Control system for a construction machine, construction machine and control method for a construction machine

Abstract

A control system (200) for a construction machine (100) comprising a working device (1) including an arm (7) and a tilting bucket (8), and a swing body (2) supporting the working device (1), the control system (200) comprising: a construction surface detection unit (54) configured to detect a construction surface (IS) indicating a target shape of a construction target; an operation data acquisition unit (53) configured to acquire operation data of an actuating device (40) that actuates the working device (1) and the swivel body (2); a target value generation unit (55) configured to generate a target value of an amount of control with respect to a tilt rotation of the tilt bucket (8) and a target value of an amount of control of the swing body (2) based on the operation data obtained when the work implement (1) and the swing body (2) are operated, and further based on the design area (IS); a prediction unit (562) configured to calculate a prediction value of the amount of control with respect to the tilting rotation of the tilting bucket (8) and a prediction value of an amount of control with respect to the swinging of the swing body (2) on the basis of the target values ​​and a prediction model for the construction machine (100), and configured to calculate, based on the prediction values ​​and the construction surface (IS), control amounts for controlling the work implement (1) and the swing body (2) to maintain a distance from a predetermined portion (9) of the tilting bucket (8) to the construction surface (IS) and a posture of the tilting bucket (8); and a command unit (58) configured to output control commands for controlling the working device (1) and the swing body (2) based on the control amounts.

Description

[0001] The present invention relates to a control system for a construction machine, a construction machine and a control method for a construction machine.

[0002] In a technical field related to construction machinery, a control system for a construction machine that moves a bucket of a work tool along a construction surface indicating a target shape of a construction target is known, as disclosed in Patent Document 1. Patent literature

[0003] WO 2014 / 167718 A, US 2014 / 0 107 832 A1, DE 11 2017 002 603 T5, DE 11 2014 000 074 T5, DE 11 2016 000 072 T5.

[0004] DE 11 2017 002 603 T5 discloses a control system for a construction machine including a work implement with an arm and a dump bucket, and a swing body supporting the work implement, the control system comprising: a construction surface detection unit configured to detect a construction surface indicating a target shape of a construction target; an operation data detection unit configured to detect operation data of an operation device that operates the work implement and the swing body;a target value generation unit configured to generate a target value of an amount of control regarding the tilt rotation of the tilt bucket and a target value of an amount of control of the swing body based on the operation data obtained when the work implement and the swing body are operated, and a command unit that outputs control commands for controlling the work implement and the swing body based on the control amounts; SummaryTechnical problem

[0005] The construction machine has a swing body. The working tool is supported by the swing body. In some cases, the construction machine has a tiltable dump bucket. The construction machine is configured to form a slope on the construction target only when the working tool is operated so that the dump bucket approaches the swing body. In some cases, when forming the slope on the construction target using the dump bucket, the working tool is operated while the swing body is swinging to prevent the dump bucket from digging below the construction surface. If the swing body swings due to the operation of an operating device by a driver, the dump bucket may dig below the construction surface at a high swing speed, thereby preventing the construction target from being excavated into the desired shape.

[0006] An object of the present invention is to bring a design goal into a desired form. Solution to the problem

[0007] According to a first aspect of the present invention, a control system for a construction machine including a work implement including an arm and a tilt bucket, and a swing body supporting the work implement, the control system comprising: a construction surface acquisition unit configured to acquire a construction surface indicating a target shape of a construction target; an operation data acquisition unit configured to acquire operation data of an operating device that operates the work implement and the swing body; a target value generation unit configured to generate a target value of an amount of control related to the tilt rotation of the tilt bucket and a target value of an amount of control of the swing body based on the operation data obtained when the work implement and the swing body are operated, and further based on the construction surface;a prediction unit configured to calculate, based on the target values ​​and a prediction model for the construction machine, a prediction value of the amount of control with respect to the tilting rotation of the tilting bucket and a prediction value of the amount of control with respect to the swinging of the swing body, and configured to calculate, based on the prediction values ​​and the construction surface, control amounts for controlling the work implement and the swing body to maintain a distance from a predetermined portion of the tilting bucket to the construction surface and a posture of the tilting bucket; and a command unit configured to output control commands for controlling the work implement and the swing body based on the control amounts.

[0008] Preferred embodiments are defined in dependent claims 2 to 7.

[0009] A second aspect of the present invention relates to a construction machine having a swing body configured to support a work implement and a control system for a construction machine according to any one of claims 1 to 7.

[0010] A third aspect of the present invention relates to a control method for a construction machine including a work implement including an arm and a tilt bucket, and a swing body supporting the work implement, the control method comprising: detecting a construction surface indicating a target shape of a construction target; detecting operation data of an actuator that operates the work implement and the swing body; generating a target value of an amount of control related to the tilt rotation of the tilt bucket and a target value of an amount of control of the swing body based on the operation data obtained when the work implement and the swing body are operated, and further based on the construction surface;Calculating a predicted value of the amount of control related to the tilt rotation of the dump bucket and a predicted value of the amount of control related to the swing of the swing body based on the target values ​​and a predictive model for the construction machine; calculating control amounts for controlling the work tool and the swing body based on the predicted values ​​and the design surface to maintain a distance from a predetermined portion of the dump bucket to the design surface and a posture of the dump bucket; and outputting control commands for controlling the work tool and the swing body based on the control amounts. Advantageous effects of the invention

[0011] According to the aspect of the present invention, the design target can be excavated into the desired shape. Brief description of the drawings Fig. 1 is a perspective view showing an example of a construction machine according to the present embodiment. Fig. 2 is a block diagram illustrating a control system for the construction machine according to the present embodiment. Fig. 3 is a diagram schematically illustrating the construction machine according to the present embodiment. Fig. 4 is a diagram schematically illustrating a blade according to the present embodiment. Fig. 5 is a functional block diagram illustrating a control device according to the present embodiment. Fig. 6 is a diagram illustrating a method of calculating a target translation speed of the blade by a target translation speed calculating unit according to the present embodiment. Fig. 7 is a graph showing an example of a speed limit table according to the present embodiment. Fig. 8 is a diagram illustrating a method of calculating a target rotational speed of the blade by a target rotational speed calculating unit according to the present embodiment. Fig. 9 is a diagram illustrating an example of operation of the construction machine according to the present embodiment. Fig. 10 is a diagram illustrating an example of operation of the construction machine according to the present embodiment. Fig. 11 is a flowchart illustrating a control method for the construction machine according to the present embodiment. Fig. 12 is a block diagram showing an example of a computer system according to the present embodiment. Description of the embodiments

[0012] Embodiments of the present invention will be described below with reference to the drawings. Component elements according to the embodiments described below can be combined with each other as appropriate. Furthermore, in some cases, some of the component elements are not used.

[0013] In the following description, a three-dimensional vehicle body coordinate system (X, Y, Z) is defined and a positional relationship between respective component elements is described. The vehicle body coordinate system represents a coordinate system whose origin is set on a construction machine. The vehicle body coordinate system is defined by an X-axis extending in a defined direction with respect to the origin set on the construction machine, a Y-axis orthogonal to the X-axis, and a Z-axis orthogonal to both the X-axis and the Y-axis. A direction parallel to the X-axis is an X-axis direction. A direction parallel to the Y-axis is a Y-axis direction. A direction parallel to the Z-axis is a Z-axis direction. A rotation or tilt direction about the X-axis is a θX direction. A rotation or tilt direction about the Y-axis is a θY direction. A rotation or tilt direction about the Z-axis is a θZ direction. [Construction machine]

[0014] Fig. 1 is a perspective view showing an example of a construction machine 100 according to the present embodiment. In the present embodiment, an example of the construction machine 100 is described as an excavator. In the following description, the construction machine 100 is conveniently referred to as an excavator 100.

