JPS6234888B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for controlling the trajectory of a working tool of an arm-type working machine such as a loading hydraulic shovel or a backhoe hydraulic shovel.

When excavating horizontal surfaces or slopes with a loading hydraulic excavator or backhoe hydraulic excavator, the two work arms, the boom and the arm, must be operated simultaneously and delicately so that the work implement follows a predetermined trajectory. It requires advanced technology and a lot of effort. In order to solve this problem, it is only necessary to make the work tool automatically draw a predetermined trajectory by simply operating either the boom or the arm. Methods for this include a link method, Hydraulic methods, electrical methods, etc. have been proposed, but the electrical method has the advantages of being easy to switch from ordinary arc-shaped excavation and having more freedom in selecting the trajectory. have

FIG. 1 is a diagram showing the front part of a loading hydraulic excavator. In the figure, 1 is the main body of a hydraulic excavator, 2 is a boom that is pivotally connected to the main body 1, 3 is an arm that is pivotally connected to the tip of the boom 2, 4 is a bucket that is a working tool that is pivotally attached to the tip of the arm 3, and 5 is a is a boom cylinder that raises and raises the boom 2; 6 is an arm cylinder that swings the arm 3; 7 is a bucket cylinder that rotates the bucket 4; 8 detects the angle of the boom 2 with respect to the main body 1, that is, the boom angle; Angle meter that outputs angle signal α, 9 is boom 2
This is an angle meter that detects the angle of the arm 3 with respect to the arm angle, that is, the arm angle, and outputs an arm angle signal β.

FIG. 2 is a diagram showing an apparatus for implementing a conventional work tool trajectory control method. 10,1 in the figure
1 is a hydraulic pump; 12 is a manually operated valve provided between the hydraulic pump 10 and the boom cylinder 5; 13
14 is a boom operation lever for operating the manual operation valve 12, and 14 is a hydraulic pump 11 and a boom cylinder 5.
15 is a height calculator that calculates the height of bucket 4, that is, the height H of point P in FIG. 18 is a storage device 16 for storing the output signal h of the height calculator 15.
An adder/subtractor 19 calculates the difference between the output signal of the adder/subtractor 18, that is, the target height signal h _p , and the output signal of the height calculator 15, that is, the actual height signal h. Coefficient multiplier, 20 is multiplied by the coefficient 19 when switch 21 is on
The solenoid control valve 1 is used to amplify and compensate the output signal kΔh of
4, and switches 17, 21
is turned on when the boom operating lever 13 is placed in the neutral position.

In this device, when the boom operating lever 13 is in the operating position, the switches 17 and 21 are off, the boom cylinder 5 operates at a speed corresponding to the operating amount of the boom operating lever 13, and the boom 2
The angular velocity also has a value according to the amount of operation of the boom operation lever 13. When the boom operating lever 13 is returned to the neutral position and the arm 3 is activated, the switches 17 and 21 are turned on, and the output signal h of the height calculator 15 at that time is stored in the storage device 16 and sent from the adder/subtracter 18. The height deviation signal Δh is output, the coefficient unit 19 outputs the signal kΔh, the amplifier 20 switches the electromagnetic control valve 14 by an amount corresponding to the signal kΔh, and the boom cylinder 5 operates at a speed corresponding to the signal kΔh. Therefore, the angular velocity of the boom 2 has a value corresponding to the signal kΔh. Therefore, by simply operating the arm 3 without operating the boom operating lever 13, the height H at point P in FIG.
can be maintained at a value corresponding to the target height signal h _p . In this state, when the boom operation lever 13 is set to the operating position, the switches 17 and 21 are turned off, and the boom 2 rotates at an angular velocity according to the amount of operation of the operation lever 13.

That is, in the conventional work tool trajectory control method, when only the arm 3 is manually controlled, the actual height H of the bucket 4 is determined based on the target height signal h _p when the bucket 4 draws a predetermined trajectory, and the actual height H of the bucket 4. The difference from the height signal h, that is, the height deviation signal Δh, is obtained, and the boom 2 is raised and raised at a speed corresponding to the signal kΔh, which is obtained by multiplying the height deviation signal Δh by a gain, and the follow-up control is performed using position feedback. Therefore, in order to raise and lower the boom 2 at a certain speed, it is necessary that the height deviation signal Δh is always not zero. Normally, the height deviation signal Δh can be kept small by increasing the gain k of the control system, but in a system with a large delay such as a hydraulic excavator, increasing the gain k will cause hunting. The gain k must be made small, and in this case the height deviation signal Δh becomes considerably large, making it impossible to perform accurate trajectory control.

