IMU Model: how to specify the bias correlation time?

Hi,

I'm tryng to set up the simulation of a gyroscope, and I'm interested in the stochastic errors only. To do so, I identified on the Allan variance curve the following parameters that I can then set in the the gyroparams for simulation:

• NoiseDensity (Angle Random Walk), generally noted N in the litterature
• BiasDensity (Bias instability), generally noted B
• RandomWalk (Rate Random Walk), generally noted K

There parameters are sufficient to launch a simulation of the stochastic errors with a gyro sensor model in Matlab.

However, following the reference [1], there is also the parameter Bias correlation time noted T that can be measured on the Allan variance curve, but I can't find how to specify it in the gyroparams.

I have therefore two questions:

1. Does the fact that we can't specify this bias correlation time comes from the fact that Bias is modelled differently in Matlab (instead of a first-order Gauss-Markov model)?
2. Is there a way to incorporate this parameter to the simulation still?

Thank you.

[1] J. A. Farrell, F. O. Silva, F. Rahman, and J. Wendel, “Inertial Measurement Unit Error Modeling Tutorial: Inertial Navigation System State Estimation with Real-Time Sensor Calibration,” IEEE Control Syst., vol. 42, no. 6, pp. 40–66, Dec. 2022, doi: 10.1109/MCS.2022.3209059.

Answer 1

[Ryan Salvo]

Hi Thomas,

Unfortunately, the Bias correlation time, T, cannot be directly specified on the gyroparams object. However, starting in R2023b, the BiasInstabilityCoefficients can be specified to incorporate this parameter into simulation.

Thanks,

Ryan

[Thomas]

Hi Ryan,

Thank you very much for the update. Look forward to it. I'll develop my own model for now.

Thomas