JP2006291647A - Controller of work machine for avoiding interference - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To avoid interferences with a high precision in a hydraulic shovel 1 even if the expansion and contraction speeds differ among its hydraulic cylinders, when a PID control method is used in maneuvering the bucket 7 so that its edge does not enter the interference avoiding range F. <P>SOLUTION: In order to make precision control for avoiding the interferences, a method is used, where driving force required for controlling the expansion and contraction of hydraulic cylinders does not depend on the expansion and contraction speeds, but is determined by the control value according to differentials between data for the position of the bucket 7 edge and those for its position to avoid interferences, in addition to the control value calculated in consideration of the hydraulic cylinder expansion and contraction speeds. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention belongs to the technical field of interference avoidance control devices for work machines such as hydraulic excavators.

In general, in this type of work machine, particularly a hydraulic excavator, work attachments (buckets, etc.) are connected via a plurality of work arms (booms, arms, etc.) whose postures can be freely changed, and a plurality of the work arms, work attachments are attached. The posture is changed by an actuator such as a hydraulic cylinder. In this case, there is one in which interference avoidance control is performed so that the work attachment does not interfere (collision) with the machine itself or surrounding obstacles (for example, Patent Document 1). In addition, in this system, the interference avoidance control is performed using PID control (differential integration control).
JP 2000-144791 A

By the way, the conventional interference avoidance control calculates the position deviation between the work attachment and the interference position, and determines the operating force of the work attachment based on the magnitude of the position deviation, so that the work attachment is operating at high speed. There was a difference in the accuracy of stopping at the interference avoidance position between when operating at low speed.
In addition, when PID control is used for interference avoidance control, the speed component is also taken into account when approaching the interference avoidance position, so that the work attachment can be brought close to the marginal position of the interference avoidance position regardless of the state of operation. However, since the PID control was performed even when the work attachment was far away from the interference avoidance position, the case where the operation speed of the work attachment did not correlate with the lever operation amount appeared, and the operation became uncomfortable. There are problems, and these are the problems to be solved by the present invention.

The present invention was created in order to solve these problems in view of the above situation, and the invention of claim 1 is a hydraulic actuator that operates by pressure oil supply based on operation tool operation, Interference avoidance control for avoiding the work attachment from entering a preset interference avoidance region in a work machine having a work arm that operates based on the operation of the hydraulic actuator and a work attachment attached to the actuating arm. In providing the device, the interference avoidance control device includes a set pressure oil flow rate output means for outputting a pressure oil supply flow rate set in accordance with an operation amount of the operation tool, and an operating state for detecting an operating state of the hydraulic actuator. Detecting means; difference calculating means for calculating a difference between the detected operating state data and preset interference avoidance position data; and the difference calculating means Based on the calculated difference data and the pressure oil supply flow rate data output from the set pressure oil flow rate output means, the target flow rate calculation means for calculating the target flow rate for the hydraulic actuator, and the detected operating state data A change speed calculating means for calculating a change speed of the hydraulic actuator, and an actual pressure oil supply flow rate for calculating an actual pressure oil supply flow rate actually supplied to the hydraulic actuator from the change speed of the hydraulic actuator calculated by the change speed calculating means. A flow rate error calculating unit for calculating a flow rate error from a difference between the target flow rate calculated by the target flow rate calculating unit and the actual pressure oil supply flow rate calculating unit, and the flow rate error; PID control means for calculating an output flow rate when executing PID control based on the error flow rate calculated by the calculation means, and the PID control means In an interference avoidance control device for a working machine, characterized by being configured and an actuator control command output means for outputting the calculated output flow to the hydraulic actuator.
According to a second aspect of the present invention, in the first aspect, the interference avoidance control device executes PID control based on the size of the difference data between the operating state data calculated by the difference calculation means and the interference avoidance position data. An interference avoidance control apparatus for a work machine, characterized in that gain schedule determination means for determining whether or not to execute a gain scheduler is provided.
According to a third aspect of the present invention, the interference avoidance control apparatus according to any one of the first and second aspects is reflected in the PID control from the difference data between the operation state data calculated by the difference calculating means and the interference avoidance position data. An interference avoidance control device for a work machine, characterized in that a reflection amount calculation means for calculating a reflection amount for performing the operation is provided.
According to a fourth aspect of the present invention, in any one of the first to third aspects, the work arm is provided on a work machine so as to be swingable in a vertical direction, and is provided at a distal end portion of the rear boom so as to be capable of a lateral offset operation. An interference avoidance control device for a work machine, characterized in that the front boom is configured to include a front boom and an arm that is swingable in a vertical direction at a front end portion of the front boom.

