In this paper, based on a disturbance observer (DO), an adaptive neural network (ANN) tracking control scheme is proposed for the multi-input and multi-output (MIMO) strict-feedback discrete-time system (SFDTS). The unknown nonlinear functions, dead-zone input and external disturbance are all considered in the studied SFDTS. Before starting to design the controller, the MIMO SFDTS is transformed into a maximum N-step ahead predictor to solve the noncausal problem. Then, the backstepping method is successfully used to design the control scheme for the new system. The unknown nonlinear functions are approximated by radial basis function neural networks. The external disturbance is estimated based on the DO, and the ANN controller is designed on the basis of the outputs of the DO. By applying the Lyapunov stability theory, all the signals in the whole closed-loop system are ensured bounded. Finally, a numerical simulation is provided to verify the validity of the proposed control scheme.

A disturbance-observer-based adaptive neural network (ANN) control scheme is discussed for the discrete-time nonlinear system with strict-feedback form in this paper. To monitor the external disturbance, a disturbance observer (DO) is proposed. Then, an ANN controller is developed with the outputs of the DO and the radial basis function neural network (RBFNN). The bounded stability of the whole closed-loop system is guaranteed by choosing the appropriate parameters. At last, the validity of the proposed control scheme is verified by a numerical simulation.

以STM32F103RCT芯片为核心,结合麦克纳姆轮、TPS5430稳压模块、ICM-20602六轴IMU惯性单元及SYN-7318语音交互模块等设计了一款多功能语音机器人.其具有全向移动、自主定位、语音交互、测距避障、温湿度检测、可燃气体检测、明火检测等多种功能,能够在发现险情时发送报警信息.

In this paper, the problem of disturbance-observer-based sliding mode control (SMC) is studied for a class of Takagi–Sugeno (T–S) fuzzy discrete-time systems subject to dead-zone input and external disturbance. The disturbance is monitored by a disturbance observer (DO). Then, a DO-based sliding mode controller is derived. By selecting the suitable gain matrices, the DO can approximate the external disturbance effectively, and the stability of the system can be guaranteed. Finally, the validity of the proposed SMC scheme is verified with the simulation results of the tunnel diode circuit system.

The core part of the function wave generator was made up of IC MAX038 chip in this paper. The design of the external circuit was simple and tried. Sine pulse and triangle waveforms could be produced by the function wave generator. 10-4 was achieved in the frequency stability and accuracy. The distortion of sine waveform was about 1%. By using the control chip made up of the C8051F005 Single Chip Micyoco, the function wave generator could output waveforms selected with keyboard, and show the frequency of outputting signal on LCD.

The fault tolerant control problem is investigated for a class of uncertain networked control systems (NCSs) subject to actuator faults and actuator saturation in this paper. System parameter uncertainties are considered and a sector condition method is employed to deal with the saturation problem. Based on the network transmission environment, the NCSs can be modeled as a class of saturated discrete-time systems with time-varying delays and actuator faults. By using Lyapunov-Krasovskii (L-K) stability theory, a sufficient condition for the fault tolerant controller design of NCSs is derived in the form of linear matrix inequalities. Finally, simulation results are given to demonstrate the effectiveness of the proposed method.

The problem of state feedback stabilization is studied for networked control systems (NCSs) subject to actuator saturation and network-induced delays. To facilitate the controller design, the NCSs are modeled as a class of discrete-time systems with bounded delays and input saturation. Based on Lyapunov-Krasovskii theory and free weighting matrix approach, the sufficient condition is derived in terms of linear matrix inequality for the asymptotic stability. Finally, the effectiveness of the developed control approach is proved through numerical examples.

A bounded controller is proposed for a class of uncertain discrete time-delay systems with nonlinearity and disturbance based on state estimator and disturbance observer technique. A state estimator is developed to estimate the unmeasured system state vector. Suppose that the disturbance is generated by an exogenous system; a disturbance observer is designed to estimate the unknown disturbance. The parameters of the state estimator and the disturbance observer are calculated by solving linear matrix inequalities (LMIs). By applying the outputs of the state estimator and the disturbance observer, the sufficient condition for the existence of the bounded controller is derived based on an appropriate Lyapunov function candidate. Under the developed bounded controller, the stability of the closed-loop system can be guaranteed. Simulation examples are provided to show the effectiveness of the proposed bounded control scheme.