A method of operating a collision avoidance protocol of a work vehicle

Abstract

A method (100) of operating a collision avoidance protocol (69) of a work vehicle 10, a controller 51 configured to perform such a method and a work vehicle comprising said controller. The collision a

Description

Technical Field The present disclosure relates to a method of operating a collision avoidance protocol of a work vehicle, a controller configured to perform such a method and a work vehicle comprising said controller. Background Work vehicles or machines such as, excavators, motor graders, loaders, and the like may be used at various construction worksites to perform operations, such as, material removal, transportation, and the like. Such work machines may typically operate in highly interactive environments with ground crew moving around the work machine, varying road surfaces being cut and repaired, and barriers and obstacles that need to be navigated by the work machine. It may be challenging for an operator to be fully aware in such dynamic environments and accordingly navigate the work machine. More particularly, visibility of the operator may be obstructed by portions of the work machine itself or the obstacles present near the work machine. As a result, there may be foreign objects in proximity to the work vehicle which it is important for the work vehicle to avoid contact with, which the operator may not be aware of. For example, large foreign objects could cause damage to the work vehicle if there is a collision. These risks of collisions are enhanced due to the limits on operator visibility of the operator working the work machine. To reduce the risk of collisions, work machines may be equipped with control systems comprising collision avoidance protocols, and foreign object proximity sensors to reduce the risk of a collision between the work vehicle and a foreign object. The collision avoidance protocol may comprise the activation of an alert or automatic braking when a foreign object is detected by the foreign object proximity sensors. However, even with increased sensor coverage using a plurality of foreign object proximity sensors, there may be regions with unreliable sensor coverage, such as blind spots around the work machine, or locations with reduced sensor sensitivity. If a foreign object is within these regions, it may not be detected by the foreign object proximity sensor. An additional problem is that with the increased use of foreign object proximity sensors, there is an increased chance of a false positive foreign object detection. False positive detections may be when the foreign object proximity sensors outputs a signal indicating the presence of a foreign object despite no foreign object, or only an insignificant object, being present, and may be referred to as nuisance. This may lead to an unnecessary collision avoidance protocol being activated when there is no risk of a collision. This may cause reduced performance of the work vehicle and can distract an operator from operating the work vehicle in an efficient manner. US2021 / 0010228 provides a system to automatically brake a drive unit when an object detection device detects an object, and then deactivate the state when it is determined that an operator has an intention to continue operation. This document describes a solution to make it easier to deactivate the state of automatic braking. However, US2021 / 0010228 does not address the issue of poor detection of foreign objects due to blind spots in the sensor coverage. In addition, by providing an easy way to deactivate the braking, there is a risk that an operator will deactivate the braking even when a real foreign object is present. Therefore, there is still a need to address these problems and provide an improved method for operating a collision avoidance protocol of a work vehicle. Summary Generally, the present disclosure provides a method of operating a collision avoidance protocol of a work vehicle which may operate when a foreign object is detected, and the data then indicates that the foreign object is no longer present. The method assesses whether there is a risk that the foreign object, and a risk of collision, is still present. If there is a risk of collision, the method requires a user input to cancel the collision avoidance protocol. This can ensure that the user first checks if the foreign object is still present. If the method assesses that the foreign object previously detected is no longer a risk, or was never present, then the method automatically stops the collision avoidance protocol. There is therefore provided a method of operating a collision avoidance protocol of a work vehicle, wherein the collision avoidance protocol adapts operation of the work vehicle to account for a foreign object. The method comprises, by a control system receiving foreign object proximity data from at least one foreign object proximity sensor of the work vehicle, the foreign object proximity data indicative of a detection of a foreign object in proximity to the work vehicle. A change is detected in the foreign object proximity data indicative of an absence of the foreign object. Upon the detected change and based upon the foreign object proximity data, the detection of the foreign object is categorised as a critical foreign object detection or a non-critical foreign object detection. If the detection of the foreign object is categorised as the critical foreign object detection, the control system activates or maintains the collision avoidance protocol until a user input is received. If the detection of the foreign object is categorised as the non-critical foreign object proximity detection, the control system does not activate or automatically stops the collision avoidance protocol. As the system categorises detections into critical and non-critical foreign object detections, only critical detections may require a user to enter a user input to stop the collision avoidance protocol. Therefore, a user may only be required to input a command when there is a risk of a foreign body being present. This may reduce the effort on the part of the user and may result in the user paying more attention when there is an actual risk of a foreign body being present. Since the detection may be categorised as a non-critical foreign object detection when there is a reduced or negligible risk of a foreign object being present, the user may not be required to enter a command when there is a reduced risk. This may reduce the burden on the user and may ensure that the user pays sufficient attention when there is an increased risk. The present disclosure further provides a controller for controlling a collision avoidance protocol of a work vehicle, wherein the collision avoidance protocol adapts operation of the work vehicle to account for a foreign object. The controller is configured to receive foreign object proximity data from at least one foreign object proximity sensor of the work vehicle, the foreign object proximity data indicative of a detection of a foreign object in proximity to the work vehicle. The controller detects a change in the foreign object proximity data indicative of an absence of the foreign object and categorises, upon the detected change and based upon the foreign object proximity data, the detection of the foreign object as a critical foreign object detection or a non-critical foreign object detection. If the detection of the foreign object is categorised as the critical foreign object detection, the controller activates or maintains the collision avoidance protocol until a user input is received. If the detection of the foreign object is categorised as the non-critical foreign object proximity detection, the controller automatically stops or does not activate the collision avoidance protocol. The present disclosure further provides a work vehicle comprising at least one foreign object proximity sensor configured to generate foreign object proximity data indicative of a detection of a foreign object in proximity to the work vehicle and a