Quanser qbot User Manual page 16

Quanser Qbot: User Manual
Block set
Interface
(Figure 12)
Application
(Figure 13)
Image Processing
(Figure 14)
Table 2: Description of the Relevant Qbot Block Sets for the Qbot in QUARC
Block
Table 3: Important Qbot Blocks
This block set implements the basic application program interfaces (APIs) provided by
iRobot Create®. The APIs can be broadly categorized based on the following
functionalities:
serial connection configuration between the high level controller (e.g., PC or
●
Gumstix) and Qbot,
setting operation mode of Qbot,
●
accessing Qbot's sensory information,
●
other hardware configuration (e.g., setting digital and analog I/O ports, and
●
changing LED colours.
This block set allows a user to implement navigation algorithms using available sensory
information. The present blocks use only wheel encoder data and bump sensors for
navigation and obstacle avoidance.
This block set implements image acquisition and processing functionalities using the
OpenCV library. The image processing block set allows to capture images from a USB
camera, to process it on-line, and to save it to a disk for further analysis.
This block is required to establish a serial connection to a Qbot.
A Qbot is identified by a Universal Resource Identifier (URI), such as
serial://localhost:1baud=57600,word=8,parity=none,stop=1
where communication port 1 of the target is connected to the Qbot serial port
with the specified parameters.
Note: The "rmb" output of this block must be connected to the "rmb" input of
the blocks in the Roomba block set in order to access the Roomba.
This block drives the Qbot with two inputs: velocity and radius. To drive
straight, the radius input takes 32768 or 32767. This is a special case, and refer
to the MATLAB Help page for a more complete list of possible commands.
This block retrieves various sensor data from the Qbot. The pack_id input
ranges from 7 to 42, and each input will display a value from the pack output.
See the MATLAB Help page for a full description for each of the packet IDs.
Notable pack_id values:
8 = wall (0 = no wall, 1 = wall seen)
19 = distance (The distance that the Qbot has traveled in millimeters)
20 = angle (The angle in degrees that the Qbot has turned)
22 = voltage (Voltage of the Qbot's battery in millivolts)
23 = current (Current in milliamps flowing into or out of the Qbot's
battery)
Description
Description
Document Number: 830  Revision: 7  Page: 13
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