Research On Multi Performance Index Constraint Control Method Of Vehicle Active Suspension System

Suspension system plays an important role in active vehicle systems,which can adjust the height of vehicle body to reduce the vibration of vehicle body.Active suspension can improve the driving performance of vehicle through the control strategy,which improves the ride comfort,operation stability and ride comfort of the vehicle.Firstly,the different characteristics of the active suspension actuator are studied in this paper.The input saturation characteristics of active suspension actuators are considered and a quarter active suspension model is established.A 1/2 hydraulic active suspension mode is established;the relevant knowledge of command filtered and anti-saturation theory are introduced.Secondly,a 1/4 active suspension model is established.An auxiliary system is designed to deal with the input saturation,which effectively reduces the impact of actuator input saturation on the suspension system.The conflicts between the vertical acceleration and the suspension working are considered.Moreover,the suspension working space will become large if the acceleration is small.The acceleration will be large if the suspension working space is too small.The nonlinear filter coordinates the relationship between the vertical acceleration and suspension working space.In addition,the uncertain parameters are effectively solved by the designed control method in the active suspension system.Simulation results shown that the ride comfort,operational stability and driving safety are improved by the proposed method.Finally,a multi-performance-index adaptive control based on command filtered is proposed for half-vehicle active suspension systems with a hydraulic actuator,which enhances the vehicle performance.The dynamic characteristics of hydraulic actuators are considered and a half-vehicle nonlinear hydraulic active suspension model is established.An adaptive parameter estimation law is designed to estimate uncertain parameters of the suspension due to load mass.A command filter is designed to solve the problem of explosion of complexity.Furthermore,the output of the command filter is used to replace the derivative of the virtual control to reduce the amount of online calculation.The error compensation signals are introduced to eliminate the effects of command filtering errors,which is benefit for the control performance.Moreover,all error compensation signals are proved to be bounded.The performance constraints of the suspension working space and dynamic load ratio are considered.Simulations show that the method proposed in this paper not only significantly improves the ride comfort,but also improves driving safety and operational stability.