A highly compact fiberoptic rotation sensor for a neurosurgical robot

This paper presents the development of a fiberoptic rotation sensor for the motion feedback of a meso-scale shape memory alloy (SMA) torsion actuator for a neurosurgical robot. Multiple bundles of optical fibers for transmitting and receiving light are employed to achieve large measurement range and high precision. The voltage output as a function of the rotation angle via light intensity modulation (LIM) is modeled. A series of experimental studies are performed to calibrate the developed fiberoptic rotation sensor and evaluate its working performance for a variety of motion profiles. The experimental results show that the developed sensor is capable of measuring large range of motion with relatively high precision.