JPH0535442B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an operation control device for a working machine in a construction vehicle such as a hydraulic excavator, which can be efficiently controlled either automatically or manually.

(Prior art) Conventionally, as a means of automating working equipment of construction vehicles such as hydraulic excavators, the current position of the working equipment is detected, and the flow rate is controlled according to the deviation between the detected value and a preset setting value. A device that outputs a signal and controls the position of a working machine by operating a hydraulic control valve based on the flow rate control signal (for example, Japanese Patent Application Laid-Open No. 54-45469)
It has been known.

(Problem to be Solved by the Invention) However, the conventional control device described above has a manual switching valve that is switched by an operating lever and a hydraulic control valve (proportional control valve) exclusively for automatic control in the main pipe line of the hydraulic circuit. At the same time, a switching valve is installed to switch the main pipeline between manual and automatic operation. During manual operation, the manual switching valve is operated directly by a control lever, and during automatic control, the manual switching valve is operated directly by a flow control signal sent from the control circuit. The hydraulic control valve controls the hydraulic control valve, and the flow rate controlled by the hydraulic control valve is supplied to the cylinder via a manual switching valve, thereby controlling the position of the working machine. Therefore, the hydraulic circuit requires two large-capacity valves, a manual switching valve and a hydraulic control valve, as main control valves, and a manual-automatic switching valve, resulting in a complicated circuit configuration and increased costs. In addition, during automatic control, the manual switching valve is located downstream of the hydraulic control valve and only functions as a passage, which is extremely uneconomical and causes problems such as pressure loss, reducing control accuracy. . Moreover, during manual operation, the manual switching valve is simply switched directly by lever operation, so control can only be performed using a fixed control pattern that follows the spool characteristics of the manual switching valve, resulting in poor operability and poor work performance. There were problems such as it was difficult to perform delicate control according to the requirements, and the machine lacked versatility.

The present invention has been made in order to solve the above-mentioned conventional problems, and it enables one flow control valve provided as a main control valve in a hydraulic circuit to be operated either manually or automatically, and improves the hydraulic circuit configuration. Simplify and reduce costs, and
Control characteristics can be set arbitrarily in either automatic or manual mode, enabling high-precision control with control characteristics without dead zones during automatic control, and control with arbitrary control characteristics including dead zones during manual operation. The present invention provides a work machine operation control device for a construction vehicle that can improve manual operability and improve the versatility of the machine.

(Means for Solving the Problems) The present invention provides a hydraulic actuator for operating a working machine, a flow control valve that controls the supply of pressure oil to the hydraulic actuator and does not have a dead zone near neutral, and a flow control valve for controlling the supply of pressure oil to the hydraulic actuator. an automatic control circuit and a manual operation circuit that output electrical control signals for the automatic control circuit and a manual operation circuit; a switching means that selects and outputs a signal from the automatic control circuit and a signal from the manual operation circuit; and a controller that outputs a control signal to the flow rate control valve, and the automatic control circuit includes a detector that detects the current position of the work equipment, an automatic signal generator that outputs a target position signal of the work equipment, A calculator that calculates the deviation between the work equipment current position signal from the above detector and the work equipment target position signal from the automatic signal generator, and an automatic controller that stores the response characteristics of the flow control valve during automatic control in variable settings. The manual operation circuit includes a storage device and a calculator that outputs a control signal for the flow rate control valve based on the deviation and the stored value stored in the automatic storage device, and the manual operation circuit operates according to the amount of operation of the manual operation means. A manual signal generator that outputs an operation signal, and a response characteristic of the flow control valve during manual operation that generates a dead zone near neutral and outputs a flow control signal after the dead zone is exceeded, is stored in variable settings. It is characterized by comprising a manual storage device, and a calculator that outputs a control signal for the flow control valve based on the signal from the manual signal generator and the stored value stored in the manual storage device. That is.

(Function) With this configuration, one
Flow control valves with a signal from an automatic control circuit,
It can be activated with any signal from the manual operation circuit, and the response characteristics when activated can be set arbitrarily. Particularly in manual operation, by providing a dead zone near the neutral position, even if the lever is accidentally touched, it will not activate, increasing safety and making operation easier for the operator. Furthermore, in automatic control, the dead zone is eliminated, and optimal control is immediately performed in accordance with the control signal, making highly accurate control possible.

(Example) In FIG. 1, 1 indicates a boom (working machine) of a hydraulic excavator, and 2 indicates a cylinder (hydraulic actuator) that raises and raises the boom 1. 3 is a flow control valve;
For example, an electromagnetic proportional control valve is used in which the position of the spool, that is, the direction of oil flow and the opening area are controlled according to a control signal (electrical signal) from the controller 18. Pressure oil is supplied to and discharged from the cylinder 2 through pipes 5 and 6, and the cylinder 2 is expanded and contracted to raise and lower the boom 1. The basic characteristic of the valve 3 is that it has no dead zone and is configured so that the spool stroke and opening area are in a completely proportional relationship.The following control means is used to switch the valve 3. is used.

