Polymer Optical Fiber Sensor System for Multi Plane Bending Angle Assessment

Abstract

In this paper, a polymer optical fiber (POF) sensor system for angle estimation in multi-planar movements is proposed. The sensor system comprises of three intensity variation-based POF sensor multiplexed via a time multiplexing technique with the side-coupling of the light sources. A theoretical analysis is performed for the sensor system as well as a numerical analysis using the finite element method (FEM) in order to investigate the cross-sensitivity for multi planar movement and the effect of the sensors positioning on the sensor sensitivity due to the stress distribution on the fiber. Such analyses indicate the possibility of not only increasing the sensor accuracy on single plane angle estimation by combining the responses of two sensors, but also the possibility of obtaining an angle estimation combining the sensor responses for multi plane movements. Then, an experimental analysis is performed on the sensor system, which corroborates the numerical and analytical responses and enable a threefold error reduction when two sensors are used on the single plane estimation instead of one. In addition, errors as low as 1.15% in the best case and 4.30% in the worst case were obtained on the tests with multi plane movement. The results obtained in this paper indicate the possibility of using this sensor system on the shape reconstruction applications in structural health monitoring, robotics and movement analysis.