Patent ID: 6844693
Filing Date: 2005-01-18
Classification: H02P

Abstract:
1. An electric motor position control apparatus comprising: a position/speed calculation section for calculating speed of an electric motor from a detection position of said electric motor or for calculating a position of said electric motor from a detection speed of said electric motor, a position control section for making said detection position follow a position command value, a speed control section for making said detection speed follow a speed command value depending on the output of said position control section: an electric motor drive section for driving said electric motor on the basis of a torque command value depending on the output of said speed control section, and a control parameter adjustment section having a plurality of sets of control parameters including at least the proportional gain of said position control section and the proportional gain of said speed control section, wherein set selection and the measurement operation of the response state of said electric motor to a position command at the time when said electric motor is controlled by using the control parameters of the selected set are carried out sequentially, and the control parameters of one set are set depending on the result of the measured response, wherein said control parameter adjustment section is configured so that: when set selection and the measurement operation of the response state of said electric motor by controlling said electric motor by using the control parameters of the selected set are carried out sequentially, among the detection of a vibration component having a predetermined frequency or more and included in the detection position or the detection speed of said electric motor, the detection of a vibration component having a predetermined frequency or more and included in a torque command input to said electric motor drive section and the detection of the error between the position command value and the detection position after the end of the position command, the measurement operation including at least one vibration component detection is carried out sequentially from a set having a low proportional gain of said speed control section to a set having a higher proportional gain thereof; and in the measured response result, (1) condition (1) wherein the period in which the amplitude of said vibration component has first predetermined value or more is less than said first predetermined time, in the period from the start of a position command to the start of the next command; (2) condition (2) wherein the period in which the amplitude of said vibration component has said first predetermined value or more is less than a second predetermined time shorter than said first predetermined time, in the period from the start of a position command to the start of the next command; and (3) condition (3) wherein the number of times the error between the position command value and the detection position intersects a preset positioning tolerance is less than a predetermined first number of times, in the period from the end time of a position command to the start of the next command; one of sets satisfying one or more of said three conditions, including at least the condition (1), is selected, and the control parameters of the selected set are set.