JPH01153292A - Overrun detector for flexible arm robot - Google Patents

Abstract

PURPOSE: To enable the second flexible arm to oscillate without interfering with obstruction in response to the position of the first flexible arm by providing a means for outputting an overrun detecting signal when the oscillating direction and a stroke of the second flexible arm become set values, based on the oscillating direction and a stroke of the first flexible arm. CONSTITUTION: Linear potentiometers (the first detecting means) 101 to 104 for detecting the oscillating direction and a stroke of the first flexible arm A1 are provided, and linear potentiometers 105 to 108 (the second detecting means) for detecting the oscillating direction and a stroke of the second flexible arm A2 are provided. Based on the detected signals of the first detecting means (101 to 104 ), when the oscillating direction and the stroke of the second flexible arm become set values, the second detecting means (105 to 108 ) outputs an overrun detecting signal from a control circuit to regulate the movable range of the second flexible arm A2 . As a result, when a flexible arm robot is installed adjacent to an obstruction, the second flexible arm A2 can oscillate at a position which does not interfere with the obstruction, in response to the position of the first flexible arm A1 .

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an overrun detection device that detects when a flexible arm robot swings beyond a predetermined movable range.

[Prior Art] A flexible arm as shown in Japanese Patent Publication No. 59-21756 is known.

That is, as shown in FIG. 4, a large number of joint members 2 having convexly curved upper and lower contact surfaces 1 are arranged one after another so that the contact surfaces contact each other, and the most advanced joint member 2' four flexible cords, e.g. wire 3 connected to
are connected to four cylinders 5 installed in the base 4 through each joint member 2, and each joint is This is a flexible arm in which the member 2 can be bent in any direction by swinging in any direction.

In a flexible arm robot that combines two such flexible arms as shown in FIG. Because I can,
A tool attached to the tip of the second flexible arm A2, such as a paint sprayer 6, can be moved in any direction.

[Problem that the invention seeks to solve]

For example, when such a flexible arm robot is installed adjacent to an obstacle B as shown in FIG. 6, the first flexible arm A1 is moved from a vertical position as shown in FIG. 6(a). When the first flexible arm A is swung to the left, it may interfere with the obstacle B, and when the first flexible arm A is swung 90 degrees to the right, the second flexible arm A2 can be swung within a range of 360 degrees, but as shown in FIG. 6(a), the first flexible arm A
, is in a vertical position, and if the second flexible arm A2 is swung to the left of the vertical position, it will interfere with an obstacle.

Therefore, the present invention provides an overrun detection device for a flexible arm robot, which allows a movable range to be set in advance based on the installation location, rocking posture, etc., and detects when the robot swings beyond the movable range. The purpose is to provide.

[Means and actions for solving the problem] In a flexible arm robot in which a second flexible arm A2 that swings in any direction is attached to the tip of a first flexible arm A that swings in any direction. , a first means for detecting the swing direction and stroke of the first flexible arm A1, a second means for detecting the swing direction and stroke of the second flexible arm A2, and the first means for detecting the swing direction and stroke of the second flexible arm A2. means for outputting an overrun detection signal when the detection signal of the second means reaches a set value based on the detection signal of the first means; The movable range of the second flexible arm A2 can be defined, and when installed adjacent to an obstacle, the second flexible arm A2 can be adjusted so as not to interfere with the obstacle according to the posture of the first movable arm A1. It is made to be able to swing.

〔Example〕

FIG. 1 is a schematic perspective view of a flexible arm robot, in which a second flexible arm A2 is attached to the tip of the first flexible arm A1, and a stroke sensor, such as a linear potentiometer, is used to detect the stroke of each wire 3. 10 are provided respectively.

The first cylinder 51 and the third cylinder 53 of the first flexible arm A are located on the straight line X1, and the second cylinder 52 and the fourth cylinder
The cylinder 54 is located on the straight line X2 orthogonal to the straight line X1, and the fifth cylinder 55 and the seventh cylinder 5 of the second flexible arm A2
7 is located on the straight line Y1, the sixth cylinder 56 and the eighth cylinder 58 are located on the straight line Y2 perpendicular to the straight line Y, and if the stroke of each cylinder 5 is the same, the first and second flexible arms A1 + A2 becomes a vertical posture, and the straight line
+ x2, straight line Y1. If the strokes of the two cylinders 5 located on Y2 are made different, they will swing in the linear direction.

For convenience of explanation, the linear potentiometers corresponding to each cylinder are referred to as the first to eighth linear potentiometers 10.
．． ~108.

FIG. 2 is a circuit diagram, in which the first linear potentiometer 1
0. The output signal of the second linear potentiometer 102 is the position signal in the direction of the straight line
In other words, the 2-axis position signal V2 becomes the 1-axis position signal v1.
is input to one side 11a of the first trimmer potentiometer 11 that sets the angle of the composite axis, and the two-axis position signal v2 is directly input to the other side 11b by the angle range changeover switch 12, or the two-axis position signal v2 is inverted by the inversion buffer 13. The shaft position signal V2 is input, and the output signal of the first trimmer potentiometer 11 becomes the composite shaft position signal Vx.

That is, the composite axis position signal Vx is expressed by the following equation (1).

Vx-(1-α)Vl +aV2-.-(1)α represents the position of the variable terminal of the first trimmer potential B11, and satisfies 0≦α≦1.

The angle θ of the composite axis is 90'Xα when the angle range changeover switch 12 is in the first position 121, and -90°Xα when it is in the second position 122.

For example, in FIG. 3, composite axis 2. When the angle θ is 45 degrees, α-0,5 is obtained, and from equation (1), the composite axis position signal Vx is (1-0,5)V.

