l2bot_examples

Examples for use with LTU's L2Bot

Installation

ROS

Install L2bot

Make sure you have gone through the installation procedure for the L2Bot interface:

• Installation instructions: https://github.com/LTU-AutoEV/l2bot

Install Examples

Clone this repository into the src directory of l2bot_ws created during the L2Bot install.

$ cd ~/l2bot_ws/src
~/l2bot_ws/src$ git clone https://github.com/LTU-AutoEV/l2bot_examples.git

Install dependencies

Joystick

~/l2bot_ws$ sudo apt-get install ros-kinetic-joy ros-kinetic-joystick-drivers

Camera

To use camera a camera with ROS, we must first install opencv.

~/l2bot_ws$ sudo apt-get install ros-kinetic-cv-bridge
~/l2bot_ws$ sudo apt-get install ros-kinetic-vision-opencv

rosdep Once other dependencies are installed, run the following command

~/l2bot_ws$ rosdep install --from-paths src --ignore-src -r -y

Build

Run catkin_make from the workspace directory.

~/l2bot_ws/src$ cd ..
~/l2bot_ws$ catkin_make
~/l2bot_ws$ source devel/setup.sh

Running the examples

If you get the following error, remember to run source devel/setup.bash from the workspace directory.

[NODE.launch] is neither a launch file in package [l2bot_examples] nor is [l2bot_examples] a launch file name
The traceback for the exception was written to the log file

forward: Sending commands to the L2Bot

This example makes the l2bot drive forward for 8 seconds.

roslaunch l2bot_examples forward.launch

joy_nav: Converting hardware input messages into L2Bot controls

This example allows the user to drive the l2bot with a joystick. This example is currently know to work with a basic Logitech controller.

roslaunch l2bot_examples joy_nav.launch

cam_pub and cam_edge_detect: Camera publisher, camera subscriber, and OpenCV

This example demonstrates how to publish and subscribe to images in ROS. It also demonstrates simple OpenCV library usage.

To change the input camera, you can change the source parameter in claunch/camera.launch.

roslaunch l2bot_examples camera.launch

stop_on_white: Controlling the L2Bot with camera input & dynamic_reconfigure.

The L2Bot will drive forward until the camera detects a large white object. This example demonstrates how to control the L2bot based on camera input only. This example also demonstrates how to use dynamic_reconfigure to adjust parameters while ROS nodes are running.

To change the input camera, you can change the source parameter in claunch/camera.launch. You may also need to change the threshold values in src/stop_on_white.cpp based on the lighting conditions in the environment.

roslaunch l2bot_examples stop_on_white.launch