Classifications

• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02F—DREDGING; SOIL-SHIFTING
  • E02F3/00—Dredgers; Soil-shifting machines
  • E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
  • E02F3/28—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets
  • E02F3/36—Component parts
  • E02F3/42—Drives for dippers, buckets, dipper-arms or bucket-arms
  • E02F3/43—Control of dipper or bucket position; Control of sequence of drive operations
• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02F—DREDGING; SOIL-SHIFTING
  • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
  • E02F9/20—Drives; Control devices
  • E02F9/22—Hydraulic or pneumatic drives

Definitions

• This disclosure relates to a command generation system and a command generation method for a work machine that includes a hydraulic actuator, such as a hydraulic excavator.
• the hydraulic power shovel disclosed in Patent Document 1 has a boom connected to a rotating body including a cab, an arm connected to the boom, and a bucket connected to the arm.
• the boom, arm, and bucket are driven by a boom cylinder, arm cylinder, and bucket cylinder, respectively.
• the present disclosure aims to provide a command generation system and command generation method that can increase the tracking speed by which the tips of multiple sequentially connected components are made to follow a target trajectory using hydraulic actuators.
• a command generation system is a command generation system for a work machine that includes a plurality of members connected in sequence from the base end side to the tip end side, and a plurality of hydraulic actuators arranged for each set of adjacent base end and tip end members in the plurality of members, and that rotate the tip end members relative to the base end members.
• the command generation system includes a processing circuit that acquires current angle information indicating the current angle of the tip end member relative to the base end member, and calculates the rotation angle of the tip end member relative to the base end member based on the current angle information by inverse dynamics calculation.
• the system is configured to estimate the current torque to rotate the hydraulic actuator, acquire target angle information indicating the target angle of the tip-side member relative to the base-side member, calculate a target torque for causing the current angle to follow the target angle based on the target angle information, calculate a reference speed command value indicating the target speed of the hydraulic actuator based on the target angle information, and correct the reference speed command value so that the torque deviation, which is the deviation between the target torque and the current torque, is reduced, thereby generating a control command value for controlling the speed of the hydraulic actuator.
• a command generation method is a command generation method for a work machine including a plurality of members connected sequentially from the base end to the tip end, and a plurality of hydraulic actuators arranged in sets of adjacent base end and tip end members among the plurality of members, for rotating the tip end members relative to the base end members.
• the command generation method includes the steps of: acquiring current angle information indicating the current angle of the tip end member relative to the base end member; estimating a current torque for rotating the tip end member relative to the base end member based on the current angle information by inverse dynamics calculation; acquiring target angle information indicating a target angle of the tip end member relative to the base end member; calculating a target torque for causing the current angle to follow the target angle based on the target angle information; calculating a reference speed command value indicating a target speed of the hydraulic actuator based on the target angle information; and correcting the reference speed command value to reduce a 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.
• the tracking speed at which the tips of multiple sequentially connected members are caused to follow a target trajectory by a hydraulic actuator can be increased.
• FIG. 1 is a schematic side view of a hydraulic excavator, which is an example of a work machine.
• 2 is a diagram showing a hydraulic circuit incorporated in the work machine of FIG. 1;
• 1 is a schematic configuration diagram of a control system for a work machine including a controller that is a command generating system according to a first embodiment.
• FIG. FIG. 2 is a block diagram showing the functional configuration of a processing circuit of the controller.
• FIG. 10 is a diagram illustrating a command generation system according to a second embodiment.
• First Embodiment 1 shows a work machine 1 in which a command generation system according to a first embodiment is used.
• the work machine 1 is a hydraulic excavator 10.
• the work machine 1 includes a plurality of members 11 connected in sequence from the base end toward the tip end.
• the plurality of members 11 include a running body 12, a rotating body 13, a boom 14, an arm 15, and a bucket 16.
• the bucket 16 side is the tip end, and the running body 12 side opposite the bucket 16 is the base end.
• the running body 12 includes a pair of crawlers.
• a cabin 17 including a driver's seat and other components is mounted on the left front side of the rotating body 13.
• the rotating body 13 is rotatably connected to the running body 12.
• the boom 14 is rotatably connected to the rotating body 13.
• the arm 15 is rotatably connected to the boom 14.
