Research On Control Strategy Of Electro-hydraulic Servo Control Active Suspension

Suspension system is one of the important components of the vehicle,which can supportthe vehicle body and ease body vibration or shock due to uneven road,and keep the dynamicperformance of the ties. Passive suspension is a kind of shock absorbing device based onvibration isolation theory. Due to fixed spring stiffness and damping coefficient,it’s limitedto improve the vehicle comfort. Active suspension can adjust actuator’s force throughexternal energy, it will improve the vehicle’s comfort easily. But it is only applied in a smallamount of vehicles, because of its complexity of actuator design and high requirement ofcontrol accuracy. With the development of modern science and technology, includingadvanced materials and computer technology, active suspension technology has a extensiveprospect of application.Through analysis of foreign and domestic active suspension technology and combiningwith the special fund project of Jilin province automobile industry development "Researchand manufacture on inertial control technology for the car’s active suspension "(Project No.20112330), the paper researched on the electro-hydraulic servo control active suspension inexperiment and theory. Firstly,the paper built the math modles of the random road, the sevendegrees of vehicle and the hydraulic cylinder controlled by valve,which were based on theactive suspension control structure. Then using the theories of1/4suspension and1/2suspension skyhook control, gave the way to realize the whole vehicle skyhook control byconstructing pseudoinverse matrix. The damping coefficient K was adjusted online throughfuzzy control strategy. For three kind of movement of vehicle body,three fuzzy controllerswere designed. The adaptive controller was designed through constructing the third orderreference model to solve the defects of actuator such as asymmetric dynamic performance,response lag and so on. For the active suspension test car of this project, the filteringamplifying circuit and power amplifier circuit were designed to deal with the input and output signal. Control program was finished with Labview.In order to verify the validity of the control method, The modles and co-simulationwere completed with the AMESim and Simulink on the random road grade C.Then usedelectro-hydraulic servo control active suspension test car to complete road test on thecontinuous pulse road.The simulation and test results show that the vertical acceleration,pitch angle acceleration and roll angle acceleration of fuzzy skyhook control activesuspension are lower than passive suspension. The performance of vehicle with fuzzyskyhook control is better than the ones with fixed skyhook damping coefficient control.