JP2000204581A - Attitude angle controller of working machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the control of an attitude angle of a working machine based on the deviation to a target value and, at the same time, to control a haunching in the neighborhood of an attitude angle deviation making a code of controlled variable invert. SOLUTION: A change-over apparatus 606 is so constituted that -|Δδ| when an attitude angle deviation Δδcoincides with a code of rotational speed Tv4 of a bucket and |Δδ| when the code does not coincide are inputted to a function generation apparatus 607. Then, the function generating apparatus 607 outputs a coefficient (c) getting bigger than 1 with the decrease of an input value when input is negative and smaller than 1 with the increase of the input value when input is positive, and the rotation speed Tv4 is multiplied by coefficient (c) by means of a multiplier 608. A function generating apparatus 650 inputs an increasing and decreasing rotation speed Tv4d based on the attitude angle deviation Δδ, and the output of the multiplier 608 and rotation speed Tv4d are added by means of an additional point 651. A limiting circuit 660 is outputted when the rotation speed added by the additional point 651 is the same direction as that of the rotation speed Tv4, and it is so limited that the added rotation speed is not outputted when it is the opposite direction. Then, a blind sector additional circuit 670 adds value based on the attitude angle deviation Δδ to the output of the limiting circuit 660 when the attitude angle deviation Δδ is bigger than specific value in the direction opposite to the rotation speed Tv4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for controlling a posture angle of a work attachment rotatably mounted on a work machine.

[0002]

2. Description of the Related Art Conventionally, a foundation working machine (hereinafter referred to as a working machine) in which a rotary excavating bucket is attached to the tip of an articulated arm is known. Each of the working machines includes first to third units on an upper revolving unit that is rotatably provided on the lower traveling unit.
A first arm, a second arm driven by a hydraulic cylinder of
It has a third arm, and a rotary excavation bucket is mounted on the tip of the third arm. And the rotary digging bucket is the fourth
The attitude angle of the cylinder is controlled in various angular directions.

[0003] In the excavation using such a working machine, it is necessary to keep the attitude angle of the rotary excavation bucket constant. In particular, in the case of a rotary excavation bucket, if the attitude angle error is large, the excavated hole is broken, an embedded object such as a pipe is damaged, or the excavation resistance increases, and the rotation of the bucket is stopped. Control is required. By the way, in a hydraulic power shovel having a shovel body, a boom, an arm, and a bucket attached to a tip of the arm, various control devices for keeping a constant posture angle of the bucket are known. For example, in Japanese Patent Publication No. 61-45025 (hereinafter referred to as a first prior art), a value obtained by inverting the sign of the sum of the boom rotation speed and the arm rotation speed is used to maintain the bucket posture. The speed is obtained as a speed, and the flow rate of the bucket cylinder is controlled based on the speed. Further, in Japanese Patent No. 2509368 (hereinafter referred to as a second prior art), in order to maintain the attitude of the bucket, the rotation speed of the work attachment is determined, the deviation of the detected attitude angle from the target value, and the determined rotation angle. The rotation speed is corrected based on the speed direction and the rotation speed after the correction is used to control the rotation speed of the work attachment.

[0004]

However, according to the first prior art, if there is an error in the actual flow rate output value with respect to the flow rate control value of the bucket cylinder, an error is generated in the attitude angle and the attitude angle is accumulated. There are drawbacks. Further, when the boom and arm rotation speeds for obtaining the bucket rotation speed are extremely low, the differential value of the angle sensor output representing the actual rotation speed cannot be used. Since the obtained flow control value is used, the error of the actual flow output value with respect to the flow control value of the boom and the arm cylinder is also added to the error of the attitude angle.

In the second prior art, since a dead zone is provided near the control target value in the feedback characteristic of the deviation of the attitude angle from the target value, the improvement of the attitude angle accuracy is limited to the case where the deviation is large. There was a problem. Further, when the feedforward amount corrected based on the posture angle deviation and the posture angle deviation feedback amount are added, the hunting is performed near the posture angle deviation where the sign of the control amount is reversed because the control direction of the posture angle is not always constant. Could have happened.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a work machine attitude angle control device capable of performing control based on an attitude angle deviation even when a deviation of the attitude angle from a target value is small. Another object of the present invention is to provide a posture angle control device for a working machine that suppresses hunting near a posture angle deviation where the sign of the control amount of the posture angle control is inverted.