• the bucket 16 is a work tool used to excavate earth and sand.
• the bucket 16 is rotatably connected to the arm 15.
• the member on the base end side will be referred to as the base end member 11a
• the member on the tip end side will be referred to as the tip end member 11b.
• the work machine 1 includes a hydraulic circuit 2 shown in Figure 2.
• the hydraulic circuit 2 includes a pump device 21, travel motors 31, 32, and multiple hydraulic actuators 33.
• the pump device 21 is connected to a valve unit 22 that includes multiple control valve devices 40, and the travel motors 31, 32 and hydraulic actuators 33 are connected to this valve unit 22.
• the pump device 21 includes a variable displacement pump (swash plate pump or bent-axis pump) 21a with a variable tilt angle, and a regulator 21b that changes the tilt angle of the pump 21a.
• the discharge flow rate of the pump device 21 is controlled using an electrical positive control system.
• Travel motors 31 and 32 each drive a pair of crawlers on the travelling body 12.
• Each hydraulic actuator 33 is arranged for each set of adjacent base-end members 11a and tip-end members 11b, in other words, for each joint. Each hydraulic actuator 33 rotates the tip-end member 11b relative to the base-end member 11a of each set. As shown in Figure 2, the hydraulic actuator 33 includes a swing motor 34, a boom cylinder 35, an arm cylinder 36, and a bucket cylinder 37.
• the rotation motor 34 rotates the rotating body 13 relative to the running body 12 around a rotation axis Jsw that extends at the center of the running body 12 in a direction perpendicular to the front-to-rear and width directions of the running body 12.
• the boom cylinder 35 is disposed between the revolving unit 13 and the boom 14.
• the boom cylinder 35 rotates the boom 14 relative to the revolving unit 13 around a rotation axis Jbm that extends in the width direction of the revolving unit 13 at the base end of the boom 14.
• the base end of the boom cylinder 35 is rotatably connected to the revolving unit 13, and the tip end of the boom cylinder 35 is rotatably connected to the center of the boom 14.
• the base end of the boom cylinder 35 is the head portion
• the tip end of the boom cylinder 35 is the rod portion.
• the arm cylinder 36 is disposed between the boom 14 and the arm 15.
• the arm cylinder 36 rotates the arm 15 relative to the boom 14 around a rotation axis Jam that extends in the width direction of the rotating body 13 at the tip of the boom 14.
• the base end of the arm cylinder 36 is rotatably connected to the center of the boom 14, and the tip end of the arm cylinder 36 is rotatably connected to the base end of the arm 15.
• the base end of the arm cylinder 36 is the head portion
• the tip end of the arm cylinder 36 is the rod portion.
• the bucket cylinder 37 is disposed between the arm 15 and the bucket 16.
• the bucket cylinder 37 rotates the bucket 16 relative to the arm 15 around a rotation axis Jbt that extends at the tip of the arm 15 in the width direction of the rotating body 13.
• the base end of the bucket cylinder 37 is rotatably connected to the base end of the arm 15.
• the tip end of the bucket cylinder 37 is connected to the tip end of the arm 15 and the back surface of the bucket 16 via a first auxiliary link 18a and a second auxiliary link 18b.
• the base end of the bucket cylinder 37 is the head portion
• the tip end of the bucket cylinder 37 is the rod portion.
• the multiple control valve devices 40 include two travel motor control valve devices 41, a swing control valve device 42, a boom control valve device 43, an arm control valve device 44, and a bucket control valve device 45.
• the two travel motor control valve devices 41 control the flow of hydraulic oil supplied from the pump device 21 to the travel motors 31, 32, respectively.
• the swing control valve device 42 controls the flow of hydraulic oil supplied from the pump device 21 to the swing motor 34.
• the boom control valve device 43 controls the flow of hydraulic oil supplied from the pump device 21 to the boom cylinder 35.
• the arm control valve device 44 controls the flow of hydraulic oil supplied from the pump device 21 to the arm cylinder 36.
• the bucket control valve device 45 controls the flow of hydraulic oil supplied from the pump device 21 to the bucket cylinder 37.
• valve unit 22 may be composed of multiple units, or multiple control valve devices 40 may be incorporated into multiple, mutually independent units.
