JPH07109748A - Interference prevention controller of working machine - Google Patents

Abstract

PURPOSE:To ensure safety to control an interference prevention controller at a position not interfering with at least an operation room without operating a system manually by resetting the system in the case something is wrong with angle sensors. CONSTITUTION:An interference prevention controller is equipped with a hydraulic driving circuit 70 driving the front consisting of a first boom, a second boom and an arm, an operating section 60 calculating a position of a bucket provided to the front end of the arm through detection output from angle sensors 31, 32 and 33 detecting turning angles of connections of the front and a driving control section 77 inhibiting the front from moving in the case the bucket enters an interference dangerous resion besides a moving speed of the front is controlled by the operating section 60. In the operating section 60, when any output of the angle sensors 31-33 shows abnormal value, an abnormality detection section 65 outputs most interference measured value instead of the abnormal value as virtual value to a co-ordinate operating section 61, the position of the bucket is calculated to output to the driving control section 77.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an interference of a work machine such as a hydraulic excavator, which mainly stops the operation of each front member when the front of the work machine for excavating work approaches a driver's cab to avoid a collision. More particularly, the present invention relates to an interference prevention control device for a work machine capable of performing appropriate processing when an angle sensor indicates an abnormal value.

[0002]

2. Description of the Related Art An interference prevention device for a work machine of this type is disclosed in, for example, Japanese Patent Laid-Open No. 4-11128. An interference prevention device for a work machine according to this conventional technique will be described with reference to FIGS. 9 and 10. FIG. 9 shows an interference danger area Zi (i = 1 to 4) between the front and the driver's cab 103 and a front deceleration area Li set by this conventional technique.
FIG. 10 is a diagram showing (i = 1, 2), and FIG.
FIG. 6 is a diagram showing setting of cylinder speeds of front members forming the front in FIG. It should be noted that this explanatory view shows a first boom pivotally connected to the working machine body by a pin, a second boom connected laterally to the first boom by an offset cylinder, and a second boom. The figure shows one applied to a working machine including a front formed of an arm that is rotatably pin-connected to two booms and a bucket that is rotatably pin-connected to this arm.

In this conventional technique, as shown in FIG. 9, a first interference danger area (Z ₁ , Z ₃ ) and a second interference danger area (Z ₂ , Z
₄ ) and the deceleration area (L ₁ , L ₂ ) is set outside the interference danger area. Then, in the first interference danger area and the second interference danger area, the operations of the first boom, the second boom, the arm, and the bucket are regulated according to the distance between the bucket and the cab 103, respectively. That is, the second interference risk area (Z ₂ , Z ₄ ) closer to the cab 103 than the first interference risk area (Z ₁ , Z ₃ ).
Then, the operation toward the side closer to the cab 103 is as follows:
While the boom, arm, and bucket are all prohibited, in the first interference danger area (Z ₁ , Z ₃ ), the first and second
Boom and arm movements are prohibited, but bucket movements are not restricted.

Further, when the bucket enters the deceleration area L _i , the speeds of the first boom, the second boom and the arm are gradually decreased as the bucket approaches the interference danger area as shown in FIG. . In the deceleration area L _i and the interference danger area Z _i , the operation toward the driver's cab 103 side is restricted, but the operation in the away direction is not restricted.

Therefore, in the above-mentioned prior art, when the driver's cab 103 and the bucket approach each other, the operating speed of each front member is gradually decreased, and when the approaching state becomes closer, the operation of the front is stopped. In addition to ensuring the safety of personnel, the width of the danger area of interference can be narrowed, so that the work range can be widened.

By the way, this type of interference prevention device is
An angle sensor is used to detect the positions of the boom, the second boom, and the arm, but when the angle sensor shows an abnormal output due to a disconnection, a short circuit, a failure, or the like, a valve drive output is generally output from a microcomputer, which is a control device. Controls are in place to prohibit or cut pilot pressure to prohibit full hydraulic operation. This is a measure for avoiding the bucket from colliding with the cab 103 due to abnormal operation.

[0007]

By the way, when the valve drive output is prohibited by the microcomputer at the time of the abnormal output of the angle sensor or the pilot pressure is cut to prohibit the full hydraulic operation, the boom raising operation and the arm cloud operation are performed. Since it is not possible to perform operations such as operations in the raising direction at all, it is not only impossible to continue work unless the system is released, but also the work machine may not even be able to get out of the place where it is currently working. . In such a case, it is possible to manually operate the system only after the system is released, and it is possible to escape from this state by the manual operation.

