Trajectory Following Control Using Cogging Force Model in Linear Positioning System

  • Published : 2002.07.01

Abstract

To satisfy the requirement of the one axis linear positioning system, which is following control of the desired trajectory without following error and is the high positioning accuracy, feed-forward loop having cogging force model is proposed. In the one axis linear positioning system with linear PM motor, cogging force acting as disturbance is modeled analytically. Analytic model of cogging force is verified by result measured from positioning system constructed with linear PM motor. Measured result is very similar with proposed analytic model. Cogging force model is used as feet forward loop in control scheme of linear positioning system. Cogging force feed-forward'loop is obtained from analytic model of cogging farce. Trajectory following error is reduced from 300nm to 100nm by applying the proposed cogging farce feed-forward loop. By using analytic model of cogging force, the control scheme is simplified. Also this analytic model is applicable to calculation of characteristic value of positioning system in design process.

References

  1. Ryu, J. W. and Gweon, D. G., 'The optimal design of a flexure hinge based xy-theta wafer stage,' ASPE, Vol.21, No. 1, pp. 18-28, 1997 https://doi.org/10.1016/S0141-6359(97)00064-0
  2. Lee, M. G. and Gweon, D. G., 'CD/DVD compatible optical pickup actuator design,' KSPE, Vol. 15, No. 7, pp. 98-103, 1998
  3. Braembussche, P. V. D. et al., 'Accurate tracking control of linear synchronous motor machine tool axes,' Mechatronics, Vol. 6, No. 5, pp. 507-521, 1996 https://doi.org/10.1016/0957-4158(95)00090-9
  4. Low, T. S. et al, 'Servo performance of a BLDC drive with instantaneous torque control,' IEEE Trans. on Industrial Application, Vol. 28, No. 2, pp. 455-462, 1992 https://doi.org/10.1109/28.126756
  5. Otten, G. et al, 'Linear motor motion control using a learning feedforward controller,' IEEE/ASME Trans. on Mechatronics, Vol. 2, No. 3, pp. 179-187, 1997 https://doi.org/10.1109/3516.622970
  6. Chung, M. J. and Gweon, D. G., 'Modeling of the armature slotting effect in the magnetic field distribution of a linear permanent magnet motor,' Electrical Engineering, Vol. 84, No. 2, pp. 101-108, 2002 https://doi.org/10.1007/s00202-001-0108-0