WORK CONTROL METHOD OF CONSTRUCTION MACHINE, WORK CONTROL SYSTEM, AND WORK CONTROL APPARATUS

Abstract

A work control method according to the present invention includes: an initial motion input model generation step; and a feedback control step, in which the initial motion input model generation step includes: a first initial motion input value measurement step of measuring a first initial motion measurement value at which the movable part is caused to start to move in a first state of the movable part; a second initial motion input value measurement step of measuring a second initial motion measurement value at which the movable part is caused to start to move in a second state of the movable part; and a model generation step of generating an initial motion input model that complements between the first initial motion measurement value and the second initial motion measurement value and derives the initial motion input value with respect to a desired posture of the construction machine.

Description

TECHNICAL FIELD

The present invention relates to a work control method of a construction machine, a work control system, and a work control apparatus, and in particular, to a work control method of a construction machine including a manipulation lever that controls the posture of the construction machine, a work control system, and a work control apparatus.

BACKGROUND ART

In recent years, many unmanned controls for construction machines have been proposed. For example, Patent Literature 1 and 2 disclose techniques regarding control of construction machines.

Patent Literature 1 discloses a technique regarding a work machine control apparatus of a construction machine. The work machine control apparatus of the construction machine disclosed in Patent Literature 1 is a construction machine including work machine cylinders that rotationally drive respective arms of a work machine, work machine manipulation levers provided for the respective arms, and a flow rate control system that controls a pressure oil supply flow rate to each of the work machine cylinders in accordance with command signals from the respective levers, the construction machine including: a reference model unit in which desired manipulation response characteristics of each of the work machines is specified, reference model setting means for setting manipulation response characteristics of the reference model, cylinder speed detection means of each of the work machines, and adaptive control means for executing, using a detection value of the cylinder speed detection means as a feedback signal, adaptive control in such a way that the manipulation response characteristics of each of the work machines correspond to the manipulation response characteristics of the reference model unit, correcting a control command value of a pressure oil supply flow rate for each of the work machines, and controlling the speed of each of the work machine cylinders by this corrected control command value.

Further, Patent Literature 2 discloses a technique regarding an electromagnetic valve control apparatus in a hydraulic circuit of an industrial vehicle. In the electromagnetic valve control apparatus in the hydraulic circuit of the industrial vehicle disclosed in Patent Literature 2, a CPU performs feedback control of a duty output value Dout for deciding a duty value (%) of a PWM signal to be input to a transistor provided between a battery and an electromagnetic valve. A duty output value Dout at a timing when a predetermined period of time (300 ms) has passed after a tilt lever is manipulated (tilt manipulation) for the first time after key-ON, and a target current value Iaim at this time are stored as learning values Drec and Irec, respectively. In the second and subsequent tilt manipulations after key-ON, the learning values Drec and Irec learned in the previous tilt manipulation are used to determine Dout=Iaim·Drec/Irec computed in accordance with the target current value Iaim at this time to be an initial value of the duty output value.

CITATION LIST

Patent Literature

• [Patent Literature 1] Japanese Unexamined Patent Application Publication No. H09-328785
• [Patent Literature 2] Japanese Unexamined Patent Application Publication No. H11-171498

SUMMARY OF INVENTION

Technical Problem

In construction machines, play, which is a deviation that occurs between a manipulation start point of a manipulation lever and an operation start point of a cylinder, is provided. However, in the techniques disclosed in Patent Literature 1 and 2, the amount of play of the manipulation lever is not taken into account, which causes a problem that an accuracy of unmanned control of the construction machine is not sufficiently high.

Solution to Problem

One aspect of a work control method of a construction machine according to one example embodiment includes: an initial motion input model generation step of generating an initial motion input model for computing an initial motion input value at which a movable part of a construction machine is caused to start to move; and a feedback control step of computing the initial motion input value that corresponds to the posture of the construction machine using the initial motion input model and determining a control input value equal to or larger than the initial motion input value, in which the initial motion input model generation step includes: a first initial motion input value measurement step of measuring a first initial motion measurement value at which the movable part is caused to start to move in a first state in which the movable part is controlled to a first position within a movable range of the movable part; a second initial motion input value measurement step of measuring a second initial motion measurement value at which the movable part is caused to start to move in a second state in which the movable part is controlled to a second position that is different from the first position within the movable range of the movable part; and a model generation step of generating the initial motion input model that complements between the first initial motion measurement value and the second initial motion measurement value and derives the initial motion input value with respect to a desired posture of the construction machine.

One aspect of a work control system of a construction machine according to one example embodiment includes: an initial motion input model generation unit configured to generate an initial motion input model for computing an initial motion input value at which a movable part of a construction machine is caused to start to move; and a feedback control unit configured to compute the initial motion input value that corresponds to the posture of the construction machine using the initial motion input model and determine a control input value equal to or larger than the initial motion input value, in which the initial motion input model generation unit performs: first initial motion input value measurement processing for measuring a first initial motion measurement value at which the movable part is caused to start to move in a first state in which the movable part is controlled to a first position within a movable range of the movable part; second initial motion input value measurement processing for measuring a second initial motion measurement value at which the movable part is caused to start to move in a second state in which the movable part is controlled to a second position that is different from the first position within the movable range of the movable part; and model generation processing for generating the initial motion input model that complements between the first initial motion measurement value and the second initial motion measurement value and deriving the initial motion input value with respect to a desired posture of the construction machine.

One aspect of a work control apparatus of a construction machine according to one example embodiment includes: an initial motion input model generation unit configured to generate an initial motion input model for computing an initial motion input value at which a movable part of a construction machine is caused to start to move; and a feedback control unit configured to compute the initial motion input value that corresponds to the posture of the construction machine using the initial motion input model and determine a control input value equal to or larger than the initial motion input value, in which the initial motion input model generation unit performs: first initial motion input value measurement processing for measuring a first initial motion measurement value at which the movable part is caused to start to move in a first state in which the movable part is controlled to a first position within a movable range of the movable part; second initial motion input value measurement processing for measuring a second initial motion measurement value at which the movable part is caused to start to move in a second state in which the movable part is controlled to a second position that is different from the first position within the movable range of the movable part; and model generation processing for generating the initial motion input model that complements between the first initial motion measurement value and the second initial motion measurement value and deriving the initial motion input value with respect to a desired posture of the construction machine.

