Development, Implementation and Verification of a Procedure to Characterize a Tetraxial Inertial Measurement Unit (IMU)

Abstract

Inertial Measurement Units (IMUs) are versatile devices to measure inertial motion and orientation. Among other applications, they are used for reliable short-term navigation in highly dynamic or isolated environments where external guidance is not available. An experimental navigation system for reusable launcher systems with a tetraxial IMU is currently being developed at the Institute of Space Systems from the German Aerospace Center in Bremen and this document proposes, tests and analyses a procedure to characterize its performance. Moreover, this thesis demonstrates how to determine the model coefficients of accelerometers according to IEEE standards by applying the proposed procedure to a developed prototype of the new IMU. The latter uses a Front-End-Electronic with self-written firmware to convert and process the analog signals from the accelerometers. As a result, the scale factors, biases and misalignments of these sensors can be controlled against the data sheets and additionally, two noise characteristics were determined. Furthermore, the procedure was verified with a simulation that generated artificial sensor data from defined model coefficients.