In addition, in the conventional employee tool trajectory control method,
If arm 3 is manually operated and boom 2 is automatically controlled, if you start manual operation of boom 2,
The boom 2 is raised and raised at an angular velocity according to the amount of operation of the boom operation lever 13. Therefore, when the boom 2, which was being raised and raised at a predetermined angular velocity during automatic control, operates the boom operation lever 13,
Since it starts to move up and down at an angular velocity that has nothing to do with the previous angular velocity, a smooth operation feeling cannot be obtained. For example, in order to keep the height H of the bucket 4 constant during automatic control, when the boom 2 is moving downward in the clockwise direction in Figure 1 at an angular velocity = α ₁ , if the operator holds the height H When the boom operating lever 13 is operated so that the boom 2 moves upward in order to correct the problem, if the angular velocity 〓α ₂ of the boom 2 commanded by the boom operating lever 13 is smaller than the angular velocity 〓 α ₁ , the height H does not become smaller but instead becomes larger, which is dangerous and contrary to the operator's intention.
In order to solve this problem, when the boom operating lever 13 is operated during automatic control, the output signal of the boom operating lever 13 is changed to the target height signal h.
This can be done by adding it to _p , but in this case there are problems such as cost and responsiveness, and it is currently difficult to implement.

This invention was made to solve the above-mentioned problems, and the trajectory of the work tool can be controlled with high accuracy.
Another object of the present invention is to provide a method for controlling the trajectory of a working tool for an arm-type working machine, which allows smooth adjustment of the position of the working tool during automatic control.

In order to achieve this object, the present invention includes a first working arm that is pivotally connected to the work machine body and is moved up and down by a first hydraulic cylinder, and a first working arm that is pivotally connected to the tip of the first working arm and is swung by a second hydraulic cylinder. In the work tool trajectory control device for an arm-type work machine, which includes a second work arm that is moved and a work tool attached to the tip of the second work arm, the angle of the first work arm and the second work arm are controlled. The angle of the arm is detected, and one of the first working arm and the second working arm is operated when the working tool draws a predetermined trajectory based on the angle of the first working arm and the angle of the second working arm. Find the angular velocity ratio between the angular velocity of the arm and the angular velocity of the other working arm, detect the angular velocity of the other working arm, multiply the angular velocity ratio by the angular velocity of the other working arm, and calculate the angular velocity of the one working arm. A control speed signal corresponding to the angular velocity to be moved is determined, and the control speed signal is determined according to the difference between the target position of the work implement and the actual position determined from the detected values of the angle of the first work arm and the angle of the second work arm. When operating the other working arm, the one working arm is operated at an angular velocity according to the signal obtained by adding the control speed signal and the positional correction signal, and the other working arm is When the one working arm is manually operated during the operation, the one working arm is operated at an angular velocity according to a signal obtained by adding the control speed signal and the manual operation signal of the one working arm, and the other working arm is When operating the working arm, the one working arm is operated at an angular velocity according to the signal obtained by adding the control speed signal and the position correction signal, and when the other working arm is operated, the one working arm is manually operated. When operated,
The one working arm is operated at an angular velocity according to a signal obtained by adding the control speed signal and the manual operation signal for the one working arm.

FIG. 3 is a diagram showing an apparatus for carrying out the method for controlling the trajectory of an arm-type working machine according to the present invention. In the figure, 22 is a speed ratio calculator that calculates the ratio of the angular velocities of the boom 2 and arm 3 when the bucket 4 draws a predetermined trajectory, here a horizontal trajectory, from the boom angle signal α and the arm angle signal β, and 23 is the arm angle signal β 24 is a speed ratio calculator 2
A multiplier that calculates the product of the output signal 〓α/〓β of 2 and the output signal 〓β of the differentiator 23. 25 is the output signal of the multiplier 24, that is, the angular velocity that the boom 2 should take when the bucket 4 draws a horizontal trajectory. Control speed signal according to 〓α
An adder that calculates the sum of _r and the output signal kΔh of the coefficient unit 19; 26, a manual operating device that outputs a signal according to the amount of operation of the boom operating lever 13; 27, the output signal of the adder 25 and the manual operating device 26; 28 is a switch provided between the adder 25 and the adder 27, 29 is an arm operating lever, and 30 and 31 detect the operating state of the operating levers 29 and 13, respectively. A lever operation detector 32 outputs a control signal A when the arm operating lever 29 is in the operating position, and outputs a control signal B when the arm operating lever 29 is in the operating position and the boom operating lever 13 is not in the operating position. When the command device outputs the control signal A, the switch 28
is turned on, and when control signal B is output, switches 17 and 21 are turned on.

