WO2023032949A1

WO2023032949A1 - Control system, control method, and control program

Info

Publication number: WO2023032949A1
Application number: PCT/JP2022/032508
Authority: WO
Inventors: 和生竹原
Original assignee: 株式会社小松製作所
Priority date: 2021-08-31
Filing date: 2022-08-30
Publication date: 2023-03-09
Also published as: JP2023034969A; KR20240026519A; CN117836491A; DE112022003034T5

Abstract

A processor generates a design plane defined by a flat plane on a vehicle body coordinate system in which a representative point of a pivoting body is the origin. The processor rotationally transforms the design plane around the origin of the vehicle body coordinate system as the pivoting body pivots. The processor identifies the position of a work implement in the vehicle body coordinate system. The processor controls the work implement on the basis of the identified position of the work implement and the design plane.

Description

Control system, control method and control program

The present disclosure relates to control systems, control methods, and control programs.
This application claims priority to Japanese Patent Application No. 2021-141520 filed in Japan on August 31, 2021, and the contents thereof are incorporated herein.

As disclosed in Patent Literature 1, there is known a technique for controlling a work machine so that a bucket provided on the work machine does not intrude ahead of a design surface indicating a target shape of an excavating object.

Japanese Patent No. 5654144

With the technology described in Patent Document 1, the control device recognizes the position of the work machine in the global coordinate system using GNSS, so that the cutting edge can be controlled with respect to the design surface. However, it is not always possible to refer to the global coordinate system depending on the line-of-sight environment of the satellite and the configuration of the work machine. For example, when a work machine works indoors, it may not be possible to refer to GNSS due to poor satellite visibility.

An object of the present disclosure is to provide a control system, control method, and control program capable of generating a design surface for controlling a working machine without referring to the global coordinate system.

According to a first aspect of the present invention, a control system includes a traveling body, a revolving body rotatably supported by the running body, and a working machine operably supported by the revolving body. control the machine. The control system comprises a processor. The processor generates a design surface defined by a plane on vehicle body coordinates with the representative point of the vehicle body as the origin. The processor rotationally transforms the design plane around the origin of the vehicle body coordinate system as the revolving superstructure turns. The processor identifies the position of the work implement in the vehicle body coordinate system. The processor controls the work machine based on the identified position and design aspect of the work machine.

According to a second aspect of the present invention, there is provided a control method for a work machine including a travelable running body, a revolving body rotatably supported by the running body, and a work machine operably supported by the revolving body. comprises a generation step, a rotation transformation step, an identification step, and a control step. The generation step generates a design surface defined by a plane on a vehicle body coordinate system having a representative point of the revolving body as an origin. The rotational transformation step rotationally transforms the design surface around the origin of the vehicle body coordinate system as the revolving body turns. The identification step identifies the position of the work implement in the vehicle body coordinate system. The control step controls the working machine based on the identified position and design of the working machine.

According to a third aspect of the present invention, the control program includes a work including a travelable running body, a revolving body rotatably supported by the running body, and a working machine operably supported by the revolving body. A control program executed by the computer of the machine that causes the generation step, the rotation conversion step, the identification step, and the control step to be performed. The generation step generates a design surface defined by a plane on a vehicle body coordinate system having a representative point of the revolving body as an origin. The rotational transformation step rotationally transforms the design surface around the origin of the vehicle body coordinate system as the revolving body turns. The identification step identifies the position of the work implement in the vehicle body coordinate system. The control step controls the working machine based on the identified position and design of the working machine.

According to at least one of the above aspects, it is possible to generate a design surface for controlling the working machine without referring to the global coordinate system.

1 is a schematic diagram showing the configuration of a working machine according to a first embodiment; FIG. It is a figure which shows the drive system of the working machine which concerns on 1st Embodiment. 1 is a schematic block diagram showing the configuration of a control device according to a first embodiment; FIG. FIG. 5 is a diagram showing an example of resetting of a design surface accompanying revolving of the revolving superstructure in the first embodiment; 4 is a flowchart showing a design surface setting method according to the first embodiment; 4 is a flow chart showing design surface update and intervention control associated with turning set in the first embodiment. 6 is a flowchart showing design surface update processing by the control device according to the first embodiment. FIG. 4 is a diagram showing changes in the design surface before and after movement of the work machine in the first embodiment; FIG. 10 is a diagram showing movement of a design surface in the first embodiment; FIG.

<First embodiment>
<<Construction of working machine>>
Hereinafter, embodiments will be described in detail with reference to the drawings.
FIG. 1 is a schematic diagram showing the configuration of a working machine 100 according to the first embodiment. A working machine 100 according to the first embodiment is, for example, a hydraulic excavator. The working machine 100 includes a traveling body 120 , a revolving body 140 , a working machine 160 , an operator's cab 180 and a control device 200 . The work machine 100 according to the first embodiment is controlled by an operator to generate a planar design plane and prevent the cutting edge from exceeding the design plane. At this time, since the design plane is set in the vehicle body coordinate system, construction using the design plane can be realized even when positioning cannot be performed by GNSS or the like, such as when work machine 100 constructs a tunnel.