To release the system, for example, it is necessary to press a reset button (system release button), but this operation button is placed on the back side of the seat or the like so as not to be operated by mistake during normal work. It is provided so that manual operation cannot be performed unless this button is pressed. However, as an operator, when it comes to the above state, it is troublesome to operate with the button pressed, so for example, you may continue the work manually by putting the button in the button with gum game. . Working in this way is dangerous and can cause accidents.

The present invention has been made in view of such a background, and an object thereof is at least a driver's seat without an operator resetting the system and manually operating the system when an abnormality occurs in the angle sensor. At a position that does not interfere with
An object of the present invention is to provide an interference prevention control device for a work machine that can be operated while ensuring safety.

[0010]

To achieve the above object, the present invention provides a first boom, a second boom movably laterally connected to the first boom by an offset cylinder.
Drive means for driving the front composed of a boom and an arm, a boom angle sensor for detecting a rotation angle of the first boom, an arm angle sensor for detecting a rotation angle of the arm, and a lateral side of the second boom. Calculating means for calculating the position of the bucket provided at the tip of the arm from the detection output from the offset angle sensor indicating the amount of movement in the direction, and front movement speed control corresponding to the bucket position calculated by this calculating means Along with this, when it is determined that the bucket has entered a preset interference risk area, it is provided with control means for prohibiting movement of the front, and prevents interference between the front of the working machine and the working machine body including the driver's seat. In the work implement interference prevention control device, when the output of any one of the angle sensors shows an abnormal value, the calculation means determines the difference. Instead of the output value of the angle sensor indicated a value, it calculates the position of the bucket a preset highest interfering value as a virtual value, and set to be output to the control means.

[0011]

In the above arrangement, the calculating means calculates the position of the bucket using the preset most interference side value as a virtual value instead of the abnormal value of the angle sensor, and outputs it to the control means. As a result, the control means controls the moving speed of each part of the front part based on the position information of the bucket input from the calculation means, so that at least dangerous operations in the raising direction such as boom raising operation and arm cloud operation are sufficiently decelerated. It Therefore, when the bucket enters the interference danger area and comes to a position where it interferes with the driver's seat, it can be completely stopped visually, avoiding an inoperable state, and replacing the virtual area with the deceleration area. If the vehicle does not enter any of the interference risk areas, the vehicle is not decelerated, and normal work can be continued.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

First, an outline of the working machine will be described. As shown in the side view of the working machine of FIG. 3, the working machine includes a working machine body 2 mounted on the traveling device 1, a first boom 11 rotatably provided on the working machine body 2, First boom 1
As shown in FIG. 4, the second cylinder 12 horizontally moves the arm 14 and the bucket 15 in parallel with each other by the offset cylinder 22, the arm 14 rotatably provided on the second boom 12, and the arm 14 Against pin 51
The present invention is applied to a hydraulic excavator including a front 10 including a bucket 15 that is rotatably connected by. In addition, O ₁ shown in FIGS. 3 and 4 indicates a connecting portion between the working machine body 2 and the first boom 11, O ₂ indicates a connecting portion between the first boom 11 and the second boom 12, and O ₃ indicates a first connecting portion. 2 The connecting portion between the boom 12 and the arm 14, O ₄ indicates the arm 14 and the bucket 1.
5 shows a connection part with 5. The first boom 11, the second boom 12, the arm 14, and the bucket 15 are operated by the hydraulic cylinders 21, 22, 23, and 24, respectively.

In addition, the main body 2 and the first boom 11, the first boom 11 and the second boom 12, the second boom 12 and the arm 14
Angle sensors 31, 32, 33, such as potentiometers, for detecting relative angles α, β, γ between the front members are provided in the vicinity of the respective connecting portions with and. Then, relative angle signals α, β between the front members detected by these angle meters 31, 32, 33,
γ is input to the arithmetic unit 60 as the arithmetic means shown in the control block diagram of FIG. In addition, these goniometers 31, 3
The output values from 2, 33 are checked by the abnormality detecting section 65.