• the configuration of the control valve device 40 is not particularly limited as long as it is capable of controlling the flow of hydraulic oil supplied to and discharged from the corresponding actuator.
• the control valve device 40 may be an electromagnetic spool valve.
• the control valve device 40 may include a pilot-operated spool valve and an electromagnetic proportional valve that outputs pilot pressure to the pilot-operated spool valve.
• FIG. 3 shows a control system 4 for a work machine 1, which includes a controller 7, which is a command generation system of this embodiment.
• the control system 4 includes multiple attitude angle sensors 5, a controller 7, and the multiple control valve devices 40 and pump device 21 that are controlled by the controller 7.
• the multiple attitude angle sensors 5, the multiple control valve devices 40, and the pump device 21 are connected to the controller 7 by wire or wirelessly.
• the attitude angle sensor 5 detects the attitude of the work machine 1 as attitude information.
• the attitude angle sensor 5 includes a vehicle attitude angle sensor 51, a swing attitude angle sensor 52, a boom attitude angle sensor 53, an arm attitude angle sensor 54, and a bucket attitude angle sensor 55.
• the vehicle attitude angle sensor 51 detects the vehicle attitude angle, which is the inclination angle of the running body 12 with respect to the horizontal plane.
• the swing attitude angle sensor 52 detects the swing attitude angle, which is the angle of the fore-and-aft direction of the swing body 13 with respect to the fore-and-aft direction of the running body 12 on a plane perpendicular to the rotation axis Jsw.
• the boom attitude angle sensor 53 detects the boom attitude angle, which is the inclination angle of the boom 14 with respect to the horizontal plane.
• the arm attitude angle sensor 54 detects the arm attitude angle, which is the inclination angle of the arm 15 with respect to the horizontal plane.
• the bucket attitude angle sensor 55 detects the bucket attitude angle, which is the inclination angle of the bucket 16 with respect to the horizontal plane.
• the controller 7 includes a processing circuit 70.
• the processing circuit 70 includes a processor 71, a system memory 72, and a 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.
• the controller 7 may include at least one user interface 74.
• the user interface 74 may be located in the cockpit.
• the user interface 74 includes an input interface and an output interface.
• the input interface may be a touch panel, a steering wheel, a lever, a switch, etc.
• the output interface may be a display.
• the controller 7 may include at least one communication interface 75.
• the communication interface 75 includes an interface that connects an external device to the controller 7 so that communication is possible via a wired or wireless connection.
• the communication interface 75 may also include an interface that connects to a communication network such as the Internet so that communication is possible via a wired or wireless connection.
• the program 73a stored in the storage memory 73 includes a trajectory tracking program.
• the trajectory tracking program is a program for executing trajectory tracking control, which causes the tip of the bucket 16, which is the tip of the multiple members 11, to follow a target trajectory using the hydraulic actuator 33.
• the trajectory tracking control is control for causing the hydraulic excavator 10 to perform excavation operations in automatic operation.
• the hydraulic excavator 10 is modeled as a four-link mechanism including a swing link 1a, boom link 1b, arm link 1c, and bucket link 1d corresponding to the swing unit 13, boom 14, arm 15, and bucket 16, respectively, and calculations are performed based on this model.
• the swing link 1a is represented by a straight line between the swing axis Jsw and the swing axis Jbm of the swing unit 13.
• the boom link 1b is represented by a straight line between the swing axis Jbm and the swing axis Jam of the boom 14.
• the arm link 1c is represented by a straight line between the swing axis Jam and the swing axis Jbt of the arm 15.
• the bucket link 1d is represented by a straight line between the swing axis Jbt and the tip of the bucket 16.
• the hydraulic excavator 10 also includes a boom cylinder 35, arm cylinder 36, bucket cylinder 37, and first and second auxiliary links 18a, 18b.
• the hydraulic excavator 10 is actually a multi-link mechanism including five or more links.
• the reason for simplifying a multi-link mechanism including five or more links such as the hydraulic excavator 10 as a four-link mechanism model is to reduce the amount of calculation required for trajectory tracking control.
• the rotating body 13, boom 14, arm 15, and bucket 16, which correspond to links 1a, 1b, 1c, and 1d included in the model, may be referred to as main links.