Traveling body 120 supports work machine 100 so that it can travel. The traveling body 120 is, for example, a pair of left and right endless tracks.
The revolving body 140 is supported by the traveling body 120 so as to be able to revolve around the revolving center. Revolving body 140 is an example of a vehicle body of work machine 100 .
Work implement 160 is operably supported by revolving body 140 . Work implement 160 is hydraulically driven. Work machine 160 includes a boom 161, an arm 162, and a bucket 163 that is a work implement. A base end of the boom 161 is rotatably attached to the revolving body 140 . A proximal end of the arm 162 is rotatably attached to a distal end of the boom 161 . The base end of the bucket 163 is rotatably attached to the tip of the arm 162 . Here, a portion of the revolving body 140 to which the work implement 160 is attached is referred to as a front portion. In addition, with respect to the revolving body 140, the front portion is referred to as the rear portion, the left portion is referred to as the left portion, and the right portion is referred to as the right portion.

The operator's cab 180 is provided in the front part of the revolving body 140 . Inside the operator's cab 180, an operation device 141 for an operator to operate the work machine 100 and a monitor device 142 as a man-machine interface of the control device 200 are provided. The monitor device 142 is realized by a computer having a touch panel, for example.

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

<<Drive System of Working Machine 100>>
FIG. 2 is a diagram showing the drive system of the work machine 100 according to the first embodiment.
Work machine 100 includes a plurality of actuators for driving work machine 100 . Specifically, work machine 100 includes an engine 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 a bucket cylinder 118 .

The engine 111 is a prime mover that drives the hydraulic pump 112 .
Hydraulic pump 112 is driven by engine 111 and supplies working oil to travel motor 114 , swing motor 115 , boom cylinder 116 , arm cylinder 117 and bucket cylinder 118 via control valve 113 .
Control valve 113 controls the flow rate of hydraulic oil supplied from hydraulic pump 112 to travel motor 114 , swing motor 115 , boom cylinder 116 , arm cylinder 117 and bucket cylinder 118 .
The traveling motor 114 is driven by hydraulic oil supplied from the hydraulic pump 112 to drive the traveling body 120 .
The swing motor 115 is driven by hydraulic fluid supplied from the hydraulic pump 112 to swing the swing body 140 with respect to the traveling body 120 .

Boom cylinder 116 is a hydraulic cylinder for driving boom 161 . A proximal end of the boom cylinder 116 is attached to a rotating body 140 . A tip of the boom cylinder 116 is attached to the boom 161 .
Arm cylinder 117 is a hydraulic cylinder for driving arm 162 . A base end of the arm cylinder 117 is attached to the boom 161 . A tip of the arm cylinder 117 is attached to the arm 162 .
Bucket cylinder 118 is a hydraulic cylinder for driving bucket 163 . The proximal end of bucket cylinder 118 is attached to arm 162 . A tip of the bucket cylinder 118 is attached to the bucket 163 .

<<Measurement System of Work Machine 100>>
Work machine 100 includes a plurality of sensors for measuring the attitude and position of work machine 100 . Specifically, work machine 100 includes tilt measuring instrument 101 , turning angle sensor 102 , boom angle sensor 103 , arm angle sensor 104 and bucket angle sensor 105 .

The tilt measuring instrument 101 measures the attitude of the revolving body 140 . The tilt measuring device 101 measures the tilt (for example, roll angle, pitch angle and yaw angle) of the revolving superstructure 140 with respect to the horizontal plane. An example of the tilt measuring instrument 101 is an IMU (Inertial Measurement Unit). In this case, the tilt measuring instrument 101 measures the acceleration and angular velocity of the revolving structure 140, and calculates the tilt of the revolving structure 140 with respect to the horizontal plane based on the measurement results. The tilt measuring instrument 101 is installed, for example, below the driver's cab 180 . The inclination measuring instrument 101 outputs the posture data of the revolving body 140 as measured values to the control device 200 .

The turning angle sensor 102 measures the turning angle of the turning body 140 with respect to the traveling body 120 . The measured value of the turning angle sensor 102 indicates zero when the directions of the traveling body 120 and the turning body 140 match, for example. The turning angle sensor 102 is installed, for example, at the turning center of the turning body 140 . The turning angle sensor 102 outputs turning angle data, which is a measured value, to the control device 200 .

The boom angle sensor 103 measures the boom angle, which is the rotation angle of the boom 161 with respect to the revolving body 140 . Boom angle sensor 103 may be an IMU attached to boom 161 . In this case, the boom angle sensor 103 measures the boom angle based on the tilt of the boom 161 with respect to the horizontal plane and the tilt of the revolving body measured by the tilt measuring device 101 . The measured value of the boom angle sensor 103 indicates zero when, for example, the direction of a straight line passing through the base end and the tip end of the boom 161 coincides with the longitudinal direction of the revolving body 140 . Note that the boom angle sensor 103 according to another embodiment may be a stroke sensor attached to the boom cylinder 116 . Also, the boom angle sensor 103 according to another embodiment may be a rotation sensor provided on a pin that connects the revolving body 140 and the boom 161 . Boom angle sensor 103 outputs boom angle data, which is a measured value, to control device 200 .

