Construction machine

Abstract

To provide a construction machine executing control that can be easily applied to an operation control of a construction machine.SOLUTION: A controller of a construction machine performs: coordinate calculations to calculate coordinates of a machine body and a work tool on the basis of detection information from an attitude detection device; target state amount calculations to calculate, on the basis of a construction target surface and the coordinates of the work tool that is the calculation result of the coordinate calculation, a time series of target state amounts of the work tool that are target values of state amounts of the work tool in a prescribed time interval that satisfies prescribed conditions; command calculations to calculate speed command values of a plurality of hydraulic actuators by using a prediction model that predicts the state amounts of the work tool with speeds of the plurality of hydraulic actuators as control inputs on the basis of a deviation between the state amounts of the work tool in the prescribed time interval and the time series of the target state amounts of the work tool that is the calculation result of the target state amount calculation; and control of driving of the plurality of hydraulic actuators so that the actual speeds of the plurality of hydraulic actuators based on the detection information from the attitude detection device coincide with the speed command values of the plurality of hydraulic actuators.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a construction machine equipped with an articulated working device made up of a plurality of driven members including a working implement, and more particularly to a construction machine that controls the operation of the working device under predetermined conditions. [Background technology]

[0002] In the field of construction machinery such as hydraulic excavators, the introduction of information-based construction is progressing, which aims to streamline construction by efficiently utilizing a variety of information through the application of information and communication technology to construction work.To accommodate information-based construction, construction machinery is being developed that has functions to assist the operator in driving operations (driving operation assistance control), such as machine guidance that displays to the operator the position and posture of a work device made up of multiple driven members, and machine control that controls the work device to move along the construction target surface.

[0003] In conventional machine control for hydraulic excavators, in order to control the operation of a work implement consisting of a boom, arm, and bucket (work implement), target drive amounts (e.g., target speeds) of hydraulic actuators that drive each component of the work implement are calculated. In such conventional machine control, when controlling the tip position of the bucket (work implement) of the work implement in three-dimensional space, if the swinging motion of the machine body is not taken into consideration, when an operator operates one of the components of the work implement (e.g., the boom), the two hydraulic actuators that drive the remaining two components (the arm and bucket) become the control targets of the machine control. In this case, the degrees of freedom (two dimensions) of the bucket tip position match the number (two) of hydraulic actuators that are the control targets of the machine control. Therefore, when controlling the tip position of the bucket, setting the target drive amount for one of the two controlled hydraulic actuators uniquely determines the target drive amount for the other. On the other hand, if the work implement is changed from a bucket to a rotary tilt bucket and the range of machine control is adjusted to accommodate this change, the number of hydraulic actuators to be controlled by the machine control increases because the number of hydraulic actuators that drive the rotary tilt bucket (two) is greater than the number of hydraulic actuators that drive the bucket (one). In this case, when an operator operates one of the components of the work equipment, the number of hydraulic actuators to be controlled (three) is greater than the degree of freedom (two dimensions) of the toe position of the work implement. For this reason, it is necessary to appropriately set how to simultaneously control the multiple hydraulic actuators that are the target of machine control and with what combination of target drive amounts.

[0004] One useful solution to this problem is the technology described in Patent Document 1. The construction machinery control system described in Patent Document 1 calculates a predicted value of the control amount of the work machine based on a target value of the control amount of the work machine and a predictive model of the work machine, and calculates a drive amount for controlling the work machine based on the predicted value and the design surface, in order to move the bucket of the work machine (work implement) along a design surface that represents the target shape of the construction target. This control system generates a target value based on operation data of an operating device operated by an operator, and performs control equivalent to a driving assistance function. This control system also utilizes model predictive control. Model predictive control is capable of handling control of multi-input, multi-output systems, and enables the determination of appropriate control inputs by using an appropriate evaluation function. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2020-125595 Summary of the Invention [Problem to be solved by the invention]

[0006] In the construction machinery control system described in Patent Document 1, the torque that drives the work machine (working device) is used as the control input for the predictive model. In the case of a multi-joint structure such as an industrial robot, the structure can be rotated by applying torque from an electric motor. However, in the case of a multi-joint work machine such as a hydraulic excavator, the rotation of the work device is achieved by the extension and contraction of multiple hydraulic cylinders. Therefore, some kind of ingenuity is required to actually apply torque control using the predictive model described in Patent Document 1 to the work machine of a hydraulic excavator.

[0007] Furthermore, even if torque control using the model predictive control described in Patent Document 1 can be applied to a hydraulic excavator work machine with some ingenuity, it is not easy to control the work machine as intended unless the influence of modeling error is taken into account. This is because the equation of motion used as a predictive model in the technology described in Patent Document 1 includes terms whose parameters are not easy to identify (e.g., inertia force terms and Coriolis force terms). In the technology described in Patent Document 1, if these parameters are not appropriately set, when the operator does not intend to operate the hydraulic excavator, that is, when the target speed of the work machine is 0, the torque (balance torque) for bringing the work machine to a stop state according to Equation (11) (state equation of the predictive model) described in Patent Document 1 will not match the actually required balance torque, which could result in unintended operation of the work machine. As such, it is difficult to control the work machine as intended unless the influence of modeling error is taken into account.

[0008] As described above, there are concerns that various problems may arise when actually applying the control method described in Patent Document 1 to the work implement (work machine) of a hydraulic excavator. However, Patent Document 1 does not disclose any ideas for solving these problems.

[0009] The present invention has been devised in view of the above problems, and its object is to provide a construction machine that executes control that can be easily applied to the operation control of the construction machine. [Means for solving the problem]

[0010] The present application includes a plurality of means for solving the above-mentioned problems. One example of the present application is a construction machine including an articulated working device constituted by a plurality of driven members including a working implement, a machine body to which the working device is rotatably attached, a plurality of hydraulic actuators for driving the machine body and the working device, an attitude detection device for detecting information regarding the attitude of the machine body and the working device, a state quantity detection device for detecting information regarding state quantities of the plurality of hydraulic actuators, and a controller for controlling the operation of the machine body and the working device, wherein the controller performs coordinate calculation to calculate the coordinates of the machine body and the working device based on the detection information from the attitude detection device, and calculates a predetermined coordinate from the time of calculation so as to satisfy a predetermined condition based on a construction target surface set as a work target of the working device and the coordinates of the working device which are the calculation result of the coordinate calculation. a target state quantity calculation for calculating a time series of target state quantities of the work tool, which are target values of the state quantities of the work tool in a predetermined time interval up to a time of a predetermined time interval; a command calculation for calculating speed command values of the plurality of hydraulic actuators based on a deviation between the state quantities of the work tool in the predetermined time interval, which is obtained by using a prediction model capable of predicting the state quantities of the work tool using the speeds of the plurality of hydraulic actuators as a control input, and the time series of the target state quantities of the work tool, which is the calculation result of the target state quantity calculation; and controlling the drive of the plurality of hydraulic actuators so that actual speeds of the plurality of hydraulic actuators, which are obtained based on detection information from the state quantity detection device, coincide with the speed command values of the plurality of hydraulic actuators, which are the calculation result of the command calculation. [Effects of the Invention]

[0011] According to one example of the present application, operation control of a work implement of a construction machine is performed by simultaneously controlling a plurality of hydraulic actuators using speed command values calculated using a predictive model in which the speeds of the plurality of hydraulic actuators are control inputs, and this model predictive control can be easily applied to operation control of a construction machine. Problems, configurations, and effects other than those described above will become apparent from the following description of the embodiments. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is an external view showing a hydraulic excavator as a construction machine according to a first embodiment of the present invention. [Figure 2] 2 is a block diagram showing the hardware configuration and functional configuration of a controller provided in the construction machine according to the first embodiment shown in FIG. 1. FIG. [Figure 3] 3 is a block diagram showing a configuration in which the functions of the controller of the construction machine according to the first embodiment shown in FIG. 2 are subdivided. FIG. [Figure 4] 4 is an explanatory diagram showing an example of an operation limited area set by a limited area setting unit in the controller of the construction machine according to the first embodiment shown in FIG. 3. FIG. [Figure 5] FIG. 3 is an explanatory diagram showing the definition of the angle θi of each component of the working mechanism of the construction machine according to the first embodiment. [Figure 6] 4 is a diagram showing an example of a display screen of a display device displayed by a toe trajectory display unit in the controller of the construction machine according to the first embodiment shown in FIG. 3. FIG. [Figure 7] 4 is a flowchart showing an example of a processing procedure of a controller of the construction machine according to the first embodiment shown in FIG. 3. [Figure 8] 3 is a diagram showing a first example of a location where improvement in construction accuracy is expected by controlling the operation of a working implement in the construction machine according to the first embodiment. FIG. [Figure 9] 5 is a diagram showing a second example of a location where improvement in construction accuracy is expected due to operation control of a working implement in the construction machine according to the first embodiment. FIG. [Figure 10] FIG. 6 is a block diagram showing the functional configuration of a controller in a construction machine according to a second embodiment of the present invention. [Figure 11] FIG. 10 is a block diagram showing the functional configuration of a controller in a construction machine according to a third embodiment of the present invention. [Figure 12] FIG. 10 is a block diagram showing the functional configuration of a controller in a construction machine according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a construction machine according to the present invention will now be described with reference to the accompanying drawings. In the present embodiment, a hydraulic excavator will be taken as an example of a construction machine.

[0014] [First embodiment] First, the configuration of a hydraulic excavator as a construction machine according to a first embodiment of the present invention will be described with reference to Figures 1 and 2. Figure 1 is an external view showing a hydraulic excavator as a construction machine according to the first embodiment. Figure 2 is a block diagram showing the hardware configuration and functional configuration of a controller provided in the construction machine according to the first embodiment shown in Figure 1. Here, the description will be given using the direction as seen from an operator seated in the driver's seat.

[0015] In Fig. 1, a hydraulic excavator as a construction machine includes a working device 1 for performing excavation work and the like, and a machine body to which the working device 1 is rotatably attached. The machine body is made up of a self-propelled running body 2 and a rotating body 3 that is rotatably mounted on the running body 2. The rotating body 3 is configured to rotate relative to the running body 2 by, for example, a swing hydraulic motor 4, which is a hydraulic actuator.

[0016] The work device 1 is an articulated device configured by connecting multiple driven members so that they can rotate vertically. The multiple driven members include, for example, a boom 6, an arm 7, and a bucket 8 as a work implement. The base end of the boom 6 is rotatably supported on the front of the revolving unit 3 via a boom pin 6a (see FIG. 2 ). The base end of an arm 7 is rotatably supported on the tip of the boom 6 via an arm pin 7a. The bucket 8 is rotatably supported on the tip of the arm 7 via a bucket pin 8a. The boom 6, arm 7, and bucket 8 are driven by hydraulic actuators: a boom cylinder 10, an arm cylinder 11, and a bucket cylinder 12, respectively. The bucket cylinder 12 drives the bucket 8 via a link member 13 that rotates in conjunction with the bucket 8.

