JP3437348B2 - Trajectory control device for construction machinery - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a trajectory control device for a construction machine having an articulated front device, and more particularly to a hydraulic excavator having a front device including front members such as a boom, an arm and a bucket. In the above, the present invention relates to a trajectory control device for moving the tip of the front device by inputting the moving velocity vector of the tip of the front device with the operating means.

[0002]

2. Description of the Related Art In a hydraulic excavator, an operator operates a front member such as a boom with respective manual operation levers. However, since the front device is an articulated type composed of a plurality of front members, straight excavation or the like can be performed. When it is performed, it becomes a complex operation of them, and a considerable skill is required.

Therefore, various trajectory control devices have been proposed in order to facilitate such work. As one example thereof, JP-A-61-270421 and JP-A-62-7
There is a 2826 publication.

In the trajectory control device described in Japanese Patent Laid-Open No. 61-270421, an operator presets an inclination angle θ of the excavation plane with a digital switch or the like, and an arm operation signal from an arm operation lever and a posture of the front device are set. By calculating a boom operation signal based on this, when the operator turns the arm by the arm operation lever, the boom is also turned so that the tip of the bucket moves linearly along the set angle θ. According to this proposal, the arm operation is performed by the arm operation lever, and only the boom operation is controlled by the error from the target position, so that stable automatic operation without hunting can be performed.

The locus control device disclosed in Japanese Patent Laid-Open No. 62-72826 obtains a target position from the set value of the velocity vector setting means, obtains a velocity vector for moving from the current position to the target position, and uses it. Based on this, the flow rate of the boom and arm cylinders is controlled. According to this proposal, the operation of the boom and arm is controlled by the error between the current position and the target position based on the moving direction and speed of the set arm tip point. It can be moved.

[0006]

However, the above-mentioned prior art has the following problems.

In the trajectory control device disclosed in Japanese Patent Laid-Open No. 61-270421, when the operator operates the arm operation lever, the trajectory of the bucket is controlled to move along the preset inclination angle θ of the plane. Regardless of how the operation lever is operated, the trajectory-controlled angle is constant at a preset angle θ, and the trajectory-controlled operation is limited to a linear movement of one plane of the angle θ.

In the trajectory control device described in Japanese Patent Laid-Open No. 62-72826, since both the boom and the arm are controlled by the error between the current position and the target position, hunting is likely to occur due to mutual interference.

An object of the present invention is to provide a locus control device for a construction machine, which can freely set a target locus for locus control by an input moving velocity vector and can stably operate the tip of the front device. is there.

[0010]

In order to achieve the above object, a trajectory control device for a construction machine according to the present invention adopts the following configuration. That is, a multi-joint type front device composed of a plurality of front members that can be rotated in the vertical direction,
A trajectory control device for a construction machine, comprising: a plurality of hydraulic actuators that drive the front device; and a plurality of flow rate control valves that control the flow of pressure oil supplied to the plurality of hydraulic actuators, wherein: (a) the front Operation means for inputting a moving velocity vector of the tip of the device; (b) detection means for detecting a state quantity relating to the attitude of the front device; (c) calculation of the attitude of the front device based on a signal from the detection means. And (d) a request for each of the plurality of front members based on the movement velocity vector of the tip of the front device input by the operating device and the attitude of the front device calculated by the first operating device. The moving speed is calculated, the front member having the maximum required moving speed is selected from the plurality of front members, and the selected front member is the front member. In order to move at the required moving speed, the other front member corrects the required moving speed so as to reduce the deviation between the current position of the front end of the front device and the target trajectory based on the input moving speed vector, and this correction is performed. And second calculating means for calculating and outputting command values of the corresponding flow rate control valves so as to move at different moving speeds.

In the present invention configured as described above,
Since the front member is moved by the movement velocity vector input by the operating means, the target trajectory for trajectory control can be freely set by the operating means, and linear excavation can be performed freely and easily.

Further, a selected front member among the plurality of front members is controlled by an open loop so as to move at the maximum required moving speed, and the other front members are displaced from the current position of the front end of the front device and the target locus. Since the feedback control is performed so as to reduce, the stable trajectory control with less mutual interference can be performed.

