Stability Analysis of an Electric Parking Brake (EPB) System with a Nonlinear Proportional Controller

Slide Mode Control for Integrated Electric Parking Brake System

“…The proposed SMC control law is validated by simulation performed in Matlab/Simulink. Figure 6 shows the target motor angle tracking performance between the Bang-bang control [4], nonlinear Proportion control [3,7], and sliding mode control with the desired motor angle 492 rad. From Figure 6(a), it is obvious that before 0.6 sec, there is nearly no difference among these three controllers.…”

“…Based on (15) and researches in [1,[3][4][5][6][7]12], we know that the clamping force has a direct relationship with the motor angle.…”

“…A nonlinear clamping force control law using nonlinear P control theory for traditional EPB system was developed by Lee et al [3][4][5][6][7]. The control input can be written as…”

“…Hence, the EPB system can increase the vehicle cabin space, facilitate the parking process, and have potential function [3]. There are mainly two kinds of EPB: the first one generates the force by pulling down traditional parking cable, as seen in [3][4][5][6][7][8][9]. The second one is called integrated EPB (IEPB), which has the similar structure with the electromechanical brake [10][11][12] and hence it can offer numerous possibilities [13].…”

“…For EPB with traditional cables, Lee et al studied the bang-bang [4], nonlinear P controllers [3,6,7] to control the clamping force and the controller stability is also analyzed in [3,7]. The traditional EPB system models were built in [3][4][5][6][7]; however, motor friction and screw-nut system inertia were neglected. Actually, during the motor idle stage, the motor friction and the nut inertia have direct effects on the modeling precision.…”