Can we Calculate Speed using MMA8451Q Accelerometer

[ranjithhebbar]

Hi All,

  I am using MMA8451Q Accelerometer and that one will be placed in the moving object, It will give X, Y and Z values. From those x,y,z values  whether it is possible to determine  speed and aceleration of a moving Object.

[markpedley]

The answer if unfortunately a definite "No". Accelerometers measure acceleration plus gravity with some measurement error. Integrating acceleration to get velocity and integrating a second time to get displacement simply results in the measurement errors also being integrated without limit. Within a couple of seconds maximum the velocity and displacement will be highly inaccurate and these errors will increase linearly and quadratically with time and without limit.

[david_diaz]

Hello to all,

If the acceleration of an object is known, we can get a proportional approximation of the velocity data if an integration is applied.

Unfortunately we do not have any updated document with information about how to do this with one of our new accelerometers, however, we do have an application note that mentions how to calculate velocity (and positioning) using the accelerometer MMA7260 (which is no longer manufactured), that can be used as a reference.

Implementing Positioning Algorithms Using Acceleromenters - AN3397

In case it is useful for you, please find sample code for the MMA8451 at:

MMA8451Q - Bare metal example project

I hope this information will be useful for you.

Have a great day.

David Diaz.

[pankajrana]

Can anyone respond on this one ?

Has anybody tried calculating the speed using Accelerometer "MMA8451Q"