[0015] As in Fig. As shown in Figure 1, the excavator 100 includes a working device 1 driven by hydraulic pressure, a swing body 2 configured to support the working device 1, and a traveling body 3 configured to support the swing body 2. The swing body 2 has a cab 4 into which an operator enters. A seat 4S is arranged in the cab 4, on which the operator sits. The swing body 2 is pivotable about a pivot axis RX, with the swing body 2 being supported by the traveling body 3.

[0016] The traveling body 3 has a pair of crawler tracks 3C. The excavator 100 travels by rotating the crawler tracks 3C. Note that the traveling body 3 may be equipped with tires.

[0017] The working device 1 is supported by the swing body 2. The working device 1 includes a boom 6 connected to the swing body 2, an arm 7 connected to a distal end of the boom 6, and a bucket 8 connected to a distal end of the arm 7. The bucket 8 has a cutting edge 9. In the present embodiment, the cutting edge 9 of the bucket 8 is the edge of a straight cutting edge. The cutting edge 9 of the bucket 8 may be the tip of a protruding tooth provided on the bucket 8.

[0018] The boom 6 is rotatable about a boom axis AX1 relative to the swivel body 2. The arm 7 is rotatable about an arm axis AX2 relative to the boom 6. The bucket 8 is rotatable about a bucket axis AX3, a tilt axis AX4, and a rotation axis AX5 relative to the arm 7. The boom axis AX1, the arm axis AX2, and the bucket axis AX3 are parallel to the Y-axis. The tilt axis AX4 is orthogonal to the bucket axis AX3. The rotation axis AX5 is orthogonal to the bucket axis AX3 and the tilt axis AX4. The swivel axis RX is parallel to the Z-axis. The X-axis direction is a front-rear direction of the swing body 2. The Y-axis direction is a vehicle width direction of the swing body 2. The Z-axis direction is a vertical direction of the swing body 2. A direction of the work machine 1 relative to the operator sitting on the seat 4S is a front direction.

[0019] Fig. 2 is a block diagram illustrating a control system 200 for the excavator 100 according to the present embodiment. Fig. 3 is a diagram schematically illustrating the excavator 100 according to the present embodiment. Fig. 4 is a schematic diagram of the blade 8 according to the present embodiment.

[0020] As in Fig. 2, the control system 200 for the excavator 100 includes an engine 5, a plurality of hydraulic cylinders 10 configured to operate the work implement 1, a swing motor 16 configured to drive the swing body 2, a hydraulic pump 17 configured to discharge hydraulic oil, a valve device 18 configured to distribute the hydraulic oil discharged from the hydraulic pump 17 to each of the plurality of hydraulic cylinders 10 and the swing motor 16, a position calculation device 20 configured to calculate position data of the swing body 2, an angle detection device 30 configured to detect angles θ of the work implement 1, an actuating device 40 configured to actuate the work implement 1 and the swing body 2, and a control device 50.

[0021] The work machine 1 is operated by the power generated by the hydraulic cylinders 10. Each of the hydraulic cylinders 10 is driven based on the hydraulic oil supplied from the hydraulic pump 17. The hydraulic cylinder 10 includes a boom cylinder 11 configured to operate the boom 6, an arm cylinder 12 configured to operate the arm 7, and a bucket cylinder 13, a tilt cylinder 14, and a rotation cylinder 15 configured to operate the bucket 8. The boom cylinder 11 generates power to rotate the boom 6 about the boom axis AX1. The arm cylinder 12 generates power to rotate the arm 7 about the arm axis AX2. The bucket cylinder 13 generates power to rotate the bucket 8 about the bucket axis AX3. The tilt cylinder 14 generates power to rotate the bucket 8 about the tilt axis AX4. The rotary cylinder 15 generates the power to rotate the blade 8 around the rotation axis AX5.

[0022] In the following description, the rotation of the blade 8 about the blade axis AX3 is expediently referred to as blade rotation and the rotation of the blade 8 about the tilting axis AX4 is expediently referred to as tilting rotation and the rotation of the blade 8 about the rotation axis AX5 is expediently referred to as rotation.

[0023] The slewing body 2 slews using the power generated by the slewing motor 16. The slewing motor 16 is a hydraulic motor and is driven by the hydraulic oil supplied by the hydraulic pump 17. The slewing motor 16 generates power to cause the slewing body 2 to slew about the slewing axis RX.

[0024] The motor 5 is mounted on the swivel body 2. The motor 5 generates power to drive the hydraulic pump 17.

[0025] The hydraulic pump 17 supplies the hydraulic oil to drive the hydraulic cylinder 10 and the swivel motor 16.

[0026] The valve device 18 includes a plurality of valves configured to distribute the hydraulic oil supplied from the hydraulic pump 17 to the plurality of hydraulic cylinders 10 and the swing motor 16. The valve device 18 adjusts the flow rate of the hydraulic oil supplied to each of the plurality of hydraulic cylinders 10. By adjusting the flow rate of the hydraulic oil supplied to the hydraulic cylinder 10, the operating speed of the hydraulic cylinder 10 is adjusted. The valve device 18 regulates the flow rate of the hydraulic oil supplied to the swing motor 16. By adjusting the flow rate of the hydraulic oil supplied to the swing motor 16, the rotational speed of the swing motor 16 is adjusted.

[0027] The position calculation device 20 calculates the position data of the swivel body 2. The position data of the swivel body 2 contain the position of the swivel body 2, the attitude of the swivel body 2 and the orientation of the swivel body 2. The position calculation device 20 has a position calculator 21 configured to calculate the position of the swivel body 2, a position calculator 22 configured to calculate the attitude of the swivel body 2, and an orientation calculator 23 configured to calculate the orientation of the swivel body 2.

[0028] The position computer 21 calculates the position of the swivel body 2 in a global coordinate system, as the position of the swivel body 2. The position computer 21 is arranged in the swivel body 2. The global coordinate system represents a coordinate system whose origin is on the Earth. The global coordinate system is a coordinate system defined by a global navigation satellite system (GNSS). The GNSS is a global navigation satellite system. A global positioning system (GPS) is an example of a global navigation satellite system. The GNSS has a plurality of positioning satellites. The GNSS acquires a position defined by coordinate data of a latitude, a longitude, and an altitude. The swivel body 2 is equipped with a GPS antenna.The GPS antenna receives a radio wave from a GPS satellite and outputs a signal generated based on the received radio wave to the position calculator 21. The position calculator 21 calculates the position of the rotating body 2 in the global coordinate system based on the signal supplied from the GPS antenna. The position calculator 21 calculates the position of a representative point O of the rotating body 2, such as shown in FIG. Fig. 3. In the Fig. In the example shown in Figure 3, the representative point O of the swivel body 2 is set on the swivel axis RX. The representative point O can be set on the boom axis AX1.

[0029] The attitude computer 22 calculates the inclination angle of the swivel body 2 relative to a horizontal plane in the global coordinate system, as the attitude of the swivel body 2. The attitude computer 22 is arranged in the swivel body 2. The attitude computer 22 contains an inertial measurement unit (IMU). The inclination angle of the swivel body 2 relative to the horizontal plane includes a roll angle α, which indicates an inclination angle of the swivel body 2 in the vehicle width direction, and a pitch angle β, which indicates an inclination angle of the swivel body 2 in the front-rear direction.

[0030] The orientation computer 23 calculates the orientation of the swivel body 2 relative to a reference orientation in the global coordinate system as the orientation of the swivel body 2. The reference orientation is, for example, north. The orientation computer 23 is arranged in the swivel body 2. The orientation computer 23 contains a gyroscope sensor. The orientation computer 23 can calculate the orientation based on the signal supplied by the GPS antenna. The orientation of the swivel body 2 relative to the reference orientation includes a yaw angle γ, which indicates an angle formed by the reference orientation and the orientation of the swivel body 2.

