Instruction generation system and instruction generation method

Abstract

A processing circuit of an instruction generating system for a work machine including a plurality of members and a plurality of hydraulic actuators is configured to execute the following steps: acquire current angle information indicating a current angle of a tip end side member with respect to a base end side member; calculate a current torque that rotates the tip end side member with respect to the base end side member based on the current angle information by inverse dynamics calculation; acquire target angle information indicating a target angle of the tip end side member with respect to the base end side member; calculate a target torque for tracking the target angle by the current angle based on the target angle information; calculate a reference speed command value indicating a target speed of the hydraulic actuator based on the target angle information; and correct the reference speed command value in a manner that reduces a torque deviation that is a deviation of the target torque from the current torque, and generate a control command value for controlling a speed of the hydraulic actuator.

Description

Technical Field

[0001] This disclosure relates to an instruction generation system and method for use in hydraulic excavators and other working machinery including hydraulic actuators. Background Technology

[0002] Among the work machines used for civil engineering, inspection, or material handling, there is a type that uses hydraulic actuators to move multiple sequentially connected components to propel the machine. For example, the hydraulically powered excavator disclosed in Patent Document 1 has a boom connected to a rotating body including a cab, a stick connected to the boom, and a bucket connected to the stick. The boom, stick, and bucket are driven by a boom cylinder, a stick cylinder, and a bucket cylinder, respectively.

[0003] Existing technical documents: Patent documents: Patent document 1: Japanese Patent Application Publication No. 9-279633. Summary of the Invention

[0004] The problem the invention aims to solve: In a system that uses hydraulic actuators to operate multiple sequentially connected components, there is a need to increase the tracking speed in the control that enables the tips of these components to track the trajectory of a target.

[0005] The purpose of this disclosure is to provide an instruction generation system and method that can improve the tracking speed of the tip of a series of sequentially connected components tracking a target trajectory via a hydraulic actuator.

[0006] Solution methods: One aspect of this disclosure relates to an instruction generation system for a working machine, the working machine comprising: a plurality of components connected sequentially from a base end to a tip end; and a plurality of hydraulic actuators configured for each group of adjacent base end and tip end components of the plurality of components, such that the tip end component rotates relative to the base end component. The instruction generation system includes a processing loop configured to perform the following steps: acquiring current angle information representing a current angle of the tip end component relative to the base end component; calculating, based on the current angle information, a current torque for rotating the tip end component relative to the base end component using inverse dynamics calculations; acquiring target angle information representing a target angle of the tip end component relative to the base end component; calculating, based on the target angle information, a target torque for tracking the target angle; calculating, based on the target angle information, a reference speed command value representing a target speed of the hydraulic actuator; and correcting the reference speed command value in a manner that reduces a torque deviation, which is a deviation between the target torque and the current torque, to generate a control command value for controlling the speed of the hydraulic actuator.

[0007] One aspect of this disclosure relates to a command generation method for a working machine, the working machine comprising: a plurality of components connected sequentially from a base end to a tip end; and a plurality of hydraulic actuators configured for each group of adjacent base end and tip end components of the plurality of components, such that the tip end component rotates relative to the base end component. The method includes the following steps: acquiring current angle information representing a current angle of the tip end component relative to the base end component; calculating a current torque for rotating the tip end component relative to the base end component based on the current angle information using inverse dynamics calculations; acquiring target angle information representing a target angle of the tip end component relative to the base end component; calculating a target torque for tracking the target angle based on the target angle information; calculating a reference speed command value representing a target speed of the hydraulic actuator based on the target angle information; and correcting the reference speed command value in a manner that reduces a torque deviation, which is a deviation between the target torque and the current torque, to generate a control command value for controlling the speed of the hydraulic actuator.

[0008] Invention effects: According to one aspect of this disclosure, it is possible to improve the tracking speed of the tips of a plurality of sequentially connected components tracking a target trajectory via a hydraulic actuator. Attached Figure Description

[0009] Figure 1 This is a schematic side view of a hydraulic excavator, an example of a working machine. Figure 2 It shows the assembly in Figure 1 A diagram of the hydraulic circuit of the operating machinery; Figure 3 This is a schematic structural diagram of the instruction generation system involved in the first embodiment, namely, the control system for working machinery including the controller; Figure 4 This is a block diagram showing the functional structure of the controller's processing loop; Figure 5 This is a diagram illustrating the instruction generation system involved in the second embodiment. Detailed Implementation

[0010] The embodiments will now be described with reference to the accompanying drawings.

[0011] <First Implementation Method> Figure 1 The diagram shows a work machine 1 using the instruction generation system of the first embodiment. In this embodiment, the work machine 1 is a hydraulic excavator 10.

[0012] The working machine 1 includes multiple components 11 connected sequentially from the base end to the tip end. Specifically, such as... Figure 1 As shown, the multiple components 11 include a traveling body 12, a rotating body 13, a boom 14, a stick 15, and a bucket 16. The side opposite to the bucket 16, i.e., the traveling body 12, is the base end side. The traveling body 12 includes a pair of tracks. A compartment 17, including an operator's seat, is mounted on the front left side of the rotating body 13. The rotating body 13 is rotatably connected to the traveling body 12. The boom 14 is rotatably connected to the rotating body 13. The stick 15 is rotatably connected to the boom 14. The bucket 16 is a working tool for digging sand, soil, etc. The bucket 16 is rotatably connected to the stick 15.

[0013] In the following description, among any two adjacent members of a plurality of sequentially connected members 11, the member located on the base end side is referred to as base end side member 11a, and the member located on the tip end side is referred to as tip end side member 11b.

