Accelerometer for mobile robot positioning

An evaluation of a low-cost small-sized solid-state accelerometer is descri bed in this paper. The sensor is intended for Positioning of a mobile robot or platform. The acceleration signal output by the sensor is doubly integr ated with time, which yields the traveled distance. Bias offset drift exhib ited in the acceleration signal is accumulative and the accuracy of the dis tance measurement deteriorates with time due to the integration, This probl em can be fixed by periodic recalibration by the use of external measuremen ts on position, velocity, and attitude which can be compared with the corre sponding quantities calculated by the inertial system. A Kalman filter coul d use the differences between those values to provide an optimum estimate o f the system error, The random bias drift of the accelerometer was found ex perimentally to be 2.5 mg. The accelerometer was moved back and forth three times for a distance of 40 cm with an acceleration of 8 m/s(2), The final distance error accumulated was -1.08 cm, The bias drift rate due to tempera ture was 0.108 mug/s when the accelerometer was placed at room temperature. The results show that the accelerometer could be a viable solution as a sh ort-duration distance-measuring device for a mobile robot or platform.