control system comprising the controller described above. By way of example only, embodiments according to the present disclosure are now described with reference to, and as shown in, the accompanying drawings. Brief Description of the Drawings Figure 1 illustrates a work vehicle of the present disclosure, which may be operated in accordance with the method of the present disclosure; Figure 2 is a schematic of a control system of the work vehicle of Figure 1; Figure 3 is a schematic of a sensor coverage map of the control system of Figure 2; Figure 4 is a further schematic of the sensor coverage map of the control system of Figure 2; Figure 5 is a further schematic of the sensor coverage map of the control system of Figure 2, showing a critical region of the sensor coverage map; Figure 6 is a flow diagram of the method of the present disclosure; Figure 7 is an example of a step of ‘categorising detection of the foreign object’ of the method of Figure 6; and Figures 8a to 8d illustrates examples of the step of ‘categorising detection of the foreign object’ of Figure 7. Detailed Description The ensuing description provides preferred exemplary embodiment(s) only, and is not intended to limit the scope, applicability or configuration of the invention. Rather, the ensuing description of the preferred exemplary embodiment(s) will provide those skilled in the art with an enabling description for implementing a preferred exemplary embodiment of the invention, it being understood that various changes may be made in the function and arrangement of elements, including combinations of features from different embodiments, without departing from the scope of the invention. Specific details are given in the following description to provide a thorough understanding of the embodiments. However, it will be understood by one of ordinary skill in the art that embodiments may be practised without these specific details. For example, well-known circuits, processes, algorithms, structures, and techniques may be shown without unnecessary detail in order to avoid obscuring the embodiments. Also, it is noted that the embodiments may be described as a process which is depicted as a flowchart, a flow diagram, a data flow diagram, a structure diagram, or a block diagram. Although a flowchart may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be re-arranged. A process is terminated when its operations are completed but could have additional steps not included in the figure. A process may correspond to a method, a function, a procedure, a subroutine, a subprogram, etc. When a process corresponds to a function, its termination corresponds to a return of the function to the calling function or the main function. Moreover, as disclosed herein, the term "storage medium" may represent one or more devices for storing data, including read only memory (ROM), random access memory (RAM), magnetic RAM, core memory, magnetic disk storage mediums, optical storage mediums, flash memory devices and / or other machine-readable mediums for storing information. The term "computer-readable medium" includes but is not limited to portable or fixed storage devices, optical storage devices, wireless channels and various other mediums capable of storing, containing or carrying instruction(s) and / or data. Furthermore, embodiments may be implemented by hardware, software, firmware, middleware, microcode, hardware description languages, or any combination thereof. When implemented in software, firmware, middleware or microcode, the program code or code segments to perform the necessary tasks may be stored in a machine-readable medium such as storage medium. A processor(s) may perform the necessary tasks. A code segment may represent a procedure, a function, a subprogram, a program, a routine, a subroutine, a module, a software package, a class, or any combination of instructions, data structures, or program statements. A code segment may be coupled to another code segment or a hardware circuit by passing and / or receiving information, data, arguments, parameters, or memory contents. Information, arguments, parameters, data, etc. may be passed, forwarded, or transmitted via any suitable means including memory sharing, message passing, token passing, network transmission, etc. It is to be understood that the following disclosure provides many different embodiments, or examples, for implementing different features of various embodiments. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. In addition, the present disclosure may repeat reference numerals and / or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and / or configurations discussed. Moreover, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact and may also include embodiments in which additional features may be formed interposing the first and second features, such that the first and second features may not be in direct contact. Figure 1 illustrates an embodiment of a system 9 comprising a work vehicle 10, in this case an excavator. The work vehicle 10 may be any suitable type of work vehicle 10, including multi-purpose work vehicles, such as excavators, backhoes, loaders, dozers, shovels, mining shovels, cranes, fellers, harvesters, material handlers and other such work vehicles. The work vehicle 10 may comprise at least one movable member 16, 18. The at least one movable member 16, 18 may comprise at least one ground engager 16, such as one or more continuous tracks 16 and / or one or more wheels (not shown) for movement of the work vehicle 10. The at least one movable member 16, 18 may comprise a rotating structure 18 of the work vehicle 10. The at least one ground engager 16may be for movement of the work vehicle 10. The at least one ground engager 16 may be powered by a motion power unit 20 (Figure 2) such as an engine or an electric motor. The at least one ground engager 16 may be arranged symmetrically on either side of the work vehicle 10 and may be operated to provide linear motion and / or turning motion. The work vehicle 10 may comprise a motion brake 22 (Figure 2). The motion brake 22 may be operable to slow or stop motion of the work vehicle 10. The motion brake 22 may be provided on the at least one ground engager 16. The rotating structure 18 of the work vehicle 10 may comprise an upper rotating structure 30. The work vehicle 10 may further comprise a lower structure 32. The upper rotating structure 30 may be rotatable relative to the lower structure 32. The work vehicle 10 may comprise a swing actuator 33 (Figure 2) to rotate the upper rotating structure 30 relative to the lower structure 32. The swing actuator 33 may be a hydraulic actuator and / or an electric motor. The work vehicle 10 may comprise a swing brake 34 (Figure 2) to slow, stop and / or prevent rotation of the upper rotating structure 30 relative to the lower structure 32. The upper rotating structure 30 may comprise an arm arrangement 35, a main body 36 and a counterweight 38. The arm arrangement 35 may be pivotally attached to the main body 36 and may comprise a boom, a stick and a tool. The boom, stick and tool may be pivotally attached to one another. The arm arrangement 35 may be operated using arm actuators (not shown), which may be hydraulic actuators or electric actuators. The arm arrangement 35 may be operated by an operator to carry out the work of the work vehicle 10, such as excavation. The main body 36 may comprise a cab 40. The cab 40 may be for the operator to sit therein and operate the work vehicle 10. The cab 40 may be situated at the front of the main body 36, and / or the same side of the main body 36 as the arm arrangement 35. The cab 40 may provide the operator with good visibility of the area in front of the main body 36, where the arm arrangement 35 may be operated to conduct the work of the work vehicle 10. The cab 40 may provide reduced visibility of the area behind the main body 36. The main body 36 and / or the lower structure 32 may comprise the motion power unit 20. The counterweight 38 may be provided on a rear of the main body 36, and / or on a side of the main body 36 opposite to the arm arrangement 35. The counterweight 38 may provide balance to the work vehicle 10 when the arm arrangement 35 is used to raise a load. The lower structure 32 may comprise the at least one ground engager 16 and may comprise a fixed platform and / or form an undercarriage of the work vehicle 10. The work vehicle 10 comprises at least one foreign object proximity sensor 42. The at least one foreign object proximity sensor 42 is configured to generate foreign object proximity data 43 (Figure 2) indicative of a detection of a foreign object 44 in proximity to the work vehicle 10. The at least one foreign object proximity sensor 42 may comprise radar; a radar sensor; lidar; a lidar sensor; an ultrasonic sensor; a camera and / or a stereo camera. The foreign object proximity sensors may comprise a selection of different foreign object proximity sensor 42, for example, at least one camera and at least one lidar, and / or at least one camera and at least one radar. The foreign object proximity sensors 42 may comprise any number of any of the above sensors 42 in combination, or other suitable sensors for generating foreign object proximity data 43. The at least one foreign object proximity sensor 42 may a detect foreign object 44 within about 1 m , about 3 m, about 5 m, about 10 m, or about 20 m of the work vehicle 10. The at least one foreign object proximity sensor 42 may comprise two, three, four, five, seven, ten or more foreign object proximity sensors 42. The foreign object proximity sensors 42 may be arranged at different locations around the work vehicle 10, may be arranged symmetrically around the work vehicle 10 and / or may be arranged to give a broad sensor coverage around the work vehicle 10. The foreign object proximity sensors 42 may be arranged to provide sensor coverage around a rear angle of at least 250, 290, 300, 315, and / or 330 degrees of the work vehicle 10, and / or may be arranged to provide sensor coverage of an area not visible to an operator of the work vehicle 10. The rear angle may define a central angle of a sector area adjacent to the work vehicle 10 on the side opposite the cab 40. The at least one foreign object proximity sensor 42 may be mounted to the lower structure 32, the upper structure 30, the main body 36, and / or the counterweight 38. The foreign object proximity data 43 may comprise radar data, lidar data, ultrasound data, image data, and / or stereo image data. The foreign object proximity data 43 may comprise the distance and / or location of the foreign object 44 relative to the at least one foreign object proximity sensor 42 and / or to the work vehicle 10. The foreign object proximity data 43 may comprise data derived from a mixture of sources, and / or may comprise data derived from a combination of the radar data, lidar data, ultrasound data, image data, and / or stereo image data. This may enhance the accuracy and / or reliability of the foreign object proximity data 43. The foreign object proximity data 43 may comprise the identification and / or tracking of the foreign object 44. When the foreign object proximity data 43 comprises image data, image recognition may be used to identify and track a specific foreign object 44. When the foreign object proximity data 43 comprises radar data, lidar data, or ultrasound data, a signal size may be used to identify and track a specific foreign object 44. The foreign object proximity data 43 may comprise a time series sequence of distance and / or location of the specific foreign object 44 relative to the at least one foreign object proximity sensor 42 and / or to the work vehicle 10. The foreign object proximity data 43 may comprise the trajectory of the foreign object 44. The foreign object proximity data 43 may comprise data indicative of an absence of the foreign object 44. When the foreign object proximity data 43 comprises image data, image recognition may be used to identify the absence of the foreign object 44. When the foreign object proximity data 43 comprises radar data, lidar data, or ultrasound data, a dropped signal, or lack of signal may be used to identify the absence of the foreign object 44. The foreign object proximity data 43 may comprise signal characteristics which are indicative a weak detection, which may be indicative of an absence of the foreign object 44. The system 9 and work vehicle 10 comprises a control system 50 and a controller 51, described in more detail below. The system 9 comprise a control system 50, which may be configured to perform the methods of the present disclosure. As illustrated in Figure 2, the control system 50 may comprise the controller 51, which may comprise a memory 53, which may store instructions or algorithms in the form of data, and a processing unit 55, which may be configured to perform operations based upon the instructions. The controller 51 may be of any suitable known type, may be located close to the foreign object proximity sensor 42, may comprise a central computer architecture and / or may comprise an engine control unit (ECU) or the like. The memory 53 may comprise any suitable computer-accessible or non-transitory storage medium for storing computer program instructions, such as RAM, SDRAM, DDR SDRAM, RDRAM, SRAM, ROM, magnetic media, optical media and the like. The processing unit 55 may comprise any suitable processor capable of executing memory-stored instructions, such as a microprocessor, uniprocessor, a multiprocessor and the like. The controller 51 may further comprise a graphics processing unit for rendering objects for viewing on a display 57 of the control system 50. The display 57 may be located in the cab 40 and / or external to the work vehicle 10 for remote viewing, and / or may be a graphic user interface. The controller 51 may also comprise and / or be in communication with least one work vehicle communication module 59 for transferring data with an external computing system 61 via a wired or wireless network 63 (such as Ethernet, fibre optic, satellite communication network, broadband communication network, cellular, Bluetooth). The external computing system 61 may comprise computing systems, processors, servers, memories, databases, control systems and the like. The methods of this disclosure may be performed by the external computing system 61 instead of and / or as well as the controller 51. The controller 51 may also comprise the foreign object proximity data 43, which may be stored on the memory 53. The controller 51 may access and use the foreign object proximity data 43 according to the methods of this disclosure. The controller 51 may access the foreign object proximity data 43 from the at least one foreign object proximity sensor 42. The controller 51 may access further sensor data from further sensors in addition to the foreign object proximity data 43 from the at least one foreign object proximity sensor 42. The controller 51 may be in communication with at least one system actuator 65 and / or at least one system brake 67. The at least one system actuator 65 may be arranged to actuate the movable members 16, 18 of the work vehicle 10 and may include the motion power unit 20 and / or the swing actuator 33. The at least one system brake 67 may may be arranged to slow, stop or prevent movement of the movable members 16, 18 of the work vehicle 10 and may comprise the motion brake 22 and / or the swing brake 34. The controller 51 comprises (such as by being stored on the memory 53) and / or is configured to operate in accordance with a collision avoidance protocol 69. The collision avoidance protocol 69 adapts operation of the work vehicle 10 to account for a foreign object 44. The collision avoidance protocol 69 may prevent a collision of the work vehicle 10 with the foreign object 44, and / or may aid the operator in avoiding a collision of the work vehicle 10 with the foreign object 44. The collision avoidance protocol 69 may be activated based on the foreign object proximity data 43 from the at least one foreign object proximity sensor 