JP3007335B1 - Work machine interference avoidance control device - Google Patents

Abstract

A high-precision control is performed to control the work to be continued while avoiding interference between a bucket and the attachment when the attachment approaches the cab during the work. SOLUTION: In setting an arm limit angle β _LT for performing an automatic interference avoidance operation of an arm, an actual boom angle α _act and an actual offset angle γ inputted from a boom angle sensor 33 and an offset angle sensor 34 are set.
_{Based on act} and detected pressures input from boom pressure sensors 27A and 27B and offset pressure sensor 28B, expected boom angle α _exp and expected offset angle γ
_exp is set, and the arm limit angle is calculated based on these expected angles.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a hydraulic control circuit for a working machine such as a hydraulic shovel.

[0002]

2. Description of the Related Art Generally, a working unit mounted on a working machine such as a hydraulic excavator includes an offset type boom that swings up and down and right and left, and an arm that is connected to the tip of the boom so as to swing back and forth. Although there is an attachment such as a bucket connected to the tip of the arm, the attachment may contact (interfere with) the driver's seat when the boom or the arm is swung. In such a case, care must be taken to avoid contact between the attachment and the driver's seat. Therefore, conventionally, a posture detecting means for detecting the posture of the working unit, and a control unit for determining whether the attachment is within a predetermined range of the driver's seat portion based on a detection signal from the posture detecting means, If it is determined that the attachment is within a predetermined range of the driver's seat,
There is a configuration in which a control command is output from a control unit to a hydraulic circuit of a working unit hydraulic actuator to stop the working unit. As such a device, for example, a device as shown in FIG. 11 is known, which is a pilot-type control for controlling the supply of pressurized oil to a working unit hydraulic actuator 42 such as an arm cylinder. Between the valve 43 and pilot valves 44A and 44B that output pilot pressure oil based on the operation of the operating tool,
Electromagnetic proportional pressure reducing valve 4 that operates based on a command from the control unit
5A and 45B are provided. When the attachment is away from the driver's seat, the electromagnetic proportional pressure reducing valves 45A and 45B are opened to allow the supply of pilot pressure oil to the control valve 43, while the attachment approaches the driver's seat. Has an electromagnetic proportional pressure reducing valve 45
A and 45B are closed to cut off the supply of pilot pressure oil to the control valve 43, thereby stopping the working unit.

[0003]

However, as described above, when the attachment approaches the driver's seat, the electromagnetic proportional pressure reducing valve is closed to stop the working unit. Work part will be stopped halfway through. In this case, once the attachment is moved away from the driver's seat, the operation of continuing the interrupted work must be restarted, which causes a problem that the work efficiency is reduced, and the present invention aims to solve the problem. There were challenges.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has been created with the object of solving these problems. In a working machine including a mold boom, an arm connected to the tip of the boom so as to be able to swing back and forth, and an attachment connected to the tip of the arm, interference between the machine body and the attachment is avoided. In providing the interference avoidance control means for avoiding the intrusion of the attachment into the interference avoidance area set in advance,
The interference avoidance control means includes a pilot for a boom cylinder.
Set according to the detection pressure of the pressure sensor installed in the oil passage
Expected boom that outputs the expected increase of the boom angle
An angle setting device, the predicted boom angle setting device, a boom angle detection means for detecting a swing angle of the boom with respect to the machine body,
And a signal from the arm angle detecting means for detecting the swing angle of the arm with respect to the boom, respectively, and the signal is set to the boom angle input from the boom angle detecting means .
Arm limit angle setting means for predicting an expected boom angle by adding the expected increase angle, and setting an arm limit angle for preventing the attachment from entering the interference avoidance area based on the predicted boom angle; and the set arm limit Control signal setting means for determining an angle deviation between the angle and the arm angle input from the arm angle detection means, and setting a control signal to the arm driving means to perform an automatic interference avoidance operation of the arm based on the angle deviation; Is provided. By doing so, the arm limit angle is set based on the expected boom angle, and even when the operating speed of the boom is high, the interference of the arm that quickly follows the operation speed can be set. An avoidance operation can be performed. In this device, the arm limit angle setting means inputs a signal from the operation state detection means for detecting the operation state of the boom drive means by the boom operation tool,
By predicting the expected boom angle using the detected boom operation state and the boom angle input from the boom angle detection means, and calculating the arm limit angle based on the predicted boom angle, the boom The predicted boom angle can be predicted according to the operation state. Further, the control signal setting means performs a proportional-integral control operation when setting the control signal based on the angle deviation, so that more precise control can be performed. Further, the interference avoidance control means includes an operation signal setting means for setting an operation signal to the arm driving means based on the operation of the arm operating tool, and an operation signal from the operation signal setting means and a control signal from the control signal setting means. By providing a selection means for selecting one of the control signals and outputting the selected signal to the arm driving means, the operation signal or the control signal is selected according to the operation state or the angle deviation of the arm operating tool. Furthermore, when the attachment approaches the interference avoidance area at least in a state where the boom is swinging, the interference avoidance control means causes the arm to swing in a direction away from the interference avoidance area so that the arm avoids the interference avoidance area. By providing a mechanism for continuing the boom swing while avoiding the intrusion of the attachment, the work can be continued while avoiding intrusion into the interference avoidance area, and the work efficiency is improved.

