Modeling Electronic Throttle Control (ETC) in Simulink. (Formula Student Project)

I am a Formula Student member and currently trying to develop the ETC(Electronic Throttle Control) system of an internal combustion engine.

So I'm trying to figure out a way to implement a closed loop system model in Simulink with the following requirments. One servo motor as throttle actuator, one Throttle Position Sensor (TPS) which measure the throttle opening angle, one poteniometer which measure the accelerator pedal position and an ECM (Engine Control Module) which takes as inputs two signals, the one from the potentiometer and the other from the TPS.Then the ECM calculates the difference between the expected throttle position(accelerator pedal position signal) and the actual throttle position(throttle position signal), in order to determine the servo motor control and thus control the opening angel of the throttle. So I was wondering if there is already a similar existing model implemented or if I could get any help?

p.s. I have already learned of PID tuning controlers which are neccesary for the purpose of this project , but I'm realy finding it hard to the find the differential equations which discribe the behavior of the throttle actuator(servo) . Should I use a diffrent method to achieve the parameterization of the servo?