Position Estimation for a Mobile Robot, Using an Accelerometer with Impedance-Type Detector.

Abstract

In this paper, we present a method of position estimation for a mobile robot using a novel accelerometer. Compared to other methods involving landmarks utilization, odometry and GPS, an accelerometor-based method has the following advantages: (1) it is easy to install and (2) it is possible estimate position on uneven ground and indoors. However, because slight acceleration errors cause enormous distance errors, it is difficult to estimate the position by using an accelerometer. Therefore a servo-type accelerometer that has the highest accuracy among conventional accelerometers is used for the position estimation. But the sensor is expensive and is not good at estimating the position of an object that moves slowly like a robot. One of the reasons for the latter is that the data of the sensor is analog and the sensor needs AD converter. In this study we developed a new accelerometer with the aim of an accurate and inexpensive sensor, and proposed a method for using it in position estimation. The detecting module, an Inductcoder, provides digital data. The mobile module consists of a ball and two springs that causes no drift for the fluctuation of the temperature. The performance of this device was evaluated experimentally.