• links not included in the model such as the boom cylinder 35, arm cylinder 36, bucket cylinder 37, and first and second auxiliary links 18a and 18b, may be referred to as slave links to distinguish them from main links.
• the slave link correction unit 85 which will be described later, performs parameter correction that takes into account slave links that were not included in the model.
• the slave link correction unit 85 will be described in more detail below.
• FIG. 4 is a block diagram showing the functional configuration of the processing circuit 70 of the controller 7.
• the processing circuit 70 functions as a target angle acquisition unit 81, a reference speed calculation unit 82, a speed correction unit 83, a four-link inverse dynamics calculation unit 84, a slave link correction unit 85, a target torque calculation unit 86, and a hydraulic control unit 87.
• the processing of each functional unit 81, 82, 83, 84, 85, 86, and 87 in trajectory tracking control is explained below.
• the target angle acquisition unit 81 acquires target angle information indicating the target angle ⁇ tar of the tip-side member 11b relative to the base-side member 11a.
• the target angle information is information for operating the multiple hydraulic actuators 33 so that the tips of the multiple members 11, i.e., the tip of the bucket 16, follow a predetermined target trajectory when the work machine 1 is operated automatically.
• the target angle ⁇ tar is the target angle for making the tip of the bucket 16 follow the target trajectory.
• the target angle ⁇ tar is expressed by the following equation 1.
• the target angle acquisition unit 81 acquires target angle information by generating a time-series target angle ⁇ tar based on, for example, a trajectory tracking program stored in memory 73.
• the time-series target angle ⁇ tar may be stored in memory 73 in advance, and the target angle acquisition unit 81 may acquire target angle information by reading from memory 73.
• the target angle acquisition unit 81 may also receive target angle information from outside the work machine 1.
• 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 indicates the target speed of each hydraulic actuator 33 according to the target angle ⁇ tar.
• the reference speed calculation unit 82 converts the target angle ⁇ sw_tar into a rotational angle of the swing motor 34 corresponding to the target angle ⁇ sw_tar, and calculates the rotational speed of the swing motor 34 as the reference speed of the swing motor 34 by differentiating the rotational angle with respect to time. Furthermore, for example, the reference speed calculation unit 82 converts the target angle ⁇ bm_tar into a stroke of the boom cylinder 35 corresponding to the target angle ⁇ bm_tar, and calculates the reference speed of the boom cylinder 35 by differentiating the stroke with respect to time.
• the reference speed calculation unit 82 calculates the reference speed of the arm cylinder 36 from the target angle ⁇ am_tar, and calculates the reference speed of the bucket cylinder 37 from the target angle ⁇ bt_tar, using the same calculation method as for the reference speed of the boom cylinder 35.
• the speed correction unit 83 corrects the reference speed command value according to the torque deviation ⁇ .
• the torque deviation ⁇ is the difference between the target torque ⁇ tar and the current torque ⁇ cur.
• the current torque ⁇ cur is calculated by the four-link inverse dynamics calculation unit 84, and the target torque ⁇ tar is calculated by the target torque calculation unit 86.
• the current torque ⁇ cur is the torque currently acting on the joint between the base-end member 11a and the tip-end member 11b, in other words, the torque that rotates the tip-end member 11b relative to the base-end member 11a.
• the current torque ⁇ cur is expressed by the following equation 2.
• the four-link inverse dynamics calculation unit 84 estimates the current torque ⁇ cur by inverse dynamics calculation using the following equation 3, based on current angle information indicating the current angle ⁇ of the tip-end member 11b relative to the base-end member 11a.
• the current angle ⁇ is calculated by the processing circuit 70 from the attitude information detected by the attitude angle sensor 5.
• the current angle ⁇ is expressed by the following equation 4.
• M( ⁇ ) is a matrix whose components are the inertia tensors around each rotation axis.
• h( ⁇ , d ⁇ /dt) is a matrix whose components are the centrifugal force and Coriolis force around each rotation axis.
• G( ⁇ ) is a matrix whose components are the gravity of each member 11.
• the components of M( ⁇ ) and G( ⁇ ) are functions with the current angle ⁇ as a variable, and the components of h( ⁇ , d ⁇ /dt) are functions with the current angle ⁇ and its time-differentiated angular velocity d ⁇ /dt as variables.