First, for manual operation, a control lever 7, a manual signal generator 8, an arithmetic unit 9, and a manual storage device 10 are provided.
A detector 11, an automatic signal generator 12, arithmetic units 13, 14, and an automatic storage device 15 are provided for automatic control, and a changeover switch 17 for selecting manual or automatic mode and a changeover operation means 16 are provided. ,
A controller 18 is provided. Note that the arithmetic unit 9, manual memory device 10, automatic signal generator 12, arithmetic units 13 and 14, automatic memory device 15,
The changeover switch 17 is constituted by a microcomputer.

The manual signal generator 8 converts the amount of operation of the operating lever 7 into an electrical signal using a potentiometer or the like, and outputs a signal s corresponding to the amount of operation. In this case, positive and negative signals ±s are output in accordance with the operating direction of the operating lever 7, that is, whether the boom 1 is raised or lowered.

The manual storage device 10 stores the relationship between the operation signal ±s corresponding to the operation of the operation lever 7 and the signal ±Vs for manual operation. For example, as shown in FIG. s and output signal ±
The relationship with Vs is stored so as to change with nonlinear characteristics in correspondence with the relationship between the spool stroke and the opening area during manual operation of a general flow control valve. In other words, the operating amount of the operating lever 7, that is, the operating signal ±s is in a small range (0≦s≦s ₁ ,
A dead zone is provided at 0≧s≧−s ₁ ), and the signal Vs is not output in this dead zone, and the respective operation signals are output when the operation signal s exceeds the dead zone (s>s ₁ , s<−s ₁ ). _The signal _{Vs ( Vs 2}
~Vs ₅ , −Vs ₂ ~ −Vs ₅ ) are output.

The calculator 9 generates a signal ±s for manual operation based on the operation signal ±s outputted from the manual signal generator 8 and the stored value stored in the manual storage device 10.
Output Vs.

On the other hand, the detector 11 is for detecting the current position (elevation angle) of the boom 1, and is composed of, for example, a potentiometer. A signal θ corresponding to the current position of No. 1 is output. Note that the detector 11 may be provided at the pivot portion of the cylinder 2 relative to the base machine or at the rod of the cylinder 2.

The automatic control signal generator 12 outputs a signal θ31 corresponding to the target position (angle) to which the boom 1 is raised or raised. In this case, when performing combined work using the boom 1 and arm, such as horizontal extrusion of the bucket or circular excavation, the boom 1 is calculated based on the amount of arm movement so that the boom 1 moves up and down to follow the movement of the arm. The required movement amount of 1 is sequentially output as the target position. Note that when the boom 1 works alone, a preset dump position, excavation position, or the like is output as a target position. This target position can be set arbitrarily.

The calculator 13 calculates both signals θ and θ based on the current position signal θ of the boom 1 output from the detector 11 and the target position signal θ ₀ of the boom 1 output from the automatic signal generator 12. ₀ deviation is determined and a signal eθ (=θ ₀ −θ) corresponding to the deviation is output. In this case, positive and negative deviation signals ±eθ are output in accordance with the raising and lowering of the boom 1.

The automatic storage device 15 stores the relationship between the deviation signal ±eθ and the signal ±Ve for automatic control. For example, as shown in FIG. 3, the relationship between the deviation signal ±eθ and the output signal ±Ve is stored. The relationship is stored as a proportional linear characteristic that is optimal for automatic control without providing a dead zone as in the case of manual operation. In this case, as a means to obtain the output signal Ve, for example, the flow rate eq (=eθ・kθ) of the cylinder 2 required to operate the boom 1 to the target position is obtained by multiplying the position error signal eθ by a proportionality constant kθ. ,
Next, the required opening area ea (=eq/kq) of the flow control valve 3 corresponding to the above-mentioned required flow rate is determined by dividing this required flow rate eq by the proportionality constant kq, etc., and the output signal Ve corresponding to the required opening area ea is determined. demand. and,
The deviation signal ±eθ and the output signal ±Ve are stored in the storage device 15 in a correlated manner.

The computing unit 14 generates a signal ± for automatic control based on the position deviation signal ±eθ outputted from the computing unit 13 and the stored value stored in the automatic storage device 15.
Output Ve.

The changeover switch 17 is switched by the changeover operation means 16 to switch between the signal ±Vs for manual operation output from the arithmetic unit 9 and the signal ±Ve for automatic control output from the arithmetic unit 14. Select one and send it to the controller 18. Also,
The controller 18 determines whether the signal ±Vs or ±Ve input from the switching switch 17 is positive or negative, that is, whether the boom is raised or lowered, and sends it to the flow rate control valve 3.

