METHOD AND DEVICE FOR MONITORING THE CONDITION OF AN INDUSTRIAL ROBOT

A method for monitoring the condition of an industrial robot having a plurality of links movable relative to each other, and a plurality of actuators controlling the movements of the links. A feed forward torque is calculated for at least one of the actuators based on reference values for the position of the actuator and a mathematical model of the robot calculating a feedback torque for the actuators based on measured values from the actuators and reference values for the position of the actuator. A torque is calculated for the actuator at least based on the feedback torque. A difference is monitored between the calculated torque for the actuator and the feed forward torque. It is determined whether the difference is normal or non-normal, and based thereon monitoring the condition of the robot.