A spherical encoder for real-time measurements of three-DOF wrist orientations

The need for simultaneous measurement of that sophisticated image processing is needed. In addition, the more-than-one degrees-of-freedom (DOF) motions of an object lack of an appropriate vision system for machine applications can be found in numerous applications such as robotic has also posed a significant challenge to real-time assemhlv. urecision machining, oDtical tracking. wrist actuators, imulementation of such a vision-based wrist orientation sensor. -. . -. and active joysticks. Conventional single-axis encoders, though capable of providing high-resolution limear or angular measurements, require additional mechanical l i g e s that often introduce frictions, backlashes, and singularities. In this paper, a non-contact optical sensor for three-DOF orientation measurement is present. Unlike other contemporary designs, which often require a specific pattem to be drawn on a surface, this optical sensor presented here relies only on microscope features on natural surfaces to detect incremental motions. Here we offer a detailed description of the design and the development of a dual-sensor system capable of measuring three-DOF motions in real time. The analysis that is essential for optimizimg the sensor design, has been validated experimentally.