Patent ID: 6979971
Filing Date: 2005-12-27
Classification: G05B

Abstract:
1. A cylinder servo motor with a built-in control device, comprising: a servo motor unit having a rotor; a rotational/linear motion converting mechanism which is disposed on a rotating shaft of the servo motor unit and which converts rotational motion of the rotating shaft to linear motion; a current detector for detecting a current flowing in said servo motor unit; a rotation detector for detecting a rotation angle of said servo motor unit; and a control unit for controlling the servo motor unit; wherein the servo motor unit and the control unit are mechanically combined, and wherein said control unit includes: a command memory for storing commands used in positional error measurement of said servo motor unit; input means for inputting a measurement result obtained from a length measuring device, which measures a position of an output shaft of said rotational/linear motion converting mechanism which is operated based on the commands stored in said command memory, the input means further inputting commands from an external command device; operation mode switching means for switching an operation mode of said cylinder servo motor with the built-in control device between a normal operation mode and a test operation mode; positioning error compensation data calculating means for calculating an estimated position of the output shaft of said rotational/linear motion converting mechanism based on the detection angle detected by said rotation detector, when the test operation mode is selected by the operation mode switching means, and for then calculating positioning error compensation data based on the estimated position of said output shaft and the measurement result of the length measuring device which is input through the inputting means; a compensation memory for storing the positioning error compensation data calculated by the positioning error compensation data calculating means; and compensating means for compensating for a positioning error based on the positioning error compensation data stored in the compensation memory for controlling the servo motor unit when the normal operation mode is selected by the operation mode switching means.