METHOD FOR ESTIMATION OF EXTERNAL FORCES AND TORQUES ON A ROBOT ARM

摘要

The invention is related to a method for estimating the externally applied wrench (12, fext) on the robot arm (46) caused by collision, based on the calculation of the sum of all the torques applied (e.g. joint motor, friction, gravity, dynamic behaviour) and wherein the robot comprises a robot controller (28) which is foreseen to control the movement of the robot arm (46) according to data of a robot program and to continuously provide: the torque vector of the joint motors (τmot), the dynamic behavior of the robot arm, a torque vector due to gravity effects (τgrav(q)) and the current joint angles (q) of the robot arm. The method is characterized by the following steps: moving the robot arm (46) according to the data of a robot program, continuously determining the friction torque vector (τfric), continuously determining the external torque vector (τext) by use of the following equation: (A) providing the Jacobian Matrix (J) of the robot arm and continuously estimating the externally applied wrench (fext) of the robot arm (46) dependent on the angle vector (q) based on the Jacobian matrix (J) and the external torque vector (τ ext ).