A non-inertial acceleration suppressor for low cost inertial measurement unit attitude estimation

This paper presents a method to evaluate the attitude of a rigid body under condition of high non-gravitational acceleration. Most of the attitude estimation algorithms based on data from low cost Inertial Measurement Units (IMU), assume that the total acceleration perceived by the accelerometer be gravity or at most small variations of it. When the actual conditions are far away from such assumption, the attitude estimation results in wrong evaluations. We propose a method that uses an external RGB-D camera to measure The non-inertial linear acceleration. Such acceleration is subtracted to the total acceleration reading of the accelerometer in order to obtain a truthful gravity direction that will be fed into the fusion algorithm. Performance of our attitude estimation has been evaluated empirically under non-gravitational acceleration. We compare our results against the output of a commercially avalaible IMU sensor based on a Kalman Filter algorithm as well as the estimation of a recently developed fusion algorithm based on a gradient descent algorithm, showing significant improvement.