[0017] The traveling body 2 is provided with, for example, crawler-type traveling devices 14 (only the left one is shown) on the left and right sides. The traveling devices 14 are driven by a traveling hydraulic motor 14a, which is a hydraulic actuator.

[0018] The rotating bed 3 includes a cab 16 in which an operator sits and a machine room 17 that houses various devices. The cab 16 is equipped with operating devices 18a, 18b, and 18c for operating the hydraulic actuators 4, 10, 11, 12, and 14a. The operating devices 18a and 18b are, for example, electric devices with operating levers that can be tilted forward, backward, left, and right. The electric operating devices 18a and 18b have a detector (not shown) that electrically detects the tilt direction and amount of tilt of the operating lever, i.e., the operating direction and amount, and outputs an operating signal corresponding to the detected operating direction and amount to a controller 40 (see FIG. 3 , described later). The forward and left-right operation of the operating devices 18a and 18b is assigned to operate the hydraulic actuators 4, 10, 11, and 12, respectively. That is, each operation of the operating devices 18a, 18b is assigned to operate the work implement 1 (to issue a drive command to the hydraulic actuators 10, 11, and 12) and to operate the rotating body 3 (to issue a drive command to the hydraulic actuator 4). The operating device 18c is an electric operating device that has a travel lever and a travel pedal that can be tilted forward and backward. The operating device 18c is assigned to operate the left and right traveling devices 14, i.e., to operate the hydraulic actuator 14a (to issue a drive command). Also, a monitor 19 (see FIG. 2) is provided in the operator's cab 16 as a display device that displays various information.

[0019] The machinery room 17 accommodates a prime mover 21 such as an engine or an electric motor, a hydraulic pump unit 22 driven by the prime mover 21, and the like. Pressurized oil discharged from the hydraulic pump unit 22 is supplied to each of the hydraulic actuators 4, 10, 11, 12, and 14a, thereby driving each of the hydraulic actuators 4, 10, 11, 12, and 14a. The driving of each of the hydraulic actuators 4, 10, 11, 12, and 14a is controlled by a control valve unit 23, which is an assembly of control valves corresponding to each of the hydraulic actuators 4, 10, 11, 12, and 14a. Each control valve constituting the control valve unit 23 controls the direction and flow rate of the pressurized oil supplied from the hydraulic pump unit 22 to the corresponding hydraulic actuator 4, 10, 11, 12, and 14a. The driving of each control valve is controlled, for example, by a pilot pressure (drive signal) output from a pilot pump (not shown) via an electromagnetic proportional valve (not shown). The controller 40 controls each of the electromagnetic proportional valves based on operation signals from the operation devices 18a, 18b, and 18c, thereby controlling the operation of each of the hydraulic actuators 4, 10, 11, 12, and 14a via the control valve unit 23.

[0020] As shown in FIGS. 1 and 2 , the rotating structure 3 is equipped with an inertial measurement unit (IMU) 25 for measuring information related to the attitude of the machine body. In addition, the boom 6, arm 7, and bucket 8, which are components of the work implement 1, are equipped with inertial measurement units (IMUs) 26, 27, and 28 for measuring information related to the attitudes of the respective components 6, 7, and 8. To distinguish between these four inertial measurement units 25, 26, 27, and 28, the inertial measurement unit 25 for the rotating structure 3 (machine body) may be referred to as the machine body IMU, the inertial measurement unit 26 for the boom 6 as the boom IMU, the inertial measurement unit 27 for the arm 7 as the arm IMU, and the inertial measurement unit 28 for the bucket 8 as the bucket IMU. Note that the bucket IMU 28 is generally installed on the link member 13 that rotates in conjunction with the bucket 8, but it may be installed on any member that drives in conjunction with the bucket 8.

[0021] Each of the IMUs 25, 26, 27, and 28 has two sensors: an angular velocity sensor that measures the angular velocity of the portion where the IMU is installed, and an acceleration sensor that measures acceleration. In this embodiment, it is assumed that each of the IMUs 25, 26, 27, and 28 is equipped with an angle calculation function that calculates an angle using the angular velocity measured by the angular velocity sensor and the acceleration measured by the acceleration sensor. Note that if each of the IMUs 25, 26, 27, and 28 does not have the angle calculation function, it is possible to configure the controller 40, described below, to include the angle calculation function.

[0022] For example, when the rotating unit 3 is stationary, the airframe IMU 25 can calculate the tilt (pitch angle) of the rotating unit 3 in the forward / backward direction and the tilt (roll angle) of the rotating unit 3 in the left / right direction (widthwise direction of the rotating unit 3) with respect to a horizontal plane (reference plane) based on the direction of gravitational acceleration (vertical downward direction) measured in an IMU coordinate system set in the airframe IMU 25 and the mounting state of the airframe IMU 25 (the relative positional relationship between the airframe IMU 25 and the rotating unit 3). The airframe IMU 25 outputs the calculation results of the pitch angle and roll angle of the rotating unit 3 (attitude information of the airframes 2, 3) to the controller 40. The airframe IMU 25 can calculate the rotation angle (yaw angle) of the rotating unit 3 by integrating the detected angular velocity.

[0023] The boom IMU 26, arm IMU 27, and bucket IMU 28 measure the angular velocity and acceleration of the installation parts (boom 6, arm 7, bucket 8), respectively, and perform angle calculations to calculate the angles of the installation parts 6, 7, and 8 relative to a reference point based on the measurement results (acceleration and angular velocity). Specifically, each of the IMUs 26 to 28 detects the direction of gravity and integrates the detected angular velocity, thereby being able to calculate the rotation angle of the components 6, 7, and 8 of the work device 1. The boom IMU 26, arm IMU 27, and bucket IMU 28 output the measurement results of the angular velocity and acceleration of each of the components 6, 7, and 8, respectively, and the calculation results of angle information of each of the components 6, 7, and 8 (posture information of each of the components 6, 7, and 8) to the controller 40.

[0024] These four IMUs, namely, the machine body IMU 25 , the boom IMU 26 , the arm IMU 27 and the bucket IMU 28 constitute an attitude detection device that detects information relating to the attitude of the machine body including the revolving unit 3 and the work implement 1 .

[0025] In this embodiment, by using the measurement results and calculation results of the machine body IMU 25, boom IMU 26, arm IMU 27, and bucket IMU 28, it is possible to calculate the state quantities (angle, angular velocity, angular acceleration) of the swing hydraulic motor 4 and the state quantities (displacement, velocity, acceleration) of the boom cylinder 10, arm cylinder 11, and bucket cylinder 12. In other words, these IMUs 25, 26, 27, and 28 function as state quantity detection devices that detect information related to the state quantities of the hydraulic actuators 4, 10, 11, and 12. Therefore, there is no need to separately provide sensors that detect the state quantities of the hydraulic actuators 4, 10, 11, and 12. However, it is also possible to configure the system so as to further include an actuator sensor (see FIG. 3 described below) that detects the state quantities of the hydraulic actuators 4, 10, 11, and 12, for example, a cylinder stroke sensor that can detect the stroke of the hydraulic cylinder.

[0026] The rotating unit 3 is also equipped with two GNSS antennas 36 and 37, which function as receiving devices capable of receiving positioning signals from multiple satellites. The positioning signals received by each of the GNSS antennas 36 and 37 are input to a GNSS receiver 38 shown in FIG. 2. The GNSS receiver 38 performs positioning calculations, such as calculating antenna coordinates and the azimuth angle of the rotating unit 3 (aircraft), based on the positioning signals received by the GNSS antennas 36 and 37. The GNSS receiver 38 can perform real-time kinematic (RTK) positioning by wirelessly connecting to a GNSS fixed station installed on-site. In cases where a GNSS fixed station is not available on-site, positioning can be performed using network-based RTK, which obtains information from electronic reference stations via the Internet. Hereinafter, it is assumed that the GNSS receiver 38 can perform RTK positioning regardless of whether a fixed station is available on-site. The GNSS receiver 38 outputs the results of the positioning calculation, such as the position and speed of the GNSS antennas 36 and 37 (machine) and the azimuth angle of the rotating unit 3 (machine), to the controller 40. The GNSS antennas 36 and 37 and the GNSS receiver 38 constitute a positioning calculation device 35 that performs calculations for satellite positioning of the hydraulic excavator.

[0027] 2, the controller 40 controls the operation of the hydraulic excavator, and includes, as its hardware configuration, a storage device 41 made up of RAM, ROM, etc., and a processing device 42 made up of a CPU, MPU, etc. The storage device 41 stores in advance programs and various information necessary for controlling the operation of the hydraulic excavator. The processing device 42 reads the programs and various information from the storage device 41 as appropriate, and executes processing in accordance with the programs, thereby realizing various functions including the following functions:

[0028] The controller 40 has, as functional units executed by the processing device 42, a positioning calculation unit 51, a construction target surface calculation unit 52, an operation control unit 53, and a monitor display control unit 54. In the following, the combination of the functions of the construction target surface calculation unit 52 and the monitor display control unit 54 may be referred to as a machine guidance system. Also, the combination of the functions of the construction target surface calculation unit 52 and the operation control unit 53 may be referred to as a machine control system.

[0029] The positioning calculation unit 51 performs attitude calculation to calculate the position (coordinates) and direction of the hydraulic excavator within the work site and the attitude of the work implement 1 based on the position information calculated by the GNSS receiver 38 and the measurement and calculation results of the IMUs 25 to 28 serving as attitude detection devices. The positioning calculation unit 51 outputs the calculation results to the construction target surface calculation unit 52, the operation control unit 53, and the monitor display control unit 54. The positioning calculation unit 51 also has a function for verifying the accuracy of the attitude information of the calculation results, for example. Therefore, the positioning calculation unit 51 can be configured to display a screen on the monitor 19 via the monitor display control unit 54 to alert the operator if an abnormality occurs in the positioning results of the GNSS receiver 38 or if the accuracy of the angle information of the calculation results of the IMUs 25 to 28 decreases.

[0030] The construction target surface calculation unit 52 calculates a construction target surface that defines the target shape of the construction object, based on construction information such as three-dimensional construction drawings pre-stored in the storage device 41, and position information and attitude information of the hydraulic excavator that are the calculation results of the positioning calculation unit 51. The construction information pre-stored in the storage device 41 is, for example, information input by a construction manager via an input device such as the monitor 19 or an external construction management system 70. The construction target surface calculation unit 52 also calculates the distance between the construction target surface and a reference point (for example, the tip of the bucket 8). The construction target surface can also be set on the spot by an operator by operating the monitor 19. The construction target surface calculation unit 52 outputs the calculation results of the construction target surface, etc. to the operation control unit 53 and the monitor display control unit 54.