The arm angle sensor 104 measures the arm angle, which is the rotation angle of the arm 162 with respect to the boom 161 . Arm angle sensor 104 may be an IMU attached to arm 162 . In this case, the arm angle sensor 104 measures the arm angle based on the tilt of the arm 162 with respect to the horizontal plane and the boom angle measured by the boom angle sensor 103 . The measured value of the arm angle sensor 104 indicates zero when the direction of the straight line passing through the proximal end and the distal end of the arm 162 matches the direction of the straight line passing through the proximal end and the distal end of the boom 161, for example. Note that the arm angle sensor 104 according to another embodiment may calculate the angle by attaching a stroke sensor to the arm cylinder 117 . Also, the arm angle sensor 104 according to another embodiment may be a rotation sensor provided on a pin that connects the boom 161 and the arm 162 . Arm angle sensor 104 outputs arm angle data, which is a measured value, to control device 200 .

The bucket angle sensor 105 measures the bucket angle, which is the rotation angle of the bucket 163 with respect to the arm 162 . Bucket angle sensor 105 may be a stroke sensor provided on bucket cylinder 118 for driving bucket 163 . In this case, the bucket angle sensor 105 measures the bucket angle based on the stroke amount of the bucket cylinder. The measured value of the bucket angle sensor 105 indicates zero, for example, when the direction of the straight line passing through the proximal end and the cutting edge of the bucket 163 matches the direction of the straight line passing through the proximal end and the distal end of the arm 162 . Bucket angle sensor 105 according to another embodiment may be a rotation sensor provided on a pin that connects arm 162 and bucket 163 . Bucket angle sensor 105 according to another embodiment may be an IMU attached to bucket 163 . Bucket angle sensor 105 outputs bucket angle data, which is a measured value, to control device 200 .

<<Configuration of Control Device 200>>
FIG. 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 that includes a processor 210 , main memory 230 , storage 250 and interface 270 . Control device 200 is an example of a control system. Controller 200 receives measurements from tilt gauge 101 , turning angle sensor 102 , boom angle sensor 103 , arm angle sensor 104 and bucket angle sensor 105 .

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

The control program may be for realizing part of the functions that the control device 200 is to perform. For example, the control program may function in combination with another program already stored in the storage 250 or in combination with another program installed in another device. In other embodiments, the control device 200 may include a custom LSI (Large Scale Integrated Circuit) such as a PLD (Programmable Logic Device) in addition to or instead of the above configuration. Examples of PLDs include PAL (Programmable Array Logic), GAL (Generic Array Logic), CPLD (Complex Programmable Logic Device), and FPGA (Field Programmable Gate Array). In this case, part or all of the functions implemented by the processor may be implemented by the integrated circuit.

The storage 250 records geometry data representing the dimensions and center-of-gravity positions of the revolving structure 140, the boom 161, the arm 162, and the bucket 163. Geometry data is data representing the position of an object in a predetermined coordinate system.

《Software configuration》
By executing the control program, the processor 210 performs the operation amount acquisition unit 211, the input unit 212, the display control unit 213, the measured value acquisition unit 214, the position specifying unit 215, the generation unit 216, the rotation conversion unit 217, and the intervention determination unit. 218 , an intervention control unit 219 , a control signal output unit 220 and an update unit 221 .

The operation amount acquisition unit 211 acquires an operation signal indicating the operation amount of each actuator from the operation device 141 .
The input unit 212 receives operation input from the operator from the monitor device 142 .
The display control unit 213 outputs screen data to be displayed on the monitor device 142 to the monitor device 142 .
The measured value acquisition unit 214 acquires measured values from the tilt measuring device 101 , the turning angle sensor 102 , the boom angle sensor 103 , the arm angle sensor 104 and the bucket angle sensor 105 .

The position specifying unit 215 specifies the position of the cutting edge of the bucket 163 in the vehicle body coordinate system based on the various measurement values acquired by the measurement value acquisition unit 214 and the geometry data recorded in the storage 250 . The vehicle body coordinate system is an orthogonal coordinate system whose origin is a representative point of the revolving body 140 (for example, a point passing through the center of revolving). The calculation of the position specifying unit 215 will be described later.

When the input unit 212 receives a design surface generation instruction from the operator, the generating unit 216 calculates the parameters of the design surface based on the position of the cutting edge of the bucket 163 identified by the position identifying unit 215 . The generator 216 records the generated parameters of the design surface in the vehicle body coordinate system in the main memory 230 .

The rotation conversion unit 217 updates the parameters of the design surface stored in the main memory 230 as the revolving body 140 revolves. Specifically, the rotation conversion unit 217 rotates the parameters of the design surface about the origin of the vehicle body coordinate system by the amount of change in the pitch angle, roll angle, and yaw angle measured by the tilt measuring device 101 . FIG. 4 is a diagram showing an example of resetting the design surface as the revolving superstructure revolves according to the first embodiment. For example, as shown in FIG. 4 , when the revolving superstructure 140 revolves after setting the design surface, the rotation conversion unit 217 refers to the measurement values of the tilt measuring device 101 acquired by the measurement value acquiring unit 214 to The amount of change in the roll angle, pitch angle, and yaw angle caused by the turning of the vehicle is calculated, and the parameters of the design surface are rotationally transformed around the origin of the vehicle body coordinate system. As a result, the rotation conversion unit 217 can cancel the rotation of the design surface caused by the turning of the turning body 140 .

