Elevating work platform collision protection

Abstract

Provided is a collision protection system 10 for an elevating work platform (EWP) 8, said protection system 10 comprising a plurality of ultrasonic sensors 12 operatively mountable to an EWP 8 and arranged as respective responder nodes in a LIN-BUS topology using a single cable 14. Also included is a human- machine interface (HMI) 16 arranged as a responder node in the LIN-Bus topology and whereby a user is able to input information and be provided with information. Lastly, a controller 18 is arranged in signal communication as commander node with the sensors 12 and HMI 16, the controller 18 configured to, upon activation of the EWP 8, generate a schedule 20 of LIN frames according to the responder nodes 12 configured on the LIN-Bus topology, and via round-robin scheduling, interrogate the LIN- Bus topology according to the generated schedule 20 to determine a proximity of an object to a sensor 12. If a determined object proximity exceeds a user-selectable value, the controller 18 generates an alarm via the HMI 16, wherein the system 10 minimises ultrasonic wave interference between sensors 12 to monitor for collision hazards proximate the EWP 8 according to said user-selectable value.

Description

ELEVATING WORK PLATFORM COLLISION PROTECTIONTECHNICAL FIELD

[0001] This invention relates broadly to elevating work platforms and associated industrial machinery, and more speci fically to an elevating work platform collision protection system and associated elevating work platform collision protection methodology .BACKGROUND ART

[0002] The following discussion of the background art is intended to facilitate an understanding of the present invention only . The discussion is not an acknowledgement or admission that any of the material referred to is or was part of the common general knowledge as at the priority date of the application .

[0003] Aerial or elevating work platforms are well-known in the art . A mobile elevating work platforms (MEWP ) is typically a mobile mechanical device used to provide temporary access for people or equipment to inaccessible areas , usually at height . They are generally used for temporary, flexible access purposes such as maintenance and construction work .

[0004] In general , MEWPs have strict safety criteria for operation to minimise inj ury to work personnel . In many countries , a licence is required to operate a MEWP . MEWPs are generally fitted with safety or guard rails around the platform itsel f to contain operators and passengers . This i s supplemented in most models by a restraining point , designed to secure a safety harness or fall arrester . Some work platforms also have a lip around the floor of the platform itsel f to avoid tools or supplies being accidentally kicked of f the platform .

[0005] Many MEWPs often come equipped with a variety of tilt sensors, with the most commonly activated sensor being an overweight sensor that will not allow the platform to raise if the maximum operating weight is exceeded. Similarly, sensors within the machine typically detect when weight on the platform is off- balance to such a point as to risk a possible tip-over if the platform is raised further. Another sensor will refuse to extend the platform if the machine is on a significant incline.

[0006] Mobile Elevating Work Platforms (MEWPs) assist in making working at heights safer; however, there are still risks present that can endanger life. Even with weight and tilt sensors, there is a risk that a MEWP operator or platform occupants can become trapped or crushed. As a mobile platform, serious and even fatal injuries may occur to MEWP operators as a result of themselves or passengers being crushed against overhead or ad acent structures whilst the EWP is in operation.

[0007] While prior art crush and collision protection systems exist, the Applicant has identified a need in the art for a simple and robust MEWP collision protection system which is readily retrofittable and configurable to existing MEWPs. The current invention was conceived with this goal in mind.SUMMARY OF THE INVENTION

[0008] The skilled addressee is to appreciate a Local Interconnect Network or LIN communication protocol, i.e. LIN-Bus, is a serial network protocol used for communication between components, as broadly based on ISO 17897, which specifies the interchange of digital information between on-board Electronic Control Units (ECUs) of road vehicles and suitable on-board diagnostics (OBD) testers.

[0009] It is further to be appreciated that reference herein to ' round-robin scheduling' or RRS comprises general reference to computing scheduling, which typically comprises an algorithm executed by a controller as a process or network scheduler where time slices or time quanta are assigned to each process in sequence and in equal portions in circular order on a network topology, where such quanta-assigned processes are handled sequentially and without priority .

[0010] The skilled addressee will further appreciate that , while the present invention is described with reference to an elevating work platform (EWP ) , such as a scissor-li ft or cherrypicker, the invention may also find application with other industrial machinery . As a result , reference herein to an EWP is made in a non-exclusive manner and may include other industrial machines and equipment , such as cranes , excavators , etc .

[0011] According to a first aspect of the invention there is provided a coll ision protection system for an elevating work platform (EWP ) , said protection system comprising : a plurality of ultrasonic sensors operatively mountable to an EWP and arranged as respective responder nodes in a LIN-BUS topology using a single cable ; a human-machine interface (HMI ) arranged as a responder node in the LIN-Bus topology and whereby a user is able to input information and be provided with information; and a controller arranged in signal communication as commander node with the sensors and HMI , the controller configured to : i . upon activation of the EWP, generate a schedule of LIN frames according to the responder nodes configured on the LIN-Bus topology; ii . via round-robin scheduling, interrogate the LIN-Bus topology according to the generated schedule to determine a proximity of an obj ect to a sensor ; andiii. if a determined object proximity exceeds a user- selectable value, generate an alarm via the HMI; wherein the system minimises ultrasonic wave interference between sensors to monitor for collision hazards proximate the EWP according to said user-selectable value.

