The step angle of a two-phase hybrid stepping motor is generally 3.6 degrees and 1.8 degrees, while the step angle of a five-phase hybrid stepping motor is generally 0.72 degrees and 0.36 degrees. There are also some high performance stepper motors with a small pitch angle. For example, a stepper motor manufactured by Sitong is used for a slow-motion traveling machine with a step angle of 0.09 degrees; the step angle of a three-phase hybrid stepping motor produced by Bergerlahr can be set to 1.8, 0.9 by a DIP switch. , 0.72, 0.36, 0.18, 0.09, 0.072, 0.036, with two-phase step angle and five-phase hybrid stepping motor.
The control accuracy of the AC servo motor is guaranteed by the rotary encoder at the rear of the motor shaft. Take Panasonic's all-digital AC servo motor as an example. For the standard 2500 line encoder motor, the pulse equivalent is 360 degrees / 10000 = 0.036 degrees because the driver uses quadruple frequency technology. For a motor with a 17-bit encoder, the drive will rotate one revolution for each 217 = 131072 pulse motor, that is, its pulse equivalent is 360 degrees / 131072 = 9.89 seconds. It is 1/655 of the pulse equivalent of a stepping motor with a pitch angle of 1.8 degrees.