Research On Active Suspension Control Of Emergency Rescue Vehicle Based On Actuator Friction Compensation

The suspension system plays an important role in the ride comfort of emergency rescue vehicles.However,the control of active suspension actuator is mainly to search for more effective control strategies,ignoring the influence of actuator friction on the suspension system.So there are adeviations between the suspension control theory and practice.This subject is derived from the China’s National Key R&D Programmes "Research on Key Chassis and Suspension Technology for High-Mobility Emergency Rescue Vehicles(Including fire trucks)"(Project No.:2016YFC0802902).In order to improve the ride comfort of three-axis emergency rescue vehicle,the friction compensation control technology of active suspension actuator is studied to control the actuator accurately and improve the ride comfort of the whole vehicle.The main research content of this paper includes the following aspects: Firstly,Lu Gre dynamic friction compensation model is established,and the characteristics of Lu Gre friction model are analyzed.Four static parameters and two dynamic parameters are identified by step-by-step identification method.The pre sliding displacement characteristic and friction hysteresis characteristic of friction are verified by simulation;Secondly,based on the valve-controlled asymmetric cylinder hydraulic control system,a nonlinear dynamic model of the active suspension unit actuation system is established,and the Lu Gre friction is added for compensation control,by using PID control strategy;The random road excitation input model and vehicle active suspension system dynamic model are established,and the MATLAB / Simulink model is built.The simulation results show that under the excitation of random uneven roads,the vehicle suspension dynamic stroke,tire dynamic deflection,body vertical acceleration,pitch angular acceleration and roll angular acceleration are all reduced after the friction compensation,which improves the smooth driving of the vehicle.The single-side and double-side trigonometric obstacle tests were carried out respectively,and the integrated total weighted acceleration root-mean-square value of the driver’s human body and foot bottom under the two working conditions is obtained,which is reduced compared to before compensation,which improves the ride comfort of the vehicle.The results show that the actuator friction compensation active suspension system designed in this paper can effectively improve the vehicle ride comfort.