BREAKING DETECTING DEVICE AND BREAKING DETECTING TECHNIQUE OF ROTARY ENCODER

摘要

PPROBLEM TO BE SOLVED: To detect surely and quickly breaking of encoder even if a rotating body is in low-speed condition close to "zero velocity". PSOLUTION: A current position operating section 30A obtains the present rotational position of a rotating body from A and B phase pulses an encoder 25 generates. A current position constant measuring section 30B determines whether the present rotational position is constant. A remaining distance operating section 30D obtains the difference between a target rotational position and the present rotational position with absolute value. A breaking detection exceptional domain determining section 30E determining whether remaining distance is within a breaking detection exceptional domain established as a domain close to the target rotational position or outside the domain. A co-establishment determining section 30F determines breaking based on co-establishment of both determination of "the present position being constant" and determination of "the remaining distance being outside the exceptional domain". PCOPYRIGHT: (C)2010,JPO&INPIT