[0031] The angle detection device 30 detects the angle θ of the working device 1. The angle detection device 30 is arranged in the working device 1. As in Fig. 3 and Fig. 4, the angles θ of the work tool 1 include a boom angle θ1 indicating the angle of the boom 6 relative to the Z axis, an arm angle θ2 indicating the angle of the arm 7 relative to the boom 6, a bucket angle θ3 indicating the angle of the bucket 8 in a bucket rotation direction relative to the arm 7, a tilt angle θ4 indicating the angle of the bucket 8 in a tilt rotation direction relative to an XY plane, and a rotation angle θ5 indicating the angle of the bucket 8 in a rotation direction relative to a YZ plane.

[0032] The angle detection device 30 includes a boom angle detector 31 that detects the boom angle θ1, an arm angle detector 32 that detects the arm angle θ2, a bucket angle detector 33 that detects the bucket angle θ3, a tilt angle detector 34 that detects the tilt angle θ4, and a rotation angle detector 35 that detects the rotation angle θ5. The angle detection device 30 may include a stroke sensor configured to detect a stroke of the hydraulic cylinder 10, or it may include an angle sensor, such as a stroke sensor, configured to detect the angles θ of the work machine 1. When the angle detection device 30 includes the stroke sensor, the angle detection device 30 calculates the angles θ of the work machine 1 based on the detection data of the stroke sensor.

[0033] The operating device 40 is operated by the operator to drive the hydraulic cylinder 10 and the swing motor 16. The operating device 40 is arranged in the cab 4. The operator's operation of the operating device 40 controls the work implement 1. The operating device 40 includes a lever that is operated by the operator of the excavator 100. The lever of the operating device 40 includes a right operating lever 41, a left operating lever 42, and a tilt operating lever 43.

[0034] When the right control lever 41 is moved forward in a neutral position, the boom 6 is lowered, and when the right control lever 41 is moved backward, the boom 6 is raised. When the right control lever 41 is moved right in the neutral position, the bucket 8 tilts, and when the right control lever 41 is moved left, the bucket 8 digs.

[0035] When the left control lever 42 is moved forward in a neutral position, the arm 7 tilts, and when the left control lever 42 is moved backward, the arm 7 digs. When the left control lever 42 is moved right in the neutral position, the swing body 2 swings right, and when the left control lever 42 is moved left, the swing body 2 swings left.

[0036] The operation of the tilt control lever 43 causes a tilting rotation or rotation of the bucket 8. [Control device]

[0037] Fig. 5 is a functional block diagram illustrating the control device 50 according to the present embodiment. The control device 50 includes a position data acquisition unit 51, an angle data acquisition unit 52, an operation data acquisition unit 53, a design surface acquisition unit 54, a target value generation unit 55, a model prediction control unit 56, a constraint calculation unit 57, a command unit 58, and a storage unit 60.

[0038] The position data acquisition unit 51 acquires the position data of the swivel body 2 from the position calculation device 20. The position data of the swivel body 2 includes the position of the swivel body 2, the attitude of the swivel body 2, and the orientation of the swivel body 2.

[0039] The angle data acquisition unit 52 acquires angle data indicating the angles θ of the work machine 1 from the angle detection device 30. The angle data of the work machine 1 includes the boom angle θ1, the arm angle θ2, the bucket angle θ3, the tilt angle θ4, and the rotation angle θ5.

[0040] The operation data acquisition unit 53 acquires operation data of the operating device 40 that operates the work implement 1. The operation data of the operating device 40 includes an operation amount of the operating device 40. The operating device 40 is equipped with an operation amount sensor that detects an operation amount of each lever. The operation data acquisition unit 53 acquires the operation data of the operating device 40 from the operation amount sensor of the operating device 40.

[0041] The construction surface acquisition unit 54 acquires a construction surface indicating a target shape of a construction target. The construction surface indicates a three-dimensional target shape after construction by the excavator 100. In the present embodiment, a construction surface data supply device 70 generates construction surface data indicating the construction surface. The construction surface acquisition unit 54 acquires the construction surface data from the construction surface data supply device 70. The construction surface data supply device 70 may be provided at a location remote from the excavator 100. The construction surface data generated by the construction surface data supply device 70 may be transmitted to the control device 50 via a communication system. Note that the construction surface data generated by the construction surface data supply device 70 may be stored in the storage unit 60.The construction surface acquisition unit 54 can acquire the construction surface data from the storage unit 60.

[0042] The target value generation unit 55 generates a target value for a control amount of the work machine 1. In the present embodiment, the control amount of the work machine 1 includes one or both of the moving speed of the bucket 8 and the position of a predetermined portion of the bucket 8. The predetermined portion of the bucket 8 includes the cutting edge 9 of the bucket 8. The moving speed of the bucket 8 includes a moving speed of the cutting edge 9. The position of the predetermined portion of the bucket 8 includes the position of the cutting edge 9. The target value generation unit 55 generates the target value of the control amount of the work machine 1 based on the operation data acquired by the operation data acquisition unit 53. Further, the target value generation unit 55 generates a target value of a control amount of the swing body 2.In the present embodiment, the amount of control of the swing body 2 includes a swing speed of the swing body 2. The target value generation unit 55 generates the target value of the amount of control of the swing body 2 based on the operation data acquired by the operation data acquisition unit 53. In the present embodiment, the target value generation unit 55 generates a target value of an amount of control related to the tilt rotation of the bucket 8 and a target value of an amount of control related to the swing of the swing body 2 based on at least the operation data obtained when the work machine 1 and the swing body 2 are operated, and the design area.

[0043] The amount of control related to the tilt rotation of the bucket 8 includes at least one of the tilt angle θ4 indicating the position of the bucket 8 in a tilt direction, a tilt speed indicating a rotational speed of the bucket 8 in the tilt direction, and a tilt acceleration indicating a rotational acceleration of the bucket 8 in the tilt direction. The amount of control related to the swing of the swing body 2 includes the swing speed of the swing body 2.

[0044] In the following description, it is assumed that the predetermined portion of the blade 8 is the cutting edge 9. Note that the predetermined portion of the blade 8 does not necessarily have to be the cutting edge 9. The predetermined portion of the blade 8 may be a bottom surface (bottom surface) of the blade 8.

[0045] The moving speed of the blade 8 includes a translational speed and a rotational speed of the blade 8. The translational speed of the blade 8 represents a moving speed in the X-axis direction, the Y-axis direction, and the Z-axis direction. The rotational speed of the blade 8 represents a rotational angular speed in the θX direction, the θY direction, and the θZ direction. In the present embodiment, the target value generation unit 55 includes a target translational speed calculation unit 551 configured to calculate a target translational speed v target which is a target value of the translational speed, and a target rotational speed calculation unit 552 which is configured to calculate a target rotational speed ω target which is a target value of the rotational speed. The target value generation unit 55 calculates both the target translation speed v targetas well as the target rotational speed ω target based on the angle data acquired by the angle data acquisition unit 52, the operation data acquired by the operation data acquisition unit 53, and the construction area acquired by the construction area acquisition unit 54.

[0046] Fig. 6 is a diagram showing a method for calculating the target translation speed v targetof the bucket 8 by the target translation speed calculation unit 551 according to the present embodiment. The target translation speed calculation unit 551 includes a translation speed calculation unit 551A configured to calculate the translation speed of the bucket 8 based on the operation data of the operating device 40 and the angle data of the work implement 1, a speed limit calculation unit 551B configured to calculate a speed limit of the bucket 8 based on a distance between the cutting edge 9 and the design surface and the design surface data, a PI control unit 551C, and a deceleration processing unit 551D.