• the components of M( ⁇ ), h( ⁇ , d ⁇ /dt), and G( ⁇ ) are calculated by inverse dynamics calculation using the four-link inverse dynamics calculation unit 84 based on parameters related to the rotating unit 13, boom 14, arm 15, and bucket 16, i.e., parameters related to the main link (hereinafter referred to as main link parameters).
• the main link parameters include, for example, the mass of the main link and the position of the center of gravity of the main link.
• the main link parameters are corrected by the slave link correction unit 85, taking into account slave links not included in the model.
• the slave link correction unit 85 acquires multiple master link parameters.
• the slave link correction unit 85 also acquires parameters related to multiple slave links that were not included in the model (hereinafter referred to as slave link parameters). These parameters are pre-stored in the memory 73, for example.
• the slave link parameters may include the mass and center of gravity of each of the boom cylinder 35, arm cylinder 36, bucket cylinder 37, and first and second auxiliary links 18a, 18b.
• the mass of the hydraulic cylinder which is a slave link parameter, may include the mass of each of the head and rod portions of the hydraulic cylinder.
• 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 ⁇ cur by inverse dynamics calculation using the multiple master link parameters corrected by the slave link correction unit 85.
• the slave link correction unit 85 corrects the mass of the master link by adding the mass of some or all of the slave links connected to the master link to the mass of the master link. More specifically, the slave link correction unit 85 adds a mass that is a predetermined ratio (including 100%) of the total mass of the slave link to the mass of the master link connected to the slave link. The ratio may be a fixed value or a variable value that depends on the current angle ⁇ .
• the boom cylinder 35 which is one of the slave links, is connected to both the revolving unit 13 and the boom 14.
• the slave link correction unit 85 adds a predetermined proportion of the mass of the boom cylinder 35 to the mass of the revolving unit 13, and adds the remaining mass of the boom cylinder 35 to the mass of the boom 14.
• the slave link correction unit 85 calculates the center of gravity of the master link by combining the center of gravity of the master link with the centers of gravity of some or all of the slave links connected to the master link.
• the master link parameters are corrected based on the slave link parameters, thereby suppressing the deterioration in the estimation accuracy of the current torque ⁇ cur that can result from simplifying a multi-link mechanism into a model with fewer link mechanisms.
• the slave link correction unit 85 may not only correct the master link parameters, but also correct the current torque ⁇ cur calculated by the four-link inverse dynamics calculation unit 84. For example, the slave link correction unit 85 may calculate, as the correction torque, the torque due to the weight of the slave link that would actually act because the slave link is connected to the master link. The slave link correction unit 85 may then correct the current torque ⁇ cur by adding the calculated correction torque to the current torque ⁇ cur estimated by the four-link inverse dynamics calculation unit 84 using Equation 3 inverse dynamics calculation.
• the target torque ⁇ tar is the torque that causes the current angle ⁇ to follow the target angle ⁇ tar.
• the target torque ⁇ tar is the torque that should be applied to the joint between the base-end member 11a and the tip-end member 11b in order to cause the tip of the bucket 16 to follow the target trajectory.
• the target torque ⁇ tar is expressed by the following equation 8.
• the target torque calculation unit 86 calculates the target torque ⁇ tar based on the current angle information and the target angle information. The method for calculating the target torque ⁇ tar is explained below.
• Equation 3 Because the system shown in Equation 3 is nonlinear, linear control theory cannot be applied. For this reason, in this embodiment, linearization feedback is used to calculate the nonlinear system shown in Equation 3 as an equivalent controllable linear system. Specifically, by linearizing Equation 3, the following linear state equation, Equation 9, is obtained, with the state variable being X and the input being u.
• Equation 9 The state variable X and input u in equation 9 are expressed by equations 10 and 11 below, respectively.
• ⁇ is the angle deviation between the target angle ⁇ tar and the current angle ⁇
• d ⁇ /dt is the angular velocity deviation obtained by time-differentiating the angle deviation ⁇ .
• M( ⁇ ), h( ⁇ , d ⁇ /dt), and G( ⁇ ) are the same as M( ⁇ ), h( ⁇ , d ⁇ /dt), and G( ⁇ ) calculated by the four-link inverse dynamics calculation unit 84.