Further, among the plurality of front members, the front member having the maximum required moving speed is moved at the maximum required moving speed, and the other front members are moved while being corrected so as to reduce the deviation from the target locus. The front member having an input component close to the traveling speed (direction of the moving velocity vector) input by the operation lever device 5 is directly moved at the maximum required moving velocity, and the front member having an input component nearly vertical to the traveling direction. An error is corrected by the member with respect to the target locus, so that the controlled movement of the front device becomes close to a normal operation, and the operator can move the front end of the front device without feeling discomfort.

In the above trajectory control device, the second computing means obtains, for example, the angular velocity of the front member as the required moving velocity of each of the plurality of front members.

When the present invention is applied to a hydraulic excavator, the plurality of front members include a boom and an arm that form the front member of the hydraulic excavator.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments in which the present invention is applied to a hydraulic drive system for a front device of a hydraulic excavator will be described below with reference to FIGS.

In FIG. 1, a hydraulic drive device of a front device of a hydraulic excavator to which the present invention is applied is a hydraulic pump 2
And a plurality of hydraulic actuators including a boom cylinder 3a, an arm cylinder 3b, and a bucket cylinder 3c driven by pressure oil from the hydraulic pump, and a plurality of hydraulic actuators for controlling the flow rate of the pressure oil supplied to the hydraulic actuators 3a to 3c. It has flow control valves 4a-4c.

As shown in FIG. 2, the hydraulic excavator includes an articulated front device 1A composed of a boom 1a, an arm 1b, and a bucket 1c that rotate in the vertical direction, an upper revolving structure 1d, and a lower traveling structure 1e. The boom 1a of the front device 1A is supported by the front portion of the upper swing body 1d. The boom 1a, arm 1b, and bucket 1c of the front device 1A are the boom cylinder 3a and arm cylinder 3 of the hydraulic drive system shown in FIG.
b and the bucket cylinder 3c, respectively.

The trajectory control device according to the present embodiment is provided in the hydraulic drive system for the front device of the hydraulic excavator as described above. This trajectory control device is provided with an operation lever device 5 for inputting a moving speed vector and a rotation speed of the bucket 1c.
And the angle detectors 6a, 6b, 6c provided on the respective pivots of the boom 1a, the arm 1b, and the bucket 1c, and detecting the respective pivot angles as state quantities related to the attitude of the front device 1A, and the operating lever device. 5 and the angle detectors 6a to 6c, and a control unit 7 that outputs an electric signal for controlling the trajectory.

The processing contents of the control unit 7 will be described with reference to FIGS.

FIG. 3 is a flowchart showing the overall control flow for explaining the processing contents of the control unit 7, and FIG.
FIG. 3 is an overall view of a hydraulic excavator showing parameters relating to the control flow.

In step 100, the angle detectors 6a-6a
Input each joint angle with c.

Next, in step 110, the front posture such as the tip device of the arm 1b and the ground angle of the bucket 1c is calculated from these joint angles.

Next, in step 120, an input signal from the operating lever device 5 is input.

Next, in step 130, the moving speed vector (VX, VX, of the bucket 1c inputted by the operation lever device 5 based on the inputted input signal of the operation lever device 5).
VY) and the rotation speed Vθ are calculated.

Next, in step 140, the moving speed vector (VX, VY) and the rotation speed V of the bucket 1c are converted by coordinate conversion based on the front posture obtained in step 110.
Let θ be the required moving speed for each of the boom 1a, the arm 1b, and the bucket 1c.
It is decomposed into input components V1, V2, V3 of each angular velocity of the bucket 1c.

Next, in step 150, of the input components of the angular velocity obtained in step 140, boom 1a and arm 1b
The angular velocities V1 and V2 of the arm 1b
Is larger, the procedure proceeds to step 160, and otherwise, the procedure proceeds to step 170.

In step 160, the boom angular velocity correction component ΔV1 is used to correct the trajectory only with the boom 1a.
To calculate.

The procedure 160 will be described in detail with reference to the flow chart of FIG. 5 and the movement trajectory of the bucket of FIG. In FIG. 6, the solid line indicates the target locus, the dotted line indicates the actually moved locus, and P1 to P4 indicate the current point at each sample time. However, when the power is turned on, the current point P1 is set as the reference point S1. The operation lever device 5 is provided between S1 and S4.
To move the horizontal movement velocity vector (V
X, VY) is input, the operation lever device 5 is operated in an oblique direction between S5 and S7, and the moving speed vector (VX, VY) in the oblique direction is input.

