| Abstract: | It is well known that the angle-dependent disturbance in a servo motor caused by nonuniformity of field windings, armature cogging, rotor imbalance, nonuniform load and so on, may influence the speed control performance greatly. This often leads to large speed fluctuations which are undesired in practical situations. Therefore speed fluctuation reduction techniques in the presence of angle-dependent disturbances are strongly required and have been studied by many researchers. In this paper, the authors propose a new approach to this problem via adaptive control with the aid of a radial basis function (RBF) network composed of Gaussian basis functions. The angle-dependent disturbance, viewed as a periodic non-linear function with a period of 2π radians in the angular domain, is approximated by an RBF network in (0, 2π) radians. Then an adaptive linearization control system employing the RBF network which compensates for the disturbance is proposed. The RBF network has the advantage that it is linear in the parameters and hence parameter adaption is very fast and easy to implement. It is proved through theoretical analysis that the stability of adaptive control is guaranteed by Lyapunov stability theory. Finally, simulation and experimental results are included in the paper to show the excellent performance of the proposed method. © 1997 Scripta Technica, Inc. Electr Eng Jpn, 119(4): 77–86, 1997 |
