Re: Filtering out Vibration while using a KOP Accelerometer
 

I believe this has been discussed in other threads, but if not, here's a short answer.

Yes, rotation has to be considered as well. However, gyro's are in general much, much more accurate that accelerometers.

Among the reasons is the fact that gyro gives you change in angle so only a single integration is necessary as compared to the double integration of accelerometers. Also, in general, vibrations and other forms of noise will cause small accelerations more so than they will cause torques and rotations. In the 3D case you also have to worry about subtracting out the gravity vector (gravity is identical to an acceleration), whereas the earth's rotation can more justifiably be ignored.

I'm sure the physical mechanism plays a role in the difference of reliability as well, but I don't know off the top of my head what the exact mechanisms are.

So yes, this is a source of error. If you're using accelerometers though, they will almost surely dominate your error.

As for wheel odometry vs. accelerometers, I would strongly suggest wheel odometry. Once more, in wheel odometry (like a gyro), you only have a single integration, which bounds the error growth more reasonably. It is again largely an issue of single vs. double integration.

However, even with wheel odometry, gyro is still going to be very useful in keeping track of your orientation since most forms of rotation involve wheel-slip, making an odometry-based rotation estimate hard to do accurately.

Re: Filtering out Vibration while using a KOP Accelerometer
 

You may want to try the gear tooth sensors that came in the kit. You mount them in your gear box, then you can sense FWD/REV direction with accelerometer and pwm outputs to the motor.