[0047] The target translation speed calculation unit 551 calculates the target translation speed v targetof the bucket 8 to avoid digging below the construction surface. The target translation speed v target the blade 8 is calculated based on formulas (1) to (6). vtargent=wR1[100000001](a+b)+jv[θ˙ope10000]T a={(1vsagyo⋅1eXZ)1eXZ((1vsagyo⋅1eXZ)>VMAX)VMAX1eXZ((1vsagyo⋅1eXZ)≤VMAX) b=1vsagyo−(1vsagyo⋅1eXZ)1eXZ 1eXZ=−[100000001] 1Rwn vsagyo=JV[0000001000001000000000000]θ˙ope J=[JvJω]

[0048] n ∈ R 3 is a unit normal vector of the construction surface closest to the cutting edge 9, w R1 ∈ R 3 × 3 is a rotation matrix for transformation from the vehicle body coordinate system to the global coordinate system, v sagyo ∈ R 3is a translational speed component of the bucket operated by the boom 6 and the arm 7 on a work implement plane (XZ plane in the vehicle body coordinate system) of the translational speed when the work implement 1 is operated based on the operation of the operating device 40, and V MAX is a maximum speed of the bucket 8 in a direction perpendicular to the construction surface to prevent digging below the construction surface. J v ∈ R 3 × 5 and J ω ∈ R 3 × 5 represent a translational velocity component and a rotational velocity component of the Jacobian matrix, respectively.

[0049] The target translation speed calculation unit 551 is configured to calculate the distance between the cutting edge 9 and the design surface based on the position data of the swing body 2 acquired by the position data acquisition unit 51, the angle data of the work tool 1 acquired by the angle data acquisition unit 52, and the work tool data stored in the storage unit 60. As shown in Fig. 3 and Fig. 4, the work tool data includes a boom length L1, an arm length L2, a bucket length L3, a tilt length L4, and a bucket width L5. The boom length L1 is a distance between the boom axis AX1 and the arm axis AX2. The arm length L2 is a distance between the arm axis AX2 and the bucket axis AX3. The bucket length L3 is a distance between the bucket axis AX3 and the cutting edge 9 of the bucket 8. The tilt length L4 is a distance between the bucket axis AX3 and the tilt axis AX4. The bucket width L5 is a dimension in the width direction of the bucket 8. The work tool data includes bucket profile data indicating the shape and dimensions of the bucket 8. The bucket profile data includes outer surface data of the bucket 8, which includes the profile of an outer surface of the bucket 8. The bucket profile data includes coordinate data of a plurality of outline points RP of the bucket 8 based on the predetermined portion of the bucket 8.

[0050] The target translation speed calculation unit 551 calculates position data of each of the contour points RP. The target translation speed calculation unit 551 calculates a relative position between the representative point O of the swing body 2 and each of the plurality of contour points RP in the vehicle body coordinate system. The target translation speed calculation unit 551 is configured to calculate the relative position between the representative point O of the swing body 2 and each of a plurality of outline points RP of the bucket 8 in the vehicle body coordinate system based on the work machine data including the boom length L1, the boom length L1, the arm length L2, the bucket length L3, the tilt length L4, the bucket width L5, and the bucket profile data, as well as the angle data of the work machine 1 including the boom angle θ1, the boom angle θ2, the bucket angle θ3, the tilt angle θ4, and the rotation angle θ5.Setting the outline points RP on the cutting edge 9 allows the target translation speed calculation unit 551 to calculate a relative position between the representative point O and the cutting edge 9. The design surface is defined in the vehicle body coordinate system. Therefore, the target translation speed calculation unit 551 can calculate the distance between the cutting edge 9 and the design surface in the vehicle body coordinate system. Furthermore, the target translation speed calculation unit 551 calculates a position of each of the plurality of outline points RP in the global coordinate system.The target translation speed calculation unit 551 can calculate the position of each outline point RP of the bucket 8 in the global coordinate system based on an absolute position of the representative point O of the swing body 2 and the relative position between the representative point O of the swing body 2 and the position of the outline point RP of the bucket 8.

[0051] The speed limit calculation unit 551B determines a speed limit of the boom 6 in the direction perpendicular to the construction surface using a speed limit table indicating a relationship between the distance between the bucket 8 and the construction surface and a speed limit of the work machine 1.

[0052] Fig. Fig. 7 is a graph showing an example of the speed limit table according to the present embodiment. As shown in Fig. As shown in Figure 7, the speed limit table shows the relationship between the distance between the cutting edge 9 and the design surface and the speed limit of the work tool 1. When the distance between the cutting edge 9 and the design surface is 0, the speed of the work tool 1 in the direction perpendicular to the design surface becomes 0 in the speed limit table. When the cutting edge 9 is located above a design surface, the distance between the cutting edge 9 and the design surface has a positive value in the speed limit table. When the cutting edge 9 is located below the design surface, the distance between the cutting edge 9 and the design surface has a negative value. In the speed limit table, a speed for moving the cutting edge 9 upward has a positive value.When the distance between the cutting edge 9 and the design surface is equal to or less than a work implement control threshold th, which has a positive value, the speed limit of the work implement 1 is defined based on the distance between the cutting edge 9 and the design surface. When the distance between the cutting edge 9 and the design surface is equal to or greater than the work implement control threshold th, an absolute value of the speed limit of the work implement 1 has a value greater than a maximum value of a target speed of the work implement 1.In other words, when the distance between the cutting edge 9 and the design surface is equal to or greater than the work tool control threshold th, an absolute value of the target speed of the work tool 1 is always smaller than the absolute value of the speed threshold, and thus the boom 6 is always controlled at the target speed.

[0053] Fig. 8 is a diagram illustrating a method for calculating the target rotational speed ω target of the blade 8 by the target rotational speed calculation unit 552 according to the present embodiment. The target rotational speed calculation unit 552 includes an actual position calculation unit 552A configured to calculate an actual position R cur of the bucket 8 based on the angle data of the working device 1, a target position calculation unit 552B which is configured to calculate a target position R targetof the blade 8 on the basis of the actuation data of the actuating device 40 and the design surface data, a rotational speed calculation unit 552C which is configured to calculate a rotational speed ω' target based on the current situation R cur and the target position R target of the blade 8, and a P-control unit 552D which is arranged to carry out a P-control of the rotational speed ω' target to achieve the target rotational speed ω target to calculate.

[0054] The target rotational speed ω' target is calculated based on formulas (7) to (10). ωtarget'=Rcurω θ=cos−1(r11+r22+r33−12) ω={

[000] T(θ=0)θ2ΔTtargetsin θ[r32−r23r13−r31r21−r12](θ≠0) R[r11r12r13r21r22r23r31r32r33]=RcurTRtarget

[0055] ΔT targetis a parameter corresponding to a time required to correct the position of the blade 8. The P control unit 552D calculates the target rotational speed ω target by performing the P control based on the rotation speed ω' calculated by the rotation speed calculation unit 552C target' carries out.

[0056] The model prediction control unit 56 calculates a predicted value of the control amount of the work tool 1 and a predicted value of the control amount of the swing body 2 based on the target value of the control amount of the work tool 1 and the target value of the control amount of the swing body 2, which are generated by the target value generation unit 55 and a prediction model for the excavator 100 with the work tool 1 and the swing body 2. The model prediction control unit 56 calculates a control amount for controlling the work tool 1 and the swing body 2 based on the predicted value of the control amount of the work tool 1, the predicted value of the control amount of the swing body 2, and the design surface in order to maintain the distance between the predetermined portion of the bucket 8 and the design surface and the posture of the bucket 8, that is,so that the bucket 8 follows a target construction surface at a predetermined attitude. The predicted value of the amount of control of the work implement 1 also includes a predicted value related to the tilt rotation of the bucket 8.