42. The collision avoidance protocol 69 may comprise an automatic braking of at least one movable member 16, 18 of the work vehicle 10. The collision avoidance protocol 69 may comprise automatic activation of the at least one system brake 67, motion brake 22 and / or swing brake 34. The collision avoidance protocol 69 may comprise activation of the at least one system brake 67 without any user input. The collision avoidance protocol 69 may comprise automatic deactivation of the at least one system actuator 65, the motion power unit 20, and / or the swing actuator 33. The collision avoidance protocol 69 may comprise an audio and / or visual alert. The visual alert may be displayed on display 57. The audio and / or visual alert may be present in the cab 40 and may alert the user to the presence of a foreign object 44 in proximity to the work vehicle 10. The work vehicle 10 further comprises a user input 71. The user input 71 may be in communication with the controller 51 for control of the work vehicle 10. The user input 71 may comprise a button on a console and / or a joystick of the work vehicle 10. The user input 71 may comprise selection of a pop-up on the display 57 of the work vehicle 10 and / or a graphic user interface. The user input 71 may, when activated, stop, end, and / or deactivate the collision avoidance protocol 69. If the collision avoidance protocol 69 comprises an automatic braking, the user input 71 may deactivate the automatic braking and allow the at least one movable member 16, 18 to move again and / or return control of the at least one movable member 16, 18 to the operator. If the collision avoidance protocol 69 comprises an audio and / or visual alert, the user input 71 may deactivate and / or end the alert. The control system 50 may comprise further inputs, which may include further buttons, a wheel, at least one joystick, at least one pedal or other controls. The user input 71 may require that a further input such as a wheel, joystick, and / or pedal is returned to a neutral position before the user input 71 can be activated. The control system 50 may comprise a sensor coverage map 73, which may be associated with the work vehicle 10 and based on the at least one foreign object proximity sensor 42. The sensor coverage map 73 may be stored on the controller 51, such as by being loaded onto the memory 53, and / or may be accessed and / or accessible by the controller 51. The sensor coverage map 73 may define and / or represent the level of sensor coverage of the at least one foreign object proximity sensor 42 and variations thereof around the work vehicle 10. The sensor coverage map 73 may be used with the methods of the present disclosure for controlling the collision avoidance protocol 69. Figure 3 illustrates an example of the sensor coverage map 73. The example illustrates a 2D ‘bird’s eye view’ of the sensor coverage map 73. The sensor coverage map 73 may be a 3D map, and / or the areas of the sensor coverage map 73 may be 3D areas and / or volumes. Each foreign object proximity sensor 42 may have an associated area of coverage 75 with respect to the work vehicle 10 and / or the sensor coverage map 73. Each area of coverage 75 may be bordered by a sensor coverage boundary 77. The sensor coverage boundary 77 may represent the border which separates the area of coverage 75 from an area in which the foreign object proximity sensor 42 does not provide sensor coverage. The foreign object proximity sensor 42 may only detect the foreign object 44 if it is within the area of coverage 75. The sensor coverage boundaries 77 of the proximity sensors 42 may at least partially overlap as illustrated. Each area of coverage 75 may comprise an area of strong sensor coverage 79 and an area of weak sensor coverage 81. The foreign object proximity sensor 42 may detect the foreign object 44 if it is within the area of strong sensor coverage 79 with more reliability than if the foreign object 44 is in the area of weak sensor coverage 81. Due to the weaker sensor coverage, the foreign object proximity sensor 42 may sometimes not detect the foreign object 44 if it is within the area of weak sensor coverage 81. The area of weak sensor coverage 81 may be the area near the sensor coverage boundary 77. The area of strong sensor coverage 79 may be demarcated from the area of weak sensor coverage 81 by a strong sensor coverage boundary 83. The area of strong sensor coverage 79 and the area of weak sensor coverage 81 may not be distinct areas as shown in Figure 3, and / or there may be a gradual change from the area of strong sensor coverage 79 to the area of weak sensor coverage 81. For the purposes of the sensor coverage map 73, the area of strong sensor coverage 79 and the area of weak sensor coverage 81 may be considered as distinct areas. The sensor coverage map 73 may further comprise visibility lines 85. The visibility lines 85 may define the extent of the operator’s field of view from the cab 40. The visibility lines 85 may define an area of visibility 87 which is in view of an operator in the cab 40. In remote control or autonomous applications, an operator may not be present, and the system 9 may comprise further foreign object proximity sensors 42, which may comprise an area of coverage 75 covering the area of visibility 87. Figure 4 illustrates a further example of the sensor coverage map 73, based on the area of coverage 75, the sensor coverage boundary 77, the area of strong sensor coverage 79, the area of weak sensor coverage 81, and the strong sensor coverage boundary 83 of each of the at least one foreign object proximity sensor 42 and the visibility lines 85, and the area of visibility 87 shown in Figure 3. Figure 4 shows the area(s) of strong sensor coverage 79, weak sensor coverage 81, and visibility 87 which may be due to the collective coverage of all of the foreign object proximity sensors 42 on the work vehicle 10, and the operator. The area within the area of visibility 87 of the cab 40 may be defined as the area of visibility 87 of the sensor coverage map 73 even if it overlaps a sensor coverage area 75. The area of strong sensor coverage 79 of the sensor coverage map 73 may include the area of strong sensor coverage 79 of any foreign object proximity sensor 42, even if it overlaps an area of weak sensor coverage 81 of another foreign object proximity sensor 42. The area of weak sensor coverage 81 may include the area of weak sensor coverage 81 of any foreign object proximity sensor 42 which does not overlap an area of strong sensor coverage 79 or area of visibility 87. The sensor coverage map 73 may comprise one or more areas of no sensor coverage 89. The area of no sensor coverage 89 maybe referred to as a blind spot 89 and may be one or more areas which are not included in the sensor coverage area 75 of any foreign object proximity sensor 42, nor the area of visibility 87 of the cab 40. The foreign object 44 may not be detected if it is within the area of no sensor coverage 89. Figure 5 illustrates a further example of the sensor coverage map 73, which may function independently and / or together with the sensor coverage map 73 of Figure 4. Figure 5 shows the sensor coverage map 73 may comprise a critical region 91 proximal to the work vehicle 10, and a non-critical region 93 distal from the work vehicle 10. The critical region 91 may be demarked from the non-critical region 93 by a critical-region boundary 95. The critical region 91 may represent the area around the work vehicle 10 in which there is an increased risk of a collision between the work vehicle 10 and the foreign object 44 if the foreign object 44 is present therein. The non-critical region 93 may represent the area around the work vehicle 10 in which there is a reduced risk of a collision between the work vehicle 10 and the foreign object 44 if the foreign object 44 is present therein. A size of the critical region 91 may be calculated based on a size of the work vehicle 10 and / or a size of the upper rotating structure 30. The size may be a percentage, and may be 150%, 