[0012] In an embodiment, the ultrasonic sensor comprises a low- profile button-type ultrasonic sensor having a predetermined f ield-of-view .

[0013] In an embodiment, the human-machine interface (HMI) comprises a touch screen display.

[0014] In an embodiment, the controller comprises a CAN bus interface for interfacing with an existing Controller Area Network (CAN bus) control network of the EWP, said controller configured to interrupt motion of the EWP if a detected object proximity exceeds the user-selectable value.

[0015] In an embodiment, the controller comprises a wireless transmitter configured to transmit information under the Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of wireless protocol standards and / or 802.15 standard for wireless communications protocol, or similar wireless communications protocols, e.g. wi-fi, ANT, ANT+, Bluetooth, BLE, ZigBee, or the like .

[0016] In an embodiment, the wireless transmitter is configured to facilitate interaction between the controller and a remote processing system, such as a mobile telephone or a tablet.

[0017] In an embodiment, the responder nodes are configurable on the LIN-Bus topology by means of the remote processing systemproviding responder node information to the controller via the wireless transmitter.

[0018] In an embodiment, the schedule of LIN frames comprises a plurality of LIN frames, at least one for each responder node, with each LIN frame comprising a rate at which frames are sent, an expected return data length in bytes, a time at which a frame was last requested, and a responder node identification identifying each registered responder node.

[0019] In an embodiment, the controller is configured to interrogate a specific responder node in the LIN-Bus topology upon receipt of an external request via the HMI or remote processing system.

[0020] In an embodiment, the user-selectable value is programmable in the controller via the HMI and / or remote processing system.

[0021] In an embodiment, the HMI and / or remote processing system is configured to provide an indication of sensed object proximity .

[0022] In an embodiment, the alarm generated by the controller comprises an audio and / or visual alarm.

[0023] In an embodiment, the collision protection system comprises at least one secondary sensor or transducer arranged as a responder node in the LIN-BUS topology.

[0024] In an embodiment, said secondary sensor is selectable from a non-exclusive group consisting of an air quality sensor, a temperature sensor, a load cell or strain gauge, a photodetector, a motion sensor, or the like.

[0025] According to a second aspect of the invention there is provided an elevating work platform (EWP ) including a collision protection system comprising : a plurality of ultrasonic sensors operatively mounted to the EWP and arranged as respective responder nodes in a LIN-BUS topology using a single cable ; a human-machine interface (HMI ) arranged as a responder node in the LIN-Bus topology and whereby a user is able to input information and be provided with information; and a controller arranged in signal communication as commander node with the sensors and HMI , the controller configured to : i . upon activation of the EWP, generate a schedule of LIN frames according to the responder nodes configured on the LIN-Bus topology; ii . via round-robin scheduling, interrogate the LIN- Bus topology according to the generated schedule to determine a proximity of an obj ect to a sensor ; and iii . i f a determined obj ect proximity exceeds a user- selectable value , generate an alarm via the HMI ; wherein the controller minimises ultrasonic wave interference between sensors to monitor for collision hazards proximate the EWP according to said user-selectable value .

[0026] According to a third aspect of the invention there is provided an elevating work platform (EWP ) collision protection methodology comprising the steps of : providing an EWP having a plurality of ultrasonic sensors mounted thereto and arranged as respective responder nodes in a LIN-BUS topology using a single cable ; by means of a controller arranged in signal communication as commander node with the sensors and HMI , generating a schedule of LIN frames according to the responder nodes configured on the LIN- Bus topology whenever the EWP is activated;via the controller, interrogating the LIN-Bus topology via round-robin scheduling according to the generated schedule to determine a proximity of an obj ect to a sensor ; and via the controller, i f a determined obj ect proximity exceeds a user-selectable value , generating an alarm via a human-machine interface (HMI ) arranged as a responder node in the LIN-Bus topology; wherein ultrasonic wave interference between sensors is minimised during monitoring for collision hazards proximate the EWP according to said user-selectable value .

[0027] In an embodiment , the methodology includes the step of , via the controller having a CAN bus interface for interfacing with an existing Controller Area Network (CAN bus ) control network of the EWP, interrupting motion of the EWP i f a detected obj ect proximity exceeds the user-selectable value .

[0028] In an embodiment , the responder nodes are configurable on the LIN-Bus topology by means of the remote processing system providing responder node information to the controller via the wireless transmitter .

