近年來，隨著科技的進步，越來越多電子技術應用在工業產品上。因為電子控制系統的精確控制與應用的產品越來越廣泛，人們的生活也因此更安全與便利。
　　本篇論文提出一個可移動式車體之動力輔助系統之研究。一般而言，動力輔助系統都需要一個力矩感測器去量測力矩的大小，藉此來計算馬達所需補償的力，達到動力輔助的效果。但是安裝這些力矩感測器會使得驅動系統體積變大、昂貴、易壞。另外，力矩感測力所量測出來的力矩會隨著安裝地方不同而有不同的值。因此使用力矩感測器去量測一個準確的力矩是很困難的。本篇論文是採用無感測器力矩估測的方式來實現動力輔助系統。藉著力矩估測器來取代一般動力輔助系統所使用的力矩感測器，並且能精準地估測出力矩值。所以本論文的重點就是設計一個力矩估測器，並且證明所提出的控制系統是有效的。
　　本論文所提出的估測器設計步驟是利用Lyapunov穩定原理來分析，並且從分析中得到所需的估測器增益。藉由電腦模擬結果來證明所提出的控制架構的可行性。再由實做的結果來展現所提出的方法是具有高準確度與高效率的。

　　In recent years, more and more electronic control techniques have been applied to the industrial product along with the technological advance. Because of the accurate control of electronic control system and applied products more and more widely, the life of the people is more convenient and safe.
　　The study of power-assisted system of the mobile vehicle is presented in this thesis. In general, the power-assisted system needs a torque sensor to measure the unknown torque. Using the measured torque to calculate the motor generating torque and obtain the effect of power-assisted system. However, installation of such sensors causes large size, high cost, easy injury, and a decline in the reliance of the drive system. In addition, the detection of the external torque depends on the position of the torque sensors. Hence, it is difficult to measure an accurate external torque using the torque sensors. This thesis adopts the sensorless torque observer to realize the power-assisted system. The torque observer is used to replace the torque sensor of general power-assisted system and to estimate the external torque accurately. The main purpose of this thesis is to design a torque observer and to verify the effectiveness of proposed control system.
　　In this thesis, the design procedure of the proposed observer is analyzed by the Lyapunov stability theorem, and the observer gain is obtained from this analysis. By using the results of computer simulation, the feasibility of proposed control frame is proved. The experimental results show the developed approach is high precision and efficiency.

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