175%, or 200%, of the size of the work vehicle 10 and / or the size of the upper rotating structure 30. The size of the critical region 91 may be fixed based on the work vehicle 10, and / or may be user adjustable based on a user requirement and. / or a configurable safety buffer. The size of the critical region 91 may vary during operation of the work vehicle 10 and may be based on a speed / direction of movement and / or stopping capability of the work vehicle 10. A method 100 of operating the collision avoidance protocol 69 of the work vehicle 10 is now described with reference to Figure 6. The method 100 comprises, by the control system 50, receiving 101 foreign object proximity data 43 indicative of a detection of the foreign object 44 in proximity to the work vehicle 10. The step of receiving 101 may be a step of detecting the foreign object 44. As described above, the foreign object proximity data 43 is received from the at least one foreign object proximity sensor 42 of the work vehicle 10. The foreign object 44 may be detected in the critical region 91, the non-critical region 93, the area of strong sensor coverage 79, and / or the area of weak sensor coverage 81. The method may comprise activating the collision avoidance protocol 69 in response to the detection of the foreign object 44 in proximity to the work vehicle 10. The collision avoidance protocol 69 may be activated if the foreign object 44 is detected in the critical region 91. The method 100 then comprises detecting a change 103 in the foreign object proximity data 43 indicative of an absence of the foreign object 44. The change in the foreign object proximity data 43 indicative of an absence of the foreign object 44 may be the radar or lidar outputting a signal showing that no foreign object 44 is present and / or image data from the camera indicating showing that no foreign object 44 is present. The change 103 in the foreign object proximity data 43 indicative of an absence of the foreign object 44 may be the stopping and / or dropping of the signal of the foreign object 44. The method 100 then comprises categorising 105 the original detection of the foreign object 44, before its absence, as a critical foreign object detection 107 or a non-critical foreign object detection 109. The method 100 may comprise categorising 105 the detection of the foreign object 44 as one of the following two options: 1) a critical foreign object detection 107; or 2) a non-critical foreign object detection 109. The categorising 105 takes place upon the detected change, and / or takes place after the step of detecting a change 103. The categorising 105 may be that the detection of the foreign object 44 was a critical foreign object detection 107 or was a non-critical foreign object detection 109. The categorising 105 is based upon the foreign object proximity data 43. The critical foreign object detection 107 may be a detection with an increased risk of a collision and / or a reduced probability that the detection was a false positive. The non-critical foreign object detection 109 may be a detection with a reduced risk of a collision and / or an increased probability that the detection was a false positive. Examples which may be categorised as the critical foreign object detection 107 or the non-critical foreign object detection 109 are described in more detail below. If the detection of the foreign object 44 is categorised 105 as the critical foreign object detection 107, the method 100 then comprises activating or maintaining 111 the collision avoidance protocol 69. If the collision avoidance protocol 69 is already activated, the method may comprise maintaining 111 the collision avoidance protocol 69. If the collision avoidance protocol 69 is not yet activated, the method may comprise activating 111 the collision avoidance protocol 69. The collision avoidance protocol 69 is activated or maintained 111 until the user input 71 is received 112. The collision avoidance protocol 69 may be deactivated once the user input 71 is received. The user input 71 may comprises activation of the button on the console of the work vehicle 10; activation of the button on the joystick of the work vehicle 10; and / or selection of a pop-up on the display 57 of the work vehicle 10. If the detection of the foreign object 44 is categorised 105 as the non-critical foreign object detection 109, the method 100 then comprises not activating or automatically stopping 113 the collision avoidance protocol 69. If the collision avoidance protocol 69 is already activated, the method may comprise automatically stopping 113 the collision avoidance protocol 69. If the collision avoidance protocol 69 is not yet activated, the method may comprise not activating 113 the collision avoidance protocol 69. The step of categorising 105 the detection of the foreign object 44 as a critical foreign object detection 107 or a non-critical foreign object detection 109 is now discussed in more detail with reference to Figures 7 and 8. Figure 7 illustrates steps 121, 123, 125, 127, 129 which may be used to categorise 105 the detection of the foreign object 44 as a critical foreign object detection 107 or a non-critical foreign object detection 109. The steps 121, 123, 125, 127, 129 may be used in any combination, as parallel steps or in series and ordered in anyway. There may be further steps used to categorise 105 the detection of the foreign object 44. The steps 121, 123, 125, 127, 129 may be examples of how the foreign object 44 is categorised 105 as a critical foreign object detection 107 or a non-critical foreign object detection 109. As described in step 121, the control system 50 may categorise 105 a detection of the foreign object 44 in the area of weak sensor coverage 81 and / or a detection of the foreign object 44 in proximity to the area of weak sensor coverage 81, and / or no sensor coverage 89 as the critical foreign object detection 107. Proximity to the area of weak sensor coverage 81, and / or no sensor coverage 89 may include the data indicating that the foreign object 44 was within 0.2 m, 0.5 m, 1.0 m, or 1.5 m of the area of weak sensor coverage 81, and / or no sensor coverage 89. When the detection of the foreign object 44 is in the area of weak sensor coverage 81 and / or the detection of the foreign object 44 is in proximity to the area of weak sensor coverage 81, and / or no sensor coverage 89, the reason for the detection of a change 103 in the foreign object proximity data 43 indicative of an absence of the foreign object 44 may be due to the foreign object 44 moving into the area of weak sensor coverage 81, and / or no sensor coverage 89. Therefore, the control system 50 may categorise the detection as the critical foreign object detection 107. The collision avoidance protocol 69 may be activated or maintained 111 until the user input 71 is received 112. This may ensure that the operator checks if the foreign object 44 is still in proximity to the work vehicle 10 before deactivating the collision avoidance protocol 69. This may reduce the risk of a collision between the work vehicle 10 and the foreign object 44. As described in step 123, the control system 50 may categorise 105 the detection of the foreign object 44 in proximity to the area of weak sensor coverage 81, and / or no sensor coverage 89 as the critical foreign object detection 107 upon initial activation of the control system 51, and / or upon initiating movement of one or more movable members 16, 18 of the work vehicle 10. Upon initial activation of the control system 51 may comprise within 30 s, 45 s, 60 s, or 100 s of initial activation and / or power being applied to the control system 51. Upon initiating movement of one or more movable members 16, 18 may comprise within 30 s, 45 s, 60 s, or 100 s of initiating movement. Initial movement of one or more movable members 16, 18 may comprise deactivating a parking brake of the work vehicle 10. When the detection of the foreign object 44 is in proximity to the area of weak sensor coverage 81, and / or no sensor coverage 89 is