On the improvement of tracking performance of flexible robot arm using FFT method

The problem of how to improve the transient performance of a single-link flexible robot arm rotating in a horizontal plane using FFT method is addressed in this paper. Lyapunov's direct method is used to prove the stability of the closed-loop system under the proposed control law. However, the performance of the system is limited by the factors such as nonlinearity, lower resonate frequency and time-delay. In order to further improve the tracking performance, we proposed to use FFT to analyze the tracking error. Through the analysis we can obtain the information of the system in the frequency-domain. The information then is feedback to the system, so that the performance of the system can be enhanced. The experimental results of a single flexible arm are presented in this paper for illustration.