[0005]

Next, embodiments of the present invention will be described with reference to the drawings. 1 and 2, reference numeral 1 denotes an offset type excavator.
Are the lower traveling unit 2, the upper revolving unit 3, the cab 4, and the working unit 5.
The working unit 5 is further connected to a rear boom 6 whose base end is supported by the upper swing body 3 so as to be able to swing up and down, and to the tip of the rear boom 6 so as to be able to swing left and right. A front boom 7, an arm 8 connected to the front end of the front boom 7 so as to be able to swing back and forth, a bucket 9 connected to a front end of the arm 8 so as to be able to swing back and forth, and a device for swinging these. Although the basic configuration such as the configuration including the boom cylinder 10, the offset cylinder 11, the arm cylinder 12, the bucket cylinder 13, and the like is the same as the conventional one, in the present embodiment, the cab 4 is 3 is provided on the left side. Further, the rear boom 6 is configured to move down as the boom cylinder 10 contracts and rise as the boom cylinder 10 extends. Also, the front boom 7
When the offset cylinder 11 is contracted, it moves in the left direction, that is, in the direction approaching the cab 4, and when the offset cylinder 11 is extended, it moves in the right direction. Further, the arm 8 includes the arm cylinder 1
2 swings to the rear side of the fuselage due to extension (arm in)
When the arm cylinder 12 contracts, it swings (arms out) to the front side of the fuselage.

The boom cylinder 10, the offset cylinder 11, and the arm cylinder cylinder 12 extend and contract with hydraulic oil supplied from a main pump 14, and a circuit for supplying hydraulic oil to these cylinders 10 to 12 is provided. Since they are the same, the arm cylinder 12 will be described as an example with reference to FIG. In FIG. 3, 14 is a main pump, 15 is a pilot hydraulic pressure source, 16 is an oil tank, 17 is a control valve, 18A and 18B are expansion side and reduction side pilot valves, and 19A and 19B are expansion side and reduction side switching valves. , 20A and 20B are expansion-side and reduction-side electromagnetic proportional pressure reducing valves, 21A and 21B are expansion-side and reduction-side pressure sensors, and the control valve 17 is
It comprises a pilot-operated three-position switching valve having an extension-side pilot port 17a and a reduction-side pilot port 17b. And the control valve 1
7 is an arm cylinder 1 when the pilot pressure oil is not supplied to both pilot ports 17a and 17b.
Although it is located at the neutral position N where the supply of pressure oil to the cylinder 2 is stopped, the supply of pilot pressure oil to the extension-side pilot port 17 a supplies pressure oil to the extension-side oil chamber of the arm cylinder 12. By switching to the extension side position X and supplying pilot pressure oil to the reduction side pilot port 17b, the configuration is switched to the reduction side position Y for supplying pressure oil to the reduction side oil chamber of the arm cylinder 12. ing.

The expansion and contraction side pilot valves 18A and 18B, the switching valves 19A and 19B, the electromagnetic proportional pressure reducing valves 20A and 20B, and the pressure sensors 21A and 21B correspond to the extension and contraction side pilot valves of the control valve 17. The expansion side and the reduction side pilot oil passages for supplying pilot pressure oil to the ports 17a and 17b are provided respectively. However, since they are the same, the expansion side pilot valve 18A will be described first. By operating the arm operation tool 22 to the extension side, the pilot pressure oil having a pressure corresponding to the operation amount is output from the output port 18a.
Is output from the device.

The extension-side switching valve 19A is a five-port two-position switching valve disposed on the secondary side of the extension-side pilot valve 18A. The first port 19a is connected to the oil tank 16, and the second port 19a is connected to the second port. Reference numeral 19b denotes an output port 18a of the expansion-side pilot valve 18A, a third port 19c is connected to the pilot hydraulic pressure source 15, a fourth port 19d is connected to a first port 20a of a later-described expansion-side electromagnetic proportional pressure reducing valve 20A, and a fifth port 19e. Are connected to the second port 20b of the extension side electromagnetic proportional pressure reducing valve 20A, respectively. The expansion-side switching valve 19A is provided with a pilot port 19f. The pilot port 19f is connected to a pilot oil passage connecting the expansion-side pilot valve output port 18a and the expansion-side switching valve second port 19b. The pilot pressure oil is also supplied to the pilot port 19f as the pilot pressure oil is output from the extension side pilot valve 18A. When the pilot pressure oil is not supplied to the pilot port 19f, the extension side switching valve 19A closes the first port 19a by the urging force of the armature 19g and closes the second port 19a.
b is located at a first position X where a valve path connecting the fourth port 19d is open and a valve path connecting the third port 19c and the fifth port 19e is open.
Is supplied to the extension side electromagnetic proportional pressure reducing valve second port 20b, and oil from the extension side electromagnetic proportional pressure reducing valve first port 20a is supplied to the extension side pilot valve 18A.
Through the oil tank 16.
On the other hand, when the pilot pressure oil is supplied to the pilot port 19f, the third port 19c is closed, the valve connecting the first port 19a and the fourth port 19a is opened, and the second port 19b is connected to the fifth port 19b. The valve is switched to the second position Y in which the valve path communicating with the port 19e is opened, and the pilot pressure oil from the pilot valve output port 18a is supplied to the expansion-side electromagnetic proportional pressure-reducing valve second port 20b. The oil from the pressure valve first port 20a can be discharged to the oil tank 16.

