| 摘要 |
PROBLEM TO BE SOLVED: To provide a motor drive unit capable of solving conventional problems that when the command update period of a host controller is longer than the control period of the motor drive unit, a periodic variation is generated on the command update period; the ratio between the command update period and the control period has to be known to correct the periodic variation, which is not always obtained at job site; and when the ratio is not integer, the periodic variation is hardly eliminated.SOLUTION: The motor drive unit includes: a receiving section that reads commands at every control period from the host controller which are updated at every command update period; and a controller for controlling a motor according to the output from a receiving section. The motor drive unit further includes; a differentiator that performs differentiation on the commands predetermined times; a calculator that calculates an autocorrelation function on the output from the differentiator at a delay time in a specific range; an estimation section constituted of an identification device for identifies the command update period from the output from the calculator; and an interpolation section that performs a processing to control the periodic variation at every command update period on the commands based on the output from the estimation section. |
