TurtleMobility

simple module

A LOGO-style movement model, with the script coming from XML. It can be useful for describing random as well as deterministic scenarios.

First, a few examples.

Node will move along a square's borders:

    <movement>
        <set speed="10" angle="180"/>
        <repeat n="4">
            <forward d="50"/>
            <turn angle="90"/>
        </repeat>
    </movement>

MassMobility (in which the node is assumed to have a mass, and cannot turn abruptly):

    <movement>
        <repeat>
            <set speed="uniform(10,20)"/>
            <turn angle="uniform(-30,30)"/>
            <forward t="uniform(0.1,1)"/>
        </repeat>
    </movement>

RandomWaypointMobility:

    <movement>
        <repeat>
            <set speed="uniform(20,60)"/>
            <moveto x="uniform($MINX,$MAXX)" y="uniform($MINY,$MAXY)"/>
        </repeat>
    </movement>

Commands (XML element names) are: repeat, set, forward, turn, wait, moveto, and moveby.

Accepted attributes:

repeat: n (optional)
set: x, y, speed, angle, borderPolicy (all optional)
forward: d, t (at last one of them must be present)
turn: angle (required)
wait: t (required)
moveto: x, y, t (all optional)
moveby: x, y, t (all optional)

Attribute values can be literal numbers (e.g. x="100"), or any distribution accepted in omnetpp.ini (e.g. speed="uniform(10,20)"). A new value will be chosen each time the statement is executed. The $MINX, $MAXX, $MINY and $MAXY strings will be substituted with the limits of constraint area, respectively.

t is time interval, calculated from the end of the previous movement. x, y are absolute coordinates with <set> and <moveto>, and relative with <moveby>. angle is clockwise in degrees, with 0 pointing west. d is distance in meters (speed is m/s).

borderPolicy controls what happens when a node reaches the edge of the constraint area, and can take one of the values "reflect", "wrap", "placerandomly". In the first case, the node reflects off the wall; with "wrap", it'll come in on the other side (torus); and with "placerandomly", it will be placed at a random position on the constraint area.

In addition to the node position, the module maintains two interval variables, 'speed' and 'angle', which can be adjusted by <set> and <turn>. The <forward> statement, if only t or d is given, uses the speed variable. If you specify d and t together, that determines speed as well, so the speed variable will be ignored completely.

Likewise, <moveto> and <moveby> will ignore the angle variable, and will only use the speed variable if the t attribute is omitted.

If the repeat count n is omitted for the <repeat> statement, that means an infinite loop.

You can find the DTD with the sources: TurtleMobility.dtd.

TODO update documentation; <turn heading=".."> is strange

Inheritance diagram

The following diagram shows inheritance relationships for this type. Unresolved types are missing from the diagram.

Extends

Name	Type	Description
MovingMobilityBase	simple module	Abstract base module for mobility models.

Parameters

Name	Type	Default value	Description
subjectModule	string	"^"	module path which determines the subject module, the motion of which this mobility model describes, the default value is the parent module
coordinateSystemModule	string	""	module path of the geographic coordinate system module
displayStringTextFormat	string	"p: %p\nv: %v"	format string for the mobility module's display string text
updateDisplayString	bool	true	enables continuous update of the subject module's position via modifying its display string
constraintAreaMinX	double	-inf m	min x position of the constraint area, unconstrained by default (negative infinity)
constraintAreaMinY	double	-inf m	min y position of the constraint area, unconstrained by default (negative infinity)
constraintAreaMinZ	double	-inf m	min z position of the constraint area, unconstrained by default (negative infinity)
constraintAreaMaxX	double	inf m	max x position of the constraint area, unconstrained by default (positive infinity)
constraintAreaMaxY	double	inf m	max y position of the constraint area, unconstrained by default (positive infinity)
constraintAreaMaxZ	double	inf m	max z position of the constraint area, unconstrained by default (positive infinity)
updateInterval	double	0.1s	the simulation time interval used to regularly signal mobility state changes and update the display
faceForward	bool	true
turtleScript	xml		describes the movement