[0007]

The present invention will be described with reference to FIGS. 2, 4 and 5 showing one embodiment. (1) The invention of claim 1 is a posture angle detecting means 101 to 104, 201 which is mounted on a driving body rotatably mounted on a base and detects a posture angle of a work attachment whose posture angle is controlled by an actuator. To 203, a deviation calculating means 302 for calculating a deviation Δδ between the attitude angle of the work attachment based on the values detected by the attitude angle detecting means 101 to 104 and 201 to 203 and a target value thereof, First rotation speed calculating means 400, 501-502 for calculating and outputting a first rotation speed Tv4 of the work attachment necessary for maintaining the attitude angle at the target value;
A second rotation speed calculating means 650 for calculating and outputting a second rotation speed Tv4d of the work attachment based on the posture angle deviation Δδ, and the calculated first and second rotation speeds Tv4, Tv
The present invention is applied to a work attachment attitude angle control device having an addition means 651 for adding 4d. Then, when the added rotation speed is the same direction as the first rotation speed Tv4, the added rotation speed is output, and when the added rotation speed is in the opposite direction, the added rotation speed is limited so as not to be output.
By driving the actuator with the output of the limiting means 660, the above-described object is achieved. (2) The invention of claim 2 is a posture angle detecting means 101 to 104, 201 which is mounted on a driving body rotatably mounted on a base and detects a posture angle of a work attachment whose posture angle is controlled by an actuator. To 203, a deviation calculating means 302 for calculating a deviation Δδ between the attitude angle of the work attachment based on the values detected by the attitude angle detecting means 101 to 104 and 201 to 203 and a target value thereof, First rotation speed calculating means 400, 501-502 for calculating and outputting a first rotation speed Tv4 of the work attachment necessary for maintaining the attitude angle at the target value;
A second rotation speed calculating means 650 for calculating and outputting a second rotation speed Tv4d of the work attachment based on the posture angle deviation Δδ, and the calculated first and second rotation speeds Tv4, Tv
The present invention is applied to a work attachment attitude angle control device having an addition means 651 for adding 4d. When the posture angle of the work attachment is behind the target value, the first rotation speed Tv4 is determined based on the posture angle deviation Δδ.
Is increased, and when the attitude angle of the work attachment is ahead of the target value, the first rotational speed Tv4 is corrected based on the attitude angle deviation Δδ so as to reduce the first rotational speed Tv4. Correction means 601 to 608;
Limiting means 660 for outputting the added rotation speed when the added rotation speed is in the same direction as the first rotation speed Tv4, and limiting the added rotation speed not to be output when the added rotation speed is in the opposite direction. By driving the actuator with the output of the limiting means 660, the above-described object is achieved. (3) The invention of claim 3 is a posture angle detecting means 101 to 104, 201 which is mounted on a driving body rotatably mounted on a base and detects the posture angle of a work attachment whose posture angle is controlled by an actuator. To 203, a deviation calculating means 302 for calculating a deviation Δδ between the posture angle of the work attachment based on the values detected by the posture angle detecting means 101 to 104 and 201 to 203 and a target value thereof, First rotation speed calculating means 400, 501-502 for calculating and outputting a first rotation speed Tv4 of the work attachment necessary for maintaining the attitude angle at the target value;
A second rotation speed calculating means 650 for calculating and outputting a second rotation speed Tv4d of the work attachment based on the posture angle deviation Δδ, and the calculated first and second rotation speeds Tv4, Tv
The present invention is applied to a work attachment attitude angle control device having first addition means 651 for adding 4d. And
Limiting means 660 for outputting the added rotation speed when the added rotation speed is in the same direction as the first rotation speed Tv4, and for not outputting the added rotation speed when the added rotation speed is in the opposite direction; When the attitude angle of the attachment is delayed with respect to the target value, the rotation speed is set to 0, and when the attitude angle is advanced with respect to the target value and the attitude angle deviation Δδ is within a predetermined value, the rotation speed is set to 0, When the posture angle is advanced with respect to the target value and the posture angle deviation Δδ exceeds a predetermined value, the third rotation speed in the direction opposite to the first rotation speed Tv4 is determined based on the posture angle deviation Δδ.
A third rotation speed calculating means 671 to 673 for calculating and outputting the rotation speed Tv4a of the second rotation speed, and a second adding means 674 for adding the third rotation speed Tv4a and the output of the limiting means 660. By driving the actuator with the output of the means 674, the above-mentioned object is achieved. (4) According to a fourth aspect of the present invention, in the attitude control apparatus for a work implement according to the third aspect, when the attitude angle of the work attachment is behind the target value, the attitude angle deviation Δδ.
The first rotation speed Tv4 is further increased based on the attitude angle deviation Δδ based on the attitude angle deviation Δδ when the attitude angle of the work attachment is ahead of the target value. It is characterized by further comprising speed correction means 601 to 608 for correcting the first rotation speed Tv4.

In the means for solving the above-mentioned problems, for the sake of simplicity, the drawings are associated with the embodiments, but the present invention is not limited to the embodiments.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. -First Embodiment- Fig. 6 shows an example of a conventionally known work machine equipped with an attitude angle control device according to the present invention. This work machine is configured such that an upper swing body US is rotatably provided on a lower traveling body LT, and a first arm 1, a second arm 2,
A third arm 3 and a first cylinder 5 for driving them;
It has a second cylinder 6, a third cylinder 7, and a third arm 3
The rotary excavation bucket 4 is attached to the tip of the
Control the attitude angle as shown in FIGS. 6 (a), 6 (b) and 6 (c).

