Robust position/force controller design on an industrial robot for medical application using LMI optimization

This paper presents a controller design to cope with the problem of closed architecture of industrial robot. The task at hand is the position/force maneuvering of an ultrasound probe in contact with a patient. The system in contact being identified as a simple interval of stiffness, a controller is designed using the linear matrix inequality and the stability proven by the small gain theorem. The system is identified in practice and then the controller is calculated using MatLab. Experimental data of the implementation of the controller in contact with two materials, one being similar to human soft tissues, showed the stability and performance of the controller design.