The extension side electromagnetic proportional pressure reducing valve 20A is disposed between the extension side switching valve 19A and the control valve extension side pilot port 17a.
The third port 20a, 20b, 20c and the solenoid 20d are provided, the first port 20a is connected to the extension side switching valve fourth port 19d, the second port 20b is connected to the extension side switching valve fifth port 19e, The port 20c is connected to the control valve extension side pilot port 17a. The extension side electromagnetic proportional pressure reducing valve 20
A indicates that when the solenoid 20d is not excited, the valve path connecting the first port 20a and the third port 20c is opened and the second port 20b is closed. Solenoid 20d based on command
Is excited to open an output valve path communicating between the second port 20b and the third port 20c. When the output valve path is opened, the pilot hydraulic pressure source 1 via the extension side switching valve 19A at the first position X is opened.
5 or the pilot pressure oil from the extension side pilot valve 18A via the extension side switching valve 19A at the second position Y is output to the control valve extension side pilot port 17a. The output pressure increases and decreases in response to a control command output from the control unit 23 to the drive circuit of the solenoid 20d.

The extension-side pressure sensor 21A detects the pressure of the pilot pressure oil output from the extension-side pilot valve 21A. The detection signal of the extension-side pressure sensor 21A is supplied to the control unit 23. To be entered.

On the other hand, the control unit 23 is constructed by using a microcomputer or the like, and includes a relative angle (actual boom angle α _act described later) of the rear boom 6 with respect to the upper swing body 3. A boom angle sensor 24 for detecting, an offset angle sensor 25 for detecting a relative angle of the front boom 7 with respect to the rear boom 6 (actual offset angle γ _act described later), and a relative angle of the arm 8 with respect to the front boom 7 (actual angle described later). Arm angle sensor 2 for detecting arm angle β _act )
6. The extension-side and reduction-side pressure sensors 21A and 21B provided in the extension-side and reduction-side pilot oil passages of the arm cylinder 12 described above, and similarly, the extension-side and reduction-side pilots of the boom cylinder 10. The extension-side and reduction-side pressure sensors 27A, 27B provided in the oil passages, respectively.
Signals from various sensors and switches, such as extension-side and contraction-side pressure sensors 28A and 29B provided in the extension-side and contraction-side pilot oil passages of the offset cylinder 11, respectively, are input. Based on the signal, setting, calculation, selection, etc. are performed by various setting devices, computing devices, selectors and the like, which will be described later. , The reducing valve 20A,
0B, extension side and reduction side electromagnetic proportional pressure reducing valves 29A and 29B provided in the extension side and reduction side pilot oil passages of the boom cylinder 10 in the same manner, and extension side and reduction side pilot oil of the offset cylinder 11, respectively. Extension-side and reduction-side electromagnetic proportional pressure reducing valves 30A, 3
It is configured to output a control command to 0B or the like.