FIG. 1 is a diagram showing a posture angle control device for a work attachment according to a first embodiment of the present invention.
In the working machine shown in FIG. 6, the ground angle and the relative angle of each arm are defined as shown in FIG. That is, in FIG. 7, the point O is defined as the pivot point of the first arm 1, the ground angle of the first arm 1 is α, the relative angle of the second arm 2 to the first arm 1 is T 2, and the third arm 3 is Assuming that the relative angle with respect to the second arm 2 is T3 and the relative angle of the bucket 4 with respect to the third arm 3 is T4, the attitude angle δ of the bucket 4 relative to the ground is
Is given by the following equation (1).

Δ = α−T2−T3−T4 (1)

In FIG. 1, an angle detector 101 is mounted near the pivot of the first arm 1, and detects the ground angle α of the first arm 1 by a well-known pendulum mechanism and a potentiometer. The angle detectors 102, 103, and 104 are attached to the pivots of the second arm 2, the third arm 3, and the bucket 4, respectively. The first arm 1 and the second arm 2 are provided by a well-known lever mechanism and a potentiometer. , A relative angle T3 between the second arm 2 and the third arm 3, and a relative angle T4 between the third arm 3 and the bucket 4. Numerals 201 to 203 denote addition points, and the bucket attitude angle δ shown in the equation (1) is calculated at these addition points 201 to 203.
Reference numeral 301 denotes a storage for storing a target bucket attitude angle δ0. In this embodiment, the storage 301 stores and holds the bucket attitude angle at the start of control. Reference numeral 302 denotes an addition point, which calculates a deviation Δδ between a target bucket attitude angle δ0 and an actual bucket attitude angle δ as in the following equation (2).

## EQU2 ## Δδ = δ−δ0 (2)

The arm rotation speed calculation circuit 400 is a part of a trajectory control device (not shown), and the rotation speeds αv and Tv2 of the respective arms calculated to control the trajectory of the bucket attachment point (PB in FIG. 6). , Tv3 are output. For example,
With the first arm 1 fixed, the second arm 2, the third arm 3
When the trajectory is controlled by the following equation, the rotation speed of each arm is given by the following equation (3).
Can be calculated.

(Equation 3)

To keep the bucket attitude angle constant,
The two sides of the equation (1) are differentiated with respect to time and controlled to the bucket rotation speed Tv4 before correction obtained by the following equation (4).

Δv = αv−Tv2−Tv3−Tv4 = 0 ∴Tv4 = αv−Tv2−Tv3 (4) where: δv is the rotation speed of the bucket 4.

Reference numerals 501 and 502 denote addition points for calculating the bucket rotation speed Tv4 of the equation (4). Attitude angle deviation Δδ
And the bucket rotation speed Tv4 are inputted to a bucket rotation speed correction circuit 600 described later, and the bucket rotation speed Tv
The rotation speed T is corrected based on the attitude angle deviation Δδ,
Output as v4k. A function generator 701 converts the bucket angle T4 into a coefficient for link correction when the bucket angle T4 is input. Reference numeral 702 denotes a multiplier, which converts the converted coefficient and the corrected bucket rotation speed Tv4k.
To calculate the bucket cylinder speed. 7
Numeral 703 denotes a coefficient unit, and 703 multiplies the cylinder speed by the pressure receiving area of the bucket cylinder 8 to calculate a bucket cylinder flow rate control value Q4 using the following equation (5). In addition,
Since the cylinder area a4 is actually different between the rod side and the bore side, the cylinder area a4 is appropriately switched based on expansion and contraction.

## EQU5 ## Q4 = a4.f (T4) .Tv4k (5)

FIG. 2 is a diagram showing details of the bucket rotation speed correction circuit 600 according to the first embodiment. The function generator 650 outputs a rotation speed Tv4d of the work attachment based on the posture angle deviation Δδ. This function generator 6
Feedback control 50 outputs a positive rotation speed Tv4d when the attitude angle deviation Δδ increases in the positive direction, and outputs a negative rotation speed Tv4d when the attitude angle deviation Δδ increases in the negative direction. Construct the system. The function generator 650 has no dead zone in its input / output characteristics. Further, the maximum output value of the function generator 650 is not limited and is limited to a predetermined value by a circuit configuration. The addition point 651 adds the rotation speed Tv4d of the bucket calculated at the addition points 501 and 502 and the rotation speed Tv4d based on the posture angle deviation Δδ of the work attachment output from the function generator 650. . The output of the addition point 651 is input to the limiting circuit 660. The limiting circuit 660 includes a negative limiter circuit 661, a positive limiter circuit 662, and a switch 66.
And a positive limiter circuit 6 by a switch 663.
61 and a signal limited by one of the negative limiter circuit 662 is output. The switch 663 is an encoder 604
, The contacts a and b are switched.

