Xianlin Huang

Stability analysis of the simplest Takagi-Sugeno fuzzy control system using circle criterion

In this paper, we present two sufficient conditions in the frequency domain for the global stability analysis of the simplest Takagi-Sugeno (T-S) fuzzy control system, based on the circle criterion and its graphical interpretation. These conditions are significant in graphically designing the simplest T-S fuzzy controller in the frequency domain. Four numerical examples are provided to demonstrate the efficiency of our two frequency domain-based conditions. Furthermore, this T-S fuzzy controller and the linear proportional controllers are also compared. It is concluded that the simplest T-S fuzzy controller can outperform the linear proportional controllers in a noisy environment with external disturbances.

Stability Analysis of the Simplest Takagi-Sugeno Fuzzy Control System Using Circle Criterion

In this paper, a sufficient condition is derived to guarantee the globally asymptotic stability of the simplest Takagi-Sugeno (T-S) fuzzy control system based on the circle criterion. Two numerical examples are given to demonstrate how to use this condition in analyzing the T-S fuzzy control systems. Performance comparisons are also made between the simplest T-S fuzzy controller and linear compensators.

Adaptive reaching law based sliding mode control for electromagnetic formation flight with input saturation

Abstract Electromagnetic formation flight utilizes electromagnetic forces to control the relative positions of satellites, and offers a promising alternative to a traditional propellant-based spacecraft formation flying due to no fuel expenditure. Since available electromagnetic forces generated on board are small, their efficient use is a challenging issue in the presence of saturation. This paper proposes a novel adaptive reaching law based sliding mode control for the trajectory tracking of electromagnetic formation flight with actuator saturation. The adaptive reaching law is characterized by a modulation function which combines a saturated term with a non-switching term. The saturated term makes the sliding variable converge as fast as possible under input saturation, while the non-switching term is used to guarantee a terminal tracking performance and remove chattering. Thus, the introduced modulation function enables a smooth transition of the reaching law between two terms and an adaptive decrease rate of sliding variable. The proposed control can achieve a fast convergence and offers the robustness against external disturbance with input saturation. Simulation results are given to demonstrate the performance of the presented method.

Extended dissipative filtering of fuzzy systems with time-varying delay under imperfect premise matching

ABSTRACT This paper investigates the extended dissipative filter design problems for continuous-time fuzzy systems with time-varying delays under imperfect premise variables based on a unified performance index−extended dissipative. Attention is focused on solving the H∞, L2 − L∞, passive and dissipative filtering problems for fuzzy systems with time-varying delays under this unified framework. Based on the unified performance index, a new delay-dependent filter design approach in terms of linear matrix inequalities is obtained by employing Lyapunov–Krasovskii functional method together with a novel efficient integral inequality. The designed filter can guarantee the filtering error system satisfy the prescribed H∞, L2 − L∞, passive and dissipative performance by tuning the weighting matrices in the conditions. Moreover, in this paper, the fuzzy filter does not need to share the same membership function with fuzzy model, which can enhance design flexibility and robust property of the fuzzy filter system. Finally, two examples are provided to illustrate the effectiveness and significant improvement of the method proposed in this paper.

Principles and Applications of Polarized-light-aided Attitude Determination in Integrated Navigation

To improve the attitude error correcting capabilities of GPS/SINS integrated navigation systems, a new method of polarized-light-based GPS/SINS integrated navigation is presented. The principles of polarized-light-aided attitude determination are demonstrated, and a multi-module approach is proposed to increases the degree of observability. The integrated navigation algorithm is implemented in frame of federated Kalman filtering. To verify the effects of the method, Matlab simulation is performed. The results indicate that the degree of observability and precision of the navigation system can be obviously improved, and the performance of the system can be improved more by using multi-polarized-light modules whose lines of sight are non-parallel with each other.

Type-2 fuzzy logic control for underactuated truss-like robotic finger with comparison of a type-1 case1

Underactuated mechanical systems have their own difficulties within the control criterion. As a particular and complex underactuated mechanical system, underactuated truss-like robotic finger(UTRF) is studied by establishing its dynamic model. The control problems include high nonlinearity, model inaccuracy and uncertainties. Type-2 fuzzy logic control method is supposed to be a proper way to solve these problems, because fuzzy logic control itself does not depend on an accurate model of the controlled object, and type-2 fuzzy logic control is able to handle uncertainties. Based on a brief introduction on type-2 fuzzy logic systems, an interval type-2 fuzzy logic controller is designed for UTRF to accomplish the goal of stabilization in its equilibrium point. As an extension of the type-1 fuzzy, the performances of the proposed controller are compared with the type-1 one case to show the advantages of the type-2 fuzzy. Simulation results show that the designed interval type-2 fuzzy logic controller is correct and effective and has better performances than that of type-1 fuzzy control.

Calibration and error analysis for polarized-light navigation sensor

In order to improve the calculation accuracy of polarized-light navigation sensor, the system error model was derived. Through the system error model, the system error source parameters could be calibrated outline, and the system error could be compensated greatly. The random error model was also derived in this paper. The transitive relation between random error and calculation accuracy of polarization direction was obtained. The transitive relation indicates that the angle error caused by random error is independent of polarization direction. According to this relation, the bound of angle error caused by random error could be calculated in real-time. The simulation results show that the system error model and random error model are correct and effective.

Observability of Geomagnetism/GPS/SINS integration during maneuvers

Observability of Geomagnetism/Global Positioning System/strapdown inertial navigation system (Geomagnetism/GPS/SINS) integrated system was analyzed during maneuvers. Instantaneous observability was adopted for the observability analysis of time-invariant and time-varying system. When there was no rotation relative to the Earth and the linear acceleration was constant, the system model became time-invariant. Observability analysis results show that there are at least one and at most two instantaneous unobservable states in the time-invariant Geomagnetism/GPS/SINS system, which are at least three in the time-invariant GPS/SINS system. The observability of time-varying system was analyzed for two types of maneuvers, nonconstant accelerating maneuvers and constant angular rate turn maneuvers. The sufficient conditions for instantaneous observability of system are presented for these two maneuvers. And the necessary condition for instantaneous observability is presented for nonconstant accelerating maneuvers. It is shown that the appropriate maneuver can enhance the instantaneous observability of system and all the states in Geomagnetism/GPS/SINS integrated system can be made instantaneous observable by appropriate maneuver.

Comments on “Stability analysis for a class of Takagi--Sugeno fuzzy control systems with PID controllers”

This note points out that some results in the paper (International Journal of Approximate Reasoning 46 (2007) 109-119) are incorrect.

A precise vision-based navigation method for autonomous soft landing of lunar explorer

During the entry, descent and landing (EDL) phase of the lunar explorer with a high degree of accuracy, the dual quaternion and the unscented Kalman filter (UKF) based vision navigation method is presented, in order to accomplish navigation task. The lunar explorers pose estimation method is developed through dual-quaternion calculation. The state equation is derived according to the dynamic model of the lunar explorer during the power descent phase, and the measurement equation is derived by constructing feature points triangle. Because of the nonlinear property of the state function and measurement function, the UKF method is used to estimate the pose of lunar explorer. Simulations demonstrate the validity of the proposed method.