• a state feedback F is set using a known pole placement method to converge the state variable X in equation 9 to an arbitrary target value. Specifically, by setting an eigenvalue p corresponding to the dynamics of each axis in equation 9 above, the feedback gain F is determined, and then incorporating the feedback gain F into equation 3 above, the following equation 12 is obtained.
• the feedback gain F may be calculated by a method other than the pole placement method.
• the feedback gain F may be calculated by using a known optimal regulator method, which sets a certain evaluation function and determines the feedback gain F that minimizes this function.
• the target torque calculation unit 86 calculates the target torque ⁇ tar based on the above linear state equation, Equation 9, the target angle ⁇ tar, and the current angle ⁇ . In other words, the target torque calculation unit 86 calculates the target torque ⁇ tar by combining the acquired target angle ⁇ tar and current angle ⁇ with Equation 12, which is obtained based on Equation 9.
• the speed correction unit 83 obtains the torque deviation ⁇ , which is the difference between the target torque ⁇ tar and the current torque ⁇ cur, and corrects the reference speed command value using PID control to reduce this torque deviation ⁇ . In other words, if the current torque ⁇ cur is insufficient relative to the target torque ⁇ tar, the speed correction unit 83 corrects the speed command value to increase the current torque ⁇ cur, and if the current torque ⁇ cur is in excess of the target torque ⁇ tar, the speed correction unit 83 corrects the speed command value to decrease the current torque ⁇ cur.
• the hydraulic control unit 87 generates control command values for the control objects based on the speed command values corrected by the speed correction unit 83, and outputs them to each control object. For example, information indicating the correspondence between speed command values and control command values is stored in advance in memory 73, and the hydraulic control unit 87 uses this correspondence information to convert the speed command values corrected by the speed correction unit 83 into control command values.
• the control command values include a valve opening command value and a pump flow rate command value.
• the hydraulic control unit 87 outputs the generated pump flow rate command value to the pump device 21, and outputs valve opening command values to the swing control valve device 42, boom control valve device 43, arm control valve device 44, and bucket control valve device 45.
• the target torque and current torque are calculated for each joint between the multiple members 11, and the reference speed command value is corrected based on the torque deviation ⁇ between the target torque ⁇ tar and the current torque ⁇ cur.
• This makes it possible to generate a control command value that absorbs torque deviations caused by the nonlinearity of the hydraulic actuator 33 (for example, oil compressibility or flow force). This makes it possible to improve the tracking speed and tracking accuracy when controlling the tip of the bucket 16 to follow the target trajectory using the hydraulic actuator 33.
• Second Embodiment 5 is a diagram illustrating a command generation system 100 according to the second embodiment.
• the command generation system 100 comprises a plurality of attitude angle sensors 5 included in the work machine 1, and a command generation device 9 that is an external device of the work machine 1.
• the work machine 1 is the same as that described in the first embodiment, and therefore a description thereof will be omitted.
• the trajectory tracking processing was executed by the controller 7 of the work machine 1, but in the second embodiment, part or all of the trajectory tracking processing is executed by the command generation device 9.
• the command generating device 9 is located outside the work machine 1.
• the command generating device 9 is configured to be able to communicate with the controller 7 of the work machine 1.
• the command generating device 9 may be a server or an information processing terminal that can be operated by the user.
• the command generation device 9 includes a processing circuit 90.
• the processing circuit 90 includes a processor 91, a system memory 92, and a storage memory 93.
• the command generation device 9 also includes at least one user interface 94 and at least one communication interface 95.
• the hardware configuration of the command generation device 9 is generally the same as that of the controller 7, so a description thereof will be omitted.
• the command generating device 9 receives attitude information obtained by the attitude angle sensor 5 from the work machine 1.
• the processing circuit 90 receives the current angle ⁇ from the work machine 1, but otherwise executes the same processing as described in the first embodiment. That is, the processing circuit 90 functions as the functional units 81, 82, 83, 84, 85, 86, and 87 described in the first embodiment.
• the control command values generated by the command generating device 9 are sent to the controller 7 of the work machine 1, and the controller 7 sends the received control command values to various control targets. Note that the processing circuit 90 may execute only some of the functional units 81, 82, 83, 84, 85, 86, and 87 described in the first embodiment.
