Research On Adjustable Shock Absorber And Vehicle Yaw Attitude Immune PID Control

Passive suspension can not guarantee the ride comfort and vehicle handling stability to be the best in the same time. Although active suspension overcomes the Shortcomings of passive suspension system, but it is complex, cost more and it is very unreliable. Semi-active suspension system cost less, can be controlled easily, and has the Advantage as the active suspension. So semi-active suspension is highly useful, and semi-active suspension has great practical significance.Adjustable shock absorber is the key component of semi-active suspension. Simulation model design of absorber is one of the key issues of adjustable shock development. It is very important to the actual production that adjusting parameters in the simulation model will make computer simulation quickly able to come through changes of the Damping characteristics. Traditional damper velocity characteristic models are lumped parameter model. They use semi-empirical formula of engineering fluid mechanics in analyzing the absorber. and the deformation of the throttle valve is calculated by using various deflection theories. So the velocity characteristics from simulation model makes much difference from the reality.This paper introduces the idea of the finite element method and the use of ANSYS finite element analysis software. It also recites the use of FSI. Then take the shock absorber of a car as an example. Use FSI in establishing solid-liquid coupling model which simulate the work trip of the absorber. Imputing the speed of the piston to the surface which contacts piston and liquid will become the pressure difference of the piston surface. Then we can calculate the shock absorber damping force and draw the velocity characteristic curves Finally, Test on a shock absorber and then come and show their speed curve diagram. Based on the results of analysis and simulation results to amend and improve the absorber velocity characteristics simulation model. Using such method to study the goal absorber to prove this method feasible in order to apply this production in developing the adjustable absorber. This Study result will then be used in guiding the development of goal adjustable shock absorber and work out the adjustable shock absorber with electromagnetic valve bypass valve. It comes from the passive shock absorber which was added a middle chamber. Middle chamber connected with the work chamber at the top and connected with the reserve chamber at the bottom. Two screw cylinders clamp the middle chamber in the middle of work chamber and reserve chamber. Middle chamber is connected with the work chamber through large orifice and there is no damping. Middle chamber is connected with the work chamber through large orifice and there is no damping. Middle chamber is connected with the reserve chamber by a electromagnetic valve which control the oil flow. When the electromagnetic valve is closed, oil access is as same as the original and forming hard damping. When the electromagnetic valve is opened, oil flows into reserve chamber from work chamber via electromagnetic valve, thus realizing the soft damping.Computer in controllable Suspension System is the center of all information processing and management. It can receive signals from the various sensors and decided to take what operations will control Depending on the particular method of data processing and control law. Changing the body's movement to meet performance requirements of the traffic and controlling the export of the implementing agencies. In the process of Suspension control, the operation of the computer control algorithms is the key to the quality of decision Intelligent Suspension Control System.Vehicle initiative safety can be improved by improving attitude control through the damper of the suspension. PID control algorithm is widely used as a simple and practical algorithm But tuning PID controller is difficult, So various self-learning control algorithms such as neural networks, Immunity, PSO, ant algorithms is introduced to determine PID parameters. In this paper, based on the damper suspension I design the algorithm which tuning PID control parameters on-line by immune algorithm, and control the vehicle based on the yaw stability. By the time emergency evasive maneuver "to step" and the "single-shift" working conditions for simulation analysis: attachments on the high road, the suspension can control the yaw damper vehicle control and cornering campaign. Control effect is very obvious that the control algorithm design can effectively improve the vehicle active safety. Algorithms controlled vehicle stability well through controlled by the front suspension and both front and rear suspension. Moreover it can determine PID parameters on-line. From the simulation results, we can see that front suspension request large damping value when control the front suspension only so need a shock absorber with wide adjustment. It is too hard. but we can achieve the same result and need not the wide absorber adjustment by controlling the front suspension and rear suspension in the same time.In short, this paper based on Changchun Technology Projects. In this paperâ… designed the shock absorber velocity characteristic model by using ANSYS finite element analysis software and use this method in developing the adjustable shock absorber. I design the algorithm based on the damper suspension which tuning PID control parameters on-line by immune algorithm and simulate the typical conditions. The result implied that this control algorithm can improve the vehicle initiative safety.