A robotic joint sensor

Abstract

This work reports on the current state of a robotic joint sensor unit capable of estimating the relative angular acceleration, velocity and position of hinged robotic links. To this end the accelerometer-only Inertial Measurement Unit (IMU) concept is built upon to incorporate an incremental encoder and extra accelerometer to gather the extra information required to estimate the relative position, velocity and acceleration components. Two cascaded Unscented Kalman Filters are then used to separately estimate the IMU component and the relative component. Simulation of the system shows promising results with all states being estimated under a range of dynamic motions.