Current Issue : January - March Volume : 2020 Issue Number : 1 Articles : 5 Articles
In this paper, an integrated scheme including fault diagnosis and fault-tolerant controller design is proposed for the manipulator\nsystem with the sensor fault. Any constant fault or time-varying fault can be estimated by the fault diagnosis scheme based on the\nadaptive observer rapidly and accurately, and the designed parameters can be solved by the linear matrix inequality. Using the\nfault estimation information, a fault-tolerant controller combining the characteristics of the proportional differentiation control\nand the sliding model control is designed to trace the expected trajectory via the back-stepping method. Finally, the effectiveness of\nthe above scheme is verified by the simulation results....
This paper investigates a relative coupling control strategy based on the sliding mode controller to solve the problem of poor\nsynergy performance of the axes of the dynamic seat during operation and to realize the multiaxis servo synergic control with\nvariable proportions during the operation of the system. Firstly, the proposed method is theoretically proven to be accurate in\neliminating tracking errors and synchronization errors between servos in the process of system operation. Secondly, the system\nsimulation model is built in the Simulink simulation environment of MATLAB. On one hand, the final simulation result verifies\nthe accuracy of the theoretical proof. On the other hand, the control strategy is characterized by fast convergence, high synchronization\naccuracy, and strong robustness; thus, the system has excellent synergy performance. Finally, the motion control\nplatform of the dynamic seat was built for physical verification. The experimental result shows the effectiveness and feasibility of\nthe control strategy....
This paper proposes an adaptive switch controller (ASC) design for the nonlinear multi-input multi-output system (MIMO). In\nfact, the proposed method is an online switch between the neural network adaptive PID (APID) controller and the neural network\nindirect adaptive controller (IAC). According to the design of the neural network IAC scheme, the adaptation law has been\ndeveloped by the gradient descent (GD) method. However, the adaptive PID controller is built based on the neural network\ncombining the PID control and explicit neural structure. The strategy of training consists of online tuning of the neural controller\nweights using the backpropagation algorithm to select the suitable combination of PID gains such that the error between the\nreference signal and the actual system output converges to zero. The stability and tracking performance of the neural network\nASC, the neural network APID, and the neural network IAC are analyzed and evaluated by the Lyapunov function. Then, the\ncontroller results are compared between APID, IAC, and ASC, in this paper, applying to a nonlinear system. From simulations, the\nproposed adaptive switch controller has better effects both on response time and on tracking performance with smallest MSE....
The human tongue has superior movement and tactile sensations. For individuals\nwith severe disabilities, a tongue operated interface device can be used\nto operate life-support equipment, such as powered wheelchairs and robotic\nmanipulators. A joystick-type device can directly translate various tongue\nmotions to external equipment behavior. In addition, the user can interactively\ncommunicate with the equipment by tactile feedback. This helps the\nuser to control the equipment safely and skillfully. Considering these factors,\nin a previous study [1], we developed a novel tongue-operated joystick device\nwith reaction force feedback mechanism. We described the design process including\nthe analysis of human tongue movement and tactile sensations and\nshowed fundamental performances of reaction force feedback with the prototype\ndevice. In this study, we discuss the shape of the operational part that\nis used by the tongue. Two types of operational tools are prepared and their\noperability and perception of reaction force feedback are compared. Furthermore,\nwe confirm the effectiveness of reaction force feedback to operate\nthe joystick device safely and skillful controlling a mobile robot in an unknown\nenvironment....
The purpose of this paper is to solve the problem of controlling of the quadrotor exposed to external constant disturbances. The\nquadrotor system is partitioned into two parts: the attitude subsystem and the position subsystem. A new robust integral\nterminal sliding mode control law (RITSMC) is designed for stabilizing the inner loop and the quick tracking of the right\ndesired values of the Euler angles. To estimate the disturbance displayed on the z-axis and to control the altitude position\nsubsystem, an adaptive backstepping technique is proposed, while the horizontal position subsystem is controlled using the\nbackstepping approach. The stability of the quadrotor subsystems is guaranteed by the Lyapunov theory. The effectiveness of the\nproposed methods is clearly comprehended through the obtained results of the various simulations effectuated on\nMATLAB/Simulink, and a comparison with another technique is presented....
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