According to the first aspect of the present invention, while the interference avoidance control of the work attachment is executed using the PID control, the output flow rate output to the hydraulic actuator is set in advance with the operation state data of the hydraulic actuator. This is calculated not only based on the difference from the interference avoidance position data, but also considering the operating speed of the hydraulic actuator. As a result, there is a difference in the operating speed when approaching the interference avoidance position. However, accurate interference avoidance can be achieved without entering the interference avoidance position.
According to the invention of claim 2, when the difference data between the operation state data of the hydraulic actuator and the preset interference avoidance position data is large, the PID control is not executed and the operation amount of the operation tool operation is set. The corresponding control can be performed, and an operation without a sense of incongruity between the operation amount can be performed.
According to the invention of claim 3, it is possible to execute PID control that is partially limited by reflecting the difference data between the data on the operating state of the hydraulic actuator and the data on the interference avoidance position set in advance. Thus, the operability becomes more excellent.
According to the invention of claim 4, it is possible to surely avoid interference even with an offset type work arm.

  Next, embodiments of the present invention will be described with reference to the drawings. In the figure, reference numeral 1 denotes a hydraulic excavator. The hydraulic excavator 1 includes a lower traveling body 2 provided with an upper swing body 3 so as to be capable of swinging. A front boom 5 is provided at the tip so that it can be offset from side to side, and an arm 6 is pivotally supported by the front boom 5a so as to be swingable in the vertical direction to constitute the working arm of the present invention. A bucket 7 (corresponding to the “work attachment” of the present invention) is pivotally supported so as to be swingable in the vertical direction. The bucket 7 is a hydraulic cylinder 8, 9, 10, 11 for operating the booms 4, 5, the arm 6, and the bucket 7 (the cylinders 8, 9, 10, 11 correspond to the “hydraulic actuator” of the present invention). As in the conventional case, the position is freely displaced by the expansion and contraction operation.

  Since each of the hydraulic cylinders 8 to 11 performs the same expansion and contraction control, a hydraulic control circuit diagram of the arm hydraulic cylinder 10 as a representative example is shown in FIG. In FIG. 3, 12 is a main pump, 13 is a pilot hydraulic pressure source, 14 is an oil tank, 15 is a control valve, 16A and 16B are expansion side and reduction side pilot valves, and 17A and 17B are extension side and reduction side switching valves. , 18A and 18B are electromagnetic proportional pressure reducing valves on the expansion side and the reduction side, 19A and 19B are pressure sensors on the expansion side and the reduction side, 20 is an arm operating tool, and the control valve 15 is an expansion side pilot port 15a. And a pilot operated three-position switching valve provided with a reduction pilot port 15b.

  The control valve 15 is positioned at a neutral position N where the supply of pressure oil to the arm cylinder 10 is stopped when no pilot pressure oil is supplied to the pilot ports 15a and 15b. Supplying pilot pressure oil to the port 15a switches to the extension side position X for supplying pressure oil to the extension side oil chamber of the arm cylinder 10, and pilot pressure oil is supplied to the reduction side pilot port 15b. Thus, the configuration is switched to the reduction side position Y for supplying pressure oil to the reduction side oil chamber of the arm cylinder 10.

