JPH0762360B2 - Control method of operation part in earthworking machine - Google Patents

Description

TECHNICAL FIELD The present invention relates to an improvement in a method of controlling an operation unit in an earthmoving vehicle.

[Prior Art and its Problems] Conventionally, when operating an operation part of an earthmoving vehicle, for example, a turning part of a hydraulic excavator, an arm, a boom, and a bucket,
Operating each of these operating parts independently causes a great deal of operator fatigue and requires a high degree of skill.
A control method is known in which the actuators of these operating portions can be interlocked according to different movements of a single operating handle (for example, Japanese Utility Model Publication No. 58-25006 and Japanese Utility Model Publication No. 58-2804).
Four).

However, in the control method described above, the operation of each actuator is performed by a single operation handle, and the operation amount is given according to the individual movement amounts of different movements of the single operation handle, Since each operating unit is driven by a common hydraulic power source, during normal interlocking operation or sudden interlocking operation, a large amount of hydraulic oil is supplied to the actuator with a low load, and most of the actuator with a high load is hydraulic oil. Therefore, even if the amount of movement of the operation handle by the operator is the same, the operation amount of the actuator changes due to the change in the load of each operation unit, and the operation trajectory that the operator intended can be obtained. It has the drawback of not having it.

[Means for Solving Problems] The present invention has been made to eliminate the above-mentioned conventional drawbacks. Therefore, the control method according to the present invention includes a plurality of operating units driven by a common hydraulic power source. In the earthmoving machine having the above, the actuators of the respective operation sections are given priority, and the control deviation signal which is the deviation between the operation command signal and the feedback signal of each actuator is detected, and the control deviation signal of the actuator having the higher priority is set to a predetermined value. When it becomes larger, the control deviation signal of the actuator having a lower priority is limited so that the signal becomes smaller than the detected value, whereby each actuator operates according to the priority.

[Operation] In the fine operation, there is no particular problem because the hydraulic oil is sufficiently supplied to each actuator. However, in the normal operation and the abrupt operation, when the actuator with the higher priority does not follow the operation command signal and the control deviation signal exceeds the predetermined value, the actuator with the higher priority will be affected by the control deviation signal. The control deviation signal of the actuator with the lower priority is restricted so that the signal becomes smaller than the detected value, and the operation of the actuator with the lower priority is slowed down. The above-mentioned limitation is obtained, for example, by integrating the control deviation signal of the actuator with the low priority order with the limiting function output that takes a value between 0 and 1 when the control deviation signal of the actuator with the high priority order exceeds a predetermined value. be able to.
When the control deviation signal of the high-priority actuator falls below a predetermined value, the restriction on the low-priority actuator is released.

As a result, even if the load applied to each actuator changes, it is possible to operate so as to draw an operation trajectory that substantially matches the operation command of the operator in order from the actuator with the highest priority.

[Examples] Preferred examples of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows an embodiment in which the control method according to the present invention is applied to a control circuit of a hydraulic excavator, which is an actuator for a boom system, an arm system, a bucket system and a swing system of the hydraulic excavator. These actuators are preferentially operated in the order of the swing system, the arm system, the boom system, and the bucket system. However,
The control circuit of FIG. 1 is applied only when the operation command is positive.

In the figure, 1, 2, 3, and 4 are the boom system operation transmitter, the arm system operation transmitter, the bucket system operation transmitter, and the swing system operation transmitter, and 5, 6, 7, and 8 are the above. It is a comparison point between the operation command signal and the feedback signal of each operation transmitter,
Reference numerals 9, 10, 11, and 12 are boom system, arm system, bucket system, and swing system amplifiers, respectively. Reference numerals 13, 14, 15, and 16 are boom-type, arm-type, bucket-type, and swing-type electrohydraulic control valves, 17 is a boom cylinder, 18 is an arm cylinder, 19 is a bucket cylinder, and 20 is a swing motor.
21 is a boom cylinder displacement detector, 22 is an arm cylinder displacement detector, 23 is a bucket cylinder displacement detector, and 24 is a bucket cylinder displacement detector.
Is a rotation speed detector of the swing motor. Reference numeral 29 is a hydraulic circuit that connects the boom hydraulic electro-hydraulic control valve 13 and the boom cylinder 17. The same applies between the arm system electro-hydraulic control valve 14 and the arm cylinder 18, between the bucket system electro-hydraulic control valve 15 and the bucket cylinder 19, and between the swing system electro-hydraulic control valve 16 and the swing motor 20. It is connected by a hydraulic circuit. 30
Is a pump, 31 is a tank, 32 is an oil supply line from the pump 30 to each electrohydraulic control valve 13, 14, 15, 16 and 33 is a return line from each electrohydraulic control valve to the tank 31. Reference numeral 50 is a boom system operation unit, and the boom system control deviation signal Δα,
The control deviation signal Δβ of the arm system and the rotation speed deviation signal Δ of the turning system are input. Reference numeral 51 is an arm system operation unit, and the arm system control deviation signal Δβ is input to the rotation speed deviation signal Δ of the swing system. Reference numeral 52 denotes a bucket system computing unit, which inputs a bucket system control deviation signal Δγ, a boom system control deviation signal Δα, an arm system control deviation signal Δβ, and a swing system rotation speed deviation signal Δ. To be done.

