臺灣博碩士論文加值系統

摘要

　　隨著醫療科技的進步，身心障礙人口持續成長，電動輪椅成為較嚴重神肌肉病變、慢性病銀髮族的日常生活行動輔具。目前國內、外電動輪椅電力系統主要包括：永磁式直流有刷（PMDC）馬達、開迴路控制器、機械傳動裝置及電瓶。因此本研究目的為設計閉迴路的電動輪椅數位差速控制器，以改善電動輪椅的安全性及續航能力。

　　本系統化研發包括：一.選配適合之PMDC馬達動力規格，並且探討Dynamic、P&G、Curtis控制器驅動馬達在不同負載下，其電流、轉速的響應特性及電壓、電流、轉矩、轉速、效率等參數之相關特性；二.應用測試結果來預測馬達速度並且設計電動輪椅閉迴路差速控制器。數位控制器設計採用德州儀器(TI)之單晶片DSP微控器，發展軟體為Code Composer來達成電子差速輪椅控制器的軟硬體設計。

　　PMDC馬達測試結果顯示：一.馬達的轉矩與電流呈線性正比並且不同電壓下轉矩與電流之關係曲線變化非常小;二.馬達轉矩與轉速呈線性反比且在不同的電壓下電流與轉速關係曲線皆呈平行的關係。驅動控制器驅動PMDC馬達結果顯示：PWM平均電壓及頻率為18 V、15 ~ 20 KHz及電流控制在7A∼13A將提供最佳的馬達驅動效率。應用PMDC馬達特性方程式來模擬預測轉速與測試實際轉速差距約在10 rpm範圍內，因此預測出之轉速可用於馬達的閉迴路速度控制。本研究完成電動輪椅差速控制器實體雛型包含：雙軸差速控制電路、串列資料通訊傳輸、馬達正反轉控制電路、濾波電路、A/D、PWM及閉迴路PID速度控制。

　　馬達特性測試提供設計電動輪椅差速控制器的的基本資料，以發展差速安全性及改善續航能力。建議控制器未來研究方向，包含：一.以實際場試來提升電動輪椅控制器的穩定性及續航能力。二.考量使用者之乘坐之重心位置來設計出更具有安全性的電子差速控制器。

Abstract

　Powered wheelchairs (W/C) and scooters are the major mobility-aided devices for people with moderate/severe physical disability and chronic diseases as well as the elder. The Powered wheelchairs system includes: PMDC motor, open-loop controller, gear box, battery. This research was to design a digital differential speed controller with velocity feedback for Powered wheelchairs to improve the safety and efficiency.

　The specific aims of this R/D project are: (1) selecting a suitable PMDC motor and measuring voltage, current, torque, speed, efficiency for the motor characteristics as well as evaluating the performance of Dynamic, P&G controller on driving the PMDC motor under different torque loading; (2) to design a digital differential speed controller using the data from motor testing to estimate speed for feedback control. A TI digital signal processor chip and accompanied Code Composer software is mainly used to design the digital speed controller.

　The results of PMDC motor testing show that: (1) Torque is positively linear to current and the relations has small variation under different voltage input; (2) Torque is negatively linear to speed and the relationships are parallel for different voltage input. The results of PMDC motor driven through the controllers indicate that the performance of PMDC motor achieve to optimal driving efficiency with the average PWM voltage of 18 V and the frequency of 15 kHz to 20 kHz as well as motor current between 7 A to 13 A. The results of applying PMDC motor characteristic equation to simulate the motor speed indicate that the maximum error between the predicted speed and the motor testing speed is 10 rpm. The findings are useful to measure motor current for predicted velocity feedback control in the controller design. The prototype of differential speed controller system including differential speed driving control circuit, RS-232 data communication, motor positive and negative direction control, filter circuit, A/D, PWM, and close-loop speed PID control has been designed completely.
　The data from PMDC motor testing provides fundamental and valuable information to develop more efficiency and safety differential speed controller for improved powered wheelchairs. The future works are recommended to (1) conduct field testing of the controller and (2) measure the center of gravity of Powered Wheelchair and the user to provide more accurate loadings of two rear wheels for differential speed of controller design.

