IMU Plugin - ADIS16448 Noise Parameterization

[maximilian-nitsch]

Hi,

could you explain how you arrive at the parameterization for ADIS IMU:
https://github.com/uuvsimulator/uuv_simulator/blob/master/uuv_sensor_plugins/uuv_sensor_ros_plugins/urdf/imu_snippets.xacro
?

Especially the noise densitity values. The values do not correspond with the data sheet:
https://www.analog.com/media/en/technical-documentation/data-sheets/adis16448.pdf

Furthermore I do not exactly understand how the discrete model in:
https://github.com/uuvsimulator/uuv_simulator/blob/master/uuv_sensor_plugins/uuv_sensor_ros_plugins/src/IMUROSPlugin.cc
works.

// Compute exact covariance of the process after dt [Maybeck 4-114]
double sigmaBAD = sqrt(- sigmaBA * sigmaBA * tauA / 2.0 * (exp(-2.0 * _dt / tauA) - 1.0));
// Compute state-transition.
double phiAD = exp(-1.0 / tauA * _dt);

What is the exact name of the book (Maybeck)? As far as I understand, you discretize the continous covariance.

Best regards,
Max