JPH01289682A - Own weight compensating method for master manipulator for remote control - Google Patents

Abstract

PURPOSE:To reduce sense of fatigue at the time of operation by applying a torque to a master manipulator directed upward at all times when the attitude of one's own arm is to be held constant, and allowing the arm of the operator to be placed upon a master arm. CONSTITUTION:The output from an angle sensing means 3 is entered into a computer 10, and at an own weight torque calculating means 4, the target value for the torque due to own weight of each shaft of a master arm 1 is determined on the assumption that the value of compensative acceleration alphais greater than the acceleration g of the gravity. As a result an upward directed force is generated to the master arm 1, and when the operator wishes to keep his arm in constant attitude during operation of the master arm 1, he can put his own arm on the master arm 1 to lead to reduction of fatigue at the time of operation.

Description

[Detailed Description of the Invention] [Industrial Field of Application]
This invention relates to a self-weight compensation method applied to a manipulator.

[Prior Art] Conventionally, a self-weight compensation method has been adopted in which the torque due to only the dead weight of a remote control master manipulator is calculated, and the compensating torque is generated by the actuator of each axis. That is, the gravitational acceleration g (g −9,8” /
5ee2) I:: Torque target value was calculated based on the weight of each axis, assuming that it was the force applied to the torque master manipulator.

[Problems to be Solved by the Invention] When attempting to maintain a slave Φ manipulator in a constant posture during remote control of a manipulator using the mask-slave method, it is necessary to maintain a constant posture of the master manipulator. Therefore, the operator must keep his arm in a constant position. At this time, in the conventional method, only the dead weight of the mask arm is completely compensated for, so the operator must reduce the torque due to the weight of the arm to zero, and must maintain a constant posture with his arm suspended in the air. There is. However, for an operator to maintain a fixed posture with his or her arm suspended in the air for more than several tens of seconds requires a considerable amount of tension, and the operator gets tired easily and his or her arm quickly becomes tired.

An object of the present invention is to provide a method for compensating the dead weight of a master manipulator that can solve the above-mentioned problems.

[Means for Solving the Problems] The dead weight compensation method according to the present invention calculates the torque due to the dead weight of a remote control master manipulator, and generates the compensation torque by the actuator of each axis. The value of α is the acceleration of gravity g
[Function] If self-weight compensation is performed with the velocity set to α (α>g), the mask arm will have a vertical Generates an upward force. Therefore, if the operator tries to keep the arm in a constant posture when operating the mask arm.

The operator only needs to place their arm on the mask arm (less fatigue compared to conventional methods).

[Example] An embodiment of the invention is shown in FIG.

First, the structure will be explained using a two-degree-of-freedom master manipulator as an example. In FIG. 1, the operator grips the gripper 7 and operates the mask arm 1.

The mask arm 1 is provided with an angle detection means 3 and a mask arm drive means 6 at portions corresponding to the shoulders and elbows, respectively. The output of the angle detection means 3 is input to the calculator 10, and the dead weight torque calculation means 4 (the calculation contents are as follows (1), (
2)) and is output to the mask arm drive means 6 via the torque control means 5.

Next, the effect will be explained. A model of the mask arm shown in FIG. 1 is shown in FIG. Measure the length from shoulder to elbow.
The length from the elbow to the gripper is 1172, and the concentration between the elbow and the gripper is ff1m1. Assume that m2 exists. At this time, the dead weight torque target value T1 around the shoulder joint θ1 axis and the dead weight torque target value T2 around the elbow joint 02 axis are as follows. However, α is the compensation acceleration and is a constant.

T1-(+l+l12)
φ a conflict, l+ 11 sin
θ ]+I12 a l! 2 ・5in(θl+θ
2) −(1)T2 = (m 2 a) 2 sin
(θ1+θ2) = 12) If α>g in equations (1) and (2), torque T1α+T2α expressed by the following equation is constantly applied to each joint of the shoulder and elbow to direct the gripper 7 vertically upward.

T1 α-(m 1+12 )(cr-g)ノ1eS1
n θ1Jpfp2 Ca g ), 1'2
・51n(θ1+θ2)...(3) T 2 a-m2 ((Z-g)l 25in(θ
1+θ2 ) −(4) Note that in the conventional method shown in FIG. 3, α−g is used in equations (1) and (2), so T1α−0 and T2α−0 are obtained.

The value of α is selected so that when the operator puts his arm on the mask arm, the torque due to the weight of the arm is balanced with the torque calculated by formula (3) (41).In normal cases, α is 1
．． It is desirable to choose around 3g.

[Effects of the Invention] As described above, according to the present invention, when the operator tries to maintain the posture of his arm constant when operating the mask slave manipulator, the master manipulator always exerts a force ( Torque) allows you to rest your arm on the mask arm, reducing fatigue during operation.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a mask arm self-weight compensation method according to an embodiment of the present invention, FIG. 2 is a model diagram of a mask arm, and FIG. 3 is a block diagram of a mask arm dead weight compensation method according to a conventional method. DESCRIPTION OF SYMBOLS 1...Mask arm, 2...Shoulder actuator, 3...Mask arm shoulder angle detection means, 4...
Dead weight torque calculating means according to the present invention, 5... Torque control means, 6... Mask arm driving means, 7... Gripper, 10... Calculator, 20... Dead weight torque calculating means by conventional method, 21′...shoulder actuator,
31...Mask arm shoulder angle detection means.

Claims (1)

[Claims] In a self-weight compensation method in which the torque due to the self-weight of a master manipulator for remote control is calculated and the compensating torque is generated by the actuator of each axis, the value of the compensating acceleration α is set to a value larger than the acceleration of gravity g. A self-weight compensation method characterized by calculating a target torque value based on the self-weight of each axis.