[0014] Operating machinery 1 includes Figure 2 Hydraulic circuit 2 is shown. Hydraulic circuit 2 includes a pump unit 21, travel motors 31 and 32, and multiple hydraulic actuators 33. The pump unit 21 is connected to a valve unit 22, which includes multiple control valve units 40, and the travel motors 31 and 32 and the hydraulic actuators 33 are connected to the valve unit 22.

[0015] In this embodiment, the pump assembly 21 includes a variable-capacity pump (swashplate pump or swashplate pump) 21a with an adjustable tilt angle and an adjuster 21b for changing the tilt angle of the pump 21a. Furthermore, in this embodiment, the discharge flow rate of the pump assembly 21 is controlled by an electrically positive control method.

[0016] The travel motors 31 and 32 drive a pair of tracks of the traveling body 12 respectively.

[0017] Each hydraulic actuator 33 is configured for each group of adjacent base-side members 11a and tip-side members 11b, in other words, for each joint. Each hydraulic actuator 33 causes the tip-side members 11b of each group to rotate relative to the base-side members 11a. The hydraulic actuator 33 is as follows: Figure 2 As shown, it includes a rotary motor 34, a boom cylinder 35, a stick cylinder 36, and a bucket cylinder 37.

[0018] The rotary motor 34 causes the rotating body 13 to rotate relative to the traveling body 12 about the rotation axis Jsw, which extends at the center of the traveling body 12 in a direction orthogonal to the front-back direction and the width direction of the traveling body 12.

[0019] boom cylinder 35 Figure 1 As shown, it is positioned between the rotating body 13 and the boom 14. The boom cylinder 35 causes the boom 14 to rotate relative to the rotating body 13 about a rotation axis Jbm, which extends along the width direction of the rotating body 13 at the base end of the boom 14. The base end of the boom cylinder 35 is rotatably connected to the rotating body 13, and the tip end of the boom cylinder 35 is rotatably connected to the center of the boom 14. Figure 1 As shown, in this embodiment, the base end of the boom cylinder 35 is the head, and the tip end of the boom cylinder 35 is the rod.

[0020] A boom cylinder 36 is disposed between the boom 14 and the stick 15. The boom cylinder 36 causes the stick 15 to rotate relative to the boom 14 about a rotation axis Jam, which extends along the width direction of the rotating body 13 at the tip end of the boom 14. The base end of the boom cylinder 36 is rotatably connected to the central portion of the boom 14, and the tip end of the boom cylinder 36 is rotatably connected to the base end of the stick 15. Figure 1 As shown, in this embodiment, the base end of the boom cylinder 36 is the head, and the tip end of the boom cylinder 36 is the rod.

[0021] A bucket cylinder 37 is disposed between the stick 15 and the bucket 16. The bucket cylinder 37 causes the bucket 16 to rotate relative to the stick 15 about a rotation axis Jbt, which extends along the width direction of the rotating body 13 at the tip end of the stick 15. The base end of the bucket cylinder 37 is rotatably connected to the base end of the stick 15. The tip end of the bucket cylinder 37 is connected to the tip end of the stick 15 and the back end of the bucket 16 via a first auxiliary link 18a and a second auxiliary link 18b. Figure 1 As shown, in this embodiment, the base end of the bucket cylinder 37 is the head, and the tip end of the bucket cylinder 37 is the rod.

[0022] like Figure 2 As shown, the multiple control valve devices 40 include two travel motor control valve devices 41, a slewing control valve device 42, a boom control valve device 43, a stick control valve device 44, and a bucket control valve device 45. The two travel motor control valve devices 41 control the flow of working oil supplied from the pump device 21 to the travel motors 31 and 32, respectively. The slewing control valve device 42 controls the flow of working oil supplied from the pump device 21 to the slewing motor 34. The boom control valve device 43 controls the flow of working oil supplied from the pump device 21 to the boom cylinder 35. The stick control valve device 44 controls the flow of working oil supplied from the pump device 21 to the stick cylinder 36. The bucket control valve device 45 controls the flow of working oil supplied from the pump device 21 to the bucket cylinder 37.

[0023] exist Figure 2 In the example shown, multiple control valve devices 40 are assembled into a valve unit 22, but the valve unit 22 can also be composed of multiple units, and the multiple control valve devices 40 can also be assembled into multiple independent units. Furthermore, the structure of the control valve device 40 is not particularly limited, as long as it can control the flow of working oil supplied to the corresponding actuator. For example, the control valve device 40 can be a solenoid-type spool valve. Alternatively, the control valve device 40 can also include a pilot-operated spool valve and a solenoid proportional valve that outputs pilot pressure to the pilot-operated spool valve.

[0024] Figure 3 The diagram shows the instruction generation system of this embodiment, namely the control system 4 for the working machinery 1, which includes the controller 7. For example... Figure 3 As shown, the control system 4 includes multiple attitude angle sensors 5, a controller 7, and multiple control valve devices 40 and pump devices 21, which are controlled by the controller 7. The multiple attitude angle sensors 5, multiple control valve devices 40, and pump devices 21 are connected to the controller 7 via wired or wireless means.

[0025] The attitude angle sensor 5 detects the attitude of the working machinery 1 as attitude information. In this embodiment, the attitude angle sensor 5 includes a vehicle attitude angle sensor 51, a rotation attitude angle sensor 52, a boom attitude angle sensor 53, a stick attitude angle sensor 54, and a bucket attitude angle sensor 55. The vehicle attitude angle sensor 51 detects the tilt angle of the traveling body 12 relative to the horizontal plane, i.e., the vehicle attitude angle. The rotation attitude angle sensor 52 detects the angle of the forward / backward direction of the rotating body 13 relative to the forward / backward direction of the traveling body 12 on a plane orthogonal to the rotation axis Jsw, i.e., the rotation attitude angle. The boom attitude angle sensor 53 detects the tilt angle of the boom 14 relative to the horizontal plane, i.e., the boom attitude angle. The stick attitude angle sensor 54 detects the tilt angle of the stick 15 relative to the horizontal plane, i.e., the stick attitude angle. The bucket attitude angle sensor 55 detects the tilt angle of the bucket 16 relative to the horizontal plane, i.e., the bucket attitude angle.