[0031] The operation control unit 53 controls the operation of the hydraulic excavator (machine bodies 2, 3 and work implement 1) by controlling the hydraulic system including the hydraulic pump unit 22, the multiple hydraulic actuators 4, 10, 11, 12, 14a, and the control valve unit 23 (all see FIG. 1 ). The operation control unit 53 calculates target values for the operation of the machine bodies 2, 3 and work implement 1 that satisfy predetermined conditions, based on, for example, the construction target surface calculated by the construction target surface calculation unit 52 and the position information and attitude information of the machine bodies 2, 3 and work implement 1 calculated by the positioning calculation unit 51, and controls the hydraulic system to realize the operation of the machine bodies 2, 3 and work implement 1 according to the calculation results. The operation control unit 53 performs part of the function of a machine control system, such as limiting the operation so that the toe of the bucket 8 does not get closer to the construction target surface than a certain level, and controlling the bucket 8 to move along the construction target surface. When an abnormality occurs in the positioning results of the GNSS receiver 38 or when the accuracy of the angle information of the calculation results of any of the four IMUs 25, 26, 27, and 28 does not meet the predetermined required accuracy, and the monitor display control unit 54 stops the execution of the guidance described below or displays a warning, it is desirable for the operation control unit 53 to stop the machine control function accordingly.

[0032] The monitor display control unit 54 controls, for example, the display on the monitor 19 in the operator's cab 16. The monitor display control unit 54 calculates operation support instructions for the operator based on the construction target surface, which is the calculation result of the construction target surface calculation unit 52, and the position information and attitude information of the hydraulic excavator, which are the calculation results of the positioning calculation unit 51, and displays the calculation results on the monitor 19. The monitor display control unit 54 performs part of the function of a machine guidance system that supports the operator's operation by displaying, for example, the attitude of the work implement 1, as well as the tip position of the bucket 8 (work implement) of the work implement 1 and its angle with respect to the construction target surface on the monitor 19. Furthermore, the monitor display control unit 54 according to this embodiment is configured to display the calculation results of the operation control unit 53 on the monitor 19. The monitor display control unit 54 can be configured to display a warning to stop the execution of guidance or interrupt guidance on the monitor 19, for example, when an abnormality occurs in the positioning results of the positioning calculation device 35, or when the accuracy of the angle information of the calculation results of any of the four IMUs 25, 26, 27, and 28 does not satisfy a set required accuracy. Note that the monitor 19 is preferably equipped with a touch panel so that it can be used as an input device that can input various types of information. The monitor 19 can be configured, for example, as a configuration that is installed in the cab 16 or as a portable tablet terminal that can be detachably installed in the cab 16.

[0033] Next, the configuration in which each function of the controller of the construction machine according to the first embodiment is broken down will be described with reference to Figures 3 to 5. Figure 3 is a block diagram showing the configuration in which the functions of the controller of the construction machine according to the first embodiment shown in Figure 2 are broken down.

[0034] 3, the positioning calculation unit 51 of the controller 40 includes a coordinate calculation unit 511 that calculates the three-dimensional coordinates of a predetermined portion of the hydraulic excavator using detection information from the attitude detection devices 25 to 28 and positioning information from the positioning calculation device 35. The coordinate calculation unit 511 can be configured to simultaneously calculate the coordinates of multiple portions of the hydraulic excavator. The predetermined portion of the hydraulic excavator can be set to any portion of the hydraulic excavator, such as the tip of the bucket 8, a certain portion of the boom 6 or arm 7, or a certain portion of the rotating body 3. In addition, since the IMUs 25 to 28 as attitude detection devices function as state quantity detection devices for the hydraulic actuators 4, 10, 11, 12, and 14a, the coordinate calculation unit 511 can also be configured to calculate actual state quantities (such as speed or angular velocity) of the hydraulic actuators 4, 10, 11, and 12 based on detection information from the state quantity detection devices 25 to 28. The coordinate calculation unit 511 executes geometric calculations for the hydraulic excavator and does not include a distinctive calculation method, so a description of the calculation method will be omitted.

[0035] The construction target surface calculation unit 52 of the controller 40 includes a construction target surface setting unit 521 that sets a construction target surface as a work target for the work implement 1, and a limited area setting unit 522 that sets an operation limited area that is an area in which operation of the hydraulic excavator is permitted. The construction target surface setting unit 521 sets the construction target surface based on, for example, construction information from the construction management system 70 and the positions of the machines 2 and 3, which are the calculation results of the coordinate calculation unit 511 of the positioning calculation unit 51.

[0036] The limited area setting unit 522 sets an operation limited area, for example, as shown in FIG. 4. FIG. 4 is an explanatory diagram showing an example of an operation limited area set by the limited area setting unit 522 of the controller 40. The operation limited area is set so as not to include obstacles that the hydraulic excavator must not come into contact with. Examples of obstacles include a fence 101 and an overhead wire 102. The operation limited area does not define a specific part of the hydraulic excavator, but defines an area that all of the components of the hydraulic excavator must not deviate from. In other words, the operation of the hydraulic excavator must be controlled so that not only the tip position P1 of the bucket 8 of the working implement 1 shown in FIG. 4, but also the position P2 of the connecting pin of the bucket cylinder 12 and the position P3 of the connecting pin of the arm cylinder 11, do not deviate from the operation limited area.

[0037] The operation limited area can be set based on construction information from the construction management system 70 or input information (information set by the operator) from the monitor 19 as an input device. If the imported construction information includes obstacle information, it is desirable that the limited area setting unit 522 automatically set the operation limited area. If the construction information does not include obstacle information or if there is a moving obstacle such as a construction machine or work vehicle other than the hydraulic excavator, it is desirable that the operator set the operation limited area via the monitor 19. Note that if an operation limited area is not set, the operation area of the hydraulic excavator is not limited. Therefore, the hydraulic excavator can operate freely within the range in which the hydraulic actuator can be driven. In other words, the revolving body 3 is allowed to rotate 360 degrees, and the working device 1 is allowed to operate up to its maximum reach range.

[0038] The operation control section 53 of the controller 40 uses model predictive control that can be easily applied to the operation control of a hydraulic excavator, and is configured to control the operation of the work implement 1 based on a control input that causes a predicted value of a state quantity (position or speed) of a predetermined part of the work implement 1, obtained using the predictive model, to follow its target value. For the sake of simplicity, the following description will be given of a case where the tip of the bucket 8 serving as a work implement is set as the predetermined part of the work implement 1 to be controlled.

[0039] The operation control unit 53 of this embodiment is configured to perform position tracking control for making the toe coordinates follow target values as state quantities of the toe of the bucket 8. Specifically, the operation control unit 53 has the following functional units: a target speed calculation unit 531, a target coordinate sequence calculation unit 532, an operation limited area conversion unit 533, an actuator speed command calculation unit 534, a control intervention determination unit 535, and an actuator control unit 536.

[0040] The target speed calculation unit 531 calculates a target speed Vt of the tip of the bucket 8 that satisfies predetermined conditions, based on the construction target surface set by the construction target surface setting unit 521, the coordinates of the bucket 8 that are the calculation results of the coordinate calculation unit 512, and the operation of the operation devices 18a, 18b. This calculation is for controlling driving assistance that satisfies predetermined conditions while respecting the operation of the operation device 18 by the operator. The target speed calculation unit 531 calculates the target speed Vt of the tip of the bucket 8 according to the operation direction and operation amount of the operation devices 18a, 18b, while satisfying the condition that, for example, the tip of the bucket 8 does not sink below the construction target surface. The method of calculating the target speed Vt is well known, so its description will be omitted.

[0041] The target coordinate sequence calculation unit 532 calculates a time series of target coordinates ξt, which are target values of the state quantities of the tip of the bucket 8 in a time interval from time k (the time of calculation) to a predetermined time ahead, based on the tip of the bucket 8 position ξs(k) at time k (the time of calculation) which is the calculation result of the coordinate calculation unit 511 and the target speed Vt at time k which is the calculation result of the target speed calculation unit 531. Specifically, the time series of the tip of the bucket target coordinates ξt up to the tip of a predetermined step is calculated using the following equation (1). Note that Δt is the control period of the controller 40.

[0042]

number

[0043] Equation (1) assumes that the toe of the bucket 8 moves at a constant speed, Vt(k). Therefore, if the prediction step N takes a large value, there is a possibility that the future toe position will be below the target surface. To avoid this situation, if the target coordinate ξt obtained as a result of calculation comes into contact with the target surface, it is desirable to fix the target coordinate from that time (prediction step) onwards at the point of contact with the target surface. For example, as shown in equation (2), if the target coordinate ξt at a time M steps ahead (N>M) reaches the intersection ξd with the target surface, the target coordinate ξt is fixed to ξd from that time onwards, i.e., from the (M+1) step to the N step.

[0044]

number

[0045] The target speed calculation unit 531 and the target coordinate sequence calculation unit 532 constitute a target state quantity calculation unit 530 that calculates a time series of target coordinates ξt as target state quantities that are target values of the state quantities of the tip of the bucket 8 in a specified time interval so as to satisfy specified conditions, based on the coordinates as state quantities of the tip of the bucket 8 that are the calculation results of the coordinate calculation unit 511 and the construction target surface.

[0046] The limited area conversion unit 533 converts the operation limited area of the hydraulic excavator set by the limited area setting unit 522 of the construction target surface setting unit 52 into a format that can be used in the calculations described below by the actuator speed command calculation unit 535. This is a configuration for realizing operation control of the work implement 1 that integrates operation assistance control and deviation prevention control.

[0047] Specifically, limited area conversion unit 533 converts the set operation limited area so that it can be expressed in a mathematical formula as a constraint condition of an arithmetic expression (see equation (14)) described below by actuator speed command calculation unit 535. For example, the condition for preventing bucket 8 from contacting fence 101 shown in FIG. 4 can be expressed by equation (3) which indicates that the X coordinate X(k) of tip position P1 of bucket 8 is smaller than the X coordinate Xd of fence 101.

[0048]

number

[0049] Note that the constraint condition in equation (3) corresponding to the limited operation area is an example. It should also be noted that the determination of contact with an obstacle or the like is not limited to the tip of the bucket 8, but can be any part of the hydraulic excavator.

[0050] The actuator velocity command calculation unit 534 calculates velocity command values for each of the hydraulic actuators 4, 10, 11, and 12 using the coordinate ξs(k) of the tip of the bucket 8 at time k (the time of calculation) which is the calculation result of the coordinate calculation unit 511, the time series of target coordinates ξt of the tip of the bucket 8 from time k+1 to time k+N which are the calculation result of the target coordinate sequence calculation unit 532, and equations of constraint conditions which indicate the operation limited area obtained by conversion by the limited area conversion unit 533. The actuator velocity command calculation unit 534 according to this embodiment is configured to be realized by model predictive control (MPC), and is capable of simultaneous control of the work implement 1 (boom 6, arm 7, bucket 8), traveling unit 2, and rotating unit 3. However, for simplicity of explanation, a case will be specifically described here in which only the hydraulic actuators which drive the work implement 1, i.e., the boom cylinder 10, arm cylinder 11, and bucket cylinder 12, are controlled.

