optic-sensor

This project simulates the behavior of a fiber optic sensor that acts as a replacement of flex sensor. The design is taken from Wang et al (2015).

Theory

The optical sensor has an LED, two rotatable polarizers and a photo-transistor. Through the first polarizer, the light is polarized along a single axis. The second polarizer moves with the motion of finger and thus helps predict the position of finger. When the finger is straight, the two sensors are perfectly aligned.

Simulation Model

Simulation is done by first getting the response of second polarizer as its angle is changed.

Afterwards, a second order polynomial is fitted. The advantage of such an approach is that expensive calculations are done only one time.

Use Case

Run Simulink Model

By chaning the inputs, the response of model can be visualized.

Run Matlab Script

Pass any angle to poly_find() to get the ratio of amplitudes.

poly_find(10, 45)

Get coefficients of fitted polynomial curve.

poly_fit()