Study On Dynamic Characteristics Simulation And Active Control Theory Of Automobile Powerplant Mount System

TITLE: Study on Dynamic Characteristics Simulation and Active Control Theory of Automobile Powerplant Mount SystemSPECIALITY: Automotive EngineeringADVISER: Prof. Lin YiActive Control Powerplant Mount System is the key technology to automobile powerplant vibration isolation. This dissertation, taking semi-active hydraulic mount and active hydraulic mount as research object, mainly discuss about system structure, working principle and active actuator and controlling system design based on bond graph theory, also analyze simulation of their dynamic Characteristics. This dissertation designs an active mount with Piezo-actuator, and develops controlling system using fuzzy control theory, then analyze and validate the vibration isolation effect of active mount by computer simulation. The work of this dissertation offers theory and technology base to bond graph applied in powerplant mount research, and plays an important practical engineering role in developing semi-active mount and enhances homemade level. It is also the pre-research for active mount system designing, developing and application.This dissertation firstly discuss the developing direction and market foreground of powerplant after analyzing and summarizing international researchfruit and actuality of powerplant mount system. Then it focuses on bond graph theory applied in powerplant dynamic characteristics. To adopt a native car of semi-active hydraulic mount, set up a bond graph model and mathematical model adopting bond graph theory. Also it analyzes simulation of mount dynamic Characteristics. The testing results verify the exactness and applicability of bond graph model. Working principle and effecting factor of dynamic character for piezo-actuator are also studied and analyzed through test in this dissertation. And based on this, active mount with Piezo-actuator is designed and its control system model is set up. A fuzzy PID controller of active mount is developed to realize active control for engine vibration. Simulation results validate the vibration isolation effect of active mount system.There are six parts in this dissertation as following:It addresses the important effect of powerplant mount to the automobile NVH characteristic in chapter one. Then bring forward design requirement and ideal specification of powerplant mount and discuss its developing direction and market foreground and importance of this research. Finally research content is described indetail.Chapter two summarizes background and history as well as character and basic principle of bond graph as research theory. Pay much attention to bond graph applied in powerplant mount simulation. And taking a passive hydraulic mount with inertia and decoupler for a homemade light passenger car and a orifice-controlled semi-active mount for a car as research objects, analyze deeply the mount system structure and working principle, set up different kinds of bond graph model and mathematic model, establish research and simulation foundation for mount system dynamic characteristics adopting bond graph.Definition of hydraulic mount dynamic characteristics and its experimentmethod and principle are introduced in chapter three. Do some experiments on semi-active mount dynamic characteristics through some homemade car adopting ON-OFF to control flux of orifice, further verify semi-active mount controlling principle and dynamic characteristics specification, and offer experiment gist to research and design semi-active mount. Meanwhile describe parameters of the mount system model built by bond graph in term of state invariable. And Simulation and computation of mount dynamic characteristics are done by MATLAB. Simulation results and testing results verify the exactness and applicability of bond graph model.Chapter four introduces briefly basic principle and character of Piezo-actuator, analyze the effecting factor of physical parameter, linkage and pre-load to performance characteristic. Set up mechanical-electrical coupling dynamic model of Piezo-actuator. Meanwhi...