precise angle control method by analog encoder system

摘要

Disclosed is a method for controlling an SRM (Switched Reluctance Motor) switching angle by an analog encoder system that can perform a precise control of the switching angle of the SRM by comparing an analog sensor signal detected by the analog encoder system with a switching-on/off command signal. During a rotation of an encoder rotor having rotary slits formed at the same intervals on the encoder rotor and continuous contrast patterns formed between the respective rotary slits, analog sensor signals theta_a to theta_d detected in proportion to the contrast patterns are compared with a switching-on/off command signal controlled by a digital-to-analog (D/A) converter. A switching-on angle theta_on is set to a crossing point of the switching-on command signal V_on and a slope between the sensor signals theta_a and theta_o, and a switching-off angle theta_off is set to a crossing point of the switching-off command signal V_off and a slope between the sensor signals theta_o and theta_d.