System, method, and program

Abstract

This system identifies a virtual wall serving as a surface for prohibiting entry of a work machine. The system determines the travel speed of the work machine on the basis of the virtual wall.

Description

System, method and program

[0001] This application claims priority to Japanese Patent Application No. 2023-222308, filed on December 28, 2023, the contents of which are incorporated herein by reference.

[0002] A technique for setting up a virtual wall in space to limit the operating range of a work machine is known. A control device for the work machine can control the work machine so that it does not exceed the virtual wall by limiting the amount of operation of the actuator of the work machine according to the distance between the virtual wall and the work machine.

[0003] International Publication No. 2019 / 189030

[0004] However, for work machines equipped with traveling gear for moving the work machine, it is necessary to control the work machine so that it does not exceed a set virtual wall during traveling. An object of the present disclosure is to provide a system, method, and program that can control the work machine to prevent it from entering a no-entry zone.

[0005] According to one aspect of the present disclosure, a system for controlling a work machine includes a processor. The processor identifies a virtual wall that is a surface that prohibits the work machine from entering. The processor controls the travel speed of the work machine based on the virtual wall.

[0006] According to the above aspect, the system can control the work machine so that it does not enter the restricted area.

[0007] Fig. 1 is a schematic diagram showing the configuration of a work machine according to a first embodiment. Fig. 2 is a diagram showing a drive system of a work machine according to the first embodiment. Fig. 3 is a schematic block diagram showing the configuration of a control device according to the first embodiment. Fig. 4 is a flowchart showing intervention control by the control device according to the first embodiment. Fig. 5 is a diagram showing how the control device according to the first embodiment determines the control point and the distance between a virtual sphere and a virtual wall. Fig. 6 is a diagram showing a method for specifying an object to be determined as an interference when a traveling body of a work machine according to the first embodiment turns. Fig. 7 is a diagram showing the configuration of a work system according to another embodiment.

[0008] <First Embodiment> <Configuration of Work Machine> The embodiments will now be described in detail with reference to the drawings. FIG. 1 is a schematic diagram showing the configuration of a work machine 100 according to the first embodiment. The work machine 100 according to the first embodiment is, for example, a hydraulic excavator. The work machine 100 includes a vehicle body 110, a work implement 160, a cab 180, and a control device 200. The work machine 100 according to the first embodiment is controlled so as not to come into contact with a virtual wall VW that is virtually generated to define a no-entry zone at a work site. This allows the operator to operate the work machine 100 so as not to enter the no-entry zone.

[0009] The vehicle body 110 includes a running body 120 and a rotating body 140. The running body 120 supports the work machine 100 so that it can travel. The running body 120 includes a pair of left and right running devices. The running body 120 includes, for example, tracks 121 as the running devices. Each track 121 has a travel motor 114, which is a drive wheel. The travel motor 114 rotates the tracks 121. The running motor 114 rotates the tracks 121, causing the work machine 100 to run or turn. By rotating the left and right tracks 121 in the same direction but at different speeds, the work machine 100 can change course in an arc while moving forward or backward. Furthermore, by rotating only one of the left and right tracks 121, the work machine 100 can make a pivot turn around the track on the stationary side as the axis. Furthermore, the work machine 100 can perform a pivot turn around the center of the running body 120 as an axis by rotating the left and right crawler tracks 121 in different directions at a constant speed.

[0010] The revolving unit 140 is supported on the traveling unit 120 so as to be rotatable about a rotation center. The work implement 160 is movably supported on the revolving unit 140. The work implement 160 is hydraulically driven. The work implement 160 includes a boom 161, an arm 162, and an attachment 163 which is a working tool. The attachment 163 is an example of a working tool. In the example shown in FIG. 1 , the attachment 163 is a bucket. The base end of the boom 161 is rotatably attached to the revolving unit 140. The base end of the arm 162 is rotatably attached to the tip of the boom 161. The attachment 163 is rotatably attached to the tip of the arm 162. Here, the portion of the revolving unit 140 to which the work implement 160 is attached is referred to as the front. Furthermore, with respect to the revolving unit 140, the opposite portion from the front is referred to as the rear, the left portion is referred to as the left part, and the right portion is referred to as the right part.

[0011] The operator's cab 180 is provided at the front of the revolving unit 140. Inside the operator's cab 180, there are provided an operation device 141 which the operator uses to operate the work machine 100, and a monitor device 142 which is a man-machine interface for the control device 200. The monitor device 142 is realized by, for example, a computer equipped with a touch panel.

[0012] The control device 200 controls the traveling body 120, the revolving body 140, and the work machine 160 based on the operation of the operation device 141 by the operator. The control device 200 is provided inside the operator's cab 180, for example.

[0013] <<Drive system of work machine 100>> Figure 2 is a diagram showing the drive system of the work machine 100 according to the first embodiment. The work machine 100 is equipped with a plurality of actuators for driving the work machine 100. Specifically, the work machine 100 is equipped with a power source 111, a hydraulic pump 112, a control valve 113, a pair of travel motors 114, a swing motor 115, a boom cylinder 116, an arm cylinder 117, and an attachment cylinder 118.