[0051] Actuator velocity command calculation unit 534 calculates velocity commands vref (extension / contraction speed) for boom cylinder 10, arm cylinder 11, and bucket cylinder 12 so that the actual toe position of bucket 8 follows the time series of target coordinates ξt of the toe of bucket 8, which are the calculation results of target coordinate sequence calculation unit 532. Specifically, it is configured to calculate velocity command values vref for each of hydraulic actuators 10, 11, 12 based on the deviation between a predicted value of the toe coordinate of bucket 8 in a predetermined time interval, which is obtained by using a prediction model that predicts the toe coordinate, which is the state quantity of the toe of bucket 8, using the velocity of each hydraulic actuator 10, 11, 12 as a control input, and the time series of target coordinates ξt of bucket 8, which are the calculation results of target state quantity calculation unit 350.

[0052] The speed command vref (extension / contraction speed) is calculated taking the following into consideration: When the controller 40 controls the hydraulic actuators 10, 11, and 12, the actual speed response vo of each hydraulic actuator 10, 11, and 12 follows the speed command vref with some delay. This relationship can be expressed, for example, by a second-order delay transfer function such as equation (4).

[0053]

number

[0054] In equation (4), s represents the Laplace transform, ζ represents the damping coefficient, and ω represents the natural angular frequency. The subscript i is a number corresponding to the hydraulic actuator, with i = 1, 2, and 3 representing the boom cylinder, arm cylinder, and bucket cylinder, respectively.

[0055] The transfer function shown in equation (4) can be converted into the state space expression shown in equation (5). In equation (5), lo and ao included in the state vector x respectively indicate the actual displacement and extension / retraction acceleration response of the hydraulic cylinder. u indicates the velocity command as a control input. As with equation (4), the subscript i is a number corresponding to the hydraulic actuator (boom cylinder, arm cylinder, bucket cylinder).

[0056]

number

[0057] Regarding equation (5), by collecting the state vectors xi and control inputs ui for all hydraulic actuators (i=1, 2, 3), equation (6) can be obtained.

[0058]

number

[0059] By using the control period Δt, equation (6) can be discretized as shown in equation (7a), for example.

[0060]

number

[0061] Since equation (6) is a linear system, it can be accurately discretized using equation (7b).

[0062]

number

[0063] If the speed command vref of each hydraulic cylinder 10, 11, 12 as the control input u can be determined, it is possible to predict the state vector x for a predetermined time ahead by using equation (7a) or equation (7b). The state vector x includes the extension / retraction length (displacement) lo of each hydraulic cylinder 10, 11, 12, so a function h that defines the geometric relationship between the extension / retraction length lo,i of each hydraulic cylinder 10, 11, 12 that drives the working device 1 and the angle θi of each driven member 6, 7, 8 that constitutes the working device 1 can be calculated. C It is possible to calculate the angle θi of each of the driven members 6, 7, and 8 by using the formula (8). That is, the angle θi can be calculated from the following formula (8).

[0064]

number

[0065] The angle θi (i=1, 2, 3) of each driven member (boom 6, arm 7, bucket 8) is defined, for example, as shown in Fig. 5. Fig. 5 is an explanatory diagram showing the definition of the angle θi of each component member 6, 7, 8 of the working implement 1 of the hydraulic excavator.

[0066] Furthermore, a function h that defines the geometric relationship between the angle θi of each component 6, 7, 8 of the work device 1 and the tip position of the bucket 8 is D By using the above, it is possible to calculate (predict) the toe position ξp of the bucket 8. That is, the toe position ξp can be calculated from the following equation (9).

[0067]

number

[0068] By using the above series of equations (4) to (9), if it is possible to determine the time series of the control input u in the time interval from the time k at the time of calculation to a predetermined time later k+N, i.e., the time series of the speed commands vref for each of the hydraulic cylinders 10, 11, and 12, it is possible to predict the trajectory (time series of coordinates) of the toe position ξp of the bucket 8 in that time interval.

[0069] Therefore, actuator speed command calculation unit 534 calculates a time series of control input u such that the predicted trajectory of bucket 8 toe position ξp, obtained by using the above-mentioned prediction model with the speeds of each hydraulic actuator 10, 11, 12 as control input u, approaches the time series (trajectory) of bucket toe target coordinates ξt, which are the calculation results of target coordinate sequence calculation unit 532. The approach of the predicted trajectory of toe position ξp to the trajectory of toe target coordinates ξt corresponds to making the deviation e(k) between them, shown in the following equation (10), as small as possible within a predetermined time interval. e(k)=ξp(k)-ξt(k) … Equation (10)

[0070] Furthermore, the smaller the control input u(k) that reduces the deviation e(k), that is, the smaller the speed command value vref, the smaller the operation of each of the hydraulic cylinders 10, 11, 12. From this, it can be considered that the smaller the control input u(k), the more efficiently the hydraulic excavator can be controlled.

[0071] These requirements correspond to minimizing the value of the evaluation function J given by equation (11). In equation (11), S, Q, and R are weighting matrices. It is desirable that the control input u be calculated so as to minimize the evaluation function J. However, by adjusting the parameters S, Q, and R, it is possible to select whether to prioritize eliminating the deviation e(k) or minimizing the control input u (speed command value vref).

[0072]

number

[0073] The evaluation function J shown in equation (11) is one example of a method for calculating the control input u(k). If the above-mentioned concept is followed, it is also possible to configure the control input u(k) to be calculated using a different evaluation function.

[0074] Incidentally, the hydraulic actuator that drives the work implement 1 is a hydraulic cylinder, and so there are limits to the range in which it can extend and retract. Similarly, there are limits to the extension and retraction speed and acceleration of the hydraulic cylinder. These conditions can be expressed by the following equation (12). In equation (12), the subscript min indicates a minimum value, and the subscript max indicates a maximum value. The minimum and maximum values are set to different values or the same values for the boom cylinder 10, arm cylinder 11, and bucket cylinder 12, respectively, depending on the specifications.

[0075]

number

[0076] Furthermore, the constraint condition (such as equation (3)) indicating the motion limitation area converted by the motion limitation area conversion unit 533 can be expressed as a more general equation (13) by using the function c.

[0077]

number

[0078] With the above preparations, calculations are performed using model predictive control. Specifically, the calculations of model predictive control involve solving the optimization problem of equation (14) with constraints, and the optimal control input u * Time series data U * In addition, "st" in equation (14) stands for "subject to" and means that the following equation is a constraint. In model predictive control, the control input U * Among them, the first input u at time k * Only (k) is used as the actual control command.

[0079]

number

[0080] The optimization problem of equation (14) means calculating a control input u such that the toe position ξp of the bucket 8 predicted using a prediction model follows the toe target coordinate ξt of the bucket 8 calculated to respond to the operation of the control device 18 while satisfying predetermined conditions within the performance limits of each of the hydraulic cylinders 10, 11, and 12 that drive the work implement 1 and within the limited operational range of the hydraulic excavator. This means automatically calculating the optimal control variables for the hydraulic actuators 10, 11, and 12 to eliminate the deviation between the predicted value of the toe position ξp and the toe target coordinate ξt. Therefore, even if the number of hydraulic actuators to be controlled is increased, such as the hydraulic motor that rotates the rotating bed 3 or the rotary tilt bucket, it is possible to calculate a control variable that optimizes the overall operation of the hydraulic excavator without having to calculate the control variable for each hydraulic actuator individually.

[0081] The actuator velocity command calculation unit 534 is configured to calculate the control input u by solving the optimization problem of equation (14). For this reason, if operation control is executed using the control input u resulting from the calculation by the actuator velocity command calculation unit 534, control will intervene to make the toe position of the bucket 8 follow the target coordinate ξt regardless of any operation of the operation device 18 by the operator. If control using the control input u resulting from the calculation by the actuator velocity command calculation unit 534 always intervenes, there is a concern that an operation different from the operator's intention will be performed.

[0082] To prevent such a situation, the operation control unit 53 includes a control intervention determination unit 535. Roughly speaking, the control intervention determination unit 535 determines whether to execute position tracking control of a predetermined part of the hydraulic excavator based on the calculations of the actuator speed command calculation unit 534, or whether to execute operation control of the hydraulic excavator in accordance with the operation of the operation device 18 by the operator. For example, if it is determined that the movement direction indicated by the time series of target coordinates ξt of the toe of the bucket 8, which are the calculation results of the target coordinate sequence calculation unit 532, deviates from (is not approaching) the construction target surface, in other words, if the operator intends to work on a surface other than the construction target surface, the control intervention determination unit 535 does not execute the calculation of the actuator speed command calculation unit target 534, and determines to prioritize operation control (speed control) of the working device 1 in accordance with the operation of the operation device 18 by the operator. The control intervention determination unit 535 can also be configured not to execute the calculation of the actuator velocity command calculation unit target 534 even when it is determined that the moving direction indicated by the target velocity Vt of the tip of the bucket 8, which is the calculation result of the target velocity calculation unit 531, deviates from (is not approaching) the construction target surface. Also, when a command to stop the control intervention of the controller 40 in response to the operation of the operation device 18 by the operator is input from the input device, the calculation processing of the actuator velocity command calculation unit target 534 can be stopped regardless of the determination of the control intervention determination unit 535.

[0083] The actuator control unit 536 converts the actual speeds of the hydraulic actuators 10, 11, 12 obtained based on the detection information of the actuator sensor 31 as a state quantity detection device or the actual speeds of the hydraulic actuators 10, 11, 12 which are the calculation results of the coordinate calculation unit 511 into actuator speed commands vref(u *(k)). Specifically, the actuator control section 536 calculates a command value for the control valve unit 23 that realizes the actuator speed command vref based on the deviation between the actual speed of the hydraulic actuators 10, 11, 12 and the actuator speed command vref. A detailed description of such a control method for the hydraulic actuators is omitted here, as it is well known.

[0084] The monitor display control unit 54 of the controller 40 includes a toe trajectory display unit 541 that displays, for example, the trajectory of the toe of the bucket 8 serving as a work implement of the work device 1. Specifically, the toe trajectory display unit 541 displays on the monitor 19 the toe coordinate ξs of the bucket 8 (the toe position at the time of calculation), which is the calculation result of the coordinate calculation unit 511 of the positioning calculation unit 51, and a time series (control target) of the target coordinates ξt of the bucket 8, which is the calculation result of the target coordinate sequence calculation unit 532 of the operation control unit 53. FIG. 6 is an image of the display screen output by the toe trajectory display unit 541. In FIG. 6, the current position P1 of the toe of the bucket of the hydraulic excavator is represented by a "●", and the predicted toe trajectory Ps is represented by a "◯". It is also possible to configure the system so that the predicted value of the bucket toe coordinates one step ahead, which is realized by the speed command vref (control input) of each hydraulic actuator 10, 11, 12, which is the calculation result of the actuator speed command calculation unit 534 of the operation control unit 53, is displayed as the predicted toe trajectory Ps.

