Help with a navigation mobile robot

I am MSC student and I am working on my project which is a mobile robot for navigating and avoiding obstacles , now I am in the simulation stage , I have a dynamic model of mobile robot with PID controllers to control the velocity and angle of robot .To make a trajectory tracking I should tuning PIDs parameters so that the inputs (desired value) to the controller ( which is a circular path ) match with outputs (actual values) from model , the picture below showed trajectory tracking circuit which is to learn the controller with model so to make input values match output values from model after tuning PIDs parameters (Kp,Ki,Kd) with correct values . the values to the controller (velocity_d & theta_d ) which made a circular path , after matching the input of circular path with output of circular path , so now the trajectory tracking circuit is OK , now I should remove inputs (velocity_d & theta_d ) and substitute them with variables which come from other controllers which sense the environment by sensors or comes from algorithms and as in my project I used Artificial Potential Field algorithm which provide the controller the desired velocity and correct angle to avoid obstacles and reach to the goal . I don’t know if all my speech is correct or not because I am beginner with robotics field .

So the question is

1-what is the wrong thing in what I wrote above ?
2-is trajectory tracking circuit correct or not ?
3- is the model of robot which I used right or not ?
So please I need your help and guidance to go ahead correctly

Dears All

Please could any one help me ???

The questions you ask cannot be answered based on the information you posted.
Although the answer to 1. is “what you wrote seems consistent, if we assume certain basics are correct.”