Devising Simulink Optical Encoder Pulse Manipulation and its Evaluation

Incremental optical encoder is a versatile digital transducer, employed for angular displacement and velocity estimation. It has been observed that both frequency and period counting methods employed for angular velocity estimation, from incremental optical encoder pulses are prone to quantization error. A modified Simulink based period counting method is proposed, to reduce the quantization error inherent in the ordinary one. This was accomplished by time period multiplication of encoder pulses. The algorithm was tested and evaluated using a Simulink model of the physical optical encoder. Percentage error for different ranges of angular velocity is studied, for both normal and period counting method.