[0014] The power source 111 drives the hydraulic pump 112. The power source 111 is, for example, an engine. The hydraulic pump 112 is driven by the power source 111 and supplies hydraulic oil to the travel motor 114, the swing motor 115, the boom cylinder 116, the arm cylinder 117, and the attachment cylinder 118 via a control valve 113. The control valve 113 controls the flow rate of hydraulic oil supplied from the hydraulic pump 112 to the travel motor 114, the swing motor 115, the boom cylinder 116, the arm cylinder 117, and the attachment cylinder 118. The travel motor 114 is driven by hydraulic oil supplied from the hydraulic pump 112 and rotates the crawler belt 121. The swing motor 115 is driven by hydraulic oil supplied from the hydraulic pump 112 and rotates the swing unit 140 relative to the travel unit 120.

[0015] The boom cylinder 116 is a hydraulic cylinder for driving the boom 161. The base end of the boom cylinder 116 is attached to the rotating body 140. The tip end of the boom cylinder 116 is attached to the boom 161. The arm cylinder 117 is a hydraulic cylinder for driving the arm 162. The base end of the arm cylinder 117 is attached to the boom 161. The tip end of the arm cylinder 117 is attached to the arm 162. The attachment cylinder 118 is a hydraulic cylinder for driving the attachment 163. The base end of the attachment cylinder 118 is attached to the arm 162. The tip end of the attachment cylinder 118 is attached to the attachment 163.

[0016] <<Measurement System of Work Machine 100>> The work machine 100 is equipped with a plurality of sensors for measuring the attitude and position of the work machine 100. Specifically, the work machine 100 is equipped with an inclinometer 101, a position and orientation detector 106, a swing angle sensor 102, a boom angle sensor 103, an arm angle sensor 104, and an attachment angle sensor 105.

[0017] The inclinometer 101 measures the attitude of the revolving unit 140. The inclinometer 101 measures the inclination (e.g., roll angle, pitch angle, and yaw angle) of the revolving unit 140 with respect to a horizontal plane. An example of the inclinometer 101 is an IMU (Inertial Measurement Unit). In this case, the inclinometer 101 measures the acceleration and angular velocity of the revolving unit 140 and calculates the inclination of the revolving unit 140 with respect to a horizontal plane based on the measurement results. The inclinometer 101 is installed, for example, below the operator's cab 180. The inclinometer 101 outputs attitude data of the revolving unit 140, which is a measurement value, to the control device 200.

[0018] The turning angle sensor 102 measures the turning angle of the revolving unit 140 relative to the running unit 120. The measurement value of the turning angle sensor 102 indicates zero, for example, when the directions of the running unit 120 and the revolving unit 140 are the same. The turning angle sensor 102 is installed, for example, at the center of rotation of the revolving unit 140. The turning angle sensor 102 outputs turning angle data, which is the measurement value, to the control device 200.

[0019] The boom angle sensor 103 measures the boom angle, which is the rotation angle of the boom 161 relative to the revolving structure 140. The boom angle sensor 103 may be an IMU attached to the boom 161. In this case, the boom angle sensor 103 measures the boom angle based on the inclination of the boom 161 with respect to a horizontal plane and the inclination of the revolving structure measured by the inclination measuring device 101. The measurement value of the boom angle sensor 103 indicates zero when, for example, the direction of a line passing through the base end and tip end of the boom 161 coincides with the fore-and-aft direction of the revolving structure 140. Note that, in other embodiments, the boom angle sensor 103 may be a stroke sensor attached to the boom cylinder 116. Furthermore, in other embodiments, the boom angle sensor 103 may be a rotation sensor provided on a boom pin connecting the revolving structure 140 and the boom 161. The boom angle sensor 103 outputs boom angle data, which is the measurement value, to the control device 200.

[0020] The arm angle sensor 104 measures the arm angle, which is the rotation angle of the arm 162 relative to the boom 161. The arm angle sensor 104 may be an IMU attached to the arm 162. In this case, the arm angle sensor 104 measures the arm angle based on the inclination of the arm 162 with respect to the horizontal plane and the boom angle measured by the boom angle sensor 103. The measurement value of the arm angle sensor 104 indicates zero when, for example, the direction of a line passing through the base end and tip end of the arm 162 coincides with the direction of a line passing through the base end and tip end of the boom 161. Note that, in another embodiment, the arm angle sensor 104 may calculate the angle by attaching a stroke sensor to the arm cylinder 117. In another embodiment, the arm angle sensor 104 may be a rotation sensor provided on an arm pin connecting the boom 161 and the arm 162. The arm angle sensor 104 outputs arm angle data, which is the measurement value, to the control device 200.

[0021] The attachment angle sensor 105 measures the attachment angle, which is the rotation angle of the attachment 163 relative to the arm 162. The attachment angle sensor 105 may be a stroke sensor provided on the attachment cylinder 118 for driving the attachment 163. In this case, the attachment angle sensor 105 measures the attachment angle based on the stroke amount of the attachment cylinder 118. The measurement value of the attachment angle sensor 105 indicates zero, for example, when the direction of a line passing through the base end and tip end of the attachment 163 coincides with the direction of a line passing through the base end and tip end of the arm 162. Note that, in another embodiment, the attachment angle sensor 105 may be a rotation sensor provided on a bucket pin connecting the arm 162 and the attachment 163. Furthermore, in another embodiment, the attachment angle sensor 105 may be an IMU attached to the attachment 163. The attachment angle sensor 105 outputs attachment angle data, which is the measurement value, to the control device 200.

