W. Wilfred Godfrey

An Immune System Based Multi-robot Mobile Agent Network

A biological immune system comprises components that circulate within the body and defend it from attacks by pathogens. Its artificial counterpart has found applications in a wide spectrum of domains including Robotics. The cells in an immune system can be viewed to be analogous to mobile agents that migrate from one node (organ) to another. Mobility of such agents provides the framework for movement of components within a system. In this paper we describe the modeling of a mobile agent based robotic system that works on the principles of an artificial immune system. The mobile agents form the B-cell equivalents, generating rule-sets (antibodies) that help the robot to overcome a problem (antigen).

On Realizing a Multi-Agent Emotion Engine

Emotions have always been a complex phenomenon and research on their causes and effects have been fraught with debates. Though a reasonable and unified theory seems lacking, there have been many attempts at building models that emote. This paper describes a multi-agent approach that aids robot emotion. Emotions are grounded on percepts from sensors and generated by dedicated emotion agents that work concurrently with others – the positive suppressing the negative and vice versa while stimulating their own kinds. Each agent forms a metaphor of an emotion-generating entity that has a replenishing capability. Both the replenishing of an emotion resource and the sampling of the environment are based on fuzzy logic. Sampling of the percepts from the sensors is based on an adrenaline-like effect. Stimulations, suppressions, emotion resource, and a look-back before decay feature embed a deep and dynamic emotional milieu into a machine. The paper presents and discusses how three emotions churned from percepts gathered by a robot act as an emotional control juice capable of governing the manner of its motion along a path.

On a Mobile Agent Framework for an Internet of Things

With a large number of heterogeneous devices and gadgets ready to populate the Internet, finding an effective mechanism for communication amongst them has become imperative. Communication between networked heterogeneous devices can allow them to utilize each others individual capabilities to perform a task co-operatively. We propose the use of mobile agents to not only achieve such communication but also to pro-actively search for resources and provide services to the various devices populating such a network. In this paper we describe a mobile agent framework for an Internet of Things and discuss its working through a real implementation.

Towards a dynamic emotional model

Emotions in general are a complex phenomenon to comprehend. They have been known to influence decisions as also behavior. Several computational models for emotions have been attempted. In this paper we present the dynamics and working of a multi-agent emotion generating system. Three basic emotions viz. happiness, fear and anger have been used to generate a resultant internal mood for a machine or a robot whose state depends on the immediate past. We compare the results obtained with those generated by a conventional fuzzy model to highlight their significance.

Mobile agent cloning for servicing networked robots

In this work we present how the concept of cloning of mobile agents can aid in enhancing the performance of a multi robot system by providing faster services to the robots. The mobile agents carry solutions to problems faced by robots, as their payload. These agents move conscientiously in the network till they sense a pheromone gradient formed by a Robot Requesting Service (RRS) and its neighbours. Mobile agents tend to clone when they discover pheromones diffused by different RRSs thereby resulting in a faster and concurrent service. Simulation results have shown that cloning agents in high density RRS areas greatly decreases the waiting times for a service.

STIGMERGY-BASED SYNCHRONIZATION OF A SEQUENCE OF TASKS IN A NETWORK OF ASYNCHRONOUS NODES

Social insects are able to build complex architectural structures in spite of their limited capabilities and simple behaviors. The coordination of various activities within a colony of such insects is performed stigmergically through indirect communication. This article describes a stigmergy-based technique by which a set of mobile agents trigger the execution of a sequence of tasks at every node in a network, in a near synchronous manner. These agents use a concept of an innate task-specific potential, which guides them to initiate the execution of a task at various asynchronously operating nodes of a network, in a synchronous manner. This innate potential maintained within the agent also assists in self-healing. The technique is oblivious to both the number of agents and nodes in the network and, hence, is scalable. The proposed technique was emulated on various real static and dynamic topologies by varying different parameters. The results obtained validate the efficacy of the concept of potential. An implementation using real robots has also been presented to portray the practical viability of the proposed technique.

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.

On Stigmergically Controlling a Population of Heterogeneous Mobile Agents Using Cloning Resource

Cloning can greatly enhance the performance of networked systems that make use of mobile agents to patrol or service the nodes within. Uncontrolled cloning can however lead to generation of a large number of such agents which may affect the network performance adversely. Several attempts to control a population of homogeneous agents and their clones have been made. This paper describes an on-demand population control mechanism for a heterogeneous set of mobile agents along with an underlying application for their deployment as service providers in a networked robotic system. The mobile agents stigmergically sense and estimate the network conditions from within a node and control their own cloning rates. These agents also use a novel concept called the Cloning Resource which controls their cloning behaviour. The results, obtained from both simulation and emulation presented herein, portray the effectiveness of deploying this mechanism in both static and dynamic networks.

Survey on prioritized multi robot path planning

Multi robot path planning is a rising field in the zone of robotics because of its broad true applications like distribution center applications, pursuit and safeguard, military activities, and so forth. The significant favorable position of multi robot path planning is its simultaneousness, which is extremely helpful for reducing the time required for an operation. Coordination among different robots is important to perform proficient path planning. Quality and accuracy additionally require collaboration between numerous robots to accomplish its objective. As the quantity of robots builds, one of the concerns is the manner by which to dole out priority to the robots with the goal that they can perform the assignment in a collision free condition. In this paper, we are discussing some of the methods that how to find multi robot prioritized path planning techniques.

Technique for edge detection based on interval Type-2 fuzzy logic with sobel filtering

Edge detection is a primitive process required for any complex image processing and recognition task. This paper introduces an idea to improve the conventional edge detection methods. Type-2 fuzzy logic is used for representing uncertainty in the image gradients and aggregation. The uncertainty in the image gradients help to identify true edges which may be ignored by other edge detection techniques.