Whisker array based on fiber Bragg grating for surface shape sensing

In this paper, a whisker array sensor for object surface shape measurement is designed and experimentally demonstrated. The developed sensor is based on a 4×4 whisker array with fiber Bragg grating, which imitates the structure of the facial whiskers of animals like mice and dogs. The surface shape reconstruction is based on the curvature information of each sensing point by measuring the wavelength shift of each fiber Bragg grating fixed on the whisker. The conversion coefficient between wavelength shift and bending curvature is obtained then the change of fiber Bragg grating is converted into corresponding bending curvature. The measurement error on the altitude of the whisker of each sensing point is about 1.2%. By curve fitting the curvature information of the whole fiber Bragg grating whisker array, the surface shape of the target surface is reconstructed. In this experiment, the spatial resolution of the sensor is 10 mm, which can theoretically meet the need of any spatial resolution by adjusting the measurement algorithm. The design successfully realizes surface shape sensing, which has important practical value in the field of robot tactile, in aviation and disaster relief.