The encoder 604 calculates the bucket rotation speed Tv before correction calculated at the addition points 501 and 502 described above.
4 is determined, and the switch 66 is determined by the determined code.
Switch 3 contacts. That is, the bucket rotation speed Tv
When the sign of 4 is positive, the contact of the switch 663 is switched to the a side, and when negative, the contact is switched to the b side. The negative limiter circuit 661 outputs 0 when the input signal is negative, and outputs a signal based on the input signal when the input signal is 0 or positive. The positive limiter circuit 662 outputs 0 when the input signal is positive, and outputs a signal based on the input signal when the input signal is 0 or negative.

The rotation speed correction circuit 600 shown in FIG.
Is switched to the negative limiter circuit 661 by the switch 663 when the output of the encoder 604 is positive.
A signal is output only when the value output from 1 is 0 or more. Conversely, when the output of the encoder 604 is negative, the output is switched to the positive limiter circuit 662 by the switch 663.
A signal is output only when the value output from the addition point 651 is 0 or less. When Tv4 is 0, Tv4 is 0.
Then, a signal based on the code that was output before is output (the following equation (6)).

(Equation 6)

The posture angle control of the working machine according to the first embodiment will be described in more detail. When a power switch (not shown) is turned on, the angle detectors 101 to 10
The bucket posture angle δ is calculated at the addition points 201 to 203 based on the angles α, T2, T3, and T4 detected at step S4. When the control of the arm is started, the bucket attitude angle δ0 at the start is held in the storage device 301, and thereafter, the attitude angle deviation Δδ is calculated at the addition point 302. On the other hand, addition points 501 and 502 are calculated based on the arm rotation speeds αv, Tv2 and Tv3 calculated by the arm rotation speed calculation circuit 400.
Calculates the rotation speed Tv4 of the bucket before correction in order to keep the bucket attitude angle constant. The bucket rotation speed correction circuit 600 adds the rotation speed Tv4d of the work attachment output from the function generator 650 as a feedback amount based on the attitude angle deviation Δδ to the bucket rotation speed Tv4 at an addition point 651. The addition result Tv4d + Tv4 is input to the positive and negative limiter circuits 661 and 662.
On the other hand, the encoder 604 calculates the input bucket rotation speed T
The sign of v4 is determined, and the switch 6 is determined based on the determined sign.
Switch 63. As a result, the negative limiter circuit 661 or the positive limiter circuit 662 selected by the switch 663 limits the output of the added value output from the addition point 651, and the corrected bucket rotation speed Tv4k is calculated by the above equation (6). ).

Here, the relationship between the attitude angle deviation Δδ and the sign of the bucket rotation speed Tv4 before correction is summarized as follows. When Tv4> 0 and Δδ> 0, the deviation correction in the bucket cylinder extension direction is also in the extension direction (the rotation of the bucket is delayed). When Tv4 <0 and Δδ <0, the deviation correction in the bucket cylinder contraction direction is also in the contraction direction (the rotation of the bucket is delayed). When Tv4> 0 and Δδ <0, the deviation correction is in the contraction direction in the bucket cylinder extension direction (the bucket is rotating). When Tv4 <0 and Δδ> 0, the deviation correction in the bucket cylinder contraction direction is the extension direction (the bucket is rotating). If Tv4> 0, the attitude angle deviation is reduced by feedback control and feedforward control when (Tv4d + Tv4)> 0, but (Tv4d + Tv4) <
When 0, the correction value is set to 0. On the other hand, if Tv4 <0, the attitude angle deviation is reduced by feedback control and feedforward control when (Tv4d + Tv4) <0, but the correction value is set to 0 when (Tv4d + Tv4)> 0. That is, the limiting circuit 660 sets the addition point 651
Is the bucket rotation speed Tv before correction.
In the same direction as 4, the added rotation speed is output, and in the opposite direction, the added rotation speed is limited so as not to be output.

FIG. 3A is a graph showing the relationship between the attitude angle deviation Δδ at the pre-correction bucket rotation speed Tv4> 0 and the post-correction bucket rotation speed Tv4k. A thin line L1 in the figure is a line indicating the rotation speed Tv4 of the bucket before correction, and is a feedforward amount in the present embodiment. The bold line L2 in the figure indicates the bucket rotation speed Tv4k after correction according to the present embodiment. For reference, the first
FIGS. 3D and 3E show the rotational speed after correction according to the prior art and the rotational speed after correction according to the second conventional technology, respectively. The feedforward amount in FIG. 3D is Tv4, which is the same as in the present embodiment, and the corrected rotation speed Tv4k is shown by a waveform Ld. The feedforward amount in FIG. 3E is obtained by multiplying Tv4, which is the same as in the second embodiment described later, by a coefficient based on the magnitude and direction of the attitude angle deviation Δδ. Tv4k is indicated by waveform Le.

