Gyroscope Output Noise - BMI088

[shsu]

Hi all,

I am testing BMI088 on a rate table (benchmark) and see how it performs. The following is the plot for the x axis.

The rms of the noise is increasing from 0.4 to 1 deg/sec as the rate goes up. The output density in the datasheet is 0.014 deg/sec/sqrt(Hz) and the BW=32 in my case, so the rms should be around 0.08 deg/sec. This is way smaller than what I got especially when increasing the rate.

Is this normal? If not, what may cause the issue?

Thanks!

[FAE_CA1]

Hi,

The RMS noise level of BMI088 gyro (1-sigma) = noise density * sqrt(1.22 * BW), where 1.22 is the coefficient of the internal low pass filter. So at 32Hz BW, the RMS noise level (1-sigma) = 0.014 dps/rt(Hz) * sqrt(1.22 * 32Hz) = 0.087dps.

Thanks.

[Crane]

This is actually very old topic and already solved but I would like to give some feedbacks as well. This is not a stochaistic noise alone it is a deterministic noise and called Scale Factor nonlinearity. The gyroscopes'  Scale factor can change depending on the rate. This is why you get different noise levels at different rate outputs.