[0029] According to a further aspect of the invention there is provided a coll ision protection system for an elevating work platform, an elevating work plat form (EWP ) including a collision protection system, and an associated elevating work platform collision protection methodology, substantial ly as herein described and / or illustrated .BRIEF DESCRIPTION OF THE DRAWINGSThe description will be made with reference to the accompanying drawings in which :Figure 1 is a diagrammatic perspective-view representation of one embodiment of a collision protection system for an elevating work platform, in accordance with aspects of the present invention;Figure 2 is a simplified diagrammatic schematic representation o f one implementation of a LIN driver for a responder node of the system of Figure 1 ;Figure 3 is diagrammatic overview representation of a LIN- BUS topology of the collision protection system of Figure 1 ;Figure 4 is a diagrammatic overview representation of a controller of the collision protection system of Figure 1 generating a schedule of LIN frames according to the responder nodes configured on the LIN-Bus topology of Figure 3 ; andFigure 5 is diagrammatic perspective-view representation of an elevating work platform with a controller of the collision protection system of Figure 1 wirelessly interacting with a remote processing system .DETAILED DESCRIPTION OF EMBODIMENTS

[0030] Further features of the present invention are more fully described in the following description of several non-limiting embodiments thereof . This description is included solely for the purposes of exempli fying the present invention to the skilled addressee . It should not be understood as a restriction on the broad summary, disclosure or description of the invention as set out above .

[0031] In the figures , incorporated to illustrate features of the example embodiment or embodiments , like reference numerals are used to identi fy like parts throughout . Additionally, features ,mechanisms and aspects well-known and understood in the art will not be described in detail , as such features , mechanisms and aspects will be within the understanding of the skilled addressee .

[0032] Additionally, the accompanying figures do not represent engineering or design drawings , but provide a functional overview of the invention only . As a result , features and practical construction details required for various embodiments may not be indicated in each figure , but such construction requirements will be within the understanding of the skilled addressee .

[0033] Broadly, the present invention provides for a crush and collision protection system 10 for an elevating work platform (EWP ) 8 . In particular, the system 10 has been conceived to be robust , simple ( and thus relatively inexpensive to produce ) , and which is easily-retrof ittable to an existing mobile EWP or MEWP . As described in more detail below, the system 10 makes use of a LIN- BUS topology which provides inherent safety and redundancy and is particularly suited to the system' s goals of simplicity, reliability and retrofittability .

[0034] As described, while the present invention is exempli fied with reference to an EWP, the system 10 may also find application with other industrial machinery . For example , other machines and machinery requiring obj ect proximity detection for collision avoidance are apposite and within the scope of the present disclosure .

[0035] With reference now to the accompanying figures , one embodiment of the collision protection system 10 for a mobile elevating work platform (MEWP ) 8 comprises a plurality of ultrasonic sensors 12 that are operatively mountable to an EWP 8 and which are arranged as respective responder nodes ( also broadly indicated with reference numeral 12 ) in a LIN-BUS topology usinga single physical cable 14 , as shown . In a typical embodiment , each ultrasonic sensor 12 comprises a low-profile button-type ultrasonic sensor having a predetermined f ield-of-view . Such a predetermined or known f ield-of-view is generally taken into account when mounting the sensors 12 to the EWP 8 in order to ensure that desired areas are monitored, as described in more detail below .

[0036] In another embodiment , the collision protection system 10 may also comprise at least one secondary sensor or transducer (not shown) arranged as a responder node 12 in the LIN-BUS topology . For example , depending on requirements , the secondary sensor may comprise an air quality sensor, a temperature sensor, a load cell or strain gauge , a photodetector, a motion sensor, or the like . In this manner, system 10 may be used to sense obj ect proximity to minimise collisions , but may also be used to sense secondary characteristics , such as air quality, movement , personnel position, etc .

[0037] System 10 further typically includes a human-machine interface (HMI ) 16 which is also arranged as a responder node in the LIN-Bus topology and whereby a user is able to input information and be provided with information . The skilled addressee will appreciate that such an HMI may take a variety of forms . For example , in one embodiment , the human-machine interface (HMI ) 16 comprises a touch screen display, a control panel such as an aluminium housing comprising 2 LED indicators and an antitamper low profile button, a mobile phone arranged in communication with the controller 18 , as described in more detail below, and / or the like , but of course variations hereon are possible and anticipated .

[0038] System 10 also includes a controller 18 which is arranged in signal communication as commander node with the sensors 12 andHMI 16 as part of the LIN-Bus topology . Typically, the controller 18 may comprise any suitable processor or microcontroller configured to receive input , perform logical and arithmetical operations on a suitable instruction set , and provide output , as well as transitory and / or non-transitory electronic storage . In one embodiment , the controller 18 comprises an ESP32 ARM 32-bit LX6 integrated microcontroller, but variations hereon are possible and included within the scope of the present disclosure .

[0039] Importantly, the controller 18 is broadly configured, upon activation of the EWP 8 , to generate a schedule 20 of LIN frames according to the responder nodes 12 configured on the LIN- Bus topology . This step of generating the schedule 20 is performed each time the system 10 starts-up or boots , which facilitates reliability and error-detection, as described in more detail below .

[0040] In a typical embodiment , the responder nodes are configurable on the LIN-Bus topology by means of the remote processing system, such as a mobile phone 22 , providing responder node information to the controller via the wireless transmitter, e . g . a user may use a suitable ' app' to provide responder node identi fications uniquely identi fying each registered responder node 12 as part of an initial setup, or the like . Alternatively, the controller 18 may be configured to detect connected responder nodes 12 on the LIN-Bus topology when initialising at start-up, or the like . Similarly, the HMI 16 may be configured to allow configuring the responder nodes 12 on the LIN-Bus topology, or the like .

