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Journals

2010 International Journal of Hydrogen Energy

Multivariable Robust PID Control for a PEMFC System

 

Fu-Cheng Wang and Chin-Chun Ko

 

 
Abstract
This paper proposes robust proportional-integral-derivative (PID) control for a proton exchange membrane fuel cell (PEMFC) system. We model a PEMFC as a multivariable system, and apply identification techniques to obtain the system’s transfer function matrices, where system variations and disturbances are regarded as uncertainties. Because robust control can cope with system uncertainties and disturbances, it has been successfully applied to improve the stability, performance, and efficiency of PEMFC systems in previous studies. However, the resulting robust controllers might be too complicated for hardware implementation. On the other hand, PID control has been widely applicable to engineering practices because of its simple structure, but it lacks stability analysis for systems with uncertainties. Therefore, by combining the merits of robust control and PID control, we design robust PID controllers for the PEMFC system. Based on evaluation of stability, performance, and efficiencies, the proposed robust PID controllers are shown to be effective.

2010 Proceedings of the Institution of Mechanical Engineers, Part C, Journal of Mechanical Engineering Science

Building Suspensions with Inerters

 

Fu-Cheng Wang, Min-Feng Hong and Cheng-Wei Chen

 

 

Abstract
This article investigates the performance benefits of building suspension systems that employ a newly developed mechanical element called an inerter. The inerter was proposed as a genuine two-terminal mechanical device to substitute for the mass element, which allows mechanical and electrical networks to become truly analogous. This study applied inerters to building suspension control. First, a one-degree-of-freedom (DOF) building model was examined in order to show the significant performance improvement by inerters, especially with a multilayer design. Second, the discussion was extended to a two-DOF building model. Finally, a ballscrew inerter was constructed for testing. From the results, the inerters were deemed effective in reducing building vibrations.

2010 Japanese Journal of Applied Physics

Robust Control Design for Vibration Isolation of an Electron Beam Projection Lithography System

 

Fu-Cheng Wang, Min-Feng Hong and Jia-Yush Yen

 

 

Abstract
This paper describes vibration control for an electron beam projection lithography (EPL) system. Two kinds of disturbances should be considered for an EPL: load disturbances from the machine and ground disturbances from the environment. However, the suspension settings for insulating these two disturbances conflict with each other. Therefore, we propose a double-layer optical table and apply disturbance response decomposing (DRD) techniques to independently control the disturbances. We use a passive control structure to isolate the ground disturbances, and an active control structure to suppress load disturbances. In addition, symmetric transformation is applied to decouple a full optical table into bounce/pitch and roll/warp half-table models, which can be further decoupled into quarter-table models to simplify controller design. Finally, we apply robust control techniques to design active controllers. From both simulation and experimental results, the designed H-infinity  robust controllers are proven effective in reducing EPL system vibrations.

2010 Vehicle System Dynamics

The Lateral Stability of Train Suspension Systems Employing Inerters

 

Fu-Cheng Wang and Min-Kai Liao

 

 

Abstract
This paper investigates the benefits of lateral stability of train suspension systems employing a newly developed mechanical network element known as an inerter. An inerter was proposed as an ideal mechanical two-port element to substitute for the mass element in the mechanical/electrical analogy. As of now, inerters have been successfully applied to car and motorcycle suspension systems, for which significant performance benefits were reported. This paper discusses the improvements on lateral stability of train suspension systems employing inerters. The study was carried out in three parts. First, an existing 12 degrees-of-freedom (DOF) train model was built and verified by a multi-body-builder, AutoSim. Second, inerters were applied to the train suspension system to increase the critical speed. Finally, the discussion was extended to a 16-DOF model to demonstrate the performance improvement by inerters. From the results, inerters were deemed effective in improving the lateral stability of train suspension systems.

2010 IEEE Transactions on Power Electronics

Multivariable Robust Control for a Red-Green-Blue LED Lighting System

 

Fu-Cheng Wang, Chun-Wen Tang and Bin-Juine Huang

 

 

Abstract
This paper proposes a novel control structure for a red–green–blue (RGB) LED lighting system, and applies multivariable robust control techniques to regulate the color and luminous intensity outputs. RGB LED is the next-generational illuminant for general lighting or liquid crystal display backlighting. The most important feature for a polychromatic illuminant is color adjustability; however, for lighting applications using RGB LEDs, color is sensitive to temperature variations. Therefore, suitable control techniques are required to stabilize both luminous intensity and chromaticity coordinates. In this paper, a robust control system was proposed for achieving luminous intensity and color consistency for RGB LED lighting in a three-step process. First, a multivariable electrical–thermal model was used to obtain RGB LED luminous intensity, in which a lookup table served as a feedforward compensator for temperature and power variations. Second, robust control algorithms were applied for feedback control design. Finally, the designed robust controllers were implemented to control the luminous and chromatic outputs of the system. From the experimental results, the proposed multivariable robust control was deemed effective in providing steady luminous intensity and color for RGB LED lighting.