• the same effects as in the first embodiment can be obtained. Furthermore, because the calculations for generating the control command values are performed by equipment external to the work machine 1, the amount of calculations performed by the controller 7 of the work machine 1 can be reduced.
• a hydraulic excavator was shown as an example of a work machine, but the work machine may be a construction machine other than a hydraulic excavator. Furthermore, the work machine may be configured to include a plurality of members connected in sequence from the base end to the tip end, and a plurality of hydraulic actuators that rotate the tip end members relative to the base end members.
• the work machine does not have to be a construction machine, and may also be a hydraulically driven humanoid robot or industrial robot.
• the running body 12 may include multiple wheels instead of a pair of crawlers.
• the hydraulic circuit 2 may not include the travel motors 31, 32, and the wheels may be driven by an engine or an electric motor.
• the discharge flow rate of the pump device 21 was controlled using an electrical positive control method, but the discharge flow rate of the pump device 21 may also be controlled using another method, such as a hydraulic negative control method. In this case, the processing circuit does not need to generate a pump flow command value.
• the processing of the processing circuit described in the first and second embodiments can also be applied to manual operation of a work machine by an operator.
• the target angle information may be generated in response to operation by the operator, such as lever operation.
• the operator may operate the work machine 1 while riding on the work machine 1, or may remotely operate it from outside the work machine 1, for example, from the command generation device 9 of the second embodiment.
• the current angle ⁇ may be information calculated by the processing circuit from the attitude information detected by the attitude angle sensor, or it may be information received from an external source.
• the method of calculating the target torque uses the linear state equation of Equation 9, which is obtained by linearizing the nonlinear equation of motion of Equation 3, but the method of calculating the target torque is not limited to this.
• the target torque may be calculated by substituting the target angle into Equation 3.
• the target torque may be determined by performing a predetermined calculation using predetermined parameters (for example, three parameters: a proportional element, an integral element, and a differential element) on the deviation between the target angle and the current angle for each joint.
• the boom cylinder 35, arm cylinder 36, bucket cylinder 37, and first and second auxiliary links 18a, 18b have been described as slave links, but the slave link correction unit does not need to use all of these parameters to correct the master link parameters.
• the slave link correction unit may use only parameters related to the hydraulic cylinder 33 to correct the master link parameters.
• circuits or processing circuits including general-purpose processors, special-purpose processors, integrated circuits, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), conventional circuits, and/or combinations thereof, configured or programmed to perform the disclosed functions.
• Processors are considered processing circuits or circuits because they include transistors and other circuitry.
• a circuit, unit, or means is hardware that performs the recited functions or hardware that is programmed to perform the recited functions.
• the hardware may be hardware disclosed herein or other known hardware that is programmed or configured to perform the recited functions. Where the hardware is a processor, which is considered a type of circuit, the circuit, means, or unit is a combination of hardware and software, and the software is used to configure the hardware and/or processor.
• the programs disclosed in this specification may be stored on a computer-readable storage medium.
• the storage medium is a non-transitory, tangible medium.
• the storage medium may be built into or external to a computer (e.g., a mobile information terminal, personal computer, server, etc.).
• the storage medium may include RAM, ROM, EEPROM, storage, etc., and may be, for example, a hard disk, flash memory, optical disk, etc.
• the program stored on the storage medium may be executed on a computer to which the storage medium is directly connected, or on a computer connected to the storage medium via a communications network (e.g., the Internet).
• a communications network e.g., the Internet
• a command generation system for a work machine comprising: a plurality of members sequentially connected from a base end side toward a tip end side; and a plurality of hydraulic actuators arranged for each set of a base end side member and a tip end side member adjacent to each other in the plurality of members, the hydraulic actuators rotating the tip end side member relative to the base end side member
• the command generation system comprises a processing circuit;
• the processing circuitry acquiring current angle information indicating a current angle of the distal side member relative to the proximal side member; estimating a current torque for rotating the distal end side member relative to the proximal end side member by inverse dynamics calculation based on the current angle information; acquiring target angle information indicating a target angle of the distal side member relative to the proximal side member; calculating a target torque for making the current angle follow the target angle based on the target angle information; calculating a reference speed command value indicating a target speed of the hydraulic actuator based on the target angle information; and correcting the
• the target torque and current torque are calculated for each joint between multiple members, and the reference speed command value is corrected based on the torque deviation between the target torque and the current torque.