Next, the effect will be explained.

First, during manual operation, with the changeover switch 17 switched to the manual side as shown in the figure, the operating lever 7
operate. Now, when the lever 7 is operated in the direction of raising the boom, the manual signal generator 8 outputs an operation signal +s corresponding to the direction and amount of operation of the lever, and this operation signal +s and the operation signal +s are stored in the manual storage device 10. Based on the stored value, the signal +Vs for manual operation is output from the calculator 9, and this signal +Vs
is sent to the controller 18 via the changeover switch 17. Then, the controller 18 determines whether the signal +Vs is positive or negative, that is, whether the boom is raised or lowered (in this case, raised), and the signal +Vs is sent to the boom-raising side input section of the flow control valve 3. is switched to the boom raising side. Along with this, pressure oil is supplied from pipe 4 to the head side oil chamber of cylinder 2 via flow control valve 3 and pipe 5, and oil in the rod side oil chamber flows through pipe 6 and flow control valve 3. Thereafter, the boom 1 is returned to the tank (not shown), the cylinder 2 is extended, and the boom 1 is raised.

In addition, if the operating lever 7 is operated in the boom lowering direction, a negative operating signal -s is generated from the manual signal generator 8.
is output, and thereafter, the operation unit 9 is operated in the same manner as above.
A signal -Vs is outputted from the pump, the flow control valve 3 is switched to the boom lowering side, the cylinder 2 is retracted, and the boom 1 is lowered.

During this manual operation, an operation signal s is output in response to the operation of the operation lever 7, and this operation signal s and
A signal Vs is output from the calculator 9 based on the characteristics stored in the manual storage device 10, and the opening area of the flow control valve 3 is controlled by this signal Vs, and the flow rate supplied to the cylinder 2 is controlled. The amount of contraction is controlled, and the amount of elevation of the boom 1 is controlled. Therefore, the amount of elevation of the boom 1 can be controlled at will using the operating lever 7. Moreover, the manual storage device 10 stores characteristics suitable for manual operation, and there is a dead zone in a range where the operation amount of the operation lever 7 is small, so that the signal Vs is not output and the flow rate control valve 3 cannot be switched. Therefore, there is no risk that the boom 1 will be activated even if the operating lever 7 is touched by mistake, and the boom 1 can be operated safely and smoothly with a good operating feeling.

On the other hand, during automatic control, the changeover switch 17 is switched to the automatic side. When automatic control is started in this state, the target position signal θ ₀ of the boom 1 is output from the automatic signal generator 12, and the detector 1
1 detects the current position of the boom 1 and outputs its current position signal θ, and then, based on the target position signal θ ₀ and the current position signal θ, a computing unit 13 calculates and outputs a deviation signal eθ, Furthermore, a control signal Ve for automatic control is calculated and outputted by the calculation unit 14 based on the deviation signal eθ and the stored value stored in the automatic storage device 15 (see FIG. 3),
The signal Ve is sent to the controller 18.

Here, when it is desired to lower the boom 1 from a high position to the target position (θ>θ ₀ ), a negative deviation signal -eθ is output from the computing unit 13, and the negative control signal -eθ of the controller 18 is subsequently outputted by the above-mentioned action. Ve is sent. Then, the controller 18 determines whether the control signal -Ve is positive or negative, that is, whether the boom is raised or lowered (in this case, lowered), and the signal -Ve is sent to the boom lowering side input section of the flow control valve 3. The valve 3 is switched to the boom lowering side. Along with this, pressure oil is supplied from pipe 4 to the rod-side oil chamber of cylinder 2 via flow control valve 3 and pipe 5, and oil in the head-side oil chamber flows through pipe 5 and flow control valve 3. Afterwards, it is returned to the tank (not shown), the cylinder 2 is retracted, and the boom 1 is lowered.

In addition, when raising the boom 1 from a low position to a high target position, contrary to the above, a positive deviation signal +eθ is output from the computing unit 13, and thereafter, a positive control signal is output from the computing unit 14 in the same manner as above. +Ve is output, and the signal +Ve is sent via the controller 18 to the input section on the boom-up side of the flow control valve 3, which switches the valve 3 to the boom-up side.
is extended and the boom is controlled to raise.

In addition, in the above-mentioned automatic control, for example, when horizontal excavation with a bucket is performed while lowering the boom 1 following arm push in combined work using the arm and boom 1, the position and amount of movement of the arm are input to the signal generator 12. The signal generator 12 calculates the necessary movement amount of the boom 1 corresponding to the movement amount of the arm, and outputs the necessary movement amount as the target position signal θ ₀ to perform the above control. As a result, the boom 1 is lowered following the arm push, and automatic horizontal extrusion of the bucket is performed.