In this device, when only the boom operation lever 13 is operated, the control signals A and B are not output from the control command device 32, so the switches 17, 21, and 28 are off, and the solenoid control valve 14 is turned off.
is switched by an amount corresponding to the amount of operation of the boom operation lever 13, and the angular velocity of the boom 2 has a value corresponding to the amount of operation of the boom operation lever 13. Also, by operating the arm operating lever 29, the boom operating lever 13
If the switches 17 and 2 are not operated, the control signals A and B are output from the control command device 32.
1,28 is turned on. Therefore, the boom 2 is rotated at an angular velocity according to the output signal 〓α _r +kΔh of the adder 25. That is, since the boom 2 is raised and raised at an angular velocity according to the control speed signal α _r , the height H of the bucket 4 is constant. When the height H fluctuates from the height H at the start of operation of the arm operation lever 29 due to the influence of disturbance, the height H is corrected at a speed according to the signal kΔh proportional to the amount of fluctuation, and the height H is increased. The value H is kept constant. next,
If the boom operation lever 13 is also operated in this state, only the control signal A is output from the control command device 32, so the switches 17 and 21 are turned off.
Therefore, since the boom 2 moves up and down at an angular velocity according to the signal obtained by adding the output signal of the manual operation device 26 to the control speed signal α _r , the height H of the bucket 4 corresponds to the operation amount of the boom operation lever 13. can be corrected at the same speed. Next, when the boom operating lever 13 is returned to the neutral position in this state, the control signal B is output from the control command device 32, and the switch 1
7 and 21 are turned on, a target height signal h _p having a value corresponding to the height H at that time is stored in the storage device 16, and the bucket 4 maintains the height H from then on.

FIG. 4 is a diagram showing a part of another device for carrying out the method for controlling the trajectory of a work tool for an arm-type work machine according to the present invention. In the figure, 33 is a storage device that calculates the height H of the bucket belt 4 when the switch 17 is turned on from the boom angle signal α and the arm angle signal β, and calculates the initial position from the height H and the trajectory that the bucket belt 4 should follow. , 34 is a target boom angle calculator for calculating the target boom angle signal α _r from the arm angle signal β and the initial position signal of the storage device 33, and 35 is a target boom angle signal α of the target boom angle calculator 34.
An adder/subtractor 36 calculates the difference between _r and the boom angle signal α corresponding to the actual boom angle; 36 is an adder/subtractor 35
The coefficient unit 36 is a coefficient unit that multiplies the output signal of , that is, the boom angle deviation signal Δα, by a coefficient, and the coefficient unit 36 outputs a signal kΔα.

While the device shown in FIG. 3 calculates the height deviation signal Δh as a position correction signal from the target height signal h _p and the actual height signal h, the device shown in FIG. A boom angle deviation signal Δα is generated from the signal α _r and the boom angle signal α as a position correction signal.
seek.

FIG. 5 is a diagram showing a part of another device for carrying out the work tool trajectory control method according to the present invention.
In the figure, 37 stores the boom angle deviation signal Δα when the switch 17 is turned on. A storage device 38 calculates a target boom angle to obtain a target boom angle signal α _r from the arm angle signal β and the output signal of the storage device 37. It is a vessel.

In this device, the function for determining the target boom angle signal α _r is changed based on the boom angle deviation signal Δα when the switch 17 is turned on, and the arm angle signal β is substituted into this changed function to generate the target boom. Find the angle signal α _r . That is, when the switch 17 is turned on, the function for determining the target boom angle signal α _r corresponds to the boom angle deviation signal Δα at that time. Then, after calculating the target boom angle signal α _r based on the function and performing automatic control, when the switch 17 is turned off and the boom 2 is operated, the target boom angle signal α _r calculated using the above function and the boom angle signal α , that is, the boom angle deviation signal Δα has a value corresponding to the displacement amount when the switch 17 is turned off and the boom 2 is operated. Therefore, when the switch 17 is turned on again, the function for determining the target boom angle signal α _r is changed in accordance with the boom angle deviation signal Δα at that time, and the target boom angle signal α _r is determined by the function. In this way, the apparatus becomes simpler than the apparatus shown in FIG.

