電動輪椅或代步車為較嚴重神經肌肉病變之功能障礙者、老年人或慢性病患主要的日常生活行動輔具。國內高經濟價值的電動輪椅及代步車之控制器仰賴歐美進口(紐西蘭Dynamics及英國Curtis公司)。一般數位式控制器開發過程缺乏整體性(車體結機構、運動及動力驅動、馬達動力匹配等)考量設計，往往無法提昇整體效益。因此在欠缺系統規格設定、驅動力學分析模擬、操作環境及系統響應分析的研究發展及文獻參考資料情況下，無法系統化的選取適當操作控制參數及元件匹配，來開發高效能控制及易擴充性之多元化操作功能的電動輪椅或代步車。
控制器與馬達驅動裝置為影響輪椅驅動的主要因素，因此本研究系統化的研發包括：一. 應用微控制處理晶片電路、PWM驅動控制、編碼器速度迴授及控制法則的軟體演算，設計PID閉迴路速度控制器；二. 探討電動輪椅負載重量及相關國際安全規範等主要參數，並建立驅動馬達的控制設計規格，包括：馬達動力、速度及轉矩額度等；三. 馬達功能性測試及探討馬達驅動控制的特性響應、控制法則及參數選取；四. I/O擴充介面提供一般輸出入控制；五. 控制器於馬達驅動平台功能性測試。
本研究控制器現階段已完成單軸代步車控制實體雛形，硬體實體模組包括微處理器單元、操控介面、A/D、D/A、馬達驅動模組及電流檢測單元等，軟體方面以8051 C語言撰寫控制系統各單元及馬達之PID比例積分微分動作。各系統性能測試研究結果顯示：一. 在20KHz 之PWM載波頻率下系統響應為最佳值，且控制器效率表現為最佳；二. 驅動器設計規格為輸出最大耐流50A、輸出電壓範圍24V，驅動最大負載重量(平地運動) 300 kg，適用於馬達規格為1/2馬力、轉速3600 rpm及最低額定轉矩60 kg-cm之電動輪椅及代步車。
系統未來研究及改良方向，包括：擴充為電動輪椅雙軸控制系統、介面系統整合在單一晶片中、發展泛用型使用者操作介面系統。

Powered wheelchairs (W/C) and scooters are the major mobility-aided device for persons with moderate/severe physical disability and chronic diseases as well as the elderly. Domestic W/C industries fully rely on imported controllers from two major manufacturers (Dynamics of New Zealand and Curtis of England). For most controller design, it is lack of systematic consideration in W/C structure, kinematics/kinetic, dynamics driven, slope, speed, rolling resistance and motor power factors. Therefore, it has led to poor efficiency and mismatching of system components. With much more demands in matching the need of individual’ disabilities, this research was to develop an innovative design of digital controller for scooters and motors testing for improved powered mobility.
Controller and motor driver are critical to influence the powered W/C propulsion. The specific aims of this R/D project are: (1) digital controller design with MCU IC, PWM driven control, speed encoder and feedback control by software design, and PID closed-loop control; (2) investigate and establish the design specifications for motor driven control (e.g. motor power, speed, torque); (3) DC motor testing for dynamic response and to investigate control rules for motor driven; and (4) functional calibration of the designed controller on motor testing device and field testing with commercial scooters.
This project has completed a digital controller product for scooters with an axial control. Field testing by placing the controller on commercial scooters has shown good performance with a year experiment. The hardware consists of MCU, interface controller, A/D and D/A, motor driver, and current detection units. Based on 8051 C Language, the control software includes control programming for each unit and PID feedback closed-loop current control. The results of system calibration indicate that the system response and efficiency is functional well at the PWM of 20 KHz. The design specifications of digital controller and driver are output maximal tolerable current of 50A, output voltage of 24V( ±2V), maximal driven loading of 300Kg at horizontal surface, and selective PMDC motor with 1/2 horsepower, 3600 rpm and 60 kg-m. The completed digital controller design provides programmable functions for parameters setting in PID control and acceleration/deceleration strategic planning, emergency handling control and expandable capability in matching to various motors and drivers for optimal efficiency.
The future development will include functional testing of completed digital controller on motor control, investigation of motor design for powered W/C, development of powered W/C’s dynamic simulation system and implementation of torque control.

[1] Ruei-Xi Chen, liang-Gee Chen, ”System Design Consideration for Digital Wheelchair Controller,” IEEE Transactions on Industrial Electronics, pp. 898-906, 2000.
[2] V. Diaz, ”New sonar configuration for a powered wheelchair,” IEEE Engineering in Medicine and Biology, pp. 113 -119, 1999.
