Reduced Measurement Time in Absolute Pseudorandom Optical Encoders

Optical rotary pseudorandom encoders are an excellent solution for reliable and precise angular position measurement in various industrial motion systems. The paper describes an improved optical rotary pseudorandom encoder solution that has a reduced angular position measurement time. The presented encoder uses two heads to read the pseudorandom code and to form the main and control code words. The encoder algorithm has been improved so that code conversion is not performed after each new code word. In presented solution, after each new code word, a code reading error checking is performed, and the position is determined based on the previous measured value if no code reading error is detected. The functionality of the proposed encoder solution in the LabVIEW environment is tested.