How to Implement Networked Robotics in ns2

To implement the Networked Robotics within NS2 has needs to include simulating a network of robots that communicate and work together to execute the tasks. These robots can contain ground vehicles, aerial drones, or stationary robotic systems, and its communication network that can include exchanging sensor data, control commands, and status updates.

Refer to the supplied manual to set up Networked Robotics with ns2. For customized services, feel free to reach out to us.

Step-by-Step Implementation:

  1. Understand Networked Robotics Components:
  • Robots: Autonomous or semi-autonomous units that execute tasks and communicate with each other or a central controller.
  • Central Controller (Optional): A central unit that handles and coordinates the actions of the robots.
  • Communication Nodes: These nodes that help communication among the robots and the central controller.
  1. Set Up the NS2 Environment:
  • Make sure NS2 is installed on the system.
  • Get to know the writing TCL scripts, as NS2 simulations are controlled through the TCL.
  1. Define the Network Topology:
  • Make a nodes that signifying the robots and, if required, a central controller and these nodes will interact to mimic the networked robotics environment.

# Define the simulator

set ns [new Simulator]

# Create a trace file for analysis

set tracefile [open out.tr w]

$ns trace-all $tracefile

# Create a NAM file for animation

set namfile [open out.nam w]

$ns namtrace-all-wireless $namfile 10

# Set up the network parameters

set opt(chan)   Channel/WirelessChannel      ;# Channel type

set opt(prop)   Propagation/TwoRayGround     ;# Radio-propagation model

set opt(netif)  Phy/WirelessPhy              ;# Network interface type

set opt(mac)    Mac/802_11                   ;# MAC type

set opt(ifq)    Queue/DropTail/PriQueue      ;# Interface queue type

set opt(ll)     LL                           ;# Link layer type

set opt(ant)    Antenna/OmniAntenna          ;# Antenna model

set opt(ifqlen) 50                           ;# Max packet in ifq

set opt(x)      1000                         ;# X dimension of the topography

set opt(y)      1000                         ;# Y dimension of the topography

set opt(adhocRouting) AODV                   ;# Ad hoc routing protocol

# Create a topography object

create-god 50

# Configure the nodes (e.g., robots, central controller)

$ns node-config -adhocRouting $opt(adhocRouting) \

-llType $opt(ll) \

-macType $opt(mac) \

-ifqType $opt(ifq) \

-ifqLen $opt(ifqlen) \

-antType $opt(ant) \

-propType $opt(prop) \

-phyType $opt(netif) \

-channelType $opt(chan) \

-topoInstance $topo \

-agentTrace ON \

-routerTrace ON \

-macTrace OFF \

-movementTrace ON

# Create nodes: Robots and Central Controller

set robot1 [$ns node]        ;# Robot 1

set robot2 [$ns node]        ;# Robot 2

set robot3 [$ns node]        ;# Robot 3

set controller [$ns node]    ;# Central Controller

# Set initial positions for the nodes

$robot1 set X_ 200.0

$robot1 set Y_ 500.0

$robot1 set Z_ 0.0

$robot2 set X_ 400.0

$robot2 set Y_ 500.0

$robot2 set Z_ 0.0

$robot3 set X_ 600.0

$robot3 set Y_ 500.0

$robot3 set Z_ 0.0

$controller set X_ 800.0

$controller set Y_ 500.0

$controller set Z_ 0.0

  1. Simulate Communication Between Robots:
  • Configure the communication links among the robots and among the robots and the central controller.

# Create duplex links between robots

$ns duplex-link $robot1 $robot2 10Mb 10ms DropTail

$ns duplex-link $robot2 $robot3 10Mb 10ms DropTail

# Create duplex link between Robot 3 and Central Controller

$ns duplex-link $robot3 $controller 10Mb 10ms DropTail

  1. Simulate Data Exchange:
  • Execute the data exchange among robots, such as sensor data sharing, status updates, or coordination messages.