The intervention determination unit 218 determines whether or not to limit the speed of the work implement 160 based on the positional relationship between the cutting edge of the bucket 163 and the design surface specified by the position specifying unit 215 . Hereinafter, the restriction of the speed of work implement 160 by control device 200 is also referred to as intervention control. Specifically, intervention determination unit 218 obtains the minimum distance between the design surface and bucket 163 , and determines that intervention control is to be performed for work implement 160 when the minimum distance is equal to or less than a predetermined distance.

When the intervention determination unit 218 determines that intervention control should be performed, the intervention control unit 219 controls the operation amount to be intervened among the operation amounts acquired by the operation amount acquisition unit 211 . In intervention control, intervention control unit 219 controls the amount of operation of boom 161 so that work implement 160 does not enter the control line. As a result, the boom 161 is driven such that the speed of the bucket 163 corresponds to the distance between the bucket 163 and the control line. In other words, when the operator operates the arm 162 to excavate, the intervention control unit 219 limits the speed of the cutting edge of the bucket 163 by raising the boom 161 in accordance with the design.

The control signal output unit 220 outputs the operation amount acquired by the operation amount acquisition unit 211 or the operation amount controlled by the intervention determination unit 218 to the control valve 113 .

The update unit 221 updates the parameters of the design surface stored in the main memory 230 as the work machine 100 travels. Specifically, before and after work machine 100 travels, the operator operates work machine 160 to bring the cutting edge of bucket 163 into contact with a specific position on the site. The updating unit 221 moves the design surface based on the difference in the position of the cutting edge of the bucket 163 in the vehicle body coordinate system before and after traveling.

<<Calculation of position specifying unit 215>>
Here, a method for specifying the position of the cutting edge of bucket 163 by position specifying unit 215 will be described. The position specifying unit 215 specifies the position of the cutting edge of the bucket 163 based on the various measurement values acquired by the measurement value acquiring unit 214 and the geometry data recorded in the storage 250 . The storage 250 records geometry data representing the dimensions of the revolving structure 140 , the boom 161 , the arm 162 and the bucket 163 .

The geometry data of the rotating body 140 indicates the positions (x _bm , y _bm , z _bm ) of the pins supporting the boom 161 of the rotating body 140 in the vehicle body coordinate system, which is the local coordinate system. The vehicle body coordinate system is a coordinate system composed of the X _sb axis extending in the front-rear direction, the Y _sb axis extending in the left-right direction, and the Z _sb axis extending in the up-down direction with reference to the turning center of the turning body 140 . Note that the vertical direction of the revolving body 140 does not necessarily match the vertical direction.

The geometry data of the boom 161 indicates the boom top position (x _am , y _am , z _am ) in the boom coordinate system, which is the local coordinate system. The boom coordinate system is based on the position of the pin that connects the boom 161 and the revolving body 140, and is orthogonal to the _Xbm axis extending in the longitudinal direction, the _Ybm axis extending in the direction in which the pin extends, and the _Xbm axis and the _Ybm axis. It is a coordinate system composed of the _Zbm axis. The boom top is the position of the pin that connects the boom 161 and arm 162 .

The geometry data of the arm 162 indicates the arm top position (x _bk , y _bk , z _bk ) in the arm coordinate system, which is the local coordinate system. The arm coordinate system is based on the position of the pin that connects the arm 162 and the boom 161, the X _am axis extending in the longitudinal direction, the Y _am axis extending in the direction in which the pin extends, and the Z axis perpendicular to the X _am axis and the _Yam axis. It is a coordinate system composed of _{the am-} axis. Arm top is the location of the pin that connects arm 162 and bucket 163 .

The geometry data of the bucket 163 indicates the position (x _ed , y _ed , z _ed ) of the cutting edge of the bucket 163 in the bucket coordinate system, which is the local coordinate system. The bucket coordinate system is based on the position of the pin that connects the bucket 163 and the arm 162. The _Xbk axis extends in the direction of the cutting edge, the _Ybk axis extends in the direction in which the pin extends, and the _Xbk axis and the _Ybk axis are perpendicular to each other. It is a coordinate system composed of the _Zbk axis.

The position specifying unit 215 converts the boom coordinate system to the vehicle body coordinate system using the following formula (1) based on the measured value of the boom angle _θbm acquired by the measured value acquisition unit 214 and the geometry data of the swing body 140. Generate a boom-to-body transformation matrix T ^bm _sb for The boom-body transformation matrix T ^bm _sb is rotated about the Y _bm axis by the boom angle θ _bm and moved by the deviation (x _bm , y _bm , z _bm ) between the origin of the body coordinate system and the origin of the boom coordinate system. matrix. Further, the position specifying unit 215 obtains the product of the position of the boom top in the boom coordinate system indicated by the geometry data of the boom 161 and the boom-vehicle transformation matrix T ^bm _sb , thereby determining the position of the boom top in the vehicle body coordinate system. demand.

