CarND-Controls-PID

Self-Driving Car Engineer Nanodegree Program

Rubric Points

Describe the effect each of the P, I, D components had in your implementation.
- The 'P' or proportional component changes the steering of the car based on how far the car is from the center (CTE).
- The 'D' or differential component changes the direction of the car based on the change from previous CTE. This is useful to prevent the car from overshooting and swinging around the center. It reduces the steering angle as the car approaches the center.
- The 'I' or integral component is used to account for any initial steering bias. In this project the car starts with a steering turned to right, hence we need a small 'I' component to account for the initial turn.

I also used the PID controller for the throttle. To drive the throttle value, I used the absolute steering angle (reported by the steering PID controller) as the CTE. The idea was to reduce the speed if the car is changing direction. I used a small 'P' value to have a reduced speed if the car is turning at a constant steering angle. However, there is a larger 'D' value which ensures that the speed is dropped proportionally if steering angle is changing. The 'I' component is set to 0 since there is no bias to account for.

Describe how the final hyperparameters were chosen.

I chose to tune the parameters manually. First, I kept the throttle constant and started varying the 'P' and 'D' component till I could get the car to center quickly. Further down the track, the car started swinging. 'I' value stabilized that. Then, I started to control the throttle, as the speed increased the car became very unstable and started going over the ledges. Due to this, I had to re-tune the steering parameters which work reasonable with higher speed.

The current implementation does not feel to stable, by looking at how the car drives I believe the car may at some point, if left to keep doing laps, would go over or crash to the sides.

Car had better stability at a constant and low speed.

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.

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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psharm8 / CarND-PID-Control-Project