upon initial activation of the control system 51, and / or is upon initiating movement of one or more movable members 16, 18 of the work vehicle 10, the reason for the foreign object proximity data 43 indicative of a detection of the foreign object 44 in proximity to the work vehicle 10 followed by the detection of a change 103 in the foreign object proximity data 43 indicative of an absence of the foreign object 44 may be due to the foreign object 44 being in said location prior to the initial activation and / or movement. At other times, not upon initial activation and / or movement, the detection of a foreign object 44 which starts in proximity to the area of weak sensor coverage 81, and / or no sensor coverage 89 which is then lost may be indicative of the detection of a foreign object 44 being a non-critical detection 109, or a false positive. The detection of the foreign object 44 which is then lost may be indicative of the detection of a foreign object 44 being a non-critical detection 109, and / or a false positive if the detection of the foreign object 44 only occurred for a short time, such as 1 s, 5 s, 20 s, 60 s, 120 s, 300 s before the change 103 indicative of an absence of the foreign object 44, or only was present in the area of weak sensor coverage 81. This may be in distinction from a detection of a foreign object 44 which travels through other areas of the sensor map 73 to reach the area of weak sensor coverage 81. Upon initial activation and / or movement, there may not be data from the short time, such as 1 s, 5 s, 20 s, 60 s, 120 s, 300 s before the change 103. There may be no data showing if the foreign object 44 travelled through other areas of the sensor map 73 to reach the area of weak sensor coverage 81, or only was present in the area of weak sensor coverage 81. There may be a higher risk of the detected foreign object 44 being in proximity to the work vehicle 10 upon initial activation and / or movement. Therefore, the control system 50 may categorise this detection as the critical foreign object detection 107. The collision avoidance protocol 69 may be activated or maintained 111 until the user input 71 is received 112. This may ensure that the operator checks if the foreign object 44 is still in proximity to the work vehicle 10 before deactivating the collision avoidance protocol 69. This may reduce the risk of a collision between the work vehicle 10 and the foreign object 44. As described in step 125, the control system 50 may categorise 105 the detection of the foreign object 44 for a time longer than a given time period as the critical foreign object detection 107. The given time period may be 1 s, 5 s, 20 s, 60 s, 120 s, 300 s. The control system 50 may categorise 105 the detection of the foreign object 44 for a time shorter than the given time period as the non-critical foreign object detection 105. The detection of the foreign object 44 being maintained for the time longer than the given time period may be indicative that there is a higher risk of a foreign object 44 being in proximity to the work vehicle 10 rather than a false positive. Therefore, the control system 50 may categorise this detection as the critical foreign object detection 107. The collision avoidance protocol 69 may be activated or maintained 111 until the user input 71 is received 112. This may ensure that the operator checks if the foreign object 44 is still in proximity to the work vehicle 10 before deactivating the collision avoidance protocol 69 and may reduce the risk of a collision between the work vehicle 10 and the foreign object 44. The detection of the foreign object 44 being maintained for the time shorter than the given time period may be indicative that there is a lower risk of a foreign object 44 being in proximity to the work vehicle 10 and / or or a greater probability that the detection was a false positive. Therefore, the control system 50 may categorise this detection as the non-critical foreign object detection 109. The collision avoidance protocol 69 may be not activated or automatically stopped 113. This may reduce the burden on the operator and may ensure that the operator pays more attention when a critical foreign object detection 107 is categorised 105. As described in step 127, the control system 50 may categorise 105 the detection of the foreign object 44 more than a predetermined number of times within a predetermined period as the critical foreign object detection 107. The predetermined period may be 1 s, 5 s, 20 s, 60 s, 120 s, 300 s and / or the predetermined number of times may be 3, 5, or 10 times. The control system 50 may categorise 105 the detection of the foreign object 44 less than a predetermined number of times within a predetermined period as the non-critical foreign object detection 105. The distinct detections of the foreign object 44 may comprise the data indicating that the foreign object 44 is present and subsequently absent one or more times. The detection of the foreign object 44 more than the predetermined number of times within the predetermined period may be indicative that there is a higher risk of a foreign object 44 being in proximity to the work vehicle 10 rather than a false positive. Therefore, the control system 50 may categorise this detection as the critical foreign object detection 107. The collision avoidance protocol 69 may be activated or maintained 111 until the user input 71 is received 112. This may ensure that the operator checks if the foreign object 44 is still in proximity to the work vehicle 10 before deactivating the collision avoidance protocol 69. This may reduce the risk of a collision between the work vehicle 10 and the foreign object 44. The detection of the foreign object 44 less than the predetermined number of times within the predetermined period may be indicative that there is a lower risk of a foreign object 44 being in proximity to the work vehicle 10 and / or or a greater probability that the detection was a false positive. Therefore, the control system 50 may categorise this detection as the non-critical foreign object detection 109. The collision avoidance protocol 69 may be not activated or automatically stopped 113. This may reduce the burden on the operator. This may ensure that the operator pays more attention when a critical foreign object detection 107 is categorised 105. The foreign object proximity data 43 may be processed in cycles which may be 40 to 80 ms long and the data 43 may be grouped in sets of two to three cycles for the purpose of categorising 105 the detection of the foreign object 44. As described in step 129 and illustrated in Figures 8a to 8d, the control system 50 may categorise 105 the detection of the foreign object 44 with foreign object proximity data 43 indicating that the foreign object 44 is projected to be in the critical region 91 as the critical foreign object detection 107. The control system 50 may categorise 105 the detection of the foreign object 44 with foreign object proximity data 43 indicating that the foreign object 44 is projected to be in the non-critical region 93 as the non-critical foreign object detection 109. The foreign object proximity data 43 generated by the foreign object proximity sensor 42 may include the trajectory of the foreign object 44, and / or the foreign object proximity data 43 may indicate the trajectory of the foreign object 44, which may be derived from the time ordered positions and / or locations of the foreign object 44 in the foreign object proximity data 43, and may be further based upon vehicle movement data generated by from other sensors. The trajectory of the foreign object 44 may be the positions and / or locations of the foreign object 44 relative to the work vehicle 10 and may be affected by movement of the foreign object 44 towards the work vehicle 10 and / or movement of the work vehicle 10 towards the foreign object 44. The foreign object proximity data 43 may indicate that the foreign object 44 is projected to be in the critical region 91 by extending the trajectory of the foreign object 44. Therefore, even though the change 103 indicative of an absence of the foreign object 44 is detected, the previously detected foreign object 44 may be present in the critical region 91. The presence of the foreign object 44 in the critical region 91 may result in a higher risk of a collision. Therefore, the control system 50 may categorise this detection as the critical foreign object detection 107. The collision avoidance protocol 69 may be activated or maintained 111 until the user input 71 is received 112. This may ensure that the operator checks if the foreign object 44 is still in proximity to the work vehicle 10 before deactivating the collision avoidance protocol 69 and may reduce the risk of a collision between the work vehicle 10 and the foreign object 44. An indication from the foreign object proximity data 43 may that the foreign object 44 is projected to be in the critical region 91 within a certain time period, such as 2 s, 5 s, 10 s, or 20 s, may be categorised 105 as the critical foreign object detection 107. An indication from the foreign object proximity data 43 that a collision between the work vehicle 10 and the foreign object 44 may occur within a certain time period may be categorised 105 as the critical foreign object detection 107. The foreign object proximity data 43 may indicate that the foreign object 44 is projected to be in the non-critical region 93 by extending the trajectory of the foreign object 44. The presence of the foreign object 44 in the non-critical region 93 may result in a lower risk of a collision. Therefore, the control system 50 may categorise this detection as the non-critical foreign object detection 109. The collision avoidance protocol 69 may be not activated or automatically stopped 113. This may reduce the burden on the operator and may ensure that the operator pays more attention when a critical foreign object detection 107 is categorised 105. An indication from the foreign object proximity data 43 that the foreign object 44 is projected to be in the non-critical region 93 within a certain time period, such as 2 s, 5 s, 10 s, or 20 s, may be categorised 105 as the non-critical foreign object detection 109. An indication from the foreign object proximity data 43 that a collision between the work vehicle 10 and the foreign object 44 may not occur within a certain time period may be categorised 105 as the non-critical foreign object detection 109. Figures 8a to 8d illustrate step 129 of Figure 7 in more detail. As shown, foreign object 44 may be first detected in the critical region 91 (Figure 8c, 8d) or the non-critical region 93 (Figure 8a, 8b). The foreign object 44 may have a trajectory as represented by arrows 130. The projected location of the foreign object 44 at the time of the change 103 in the foreign object proximity data 43 indicative of an absence of the foreign object 44 is represented by a cross 131. The projected location of the foreign object 44 upon change 103 may be in the critical region 91 (Figure 8a, 8c) or the non-critical region 93 (Figure 8b, 8d). Since in Figures 8a and 8c, the projected location of the change 103 is in the critical region 91, this may be categorised as the critical foreign object detection 107. Since in Figures 8b and 8d, the projected location of the change 103 is in the non-critical region 93, this may be categorised as the non-critical foreign object detection 109. In Figures 8a and 8c, the foreign object 44 may be projected to be in the critical region 91. In Figure 8a, the foreign object 44 may be projected to enter the critical region 91, and in Figure 8c, the foreign object 44 may be projected to remain in the critical region 91. In both cases, the foreign object 44 may be projected to be in the critical region 91, and so the collision avoidance protocol 69 may be activated or maintained 111 until the user input 71 is received 112. In Figures 8b and 8d, the foreign object 44 may be projected to be in the non-critical region 93. In Figure 8d, the foreign object 44 may be projected to enter the non-critical region 93, and in Figure 8b, the foreign object 44 may be projected to remain in the non-critical region 93. In both cases, the foreign object 44 may be projected to be in the non-critical region 93, and so the collision avoidance protocol 69 may be not activated or automatically stopped 113. Industrial Applicability The method 100 may thus determine if data and / or the signal detecting a foreign object 44 which is subsequently lost is the critical foreign object detection 107 or non-critical foreign object detection 109. The critical foreign object detection 107 may be indicative of a detection with an increased risk of a collision, or a reduced probability that the detection was a false positive. The non-critical foreign object detection 109 may be indicative of a detection with a reduced risk of a collision, or an increased probability that the detection was a false positive. Therefore, the method 100 may allow a distinction on how these two categories of detections which are subsequently lost are treated. If there is a critical foreign object detection 107, the collision avoidance protocol 69 is activated or maintained 111 until the user input 71 is received 112. This may ensure that the operator checks if the foreign object 44 is still in proximity to the work vehicle 10 before deactivating the collision avoidance protocol 69, reducing the risk of a collision between the work vehicle 10 and the foreign object 44. If it is the non-critical foreign object detection 109, the collision avoidance protocol 69 may be not activated or automatically stopped 113. This may reduce the burden on the operator and may ensure that the operator pays more attention when a critical foreign object detection 107 is categorised 105. If the collision avoidance protocol 69 is the automatic braking of the at least one movable member 16, 18, then the collision avoidance protocol may prevent a collision between the work vehicle 10 and the foreign object 44 when the critical foreign object detection 107 is detected. If the collision avoidance protocol 69 is the alert, then the collision avoidance protocol may ensure the operator checks for the presence of the forging object 44 and / or stops movement of the work vehicle 10 when the critical foreign object detection 107 is detected. If the control system 50 comprises the sensor coverage map 73, the method 100 may be able to better categorise 105 the detection of the foreign object 44 as the critical foreign object detection 107 or non-critical foreign object detection 109 based on its location in the sensor coverage map 73. If the sensor coverage map 73 comprises the at least two areas of strong sensor coverage 79, weak sensor coverage 81, and no sensor coverage 89, the method 100 may be able to categorise 105 the detection of the foreign object 44 as the critical foreign object detection 107 or non-critical foreign object detection 109 based on its proximity to locations of weak sensor coverage, or no sensor coverage. Locations where the signal being lost may be likely due to the foreign object 44 moving into a blind spot 89, rather than being a false 5 positive may be categorised as the critical foreign object detection 107. This may reduce the risk of collisions and may reduce the burden on the operator when false positives are detected. If the sensor coverage map 73 comprises the critical region 91 and the non-critical region 10 93, the method 100 may be able to categorise 105 the detection of the foreign object 44 as the critical foreign object detection 107 or non-critical foreign object detection 109 based on the projected position of the foreign object 44 relative to the work vehicle 10. When the foreign object 44 is projected to enter the critical region 91, this may be indicative of a higher risk of collision, and this may be categorised as the critical foreign object detection 15 107. This may reduce the risk of collisions and may reduce the burden on the operator when a detection with a reduced risk of collision is detected.

Claims

1. A method of operating a collision avoidance protocol of a work vehicle, wherein the collision avoidance protocol adapts operation of the work vehicle to account for a foreign object, the method comprising, by a control system:receiving foreign object proximity data from at least one foreign object proximity sensor of the work vehicle, the foreign object proximity data indicative of a detection of a foreign object in proximity to the work vehicle;detecting a change in the foreign object proximity data indicative of an absence of the foreign object; andcategorising, upon the detected change and based upon the foreign object proximity data, the detection of the foreign object as a critical foreign object detection or a non-critical foreign object detection, wherein the method further comprises:if the detection of the foreign object is categorised as the critical foreign object detection, activating or maintaining the collision avoidance protocol until a user input is received; orif the detection of the foreign object is categorised as the non-critical foreign object detection, not activating or automatically stopping the collision avoidance protocol.

2. The method of claim 1, wherein the collision avoidance protocol comprises an automatic braking of at least one movable member of the work vehicle.

3. The method of claim 2, wherein the at least one movable member comprises: one or more continuous tracks for movement of the work vehicle;one or more wheels for movement of the work vehicle; and / or a rotating structure of the work vehicle.

4. The method of any preceding claim, wherein the collision avoidance protocol comprises an audio and / or visual alert.

5. The method of any preceding claim, wherein the at least one foreign object proximity sensor comprises: radar; lidar; an ultrasonic sensor; a camera and / or a stereo camera.

6. The method of any preceding claim, wherein the user input comprises: activation of a button on a console of the work vehicle; activation of a button on a joystick of the work vehicle; and / or selection of a pop-up on a graphic user interface of the work vehicle.

7. The method of any preceding claim, wherein the control system comprises a sensor coverage map associated with the work vehicle and based on the at least one foreign object proximity sensor.

8. The method of claim 7, wherein the sensor coverage map comprises at least two areas of:strong sensor coverage;weak sensor coverage; and / or no sensor coverage.

9. The method of claim 8, wherein the control system categorises a detection of the foreign object in proximity to the area of weak sensor coverage, and / or no sensor coverage as the critical foreign object detection.

10. The method of claim 8 or 9, wherein the control system categorises a detection of the foreign object in proximity to the area of weak sensor coverage, and / or no sensor coverage as the critical foreign object detection, when the detection of the foreign object in proximity to the area of weak sensor coverage, and / or no sensor coverage occurs upon initial activation of the control system, and / or upon initiating movement of one or more movable members of the work vehicle.

11. The method of any of claims 7 to 10, wherein the sensor coverage map comprises a critical region proximal to the work vehicle, and a non-critical region distal from the work vehicle.

12. The method of claim 11, wherein the control system categorises a detection of the foreign object with foreign object proximity data indicating that the foreign object is projected to be in the critical region as the critical foreign object detection.

13. The method of claim 11 or 12, wherein the control system categorises a detection of the foreign object with foreign object proximity data indicating that the foreign object is projected to be in the non-critical region as the non-critical foreign object detection.

14. A controller for controlling a collision avoidance protocol of a work vehicle, wherein the collision avoidance protocol adapts operation of the work vehicle to account for a foreign object, the controller being configured to:receive foreign object proximity data from at least one foreign object proximity sensor of the work vehicle, the foreign object proximity data indicative of a detection of a foreign object in proximity to the work vehicle;detect a change in the foreign object proximity data indicative of an absence of the foreign object; andcategorise, upon the detected change and based upon the foreign object proximity data, the detection of the foreign object as a critical foreign object detection or a non-critical foreign object detection, wherein the controller is further configured to:if the detection of the foreign object is categorised as the critical foreign object detection, activate or maintain the collision avoidance protocol until a user input is received;orif the detection of the foreign object is categorised as the non-critical foreign object detection, automatically stop or not activate the collision avoidance protocol.

15. A work vehicle comprising:at least one foreign object proximity sensor configured to generate foreign object proximity data indicative of a detection of a foreign object in proximity to the work vehicle; anda control system comprising the controller of claim 14.

Images