Conference

2010 Proceedings of the 2010 IEEE Multi-conference on Systems and Control

Robust PID Control of a PEMFC System

 

Fu-Cheng Wang and Chin-Chun Ko

 

 

Abstract
This paper proposes robust proportional –integral -derivative (PID) control for a proton exchange membrane fuel cell (PEMFC) system. We model a PEMFC as a multivariable system, and apply identification techniques to obtain the system’s transfer function matrices, where system variations and disturbances are regarded as system uncertainties. In previous studies, robust control has been successfully applied to improve the stability, performance, and efficiency of a PEMFC system. However, the resulting robust controllers can be complicated. On the other hand, PID control has been widely applicable to engineering practices because of its simple structure, though it lacks stability analysis for systems with uncertainties. Therefore, combining the merits of robust control and PID control, we design robust PID controllers to regulate hydrogen and air flow rates of a PEMFC system. From the discussion of stability, performance, and efficiency, the proposed robust PID controllers are shown to be effective.

2010 Proceedings of the 2010 IEEE Multi-conference on Systems and Control

Multivariable Robust Control of a Gait Trainer

 

Chung-Huang Yu, Tai-Yu Chou and Fu-Cheng Wang

 

 

Abstract
This paper proposes multivariable robust control for a gait trainer for people with walking disability. The gait trainer composes of linkages and motors, which drive the linkages to produce preferred gait traces. To simplify the traditional motor control, the tracking error and motor current are feedback for control design to regulate the motor voltage. First, the transfer function matrices of the multivariable system are obtained by identification techniques. Then robust control algorithms are applied to deal with system variations and disturbances. Finally, the designed controllers are implemented for performance verification. From the experimental results, the proposed multivariable robust control is shown to be effective for the gait trainer.

2010 Proceedings of the 5th Asian Conference on Multibody Dynamics

Stability and Performance Analysis of a Full Train Model with Inerters

 

Fu-Cheng Wang and Min-Ruei Hsieh

 

 

Abstract
This paper discusses stability and performance of a full-train system employing inerters. First, a twenty-eight degree-of-freedom (DOF) train model was built on AutoSim and linearized for analysis in Matlab. We then optimized the critical speed of the system and showed that the critical speed can be significantly improved by employing inerters. Third, we discussed the system’s transient responses and illustrated that the settling time can be greatly shortened by using inerters. Lastly, a novel mechatronic inerter was considered for further improvement of the train system.

2010 SICE Annual Conference

Design and Control of a RGB LED System

 

Chun-Wen Tang, Fu-Cheng Wang and Bin-Juine Huang

 

 

Abstract
This paper proposes a novel control structure for a red-green-blue (RGB) light-emitting diode (LED) lighting system, and applies multivariable robust control techniques to regulate the color and luminous intensity outputs. The most important feature for a polychromatic illuminant is color adjustability; however, for lighting applications using RGB LEDs, color is sensitive to temperature variations. Therefore, in this paper we propose a robust control system for achieving luminous intensity and color consistency for RGB LED lighting. First, we found a multivariable electrical-thermal model to describe the dynamics of RGB LED lighting system, and used a feed-forward controller to compensate temperature and power variations. Second, we applied robust control algorithms for feedback control design. Finally, the designed controllers were implemented to regulate the luminous and chromatic outputs of the system. From the experimental results, the proposed multivariable robust control structure was deemed effective in providing steady luminous intensity and color for RGB LED lighting.

2010 SICE Annual Conference

Robust Control of a Furuta Pendulum

 

Chung-Huang Yu, Fu-Cheng Wang and Yu-Ju Lu

 

 

Abstract
This paper designs robust controllers for a Furuta pendulum, and verifies the system performance and robustness by experiments. First, we derive the system’s transfer functions, and design a standard H-infinity robust controller for balancing control. Because lower-order controllers are preferable for hardware implementation, we then apply fixed-order robust control techniques to simplify the controller structure. The effects of these controllers are experimentally compared. Finally, we designed some experiments to test the robustness of these controllers. From the results, the H-infinity fixed-order controller is shown to be effective.

2010 Proceedings of the 19th International Symposium on Mathematical Theory of Networks and Systems

Network Optimization and Synthesis using a Combined Mechanical and Electrical System: Application to Vehicle Suspension Control

 

Fu-Cheng Wang and Hsiang-An Chan

 

 

Abstract
This paper introduces a mechatronic network and applies it to vehicle suspensions for performance optimization. The mechatronic network consists of a ball-screw and permanent magnet electric machinery (PMEM), such that the system impedance is a combination of mechanical and electrical impedances. We then apply the network to vehicle suspensions, and demonstrate the performance benefits and their sensitivities to parameter variations. The optimal electrical impedances are constructed and experimentally verified. Based on the results, the mechatronic network is deemed effective.

2010 Proceedings of the 7th International Conference on Optics-photonics Design & Fabrication

Robust Control Design and Implementation for a LED Lighting System

 

Fu-Cheng Wang, Chun-Wen Tang and Bin-Juine Huang

 

 

Abstract
This paper applies robust control techniques to a red-green-blue (RGB) lighting-emitting diode (LED) lighting system. The experimental results show the effectiveness of the controllers in providing steady luminous intensity and color for RGB LED lighting.