Distributed-force recovery for a planar photoelastic tactile sensor

In this paper, a novel planar photoelastic tactile transducer is presented. A distributed force profile input to the transducer generates stress in the photoelastic layer of the transducer making it birefringent. Circularly-polarized input is elliptically polarized at the output due to phase-lead created in the stressed photoelastic layer. Our main objective is to recover the phase-lead distribution and correlate it to the input force profile. Since this distribution is a linear function of the force profile, the solution of the inverse tactile problem is significantly simplified. Herein, it is assumed that the light-intensity distribution can be detected by a CCD camera linked to an A/D converter