[0041] Once the schedule 20 has been generated, the controller 18 then interrogates the LIN-Bus topology via round-robin scheduling (RRS ) and in accordance with the generated schedule 20 to determine a proximity of an obj ect to a sensor 12 , and i f adetermined obj ect proximity exceeds a user-selectable value , i . e . an obj ect is detected too close to a particular sensor, the controller 18 generates an alarm via the HMI 16 . The alarm generated by the controller 18 generally comprises an audio and / or visual alarm . In this manner of using RRS interrogation across the LIN-Bus topology, the system 10 minimises ultrasonic wave interference between individual sensors 12 in order to monitor for crush and collision hazards proximate the EWP 8 according to said user-selectable value of acceptable obj ect proximity .

[0042] In the manner described, the system 10 is designed to detect obstacles and their proximity to the EWP 8 in order to protect the EWP operator and passengers from a crush or collision hazard . The system 10 is typically employed on, but not limited to , machinery such as a scissor lift or elevated work platform to alert an operator to hazardous proximity to obstacles or obj ects that could cause a crush or collision inj ury .

[0043] The use of the LIN-Bus topology provides a simple , yet cost-ef fective communication interface that does not require a dedicated communication controller integrated circuit . Instead, the controller 18 is programmed with a LIN-based communications protocol and used to drive the communication to a transceiver via a serial interface , e . g . a Serial Communication Interface ( SCI ) , or the like . Both transceiver and interface are typical of most modern microcontrollers , which require less complexity to implement .

[0044] Importantly, the LIN bus transmission only requires one cable between nodes 12 , simpli fying installation and providing robustness to the overall system 10 , and a slower communication speed compared to other communications protocols can be used in order to properly handle any radiated emissions issues . All nodes 12 are passively connected to the LIN-Bus topology, and a pullupresistor is typically used to ensure the bus is at a supply voltage level when the nodes are in the off-state . Such a single cable 14 typically contains four cores for data, power and ground connections .

[0045] Using the LIN-Bus topology, the controller 18 is configured to transmit bit frames , starting with a dominant start bit , whereby all nodes on the bus is synchronised, followed generally by the least signi ficant bit to most signi ficant bit , then a stop bit . This typically constitutes one SCI frame , and a LIN message is composed of multiple SCI frames . In a LIN-Bus topology, there is one commander node , i . e . the controller 18 , and up to 16 responder nodes 12 , i . e . sensors . The commander node controls all communication on the bus and contains both the commander and responder task to be delivered . The responder nodes 12 cannot communicate with each other, contain only the responder task, and are only capable of responding to the commander node if the message is directed at them . The commander sends out a request to a designated responder as a header (beginning of the frame ) , and the responder responds to the commander, as a response frame . There is also a case where the commander sends the responder the header and response frame , and the responder only listens but with no response . Both situations guarantee predictable yet defined bus traf fic, disallowing collisions for the most part because the commander is always initiating the communication . This predictable nature allows for scheduling of messages .

[0046] Figure 2 shows a simpli fied LIN driver schematic, as based on the ISO 9141 standard . Broadly, and by way of background only, the LIN-Bus topology is a bus communication interface that is bidirectional , biased to a supply battery voltage typically of the EWP 8 through a resistor and diode ( commander node only) , and is connected to the transceiver of every node in the LIN cluster or LIN-Bus topology . The transceiver of the controller 18 is whatfacilitates the communication between the nodes . The LIN transceiver converts TTL logic levels or low voltage logic signals from the microcontroller 18 into higher voltage levels , as a transmission along the bus and vice versa . The TXD ( transmit ) and RXD ( receive ) of the LIN transceiver, facilitate the communication to and from the bus through voltage translation that happens as the signals pass through the transceiver . The TXD is connected to the microcontroller, where the mes sage is sent and then broadcasted on the LIN bus . The RXD monitors the bus and converts the messages on the LIN bus to voltage levels the microcontroller can interpret , and thus respond to the communication happening on the bus . Typical voltage levels for the TXD and RXD are typical of most microcontroller levels : 3 . 3V and 5V. The LIN bus and LIN transceivers usually operate at voltages ranging from 9 V to 18 V, but can operate at up to 30 V ( depending on the application) . A typical vehicle supply is a 12-V battery system, with many larger commercial and industrial vehicles operating from a 24 V battery supply .

[0047] In a general embodiment , the schedule 20 of LIN frames comprises a plurality of LIN frames , at least one for each responder node 12 , with each LIN frame typically comprising a frame ID, a rate at which frames are sent , an expected return data length in bytes , a time at which a frame was last requested, and a responder node identi fication identi fying each registered responder node . Of course , in one embodiment , more than one LIN frame may exist per responder node 12 . In general , LIN frames are sent with a frame ID and the target responder ID such that a responder node 12 can determine a ) i f it should respond to the frame , and b ) what data to respond with .

[0048] Accordingly, with reference to Figures 3 and 4 of the accompanying drawings , each device on the LIN-Bus topology has a list of frames that only it can respond to . When a device on thebus sees a frame with an ID in its list , it responds with the data associated with that frame ID . For example , the LIN master controller 18 is configured to have an Operator Panel ( ID 1 ) and 2 sensors ( ID 7 & 8 ) as responder nodes 12 . The controller 18 as master device generates a list of LIN Frames based on the configured sensors 12 and HMI 16 , which is the generated schedule 20 . Each LIN frame has associated data, which outlines the rate at which it is sent , the expected return data length in bytes , the time at which the frame was last requested, and which node device is expected to respond .