The waveform L2 shown in FIG.
Is compared with the waveforms Ld and Le in FIGS. 3D and 3E according to the prior art, since the dead zone is not provided by the feedback control in the waveform L2, there is no section where the waveforms L1 and L2 coincide, and the entire area of the deviation Δδ It can be seen that the attitude angle accuracy is improved. Further, the waveform L2 has the attitude angle deviation Δδ
It can be seen that a larger control amount can be obtained as the deviation Δδ increases. Further, in the waveform L2, it can be seen that the sign of the corrected rotation speed Tv4k does not change.

Therefore, according to the first embodiment as described above, the following operation and effect can be obtained. (1) Since no dead zone is provided in the feedback control based on the posture angle deviation Δδ, the posture angle accuracy can be improved even when the deviation Δδ between the posture angle and the target value is small, and the posture angle accuracy can be improved over the entire posture angle deviation. Can be improved. (2) When the sign of the corrected rotation speed is inverted, hunting can be prevented because the rotation speed in the direction opposite to the feedforward control is not output.

Second Embodiment FIG. 4 is a diagram showing details of a bucket rotation speed correction circuit 600A according to a second embodiment. The function generator 650 and the limiting circuit 660 in FIG. 4 are the same as in the first embodiment, and a description thereof will be omitted. The difference is that the posture angle deviation Δδ is added to Tv4 added at the addition point 651.
Is multiplied by a coefficient based on the size and direction of the image.

In FIG. 4, reference numeral 601 denotes an absolute value converter;
Numeral 02 denotes a sign inverter, which converts the input attitude angle deviation Δδ into | Δδ | and − | Δδ |, respectively. 603
And 604 are encoders for determining the sign of the attitude angle deviation Δδ and the sign of the bucket rotation speed Tv4 before correction, respectively.
This is an exclusive OR circuit that compares the determination results of the encoders 603 and 604. 606 are | Δδ | and-| Δδ |
And a switch for selecting one of the two.
When the signs determined in steps 604 and 604 do not match, the contact of the switch 606 is switched to the b side by the switching signal from the exclusive OR circuit 605, or when the signs match, the contact of the switch 606 is switched to the a side. To | Δδ |,-
| Δδ | is input to the function generator 607.

The function generator 607 outputs a coefficient c whose output decreases when the input is positive and increases when the input is negative. When the input is 0, that is, when the deviation Δδ between the posture angle and the target value is 0, the coefficient c = 1 is output. The maximum output value of the function generator 607 is not unlimited, but is limited to a predetermined value by a circuit configuration. Output of function generator 607 and bucket rotation speed Tv4 before correction
Is input to the multiplier 608, and the above-described coefficient c is multiplied by the bucket rotation speed Tv4 before correction, and a signal according to the following equation (7) is output from the multiplier 608.

OUT (608) = c · Tv4 (7)

Therefore, if the equation (7) is substituted for Tv4 in the above equation (6), the output of the bucket rotation speed correction circuit 600A according to the second embodiment is expressed as the following equation (8). be able to.

(Equation 8)

The posture angle control of the working machine according to the second embodiment will be described in more detail. The operation is the same as that of the first embodiment until the power switch (not shown) is turned on and the rotation speed Tv4 of the bucket before correction is calculated to keep the bucket attitude angle constant. The bucket rotation speed correction circuit 600A shown in FIG. 4 determines whether the rotation of the bucket has advanced or delayed with respect to the target value based on the input attitude angle deviation Δδ and the sign of the bucket rotation speed Tv4 before correction. Is determined by the exclusive OR circuit 605. When it is determined that the rotation of the bucket is later than the target value, the switch 606 selects-| Δδ | and multiplies the bucket rotation speed Tv4 before correction by a coefficient c greater than 1 to obtain the bucket rotation speed Tv4. When it is determined that the rotation is ahead of the target value, the switch 606 selects | Δδ | and multiplies the bucket rotation speed Tv4 before correction by a coefficient c smaller than 1 to obtain the above equation (7). Are output from the multiplier 608. In other words, in the case where the sign of Tv4 and the sign of Δδ coincide with each other as described above, the rotation of the bucket is delayed. Therefore, by setting the switch 606 to the a contact, the bucket rotation speed Tv4 before correction is increased. And the attitude angle deviation is reduced by increasing the feedforward amount. Tv4 and Δ
If the sign of δ does not match, the rotation of the bucket is progressing, and the feedforward amount is reduced in the direction to decrease the bucket rotation speed Tv4 before correction by setting the switch 606 to the b contact. Decrease the attitude angle deviation. Then, the addition value of the rotation speed Tv4d of the work attachment output from the function generator 650 as a feedback amount based on the attitude angle deviation Δδ and the output OUT (608) of the multiplier 608 is added from the addition point 651 to the limiting circuit 660. To enter. The limiting circuit 660 limits the output of the input added value, and corrects the bucket rotation speed Tv after correction.
4k is output as in the above equation (8).

