Measurement and Analysis for Positioning Control Characteristics using Encoder Signal of NC Machine Controller

공작기계용 NC제어기의 엔코더 신호를 이용한 위치제어 특성 측정 및 분석

  • 김종길 (충북대학교 대학원 기계공학부) ;
  • 이응석 (충북대학교 기계공학부)
  • Published : 2005.02.01


NC controller parameters are fixed when the controller is combined with a machine. However, the characteristics of controller could be changed as it has being used by the machine or other environmental conditions. Ultimately, it results in tool positioning accuracy changing. The loading torque in servo motor also influences on the positioning accuracy. This study focus on a measuring and analysing method for verifying the angular positioning accuracy of NC servo motor. We used a high resolution A/D converter for acquiring analogue signal of rotary encoder in servo motor. Generating tool path by the combination of axial movements (X,Y,Z) is compared with the encoder signals with the servo motor torque. The current variation signal is also read from the servo motor power using a hall sensor and converted to the motor torque. The method of analysing proposed in this study will be used for determining the gains (tuning) of parameter in NC controller, when the controller is set up at a machine initially or the controller condition is changed during the work.


Encoder;Hall Sensor;Interpolation;NC Controller;Positioning Control Error;Velocity Gain;Time Constant


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