目錄 IV
第一章 緒論
1.1 電動輪椅的科技 01
1.1.1 電動輪椅驅動之影響因子與動態模式 02
1.1.2 操作介面 10
1.1.3 永磁直流馬達(PMDC) 12
1.1.4 驅動控制器的相關設計原理 16
1.1.5 電瓶 27
1.2 電動輪椅的功率損耗 28
1.2.1 電池轉換效率 29
1.2.2 驅動控制器之功率損耗 31
1.2.3 直流馬達效率及功率損耗 33
1.2.4 齒輪箱效率 33
1.3 文獻回顧 33
1.4 研究動機與目的 35

第二章 材料方法
2.1 選取合適之馬達動力規格 37
2.2 馬達及馬達驅動控制器的特性量測流程 38
2.2.1 士林代步車PMDC馬達特性量測規劃 38
2.2.2 Dynamic、P&G、Curtis驅動士林PMDC馬達量測規劃 38
2.2.3 必翔代步車及控制器匹配量測規劃39
2.3 永磁直流有刷馬達的速度估測 44
2.4 電動輪椅PID閉迴路速度控制設計 46
2.4.1 電動輪椅PID閉迴路速度差速控制設計理念46
2.4.2 電動輪椅行進之差速區間選用分析 47
2.4.3 電動輪椅控制器閉迴路系統方塊圖 48

第三章 結果與討論
3.1 永磁直流馬達及驅動控制器測試結果討論 54
3.1.1 士林PMDC馬達暫態響應 58
3.1.2 士林PMDC馬達穩態響應 62
3.1.3 控制器驅動馬達暫態響應及驅動效率 66
3.1.4 比較PMDC馬達直流驅動與PWM驅動測試 73
3.1.5 必翔代步車及控制器匹配測試 76
3.2 電動輪椅左、右輪差速限制與速度預測之結果討論 82
3.2.1 馬達驅動電壓與差速限制之關係 82
3.2.2 永磁直流馬達速度預測 86
3.3 數位電動輪椅控制器量測結果討論 90

第四章 結論與未來發展

[1] B. W. Johnson and J. H. Aylor, “Dynamic Modeling of an Electric Wheelchair,” IEEE Transactions on Industry Applications, IA-21, No. 5, 1985.

[2] Ruei-Xi Chen, liang-Gee Chen, ”System Design Consideration for Digital Wheelchair Controller,” IEEE Transactions on Industrial Electronics, pp. 898-906, 2000.V. Diaz, ”New sonar configuration for a powered wheelchair,” IEEE Engineering in Medicine and Biology, pp. 113 -119, 1999.

[3] J. G. Thacker et. al., “Understanding the Technology When Selecting Wheelchairs,” RESNA PRESS, UVA, 1994.

[4] C. A. MacLaurin et. al., “Wheelchair Mobility – A Summary of Activities,” RESNA PRESS, UVA, 1981.

[5] Yasuhiko Dote, “ Servo Motor and Motion Control Using Digital Signal Processors,” Prentice Hall, New Jersey, 1990.

[6] R. A. Cooper, “Intelligent Control of Power Wheelchairs.”, IEEE Engineering in Medicine and Biology, pp. 423-431, 1995.

[7] 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.

[8] B. W. Johnson and J. H. Aylor, “Dynamic Modeling of an Electric Wheelchair,” IEEE Transactions on Industry Applications, IA-21, No. 5, 1985.

[9] 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.

[10] 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.

[11] 張簡嘉壬, “數位式電動輪椅代步車控制器系統之設計與發展” 國立成功大學醫學工程研究所碩士論文, 1999.

[12] 李榮茂, “馬達與電動輔具車測試系統之設計發展” 國立成功大學醫學工程研究所碩士論文, 1999.

[13] 黃庚取，“電動輪椅馬達控制器之研製”國立中興大學電機工程學系碩士論文, 2002.