Next, various setting units, arithmetic units, selectors and the like provided in the control unit 23 will be described with reference to FIGS. 5 to 8. In the block diagram of FIG.
B is an arm operation signal setting device on the extension side and the reduction side,
The pressure sensors 21A, 2A, 2A, 2B, 2C, 2C, 2C, 2C, 2C, 2C, 2C and 2C are provided on the extension side and the reduction side
1B, and outputs and sets arm operation signals for the extension-side and reduction-side electromagnetic proportional pressure reductions 20A and 20B based on the detection signals. In this case, the arm operation signal setting devices 31A and 31B
As shown in the characteristic diagrams (A) and (B) of FIG.
A, 21A, 21B, that is, a pressure for generating a pressure equal to the output pressure of the arm pilot valves 18A, 18B to the arm electromagnetic proportional pressure reducing valves 20A, 20B.
Set a signal of ~ 100%. Reference numeral 32 denotes a predicted offset increase angle setting device, which inputs a detection signal from a pressure sensor 28B provided in a reduction-side pilot oil passage of the offset cylinder 11, and sets an offset angle based on the input signal. The expected increase angle Δγ is set and output. In this case, the expected offset increase angle setting unit 32
As shown in the characteristic diagram of FIG.
When the detected pressure of B, that is, the output pressure of the offset reducing pilot valve (not shown) increases, the expected increase angle Δγ is set to increase. 33 is a first adder, which adds the actual offset angle γ _act detected by the offset angle sensor 25 and the expected offset increase angle Δγ output from the expected offset increase angle setting unit 32. , And outputs the sum as the expected offset angle γ _exp . 34A and 34B are extension-side and reduction-side predicted boom increase angle setting devices, which are detected by extension-side and reduction-side pressure sensors 27A and 27B provided in the pilot oil passage of the boom cylinder 10. A signal is input, and expected increase angles Δα ₁ and Δα ₂ of the boom angle are set and output based on the input signal. In this case, the extension-side predicted boom increase angle setting device 3
4A, as shown in the characteristic diagram of FIG. 7 (B), the detected pressure of the extension-side pressure sensor 27A, that is, the output pressure of the boom extension side pilot valve (not shown) increases the expected increase angle [Delta] [alpha] ₁ is positive Is set to be larger.
Further, the reduction-side expected boom increase angle setting device 34B is provided in the manner shown in FIG.
As shown in the characteristic diagram of (C), the detected pressure of the reduced pressure sensor 27B, that is so that the output pressure of the boom contraction side pilot valve (not shown) and becomes larger than expected increase angle [Delta] [alpha] ₂ increases on the negative side Is set. Reference numeral 35 denotes a second adder, which is an actual boom angle α _act detected by the boom angle sensor 24 and a predicted boom increase angle setting unit 34A, 34B on the extension side or the reduction side. The boom increase angles Δα ₁ and Δα ₂ are added, and the sum is output as an expected boom angle α _exp . Reference numeral 36 denotes an arm limit angle calculator which calculates an arm limit angle based on the predicted offset angle γ _exp output from the first adder 33 and the predicted boom angle α _exp output from the second adder 35. The limit angle β _LT is calculated and output. The calculation of the arm limit angle β _LT will be described later. A subtractor 37 subtracts the actual arm angle β _act detected by the arm angle sensor 26 from the arm limit angle β _LT calculated by the arm limit angle calculator 36, and subtracts the subtracted result. Is output as the angle deviation Δβ. Numeral 38 denotes a PI control arithmetic unit which performs a PI control (proportional-integral control) operation based on the angle deviation Δβ output from the subtracter 37, and includes a proportional gain setting unit 38a , An integral gain setter 38b, an integral calculator 38c, and a third adder 38d for adding the proportional component and the integral component. It is set so that it is reset when the reduction-side arm operation signal is output from 31B. 39A, 39B
Are arm control signal setting devices on the extension side and the reduction side,
This sets and outputs the extension side and reduction side arm control signals for the arm electromagnetic proportional pressure reducing valves 20A and 20B based on the output value P from the PI control calculator 38. In this case, the extension side arm control signal setting unit 3
9A, as shown in the characteristic diagram of FIG. 8A, when the output value P of the PI control calculator 38 is minus (P <0), the output valve path of the extension side electromagnetic proportional pressure reducing valve 20A is fully closed. 0
%, And when the output value P is equal to or more than a preset plus value D (P ≧ D), a 100% signal for fully opening the output valve path is output, and the output value P becomes zero. When the output pressure P increases from 0% to less than 100%, the signal is set so that the output pressure increases as the output value P increases. ing. As shown in the characteristic diagram of FIG. 8B, when the output value P of the PI control calculator 38 is plus (P> 0), the reduction-side arm control signal setter 39B sets the reduction-side electromagnetic proportional pressure-reducing valve 20B. A 0% signal for fully closing the output valve path is output, and when the output value P is equal to or less than a preset negative set value E (P ≦ E), a 100% signal for fully opening the output valve path is output. Output, and the output value P is between the set value E and zero (E <P ≦ 0).
In this case, the output pressure P is set so that the output pressure of the electromagnetic proportional pressure reducing valve 20A increases as the output value P increases to the minus side. Reference numeral 40 denotes a MIN signal selector, which is an extension-side arm operation signal setting unit 31.
A minimum value is selected from the extension side arm operation signal output from A and the extension side arm control signal output from the extension side arm control signal setting unit 39A, and the selected signal value is used as the extension side arm drive signal. Is output to the drive circuit of the arm extension side electromagnetic proportional pressure reducing valve 20A. Reference numeral 41 denotes a MAX signal selector which is a reduction side arm operation signal output from the reduction side arm operation signal setting unit 31B and a reduction side arm control signal output from the reduction side arm control signal setting unit 39A. Is selected, and the selected signal value is output to the drive circuit of the reduction side electromagnetic proportional pressure reducing valve for arm 20B as the reduction side arm drive signal.

