Figure 2.
rosrun teleop_twist_keyboard
teleop_twist_keyboard.py
If everything has been done
right, you should get instructions
on the screen about how to
control the robot. The robot
should now react to the proper
key presses.
This handy program can be
used to control the robot while
mapping, or any other purpose
which involves controlling the
Neato robot manually from a
distance.
Visualizing the
LiDAR Data
Maximize it and change the Topic to /base_scan. As soon
as you press Enter, you will see a collection of points on the
grid. This is your live laser data visualized (Figure 2).
To read the laser data that is constantly steaming from
the Neato, we will need to look at an ROS topic. Topics are
specific names that a node uses to pass data to other
nodes — one node publishes, the other subscribes, and vice
versa. After you have launched the neato_node, you can
view all the topics currently open by running the command
rostopic list in a new terminal window or tab. You will
see a list containing topics such as /base_scan (laser data)
and /cmd_vel (motor control).
Of course, this is only the tip of the Rviz iceberg. The
program is full of many interesting and exciting features
that can be used for even the most complex robots. SV
In this case, we will need the /base_scan topic. With
rostopic echo /base_scan, you will be able to view the
raw data coming from the laser; these are angles and
distances the laser is currently reading. From this data, it is
quite hard to figure out what the robot is actually seeing.
Extreme Robot
Motor Control
This is why there is a program built into ROS that does
exactly that.
Open Rviz by running: rosrun rviz rviz.
MEGAMOTO Plus Shield
Software and
plug compatible
with our
MegaMoto
shield
You will see a window open with a 3D grid in the
center. In the General Options section in the hierarchy on
the left hand side, click on the Fixed Frame drop-down
menu. Select /base_laser_link.
New
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40A peak
High-Current motor control for Arduino;
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; Stack up to three units on one Uno or compatible
; Independent half-bridges can control
brushless/steppers too!
Now, click Add in the bottom left corner. Select
THE USA
Scorpion XXL
LaserScan, and click OK. You will see that a LaserScan
module appeared in the hierarchy just below the grid.
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; 30A Continuous with fan -
; 7V - 28V
; Dual 40A+ Peak H-Bridges
; Current/Temp limiting
; R/C inputs w/mixing
; Optional enclosure
; 3. 25” x 2. 25” x . 5”
SERVO 12.2014 45
Resources:
Michael Ferguson
http://fergy.me/
The Vyper
ROS
www.ros.org/
200A Peak!
MADE IN
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Willow Garage
www.willowgarage.com/
Teleop Package
http://wiki.ros.org/teleop_
twist_keyboard
Big Bots!
; RC and Analog Pot input
Big Power!
; Supports 8 AWG wires!
Big Motors!
; Optional enclosure
Neato Robotics
www.neatorobotics.com/
; 2.85” x 2. 25” x 1.75”
Ubuntu
www.ubuntu.com/