PROPOSAL POSITIONING SYSTEM BASED ON THE USE OF TWO IMS PLACED ON COMMON BASELINE AND OPTICAL ENCODER

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgem.org, SGEM2017 Conference Proceedings, ISBN 978-619-7408-02-7 / ISSN 1314-2704, 29 June - 5 July, 2017, Vol. 17, Issue 22, 477-484 pp, DOI: 10.5593/sgem2017/22/S09.060

ABSTRACT

Inertial measuring system (IMS) is a self-contained navigation system which enables monitoring of 3D position and orientation of the navigated object in indoor environment. Determination of the position and orientation of an IMS is based on integration process, where the displacement and the change of the orientation are calculated from inertial measurements (acceleration and angular rate). The measurements of inertial sensors are influenced by systematic errors, which are accumulated in the integration process. Accumulation of systematic errors causes exponential growth of position error, which is the main problem of IMS.
The paper describes a measuring system designed for application in indoor environment. Sensory part of the measuring system consists of two IMS placed on common baseline and an optical encoder. The proposed measuring system uses two IMSs placed on a baseline, due to the fixed geometric relationships between the coordinate systems of both IMSs, which gives the corrections for the position and the orientation of the navigated object. The optical encoder measures the speed of movement of the navigated object, which is independent on the time of measurement that enables the elimination of systematic errors of accelerations obtained by IMS. The basic advantages of the proposed system are low-cost components, low-power requirements and independence on external signals. The proposed measuring system itself, the model of data processing and experimental measurements are described. The accuracy of the results is analyzed also.

Keywords: IMS, measuring system, optical encoder, baseline, systematic errors.