That is, in the work tool trajectory control method according to the present invention, in order to manually operate the arm 3 and automatically operate the boom 2 to draw a predetermined trajectory on the bucket 4, the boom angle signal α and the arm angle signal β are used. From the arm angular velocity signal 〓β, a control speed signal 〓α _r corresponding to the boom angular velocity when the bucket 4 draws the above-mentioned predetermined trajectory is determined, and the boom 2 is raised and raised at an angular velocity according to this control speed signal 〓α _r . to perform open-loop control. Moreover, the open loop control of the present invention has faster response than the conventional position feedback control method that controls the angular velocity of the boom 2 using a position correction signal such as a height deviation signal Δh, and also reduces hunting. changes in system parameters, such as the weight of the load, without causing
If the influence of disturbances such as when the bucket cart 4 hits something is small, the trajectory of the bucket cart 4 can be controlled with high precision. In the work tool trajectory control method according to the present invention, the height deviation signal Δ
h. Since control is also performed using position correction signals such as the boom angle deviation signal Δα, the control is a combination of open loop control and position feedback control, and even if the system parameters change or the influence of disturbance is large, Since the resulting positional change can be corrected by position feedback control, the locus of the bucket cart 4 can be controlled with great precision.

Further, in the work implement trajectory control method according to the present invention, when the arm 3 is manually operated and the boom 2 is automatically operated, when the boom operation lever 13 is set to the operation position, the boom manual operation is sent instead of the position correction signal. Since the operation signal is added to the control speed signal 〓 α _r ,
Since the position of the bucket can be changed at a speed corresponding to the manual operation signal of the boom 2, the position of the bucket can be smoothly corrected during automatic control.

In addition, in the above-mentioned Example, although the working implement locus control method of a hydraulic excavator was demonstrated, it is not limited to a hydraulic excavator. Further, in the above-described embodiment, the bucket locus control method for a loading hydraulic shovel has been described, but the method is exactly the same for a backhoe hydraulic shovel. Furthermore, in the above-mentioned embodiment, the case where the boom 2 is automatically controlled is explained, but the boom 2 is manually controlled and the arm 3 is
may be automatically controlled. Further, in the above embodiment, the boom angle signal α and the arm angle signal β are directly detected by the angle meters 8 and 9, but the angle signals α and β are detected by detecting the amount of extension of the cylinders 5 and 6, etc. may be determined indirectly. Further, in the above embodiment, the angular velocity signal 〓β was indirectly obtained by differentiating the angular signal β, but the angular velocity signals 〓α, 〓β may be directly obtained, and Values corresponding to the angular velocity signals 〓α, 〓β, such as the speed or the flow rate of the pipes connected to the cylinders 5 and 6, may be used. In the above-described embodiment, the operating state of the arm operating lever 29 is detected by the lever operating detector 30, but when the boom 2 and arm 3 are operated by another automatic control signal, the operating state of the operating lever 29 is detected by that automatic control signal. . Further, the arithmetic unit may be configured with an analog circuit or a digital circuit such as a microcomputer. In addition, the manual operation method is as shown in FIG. 2, by providing a manual operation valve 12,
The flow rate controlled by the electromagnetic control valve 14 may be combined with the flow rate by the manually operated valve 12. moreover,
The electromagnetic control valve 14 may be a combination of an electro-hydraulic conversion valve and a pilot-operated flow valve, and the manual operation signal may be taken out as pilot pressure and added to the pilot pressure from the electro-hydraulic conversion valve. Further, by controlling a valve such as the electromagnetic control valve 14, the cylinder 5,
Instead of controlling the cylinders 5 and 6, the cylinders 5 and 6 may be controlled by controlling the discharge amount of a pump that is a fluid pressure source. Furthermore, in the above embodiment, the control speed signal α _r was obtained from the angles α and β of the boom 2 and the arm 3 and the angular velocity β of the arm 3, but the angular velocity of the arm 3
From only or angle α of boom 2 and arm 3
The control speed signal 〓α may be obtained from the angular velocity 〓β.

