Hi,
I'm Benoît, a recently graduated electronics engineer. One of the courses in my last year of studies was about automatic control (feedback control of dynamic systems) and was by far my favorite one, I would therefore be more than happy to help you with this project.
We have, during some laboratory experiments, implemented an inverted pendulum which has the same basic functioning principle as a self balancing vehicle, so I already have experience in this kind of regulation. Moreover, I have already implemented several regulation loops on different microcontrollers, so I'm experienced with this aspect of the project too.
I am used to working in a very systematic way when dealing with regulation problems, first measuring characteristics of the system to establish its transfer function, establish the regulator's transfer function from there, implement it, and finally test the regulation on the real system, making slight adjustments if needed (to take into account the non-idealities of the system).
Do not hesitate to contact me if you have any further question.