在常見的永磁同步馬達控制系統中有要求控制精密度高的特點，為機械手臂及電動車主要的致動器，其狀態直接影響系統的性能。目前業界普遍採用馬達狀態監控系統，在馬達上安裝各式感測器如加速規、扭力計及轉速計等，即時感知馬達異常狀況，以達到預知保養的目的。然而架設感測器除了造成成本增加之外，感測器本身也有故障的風險，因此本研究採用線上估測的方法估測永磁馬達動態系統模型參數，以取代感測器的量測。
線上估測馬達系統參數除了能實現無感測器技術控制馬達運轉之外，也能進行馬達的故障診斷。過去文獻使用線上估測方式診斷定子繞阻短路、斷路、溫度變化、磁場漪波等馬達故障，但並未使用估測器估測機械故障造成的異常扭矩情況。因此本研究提出遺忘因子遞迴最小平方及擴展卡爾曼濾波器的混合方法，透過量測電壓與電流即能估測永磁式交流伺服馬達模型的定子電阻、直交軸電感、磁通量、扭矩等五個參數。此估測方法和文獻中提及之估測器相比能識別較多的參數，其估測結果可以做為馬達故障診斷的基礎。

The control system of permanent magnet synchronous motor has the characteristics of the high precision control. It is the main actuator of robot arm and electric vehicle, and its state directly affects the performance of the system. At present, the motor condition monitoring system is widely used in the industry. Various sensors such as the accelerometer, the torque meter and the tachometer are installed on the motor to instantly sense the abnormal condition of the motor and achieve the predictive maintenance. However, the installation of sensors would increase the cost and the sensor itself also has the risk of failure. Therefore, this study uses the online estimation methods to estimate the parameters of the permanent magnet synchronous motor (PMSM) dynamic system model to replace the sensor measurement.
In addition to the implementation of sensorless technology to control the motor operation, the online estimation of the motor parameters can also conduct motor fault diagnosis. Previous literatures used online estimation methods to diagnose motor faults such as stator winding short circuit, open circuit, temperature change, and magnetic field chopping, but they didn’t use the estimator to estimate the abnormal torque caused by the mechanical failure. Therefore, this study proposed a hybrid method of the forgetting factor of recursive least squares and extended Kalman filter. By measuring the voltage and current, the stator resistance, orthogonal axis inductance, magnetic flux and torque of the permanent PMSM model can be estimated. This estimation method can identify more parameters than the estimator mentioned in the literatures, and the estimation result can be used as the foundation for motor fault diagnosis.

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