The position specifying unit 215 converts the arm coordinate system to the boom coordinate system using the following formula (2) based on the measured value of the arm angle θ _am acquired by the measured value acquiring unit 214 and the geometry data of the boom 161. Generate an arm-to-boom transformation matrix T ^am _bm for . The arm-boom transformation matrix T ^am _bm rotates about the Y _am axis by the arm angle θ _am and moves by the deviation (x _am , y _am , z _am ) between the origin of the boom coordinate system and the origin of the arm coordinate system. matrix. Further, the position specifying unit 215 obtains the product of the boom-body transformation matrix T ^bm _sb and the arm-boom transformation matrix T ^am _bm , thereby obtaining the arm-body transformation matrix T for transformation from the arm coordinate system to the vehicle body coordinate system. Generate ^am _sb . Further, the position specifying unit 215 obtains the product of the position of the arm top in the arm coordinate system indicated by the geometry data of the arm 162 and the arm-to-body transformation matrix T ^am _sb , thereby determining the position of the arm top in the body coordinate system. demand.

The position specifying unit 215 converts the bucket coordinate system into the arm coordinate system using the following formula (3) based on the measured value of the bucket angle _θbk acquired by the measured value acquiring unit 214 and the geometry data of the arm 162. Generate a bucket-to-arm transformation matrix T ^bk _am for . The bucket-to-arm transformation matrix T ^bk _am is rotated about the Y _bk axis by the bucket angle θ _bk and translated by the deviation between the origin of the arm coordinate system and the origin of the bucket coordinate system (x _bk , y _bk , z _bk ) matrix. Further, the position specifying unit 215 obtains the product of the arm-body transformation matrix T ^am _sb and the bucket-arm transformation matrix T ^bk _am , thereby obtaining the bucket-body transformation matrix T for transforming from the bucket coordinate system to the vehicle body coordinate system. Create ^bk _sb .

The position specifying unit 215 obtains the position of the cutting edge of the bucket 163 in the vehicle body coordinate system by multiplying the position of the cutting edge in the bucket coordinate system indicated by the geometry data of the bucket 163 by the bucket-vehicle transformation matrix T ^bk _sb . .

<<Method of Controlling Work Machine 100>>
A control method for the work machine 100 according to the first embodiment will be described below.
First, the operator of the work machine 100 operates the monitor device 142 to set the design surface.

《Setting the design surface》
FIG. 5 is a flow chart showing a design surface setting method according to the first embodiment.
When the input unit 212 receives a design surface setting instruction from the monitor device 142, the display control unit 213 causes the monitor device 142 to display a guidance screen including a distance input field, an inclination input field, and a setting button (step S101). On the guidance screen, move the cutting edge of the bucket 163 above the point where the design surface is to be set, enter the distance from the cutting edge to the design surface in the distance input field, and the inclination angle of the design surface in the inclination input field. A message to operate the button is displayed. A distance of 0 meters, a pitch angle of 0 degrees, and a roll angle of 0 degrees are entered as initial values in the distance input field and the tilt angle input field. Hereinafter, the distance input in the distance input field will be referred to as input distance, and the tilt angle input in the tilt angle input field will be referred to as input tilt angle (input pitch angle, input roll angle). The operator operates work machine 100 to move the cutting edge of bucket 163 to a desired position, and then operates the setting button. The input unit 212 receives inputs from the monitor device 142 in the distance input field and the tilt angle input field and the operation of the setting button (step S102). The input unit 212 acquires the values in the distance input field and the tilt angle input field when the setting button is operated (step S103). The input tilt angle is a tilt angle based on the vertical direction and the front of work machine 100 when the design surface is set. That is, the input pitch angle and input roll angle are the inclinations of the normal to the design surface with respect to the vertical axis.

The measured value acquisition unit 214 acquires the measured values of the tilt measuring device 101, turning angle sensor 102, boom angle sensor 103, arm angle sensor 104, and bucket angle sensor 105 at the time the setting button is operated (step S104). The position specifying unit 215 specifies the position of the cutting edge of the bucket 163 in the vehicle body coordinate system based on the acquired measurement values (step S105).