Advantageous Effects of Invention

With a work control method of a construction machine, a work method system, and a work control apparatus according to example embodiments, it is possible to control the posture of a construction machine with a high accuracy even when an amount of play in a manipulation lever is changed.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic view of a work control system according to a first example embodiment;

FIG. 2 is a schematic block diagram of the work control system according to the first example embodiment;

FIG. 3 is a detailed block diagram of the work control system according to the first example embodiment;

FIG. 4 is a flowchart for describing an operation of the work control system according to the first example embodiment;

FIG. 5 is a flowchart for describing an operation of an initial motion input model generation unit according to the first example embodiment;

FIG. 6 is a flowchart for describing an operation of a feedback control unit according to the first example embodiment;

FIG. 7 is a block diagram of a work control system according to a second example embodiment; and

FIG. 8 is a flowchart for describing an operation of a feedback control unit according to the second example embodiment.

EXAMPLE EMBODIMENT

First Example Embodiment

Hereinafter, with reference to the drawings, example embodiments of the present invention will be described. A work control method, a work control system, and a work control apparatus of a construction machine described below control a construction machine that drives joints of a machine using a cylinder. The following description will be made taking a backhoe as an example of the construction machine. Further, while a work control system in which process blocks that perform work control processing are arranged in a plurality of places in a distributed manner via a network will be described in the following description, a work control apparatus in which the process blocks included in the work control system are formed of one apparatus may be employed. Further, the content of the control performed in the work control system will be referred to as a work control method. Specific examples thereof will be described later in detail.

FIG. 1 shows a schematic view of a work control system 1 according to a first example embodiment. A construction machine 10 shown in FIG. 1 is a backhoe. The construction machine 10 includes a crawler 11, a turning base 12, a cockpit 13, a boom 14, an arm 15, and a bucket 16. The crawler 11 is a caterpillar for moving the construction machine 10. The turning base 12 turns a chassis on which the cockpit 13, the boom 14 and the like are mounted. The cockpit 13 is a manipulation room in which a manipulation lever and the like for manipulating the posture of the construction machine 10 are disposed. Further, while the drawings are in a simplified form, in the work control system 1, an actuator 17 for manipulating the manipulation lever is disposed in the cockpit 13. Further, each of the boom 14, the arm 15, and the bucket 16 corresponds to a movable part and is operated by a hydraulic cylinder. This hydraulic cylinder is elongated or contracted by manipulating the manipulation lever installed in the cockpit 13. While the part that corresponds to the movable part includes, for example, besides the hydraulic cylinder, a part that is driven by a motor, a hydraulic cylinder will be described as an example of the movable part in the following description.

Further, in the work control system 1 according to the first example embodiment, posture sensors 181-184 for detecting posture angles are attached to the movable parts of the construction machine 10. In the example shown in FIG. 1, the posture sensor 181 detects the rotation angle of the turning base 12, the posture sensor 182 detects the current angle of the boom 14, the posture sensor 183 detects the relative angle of the boom 14 and the arm 15, and the posture sensor 184 detects the relative angle of the arm 15 and the bucket 16.

In the work control system 1 according to the first example embodiment, a posture control apparatus 20 and a work control apparatus 30 that correspond to the construction machine 10 are provided. The posture control apparatus 20 provides instructions for operating the actuator 17. The posture control apparatus 20 further generates a posture detection value based on information on the angles acquired from the posture sensors 181-184. The work control apparatus 30 generates a control input value for deciding the posture of the construction machine 10 based on the information obtained from the posture control apparatus 20.

In the work control system 1 according to the first example embodiment, an input value at which the movable parts such as the boom 14 of the construction machine 10 are caused to start to operate in accordance with an amount of displacement of the manipulation lever of the construction machine 10 provided via the actuator 17 will be referred to as an initial motion input value. Then the construction machine 10 is controlled using the initial motion input value as the basis for control. Further, this initial motion input value varies depending on an amount of elongation or contraction of the cylinder in terms of the characteristics of the cylinder. The work control system 1 according to the first example embodiment generates an initial motion input model from different elongated/contracted states of the cylinder and updates, using the initial motion input model, the initial motion input value for each posture when the control of the construction machine 10 is started. Then, the work control system 1 according to the first example embodiment computes a feedback control input value to the construction machine control unit so as to compensate the updated initial motion input value as the minimum value of the input value to be provided for the construction machine 10. In the following description, the work control system 1 according to the first example embodiment will be described below in detail.

First, a configuration of a process block of the work control system 1 according to the first example embodiment will be described. FIG. 2 shows a schematic block diagram of the work control system according to the first example embodiment. Note that the construction machine 10 is shown in FIG. 2 as a target to be controlled by the work control system 1. In the example shown in FIG. 2, the posture control apparatus 20 is provided with a construction machine control unit 21 and a posture detection unit 22. The work control apparatus 30 is provided with an initial motion input model generation unit 31 and a feedback control unit 32. Then the construction machine 10 is manipulated using the posture control apparatus 20 and the work control apparatus 30.

The example shown in FIG. 2 is merely one example. For example, the posture control apparatus 20 and the work control apparatus 30 may be integrated as one apparatus and the construction machine 10 and the posture control apparatus 20 may be connected to each other by communication. Further, the posture control apparatus 20 may be provided in such a way that the posture control apparatus 20 and the construction machine 10 are integrated with each other to obtain a form in which the posture control apparatus 20 and the work control apparatus 30 are connected to each other by communication. For example, the work control apparatus 30 may be disposed in a cloud storage and the work control apparatus 30 may be connected to the posture control apparatus 20 via communication. Further, the construction machine 10 is a target to be controlled by the work control apparatus 30 and the posture control apparatus 20 may be an interface for allowing the work control apparatus 30 to actually operate the construction machine 10. In this case, it can be considered that the work control apparatus 30 is a main part of the work control system 1.