[0049] As described, the schedule 20 is generated every time the system 10 boots , and when any configuration changes are made to the system, such as adding or removing sensors 12 , or the like . This ensures that only frames that are necessary for the current , i . e . up-to-date at start-up, system configuration are used, which reduces the overall load on the LIN-Bus and allows the system 10 to check for missing devices .

[0050] Importantly, the controller 18 as commander node or master device continuously checks the schedule frames one-by-one in order via round-robin schedul ing (RRS ) and in accordance with the generated schedule 20 until said controller 18 finds one that is due to be requested . When such a due frame is found, the frame is requested on the LIN-Bus and the controller 18 waits for the response data from the speci fic responder node or device 12 that is meant to handle that frame . I f no data is received, then it is a clear indication that the device that was supposed to respond is not properly connected to the LIN-Bus . After the requested frame has been handled, the round-robin schedule checking continues , starting from the frame that was j ust sent .

[0051] As shown in Figure 4 , frames can also be immediately requested on the LIN-Bus by events external to the schedule . Inthis case, the schedule checking is paused until the immediately requested frame has been handled. For example, in one embodiment, the controller is configured to interrogate a specific responder node in the LIN-Bus topology upon receipt of an external request via the HMI (or remote processing system 22, described below) .

[0052] Typically, the system 10 also wires into an existing control circuit on the EWP machine 8 to stop machine motion if a hazard is detected. For example, in one embodiment, the controller 18 comprises a CAN bus interface for interfacing with an existing Controller Area Network (CAN bus) control network of the EWP 8, said controller 18 configured to interrupt motion of the EWP 8 if a detected object proximity exceeds the user-selectable value.

[0053] In a typical embodiment, the controller 18 comprises a wireless transmitter configured to transmit information under the Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of wireless protocol standards and / or 802.15 standard for wireless communications protocol, or similar wireless communications protocols, e.g. wi-fi, ANT, ANT+, Bluetooth, BLE, ZigBee, or the like. Such a wireless transmitter is generally configured to facilitate interaction between the controller 18 and a remote processing system 22, such as a mobile telephone or a tablet, as shown in Figure 5. In a typical embodiment, the user- selectable value of object proximity is programmable in the controller 18 via the HMI 16 or remote processing system 22. Similarly, in a typical embodiment, the HMI 16 and / or remote processing system 22 is configured to provide an indication of sensed object proximity.

[0054] For example, a single sensor 12 may be pointing upwards from an EWP 8 to determine the overhead clearance from the top rail of a working platform basket to a roof of a building, or the like. In this case, the sensor 12 would be set to invoke a stopalert / action at , for example 1 . 0 metre above the top rail of the EWP basket , which may be deemed to be safe for the operator . The system 10 could further be set to 1 . 5 metres proximity as an additional safety factor to warn the operator when approaching a hazard while not stopping machine motion . An override function may be provided so that i f the operator wishes , once the EWP 8 has been stopped, the alarm and stop signal can be reset to allow machine motion within the hazardous zone as monitored by the operator . The override function can be set to either reset automatically after a preset time period or when the EWP machine is cleared for the hazard zone .

[0055] In light of the above general description, the system 10 is configured to be active when the EWP machine 8 is switched on in order to continuously measure the distance above the EWP, i . e . the relative distance from the sensors 12 to an obj ect . A vertically mounted sensor 12 would have a vertical f ield-of-view directly upwards . I f , when raising the platform, the sensor 12 determines that the minimum safe distance is approaching, visual and audible alerts are initiated to warn the operator of an impending hazard . Should motion continue past this detection zone , the alerts intensi fy, and i f the system 10 is wired into the existing EWP machine control system, machine motion is stopped, preventing inj ury to the operator . I f desired, the operator can continue to move the machine further, being aware that a hazardous condition exists , by pressing an override button to silence the audible alert and re-enable machine motion . The override function can be set to time out automatically or reset only once the machine has been moved out of the hazard zone .

[0056] The system 10 typically includes comprehensive sel f-test and fault indication features . Each LIN node , such as the sensors 12 and the HMI or operator panel 16 , is continuously monitored and should a device fail due to , for example , electronic failure , aconnector disconnection or cable fault, the controller 18 will detect this and initiate an alarm condition. If the HMI 16 is still functional, it will indicate an alarm condition. If only the controller 18 is still functional, an internal beeper will sound an alarm.