[0022] The position and orientation detector 106 detects the position and orientation of the work machine 100. The position and orientation detector 106 is equipped with two receivers that receive positioning signals from artificial satellites that make up the Global Navigation Satellite System (GNSS). An example of a GNSS is the Global Positioning System (GPS). The two receivers are installed at different positions on the work machine 100. The position and orientation detector 106 detects the position of a representative point of the rotating unit 140 in the site coordinate system based on the positioning signals received by the receivers. The position and orientation detector 106 uses the positioning signals received by the two receivers to calculate the orientation of the rotating unit 140 as the relationship between the installation position of one receiver and the installation position of the other receiver.

[0023] 3 is a schematic block diagram showing the configuration of the control device 200 according to the first embodiment. The control device 200 is a computer including a processor 210, a main memory 230, a storage 250, and an interface 270. The control device 200 is an example of a control system. The control device 200 receives measurement values ​​from the inclination measuring device 101, the rotation angle sensor 102, the boom angle sensor 103, the arm angle sensor 104, the attachment angle sensor 105, and the position and orientation detector 106.

[0024] Storage 250 is a non-transitory tangible storage medium. Examples of storage 250 include a magnetic disk, an optical disk, a magneto-optical disk, and a semiconductor memory. Storage 250 may be an internal medium directly connected to the bus of control device 200, or may be an external medium connected to control device 200 via interface 270 or a communication line. Storage 250 stores a control program for controlling work machine 100.

[0025] The control program may be for realizing some of the functions to be performed by the control device 200. For example, the control program may be combined with other programs already stored in the storage 250 or other programs implemented in other devices to perform the functions. In other embodiments, the control device 200 may include a custom large-scale integrated circuit (LSI) such as a programmable logic device (PLD) in addition to or instead of the above configuration. Examples of PLDs include programmable array logic (PAL), generic array logic (GAL), complex programmable logic device (CPLD), and field programmable gate array (FPGA). In this case, some or all of the functions realized by the processor may be realized by the integrated circuit.

[0026] The storage 250 stores geometry data representing the dimensions and center of gravity positions of the running body 120, the revolving body 140, the boom 161, the arm 162, and the attachment 163. The geometry data represents the position of an object in a predetermined coordinate system.

[0027] Parameter data for each virtual wall VW is recorded in the storage 250. The virtual wall VW according to the first embodiment is disposed perpendicular to the ground surface. The parameters of the virtual wall VW may be the positions (latitude and longitude) of two points in a site coordinate system. In this case, a plane formed between edges extending vertically from the two specified points is identified as the virtual wall VW. Note that, in other embodiments, this is not limited to this, and the parameters of the virtual wall VW may be expressed by the three-dimensional position of a point in the site coordinate system and the orientation of the wall surface.

[0028] A traveling speed table, which is a function showing the relationship between the distance to the virtual wall VW and the speed limit, is recorded in the storage 250. The speed limit is a speed at which the work machine 100 can stop without passing the virtual wall VW when traveling at that speed. The traveling speed table is a function in which the speed limit decreases as the distance to the virtual wall VW decreases.

[0029] <<Software Configuration>> By executing a control program, the processor 210 is provided with an operation signal receiving unit 211, an input unit 212, a display control unit 213, a measurement value receiving unit 214, a position identification unit 215, an intervention determination unit 218, an intervention control unit 219, and a control signal output unit 220.

[0030] The operation signal receiving unit 211 receives operation signals indicating the operation direction and operation amount of each actuator from the operation device 141. The display control unit 213 outputs screen data to be displayed on the monitor device 142 to the monitor device 142. The measurement value receiving unit 214 receives measurement values ​​from the inclination measuring instrument 101, the rotation angle sensor 102, the boom angle sensor 103, the arm angle sensor 104, the attachment angle sensor 105, and the position and orientation detector 106.

[0031] The position identification unit 215 identifies the position of the hull of the work machine 100 in the vehicle body coordinate system. The hull of the work machine 100 is the external shape of the work machine 100. The hull of the work machine 100 is defined, for example, by the shapes that form the external shapes of the revolving unit 140 and the work implement 160. Specifically, the position identification unit 215 identifies the positions of multiple points (control points) on the hull of the work machine 100 in the vehicle body coordinate system based on the various measurement values ​​received by the measurement value receiving unit 214 and the geometry data recorded in the storage 250. The control points identified by the position identification unit 215 include the tip of the attachment 163 (e.g., the tip of the bucket), the end of the arm 162 on the attachment 163 side (arm top), the end of the arm 162 on the boom 161 side (arm bottom), a point behind the counterweight of the revolving unit 140, and the end of the crawler track 121. The vehicle body coordinate system is an orthogonal coordinate system with its origin at a representative point of the rotating unit 140 (for example, a point passing through the center of rotation). The calculations of the position identification unit 215 will be described later. Note that the points identified by the position identification unit 215 are not limited to this. In the first embodiment, the shapes of the outer shells of the attachment 163, arm top, and arm bottom are simulated by a virtual sphere VS. The virtual sphere VS is a virtual sphere that contains the outer shell of a target part whose shape changes depending on the angle between two objects, such as a joint part of the work implement 160. By regarding the surface of the virtual sphere VS as the outer shell of the target part, the control device 200 can determine the possibility of contact between the virtual wall VW and the outer shell while reducing the amount of calculation.

[0032] The intervention determination unit 218 determines whether to limit the speed of the traveling object 120 based on the positional relationship between the control point identified by the position identification unit 215 and the virtual wall VW. Hereinafter, limiting the speed of the traveling object 120 by the control device 200 is also referred to as intervention control. Specifically, the intervention determination unit 218 calculates the minimum distance between the virtual wall VW and the work machine 100, and determines to perform intervention control on the traveling object 120 if the minimum distance is equal to or less than a predetermined distance. Note that the control device 200 according to other embodiments may perform intervention control on the revolving unit 140 and the work machine 160 in addition to the intervention control on the traveling object 120.

