Frequency of Gyroscope

I am using 400 Hz to collect data on the MMR sensor, however when I export the data from the MetaBase App to my computer and read it into MATLAB, the time values are not consistently spaced. There are 405 data points per second and the difference between subsequent values ranges from 0.003s and 0.001s. Over a large range this might not be a huge concern, but when integrating the gyroscopes angular rate data over a very small time step, this discrepancy could make a big difference in the angle calculated. Does anyone have any comments or advice regarding this issue?

Comments

  • Are you streaming or logging?

  • edited June 23

    @Laura said:
    Are you streaming or logging?

    I am logging, not streaming.

    Does this make a difference?

  • edited June 24

    I don't see any issues when I log at 400Hz on my MMR.
    Can you elaborate? Post data, be more specific about expectations versus reality and so on.

  • edited June 25

    Here is a screenshot of the data exported from the MMR into Excel. I expected the time difference between data points to be 1/400s (0.0025s), however this is not the case. Under elapsed (s) column, some data points appear to be collected 0.001s apart, others 0.002s apart, and others 0.003s apart thus the sensor is not sampling at consistent frequency.

  • edited June 28

    Take a look at the epoch instead, don't use the time elapsed.
    Also note this is all within the acceptable error rate for bosch sensors + bluetooth latency.

Sign In or Register to comment.