Update logging tool and control

[borisdayma]

Following features have been implemented:

• logging separates pid for throttle and braking
• logging is enabled even if dbw is set to 0 (manual)
• logging was added for traffic light detection
• csv log files are now within specific instance directory "log/latest"
• there was an issue with the integral portion of PID (due to wrong update of intermediate value). In addition it was not capped and could grow high.
• steering is controlled using a lowpass filter. The issue with pid is that it is based on steering_error = target_steering - current_steering. However current_steering cannot be measured properly (we could only have used previous value). The Yaw Controller is supposed to already predict steering, which we make smooth by using the lowpass filter
• Feedforward was removed due to differences of calibration between Carla and simulator. Also due to the range of feedforward and pid, the command throttle could have discontinuous range.
• adjusted parameters for throttle PID based on trial and error (see below graph)
• set parameters for brake PID as percentages (due to undefined calibration on Carla vs simulator) and adjusted based on trial and error
• we added low pass filters to all commands, which create a smoother control, especially for braking.

[taikione]

I have confirmed this pr work correctly. thank you boris.

logging is enabled even if dbw is set to 0 (manual)

Does this dbw mean self.log_to_csv on dbw_node.py L72?

[borisdayma]

Yes that is correct Taiki. It also means the change at L82 ensures that the loop is executed even when dbw is False. The only value it does not get executed is when it is None (meaning it has not been initialized through self.upd_dbw_enabled yet). I only added a new modification to stop closer to lights.