In step 161, the reference point S is obtained by drawing a perpendicular line from the current point Pi on the previous target locus.
Calculate i. Here, the previous target locus is given by extending the direction of the moving velocity vector input by the operation lever device 5 at that time.

Next, in step 162, the target locus for this time is obtained by extending a straight line in the direction of the moving velocity vector input by the operation lever device 5 with the reference point Si as the base point.

Next, in step 163, a correction vector proportional to the distance between the current target locus and the current point is obtained.

By performing the processing in steps 161 to 163 as described above, the correction vector becomes 0 at the current point P1 in FIG. 6, and at the current points P2 to P4 and P6 and P7 on the previous target locus from the current point Pi. A correction vector that coincides with the perpendicular drawn down is obtained, and at the current point P5, a correction vector that coincides with the perpendicular drawn to the target locus given by the diagonal movement velocity vector is obtained.

Next, in step 164, the correction vector obtained as described above is converted into a boom angular velocity ΔV1 including this correction belt by coordinate conversion.
This is the correction component of the boom angular velocity.

In step 170 as well, the above calculation is similarly performed for the arm 1b, and the correction component ΔV2 of the arm angular velocity is calculated in order to correct the locus only by the arm 1b.

Next, in step 180, the bucket angular velocity correction component ΔV3 is calculated.

This procedure 180 will be described in detail with reference to the flowchart of FIG. 7 and the bucket rotation schematic diagram of FIG. In FIG. 7, the solid line shows the target angle and the dotted line shows the angle rotated to the solid line.

In step 181, the target angle is obtained by integrating the bucket rotation speed Vθ input by the operation lever device 5.

Next, in step 182, the correction angular velocity ΔV3 of the bucket 1c proportional to the target angle and the actual angle is obtained.

Now, returning to the flowchart of FIG. 3 again, the procedure 190 and subsequent steps will be described.

In step 190, the input components V1, V2 and V3 of the respective angular velocities obtained in step 140 and steps 150 to
By the sum with the correction component of each angular velocity obtained in step 170,
The angular velocity values U1, U2, U3 output for control are determined.

That is, in step 150, the boom 1
When the angular velocity V2 of the arm 1b is larger than the angular velocity V1 of a, the calculation of U1 = V1 + ΔV1 U2 = V2 U3 = V3 + ΔV3 is performed, and the boom 1a is calculated from the angular velocity V2 of the arm 1b.
When the angular velocity V1 of is larger, the calculation of U1 = V1 U2 = V2 + ΔV2 U3 = V3 + ΔV3 is performed.

Next, in step 200, the output angular velocity U of the boom 1a, arm 1b, and bucket 1c is calculated.
1, U2, U3, considering the flow rate characteristics of the flow rate control valves 4a to 4c and the link mechanism of the front device 1A,
A command value to each of the flow rate control valves 4a-4c is obtained.

Next, in step 210, the flow control valves 4 to 4 are connected.
In order to drive 4c, a voltage is output to the amplifier and the procedure returns to the beginning.

In this embodiment constructed as described above, for example, when the operating lever device 5 is moved horizontally to move the bucket horizontally, the input component V2 of the angular velocity with respect to the arm 1b is the angular velocity with respect to the boom 1a. Since the input component V1 is larger than the input component V1, the open-loop control is performed for the arm 1b with the angular velocity component V2 as the output angular velocity U2, and the output for the boom 1a is set so that the bucket 1c approaches the target trajectory. Angular velocity U1 is calculated,
Feedback control is performed. When the magnitude relationship between the angular velocity input components of the boom 1a and the arm 1b is reversed, the control method is also reversed.

As described above, according to the present embodiment, the open loop control is performed so that one of the boom 1a and the arm 1b is moved by the angular velocity input component (requested moving speed) by the operating lever device 5 (U1 = V1 or U2 = V2),
On the other hand, feedback control is performed so that the bucket 1c approaches the target trajectory (U2 = V2 + ΔV2 or U1 = V1 + ΔV1), so stable trajectory control with little mutual interference can be performed.