[0026] The controller 7 includes a processing loop 70. The processing loop 70 includes a processor 71, system memory 72, and storage memory 73. The processor 71 may include a CPU. The system memory 72 may include RAM. The storage memory 73 may include a hard disk, flash memory, or a combination thereof. The storage memory 73 stores a program 73a.

[0027] The controller 7 may include at least one user interface 74. The user interface 74 may be configured on a control panel. For example, the user interface 74 may include input interfaces and output interfaces. For example, the input interface may be a touchscreen, a gamepad, a joystick, a switch, etc. For example, the output interface may be a display.

[0028] The controller 7 may include at least one communication interface 75. The communication interface 75 includes an interface for connecting external devices to the controller 7 via wired or wireless means. The communication interface 75 may also include an interface for connecting to communication networks such as the Internet via wired or wireless means.

[0029] In this embodiment, the program 73a stored in the storage memory 73 contains a trajectory tracking program. The trajectory tracking program is used to execute trajectory tracking control, which uses the hydraulic actuator 33 to cause the tip of the bucket 16, which is the tip of a plurality of components 11, to track a target trajectory. In this embodiment, the trajectory tracking control is used to control the hydraulic excavator 10 to perform digging actions through automatic operation.

[0030] In the trajectory tracking control of this embodiment, the hydraulic excavator 10 is modeled as a four-bar linkage including rotating links 1a, boom links 1b, stick links 1c, and bucket links 1d corresponding to the rotating body 13, boom 14, stick 15, and bucket 16, respectively, and calculations are performed based on this model. Figure 1As shown, the rotating link 1a represents the rotating body 13 through the straight line between the rotating shafts Jsw and Jbm. The boom link 1b represents the boom 14 through the straight line between the rotating shafts Jbm and Jam. The stick link 1c represents the stick 15 through the straight line between the rotating shafts Jam and Jbt. The bucket link 1d represents the bucket 16 through the straight line between the rotating shaft Jbt and the tip of the bucket 16.

[0031] The hydraulic excavator 10, in addition to the four linkages of the rotating body 13, boom 14, stick 15, and bucket 16, also includes a boom cylinder 35, a stick cylinder 36, a bucket cylinder 37, and first and second auxiliary linkages 18a and 18b. That is, the hydraulic excavator 10 is actually a multi-link mechanism with more than five linkages. In this embodiment, the reason for simplifying this multi-link mechanism with more than five linkages into a four-link mechanism model is to reduce the computational load in trajectory tracking control.

[0032] In the following description, the rotating body 13, boom 14, stick 15, and bucket 16, which correspond to the connecting rods 1a, 1b, 1c, and 1d included in the model, are sometimes referred to as main connecting rods. Furthermore, connecting rods not included in the model, such as boom cylinder 35, stick cylinder 36, bucket cylinder 37, and the first and second auxiliary connecting rods 18a and 18b, are sometimes referred to as secondary connecting rods to distinguish them from the main connecting rods.

[0033] Furthermore, in this embodiment, to suppress the decrease in computational accuracy that may be caused by model simplification, parameter correction for slave links not included in the model is performed by the slave link correction unit 85, which will be described later. Details regarding the slave link correction unit 85 will be explained later.

[0034] Figure 4 This is a block diagram showing the functional structure of the processing loop 70 of the controller 7. The processing loop 70, for example, executes a trajectory tracking program read from the storage memory 73 via the processor 71, thereby functioning as a target angle acquisition unit 81, a reference speed calculation unit 82, a speed correction unit 83, a four-bar linkage inverse dynamics calculation unit 84, a link correction unit 85, a target torque calculation unit 86, and a hydraulic pressure control unit 87. The processing of each functional unit 81, 82, 83, 84, 85, 86, and 87 in the trajectory tracking control will be described below.

[0035] The target angle acquisition unit 81 acquires target angle information representing the target angle θtar of the tip-side member 11b relative to the base-side member 11a. The target angle information is used to actuate multiple hydraulic actuators 33 by automatically operating the machine 1 so that the tips of the multiple components 11, i.e., the tip of the bucket 16, follow a predetermined target trajectory. That is, the target angle θtar is the target angle used to make the tip of the bucket 16 follow the target trajectory. The target angle θtar is represented by the following Equation 1.

[0036] [Mathematical Expression 1] , θsw_tar: The target angle of the rotating body 13 relative to the traveling body 12 (In the model, this is the target angle between the forward and backward direction of the traveling body 12 and the rotating link 1a on a plane orthogonal to the rotation axis Jsw.) θbm_tar: Target angle of boom 14 relative to rotating body 13 (In the model, this is the target angle between the rotating link 1a and the boom link 1b.) θam_tar: Target angle of stick 15 relative to boom 14 (In the model, this is the target angle between boom link 1b and stick link 1c.) θbt_tar: Target angle of bucket 16 relative to stick 15 (In the model, this is the target angle between boom link 1c and bucket link 1d).

[0037] In this embodiment, the target angle acquisition unit 81 acquires target angle information, for example, by generating a time-series target angle θtar based on a trajectory tracking program stored in memory 73. Alternatively, the time-series target angle θtar can be pre-stored in memory 73, and the target angle acquisition unit 81 can acquire the target angle information by reading from memory 73. Furthermore, the target angle acquisition unit 81 can also receive target angle information from outside the working machine 1.

