Chuanjiang Li

Brief paper: Subspace aided data-driven design of robust fault detection and isolation systems

This paper deals with subspace method aided data-driven design of robust fault detection and isolation systems. The basic idea is to identify a primary form of residual generators directly from test data and then make use of performance indices to make uniform the design of different type robust residuals. Four algorithms are proposed to design fault detection, isolation and identification residual generators. Each of them can achieve robustness to unknown inputs and sensitivity to sensor or actuator faults. Their existence conditions and multi-fault identification problem are briefly analyzed as well and the application of the method proposed is illustrated by a simulation study on the vehicle lateral dynamic system.

Adaptive neural network tracking control for multiple uncertain Euler–Lagrange systems with communication delays

Abstract This paper considers the distributed coordinated tracking control problems for multiple Euler–Lagrange systems with nonlinear uncertainties, external disturbances, and communication delays under the directed graph. First, distributed observers are designed such that all the followers can obtain the state information of the dynamic leader. Then, based on neural network and backstepping techniques, three distributed adaptive coordinated control algorithms are proposed to ensure that the tracking errors for each follower can be bounded. Compared with the first algorithm, the second algorithm guarantees the higher leader-following control accuracy. The third algorithm solves the chattering problem caused by discontinuous functions in the second algorithm. The closed-loop systems are investigated using the graph theory, Lyapunov theory, and Barbalat lemma. Finally, numerical examples and comparisons are provided to show the effectiveness and the performance of the proposed methods.

Passivity-based Nonlinear Attitude Regulation of Rigid Spacecraft Subject to Control Saturation

This paper investigated the problem of attitude regulation control of rigid spacecraft subject to control saturation. Both full-state feedback and output feedback control schemes were presented. For the latter case, the requirement for angular velocity measurement was eliminated using passivity technique. Both controllers were shown to guarantee global asymptotic stabilization for the spacecraft attitude and angular velocity, and the control torques required were well within the specified control magnitude constraint. Unit quaternion representation was used in the kinematics due to its void of singularity. The controllers derived are independent of spacecraft inertia matrix, and thus robust to parametric uncertainty. Simulation results were included to confirm the validity of the proposed approach

Distributed finite-time coordinated control for multi-robot systems

In this paper, we study the finite-time coordinated control problems under directed topologies for multi-robot systems with general disturbances. The dynamics model of each robot is described by a Euler–Lagrange equation. When considering that only a subset of the follower robots has access to the leader information, the distributed finite-time tracking algorithm with an active leader robot is proposed. Then, we extend the tracking method to the case of containment control. Some special error functions and terminal sliding variables are defined. The finite-time convergence properties of the closed-loop systems are investigated by using a combination of matrix properties of graph theory and Lyapunov theory. Numerical examples and comparisons with other methods are provided to show the effectiveness and the performance of the proposed control strategies.

Backstepping sliding mode control for combined spacecraft with nonlinear disturbance observer

To attenuate the effects of inertia uncertainty and external disturbance of combined spacecraft on attitude control accuracy and stability, a composite control law by combining nonlinear disturbance observer (NDO) and backstepping sliding mode control is proposed. In this paper, the nonlinear disturbance observer (NDO) is added to observe the unknown inertia and external disturbance, and asymptotic stability of the backstepping sliding mode control with NDO is demonstrated. The performance of the proposed attitude control for combined spacecraft is discussed, and the simulation results demonstrate the effectiveness and feasibility of the proposed controller.

Robust fuzzy controller design for a rigid spacecraft attitude regulation system

The main problem addressed is attitude regulation of a rigid spacecraft with inertia parameter uncertainty, control input saturation and external disturbances. A robust fuzzy attitude control scheme is presented. The parallel distributed compensation (PDC) is applied to design the robust fuzzy controller, which guarantees robust stability of the close-loop system with respect to parametric uncertainty and bounded L2-gain performance with respect to disturbances. Both robust stability and L2-gain performance, together with input constraint, are incorporated in the linear matrix inequality (LMI) conditions. The feedback gains are obtained by the convex optimization technique based on LMI. Simulation results are included to demonstrate the effectiveness of the approach

Active vibration control of a flexible plate structure using LMI-based H/sub /spl infin// output feedback control law

An approach for active vibration control of a flexible plate structure using LMI-based H/sub /spl infin// robust control is presented in this paper. In contrast to the results of Kar et al, the proposed approach handles dynamic output feedback control problems. This practically attractive extension is derived by using specific transformations of Lyapunov variable with appropriate linearizing transformations of the controller variables, which gives rise to a tractable and practical LMI formulation of the vibration control problem. Based on LMI, a H/sub /spl infin// output feedback controller is designed to suppress the low-frequency vibrations caused by external disturbances and to guarantee the stability and performance of the closed-loop system under uncertainties. The simulation results show that the proposed robust active control method is efficient for active vibration suppression.

Steering law design to control moment gyroscopes for near minimum time attitude maneuver

In this paper a simple and more effective steering law is presented for spacecraft attitude maneuver with control moment gyroscopes (CMG) as actuator. The singularity problem and fast exchanging requirement of angular momentum are taken into consideration. Moreover, a near minimum time rest to rest eigenaxis rotation maneuver algorithm using CMG cluster is also proposed. Finally, simulations have been performed to demonstrate the effectiveness and advantages of the proposed steering law and maneuver algorithm.

Quaternion-Based Fuzzy Attitude Regulation of a Rigid Spacecraft

The main problem addressed was the quaternion-based, attitude regulation of a rigid spacecraft in the presence of external disturbances. A model-based fuzzy attitude control scheme was presented. The parallel distributed compensation was employed to arrive at a controller that guaranteed the stability of closed-loop system and performance specifications in terms of constraints on input and disturbance rejection. Both the stability and control performance were incorporated in the linear matrix inequality (LMI) conditions. The feedback gains were obtained by the convex optimization technique based on LMI. Simulation results demonstrate that the proposed control scheme is efficient

Distributed sliding-mode tracking control for multiple mechanical systems

Based on the sliding-mode and adaptive control theories, the distributed consensus tracking problem under directed topology is investigated for multiple mechanical systems in the presence of general disturbances. We consider that only a subset of the follower mechanical systems can get the information from the dynamic leader mechanical system. First, with the upper bounds of the general disturbances and the leader’s acceleration, a distributed sliding-mode tracking scheme is proposed. Then, when considering the high conservation of sliding-mode control, an improved algorithm with adaptation laws for the upper bounds is developed. Both the proposed algorithms can make tracking errors for each follower mechanical system asymptotically stable. Numerical examples and comparisons are provided to show the effectiveness and the performance of the proposed control strategies.