Robobot mission

Revision as of 12:04, 1 January 2020

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Robobot mission software

This figure shows the mission functional blocks. The main connection is to the robobot_bridge, through which the robot is controlled. The red mission block is the main block, where the behaviour is controlled. To help decide and control the behaviour, there is a number of data elements available in the bottom row of boxes, available through the bridge. A camera block is available, where image processing is assumed to happen. From the camera block, there is support for ArUco marker detection.

The blocks marked with a circle arrow is running their own thread. The yellow boxes are features available outside the mission application.

Main

The main block is the entry point of the application. This block creates all the other blocks, and if there is a successful connection to the robobot_bridge, then the mission thread is started, and the main thread now just listens for keyboard input.

The keyboard input (console input) can be used to get status of the individual blocks and issue some simple (mostly debugging) commands.

Press h (and enter) to get a list of features:

>> h
# got 'h' n=1
# mission command options
#    h    This help
#    a    Do an ArUco analysis of a frame (no debug - faster)
#    d    Do an ArUco analysis of a frame (with debug images)
#    c    Capture an image and save to disk (image*.png)
#    o    Loop-test for steady ArUco marker (makes logfile)
#    t 99 Camera tilt degrees (positive down), is 10.0 deg
#    p 99 Camera pan (Yaw) degrees (positive CCV) is 0.0 deg
#    lo xxx  Open log for xxx (pose 0, hbt 0, bridge 0, imu 0
#               ir 0, motor 0, joy 0, event 0, cam 0, aruco 1)
#    lc xxx  Close log for xxx
#    s    Status (all)
#    q    Quit now

Logfiles

The data blocks have a data logger feature that can be enabled and disabled. The interface logfile will be in a text format for MATLAB import. The name of the logfile will include date and time, and will therefore not overwrite the previous logfile.

The IR logfile could be named 'log_irdist_20191227_095545.054.txt' look like this:

% robobot mission IR distance log
% 1 Timestamp in seconds
% 2 IR 1 distance [meter]
% 3 IR 2 distance [meter]
% 4 IR 1 raw [AD value]
% 5 IR 2 raw [AD value]
1577436945.093 0.197 0.436 44943 15573
1577436945.139 0.197 0.421 44925 16430
1577436945.180 0.197 0.416 44896 16768
1577436945.225 0.196 0.410 44996 17123
1577436945.266 0.197 0.404 44922 17463
1577436945.311 0.197 0.423 44920 16341

And can be displayed in MATLAB using a script like this

data = load('log_irdist_20191227_095545.054.txt');
h = figure(200)
hold off
plot(data(:,1) - data(1,1), data(:,2))
hold on
plot(data(:,1) - data(1,1), data(:,3))
grid on
legend('IR1', 'IR2')
xlabel('sec')
ylabel('distance [m]')
saveas(h, 'ir_plot.png')

And in this case, the plot shows:

The plot shows that longer distances (IR2) have more noise than short distances (IR1).

Bridge

This part handles the interface with the regbot_bridge application. This two-way communication handles each direction individually.

Sending messages is mostly handled by the mission block, here regular updates of data is requested for the data blocks - e.g. robot pose, joystick buttons, IR-sensor measurements etc.

The receiving part of the bridge is always waiting for messages and distribute them for the relevant data block for decoding.

In a normal setup, about 150 messages will be received each second.

Data elements

This is a list of the features of each of the data elements.

IMU

Has

IR-dist

Has

Pose

Joy

Motor

Info

The info block holds som static data, but also data from the heartbeat message - the only part that can be logged).

Event

Holds all 32 events. The logfile has a list of when each of then has been set or cleared.

Edge

The edge sensor (also called line sensor).

Camera

The camera interface sets the camera to 1280 x 960 pixels at 30 frames per second.

...

ArUco

This part of the camera system is configured to detect ArUco codes with their position relative to the robot. The position is in (x, y, z), where x is forward, y is left and z is up. The reference position is the center between the driving wheels at ground level.

Mission

The mission block has access to all the other elements and controls the performance of the robot.

The mission code is described in a bit more detail here.

Installation

Get software

Get the ROBOBOT software from the svn repository:

svn checkout svn://repos.gbar.dtu.dk/jcan/regbot/mission mission

or just update if there already

svn up

Compile

To be able to compile the demo software CMAKE needs also to use the user installed library (raspicam installed above), so add the following line to ~/.bashrc:

export CMAKE_PREFIX_PATH=/usr/local/lib

Then build Makefiles and compile:

cd ~/mission
mkdir -p build
cd build
cmake ..
make -j3

Then test-run the application:

./mission

It should print that the camera is open and the bridge is connected to the REGBOT hardware.

Sound

The robot has small speakers

Music

Speak

system("espeak \"bettina reached point 3\" -ven+f4 -a30 -s130");

This line makes the robot say "bettina reached point 3" the parameters "-a30" turns amplitude down to 30%, "-ven+f4" sets language to english with female voice 4 and "-s130" makes the speech a little slower and easier to understand. It requires that espeak is installed (sudo apt install espeak).

To use on Raspberry pi, it is better to use

system("espeak \"Mission paused.\" -ven+f4 -s130 -a60 2>/dev/null &");

The "2>/dev/null" tell that error messages should be dumped, and the final "&" say that it should run in the background (not to pause the mission).

AruCo Marker

The camera class contains some functions to detect Aruco markers. It it described in more details on AruCo Markers.

Software documentation (doxygen)

Figure: generated with doxygen http://aut.elektro.dtu.dk/robobot/doc/html/classes.html

The classes that inherit from UData are classes that makes data available for the mission, e.g. joystick buttons (in UJoy) event flags (in UEvent) or IR distance data (in UIRdist).

The classes that inherit from URun has a thread running to receive data from an external source, e.g. UBridge that handles communication with the ROBOBOT_BRIDGE.

The camera class (UCamera) is intended to do the image processing.

HTML documentation - Doxygen

To generate doxygen html files go to mission directory and run doxygen.

cd ~/mission
doxygen Doxyfile

then open the index.html with a browser.

If doxygen is not installed, then install using

sudo apt install doxygen