In this paper, the nonlinear phenomenon including hump and chaos analysis along with chaos control of an active suspension in vehicles has been studied. The unstable periodic orbits of the system are stabilized using the novel developed delay feedback control algorithm based on the fuzzy sliding mode system. The chaotic Equations of motions are derived via Newton-Euler relations then, the nonlinear phenomenon such as jump and chaos in the vehicle dynamics has been confirmed using forcing frequency method. The results of the forcing frequency demonstrate the changes in system behaviour from the periodic to the irregular chaotic responses. In order to eliminate the chaotic responses in the vertical dynamics of the vehicle, a new fuzzy sliding delay feedback control algorithm is designed on the active suspension. The controller gain of the sliding feedback control is online estimated via fuzzy logic causing to rejection of the chattering phenomenon in the sliding mode algorithm besides the improvement in the responses of the feedback system. Simulation results of the control system depict a reduction of settling time and energy consumption along with eliminating the overshoots and chaotic vibrations. Manuscript profile