This paper proposes an enhanced sliding mode observer for the load torque estimation. To suppress the chattering, this paper utilizes a feedforward compensation of the state variable. With the modified structure of sliding mode observer, the estimated load torque has a reduced magnitude of the ripple with higher bandwidth. The difference of the system equation between conventional observer and the proposed method is explained, and the stability of the proposed observer is analyzed using a Lyapunov criterion. The analyzed criterion is used to establish the gain value and also the bandwidth of the estimation.
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