In addition, 25 is an output signal of the comparison point 5, 26 is an output signal of the comparison point 6, and 27 is an output signal of the comparison point 8. 28 is a displacement detector 21
From the other displacement detector to the comparison point, there is a feedback signal from the other displacement detector to the comparison point in the same manner. In the figure, arrows indicate signal flows, and hatch arrows indicate hydraulic circuits.

As can be seen from the figure, the boom system, the arm system, and the bucket system are feedback circuits, but the swing system is an open circuit, and the feedback signal of the swing system is used only for control of other systems. Is.

2, FIG. 3, and FIG. 4 are arithmetic units 50, 51, 52, respectively.
Is specifically shown. As described above, the control deviation signal Δα of the boom system, the control deviation signal Δβ of the arm system, and the rotation speed deviation signal Δ of the turning system are input to the calculation unit 50, and the output signal of the limiting function 50-1 by Δβ is input. Δα is integrated by the integrator 50-3, and the limiting function 50-2 by Δ
Output signal and Δα are integrated by the integrator 50-4, and the minimum value of the integrated values from the integrators 50-3 and 50-4 and the above Δα is selected by the minimum value selector 50-5. It is designed to output the value. Further, as described above, the control deviation signal Δβ of the arm system and the rotation speed deviation signal Δ of the turning system are input to the calculation unit 51, and the output signal of the limiting function 51-1 by Δ and Δβ are added to the integrator 51-2. The minimum value of the integrated value from the integrator and the Δβ is selected by the minimum value selector 51-3 and the value is output. Further, as described above, the control deviation signal Δ of the bucket system is sent to the calculation unit 52.
γ, the rotational speed deviation signal Δ of the swing system, the control deviation signal Δβ of the arm system, and the control deviation signal Δα of the boom system are input, and the output signal of the limiting function 52-1 by Δ and Δγ are integrators. 52-4 is integrated and the limiting function by Δβ 52-2
Output signal and Δγ are integrated by the integrator 52-5, and the output signal of the limiting function 52-3 by Δα and Δγ are integrated by the integrator 52-6.
The minimum value of the integrated values from the integrators 52-4, 52-5, 52-6 and the above Δγ is selected by the minimum value selector 52-7 and the value is output. There is. The limiting functions 50-1 and 52-2 are the same function, and 50-
2, 51-1 and 52-1 have the same function. Each limiting function has a control deviation signal or a rotation speed deviation signal on the horizontal axis and an output on the vertical axis. The maximum output is 1, and 0 when the deviation signal exceeds a predetermined value P, Q, R. It takes a value between 1. The values of P, Q, and R have a relationship of P <Q <R so that actuators with higher priorities can be given priority to limit the output of other actuators. The values of the break points P, Q, R (P <Q <R) of each of these limiting functions are
The optimum value can be determined based on the actual feeling of the actual machine or based on simulation calculation or the like.

Next, the operation of the control device for the hydraulic excavator having the above configuration will be described.

(1) During fine operation; When finely operating each actuator, boom, arm,
Both the displacement of the bucket and the rotation speed of the swivel unit sufficiently follow the operation command from the operator, and the deviation signal of each operation unit is sufficiently small, so that there is no restriction to actuators of low priority.

(2) When the arm and the swing unit are interlocked: In this case, the priority is given to the swing unit and the arm.

When the load on the swivel unit is small, the swivel motor quickly follows the operation command from the operator, and therefore the rotation speed deviation signal Δ
Is below the break point P (FIG. 3) and the arm system is not restricted by the swing system.

However, when the load of the swing system is large, the swing motor 20 does not quickly follow the operation command of the operator, so that the rotation speed deviation signal Δ becomes larger than the point P and the limiting function 51-1
Output is less than or equal to 1. The control deviation signal Δβ of the arm system and the output of the limiting function are integrated by the integrator 51-2,
The minimum value selector 51-3 selects the integrated signal Δβ × (limit function output). For example, when Δβ> 0 and the output of the limiting function 51-1 is 0.5, since Δβ> Δβ × 0.5, Δβ × 0.5 is selected as the operation command signal to the electrohydraulic control valve 14 of the arm system, and The operation amount of the hydraulic control valve 14 becomes 1/2 of the command value, and the speed of the arm cylinder 18 is limited to 1/2. In this way, when the swing motor with the higher priority does not follow the operation command signal, by limiting the operation of the arm cylinder with the lower priority, the operation of the swing motor with the higher priority is made closer to the operation command. be able to.

