Anti-Saturation Control For A Class Of Integral System With Uncertain Parameters

Constraints are ubiquitous in the actual control systems. According to the performance requirements of the system or the actual physical restrictions, common constraints mainly are as follows: states boundedness, actuator staturation and space limitation. Violation of the constraints will result in performance degradation, instability or hazards of the system or plant even. In addition, most of the physical systems have uncertain parameters casused by inaccuracy of modeling or disturbances, so designing the controller of such systems become a hot but di?cult topic nowadays.According to the above problems, this paper selected a class of uncertain integral cascade system for multi-target control designning. Dynamic expressions of such system that is present of external disturbance, uncertainty and actuator saturation is the integral structure. Backstepping method is used to deal with the nonlinearity of this system. Its an effective tool with specific systemetic procedure for nonlinear problems. In order to solve uncertainty problem, adaptive control method which can estimate unknown parameters on-line is presented in this work. At the same time, appropriate saturation function is applied to design the controller and on the basis of the maximum of actuator output value and the objective of control, right relationship between each parameter of system is selected to ensure the system performance and stability.The rest section of the paper will investigate the quarter-car active suspension system with previously proposed adaptive backstepping anti-saturation control method. The quarter-car active suspension system is a multi-objective control system with uncertainty,external disturbance, actuator saturation and performance constraints after modeling. The proposed adaptive robust anti-saturation control is used to not only stabilize vertical displacement of the car body in the cases of uncertainty and external disturbance in suspension system,but also solve the actuator saturation problem and performance constraints.Besides, it can also set the settling time of the closed loop system with the adaptive robust anti-saturation control algorithm by choosing a special polynomial as a system desired trajectory.Finally, verify the effectiveness of the improved adaptive robust control technology and compare the results between theoretical simulation and semi-physical simulation.Reach a relative conclusion that the performance of the suspension system with proposed robust adaptive anti-saturation control method is better than passive suspension system and standard active suspension system. And validate the effectiveness and importance furtherly in practical application of the algorithm proposed in this paper.