  Further, the expansion side and reduction side pilot valves 16A and 16B, the switching valves 17A and 17B, the electromagnetic proportional pressure reducing valves 18A and 18B, and the pressure sensors 19A and 19B are respectively connected to the expansion side and reduction side pilot port 15a of the control valve 15. 15b are provided in the extension side and the reduction side pilot oil passages for supplying pilot pressure oil, respectively. Since they are the same, the extension side pilot valve 16A will be described first. By operating 20 to the arm extension side, pilot pressure oil having a pressure corresponding to the operation amount is output from the output port 16a.

Further, the extension side switching valve 17A is a five-port two-position switching valve disposed on the secondary side of the extension side pilot valve 16A. The first port 17a is the oil tank 14, and the second port 17b is the above-mentioned The output port 16a of the extension side pilot valve 16A, the third port 17c to the pilot hydraulic pressure source 13, the fourth port 17d to the first port 18a of the extension side electromagnetic proportional pressure reducing valve 18A described later, and the fifth port 17e to the extension side Each is connected to the second port 18b of the electromagnetic proportional pressure reducing valve 18A.
The extension side switching valve 17A is provided with a pilot port 17f. The pilot port 17f is a pilot oil passage that connects the extension side pilot valve output port 16a and the extension side switching valve second port 17b. The pilot pressure oil is also supplied to the pilot port 17f as the pilot pressure oil is output from the extension-side pilot valve 16A.
When the pilot pressure oil is not supplied to the pilot port 17f, the extension side switching valve 17A closes the first port 17a by the urging force of the ammunition 17g, and connects the second port 17b and the fourth port 17d. Is located at the first position X where the valve path that opens and the valve path that communicates the third port 17c and the fifth port 17e is open, and the pilot pressure oil from the pilot hydraulic source 13 is supplied to the expansion-side electromagnetic proportional pressure reducing valve. While supplying to the 2nd port 18b, the oil from the expansion | extension side electromagnetic proportional pressure reducing valve 1st port 18a can be discharged | emitted to the oil tank 14 via the expansion | extension side pilot valve 16A.

  On the other hand, when the pilot pressure oil is supplied to the pilot port 17f, the third port 17c is closed, the valve path that connects the first port 17a and the fourth port 17d is opened, and the second port 17b and the fifth port 17f are opened. The pilot pressure oil from the pilot valve output port 16a is supplied to the expansion side electromagnetic proportional pressure reducing valve second port 18b by switching to the second position Y where the valve path communicating with the port 17e is opened, and the expansion side electromagnetic proportional valve The oil from the pressure valve first port 18 a can be discharged to the oil tank 14.

The expansion side electromagnetic proportional pressure reducing valve 18A is disposed between the expansion side switching valve 17A and the control valve expansion side pilot port 15a, but the first to third ports 18a, 18b, 18c, and the solenoid 18d. The first port 18a is connected to the expansion side switching valve fourth port 17d, the second port 18b is connected to the expansion side switching valve fifth port 17e, and the third port 18c is connected to the control valve expansion side pilot port 15a. It is connected.
The extension-side electromagnetic proportional pressure reducing valve 18A opens the valve path communicating the first port 18a and the third port 18c and closes the second port 18b in a state where the solenoid 18d is not excited. When the solenoid 18d is excited based on an operation command from the control unit 21 described later, the output valve path that connects the second port 18b and the third port 18c is opened. When the output valve path is opened, the pilot pressure oil from the pilot hydraulic source 13 via the extension side switching valve 17A at the first position X or the extension side via the extension side switching valve 17A at the second position Y The pilot pressure oil from the pilot valve 16A is output to the control valve extension side pilot port 15a. The output pressure corresponds to the control command output from the control unit 21 to the drive circuit of the solenoid 18d. Increase or decrease.

  Further, the extension side pressure sensor 19A detects the pressure of the pilot pressure oil output from the extension side pilot valve 16A, and the detection signal of the extension side pressure sensor 19A is inputted to the control unit 21. It has become so.