The work control apparatus 30 includes the initial motion input model generation unit 31 and the feedback control unit 32. The initial motion input model generation unit 31 generates an initial motion input model for computing an initial motion input value at which the movable parts of the construction machine 10 (e.g., the turning base 12, the boom 14, the arm 15, and the bucket 16) start to operate. The feedback control unit 32 computes the initial motion input value that corresponds to the posture of the construction machine 10 using the initial motion input model and determines a control input value which is equal to or larger than the initial motion input value. Here, the initial motion input model generation unit 31 performs first initial motion input measurement processing, second initial motion input measurement processing, and model generation processing. In the first initial motion input measurement processing, a first initial motion measurement value at which the movable parts are caused to start to move is measured in a first state in which the movable parts are controlled to a first position in the movable range of the movable parts. In the second initial motion input measurement processing, a second initial motion measurement value at which the movable parts are caused to start to move is measured in a second state in which the movable parts are controlled to a second position, which is different from the first position in the movable range of the movable parts. In the model generation processing, an initial motion input model that complements between the first initial motion measurement value and the second initial motion measurement value and derives the initial motion input value with respect to a desired posture of the construction machine 10 is generated.

Next, a more detailed configuration of the work control system 1 according to the first example embodiment will be described. FIG. 3 shows a block diagram of the work control system 1 according to the first example embodiment. Note that, in FIG. 3, the construction machine 10 controlled by the work control system 1 is also shown for the explanation. As shown in FIG. 3, the work control system 1 according to the first example embodiment includes the posture control apparatus 20 and the work control apparatus 30. Then, the posture control apparatus 20 is provided with the construction machine control unit 21 and the posture detection unit 22. Further, the work control apparatus 30 is provided with the initial motion input model generation unit 31 and the feedback control unit 32.

The construction machine control unit 21 operates the actuator based on a feedback control input value computed by the feedback control unit 32, thereby displacing the manipulation lever in the construction machine 10. Further, when the initial motion input model generation unit 31 generates an initial motion input model, the construction machine control unit 21 is provided with the control input value from the initial motion input model generation unit 31 and displaces the manipulation lever of the construction machine 10 based on the control input value.

The posture detection unit 22 acquires the joint angles of the respective movable parts from the sensors 181-184 provided in the movable parts such as the arm of the construction machine 10 and outputs the acquired joint angles as posture detection values indicating the posture of the construction machine 10. The initial motion input model generation unit 31 generates an initial motion input model for computing the initial motion input value at which movable parts of the construction machine 10 are caused to start to move. Further, the feedback control unit 32 computes an initial motion input value that corresponds to the current posture using the initial motion input model and computes a feedback control input value that compensates the initial motion input value as the minimum value.

Here, the initial motion input model generation unit 31 and the feedback control unit 32 will be described in detail. The initial motion input model generation unit 31 includes an initial motion input measurement unit 311 and a model generation unit 312. The initial motion input measurement unit 311 outputs, when the initial motion input model is generated, an input value to be provided to the construction machine control unit 21 in order to displace the movable parts of the construction machine 10 and detects the state of the movable parts when they start to move based on the posture detection value output from the posture detection unit 22, thereby measuring the initial motion input value for each posture. More specifically, the initial motion input measurement unit 311 executes a first initial motion input value measurement step and a second initial motion input value measurement step.

In the first initial motion input measurement step, the first initial motion measurement value at which the movable parts are caused to start to move is measured in the first state in which the movable parts are controlled to the first position in the movable range of the movable parts. In the second initial motion input measurement step, the second initial motion measurement value at which the movable parts are caused to start to move is measured in the second state in which the movable parts are controlled to the second position, which is different from the first position in the movable range of the movable parts. Examples of more specific operations of the first initial motion input measurement step and the second initial motion input measurement step will be those as described below.

In the first initial motion input value measurement step, the input value that changes in a stepwise manner is applied to the construction machine control unit 21 in the first state in which the cylinder that drives the movable parts is elongated, and the input value at the timing when the movable parts start to move is measured as the first initial motion measurement value. Further, in the first example embodiment, in the first initial motion input value measurement step, the input value is provided for the cylinder which is in the first state in such a way that the cylinder moves in each of a positive direction in which the cylinder is elongated and a negative direction in which the cylinder is contracted and the first initial motion measurement value is measured for each of the positive direction and the negative direction.

In the second initial motion input value measurement step, an input value that changes in a stepwise manner is applied to the construction machine control unit 21 in the second state in which the cylinder that drives the movable parts is contracted, and the input value at the timing when the movable parts start to move is measured as the second initial motion measurement value. Further, in the first example embodiment, in the second initial motion input value measurement step, the input value is provided for the cylinder which is in the second state in such a way that the cylinder moves in each of the positive direction in which the cylinder is elongated and the negative direction in which the cylinder is contracted and the second initial motion measurement value is measured for each of the positive direction and the negative direction.

The model generation unit 312 executes a model generation step of generating the initial motion input model that complements between the first initial motion measurement value and the second initial motion measurement value and derives the initial motion input value with respect to a desired posture of the construction machine 10.

The feedback control unit 32 includes an initial motion input update unit 321, an error update unit 322, and a control input computation unit 323. The initial motion input update unit 321 executes an initial motion input update step of acquiring the posture of the construction machine 10 based on the positional information (e.g., posture detection value) of the movable parts of the construction machine 10 and updating the initial motion input value that corresponds to the posture by the value computed using the initial motion input model. The error update unit 322 executes the error update step of updating the error between the current posture and the target posture of the construction machine 10. The control input computation unit 323 executes a control input computation step of receiving the error and the initial motion input value, computing a feedback control input value that reduces the error, and provides the computed feedback control input value for the construction machine 10.

Next, an operation of the work control system 1 according to the first example embodiment will be described. FIG. 4 shows a flowchart for describing an operation of the work control system according to the first example embodiment. As shown in FIG. 4, the work control system 1 according to the first example embodiment performs initial motion input model generation processing before it starts the operation (Step S1). In this Step S1, processing of generating the initial motion input model using the construction machine control unit 21, the posture detection unit 22, and the initial motion input model generation unit 31 is performed. Further, in the initial motion input model generation processing in Step S1, first initial motion input measurement processing, second initial motion input measurement processing, and model generation processing are performed. Then, in the work control system 1 according to the first example embodiment, the feedback control processing for executing the operation of the construction machine 10 using the initial motion input model generated in Step S1 continues until the operation ends (Steps S2 and S3). That is, the work control system 1 according to the first example embodiment generates the initial motion input model in a period other than the operation period in which the construction machine 10 performs the work. In this way, by generating the initial motion input model in the period other than the period during which the construction machine 10 works, it is possible to prevent the initial motion input model from changing during the operation of the construction machine 10 and to stably operate the construction machine 10.

Now, the initial motion input model generation processing in Step S1 and the feedback control processing in Step S2 will be described in detail. FIG. 5 shows a flowchart for describing an operation of the initial motion input model generation unit according to the first example embodiment.

