A delay-dependent approach to H∞ filtering for stochastic delayed jumping systems with sensor non-linearities

This is the post print version of the article. The official published version can be obtained from the link below - Copyright 2007 Taylor & Francis Ltd.In this paper, a delay-dependent approach is developed to deal with the stochastic H∞ filtering problem for a class of It type stochastic time-delay jumping systems subject to both the sensor non-linearities and the exogenous non-linear disturbances. The time delays enter into the system states, the sensor non-linearities and the external non-linear disturbances. The purpose of the addressed filtering problem is to seek an H∞ filter such that, in the simultaneous presence of non-linear disturbances, sensor non-linearity as well as Markovian jumping parameters, the filtering error dynamics for the stochastic time-delay system is stochastically stable with a guaranteed disturbance rejection attenuation level γ. By using It's differential formula and the Lyapunov stability theory, we develop a linear matrix inequality approach to derive sufficient conditions under which the desired filters exist. These conditions are dependent on the length of the time delay. We then characterize the expression of the filter parameters, and use a simulation example to demonstrate the effectiveness of the proposed results.This work was supported in part by the Engineering and Physical Sciences Research Council (EPSRC) of the U.K. under Grant GR/S27658/01, the Nuffield Foundation of the U.K.under Grant NAL/00630/G, and the Alexander von Humboldt Foundation of Germany

The development of product design guidelines based on a new conceptual framework

The work described provides the development, implementation and evaluation of engineering product design guidelines suitable for engineering product designers. The motivation arises from collaborative efforts that continue to be made by the Least Economically Developed Countries (LDC) and the Most Economically Developed Countries (MDC) towards the development of the engineering design field. It is argued here that product design guidelines which are derived from existing product design methods enhance the capability of engineering designers to shorten time to market, deal adequately with product design constraints and boost supply chains. The sample for the proposed study is comprised of companies in Botswana (a least economically developed country) and the United Kingdom (a most economically developed country). The research has been conducted using a mixed qualitative research approach comprised of aspects from the framework method, cluster analysis and Kolb's model. The findings have identified five themes central to the product design process which are incorporated into the engineering product design guidelines. Case study work was conducted to validate the approach. The following claims are made for contributions to knowledge: 1. A conceptual framework which is a graphical co-ordinate system of engineering and management techniques required by nine engineering product design methods. The conceptual framework is arranged according to two orthogonal axes that describe the structure of the product design process and incorporate the need function form structure, the divergent convergent structure, the product design drivers, product realisation process and product development lifecycles. 2. The product design method notation which is a register of the expressions derived from the conceptual framework and is used to communicate and aid in the selection of a group of techniques being implemented, or intended for implementation by design teams; and 3. The configuration scheme which provides a clear link between components, subassemblies, products, projects, programmes and policies. The critical point put forward by this work is that the conceptual framework is only comprehensible today because the engineering product design methods in the public domain have imparted knowledge about the functions of physical products (described here as part of the need function form structure) at the expense of human needs and the interactive forms of human responses to physical products. The contributions of this research provide a holistic and coherent means of integrating design methodologies for the benefit of design teams in Botswana. The approach is, however, universal and may also be beneficial for design projects in the most economically developed countries

Reliable l

The reliable l2–l∞ and H∞ control for a class of Lipschitz nonlinear discrete-time singular systems with time delay is investigated via dynamic feedback control. The main goal of this paper is to design a generalized nonlinear controller such that, for possible actuator failures, the closed-loop system is regular, casual, and stable with a given l2–l∞ and H∞ disturbance attenuation level being satisfied. Some sufficient conditions are obtained in terms of linear matrix inequalities (LMIs), and the controller design method is also proposed. Finally, a numerical example is included to illustrate the effectiveness of our proposed results

Design Patterns for Avionics Control Systems

this document combine observations, reinterpretations, rational reconstructions, and redesigns of Avionics Control Systems within the realm of the DSSA ADAGE project[3]. An Avionics Control System (ACS) is the main navigation system of an aircraft. An ACS continuously collects sensor data to estimate actual state of an aircraft, computes desired aircraft state with respect to guidance modes, and performs actions that advise pilots and/or directly manipulate aircraft effectors in ways that bring actual and desired state in closer agreement. These patterns describe domain-specific architecture concerns and steps in the construction of an ACS using a minimal vocabulary (e.g., "components", "interfaces", "functions", "attributes"), and with minimal commitment to how these should be expressed within any particular design method, notation, engineering tool, or development process. However, because of the critical impact of Avionics Control Systems on human safety, it is essential to capture the resulting designs into appropriate formalisms and semi-formalisms that can be analyzed and reasoned about. Most patterns address only the architectural forms of components, interfaces, connections, and protocols, delving into details only when they impact overall design. These patterns may be used to generate instances of a family of concrete architectures and designs that may be implemented using a number of different languages, tools, and systems. Because of the diversity of platforms and programming languages used in avionics systems, implementation details are notably absent. This collection of patterns also omits sufficient description of signal processing and control algorithms, device characteristics of radar systems and other navigation hardware, pilot instrument and user inter..