Research On Adaptive Control Of Vehicle Inertial Suspension Based On Power Driven Damper Strategy

As a new type of mass element with two ends,the introduction of inerter breaks the inherent “spring-damping” structure of traditional suspension,and forms a new inertial suspension system based on the “inerter-spring-damping” structure network,and enriches the theoretical system of vehicle suspension.According to the theory of mechanical and electrical simulation,compared with the capacitor of the circuit components,the inerter has the characteristics of "high frequency on,low frequency resistance",which can effectively improve the vibration transmission characteristics at the vehicle body frequency offset,but the vibration suppression effect in the frequency band above the vehicle body frequency offset is not significant.In order to further improve the vibration transmission characteristics of the vehicle’s inertial suspension body in the frequency band above the bias frequency,this paper applies the “Power Driven Damper(PDD)” control strategy to the inertial suspension,which can suppress the vehicle body acceleration amplitude in the middle and high frequency bands.Through the design of mechatronic inerter with ball screw,the active control mechanism of vehicle controllable inertial suspension is constructed.The vibration suppression in wide frequency domain(from low frequency to high frequency)of inertial suspension is realized,the ride comfort of vehicle is improved,and new ideas and methods are provided for the research of controllable inertial suspension.Firstly,the inertial suspension model of sky-hook strategy and “acceleration driven damper(ADD)” strategy is established,and the improvement effect of acceleration is analyzed by simulation.From the energy point of view,this paper studies the power transmission law of each component in the inertial suspension system,designs the PDD control algorithm of the inertial suspension,and compares it with the sky-hook strategy and the ADD strategy respectively.It is found that the PDD strategy can greatly improve the acceleration performance of the vehicle body,realize the vibration suppression of the frequency band above the body offset frequency,and eliminate the “oscillation” phenomenon in ADD strategy.Therefore,the reference model of the inertial suspension based on PDD control strategy is constructed to study the influence of the damping coefficient in the control strategy on the performance output of the inertial suspension.Particle swarm optimization(PSO)is used to find the optimal model parameters,which is based on the constraints of suspension system.Secondly,a model reference adaptive control mechanism considering vehicle acceleration,suspension dynamic travel and tire dynamic load is constructed.The integrated control problem of the inertial suspension is transformed into the problem of tracking the performance output based on the PDD reference model to realize the coordinated control of the controllable inertial suspension.By establishing the mathematical model of reference object and controlled object,the adaptive law of the system is designed by using Lyapunov stability theorem to modify the state of the controlled system.The system controller is built in MATLAB to simulate the vibration isolation performance of the controllable inertial suspension.Under the random road input conditions of the vehicle speed of 10m/s,20m/s and 30m/s,the RMS acceleration of the vehicle body is 31.6%,31.4% and 31.1% lower than that of the traditional passive suspension.From the perspective of frequency domain,the acceleration amplitude of the controlled inertial suspension is significantly smaller than that of the traditional passive suspension and passive inertial suspension in vehicle body bias frequency and above,which effectively improves the ride comfort of the vehicle.Finally,through the selection of ball screw pair and rotating motor,the principle prototype of the mechatronic inerter with ball screw is developed,and the mechanical properties of the inerter are tested on the Instron hydraulic servo vibration excitation platform to verify that the inerter meets the theoretical design requirements.On this basis,a quarter of the controlled inertial suspension test system is built to test the performance of the controlled inertial suspension under different road inputs.The test results show that the RMS acceleration of the controlled inertial suspension is lower than that of the traditional passive suspension and passive inertial suspension under the sinusoidal road input of different frequencies;The RMS acceleration of the controlled inertial suspension is 29.9% lower than that of the traditional passive suspension under the random road input of 20m/s,and the amplitude of the acceleration is significantly reduced from the low frequency to the high frequency.The test results show that the controlled inertia suspension can improve the vibration isolation performance of the vehicle,achieve a wider frequency domain vibration suppression,and improve the ride comfort of the vehicle.In conclusion,this paper uses the characteristics of the inertial suspension which can effectively suppress the vibration at the vehicle body frequency offset,and combines with the PDD control strategy to improve the advantages of the acceleration amplitude above the vehicle body frequency offset,and studies the wide-band vibration suppression of the suspension,and promates the vibration transmission characteristics of the vehicle controllable inertial suspension in the wide-frequency domain,greatly elevates the vibration isolation performance of the vehicle,and provides a new way for the research of the controllable inertial suspension guidance.