[0038] The reference speed calculation unit 82 calculates a reference speed command value based on the target angle information acquired by the target angle acquisition unit 81. The reference speed command value represents the target speed of each hydraulic actuator 33 corresponding to the target angle θtar. When the speed of each hydraulic actuator 33 tracks the target speed represented by the reference speed command value without time delay, the tip of the bucket 16 will follow the target trajectory.

[0039] For example, the reference speed calculation unit 82 converts the target angle θsw_tar into the rotation angle of the rotary motor 34 corresponding to the target angle θsw_tar, and performs time differentiation on the rotation angle to calculate the rotation speed of the rotary motor 34 as the reference speed of the rotary motor 34. Furthermore, for example, the reference speed calculation unit 82 converts the target angle θbm_tar into the stroke of the boom cylinder 35 corresponding to the target angle θbm_tar, and performs time differentiation on the stroke to calculate the reference speed of the boom cylinder 35. Using the same calculation method as for the reference speed of the boom cylinder 35, the reference speed calculation unit 82 calculates the reference speed of the stick cylinder 36 from the target angle θam_tar, and the reference speed of the bucket cylinder 37 from the target angle θbt_tar.

[0040] The speed correction unit 83 corrects the reference speed command value based on the torque deviation Δτ. The torque deviation Δτ is the difference between the target torque τtar and the current torque τcur. The current torque τcur is calculated by the four-link inverse dynamics calculation unit 84, and the target torque τtar is calculated by the target torque calculation unit 86.

[0041] The calculations for the current torque τcur and the target torque τtar are explained. The current torque τcur is the torque currently acting on the joint between the base-side member 11a and the tip-side member 11b, i.e., the torque causing the tip-side member 11b to rotate relative to the base-side member 11a. The current torque τcur is expressed by the following Equation 2.

[0042] [Mathematical Expression 2] , τsw_cur: The current torque that causes the rotating body 13 to rotate about the rotation axis Jsw. τbm_cur: The current torque that causes boom 14 to rotate about the rotation axis Jbm. τam_cur: The current torque that causes the boom 15 to rotate about the rotation axis Jam. τbt_cur: The current torque that causes the bucket 16 to rotate about the rotation axis Jbt.

[0043] The four-bar inverse dynamics calculation unit 84 calculates the current torque τcur based on the current angle information representing the current angle θ of the tip-side member 11b relative to the base-side member 11a, using the inverse dynamics calculation of Equation 3 below. Furthermore, the current angle θ is calculated by the processing loop 70 from the attitude information detected by the attitude angle sensor 5. The current angle θ is represented by Equation 4 below.

[0044] [Mathematical Expression 3] .

[0045] [Mathematical Expression 4] , θsw: The current angle of the rotating body 13 relative to the traveling body 12 (In the model, this is the current angle between the forward and backward direction of the traveling body 12 and the rotating link 1a on a plane orthogonal to the rotation axis Jsw.) θbm: The current angle of boom 14 relative to rotating body 13 (In the model, this is the current angle between the rotating link 1a and the boom link 1b.) θam: The current angle of stick 15 relative to boom 14 (In the model, this is the current angle between boom link 1b and stick link 1c.) θbt: The current angle of bucket 16 relative to stick 15 (In the model, this is the current angle between boom link 1c and bucket link 1d).

[0046] In Equation 3 above, M(θ) is a matrix that includes the inertial tensor about each rotation axis as a component. h(θ, dθ / dt) is a matrix with the centrifugal force and Coriolis force about each rotation axis as components. G(θ) is a matrix with the gravity of each component 11 as a component. M(θ), h(θ, dθ / dt), and G(θ) are represented by Equations 5, 6, and 7 below, respectively.

[0047] [Mathematical Expression 5] .

[0048] [Mathematical Expression 6] .

[0049] [Mathematical Expression 7] .

[0050] Each component of M(θ) and G(θ) is a function of the current angle θ, and each component of h(θ, dθ / dt) is a function of the current angle θ and its time derivative angular velocity dθ / dt. Furthermore, each component of M(θ), h(θ, dθ / dt), and G(θ) is calculated by the four-bar inverse dynamics calculation unit 84 through inverse dynamics calculations, based on parameters related to the rotating body 13, boom 14, stick 15, and bucket 16, i.e., parameters related to the main connecting rod (hereinafter referred to as main connecting rod parameters). The main connecting rod parameters include, for example, the mass of the main connecting rod and the position of its center of gravity. The method for calculating each component of M(θ), h(θ, dθ / dt), and G(θ) based on the main connecting rod parameters is known and therefore omitted from explanation. However, in this embodiment, the main connecting rod parameters are corrected by the connecting rod correction unit 85, taking into account the secondary connecting rods not included in the model.

[0051] Specifically, multiple main link parameters are obtained from the link correction unit 85. Additionally, parameters related to multiple secondary links not included in the model (hereinafter referred to as secondary link parameters) are obtained from the link correction unit 85. These parameters are, for example, pre-stored in memory 73.

[0052] The linkage parameters may include the mass and center of gravity of each part of the boom cylinder 35, stick cylinder 36, bucket cylinder 37, and first and second auxiliary linkages 18a and 18b. The mass of the hydraulic cylinder, as a linkage parameter, may also include the mass of the cylinder head and the mass of the rod.

[0053] The slave link correction unit 85 corrects multiple master link parameters based on the current angle information and multiple slave link parameters. The four-link inverse dynamics calculation unit 84 calculates the current torque τcur using inverse dynamics calculations of the multiple master link parameters corrected by the slave link correction unit 85.

