Trajectory Phase–Plane Method – Based Analysis of Stability and Performance of a Fuzzy Logic Controller for an Anti–Lock Braking System

The trajectory phase–plane method provides an increased significance to the analysis of stability and performance of the controllers for complex nonlinear plants. The aim of this study is the stability and performance analysis of a fuzzy logic controller for anti–lock braking system applying the trajectory phase–plane technique. The controller’s main task is to hold optimal braking performance by recognizing road surface. The stability and performance of the anti–lock braking system controller are examined with respect to the conventional friction brake and electric motors separately. The applied methodology allows for visual assessment of the stability and performance of studied nonlinear systems. The work refers to hardware–in–the–loop simulations conducted at the Technische Universität Ilmenau. The results demonstrate that the fuzzy logic controller is stable independently of the employed actuator. Moreover, the electric actuators allow for faster convergence and more accurate tracking of the optimal wheel slip.