Abstract
A robust and compact magneto-optical rotary encoder for the characterisation of robotic rotary joints is demonstrated. The system employs magnetic field-induced optical attenuation in a double-pass configuration using rotating nonuniform magnets around an optical circulator operating in reflection. The encoder tracks continuous 360{\deg} rotation with rotation sweep rates from {\nu} = 135 {\deg}/s to {\nu} = 370 {\deg}/s, and an angular resolution of {\Delta}{\theta} = 0.3{\deg}. This offers a low-cost and reliable alternative to conventional robot rotation encoders while maintaining competitive performance.