[0057] In the prediction model storage unit 561, a prediction model for the excavator 100 including the work tool 1 is stored. The prediction model includes a dynamic model for the excavator 100. The prediction model includes a model for the swing body 2 that swings around the swing axis RX, a model for the boom 6 that rotates around the boom axis AX1, a model for the arm 7 that rotates around the arm axis AX2, and a model for the bucket 8 that rotates around the bucket axis AX3, the tilt axis AX4, and the rotation axis AX5.

[0058] The prediction model is represented by a discrete state equation and an output equation. The state equation of the prediction model for controlling the excavator 100, discretized with a sampling time ΔT, is represented by formula (11). The matrices of the state equation are represented by formulas (12) and (13). The output equation of the prediction model is represented by formula (14). [θ(t+1)θ˙(t+1)]=A[θ(t)θ˙(t)]+B[τ(t)−Co(t)Ctay(t)] A=[I5×5I5×5ΔTO5×5I5×5]∈R10×10 B=[12ΔT2M−112ΔT2M−1O5×4ΔTM−1ΔTM−1O5×4]∈R10×14 [v(t)ω(t)θ(t)Tθ˙(t)Td(t)QA(t)]=C[θ(t)θ˙(t)]+D[τ(t)−Co(t)Ctay(t)]

[0059] Each of M ∈ R 5×5 and Co ∈ R 5 is an inertial matrix of an equation of motion and a Coriolis force / gravity vector. C tay ∈ R 2np is a constant term when a Tailor expansion of np by an angle θ is performed at the predetermined time t. np is the number of design surfaces to be considered. The outputs of the output equation of the prediction model are an angle θ, an angular velocity, the target translation velocity v target , the target rotational speed ω target , the distance d between the cutting edge 9 and the design surface and the flow rate Q of the hydraulic oil.

[0060] The prediction unit 562 performs an optimization operation based on the prediction model and calculates the prediction value of the amount of control of the work machine 1. As described above, in the present embodiment, the amount of control of the work machine 1 includes one or both of the moving speed of the bucket 8 and the position of the predetermined portion of the bucket 8. The predetermined portion of the bucket 8 includes the cutting edge 9. Further, the amount of control of the work machine 1 includes an angular velocity of the boom 6, an angular velocity of the arm 7, and an angular velocity of the bucket 8. The angular velocity of the bucket 8 includes an angular velocity about the bucket axis AX3, an angular velocity about the tilt axis AX4, and an angular velocity about the rotation axis AX5.

[0061] In the present embodiment, the prediction unit 562 calculates a prediction value of the amount of control related to the tilt rotation of the bucket 8 based on the target value of the amount of control related to the tilt rotation of the bucket 8 and the prediction model, and controls the work machine 1 based on the prediction value. As described above, the amount of control related to the tilt rotation of the bucket 8 includes at least one of the inclination angle θ4, the tilt speed, and the inclination acceleration of the bucket 8. In addition, the prediction unit 562 calculates the prediction value of the amount of control of the swing body 2 based on the target value of the amount of control of the swing body 2 and the prediction model, and controls the swing body 2 based on the prediction value so that the bucket 8 follows the target design surface at the predetermined posture.

[0062] The prediction unit 562 predicts a value on the left side of formula (14) several steps ahead of the current time.

[0063] The prediction unit 562 calculates the control amount for controlling the work machine 1 based on at least one of a prediction value of the movement speed of the bucket 8, a prediction value of the angular velocity of each axis, a prediction value of the position of the cutting edge 9 of the bucket 8, and a prediction value of the flow rate of the hydraulic oil. The prediction unit 562 calculates the control amount so that the prediction value of the control amount follows its target value. The prediction unit 562 calculates the control amount for controlling the swing body 2 based on a prediction value of the swing speed of the swing body 2.

[0064] In the present embodiment, the prediction unit 562 calculates the drive amount so that the bucket 8 follows a target design surface at a predetermined posture, based on the prediction value of the moving speed of the bucket 8, the prediction value of the angular velocity of each axis, the prediction value of the position of the cutting edge 9 of the bucket 8, the prediction value of the flow rate of the hydraulic oil, a prediction value of a swing speed of the swing body 2, and the design surface. In other words, the prediction unit 562 calculates the drive amount so that the bucket 8 does not dig below the design surface and the position of the cutting edge 9 and the position of the design surface coincide with each other.

[0065] The prediction unit 562 calculates the control amount for controlling the work device 1 and the swing body 2 such that an evaluation function has a minimum value and each boundary condition is satisfied.

[0066] In model prediction control, the evaluation function shown in formula (15) is generally used. E(t)=Ey(t)+Eu(t)+EΔu(t)+Ec(t)

[0067] E y (t) is a difference between a target value and a prediction value in the output, E u (t) is a difference between a target value and a prediction value in the input, EΔ u (t) is an order of magnitude of the change in the input, and E c (t) is a penalty function that is imposed when the constraints described later are not met. In the present embodiment, E u (t) = 0 and EΔ u(t) = 0, and the tracking error in the output relative to the target value in the output is used as the evaluation function. The evaluation function is shown in formulas (16) and (17). E(t)=∑i=1HpΔri(t+i|t)TWΔri(t+i|t)+Ec(t) Δri(t+i|t)=ri(t+i|t)−y(t+i|t)

[0068] r(t + ilt) is a target value of time t+1 at time t, y(t + ilt) is a plant output predicted at time t+i, H p is a prediction horizon that determines how many steps ahead a prediction is made, and W is a diagonal matrix that weights prediction variables.

[0069] The constraint calculation unit 57 calculates the constraints. The constraints include a first constraint related to the power of the excavator 100 and a second constraint related to the position of the bucket 8. The prediction unit 562 calculates the control amount so that the constraints calculated by the constraint calculation unit 57 are satisfied.

[0070] The excavator 100 as the control target has a limit value for the angle θ, the angular velocity, the angular acceleration, and the flow rate of the hydraulic oil of the work machine 1. For example, each angle θ by which the work machine 1 travels has a limit value. Likewise, there are each limit values ​​for the angular velocity and the angular acceleration of the work machine 1. Furthermore, the flow rate of the hydraulic oil discharged from the hydraulic pump 17 is limited. As described above, the excavator 100 has a limit value for the hardware. Therefore, it is necessary to also consider the first constraint indicating a limit value of the hardware of the excavator 100 in the model prediction control. The constraint calculation unit 57 calculates the first constraint including the angle θ, the angular velocity, the angular acceleration, and the flow rate of the hydraulic oil of the work machine 1.The prediction unit 562 calculates the drive amount to satisfy the first constraint.

[0071] The boundary conditions for the angles θ, the angular velocity and the flow rate of the hydraulic oil are shown in formulas (18) to (21). θmin≤θ(t)θmax θ˙min≤θ˙(t)θ˙max QA(t)=∑i=15Qi≤QAmax QA=Gθ˙≤QAmax132×1

[0072] The boundary conditions of the angular acceleration are shown in formula (22). θ¨min≤θ¨(t)θ¨max

[0073] In the present embodiment, the constraint calculation unit 57 converts the angular acceleration constraint into the torque constraint. The angular acceleration constraint after the conversion is shown in Formula (23). θ¨min≤M−1(t)τ(t)Co(t)≤θ¨max

[0074] When controlling the work machine 1, the bucket 8 must be prevented from digging below the design surface. In other words, the bucket 8 has a position limit to prevent it from digging below the design surface. Therefore, the second constraint specifying the position limit of the bucket 8 must also be considered in the model prediction control. The constraint calculation unit 57 calculates the second constraint including the position of the bucket 8 relative to the design surface. The prediction unit 562 calculates the control amount to satisfy the second constraint.