[3] Clifford Brubaker, “Ergonometric Considerations,” Departments of Veterans Affairs, Journal of rehabilitation Research and Development-Clinical Supplement, No. 2, 1990.
[4] R. A. Cooper, “Intelligent Control of Power Wheelchairs.”, IEEE Engineering in Medicine and Biology, pp. 423-431, 1995.
[5] J. G. Thacker et. al., “Understanding the Technology When Selecting Wheelchairs,” RESNA PRESS, UVA, 1994.
[6] C. A. MacLaurin et. al., “Wheelchair Mobility – A Summary of Activities,” RESNA PRESS, UVA, 1981.
[7] J. H. Aylor et. al., “A Fault-Tolerant Optical Joystick Control Integated Circuit for A Powered Wheelchair,” RESNA International ’92, pp. 307-309 , 1992.
[8]Fred Powell and R. M. Inigo, “Microprocessor Based D.C. Brushless Motor Controller for Wheelchair Propulsion,” RESNA International ’92, pp. 313-315, 1992.
[9]R. M. Inigo, “Electric Wheelchair Permanent Magnet DC Motor Efficiency Tests,” UVA-REC pp.105-82, 1982.
[10]S. T. Chapman, “Electric Machinery Fundamantals,” McGraw-Hill, New York, 1991.
[11]ECRI, “Evaluation : Rechargeable, Deep-Cycle, Lead-Acid Batteries for Powered Wheelchair and Scooter Users,” Health Devices, ECRI, Plymouth Meeting, PA, Vol. 20, No. 12, pp. 474-494, 1991.
[12]B. W. Johnson and J. H. Aylor, “Dynamic Modeling of an Electric Wheelchair,” IEEE Transactions on Industry Applications, IA-21, No. 5, 1985.
[13]R. M. Inigo et. al., “A Improved DC-DC Converter for Electric Wheelchair Propulsion ,” RESNA 14th Annual Conference, pp. 148-150, 1991
[14]M. R. Ford et. al., ”Improved Wheelchair Gearbox Efficiency,” RESNA proceedings of the 14th Annual Conference, 1991.
[15]Yasuhiko Dote, “ Servo Motor and Motion Control Using Digital Signal Processors,” Prentice Hall, New Jersey, 1990.
[16]游許銓, “電動輪椅動力驅動之解析模型,” 國立成功大學醫學工程研究所碩士論文, 2001.
[17]邱毓賢, “數位式行動輔具控制器設計及測試,” 國立成功大學醫學工程研究所碩士論文, 1999.
[18]許景淵, “電子差速式電動輪椅動力模組,” 國立台灣大學機械工程研究所碩士論文, 1997.
[19]S. J. Chapman, Electric Machinery Fundamentals, McGraw-Hill, Inc., 1991.DC Motors, Speed Controls, Servo Systems, including Optical Encoders, An Engineering Handbook by Electro-Craft Corporation, Hopkins, MN, 5th Edition, 1980.
[21]B. C. Kuo and T. Jacob, DC Motors in Incremental Motion Systems, Chap. 5 of Incremental Motion Control: DC Motors and Control Systems, 1978.
[22]A. E. Fitzgerald, C.K. Jr., and S.D. Umans, Electric Machinery, 5th Edition, McGraw-Hill Book Company, 1990.
[23] P. C. Krause, Analysis of Electric Machinery, McGraw-Hill,1987.
[24]Y. C. Liang and V. J. Gosbell, DC machine models for SPICE2 simulation, IEEE Trans. on Power Electronics, vol. 5, no. 1, pp. 16-20, Jan. 1990.
[25]S. N. Singh, D. R. Kohli, Analysis and performance of a chopper controlled separately excited dc motor, IEEE Trans. Ind. Electron., vol. 29, no. 1, pp. 1-6, Feb. 1982.
[26]J. S. Ewing, Lumped circuit impedance representation for dc machines, IEEE Trans. Power App. Syst., vol. 87, no. 4, pp. 1106-1110, April 1968.
[27]R. A. Schulz, A frequency response method for determining the parameters of high-performance dc motors, IEEE Trans. on Ind. electron., vol. 30, no. 1, pp. 39-42, Feb. 1983.
[28]J. L. Adcock, Analyzer synthesizes frequency response of linear systems, Hewlett-Packard Journal, pp. 25-32, Jan. 1987.
[29]J. L. Adcock, Curve fitter for pole-zero analysis, Hewlett-Packard Journal, pp. 33-36, Jan. 1987.
[30]G. A. Perdikaris and K. W. VanPatten, Computer schemes for modeling, tuning, and control of dc motor drive systems, PCI Proc., pp. 83-90, March 1982.
[31]S. Meshkat, A servo system parameter identification for optimum compensation design, MOTOR-CON Proc., pp. 348-354, April 1985