Realistic Velocity Calculation

[Joshua Sicz]

Originally Posted by GeeTwo

In order to even have a chance at making this work, you would also need a gyroscope. At each time step, you would have to rotate the previous time step's x and y by the amount of angle you've turned (theta), then add the change in speed. Assuming x is to the right and y is forward, and theta is rotation to the right, you'd have to do:

• ynew = yold*cos(theta) + xold*sin(theta) + yacc*rdelta
• xnew = xold*cos(theta) - yold*sin(theta) + xacc*tdelta

This is known as inertial navigation, and you can very quickly get lost in the intricacies if you're actually trying to use it for more than a few seconds, or in more than two dimensions, or across more than an area the size of, say, an FRC arena. Even staying in a 27-foot square box and limiting yourself to 2 minutes and 30 seconds, it would probably be a good idea to have a "reset" button that you can hit when the robot is actually stopped that sets both values to zero.

Awesome! We have actually played around we this exact thing this season and have got it to work with exactly they way you have said it to be done. Now I just need to get velocity from the x and y direction relative to the frame. Getting the code to output a realistic velocity because we get random numbers out of the accelerator.