  On the other hand, the control unit 21 is configured using a microcomputer or the like, and the control unit 21 detects a vertical relative position (may be a relative angle) with respect to the upper swing body 3 at the tip of the rear boom 4. Rear boom hydraulic cylinder length detection sensor 22R, front boom cylinder (offset cylinder) length detection sensor 22F for detecting the left-right offset relative position (or relative angle) to the rear boom 4 at the front boom 5 tip, arm 6 Arm hydraulic cylinder length detection sensor 23 for detecting the vertical relative position (may be a relative angle) with respect to the front boom 5 at the front end, for detecting the vertical relative position (may be a relative angle) with respect to the arm 6 of the bucket 7 tooth tip. Hydraulic cylinder length detection sensor 24 for these buckets (the cylinder length detection sensor 2 R, 22F, 23, 24 is adapted to input the detection signals from.) Corresponding to the "working state detection means" of the present invention. Further, the control unit 21 includes the above-described extension side and reduction side pressure sensors 19A and 19B provided in the extension side and reduction side pilot oil passages of the arm cylinder 6, and the extension side of the rear boom cylinder 8 in the same manner. The expansion side and reduction side pressure sensors 25A and 25B provided in the reduction side pilot oil passages respectively, the extension side and reduction side pressure sensors provided in the extension side and reduction side pilot oil passages of the front boom cylinder 9, respectively. 26A and 26B, detection signals from various sensors such as the pressure detection sensors 11A and 11B on the expansion / contraction side and the reduction side of the bucket cylinder 11, and signals from various switches (not shown) are input. Based on these input signals, the control unit 21 performs setting, calculation, selection, and the like by various setting units, calculation units, selection units and the like, which will be described later, and the pilot oil on the expansion side and reduction side of the arm cylinder 10 described above. The expansion-side and reduction-side electromagnetic proportional pressure reducing valves 18A and 18B provided on the road, respectively, and the expansion side and reduction-side of the rear boom cylinder 8 set in the same manner are provided on the extension side and reduction side pilot oil passage, respectively. Electromagnetic proportional pressure reducing valves 27A and 27B, expansion side and reduction side electromagnetic proportional pressure reducing valves 28A and 28B provided on the extension and reduction side pilot oil passages of the front boom cylinder 9, expansion side and reduction of the bucket cylinder 11, respectively. Control commands are output to various solenoid valves such as the expansion-side and reduction-side electromagnetic proportional pressure reducing valves 11A, 11B provided in the pilot oil passage on the side It is configured.

  Next, various setting devices, arithmetic units, selectors and the like provided in the control unit 21 will be described based on the block circuit diagram of FIG. 4. 29 is an operation command signal output when the operator operates the operation tool 20. Means (corresponding to “setting hydraulic flow rate output means” of the present invention), and the operation command signal output means 29 is preset to be supplied based on the operation amount of the operation tool 20. The set supply flow rate is output as an operation command signal.

  Reference numeral 30 denotes a preset interference avoidance position data output means. The set interference avoidance position data output means 30 is provided for the bucket 7 calculated from the expansion / contraction length of each of the hydraulic cylinders 8, 9, 10, and 11. The interference avoidance position of the tooth tip positions, usually as a range where the tooth tip of the bucket 7 should not enter any more, that is, as shown in FIG. The interference avoidance position data that is set and output is output as cylinder length data of each of the hydraulic cylinders 8, 9, 10, and 11.

  31 is a difference between the interference avoidance position data output from the interference avoidance position data output means and the detection data of each of the hydraulic cylinders 8, 9, 10, 11 and the current cylinder length detection sensors 22R, 22F, 23, 24. The difference calculation means 32 for calculating the data of 32 is a ratio of executing the PID control as the difference data calculated by the difference calculation means 31 is smaller, that is, a reflection amount (reflection ratio) for reflecting the difference data in the PID control. This is a reflection amount calculation means 32 for calculating an adjustment gain u (1) in which is adjusted to a numerical value from 0 to 1.

