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2011 European Journal of Control

Multivariable Robust Control for a 500W Self-Humidified PEMFC System

Fu-Cheng Wang, Liu-Hsu Lin and Ming-Cheng Chou

Abstract

This paper illustrates the integration and control of a 500 W self-humidified proton exchange membrane fuel cell (PEMFC) system. From the system point of view, the PEMFC can be regarded as a two-input-two-output system with the inputs of hydrogen and oxygen, and the outputs of cell voltage and current. By identification techniques, we find transfer functions of the PEMFC system at different operating points, and treat the un-modeled dynamics as system uncertainties. In this way, robust control strategies can be applied to stabilize the system and to increase the system performance. This paper describes the design of a standard H-infinity robust controller for stabilizing the PEMFC system, and further applies fixed-order robust control and robust PID control algorithms for controller simplification. Finally, the system performance and efficiency are experimentally verified. The results show the effectiveness of these controllers.

2011 Vehicle System Dynamics

Vehicle Suspensions with a Mechatronic Network Strut

Fu-ChengWang and Hsiang-An Chan

Abstract

This paper applies a novel mechatronic network strut to vehicle suspensions and discusses the benefits of system performance. The proposed mechatronic strut consists of a ball-screw inerter and permanent magnet electric machinery, such that the system impedance can be realised through a combination of mechanical and electrical networks. Applying the mechatronic strut to vehicle suspensions, we evaluate the improvement of system performance using passive electrical networks. Furthermore, a prototype mechatronic strut is constructed for properties verification. Finally, nonlinearities of the mechatronic strut are taken into account to modify the suspension design. From the simulation and experimental results, the proposed mechatronic network strut is shown to be effective.

2011 Proceedings of the Institution of Mechanical Engineers, Part C, Journal of Mechanical Engineering Science

Designing and Testing a Hydraulic Inerter

Fu-Cheng Wang, Min-Feng Hong and Tz-Chien Lin

Abstract

This article proposes a novel hydraulic inerter and experimentally verifies its properties. The inerter is a true two-terminal mechanical network element, which was invented to substitute for the mass in mechanical/electrical analogies. Previously, inerter concepts have been realized by rack-and-pinion and ball-screw devices. This article introduces a new hydraulic inerter device in which the forces are translated by hydraulic means. The dynamics of the device is discussed and experimentally verified. On the basis of the results, the proposed hydraulic inerter is shown to be effective.

Conference

2011 Proceedings of the 14th Asia Pacific Vibration Conference

Vibration Control of an Optical Table by Mechatronic Inerter Networks

Fu-Cheng Wang and San-Ho Yang

Abstract

This paper applies a newly developed mechatronic inerter network to control the vibrations of an optical table. As technology is advanced, the requirements for vibration control are becoming increasingly stringent. Therefore, optical tables are normally applied to precision systems to suppress two main vibrations: load disturbances from the machine and ground disturbances from the environment. However, the suspension settings need to be stiff to isolate the load disturbances but soft to suppress the ground disturbances. Therefore, we apply disturbance response decoupling techniques for independent treatment of these two vibration sources. We combine a mechatronic inerter network with spring-damper sets to suppress ground disturbances in a passive way, and use piezoelectric transducers to actively improve load responses. Based on the simulation and experimental results, the design is deemed effective.

2011 Proceedings of the SICE Annual Conference

Control and Integration of a Fuel-Cell Powered Wheelchair

Fu-Cheng Wang, Yu-Shu Chiang and Yee-Pien Yang

Abstract

This paper proposes a fuel-cell powered wheelchair. As an alternative energy source, fuel-cell has drawn much attention and research. To improve mobility for people with walking disability, we combine a fuel cell module with two battery sets to provide long-lasting power for an electrical wheelchair. The study is carried out in three steps: the fuel-cell control, power management, and system integration. First, we apply multivariable robust control strategies to regulate the hydrogen and air flow rates of a proton exchange membrane fuel cell module, which provides steady electrical power for the system. Second, we design a serial power-train, where the fuel-cell charges two Lithium Iron battery sets which in turns drive the wheelchair’s motors. Lastly, the aforementioned subsystems are integrated for experimental verification. The results demonstrate the effectiveness of the proposed system.

2011 Proceedings of the SICE Annual Conference

Vibration Control of an Optical Table by Piezoelectric Transducers

Fu-Cheng Wang and San-Ho Yang

Abstract

This paper proposes the design and control of an optical table. As technology is advanced, the requirements for vibration control are becoming increasingly stringent. Optical tables are normally applied to suppress vibrations for improving system performances. There are two main vibration sources, namely load disturbances from the machine and ground disturbances from the environment. However, the suspension settings to isolate these two disturbances are conflicting: they need to be soft for the ground disturbances but stiff for the load disturbances. Therefore, we apply disturbance response decoupling techniques to independently treat these two vibration sources: using passive elements to suppress ground disturbances, and active piezoelectric transducers to improve load responses. From the simulation and experimental results, the design is deemed effective.

