Flying Car Project

The Teleop Package

The teleop package, since it has the control interfaces between the Crazyflie and the user, is has the most frequently launched files.

The Launch Files

• start_mocap.launch - Front end for starting mocap teleop for one or more Crazyflies. Starts server, mocap, and RVIZ.
  Parameters:
  • name (required!): name of the Crazyflie, defined in the crazyflie_driver/config folder
  • number: Rigid Body number of the Crazyflie from Optitrack. Also the Robot_X prefix from mocap_optitrack.
  • path_name: file defining the robot's path. Relative to crazyflie_teleop/paths/.
• hover_mocap.launch - Called by start_mocap.launch to add Crazyflie to server and setup navigation goals and flight controller.
  Parameters:
  • Same as start_mocap.launch.
• start_teleop.launch - Front end for joystick operation of the Crazyflie. Launches server and script for switching between multiple Crazyflies.
  Parameters:
  • name: name of the Crazyflie.
• teleop_ps3.launch - Adds Crazyflie with joystick control.
  Parameters:
  • Same as start_teleop.launch

The rest of the files should not be explicitly launched by the user. They are launched from within other files. The RVIZ-related files display the Crazyflie's position.

localization.launch is a launch file for the package robot_localization. It mixes the Crazyflie's IMU data with the mocap position data so we can ignore the (currently) incorrect orientation data. Anything directly outputed from the localization node will be of type PoseWithCovarianceStamped, in contrast to the normal PoseWithCovariance. This is an issue if you are writing a subscriber node. The current issue is that the coordinate system for the optitrack system is Y-up, while ROS expects a Z-up system. Adjusting the position to the right system is trivial, but adjusting the quaternion orientation is tricky and has not been implemented correctly.

The Paths Directory

The Teleop package includes the directory /paths, which contains flight path files for the Crazyflie to follow during mocap teleop. The filenames should not include spaces, and do not need a file extension. The format of the files are one waypoint per line of the file, in the form x pos, y pos, z pos(, hover time in seconds). Hover time is only needed if you plan to fly in mode 3, which includes a wait time after the Crazyflie has reached its position to move on to the next point.

Waypoint Navigation

The flight paths are defined as stated above. The file takes in 2 inputs, flight mode and the file name of the flight path. There are 3 currently-implemented modes:

1. Crazyflie moves to next point upon user hitting enter on the keyboard
2. Crazyflie moves to point, stabilizes, ansd continues to next point.
3. Crazyflie moves to point, stabilizes, waits for defined period, and continues to next point.