Kou-Cheng Hsu

Design of large-scale time-delayed systems with dead-zone input via variable structure control

To deal with time delay in the interconnection and dead-zone nonlinearity in the input, a new decentralized variable structure control (DVSC) law is proposed for a class of uncertain large-scale system (LSS) in this paper. The developed DVSC for the interconnected systems is realized independently through the delay terms. The applied control effort of the DVSC law is always out of the dead-band to eliminate the effects arisen from the dead-zone nonlinearity in the input function. In the sliding mode, it can be seen that the invariance condition also holds. It is worth noting that the traditional large-scale time-delayed system is only a special case in this work. Illustrative examples are given to verify the validity of the developed controller.

Decentralized variable-structure control design for uncertain large-scale systems with series nonlinearities

This paper presents a robust decentralized control for large-scale interconnected systems with series nonlinearities through variable-structure control. The proposed variable-structure control ensures the global reaching condition of the sliding mode of the composite system. The uncertain nonlinear system also possesses insensitivity to uncertainties and disturbances like a linear system does. Furthermore, the sliding mode can converge within a specified exponential speed.

Sliding mode control for uncertain nonlinear systems with multiple inputs containing sector nonlinearities and deadzones

In this paper, we investigate a novel robust control approach for a class of uncertain nonlinear systems with multiple inputs containing sector nonlinearities and deadzones. Sliding mode control (SMC) is suggested to design stabilizing controllers for these uncertain nonlinear systems. The controllers guarantee the global reaching condition of the sliding mode in these systems. They can work effectively for systems either with or without sector nonlinearities and deadzones in the inputs. Moreover, the controllers ensure that the system trajectories globally exponentially converge to the sliding mode. Illustrative examples are demonstrated to verify the effectiveness of the proposed sliding mode controller.

Adaptive variable structure control design for uncertain time-delayed systems with nonlinear input

This paper presents a new robust control for uncertain dynamic time-delayed systems with series nonlinearities. It is implemented by using variable structure control. The proposed variable structure controller ensures the global reaching condition of the sliding mode of the uncertain time-delayed system. However, in the sliding mode, the investigated uncertain time-delayed system still bears the insensitivity to the uncertainties and disturbances as the systems with linear input. Furthermore, the proposed controller is achieved through adaptive variable structure control without the limitation of knowing the bounds of the uncertainties and perturbations in advance.

Decentralized variable structure model-following adaptive control for interconnected systems with series nonlinearities

The problem of model-referenced control for interconnected systems with series non-linearities is investigated. By applying variable structure control theory, we propose a controller which is able to drive the error subsystem between the model state and the plant state to zero. The presented variable structure controller ensures the global reaching condition of the sliding mode of the error system. It shows that the uncertain nonlinear dynamic system also possesses the property of insensitivity to uncertainties and disturbances as a linear system does. Furthermore, the sliding mode can be designed to converge within a specified exponential speed.

Modified Fuzzy Variable Structure Control Method to the Crane System with Control Deadzone Problem

This paper proposes a modified fuzzy based variable structure control to achieve the position and swing control of the 3-D nonlinear overhead crane system. One derives the control power according to the variable structure controller and feedback signals-trolley position and payload swing angle. Compensating algorithm for the deadzone problem is provided in this paper and the heuristic sliding factors are also tuned automatically by the proposed fuzzy method to enrich the system performance without plant information of crane. Several experiments for the position and swing control of the nonlinear overhead crane system demonstrate the effectiveness of the proposed scheme.

An Enhanced Adaptive Sliding Mode Fuzzy Control for Positioning and Anti-Swing Control of the Overhead Crane System

An enhanced adaptive sliding mode fuzzy approach is applied to control the position and load swing of a 3D overhead crane system. The merits of this method include the robustness and model free properties of the sliding mode and fuzzy logic controllers, respectively. An adaptable slope of sliding surface is presented and the chattering phenomenon of sliding mode control is also discussed to enhance the control performance. Furthermore, this paper provides a compensating algorithm to the control deadzone of overhead crane system. At last, several simulation results demonstrate the effectiveness.

Robust sliding mode-like fuzzy logic control for anti-lock braking systems with uncertainties and disturbances

In this paper, we propose a robust sliding mode-like fuzzy logic controller for an anti-lock brake system (ABS) with self-tuning of the dead-zone parameters. The main control strategy is to force the wheel slip ratio tracking the optimum value 0.2. The proposed controller for anti-lock braking systems provides a stable and reliable performance under the uncertainties in vehicle brake systems. Simulation results will show the validity and effectiveness of the proposed sliding mode-like fuzzy logic controller.

Variable structure control of uncertain nonlinear system with a dead-zone input

In this paper, a novel variable structure model reference control design is presented for uncertain nonlinear systems containing a dead-zone and/or series nonlinearity in the input. Given a model with ideal reference characteristics, the developed variable structure model-following controller assures the global reaching condition of the sliding mode of the error system. It shows that the proposed controller can be applied to the systems either with or without series nonlinearity and/or dead-zone in the input. However, the traditional variable structure controllers cannot work effectively for systems with dead-zone in the input.

Using a fuzzy control model to navigate a mobile robot

In this paper, it developed a fusion navigation system for a mobile robot. It used a fuzzy logic control model to handle three different behaviors of robot movement, including the obstacle avoidance, goal seeking and central route path. These behaviors are independently studied and solved for each situation. After all, three behaviors are fused by using a weight assignment equation to determine the velocities of two wheels of robot which it controls the movement of robot navigation.