[0033] When the intervention determination unit 218 determines that intervention control should be performed, the intervention control unit 219 controls the amount of operation of the actuator that is the target of intervention, out of the operation signals received by the operation signal receiving unit 211. The control signal output unit 220 outputs the operation signal received by the operation signal receiving unit 211 or the operation signal controlled by the intervention determination unit 218 to the control valve 113.

[0034] <<Calculations by Position Identification Unit 215>> Here, a method for identifying the positions of points on the hull of the work machine 100 by the position identification unit 215 will be described. The position identification unit 215 identifies the positions of points on the hull based on the various measurement values ​​received by the measurement value receiving unit 214 and the geometry data recorded in the storage 250. Geometry data representing the dimensions of the revolving unit 140, boom 161, arm 162, and attachment 163 is recorded in the storage 250.

[0035] The geometry data of the vehicle 120 is the position (x ｔｂ , y ｔｂ , z ｔｂ ) is shown. The points on the outer hull of the running body 120 include, for example, the outer points of the front and rear ends of the crawler 121. The running body coordinate system is based on the rotation center of the rotating body 140 and is defined by an X ｔｂ Axis, Y extending left and right ｔｂ Axis, Z extending in the vertical direction ｔｂ The coordinate system is configured by the axes. Note that the up-down direction of the rotating body 140 does not necessarily coincide with the vertical direction.

[0036] The geometry data of the rotating unit 140 is the position (x ｂｍ , y ｂｍ , z ｂｍ ), and the position of a point on the hull of the rotating bed 140 (x ｓｐ , y ｓｐ , z ｓｐ ) is shown. The points on the outer hull of the rotating body 140 are points that are likely to come into contact with a wall surface during rotation, such as the protruding points of the counterweight. The vehicle body coordinate system is based on the X axis, which extends in the front-rear direction with the center of rotation of the rotating body 140 as the reference.ｓｂ Axis, Y extending left and right ｓｂ Axis, Z extending in the vertical direction ｓｂ The coordinate system is configured by the axes. Note that the up-down direction of the rotating body 140 does not necessarily coincide with the vertical direction.

[0037] The geometry data of the boom 161 is the position of the arm pin in the boom coordinate system, which is a local coordinate system (x ａｍ , y ａｍ , z ａｍ The boom coordinate system is based on the position of the pin connecting the boom 161 and the rotating body 140, and is defined by an X axis extending in the longitudinal direction. ｂｍ Y extends in the direction that the shaft and pin extend ｂｍ axis, X ｂｍ Axis and Y ｂｍ Z perpendicular to the axis ｂｍ It is a coordinate system consisting of axes.

[0038] The geometry data of the arm 162 is the position of the bucket pin in the arm coordinate system, which is a local coordinate system (x ａｔ , y ａｔ , z ａｔ The arm coordinate system is based on the position of the pin connecting the arm 162 and the boom 161, and is defined by an X axis extending in the longitudinal direction. ａｍ Y extends in the direction that the shaft and pin extend ａｍ axis, X ａｍ Axis and Y ａｍ Z perpendicular to the axis ａｍ The arm 162 is a coordinate system composed of axes. The geometry data of the arm 162 also has information on the center points and radii of virtual spheres VS1 and VS2 that simulate the outer hulls of the arm bottom and arm top. The virtual sphere VS1 representing the arm bottom is centered on the arm pin and includes at least the base end of the arm 162. The virtual sphere VS2 representing the arm top is centered on the bucket pin and includes at least the tip of the arm 162. The arm bottom and arm top are one of the points on the outer hull of the work machine 100.

[0039] The geometry data of the attachment 163 includes information on the center point and radius of a virtual sphere VS3 that simulates the outer shell of the attachment 163. The virtual sphere VS3 that represents the attachment 163 contains the entire attachment 163. The center point of the virtual sphere VS3 may be the midpoint of a line segment that connects the midpoint of the rotation axis of the attachment 163 and the midpoint of the tip of the attachment 163. Furthermore, the center point of the virtual sphere VS3 according to other embodiments may be the geometric center of the attachment 163, or may be a point at which the virtual sphere VS that contains the attachment 163 becomes the smallest containing sphere. The geometry data of the attachment 163 includes the position (x ｃｐ , y ｃｐ , z ｃｐ The attachment coordinate system is based on the position of the pin connecting the attachment 163 and the arm 162, and is defined by an X axis extending in the direction of the tip. ａｔ Y extends in the direction that the shaft and pin extend ａｔ axis, X ａｔ Axis and Y ａｔ Z perpendicular to the axis ａｔ It is a coordinate system consisting of axes.