[0085] The display screen 19a (see FIG. 6) output by the toe trajectory display unit 541 shows the operator how the controller 40 plans to control the hydraulic excavator. This makes it possible to clearly communicate to the operator how the controller 40 is intervening in the operator's operation. Furthermore, in the unlikely event that the controller 40 is about to execute operation control that differs from the operator's instructions (operation), the display screen 19a makes it possible for the operator to become aware of this before the operation is realized, thereby making it possible to avoid driving assistance that does not follow the operator's instructions.

[0086] Next, an example of the processing procedure of the controller of the construction machine according to the first embodiment will be described with reference to Fig. 7. Fig. 7 is a flowchart showing an example of the processing procedure of the controller of the construction machine according to the first embodiment shown in Fig. 3. However, the controller of this embodiment is not limited to the processing procedure of the flowchart shown in Fig. 7.

[0087] 7, the controller 40 shown in FIG. 3 first takes in the calculation results of the positioning calculation device 35, and also takes in the measurement results and calculation results of the IMUs 25 to 28 serving as attitude detection devices (step S10).

[0088] Next, the controller 40 (coordinate calculation unit 511 of the positioning calculation unit 51) calculates the attitude of the hydraulic excavator based on the positioning information (coordinates of the antennas 37, 38, etc.) from the positioning calculation device 35 and the detection information (angles, etc.) of the attitude detection devices 25 to 28 (step S20). Calculating the attitude of the hydraulic excavator involves calculating the three-dimensional coordinates of predetermined parts of the hydraulic excavator, such as the tip of the bucket 8 and parts of the boom 6 and arm 7. If the hydraulic excavator does not have an actuator sensor 31 (see FIG. 3), in step S20 the controller 40 (coordinate calculation unit 511) calculates the state quantities (operation information, such as the actual speed at the time of calculation) of the hydraulic actuators 4, 10, 11, 12, 14a by using the detection information of the IMUs 25 to 28, which function as state detection devices.

[0089] Next, the controller 40 (the construction target surface setting unit 521 of the construction target surface calculation unit 52) refers to the coordinates of specific parts of the vehicle bodies 2 and 3 and the coordinates of the toe of the bucket 8, which are the calculation results of step S20, and selects a construction target surface from the construction information acquired from the construction management system 70, etc. (step S30).

[0090] Furthermore, the controller 40 (limited area setting unit 522 of the construction target surface calculation unit 52) sets the operation limited area of the hydraulic excavator based on the acquired construction information or input information from the operator via an input device (such as the monitor 19) using the coordinates of the vehicle bodies 2 and 3, which are the calculation results of step S20, as a reference (step S40).

[0091] The processing order of steps S30 and S40 is arbitrary. After the processing of both steps S30 and S40 is completed, the controller 40 (target speed calculation unit 531 of the operation control unit 53) calculates a target speed Vt of the tip of the bucket 8 in accordance with the operation from the operation device 18 while satisfying predetermined conditions, based on the coordinates of the vehicle bodies 2 and 3 which are the calculation results of step S20 and the construction target surface set in step S30 (step S50).

[0092] Next, the controller 40 (target coordinate sequence calculation unit 532 of the operation control unit 53) calculates a time series of target coordinates ξt in a time interval from the calculation point in time (time k) of the tip of the bucket 8 to N steps ahead (a predetermined time ahead) based on the tip coordinate ξs of the bucket 8 at the calculation point in time, which is the calculation result of step S20, and the target velocity Vt of the tip of the bucket 8, which is the calculation result of step S50 (step S60).

[0093] Furthermore, the controller 40 (the control intervention determination unit 535 of the operation control unit 53) determines whether or not operation assistance (control intervention) is required based on the construction target surface set in step S30 and the time series of the target coordinates ξt, which are the calculation results of step S60 (step S70). If it is determined in step S70 that the movement direction indicated by the time series of the target coordinates ξt is approaching the construction target surface, the controller 40 (the control intervention determination unit 535) determines YES and proceeds to step S80. On the other hand, if it is determined that the movement direction indicated outside the time series of the target coordinates ξt is not approaching the construction target surface, the controller 40 (the control intervention determination unit 535) determines NO and proceeds to step S120.

[0094] If the determination in step S70 is YES, the controller 40 (limited area conversion unit 533 of the motion control unit 53) converts the motion limited area set in step S40 into a constraint condition expressed by a mathematical formula (for example, the above-mentioned formula (13)) (step S80). The process of step S80 can also be executed simultaneously with step S40.

[0095] Next, the controller 40 (actuator speed command calculation unit 534 of the operation control unit 53) uses the time series of the toe coordinate ξs(k) of the bucket 8 at the calculation time point (step k), which is the calculation result of step S20, and the target toe coordinate ξt of the bucket 8, which is the calculation result of step S60, as well as the constraint condition equation converted in step S80, to calculate a speed command vref of each of the hydraulic actuators 10, 11, 12 as a control input u by calculation based on a prediction model (for example, calculation of the above-mentioned equation (14)) (step S90).

[0096] Next, the controller 40 (toe trajectory display unit 541 of the monitor display control unit 54) displays on the monitor 19 (display device) the toe coordinate ξs of the bucket 8 at the time of calculation, which is the calculation result of step S20, the toe position of one step ahead realized by the speed commands vref (control inputs) of the hydraulic actuators 10, 11, 12, which is the calculation result of step S90, and a time series of the target coordinate ξt, which is the calculation result of step S60, as the future toe trajectory of the bucket 8 (step S100).

[0097] Furthermore, the controller 40 (actuator control section 536 of the operation control section 53) outputs control commands corresponding to the speed commands vref of the hydraulic actuators 10, 11, 12, which are the calculation results of step S90, to the control target (control valve unit 23), thereby controlling the driving of the hydraulic actuators 10, 11, 12 (step S110). If the controller 40 is configured to be capable of parallel processing, it is desirable that step S110 be processed in parallel with step S100.

[0098] If the determination in step S70 is NO, the controller 40 (monitor display control unit 54) displays on the monitor that operation assistance control (control intervention) is not being executed (step S120). Note that step S120 is an optional process, and it is possible to skip it and proceed to step S130.

[0099] In step S130, the controller 40 (actuator control section 536 of the operation control section 53) calculates the required speed of each of the hydraulic actuators 10, 11, 12 in response to the operation from the operating device 18, and outputs a control command corresponding to the required speed of each of the hydraulic actuators 10, 11, 12 as a result of the calculation to the controlled object (control valve unit 23). As a result, the hydraulic actuators 10, 11, 12 are controlled in response to the operation of the operating device 18 without executing operation assistance control (control intervention).

[0100] When the process of step S110 or step S130 ends, one control cycle ends, and the controller 40 moves on (returns) to the next control cycle.

[0101] The predictive model control by controller 40 according to this embodiment defines the speed command vref of each of the hydraulic cylinders 10, 11, and 12 that drive the components 6, 7, and 8 of the work implement 1 as the control input u. This differs from the predictive model control technology described in Patent Document 1, in which the drive torque for the components of the work implement is used as the control input. In this embodiment, the predictive model control input u (speed command vref) can be applied directly to the functional parts of a conventional actuator control section in the controller of the hydraulic excavator, making it easy to achieve follow-up control of the toe position of the bucket 8 using predictive model control.

[0102] Furthermore, the predictive model control according to this embodiment differs from the predictive model control described in Patent Document 1, which uses a torque command for the working implement, in that it uses a speed command vref for the hydraulic actuators 10, 11, and 12 that drive the working implement 1. For this reason, when the hydraulic actuators 10, 11, and 12 are stopped, the speed command as a control command value becomes 0. Therefore, when the speed command for the hydraulic actuators is used as the control input, it is less susceptible to the influence of modeling errors.

[0103] In this embodiment, the control input u is directly calculated by solving the above equation (14). Therefore, unlike conventional control methods, calculations using a Jacobian matrix or an inverse Jacobian matrix are not required to calculate the control input u. Control techniques using a Jacobian matrix or an inverse Jacobian matrix, such as the technique described in Patent Document 1, are expected to perform high-precision construction only when the shape of the construction target surface can be linearly approximated with high accuracy, i.e., when the shape of the construction target surface changes smoothly. This is because Jacobian matrices and inverse Jacobian matrices are used to linearly approximate nonlinear transformations. However, this control method requires some additional ingenuity to ensure sufficient construction accuracy when the shape of the construction target surface does not change smoothly, such as the slope toe T1 and slope toe T2 during slope shaping shown in Figure 8 and the bottom surface T3 during trench digging shown in Figure 9. In contrast, the predictive model control according to this embodiment does not use linear approximation calculations, so construction can be performed with high accuracy even when controlling the operation of the slope toe T1 and slope toe T2 shown in Figure 8 and the bottom corner T3 shown in Figure 9.

[0104] As described above, the hydraulic excavator (construction machinery) according to the first embodiment comprises an articulated working device 1 made up of a plurality of driven members 7, 8 including a bucket 8 as a working implement, machines 2, 3 to which the working device 1 is rotatably attached, a plurality of hydraulic actuators 4, 10, 11, 12 that drive the machines 2, 3 and the working device 1, attitude detection devices 25-28 that detect information relating to the attitude of the machines 2, 3 and the working device 1, state quantity detection devices 25-28 or actuator sensor 31 that detect information relating to the state quantities of the plurality of hydraulic actuators 4, 10, 11, 12, and a controller 40 that controls the operation of the machines 2, 3 and the working device 1. The controller 40 performs coordinate calculations to calculate the coordinates of the machine bodies 2, 3 and the bucket 8 (work implement) based on the detection information from the attitude detection devices 25-28, and performs target state quantity calculations to calculate a time series of target coordinates as a time series of target state quantities that are target values of the state quantities of the bucket 8 (work implement) in a predetermined time interval from the calculation time to a predetermined time so as to satisfy predetermined conditions, based on the construction target surface set as the work target of the work implement 1 and the coordinates of the bucket 8 (work implement) that are the calculation results of the coordinate calculations, and calculates a predetermined value obtained by using a prediction model that can predict the state quantities of the bucket 8 (work implement) using the speeds of the multiple hydraulic actuators 4, 10, 11, 12 as control inputs. A command calculation is performed to calculate speed command values vref for the multiple hydraulic actuators 10, 11, 12 based on the deviation between the predicted coordinate values, which are the state quantities of the bucket 8 (work implement) in the time interval, and the time series of target coordinates, which are the time series of the target state quantities of the bucket 8 (work implement), which are the calculation results of the target state quantity calculation, and the drive of the multiple hydraulic actuators 10, 11, 12 is controlled so that the actual speeds of the multiple hydraulic actuators 10, 11, 12 obtained based on detection information from the state quantity detection devices 25 to 28 or the actuator sensor 31 match the speed command values vref for the multiple hydraulic actuators 10, 11, 12, which are the calculation results of the command calculation.

[0105] According to this configuration, the operation control of the working device 1 of the hydraulic excavator (construction machinery) is performed by simultaneously controlling the multiple hydraulic actuators 10, 11, 12 using a speed command value vref calculated using a prediction model in which the speeds of the multiple hydraulic actuators 10, 11, 12 are used as control inputs, and this model predictive control can be easily applied to the operation control of the hydraulic excavator (construction machinery).