2011 Proceedings of the 18th IFAC World Congress

Robust Control of a Two-Axis Piezoelectric Nano-Positioning Stage

Fu-Cheng Wang, Yan-Chen Tsai, Chin-Hui Hsieh, Lian-Sheng Chen and Chung-Huang Yu

Abstract

This paper applies robust control to a two-axis piezoelectric nano-positioning stage. As technology develops, the precision requirement for positioning platforms is becoming increasingly stringent. Since a traditional mechanical transmission structure cannot achieve high precision, a piezoelectric actuator is usually applied to drive the mechanism because of its high resolution, high accuracy, and large driving force. However, the non-linear dynamic characteristics of piezoelectric materials, such as hysteresis, might degrade system performance. Therefore, in the present study, we model a piezoelectric stage as a linear system, and regard the nonlinear factors as system uncertainties. We then apply robust control strategies to guarantee system stability and performance. Lastly, the designed controllers are implemented for experimental verification. The results demonstrate the effectiveness of these robust controllers.�n

2011 Proceedings of the 22nd International Symposium on Dynamics of Vehicles on Roads and Tracks

A Full-Train with Inerters: Stability and Performance

Fu-Cheng Wang, Min-Ruei Hsieh and Hsueh-Ju Chen

Abstract

This paper discusses the use of inerters to improve the stability and performance of a thirty-seven degree-of-freedom full-train model. We build the nonlinear full-train model in AutoSim, and obtain the linearised model for analysis in Matlab. We consider three basic suspension layouts, and optimize the suspension parameters for two indexes: the critical speed and passenger’s comfort. From the optimization results, inerters are deemed effective in improving the stability and performance of the full-train system.

2011 Proceedings of the 4th International Conference on Human System Interaction

Synchronized Robust Control of a Gait Trainer

Fu-Cheng Wang, Chung-Huang Yu, Chia-Hui Chen, Tai-Yu Chou and Chen-En Tsai

Abstract

This paper proposes synchronized robust control for an active gait trainer. We design an active gait trainer, which composes of linkage mechanism and motors, to produce preferred gait traces for people with walking disability. The goal of this work is to simultaneously control the motors to mimic normal gaits. By finding the transfer functions of the mechanism and motors, we design robust controllers to regulate the trainer in a synchronic way. The designed controllers are implemented on a cRIO system for experimental verification. From the results, the proposed synchronized robust control is deemed effective.

Domestic Conference

2011 行政院國科會工程處控制學門99年度成果發表會暨SIRCon2011

創新手輪馬達電動輪椅混合動力系統整合研究與開發
子計畫二：質子交換膜燃料電池模組的系統識別、控制與系統整合

王富正, 蔣育書, 柯致雋, 周銘城

摘要

本計畫之目標在於整合燃料電池系統與電動輪椅系統，以質子交換膜燃料電池搭配二次電池，作為電動輪椅的電力來源。研究分為三部分進行：燃料電池的控制、電力管理系統的設計、輪椅馬達的控制與全車之整合。
首先，在燃料電池控制方面，我們將其視為一雙輸入單輸出的系統，輸入為氫氣與空氣的流量，輸出為燃料電池的電壓，透過強韌控制器的設計與安裝，以達到穩定輸出電壓的目標，並同時減少了氫氣消耗與能量消耗。
其次，將燃料電池搭配兩組磷酸鋰鐵電池，規劃串聯式混合電力鏈，依據它們的動態特性，制定合適的電力管理策略。首先建立充電與供電迴路，其中一個電池組提供電力給後端負載，另一個電池組作為備用電力。當第一個電池組的電量降至一個選定值時，切斷其供電迴路並控制燃料電池以定電壓對其進行充電，而當其供電迴路被切斷的同時，另一個備用電池的供電迴路會被打開，使後端的電力供應不會間斷。由實驗結果顯示，整個電力轉換和傳輸的過程相當成功。
最後，進行電動輪椅馬達的控制，利用馬達控制卡與二維操縱搖桿，控制雙輪馬達的行進、加速與轉向。並將前面所設計的兩個子系統與電動輪椅進行系統整合，以提供電動輪椅穩定且持續的電力供應。

2011 行政院國科會工程處控制學門99年度成果發表會暨SIRCon2011

以波帶片陣列為基礎之極紫外光直寫微影系統之研發
子計畫五：極紫外光直寫微影系統之伺服控制

王富正, 謝錦輝, 蔡彥臣

摘要

本計畫係針對極紫外光微影 (Extreme Ultra-Violet Lithography, EUVL)系統，所進行的多自由度奈米定位平台之精密定位研究。吾人使用壓電材料驅動定位平台，利用壓電材料之高解析、高精度的特性，達到所要求的精密定位控制。然而由於壓電材料之非線性特性，可能影響控制精度，所以我們利用強韌控制理論設計H-infinity強韌控制器，以確保奈米定位平台系統之穩定性及性能。本年度的主要進展，是使用回路成形 (loop-shaping) 技巧，有效地抑制高頻擾動，將系統定位精度提昇至奈米等級。