FIG. 3B is a graph showing the relationship between the attitude angle deviation Δδ at the pre-correction bucket rotation speed Tv4> 0 and the post-correction bucket rotation speed Tv4k. A thin line L11 in the figure is a feedforward amount which is an output of the multiplier 608. That is, c · Tv4 output from the multiplier 608 based on the magnitude and sign of the attitude angle deviation Δδ. A bold line L12 indicates the corrected bucket rotation speed Tv4k according to the present embodiment. FIG. 3D shows a comparison between the waveform Ld indicating the corrected rotation speed Tv4k according to the first conventional technique and the waveform Le of FIG. 3E indicating the corrected rotation speed Tv4k according to the second conventional technique. The waveform L12 of the corrected rotation speed Tv4k shown in FIG.
It can be understood that a larger control amount can be obtained with respect to the change in the deviation Δδ since the inclination with respect to is large.

As described above, according to the second embodiment, the following operation and effect can be obtained in addition to the operation and effect of the first embodiment. (1) Since the rotation speed is corrected by changing the feedforward amount based on the posture angle deviation Δδ, the followability of the posture angle control when the posture angle deviation Δδ occurs is improved, and the posture angle accuracy is improved. Is improved.

Third Embodiment FIG. 5 is a diagram showing details of a bucket rotation speed correction circuit 600B according to a third embodiment. The difference from the second embodiment is that a dead zone adding circuit 670 is added. Therefore, the dead zone adding circuit 670 will be mainly described, and other description will be omitted. In FIG. 5, dead zone adding circuit 670 includes function generators 671 and 672 and switch 6
73 and an addition point 674. The negative function generator 671 determines that the value of the input attitude angle deviation Δδ is a predetermined value −
When it is less than or equal to p, a negative value Tv4a based on the magnitude of the input is output, and when the input deviation Δδ increases and approaches 0,
In a region where the input value Δδ is larger than the predetermined value −p, the output Tv
4a is restricted to 0. Similarly, the positive function generator 672:
When the input deviation Δδ is equal to or more than a predetermined value + p, a positive value Tv4a based on the magnitude of the input is output, and when the input deviation Δδ decreases and approaches 0, the input value Δδ increases to a predetermined value +
In an area smaller than p, the output Tv4a is limited to zero. Note that the maximum output values of the function generators 671 and 672 are not limited and are limited to predetermined values by the circuit configuration.

The switch 673 switches in the same manner as the switch 663 in the first embodiment. That is, when the sign of the bucket rotation speed Tv4 is positive, the contact of the switch 673 is switched to the a side, and when the sign is negative, the contact is switched to the b side.
The addition point 674 adds the signal output from the limiting circuit 660 and the signal selected by the switch 673.

Therefore, by adding a dead zone adding circuit 670 to the output of the bucket rotation speed correction circuit 600B according to the second embodiment, a bucket rotation speed correction circuit 600C according to the third embodiment is formed. The output of the circuit can be expressed as in the following equation (9).

(Equation 9)

The posture angle control of the working machine according to the third embodiment will be described in more detail. The operation from when the power switch (not shown) is turned on until the output from the limiting circuit 660 is obtained is the same as in the second embodiment. In the control circuit according to the second embodiment, as described above, Tv4 and Δv
If the sign of δ does not match, the bucket has been advanced, so the bucket rotation speed Tv4 before the correction
The attitude angle deviation is reduced by reducing the amount of feed forward so as to reduce the angle. On the other hand, in the control circuit 600B according to the present embodiment, in the case described above, the dead zone adding circuit 670 determines the rotation speed Tv4a based on the posture angle deviation Δδ in the opposite direction to the bucket rotation speed Tv4 before correction. Addition was made. Further, the vicinity where the sign of the corrected rotation speed Tv4k is inverted (−p <Δ
Since a dead zone is provided at δ <p) and the rotation speed Tv4a of the work attachment based on the posture angle deviation Δδ is added at the addition point 674, the corrected bucket rotation speed Tv is added.
4k is output as in the above equation (9).

FIG. 3C is a graph showing the relationship between the attitude angle deviation Δδ at the pre-correction bucket rotation speed Tv4> 0 and the post-correction bucket rotation speed Tv4k. A thin line L11 in the figure is a feedforward amount which is an output of the multiplier 608. That is, c · Tv4 output from the multiplier 608 based on the magnitude and sign of the attitude angle deviation Δδ. A bold line L22 indicates the bucket rotation speed Tv4k after correction according to the present embodiment. Compared with the waveform L12 in FIG. 3B showing the control amount according to the second embodiment, in the waveform L22 in FIG. 3C, the attitude angle deviation Δδ has a predetermined value −
It can be seen that when the rotation speed is smaller than p, a rotation speed Tv4k in a direction opposite to the rotation speed Tv4 before correction is output. Furthermore, comparing the waveform Ld of FIG. 3D and the waveform Le of FIG.
In the region where the sign of the control amount Tv4k is inverted,
It can be seen that a dead zone is obtained so that Tv4k does not change in a predetermined section.

