This paper proposes a methodology for the quantitative robustness evaluation of PID controllers employed in a DC motor. The robustness analysis is performed employing a 2~3 factorial experimental design for a fraction...This paper proposes a methodology for the quantitative robustness evaluation of PID controllers employed in a DC motor. The robustness analysis is performed employing a 2~3 factorial experimental design for a fractional order proportional integral and derivative controller(FOPID), integer order proportional integral and derivative controller(IOPID)and the Skogestad internal model control controller(SIMC). The factors assumed in experiment are the presence of random noise,external disturbances in the system input and variable load. As output variables, the experimental design employs the system step response and the controller action. Practical implementation of FOPID and IOPID controllers uses the MATLAB stateflow toolbox and a NI data acquisition system. Results of the robustness analysis show that the FOPID controller has a better performance and robust stability against the experiment factors.展开更多
Because of the tire nonlinearity and vehicle＇s parameters＇uncertainties,robust control methods based on the worst cases,such as H_∞,μsynthesis,have been widely used in active front steering control,however,in orde...Because of the tire nonlinearity and vehicle＇s parameters＇uncertainties,robust control methods based on the worst cases,such as H_∞,μsynthesis,have been widely used in active front steering control,however,in order to guarantee the stability of active front steering system（AFS）controller,the robust control is at the cost of performance so that the robust controller is a little conservative and has low performance for AFS control.In this paper,a generalized internal model robust control（GIMC）that can overcome the contradiction between performance and stability is used in the AFS control.In GIMC,the Youla parameterization is used in an improved way.And GIMC controller includes two sections：a high performance controller designed for the nominal vehicle model and a robust controller compensating the vehicle parameters＇uncertainties and some external disturbances.Simulations of double lane change（DLC）maneuver and that of braking on split-μroad are conducted to compare the performance and stability of the GIMC control,the nominal performance PID controller and the H_∞controller.Simulation results show that the high nominal performance PID controller will be unstable under some extreme situations because of large vehicle＇s parameters variations,H_∞controller is conservative so that the performance is a little low,and only the GIMC controller overcomes the contradiction between performance and robustness,which can both ensure the stability of the AFS controller and guarantee the high performance of the AFS controller.Therefore,the GIMC method proposed for AFS can overcome some disadvantages of control methods used by current AFS system,that is,can solve the instability of PID or LQP control methods and the low performance of the standard H_∞controller.展开更多
In conjunction with a second order uncertain nonlinear system, this paper makes some comparisons between PID control and general-integral-proportional-derivative (GI-PD) control;that is, by Routh’s stability criterio...In conjunction with a second order uncertain nonlinear system, this paper makes some comparisons between PID control and general-integral-proportional-derivative (GI-PD) control;that is, by Routh’s stability criterion, we demonstrate that the system matrix under GI-PD control can be stabilized more easily;by linear system theory and Lyapunov method, we demonstrate that GI-PD control can deal with the uncertain nonlinearity more effectively;by analyzing and comparing the integral control action, we demonstrate that GI-PD control has the better control performance. Design example and simulation results verify the justification of our conclusions again. All these mean that GI-PD control has the stronger robustness and higher control performance than PID control. Consequently, GI-PD control has broader application prospects than PID control.展开更多
Airborne electro-optical tracking and sighting system is a three-degree-of-freedom angular position servo system which is influenced by multi-disturbance,and its control system consists of stabilizing and tracking com...Airborne electro-optical tracking and sighting system is a three-degree-of-freedom angular position servo system which is influenced by multi-disturbance,and its control system consists of stabilizing and tracking components.Stabilizing control is applied to track angular velocity order and control multi-disturbance under airborne condition,and its robustness should be very good;tracking control is applied to compensate tracking error of angular position.A mathematical model is established by taking the control of yaw loop as example.H∞ stabilizing controller is designed by taking the advantage of H∞ control robustness and combining with Kalman filter.A fuzzy control is introduced in general PID control to design a decoupled fuzzy Smith estimating PID controller for tracking control.Simulation research shows that the control effect of airborne electro-optical tracking and sighting system based on fuzzy PID and H∞ control is good,especially when the model parameters change and the multi-disturbance exists,the system capability has little fall,but this system still can effectively track a target.展开更多
针对BP-PID控制器的控制性能受参数初值影响大、易陷入局部极值、对噪声敏感,且低信噪比条件下控制稳定性差等问题,提出了一种基于改进果蝇优化算法(Improved Fruit Fly Optimization Algorithm,IFOA)和径向基神经网络-卡尔曼滤波(Radia...针对BP-PID控制器的控制性能受参数初值影响大、易陷入局部极值、对噪声敏感,且低信噪比条件下控制稳定性差等问题,提出了一种基于改进果蝇优化算法(Improved Fruit Fly Optimization Algorithm,IFOA)和径向基神经网络-卡尔曼滤波(Radial Basis Function Network-Kalman Filter,RBF-KF)的噪声稳健BP-PID控制方法。首先提出了一种IFOA随机搜索算法对BP-PID初值进行全局寻优,自动获得全局最优解,提升系统控制精度。然后利用所提RBF-KF对观测数据进行滤波平滑,降低量测和控制噪声对系统的影响,提升低信噪比条件下的控制稳定性。基于某智能车车速控制真实数据开展试验,结果表明,所提方法相对于传统方法控制精度提升超过50%,控制稳定性提升超过60%,并且在低信噪比条件下优势更加明显,更适合实际工程应用场景。展开更多
文摘This paper proposes a methodology for the quantitative robustness evaluation of PID controllers employed in a DC motor. The robustness analysis is performed employing a 2~3 factorial experimental design for a fractional order proportional integral and derivative controller(FOPID), integer order proportional integral and derivative controller(IOPID)and the Skogestad internal model control controller(SIMC). The factors assumed in experiment are the presence of random noise,external disturbances in the system input and variable load. As output variables, the experimental design employs the system step response and the controller action. Practical implementation of FOPID and IOPID controllers uses the MATLAB stateflow toolbox and a NI data acquisition system. Results of the robustness analysis show that the FOPID controller has a better performance and robust stability against the experiment factors.
