Quantification and Mitigation of Errors in the Inertial Measurements of Distance
The accurate measurement of the distance travelled, velocity and acceleration at low velocities to supersonic speeds is an active area of research. The captive flight at Rail Track Rocket Sled (RTRS) facility provides a unique environment for kinematic testing at supersonic speeds. Using RTRS facility, an accurate distance measurement method is developed, tested and experimentally verified. Three accelerometers, with different noise density, identically moving, have been chosen for sensing forward motion. A number of measures such as different mountings, bias correction, capping, digital filtering and position fix have been tried in a practical implementation. To keep the measurement error within tolerable limits a novel method of obtaining position fix is proposed by using a pair of magneto-inductive sensors. The bias correction is applied in the position to derive corrected velocity and acceleration. To know the truthfulness of results and to validate the proposed methods, a system has been developed to generate reference values for computation of error. This reference system has an error of 0.046 % which is much better than reported in previous study. After mitigation of various errors using proposed methods, an error within 1.5 % was attained with one of the sensors used in trials. The proposed work identifies the elements which contribute in errors and quantify the mitigated errors in some cases and highlights the measures which bring about significant improvement in error. It also suggests how to obtain more accurate results using economical MEMS accelerometers.
KeywordsDistance Velocity Acceleration Rocket sled Sled motion MEMS accelerometer Inertial acceleration Rail measurements
- J. Jerosch and J. Heisel, Management der Arthrose: Innovative Therapiekonzepte (in German), Deutscher Ärzteverlag. ISBN 978-3-7691-0599-5, Retrieved (2011) 107.Google Scholar
- S. Nikbakht, M. Mazlom and A. Khayatian, Evaluation of solid state accelerometer sensor for position estimation, IEEE International Conference on Industrial Technology, Hong Kong (2005) pp. 729–723.Google Scholar
- Y. Hirao, S. Kunimatsu and T. Hamamoto, Wireless measurement system for ground-borne vibration and vibration amplifications in buildings, MAPAN-J. Metrol. Soc India, 27 (4) (2012) 231–239.Google Scholar
- P. Neto, J.N. Pires and A.P. Moreira, 3-D position estimation from inertial sensing: minimizing the error from the process of double integration of accelerations, Annual Conference of the IEEE Industrial Electronics Society, IECON Vienna, Austria (2013) pp. 4024–4029.Google Scholar
- H. Liu and G. Pang, Evaluation of a low cost solid-state accelerometer as a distance measuring sensor for vehicle positioning system, IEEE Proceedings of International Conference on Intelligent Transportation Systems, Tokyo (1999) pp. 435–439.Google Scholar
- K.N. Suryanarayana Rao, GAGAN—The Indian satellite based augmentation system, Indian J. Radio Space Phys., 36 (2007) 293–302.Google Scholar
- Indian Space Projects, http://isp.justthe80.com/space-applications/gagan, January 2014.
- News Paper “The Hindu”, GAGAN will be put in place by end of 2014: Defence Secretary, Statement of Defence Secretary and Director General DRDO, 14 Dec (2013).Google Scholar
- V.N. Ojha, K. Sudhir, S.K. Sharma, S. Singhal and G.S. Lamba, Insulation resistance measurement of high impedance accelerometer cables, MAPAN-J. Metrol. Soc. India, 19 (1–2) (2004) 117–120.Google Scholar