[0057] Typically, the LIN-Bus topology comprises a daisy chain, star, or mixed wiring method, which simplifies wiring layouts as there are no restrictions on the topology of the wiring other than the aggregate cable length being kept to a maximum of around 40 metres. Devices or nodes can be connected in a daisy chain scheme, a star scheme or a mix of both, maximising the flexibility of cabling and positioning of devices. LIN bus communications are noise tolerant due to the relatively low speed (19,200 baud) and very high signal levels approaching the EWP supply voltage of 12 or 24 volts. Cable requirements are simplified as there is no need to have a twisted pair or specialised instrument-style cable to carry the LIN bus signals. As mentioned, the controller 18 or control module requires a 12-24-volt power connection and generally provides a dry relay contact to connect into an existing emergency stop, dead man switch or similar control input on the EWP machine 8 to stop the EWP 8 when a proximity alarm is raised. Unlike other communications topologies, such as RS422 / 485, CAN BUS and other balanced cable communications schemes that require termination resistors at each end of the bus, the LIN BUS topology of the present invention removes the need for such terminations, further simplifying wiring and cabling of the system 10.

[0058] Fo r example, to effect EWP machine control, i.e., motion stop, the controller 18 may provide a dry SPDT relay contact to allow connection into an E-stop, dead man switch circuit, or the like. Typically, a N / 0 relay contact would be used, as during regular operation, the relay is energised, and the contact closed when the system 10 is active but not in a STOP condition. Thisscheme provides fail-safe operation of the system 10 and the EWP machine 8 since the system 10 must be powered-up and clear of hazards ( relay contact closed) for the EWP machine 8 to be operated . I f a STOP event is encountered, the relay contact will open and interrupt the circuit into which it is wired . A second N / O contact may be provided, which is closed on the STOP condition . Depending on the load, this can be used to drive an auxiliary device , such as an external horn or lamp . I f the current is expected to be more than 1A or so , a slave relay or contactor may be used .

[0059] Typically, retrofitting of the system 10 requires that the number of sensors 12 and their respective locations are determined according to sensor f ield-of-view for the best coverage to protect the operator on a particular EWP machine . Once suitably located and wired into the system 10 , each sensor 12 may be configured using a suitable software application or ' app' via a Bluetooth connection to the controller 18 . Each sensor 12 can be individually added to the system 10 and set up for detection ranges between, for example , 0 . 5 to 4 . 5 metres , af fording flexibility for such retrofitting .

[0060] In a speci fic example , the controller 18 includes power protection, where incoming electrical power is passed through a protection network that protects against reverse polarity connections and against transients on the incoming power as speci fied in ISO 7637 . A diode may be used to provide reverse polarity protection whilst a circuit controlling a series pass P- Channel MOSFET interrupts incoming power to the controller circuitry should the incoming voltage exceed around 35 volts . This af fords protection to the controller 18 electronic components against incoming power transients . A number of power regulators may further be provided to step-down an incoming 12-24V electrical input , such as from an EWP battery, to 9V and 3 . 3V . The 9V supplyis typically used to supply visual HMI lamps and control relays , while the 3 . 3V supply powers internal logic of the controller 18 . The 3 . 3V supply is also made available on a terminal block to supply downstream LIN bus devices , such as the sensors 12 .

[0061] For example , a 15-way terminal block allows for the connection of the controller 18 to the rest of the system 10 . Normally the controller 18 is housed in an enclosure and is prewired in a standard factory configuration that suits most applications . However, the controller 18 can be integrated into an existing control panel on a EWP machine 8 .

[0062] In such a speci fic example , the controller 18 comprises an ESP32 ARM 32-bit LX6 integrated microcontroller with Bluetooth module with onboard peripherals such as a UART , timers , I2C interface , RAM, and FLASH memory . The control ler 18 executes firmware incorporating a real-time operating system that schedules the tasks required to manage communications on the LIN and CAN buses and control of the I / O for relays and other switching devices . Additionally, the controller 18 communicates internally with a real-time clock and FRAM to maintain an event logging function . This includes running a file system to manage opening and closing log files on the FLASH memory of the controller 18 . Logged events are initially saved in real-time to the FRAM, and on every system startup, the log file is trans ferred to FLASH . Using this method reduces the chance of losing logged data or corrupting FLASH contents when attempting to write to FLASH on system power down . This method also mitigates the need to hold up the power supply on power down .

[0063] The Real Time Clock (RTC ) maintains the time and date for the local time zone . Setting of the RTC is typically managed by the Bluetooth app, which allows synchronisation to the phone / tablet 22 time . The RTC time stamp is used when any systemevent is logged so that all event data can be traced back in realtime. This is useful for data collection on machine usage or forensic analysis. The RTC is backed up with a battery to allow timekeeping when the system is switched off.

[0064] Controller 18 typically employs Ferro-Electric Random Access Memory (FRAM) , which allows random reads and writes to any location and is non-volatile, i.e. data is stored within its memory cells even when power is removed. The FRAM is used as storage for the event log as read-write access is virtually instantaneous, allowing for the log to be kept up to date real time. The FRAM buffers the log data until a new power-up event occurs, whereupon the new log file data is updated to FLASH. This method is much more robust than using FLASH directly for logging, as FLASH has rather long access times and requires the storage of large discrete blocks of data. These long access times would impact the Control Module's operation speed and increases the risk of data loss should the power be removed when data is being written to FLASH.