[0040] The position specifying unit 215 receives the turning angle θ ｓｂ Based on the measured values ​​and the geometry data of the vehicle 120, a vehicle-vehicle body transformation matrix T for transforming from the vehicle body coordinate system to the vehicle body coordinate system is calculated using the following equation (1): ｔｂ ｓｂ Generate the vehicle-to-vehicle transformation matrix T ｔｂ ｓｂ Is Z ｔｂ Rotation angle θ around the axis ｓｂ The position specifying unit 215 also calculates the position of the outer shell of the running object 120 in the running object coordinate system indicated by the geometry data of the running object 120 and the running object-body transformation matrix T ｔｂ ｓｂ The position of the outer shell of the vehicle 120 in the vehicle body coordinate system is obtained by calculating the product of

[0041]

[0042] The position specifying unit 215 receives the boom angle θ ｂｍ Based on the measurement values ​​and the geometry data of the rotating body 140, a boom-to-body transformation matrix T for transforming from the boom coordinate system to the body coordinate system is calculated using the following equation (2): ｂｍ ｓｂ Generate the boom-body transformation matrix T ｂｍ ｓｂ Is Y ｂｍ Boom angle θ around the axis ｂｍ and the deviation between the origin of the vehicle coordinate system and the origin of the boom coordinate system (x ｂｍ , y ｂｍ , z ｂｍ ) is a matrix that translates the boom 161 by the position of the arm pin in the boom coordinate system indicated by the geometry data of the boom 161. ｂｍ ｓｂ The position of the arm pin in the vehicle body coordinate system is found by calculating the product of

[0043]

[0044] The position specifying unit 215 receives the arm angle θ ａｍ Based on the measurement values ​​and the geometry data of the boom 161, an arm-boom transformation matrix T for transforming from the arm coordinate system to the boom coordinate system is calculated by the following equation (3). ａｍ ｂｍ The arm-boom transformation matrix T ａｍ ｂｍ Is Y ａｍ Arm angle θ around the axis ａｍ and the deviation between the origin of the boom coordinate system and the origin of the arm coordinate system (x ａｍ , y ａｍ , z ａｍ ) is a matrix that translates the boom-vehicle body transformation matrix T ｂｍ ｓｂ and the arm-boom transformation matrix T ａｍ ｂｍ By calculating the product of these, the arm-body transformation matrix T for transforming from the arm coordinate system to the body coordinate system is obtained. ａｍ ｓｂFurthermore, the position specifying unit 215 generates the position of the bucket pin in the arm coordinate system indicated by the geometry data of the arm 162 and the arm-vehicle body transformation matrix T ａｍ ｓｂ The position of the bucket pin in the vehicle body coordinate system is calculated by calculating the product of

[0045]

[0046] The position specifying unit 215 receives the attachment angle θ ａｔ Based on the measured values ​​and the geometry data of the arm 162, the attachment-arm transformation matrix T for transforming from the attachment coordinate system to the arm coordinate system is calculated by the following equation (4): ａｔ ａｍ The attachment-arm transformation matrix T ａｔ ａｍ Is Y ａｔ Attachment angle θ around the axis ａｔ and the deviation between the origin of the arm coordinate system and the origin of the attachment coordinate system (x ａｔ , y ａｔ , z ａｔ ) is a matrix that translates the arm-vehicle body transformation matrix T ａｍ ｓｂ and the attachment-arm transformation matrix T ａｔ ａｍ By calculating the product of these, the attachment-body transformation matrix T for transforming from the attachment coordinate system to the body coordinate system is obtained. ａｔ ｓｂ Generate.

[0047]

[0048] The position specifying unit 215 determines the position of the tip of the attachment 163 in the attachment coordinate system indicated by the geometry data of the attachment 163 and the attachment-vehicle body transformation matrix T ａｔ ｓｂ By calculating the product of these, the position of the center point of the virtual sphere VS3 of the attachment 163 in the vehicle body coordinate system is calculated.

[0049] <<Control Method of Work Machine 100>> A control method of the work machine 100 according to the first embodiment will now be described. When the control device 200 is started, it reads into the main memory 230 the parameters of the virtual wall VW, the geometry data, the angular velocity limit table, and the speed limit table that are recorded in the storage 250.

[0050] 4 is a flowchart showing intervention control by the control device 200 according to the first embodiment. The control device 200 starts the following control.

[0051] The operation signal receiving unit 211 receives an operation signal for the pair of left and right traveling devices of the traveling body 120 from the operation device 141 (step S1). The measurement value receiving unit 214 receives measurement values ​​from the inclination measuring device 101, the swing angle sensor 102, the boom angle sensor 103, the arm angle sensor 104, the attachment angle sensor 105, and the position and orientation detector 106 (step S2).

[0052] The intervention control unit 219 determines the position and orientation of the rotating unit 140 based on the measurement values ​​received in step S2. The intervention control unit 219 specifies the position of the virtual wall VW in the vehicle body coordinate system based on the parameters of the virtual wall VW and the position and orientation of the rotating unit 140 (step S3). The position identifying unit 215 specifies the positions of the control point of the work machine 100 and the virtual sphere VS in the vehicle body coordinate system based on the measurement values ​​received in step S2 (step S4).

[0053] The intervention determination unit 218 selects each of the virtual walls VW whose positions were identified in step S3 (step S5) and executes the following processing in steps S6 to S15. The intervention determination unit 218 calculates the distance between the virtual wall VW selected in step S5 and the control point and virtual sphere VS identified in step S4 (step S6). FIG. 5 is a diagram showing how the control device 200 according to the first embodiment calculates the distance between the control point and virtual sphere VS and the virtual wall VW. The intervention determination unit 218 calculates the length of a line segment that connects the control point or virtual sphere VS of the work machine 100 and the virtual wall VW, and that is parallel to the direction in which the vehicle 120 is facing, as the distance between the control point or virtual sphere VS and the virtual wall VW. Note that if the wall surface of the virtual wall VW is parallel to the direction in which the vehicle 120 is facing, the distance cannot be calculated. In this case, the intervention determination unit 218 may determine that the distance between the control point or the virtual sphere VS and the virtual wall VW is a distance at which the speed is not limited in the speed limit table.

