Autocompensation of torque ripple of direct drive motor by torque observer

Dept. of Electr. & Comput. Eng., Nagoya Inst. of Technol.
IEEE Transactions on Industry Applications (Impact Factor: 1.67). 02/1993; DOI: 10.1109/28.195906
Source: IEEE Xplore

ABSTRACT Since a direct drive motor (DDM) does not require a reduction
gear, the drive system can be made simple, and therefore it is used in
high-precision robot and machine tool applications. However, without
reduction gear, a disturbance torque is directly reflected to the motor
shaft, and a torque ripple generated by the motor is directly
transmitted to the load, causing poor speed control characteristics. An
improved torque control system for DDM with a permanent magnet rotor,
equipped with a torque observer implemented by digital signal software,
is proposed. The speed fluctuation can be fully removed with a torque
feedforward loop

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