[0065] Controller 18 is typically configured to generate multiple tones to drive an onboard Piezo transducer or sounder. The sounder is driven via a MOSFET from the inbound 12 or 24-volt power. A Zener diode clamps the voltage to 16 volts in the event the controller 18 is powered from 24 volts. Typically, the sounder is driven with a square wave of 50% duty cycle near its resonant frequency of around 2.2kHz. To differentiate a warning from a stop alert, the sounder is driven with a pulsed or steady tone. System alarms and faults are indicated with a steady tone.

[0066] The skilled addressee is further to appreciate that the present invention includes an associated elevating work platform (EWP) collision protection methodology, typically comprising the steps of:providing an EWP 8 having a plurality of ultrasonic sensors 12 mounted thereto and arranged as respective responder nodes in a LIN-BUS topology using a single cable 14 ; by means of a controller 18 arranged in signal communication as commander node with the sensors 12 and HMI 16 , generating a schedule 20 of LIN frames according to the responder nodes configured on the LIN-Bus topology whenever the EWP 8 is activated; via the controller 18 , interrogating the LIN-Bus topology via round-robin scheduling (RRS ) according to the generated schedule 20 to determine a proximity of an obj ect to a sensor ; and via the controller 18 , i f a determined obj ect proximity exceeds a user-selectable value , generating an alarm via a humanmachine interface (HMI ) 16 arranged as a responder node in the LIN-Bus topology; wherein ultrasonic wave interference between sensors 12 is minimised during monitoring for collision hazards proximate the EWP 8 according to said user-selectable value .

[0067] Applicant believes it particularly advantageous that the present invention provides for a simple and robust EWP crush and collision protection system 10 which is readily retrofittable and configurable to existing MEWPs . In particular, the use of relatively small ultrasonic sensors 12 linked together and with the controller 18 via a single cable 14 , makes the system 10 easily fittable to an MEWP without requiring signi ficant changes or adaptations . The use of a suitably-configured LIN protocol ensures all non-master devices or nodes respond only when they are requested to do so by controller 18 . Because only one frame can be requested on the LIN bus at a time , and only one device 12 may respond to that frame , there is no chance of devices with di f ferent ID' s trying to communicate at the same time . Since the sensors 12 connected to the LIN-Bus topology all have unique IDs to denote their position around an EWP, no two sensors can respond with their distance and proximity threshold data at the same time . In thecase where two identical devices ( same ID) exist on the bus at the same time , both devices will respond to their associated frames as expected . This will cause a CRC mismatch in the response data, which indicates that a duplicate device ID exists on the bus , and the detected error is handled by the system 10 .

[0068] The controller 18 can interrogate data from the connected ultrasonic sensors 12 at a rate determined based on the number of sensors configured to the system 10 . I f two or more ultrasonic sensors 12 try to measure the distance to an obj ect at the same time , the resulting value can be corrupted due to one sensor receiving the reflected ultrasonic waves transmitted by another . To counter this , it is possible to have each sensor module in a system synchronise its distance measurements with a common frame on the LIN-BUS . Since all sensors receive the frame at the same time , the sensors can generate a time of fset based on their own ID and the time it takes for an ultrasonic pulse to be processed . This time of fset can then be used to delay the regular polling of the sensors in such a way that either a ) no 2 sensors will transmit concurrently ( 1 to 4 sensors ) or b ) pairs of sensors transmit concurrently such that their ultrasonic bursts are least likely to collide with each other ( 5 to 8 sensors ) .

[0069] In the example embodiments , well-known processes , well- known device structures , and well-known technologies are not described in detail , as such will be readily understood by the skilled addressee . Optional embodiments of the present invention may also be said to broadly consist in the parts , elements and features referred to or indicated herein, individually or collectively, in any or all combinations of two or more of the parts , elements or features .

[0070] It is to be appreciated that reference to "one example" or " an example" of the invention, or similar exemplary language(e.g., "such as") herein, is not made in an exclusive sense. Various substantially and specifically practical and useful exemplary embodiments of the claimed subject matter are described herein, textually and / or graphically, for carrying out the claimed subject matter. Accordingly, one example may exemplify certain aspects of the invention, whilst other aspects are exemplified in a different example.

[0071] Variations (e.g. modifications and / or enhancements) of one or more embodiments described herein might become apparent to those of ordinary skill in the art upon reading this application. The inventor (s) expects skilled artisans to employ such variations as appropriate, and the inventor (s) intends for the claimed subject matter to be practiced other than as specifically described herein.

[0072] The use of the terms "a", "an", "said", "the", and / or similar referents in the context of describing various embodiments (especially in the context of the claimed subject matter) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms "comprising, " "having, " "including, " and "containing" are to be construed as open-ended terms (i.e., meaning "including, but not limited to,") unless otherwise noted. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. No language in the specification should be construed as indicating any non-claimed subject matter as essential to the practice of the claimed subject matter.

[0073] Any method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed .

