Abstract: To address the issue that traditional vehicle suspension control systems struggle to accommodate multiple influencing parameters, a multi-condition feedback adjustment-based graded control strategy for vehicle suspension is proposed. This strategy introduces three factors affecting comprehensive vehicle suspension performance-spring mass acceleration, unsprung mass acceleration, and road surface excitation-into the traditional PID control system. By employing multiple controllers to form several control loops, spring mass acceleration is used as the primary control factor for direct adjustment of vehicle suspension performance, while unsprung mass acceleration and road surface excitation serve as control factors for two auxiliary adjustment loops, which adjust the PID controller parameters in the primary control loop. This allows simultaneous feedback control from multiple control loops, making full use of various factors affecting vehicle suspension performance and keeping the PID controller parameters within an optimal range. Simulation results show that, on a single bump road surface, the time for spring mass acceleration to decay to 0 in the optimized control system is 0.8 s, which is 77.1 % and 60.0 % shorter compared to passive suspension and PID control, respectively. On a sinusoidal wave road surface, spring mass acceleration is reduced by 58.3 % and 35.1 % compared to passive suspension and PID control, respectively. Additionally, on random graded road surfaces, spring mass acceleration, dynamic deflection, and dynamic load are significantly improved, enhancing vehicle ride comfort and driving safety.

Key words: multi conditional feedback, hierarchical control, comfort, safety, automobile suspension