Hu Weili

A new Geometrical Method for the Inverse Kinematics of the Hyper-Redundant Manipulators

Aimed at the inverse kinematics of hyper-redundant planar manipulators, a new and simple geometrical method was proposed in this paper. The proposed method can obtain a optimal solution of the inverse manipulators with less computations. Some disadvantages of the existing methods were overcome by the proposed method. The proposed method can be applied to any planar manipulators with n-links serially connected by revolute joints. Finally, through a detail computing procedure for a planar manipulator with five joints, the effectiveness of the proposed method was shown.

Robust reliable control of switched uncertain systems with time-varying delay

This paper is concerned with reliable control problems for the switched uncertain systems with time varying delay. A method for designing robust reliable controller is presented by means of the multiple Lyapunov functions technique so that the energy-like functional does not have to decrease along the switching instants. The proposed controller is reliable in that it can guarantee the closed loop asymptotic stablility of switched delay systems in the case of the possible presence of failures of partial actuators. Delay independent results of the reliable controller design are presented in terms of Linear Matrix Inequalities (LMIs). Finally, a numerical example is given to illustrate the applicability of the proposed results.

Stabilization and optimal control of nonholonomic mobile robot

The stabilization and optimal control of nonholonomic mobile robot has been an important control problem in the mobile robot research area in the past few years. In this paper, a controller with two parameters for the stabilization of a mobile robot with two-wheel is proposed. And a procedure of parameters optimization using the genetic algorithm is presented in order to minimize the performance criterion function. Finally, simulation results illustrate the effectiveness of the proposed controller and parameter optimization method.

Fuzzy model and control of nonlinear networked control systems

Tins paper is concerned with a class of nonlinear networked control systems with network-induced delay shorter than one sample period. Based on the assumptions that the actuator node is time-driven and the controller node is event-driven, a Takagi-Sugeno (T-S) fuzzy model is used to approximate the nonlinear networked systems with delay. By means of Lyapunov functions, a method for designing a fuzzy state feedback controller to satisfy the prescribed H/sub /spl infin// performance index is proposed. The results are presented in terms of linear matrix inequalities (LMIs) which can be solved by LMI toolbox in Matlab 6.5. Finally, a numerical example is given to validate the proposed method.

Decentralized output feedback fault-tolerant control for uncertain large-scale systems

In this paper, three decentralized output feedback fault-tolerant control methods of design integrity with actor failures, sensor failures and mixed failures are presented for uncertain interconnected large-scale systems. Not only can they make the faulty closed large-scale systems asymptotically stable under the uncertain bounded parameters, but also assure the H/sup /spl infin// properties are optimal or suboptimal. The example simulations demonstrate that the methods are effective.<<ETX>>

Behavior Selection Mechanism of Two Typical Brain Movement Disorders: Comparative Study Using Robot

Parkinsons disease and Huntingtons disease are two typical brain movement disorders, both of which have been studied extensively for decades. Dysfunctions in the basal ganglia-a group of sub cortex nuclei in vertebrate brains-are generally considered to account for these two diseases. But what will happen if a robot gets Parkinsons disease or Huntingtons disease? Based on the concepts in behavior based robotics, this paper studied the behavior patterns of a real robot when it suffers such two diseases. The experiment results showed that the sick robot exhibited some symptoms of Parkinsons disease or Huntingtons disease to some extent. This study made explorations to mimic high level brain functions and casted light on designing more intelligent behavior selection methods in the future.

Study of the Networked Control System with Long Delay

A class of networked control systems with long control and output delay is considered, the stage is used to fix the control delay, and an observer is designed to compensate the output delay, the model of the networked control system is given. Using the separate principle, the control design approach is given, and the design method of the observer is given with switched system theory and LMIs. The simulation result validates the method.

Fuzzy Robust H &#8734; Control for Networked Control Systems

This paper is concerned with the robust Hinfin controller design of nonlinear networked control systems (NCSs). A Takagi-Sugeno (T-S) fuzzy model with parametrical uncertainties is used to approximate the NCS in which network-induced delay is time-vary and less than one sample period. In terms of the given model, a fuzzy controller design method is proposed based on Lyapunov approach and linear matrix inequality (LMI). A feedback gain of a memoryless controller can be obtained by solving a set of LMIs. An example is given to show the effectiveness of the proposed method

Iterative learning control of wheeled robot trajectory tracking

This paper builds and analyzes kinematics model for a class of wheeled mobile robot. Trajectory tracking problem of the WMRs is analyzed and a new control scheme is presented. In the paper, the rear wheel angle velocity is gained by iterative learning algorithm of tracking a virtual wheeled robot and deflection angular velocity is gained by D-type iterative learning algorithm. The convergent conditions of the iterative learning control algorithm are given. This algorithm has advantages of simplicity and depending little on the model. The results of simulation show that the presented iterative learning control can solve the problems of trajectory tracking for nonholonomic system successfully. The algorithm has good robustness to measuring parameter errors. Good tracking performance has been obtained.

On fault-tolerant functional observer

In this paper, a new procedure for designing functional observers of linear multi-output systems is presented. Such observer can reconstruct partial-state information asymptotically even when some of the output measurements of the given system are unreliable and it will reconstruct all-state information once these unreliable measurements become regular. Partial closed-loop poles of a certain stabilizable system can be assigned arbitrarily and its closed-loop stability may be guaranteed when some of the output measurements are unreliable.