Based on the angle signals α, β and γ, the arithmetic unit 60 calculates the coordinates (x ₄ , y ₄ , etc.) of a predetermined position on the front 10, for example, the center O ₄ of the connecting portion between the arm 14 and the bucket 15.
z ₄ ), and a deceleration region for reducing the moving speed of only the first boom 11 or the first boom 11 and the arm 14 by the coordinate calculation unit 61 and the coordinate values (x ₄ , y ₄ , z ₄ ). Set deceleration area storage unit 63
When the coordinate value of _{O 4 (x 4, y 4} , z 4) regions to prohibit the operation of all of the front member in accordance with, i.e., the interference dangerous zone storage unit 64 that the interference dangerous zone is set, O ₄ Based on the coordinate values (x ₄ , y ₄ , z ₄ ) of the above, it is determined whether the front 10 has entered the deceleration area (L _i described above) or the interference risk area (Z _i described above). Depending on the result, the arm cylinder 23 and the first boom cylinder 2
A comparison calculation unit 62 including means for outputting a speed signal of 1;
A signal from the comparison calculation unit 62 and an instruction signal from an operation lever 69 for operating each front member provided in the operator's cab 3 are input, and drive means for supplying hydraulic oil to each cylinder based on these signals. Drive control section 77 as control means for outputting a drive control signal to the hydraulic drive circuit 70 as
It has and. The coordinate value of O ₄ (x ₄ , y ₄ , z
₄ ), the coordinate system (x, y,
As z), for example, calculation is performed with the connection center O ₁ between the main body 2 and the first boom 11 as the coordinate origin.

Further, the abnormality detecting section 65 checks whether the detection output values from the angle sensors 31, 32, 33 deviate from the normal range. If it deviates, the value on the most interference side, which will be described later, is replaced with the detected value of the angle sensor indicating the abnormal value, and the value is output to the coordinate calculation unit 61 side.

The drive control unit 77 calculates the moving speed of the arm 14 and the first boom 11 based on the maximum speed signal from the comparison calculating unit 62 and the instruction signal from the operating lever 69, and the moving speed. Cylinder 2 corresponding to
Flow rate calculation unit 67 for calculating the flow rate of hydraulic oil to 1, 23
And a converter 6 for converting into a drive control signal according to this flow rate.
And 8 are formed. The hydraulic drive circuit 70 is
It is composed of a control valve (not shown) or the like, and supplies hydraulic oil of a flow rate according to the drive control signal to each of the cylinders 21 and 23.

The operation of the embodiment configured as described above is shown in FIG.
This will be described with reference to the flowchart shown in The calculation unit 60 first takes in the values of the angle signals α, β, γ from the respective goniometers 31, 32, 33 in step S1, and in step S2, normalizes the abnormal values preset by the abnormality detection unit 65. Compare the values with the boundary values α _1, α ₂ , β _1, β ₂ , γ _1, γ ₂ . That is, the angle between the work implement body 2 and the first boom 11
: Α ₁ <α <α ₂ Offset angle of the second boom 12 with respect to the first boom 11: β ₁ <β <β ₂ Angle between the second boom 12 and the arm 14
: Γ ₁ <γ <γ ₂ is compared. If the detected value is within the above range, it is regarded as normal and the angle α,
From the values of β and γ, the coordinate calculation unit 61 calculates each connecting portion O ₁ , O ₂ ,
The coordinates of O ₃ and O ₄ are calculated to calculate the angle between the first boom 11 and the work machine body 2, the offset angle of the second boom 12, and the angle of the arm 14 with respect to the second boom 12,
In step S4, the position of the tip of the bucket 15 is calculated. The position of the tip of the bucket 15 is approximated by the region of the movement trajectory of the bucket tip from the connecting portion O ₄ .

When the position of the tip of the bucket 15 is known in this manner, the coordinate value is output to the comparison calculation unit 62.
In the comparison calculation unit 62, the deceleration area storage unit 6 is used as step S5.
The coordinate value is compared with the deceleration region L _i set in 3. Next, in step S6, it is checked whether or not the bucket tip is in the deceleration region L _i , and if it is, the deceleration process is executed in step S7 and the process returns.

If it is determined in step S6 that the bucket tip is not in the deceleration area L _i , the interference risk area Z _i is compared with the coordinate value in step S8. Next, based on this comparison result, in step S9, whether the bucket tip is located in the interference danger area Z _i , that is, whether the bucket tip has reached the stop instruction position in front of the operator's cab, and from the offset angle, the bucket 15 is detected. Check if has reached the stop position on the side of the cab. If the bucket 15 has not reached the stop instruction position in this check, the front is moved as it is in accordance with the instruction signal from the operation lever 69 (step S10), and if it has reached the stop position, it is stopped (step S11).

