Experimental evaluation of ILC applied to a six degrees-of-freedom industrial robot

Experimental evaluation of an Iterative Learning Control (ILC) algorithm is presented. The ILC algorithm is applied to all motors of a large size commercial six degrees-of-freedom industrial robot in order to minimise the error measured on the motor angles. The performance of the algorithm is evaluated with respect to the operating point of the robot, the programmed tool velocity, and the design variables of the ILC algorithm. The chosen movements are intended to represent typical paths in a laser cutting application. Even though a fairly simple ILC algorithm is applied, the error reduction is substantial after only five iterations and the algorithm shows good robustness properties.