Suspension Control-based Vehicle Ride Comfort Simulation

Suspension as an important part of the car which is more difficult to achieve a required perfect assembly, it is not only to meet the requirements of comfortable, but also to meet the requirements of handling and stability, These requirements about the suspension are mutually contradictory. Vehicle active suspension is able to adjust or produce controlling force between wheel and vehicle body according to road conditions. So it can restrict vibration and improve the performance of suspension and achieve the purpose of improving ride comfort and handing stability simultaneously.One of the key tasks of the suspension design is to find a vehicle to provide good performance for the control law. Many scholars have put forth a variety of control theory. Optimal control, PID control, fuzzy control, and Fuzzy-PID control are studied in this paper. Because PID control algorithm as a classical and practical algorithm has some advantages such as little work of accounting, good real-time trait and easy achievement, PID control strategy has also been applied. Then, the PID controller has been designed. The advantages of The optimal control is according to the state variables of the system and through evaluation of the minimum, to get an optimum integrated control targets. State variables can be selected based on needed. Fuzzy logic has been selected because it is independence on the exact mathematical model of the system. Sensitivenessless to the variant and good robustness, besides, fuzzy logic is very fit to the model of non-linear, time-chageable and delay characteristics. The control algorithm of fuzzy logic base on several control rules and is simple. Then, the fuzzy logic controller has been designed. Fuzzy-PID control combined fuzzy logic and PID control is able to achieve the parameter's self-adapative on-time status. It can furtherly improved the performance of the PID controller in order to adaptive to the changeable variant and changeable condition of the control model. Fuzzy-PID controller that combines the two strategies discussed above to eliminable the disadvantages of the singles has been designed. Establishment of quarter vehicle model and the application of four ways control theory, controllers of automobile active suspension are designed. The system model in Matlab/Simulink environment is built and used for simulation. Simulation results are compared with passive suspension.Simulation results show that all this four different forms of active suspension can remarkably deduce the vehicle body acceleration, dynamic flexibility suspension and dynamic load of tyre. That implies active suspension improves ride comfort and handing stability well. Among this four control strategies, the control effect of Fuzzy-PID control is the best.