Useful for compatibility checking and introspection.
$ rosrun kobuki_driver version_info

PART I installtion

This instruction describes how to install Kobuki ros packages and get you ready to play with Kobuki.

1. Install Kobuki
$ sudo apt-get install ros-indigo-kobuki ros-indigo-kobuki-core

2. Set udev Rule
Copy across a udev rule for /dev/kobuki port and add your user to the dialout group (you may need to log out and log back in).
Connection to the kobuki base is via usb enabled by an ftdi usb-serial converter which is always pre-flashed at the factory with the serial id kobuki. For convenience, to enable the device to appear on /dev/kobuki, use the following script to copy across the udev rule and restart udev (you’ll need your sudo password):
$ rosrun kobuki_ftdi create_udev_rules

NOTE for none ros users:
In case you are not in a ROS environment, you will need to build the package first, in order to get the create_udev_rules script.
To do so navigate to the package folder and do
$ make udev

3. Keyboard Teleoperation
Ready to rock! With all the software you have installed so far, you should be able to teleoperate your kobuki around with your keyboard!

# This launches the minimal operation configuration
$ roslaunch kobuki_node minimal.launch

# This launches the keyboard teloperation node
$ roslaunch kobuki_keyop keyop.launch

PART II Inspection

Inspect the sensors’ state and send commands.

1. start minimal.launch to bring up Kobuki’s basic software (bootstrap layer). We use the argument –screen to get verbose output in the terminal.
> roslaunch kobuki_node minimal.launch –screen

2. take a look at Kobuki’s topics.
$ rostopic list
/sensor/: Continuous streams of the sensor’s data (note that /odom and /joints_states are remapped by default, since they are widley used at the highest level/namespace)
/events/: If a sensor changes its state, e.g. bumper pressed/released, the new state is published here.
/commands/: Use these topics to make Kobuki do things like switch on LEDs, playing sounds and driving around.
/debug/: Outputs detailed info about a lot of Kobuki’s internals.

3. Check sensors
$ rostopic echo /mobile_base/events/bumper
state: 1
bumper: 2
$ rostopic echo /mobile_base/events/wheel_drop
state: 1
wheel: 0

$ rostopic echo /mobile_base/sensors/imu_data
header:
seq: 0
stamp:
secs: 1355022789
nsecs: 36483345
frame_id: gyro_link
orientation:
x: 0.0
y: 0.0
z: 0.28769484546
w: 0.957722128749

Change the color or turn off a LED:
$ rostopic pub /mobile_base/commands/led1 kobuki_msgs/Led “value: 1”
$ rostopic pub /mobile_base/commands/led1 kobuki_msgs/Led “value: 0”

Play a sound:
$ rostopic pub /mobile_base/commands/sound kobuki_msgs/Sound “value: 6”

PART III Manupulation

Make it move

$ roslaunch kobuki_node minimal.launch –screen
$ roslaunch kobuki_keyop safe_keyop.launch –screen
There is also a normal keyop launcher (keyop.launch). The difference between both is, that safe_keyop makes use of a velocity smoother and Kobuki’s safety controller.

PART IV automatic docking

This tutorial will show you how to run automatic docking with kobuki, and will give you a brief description of algorithm. The code is located in kobuki_auto_docking package.

To run automatic docking properly, docking station should be placed in an open space of at least 2 meters wide by 5 meters long. There should be no obstacles between kobuki robot and docking station. And the dock station should be held by a wall or something heavy enough to prevent the robot to push it. A static red light on top of the docking station signals that it is powered on properly.

If you already launched kobuki_node, load the auto-docking nodelet into the running kobuki core. For convenience, just type:

$ roslaunch kobuki_auto_docking minimal.launch –screen
Or if you have not launched the kobuki core yet, type:
$ roslaunch kobuki_auto_docking compact.launch –screen
Be aware that this is just loading the algorithm; it is still not active. The algorithm is implemented as a typical action server. You need to call the server via an action client.