# Robot 1 sends data to Robot 2

set tcp_robot1 [new Agent/TCP]

$ns attach-agent $robot1 $tcp_robot1

set tcp_robot2_sink [new Agent/TCPSink]

$ns attach-agent $robot2 $tcp_robot2_sink

$ns connect $tcp_robot1 $tcp_robot2_sink

# Start sending data from Robot 1 to Robot 2

set app_robot1 [new Application/FTP]

$app_robot1 attach-agent $tcp_robot1

$ns at 1.0 “$app_robot1 start”

# Robot 2 sends data to Robot 3

set tcp_robot2 [new Agent/TCP]

$ns attach-agent $robot2 $tcp_robot2

set tcp_robot3_sink [new Agent/TCPSink]

$ns attach-agent $robot3 $tcp_robot3_sink

$ns connect $tcp_robot2 $tcp_robot3_sink

# Start sending data from Robot 2 to Robot 3

set app_robot2 [new Application/FTP]

$app_robot2 attach-agent $tcp_robot2

$ns at 2.0 “$app_robot2 start”

  1. Implement Coordinated Tasks:
  • Execute the coordinated tasks in which robots collaborate to complete a mission, like moving in formation or exploring an area.

# Example procedure for coordinated movement

proc coordinated_movement {robot1 robot2 robot3} {

global ns

puts “Coordinated movement: Robot 1, Robot 2, and Robot 3 moving together”

$ns at [expr $ns now + 1.0] “$robot1 setdest 800.0 600.0 10.0”

$ns at [expr $ns now + 1.0] “$robot2 setdest 900.0 600.0 10.0”

$ns at [expr $ns now + 1.0] “$robot3 setdest 1000.0 600.0 10.0”

}

# Schedule coordinated movement

$ns at 3.0 “coordinated_movement $robot1 $robot2 $robot3”

  1. Simulate Centralized Control (Optional):
  • If a central controller is used, execute communication among the robots and the central controller to coordinate tasks or give updates.

# Central Controller sends a command to Robot 1

set tcp_controller [new Agent/TCP]

$ns attach-agent $controller $tcp_controller

set tcp_robot1_sink [new Agent/TCPSink]

$ns attach-agent $robot1 $tcp_robot1_sink

$ns connect $tcp_controller $tcp_robot1_sink

# Start sending a command from Central Controller to Robot 1

set app_controller [new Application/FTP]

$app_controller attach-agent $tcp_controller

$ns at 4.0 “$app_controller start”

  1. Run the Simulation:
  • State when the simulation should terminate and execute it. The finish procedure will close the trace files and introduce the NAM for visualization.

# Define the finish procedure

proc finish {} {

global ns tracefile namfile

$ns flush-trace

close $tracefile

close $namfile

exec nam out.nam &

exit 0

}

# Schedule the finish procedure at 10 seconds

$ns at 10.0 “finish”

# Run the simulation

$ns run

  1. Analyse the Results:
  • We can use the trace file (out.tr) to estimate the data transmission, network performance, and interactions among robots.
  • Open the NAM file (out.nam) to visualize the network operations and monitor the interactions among the robots and the central controller.
  1. Customize and Extend:
  • We can tailor the simulation by:
    • Appending more robots and executing more difficult coordination tasks.
    • Executing furthered networked robotics scenarios, like swarm robotics, in which a huge number of robots collaborate on a task.
    • Mimicking various scenarios, like robot failures, dynamic environments, or real-time communication difficulties.

Example Summary:

This instance configures the simple Networked Robotics simulation within NS2, concentrating on communication among the robots and, optionally, a central controller. The simulation establishes how robots can exchange data and coordinate tasks in a networked environment.

Advanced Considerations:

  • For more difficult scenarios, deliberate the incorporating NS2 with professional robotics simulation tools or emerging custom modules to mimic advanced robotics technologies, like multi-robot path planning, obstacle avoidance, or cooperative manipulation.
  • Expand the simulation to comprise furthered features such as Quality of Service (QoS) management, security like encryption, authentication, or fault tolerance in the networked robotics.

Debugging and Optimization:

  • We can use the trace-all command to debug the simulation and evaluate the packet flows.
  • Improve the simulation by filtering communication protocols, modifying coordination strategies, and changing network parameters for better performance and effectiveness.

The Networked Robotics was explained using the detailed procedure to implementing and analysing in the ns2 simulation. More informations will be shared according to your requirements. We specialize in exchanging sensor data, control commands, and status updates tailored to your research needs.

Our researchers also guide you with research ideas on ground vehicles, aerial drones, or stationary robotic systems by carrying on your thesis in a well-structured way