[0106] The hydraulic excavator (construction machine) according to this embodiment further includes operating devices 18a and 18b that instruct the operation of the multiple hydraulic actuators 4, 10, 11, and 12. The target state quantity calculation of the controller 40 performs a target speed calculation that calculates a target speed Vt of the bucket 8 (working implement) that satisfies predetermined conditions based on the construction target surface, the coordinate ξs of the bucket 8 (working implement) that is the result of the coordinate calculation, and the operation of the operating devices 18a and 18b, and performs a target coordinate series calculation that calculates a time series of target coordinates ξt of the bucket 8 (working implement), which are target values of the coordinates of the bucket 8 (working implement) for a predetermined time interval, using the coordinate ξs of the bucket 8 (working implement) that is the result of the coordinate calculation and the target speed Vt of the bucket 8 (working implement) that is the result of the target speed calculation, as a time series of the target state quantities of the bucket 8 (working implement) for a predetermined time interval. The prediction model in the command calculation of the controller is configured to be able to predict coordinates as state quantities of the bucket 8 (working implement). The command calculation of the controller 40 calculates speed command values vref for the multiple hydraulic actuators 4, 10, 11, and 12 based on the deviation between the predicted value of the coordinate ξp of the bucket 8 (work implement) for a specified time interval obtained using a prediction model and the time series of the target coordinate ξt of the bucket 8 (work implement), which is the result of the target coordinate series calculation.

[0107] According to this configuration, driving assistance control can be performed by position tracking, which causes the toe position of the bucket 8 (work implement) to follow its target value.

[0108] Furthermore, the controller 40 according to this embodiment is further configured to perform limited area conversion, which converts an operation limited area set as an area in which the operation of the hydraulic excavator (construction machine) is permitted as a constraint condition. Furthermore, the command calculation of the controller 40 calculates speed command values vref for the multiple hydraulic actuators 10, 11, 12 based on the above-mentioned deviation within a range that does not deviate from the above-mentioned constraint condition.

[0109] According to this configuration, the constraint conditions of the operational limit region, which corresponds to the function of deviation prevention control, are incorporated into the calculation formula for model predictive control, so that driving assistance control and deviation prevention control can be achieved at the same time.

[0110] Furthermore, when the controller 40 according to this embodiment determines that the movement direction of the bucket 8 (work implement) indicated by the time series of the target speed Vt of the bucket 8 (work implement), which is the result of the target speed calculation, or the target coordinates ξt of the bucket 8 (work implement), which are the result of the target coordinate sequence calculation, deviates from the construction target surface, the controller 40 is configured to calculate speed command values for the multiple hydraulic actuators 10, 11, 12 in response to the operation of the operating devices 18a, 18b, without using deviations based on a predictive model in the command calculation.

[0111] According to this configuration, when the operator operates the operation devices 18a and 18b with the intention of working on a surface other than the construction target surface, unnecessary control intervention by the controller 40 can be prevented.

[0112] The hydraulic excavator (construction machine) according to this embodiment is further provided with a monitor 19 (display device) that displays visual information. Controller 40 is further configured to perform trajectory display on monitor 19 (display device) as visual information in which the time series of coordinates ξs of bucket 8 (work implement), which are the results of the coordinate calculation, and target coordinates ξt of bucket 8 (work implement), which are the results of the target coordinate sequence calculation, are displayed as the trajectory of bucket 8 (work implement).

[0113] According to this configuration, by displaying the time series of the coordinate ξs of the bucket 8 (work implement) at the time of calculation and the target coordinate ξt, which are the results of the control calculation by the controller 40, as the trajectory of the bucket 8 (work implement) on the monitor 19 (display device), it is possible to present to the operator the schedule for the operation control of the hydraulic excavator by the controller 40.

[0114] [Second embodiment] Next, a construction machine according to a second embodiment of the present invention will be described with reference to Fig. 10. Fig. 10 is a block diagram showing the functional configuration of a controller in the construction machine according to the second embodiment. In Fig. 10, the same reference numerals as those shown in Figs. 1 to 9 indicate similar parts, and therefore detailed description thereof will be omitted.

[0115] The construction machine according to the second embodiment shown in Fig. 10 differs from the first embodiment in that the calculation method of the target coordinate sequence calculation unit 532A and the calculation method of the actuator velocity command calculation unit 534A in the operation control unit 53A of the controller 40A are different. The other functional units of the controller 40A according to this embodiment are the same as the functional units of the controller 40 according to the first embodiment.

[0116] The controller 40 according to the first embodiment is configured to execute control to make the toe position of the bucket 8 follow the toe target coordinate ξt, which is the calculation result of the target coordinate sequence calculation unit 532 of the operation control unit 53. Since there is a one-to-one correspondence between position and velocity, if the control precision is sufficient, the target velocity Vt of the toe position, which is the calculation result of the target velocity calculation unit 531 of the operation control unit 53, will also be satisfied by performing control to follow the toe target coordinate ξt. However, if the control precision is insufficient, there is a concern that the reproducibility of the required velocity Vt will decrease.

[0117] Therefore, the target coordinate sequence calculation unit 532A in the operation control unit 53A of the controller 40A according to the second embodiment is configured to perform a target speed sequence calculation that calculates a time series of target speeds that are target values for the speed of the tip of the bucket 8 in a predetermined time interval using the target speed Vt of the tip of the bucket 8 that is the calculation result of the target speed calculation unit 531, in addition to calculating a time series of target coordinates ξt of the tip of the bucket 8 as a time series of target state quantities of the tip of the bucket 8 in a predetermined time interval. In other words, the time series of the target speed is calculated assuming that it is constant at the target speed Vt in the predetermined time interval.

[0118] Furthermore, actuator velocity command calculation unit 534A of controller 40A according to the second embodiment calculates velocity commands vref for each of hydraulic actuators 10, 11, and 12 using not only the toe target coordinates ξt of bucket 8, which are the calculation results of target coordinate sequence calculation unit 532A, but also the time series of target velocity Vt of the toe of bucket 8, which are the calculation results of target velocity calculation unit 532A. Specifically, actuator velocity command calculation unit 534A is configured to solve the optimization problem by changing evaluation function J used in model predictive control from the above-mentioned equation (11) to the following equation (15):

[0119]

number

[0120] The deviation E in the evaluation function J of equation (15) includes not only the toe position deviation e (the deviation between the predicted trajectory of the toe position ξp according to the prediction model and the time series of target coordinates ξt calculated by the target coordinate sequence calculation unit 532A) but also the deviation between the predicted value of the toe position velocity Vp obtained using the prediction model and the target velocity Vt calculated by the target velocity calculation unit 532A. This makes it possible to calculate the control input u such that the predicted value of the toe velocity Vp for a predetermined time interval obtained using the prediction model approaches the time series of the target velocity Vt. Furthermore, the weighting matrices SE and QE are configured to include weights SV and QV for the velocity deviation in addition to weights S and Q for the deviation e. By setting the weights SV and QV for the velocity deviation to larger values relative to the weights S and Q for the deviation e, the controller 40A executes control that prioritizes velocity tracking over position tracking of the bucket 8.

[0121] The target speed calculation unit 531 and the target coordinate sequence calculation unit 532A constitute a target state quantity calculation unit 530A that calculates a time series of target coordinates ξt and a time series of target speed Vt as target state quantities of the tip of the bucket 8 in a specified time interval, based on the coordinates of the tip of the bucket 8 and the construction target surface, which are the calculation results of the coordinate calculation unit 511, so as to satisfy specified conditions.

[0122] According to the construction machine according to the second embodiment described above, it is possible to obtain the same effects as those of the first embodiment described above.

[0123] Furthermore, in the present embodiment, the calculations of target state quantity calculation section 530A of controller 40A, in addition to the calculation of target speed Vt by target speed calculation section 531 and the calculation of a time series of target coordinates ξt by target coordinate sequence calculation section 532A, also perform target speed sequence calculation that calculates a time series of target speed Vt, which is a target value for the speed of bucket 8 (work implement) in a predetermined time interval, using the target speed Vt of bucket 8 (work implement) that is the calculation result of target speed calculation section 531, as a time series of target state quantities of bucket 8 (work implement) in a predetermined time interval. Furthermore, the prediction model in the command calculations of controller 40 is configured to be able to predict speed in addition to coordinates as state quantities of the bucket 8 (work implement). Furthermore, the command calculation of controller 40 calculates speed command values vref for the multiple hydraulic actuators 4, 10, 11, 12 based on the deviation between the coordinates of the bucket 8 (work implement) in a predetermined time interval obtained by using the prediction model and the time series of target coordinates ξt of the bucket 8 (work implement) which are the calculation results of target coordinate sequence calculation section 532A, and the deviation between the speed of the bucket 8 (work implement) in a predetermined time interval obtained by using the prediction model and the time series of target speed Vt of the bucket 8 (work implement) which is the calculation result of target coordinate sequence calculation section 532A (target speed sequence calculation).

[0124] According to this configuration, when calculating the speed command value vref for the multiple hydraulic actuators 4, 10, 11, and 12 using the coordinate deviation and the speed deviation, the calculation is performed with emphasis on one of the two deviations, making it possible to switch between control that prioritizes position tracking of the bucket 8 and control that prioritizes speed tracking.

[0125] It should be noted that in this embodiment, it is also possible to configure the system so that only velocity tracking is performed using predictive model control, without performing position tracking of the bucket 8 using predictive model control. In this case, the target coordinate sequence calculation unit 532A is configured as a target velocity sequence calculation unit that calculates only a time series of the target velocity Vt of the bucket 8, without calculating a time series of the target coordinates ξt of the bucket 8. Furthermore, the actuator velocity command calculation unit 534A calculates the velocity commands vref for each of the hydraulic actuators 10, 11, 12 using only the time series of the target velocity Vt of the toe of the bucket 8, which is the calculation result of the target velocity calculation unit 532A, without using the toe target coordinates ξt of the bucket 8, which is the calculation result of the target coordinate sequence calculation unit 532A.

[0126] In this modification, the target state quantity calculation of controller 40A performs a target speed calculation that calculates a target speed Vt of the bucket 8 (work implement) that satisfies predetermined conditions based on the construction target surface and the coordinates ξs of the bucket 8 (work implement) that are the calculation results of coordinate calculation unit 511, and the operation of operation devices 18q, 18b, and performs a target speed series calculation that calculates a time series of the target speed Vt of the bucket 8 (work implement), which is a target value of the speed of the bucket 8 (work implement) in a predetermined time interval, using the target speed Vt of the bucket 8 (work implement) that is the calculation result of target speed calculation unit 531 as a time series of the target state quantity of the bucket 8 (work implement) in a predetermined time interval. In addition, the prediction model in the command calculation of controller 40A is configured to be able to predict the speed as a state quantity of the bucket 8 (work implement). Furthermore, the command calculation of the controller 40 calculates speed command values vref for the multiple hydraulic actuators 4, 10, 11, and 12 based on the deviation between the predicted value of the speed of the bucket 8 (work implement) in a specified time interval obtained using a prediction model and the time series of the target speed Vt of the bucket 8 (work implement), which is the result of the target speed series calculation.