10, 5V2.

Also, when the first axis position signal V1 and the second axis position signal v2 become negative, that is, when the first and second linear potentiometers 10. ．． When the output signal of 102 becomes negative, the composite axis becomes Z,' and moves in the negative direction.If the angle θ of the composite axis is made negative, the composite axis becomes 22 in Fig. 3, and at this time, the 1st axis position signal When V and the two-axis position signal V2 become negative, the composite axis becomes 22' in Fig. 3, so 3
The position in the composite axis direction can be detected within a range of 60 degrees.

The composite axis position signal Vx is then sent to the first and second comparators 14.15 and compared with the plus side limit of the plus side limit setter 16 and the minus side limit of the minus side limit setter 17. outputs an overrun signal.

For example, in FIG. 6(a), if the obstacle B side is set as plus (+) with respect to the vertical posture of the first flexible arm A, the composite axis position signal Vx is on the plus side of the plus side limit setter 16. The limit is set to zero, and when the composite axis position signal Vx becomes zero or more, the first comparator 14 outputs an overrun signal. In other words, in Figure 3, the composite axis is 21
', 22', an overrun signal is output to prevent the first flexible arm A1 from interfering with the obstacle B.

In FIG. 2, a two-axis reverse potential signal is input to the second position 122 of the angle range switch 12 using the inversion buffer 13 and subtracted from the one-axis position signal V1, but the fourth linear potentiometer 104 moves in the opposite phase to that of the second linear potentiometer 102, so the signal from the fourth linear potentiometer 104 may be input.

Regarding the second flexible arm A2, similarly to the above, the output signal of the fifth linear potentiometer 105 is converted into the third axis position signal v.
3. The output signal of the sixth linear potentiometer 106 is input as the fourth axis position signal V4 to one side 20a and the other side 20b of the second trimmer potentiometer 20, and addition and subtraction are performed to obtain a composite axis position signal vY. In this case as well, the third axis position signal V3 is inputted directly to the angle range changeover switch 21, or inverted and inputted to the inversion buffer 22. This allows the composite axis position signal VY to be detected within a range of degrees.

The composite axis position signal Vx and the composite axis position signal V are added via buffers 23 and 24 and first and second resistors 25. .80 and is compared with the plus side limit and minus side limit of the plus side limit setter 31 and the minus side limit setter 32, and an overrun signal is output. The swing range in which the second flexible arm A2 overruns can be set depending on the posture.

For example, the resistance values R1 and R of the first resistor 25 and the second resistor 26 are
2 are the same, the resistance R3 of the third resistor 27 is set to 1/2 of the resistance value R1 of the first resistor 26, and the plus side limit setter 31 is set to zero (v).

In this state, if the first flexible arm A1 is in a vertical posture as shown in FIG. 6(a), the composite axis position signal Vx - zero (v)
Therefore, if the composite axis position signal vY of the second flexible arm A2 is positive, the sum of the two signals Vx + Vy becomes positive, so it becomes larger than the positive limit and the overrun signal is output from the third comparator 29. The output is shown in Figure 6 (
The second flexible arm A2 is prevented from swinging to the positive side in the state of a).

Further, as shown in FIG. 6(b), when the first flexible arm A swings in the negative direction, its composite axis position signal Vx becomes negative (v), and the second flexible arm A2 becomes Vy +Vx. (
It can swing to the plus side until it reaches (minus)〉zeo (v). In other words, even if the second flexible arm A2 swings to the plus side by the angle that the first flexible arm A1 swings to the minus side, no overrun signal is output.

Note that the resistance R of the first, second, and third resistors 25, 26, and 27
1+ R2 and R3 are arbitrarily set depending on the length of the flexible arm, joint position, etc.

The changeover switch 33 for inverting the input signal to the second resistor 26 for addition and the inversion buffer 34 enable the signal to be inverted by a factor of Y, so that the axis X + + X 2
axis Y1. Overrun detection is possible at any angle of Y2.

In other words, if the axis X of the first flexible arm A1 and the axis Y1 of the second flexible arm A2 are shifted by 45 degrees, the composite axis may fall in the plus (+) and minus (-) regions. Since they cannot be added as they are, it is necessary to invert one of them.

〔Effect of the invention〕

The movable range of the second flexible arm A2 can be defined based on the swing direction and stroke of the first flexible arm A, and when installed adjacent to an obstacle, the posture of the first flexible arm A1 can be adjusted. 2nd accordingly
The flexible arm A2 can be swung without interfering with obstacles.

[Brief explanation of the drawing]

1 to 3 show embodiments of the present invention, FIG. 1 is a schematic perspective view of a flexible arm robot, FIG. 2 is a circuit diagram, FIG. 3 is an explanatory diagram of the swing direction, and FIG. 4 5 is a perspective view of the flexible arm, FIG. 5 is a perspective view of the flexible arm robot, and FIGS. 6(a) and 6(b) are explanatory views of the operation. A1 is a first flexible arm, and A2 is a second flexible arm. Applicant Komatsu Manufacturing Co., Ltd. Representative Patent Attorney Masaaki Yonehara

Claims (1)

[Claims] In a flexible arm robot in which a second flexible arm A_2 that swings in any direction is attached to the tip of a first flexible arm A_1 that swings in any direction, the swing direction of the first flexible arm A_1 is and a first means for detecting a stroke, and a second flexible arm A_2.
and a means for outputting an overrun detection signal when the detection signal of the second means reaches a set value based on the detection signal of the first means. An overrun detection device for a flexible arm robot.