[0075] An output d(t) indicates the distance between the cutting edge 9 and the construction surface. An equation of the i-th construction surface is given by a unit normal vector n i as np + d i= 0. Formulas (24) and (25) show the boundary conditions to prevent the right and left ends of the cutting edge 9 from digging below the design surface. ni⋅pL(t)≥−di ni⋅pR(t)≥−di

[0076] The coordinates of the cutting edge 9 are nonlinear with respect to an angle θ in a state variable. Therefore, a linear approximation is applied, as shown in formulas (26) and (27). ni⋅pL(t)=CiLθ(t)+CtayiL ni⋅pR(t)=CiRθ(t)+CtayiR

[0077] The prediction unit 562 uses the evaluation functions shown in formulas (16) and (17) to perform the optimization operation in the model prediction controller to satisfy the constraints shown in formulas (18) to (27). An optimization problem in the present embodiment is shown in formula (28). For the optimization, for example, quadratic programming (QP) is used, but other calculation methods may also be used. minimize E(t) τ(1),…,τ(1−(Hu−1)ΔT) depending on θmin≤θ(t)≤θmax θ˙min≤θ˙(t)≤θ˙max θ¨min≤M−1τ−M−1Co≤θ¨max Gθ˙≤QAmax132×1 ni⋅pL(t)=CiLθ(t)+CtayiL≥−di ni⋅pR(t)=CiRθ(t)+CtayiR≥−di (i=1,2,…,np)

[0078] τ(t) is a control input torque for a control system and is a solution of the optimization operation. H u is a control horizon that determines how many steps in advance the inputs in the optimization problem should be treated.

[0079] The prediction unit 562 outputs a control command to control the swing speed of the swing body 2 based on the predicted value of the amount of control related to the tilting rotation of the bucket 8 and a predicted value of the amount of control related to the swing of the swing body 2, so that the distance between the cutting edge 9 of the bucket 8 and the design surface and the posture of the bucket 8 are maintained. The swing body 2 swings due to the operator's operation of the operating device 40. When the swing speed of the swing body 2 is excessively high due to the operation of the operating device 40, the prediction unit 562 outputs a limiting command to control the valve device 18 based on the predicted value of the swing speed of the swing body 2 to reduce the swing speed of the swing body 2.As described above, the valve device 18 is configured to adjust the flow rate of the hydraulic oil supplied to the swing motor 16. By adjusting the flow rate of the hydraulic oil supplied to the swing motor 16, the rotation speed of the swing motor 16 and the swing speed of the swing body 2 are adjusted. Outputting the throttle command from the prediction unit 562 to the valve device 18 reduces the flow rate of the hydraulic oil supplied to the swing motor 16. Reducing the flow rate of the hydraulic oil supplied to the swing motor 16 reduces the swing speed of the swing body 2.

[0080] Each of the Fig. 9 and Fig. 10 is a diagram illustrating an example of operation of the excavator 100 according to the present embodiment. As shown in Fig. As shown in Figure 9, the construction surface IS containing a slope is set. The excavator 100 is configured to form the slope on the construction target by operating the work tool 1 so that the bucket 8, which is capable of tilting rotation, approaches the swing body 2. When forming the slope on the construction target, the operator of the excavator 100 operates the operating device 40 to move the bucket 8 from a first position P1 of the construction surface IS to a second position P2, which is closer to the swing body 2 than the first position P1.

[0081] If, as in Fig. 9, the position of the center of the swing body 2 and the position of the center of the construction surface IS differ from each other in the direction of the vehicle width, the working device 1 is operated during the swing of the swing body 2 in order to prevent the bucket 8 from digging into the construction surface IS in some cases. Fig. In the example shown in Figure 9, the center of the design surface IS is located to the left of the center of the swing body 2 in the vehicle width direction. Accordingly, when moving the bucket 8 from the first position P1 to the second position P2, the work tool 1 must be operated while the swing body 2 is pivoted to the left so that the cutting edge 9 of the bucket 8 can follow the design surface IS.

[0082] The swing body 2 swings due to the operation of the operating device 40 by the driver. When the swing body 2 swings due to the operation of the operating device 40, the bucket 8 may dig beneath the construction surface at a high swing speed, thereby preventing the excavation of the construction target into a desired shape. In other words, when the swing speed of the swing body 2 is high, the tilting rotation of the bucket 8 at maximum speed may cause the bucket 8 to dig beneath the construction surface because, as shown in Fig. 10, the lifting of one side of the cutting edge 9 is delayed due to a change in the position of the cutting edge 9.

[0083] In the present embodiment, the prediction unit 562 calculates a prediction value of the tilting speed of the bucket 8 based on the operation data of the operation device 40 that operates the work implement 1 and the swing body 2. Further, based on the operation data of the operation device 40 that operates the work implement 1 and the swing body 2, the prediction unit 562 calculates the drive amount for controlling the operation of the work implement 1, which includes the tilting rotation of the bucket 8, so that the cutting edge 9 follows the design surface IS.

[0084] The command unit 58 outputs the control command for controlling the working device 1 and the swing body 2 (valve device 18) based on the control amount calculated by the prediction unit 562.

[0085] The command unit 58 outputs the control command to control the swing of the swing body 2 based on the drive amount of the swing body 2 calculated by the prediction unit 562 when a prediction value of the tilting speed of the bucket 8 is equal to or greater than a predetermined defined value. The prediction value of the tilting speed of the bucket 8 is calculated based on the operation data of the actuator 40 that operates the swing body 2 so that the distance between the cutting edge 9 and the design surface IS and the posture of the bucket 8 are maintained.

[0086] The defined value relating to the tipping speed can be the maximum speed (maximum value) of the tipping speed or a speed lower than the maximum speed. The maximum tipping speed is the maximum speed of the tilting rotation of the bucket 8 and is known data determined, for example, based on the performance of the tipping cylinder 14 or the performance of the hydraulic pump 17.

[0087] In the present embodiment, the command unit 58 outputs the control command for controlling the swing speed of the swing body 2 based on the drive amount of the swing body 2 calculated by the prediction unit 562, so as to limit the swing speed of the swing body 2 when the prediction value of the tilt speed of the bucket 8 exceeds the maximum speed. The prediction value of the tilt speed of the bucket 8 is calculated based on the operation data of the actuator 40, which operates the swing body 2 so that the cutting edge 9 follows the design surface IS.

[0088] The bucket 8 is unable to perform a tilt rotation beyond the maximum tilt speed. If the swing body 2 continues to swing at a high speed due to the operation of the operating device 40 even though the predicted value of the tilt speed of the bucket 8 exceeds the maximum speed, the bucket 8 may dig below the construction surface IS. The prediction unit 562 is configured to calculate the predicted value of the swing speed of the swing body 2 based on the operation data of the operating device 40 that swings the swing body 2. If the tilt speed of the bucket 8 exceeds the maximum speed, the command unit 58 outputs the control command to limit the swing speed of the swing body 2.The tilting speed of the bucket 8 is calculated based on the predicted value of the tilting speed of the swing body 2 so that the cutting edge 9 of the bucket 8 follows the construction surface IS. In other words, when the tilting speed of the bucket 8 exceeds the maximum speed, the control unit 58 outputs the control command to swing the swing body 2 at a tilting speed calculated to prevent the bucket 8 from digging below the construction surface IS. The tilting speed of the bucket 8 is calculated so that the cutting edge 9 of the bucket 8 follows the construction surface IS. This prevents the bucket 8 from digging below the construction surface IS. [Tax procedure]

[0089] Fig. Fig. 11 is a flowchart illustrating a control method for the excavator 100 according to the present embodiment. In the present embodiment, the control method during work such as moving the bucket 8 from the first position P1 to the second position P2 will be described with reference to Fig. Fig. 9 described.

