lemonbot

Drivers for the Lemonbot hardware platform.

Bringup the system

roslaunch lemonbot_bringup all.launch

Control the PTU using the terminal

Bringup the system, see this section

and now request a new position

rostopic pub /ptu/cmd sensor_msgs/JointState "header:
seq: 0
stamp: {secs: 0, nsecs: 0}
frame_id: ''
name: ['ptu_pan','ptu_tilt']
position: [0.5,0.1]
velocity: [1,1]
effort: [0]"

Single Acquisition Mode

To take a single acquisition just execute the launch file in lemonbot_acquisition single acquisition with the specific parameters.

roslaunch lemonbot_acquisition single_acquisition.launch min:=-90 max:=90 vel:=10

System calibration

Calibration files

There are two calibration files, for the extrinsic calibration of both the camera and the laser. These files are located under lemonbot_calibration/calibration. They look like:

xyz: [0, 0, 0]
rpy: [0, 0, 0]

These files are automatically loaded to the robot_description using the xacro preprocessor.

Remote connection through SSH

It it possible to connect to the lemonbot through a ssh connection, using the wifi provided by the router in the mobile station. The first connection can be made by ssh'ing into the portable computer using the command

ssh <ip of the computer> -l lemonbot

The username and password are both lemonbot.

Passwordless login

To facilitate the login, we can use a public-private key. To do so, create a key pair in the client machine with the command ssh-keygen -t rsa and the copy the public key to the lemonbot computer using the command ssh-copy-id lemonbot@<ip of the computer>. Now use the first command to login without a password.

wstool for dependency management

Download lemonbot.rosinstall

A .rosinstall file contains the package dependencies and the versions for all the packages required to use with the lemonbot package, including their repositories (git).

To download the lemonbot.rosinstall, use the following command:

wget <lemonbot.rosinstall>

Initialize a src folder for the packages.

Then in the same folder as the .rosinstall file, clone all the dependencies into the folder src:

wstool init src lemonbot.rosinstall

To update all the repositories, just use the update command of wstool:

wstool update -t src

Note: to execute the command faster, use multiple jobs to parallelize the clone/pull, with the argument -j8.

Calibrations

Intrinsic calibration of the RGB Camera

Extrinsic calibration of the RGB Camera to the PTU (hand2eye calibration)

To start the lemonbot in calibration "mode", roslaunch the lemonbot_calibration/manual_control and the lemonbot_calibration/extrinsic_calibration and like so:

roslaunch lemonbot_calibration manual_control.launch
roslaunch lemonbot_calibration extrinsic_calibration.launch fiducial_len:=0.093 fiducial_id:=10

Then start the calibration client to capture all the required poses and follow it's instructions

rosrun lemonbot_calibration calibrate_rgb_camera.py