Compact, High Resolution Rotary Position Sensor

This compact, low-cost, high resolution angular position sensor is designed to improve the movement of rotary joints. The capacitive sensor, which includes two flat discs patterned with conductive material can be packaged in tight spaces. The sensor produces a highly robust, friction-free angular measurement using non-contact sensing technology. The sensing discs can be as thin as a few sheets of paper and have a center cutout to allow the passing of a shaft or cabling. The sensor is alignment insensitive - capable of rejecting motion noise in all directions not intended to be sensed. This allows for high precision angular measurements with low precision mounting. The sensor is also completely shielded to reject environmental electrical noise. Larger sensors or sensors with improved readout electronics will produce even higher resolution. The sensor is applicable in almost any field where angular measurements are required, such as robotics, vehicles, industrial automation, toys or game consoles.

Rotar Sensor Prototype

Stage of Research
The inventors have built prototype sensors with noise-free resolution on the order of 12,000 counts per revolution for 0.5” diameter and 60,000 counts per revolution for a 1”' diameter sensor (significantly higher than any other technology with similar form factor and cost). The sensor's high resolution also opens the door for robust, low-cost, high resolution torsion sensing and prototypes are under development.