This paper studies the performance improvement for

a sliding mode controller using fuzzy methods. By

using fuzzy gain scheduling, sliding mode controller

gains are tuned during its performance causing

energy consumption to be decreased. Furthermore

robustness characteristics are saved against

perturbations. As a result, chattering is decreased on

the sliding surface. To evaluate the method,

simulations is performed on depth control of an

underwater. -This paper studies the performance improvement for

a sliding mode controller using fuzzy methods. By

using fuzzy gain scheduling, sliding mode controller

gains are tuned during its performance causing

energy consumption to be decreased. Furthermore

robustness characteristics are saved against

perturbations. As a result, chattering is decreased on

the sliding surface. To　evaluate the method,

simulations is performed on depth control of an

underwater.