Inertial Navigation System (GF-INS)

Optomechanical accelerometers

Researchers Involved:

LASSO has developed compact optomechanical accelerometers with lower noise floors and larger bandwidth.
Why Gyro free INS? Any trajectory consists of translations and rotations. Rotations are always more challenging to deal with. Usually, gyroscopes are implemented for it, but high-grade gyroscopes can be bulky, expensive and energy consuming. Here we obtain all translations and rotations (with both positive and negative, constant and non-constant angular acceleration) with linear accelerometers only, which potentially can result in accurate, compact and cost-effective INS
Operation: We need to model the performance of established configurations, using technical parameters of our optomechanical accelerometer. We developed a universal Quaternion-based algorithm in Matlab for a cube configuration INS with six accelerometers.
We worked out several simple examples to test this algorithm for linear and circular trajectories for ex., helix, horizontal pendulum, parabola, bouncing ball.
Future work: If the model predicts significantly improved performance on existing iterations, we will design, fabricate, and test this opto-mechanical GF-INS.

We demonstrated that the algorithm is in a very good agreement with reference trajectories obtained with the same initial parameters but without gyro-free elements. Also, we confirmed these results with Python.
The below videos show, rotations with and without misalignment. This misalignment is introduced at the right bottom corner of the configuration matrix of 6 accelerometers. Two trajectories, reference (red) and gyro-free (blue) are shown. Without misalignment, reference and gyro-free trajectories coincide to the numerical error (~10-14). All these rotations are obtained with LINEAR accelerometers ONLY.