The initial motion input model generation unit 31 first selects a drive part whose initial motion input value has not yet been measured by the initial motion input measurement unit 311 (Step S11). Next, the initial motion input measurement unit 311 performs processing of Steps S12 and S13 as the first initial motion input measurement step. The initial motion input measurement unit 311 measures, for the selected drive part, the initial motion input value of the negative direction of the first initial motion input value measurement step (Step S12). More specifically, in Step S12, the initial motion input measurement unit 311 measures the initial motion input value of the negative direction in the maximum posture (e.g., the first state) detected by the posture detection unit. Here, the initial motion input value measured in Step S12 is expressed by Expression (1). In the following description, θ_upper is a posture angle that the construction machine control unit 21 has detected from the drive part when it is in the first state.

[Expression 1] Initial motion input value when movable part is changed

negative direction in maximum posture=U_min⁻(θ_upper)  (1)

• • Initial motion input value when movable part is changed in negative direction in maximum posture

Next, the initial motion input measurement unit 311 measures, for the selected drive part, the initial motion input value of the positive direction of the first initial motion input value measurement step (Step S13). More specifically, in Step S13, the initial motion input measurement unit 311 measures the initial motion input value of the positive direction in the maximum posture (e.g., the first state) detected by the posture detection unit. The initial motion input value measured in Step S13 is expressed by Expression (2).

[Expression 2] initial motion input value when movable part is changed

in positive direction in maximum posture=U_min⁺(θ_upper)  (2)

Initial motion input value when movable part is changed in positive direction in maximum posture

Next, the initial motion input measurement unit 311 performs processing of Steps S14 and S15 as the second initial motion input measurement step. The initial motion input measurement unit 311 measures, for the selected drive part, the initial motion input value of the negative direction of the second initial motion input value measurement step (Step S14). More specifically, in Step S14, the initial motion input measurement unit 311 measures the initial motion input value of the negative direction in the minimum posture (e.g., the second state) detected by the posture detection unit. The initial motion input value measured in Step S14 is expressed by Expression (3). In the following description, θ_lower is a posture angle that the construction machine control unit 21 has detected from the drive part when it is in the second state.

[Expression 3] initial motion input value when movable part is changed

in negative direction in minimum posture=U_min⁻(θ_upper)  (3)

Initial motion input value when movable part is changed in negative direction in minimum posture

Next, the initial motion input measurement unit 311 measures, for the selected drive part, the initial motion input value of the positive direction of the second initial motion input value measurement step (Step S15). More specifically, in Step S15, the initial motion input measurement unit 311 measures the initial motion input value of the positive direction in the minimum posture (e.g., the second state) detected by the posture detection unit. The initial motion input value measured in Step S15 is expressed by Expression (4).

[Expression 4] Initial motion input value when movable part is changed

in positive direction in minimum posture=U_min⁺(θ_upper)  (4)

Initial motion input value when movable part is changed in positive direction in minimum posture

Next, the initial motion input model generation unit 31 computes the initial motion input model by the model generation unit 312 using the four initial motion input values acquired by the initial motion input measurement unit 311 (Step S16). There are, for example, two initial motion input models generated in Step S16, that is, that of the positive direction in which the cylinder is elongated and that of the negative direction in which the cylinder is contracted. The initial motion input models generated in the initial motion input model generation unit 31 according to the first example embodiment are expressed by Expressions (5) and (7). Note that Expression (5) shows an initial motion input model Umin_p(θ) when the cylinder is displaced in the positive direction and Expression (7) shows an initial motion input model Umin_m(θ) when the cylinder is displaced in the negative direction. The symbol θ denotes the posture angle of the drive part detected by the posture detection unit 22.

[Expression 5]

U_{min_p}(θ)=α⁺·(θ−θ_lower)+U_min⁺(θ_lower)  (5)

Note that α⁺ in Expression (5) can be expressed by Expression (6).

$\begin{array}{cc}\left[\mathrm{Expression}6\right]& \\ {\alpha }^{+}=\frac{U_{\min }^{+}\left({\theta }_{\mathrm{upper}}\right)-U_{\min }^{+}\left({\theta }_{\mathrm{lower}}\right)}{{\theta }_{\mathrm{upper}}-{\theta }_{\mathrm{lower}}}& \left(6\right)\end{array}$ $\begin{array}{cc}\left[\mathrm{Expression}7\right]& \\ U_{\mathrm{min\_m}}\left(\theta \right)={\alpha }^{+}·\left(\theta -{\theta }_{\mathrm{lower}}\right)+U_{\min }^{+}\left({\theta }_{\mathrm{lower}}\right)& \left(7\right)\end{array}$

Note that α⁻ in Expression (7) can be expressed by Expression (8).

$\begin{array}{cc}\left[\mathrm{Expression}8\right]& \\ {\alpha }^{+}=\frac{U_{\min }^{+}\left({\theta }_{\mathrm{upper}}\right)-U_{\min }^{+}\left({\theta }_{\mathrm{lower}}\right)}{{\theta }_{\mathrm{upper}}-{\theta }_{\mathrm{lower}}}& \left(8\right)\end{array}$

The initial motion input model generation unit 31 repeats processing of Steps S11-S16 for all the drive parts of the construction machine 10. Then, the initial motion input model generation unit 31 ends the initial motion input model generation processing in accordance with generation of the initial motion input model for all the drive parts of the construction machine 10. The model generation unit 312 of the initial motion input model generation unit 31 updates the initial motion input model held in the initial motion input update unit 321 by the generated initial motion input model.

Next, feedback control processing executed by the feedback control unit 32 will be described. FIG. 6 shows a flowchart for describing an operation of the feedback control unit 32 according to the first example embodiment.

As shown in FIG. 6, the feedback control unit 32 first acquires the posture detection value of the control target part of the construction machine 10 from the posture detection unit 22 using the initial motion input update unit 321 and grasps the current posture θ of the construction machine 10 (Step S21). Next, the initial motion input update unit 321 updates the initial motion input value with respect to the current posture θ using the initial motion input model that is held (Step S22).

Next, the error update unit 322 updates the error between the current posture θ and the target posture (Step S23). After that, the control input computation unit 323 computes the feedback control input value with respect to the current posture θ (Step S24) and provides the computed feedback control input value for the construction machine control unit 21 (Step S25). Note that the feedback control unit 32 performs control until the posture of the construction machine 10 becomes a target posture while repeating the processing of Steps S23-S25.