Claims

CLAIMS1 . A collision protection system for an elevating work platform (EWP ) , said protection system comprising : a plurality of ultrasonic sensors operatively mountable to an EWP and arranged as respective responder nodes in a LIN-BUS topology using a single cable ; a human-machine interface (HMI ) arranged as a responder node in the LIN-Bus topology and whereby a user is able to input information and be provided with information; and a controller arranged in signal communication as commander node with the sensors and HMI , the controller configured to : i . upon activation of the EWP, generate a schedule of LIN frames according to the responder nodes configured on the LIN-Bus topology; ii . via round-robin scheduling, interrogate the LIN- Bus topology according to the generated schedule to determine a proximity of an obj ect to a sensor ; and iii . i f a determined obj ect proximity exceeds a user- selectable value , generate an alarm via the HMI ; wherein the system minimises ultrasonic wave interference between sensors to monitor for collision hazards proximate the EWP according to said user-selectable value .2 . The EWP collision protection system of claim 1 , wherein the ultrasonic sensor comprises a low-profile button-type ultrasonic sensor having a predetermined f ield-of-view .3 . The EWP collision protection system of either of claims 1 or 2 , wherein the human-machine interface (HMI ) comprises a touch screen display .4 . The EWP collision protection system of any of claims 1 to 3 , wherein the controller comprises a CAN bus interface forinterfacing with an existing Controller Area Network (CAN bus) control network of the EWP, said controller configured to interrupt motion of the EWP if a detected object proximity exceeds the user- selectable value.

5. The EWP collision protection system of any of claims 1 to 4, wherein the controller comprises a wireless transmitter configured to transmit information under the Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of wireless protocol standards and / or 802.15 standard for wireless communications protocol, or similar wireless communications protocols, e.g. wifi, ANT, ANT+, Bluetooth, BLE, ZigBee, or the like, and wherein the wireless transmitter is configured to facilitate interaction between the controller and a remote processing system, such as a mobile telephone or a tablet.

6. The EWP collision protection system of claim 5, wherein the responder nodes are configurable on the LIN-Bus topology by means of the remote processing system providing responder node information to the controller via the wireless transmitter.

7. The EWP collision protection system of any of claims 1 to 6, wherein the schedule of LIN frames comprises a plurality of LIN frames, one for each responder node, with each LIN frame comprising a rate at which frames are sent, an expected return data length in bytes, a time at which a frame was last requested, and a responder node identification identifying each registered responder node.

8. The EWP collision protection system of any of claims 1 to 7, wherein the controller is configured to interrogate a specific responder node in the LIN-Bus topology upon receipt of an external request via the HMI or a remote processing system.9 . The EWP collision protection system of any of claims 1 to 8 , wherein the user-selectable value is programmable in the controller via the HMI or a remote processing system .10 . The EWP collision protection system of any of claims 1 to 9 , wherein the HMI and / or a remote processing system is configured to provide an indication of sensed obj ect proximity .11 . The EWP collision protection system of any of claims 1 to 10 , wherein the alarm generated by the controller comprises an audio and / or visual alarm .12 . The EWP collision protection system of any of claims 1 to 11 , which comprises at least one secondary sensor or transducer arranged as a responder node in the LIN-BUS topology, said secondary sensor selectable from a non-exclusive group consisting of an air quality sensor, a temperature sensor, a load cell or strain gauge , a photodetector, a motion sensor, or the like .13 . An elevating work platform (EWP ) including a collision protection system comprising : a plurality of ultrasonic sensors operatively mounted to the EWP and arranged as respective responder nodes in a LIN-BUS topology using a single cable ; a human-machine interface (HMI ) arranged as a responder node in the LIN-Bus topology and whereby a user is able to input information and be provided with information; and a controller arranged in signal communication as commander node with the sensors and HMI , the controller configured to : i . upon activation of the EWP, generate a schedule of LIN frames according to the responder nodes configured on the LIN-Bus topology;ii . via round-robin scheduling, interrogate the LIN- Bus topology according to the generated schedule to determine a proximity of an obj ect to a sensor ; and iii . i f a determined obj ect proximity exceeds a user- selectable value , generate an alarm via the HMI ; wherein the controller minimises ultrasonic wave interference between sensors to monitor for collision hazards proximate the EWP according to said user-selectable value .14 . An elevating work platform (EWP ) collision protection methodology comprising the steps of : providing an EWP having a plurality of ultrasonic sensors mounted thereto and arranged as respective responder nodes in a LIN-BUS topology using a single cable ; by means of a controller arranged in signal communication as commander node with the sensors and HMI , generating a schedule of LIN frames according to the responder nodes configured on the LIN- Bus topology whenever the EWP is activated; via the controller, interrogating the LIN-Bus topology via round-robin scheduling according to the generated schedule to determine a proximity of an obj ect to a sensor ; and via the controller, i f a determined obj ect proximity exceeds a user-selectable value , generating an alarm via a human-machine interface (HMI ) arranged as a responder node in the LIN-Bus topology; wherein ultrasonic wave interference between sensors is minimised during monitoring for collision hazards proximate the EWP according to said user-selectable value .15 . The EWP collision protection methodology of claim 14 , which includes the step of , via the controller having a CAN bus interface for interfacing with an existing Controller Area Network ( CAN bus ) control network of the EWP, interrupting motion of the EWP i f a detected obj ect proximity exceeds the user-selectable value .16 . The EWP collision protection methodology of claim 14 , which includes the step of configuring the responder nodes on the LIN- Bus topology by means of the remote processing system providing responder node information to the controller via a wireless transmitter .

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