To activate it type:
$ roslaunch kobuki_auto_docking activate.launch –screen

Kobuki’s docking station has 3 IR(Infrared) emitters. The emitted IR lights cover three regions in front of the docking station: left, central and right, each divided in two sub-fields: near and far. Each beam encodes this information, so the robot knows at any moment in which region and sub-field he is. Also, as regions and fields are independently identified, they can be overlap on its borders.

Kobuki has 3 IR receivers. When the robot is placed within the field of the docking station, and at least one IR receiver is facing toward it, the robot will catch the signal and stream it to the controller netbook. The information is available on /mobile_base/sensors/dock_ir topic, in the form of kobuki_msgs/DockInfraRed messages

PART V Kobuki’s Control System

A note on Nodelets
Nodelets are heavily used in Kobuki’s control system. They have various benefits over normal nodes. The most important among them are avoiding serialising/deserialising of messages and the transmission over the TCP/IP. This is done by passing pointers to messages instead of the messages themselves. That means messages are faster processed and transmitted. When working with big messages, such as point clouds, this can also significantly lower the CPU consumption.

For our use case, the speed improvement is important, that is why we implement controllers and other speed-sensitive parts of Kobuki’s control system as nodelets.
Implementing code as nodelets instead of node is nothing to be afraid of as the the next tutorial will show.

Kobuki’s control system uses three different components.

kobuki_node: (AKA mobile base) is actually a nodelet, which wraps the C++ driver for communicating with Kobuki
cmd_vel_mux: is a velocity command multiplexer (or in otherwords a switch). It manages multiple incoming velocity commands according to the configured priority.
Kobuki controller: is a nodelet-based controller type – used for various applications; one example is the kobuki_safety_controller, which watches the bumper, cliff and wheel drop sensors and acts accordingly. Use this to implement your own reactive controller (see the next tutorial).
Furthermore, there is an implementation of a velocity smoother: yocs_velocity_smoother. This tool is optional, but highly recommended to use. In case a node publishing velocity commands can’t ensure their smoothness, put this smoother in between that node and the cmd_vel_mux.

The three components introduced above are used in a small hierarchy. Starting bottom-up, there is the mobile base, which listens for commands (LEDs, sounds, velocity) and publishes sensor information. On top of that we use the cmd_vel_mux, which makes sure, that only one velocity command at a time is relayed through to the mobile base. On the next level we have one or more controllers and other programs, such as keyboard teleop and the navi stack. There are cases, in which we want smooth velocity (e.g. keyop) and cases in which we don’t (safety controller). So, use the velocity smoother when necessary.

In the shown scenario, there are multiple programs, which want to control Kobuki’s movement. The velocity muxer allows using all of them in parallel. An example multiplexer configuration could be the following:
Priorities:
3 (highest priority): safety controller
2: keyboard teleop
1: android teleop
0 (lowest priority): navi stack teleop
In this case, the navi stack would control the robot in most of the times. However, the user can override navi stack’s commands, by triggering commands with the Android teleop app or the keyboard teleop. In case both teleops would be active at the same time, keyboard teleop would win. However, all the velocity commands above will be overridden when the safety controller kicks in (bumper, cliff or wheel drop sensor activated). This allows safe driving of Kobuki with all three tools.

IMG
https://docs.google.com/drawings/pub?id=1AP_T-5yWtVKxe981M7h8I9Paxd8gfzGIqvLZEudCG9k&w=750&h=1091

CHAPTER VI write nodelet

how to write and run a simple nodelet-based controller for Kobuki.

In this section we will create a simple “blink, when a bumper is pressed” controller, which will be similar to the Kobuki’s safety controller.

You find the code explained in the following paragraphs in the kobuki_controller_tutorial package. We will also make use of the default controller from yocs_controllers.

First create a new package for this controller in your workspace. We use roscreate-pkg to add the dependencies right away:
$ catkin_create_pkg kobuki_controller_tutorial roscpp yocs_controllers std_msgs kobuki_msgs nodelet

REF: https://charlyhuangrostutorial.wordpress.com/category/ros%E8%87%AA%E5%AD%B8%E7%AD%86%E8%A8%98/