Next, the control procedure of the control unit 23 will be described. First, the extension-side and reduction-side arm operation signal setting units 31A and 31B are operated based on the detection signals of the pressure sensors 21A and 21B. The arm-side proportional pressure reducing valves 20A, 20B are set with extension-side and reduction-side arm operation signals for generating a pressure equal to the output pressure from the pilot valves 18A, 18B, and the MIN signal selector 4
0, and output to the MAX signal selector 41, respectively.

On the other hand, the offset expected increase angle setting device 32
Sets the expected offset increase angle Δγ based on the detection signal from the reduction side offset pressure sensor 28B,
Output to the first adder 33. And the first adder 33, to the actual offset angle gamma _act detected by the offset angle sensor 25, by adding the offset forecast increase angle [Delta] [gamma], to calculate the estimated offset angular gamma _exp. Similarly, the expected boom increase angle setting device 34 on the extension side and the contraction side
A and 34B are the boom pressure sensors 2 on the extension side and the reduction side.
The predicted boom increase angles Δα ₁ and Δα ₂ are set based on the detection signals from 7A and 27B, and output to the second adder 35. In the second adder 35, the boom angle sensor 2
The actual boom angle alpha _act detected by 4, the expected boom increased angle [Delta] [alpha] _1, by adding [Delta] [alpha] _2, to calculate the estimated boom angle alpha _{ex p.}

The arm limit angle calculator 36 calculates an arm limit angle β _LT based on the expected offset angle γ _exp and the expected boom angle α _exp calculated by the first and second adders 33 and 35. . Here, FIG. 9 shows the distal end a of the rear boom 6, the distal end b of the front boom 7, and the distal end c of the arm 8 when the upper swing body 3 is viewed from the side.
The origin O is a swing fulcrum of the rear boom 6 with respect to the upper revolving unit 3, the X axis is a direction facing the front and rear direction with respect to the upper revolving unit 3, and the Y axis is a vertical direction. FIG. 10 is a view taken in the direction of the arrow A in FIG. 9, and the Z axis is a direction in the left-right direction. The boom angle α is an angle between the X axis and a straight line R _ob connecting the origin O and the tip b of the front boom 7 in FIG. 9, and the arm angle β is the straight line R in FIG.
_The offset angle γ is an angle formed between the front boom 7 moved to the left and the X axis in FIG. 10, and the boom angle sensor 24 and the arm angle The boom angle α, the arm angle β, and the offset angle γ detected by the sensor 26 and the offset angle sensor 25 are the actual boom angle α, respectively.
_act , actual arm angle β _act , actual offset angle γ
_act . Incidentally, the boom angle detection means of the present invention includes both the boom angle sensor 24 and the offset angle sensor 25 of the present embodiment, and the boom angle of the present invention is:
It includes both the boom angle α and the offset angle γ of the present embodiment. Further, the interference avoidance area H shown in FIG. 9 is an area set such that the bucket 9 should not approach the cab 4 any more. The trajectory when the tip c of the arm 8 is closest to the cab 4 when the tip c of the arm 8 is moved so as not to enter the cab 4 has a margin (dead zone) as an interference avoidance boundary line L. Show. First, the arm angle (the arm angle is referred to as an arm limit angle β _LT ) and the boom when the arm tip c is located at an arbitrary point (X _LT , Y _LT ) on the interference prevention boundary line L A relational expression for the angle α is derived. In FIG. 9, the distance _roc from the origin O to the arm tip c is given by the following equation. ^{_{r oc = {r ob 2 +}} L bc 2 -2r ob L bc cos (π-β LT)} 1/2 ··· (1) However, FIG. 9, _{r ob} Figures 10 is given by the following equation. ^{_{r ob = (L oa 2 +}} r ab 2 -2L oa r ab cosθ) 1/2 ··· (2) r ab = L ab cosγ ··· (3) where, _{L oa:} length of Riabumu 6 L _ab: length of the front boom 7 L _bc: length of the arm 8 theta: angle (constant value) between Riabumu 4 and the front boom 5 in FIG. 9 on the other hand, the tip portion c of the arm 8 is interference prevention border on L , The following equation holds. r _oc = (X _LT ² + Y _LT ² ) ^1/2 (4) From equations (1) and (4), the arm limit angle β _LT is expressed by the following equation. β _LT = π−cos ⁻¹ {( _rob ² + _Lbc ² −X _LT ² −Y _LT ² ) / 2r _{ob Lbc} } (5) Next, the arm limit angle β _LT and the boom angle α Guide relationship. The following equation holds from Δobc. r _LT / sin (π−β) = L _bc / sin (α−ε) (6) where ε = cos ⁻¹ (X _LT / r _LT ) (7) r _LT = (X _LT ² + Y _LT ² ) ^1/2 (8) The formula (6) is arranged to derive the boom angle α. α = sin ⁻¹ {r _LT sin (π−β _LT ) / L _bc } + ε (9) From the above equations (1) to (9), if the coordinates on the interference prevention boundary line L are set, The arm limit angle β _LT with respect to the boom angle α can be obtained using the offset angle γ as a parameter, and based on this, the function table β _LT = f
(Α, γ) can be created. Here, the boom angle α and the offset angle γ used in the above calculation are the expected boom angle α _exp calculated by the second adder 35 and the expected offset angle γ _exp calculated by the first adder 33.
The tip end portion b of the coordinates of the front boom 7 _{(X b, Y} b)
The coordinates ( _Xc , _Yc ) of the tip c of the arm 8 are given by the following equations. _{X b = r ob cosα ··· (} 10) Y b = r ob sinα ··· (11) X c = L bc cos (β-α) + X b ··· (12) Y c = L bc sin ( _{β-α) + Y b ···} (13)

