A decentralized control framework for modular robots

Distributed control paradigm offers robustness, scalability, and simplicity to the control and organization of module based systems. MSR (Modular Self-Reconfigurable) robot is a class of robot that best demonstrate the effectiveness of distributed systems as all modules in the robot are individuals that perform their own actuation and computation; the behavior of the complete robot is a collective behavior of all independent modules. In this paper, a general control framework, named General Suppression Framework, is proposed and a distributed control system based on the framework is presented. The control system is designed to control a set of MSR robots configured into a planar manipulator arm. All modules in the manipulator arm contain their own processing and actuation units, which allow them to evaluate and react to the environment independently. The modules can perform passive communication with their immediate neighbors and can exhibit aggressive or tolerant behavior based on the environment change to generate emergent group behaviors. A simulation program is developed to demonstrate the effectiveness of the distributed system in controlling the module based planar manipulator arm.published_or_final_versio

A responsive framework for optimal advertising policy in the digital music market

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A hybrid framework for the specification of automated material handling systems

This paper presents a hybrid framework that specifies and characterizes the capabilities of generic components in an automated material handling system (AMHS). The framework also provides rules and mechanism for binding these capabilities together so as to facilitate the process of task planning for AMHSs. As a hybrid framework, the formal mathematics of Communicating Sequential Process (CSP) is tightly integrated to the Unified Modeling Language (UML) to provide three important entities, namely, the object structure diagram, object communication diagram and CSP-based statechart to extend the capability of a UML model in specifying the key properties of AMHSs including synchronization, parallelism and communication. The results will bring us a step closer to the generation of a fully automated task-planning executive for AMHSs.published_or_final_versio

A Jacobian-based Redundant Control Strategy for the 7-DOF WAM

The mapping between the Cartesian space and joint space of robot manipulators has long been a difficult task for redundant robots. Two main methods are used in the classical approach. One is by using direct kinematic inversion in the position regime; the other is to use Jacobian Transformation in the velocity regime. However, for a redundant robot, a non-squared Jacobian matrix is resulted when mapping between the two spaces. This results in using appropriate optimization algorithms to compute along with the Jacobian matrix. Taking the second approach, the Jacobian matrix for a redundant robot will be non-square. One approach to obtain a solution is to use pseudo inverse, this approach is however computational intensive. This paper presents a pragmatic approach by which a joint of a 7-DOF Whole Arm Manipulator (WAM) is initially fixed to facilitate the computation of the squared Jacobian matrix. Based on this approach, appropriate optimization strategies that are outlined in the paper, can then be applied to determine the optimal value of the 'fixed' joint in real time. Experiments are performed to verify the viability of this approach, and the results established that a robust and flexible, Cartesian trajectory planning framework can be achieved for general redundant manipulators.published_or_final_versio

An optimization framework for modeling and simulation of dynamic systems based on AIS

Modeling and simulation can be used in many contexts for gaining insights into the functioning, performance, and operation, of complex systems. However, this method alone often produces feasible solutions under certain operating conditions of a system in which such solutions may not be optimal. This is inevitably inadequate in circumstances where optimality is required. In this respect, an approach to effectively evaluate and optimize system performance is to couple the simulation model with operations research techniques. In this paper, an optimization framework consisting of a simulation model and an immunity-inspired algorithm is proposed for optimizing the key parameters in the domain of automatic material handling.postprintThe 18th IFAC World Congress (IFAC 2011), Milano, Italy, 28 August-2 September 2011. In Conference Proceedings, 2011, p. 11608-1161

Immunology-based control framework for multi-jointed redundant manipulators

Artificial Immune System (AIS) has recently been actively researched with a number of emerging engineering applications that has capitalized from its characteristics including self-organization, distributive control, knowledge mapping and fault tolerance. This paper reports the development of an AIS paradigm for the distributive control of a multi-jointed, redundant manipulator. Traditionally, manipulator control is achieved by analytical solutions. By adopting a multiagent-based control paradigm, a multi-jointed manipulator can be thought of as a group of separately controlled agents. In this paper, we investigate the viability of a multiagent immunology-based control framework for the trajectory control of a multi-jointed redundant manipulator.published_or_final_versio

A strategic behavioral-based intelligent transport system with artificial immune system

This paper presents a distributed control framework based on human immunity to manage, coordinate and schedule a fleet of agents employed in an automated transport system. Through the study of immunology, each agent is abstracted as an independent agent operating in a multi-agent system that carries local information, searches for solution space and exhibits robust behavior to accomplish tasks. The internal behaviors of the AIS agents, which are decided by their perception of the environment, are studied to describe their strategies in performing various operations. Simulations are presented to examine the significance of each behavioral state in every necessary action or step and the impacts of these states on the overall performance of the transport system. The results of the simulations illustrate the importance of each behavioral state and their inter-relationship in establishing a truly decentralized and non-deterministic transport system. © 2004 IEEE.published_or_final_versio

Topological representation and analysis method for multi-port and multi-orientation docking modular robots

For MSR Robots to successfully configure from one configuration into another, the control system must be able to visualize the current structure of the robot, which cannot be done without appropriate information about each module's docking status. Although the type of information required to visualize the structure of a MSR robot differs with the physical design of the modules, there are essential information that are commonly required, such as docking orientation and identity of neighboring modules. This paper presents a novel multi-port and multi-orientation modular robot, and a representation method that can uniquely represent the geometric structure of a group of connected modules and to analyze the number of "reconfigurable DOF" within the structure. The proposed method uses labeled planar graphs and incidence matrices to describe the docking status of the modules within the structure, which helps to effectively encode the data in computer understandable expressions. In addition to the work in configuration analysis, an innovative mechanism for detecting the orientation of each docking port is also presented.published_or_final_versio

A tangible user interface using spatial augmented reality

In this paper, we describe the novel implementation of a tangible user interface framework, namely the MagicPad, inspired by the concept of Spatial Augmented Reality. By using an Infrared pen with any flat surface, such as a paper pad that receives projected images from a projector, a user is able to perform a variety of interactive visualization and manipulation in the 3D space. Two implementations using the MagicPad framework are presented, which include the magic lenses like interface inside a CAVE-like system and a virtual book in an art installation. ©2010 IEEE.published_or_final_versionThe 2010 IEEE Symposium on 3D User Interfaces (3DUI 2010), Waltham, MA., 20-21 March 2010. In Proceedings of 3DUI, 2010, p. 137-13

An AIS-based optimal control framework for longevity and task achievement of multi-robot systems

Extending the longevity of autonomous agent system in real life application is a difficult task, especially in applications which require continuous high system performance. This paper presents a novel decentralized balancing controlling architecture for longevity and achievement in multi-agent robot systems based on several artificial immune systems (AIS) designs and principles. Simulation experiments have verified the proposed architecture has good capability to efficiently minimize the trade-off in system achievement while maintaining system sustainability, even in very demanding situations.published_or_final_versio