ADIS16470 - exceeding 40 g

Hello,

I am building a model rocket for an extracurricular project at my school and the rocket will peak at 60 (!) g of acceleration. I wanted to know if the behaviour of the ADIS16470 IMU or any other 40 g accelerometer for that matter was known after it has saturated. Once the acceleration reduces underneath its maximum of 40 g, does it behave normally? Or does it have a sort of bias that would need to be accounted for afterwards? I am currently torn between using this IMU as-is or rotating it to be angled to split the 60 g of acceleration evenly between all three axis and therefore bringing it under 40 g.

Additionally, if someone had any advice or could point me towards a better solution where I wouldn't run into this limit. Perhaps if another known IMU can handle the 60 g of acceleration, or if I would be better off using a 3-axis accelerometer and gyroscope triad separately.

Thank you!

Joshua

  • 0
    •  Analog Employees 
    on Mar 1, 2021 4:15 PM

    Hi ,

    Sorry for the late response. 
    Here's a snippet from the datasheet:

    ABSOLUTE MAXIMUM RATINGS

    Table 3. Parameter Rating

    Mechanical Shock Survivability
    Any Axis, Unpowered 2000 g
    Any Axis, Powered 2000 g

    Stresses at or above those listed under Absolute Maximum Ratings may cause permanent damage to the product. This is a stress rating only; functional operation of the product at these or any other conditions above those indicated in the operational section of this specification is not implied. Operation beyond the maximum operating conditions for extended periods may affect product reliability.

    As for now, our IMUs have a max. acceleration range of 40g. 

    Hope this helps. 

    Best regards,
    John

  • +1
    •  Analog Employees 
    on Jun 19, 2021 1:21 AM

    Hi Joshua,

    How are things going with your project?  Just to add to what John has offered, we are not aware of any residual bias that will come from exposing these accelerometers to 60g of acceleration.  I hope that helps. 

    NevadaMark

  • Hi NevadaMark,

    Thank you for your answer. Last week we just did a first launch with our rocket at a lower altitude and speed, bringing the total acceleration to around 10g. While I haven't analyzed the data yet, it looks quite good I must say! We have another launch next Saturday with similar conditions for some more tests, as sadly the rocket didn't land properly and was slightly damaged.

    The full test at 60g should be at the end of July. Great to hear that there is no known residual bias from exposure above the maximum range.

    Thank you,

    Joshua