Next, in a subtractor 37, the arm limit angle β _LT calculated by the arm limit angle calculator 36 is set.
The actual arm angle β detected by the arm angle sensor 26
_{The act} is fed back to determine the angle deviation Δβ, and the PI control calculator 38 performs the PI control calculation based on the angle deviation Δβ.

In the PI control calculator 38, a proportional component obtained by multiplying the angle deviation Δβ by a proportional gain in a proportional gain setting unit 38a, and an integral gain setting unit 38b
Is added by the third adder 38d to the integral component obtained by integrating the value obtained by multiplying the integral gain by the integration calculator 38c. The integration calculator 38c has upper and lower limiters, and is reset to zero when the reduction (out) side arm operation signal is output from the reduction side arm operation signal setting unit 31B.

In the PI control calculation, when the arm tip c is sufficiently separated from the interference prevention boundary line L and the bucket 9
When the arm 8 is operated to the in side in a state where there is no possibility that the arm 8 enters the interference area H, in this case,
The angle deviation Δβ output from the subtractor 37 is a large positive value, and the PI control calculator 38 outputs a positive signal larger than the set value D. As a result, a 100% signal is output from the extension (in) side arm control signal setter 39A. In addition, the extension side arm operation signal setting device 3
Since 1A outputs a signal exceeding 0% to 100%, it is smaller or equal to the output signal of the extension-side arm control signal setting unit 39A. Therefore, the output signal of the extension-side arm operation signal setting unit 31A is output. Is selected by the MIN signal selector 41, and this is output as a drive signal to the extension-side electromagnetic proportional pressure reducing valve 20A. Thus, the extension side arm electromagnetic proportional pressure reducing valve 20A outputs pilot pressure oil having a pressure equal to the output pressure of the extension side arm pilot valve 18A to the extension side pilot port 17b of the arm control valve 17. On the other hand, since the PI control calculator 38 outputs a plus signal as described above, 0% is output from the reduction (out) side arm control signal setter 39B.
Is output. Since the reduction (out) side of the arm cylinder 12 is not operated, the reduction-side arm operation signal setting unit 31B outputs a 0% signal. Therefore, the MAX signal selector 40 outputs a 0% signal, and the output valve path of the reduction side arm electromagnetic proportional pressure reducing valve 20B is fully closed. Further, in the hydraulic circuit diagram of FIG. 3, since the reduction side switching valve 19B is located at the first position X, the oil discharged from the arm control valve reduction side pilot port 17b is discharged from the reduction side electromagnetic proportional pressure reducing valve 20B, Reduction side switching valve 1
9B, tank 1 via reduction side pilot valve 18B
It is led to 6. Thus, the arm control valve 17 is controlled by the output pressure of the extension-side pilot valve 18A. That is, the arm tip c is located at the interference avoidance boundary line L
When it is far away from the arm, the arm-in operation is performed at a speed corresponding to the operation of the arm operating tool 22.

When the arm 8 is operated alone or in combination with the rear boom 6 and the front boom 7 in the direction in which the arm tip c approaches the interference prevention boundary line L from the state described above, the actual arm angle β _act becomes the arm limit angle. As it approaches β _LT , the deviation angle Δβ output from the subtractor 37 gradually decreases. As a result, the output value P of the PI control calculator 38 also becomes smaller, and when the output value P becomes smaller than the set value D, the output signal from the extension-side arm control signal setter 39A becomes smaller than 100%. When the output signal of the extension-side arm control signal setter 39A becomes smaller than the output signal of the extension-side arm operation signal setter 31A, the signal of the smaller extension-side arm control signal setter 39A is changed by the MIN signal selector 40. This is selected and output as a drive signal to the extension side arm electromagnetic proportional pressure reducing valve 20A.
As a result, the actual arm angle β _act becomes the arm limit angle β
_{As LT} approaches, the output pressure of the extension-side electromagnetic proportional pressure reducing valve 20A decreases, and the pilot pressure oil reduced in pressure by the extension-side electromagnetic proportional pressure reducing valve 20A is supplied to the arm control valve extension side pilot port 17a. Will be done. Thus, as the arm tip c approaches the interference avoidance boundary line L, the operating speed of the arm-in is reduced and stopped.