[0054] There is no particular limitation on the method for correcting the main link parameters based on the slave link parameters. In this embodiment, the slave link correction unit 85 corrects the mass of the main link by adding part or all of the mass of the slave link connected to the main link to the mass of the main link. More specifically, the slave link correction unit 85 adds a predetermined proportion (including 100%) of the mass of the main link connected to the slave link to the mass of the main link connected to the slave link. This proportion can be a fixed value or a value that depends on the change in the current angle θ.

[0055] For example, the boom cylinder 35, as one of the connecting rods, is connected to both the rotating body 13 and the boom 14. The connecting rod correction unit 85 adds a predetermined proportion of the mass of the boom cylinder 35 to the mass of the rotating body 13, and adds the remaining mass of the boom cylinder 35 to the mass of the boom 14.

[0056] Furthermore, in this embodiment, the follower link correction unit 85 corrects the center of gravity of the main link by combining the center of gravity of the main link with part or all of the center of gravity of the follower link connected to the main link.

[0057] Thus, since the main link parameters are corrected based on the link parameters, the decrease in the accuracy of the current torque τcur calculation that may be caused by simplifying the multi-link mechanism into a model with fewer links can be suppressed.

[0058] The connecting rod correction unit 85 can not only correct the parameters of the main connecting rod, but also correct the current torque τcur calculated by the four-bar inverse dynamics calculation unit 84. For example, the connecting rod correction unit 85 can calculate the torque generated by the weight of the connecting rod, which should actually act because the connecting rod is connected to the main connecting rod, as the correction torque. Then, the connecting rod correction unit 85 can correct the current torque τcur by adding the calculated correction torque to the current torque τcur calculated by the four-bar inverse dynamics calculation unit 84 using the inverse dynamics calculation of Equation 3.

[0059] Next, the calculation of the target torque τtar will be explained. The target torque τtar is the torque used to make the current angle θ track the target angle θtar. That is, the target torque τtar is the torque that should act on the joint between the base end member 11a and the tip end member 11b to make the tip of the bucket 16 follow the target trajectory. The target torque τtar is expressed by the following Equation 8.

[0060] [Mathematical Expression 8] , τsw_tar: The target torque that causes the rotating body 13 to rotate about the rotation axis Jsw. τbm_tar: The target torque that causes boom 14 to rotate about the rotation axis Jbm. τam_tar: The target torque that causes the boom 15 to rotate about the rotation axis Jam. τbt_tar: The target torque that causes the bucket 16 to rotate around the rotation axis Jbt.

[0061] The target torque calculation unit 86 calculates the target torque τtar based on the current angle information and the target angle information. The calculation method of the target torque τtar will be explained below.

[0062] Since the system shown in Equation 3 is nonlinear, linear control theory cannot be applied. Therefore, in this embodiment, feedback linearization is used to treat the nonlinear system shown in Equation 3 as an equivalent controllable linear system for calculation. Specifically, by linearizing Equation 3, Equation 9 is obtained, which is a linear state equation with state variable X and input u.

[0063] [Mathematical Expression 9] .

[0064] The state variable X and input u in Equation 9 are represented by Equations 10 and 11, respectively.

[0065] [Mathematical Expression 10] .

[0066] [Mathematical Expression 11] .

[0067] In Equation 10 above, Δθ is the deviation between the target angle θtar and the current angle θ, i.e., the angle deviation, and dΔθ / dt is the angular velocity deviation after the time derivative of the angle deviation Δθ. In Equation 11 above, M(θ), h(θ, dθ / dt), and G(θ) are the same as those calculated by the four-bar inverse dynamics calculation unit 84.

[0068] Furthermore, in this embodiment, a state feedback F is set to make the state variable X in Equation 9 converge to an arbitrary target value using the known pole placement method. Specifically, the eigenvalue p corresponding to the dynamics of each axis in Equation 9 is set to determine the feedback gain F, and after substituting the feedback gain F into Equation 3, the following equation 12 is obtained.

[0069] [Mathematical Expression 12] .

[0070] The feedback gain F can also be calculated using methods other than the pole placement method. For example, the known optimal regulator method can also be used in the calculation of the feedback gain F, which involves setting a certain evaluation function and determining the feedback gain F that minimizes the evaluation function.

[0071] The target torque calculation unit 86 calculates the target torque τtar based on Equation 9, which is the linear state equation described above, the target angle θtar, and the current angle θ. That is, the target torque calculation unit 86 substitutes the obtained target angle θtar and current angle θ into Equation 12 obtained based on Equation 9 to calculate the target torque τtar.

[0072] The speed correction unit 83 acquires the torque deviation Δτ, which is the difference between the target torque τtar and the current torque τcur, and corrects the reference speed command value by reducing the torque deviation Δτ through PID control. That is, if the current torque τcur is insufficient relative to the target torque τtar, the speed correction unit 83 corrects the speed command value by increasing the current torque τcur; if the current torque τcur is excessive relative to the target torque τtar, the speed correction unit 83 corrects the speed command value by decreasing the current torque τcur.

[0073] The hydraulic control unit 87 generates control command values ​​for each controlled object based on the speed command value corrected by the speed correction unit 83, and outputs them to each controlled object. For example, the memory 73 pre-stores information indicating the correspondence between speed command values ​​and control command values. The hydraulic control unit 87 uses this correspondence information to convert the speed command value corrected by the speed correction unit 83 into a control command value. In this embodiment, the control command values ​​include valve opening command values ​​and pump flow command values. The hydraulic control unit 87 outputs the generated pump flow command value to the pump device 21, and outputs the valve opening command value to the slewing control valve device 42, the boom control valve device 43, the stick control valve device 44, and the bucket control valve device 45.