Now, a method for computing the feedback control input value in Step S24 will be described in detail. First, when the feedback control input value is denoted by u, the feedback control input value u is expressed by Expression (9). In the following expression, θ denotes a current posture, θr denotes a target posture, Umax denotes an input maximum value, Umin(θ) denotes an initial motion input value (note that the posture direction is omitted), Emax denotes a deceleration start position with respect to the error between the target posture and the current posture, and Emin denotes a convergence determination threshold with respect to the target posture.

[Expression 9]

u=K_p·e+U_min(θ)  (9)

Note that Kp can be expressed by Expression (10).

$\begin{array}{cc}\left[\mathrm{Expression}10\right]& \\ K_p=\frac{U_{\max }-U_{\min }\left(\theta \right)}{E_{\max }-E_{\min }}& \left(10\right)\end{array}$

Further, e can be expressed by Expression (11).

[Expression 11]

e=|θ_r−θ|  (11)

From the above Expression (9), it can be seen that the feedback control input value is a value that has the initial motion input value Umin(θ) as the minimum value. That is, it can be seen that the control input computation unit 323 is able to compute a feedback control input value in which the initial motion input value computed for each posture of the construction machine 10 when the control is started is compensated as the minimum value.

From the above description, the work control system 1 according to the first example embodiment sets the drive part of the construction machine 10 to be in the first state and the second state, which are different amounts of displacement, and measures the initial motion input value for each of the first state and the second state. The work control system 1 then generates an initial motion input model capable of computing an initial motion input value appropriate for a desired posture using the measured initial motion input value. The work control system 1 computes the initial motion input value that is optimal to the current posture using the initial motion input model generated by the initial motion input model generation unit 31, and the initial motion input model generation unit 31 computes a feedback control input value that compensates the initial motion input value as the lowest value.

Accordingly, the work control system 1 according to the first example embodiment is able to control the construction machine 10 by the feedback control input value with which the construction machine 10 can be controlled with a high accuracy even when the amount of play of the manipulation lever varies for each posture of the construction machine 10.

Second Example Embodiment

In a second example embodiment, a work control system 2, which is another form of the work control system 1 according to the first example embodiment, will be described. In the description of the second example embodiment, the components that are the same as those in the first example embodiment are denoted by the same reference symbols as those given to the components in the first example embodiment and the descriptions thereof will be omitted.

FIG. 7 shows a block diagram of the work control system 2 according to the second example embodiment. As shown in FIG. 7, the work control system 2 according to the second example embodiment further includes a work instruction unit 41 in addition to the components of the work control system 1 according to the first example embodiment. Further, in the work control system 2 according to the second example embodiment, the feedback control unit 32 of the work control system 1 according to the first example embodiment is replaced by a feedback control unit 42. In the feedback control unit 42, the error update unit 322 is replaced by an error update unit 422. The error update unit 422 is different from the error update unit 322 in that a parameter update unit 422a is added to the components of the error update unit 322.

The work instruction unit 41 provides information regarding the content of the work performed using the construction machine 10 for the feedback control unit 42. The error update unit 422 of the feedback control unit 42 performs, when it is recognized that a work instruction for instructing a work to be performed by the construction machine 10 has been updated based on the instruction given from the work instruction unit 41, a parameter update step of updating the control parameters including the target posture of the construction machine 10 by the parameter update unit 422a. It is assumed that the control parameters include the maximum input amount Umax and the deceleration start threshold Emax included in Expression (10).

Next, feedback control processing performed using the feedback control unit 42 according to the second example embodiment will be described in detail. FIG. 8 shows a flowchart for describing an operation of the feedback control unit 42 according to the second example embodiment. In the description of the flowchart shown in FIG. 8, Steps S31 and S32 that are different from those in the flowchart of the work control system 1 according to the first example embodiment shown in FIG. 6 will be described.

As shown in FIG. 8, in the operation of the feedback control unit 42 according to the second example embodiment, operations of Steps S31 and S32 are added to the operation performed in the feedback control unit 32 according to the first example embodiment. The processing of Steps S31 and S32 is performed between Step S22 and Step S23. In Step S31, it is determined whether or not the work instruction unit 41 has updated the content of the work. When it is determined in Step S31 that the content of the work has been updated, the error update unit 422 updates control parameters including the target posture, the input maximum amount, and the deceleration start threshold in accordance with the content of the current work using the parameter update unit 422a. Then, the work control system 2 according to the second example embodiment computes the error with the current posture (Step S24) based on the target posture, the input maximum amount, and the deceleration start threshold updated in Step S32 and computes the feedback control input value (Step SS25).

From the above description, with the work control system 2 according to the second example embodiment, by instructing the error update unit 422 to update the content of the work by the work instruction unit 41, it is possible to perform control with an accuracy as high as that in the work control system 1 according to the first example embodiment while causing the construction machine 10 to perform various kinds of work. In an excavation work, for example, compared to a case in which the bucket 16 is empty, a larger force is required to close the bucket 16 in order to enable the bucket 16 to lifting earth and sand. Therefore, in the excavation work, control parameters with which torque to be provided for the bucket 16 increases will be employed. Further, in another example, when the truck is loaded with earth and sand using the bucket 16, the control needs to be performed with a high position accuracy in order to avoid a collision between the truck and the bucket 16. Therefore, in a work for loading a truck with earth and sand, control parameters with which the position accuracy is increased are employed.

Note that the present invention is not limited to the aforementioned example embodiments and may be changed as appropriate without departing from the spirit of the present invention.

While the present invention has been described as a hardware configuration in the above example embodiments, the present invention is not limited thereto. The present invention can achieve desired processing (e.g., processing described with reference to FIGS. 4-6 and 8) by causing a Central Processing Unit (CPU) to execute a computer program. Further, the aforementioned program may be stored and provided to a computer using any type of non-transitory computer readable media. Non-transitory computer readable media include any type of tangible storage media. Examples of non-transitory computer readable media include magnetic storage media (such as flexible disks, magnetic tapes, hard disk drives, etc.), optical magnetic storage media (e.g., magneto-optical disks), CD-Read Only Memory (ROM), CD-R, CD-R/W, semiconductor memories (e.g., mask ROM, Programmable ROM (PROM), Erasable PROM (EPROM), flash ROM, Random Access Memory (RAM)). Further, the program may be provided to a computer using any type of transitory computer readable medium. Examples of transitory computer readable media include electric signals, optical signals, and electromagnetic waves. Transitory computer readable media can provide the program to a computer via a wired communication line (e.g., electric wires, and optical fibers) or a wireless communication line.