Properties

Name	Value	Description
display	i=block/cogwheel
class	TurtleMobility

Signals

Name	Type	Unit
mobilityStateChanged	inet::MobilityBase

Scheduled messages (observed)

msg	kind	ctrl	tags	msgname	context
omnetpp::cMessage	0			move

Direct method calls (observed)

call to	function	info
AttachedMobility	inet::AttachedMobility::receiveSignal	mobilityStateChanged

Source code

//
// A LOGO-style movement model, with the script coming from XML. It can be
// useful for describing random as well as deterministic scenarios.
//
// First, a few examples.
//
// Node will move along a square's borders:
//
// <pre><nohtml>
//     <movement>
//         <set speed="10" angle="180"/>
//         <repeat n="4">
//             <forward d="50"/>
//             <turn angle="90"/>
//         </repeat>
//     </movement>
// </nohtml></pre>
//
// ~MassMobility (in which the node is assumed to have a mass, and cannot turn
// abruptly):
//
// <pre><nohtml>
//     <movement>
//         <repeat>
//             <set speed="uniform(10,20)"/>
//             <turn angle="uniform(-30,30)"/>
//             <forward t="uniform(0.1,1)"/>
//         </repeat>
//     </movement>
// </nohtml></pre>
//
// ~RandomWaypointMobility:
//
// <pre><nohtml>
//     <movement>
//         <repeat>
//             <set speed="uniform(20,60)"/>
//             <moveto x="uniform($MINX,$MAXX)" y="uniform($MINY,$MAXY)"/>
//         </repeat>
//     </movement>
// </nohtml></pre>
//
// Commands (XML element names) are: repeat, set, forward, turn, wait,
// moveto, and moveby.
//
// Accepted attributes:
//    - repeat: n (optional)
//    - set: x, y, speed, angle, borderPolicy (all optional)
//    - forward: d, t (at last one of them must be present)
//    - turn: angle (required)
//    - wait: t (required)
//    - moveto: x, y, t (all optional)
//    - moveby: x, y, t (all optional)
//
// Attribute values can be literal numbers (e.g. x="100"), or any
// distribution accepted in omnetpp.ini (e.g. speed="uniform(10,20)").
// A new value will be chosen each time the statement is executed.
// The $MINX, $MAXX, $MINY and $MAXY strings will be substituted with the
// limits of constraint area, respectively.
//
// t is time interval, calculated from the end of the previous movement.
// x, y are absolute coordinates with <set> and <moveto>, and relative
// with <moveby>. angle is clockwise in degrees, with 0 pointing west.
// d is distance in meters (speed is m/s).
//
// borderPolicy controls what happens when a node reaches the edge of the
// constraint area, and can take one of the values "reflect", "wrap",
// "placerandomly". In the first case, the node reflects off the wall;
// with "wrap", it'll come in on the other side (torus); and with
// "placerandomly", it will be placed at a random position on the
// constraint area.
//
// In addition to the node position, the module maintains two interval variables,
// 'speed' and 'angle', which can be adjusted by <set> and <turn>.
// The <forward> statement, if only t or d is given, uses the speed variable.
// If you specify d and t together, that determines speed as well,
// so the speed variable will be ignored completely.
//
// Likewise, <moveto> and <moveby> will ignore the angle variable,
// and will only use the speed variable if the t attribute is omitted.
//
// If the repeat count n is omitted for the <repeat> statement, that
// means an infinite loop.
//
// You can find the DTD with the sources: TurtleMobility.dtd.
//
//TODO update documentation; <turn heading=".."> is strange
simple TurtleMobility extends MovingMobilityBase
{
    parameters:
        xml turtleScript; // describes the movement
        @class(TurtleMobility);
}

File: src/inet/mobility/single/TurtleMobility.ned