A method for weakening the chattering of sliding mode controller

On the basis of approach-rate method, an assisted sliding surface was set, sliding region was defined, and equivalent control in sliding region was given. Sliding region was used to make the system get into sliding region in limited time and oscillate at low frequency near sliding region to take the place of high frequency oscillation at sliding region of traditional sliding mode controller. The chattering can be weakened in such way. The stability of system at sliding region was analyzed with stability theory. The advantage of sliding region method was introduced, compared with high-gain method and approach-rate method. Finally, the simulation experiments were done on the ldquoXXrdquo autonomous underwater vehicle to validate this method.