Improving measurement quality of a MEMS-based gyro-free inertial navigation system

• A new solid carrier frame for installation of 5 MEMS 3-axis accelerometer.
• Removing spikes and noises from the output of the accelerometers.
• Participate all accelerometers according to their measurement quality.
• Introducing k-highest correlation analysis for assessing signal quality.

This paper introduces a solution for increasing the measurement quality of the Micro Electro Mechanical System (MEMS) accelerometers in practical applications. This solution consists of two divisions. The first division is a solid carrier with five planes on each of which, a 3-channel MEMS accelerometer is installed. The second division of the proposed solution is a novel but simple-structured software designed for achieving two crucial targets: removing spikes and noise from the output of the accelerometers without having any a priori information about the desired frequency bands. The second mission of the processing software is to participate all accelerometers according to their measurement quality for determining the solid case accelerations. The criterion for ranking the channels of the accelerometers is based on their correlation index with the most informative channels among all operating accelerometers. By some simulation studies, the accuracy of the proposed solution for correct identification of spikes is about 99.99%. Also, by adding randomly the random-walk noise and spikes to the channels of the embedded accelerometers and then by altering the amount of input noise, the relative error of the rigid body acceleration is obtained versus input acceleration quality. As an instance, by implementing the proposed noise and spike reduction algorithm to a measurement signal with the quality value about 0.90, the relative navigation error-rate is enhanced from 0.75 s−1 to 0.1 s−1 for linear positions and 1 s−1 to 0.12 s−1 for angular attitudes. Also, the full-scale error-rates associated with the aforementioned relative-error rates are 0.28 s−1, 0.02 s−1, 0.2 s−1, 0.01 s−1, respectively.