Research On Adaptive Fault Tolerant Intelligent Control Of Vehicle Active Suspension System

With the continuous development of science and technology and the improvement of people’s living standards,the car has become an indispensable means of transportation in people’s lives,and the stability and driving safety of the car is the top priority of people’s attention,and the active suspension system is an important part to ensure the stability and driving safety of the car.Therefore,it is very important to design a good suspension system by using excellent control algorithm,which has attracted more and more attention.In real life,actuator failure is inevitable.When the actuator of active suspension system fails,how to ensure the basic performance of the vehicle is also worth studying.Aiming at the active suspension system,this paper mainly studies the following three aspects(1)An adaptive fault-tolerant control method is proposed for quarter car active suspension system with displacement constraint and actuator failure.A fault model is introduced to solve the actuator fault of quarter active suspension system.Fuzzy logic system is used to approximate the unknown continuous function in suspension system.By constructing a multiobjective constraint function,a new obstacle Lyapunov function is established to ensure that the vehicle body displacement does not violate the time-varying constraint bound.Using Lyapunov stability theorem,the stability of the proposed method is proved,and the effectiveness of the proposed method is further verified in the simulation study.(2)An adaptive fault-tolerant control method is proposed for quarter car active suspension system with actuator failure.Based on Butterworth low-pass filter,two second-order systems of quarter active suspension in traditional sense are transformed into fourth-order systems.All States of quarter active suspension are considered as a whole to ensure that information will not be lost,and a new state space expression is established.The fault model is introduced.Based on the backstepping recursive method and the approximation feature of neural network,the unknown continuous function in the quarter active suspension system is identified,and the corresponding controller and parameter adaptive law are designed.According to Lyapunov stability theory,the proposed control method can ensure that all signals in the active suspension system are bounded.Simulation results show that the proposed control algorithm can meet the performance requirements of suspension and achieve the control objectives.(3)Aiming at the quarter active seat suspension system with actuator failure,the adaptive fault-tolerant control problem of the active seat suspension system is solved,and the ride comfort and stability in case of failure are further improved.In order to solve the problem of actuator failure of active seat suspension system,an adaptive law is designed to deal with the uncertainty of failure parameters.The fuzzy logic system is used to deal with the unknown continuous function in the system.The corresponding controller and adaptive law are designed based on backstepping recursive technology.According to Lyapunov stability theorem,it is proved that this method can ensure the stability of active seat suspension system.The simulation results show that the proposed adaptive fault-tolerant control algorithm is better than other control methods in the case of actuator failure of active suspension system.At the same time,two different types of road interference are considered to further verify the effectiveness of the proposed method.