• This makes it possible to generate a control command value that absorbs torque deviations caused by the nonlinearity of the hydraulic actuator. This makes it possible to increase the tracking speed when controlling the tips of multiple members to follow a target trajectory using the hydraulic actuator.
• the plurality of hydraulic actuators include a plurality of hydraulic cylinders; estimating the current torque correcting a plurality of master link parameters including masses of the plurality of members based on the acquired current angle information and a plurality of slave link parameters including masses of the plurality of hydraulic cylinders; and calculating the current torque by inverse dynamics calculation using the corrected plurality of primary link parameters.
• This configuration reduces the amount of calculation required to estimate current torque using inverse dynamics calculations and improves estimation accuracy.
• calculating the target torque includes calculating the target torque based on a linear state equation obtained by linearizing a nonlinear equation of motion of the plurality of members, the linear state equation including, as state variables, an angle deviation that is a deviation between the target angle and the current angle, and an angular velocity deviation that is a time-differentiated value of the angle deviation.
• the work machine includes a pump that discharges hydraulic fluid, and a control valve that is disposed in a fluid path that connects the pump and the hydraulic actuator, Aspect 4.
• the command generation system according to any one of aspects 1 to 3, wherein the control command value includes at least one of a pump flow rate command value for changing a flow rate of the hydraulic fluid discharged from the pump and a valve position command value for changing an opening of the control valve.
• a command generation system according to any one of aspects 1 to 4, wherein the target angle information is information for operating the plurality of hydraulic actuators so that tips of the plurality of members follow a predetermined target trajectory through automatic operation of the work machine.
• This configuration makes it possible to increase the speed at which multiple members follow the target trajectory during automatic operation of the work machine.
• the work machine is a hydraulic excavator
• the plurality of members include a traveling body, a rotating body rotatably connected to the traveling body, a boom rotatably connected to the rotating body, an arm rotatably connected to the boom, and a bucket rotatably connected to the arm
• Aspect 6 The command generation system according to any one of aspects 1 to 5, wherein the plurality of hydraulic actuators include a swing motor that generates torque to rotate the swing body relative to the traveling body, a boom cylinder that generates torque to rotate the boom relative to the swing body, an arm cylinder that generates torque to rotate the arm relative to the boom, and a bucket cylinder that generates torque to rotate the bucket relative to the arm.
• This configuration allows the hydraulic excavator to increase the speed at which the bucket tip follows the target trajectory.
• a command generation method for a work machine including a plurality of members sequentially connected from a base end side to a tip end side, and a plurality of hydraulic actuators arranged for each set of a base end side member and a tip end side member adjacent to each other in the plurality of members, the hydraulic actuators rotating the tip end side member relative to the base end side member, acquiring current angle information indicating a current angle of the distal side member relative to the proximal side member; estimating a current torque for rotating the distal end side member relative to the proximal end side member by inverse dynamics calculation based on the current angle information; acquiring target angle information indicating a target angle of the distal side member relative to the proximal side member; calculating a target torque for making the current angle follow the target angle based on the target angle information; calculating a reference speed command value indicating a target speed of the hydraulic actuator based on the target angle information; and correcting the reference speed command value so that a torque deviation, which is a deviation
• the target torque and current torque are calculated for each joint between multiple members, and the reference speed command value is corrected based on the torque deviation between the target torque and the current torque.
• This makes it possible to generate a control command value that absorbs torque deviations caused by the nonlinearity of the hydraulic actuator. This makes it possible to increase the tracking speed when controlling the tips of multiple members to follow a target trajectory using a hydraulic actuator.

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• General Engineering & Computer Science (AREA)
• Structural Engineering (AREA)
• Mechanical Engineering (AREA)
• Operation Control Of Excavators (AREA)

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• 2024
  • 2024-10-22 JP JP2025573372A patent/JPWO2025163994A1/ja active Pending
  • 2024-10-22 WO PCT/JP2024/037568 patent/WO2025163994A1/ja active Pending

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