Using imufilter and ahrs filter

Hi,

I am using imufilter to fuse some accelerometer and gyro measurements I have. How do I input the initial orientation of the sensor? Is it needed or is it calculated using the initial measurements? (Don't know how it is possible,,)

Any help much appreciated.

Sharada

Answer 1

[Benjamin9119]

Hi Sharada,

The orientation of the sensor is estimated using the initial measurements (acceleration, angular rate, magnetic field strength). The accuracy of the orientation estimation seems to be highly dependant on correctly setting the filter parameters (this may require some 'tuning' or trial and error for some of the parameters).

Best, Ben

Answer 2

[Joseph]

Hi Sharada,

The gyroscope would give you angular velocities, which can give you the orientation from a starting point. When combined with an accelerometer, the accelerometer can then be used to measure the direction of gravity and then would have an initial 'down' direction towards gravity. See here.

The accelerometer and gyro measurements are passed directly to imufilter to output the orientation.

FUSE = imufilter;
[orientation,angularVelocity] = FUSE(accelReadings,gyroReadings)

If you have a magnetometer as well, then you can use ahrsfilter to get the orientation.