SMC-I with Approach Angle Method for Slip Suppression of Electric Vehicles

This study presents SMC-I (sliding mode control with integral action) with approach angle method applied to slip suppression problem of electric vehicles (EVs). In SMC, chattering phenomenon always occurs through high frequency switching of the control inputs. It is undesirable phenomenon and degrade the control performance, since it causes the oscillations of the control inputs. Several studies have been conducted on this problem by introducing standard saturation function. However, studies about whether saturation function was really best weren ’t done so much. Therefore, in this paper, the SMC-I with approach angle method is proposed to improve the performance of chattering reduction and slip suppression. Then, several candidate functions for SMC are selected and both performances are compared with the proposed method. In the performance analysis, evaluation function based on the trade-off between slip suppression performance and chattering reduction performance is also proposed. The analyses are conducted in several numerical simulations of slip suppression problem of EVs. Received on 1 September 2017; accepted on 2 December 2017; published on 21 December 2017