Research Of Energy-efficient Hybrid Active Suspension With Fuzzy-PID Controller

Suspension with excellent performance can isolate the excitation from the rode to the maximum extent,so improving the comfort and handling stability of vehicle has been an important subject in automobile technology.In this paper,based on passive suspension and electromagnetic actuator into which concept of feed energy was brought into,an energy-feed coil was designed inside the actuator and the reliable conditions that actuators can feedback energy was analyzed.On the basis of this theoretical analysis,energy-feed coil switch of trigger conditions was designed and effects of actuator parameters on quality of actuator were studied.In the system of energy-efficient hybrid active suspension,Fuzzy control and PID control were chosen for joint control.The fuzzy PID controller was designed by the use of the MATLAB fuzzy toolbox with body acceleration and relative displacement of the car body as inputs.In environment of Simulink,the random road input model,actuator model,passive suspension model and hybrid active suspension model with fuzzy PID controller were established.Simulation of system was undertaken to verify its performance of vibration isolation and energy efficiency.Design signal acquisition circuit,rectifier circuit,charge and discharge circuit,boost circuit,driving circuit and other peripheral circuits.Based on the MC9S12EP100 micro-controller as the control unit,control program was edited which controls the actuator output force,energy-feed coil switch and charge and discharge circuit.Test bench was built,and which in combination with the hardware circuit and program designed,bench test was carried on.Results of experiment in which excitation was fixed frequency showed that near the resonance frequency of 10 Hz,performance that indicates vibration isolation of suspension improved significantly.Results under random road excitation input showed that in the various speed the car body acceleration,suspension dynamic deflection of suspension respectively reduced significantly and showed the good performance of vibration isolation.Tyre dynamicload amplitude decreased obviously,but the root mean square value increased.In the experiment of different speed,energy-feed coil's power had a rising trend with the increase of speed to a certain extent,but the percent with the total energy input remain at around 10%.The experimental results are consistent with the results of simulation analysis,validating the good performance of suspension scheme designed.