Further, of the boom 1a and the arm 1b, the front member having the maximum angular velocity input component (requested moving velocity) is moved by the angular velocity input component, and the other front members are moved so as to reduce the deviation from the target locus. Since the input component is corrected, the front member having an input component close to the traveling speed (direction of the moving velocity vector) input by the operation lever device 5 is directly moved by the maximum angular velocity input component and is perpendicular to the traveling direction. Since the front member having an input component close to is corrected for the error with respect to the target locus, the controlled movement becomes close to a normal operation, and the operator can move the bucket 1c without feeling awkward.

In the above embodiment, in order to compare the required moving speeds of the boom 1a and the arm 1b in step 150, the angular velocity input components V1 and V2 are compared, but the angular velocity input components of the boom 1a and the boom 1b are compared. Then, the moving speeds of the boom tip and the arm tip are obtained by multiplying by the distance from the turning fulcrum of the boom 1a to the tip of the boom and the distance from the turning fulcrum of the arm 1b to the tip of the arm, and comparing the moving speeds. As a result, it is possible to more strictly determine which of the boom 1a and the arm 1b the required moving speed is closer to the traveling speed input by the operation lever device 5.

[0049]

According to the present invention, since the front member is moved by the moving velocity vector input by the operating means, the target trajectory of the trajectory control can be freely set by the operating means, and the straight line excavation can be performed freely and easily. Further, since the selected front member is automatically controlled in the open loop by the input of the operating means and the other front members are feedback-controlled, stable trajectory control with little mutual interference can be performed regardless of the operation direction. Further, among the plurality of front members, the front member having the maximum required moving speed close to the input traveling direction is moved at the maximum required moving speed, and the other front members are used for correction, so that the movement of the controlled front device is controlled. Is close to a normal operation, and the operator can move the front end of the device without feeling awkward.

[Brief description of drawings]

FIG. 1 is a diagram showing a trajectory control device of a hydraulic excavator according to an embodiment of the present invention together with a hydraulic circuit thereof.

FIG. 2 is a diagram showing an appearance of a hydraulic excavator to which the present invention is applied.

FIG. 3 is a flowchart showing processing contents of a control unit.

FIG. 4 is a diagram showing a target of operation input in the hydraulic excavator.

FIG. 5 is a detailed part of a flowchart.

FIG. 6 is a diagram for explaining a correction vector of an arm tip.

FIG. 7 is a detailed part of a flowchart.

FIG. 8 is a diagram for explaining a corrected angular velocity of a bucket.

[Explanation of symbols]

1A front device 1B car body 1a boom 1b arm 1c bucket 1d Upper revolving structure 1e Undercarriage 2 pumps 3a-3c hydraulic actuator 4a-4c Flow control valve 5 Control lever device 6a to 6c Angle detector 7 control unit

Continuation of front page (56) Reference JP 62-72826 (JP, A) JP 61-270421 (JP, A) JP 7-197907 (JP, A) JP 58-54136 (JP , A) JP 55-119837 (JP, A) JP 58-33650 (JP, A) JP 3-25126 (JP, A) JP 2-261129 (JP, A) JP 60-33940 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) E02F 3/43 E02F 9/20

Claims (3)

(57) [Claims] 1. A multi-joint type front device composed of a plurality of vertically rotatable front members, a plurality of hydraulic actuators for driving the front device, and pressures supplied to the plurality of hydraulic actuators. A trajectory control device for a construction machine, comprising: a plurality of flow rate control valves for controlling the flow of oil; (a) an operating means for inputting a moving speed vector of the tip of the front device; Detecting means for detecting a state quantity relating to: (c) first calculating means for calculating the posture of the front device based on a signal from the detecting means; (d) a tip of the front device inputted by the operating means. Based on the moving speed vector and the posture of the front device calculated by the first calculating means, the required moving speed of each of the plurality of front members is calculated, Of the front members, the front member having the maximum required moving speed is selected, and the other front member is input with the current position of the tip of the front device so that the selected front member moves at the required moving speed. A second calculation for correcting the required moving speed so as to reduce the deviation from the target locus based on the moving speed vector, and for calculating and outputting the command values of the corresponding flow control valves so as to move at the corrected moving speed. A trajectory control device for a construction machine, comprising: 2. The trajectory control device for a construction machine according to claim 1, wherein the second computing means obtains an angular velocity of the front member as a required moving velocity of each of the plurality of front members. Trajectory control device. 3. The trajectory control device for a construction machine according to claim 1, wherein the plurality of front members include a boom and an arm that form a front member of a hydraulic excavator.