The generation unit 216 inputs the roll angle and pitch angle (measured roll angle and measured pitch angle) obtained from the tilt measuring instrument 101 in step S104, the position of the cutting edge obtained in step S105, and the input distance obtained in step S103. The parameters of the design surface are calculated based on the inclination angle. The generation unit 216 rotates a vector having a value of 0 on the X _sb axis, a value of 0 on the Y _sb axis, and a value of 1 on the Z _sb axis by the measured roll angle and the measured pitch angle, so that the vertical A vector is obtained (step S106). The generation unit 216 obtains the position vector of the design surface by obtaining the sum of the vector indicating the position of the cutting edge obtained in step S104 and the depth vector obtained by multiplying the vertical vector by the distance (step S107). The generator 216 also obtains the normal vector of the design surface based on the vertical vector and the input tilt angle (step S108). Specifically, the generator 216 shares the origin with the vehicle body coordinate system, and the _Zv axis extending in the vertical direction coincides with the _Xsb axis of the vehicle body coordinate system when the measured roll angle and the measured pitch angle are zero. A vertical coordinate system, which is an orthogonal coordinate system composed of the Xv _- axis and the Yv-axis that coincides with _{the Ysb} _- axis of the vehicle body coordinate system when the measured roll angle and the measured pitch angle are zero, is specified. That is, the vertical coordinate system coincides with the vehicle body coordinate system when the measured roll angle and measured pitch angle are zero. The generator 216 rotates the vertical coordinate system around the _Yv axis by the input pitch angle. The generation unit 216 also rotates the vertical coordinate system around the _Xv axis by the input roll angle. The generation unit 216 calculates the outer product of the unit vector extending in the Xv _- axis direction of the vertical coordinate system rotated about the _Yv- axis and the unit vector extending in the Yv _- axis direction of the vertical coordinate system rotated about the _Xv- axis. to find the normal vector of the design surface in the vertical coordinate system. The generation unit 216 rotates the normal vector in the vertical coordinate system by the measured roll angle and the measured pitch angle to obtain the normal vector of the design surface in the vehicle body coordinate system.

The generation unit 216 records the generated design surface parameters (normal vector and position vector) in the main memory 230 (step S109). If the design surface parameters are already recorded in the main memory 230, the old parameters are overwritten with the new parameters.

《Updating the design surface and intervention control accompanying turning》
The work machine 100 can perform work within the reach of the work machine 160 by turning the revolving body 140 . Therefore, an operator normally turns work machine 100 when performing work such as excavation. Since the vehicle body coordinate system is based on revolving body 140 , the positional relationship between the design plane set in the vehicle body coordinate system and work machine 160 does not change as work machine 100 turns. Therefore, if the design plane is not updated while being set by the above procedure, the design plane behaves as if it moves following the revolution of the revolving body 140 as seen from the viewpoint of the global coordinate system. For example, if a design surface that slopes downward when viewed from the revolving superstructure 140 is generated, the tilt direction of the design surface viewed from the revolving superstructure 140 always maintains the downward slope no matter how the revolving superstructure 140 is rotated.
Therefore, the control device 200 according to the first embodiment performs rotation conversion processing of the design surface in order to maintain the position of the design surface in the global coordinate system before and after the work machine 100 turns.

FIG. 6 is a flow chart showing design surface update and intervention control associated with turning set in the first embodiment. When the operator of work machine 100 sets the design surface by operating monitor device 142, control device 200 starts the control described below.

The operation amount acquisition unit 211 acquires operation signals for the boom 161, the arm 162, the bucket 163, and the revolving body 140 from the operation device 141 (step S201). The measured value acquisition unit 214 acquires measured values of the tilt measuring device 101, the turning angle sensor 102, the boom angle sensor 103, the arm angle sensor 104, and the bucket angle sensor 105 (step S202).

The rotation transforming unit 217 rotates and updates the design surface stored in the main memory 230 based on the roll angle, pitch angle, and yaw angle of the revolving structure 140 acquired from the tilt measuring instrument 101 in step S202 (step S203). ).

The position specifying unit 215 calculates the position of the cutting edge of the bucket 163 in the vehicle body coordinate system based on the measurement values obtained in step S202 (step S204). The intervention determination unit 218 identifies a cross section parallel to the X _sb -Z _sb plane of the vehicle body coordinate system passing through the position of the cutting edge calculated in step S204 (step S205).

The intervention determination unit 218 calculates the line of intersection between the cross section generated in step S205 and the design surface as a control line (step S206). The intervention determination unit 218 obtains the distance between the cutting edge of the bucket 163 and the control line (step S207). The intervention determination unit 218 determines whether or not the distance between the cutting edge and the control line is longer than the intervention start distance (step S208). If the distance is longer than the intervention start distance (step S<b>208 : YES), intervention control unit 219 does not perform intervention control for work implement 160 .

On the other hand, if the shortest distance is equal to or less than the intervention start distance (step S208: NO), intervention control unit 219 controls boom 161, arm 162, and A target speed of the bucket 163 is calculated (step S209). Intervention control unit 219 calculates the moving speed of the cutting edge of bucket 163 based on the target speeds and geometry data of boom 161, arm 162 and bucket 163 (step S210).

The intervention control unit 219 identifies the speed limit of the cutting edge of the bucket 163 based on the distance calculated in step S207 and a predetermined speed limit table (step S211). The angular speed limit table is a function showing the relationship between the distance between the cutting edge and the control line and the speed limit of the cutting edge, and the shorter the distance, the smaller the speed limit. The intervention control unit 219 determines whether or not the speed of the cutting edge calculated in step S210 exceeds the speed limit (step S212). If the speed of the cutting edge exceeds the speed limit (step S212: YES), the intervention control unit 219 calculates the speed of the boom 161 for matching the speed of the cutting edge with the speed limit, and sets the target speed of the boom (step S213). If the speed of the cutting edge does not exceed the speed limit (step S<b>212 : NO), intervention control unit 219 does not perform intervention control for work implement 160 .

