Trail

D-Bug's trajectory planning utility for the 2019 Destination: Deep Space season

Cloning

The project uses googletest and Eigen as Git submodules, which means that in order to clone the project you need to use --recurse-submodules:

git clone --recurse-submodules https://github.com/team3316/trail.git

Compiling

The project uses CMake in order to build. First, create a build directory and cmake inside of it:

mkdir build && cd build && cmake ..

Then just make as usual:

make

Testing

In order to test the project, follow the steps above for compiling but use make test instead.

Usage

In order to generate profiles, the program requires two JSON files: a robot configuration and a profile definition.

Creating a robot configuration JSON

This file holds relevant information about the robot the profile is generated for. Currently, the profile generation supports only robots that use tank drive (no swerve or mechanum or anything crazy like that), and ones that have the same transmission in each side and that have the same motors all around (no 2 CIM and 1 Mini CIM configurations allowed).

The file should include the following properties:

• mass - The mass of the robot in kg.
• base-width - The wheelbase width (wheel center-to-center) in m.
• free-speed - The free speed of the transmission in m/s.
• stall-torque - The stall torque of the motors in the transmission in Nm.
• gear-ratio - The overall gear ratio of the transmission as output over input.
• wheel-radius - The radius of the wheels on the drivetrain in m.
• motors - The total number of motors on the drivetrain.

Other drivetrain types and transmission configurations are planned for a future release.

An example JSON is provided in the example folder.

Creating a profile definition JSON

This file holds relevant information about the motion of the robot on the field.

The file should include the following properties:

• name - The name of this motion sequence. This will be used for the name of the CSV export file and is required.
• waypoints - An array of locations of the robot on the field. Each object inside the waypoints array has to include these properties:
  • point - A 2D array, with the x-y location of the center of the robot on the field.
  • heading - A number representing the robot's heading angle in angles (not radians).

Other inputs may be added in a future release.

An example JSON is provided in the example folder.

Using the tool

After downloading and compiling, you should have an executable called trail in the build folder. Using the JSON files you just created (let's call the robot one robot.json and the profile path.json), execute the following command:

./trail robot.json path.json

This should create a new CSV file in the current directory with the name of the path and the profile data inside of it.

And that's basically it!

Another option is to output the whole profile for viewing in Desmos. In order to do that, you just need to use the -d or --desmos flag:

./trail robot.json path.json --desmos

Then just copy and paste the output into Desmos and you should be able to see the graphs of the profile (distance vs time, x vs y...)