Virtual Pheromone Research Articles

A bio-inspired technique for servicing networked robots

Bio-inspirations have paved a way for finding new and novel ways of optimisation in several application scenarios. Virtual pheromones have been used widely for routing in mobile ad-hoc networks and wireless sensor networks as also for communication among robots. In this paper, we describe a multi-robot system wherein mobile agents act as code carriers and in turn facilitate execution of tasks by the robots. Networked robots that need a code to execute an allotted task diffuse, onto their neighbours, pheromones that specifically attract those mobile agents that carry the required code as their payload. The agents move around the network in a conscientious manner but on sensing a pheromone, home onto the concerned robot and provide the code. We compare this pheromone-conscientious method with other mobile agent-based patrolling and resource discovery strategies and portray the relevant results and conclude that the pheromone-conscientious strategy is more conservative in terms of both time and energy consumed.

Bio-inspired routing protocol for mobile ad hoc networks

A mobile ad hoc network (MANET) is a non-centralised, multihop, wireless network that lacks a common infrastructure. It therefore needs self-organisation. The MANETs are autonomous, adaptive and dynamic. In MANETs, multihop routing allows multiple routes between the source and destination to be established. This study speaks about a bio-inspired routing protocol for these networks based on AntHocNet. The design for the protocol lies in a heuristic, based on swarm intelligence, which takes into account the limited resources and highly dynamic environment, as well as the restriction on the exchange of routing information. So, the key aspects of the proposed protocol are the disjoint-link and disjoint-node routes, separation between the regular pheromone and the virtual pheromone in the diffusion process and the exploration of routes, taking into consideration the number of hops in the best routes which the authors have previously found out. The simulation results show that the protocol has lower overhead and higher delivered packet ratio than AntHocNet. Likewise, these results indicate that the routing satisfies multiple and independent quality of service constraints and can deal with faults, which provides better load balancing.

ANT STRATEGIES FOR NEGOTIATING OBSTACLES

Ants are notoriously good at finding the most direct route to food. Laying down volatile pheromones to guide their colleagues, ant colonies eventually home in on the most direct path as pheromone is lost from longer paths and added to more heavily used shorter routes. Finding the optimal paths through networks is also a challenge for human delivery agents, telephone routers and systems analysts, so software engineers have turned to trail-blazing ants for inspiration to solve these problems. Chris Reid and Madeleine Beekman from Sydney University, Australia, and David Sumpter from Uppsala University, Sweden, explain that one network-solving algorithm uses virtual ants to lay down virtual pheromone trails to identify the most direct route through, but it doesn't do well when networks continually change, as they do in real life. However, ants have faced constantly changing landscapes for millions of years, so Reid and his co-workers decided to find out how Argentine ants identify the optimal route through a changing network when they presented the insects with the Towers of Hanoi puzzle (p. 50).Of course the team didn't ask the ants to start moving puzzle discs between pegs. Instead, they converted the task into a graph of possible moves and converted that in turn into a maze of hexagons. Having initially allowed a colony of ants to explore the maze and lay down pheromones (short-lived foraging pheromone and long-lasting exploration pheromone), the team then placed food at the end of the maze and filmed the ants as they tried to identify the optimal route through the maze to the food while the team blocked off routes and opened up alternatives.The ants had little problem coping with change. Initially, the insects found the shortest route, scurrying along the outer edge of the maze to the food source. However, when the team blocked this route and opened up another through the middle of the maze, the ants changed course, zigzagging across the maze, perpendicular to their original route until they found the alternative. The team suspects that both pheromones played critical roles, with short-lived foraging pheromone allowing the ants to respond quickly when the route changed and long-lived exploration pheromone rapidly stabilising the optimal route. Also, when an ant encountered an obstacle, Reid and his colleagues noticed that she began searching for a route around the blockage, rather than retracing her steps. The team suspects that the ants don't just rely on geometry to identify paths and negotiate obstacles; they use an internal compass to help them reach their goal. Finally, the trio hopes that their new discovery that ants use multiple pheromones and possibly compasses will inspire software engineers to develop alternative ant-based algorithms to solve complex dynamic network problems.

Task Allocation in Multistate Systems

Multistate task allocation inspired by social-insect polyethism is treated from the viewpoint of proportionally regulating a population between different states, i.e., the system is homeostatic against external disturbance and environmental change. Using a dynamical model consisting of identical elements and external variable “stock materials,” adaptability to external disturbances is studied numerically. Experiments are performed with actual robots moving in virtual pheromone fields simulated by computer graphics and video camera feedback demonstrating task allocation.

