track position using a feedback

Hi, I have designed a controller using simulink. This model controls the velocity reference. Now,i want to give the controller a position reference and it should be able to reach the position given as the reference. For this, the following steps follow:

1) Position reference is given 2) Position converted to velocity signal 3) Velocity will be controlled until the vehicle reaches the defined position

I have seen the second order integrator which converts the given velocity into position, But i am not quite sure as to how to use this. Any help is much appreciated

Thank You

Answer 1

[Naty Shemer]

Hey,

It's a bit hard without a code example. In general once you have managed to complete the velocity loop and control it as desired it is now defined as the inner loop. You need to complete the PID (or different controller) for the outer loop.

[karthik pakala]

Thank You Naty for your response. I have tried to do that and surprisingly i get the signal starting at the value specified as the reference and is stabilizing at double the value. i.e., if i give the system '10' as the reference to track, this is what i get(please refer the figure)

the major problem comes using the differentiation and integrator blocks. They integrate it numerically resulting in a zero change in the position while the system actually has some constant velocity which makes no sense for real scenario.If i can get the position out of the velocity vector which should be changing with a constant velocity as in the real environment, the problem is solved.(Here, once the velocity is constant the position is simply settling at zero as opposed to a constant position change)

any advice is much appreciated thank you