[0074] As explained above, in this embodiment, a target torque and a current torque are calculated for each joint between the plurality of components 11, and the reference speed command value is corrected based on the torque deviation Δτ between the target torque τtar and the current torque τcur. Therefore, a control command value that absorbs torque deviations caused by the nonlinearity of the hydraulic actuator 33 (e.g., the compressibility of oil or flow force) can be generated. Consequently, the tracking speed and tracking accuracy in controlling the tip of the bucket 16 to track the target trajectory via the hydraulic actuator 33 can be improved.

[0075] <Second Implementation Method> Figure 5 This diagram illustrates the command generation system 100 according to the second embodiment. The command generation system 100 includes multiple attitude angle sensors 5 included in the working machine 1 and a command generation device 9, which is an external device of the working machine 1. Since the working machine 1 is the same as that described in the first embodiment, its description is omitted. In the first embodiment, trajectory tracking processing is performed by the controller 7 of the working machine 1, but in the second embodiment, part or all of the trajectory tracking processing is performed by the command generation device 9.

[0076] The instruction generation device 9 is located externally to the machine tool 1. The instruction generation device 9 is configured to communicate with the controller 7 of the machine tool 1. The instruction generation device 9 can be a server or a user-operable information processing terminal.

[0077] The instruction generation apparatus 9 includes a processing loop 90. The processing loop 90 includes a processor 91, system memory 92, and storage memory 93. Furthermore, the instruction generation apparatus 9 includes at least one user interface 94 and at least one communication interface 95. Since the hardware structure of the instruction generation apparatus 9 is substantially the same as that of the controller 7, its description is omitted.

[0078] The instruction generation device 9 receives attitude information from the working machine 1 obtained through the attitude angle sensor 5. The processing loop 90 receives the current angle θ from the working machine 1, but performs the same processing as described in the first embodiment. That is, the processing loop 90 functions as the functional units 81, 82, 83, 84, 85, 86, and 87 described in the first embodiment. The control instruction values ​​generated by the instruction generation device 9 are sent to the controller 7 of the working machine 1, and the controller 7 sends the received control instruction values ​​to various controlled objects. Alternatively, the processing loop 90 may execute only a portion of the functional units 81, 82, 83, 84, 85, 86, and 87 described in the first embodiment.

[0079] In this embodiment, the same effects as in the first embodiment can be achieved. Furthermore, since the calculations for generating control command values ​​are performed by an external device of the machine 1, the computational load on the controller 7 of the machine 1 can be reduced.

[0080] <Other Implementation Methods> This disclosure is not limited to the aforementioned embodiments, and its structure can be modified, added to, or deleted.

[0081] For example, in the first and second embodiments described above, a hydraulic excavator was shown as an example of a working machine, but the working machine can also be any construction machinery other than a hydraulic excavator. Furthermore, the working machine can be any structure comprising a plurality of components connected sequentially from the base end to the tip end and a plurality of hydraulic actuators that rotate the tip end component relative to the base end component. For example, the working machine may not be a construction machine; it can also be a hydraulically driven humanoid robot or an industrial robot.

[0082] For example, the traveling body 12 may also include multiple wheels instead of a pair of tracks. In this case, the hydraulic circuit 2 may not include the traveling motors 31 and 32, and the wheels may be driven by an engine or an electric motor.

[0083] The discharge flow rate of pump unit 21 is controlled by positive electrical control, but it can also be controlled by other methods such as negative hydraulic control. In this case, the processing circuit may not generate a pump flow rate command value.

[0084] Furthermore, while the first and second embodiments described above illustrate trajectory tracking control for the automatic operation of the work machinery, the processing loops described in the first and second embodiments can also be applied to manual operation of the work machinery by an operator. That is, the target angle information can also be generated based on operator actions such as joystick operation. When the target angle information is generated based on the operator's manual operation, the operator can operate the work machinery 1 while seated on it, or remotely from outside the work machinery 1, for example, via the command generation device 9 of the second embodiment.

[0085] The current angle θ can be calculated by the processing loop from the attitude information detected by the attitude angle sensor, or it can be information received from the outside.

[0086] In the above embodiments, a method for calculating the target torque is shown using the linear state equation of Equation 9, obtained by linearizing the nonlinear motion equation of Equation 3. However, the method for calculating the target torque is not limited to this. For example, the target torque can also be calculated by substituting the target angle into Equation 3. Alternatively, for each joint, the target torque can be obtained by performing a prescribed calculation using prescribed parameters (e.g., proportional element, integral element, and differential element) based on the deviation between the target angle and the current angle.

[0087] As shown in the description of the boom cylinder 35, stick cylinder 36, bucket cylinder 37, and first and second auxiliary connecting rods 18a and 18b, the slave link correction unit may not use all of these parameters for the correction of the main link parameters. For example, the slave link correction unit may only use the parameters related to the hydraulic cylinder 33 for the correction of the main link parameters.

[0088] As described above, the aforementioned embodiments have been illustrated as examples of the technology disclosed in this application. However, the technology disclosed herein is not limited to this and can also be applied to embodiments with appropriate modifications, substitutions, additions, omissions, etc. Furthermore, the constituent elements described in the foregoing embodiments can be combined to create new embodiments. For example, a portion of the structure or method in one embodiment can be applied to other embodiments, where a portion of the structure in one embodiment can be separated from and arbitrarily extracted from other structures in that embodiment. Moreover, the structural elements described in the drawings and detailed description include not only structural elements necessary for solving the problem but also structural elements used to illustrate the foregoing technology, rather than those necessary for solving the problem. Two blocks shown sequentially in the flowchart may, in some cases, be executed simultaneously or in reverse order.

