| 摘要 |
PURPOSE:To attain positioning with high accuracy by providing the revolving angle detectors to both output and input shafts of a reduction gear and detecting an error of rotational frequency between both shafts to correct the drive command value. CONSTITUTION:A reduction gear 1 combines many gears and reduces the revolution of an input shaft 1a down to 1/n to transmit it to an output shaft 1b. While angle detectors 2 and 3 are connected to both shafts 1a and 1b respectively and output detection pulses EP and TP for each revolution by a fixed angle. A control part 7 is driven by a motor 4 and the shaft 1a is revolved. When the gear 1 has the backlash, etc., a difference of rotational frequency is produced between both shafts 1a and 1b. Therefore the count values of both counters 5 and 6 are monitored by the part 7, and an error is obtained between both count values. Then the part 7 corrects said error with the drive command value DS and gives revolutions to the shaft 1a in an extra amount equivalent to said error. This corrects an error due to the backlash, etc. of the shaft 1b and attains the accurate positioning. |