Designing conducting polymers using bioinspired ant algorithms

Ant algorithms are inspired in real ants and the main idea is to create virtual ants that travel into the space of possible solutions depositing virtual pheromone proportional to how good a specific solution is. This creates an autocatalytic (positive feedback) process that can be used to generate automatic solutions to very difficult problems. In the present work we show that these algorithms can be used coupled to tight-binding Hamiltonians to design conducting polymers with pre-specified properties. The methodology is completely general and can be used for a large number of optimizations problems in materials science.

Using Virtual Pheromones and Cameras for Dispersing a Team of Multiple Miniature Robots

To safely and efficiently guide personnel of search and rescue operations in disaster areas, swift gathering of relevant information such as the locations of victims, must occur. Using the concept of `repellent virtual pheromones' inspired by insect colony coordination behaviors, miniature robots can be quickly dispersed to survey a disaster site. Assisted by visual servoing, dispersion of the miniature robots can quickly cover an area. An external observer such as another robot or an overhead camera is brought into the control loop to provide each miniature robot estimations of the positions of all of the other near-by robots in the robotic team. These miniature robots can then move away from the other near-by robots on the team, resulting in the robot collective becoming swiftly distributed through the local area. The technique has been simulated with differing pheromone persistence levels and implemented using the miniature Scout robots, developed by the Center for Distributed Robotics at the University of Minnesota, which are well-suited to surveillance and reconnaissance missions.

Scheduling of Large Assembly Cells with Virtual Pheromone Approach

This paper describes the interest of "virtual" pheromones to build heterarchical systems. The first part describes the bases of the stigmergy concept using pheromones. In the second part, these concepts are applied to build our Heterarchical Product-Based (HPB) system. The third part focuses on a first application of the HPB philosophy on a flexible assembly cell. The fourth part is dedicated to a future implementation on a larger flexible assembly cell.

Compound behaviors in pheromone robotics

We are pursuing techniques for coordinating the actions of large numbers of small-scale robots to achieve useful large-scale results in surveillance, reconnaissance, hazard detection, and path finding. Using the biologically inspired notion of “virtual pheromone” messaging, we describe how many coordinated activities can be accomplished without centralized control. By virtue of this simple messaging scheme, a robot swarm can become a distributed computing mesh embedded within the environment, while simultaneously acting as a physical embodiment of the user interface. We further describe a set of logical primitives for controlling the flow of virtual pheromone messages throughout the robot swarm. These enable the design of complex group behaviors mediated by messages exchanged between neighboring robots.

From Ant Trails to Pedestrian Dynamics

This paper presents a model for the simulation of pedestrian dynamics inspired by the behaviour of ants in ant trails. Ants communicate by producing a pheromone that can be smelled by other ants. In this model, pedestrians produce a virtual pheromone that influences the motion of others. In this way all interactions are strictly local, and so even large crowds can be simulated very efficiently. Nevertheless, the model is able to reproduce the collective effects observed empirically, eg the formation of lanes in counterflow. As an application, we reproduce a surprising result found in experiments of evacuation from an aircraft.

From Ant Trails to Pedestrian Dynamics

This paper presents a model for the simulation of pedestrian dynamics inspired by the behaviour of ants in ant trails. Ants communicate by producing a pheromone that can be smelled by other ants. In this model, pedestrians produce a virtual pheromone that influences the motion of others. In this way all interactions are strictly local, and so even large crowds can be simulated very efficiently. Nevertheless, the model is able to reproduce the collective effects observed empirically, eg the formation of lanes in counterflow. As an application, we reproduce a surprising result found in experiments of evacuation from an aircraft.

Pheromone Robotics

We describe techniques for coordinating the actions of large numbers of small-scale robots to achieve useful large-scale results in surveillance, reconnaissance, hazard detection, and path finding. We exploit the biologically inspired notion of a “virtual pheromone,” implemented using simple transceivers mounted atop each robot. Unlike the chemical markers used by insect colonies for communication and coordination, our virtual pheromones are symbolic messages tied to the robots themselves rather than to fixed locations in the environment. This enables our robot collective to become a distributed computing mesh embedded within the environment, while simultaneously acting as a physical embodiment of the user interface. This leads to notions of world-embedded computation and world-embedded displays that provide different ways to think about robot colonies and the types of distributed computations that such colonies might perform.