Research On Positive Synthesis Of Mechatronic Network And Passive Control Of Vehicle ISD Suspension Based On HEI

The vehicle ISD suspension,which is composed of inerter,spring and damper elements,has been a heated research topic in vehicle engineering field since it was proposed.The problem of how to effectively design the suspension system structure and to give the detailed available proposal is the key for vehicle ISD suspension research.Scientific inerter research not only perfects the mechatronic similar theory,but also opens the door of applying the electric passive network synthesis theory to design the structures in mechanical systems.With further development of the mechatronic progress,a new type of the inerter involving the mechanical inerter and the motor which deploys the electric network impedance to simulate the objective mechanical network impedance,provides a new approach to solve the problem of designing the complicated structure and performing good performance of the vehicle ISD suspension.In order to enrich the structure format of inerter element and to push the development of the vehicle ISD suspension in structural design and realization method,this dissertation investigates the problem of positive synthesis of the mechatronic network and the passive control of the vehicle ISD suspension to improve the vehicle suspension performance,which is based on the hydraulic-electric inerter by means of passive network synthesis theory.Firstly,the dynamic model of the new type hydraulic-electric inerter was built.The working principles of the translational hydraulic piston inerter and the linear motor were introduced in detail,and the dynamic model of the divided body type of the hydraulic-electric inerter was built.By analyzing the characteristics of the motion transfer relationships of the mechanical elements and the motor elements,the coupling relationships between the parameters of the mechanical elements and electric elements in the three different types of mechatronic inerters were studied.The advantages and the disadvantages in the structural selection and parameters design of different types of mechatronic inerters were also discussed,which can provide the theoretical guidance in designing the inerter device.Secondly,the optimal positive synthesis design of the mechatronic network of the vehicle suspension was finished.A high order impedance transfer function was order-reduced and converted by using the foster operation steps when designing the vehicle ISD suspensions.The general method of the optimal positive synthesis was also gained.Then,the parameters in the vehicle ISD suspension were optimized by the use of the improved particle swarm algorithm,and the suspension structure involving the basic mechanical network and low order impedance transfer function was obtained.The detailed structure of the vehicle ISD suspension was finally defined by checking the simplest realization evidence of the low order impedance transfer function.Thirdly,the detailed passive control implementation of the vehicle ISD suspension was proposed,and the dynamic model of the HE-ISD suspension was created.The passive control implementation of the vehicle ISD suspension was introduced after analyzing the structural characteristics of the HEI device and the vehicle ISD suspension.On the basis of the quarter car dynamic model,the impact of the motor inductor and resistor on the vehicle suspension performance was investigated.What’s more,the nominal working conditions of the linear motor and the electric network when designing the device were taken into consideration by studying the working performance of the electric network in the HE-ISD suspension,which can supply the technical support in designing the HE-ISD suspension system.Fourthly,the HEI device was manufactured,and the force test was finished.The structural selection and parameter design of the hydraulic piston inerter and the linear motor were separately introduced,and the HEI device was finally manufactured.The force test conditions of the HEI device was defined through investigating the working performance of the linear motor and the external load circuit elements.Then,the force tests were carried out both in the unloaded and loaded condition.Results showed that,the HEI device met the requirements in the HE-ISD suspension.At last,the experimental prototype of the HE-ISD suspension was built,and the bench tests were finished.Comparing to the traditional passive suspension,which has the same spring stiffness,the vibration isolation performance of the HE-ISD suspension were evaluated under the sine wave displacement input and the random road displacement input based on the quarter car model in the single channel hydraulic vibrator.Experimental results indicated that,under the random road displacement input,the root-mean-square of the suspension working space of the vehicle HE-ISD suspension can be reduced by at most 19.97% at the velocity of 20m/s,the root-mean-square of the dynamic tire load of the vehicle HE-ISD suspension can be reduced by at most 10.21% at the velocity of 20m/s,the root-mean-square of the vehicle body acceleration of the vehicle HE-ISD suspension was also slightly reduced.In comparison to the traditional passive suspension,the vibration isolation performance of the vehicle HE-ISD suspension was significantly improved.It was noted that,in this dissertation,the researches conclusion on the optimal positive synthesis of the mechatronic network and passive control of the vehicle ISD suspension on the basis of the HEI device can effectively solve the structural design problem in the vehicle ISD suspension system.The proposed vehicle HE-ISD suspension is superior to the traditional passive suspension for its merits of excellent vibration isolation performance,simple structure,and it’s easier to be realized in the engineering filed.The research fruits accumulate valuable experience in broadening the implementation of the inerter device and pushing the engineering realization of the vehicle ISD suspension.