During the automatic control described above, a deviation signal eθ is output according to the current position θ and target position θ ₀ of the boom 1, and a control signal Ve is output based on this deviation signal eθ and the characteristics stored in the automatic storage device 15. is output, and the opening area of the flow control valve 3 is controlled by this signal Ve, and the flow rate supplied to the cylinder 2, that is, the amount of expansion and contraction of the cylinder 2 and the amount of elevation of the boom 1 are controlled.
In other words, the position of the boom 1 is automatically and accurately controlled according to the current position θ and the target position θ ₀ of the boom 1, and the automatic storage device 15 is stored in the automatic storage device 15 as shown in FIG. Since characteristics suitable for control are stored, the control signal Ve is immediately output based on the deviation signal eθ and control is started.
Then, the above control is repeated until the deviation signal eθ becomes 0, thereby performing feedback control, and during automatic control, efficient and highly accurate control is performed without a dead zone. After that, when the deviation signal eθ becomes 0, the control signal Ve also becomes 0,
The flow control valve 3 is returned to the neutral position, the cylinder 2 is stopped, and the boom 1 is stopped and held at the target position.

In this way, during automatic control, highly accurate control without steady-state deviations can be performed by cutting the dead zone.

Further, in the above embodiment, the manual storage device 1
0 and the characteristics to be stored in the automatic storage device 15 can be arbitrarily set depending on the model, work content, etc., such as changing the dead band width during manual operation, changing the gain of nonlinear characteristics and linear characteristics, etc.
Depending on the settings, you can work in optimal conditions whether it is manual or automatic. In this case, several types of control characteristics are stored in the respective storage devices 10 and 15, and the arithmetic units 9 and 14 are stored according to the work content and other requirements.
It is also possible to arbitrarily read necessary control characteristics from the controller and output a signal in accordance with the control characteristics.

In the above embodiment, an electromagnetic proportional control valve is used as the flow rate control valve 3, but a servo valve may be used instead of this electromagnetic proportional control valve.

Further, in the present invention, the working machine is not limited to the boom 1, but may be an arm, bucket, swing or crane winch, and the hydraulic actuator is not limited to the cylinder 2, but may be a hydraulic motor. In addition, the present invention can be applied to various construction machines other than the above-mentioned hydraulic excavators and cranes.

(Effects of the Invention) As described above, the present invention provides one flow control valve having no dead zone in the main hydraulic circuit, and controls the flow control valve from a control signal sent from an automatic control circuit and from a manual operation circuit. It is designed so that it can be operated with any of the sent operation signals, thereby simplifying the circuit configuration and reducing costs. In addition, control characteristics can be set arbitrarily in either manual or automatic mode, and in particular, during manual operation, signal processing from the manual storage device creates a state suitable for manual operation with a dead zone, improving operability. , can be operated safely and at will,
On the other hand, during automatic control, control characteristics stored in the automatic storage device are used to cut out the dead zone, allowing highly accurate control without steady-state deviations.
This can improve the versatility of the machine.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a characteristic diagram stored in a manual storage device, and FIG.
The figure is a characteristic diagram stored in the automatic storage device. 1...Boom (work equipment), 2...Cylinder (hydraulic actuator), 3...Flow control valve, 7...
Operation lever (manual operation means), 8...Manual signal generator, 9...Arithmetic unit, 10...Manual memory device, 11...Current position detector, 12...Target position signal generator, 13, 14... Arithmetic unit, 15... Automatic storage device, 17... Changeover switch, 18...
controller.

Claims (1)

[Claims] 1 A hydraulic actuator that operates the work equipment,
A flow control valve that controls the supply of pressure oil to a hydraulic actuator and has no dead zone near neutral;
an automatic control circuit and a manual operation circuit that output electrical control signals for the flow control valve; a switching means that selects and outputs a signal from the automatic control circuit and a signal from the manual operation circuit; The automatic control circuit includes a controller that outputs a control signal to the flow control valve based on the signal, and the automatic control circuit includes a detector that detects the current position of the work equipment, and an automatic signal generator that outputs a target position signal of the work equipment. a calculator that calculates the deviation between the current position signal of the work machine from the above detector and the target position signal of the work machine from the automatic signal generator, and a configurable memory that stores the response characteristics of the flow control valve during automatic control. The manual operation circuit includes an automatic memory device for controlling the flow rate control valve, and an arithmetic unit for outputting a control signal for the flow rate control valve based on the deviation and the stored value stored in the automatic memory device. A manual signal generator that outputs an operation signal according to the amount, and a variable response characteristic of the flow control valve during manual operation that generates a dead zone near neutral and outputs a flow control signal after exceeding the dead zone. a manual storage device for storing information in the
Work on a construction vehicle characterized by comprising a calculator that outputs a control signal for a flow rate control valve based on the signal from the manual signal generator and the stored value stored in the manual storage device. Machine operation control device.