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2020-144049, filed on Aug. 28, 2020, the disclosure of which is incorporated herein in its entirety by reference.

Further, the above example embodiments include the following aspects.

(Supplementary Note 1)

A work control method comprising:

• • an initial motion input model generation step of generating an initial motion input model for computing an initial motion input value at which a movable part of a construction machine is caused to start to move; and
  • a feedback control step of computing the initial motion input value that corresponds to the posture of the construction machine using the initial motion input model and determining a control input value equal to or larger than the initial motion input value, wherein
  • the initial motion input model generation step comprises:
    • a first initial motion input value measurement step of measuring a first initial motion measurement value at which the movable part is caused to start to move in a first state in which the movable part is controlled to a first position within a movable range of the movable part;
    • a second initial motion input value measurement step of measuring a second initial motion measurement value at which the movable part is caused to start to move in a second state in which the movable part is controlled to a second position that is different from the first position within the movable
    • range of the movable part; and a model generation step of generating the initial motion input model that complements between the first initial motion measurement value and the second initial motion measurement value and derives the initial motion input value with respect to a desired posture of the construction machine.

(Supplementary Note 2)

The work control method according to Supplementary Note 1, wherein

• • in the first initial motion input value measurement step, an input value is provided for the construction machine in such a way that the movable part moves in each of a positive direction of the movable part and a negative direction of the movable part with respect to the movable part which is in the first state, and the first initial motion measurement value is measured for each of the positive direction and the negative direction,
  • in the second initial motion input value measurement step, an input value is provided for the construction machine in such a way that the movable part moves in each of the positive direction of the movable part and the negative direction of the movable part with respect to the movable part which is in the second state, and the second initial motion measurement value is measured for each of the positive direction and the negative direction, and
  • the model generation step includes a control input computation step of generating the initial motion input model using the first initial motion measurement value of the positive direction, the first initial motion measurement value of the negative direction, the second initial motion measurement value of the positive direction, and the second initial motion measurement value of the negative direction.

(Supplementary Note 3)

The work control method according to Supplementary Note 1 or 2, wherein

• • the feedback control step comprises:
  • an initial motion input update step of acquiring the current posture of the construction machine based on positional information of the movable part of the construction machine and updating the initial motion input value that corresponds to the current posture by the value computed using the initial motion input model;
  • an error update step of updating the error between the current posture and a target posture of the construction machine; and
  • a control input computation step of receiving the error and the initial motion input value, computing the control input value that reduces the error, and provides the computed control input value for the construction machine.

(Supplementary Note 4)

The work control method according to Supplementary Note 3, wherein, in the error update step, when a work instruction for instructing a work to be performed by the construction machine has been updated, a parameter update step of updating a control parameter including the target posture of the construction machine is performed.

(Supplementary Note 5)

The work control method according to any one of Supplementary Notes 1 to 4, wherein the initial motion input model generation step generates the initial motion input model in a period other than an operation period during which the construction machine performs work.

(Supplementary Note 6)

The work control method according to any one of Supplementary Notes 1 to 5, wherein

• • the construction machine includes a manipulation lever for manipulating the posture of the construction machine and an actuator attached to the manipulation lever, and
  • the work control method includes a construction machine control step of controlling the construction machine via the manipulation lever by manipulating the actuator based on the control input value.

(Supplementary Note 7)

A work control system comprising:

• • initial motion input model generation means for generating an initial motion input model for computing an initial motion input value at which a movable part of a construction machine is caused to start to move; and
  • feedback control means for computing the initial motion input value that corresponds to the posture of the construction machine using the initial motion input model and determining a control input value equal to or larger than the initial motion input value, wherein
  • the initial motion input model generation means performs:
    • first initial motion input value measurement processing for measuring a first initial motion measurement value at which the movable part is caused to start to move in a first state in which the movable part is controlled to a first position within a movable range of the movable part;
    • second initial motion input value measurement processing for measuring a second initial motion measurement value at which the movable part is caused to start to move in a second state in which the movable part is controlled to a second position that is different from the first position within the movable range of the movable part; and
    • model generation processing for generating the initial motion input model that complements between the first initial motion measurement value and the second initial motion measurement value and deriving the initial motion input value with respect to a desired posture of the construction machine.

(Supplementary Note 8)

The work control system according to Supplementary Note 7, wherein

• • in the first initial motion input value measurement processing, an input value is provided for the construction machine in such a way that the movable part moves in each of a positive direction of the movable part and a negative direction of the movable part with respect to the movable part which is in the first state, and the first initial motion measurement value is measured for each of the positive direction and the negative direction,
  • in the first initial motion input value measurement processing, an input value is provided for the construction machine in such a way that the movable part moves in each of the positive direction of the movable part and the negative direction of the movable part with respect to the movable part which is in the second state, and the second initial motion measurement value is measured for each of the positive direction and the negative direction, and
  • in the model generation processing, the initial motion input model is generated using the first initial motion measurement value of the positive direction, the first initial motion measurement value of the negative direction, the second initial motion measurement value of the positive direction, and the second initial motion measurement value of the negative direction.

(Supplementary Note 9)

The work control system according to Supplementary Note 7 or 8, wherein

• • the feedback control means comprises:
  • initial motion input update means for acquiring the current posture of the construction machine based on positional information of the movable part of the construction machine and updating the initial motion input value that corresponds to the current posture by the value computed using the initial motion input model;
  • error update means for updating the error between the current posture and a target posture of the construction machine; and
  • control input computation means for receiving the error and the initial motion input value, computing the control input value that reduces the error, and providing the computed control input value for the construction machine.

(Supplementary Note 10)

The work control system according to Supplementary Note 9, wherein the error update means includes parameter update means for updating a control parameter including the target posture of the construction machine when a work instruction for instructing a work to be performed by the construction machine has been updated.

(Supplementary Note 11)

The work control system according to any one of Supplementary Notes 7 to 10, wherein the initial motion input model generation means generates the initial motion input model in a period other than an operation period during which the construction machine performs work.

