A FAM-based Agent for a Ball and Beam

Abstract

This paper presents a reactive agent built under the Subsumption Architecture, which purpose is to control a Ball and Beam system. The architecture of the agent is implemented making use of a fuzzy associative memory (FAM) and feedback control laws. The FAM is used to address the action selection problem known for this architecture. The FAM defines different fuzzy conditions. These conditions are associated to feedback control laws. The integrated control signal is obtained by defuzzifying the FAM through the weighted average technique. The timeresponse of the agent is simulated on a model of the Ball and Beam system and validated with an implementation at the laboratory. The results show the behavior of the variables of the system and the dynamic characteristics of the agent. The control signals stay active at every moment and the FAM allows smooth transitions between them, depending on the fuzzy condition of the system. 89978-1-4244-1608-0/07/$25.00 ©2007 IEEE.

A granular approach to the automation of bioregenerative life support systems that enhances situation awareness

“…This section develops the FAM-based switched approach to control the LED-lamp that regulates the dissolved oxygen concentration in the fourth compartment of the aquatic habitat. The FAM defines the operating conditions and the switching characteristics of the controller, which is encapsulated within the FAM-based agent architecture [7], [8]. Subsection III-A presents a description of the agent and Subsection III-B elaborates on its application to the control of the habitat.…”

“…Furthermore, this approach also allows the implementation of fail-safe and fail-operational mechanisms, critical in any system that involves humans and automation technology. In particular, this work uses intelligent agents based on FAM's made of granular structures composed of n-dimensional noninteractive fuzzy sets [6], [7], [8], [9]. In this work, granular structures [10], [11], [12], [13] define the situations in which each control action governs the system, thus implementing a switched control paradigm to their automation.…”

A FAM-based Switched Control Approach for the Automation of Bioregenerative Life Support Systems

“…The controller is encapsulated within an architecture known as a FAM-based agent. 6,7 A description of the agent is presented in Subsection A and its application to the control of the habitat is presented in Subsection B. Note that the notation used to describe the agent architecture is not related to that of Section II.…”

“…The FAM-based agent represents a switching control approach, in which controllers are assigned in a modular fashion to each condition of the system in the form of (Situation, Controller). 7 It introduces flexibility to the automation of the system and enables its incremental development. The architecture is characterized by (1) a perception function that results in a granular structure, (2) a set of controllers, and (3) a correspondence function that associates a controller to each situation and combines all possible control actions into an integrated control signal.…”

“…The availability of abundant sensor information and the capability to define perceptual elements enables a modular approach to system automation and integration, and for the implementation of fail-safe and fail-operational mechanisms. This paper proposes the use of agents based on fuzzy associative memories (FAM's) [6][7][8] to develop granular structures composed of n-dimensional non-interactive fuzzy sets for the switching mechanism. The granular structures also allow for an incremental development and automation by associating a control task to each granule.…”