CarND-Controls-PID

Self-Driving Car Engineer Nanodegree Program

Dependencies

cmake >= 3.5
All OSes: click here for installation instructions
make >= 4.1(mac, linux), 3.81(Windows)
- Linux: make is installed by default on most Linux distros
- Mac: install Xcode command line tools to get make
- Windows: Click here for installation instructions
gcc/g++ >= 5.4
- Linux: gcc / g++ is installed by default on most Linux distros
- Mac: same deal as make - [install Xcode command line tools]((https://developer.apple.com/xcode/features/)
- Windows: recommend using MinGW
uWebSockets
- Run either ./install-mac.sh or ./install-ubuntu.sh.
- If you install from source, checkout to commit e94b6e1, i.e.
```
git clone https://github.com/uWebSockets/uWebSockets
cd uWebSockets
git checkout e94b6e1
```
  Some function signatures have changed in v0.14.x. See this PR for more details.
Simulator. You can download these from the project intro page in the classroom.

There's an experimental patch for windows in this PR

Basic Build Instructions

Clone this repo.
Make a build directory: mkdir build && cd build
Compile: cmake .. && make
Run it: ./pid.

Tips for setting up your environment can be found here

Editor Settings

We've purposefully kept editor configuration files out of this repo in order to keep it as simple and environment agnostic as possible. However, we recommend using the following settings:

indent using spaces
set tab width to 2 spaces (keeps the matrices in source code aligned)

Code Style

Please (do your best to) stick to Google's C++ style guide.

Project Instructions and Rubric

Note: regardless of the changes you make, your project must be buildable using cmake and make!

More information is only accessible by people who are already enrolled in Term 2 of CarND. If you are enrolled, see the project page for instructions and the project rubric.

Rubric points - Reflection

Describe the effect each of the P, I, D components had in your implementation.

P component:
- The proportional portion will steer vehicle back towards the centre of the road. However it easily overshoots, and will drive the vehicle on "S" path and end outside of the road.
- An example can be seen at the recoded video: Video_PID_Controller_P (./video/Video_PID_Controller_P) with PID = [1,0,0];
I component：
- The integral portion will compensate the bias of the system. In this case, the simulation has no bias involved. If we still set the integral portion, the vehicle will run along a circle.
- An example can be seen at the recoded video:Video_PID_Controller_I (./video/Video_PID_Controller_I) with PID = [0,1,0];
D component：
- The differential portion will counteract the overshooting condition caused by P component, and try to control the vehicle to converge to the centre of the road smoothly.
- An example can be seen at the recoded video: Video_PID_Controller_D (./video/Video_PID_Controller_D) with PID = [1,0,1];

Describe how the final hyperparameters were chosen.

The final hyper parameters were decided based on both manual tuning and twiddle algorithm. It started from manual tuning. Set parameters all to zero, and checked if the vehicle can go straight or not. The video showed it can. So estimated the I component will be very small or zero. To minimise the total error, then started to in crease P component, and modified D component accordingly to compensate overshooting. When the car would not go outside of the road, I used twiddle algorithm to even improve the performance, which was evaluated by total error.

At last, the PID parameter was defined as [0.135, 0, 2.25]

Hints!

You don't have to follow this directory structure, but if you do, your work will span all of the .cpp files here. Keep an eye out for TODOs.

Call for IDE Profiles Pull Requests

Help your fellow students!

We decided to create Makefiles with cmake to keep this project as platform agnostic as possible. Similarly, we omitted IDE profiles in order to we ensure that students don't feel pressured to use one IDE or another.

However! I'd love to help people get up and running with their IDEs of choice. If you've created a profile for an IDE that you think other students would appreciate, we'd love to have you add the requisite profile files and instructions to ide_profiles/. For example if you wanted to add a VS Code profile, you'd add:

/ide_profiles/vscode/.vscode
/ide_profiles/vscode/README.md

The README should explain what the profile does, how to take advantage of it, and how to install it.

Frankly, I've never been involved in a project with multiple IDE profiles before. I believe the best way to handle this would be to keep them out of the repo root to avoid clutter. My expectation is that most profiles will include instructions to copy files to a new location to get picked up by the IDE, but that's just a guess.

One last note here: regardless of the IDE used, every submitted project must still be compilable with cmake and make./

How to write a README

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AaronLPS / CarND-PID-Control-P9