[0054] The intervention determination unit 218 determines whether the operation on the running vehicle 120 is a straight-line operation, a turning operation, or a stopping operation based on the operation signal received in step S1 (step S7). The intervention determination unit 218 determines that the operation on the running vehicle 120 is a straight-line operation when the operation directions of the right track 121 and the left track 121 match and the difference in the operation amounts of the right track 121 and the left track 121 is equal to or less than a predetermined threshold. The intervention determination unit 218 determines that the operation on the running vehicle 120 is a turning operation when the operation directions of the right track 121 and the left track 121 do not match or when the difference in the operation amounts of the right track 121 and the left track 121 exceeds a predetermined threshold. The intervention determination unit 218 determines that the operation on the running vehicle 120 is a stopping operation when the operation amounts of the right track 121 and the left track 121 are both below the predetermined threshold.

[0055] When it is determined that the operation on the running object 120 is a straight-line operation (step S7: straight), the intervention determination unit 218 determines whether the running direction of the running object 120 is a direction toward or away from the virtual wall VW selected in step S5 (step S8). When it is determined that the running object 120 is in a direction toward the virtual wall (step S8: approach), the intervention determination unit 218 determines that all the control points and the virtual sphere VS identified in step S4 are to be subjected to collision determination (step S9).

[0056] If it is determined that the operation on the running object 120 is a straight-line operation in a direction in which the running object 120 moves away from the virtual wall (step S8: move away), or if it is determined that the operation on the running object 120 is a stop operation (step S7: stop), the intervention determination unit 218 determines that all of the control points and virtual spheres VS identified in step S4 are not to be subjected to interference determination (step S10). In this case, the intervention determination unit 218 replaces the distances related to the control points and virtual spheres VS that are not to be subjected to interference determination, which were determined in step S6, with distances for which the speed is not limited in the speed limit table.

[0057] If it is determined that the operation on the running object 120 is a turning operation (step S7: turning), the intervention determination unit 218 identifies the turning direction of the running object 120 based on the operation signal received in step S1 (step S11).

[0058] The intervention determination unit 218 determines the control points and virtual spheres VS that approach the virtual wall from among the control points and virtual spheres VS determined in step S4, based on the turning direction of the traveling object 120 determined in step S11 (step S12). Fig. 6 is a diagram showing a method for determining an object to be subjected to interference determination when the traveling object 120 of the work machine 100 according to the first embodiment turns. The intervention determination unit 218 determines the virtual wall VW selected in step S5 from the X coordinate system of the vehicle body. ｓｂ -Y ｓｂA judgment plane is set that is perpendicular to the plane and passes through the midpoint M of the pair of left and right crawler tracks 121. When the running unit 120 is viewed from the top-bottom direction, the midpoint M is the intersection of a line connecting the right front end of the right crawler track 121 and the left rear end of the left crawler track 121 with a line connecting the right rear end of the right crawler track 121 and the left front end of the left crawler track 121. Note that the midpoint M may also be a point that passes through the center of rotation of the rotating unit 140.

[0059] 6 , for example, if the intervention determination unit 218 determines in step S11 that the turning direction of the running object 120 is leftward, it determines that points located to the right of the judgment plane as viewed from the virtual wall VW and virtual spheres VS whose center points are on the right side of the judgment plane are to be targets for interference determination. Furthermore, for example, if the intervention determination unit 218 determines in step S11 that the turning direction of the running object 120 is rightward, it determines that points located to the left of the judgment plane as viewed from the virtual wall VW and virtual spheres VS whose center points are on the left side of the judgment plane are to be targets for interference determination. In other words, the intervention determination unit 218 determines, among the control points and virtual spheres VS identified in step S4, the control points and virtual spheres VS that rotate in a direction approaching the virtual wall VW as a result of the turning of the running object 120 are to be targets for interference determination. On the other hand, the intervention determination unit 218 does not determine, as targets for interference determination, the control points and virtual spheres VS identified in step S4 that are rotating in a direction away from the virtual wall VW due to the turning of the traveling object 120. Note that, for example, the intervention determination unit 218 may replace, among the distances between the virtual wall VW and the control points and virtual spheres VS calculated in step S6, the distances related to the control points and virtual spheres VS that are not targets for interference determination with distances for which the speed is not limited in the speed limit table.

[0060] After the control points and the virtual sphere VS to be subjected to interference detection are determined in any of steps S9 to S12, the intervention determination unit 218 identifies the control point or the virtual sphere VS that is closest to the virtual wall VW selected in step S5 among the control points to be subjected to interference detection (step S13). The intervention control unit 219 determines an allowable speed from the distance to the control point or the virtual sphere VS identified in step S13 based on a speed limit table (step S14). The intervention control unit 219 determines a deceleration rate of the tracks 121 based on the command speeds for each of the pair of left and right tracks 121 indicated by the operation signal received in step S1 and the allowable speed determined in step S14 (step S15). Specifically, the intervention control unit 219 calculates the deceleration rate by dividing the allowable speed by the command speed for each of the pair of left and right tracks 121 indicated by the operation amount, whichever speed approaches the virtual wall VW.