[0090] The construction surface acquisition unit 54 acquires the construction surface data (step S1).

[0091] The position data acquisition unit 51 acquires the position data of the swivel body 2 from the position calculation device 20 as an actual value. Furthermore, the angle data acquisition unit 52 acquires the angle data and angular velocity data of the work implement 1 from the angle detection device 30 as actual values ​​(step S2).

[0092] The operator operates the operating device 40 to move the bucket 8 from the first position P1 to the second position P2. Furthermore, the operator operates the operating device 40 to rotate the swing body 2 while the bucket 8 moves from the first position P1 to the second position P2. The operation data acquisition unit 53 acquires the operation data from the operating device 40. The target value generation unit 55 generates the target value of the amount of control of the work machine 1 and the target value of the amount of control of the swing body 2 based on at least the operation data of the operating device 40 (step S3).

[0093] The target value of the amount of control of the working device 1 includes a target value of the movement speed of the bucket 8. The target value of the movement speed of the bucket 8 includes the target translation speed v target the blade 8, described with reference to Fig. 6, and the target rotational speed ω target the blade 8, described with reference to Fig. 8. The target value generation unit 55 calculates the target value that represents the target translation speed v target and the target rotational speed ω target of the bucket 8, based on the operation data of the actuator 40, the angle data indicating each angle θ that changes by the operation of the actuator 40, and the angular velocity data indicating the amount of change in each angle θ per unit time, as well as the design surface data.

[0094] The constraint condition calculation unit 57 calculates the first constraint condition related to the power of the excavator 100 and the second constraint condition related to the position of the bucket 8 based on the operation data of the operating device 40, the angle data indicating each angle θ of the work machine 1 that changes due to the operation of the operating device 40, and the angular velocity data indicating the amount of change of each angle θ per unit time, as well as the design area data (step S4).

[0095] The prediction unit 562 calculates the drive amount for controlling the work machine 1 to satisfy the constraint condition calculated in step S4, based on the target value of the amount of control of the work machine 1 and the prediction model stored in the prediction model storage unit 561 (step S5).

[0096] For the control amount, an example of a control amount for each valve of the valve device 18 is given. A torque of the working device 1 can be calculated for the control amount.

[0097] The prediction unit 562 calculates the control amount of the working device 1 and the control amount of the swing body 2, for example, ten steps in advance from the current time.

[0098] The prediction unit 562 calculates the prediction value of the amount of control of the working device 1 and the prediction value of the amount of control of the swing body 2 based on the control amount calculated in step S5 and the actual value acquired in step S2 (step S6).

[0099] The prediction unit 562 calculates the prediction value of the moving speed of the work tool 1, the prediction value of the position of the cutting edge 9 and the prediction value of the swing speed of the swing body 2, for example, ten steps in advance from the current time.

[0100] The prediction unit 562 determines, based on the operation data of the operation device 40 that operates the work implement 1 and the swing body 2, whether a prediction value of a bucket speed calculated so that the cutting edge 9 of the bucket 8 follows the design surface IS exceeds a maximum speed (step S7).

[0101] When it is determined in step S7 that the prediction value of the bucket speed does not exceed the maximum speed (step S7: No), the prediction unit 562 recalculates the control amount so that the prediction value of the amount of control follows the target value thereof (step S5).

[0102] The prediction unit 562 recalculates the control amount to minimize the value of the evaluation function defined by the target value and the actual value of the control amount. The prediction unit 562 recalculates the control amount to satisfy the first constraint and the second constraint.

[0103] If it is determined in step S7 that the prediction value of the blade speed exceeds the maximum speed (step S7: Yes), the prediction unit 562 determines whether the evaluation function has the minimum value (step S8).

[0104] The speed of the bucket 8 may be the angular velocity or angular acceleration of each axis of the work implement 1 or the swing body 2. The maximum speed may be an upper limit. In other words, in step S7, the prediction unit 562 may determine whether a prediction value of the angular acceleration of each axis exceeds the upper limit angular acceleration.

[0105] If it is determined in step S8 that the evaluation function does not have the minimum value (step S8: No), the prediction unit 562 recalculates the control amount so that the prediction value of the amount of control follows the target value (step S5).

[0106] The prediction unit 562 repeats the processing of step S5, step S6, step S7, and step S8 until the evaluation function has the minimum value.

[0107] If it is determined in step S8 that the evaluation function has the minimum value (step S8: Yes), the command unit 58 outputs the control command for controlling the swing body 2 based on the drive amount for controlling the swing body 2 calculated so that the evaluation function has the minimum value, to limit the swing speed of the swing body 2. The command unit 58 outputs the control command to the valve device 18 to drive the valve based on the drive amount calculated by the prediction unit 562. Furthermore, the command unit 58 outputs the control command for controlling the work implement 1 based on the drive amount for controlling the work implement 1 calculated in step S5 (step S9).

[0108] As described above, the control amount is calculated, for example, up to ten steps ahead from the current time. Command unit 58 outputs the control amount calculated in the first step from the control amounts calculated ten steps ahead as a control command.

[0109] The swing body 2 swings at a limited swing speed based on the control command issued by the command unit 58. This allows the bucket 8, which moves from the first position P1 to the second position P2, to perform a tilting rotation to follow the design surface IS, as described with reference to Fig. 9. Therefore, the bucket 8 does not dig below the construction surface IS and levels the construction target into the desired shape. [Effects]

[0110] As described above, the movement of the work implement 1 and the swing body 2 by the model prediction control allows the control device 50 to issue the control command for limiting the swing speed of the swing body 2, so that the bucket 8 can follow the construction surface IS when the swing speed of the swing body 2 defined by the operation data of the actuator 40 is excessively high. Therefore, the bucket 8 is prevented from digging below the construction surface IS, and the construction target is excavated into the desired shape. [computer system]

[0111] Fig.11 is a block diagram illustrating an example of a computer system 1000 according to the present embodiment. The above-described control device 50 includes the computer system 1000. The computer system 1000 includes a processor 1001 such as a central processing unit (CPU), a main memory 1002 including non-volatile memory such as read-only memory (ROM) and volatile memory such as random access memory (RAM), a memory 1003, and an interface 1004 including an input / output circuit. The above-described functions of the control device 50 are stored in the memory 1003 as programs. The processor 1001 reads a program from the memory 1003, loads the program into the main memory 1002, and executes the above-described processing according to the program. Note that the programs can be distributed to the computer system 1000 via a network.

[0112] According to the embodiments described above, the computer system 1000 is configured to acquire the operation data of the operating device 40 operating the work implement 1 and the swing body 2, generate the target value of the control amount related to the tilt rotation of the bucket 8 and the target value of the control amount related to the swing of the swing body based on the operation data obtained during the operation of the work implement 1 and the swing body 2 and the design surface IS indicating the target shape of the design target, calculate the predicted value of the control amount related to the tilt rotation of the bucket 8 and the predicted value of the control amount related to the swing of the swing body 2 based on the target values ​​and the predictive model for the excavator 100,to calculate the control variables for controlling the working device 1 and the swivel body 2 on the basis of the preset values ​​and the target area IS in order to maintain the distance of the predetermined section of the bucket 8 from the target area IS and the position of the bucket 8, and to output the control commands for controlling the working device 1 and the swivel body 2 on the basis of the control amounts. [Other embodiments]

[0113] In the embodiments described above, the target value generation unit 55 is configured to use the speed (translation speed and rotation speed) of the blade 8 to generate the target value for the model prediction control unit 56. The target value generation unit 55 may use the position and attitude of the blade 8 to generate the target value for the model prediction control unit 56.

