Absolute Encoder-Based Dual Axis Tilt Sensor

Abstract

In this paper, an optical type dual axis tilt sensor is demonstrated for the measurement of surface inclination in the range of ±90°. The proposed sensor measured the surface tilt by tracking a pendulum motion in two different axes. Unlike the traditional tilt sensor, the proposed concept used an absolute encoder for sensing the pendulum motion. This newly designed encoding track (named as index and code track) is attached separately with two pendulum blocks. As the encoder tracks are used a gray color coded pattern instead of binary code, hence the pendulum position is encoded as the variant intensity of gray colors. Thus, during the inclination of the sensor, a pair of optical trans-receiver reads the pendulum position by capturing the track information’s as well as transformed it into the variant intensity of lights. Furthermore, a simple signal processing circuit has been used for calibrating the light intensity as measured surface inclination. The static behavior of the proposed sensor has been observed in laboratory conditions and found satisfactory performance in the above-mentioned measured range.