The control signal output unit 220 generates a control signal based on the target velocities of the boom 161, arm 162 and bucket 163 and the target angular velocity of the revolving body 140, and outputs the control signal to the control valve 113 (step S214).

《Updating the design due to the move》
The construction site of work machine 100 is usually outside the reach of work machine 160 due to the swing of revolving body 140 . Therefore, the operator makes the work machine 100 travel and moves the position of the work machine 100 to carry out construction work on the site. Since the design plane according to the first embodiment is set in the vehicle body coordinate system, when the position of the work machine 100 moves, the design plane follows the revolving body 140 from the viewpoint of the global coordinate system. behave to For example, when the pitch angle θ is set on the design surface, the height of the design surface should change tan θ every meter, but the height of the design surface does not change even if the work machine 100 moves 1 meter. .
Therefore, the control device 200 according to the first embodiment performs the design surface update process shown in FIG. 7 in order to maintain the position of the design surface in the global coordinate system before and after the work machine 100 moves.

FIG. 7 is a flowchart showing design surface update processing by the control device according to the first embodiment.
When the operator moves the work machine 100 during construction of the design surface, the operator operates the monitor device 142 and inputs an instruction to execute the update process. When the input unit 212 of the control device 200 receives an update processing execution instruction from the monitor device 142, the display control unit 213 causes the monitor device 142 to display a first guidance screen including a setting button (step S301). The guidance screen displays that the cutting edge of the bucket 163 should be applied to a target that can be touched by the bucket 163 before and after the movement, and the setting button should be operated. The operator operates the work machine 100 and operates the setting button after the cutting edge of the bucket 163 hits the target. The input unit 212 receives operation of the setting button from the monitor device 142 (step S302).

Measured value acquisition unit 214 acquires information on tilt measuring instrument 101, turning angle sensor 102, boom angle sensor 103, arm angle sensor 104, and bucket angle sensor 105 at the time (first time) when the setting button of the first guidance screen is operated. is acquired (step S303). The position specifying unit 215 specifies the position of the cutting edge of the bucket 163 in the vehicle body coordinate system based on the acquired measurement values (step S304). That is, the position specifying unit 215 specifies the position of the target in the vehicle body coordinate system at the first time. The position specifying unit 215 records the specified position of the cutting edge in the main memory 230 .

Next, the display control unit 213 causes the monitor device 142 to display a second guidance screen including setting buttons (step S305). The guidance screen displays instructions to move work machine 100 to a desired position, apply the cutting edge of bucket 163 to the same target, and operate the setting button. An operator operates the work machine 100 to make the work machine 100 travel.

While the operator is operating the work machine 100, the measured value acquiring unit 214 acquires the measured values of the tilt measuring instrument 101, turning angle sensor 102, boom angle sensor 103, arm angle sensor 104, and bucket angle sensor 105 ( step S306). The updating unit 221 determines whether or not the setting button has been operated (step S307). If the setting button has not been operated (step S307: NO), that is, if the movement to the desired position has not been completed, the rotation conversion unit 217 converts the design surface stored in the main memory 230 to the inclination measuring instrument 101. Rotational conversion is performed based on the measured value and updated (step S308). Then, the control device 200 returns the process to step S306 and repeats the process until the setting button is operated.

When the setting button is operated (step S307: YES), that is, when movement to the desired position is completed, the position specifying unit 215 moves the bucket in the vehicle body coordinate system based on the measured values acquired by the measured value acquisition unit 214. The position of the cutting edge of 163 is identified (step S309). In other words, the position specifying unit 215 specifies the position of the target in the vehicle body coordinate system at the time when the setting button of the second guidance screen is operated (second time).

Next, the updating unit 221 calculates a translational vector that is the difference between the position vector indicating the position of the cutting edge identified in step S304 and the position vector indicating the position of the cutting edge identified in step S309 (step S310). . The updating unit 221 uses the calculated translation vector to move and update the design surface stored in the main memory 230 (step S311). Thereby, the updating unit 221 can maintain the position of the design surface in the global coordinate system before and after traveling.

《Action and effect》
Here, the design surface update processing by the update unit 221 will be described with reference to the drawings. FIG. 8 is a diagram showing changes in the design surface before and after movement of work machine 100 in the first embodiment. In the example shown in FIG. 8, the design surface has a pitch angle. At time t1, the operator hits the blade edge of bucket 163 against target tgt, and then travels work machine 100 backward by distance L. FIG. Since the design surface s is defined by the vehicle body coordinate system, the relative positional relationship between the revolving body 140 and the design surface s is maintained even when the work machine 100 moves. Therefore, from the viewpoint of the global coordinate system, a deviation occurs between the design surface s1 before movement of work machine 100 and the design surface s2 after movement. At this time, the relative positional relationship between the position of the cutting edge of bucket 163 recorded at time t1 and revolving body 140 is also held in the same manner as design surface s.