[0089] The functions of the elements disclosed in this specification can be executed using circuits or processing circuits comprising or programmed to perform the disclosed functions, including general-purpose processors, special-purpose processors, integrated circuits, ASICs (Application Specific Integrated Circuits), FPGAs (Field Programmable Gate Arrays), conventional circuits, and / or combinations thereof. A processor, because it includes transistors and other circuitry, can be considered as a processing circuit or circuit. In this disclosure, a circuit, unit, or means is hardware that performs or is programmed to perform the listed functions. The hardware can be the hardware disclosed in this specification, or it can be other known hardware programmed or configured to perform the listed functions. When the hardware is considered a processor, a type of circuit, the circuit, means, or unit is a combination of hardware and software, with the software used to construct the hardware and / or the processor.

[0090] The programs disclosed in this specification can be stored on a computer-readable storage medium. The aforementioned storage medium is a non-transitory and tangible medium. The aforementioned storage medium can be built into or externally connected to a computer (e.g., a portable information terminal, personal computer, server, etc.). The aforementioned storage medium includes RAM, ROM, EEPROM, memory, etc., and may be, for example, a hard disk, flash memory, optical disk, etc. The programs stored in the aforementioned storage medium can be executed on a computer directly connected to the aforementioned storage medium, or on a computer connected to the aforementioned storage medium via a communication network (e.g., the Internet).

[0091] The following aspects are disclosures of preferred embodiments.

[0092] [Aspect 1] An instruction generation system is provided for a working machine, which includes: a plurality of components connected sequentially from a base end to a tip end; and a plurality of hydraulic actuators configured for each group of adjacent base end and tip end components, causing the tip end components to rotate relative to the base end components. The instruction generation system has a processing loop. The processing loop is configured to perform the following steps: Obtain current angle information representing the current angle of the tip-side member relative to the base-side member; Based on the current angle information, the current torque that causes the tip-side member to rotate relative to the base-side member is calculated through inverse dynamics calculation; Obtain target angle information representing the target angle of the tip-side member relative to the base-side member; Based on the target angle information, a target torque is calculated to make the current angle track the target angle; Based on the target angle information, a reference speed command value representing the target speed of the hydraulic actuator is calculated; and The reference speed command value is corrected in a way that reduces the torque deviation, which is the deviation between the target torque and the current torque, to generate a control command value for controlling the speed of the hydraulic actuator.

[0093] Based on the aforementioned structure, the target torque and current torque are calculated for each joint between multiple components, and the reference speed command value is corrected based on the torque deviation between the target torque and the current torque. Therefore, a control command value that absorbs torque deviations caused by the nonlinearity of the hydraulic actuator can be generated. This improves the tracking speed in control systems that use hydraulic actuators to track the tips of multiple components along a target trajectory.

[0094] [Aspect 2] According to the instruction generation system described in aspect 1, wherein, The plurality of hydraulic actuators include a plurality of hydraulic cylinders. The calculation of the current torque includes: Based on the acquired current angle information and multiple slave link parameters including the mass of the multiple hydraulic cylinders, multiple master link parameters including the mass of the multiple components are corrected; and The current torque is calculated using inverse dynamics calculations of the corrected main connecting rod parameters.

[0095] Based on the aforementioned structure, it is possible to reduce the computational load and improve the accuracy of the calculation when estimating the current torque through inverse dynamics.

[0096] [Aspect 3] The instruction generation system according to aspect 1 or 2, wherein, The number of groups of the base end side member and the tip end side member is two or more. Calculating the target torque includes: calculating the target torque based on a linear state equation, the target angle, and the current angle. The linear state equation is a linear state equation obtained by linearizing the nonlinear motion equations of the multiple components, and includes the deviation between the target angle and the current angle, i.e., the angle deviation, and the angular velocity deviation after time differentiation of the angle deviation as state variables.

[0097] Based on the aforementioned structure, compared to calculating the target torque without linearizing the nonlinear motion equations into linear state equations, it is possible to improve the tracking accuracy of the target angle while reducing computational costs.

[0098] [Aspect 4] According to any one of aspects 1 to 3, the instruction generation system wherein... The operating machinery includes a pump that dispenses working fluid and a control valve configured in the fluid circuit connecting the pump and the hydraulic actuator. The control command value includes at least one of the following: a pump flow command value for changing the flow rate of the working fluid discharged from the pump, or a valve opening command value for changing the opening degree of the control valve.

[0099] [Aspect 5] According to any one of aspects 1 to 4, the instruction generation system wherein... The target angle information is used to make the multiple hydraulic actuators move by causing the tips of the multiple components to follow a predetermined target trajectory through the automatic operation of the working machinery.

[0100] Based on the aforementioned structure, the tracking speed of multiple components of the machine to the target trajectory under automatic operation can be improved.

[0101] [Aspect 6] According to any one of aspects 1 to 5, the instruction generation system wherein... The machine being operated is a hydraulic excavator. The plurality of components includes a traveling body, a rotating body rotatably connected to the traveling body, a boom rotatably connected to the rotating body, a stick rotatably connected to the boom, and a bucket rotatably connected to the stick. The plurality of hydraulic actuators include: a rotary motor that generates torque to rotate the rotating body relative to the traveling body; a boom cylinder that generates torque to rotate the boom relative to the rotating body; a stick cylinder that generates torque to rotate the stick relative to the boom; and a bucket cylinder that generates torque to rotate the bucket relative to the stick.

[0102] Based on the aforementioned structure, the tracking speed of the bucket tip relative to the target trajectory in a hydraulic excavator can be improved.

