured to maintain a pressurization fluid (45) under pressure in the gaseous state in the internal volume (25), the pressurization system (40) comprising a storage tank (50) for the fluid and a fluid circuit (55) fluidically connecting the storage tank (50) to the internal volume (25) to inject a quantity of pressurization fluid (45) from the storage tank (50) into the internal volume (25), characterized in that the pressurization fluid (45) is stored in the storage tank (50) in the liquid state, the pressurization fluid (45) passing into the gaseous state when it is injected into the internal volume (25).

2. The pressurization system (40) of claim 1, wherein the pressurization fluid (45) is a dry fluid and is selected from carbon dioxide, halogenated gases, or a mixture thereof.

3. Pressurization system (40) according to claim 1 or 2, wherein the fluid circuit (55) comprises a calibrated fluid storage space (60), the fluid circuit (55) being configured to sequentially transfer pressurization fluid (45) in the liquid state from the storage tank (50) to the calibrated storage space (60) and then transfer the pressurization fluid (45) from the calibrated storage space (60) to the internal volume (25).

4. Pressurization system (40) according to claim 3, wherein the calibrated storage space (60) is sequentially fluidically isolated from the internal volume (25) of the movable mechanism during the transfer of the pressurization fluid (45) in the liquid state from the storage tank (50) to the calibrated storage space (60), and fluidically isolated from the storage tank (50) during the transfer of the pressurization fluid (45) from the calibrated storage space (60) to the internal volume (25).

5. Pressurization system (40) according to claim 3, wherein the fluid circuit (55) comprises an injection valve (65) fluidly arranged between the calibrated storage space (60) and the internal volume (25) to control the circulation of the pressurization fluid (45) from the calibrated storage space (60) to the internal volume (25).

6. Pressurization system (40) according to claim 5, wherein the injection valve (65) is a three-way valve (65A, 65B, 65C) comprising a first position for fluidly connecting the storage tank (50) to the calibrated storage space (60) to fill the calibrated storage space (60) with pressurization fluid (45) and a second position for fluidly connecting the calibrated storage space (60) to the internal volume (25) to inject the pressurization fluid (45) into the internal volume (25).

7. Pressurization system (40) according to claim 5, wherein the injection valve (65) is a simple valve, the calibrated storage space (60) being defined in the fluid circuit (55) upstream of the injection valve (65), the closing of the injection valve (65) fluidly isolating the calibrated storage space (60) from the internal volume (25), the opening of the injection valve (65) fluidly connecting the calibrated storage space (60) to the internal volume (25) for the injection of the pressurization fluid (45) into the internal volume (25).

8. Pressurization system (40) according to any one of claims 3 to 7, in which the fluid circuit (55) comprises a normally closed isolation valve (70), located upstream of the normally closed injection valve (65).

9. Pressurization system (40) according to claims 7 and 8, wherein the calibrated storage space (60) is defined between the isolation valve (70) and the injection valve (65).

10. Pressurization system (40) according to claim 8 or 9, in which the isolation valve (70) is controlled as a function of a measurement signal from a first pressure sensor (75) representative of the pressure inside the internal volume (25), in order to secure the internal volume (25) of the mobile mechanism, and the injection valve (65) is controlled as a function of the opening and closing of the isolation valve (70).

11. A pressurization system (40) according to any preceding claim, comprising a second pressure sensor (80) arranged to measure the pressure inside the storage tank (50).

12. Pressurization system (40) according to any one of the preceding claims in which the fluid circuit (55) comprises a system (78) for slowing down the expansion of the pressurization fluid (45) injected into the internal volume (25).

13. A method of pressurizing the internal volume (25) of a mobile mechanism such as a robot (10), the pressurization method comprising the steps of: storing a pressurizing fluid (45) in the liquid state in a storage tank (50) on board the mobile mechanism, injecting a quantity of pressurizing fluid (45) from the storage tank (50) into the internal volume (25) of the mobile mechanism, the injected pressurizing fluid (45) passing from the liquid state to the gaseous state, to maintain pressurization of the internal volume (25) of the mobile mechanism using the pressurizing fluid (45).

14. The method of claim 13, wherein the pressurizing fluid (45) is dry and is selected from carbon dioxide, halogenated gases, or a mixture thereof.

15. The method of claim 13 or 14, wherein the injection step is performed sequentially by transferring the quantity of pressurizing fluid (45) from the storage tank (50) to a storage space (60) and then injecting the quantity of pressurizing fluid (45) contained in the calibrated storage space (60) into the internal volume (25).

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