JPH11347983A - Manipulator action limiting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the interference to peripheral equipment by setting a control area to the coordinate value of an arm tip, obtaining the distance between the limit area and the arm tip, and limiting the moving speed by this distance. SOLUTION: The coordinate of an arm tip is operated from each axial angle of a slave arm, and the position of a hand tip is operated using the coordinate value. The distance L between the hand tip and a set limit area Lm is obtained, and attention is paid to the speed Va in the direction perpendicular to the limit area out of the components Va, Vb of the speed V when the distance L reaches a value below a boundary value. The approaching speed is corrected from the relationship between the distance L from the limit area Lm and the approaching speed, the action command position is corrected from the present position, and the action is effected at the corrected action command position. That is, the overshoot is prevented by effecting the deceleration in a condition where the hand passes the boundary value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for limiting the operating range of a slave arm in, for example, a master / slave manipulator.

[0002]

2. Description of the Related Art In an industrial robot, for example, a master / slave manipulator, the operating range of each axis of the slave arm is currently limited in order to prevent interference between the slave arm and peripheral devices.

[0003]

However, FIG.
As shown in (1), merely restricting the operation of each axis of the slave arm 1 causes interference when the peripheral device 2 is present in the operation space of the arm. It is not a restriction.

[0004] In view of the above problems, an object of the present invention is to provide a manipulator operation restriction device that prevents interference with peripheral devices.

[0005]

The present invention that achieves the above object has the following matters specifying the invention. (1) Set a restricted area for the coordinate value of the tip of the arm,
The distance between the restricted area and the tip of the arm is obtained, and the moving speed is limited by the distance. (2) In the above (1), a virtual restriction area is further obtained for the set restriction area on or above the restriction area, and this is set as a new restriction area. .

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Here, an example of an embodiment of the present invention will be described with reference to FIGS. Figure 1 shows the master
In the slave manipulator, processing blocks from a master designated angle to a slave designated angle are shown, and based on an operation of a master arm by an operator, a slave arm operates so as to follow the movement of the master arm. In this case, the master arm and the slave arm are in one-to-one control. Therefore, in the master / slave converter 10, the designated angle θ from the master arm
The conversion of n (n = 1 to 5) into the target angle θn ′ (n = 1 to 5) of the slave arm 1 as shown in FIG. 2 is represented by the following equation (1). θn ′ = θn (n = 1 to 5) (1)

Next, the forward converter 11 calculates the tip coordinate Ps of the slave arm 1 with respect to the set target angle θn 'of the slave arm 1. That is, the tip coordinates (Xs, Ys, Zs) at the X, Y, Z coordinates shown in FIG. 3 with respect to the slave arm tip coordinate reference position are calculated.

In the restricted area processing circuit 12, the forward converter 11
With respect to the tip coordinate Ps of the slave arm 1 obtained in
The correction is performed by providing a limited area Lm as shown in FIG. 4, and the tip coordinate Ps' of the slave arm 1 after this correction is obtained. That is, when the coordinates Ps of the tip of the slave arm 1 exceed the set limit area, the coordinates Ps of the tip are corrected to the limit area.

In the inverse converter 13, the target angle θn "of the slave arm 1 is obtained from the coordinate Ps' of the tip end of the slave arm which has been subjected to the limited area processing, and the reverse processing of the forward converter 11 is performed. Is used to obtain the designated angle θn of the slave arm 1. As a result, the designated angle θn of the slave arm obtained by performing the restricted area processing on the designated angle θn from the master arm is obtained.

In FIG. 1, the processing for correcting the coordinate Ps of the tip end of the slave arm is performed by the restricted area processing circuit 12, but the present invention further prevents overshoot of the hand. That is, as shown in FIG. 5, for example, when the areas A and B in the restricted area Lm are set in the X direction and the Z direction, these areas can be expressed by the following equation (2). AX + BZ + C = 0 (2) In this case, the coordinate value in the Y direction has no restriction area and the coordinate value is arbitrary. In this way, the restricted area is determined by the restricted area processing circuit 12 shown in FIG. 1. However, when the hand is actually operating at high speed, the hand may stop in a state exceeding the area, resulting in overshoot. .

