ROBOT CONTROL APPARATUS

• US 20080303473A1
• Filed: 06/04/2008
• Published: 12/11/2008
• Est. Priority Date: 06/06/2007
• Status: Abandoned Application

• Current Assignee: Fanuc Ltd (Fanuc Corporation)
• Original Assignee: Fanuc Ltd (Fanuc Corporation)
• Inventors: KATO, Tetsuaki, Kuroshita, Teruki
• Application Number:
  US12/132,879
• Publication Number:
  US 20080303473A1
• Time in Patent Office: Days
• US Class Current: 318/568.18
• CPC Class Codes: B25J 9/1628 characterised by the control loop
• CPC Class Codes: G05B 2219/41012 Adjust feedforward gain
• CPC Class Codes: G05B 2219/41028 Select gain with memory, rom table

Abstract

A robot control apparatus for soft control operation of a robot has position and velocity control loops for each control axis of the robot. The position control gain and the velocity control gain of a specified control axis in soft control operation is set lower than those of the other control axes. The orientation of the forward end of the robot arm to be assumed while following an external force, i.e., the orientation thereof immediately before starting the follow-up operation is determined. The position command or the velocity command for the control axes other than the specified control axis, which are determined based on the present position of the specified control axis moved by the external force applied to the forward end of the robot arm, the direction to follow the external force and the orientation immediately before starting the follow-up operation, is applied to the control loop of the particular control axis.

Claims

1. A robot control apparatus having position and velocity control loops for each robot control axis, comprising:

means for inputting the information on the direction in which the forward end of the robot arm is to follow an external force;

means for setting the position control gain and the velocity control gain of a specified control axis at a lower level than the position control gain and the velocity control gain, respectively, of the other control axes;

means for determining the orientation of the forward end of the robot arm to be assumed during the follow-up of the external force and the orientation of the forward end of the robot arm immediately before starting the follow-up of the external force;

means for determining the position command or the velocity command for the control axes other than the specified control axis based on the present position of the specified control axis moved by the external force applied to the forward end of the robot arm, the direction to follow the external force and the orientation of the forward end of the robot arm immediately before starting the follow-up; and

means for applying a position command or a velocity command for the control axes other than the specified control axis to the control loop of each control axis.

2. The robot control apparatus according to claim 1,

wherein the specified control axis is set by manual input.

3. The robot control apparatus according to claim 1,

wherein the specified control axis is set automatically in accordance with the direction in which the forward end of the robot arm is to follow the external force and the robot position in which the external force is applied to the forward end of the robot arm.