CarND-Controls-MPC

Self-Driving Car Engineer Nanodegree Program

Rubic points

The Model

I used the kinematic model. Its update equation are shown as below.

States are shown as below table.

variable	meaning
x	x-position of the car
y	y-position of the car
	heading direction
v	velocity of the car

Actuators are shown as below table.

variable	meaning
a	throttle
	steering angle

Meaning of other variables are shown as below.

variable	meaning
cte	cross track error
	heading direction error
	destination value of heading direction
	the distance between the center of mass of the viecle and the its front axle

Timestep Length and Elapsed Duration

I selected time step length N = 10 and elapsed duration dt = 0.10. I changed N between 10-70 and dt between 0.10-0.20. The lecture said "T should be as large as possible, while dt should be as small as possible". Because smaller dt gives finer resolution prediction and larger N gives the prediction far away. But larger N gives much computational time too. So I selected small dt(0.10) and small N(10). N=10 was enough to solve this project in the case reference velocity is 50mph.

Polynomial Fitting and MPC Preprocessing

The waypoints are preprocessed to transform them to the coordinate system which origin is car's position and direction. Polynomial fitting is used for them.

Model Predictive Control with Latency

I deal with latency in src/main.cpp(L125-134). I used kinematic equations to predict the states for after 100ms and send them to MPC.

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.
Ipopt and CppAD: Please refer to this document for installation instructions.
Eigen. This is already part of the repo so you shouldn't have to worry about it.
Simulator. You can download these from the releases tab.
Not a dependency but read the DATA.md for a description of the data sent back from the simulator.

Basic Build Instructions

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

Build with Docker-Compose

The docker-compose can run the project into a container and exposes the port required by the simulator to run.

Clone this repo.
Build image: docker-compose build
Run Container: docker-compose up
On code changes repeat steps 2 and 3.

Tips

The MPC is recommended to be tested on examples to see if implementation behaves as desired. One possible example is the vehicle offset of a straight line (reference). If the MPC implementation is correct, it tracks the reference line after some timesteps(not too many).
The lake_track_waypoints.csv file has waypoints of the lake track. This could fit polynomials and points and see of how well your model tracks curve. NOTE: This file might be not completely in sync with the simulator so your solution should NOT depend on it.
For visualization this C++ matplotlib wrapper could be helpful.)
Tips for setting up your environment are available here
VM Latency: Some students have reported differences in behavior using VM's ostensibly a result of latency. Please let us know if issues arise as a result of a VM environment.

Editor Settings

We have kept editor configuration files out of this repo 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. We omitted IDE profiles to ensure 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 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. 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./

tanutarou/CarND-MPC-Project