Prototype of An Optoelectronic Joint Sensor Using Curvature Based Reflector for Body Shape Sensing

This paper demonstrates a working prototype for shape sensing using miniature optoelectronic sensors integrated into a chain of rotational links. Wearable sensors for rehabilitation, prosthetics and robotics must be lightweight, miniature, and compact to allow comfortable range of motion without obstruction, and therefore, the integrated network of sensors and hardware must be adapted to this. The sensing principle is based on light intensity modulation using a curvature varying reflector. The modular sensing configuration design offers a low-cost, miniaturized approach to shape sensing, compatible in clinical applications. A prototype is constructed, and calibration is carried out. Shape sensing estimation is evaluated to assess accuracy. A four-link rotational chain prototype shows average estimation errors of 2.4° for shape sensing compared to an inertial measurement unit.