Low-cost motor position detection method by linear Hall-effect sensors

The method of motor position detection by two low-cost linear Hall-effect sensors mounted 90° electrically apart was proposed to reduce the cost of linear servo system.The magnetic fields of the motors with and without back iron structure were analyzed by finite element analysis(FEA).The area influenced by back iron was determined by comparing the analysis of the two motors,and the influence of the sensor mounting positions to the motor detection accuracy was analyzed.The experiments of the motor position detecting were conducted while the sensors were mounted on different positions.Experimental results proved the analysis by FEA,and the suitable sensor mounting positions were determined.The detection accuracy of the method can be increased by choosing suitable sensor mounting positions.