On the other hand, if it is not within the above range in step S2, it is judged to be abnormal, and in step S12, the abnormality detector 6
Reference numeral 5 replaces the value of the angle sensor determined to be abnormal with the value on the most interference side and outputs the value to the coordinate calculation unit 61 side. Then, step S3
Perform the following processing. The most interfering side value in step S12 is the maximum winding angle for the arm 14, the maximum raising angle for the first boom 11, and the angle when the second boom 12 is located at the leftmost position. These three angle sensors 3
As a result of calculation based on the values detected by 1, 32, and 33, if the tip of the bucket 15 is in the deceleration region L _i , the deceleration process is executed in step S7. Based on the coordinate value calculated by substituting the above-mentioned most interference side value into the front 10 as shown in FIG.
The moving speed of is decelerated. However, as a result of the substitution as described above, when it is determined that the front end does not enter the deceleration region L _i , the front end moves at the same speed as usual, so in this case there is no reduction in work efficiency.

Here, the case where an abnormal value is indicated will be supplementarily described with reference to the drawings. That is, it is assumed that the arm angle sensor 33 outputs an abnormal value at the position where the bucket 15 is lowered as shown by the solid line in FIG. In this case, it is assumed that the bucket 15 is located at the position where the maximum wrap angle is shown by the alternate long and short dash line in FIG.
As a result, the bucket tip position is calculated assuming that the tip of the bucket 15 is at the position estimated by the most interference side value, and the subsequent processing is executed. Further, in the case of the offset angle sensor 32, if an abnormal value is output at the position of the solid line in FIG. 7, the position is calculated assuming that it is at the leftmost position shown by the alternate long and short dash line, and similarly. The subsequent processing is executed. Although not particularly shown when the position of the bucket 15 is on the side of the driver's cab 3, the position on the leftmost side of the deceleration region L _i on the right of the driver's cab 3, that is, the position closest to the interference risk region. It is also possible for the abnormality detection unit 65 to output a virtual value corresponding to.

An example of calculating the position of the tip of the bucket 15 in step S4 is shown below. First, the coordinates (x ₄ , y ₄ , z of the center point O ₄ of the connecting portion between the bucket 15 and the arm 14).
_The case of calculating ₄ ) will be described using the schematic diagram of the front shown in FIG. Note that FIG. 8B is a view of FIG. 8A viewed from the direction of arrow A. This FIG. 8 (a), (b)
As can be seen, the coordinate values of O ₄ (x ₄ , y ₄ , z ₄ )
Is x ₄ = l ₁ × cos θ ₁ + l ₂ × cos θ ₁ × cos θ ₂ + l ₃ × cos (θ ₁ −θ ₃ ) y ₄ = l ₁ × sin θ ₁ + l ₂ × sin θ ₁ × cos θ ₂ + l ₃ × sin ( θ ₁ −θ ₃ ) z ₄ = l ₃ × sin θ ₂ (1) Where l ₁ is the distance between O ₁ and O ₂ , and l ₂ is O
The distance between ₂ and O ₂ , l ₃ is the distance between O ₃ and O ₄ .
Since the bucket 15 to pivot pin 51 as the fulcrum, the bucket 15 tip operating range 71 indicated by the chain line in FIG. ^{5, r 2 = (x-x} 4) 2 + (y-y 4) 2 ····・ ・ (2) Here, r represents the turning radius of the bucket 15.

Further, the interference risk area Z _i is divided into the straight line portions Z _ia and X _ic and the curved portion Z _ib shown in FIG. 5 and set in the interference risk area storage unit 65 by the following function. That, = Z _ia region y = y ₁ region of ^{_{Z ib r 1 2 (x-}} x 10) 2 + (y-y 10) 2 Z ic region x = x ₁ ······ (3) of Here, x ₁ and y ₁ are preset constants, and x ₁₀ and y ₁₀ are coordinates of the center of curvature of the interference risk area Z _ib . Then, by solving the simultaneous equations of the above equations (2) and (3), it is determined whether or not there is an intersection of the two equations, that is, whether the tip of the bucket 15 can operate within the interference danger area Z _i . You can judge. If the solution is not obtained, the operation range 71 at the tip of the bucket 15 is not included in the interference risk area Z _i .

The deceleration area L _i is the interference danger area Z _i.
5 is divided into straight line portions L _ia and L _ic and curved line portion L _ib shown in FIG. 5, and x _{2 and} y ₂ are set in the deceleration area storage unit 63 as preset constants by the function shown below. There is.