  Reference numeral 33 denotes a target flow rate for each corresponding hydraulic cylinder 8, 9, 10, 11 by multiplying the PID adjustment gain calculated by the reflection amount conversion means 32 and the predicted supply flow rate output from the operation command signal output means 29. Target flow rate calculation means 34 for calculating, cylinder speed calculation means 34 for calculating the expansion / contraction speed of each corresponding cylinder from the sensor values of the corresponding cylinder length detection sensors 22R, 22F, 23, 24 ("change speed calculation means of the present invention" , 35 is an actual pressure oil for calculating an actual pressure oil supply flow rate to each of the hydraulic cylinders 8, 9, 10, and 11, that is, an actual pressure oil supply flow rate, from the calculated corresponding cylinder expansion / contraction speeds. Supply flow rate calculation means.

  36 calculates (1-u (1)) by subtracting the PID control reflection amount adjustment gain u (1) calculated by the reflection amount calculation means 32 from 1, and the calculated value is larger than a preset value. That is, when the difference between each cylinder length data value based on the interference avoidance position data and the actual cylinder length value based on the sensor values of the cylinder length detection sensors 22R, 22F, 23, and 24 is larger than a preset setting difference. Is a gain schedule determining means for determining a gain scheduler for PID control so as not to execute PID control, 37 is a target flow rate calculated by the target flow rate calculating means 33, and an actual pressure calculated by the actual pressure oil supply flow rate calculating means 35 A flow rate error calculating means for calculating a difference from the oil supply flow rate and calculating a flow rate error from the calculated difference, and 38 is a gain schedule determining means. A gain schedule is a schedule after flow rate error calculation means for calculating the flow rate error after gain schedule multiplying the flow rate error calculated by the flow rate error calculation means 37.

  39 is a non-executable flow rate calculating means for calculating the output flow rate obtained by finely adjusting the output flow rate for the non-executed portion where the PID control is not executed from the target flow rate calculated by the target flow rate calculating means 33, and 40 is a portion for executing the PID control PID control means for calculating the output flow rate, 41 adds the output flow rate for non-execution of PID control calculated by the non-execution flow rate calculation means 39 and the output flow rate for PID control execution calculated by the PID control means 40 The cylinder control command output means for calculating the output flow rate in the PID control non-execution region and the execution region for each corresponding hydraulic cylinder and outputting the control command to each corresponding hydraulic cylinder (the “actuator control command output” of the present invention Equivalent to “means”).

  In the embodiment of the present invention configured as described above, the interference avoidance control is performed in such a way that the tooth tip position of the bucket 7 calculated based on the cylinder length detection value of each hydraulic cylinder 8, 9, 10, 11 is the interference avoidance position. When it is determined that the PID control non-execution region where the gain schedule determination unit 36 does not need to execute the PID control is separated from the H, the hydraulic cylinders 8, 9, 10, and 11 The cylinder control command output means 41 outputs the output flow rate for the non-execution PID control calculated by the non-execution flow rate calculation means 39 based on the predicted supply flow rate output from the operation command signal output means 29 based on the operation amount. As a result, the cylinder operation corresponding to the operation amount of the operation tool 20 is executed, and the bucket operation without any sense of incongruity is executed.

  On the other hand, when the tooth tip of the bucket 7 approaches the interference avoidance position H and the gain schedule determination means 36 determines that it is necessary to execute the PID control, the PID control is executed. The PID control is the difference between the current tooth tip position of the bucket 7 calculated by the difference calculating means 31 (calculated from the cylinder length detection values of the hydraulic cylinders 8, 9, 10, 11) and the interference avoidance position data. Rather than determining the driving force based on the position deviation, the expansion / contraction speed of each hydraulic cylinder 8, 9, 10, 11 calculated by the cylinder speed calculation means 34, that is, the speed at which the tooth tip of the bucket 7 approaches the interference avoidance position H. As a result, the stop or avoidance control when the tooth tip of the bucket 7 reaches the interference avoidance position H is related to the high or low movement speed. Ku will be good interference avoidance control precision is made constant.