FIG. 9 is a diagram showing movement of the design surface in the first embodiment. After that, at time t2, the operator hits the blade edge of the bucket 163 against the target tgt again. The updating unit 221 calculates a translational vector v representing the amount of change in the position of the cutting edge from the position of the cutting edge at time t1 and the position of the cutting edge at time t2. Translation vector v corresponds to the amount of movement of work machine 100 as shown in FIG. Therefore, the update unit 221 updates the design surface s2 to the design surface s3 by moving the design surface s2 after movement by the translation vector v. Design surface s3 after movement is equal to design surface s1 of work machine 100 before movement from the viewpoint of the global coordinate system.

In this way, the control device 200 according to the first embodiment can control the position of the cutting edge of the bucket 163 in the vehicle body coordinate system when the cutting edge of the bucket 163 is positioned at the reference point (for example, the target) of the site at the first time, The design surface is moved based on the difference from the position of the cutting edge when the cutting edge is positioned at the reference point at the second time. Thereby, control device 200 can maintain the position of the design surface in the global coordinate system even if the position of work machine 100 changes due to travel.

Also, the control device 200 according to the first embodiment rotationally transforms the design plane based on the measured value of the attitude of the revolving structure 140 between the first time and the second time. Accordingly, even if the posture of work machine 100 changes due to movement of work machine 100, control device 200 can maintain the position of the design plane in the global coordinate system. In another embodiment, if work machine 100 can always maintain the same posture, control device 200 does not need to rotate the design surface. An example of the work machine 100 that always maintains the same posture is the work machine 100 that runs on straight rails that are not twisted.

<Other embodiments>
Although one embodiment has been described in detail above with reference to the drawings, the specific configuration is not limited to the one described above, and various design changes and the like can be made. That is, in other embodiments, the order of the processes described above may be changed as appropriate. Also, some 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 a plurality of computers, and the plurality of computers may cooperate with each other. may function as the control device 200. At this time, a part of the computers constituting control device 200 may be mounted inside work machine 100 and the other computers may be provided outside work machine 100 .

100...Work machine 101...Inclination measuring instrument 102...Swing angle sensor 103...Boom angle sensor 104...Arm angle sensor 105...Bucket angle sensor 111...Engine 112...Hydraulic pump 113...Control valve 114...Travel motor 115...Slewing motor 116... Boom cylinder 117... Arm cylinder 118... Bucket cylinder 120... Traveling body 140... Rotating body 141... Operation device 142... Monitor device 160... Work machine 161... Boom 162... Arm 163... Bucket 180... Operator's cab 200... Control device 210... Processor 211... operation amount acquisition section 212... input section 213... display control section 214... measurement value acquisition section 215... position specifying section 216... generation section 217... rotation conversion section 218... intervention determination section 219... intervention control section 220... control signal output Part 221... Update part 230... Main memory 250... Storage 270... Interface

Claims

A control system for controlling a work machine comprising a traveling body, a revolving body rotatably supported by the running body, and a work machine operably supported by the revolving body,
with a processor
The processor
generating a design surface defined by a plane on a vehicle body coordinate system having a representative point of the revolving body as an origin;
rotationally transforming the design surface around the origin of the vehicle body coordinate system as the revolving body turns;
identifying the position of the work machine in the vehicle body coordinate system;
A control system that controls the working machine based on the identified position of the working machine and the design surface.
The processor
obtaining a measured value from an inclination measuring instrument that measures the attitude of the revolving body;
calculating the amount of change in the attitude caused by the revolving of the revolving body based on the measured values;
The control system according to claim 1, wherein the design plane is rotationally transformed based on the amount of change in attitude.
The processor
A first position, which is the position of the work implement in the vehicle body coordinate system when the work implement is positioned at the reference point of the site at a first time, and a position of the work implement at the reference point at the second time. 3. The control system according to claim 1, wherein the design surface is moved based on a difference from a second position, which is the position of the work implement in the vehicle body coordinate system when the work implement is moved.
The first time is a time before running by the running body,
4. The control system according to claim 3, wherein the second time is a time after the traveling body travels.
A control method for a work machine comprising a travelable running body, a revolving body rotatably supported by the running body, and a work machine operably supported by the revolving body, comprising:
a step of generating a design surface defined by a plane on a vehicle body coordinate system having a representative point of the revolving body as an origin;
a step of rotationally transforming the design surface around the origin of the vehicle body coordinate system as the revolving body revolves;
identifying a position of the working machine in the vehicle body coordinate system;
A control method comprising: controlling the working machine based on the identified position of the working machine and the design surface.
A computer of a work machine comprising a traveling body, a revolving body rotatably supported by the running body, and a work machine operably supported by the revolving body,
a step of generating a design surface defined by a plane on a vehicle body coordinate system having a representative point of the revolving body as an origin;
a step of rotationally transforming the design surface around the origin of the vehicle body coordinate system as the revolving body revolves;
identifying a position of the working machine in the vehicle body coordinate system;
and a step of controlling the working machine based on the specified position of the working machine and the design surface.