摘要：A new cascade control program was proposed based on modified internal model control to handle stable,unstable and integrating processes with time *** program had totally four controllers of which the secondary loop had two controllers and the primary loop had two *** two secondary loop controllers were designed using IMC *** were decoupled completely and could be adjusted independently,which avoided the undesirable influence on performance of the primary *** main controller in the primary loop was devised as a PID using the method of minimum sensitivity,which could guarantee not only the nominal performance but also the robust stability of the system.A setpoint filter was added in the primary loop to improve the tracking *** the controllers of the two closed-loops were designed analytically,and could be adjusted and optimized by single parameter *** were carried out on three various processes with time delay,and the results show that the proposed method can provide a better performance of both set-point tracking and disturbance rejection and robustness against parameters perturbation.

摘要：Precise position tracking control of the single-rod pneumatic actuator is considered and a nonlinear cascade controller is *** proposed controller comprises an extended disturbance observer(EDOB)and a nonlinear robust control law synthesized by the backstepping *** EDOB is designed to estimate not only the influence of disturbances but also the parameter *** the use of parameter and disturbance estimates,the nonlinear cascade controller,which consists of an outer position tracking loop and an inner load pressure loop,is further designed to attenuate the effects of parameter and disturbance estimation *** stability of the closed-loop system is proven by means of Lyapunov *** comparative experimental results obtained verify the effectiveness of the proposed nonlinear cascade controller and its performance robustness to parameter and external disturbance variations in practical implementation.

摘要：Model predictive controllers(MPC)with the two-loop scheme are successful approaches practically and can be classified into two main categories,tube-based MPC and MPCbased reference governors(RG).In this paper,an enhanced twoloop MPC design is proposed for a pre-stabilized system with the bounded uncertainty subject to the input and state *** proposed method offers less conservatism than the tube-based MPC methods by enlarging the restricted input *** to the MPC-based RGs,the investigated method improves tracking performance of the pre-stabilized system while satisfying the ***,the robust global asymptotic stability of the closed-loop system is guaranteed in a novel procedure with terminal constraint *** of the proposed method on a servo system shows its effectiveness in comparison to the others.