As described above, according to the third embodiment, the following functions and effects can be obtained in addition to the functions and effects of the first and second embodiments. (1) When the rotation of the bucket advances with respect to the target value,
Since the control is performed based on the posture angle deviation Δδ in the opposite direction to the feedforward amount, the followability of the posture angle control is improved and the posture angle accuracy is improved. (2) In a region where the sign of the corrected rotational speed is inverted, the hunting can be prevented because the dead zone is provided when the posture angle deviation Δδ is within the predetermined value −p.

In the description of the third embodiment, speed correction means 601 to 608 for correcting the first rotation speed Tv4.
However, these need not be included.

The correspondence between each component in the claims and each component in the embodiment of the invention will be described. The angle detectors 101 to 104 and the addition points 201 to
203 is the attitude angle detecting means, the addition point 302 is the deviation calculation means, the bucket rotation speed Tv4 before correction is the first rotation speed, the arm rotation speed calculation circuit 400 and the addition points 501 and 502 are the first rotation speed. The rotation speed calculation means calculates the attitude angle deviation Δ
The rotation speed Tv4d of the work attachment based on δ is the second rotation speed, the function generator 650 is the second rotation speed calculating means, the addition point 651 is the first addition means, and the limiting circuit 660 is the limiting means. In addition, the work attachment rotation speed correction circuits 601 to 608 provide the speed correction means with the rotation speed Tv4a based on the posture angle deviation Δδ in the opposite direction to the bucket rotation speed Tv4 before the correction, as a third rotation speed, Generator 671
672 and the addition point 673 correspond to the third rotation speed calculation means, and the addition point 674 corresponds to the second addition means.

In applying the present invention, each component of the above embodiment may be configured as follows. B) The number of arms is not limited to three. B) The arm rotation speed calculation circuit 400 is a part of the trajectory control device, but may be another control device, for example, a manual control device. That is, the speed command value of the first to third arms 3 may be output by the manual operation lever. C) The arm rotation speed was used as the calculated value.
The outputs from 1 to 103 may be differentiated and used. D) The coefficient c for the deviation 0 of the function generator 607 is set to 1, but other values can be used. E) The coefficient c is obtained by the function generator 607, but may be obtained by calculation by a calculator or other means. F) The bucket is driven by the hydraulic cylinder, but the invention is not limited to the hydraulic pressure, and other actuators such as a hydraulic motor and a hydraulic rotary actuator can be used. G) Not only can it be applied to a rotary excavation bucket, but also can be used for various other work attachments. H) The angle of the first arm 1 may be detected as a relative angle with respect to the upper swing body, and the inclination angle of the work implement body may be detected to correct the relative angle. I) By replacing the arm with the revolving structure, the present invention can be applied to an application in which the direction of the work attachment is controlled according to the revolving angle of the revolving structure.

[0039]

According to the present invention as described in detail above, the following effects can be obtained. (1) In the invention of claim 1, the first of the work attachments is provided.
And the second rotation speed based on the attitude angle deviation of the work attachment, and the added rotation speed is the first rotation speed.
In the case where the rotation speed is opposite to the rotation speed, the added rotation speed is limited so as not to be output, so that the added rotation speed is not output in the direction of the first rotation speed or output in the opposite direction. As a result, there is an effect of preventing hunting near the attitude angle deviation where the sign of the control amount for the attitude angle control is inverted. (2) In the invention of claim 2, in addition to the configuration of claim 1,
When the posture angle of the work attachment is behind the target value, the first rotation speed is corrected to be larger based on the posture angle deviation, and to be smaller based on the posture angle deviation when the work attachment is advanced. As a result, the same effects as those of the first aspect can be obtained, and the attitude angle of the work attachment can be brought closer to the target value more quickly. (3) In the invention of claim 3, in addition to the constitution of claims 1 and 2, the attitude angle of the work attachment advances with respect to the target value, and when the attitude angle deviation exceeds a predetermined value, the first rotation speed and The third rotation speed based on the posture angle deviation in the opposite direction is calculated and added, and when the posture angle deviation is within a predetermined value, the third rotation speed is set to 0. In addition to the effect, when the attitude angle of the work attachment advances beyond a predetermined value, the attitude angle can be brought closer to the target value more quickly, and further, there is an effect of preventing hunting near the attitude angle deviation.

[Brief description of the drawings]

FIG. 1 is a view showing a posture angle control device of a work attachment according to a first embodiment.

FIG. 2 is a detailed diagram of a bucket rotation speed correction circuit 600 according to the first embodiment.

FIG. 3 is a graph showing a relationship between a posture angle deviation Δδ and a bucket rotation speed Tv4k after correction when the rotation speed of the bucket before correction Tv4> 0.

FIG. 4 is a detailed diagram of a bucket rotation speed correction circuit 600A according to a second embodiment.

FIG. 5 is a detailed diagram of a bucket rotation speed correction circuit 600B according to a third embodiment.

FIG. 6 is a diagram showing an example of a multi-joint foundation working machine.

FIG. 7 is a diagram showing definitions of a ground angle and a relative angle of each arm in the work machine.