[0103] [Aspect 7] A method for generating instructions for a working machine, the working machine comprising: a plurality of components connected sequentially from a base end to a tip end; and a plurality of hydraulic actuators configured for each group of adjacent base end and tip end components, such that the tip end components rotate relative to the base end components. The method includes the following steps: Obtain current angle information representing the current angle of the tip-side member relative to the base-side member; Based on the current angle information, the current torque that causes the tip-side member to rotate relative to the base-side member is calculated through inverse dynamics calculation; Obtain target angle information representing the target angle of the tip-side member relative to the base-side member; Based on the target angle information, a target torque is calculated to make the current angle track the target angle; Based on the target angle information, a reference speed command value representing the target speed of the hydraulic actuator is calculated; and The reference speed command value is corrected in a way that reduces the torque deviation, which is the deviation between the target torque and the current torque, to generate a control command value for controlling the speed of the hydraulic actuator.

[0104] According to the aforementioned method, the target torque and current torque are calculated for each joint between multiple components, and the reference speed command value is corrected based on the torque deviation between the target torque and the current torque. Therefore, a control command value that absorbs torque deviations caused by the nonlinearity of the hydraulic actuator can be generated. This improves the tracking speed in control systems that use hydraulic actuators to track the tips of multiple components along a target trajectory.

[0105] Symbol explanation: 1: Operating machinery; 5: Attitude angle sensor; 7: Controller; 11a: Base end side member; 11b: Tip-end side member; 12: Driving body; 13: Solid of revolution; 14: Boom; 15: Fighting pole; 16: Bucket; 18a: First auxiliary link; 18b: Second auxiliary link; 21: Pump unit; 33: Hydraulic actuator; 34: Rotary motor; 35: Boom cylinder; 36: Bucket cylinder; 37: Bucket cylinder; 70, 90: Processing loop.

Claims

1. An instruction generation system, characterized in that, This is a command generation system for a working machine, which includes: a plurality of components connected sequentially from the base end to the tip end; and a plurality of hydraulic actuators configured for each group of adjacent base end and tip end components, causing the tip end component to rotate relative to the base end component. The instruction generation system has a processing loop. The processing loop is configured to perform the following steps: Obtain current angle information representing the current angle of the tip-side member relative to the base-side member; Based on the current angle information, the current torque that causes the tip-side member to rotate relative to the base-side member is calculated through inverse dynamics calculation; Obtain target angle information representing the target angle of the tip-side member relative to the base-side member; Based on the target angle information, a target torque is calculated to make the current angle track the target angle; Based on the target angle information, a reference speed command value representing the target speed of the hydraulic actuator is calculated; and The reference speed command value is corrected in such a way as to reduce the torque deviation, which is the deviation between the target torque and the current torque, to generate a control command value for controlling the speed of the hydraulic actuator.

2. The instruction generation system according to claim 1, characterized in that, The plurality of hydraulic actuators include a plurality of hydraulic cylinders. The calculation of the current torque includes: Based on the acquired current angle information and multiple slave link parameters including the mass of the multiple hydraulic cylinders, multiple master link parameters including the mass of the multiple components are corrected; and The current torque is calculated using inverse dynamics calculations of the corrected main connecting rod parameters.

3. The instruction generation system according to claim 1 or 2, characterized in that, The number of groups of the base end side member and the tip end side member is two or more. Calculating the target torque includes: calculating the target torque based on a linear state equation, the target angle, and the current angle. The linear state equation is a linear state equation obtained by linearizing the nonlinear motion equations of the multiple components, and includes the deviation between the target angle and the current angle, i.e., the angle deviation, and the angular velocity deviation after time differentiation of the angle deviation as state variables.

4. The instruction generation system according to claim 1 or 2, characterized in that, The operating machinery includes a pump that dispenses working fluid and a control valve configured in the fluid circuit connecting the pump and the hydraulic actuator. The control command value includes at least one of the following: a pump flow command value for changing the flow rate of the working fluid discharged from the pump, or a valve opening command value for changing the opening degree of the control valve.

5. The instruction generation system according to claim 1 or 2, characterized in that, The target angle information is used to make the multiple hydraulic actuators move by causing the tips of the multiple components to follow a predetermined target trajectory through the automatic operation of the working machinery.

6. The instruction generation system according to claim 1 or 2, characterized in that, The machine being operated is a hydraulic excavator. The plurality of components includes a traveling body, a rotating body rotatably connected to the traveling body, a boom rotatably connected to the rotating body, a stick rotatably connected to the boom, and a bucket rotatably connected to the stick. The plurality of hydraulic actuators include: a rotary motor that generates torque to rotate the rotating body relative to the traveling body; a boom cylinder that generates torque to rotate the boom relative to the rotating body; a stick cylinder that generates torque to rotate the stick relative to the boom; and a bucket cylinder that generates torque to rotate the bucket relative to the stick.

7. A method for generating instructions, characterized in that, This is a method for generating instructions for a working machine, which includes: a plurality of components connected sequentially from a base end to a tip end; and a plurality of hydraulic actuators configured for each group of adjacent base end and tip end components, such that the tip end components rotate relative to the base end components. The method includes the following steps: Obtain current angle information representing the current angle of the tip-side member relative to the base-side member; Based on the current angle information, the current torque that causes the tip-side member to rotate relative to the base-side member is calculated through inverse dynamics calculation; Obtain target angle information representing the target angle of the tip-side member relative to the base-side member; Based on the target angle information, a target torque is calculated to make the current angle track the target angle; Based on the target angle information, a reference speed command value representing the target speed of the hydraulic actuator is calculated; and The reference speed command value is corrected in such a way as to reduce the torque deviation, which is the deviation between the target torque and the current torque, to generate a control command value for controlling the speed of the hydraulic actuator.

Images