[0127] According to this configuration, driving assistance control can be performed by speed tracking, which causes the speed of the tip of the bucket 8 (work implement) to follow the target speed.

[0128] [Third embodiment] Next, a construction machine according to a third embodiment of the present invention will be described with reference to Fig. 11. Fig. 11 is a block diagram showing the functional configuration of a controller in the construction machine according to the third embodiment. In Fig. 11, the same reference numerals as those shown in Figs. 1 to 10 denote similar parts, and detailed description thereof will be omitted.

[0129] The controllers 40 and 40A according to the first and second embodiments have a function that is assumed to assist the operator in driving, whereas the controller 40B according to the third embodiment has a control function that corresponds to automatic driving that does not require the operation of an operator.

[0130] Specifically, the controller 40B according to this embodiment is intended for automatic driving that does not require operator operation, and therefore, two functions, namely, a target speed calculation unit 531 (calculation of the target speed Vt in accordance with the operation of the operating device 18 while satisfying predetermined conditions) and a control intervention determination unit 535 (determination of the need for operation assistance control) in the operation control unit 53 of the controllers 40, 40A according to the first and second embodiments (see Figures 3 and 10), are omitted.

[0131] Furthermore, since the target speed calculation unit 531 is omitted, the target coordinate sequence calculation unit 532, which uses the calculation results of the target speed calculation unit 531 in the first embodiment, is replaced with a target coordinate sequence generation unit 537. The target coordinate sequence generation unit 537 calculates the trajectory of the target coordinate ξt of the toe of the bucket 8 that optimizes work efficiency (excavation efficiency) based on the coordinates ξs of the machine bodies 2 and 3, which are the calculation results of the coordinate calculation unit 511 of the positioning calculation unit 51, and the construction target surface set by the construction target surface setting unit 521, without using the calculation results of the target speed calculation unit 531. This calculation can be performed using a general method, so a description thereof will be omitted. In this calculation, it is desirable to perform an optimization calculation so that the amount of soil scooped by the bucket 8 is kept to an amount that does not overflow from the bucket 8.

[0132] Actuator velocity command calculation unit 534B of operation control unit 53B calculates a time series of control input u for model predictive control using the trajectory of target coordinates ξt of the toe of bucket 8, which are the calculation results of target coordinate sequence generation unit 537, instead of the time series of toe target coordinates ξt, which are the calculation results of target coordinate sequence calculation unit 532 (see FIG. 3 or 10). In other words, it calculates velocity commands vref for each of hydraulic actuators 10, 11, 12 such that the trajectory of toe position ξp predicted using the prediction model approaches the trajectory of toe target coordinates ξt of bucket 8, which are the calculation results of target coordinate sequence generation unit 537.

[0133] Furthermore, a toe trajectory display unit 541B of the monitor display control unit 54B displays on the monitor the trajectory of the toe target coordinates ξt of the bucket 8, which are the calculation results of the target coordinate sequence generation unit 537, instead of the time series of the target coordinates ξt, which are the calculation results of the target coordinate sequence calculation unit 532 (see FIG. 3 or FIG. 10). Note that when automatic driving is assumed with no operator in the driver's seat, it is also possible to omit the toe trajectory display unit 541.

[0134] Other functional units of controller 40B according to the present embodiment are similar to the functional units of controller 40 according to the first or second embodiment, and therefore description of those functional units will be omitted. Note that target coordinate sequence generation unit 537 constitutes target state quantity calculation unit 530B that calculates a time series of target coordinates ξt as target state quantities that are target values of the state quantities of the tip of bucket 8 in a predetermined time interval so as to satisfy predetermined conditions, based on coordinate ξs of the tip of bucket 8, which are the calculation results of coordinate calculation unit 511, and the construction target surface.

[0135] According to the construction machine according to the third embodiment described above, it is possible to obtain the same effects as those of the first embodiment described above.

[0136] Furthermore, in this embodiment, the target state quantity calculation of controller 40B performs target coordinate sequence generation, which automatically generates a time series of target coordinates of bucket 8, which are target values of the coordinates of bucket 8, in a predetermined time interval so as to satisfy predetermined conditions, as a time series of target state quantities of bucket 8 (work implement) in a predetermined time interval, based on the work target surface and coordinates ξs of bucket 8, which are the calculation results of coordinate calculation unit 511. Furthermore, the prediction model in the command calculation of controller 40B is configured to be able to predict coordinates as state quantities of bucket 8. Furthermore, the command calculation of controller 40B calculates speed command values vref for the multiple hydraulic actuators 4, 10, 11, and 12, based on the deviation between the coordinates of bucket 8 in a predetermined time interval obtained using the prediction model and the time series of target coordinates ξt of bucket 8, which are the generation results of target coordinate sequence generation unit 537.

[0137] According to this configuration, the position tracking control of the bucket 8 (work implement) by model predictive control can be applied to the control of automatic driving.

[0138] [Fourth embodiment] Next, a construction machine according to a fourth embodiment of the present invention will be described with reference to Fig. 12. Fig. 12 is a block diagram showing the functional configuration of a controller in the construction machine according to the fourth embodiment. In Fig. 12, the same reference numerals as those shown in Figs. 1 to 11 denote similar parts, and detailed description thereof will be omitted.

[0139] The construction machine according to the fourth embodiment is configured to enable remote operation, instructing the operation of a plurality of hydraulic actuators 4, 10, 11, and 12 through communication from an operating device 18C (remote control device) and an input device 19C (monitor, etc.) located at a remote location. When remote operation is performed, depending on the communication environment, it is conceivable that the operator's operation may be transmitted to the construction machine with a significant delay. If the hydraulic excavator's work is stopped every time a communication delay occurs, there is a concern that construction efficiency will decrease.

[0140] Therefore, the controller 40C of the construction machine according to this embodiment shown in Fig. 12 is configured to have both the driving assistance control function of the first embodiment and the automatic driving control function of the third embodiment. The controller 40C basically executes driving assistance control for the operator's remote operation (control that respects the operator's operation while satisfying predetermined conditions that have been set in advance). However, when a situation arises in which the operation of the hydraulic excavator is likely to stop due to a communication delay, the operator's remote operation is supplemented by automatic driving control.

[0141] Specifically, controller 40C has two functions: a functional unit similar to target coordinate sequence calculation unit 532 of operation control unit 53 of controller 40 (see FIG. 3) according to the first embodiment, and target coordinate sequence generation unit 537C equivalent to target coordinate sequence generation unit 537 of operation control unit 53B of controller 40B (see FIG. 11) according to the third embodiment. When target coordinate sequence generation unit 537C according to the present embodiment receives as input a time series of toe target coordinates ξt, which are the calculation results of target coordinate sequence calculation unit 532, it outputs the calculation results as is to actuator velocity command calculation unit 534C. On the other hand, if the target coordinate sequence calculation unit 532 is unable to calculate the time series of the toe target coordinates ξt, that is, if transmission of the remote control signal to the construction machine is temporarily interrupted due to a communication delay, the target coordinate sequence generation unit 537C generates a trajectory of the toe target coordinates ξt, similar to the target coordinate sequence generation unit 537 of the controller 40B according to the third embodiment, and outputs the generation result to the actuator velocity command calculation unit 534C. The actuator velocity command calculation unit 534C calculates a velocity command vref for each of the hydraulic actuators 10, 11, 12 for position tracking control, using the time series of the toe target coordinates ξt, which are the calculation results of the target coordinate sequence calculation unit 532, or the trajectory of the toe target coordinates ξt, which are the calculation results of the target coordinate sequence generation unit 537C, output from the target coordinate sequence generation unit 537C.

[0142] A toe trajectory display unit 541C of monitor display control unit 54C displays on the monitor the trajectory of the toe target coordinates ξt of the bucket 8 output from target coordinate sequence generation unit 537C. As described above, the trajectory of the toe target coordinates ξt of the bucket 8 output from target coordinate sequence generation unit 537C is a time series of the toe target coordinates ξt that are the calculation results of target coordinate sequence calculation unit 532, or the trajectory of the toe target coordinates ξt that are the calculation results of target coordinate sequence generation unit 537C.

[0143] Other functional units of controller 40C according to the present embodiment are the same as the functional units of controller 40 according to the first embodiment, and description of those functional units will be omitted. Note that target speed calculation unit 531, target coordinate sequence calculation unit 532, and target coordinate sequence generation unit 537 constitute target state quantity calculation unit 530B that calculates a time series of target state quantities (target coordinates ξt), which are target values of the state quantities of the tip of bucket 8 in a predetermined time interval, so as to satisfy predetermined conditions, based on the coordinate ξs of the tip of bucket 8, which are the calculation results of coordinate calculation unit 511, and the construction target surface.

[0144] According to the construction machine according to the fourth embodiment described above, it is possible to obtain the same effects as those of the first embodiment described above.

[0145] Furthermore, the hydraulic excavator (construction machine) according to this embodiment is configured to be capable of remote control by a remote control device 18C arranged outside the hydraulic excavator (construction machine) to instruct the driving of the multiple hydraulic actuators 4, 10, 11, and 12. Furthermore, the target state quantity calculation of the controller 40C performs a target speed calculation to calculate a target speed Vt of the bucket 8 that satisfies predetermined conditions based on the construction target surface and the coordinates ξs of the bucket 8 that are the calculation results of the coordinate calculation unit 511, and the operation of the remote control device 18C, and performs a target coordinate sequence calculation to calculate a time series of target coordinates ξt of the bucket 8 that are target values of the coordinates of the bucket 8 in a predetermined time interval using the coordinates ξs of the bucket 8 that are the calculation results of the coordinate calculation unit 511 and the target speed Vt of the bucket 8 that are the calculation results of the target speed calculation unit 532, as a time series of the target state quantity of the bucket 8 in a predetermined time interval, and also performs target coordinate sequence generation to automatically generate a time series of target coordinates ξt of the bucket 8 that are target values of the coordinates of the bucket 8 in a predetermined time interval that satisfies predetermined conditions, based on the construction target surface and the coordinates ξs of the bucket 8 that are the calculation results of the coordinate calculation unit 511, as a time series of the target state quantity of the bucket 8 in a predetermined time interval. The prediction model in the command calculation of controller 40C is configured to be able to predict coordinates as state quantities of bucket 8. Furthermore, when target coordinate sequence calculation unit 532 is being executed, the command calculation of controller 40C calculates speed command values vref for the multiple hydraulic actuators 4, 10, 11, and 12 based on the deviation between the predicted value of coordinate ξp of bucket 8 in a predetermined time interval obtained by using the prediction model and the time series of target coordinates ξt of bucket 8 which are the calculation results of target coordinate sequence calculation unit 532, while when the target coordinate sequence calculation is not executable, the command calculation of controller 40C calculates speed command values vref for the multiple hydraulic actuators 4, 10, 11, and 12 based on the deviation between the predicted value of coordinate ξp of bucket 8 in a predetermined time interval obtained by using the prediction model and the time series of target coordinates ξt of bucket 8 which are the generation results of target coordinate sequence generation unit 537.