[Description of References] 1-3: Arm, 4: Rotating excavation bucket, 5-8 hydraulic cylinder, 9: Electro-hydraulic conversion valve, 101-104: Angle detector, 201-203: Addition point, 301: Memory, 30
2: addition point, 400: arm rotation speed calculation circuit, 50
1, 502: addition point, 600, 600A, 600B: work attachment rotation speed correction circuit, 601: absolute value converter, 602: sign inverter, 603, 604: encoder,
605: exclusive OR circuit, 606: switch, 607 ...
Function generator, 608: Multiplier, 650: Function generator, 6
51 ... Addition point, 660 ... Limiting circuit, 661 ... Negative limiter circuit, 662 ... Positive limiter circuit, 663 ... Switcher, 67
0: dead zone adding circuit, 671, 672: function generator, 6
73 ... switch, 674 ... addition point, 701 ... function generator,
608: Multiplier, 701: Function generator, 702: Multiplier, 703: Coefficient unit

Claims (4)

[Claims] 1. A posture angle detecting means mounted on a driving body rotatably mounted on a base and detecting a posture angle of a work attachment whose posture angle is controlled by an actuator, wherein the posture angle is detected by the posture angle detecting means. Deviation calculation means for calculating a deviation between the attitude angle of the work attachment and a target value thereof based on the obtained value, and the work attachment necessary to maintain the attitude angle at the target value regardless of the rotation of the driving body. A first rotation speed calculating means for calculating and outputting the first rotation speed of the work attachment; a second rotation speed calculating means for calculating and outputting a second rotation speed of the work attachment based on the attitude angle deviation; An attitude angle control device for a work attachment having an adding means for adding the first and second rotation speeds, wherein the added rotation speed is equal to the first rotation speed. In the case of a direction, the added rotation speed is output, and in the case of a reverse direction, the added rotation speed is limited so as not to be output, and the actuator is driven by the output of the limitation device. Characteristic attitude control device for working machine. 2. A posture angle detecting means mounted on a driving body rotatably mounted on a base and detecting a posture angle of a work attachment whose posture angle is controlled by an actuator, wherein the posture angle is detected by the posture angle detecting means. Deviation calculation means for calculating a deviation between the attitude angle of the work attachment and a target value thereof based on the obtained value, and the work attachment necessary to maintain the attitude angle at the target value regardless of the rotation of the driving body. A first rotation speed calculating means for calculating and outputting the first rotation speed of the work attachment; a second rotation speed calculating means for calculating and outputting a second rotation speed of the work attachment based on the attitude angle deviation; An attitude angle control device for a work attachment having an adding means for adding the first and second rotational speeds, wherein the attitude angle of the work attachment is the target angle. The first rotation speed is made larger based on the attitude angle deviation when it is late with respect to, and when the attitude angle of the work attachment is ahead of the target value, it is based on the attitude angle deviation. Speed correction means for correcting the first rotation speed so as to make the first rotation speed smaller, and when the added rotation speed is in the same direction as the first rotation speed, the added rotation Limiting means for outputting a speed, and restricting the added rotational speed so as not to be output in the case of a reverse direction, wherein the actuator is driven by the output of the limiting means. Control device. 3. A posture angle detecting means mounted on a driving body rotatably mounted on a base and detecting a posture angle of a work attachment whose posture angle is controlled by an actuator, wherein the posture angle is detected by the posture angle detecting means. Deviation calculation means for calculating a deviation between the attitude angle of the work attachment and a target value thereof based on the obtained value, and the work attachment necessary to maintain the attitude angle at the target value regardless of the rotation of the driving body. A first rotation speed calculating means for calculating and outputting the first rotation speed of the work attachment; a second rotation speed calculating means for calculating and outputting a second rotation speed of the work attachment based on the attitude angle deviation; An attitude angle control device for a work attachment having first addition means for adding the obtained first and second rotation speeds, wherein the added rotation speed is the first rotation speed; In the case of the same direction as the degree, the added rotation speed is output, and in the case of the opposite direction, the added rotation speed is limited so as not to be output, and the attitude angle of the work attachment is set to the target value. When the vehicle is late, the rotation speed is set to 0. When the posture angle is advanced with respect to the target value and the posture angle deviation is within a predetermined value, the rotation speed is set to 0, and the posture angle is set to the target value. A third rotation speed calculation for calculating and outputting a third rotation speed in a direction opposite to the first rotation speed on the basis of the posture angle deviation when the posture angle deviation exceeds a predetermined value. And a second adding means for adding the output of the third rotating speed and the limiting means, and driving the actuator with the output of the second adding means. Angle control device. 4. The work machine attitude angle control device according to claim 3, wherein when the attitude angle of the work attachment is delayed with respect to the target value, the first rotation is performed based on the attitude angle deviation. The first rotation speed is increased so as to make the first rotation speed smaller based on the posture angle deviation when the posture angle of the work attachment is advanced with respect to the target value. A posture angle control device for a working machine, further comprising a speed correcting means for correcting.