As explained above, in the work implement trajectory control method for an arm-type work machine according to the present invention, the work implement trajectory can be controlled with high accuracy, and the position of the work implement can be smoothly corrected during automatic control. I can do it. As described above, the effects of this invention are remarkable.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the front part of a loading hydraulic excavator, FIG. 2 is a diagram showing a device for carrying out a conventional work implement trajectory control method, and FIG. 3 is a diagram showing a work implement of an arm type work machine according to the present invention. 4 and 5 are diagrams showing a device for implementing the trajectory control method, and FIGS. 4 and 5 are views showing a part of other devices for implementing the work tool trajectory control method for an arm-type work machine according to the present invention, respectively. It is. 1...Hydraulic excavator body, 2...Boom, 3...
... Arm, 4 ... Bucket, 5 ... Boom cylinder, 6 ... Arm cylinder, 7 ... Bucket cylinder, 8, 9 ... Angle meter, 12 ... Manually operated valve,
13...Boom operation lever, 14...Solenoid control valve, 15...Height calculator, 16...Storage device, 1
7... switch, 18... adder/subtractor, 21... switch, 22... speed ratio calculator, 23... differentiator, 24... multiplier, 25... adder, 26...
Manual operating device, 27... Adder, 28... Switch, 29... Arm operating lever, 30, 31...
Lever operation detector, 32... Control command device, 33
...Storage device, 34...Target boom angle calculator,
35...addition/subtractor, 37...storage device, 38...
Target boom angle calculator.

Claims (1)

[Scope of Claims] 1. A first working arm which is pivotally connected to the working machine body and is moved up and down by a first hydraulic cylinder, and a first working arm which is pivotally connected to the tip of the first working arm and is swung by a second hydraulic cylinder. In the method for controlling the trajectory of an arm-type working machine having two working arms and a working tool attached to the tip of the second working arm, the angle of the first working arm and the angle of the second working arm are controlled. Detecting the angular velocity of one of the first working arm and the second working arm when the working tool draws a predetermined trajectory based on the angle of the first working arm and the angle of the second working arm. Find the angular velocity ratio with the angular velocity of the other working arm, detect the angular velocity of the other working arm, multiply the angular velocity ratio by the angular velocity of the other working arm, and calculate the angular velocity at which the one working arm should move. and a position correction signal corresponding to the difference between the target position of the working implement and the actual position determined from the detected values of the angle of the first working arm and the angle of the second working arm. seek,
Work tool trajectory control for an arm-type work machine, characterized in that when operating the other working arm, the one working arm is operated at an angular velocity according to a signal obtained by adding the control speed signal and the position correction signal. Method. 2. The target position of the working tool is determined from the position of the working tool at the time when the operation of the other working arm is started or when the operation of the one working arm is finished. A method for controlling the trajectory of an arm-type work implement. 3. A first working arm that is pivotally connected to the work equipment body and is moved up and down by a first hydraulic cylinder; a second working arm that is pivotally connected to the tip of the first working arm and is swung by a second hydraulic cylinder; In the method for controlling the trajectory of an arm-type working machine equipped with a working tool attached to the tip of a second working arm, an angle of the first working arm and an angle of the second working arm are detected; Angular velocity of one of the first working arm and second working arm and the angular velocity of the other working arm when the working tool draws a predetermined trajectory from the angle of the working arm and the angle of the second working arm. , the angular velocity of the other working arm is detected, and the angular velocity ratio is multiplied by the angular velocity of the other working arm to generate a control speed signal corresponding to the angular velocity at which the one working arm should move. When the one working arm is manually operated when the other working arm is operated, the one working arm is operated at an angular velocity corresponding to the sum of the control speed signal and the manual operation signal of the one working arm. A work tool trajectory control method for an arm-type work machine, characterized in that the method operates as follows. 4. A first working arm that is pivotally connected to the work equipment body and is moved up and down by a first hydraulic cylinder; a second working arm that is pivotally connected to the tip of the first working arm and is swung by a second hydraulic cylinder; In the method for controlling the trajectory of an arm-type working machine equipped with a working tool attached to the tip of a second working arm, an angle of the first working arm and an angle of the second working arm are detected; Angular velocity of one of the first working arm and second working arm and the angular velocity of the other working arm when the working tool draws a predetermined trajectory from the angle of the working arm and the angle of the second working arm. , the angular velocity of the other working arm is detected, and the angular velocity ratio is multiplied by the angular velocity of the other working arm to generate a control speed signal corresponding to the angular velocity at which the one working arm should move. and determining a position correction signal corresponding to the difference between the target position of the working tool and the actual position determined from the detected values of the angle of the first working arm and the angle of the second working arm,
When the other working arm is operated, the one working arm is operated at an angular velocity according to the signal obtained by adding the control speed signal and the position correction signal, and when the other working arm is operated, the one working arm is operated. When manually operated, the one working arm is operated at an angular velocity according to a signal obtained by adding the control speed signal and the manual operation signal of the one working arm. Trajectory control method.