基金Supported by National Natural Science Foundation of China(Grant Nos.11072106,51375009)
文摘Because of the tire nonlinearity and vehicle＇s parameters＇uncertainties,robust control methods based on the worst cases,such as H_∞,μsynthesis,have been widely used in active front steering control,however,in order to guarantee the stability of active front steering system（AFS）controller,the robust control is at the cost of performance so that the robust controller is a little conservative and has low performance for AFS control.In this paper,a generalized internal model robust control（GIMC）that can overcome the contradiction between performance and stability is used in the AFS control.In GIMC,the Youla parameterization is used in an improved way.And GIMC controller includes two sections：a high performance controller designed for the nominal vehicle model and a robust controller compensating the vehicle parameters＇uncertainties and some external disturbances.Simulations of double lane change（DLC）maneuver and that of braking on split-μroad are conducted to compare the performance and stability of the GIMC control,the nominal performance PID controller and the H_∞controller.Simulation results show that the high nominal performance PID controller will be unstable under some extreme situations because of large vehicle＇s parameters variations,H_∞controller is conservative so that the performance is a little low,and only the GIMC controller overcomes the contradiction between performance and robustness,which can both ensure the stability of the AFS controller and guarantee the high performance of the AFS controller.Therefore,the GIMC method proposed for AFS can overcome some disadvantages of control methods used by current AFS system,that is,can solve the instability of PID or LQP control methods and the low performance of the standard H_∞controller.
文摘In conjunction with a second order uncertain nonlinear system, this paper makes some comparisons between PID control and general-integral-proportional-derivative (GI-PD) control;that is, by Routh’s stability criterion, we demonstrate that the system matrix under GI-PD control can be stabilized more easily;by linear system theory and Lyapunov method, we demonstrate that GI-PD control can deal with the uncertain nonlinearity more effectively;by analyzing and comparing the integral control action, we demonstrate that GI-PD control has the better control performance. Design example and simulation results verify the justification of our conclusions again. All these mean that GI-PD control has the stronger robustness and higher control performance than PID control. Consequently, GI-PD control has broader application prospects than PID control.
基金Sponsored by Foundation for Excellent Young Teachers in Universities of Henan Province of China(2002[121])
文摘Airborne electro-optical tracking and sighting system is a three-degree-of-freedom angular position servo system which is influenced by multi-disturbance,and its control system consists of stabilizing and tracking components.Stabilizing control is applied to track angular velocity order and control multi-disturbance under airborne condition,and its robustness should be very good;tracking control is applied to compensate tracking error of angular position.A mathematical model is established by taking the control of yaw loop as example.H∞ stabilizing controller is designed by taking the advantage of H∞ control robustness and combining with Kalman filter.A fuzzy control is introduced in general PID control to design a decoupled fuzzy Smith estimating PID controller for tracking control.Simulation research shows that the control effect of airborne electro-optical tracking and sighting system based on fuzzy PID and H∞ control is good,especially when the model parameters change and the multi-disturbance exists,the system capability has little fall,but this system still can effectively track a target.
文摘针对BP-PID控制器的控制性能受参数初值影响大、易陷入局部极值、对噪声敏感,且低信噪比条件下控制稳定性差等问题,提出了一种基于改进果蝇优化算法(Improved Fruit Fly Optimization Algorithm,IFOA)和径向基神经网络-卡尔曼滤波(Radial Basis Function Network-Kalman Filter,RBF-KF)的噪声稳健BP-PID控制方法。首先提出了一种IFOA随机搜索算法对BP-PID初值进行全局寻优,自动获得全局最优解,提升系统控制精度。然后利用所提RBF-KF对观测数据进行滤波平滑,降低量测和控制噪声对系统的影响,提升低信噪比条件下的控制稳定性。基于某智能车车速控制真实数据开展试验,结果表明,所提方法相对于传统方法控制精度提升超过50%,控制稳定性提升超过60%,并且在低信噪比条件下优势更加明显,更适合实际工程应用场景。
