Integral-augmented state feedback control of a surgical simulator for non-linear friction identification

Integral-augmented state feedback control of a surgical simulator, which is intended to evaluate human haptic perception for low level of forces during angioplasty simulation, is performed to accomplish different test functions of the system, like velocity control to be employed in parameter identification of frictional components of the drive mechanism. The emphasis is directed to minimizing overall steady-state error of controlled output. System state equations are established considering different aspects of the availability of building necessary control algorithms, like controllability and observability of the system states. Order reduction of the system differential equations is applied to be able to create efficient control algorithms. Lastly, integral state augmentation is undertaken to obtain zero steady-state error. Simulation and real system responses are compared and finally, control algorithm is used to determine nonlinear friction parameters of the system.