[0026] L _ia region y = y ₂ L _ib region ^{_{r 2 2 = (x-x}} 10) 2 + (y-y 10) 2 L ic region x = x ₂ ······ (4 ) In the above-mentioned embodiment, the working machine having the cab entirely surrounded by the door, the window glass, etc. is explained, but the driver's seat normally called a canopy formed only by the frame protecting the driver. May be

[0027]

As is apparent from the above description, when any output of each angle sensor shows an abnormal value,
According to the present invention, in which the calculating means calculates the position of the bucket by using the most interfering side value as a virtual value instead of the output value of the angle sensor indicating the abnormal value, and outputs it to the control means, Since it is possible to control the position assuming the worst condition for the interference of the position sensor, if there is an abnormality in the angle sensor, the operator does not have to manually reset the system and operate it at a position that does not interfere with the driver's seat. With this, you can operate while ensuring safety.

[Brief description of drawings]

FIG. 1 is a block diagram showing an overall configuration of an interference prevention control device for a work machine according to an embodiment of the present invention.

FIG. 2 is a flowchart showing an operation procedure of an interference prevention control device for a working machine according to an embodiment.

FIG. 3 is a side view of a working machine that is a target of the embodiment.

FIG. 4 is an operation explanatory view showing the operation of the front of the working machine that is the target of the embodiment.

FIG. 5 is a diagram showing a relationship between a deceleration area and an interference danger area in the embodiment.

FIG. 6 is a side view for explaining a state when the angle sensor of the working machine which is the target of the embodiment outputs an abnormal value.

FIG. 7 is a schematic plan view for explaining a state when the angle sensor of the working machine which is the target of the embodiment outputs an abnormal value.

FIG. 8 is a schematic diagram illustrating a method of calculating the position of the bucket tip of the work machine according to the embodiment.

FIG. 9 is an explanatory diagram showing a relationship between a deceleration area and an interference danger area in a conventional example.

FIG. 10 is an explanatory diagram showing a deceleration pattern of a cylinder speed in a deceleration region set in a conventional example.

[Explanation of symbols]

 2 Working machine body 3 Operator's cab 10 Front 11 First boom (front member) 12 Second boom (front member) 14 Arm (front member) 15 Bucket (front member) 21 First boom cylinder 22 Offset cylinder 23 Arm cylinder 24 Bucket Cylinder 31, 32, 33 Angle meter (angle sensor) 60 Calculation unit (calculation means) 61 Coordinate calculation unit 62 Comparison calculation unit 63 Deceleration area storage unit 64 Interference danger area storage unit 65 Abnormality detection unit 66 Speed calculation unit 67 Flow rate calculation unit 67 68 conversion unit 69 operation lever 70 hydraulic drive circuit (drive unit) 77 drive control unit (control unit)

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Shudo Yamada 20 Ishigane Co., Ltd., Toyama City, Toyama Prefecture (72) Inventor Akinori Shimamae 20 Ishigane Co., Ltd., Toyama City, Toyama Prefecture (72) Invention Takashi Matsuda 20 Ishigane, Toyama City, Toyama Prefecture Fujikoshi Co., Ltd.

Claims (5)

[Claims] 1. A first boom and a second boom connected to the first boom so as to be movable laterally by an offset cylinder.
Drive means for driving the front composed of a boom and an arm, a boom angle sensor for detecting a rotation angle of the first boom, an arm angle sensor for detecting a rotation angle of the arm, and a lateral side of the second boom. Calculating means for calculating the position of the bucket provided at the tip of the arm from the detection output from the offset angle sensor indicating the amount of movement in the direction, and front movement speed control corresponding to the bucket position calculated by this calculating means Along with this, when it is determined that the bucket has entered a preset interference risk area, it is provided with control means for prohibiting movement of the front, and prevents interference between the front of the working machine and the working machine body including the driver's seat. In the interference prevention control device for a working machine, when the output of any one of the angle sensors indicates an abnormal value, Instead of the output value of the angle sensor indicating an abnormal value, the position of the bucket is calculated using a preset most interference side value as a virtual value, and is output to the control means. Work machine interference prevention control device. 2. The interference prevention control device for a work machine according to claim 1, wherein the virtual value is a value corresponding to a maximum hoisting angle of the arm in the case of an arm angle sensor. 3. The interference prevention control device for a work machine according to claim 1, wherein the virtual value is a value corresponding to a maximum raising angle of the first boom when the boom angle sensor is used. 4. The interference prevention control device for a work machine according to claim 1, wherein, in the case of an offset angle sensor, the virtual value is a value corresponding to when the bucket is located on the leftmost side. 5. The interference of the work machine according to claim 1, wherein, in the case of an offset angle sensor, the virtual value is a value corresponding to a position immediately before a bucket enters the interference risk area. Prevention control device.