Difference between revisions of "IKart"
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Revision as of 02:55, 3 January 2012
- 1 iKart hardware description
- 2 iKart Software
- 3 Using the iKart
- 4 iKart (re)installation
- 5 iKart and ROS
- 6 iKart dimensions
iKart hardware description
Motor control boards
CAN to USB converter
An UTM-30LX Laser Range finder (Hokuyo Ltd) is mounted in front of the iKart. It is powered by a 12V ...................., while the data are transmitted on through a separated USB cable. The range finder is able to detect obstacles up to 30m, with a scan angle of 270 degrees. The maximum refresh rate is 40Hz.
The laserScannerGUI provides a simple graphical interface in order to visualize the measurements performed by the frontal laser rangefinder. The module receives the measurements from the iKartCtrl module through the /ikart/laser:o yarp port. A list of all the available options (e.g. zoom, refresh rate etc.) is displayed by pressing the key 'h'.
The iKartBattteryManager is the module responsible of verifying the status of charge (SoC) of the battery. The module is automatically started from the script /etc/rc.local during the boot sequence (see also ...) and periodically reads the from the /dev/ttyUSB0 serial port the SoC of the battery. The default update rate is 10 seconds. In order to preserve the robot sensible components from dangerous brownouts, the module takes the following actions if the battery is low:
- The user will be notified with a wall message if the charge of the battery level is lower than 10%.
- If the battery reaches a critical level (below 5%), the module will start an emergency shutdown procedure, by stopping the iCub and iKart motor interfaces, and turning off the machine, with a two minutes advance notice.
The module executes independently if the yarp server is running or not. If yes, infomation about the SoC of the battery is sent through the /ikart/battery:o port. You can also ask the module to save a timestamped logfile of the performed battery measurements, by specifying the option --logToFile into the startup script (default: off).
The iKartBatteryDisplay is a graphical tool which displays the current SoC of the battery. The module receives the battery info from the iKartBatteryManager module through the /ikart/battery:o yarp port. Since the iKart obviously doesn't have a graphical output, this module will not run on the iKart machine. Instead, the iKartBatteryDisplay is thought to be executed by the user on all the machines remotely connected to the iKart. The provided always-on-top window will remember to the user the remaining autonomy of the robot, so it's a good idea to execute to keep an iKartBatteryDisplay instance always running on each user machine connected to the iKart.
Starting the iKart with the joystick
- Turn on the the iKart.
- Turn on your joystick by pressing the central joystick button.
- Wait for the beep coming from the iKart, indicating that the boot is finished.
- At this point you have for 5 seconds the chance, by pressing any button on the joystick (or moving the sticks) to initiate the joystick start-up procedure.
If a the joystick activity has been detected, the iKart will automatically initialize the following processes (and will make automatoically all the required connections):
- The Yarp server.
- The iCubInterface required to control the iKart motors.
- The iKartControl module.
- The joystickControl module.
You will be now able to move the iKart around usually the joystick as in normal operation.
How the joystick-startup procedure works
The script responsible for the joystick-startup procedure is ikart_start.sh which is originally located under $IKART_ROOT/app/iKart/ikart_boot and copied to $ICUB_BIN during the installation procedure. The scripts executes the joystickCheck module in order to verify if a joystick activity is detect, and executes initializes the yarp server and the control software if so. The ikart_start.sh script is automatically executed from the main boot script /etc/rc.local after the low-level drivers initialization.
Stopping/Restarting the joystick-startup
An analogous script ikart_stop.sh is provided in order to stop all the modules launched by the ikart_start.sh script, when controlling the iKart is no longer required. Currently, there is no way to execute this script using the joystick, so it has to be manually invoked through an ssh connection to iKart. Please also note the yarp server started by the ikart_start.sh script will be not stopped by the ikart_stop.sh script. Finally, remember that the joystick start-up procedure, which is particularly convenient during the boot, can be also manually invoked anytime, by launching the ikart_start.sh script from a console, or through an ssh connection.
Using the iKart
At the end of the boot sequence, the following line contained in /etc/rc.local initializes the Esdcan driver.
ip link set can0 up type can bitrate 1000000
iKart uses the xboxdrv userspace driver.
The driver is launched by the following line of the etc/rc.local file: