GB2640170A

GB2640170A - System and method for operating work machines around over-head power lines on worksites

Info

Publication number: GB2640170A
Application number: GB2404783.9A
Authority: GB
Inventors: Venkatraman Gowtham; Lee Steinlage Justin; Zuo Jun; Genseal Andrew
Original assignee: Caterpillar Inc
Current assignee: Caterpillar Inc
Priority date: 2024-04-04
Filing date: 2024-04-04
Publication date: 2025-10-15
Also published as: WO2025212728A1

Abstract

A system 10 for operating a number of work machines 11 around over-head power lines 60 on a worksite 35 has a number of scouts 45, each with an electric field detector 46, which move along a route over the worksite whilst the detector generates electric field data indicating electric field values around the worksite. A control system 50 receives the electric field data and identifies any over-head power lines on the worksite based on the data. The control system may identify power lines by identifying peak electric field values and/or by determining whether values are greater than a first threshold value. The control system may operate the navigation system 57 to generate location data indicating the scout’s location, processing it to identify the power lines location. The control system may generate a map indicating exclusion zones around power lines for work machines to avoid. Each work machine may have a machine controller 40 which derates performance and/or limits movement if the machine, or its arm 14 or tool 15, approaches and/or enters an exclusion zone. The scout may be an unmanned or autonomous aerial or land vehicle, or a manned land vehicle or a work machine.

Description

SYSTEM AND METHOD FOR OPERATING WORK MACHINES AROUND OVERHEAD POWER LINES ON WORKSITES

TECHNICAL FIELD

This disclosure is directed towards a system for and method of operating a work machine around a power line in a safe manner.

BACKGROUND

Excavators and other work machines often have to operate near over-head power lines or cables. There is therefore the risk of a work machine either contacting a power line causing high voltages across the work machine or approaching close to the line creating an electric arc, endangering human operators and damaging equipment (see for example EU safety regulation (EU) 2023/1230 Section 3.5.4). Various safety regulations exist to reduce such risk. Known safety methods and systems can sense the power lines and generate warnings for operators and/or control movement of the work machine if the power lines are deemed to be too close.

US2017336806A1 discloses an unmanned aerial vehicle (UAV) electromagnetic avoidance and utilization system. A flight package indicating a flight pattern associated with inspecting a structure is obtained. The flight pattern causes the UAV to remain at a standoff distance from the structure based on an electromagnetic field associated with the structure. The flight pattern is laterally constrained according to a property geofence associated with a right of way of the structure. The UAV is navigated according to the flight pattern, and the UAV captures images of the structure. The UAV determines a location at which to capture images of the structure, and the UAV provides the captured images to a user device.

SUMMARY

An object of the present disclosure is to provide improvements to the operation of work machines close to power lines. A further object is to provide a system in which a work machine can still safely operate on worksites having over-head power lines on or running across the worksite.

The present disclosure therefore provides, in accordance with the claims, a system and method for operating at least one work machine around at least one over-head power line on a worksite and a non-transitory computer-readable storage medium including program code which when executed by at least one processor causes operations comprising the method.

A mapping system is therefore provided in which the location of over-head power lines is determined and the worksite map updated to include the location of the power lines, which work machines can then use to operate safely away from the power lines. The scout(s) can be utilized to frequently update a map of the worksite to include the exclusion zone and/or electric field values and/or directions at different locations. The exclusion zone may be determined based upon a safety distance to the power lines and effectively identifies a zone of high risk in which a work machine could strike an over-head power line. The power line map data is updated such that all work machines in a fleet can avoid areas on the map in which implements, or body of the machines may reach the exclusion zones. Further, the at least one scout includes a land or an air-based device with one or more electric field sensors to define an exclusion zone that prevents the work machines from moving too close to a powerline.

The system comprises at least one scout and a control system. The at least one scout comprises at least one electric field detection sensor. The control system is in communication with the at least one electric field detection sensor. The control system is configured to perform a plurality of steps as set out below. The method comprises the steps as set out below.

The at least one scout is configured to move along a route over the worksite whilst the at least one electric field detection sensor generates electric field data indicative of electric field values around the worksite. The at least one scout may automatically move along the route, such as by being operated by the control system to do so, and/or may move along the route by an operator controlling such movement manually. The route may be predetermined or may be determined during the movement, such as by an operator driving around the worksite whilst attempting to cover as much of the worksite as possible. The electric field data is received from the at least one electric field detection sensor and, based upon the electric field data, at least one over-head power line is identified on the worksite.

The generated electric field data may be logged in a memory whilst the at least one scout moves along the route. The at least one over-head power line may be identified based upon the electric field data by either finding peaks in the electric field values and/or the direction of the electric field. Therefore, rather than relying upon magnitudes of the field values, the overall pattern of electric fields across the worksite can be used to generate the power line map data.

The control system may be configured to generate power line map data indicative of an exclusion zone around the identified at least one over-head power line, the exclusion zone being indicative of an area for at least one work machine to avoid whilst operating on the worksite. The exclusion zone is indicative of an area for at least one work machine to avoid whilst operating on the worksite.

The location of the exclusion zone may be determined as a predetermined distance from the at least one over-head power line and/or based upon an electric field value in the electric field data having a smaller magnitude than an exclusion zone threshold value. In particular, local regulations may set the predetermined distances. The exclusion zone threshold value may be indicative of such predetermined distances.

The system may further comprise at least one work machine comprising a machine controller. The work machine may comprise an alert system in communication with the machine controller and the machine controller may be configured to operate the alert system to issue an alert if the work machine approaches and/or enters the exclusion zone. Thus, operators can be alerted if their work machine is too close to a power line.

The exclusion zone may also be determined based upon the types of work machines operating on the worksite. The work machine may comprise a tool mounted to an arm arrangement mounted to a main body. The location of the exclusion zone may be determined based upon a predetermined maximum extension distance of the tool and arm arrangement. Therefore, the exclusion zone may be further away from the power line for particularly large machines or machines with long reaches, such as excavators.

The exclusion zone may also be determined based upon the configuration of the power line such that it accounts for power line sag and the like. Therefore, receive power line configuration data indicative of the configuration of the identified at least one over-head power line may be received and the power line map data may be generated to indicate the exclusion zone based upon such power line configuration data. Hence, once the location of a power line has been mapped by the at least one scout, an operator can input such power line configuration data to further refine the exclusion zone.

The control system as described herein may be embodied as a separate control system, such as located on a worksite computing system on the worksite. Alternatively, the control system may be located on the machine controller of the at least one work machine and/or located offsite, such as on an external computing system, and be in communication with the at least one work machine and at least one scout. Further alternatively, the control system may combine a plurality of such arrangements, for example being embodied in a worksite computing system, machine controller(s) and/or external computing system.

The at least one work machine of the present disclosure may be of any suitable type required to operate near power lines. In some embodiments, the work machine comprises an arm arrangement and/or tool configurable into different orientations and the method and system may be directed to avoiding contact between the arm arrangement and/or tool and power lines. The work machine may therefore comprise an excavator, backhoe, shovel, dragline, a drill and/or material handler or the like. The work machine may alternatively comprise a dozer, shovel, wheeled tractor scraper, motor grader or a hauling machine, such as a dump truck, off-highway truck, mining truck, on-highway truck or lorry/truck or articulated hauler or the like. The tool may be of any suitable type and may, for example, be a grapple, bucket, tiltable bucket, tilt rotator, hammer, handling arm, multi-processor, pulveriser, saw, shears, blower, grinder, tiller, trencher, winch, auger, broom, cutter, planer, delimber, felling head, mulcher, or rake.

BRIEF DESCRIPTION OF THE DRAWINGS

By way of example only, embodiments of the present disclosure are now described with reference to, and as shown in, the accompanying drawings, in which: Figure 1 is an illustration of a system in proximity to an over-head power line on a worksite in accordance with the present disclosure; Figure 2 is a plan view of a worksite indicating a route of a plurality of scouts of the system

of the present disclosure; and

Figure 3 is a flowchart illustrating steps of the method of the present disclosure and which a control system of the present disclosure is configured to perform.

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.

Figures 1 and 2 illustrates embodiments of a system 10 of the present disclosure comprising at least one work machine 11 and at least one scout 45 on a worksite 35 and a control system 50. The at least one scout 45 and at least one work machine 11 may be configured to communicate and/or transfer data with the control system 50 via a communication system 51.

The worksite 35 may comprise an area within which earth or other material is moved and/or manipulated and may be an off-road area. The worksite 35 may be a mine, construction site, an open or closed mine, quarry, waste dump site, aggregate site or the like. The worksite 35 includes at least one over-head power line 60 thereon and/or extending thereacross. The term "at least one over-head power line" herein includes both the power cables 61 and towers 62 and thus the worksite 35 may have a power cable 61 extending thereacross and/or at least one tower 62 thereon.

The at least one scout 45 may comprises at least one of an autonomous and/or unmanned aerial vehicle (as illustrated), an autonomous land vehicle, a manned land vehicle and/or a manned or autonomous work machine. The at least one scout 45: may be separate from or integrated with the at least one work machine 11; may comprise at least one of a manned aircraft, an unmanned aerial vehicle and/or a manned or unmanned dedicated electric field scanning vehicle.

The at least one scout 45, which may also be referred to as a scout or surveying device, comprises at least one electric field sensor 46 for generated electric field data indicative of electric field values. The electric field values may comprise a magnitude and/or direction of an electric field. The electric field data may be processed by the control system 50, such as by extrapolation between points of a point cloud, to create a virtual map of electric field values around the worksite 35. If there are a plurality of electric field sensors 46, they will be positioned such the direction of maximum detection strength is along three perpendicular axes of the at least one scout 45. If there is only one electric field sensor 46, the at least one scout 45 and/or electric field sensor 46 may be able to change its orientation to measure three axis field strength.

The at least one scout 45 may comprise a scout controller in communication with the at least one electric field sensor 46. If the at least one scout 45 is autonomous, the scout controller may control movement and operation of the at least one scout 45.

Figure 1 illustrates an embodiment of the at least one work machine 11, in this case an excavator for excavating material from the ground of the worksite 35, according to the present

disclosure.

The work machine 11 may comprise a main body 12 having a cab 8 for an operator and an arm arrangement 14 and/or tool 15 attached to the main body 12. The work machine 11 may comprise an undercarriage 30 to which the main body 12 is rotatably mounted, such as via a swing system 31. The work machine 11 comprises a power system, comprising for example an internal combustion engine and/or electrical power system with at least one battery providing power to at least one motor, for driving at least one wheel and/or track 13 for driving the work machine 11 over the worksite 35.

The work machine 11 may comprise a tool 15 connected to the arm arrangement 14 via a coupling arrangement 11. The arm arrangement 14 may comprise a boom 16, a stick 17 and a linkage arrangement 20 pivotally attached to one another. The coupling arrangement 11 may be mounted to the stick 17 and linkage arrangement 20. The arm arrangement 14 may comprise hydraulic actuators 18, 19, 21 for controlling the orientation and movement of the boom 16, stick 17 and linkage arrangement 20 and thereby the orientation and movement of the coupling arrangement 11 and tool 15.

The undercarriage 30 may comprise a chassis 32 to which the at least one wheel and/or track 13 may be mounted. The swing system 31 may be mounted to a top of the chassis 32 and the at least one wheel and/or track 13 may be mounted to opposing sides of the chassis 32. The swing system 31 may comprise at least one swing motor for rotating the main body 12 relative to the undercarriage 30.

The work machine 11 may comprise a hydraulic system 5 for operating the arm arrangement 14 and/or at least one tool 15 and around which fluid may be circulated. The hydraulic system may comprise the first, second and third hydraulic actuators 18, 19, 21 for controlling the pivoting of the arm arrangement 14 and the tool 15.

The work machine 11 may comprise a machine controller 40 for controlling the hydraulic system 5 automatically or based upon inputs received from the user interface 6 and/or automatically. The user interface 6 may comprise an input device controllable by an operator in the main body 12, such as a joystick or at least one button, and may comprise at least one display for displaying information to a user, such as a screen or lighting. The machine controller 40 may comprise a machine processor 49 configured to perform operations based upon instructions. The machine processor 49 may be communicatively connected (via a wired or wireless connection) to the power system and hydraulic system 5 for providing control signals thereto and receiving sensor signals therefrom in order to control the operation of the work machine 11. The machine processor 49 may communicate with the user interface 6, for receiving an input and controlling the work machine 11 and for displaying information to the operator.

The control system 50 is configured to perform the methods of the present disclosure. The control system 50, scout controller and machine controller 40 comprise a control processor 52 configured to perform operations based upon instructions.

The control system 50, scout controller and machine controller 40 may each comprise a memory, which may store instructions or algorithms in the form of data. The processors 49, 52 may be of any suitable known type and may comprise an engine control unit (ECU), machine electronic control module or the like. The memory 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 processors 49, 52 may comprise any suitable processor capable of executing memory-stored instructions, such as a microprocessor, uniprocessor, a multiprocessor and the like. The control system 50 and machine processor 49 may further comprise a graphics processing unit for rendering objects for viewing on the display of the user interface 6, and/or a separate display of the control system 50.

The control system 50, scout controller and machine controller 40 may also be in communication with one another and/or an external computing system 53 via the communication system 51, which may comprise at least one wired or wireless network.

Exemplary wireless networks include a satellite communication network, broadband communication network, cellular, Bluetooth, microwave, point-to-point wireless, point-tomultipoint wireless, multipoint-to-multipoint wireless, Wireless Local Service (WiFi Dongle), Dedicated Short-Range Communications (DSRC) or any other wireless communication network. Exemplary wired networks include Ethernet, fibre optic, waveguide or any other suitable wired connection. The external computing system 53 may comprise computing systems, processors, servers, memories, databases, control systems and the like. The external computing system 53 may be offsite (i.e. not on the worksite 35), whilst the control system 50 may be on the worksite 35.

The control system 50 may be separate to the at least one work machine 11 and/or scout 45 as illustrated and may, for example, be embodied as a central control system 50 of fleet management system located on the worksite 35, such as at a dedicated user terminal, personal computer, laptop, tablet computer, server, smartphone and the like. Alternatively, the control system 50 may be offsite and may form part of the external computing system 53.

Alternatively, the control system 50 may form part of and/or be the machine controller 40 and/or scout controller. In embodiments, the control system 50 may be formed across and/or partially on a central control system on the worksite 35, the external computing system 53, scout controller(s) of at least one scout 45 and/or one or more machine controllers 40 of one or more work machines 11, with the control steps described herein being distributed thereacross.

The system 10 may further comprise a navigation system 57 for determining the position of the at least one scout 45 and optionally of the at least one work machine 11 on the worksite 35. The navigation system may determine the location of the at least one scout 45 on the Earth's surface and/or may determine the location of the at least one scout 45 relative to a reference position on the worksite 35. The navigation system 57 may be of any suitable type and may be at least partially embodied in the at least one scout 45, at least one work machine 11, external computing system 53 and/or control system 50. In particular, the at least one scout 45 may comprise a position sensor operable to determine the position of the at least one scout 45 via a global navigation satellite system, such as global positioning system (GPS), or via triangulation with communication masts.

-10 -

INDUSTRIAL APPLICABILITY

In embodiments the control system 50 is generally configured to, and the method generally comprises, at least steps 82-85 and optionally steps 80, 81, 86-88 illustrated in Figure 3 and as described below. References to the control system 50 being configured to perform such steps may be considered as references to the at least one control processor 51 being configured to perform such steps and/or performing such steps.

Initially, at step 80, worksite map data indicative of a layout of the worksite 35 may be retrieved or determined by the control system 50. In particular, a site map may be determined by surveying device(s) (such as by the at least one scout 45 operating as a surveying device to scan the 3D surface profile of the worksite 35) and/or defined by a user. The worksite map data may be stored on the memory of the control system 50 and may be regularly updated as the layout of the worksite 35 changes. The worksite map data may already indicate existing avoidance zones 47, including around some already detected power lines, and/or grade data. The grade data may be used to determine the relative position of the ground to the power lines 60 where they are detected.

At step 81, a route 60 may be determined based upon the worksite map data. The route 60 is for the at least one scout 45 to travel along and collect electric field data. The route 60 may be automatically generated by the control system 50. For example, the route could be set as a spiral or other route. The route 60 may be generated by an input may be received from an operator or from the external computing system 53. The route may comprise the position of the at least one scout 45 in two dimensional coordinates X, Y representing its position on a plane parallel to the surface of the worksite 35. The route may also comprise a third dimensional coordinate Z indicative of the height of the at least one scout 45 relative to a reference height, which may be determined based upon the grade data.

At step 82, the at least one scout 45 is operated to move along the route 60, such as in response to a command to do so from the control system 50 or by an operator manually operating the at least one scout 45 to move along the route 60. The control system 50 may initially communicate the route 60 to the at least one scout 45 for the at least one scout 40 to follow. The at least one scout 45 may utilise the navigation system 57 to ensure that it travels along the route 60. The movement of the at least one scout 45 is controlled by the scout controller. The scout controllers of a plurality of scouts 45 may communicate with one another to coordinate whilst moving along the route 60.

Rather than automatically generating the route 60 as in step 81, the at least one scout 45 may instead be manually controlled by an operator to travel over a route 60. Thus the route 60 may be defined as the route 60 travelled by the at least one scout 45 across the worksite 35, with such a route 50 being tracked by the navigation system 57 (as described below).

Whilst the at least one scout 45 travels along the route 60, the at least one electric field detection sensor 46 is operated such that it generates electric field data indicative of electric field values around the worksite 35. The generated electric field data may be logged in a memory, such as on the at least one scout 45 and/or on the control system 50, whilst the at least one scout 45 moves along the route 60. The at least one electric field detection sensor 46 may determine (a) electric field magnitude and/or (b) three-axis electric field values to determine magnitude El and direction EA for each location (x,y,z).

Whilst the at least one scout 45 tracks the electric field values, the control system 50 may operate the navigation system 57 to track the path of the at least one scout 40. In particular, the navigation system 57 may generate location data indicative of the location of the at least one scout 45 whilst the at least one scout 45 moves around the worksite 35.

The control system 50 may receive the location data from the navigation system 57 and process the location data to identify the location of the at least one scout 40.

At step 83 the at least one scout 45 communicates the electric field data and optionally the location data to the control system 50, such as via the communication system 51 to the central control system and/or machine controller(s) 40, unless the scout controller(s) are performing the steps herein and forming the control system 50. If there are a plurality of scouts 45, the scouts 45 may all communicate their electric field data and optionally location data to the control system 50, which collates the electric field data together.

At step 84, the control system 50 receives the electric field data from the at least one electric field detection sensor 46 and identifies, based upon the electric field data, at least one over-head power line 60 on the worksite 35. A bandpass filter, such as around 50-60Hz, may be applied to the electric field data to substantially filter out electric field values from electric field sources other than over-head power lines 60.

-12 -As part of the identification, the control system 50 also determines the location of the at least one over-head power line 60. Such determination may be based upon linking the received electric field data with the predetermined route 60 of the at least one scout 45, such as based upon timing of movement of the at least one scout 45 along the route 60 and the timing of the electric field values. Preferably, however, the location data from the navigation system 57 is used to define the location of the at least one over-head power line 60. Thus, the accuracy of location of the powerlines 60 may be improved.

The at least one over-head power line 60 may be located by determining whether an electric field value of the electric field data has a greater magnitude than a first threshold value, based upon peak electric field values and/or electric field directions of the electric field data. In particular, the electric field data may be added as power line map data to the worksite map data to provide a three dimensional plot or array of electric field values and strengths and the at least one over-head power line 60 may be identified from the power line map data. Thus, the at least one over-head power line 60 may be located using the direction and/or trends in the electric field data such as relatively high field values.

Once the at least one over-head power line 60 has been identified, the worksite map data is updated to include the location thereof by including the power line map data.

Furthermore, if available, the exact wire profile data (including sag), which may be obtained from a laser (or other) distance sensor is loaded for each powerline into the control system 50 and the power line map data is updated to include the power line configuration.

The control system 50 may then identify, at step 85, an exclusion zone around the identified at least one power line 60 and updates the power line map data and/or worksite map data to include an exclusion zone 70. The exclusion zone 70 indicates the area or three dimensional space around the at least one over-head power line that work machines 11 should avoid whilst operating on the worksite 35 to reduce the risk of collision with the over-head power line(s) 60. The exclusion zone 70 may be at a pre-determined safety distance from the at least one over-head power line 60 and/or may be based upon where electric field values in the electric field data having a smaller magnitude than an exclusion zone threshold value. The safety distances may be determined based upon regulatory or otherwise recommended distances from power lines 60 for safe operation.

In addition, the exclusion zone 70 may be set based upon the type and size of work machine 11 operating on the worksite 35. For example, the control system 40 may be -13 -configured to determine the location of the exclusion zone 70 based upon a predetermined maximum extension distance of the tool 15 and arm arrangement 14. Thus if the work machine 11 has a long reach, the exclusion zone 70 may be set further away from the power line 60 to reduce the chances of collision.

At step 86, the control system 50 communicates the power line map data, optionally as part of the worksite map data, to the at least work machine 11, such as the machine controller 40 thereof. The machine controller 40 may then utilise the power line map data to control operation of the work machine 11.

At step 87, the machine controller 40 may further be configured to assess the location of the work machine 11, such as using navigation data from the navigation system 57, and determine whether the work machine 11, or a part thereof (such as part of the tool 15 and/or arm arrangement 14) is approaching and/or in the exclusion zone 70. The machine controller 40 may make such a determination based upon whether any machine 11 or tool (calculated based on inertial measurement unit data and (a) GPS or (b) local coordinate (such as dead reckoning) or (c) localization (such as tags or 3-D barcodes)) breaches the exclusion zone 70.

In particular, the work machine 11 may comprise an alert system 6, which may form part of or be embodied in the user interface 6, in communication with the machine controller 40. The machine controller 40 may be configured to, at step 88, operate the alert system 6 to issue an alert to the operator if the work machine 11 approaches and/or enters the exclusion zone 70. The alert may be joystick vibration, a screen alert and/or audio, for

example.

The machine controller 40 may also limit movement of the work machine 11, arm arrangement 14 and/or tool 15 and/or derate performance of the work machine 11 if the work machine 11 approaches and/or enters the exclusion zone 70. For example, a maximum velocity and/or acceleration of movement of the work machine 11 may be less when performance is derated than when it is non-derated. A direction of movement of the work machine 11 can be more restrained when performance is derated than when it is not derated. The maximum height reachable by the machine 11, particularly the tool 15, may also be automatically limited. Such derating of performance helps to (a) further inform the operator that they are close to a power line 60 and (b) reduce the risk of collision with a power line 60 by enforcing safer operation of the work machine 11. However, movement of -14 -the work machine 1 1 towards or in the exclusion zone 70 may be allowed upon receipt of an override command at the user interface 6. Such an override command may be necessary if the operator must perform work in the exclusion zone 70.

Claims

-15 -CLAIMS: 1. A system for operating at least one work machine around at least one over-head power line on a worksite, the system comprising: at least one scout comprising at least one electric field detection sensor and configured to move along a route over the worksite whilst the at least one electric field detection sensor generates electric field data indicative of electric field values around the worksite; a control system in communication with the at least one electric field detection sensor, the control system being configured to: receive the electric field data from the at least one electric field detection sensor; and identify, based upon the electric field data, at least one over-head power line on the worksite.
2. The system of claim 1 wherein the control system is configured to identify the at least one over-head power line based upon the electric field data by identifying peak electric field values and/or electric field directions and/or by determining whether an electric field value of the electric field data has a greater magnitude than a first threshold value.
3. The system of claim 1 or claim 2 wherein the control system is configured to log the generated electric field data in a memory whilst the at least one scout moves along the route and generate the power line map data.
4. The system of any preceding claim further comprising a navigation system, wherein the control system is configured to: operate the navigation system to generate location data indicative of the location of the at least one scout whilst the at least one scout moves along the route; receive the location data from the navigation system; process the location data to identify the location of the at least one over-head power line.
5. The system of any preceding claim wherein the control system is configured to generate power line map data indicative of an exclusion zone around the identified at least one overhead power line, the exclusion zone being indicative of an area for at least one work machine to avoid whilst operating on the worksite.
-16 - 6. The system of claims 4 and 5 wherein the control system is configured to process the location data to generate the power line map data indicative of the exclusion zone.
7. The system of claim 5 or claim 6 wherein the control system is configured to: determine the location of the exclusion zone as a predetermined distance from the at least one over-head power line and/or based upon an electric field value in the electric field data having a smaller magnitude than an exclusion zone threshold value; and/or receive power line configuration data indicative of the configuration of the identified at least one over-head power line and generate the power line map data to indicate the exclusion zone based upon such power line configuration data.
8. The system of any preceding claim comprising a work machine comprising a machine controller.
9. The system of claim 8 and any one of claims 5 to 7 wherein: the machine controller is configured to derate performance and/or limit movement of the work machine if the work machine approaches and/or enters the exclusion zone; and/or the work machine comprises a tool mounted to an arm arrangement mounted to a main body, wherein the control system is configured to determine the location of the exclusion zone based upon a predetermined maximum extension distance of the tool and arm arrangement.
10. The system of claim 8 or claim 9 wherein the work machine comprises an alert system in communication with the machine controller, wherein the machine controller is configured to operate the alert system to issue an alert if the work machine approaches and/or enters the exclusion zone.
11. The system of any preceding claim wherein the at least one scout comprises at least one of an unmanned aerial vehicle, an autonomous land vehicle, a manned land vehicle and/or a work machine.
12. The system of any preceding claim wherein the control system is configured to determine the route based upon worksite map data indicative of a layout of the worksite.
13. The system of any preceding claim wherein the control system is configured to automatically generate the route, generate the route based upon an input from an operator -17 -or from an external computing system and/or operate the at least one scout to move along the route.
14. A method of operating at least one work machine around at least one over-head power line on a worksite, the method comprising: operating at least one scout to move along a route over the worksite whilst at least one electric field detection sensor thereof generates electric field data indicative of electric field values around the worksite; receiving, by a control system, the electric field data from the at least one electricfield detection sensor; andidentifying, by the control system and based upon the electric field data, at least one over-head power line on the worksite.
15. The method of claim 14 further comprising generating, by the control system, power line map data indicative of an exclusion zone around the identified at least one over-head power line, the exclusion zone being indicative of an area for at least one work machine to avoid whilst operating on the worksite.
16. A non-transitory computer-readable storage medium including program code which when executed by at least one processor causes operations comprising the method of claim 14 or claim 15.