We're busy with a project, we are building a 'stabilized duocoper system' with two DC motors, they have to make the 'arm' stable, so when it goes more to the right the left motor has to turn more fast to make the angle zero, so that it stands vertical on the earth.
My question is, how do I make the mathematical model, my controller is a PID-controller, but what is there in my 'system block', I think my DC motors but what else, and how do I've so put them in my mathematical model?