Quantized Feedback Control of Active Suspension Systems Based on Event Trigger

Abstract

As the deviation error will accumulate during the data acquisition and transcoding process of an active suspension system, this paper presents a sliding-mode-based quantized feedback control method. The aim of the controller is to improve the vertical performance of vehicles in the presence of external interferences. A 7-DOF suspension model with nonlinear springs and actuator dynamics is built for the control purpose. Firstly, a static quantizer on the uplink channel and a dynamic quantizer on the downlink channel are considered in the sliding mode controller to reduce the cumulative error and suppress the sprung mass motions. Secondly, an event trigger mechanism is introduced in the controller design process to reduce energy consumption and operation frequency of the actuator. The overall stability of the designed controller is proved by the Lyapunov functions. Finally, numerical simulations are carried out to evaluate the efficacy of the proposed controller. Different quantitative and trigger conditions are discussed, and the random road excitation is considered as the external disturbance input. The results of the control method indicate that the designed controller can improve the riding comfort with little loss of handling stability compared with the passive system. In addition, the trigger mechanism can improve the working efficiency of actuators effectively.

The Dynamic Model and Control Algorithm for the Active Suspension System

“…Te system of equations describing the oscillations of the spatial model was established by Sun et al in [32].…”

“…where F s : spring force, F d : damper force, F t : tire force, F a : control force, M φ : roll moment, and M θ : Pitch moment. Te binding forces of the dynamic model are calculated more specifcally in [32].…”

“…Tis algorithm was established based on the combination of the LQR algorithm and the SMC algorithm. Besides, Wei et al also showed a new method for Figure 5: Te fully dynamic model [32].…”

Evaluate the stability of the vehicle when using the active suspension system with a hydraulic actuator controlled by the OSMC algorithm

“…To improve the efficiency of the suspension system, an active suspension system was used. Each wheel has a hydraulic actuator as part of the active suspension 7 . This mechanism works based on the opening and closing of servo valves.…”