雙動力輪智慧電動輪椅之系統整合與控制

System Integration and Control of Smart Wheelchair Driven by Dual Power Wheels

葉治緯(Chih-Wei Yeh)

指導教授 ： 陽毅平

國立臺灣大學/工學院/機械工程學研究所/碩士(2018年)

https://doi.org/10.6342/NTU201800559

摘要

本文研究的目的在於開發一個完善的手輪馬達電動輪椅之控制系統與輔助控制策略。文中先介紹手輪馬達電動輪椅之動力系統設計概念，包含手輪馬達、馬達驅動器、機械式煞車與控制器，整合於電動輪椅之動力輪。目的是希望一般輪椅車架皆能只透過換裝兩個動力輪與控制盒即可變成電動輪椅，利用向量弦波驅動使馬達驅動時降低震動感，提升手輪馬達電動輪椅之穩定性及效率，並透過輔助控制策略讓手輪馬達電動輪椅具有更方便的人性化功能。
手輪馬達電動輪椅控制系統分為主要控制系統與輔助控制系統，主要控制系統由輪椅上下控制器組成。上控制器主要功能為提供人機介面操作、藍芽連接、雙輪耦合差速控制、速度控制及傳送電流命令於下控制器。藉由人性化的人機介面，讓輪椅使用者能直覺性的了解電動輪椅的狀態並操作。下控制器主要功能為馬達弦波驅動、電子式煞車及機械式煞車控制，使手輪馬達穩定且安全的運轉。
輔助系統可透過藍芽與智慧型手機連接，讓使用者進行近距離的遙控。輔助系統可分為兩個部分，一個是電動輪椅的遙控系統，另一個是電動輪椅的路徑學習系統。遙控系統可讓使用者透過智慧型手機遙控電動輪椅，將電動輪椅行駛到使用者希望的位置。而路徑學習系統可將使用者行駛的路徑記錄下來，並透過智慧型手機發送命令，使電動輪椅自行照著紀錄的路徑移動。
本研究所使用的向量弦波驅動經實驗比較後，確實能夠提升馬達效率並降低馬達震動，輔助控制系統中的遙控系統與路徑學習系統，經過實測後，能夠穩定運行，提供電動輪椅更智慧化的人性操作介面。

關鍵字：動力輪、手輪馬達、電動輪椅、輔助系統、直流無刷馬達、無刷馬達驅動器、線性霍爾感測器、電子式煞車、閉迴路速度控制、路徑學習、循跡系統、藍芽。

關鍵字

動力輪 ； 手輪馬達 ； 電動輪椅 ； 輔助系統 ； 直流無刷馬達 ； 無刷馬達驅動器 ； 線性霍爾感測器 ； 電子式煞車 ； 閉迴路速度控制 ； 路徑學習 ； 循跡系統 ； 藍芽

並列摘要

The aim of this research is to develop a comprehensive control system and assist the control strategy of the rim motor electric wheelchair. The purpose is to electrically control all the regular wheelchair by installing two electricity wheel modules and control boxes. This study first introduces the design concept of the dynamic system of the electric wheelchair. This includes the rim motor, BLDC driver, mechanical breaking’s mechanism and controller, and they are integrated into the power wheel module. By using Space Vector PWM module, motor vibration can be reduced and the stability and efficiency of the electrical wheelchair can be improved. Furthermore, the assist control strategy in this research makes the rim motor electric wheelchair much more user-friendly and convenient.
The control system of rim motor electric wheelchair consists of two systems, which are the main control system and the assisted control system. The main control system comprises of the upper and the under controller. The upper controller provides operable user interface, Bluetooth connection, optimal cross-coupling control, and closed loop speed control. The upper controller also transfers current command to under controller. The user-friendly interface enables wheelchair users to intuitively control and acquire the status of the electronic wheelchair. The under controller drives rim motor stably and safely by using Space Vector PWM module, controlling electrical breaking and mechanical breaking。
Assisted control system can connect to smart phones via Bluetooth connection, and this allows the user to remotely control the electric wheelchair at a close distance. Assisted control system comprises of two parts, which are the remoting system of the electric wheelchair and the wheelchair tracking system. The remoting system enables users to remotely control the electric wheelchair with smart phone application and drive it wherever they want. The track learning system can record previously taken paths allowing the electric wheelchair to automatically follow the recorded paths.
This study also describes an experimental comparison of the Space Vector PWM module and the six-step square wave driving module. From this comparison, it is found that the six-step square wave can essentially increase the efficiency while the Space Vector PWM cannot. Therefore, the Space Vector PWM module is not suitable for the rim motor. The rim motor in this case is a low-rotation-speed, high-torque BLDC motor. Also, the remoting system and the track learning system in the assisted control system allows the electric wheelchair to be driven stably and provides a more user-friendly interface for the driver.

Keywords: power wheel, rim motor, electric wheelchair, assistance system, Brushless DC motor (BLDC), BLDC driver, linear hall sensor, electrical braking, closed-loop speed control, track learning, tracking system, Bluetooth.

並列關鍵字

power wheel ； rim motor ； electric wheelchair ； assistance system ； Brushless DC motor (BLDC) ； BLDC driver ； linear hall sensor ； electrical braking ； closed-loop speed control ； track learning ； tracking system ； Bluetooth

參考文獻

[41] 丁亦元, 基於霍爾感測器之改良型轉子角度估算法應用於內藏式永磁同步馬達之驅動控制, 碩士論文, 國立台灣大學, 台北, 2011.

[49] 董紹安, 手輪馬達電動輪椅之控制系統整合策略, 碩士論文, 國立台灣大學, 台北, 2016.

[51] 林怡劭, 手輪馬達電動輪椅力矩控制暨參數識別, 碩士論文, 國立台灣大學, 台北, 2017.

[55] 施華宇, 手輪馬達電動輪椅之霍爾感測器失效控制策略, 碩士論文, 國立台灣大學, 台北, 2017.

[1] K. Sakai, T. Yasuda, and K. Tanaka, "Improvements of manipulation torque transfer mechanism and assist unit for one hand drive wheelchair with a triple ring," Proceedings of the 2009 IEEE International Conference on Robotics and Biomimetics, Guilin, China, Dec. 19-23, 2009, pp.196-201.