[0061] After the control device 200 performs the calculations of steps S6 to S15 for each virtual wall VW and calculates the deceleration rate for each virtual wall VW, the intervention control unit 219 identifies the smallest of the calculated deceleration rates (step S16). The intervention control unit 219 calculates the target speed for each of the pair of left and right tracks 121 by multiplying the command speed for each of the pair of left and right tracks 121 indicated by the operation signal by the deceleration rate identified in step S16 (step S17). As a result, the ratio between the traveling speed indicated by the operation signal for the right track 121 and the target speed for the right track 121 becomes equal to the ratio between the traveling speed indicated by the operation signal for the left track 121 and the target speed for the right track 121. Therefore, the control device 200 can rotate the pair of left and right tracks 121 at the same ratio as the ratio of the operation amounts indicated by the operation signals for the pair of left and right tracks 121.

[0062] The control signal output unit 220 generates a control signal based on the target speed calculated in step S17 and outputs the control signal to the control valve 113 (step S18).

[0063] <<Actions and Effects>> In this way, the control device 200 according to the first embodiment controls the work machine 100 in the following procedure. The control device 200 identifies a virtual wall VW that is virtually generated to demarcate a no-entry zone for the work machine 100. The control device 200 controls the travel speed so that the virtual wall VW does not come into contact with the work machine 100. In this way, it is possible to control the work machine 100 so that it does not enter the no-entry zone.

[0064] Furthermore, when both of the pair of left and right tracks 121 are operated in directions approaching the virtual wall VW, the control device 200 according to the first embodiment limits the traveling speed so that the virtual wall VW does not come into contact with the work machine 100, and does not limit the traveling speed when both of the pair of left and right tracks 121 are operated in directions away from the virtual wall VW. As a result, when the work machine 100 is close to the virtual wall VW, the traveling speed is limited when an operation to approach the virtual wall VW is performed, and the work machine 100 can quickly move away from the virtual wall VW when an operation to move away from the virtual wall VW is performed.

[0065] Furthermore, when the operation directions of the pair of left and right tracks 121 differ from each other, or when the operation amounts of the pair of left and right tracks 121 differ from each other, the control device 200 according to the first embodiment identifies a portion of the hull of the work machine 100 that approaches the virtual wall VW, and determines the traveling speed based on the distance between the identified portion and the virtual wall VW. When the operation directions of the pair of left and right tracks 121 differ from each other, or when the operation amounts of the pair of left and right tracks 121 differ from each other, the work machine 100 turns. At this time, the portion of the work machine 100 that is on the opposite side of the turning direction does not come into contact with the virtual wall VW due to the turning. Therefore, the control device according to the first embodiment can appropriately control the turning speed of the traveling body 120.

[0066] <Other Embodiments> One embodiment has been described in detail above with reference to the drawings, but the specific configuration is not limited to that described above, and various design changes and the like are possible. That is, in other embodiments, the order of the above-described processes may be changed as appropriate. Furthermore, some of the processes may be executed in parallel. The control device 200 according to the above-described embodiment may be configured by a single computer, or the configuration of the control device 200 may be divided into multiple computers that function as the control device 200 by cooperating with each other. In this case, some of the computers that make up the control device 200 may be installed inside the work machine 100, and other computers may be provided outside the work machine 100.

[0067] The work machine 100 according to the embodiment described above is equipped with crawler tracks 121 as a traveling device, but is not limited to this. For example, in other embodiments, the work machine 100 may be equipped with wheels as a traveling device. Furthermore, the wheels may be steered wheels that can be steered by a steering mechanism. If the work machine 100 is equipped with steered wheels, the control device 200 can determine a turning operation based on the steering angle.

[0068] The control device 200 according to the embodiment described above identifies the operation of the running body 120 based on an operation signal, but is not limited to this. For example, the control device 200 according to another embodiment may identify the operation of the running body 120 from a measured value of the rotational speed of the crawler 121.

[0069] The virtual wall VW according to the embodiment described above is recorded in advance in the storage 250 of the control device 200, but is not limited to this. For example, the virtual wall VW according to other embodiments may be calculated based on the positions of other work machines 100 so as not to interfere with the other work machines 100. Furthermore, while the virtual wall VW according to the embodiment described above is expressed in a site coordinate system, the virtual wall VW according to other embodiments may be expressed in a vehicle body coordinate system.

[0070] The work machine 100 according to the embodiment described above is operated by an operator seated in the cab 180, but the work machine 100 according to other embodiments is not limited to this. FIG. 7 is a diagram showing the configuration of a work system according to another embodiment. The work machine 100 according to other embodiments may be operated by a remote control device 500 as shown in FIG. 7. The remotely controlled work machine 100 further includes an imaging device 119 in addition to the configuration of the embodiment described above, and the control device 200 transmits images captured by the imaging device 119 to the remote control device 500 in real time. The remote control device 500 includes a driver's seat 510, a display 520, an operation device 530, and a remote control server 540. The remote control server 540 displays images received from the work machine 100 on the display 520. This allows the operator to recognize the situation around the remote work machine 100. The remote control server 540 also transmits operation signals from the operator to the operation device 530 via a network to the work machine 100. The remote control server 540 executes at least some of the functions of the control device 200 according to the embodiment described above. In other words, in a work system equipped with a remote control server 540, the control device 200 and the remote control server 540 constitute the work system. Furthermore, the work machine 100 according to other embodiments may be an autonomously operated one. For example, when construction data from a work site is input to the control device 200 via a communication line, the control device 200 determines an operation plan for the work machine 100 based on the construction data and the position and attitude of the vehicle at the work site, and controls the work machine 100. At this time, the control device 200 determines the travel speed so that the virtual wall VW does not come into contact with the work machine 100. In this way, the control device 200 can control the work machine 100 to prevent it from entering a no-entry zone.

