CarND-Controls-PID

Self-Driving Car Engineer Nanodegree Program

Rubric Points

1. Your code should compile.

Code compiles with make and cmake.

2. The PID procedure follows what was taught in the lessons.

The PID class (defined in pid.cpp and pid.h) was used to calculate the steering value of the car in the simulator. The PID gains are initialised at the start of the simulation. On every update step, pid.UpdateError() calculates the new P, I, D errors. This is then used in pid.CalculateSteerValue() to calculate the output. I also calculated the total error in pid.TotalError() although this was mainly for debugging and twiddle purposes.

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

Kp is the proportional component - it is the gain applied directly to the CTE. It is directly proportional to the current CTE, hence a large CTE leads to a higher steering angle (in either direction). This can lead to oscillations which are resolved by the Kd component.

Ki is the integral component - it is the gain applied to the total accumulated error. It is required to offset against systematic bias in the controller (as seen in a PD-controller).

Kd is the derivative component - it is the gain applied to the rate of the change of the CTE. It is required to avoid overshoot and oscillations (as seen in a P-controller).

4. Describe how the final hyperparameters were chosen.

This was done through manual tuning. Although if I wanted better results, I would use twiddle to fine tune the coefficients further.

5. The vehicle must successfully drive a lap around the track.

It does!

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.

Fellow students have put together a guide to Windows set-up for the project here if the environment you have set up for the Sensor Fusion projects does not work for this project. There's also 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.

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./

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syedtaqi95/CarND-PID-Control-Project