From the state described above, when the arm end c is operated in a direction approaching the interference avoidance boundary line L and the actual arm angle β _act becomes smaller than the arm limit angle β _LT ,
Since the PI control calculator 38 has a negative output, a 0% signal is output from the extension-side arm control signal setter 39A. Thus, the extension-side arm control signal setting device 3
The signal of 0% of 9A is selected by the MIN signal selector 40, and the output valve path of the extension side arm electromagnetic proportional pressure reducing valve 20A is fully closed. On the other hand, as described above, the PI control
Outputs a minus signal, so that a signal exceeding 0% to 100% is output from the reduction-side arm control signal setting unit 39B. At this time, since the reduction (out) side of the arm cylinder 12 is not operated, the reduction-side arm operation signal setter 31B outputs a 0% signal. Therefore,
The signal of the reduction-side arm control signal setting unit 39B is selected by the MAX signal selector 41, and this signal is reduced (out).
It is output as a drive signal to the side arm electromagnetic proportional pressure reducing valve 20B. In this case, in the hydraulic circuit diagram of FIG.
Since the reduction side switching valve 19A is located at the first position X,
The pilot pressure oil from the pilot hydraulic pressure source 15 passes through the reduction side switching valve 19B and the reduction side electromagnetic proportional pressure reducing valve 20B,
It is supplied to the reduction side pilot port 17b of the arm control valve 17. Thus, the arm control valve 17 is controlled by the output pressure of the reduction side electromagnetic proportional pressure reduction 20B, whereby the arm cylinder 12 is reduced, the arm 8 automatically comes out, and the bucket 9 interferes. Invasion into the avoidance area H can be avoided. In this embodiment, the expected offset increase angle setting device 32 and
First adder 33 and extension-side predicted boom increase angle setting device 3
4A, a reduction-side expected boom increase angle setting unit 34B, a second adder 35, and an arm limit angle calculator 36 constitute an arm limit angle setting means 46 of the present invention. Arithmetic unit 38, extension side arm control signal setting unit 39A, reduction side arm control signal setting unit 39B
This constitutes the control signal setting means 47 of the present invention. Further, the operation signal setting means of the present invention corresponds to the extension-side arm operation signal setting device 31A and the reduction-side arm operation signal setting device 31B in the present embodiment, and the selection means of the present invention corresponds to It corresponds to the MIN signal selector 40 and the MAX signal selector 41.

In the configuration described above, the operation of the arm 8 is performed in response to the operation of the operating tool 22 when there is no fear that the bucket 9 will enter the interference avoidance area H. When the part c approaches the environmental avoidance boundary line L, the operation of the arm-in is automatically decelerated, and when the part c approaches the interference avoidance boundary line L, the arm 8 automatically operates out, and the bucket 9 enters the interference avoidance area H. Can be avoided.

As a result, for example, when the bucket 9 approaches the cab 4 when the boom lift and the arm-in are combinedly operated with the front boom 7 offset to the left to take a small turning posture, The operation of raising the boom is continued while the arm 8 is automatically out and the bucket 9 is prevented from entering the interference avoidance area H, so that the work is stopped as in the conventional case. Work efficiency is improved.

In this method, the arm limit angle β _LT is set based on the boom angle and the offset angle,
An angle deviation Δβ between the set arm limit angle β _LT and the actual arm angle β _act input from the arm angle sensor 26 is obtained, and the automatic out operation of the arm 8 is performed based on the angle deviation Δβ. However, in this case, as the boom angle and the offset angle for setting the arm limit angle β _LT , the actual boom angle α _act input from the boom angle sensor 24 is set to the extension side and the reduction side boom pilot valve. The predicted boom angle α _exp calculated by adding the predicted boom increase angles Δα ₁ and Δα ₂ set based on the output pressure, and the actual offset angle γ _act input from the offset angle sensor 25, to the offset reduction side. The expected offset angle calculated by adding the expected offset increase angle Δγ set based on the output pressure of the pilot valve γ _exp is used. As a result, the arm limit angle β _LT corresponding to the operation state of the rear boom 6 and the front boom 7 can be set, and even if the operating speed of the rear boom 6 and the front boom 7 is high, the arm limit angle β _LT can be quickly followed. The operation of avoiding interference of the arm 8 can be performed. Moreover, the expected boom angle α _exp and the expected offset angle γ
_Since the angle deviation Δβ between the arm limit angle β _LT set based on the _exp and the actual arm angle α _act is PI-controlled to control the interference avoiding operation of the arm 8, more accurate control is performed. It can be carried out.