[0071] Although a bucket is attached as the attachment 163 to the work machine 160 according to the first embodiment, this is not limiting. For example, the work machine 160 according to other embodiments may be equipped with another work tool, such as a breaker or a grapple, instead of a bucket. Furthermore, the attachment 163 according to other embodiments may be attached to the tip of the arm 162 via a tilt attachment or a tilt-rotate attachment.

[0072] The control device 200 according to the first embodiment simulates the outer shell of the arm bottom, arm top, and attachment 163 with a virtual sphere VS and identifies the distance from the virtual wall VW, but is not limited to this. For example, the work machine 160 according to other embodiments may identify the position of the outer shell using geometry data indicating the positions of a plurality of points (control points) on the outer shell of the arm bottom, arm top, and attachment 163.

[0073] According to the above aspect, the system can control the work machine so that it does not enter the restricted area.

[0074] DESCRIPTION OF SYMBOLS 100...Working machine 101...Inclination measuring device 102...Swing angle sensor 103...Boom angle sensor 104...Arm angle sensor 105...Attachment angle sensor 106...Position and orientation detector 111...Power source 112...Hydraulic pump 113...Control valve 114...Travel motor 115...Swing motor 116...Boom cylinder 117...Arm cylinder 118...Attachment cylinder 119...Imaging device 120...Traveling body 121...Crawler track 140...Swinging body 141...Operation device 142...Monitor device 160...Working machine 161...Boom 162...Arm 163...Attachment 180...Operator's cab 200...Control device 210...Processor 211...Operation signal receiving unit 212...Input unit 213...Display control unit 214...Measurement value receiving unit 215: Position identification unit 218: Intervention determination unit 219: Intervention control unit 220: Control signal output unit 230: Main memory 250: Storage 270: Interface 500: Remote control device 510: Driver's seat 520: Display 530: Operation device 540: Remote control server VW: Virtual wall

Claims

1. A system for controlling a working machine, comprising a processor, wherein the processor identifies a virtual wall that is a surface for prohibiting entry of the working machine, and controls a traveling speed of the working machine based on the identified virtual wall.

2. The system according to claim 1, wherein the processor controls the traveling speed so that the virtual wall and the working machine do not come into contact with each other.

3. The system according to claim 1, wherein the processor controls the traveling speed based on a distance between an outer shell of the working machine and the virtual wall.

4. The working machine includes a pair of left and right traveling devices, and the processor controls the traveling speed based on at least one of an operation direction of each of the pair of left and right traveling devices and an operation amount of each of the pair of left and right traveling devices. The system according to claim 3.

5. The system according to claim 4, wherein the processor controls the traveling speed so that the virtual wall and the working machine do not come into contact with each other when both of the pair of left and right traveling devices are operated in a direction approaching the virtual wall.

6. The system according to claim 4, wherein the processor does not limit the traveling speed when both of the pair of left and right traveling devices are operated in a direction away from the virtual wall.

7. The system according to claim 4, wherein when the operation directions of the pair of left and right traveling devices are different from each other, the processor identifies a portion of the outer shell of the working machine that approaches the virtual wall, and controls the traveling speed based on a distance between the identified portion and the virtual wall.

8. The processor identifies a turning direction of the working machine by the pair of left and right traveling devices based on the operation directions of the pair of left and right traveling devices, and based on the identified turning direction, a portion of the outer shell that intersects a plane passing through an axis extending in the front-rear direction of the vehicle body of the working machine and an axis extending in the left-right direction and passing through the midpoint of the pair of left and right traveling devices and rotates in a direction approaching the virtual wall on the side where there is a traveling device. The system according to claim 7, wherein the portion approaching the virtual wall is identified.

9. The processor, when the operation amounts of the pair of left and right traveling devices are different, identifies a portion of the outer shell of the work machine that approaches the virtual wall, and controls the traveling speed based on the distance between the identified portion and the virtual wall. The system according to claim 4.

10. The processor identifies a turning direction of the work machine by the pair of left and right traveling devices based on the operation amounts of the pair of left and right traveling devices, and based on the identified turning direction, identifies, as the portion approaching the virtual wall, a portion of the outer shell that intersects the virtual wall and the ground contact surfaces of the pair of left and right traveling devices and that is on the side in the direction approaching the virtual wall from a plane passing through the midpoint of the pair of left and right traveling devices. The system according to claim 9.

11. The pair of left and right traveling devices are a pair of left and right crawler tracks. The system according to claim 4.

12. The processor determines an allowable speed based on the distance between the outer shell of the work machine and the virtual wall, receives an operation amount for each of the pair of left and right traveling devices, calculates a target speed for each of the pair of left and right traveling devices based on the allowable speed and the operation amount, and controls the traveling speed such that a ratio of a commanded speed indicated by the operation amount related to a first traveling device among the pair of left and right traveling devices to the target speed is equal to a ratio of a commanded speed indicated by the operation amount related to a second traveling device among the pair of left and right traveling devices to the target speed. The system according to claim 4.

13. A method for controlling a work machine, the method comprising: identifying a virtual wall that is a surface for prohibiting entry into the work machine; and controlling a traveling speed of the work machine based on the identified virtual wall.

14. A program for causing a computer that controls a work machine to execute: identifying a virtual wall that is a surface for prohibiting entry into the work machine; and controlling a traveling speed of the work machine based on the identified virtual wall.

Images