A gradient based recursive identification of mechanical systems with backlash-like hysteresis

It is known that backlash-like hysteresis is one of the non-smooth nonlinearities usually existing in mechanical systems. Due to the characteristic of non-smoothness, it is quite difficult to apply the traditional identification method to the modeling of dynamic systems with backlash-like hysteresis in mechanical systems. In this paper, a gradient based recursive identification algorithm for dynamic systems with backlash-like hysteresis is presented. In this method, based on the concept of Clarke sub-gradient, a so-called bundle method is used to obtain the optimizing search direction at the non-smooth points. Then, the gradient based algorithm is developed for parameter estimation. Finally, an example of applying the proposed method for modeling a simulated mechanical transmission system is presented.