JPH04310381A - Master-slave robot control method - Google Patents

Abstract

PURPOSE:To conduct safe control even when large force is applied instantaneously to a slave arm by performing the feedback of the detection signal of a force sensor in the returning direction of a joy stick to its neutral position with a dead zone. CONSTITUTION:A joy stick 1 is formed to be normally returned in its neutral point by a weak spring 11. When the joy stick 1 is operated by a pilot, a tilt angle from the neutral point provides a slave arm controller 3 with the position command signal of a slave arm 2. A force sensor 4 is provided at the tip of the slave arm 2, and its detection signal is fed back by a joy stick controller 5 through an amplifier 41. The detection signal of the force sensor 4 is fed back in the returning direction of the joy stick 1 to its neutral position with a dead zone. Accordingly, even if the slave arm 2 collides against an obstruction, safe control can be performed without the runaway of the slave arm.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a master/slave control robot whose operating side is operated by a joystick.

0002

[Prior Art] Conventionally, a master/slave robot that controls the position of a slave arm using a joystick,
Control is performed using a bilateral control method in which the tilt of the joystick from the neutral point corresponds to the position of the slave arm, and the positional deviation of the slave arm is returned to the joystick as a reaction force. However, there is a time delay between the joystick's position command and the movement of the slave arm, and the slave arm may be pressed strongly against an obstacle. A method is disclosed in which the value of the position command on the master arm side is decreased in accordance with the temporal change in the contact force against which the
Publication No. 9).

0003

[Problems to be Solved by the Invention] However, according to the above method, when the pressing force of the slave arm force sensor increases over a relatively long period of time, the joystick gradually becomes heavier, and the operator is able to cope with the problem. If a large external force is applied in a very short period of time, such as when the slave arm collides with an obstacle, the external force is fed back to the joystick as an impact force. Therefore, when the operator releases the joystick, it will fall down, and the slave arm will move at maximum speed in the direction to avoid collision.
It had the drawback of running out of control. An object of the present invention is to enable safe operation even when a large force is instantaneously applied to a slave arm.

0004

[Means for Solving the Problems] The present invention allows the joystick to be constantly returned to a neutral point by a spring, commands the position of a slave arm based on the value of the tilt angle from the neutral point, and causes the tip of the slave arm to A method for controlling a master/slave robot in which a detection signal from a force sensor provided is fed back to the joystick,
This method feeds back the detection signal of the force sensor in the direction in which the joystick returns to the neutral point with a dead zone.

[0005]

[Operation] When the joystick is tilted in the "+" direction, the slave arm is moved, and it is pressed against an obstacle, a "+" feedback value is returned from the force sensor, and when the dead zone is exceeded, a value proportional to the feedback value is returned. is returned as a reaction force in the "-" direction of the joystick 1, that is, in the direction of the neutral point by the servo mechanism. Therefore, even if the operator cannot resist the reaction force and releases his/her hand, the joystick will always return to the neutral point, so there is no risk of the slave arm moving out of control.

[0006]

[Embodiment] The present invention will be described with reference to an embodiment shown in the drawings. FIG. 1 is a configuration diagram showing an embodiment of the present invention. A joystick 1 is normally returned to a neutral point by a weak spring 11, and when an operator operates the joystick, the tilt angle from the neutral point is changed by a slave arm. A position command signal for the slave arm 2 is given to the controller 3. A force sensor 4 is provided at the tip of the slave arm 2, and its detection signal is fed back to the joystick controller 5 via an amplifier 41. The output of the joystick controller 5 feeds back force to the joystick 1 via a servo mechanism 6 consisting of a spherical motor and a three-axis drive mechanism of X, Y, and Z. Here, when the joystick 1 is tilted to move the slave arm 2 and pressed against an obstacle, and the value returned as the force feedback amount of the force sensor 4 is "+", the direction in which the joystick 1 is tilted is defined as "+". . The joystick controller 5 is configured so that the force feedback value of the force sensor 4 is "
When the feedback value is "+", the force is controlled so that the joystick 1 is tilted in the "-" direction from beyond the dead zone, as shown in FIG. 2(a), and when the feedback value is "-", as shown in FIG. 2(b). As shown in FIG. 2, the servo mechanism 6 controls the force so that the joystick 1 is tilted in the "+" direction from a point beyond the dead zone.

Now, when the joystick 1 is tilted in the "+" direction and the slave arm 2 is moved and pressed against an obstacle, a "+" feedback value is returned from the force sensor 4, and when the dead zone is exceeded, the feedback value is A value proportional to the value is returned as a reaction force in the "-" direction of the joystick 1, that is, in the direction of the neutral point by the servo mechanism 6. Therefore, even if the operator cannot resist the reaction force and releases his/her hand, the joystick 1 is always returned to the neutral point, so there is no danger of the slave arm 2 running out of control. If you tilt the joystick 1 in the "-" direction, move the slave arm 2, and press it against an obstacle, as shown in Figure 2(b),
The operation is completely opposite to the case of "+" (the case of figure (a)), and the joystick 1 is always returned to the direction of the neutral point, so there is no danger of the slave arm 2 going out of control, and it is safe. is maintained. Further, when the slave arm 2 collides with an obstacle, the feedback of the impact force is absorbed in the dead zone, so the impact force is not transmitted to the operator.

[0008]

[Effects of the Invention] As described above, according to the present invention, even if the slave arm collides with an obstacle, it does not directly feed back the impact force to the operator, but provides an appropriate sense of force, and if a reaction force Even if you let go of your hand without being able to resist it, the joystick always returns to the neutral point, which prevents the slave arm from going out of control and allows for safe control.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIGS. 2(a) and 2(b) are characteristic diagrams of a servo controller.

[Explanation of symbols]

1 Joystick 11 Spring 2 Slave arm 3 Slave arm controller 4 Force sensor 5 Joystick controller 6 Servo mechanism

Claims (1)

[Claims] 1. A joystick is always returned to a neutral point by a spring, a position is commanded to a slave arm based on the value of a tilt angle from the neutral point, and a detection signal from a force sensor provided at the tip of the slave arm is transmitted. A control method for a master/slave robot in which the detection signal of the force sensor is fed back in a direction in which the joystick returns to a neutral point with a dead zone.