For this reason, the coordinates of the arm tip are calculated from each axis angle of the slave arm, and the hand tip position is calculated using the coordinate values, and as shown in FIG. seek distance L, the distance L is the boundary value L component Va of the following at the time at a velocity V reaches _B, Vb
Focus on the velocity Va in the direction perpendicular to the restricted area. The correction to correct the operation command position P ₁ to the current position P ₀ as shown in FIG. 8 to correct the 'speed Va from the relationship between the' distance L between approach speed Va from restriction region Lm shown in FIG. 7 It operates at the later operation command position P ₁ '. That is, in a state where the hand has passed a boundary value L _B is to prevent overshoot by a deceleration.

Further, according to the present invention, as the operation when the hand is on or beyond the restricted area, a virtual restricted area Lmi is further set in parallel with the restricted area Lm as shown in FIG. Thus, this is set as a new restricted area. That is, considering the case corresponding to FIG. 5, FIG.
As shown in the figure, a virtual restriction area Lmi is provided by the following equation. A′X + B′Z + C = 0 (3) Then, when an attempt is made to move from the point P ₀ to the target point P ₂ by the master arm by the operation of the operator, that is, the point P ₀ exceeds the limit area Lm. cage, and when trying to move to the point P ₂ exceeds the new virtual restricted area Lmi, the P ₂ 'points are mapping point of the point P ₂ so as to move the target point. In this way, the hand is prevented from entering the virtual restricted area Lmi. When the position to return to the original restricted area Lm is set as a target by the operation of the operator, the original restricted area is moved as it is. In this case, the virtual restricted area also moves in parallel.

When the tip of the hand exceeds the restricted area, a process of always setting the target position on the restricted area or a processing of stopping the operation and outputting an abnormality can be considered. Returning over the restricted area is dangerous because it is a fast operation, and the latter requires an abnormal return operation, which interrupts the work and makes it inconvenient. For this reason, the provision of the virtual restriction area Lmi prevents the tip of the hand from always exceeding the restriction area Lm, but if it does, the work can be continued with the virtual restriction area Lmi as the restriction area.

[0014]

As described above, according to the present invention, it is possible to prevent the hand tip from interfering with peripheral devices and to move at high speed by correcting, decelerating, and setting a virtual restriction area by setting a restriction area. Therefore, even if there is no overshoot due to the deceleration, the work can be continued even if there is a penetration of the restricted area, and the grinding work can be performed by using the restricted area as the processing surface.

[Brief description of the drawings]

FIG. 1 is a processing block diagram of an example of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a target angle of each axis of a slave arm.

FIG. 3 is an explanatory diagram of a slave arm tip coordinate reference position.

FIG. 4 is an explanatory diagram of a restriction area and a tip position of a slave arm after correction.

FIG. 5 is an explanatory diagram of setting a restricted area.

FIG. 6 is an explanatory diagram relating to a distance between a hand tip and a restricted area.

FIG. 7 is a diagram showing the relationship between distance and speed.

FIG. 8 is an explanatory diagram of an operation command position.

FIG. 9 is an explanatory diagram of a virtual restricted area.

FIG. 10 is an explanatory diagram showing an interference state.

[Explanation of symbols]

1 the slave arm 12 restricted area processing circuit A, B, Lm restricted area L length V, Va, Va ', Vb velocity (velocity component) L _B boundary values _{P 0, P 1, P 1} ', P 2, P 2 ' position

Claims (2)

[Claims] An operation restriction device for a manipulator, wherein a restriction area is set for a coordinate value of an end of an arm, a distance between the restriction area and the end of the arm is obtained, and a moving speed is limited by the distance. 2. The operation restriction of the manipulator according to claim 1, wherein a virtual restriction area is further obtained with respect to the set restriction area on or above the restriction area, and this is set as a new restriction area. apparatus.