(Supplementary Note 12)

The work control system according to any one of Supplementary Notes 7 to 11, wherein

• • the construction machine includes a manipulation lever for manipulating the posture of the construction machine and an actuator attached to the manipulation lever, and
  • the work control system includes construction machine control means for controlling the construction machine via the manipulation lever by manipulating the actuator based on the control input value.

(Supplementary Note 13)

A work control apparatus comprising:

• • initial motion input model generation means for generating an initial motion input model for computing an initial motion input value at which a movable part of a construction machine is caused to start to move; and
  • feedback control means for computing the initial motion input value that corresponds to the posture of the construction machine using the initial motion input model and determining a control input value equal to or larger than the initial motion input value, wherein
  • the initial motion input model generation means performs:
    • first initial motion input value measurement processing for measuring a first initial motion measurement value at which the movable part is caused to start to move in a first state in which the movable part is controlled to a first position within a movable range of the movable part;
    • second initial motion input value measurement processing for measuring a second initial motion measurement value at which the movable part is caused to start to move in a second state in which the movable part is controlled to a second position that is different from the first position within the movable range of the movable part; and
    • model generation processing for generating the initial motion input model that complements between the first initial motion measurement value and the second initial motion measurement value and deriving the initial motion input value with respect to a desired posture of the construction machine.

(Supplementary Note 14)

The work control apparatus according to Supplementary Note 13, wherein

• • in the first initial motion input value measurement processing, an input value is provided for the construction machine in such a way that the movable part moves in each of a positive direction of the movable part and a negative direction of the movable part with respect to the movable part which is in the first state, and the first initial motion measurement value is measured for each of the positive direction and the negative direction,
  • in the first initial motion input value measurement processing, an input value is provided for the construction machine in such a way that the movable part moves in each of the positive direction of the movable part and the negative direction of the movable part with respect to the movable part which is in the second state, and the second initial motion measurement value is measured for each of the positive direction and the negative direction, and
  • in the model generation processing, the initial motion input model is generated using the first initial motion measurement value of the positive direction, the first initial motion measurement value of the negative direction, the second initial motion measurement value of the positive direction, and the second initial motion measurement value of the negative direction.

(Supplementary Note 15)

The work control apparatus according to Supplementary Note 13 or 14, wherein

• • the feedback control means comprises:
  • initial motion input update means for acquiring the current posture of the construction machine based on positional information of the movable part of the construction machine and updating the initial motion input value that corresponds to the current posture by the value computed using the initial motion input model;
  • error update means for updating the error between the current posture and a target posture of the construction machine; and
  • control input computation means for receiving the error and the initial motion input value, computing the control input value that reduces the error, and providing the computed control input value for the construction machine.

(Supplementary Note 16)

The work control apparatus according to Supplementary Note 15, wherein the error update means includes parameter update means for updating a control parameter including the target posture of the construction machine when a work instruction for instructing a work to be performed by the construction machine has been updated.

(Supplementary Note 17)

The work control apparatus according to any one of Supplementary Notes 13 to 16, wherein the initial motion input model generation means generates the initial motion input model in a period other than an operation period during which the construction machine performs work.

(Supplementary Note 18)

The work control apparatus according to any one of Supplementary Notes 13 to 17, wherein

• • the construction machine includes a manipulation lever for manipulating the posture of the construction machine and an actuator attached to the manipulation lever, and
  • the work control system includes construction machine control means for controlling the construction machine via the manipulation lever by manipulating the actuator based on the control input value.

REFERENCE SIGNS LIST

• • 1 Work Control System
  • 2 Work Control System
  • 10 Construction Machine
  • 11 Crawler
  • 12 Turning Base
  • 13 Cockpit
  • 14 Boom
  • 16 Arm
  • 16 Bucket
  • 17 Actuator
  • 181 Posture Sensor
  • 182 Posture Sensor
  • 183 Posture Sensor
  • 184 Posture Sensor
  • 20 Posture Control Apparatus
  • 21 Construction Machine Control Unit
  • 22 Posture Detection Unit
  • 30 Work Control Apparatus
  • 31 Initial Motion Input Model Generation Unit
  • 311 Initial Motion Input Measurement Unit
  • 312 Model Generation Unit
  • 32 Feedback Control Unit
  • 321 Initial Motion Input Update Unit
  • 322 Error Update Unit
  • 323 Control Input Computation Unit
  • 41 Work Instruction Unit
  • 42 Feedback Control Unit
  • 422 Error Update Unit
  • 422a Parameter Update Unit

Claims

1. A work control method comprising:

an initial motion input model generation step of generating an initial motion input model for computing an initial motion input value at which a movable part of a construction machine is caused to start to move; and

a feedback control step of computing the initial motion input value that corresponds to the posture of the construction machine using the initial motion input model and determining a control input value equal to or larger than the initial motion input value, wherein

the initial motion input model generation step comprises: a first initial motion input value measurement step of measuring a first initial motion measurement value at which the movable part is caused to start to move in a first state in which the movable part is controlled to a first position within a movable range of the movable part; a second initial motion input value measurement step of measuring a second initial motion measurement value at which the movable part is caused to start to move in a second state in which the movable part is controlled to a second position that is different from the first position within the movable range of the movable part; and a model generation step of generating the initial motion input model that complements between the first initial motion measurement value and the second initial motion measurement value and derives the initial motion input value with respect to a desired posture of the construction machine.

2. The work control method according to claim 1, wherein

in the first initial motion input value measurement step, an input value is provided for the construction machine in such a way that the movable part moves in each of a positive direction of the movable part and a negative direction of the movable part with respect to the movable part which is in the first state, and the first initial motion measurement value is measured for each of the positive direction and the negative direction,

in the second initial motion input value measurement step, an input value is provided for the construction machine in such a way that the movable part moves in each of the positive direction of the movable part and the negative direction of the movable part with respect to the movable part which is in the second state, and the second initial motion measurement value is measured for each of the positive direction and the negative direction, and

the model generation step includes a control input computation step of generating the initial motion input model using the first initial motion measurement value of the positive direction, the first initial motion measurement value of the negative direction, the second initial motion measurement value of the positive direction, and the second initial motion measurement value of the negative direction.

