It is well known that proportional-integral-derivative (PID) controllers are dominant in industrial scenarios. PID with high-order derivative or integral terms named generalized PID is superior to the PID. However, there is little literature investigating how to tune the parameters of the generalized PID to enhance the disturbance rejection ability. Toward that end, this article illustrates that the cascade controllers based on the first-order linear active disturbance rejection controllers (LADRCs) (cascade LADRCs) and high-order LADRCs can be interpreted as the generalized PID with low-pass filters for speed servo systems and position servo systems, which in turn is an alternative method to realize the generalized PID. Moreover, the differences between the high-order LADRC and cascade LADRCs are the generalized integral terms, which can be quantified by integral time multiplied absolute error. The proposed LADRC controllers are verified and compared with the current controllers by simulations in MATLAB/Simulink. Finally, one experimental example of the LADRC controllers is implemented on the position servo dc motor system platform. 

A Generalized PID Interpretation for High-Order LADRC and Cascade LADRC for Servo Systems

Adaptive tracking control of stochastic switched nonlinear systems with unknown dead‐zone output

This paper adopts a quantization-dependent Lyapunov function to study the output feedback stabilization problem of a switched system subject to output event-triggered sampling and quantization. First, a new event-triggered mechanism related to quantization parameters is proposed, which can obtain a trade-off between the event-triggered frequency and quantization density on the premise of ensuring asymptotic stability of the switched system. Moreover, sufficient conditions are obtained to ensure asymptotic stability of the switched system by a quantization-dependent Lyapunov function. Lastly, through a numerical simulation and PWM-driven boost converter system, we demonstrate the availability of the proposed quantization-dependent Lyapunov function and event-triggered mechanism methods based on quantization parameters, respectively.

Feedback Stabilization of Switched Linear Systems: A Quantization and Triggering Joint Event-Triggered Mechanism

Finite-time rate anti-bump switching control for switched systems

This paper studies stability for a class of switched descriptor systems with state bumpless transfer performance and input bumpless transfer performance. Since the state jump is inevitable for switched descriptor systems when a switching occurs, to restrain the amplitude of the state jump induced by switchings, for the first time, the state bumpless transfer performance of switched descriptor systems is defined. Moreover, when switching occurs, to avoid the abrupt and large control input signals change damaging the system, we are the first to introduce the input bumpless transfer control scheme for switched descriptor systems. Furthermore, by using multiple Lyapunov functions, a sufficient condition is put forward to make sure the state bumpless transfer performance, input bumpless transfer performance and asymptotical stability for the closed-loop systems. Meanwhile, the switching rule and the state feedback controller are co-designed. In the end, a multiple inputs numerical example and an application on the DC motor model are used to exhibit the merit and validity of the presented control scheme.

State Bumpless Transfer Control for a Class of Switched Descriptor Systems

This article aims at proposing a regulation anti-disturbance control scheme for switched systems encountered by multiple disturbances, including the measurable disturbance and unmeasurable disturbance, through a multiple Lyapunov functions method. A switched estimator is developed for estimating the unmeasurable disturbance, under which a switched regulator and a switching law are co-designed to regulate the system output, while resisting the influence of the disturbances on the switched systems. Sufficient conditions are provided to ensure the output regulation performance and the disturbance restrain performance for the switched systems, even if all subsystems may not have the performances. These conditions are also appropriate for non-switched systems. By applying the established regulation anti-disturbance control method to the regulation of the speed for an engine model, the validity of the control scheme is displayed.

Dan Ma

Papers

Output Regulation for Switched Systems With Multiple Disturbances