Troubleshooting Accelerometer Data: Plotting and Interpreting Results

[math111]

What I am trying to do:
I am placing my accelerometer [parallax BS2] ontop of my amigobot. I move the amigobot 1 meter foward with the acceleromter ontop while taking data for x and y direction. I then read the data to my computer and plot it.

Data:
The plot shows the data jumping up and down as time increasing and then it begins to decrease until it hits 0 again.

What I know :
Acceleration in this case should be like a trapezoid going up based on the increase in velocity and then reaching a constsant velocity(accell is 0) and then coming back down to 0 when the amigobot reaches 1 Meter. It would be pretty difficult to integrate the area underneath this because it looks like there is a lot of noise invlove and that could be affecting it.

Issue: I am not sure why my data is jumping up and down. I never used an accelerometer before so this is proving the textbook stuff right but I am not in this situation I am having.

Thank you if anyone can help.

 

[A.T.]

The plot shows the data jumping up and down as time increasing and then it begins to decrease until it hits 0 again.

So it accelerates, decelerates and ends up at zero acceleration? Isn't that how you move it?

Acceleration in this case should be like a trapezoid going up based on the increase in velocity and then reaching a constsant velocity(accell is 0) and then coming back down to 0

So first it should be 0 and then come down to 0?

 

[math111]

So it accelerates, decelerates and ends up at zero acceleration? Isn't that how you move it?


So first it should be 0 and then come down to 0?

Here is my data if it helps. I am just concerned about the up and down. I did an initial without movement and then 3 runs.(from starting at 0 to 1 meter)