Question
I would deeply appreciate your help in getting a clear picture of the error
budget of ADXRS300.
1)The acceleration sensitivity , DC as well as vibrations.
2)What is the rationale behind acceleration sensitivity in rate axis
orientation?
3)The Null behavior, short and long term stability, temperature sensitivity.
4) Noise characterization
Answer
1. There is no guaranteed maximum figure for the sensitivity to linear
acceleration. The typical DC sensitivity is 0.2deg/s/g.
The ADxRS150 rev B and ADxRS401 Rev 0 datasheets have some more graphs that are
not present in the ADxRS300 Rev A datasheet and which show the sensitivity to
shock as well as random vibration.
2. I'm not sure understand the question. The rate axis is shown on the figure 2
of the ADxL300 datasheet. Page 7 of the ADxRS150 datasheets shows that the
gyros are slightly less sensitive to acceleration in the rate axis than in the
lateral or longitudinal axis.
3. We have some data for the case where the gyro output is integrated wrt time
to get the direction signal. In this case the null variation is the dominant
error source
- The temperature dependence of the ADxRS150/300 null point is the largest
effect. Three-point temperature calibration can reduce the integrated error to
about 300deg per hour.
- The long term stability of the ADxRS null point (with no temperature
variation) is characterised by an Allen varaince of about 75deg/hour.
Our life test data indicates about 3 degrees/sec null drift over a typical 10
year life. Sensitivity is essentially unchanged over life. All our data sheet
specifications include shifts over life for all parameters.
4) The ADxRS150 datasheet, revB page 11 gives the noise spectral density of the
part - also applicable to the ADxRS300 (multiply the noise by 2).