Hi Ivan,
It appears that you are encountering issues with your PID controller for a self-driving car in MATLAB. The car does not drive in the centreline as expected, and when changing the route, the error increases. I'll help you by providing a checklist to debug and improve the PID controller:
1. Retune PID Gains: Adjust “kp_lat”, “kd_lat”, “ki_lat”, “kp_lon”, “kd_lon”, “ki_lon” to improve response.
2. Check Integral Windup: Ensure anti-windup is effectively preventing integral term accumulation.
3. Verify Steering Limits: Confirm “steering_angle_limit” matches vehicle dynamics and path requirements.
4. Adjust Velocity for Curvature: Ensure reduced velocity during high curvature is appropriate.
5. Validate Trajectory: Make sure the trajectory is accurately interpolated and represents the desired path.
6. Examine State Update: Ensure the “update_state” method accurately reflects vehicle dynamics.
7. Control Input Smoothing: Confirm the low-pass filter factor is balanced for response and smoothness.
8. Error Calculation: Verify CTE calculation in “compute_error” is correct and represents lateral error accurately.
9. Simulation Parameters: Check time step (“ts”), number of steps (“N”), and initial conditions for realism.
10. Use Visualization: Plot trajectory, vehicle path, and control inputs to identify issues.
11. Search for Bugs: Review code for errors, especially in units and coordinate transformations.
12. Test Varied Conditions: Evaluate controller performance under different speeds, trajectories, and road conditions.
13. Consider External Factors: Account for road grade, friction, and environmental effects on vehicle control.
Hope this helps.