  In addition, in this case, when the PID control is executed, the difference between the interference avoidance position data calculated by the difference calculation means 31 and the cylinder length detection value is determined when the reflection amount adjustment means 32 performs the PID control. Since the reflection amount of whether or not it is reflected is calculated and PID control is performed, when entering the execution area from the PID control non-execution area, the PID control state does not become 100%, and the calculated reflection is performed. Since the PID control is based on the amount, the closer to the interference avoidance region H, the more the mixed control with the PID control can be performed, and the operability can be further improved.

  The present invention is not limited to the offset type excavator, but can be applied to an integrated front and rear boom. In this case, there is no problem of interference with the airframe body, but it can also be executed as control for avoiding collision with various obstacles such as buildings around the work site, utility poles, electric wires, or buried objects. . Further, the target work attachment site for avoiding interference is not limited to the tooth portion of the bucket, and can be set to an appropriate position as necessary, such as an arm tip position.

It is a side view of a hydraulic excavator. FIG. 3 is a hydraulic circuit diagram of an arm hydraulic cylinder. It is a block circuit diagram which shows the input / output of a control part. It is a block circuit diagram of interference avoidance control.

Explanation of symbols

1 Excavator (work machine)
7 bucket (work attachment)
20 operation tool 29 operation command signal output means (setting hydraulic flow rate output means)
31 Difference calculation means 32 Reflection amount calculation means 33 Target flow rate calculation means 34 Cylinder speed calculation means (change speed calculation means)
35 Actual pressure oil supply flow rate calculation means 36 Gain schedule determination means 37 Flow rate error calculation means 39 Non-execution portion flow rate calculation means 40 PID control means 41 Cylinder control command output means (actuator control command output means)

Claims (4)

The work attachment is provided in a work machine including a hydraulic actuator that operates by supplying pressure oil based on operation of the operation tool, a work arm that operates based on the operation of the hydraulic actuator, and a work attachment that is attached to the operation arm. In providing an interference avoidance control device that avoids entering a preset interference avoidance region, the interference avoidance control device includes:
A set pressure oil flow rate output means for outputting a pressure oil supply flow rate set corresponding to the operation amount of the operating tool;
An operating state detecting means for detecting an operating state of the hydraulic actuator;
A difference calculating means for calculating a difference between the detected operating state data and preset interference avoidance position data;
Target flow rate calculation means for calculating a target flow rate for the hydraulic actuator based on the difference data calculated by the difference calculation unit and the pressure oil supply flow rate data output from the set pressure oil flow rate output unit;
A change speed calculating means for calculating a change speed of the hydraulic actuator from the detected operating state data;
Actual pressure oil supply flow rate calculation means for calculating an actual pressure oil supply flow rate actually supplied to the hydraulic actuator from the change speed of the hydraulic actuator calculated by the change speed calculation means;
A flow rate error calculating means for calculating a flow rate error from a difference between the target flow rate calculated by the target flow rate calculating means and the actual pressure oil supply flow rate calculating means;
PID control means for calculating an output flow rate when executing PID control based on the error flow rate calculated by the flow rate error calculation means;
An interference avoidance control device for a work machine, comprising: an actuator control command output means for outputting an output flow rate calculated by the PID control means to a hydraulic actuator.   2. The gain avoidance control device according to claim 1, wherein the interference avoidance control device determines whether or not to execute the PID control based on the size of the difference data between the operating state data calculated by the difference calculating means and the interference avoidance position data. A work machine interference avoidance control apparatus, comprising: a gain schedule determining means for determining   3. The interference avoidance control device according to claim 1, wherein the interference avoidance control device calculates a reflection amount to be reflected in the PID control from the difference data between the operation state data calculated by the difference calculation means and the interference avoidance position data. An interference avoidance control device for a work machine, characterized in that a reflection amount calculation means is provided.   4. The work arm according to claim 1, wherein the work arm includes a rear boom that is provided on a work machine so as to be swingable in a vertical direction, a front boom that is provided at a distal end portion of the rear boom so as to be capable of a lateral offset operation, and the front arm. An interference avoidance control device for a work machine, comprising: an arm that is swingably movable in a vertical direction at a tip portion of a boom.

Images