Function Approximation Approach for Robust Adaptive Control of Flexible joint Robots

This paper is concerned with the problem of designing a robust adaptive controller for flexible joint robots (FJR). Under the assumption of weak joint elasticity, FJR is firstly modeled and converted into singular perturbation form. The control law consists of a FAT-based adaptive control strategy and a simple correction term. The first term of the controller is used to stability of the slow dynamics, and the second term is used to damp out the elastic oscillations of the joints. The stability analysis is provided according to the Lyapunov direct method. Simulation results on a single-link FJR demonstrate suitable performance of the proposed control schemes.