(3) When the boom, arm, and bucket are interlocked; the order of priority is arm, boom, and bucket.

As in the case of (2) above, when the load is small, each actuator quickly follows the operation command from the operator, and since each deviation signal is sufficiently small, the operation of the actuator of high priority is restricted to the actuator of low priority. Does not occur.

However, when the load on the arm system is large, the arm cylinder 18
Does not quickly follow the operation command signal, and therefore the control deviation signal Δβ of the arm system becomes larger than the point Q (Figs. 2 and 4), and the outputs of the limiting functions 50-1 and 52-2 are 1 or less. Becomes Therefore, the integrated value of the boom system control deviation signal Δα and the output of the limiting function 50-1 is created by the integrator 50-3, and the minimum value selector 50-5 outputs Δα × (limiting function 50-1 output). Signal is selected, and its output becomes an operation command signal to the electrohydraulic control valve 13 of the boom system. Similarly, for the bucket system, the bucket system control deviation signal Δγ and the limiting function 52−
The integrated value with the output of 2 is created by the integrator 52-5, and the integrated value Δγ × (output of the limiting function 52-2) is selected by the minimum value selector 52-7, and the output is the electric power of the bucket system. It serves as an operation command signal to the hydraulic control valve 15.

If the load on the boom system is large and Δα >> Δβ≈Q and the output of the limit function (52-2)> the limit function (52-3), then the output of the limit function 52-3 is integrated with Δγ. The value is selected by the minimum selector 52-7. That is, in this case, since the arm system having the highest priority almost follows the operation command signal, it is limited by the boom system having the second highest priority and the largest deviation.

In this way, when an actuator with a higher priority does not follow the operation command signal, the operation of the actuator with a lower priority is restricted so that the hydraulic oil flows to the actuator with a higher priority, so the load fluctuation Even if it occurs, each actuator can perform an operation substantially according to the operation command in the order of high priority.

Although the above description has particularly described the interlocking operation between the arm and the swivel part and the interlocking operation between the boom, the arm, and the bucket, the present invention relates to interlocking operations other than the above, for example, the interlocking operation between the boom, the arm, and the swivel part. Obviously, it is also applicable to. Further, although the above description has been made in connection with the hydraulic excavator, the present invention can be applied to earthmoving machines other than the hydraulic excavator.

[Effect] As described above, according to the present invention, the actuators of the respective operation parts of the earthworking machine are provided with the priority order, the control deviation signals of the respective actuators are detected, and the control deviation signal of the actuator having the higher priority order is higher than the predetermined value. When it becomes larger, the control deviation signal of the actuator with a lower priority is limited so that it becomes smaller than the signal detection value so that each actuator can operate according to the priority. Even when a load change occurs, the actuator can obtain an operation trajectory substantially according to the operation command according to the priority order.

[Brief description of drawings]

FIG. 1 is a control circuit diagram for explaining one application example of the present invention, and FIGS. 2, 3, and 4 are detailed diagrams of an arithmetic unit incorporated in the control circuit of FIG. 1, respectively. 1,2,3,4 …… Operating transmitter 5,6,7,8 …… Comparison point 9,10,11,12 …… Amplifier 13,14,15,16 …… Electro-hydraulic control valve 17,18 , 19 …… hydraulic cylinder 20 …… hydraulic motor, 21,22,23 …… displacement detector 24 …… rotation speed detector, 30 …… hydraulic pump 50,51,52 …… calculator 50-1,50− 2,51-1,52-1 to 52-3 ... Limiting function 50-3,50-4,51-2,52-4 to 52-6 ... Integrator 50-5,50-3,50- 7 ... Minimum value selector Δα, Δβ, Δγ ... Control deviation signal Δ ... Rotation speed deviation signal

Claims (5)

[Claims] 1. In an earthworking machine having a plurality of operating sections driven by a common hydraulic power source, the actuators of the respective operating sections are given priority, and the control is the deviation between the operation command signal and the feedback signal of each actuator. When the deviation signal is detected and the control deviation signal of the actuator with the higher priority becomes larger than the predetermined value, the control deviation signal of the actuator with the lower priority is restricted so that the signal becomes smaller than the detected value. A method for controlling an operation unit in an earthworking machine, wherein each actuator operates according to a priority order. 2. The control method according to claim 1, wherein the earthworking machine is a hydraulic excavator. 3. A bucket, an arm of a hydraulic excavator in which each of the operation parts bends and extends according to different movements of an operation handle,
The control method according to the second aspect, which is a swing unit that performs a boom and a swing. 4. The limit is a product of a control function signal having a low priority and a limit function output which takes a value between 0 and 1 when the control deviation signal of an actuator having a high priority exceeds a predetermined value. The control method of the 1st description given. 5. The priority order is a revolving part, an arm, a boom,
The control method according to the third aspect, which is in the order of buckets.