[0114] Note that in the above-described embodiments, some or all of the functions of the control device 50 may be provided in an external computer system for the excavator 100. For example, the target value generation unit 55 and the model prediction control unit 56 may be provided in the external computer system, so that the control amount calculated by the external computer system is transmitted to the excavator 100 via a wireless communication system.

[0115] Note that in the above-described embodiments, the construction machine 100 is the excavator. The component elements described in the above embodiments are applicable to a construction machine including a work implement other than the excavator.

[0116] Note that in the embodiments described above, the swing motor 16 configured to swing the swing body 2 does not have to be the hydraulic motor. The swing motor 16 may be an electric motor configured to be driven by the power supply. Furthermore, the working device 1 may be driven not by the hydraulic cylinder 10, but by the power generated by an electric actuator, such as an electric motor. List of reference symbols 1 WORKING DEVICE 2 swivel bodies 3 DRIVING BODY 3C CATERPILLAR 4 CABINS 4 SEATS 5 ENGINE 6 booms 7 ARM 8 SHOVEL 9 CUTTING EDGE 10 hydraulic cylinders 11 BOOM CYLINDERS 12 arm cylinders 13 bucket cylinders 14 TILT CYLINDERS 15 ROTARY CYLINDERS 16 SWIVEL MOTOR 17 HYDRAULIC PUMP 18 VALVE DEVICE 20 POSITION CALCULATION DEVICE 21 POSITION CALCULATORS 22 STORAGE CALCULATORS 23 ORIENTATION CALCULATOR 30 ANGLE DETECTION DEVICE 31 BOOM ANGLE DETECTOR 32 ARM ANGLE DETECTOR 33 BLADE ANGLE DETECTOR 34 Tilt Angle Detector 35 ROTATION ANGLE DETECTOR 40 ACTUATOR 41 RIGHT CONTROL LEVER 42 LEFT CONTROL LEVER 43 Tilt control lever 50 CONTROL DEVICE 51 POSITION DATA ACQUISITION UNIT 52 ANGLE DATA ACQUISITION UNIT 53 ACTUATING DATA ACQUISITION UNIT 54 Construction Area Recording Unit 55 TARGET PRODUCTION UNIT 56 MODEL PREDICTION CONTROLLER 57 BOUNDARY CONDITION CALCULATION UNIT 58 COMMAND UNIT 60 STORAGE UNIT 70 DESIGN SURFACE DATA FEEDING DEVICE 100 CONSTRUCTION MACHINERY 200 CONTROL SYSTEM 551 Target Translation Speed ​​Calculation Unit 551A TRANSLATION SPEED CALCULATION UNIT 551B Speed ​​Limit Calculation Unit 551C PI CONTROL UNIT 551D DELAY PROCESSING UNIT 552 Target rotation speed calculation unit 552A ACTUAL POSITION CALCULATION UNIT 552B Target Position Calculation Unit 552C ROTATIONAL SPEED CALCULATION UNIT 552D P-CONTROL UNIT 561 PREDICTION MODEL STORAGE UNIT 562 FORECAST UNIT AX1 BOOM AXLE AX2 ARM AXLE AX3 BLADE AXLE AX4 TILT AXIS AX5 ROTATION AXIS

Claims

[1] A control system (200) for a construction machine (100) comprising a working device (1) including an arm (7) and a tilting bucket (8), and a swing body (2) supporting the working device (1), the control system (200) comprising: a construction surface detection unit (54) configured to detect a construction surface (IS) indicating a target shape of a construction target; an operation data acquisition unit (53) configured to acquire operation data of an actuating device (40) that actuates the working device (1) and the swivel body (2); a target value generation unit (55) configured to generate a target value of an amount of control with respect to a tilt rotation of the tilt bucket (8) and a target value of an amount of control of the swing body (2) based on the operation data obtained when the work implement (1) and the swing body (2) are operated, and further based on the design area (IS); a prediction unit (562) configured to calculate a prediction value of the amount of control with respect to the tilting rotation of the tilting bucket (8) and a prediction value of an amount of control with respect to the swinging of the swing body (2) on the basis of the target values ​​and a prediction model for the construction machine (100), and configured to calculate, based on the prediction values ​​and the construction surface (IS), control amounts for controlling the work implement (1) and the swing body (2) to maintain a distance from a predetermined portion (9) of the tilting bucket (8) to the construction surface (IS) and a posture of the tilting bucket (8); and a command unit (58) configured to output control commands for controlling the working device (1) and the swing body (2) based on the control amounts. [2] The control system (200) for a construction machine (100) according to claim 1, wherein the command unit (58) outputs the control command for controlling the swing body (2) to control the swing body (2) based on the drive amount of the swing body (2) calculated by the prediction unit (562) when the predicted value of the amount of control related to the tilt rotation of the tilt bucket (8) is equal to or greater than a predetermined defined value, wherein the predicted value of the amount of control related to the tilt rotation of the tilt bucket (8) is calculated based on the target values ​​and the prediction model for the construction machine to maintain the distance from the predetermined portion (9) of the tilt bucket (8) to the construction surface (IS) and the posture of the tilt bucket (8). [3] The control system (200) for a construction machine (100) according to claim 2, wherein when the prediction value of the amount of control with respect to the tilting rotation of the tilting bucket (8) is equal to or greater than the predetermined defined value, the command unit (58) outputs the control command to control the swing body (2) while the tilting bucket (8) is moved by the actuating device (40) from a first position to a second position closer to the swing body (2) than the first position, and the swing body (2) swings. [4] A control system (200) for a construction machine (100) according to any one of claims 1 to 3, wherein the amount of control with respect to the tilting rotation of the tilting bucket (8) includes a moving speed of the tilting bucket (8). [5] The control system (200) for a construction machine (100) according to any one of claims 1 to 4, wherein the prediction unit (562) calculates the control amounts so that the prediction values ​​of the amounts of the controls follow the target values. [6] The control system (200) for a construction machine (100) according to any one of claims 1 to 5, wherein the prediction unit (562) calculates the control amounts so as to minimize a value of an evaluation function defined by the target values ​​and the prediction values ​​of the amounts of the controls. [7] Control system (200) for a construction machine (100) according to claim 6, comprising a boundary condition calculation unit (57) configured to calculate a first boundary condition relating to the performance of the construction machine (100) and a second boundary condition relating to a position of the tilting bucket (8), wherein the prediction unit (562) calculates the control amounts such that the first boundary condition and the second boundary condition are met. [8] Construction machine (100), comprising: a pivoting body (2) adapted to support a working device (1); and the control system (200) for a construction machine (100) according to one of claims 1 to 7. [9] A control method for a construction machine (100) including a working device (1) including an arm (7) and a tilting bucket (8), and a swing body (2) supporting the working device (1), the control method comprising: Acquiring a design surface (IS) that specifies a target shape of a design target; Recording actuation data of an actuating device (40) which actuates the working device (1) and the swivel body (2); Generating a target value of an amount of control with respect to the tilt rotation of the tilt bucket (8) and a target value of an amount of control of the swing body (2) based on the operation data obtained when the work implement (1) and the swing body (2) are operated, and further based on the design area (IS); Calculating a predicted value of the amount of control related to the tilting rotation of the tilting bucket (8) and a predicted value of an amount of control related to the swinging of the swing body (2) based on the target values ​​and a predictive model for the construction machine (100); Calculating control amounts for controlling the working device (1) and the swing body (2) based on the predicted values ​​and the design surface (IS) to maintain a distance from a predetermined portion (9) of the tilt bucket (8) to the design surface (IS) and a position of the tilt bucket (8); and Outputting control commands to control the working device (1) and the swivel body (2) based on the control amounts.

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