[Brief description of the drawings]

FIG. 1 is a side view of a hydraulic excavator.

FIG. 2 is a plan view of the hydraulic excavator showing a state where the front boom is swung right and left.

FIG. 3 is a hydraulic control circuit diagram of an arm cylinder.

FIG. 4 is a block diagram showing input / output of a control unit.

FIG. 5 is a block diagram of interference avoidance control.

6A is a characteristic diagram of an extension-side arm operation signal setting device, and FIG. 6B is a characteristic diagram of a reduction-side arm operation signal setting device.

7A is a characteristic diagram of an expected offset increase angle setting device, FIG. 7B is a characteristic diagram of an extension expected boom increase angle setting device, and FIG. 7C is a characteristic diagram of a reduction expected boom increase angle setting device. is there.

8A is a characteristic diagram of the extension-side arm control signal setting device, and FIG. 8B is a characteristic diagram of the reduction-side arm control signal setting device.

FIG. 9 is an explanatory diagram showing a boom angle, an arm angle, and an arm limit angle.

FIG. 10 is an explanatory diagram showing an offset angle.

FIG. 11 is a hydraulic control circuit diagram of a hydraulic actuator showing a conventional example.

[Explanation of symbols]

 Reference Signs List 4 cab 6 rear boom 7 front boom 8 arm 9 bucket 20A extension side electromagnetic proportional pressure reducing valve for arm 20B arm reduction side electromagnetic proportional pressure reducing valve 21A arm extension side pressure sensor 21B arm reduction side pressure sensor 23 control unit 24 boom angle sensor 25 Offset angle sensor 26 Arm angle sensor 27A Boom extension side pressure sensor 27B Boom reduction side pressure sensor 28B Offset reduction side pressure sensor 31A Extension side arm operation signal setting unit 31B Reduction side arm operation signal setting unit 32 Expected offset increase angle Setting device 33 First adder 34A Extension-side expected boom increase angle setter 34B Reduction-side expected boom increase angle setter 35 Second adder 36 Arm limit angle calculator 37 Subtractor 38 PI control calculator 39A Extension arm control signal Setting device 9B reduction side arm control signal setting unit 40 MIN signal selector 41 MAX signal selector H interference avoidable range

Continuation of the front page (56) References JP-A-8-333767 (JP, A) JP-A-7-207712 (JP, A) JP-A-2-120426 (JP, A) JP-A-8-284199 (JP) , A) (58) Field surveyed (Int.Cl. ⁷ , DB name) E02F 3/43 E02F 9/24

Claims (5)

(57) [Claims] 1. An arm which can swing up, down, left and right with respect to a machine body.
Fset-type boom, and the front end of the boom
And an arm connected to the distal end of the arm.
For work machines equipped with attachments that are
Of the attachment into the specified interference avoidance area.
In providing the interference avoidance control means for avoiding, the interference avoidance control means includes:Pressure sensor installed in the pilot oil passage of the boom cylinder
Of boom angle set corresponding to detected pressure
An expected boom angle setting device that outputs an increasing angle, The expected boom angle setting device, Shaking of the boom against the machine body
Boom angle detecting means for detecting a moving angle, and
Arm angle detection means for detecting the swing angle with respect to the boom
From the boom angle detection means
For the input boom angleThe set expected increase angle is
AddPredict the expected boom angle, and
The attachment does not enter the interference avoidance area based on
Limit angle setting means for setting the limit angle of the arm
From the set arm limit angle and arm angle detecting means.
Calculate the angle deviation from the input arm angle and calculate the angle deviation.
To perform automatic interference avoidance operation of the arm based on the
Control signal setting to set the control signal for the
For avoiding interference of a working machine comprising:
Control device. 2. The arm limit angle setting means according to claim 1, wherein the arm limit angle setting means inputs a signal from an operation state detection means for detecting an operation state of the boom drive means by the boom operation tool,
An interference of a working machine having a configuration in which an expected boom angle is predicted using the detected boom operation state and a boom angle input from the boom angle detection means, and an arm limit angle is calculated based on the predicted boom angle. Avoidance control device. 3. The work machine interference avoidance control device according to claim 1, wherein the control signal setting means performs a proportional-integral control operation when setting the control signal based on the angle deviation. 4. The apparatus according to claim 1, wherein the interference avoidance control means includes an operation signal setting means for setting an operation signal to the arm driving means based on an operation of the arm operating tool, and the operation signal setting means. A work machine interference avoidance control device provided with a selection means for selecting one of an operation signal from a means and a control signal from a control signal setting means and outputting the selected signal to an arm driving means. 5. The interference avoiding control means according to claim 1, wherein the arm avoids the interference avoiding area when the attachment approaches the interference avoiding area at least in a state where the boom is swinging. A work machine interference avoidance control device provided with a mechanism for continuing the boom swing while avoiding the attachment from entering the interference avoidance area by swinging the boom.