stonkens / crazyflie_clean

A clean, extensible toolbox for running experiments on the Crazyflie 2.0 quadrotor.

crazyflie_clean

A clean version of crazyflie stuff...

Repository organization

This is a ROS repository. The main ROS workspace is, unsurprisingly, located in the ros/ directory accessible from the root of the repository. Within the ROS workspace, there are multiple packages (in ros/src/) pertaining to different aspects of the testbed. The core SDK is located in the crazyflie_ros directory (which contains multiple packages). This has not been altered in any meaningful way from the raw version availaible here. Other packages' functionality should be fairly clear from the name, e.g. crazyflie_lqr provides several LQR controllers, and crazyflie_state_estimator provides multiple different state estimators.

The general architecture of this repository is as follows. For any particular state space model, there is a corresponding message in crazyflie_msgs. Similarly, there is a corresponding state estimator in crazyflie_state_estimator that periodically pings tf and publishes state. External nodes can read this state and publish control messages (which may either be Control or ControlStamped, which are defined in the crazyflie_msgs package, or some other custom control message type such as NoYawControl). If custom control messages are published along with the built-in types, then you must provide a node to merge these into a single ControlStamped message. This is done for the NoYawControl type in the no_yaw_merger_node.cpp file in the crazyflie_control_merger package. Finally, for hardware demos, this ControlStamped message type is converted to a geometry_msgs/Twist by the cmd_vel_converter_node.cpp file in the crazyflie_control_merger package. This Twist is then processed by the SDK (crazyflie_server node) to go over the radio to the crazyflie. For software demos, no conversion to Twist is necessary as the crazyflie_simulator package can directly listen for ControlStamped messages.

Usage

First, make sure you have ROS installed on your system. The project was developed in Jade, but it should be compatible with anything past Hydro. Please let us know if you have any compatibility issues. You will also need to install the following external dependencies.

Dependencies:

• Gtest -- Google's C++ unit testing library
• Eigen -- a header-only linear algebra library for C++

To build this repository, navigate to the ros/ directory (the workspace), and run

catkin_make

Every time you open a new terminal, you'll have to tell ROS how to find this package. Do this by running the following command from the ros/ directory:

source devel/setup.bash

To run unit tests, type:

catkin_make run_tests

C++ reference materials

We attempt to adhere to the philosophy put forward in the Google C++ Style Guide. Our code is written for the reader, not the writer. We write comments liberally and use inheritance whenever it makes sense.

A few tips, tricks, and customs that you'll find throughout our code:

• Lines of code are no longer than 80 characters.
• The names of all member variables of a class end with an underscore, e.g. foo_.
• When iterating through a vector, we name the index something like ii instead of just i. This makes it super easy to find and replace the iterator later.
• We use the const specifier whenever possible.
• We try to include optional guard statements with meaningful debug messages wherever possible. These may be toggled on/off with the ENABLE_DEBUG_MESSAGES cmake option.
• Whenever it makes sense, we write unit tests for self-contained functionality and integration tests for dependent functions and classes. These are stored in the test/ directory.