[0146] This configuration allows for control of operation assistance to be performed in response to remote operation by the operator. Furthermore, when a situation arises in which the operation of the hydraulic excavator is likely to stop due to a communication delay, the operator's remote operation can be supplemented by automatic operation control.

[0147] [Other embodiments] Although the above-described embodiment shows an example in which the present invention is applied to a hydraulic excavator, the present invention can be widely applied to various types of construction machinery that control the operation of an articulated working device made up of multiple link members.

[0148] Furthermore, the present invention is not limited to the above-described embodiments, and includes various modifications. The above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those including all of the described configurations. It is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. It is also possible to add, delete, or replace part of the configuration of each embodiment with other configurations.

[0149] For example, in the above-described embodiment, an example has been shown in which the bucket 8 that can only rotate vertically is used as the working implement of the working device 1. However, it is also possible to configure the working device 1 to use a bucket that has at least one of a tilt function and a rotary function (such as a rotary tilt bucket).

[0150] In the above-described embodiment, a hydraulic motor is used as a drive source for rotating the rotating body 3. However, the drive source may be an electric motor or a combination of a hydraulic motor and an electric motor.

[0151] In the above-described embodiment, the operating devices 18a, 18b, and 18c are configured electrically. However, each operating device can also be configured hydraulically. In this configuration, an operating pilot pressure corresponding to the operating direction and amount of each operating device is supplied as a drive signal to the pressure-receiving portion of each control valve of the control valve unit 23, thereby driving each hydraulic actuator 4, 10, 11, 12, and 14a.

[0152] Furthermore, in the above-described embodiment, one controller 40, 40A, 40B, 40C is configured to execute all of the functional units shown in Fig. 2. However, it is also possible to configure each functional unit shown in Fig. 2 to be executed by a different controller. When each functional unit is implemented in a separate controller, the collective of the controllers constituting each functional unit constitutes a controller that executes control using predictive model control. [Explanation of symbols]

[0153] REFERENCE SIGNS LIST 1...working device, 2...traveling body (machine body), 3...swivel body (machine body), 4...swivel hydraulic motor (hydraulic actuator), 6...boom (driven member), 7...arm (driven member), 8...bucket (working implement), 10...boom cylinder (hydraulic actuator), 11...arm cylinder (hydraulic actuator), 12...bucket cylinder (hydraulic actuator), 18...operation device, 18C...remote control device, 19...monitor (display device), 25...machine body IMU (attitude detection device, state quantity detection device), 26...boom IMU (attitude detection device, state quantity detection device), 27...arm IMU (attitude detection device, state quantity detection device), 28...bucket IMU (attitude detection device, state quantity detection device), 31...actuator sensor (state quantity detection device), 40, 40A, 40B, 40C...controller

Claims

1. a multi-joint working device configured with a plurality of driven members including a working tool; a machine body to which the working device is rotatably attached; a plurality of hydraulic actuators that drive the machine body and the working device; an attitude detection device that detects information regarding the attitude of the machine body and the working device; a state quantity detection device that detects information about state quantities of the plurality of hydraulic actuators; A construction machine including a controller that controls the operation of the machine body and the work device, The controller performing a coordinate calculation to calculate coordinates of the machine body and the work implement based on the detection information from the attitude detection device; a target state quantity calculation is performed to calculate a time series of target state quantities of the work tool, which are target values of the state quantities of the work tool in a predetermined time interval from the calculation time to a predetermined time, based on a construction target surface set as a work target of the work device and the coordinates of the work tool which are the calculation results of the coordinate calculation, so as to satisfy predetermined conditions; performing a command calculation to calculate speed command values for the plurality of hydraulic actuators based on a deviation between the state quantity of the work tool in the predetermined time interval obtained by using a prediction model capable of predicting the state quantity of the work tool using the speeds of the plurality of hydraulic actuators as control inputs and a time series of the target state quantity of the work tool, which is a calculation result of the target state quantity calculation; Controlling the driving of the hydraulic actuators so that actual speeds of the hydraulic actuators obtained based on the detection information from the state quantity detection device coincide with speed command values of the hydraulic actuators, which are the calculation results of the command calculation. Construction machinery characterized by:

2. The construction machine according to claim 1, further comprising an operating device that instructs the driving of the plurality of hydraulic actuators; The target state quantity calculation of the controller is A target speed calculation is performed to calculate a target speed of the work tool that satisfies the predetermined condition based on the construction target surface, the coordinates of the work tool that are the calculation result of the coordinate calculation, and the operation of the operation device. a target coordinate series calculation is performed to calculate a time series of target coordinates of the work tool, which are target values of the coordinates of the work tool in the predetermined time interval, using the coordinates of the work tool, which are the calculation results of the coordinate calculation, and the target speed of the work tool, which is the calculation result of the target speed calculation, as a time series of target state quantities of the work tool in the predetermined time interval; the prediction model in the command calculation of the controller is configured to be able to predict coordinates as state quantities of the work tool, The command calculation of the controller calculates speed command values for the plurality of hydraulic actuators based on the deviation between the coordinates of the work implement in the predetermined time interval obtained by using the prediction model and the time series of target coordinates of the work implement, which are the calculation results of the target coordinate sequence calculation. Construction machinery characterized by:

3. The construction machine according to claim 1, The target state quantity calculation of the controller performs target coordinate sequence generation to automatically generate a time series of target coordinates of the work tool, which are target values of the coordinates of the work tool in the predetermined time interval, as a time series of target state quantities of the work tool in the predetermined time interval, based on the construction target surface and the coordinates of the work tool, which are the calculation results of the coordinate calculation, so as to satisfy the predetermined condition; the prediction model in the command calculation of the controller is configured to be able to predict coordinates as state quantities of the work tool, The command calculation of the controller calculates speed command values for the plurality of hydraulic actuators based on a deviation between the coordinates of the work implement in the predetermined time interval obtained by using the prediction model and a time series of target coordinates of the work implement, which is a result of the target coordinate sequence generation. Construction machinery characterized by:

4. The construction machine according to claim 1, the construction machine is configured to be remotely controlled by a remote control device arranged outside the construction machine to instruct the driving of the plurality of hydraulic actuators, The target state quantity calculation of the controller is performing a target speed calculation to calculate a target speed of the work tool that satisfies the predetermined condition based on the construction target surface, the coordinates of the work tool that are the calculation result of the coordinate calculation, and the operation of the remote control device; performing a target coordinate sequence calculation to calculate a time series of target coordinates of the work tool, which are target values of the coordinates of the work tool in the predetermined time interval, using the coordinates of the work tool, which are the calculation results of the coordinate calculation, and the target speed of the work tool, which is the calculation result of the target speed calculation, as a time series of target state quantities of the work tool in the predetermined time interval; a target coordinate sequence generation method for automatically generating a time series of target coordinates of the work tool, which are target values of the coordinates of the work tool in the predetermined time interval, based on the construction target surface and the coordinates of the work tool that are the calculation results of the coordinate calculation, as a time series of target state quantities of the work tool in the predetermined time interval so as to satisfy the predetermined conditions; the prediction model in the command calculation of the controller is configured to be able to predict coordinates as state quantities of the work tool, The command calculation of the controller is When the target coordinate sequence calculation is being executed, speed command values for the plurality of hydraulic actuators are calculated based on the deviation between the coordinates of the work implement in the predetermined time interval obtained by using the prediction model and the time series of target coordinates of the work implement which are the calculation results of the target coordinate sequence calculation; When the target coordinate sequence calculation is not executable, speed command values for the plurality of hydraulic actuators are calculated based on the deviation between the coordinates of the work implement in the predetermined time interval obtained by using the prediction model and the time series of target coordinates of the work implement that are the result of the target coordinate sequence generation. Construction machinery characterized by:

5. The construction machine according to claim 1, further comprising an operating device that instructs the driving of the plurality of hydraulic actuators; The target state quantity calculation of the controller is A target speed calculation is performed to calculate a target speed of the work tool that satisfies the predetermined condition based on the construction target surface, the coordinates of the work tool that are the calculation result of the coordinate calculation, and the operation of the operation device. a target speed series calculation is performed to calculate a time series of the target speed of the work tool, which is a target value of the speed of the work tool in the predetermined time interval, using the target speed of the work tool, which is a calculation result of the target speed calculation, as a time series of the target state quantity of the work tool in the predetermined time interval; the prediction model in the command calculation of the controller is configured to be able to predict a speed as a state quantity of the work tool, The command calculation of the controller calculates speed command values for the plurality of hydraulic actuators based on the deviation between the speed of the work implement in the predetermined time interval obtained by using the prediction model and a time series of target speeds of the work implement, which is the calculation result of the target speed series calculation. Construction machinery characterized by:

6. The construction machine according to claim 2, the target state quantity calculation of the controller also performs a target speed sequence calculation, in addition to the target speed calculation and the target coordinate sequence calculation, to calculate a time series of the target speed of the work tool, which is a target value of the speed of the work tool in the predetermined time interval, using the target speed of the work tool, which is the calculation result of the target speed calculation, as a time series of the target state quantity of the work tool in the predetermined time interval; the prediction model in the command calculation of the controller is configured to be able to predict not only coordinates but also velocity as state quantities of the work tool, The command calculation of the controller calculates speed command values for the plurality of hydraulic actuators based on a deviation between the coordinates of the work implement in the predetermined time interval obtained by using the prediction model and a time series of target coordinates of the work implement, which are the calculation results of the target coordinate sequence calculation, and a deviation between the speed of the work implement in the predetermined time interval obtained by using the prediction model and a time series of target speeds of the work implement, which are the calculation results of the target speed sequence calculation. Construction machinery characterized by:

7. The construction machine according to claim 1, The controller is further configured to perform limited area conversion to convert an operation limited area set as an area in which operation of the construction machine is permitted as a constraint condition, The command calculation of the controller calculates speed command values for the plurality of hydraulic actuators based on the deviation within a range that does not deviate from the constraint conditions. Construction machinery characterized by:

8. The construction machine according to claim 2, The controller is configured to calculate speed command values for the plurality of hydraulic actuators in accordance with the operation of the operating device in the command calculation, without using the deviation based on the prediction model, when it is determined that the target speed of the work tool, which is the calculation result of the target speed calculation, or the movement direction of the work tool, which is indicated by the time series of the target coordinates of the work tool, which is the calculation result of the target coordinate sequence calculation, deviates from the construction target surface. Construction machinery characterized by:

9. The construction machine according to claim 2, Further comprising a display device for displaying visual information; The controller is further configured to perform a trajectory display on the display device, which displays a time series of the coordinates of the work tool, which are the calculation results of the coordinate calculation, and the target coordinates of the work tool, which are the calculation results of the target coordinate sequence calculation, as visual information representing the trajectory of the work tool. Construction machinery characterized by:

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