3. The work control method according to claim 1, wherein

the feedback control step comprises:

an initial motion input update step of acquiring the current posture of the construction machine based on positional information of the movable part of the construction machine and updating the initial motion input value that corresponds to the current posture by the value computed using the initial motion input model;

an error update step of updating the error between the current posture and a target posture of the construction machine; and

a control input computation step of receiving the error and the initial motion input value, computing the control input value that reduces the error, and provides the computed control input value for the construction machine.

4. The work control method according to claim 3, wherein, in the error update step, when a work instruction for instructing a work to be performed by the construction machine has been updated, a parameter update step of updating a control parameter including the target posture of the construction machine is performed.

5. The work control method according to claim 1, wherein the initial motion input model generation step generates the initial motion input model in a period other than an operation period during which the construction machine performs work.

6. The work control method according to claim 1, wherein

the construction machine includes a manipulation lever for manipulating the posture of the construction machine and an actuator attached to the manipulation lever, and

the work control method includes a construction machine control step of controlling the construction machine via the manipulation lever by manipulating the actuator based on the control input value.

7. A work control system comprising:

initial motion input model generation means for generating an initial motion input model for computing an initial motion input value at which a movable part of a construction machine is caused to start to move; and

feedback control means for computing the initial motion input value that corresponds to the posture of the construction machine using the initial motion input model and determining a control input value equal to or larger than the initial motion input value, wherein

the initial motion input model generation means performs: first initial motion input value measurement processing for measuring a first initial motion measurement value at which the movable part is caused to start to move in a first state in which the movable part is controlled to a first position within a movable range of the movable part; second initial motion input value measurement processing for measuring a second initial motion measurement value at which the movable part is caused to start to move in a second state in which the movable part is controlled to a second position that is different from the first position within the movable range of the movable part; and model generation processing for generating the initial motion input model that complements between the first initial motion measurement value and the second initial motion measurement value and deriving the initial motion input value with respect to a desired posture of the construction machine.

8. The work control system according to claim 7, wherein

in the first initial motion input value measurement processing, an input value is provided for the construction machine in such a way that the movable part moves in each of a positive direction of the movable part and a negative direction of the movable part with respect to the movable part which is in the first state, and the first initial motion measurement value is measured for each of the positive direction and the negative direction,

in the second initial motion input value measurement processing, an input value is provided for the construction machine in such a way that the movable part moves in such a way that the movable part moves in each of the positive direction of the movable part and the negative direction of the movable part with respect to the movable part which is in the second state, and the second initial motion measurement value is measured for each of the positive direction and the negative direction, and

in the model generation processing, the initial motion input model is generated using the first initial motion measurement value of the positive direction, the first initial motion measurement value of the negative direction, the second initial motion measurement value of the positive direction, and the second initial motion measurement value of the negative direction.

9. The work control system according to claim 7, wherein the feedback control means comprises:

initial motion input update means for acquiring the current posture of the construction machine based on positional information of the movable part of the construction machine and updating the initial motion input value that corresponds to the current posture by the value computed using the initial motion input model;

error update means for updating the error between the current posture and a target posture of the construction machine; and

control input computation means for receiving the error and the initial motion input value, computing the control input value that reduces the error, and providing the computed control input value for the construction machine.

10. The work control system according to claim 9, wherein the error update means includes parameter update means for updating a control parameter including the target posture of the construction machine when a work instruction for instructing a work to be performed by the construction machine has been updated.

11. The work control system according to claim 7, wherein the initial motion input model generation means generates the initial motion input model in a period other than an operation period during which the construction machine performs work.

12. The work control system according to claim 7, wherein

the construction machine includes a manipulation lever for manipulating the posture of the construction machine and an actuator attached to the manipulation lever, and

the work control system includes construction machine control means for controlling the construction machine via the manipulation lever by manipulating the actuator based on the control input value.

13. A work control apparatus comprising:

initial motion input model generation means for generating an initial motion input model for computing an initial motion input value at which a movable part of a construction machine is caused to start to move; and

feedback control means for computing the initial motion input value that corresponds to the posture of the construction machine using the initial motion input model and determining a control input value equal to or larger than the initial motion input value, wherein

the initial motion input model generation means performs: first initial motion input value measurement processing for measuring a first initial motion measurement value at which the movable part is caused to start to move in a first state in which the movable part is controlled to a first position within a movable range of the movable part; second initial motion input value measurement processing for measuring a second initial motion measurement value at which the movable part is caused to start to move in a second state in which the movable part is controlled to a second position that is different from the first position within the movable range of the movable part; and model generation processing for generating the initial motion input model that complements between the first initial motion measurement value and the second initial motion measurement value and deriving the initial motion input value with respect to a desired posture of the construction machine.

14. The work control apparatus according to claim 13, wherein

in the first initial motion input value measurement processing, an input value is provided for the construction machine in such a way that the movable part moves in each of a positive direction of the movable part and a negative direction of the movable part with respect to the movable part which is in the first state, and the first initial motion measurement value is measured for each of the positive direction and the negative direction,

in the second initial motion input value measurement processing, an input value is provided for the construction machine in such a way that the movable part moves in each of the positive direction of the movable part and the negative direction of the movable part with respect to the movable part which is in the second state, and the second initial motion measurement value is measured for each of the positive direction and the negative direction, and

in the model generation processing, the initial motion input model is generated using the first initial motion measurement value of the positive direction, the first initial motion measurement value of the negative direction, the second initial motion measurement value of the positive direction, and the second initial motion measurement value of the negative direction.

15. The work control apparatus according to claim 13, wherein

the feedback control means comprises:

initial motion input update means for acquiring the current posture of the construction machine based on positional information of the movable part of the construction machine and updating the initial motion input value that corresponds to the current posture by the value computed using the initial motion input model;

error update means for updating the error between the current posture and a target posture of the construction machine; and

control input computation means for receiving the error and the initial motion input value, computing the control input value that reduces the error, and providing the computed control input value for the construction machine.

16. The work control apparatus according to claim 15, wherein the error update means includes parameter update means for updating a control parameter including the target posture of the construction machine when a work instruction for instructing a work to be performed by the construction machine has been updated.

17. The work control apparatus according to claim 13, wherein the initial motion input model generation means generates the initial motion input model in a period other than an operation period during which the construction machine performs work.

18. The work control apparatus according to claim 13, wherein

the construction machine includes a manipulation lever for manipulating the posture of the construction machine and an actuator attached to the manipulation lever, and

the work control system includes construction machine control means for controlling the construction machine via the manipulation lever by manipulating the actuator based on the control input value.