Distributed Robust Partial State Consensus Control for Chain Interconnected Delay Systems

Partial state consensus (PSC) is investigated for chain interconnected systems with time-varying delays and parameter uncertainties. A novel design philosophy of PSC control is proposed and a sequential calculation method is presented to guarantee the robustness of the controller. A sufficient condition based on linear matrix inequalities (LMIs) is derived and the stability is proven by the Lyapunov method. The proposed approach can ensure that the states which are subject to a consensus constraint achieve consensus, while those without a consensus constraint track their own set points. Finally, numerical simulations and a solution proportioning experiment are developed to validate the effectiveness of the proposed method

Observer Design for Interconnected Systems and Implementation via Differential-Algebraic Equations

A new approach to the design of observers of nonlinear dynamical systems is presented. Generally, linear or nonlinear control systems are expressed as explicit systems of differential equations and solved either analytically or numerically. If numerically, they are implemented using standard ordinary differential equation (ODE) solvers. In this thesis, a system is decomposed and modeled as an interconnection between two observer subsystems, particularly, as canonical DAE observers. In general, control design engineers may be faced with a formidable problem of solving this system analytically or in obtaining closed-form solutions. To attest to the complexity and complications in treating a system of interconnected DAE observer systems, a scaled-down version of a publication on “Small-Gain Theorem” is included in the appendix for the reader’s perusal. (A brief introduction to “Small-Gain Theorem” can be found in Chapter 4). The premise of this thesis is to demonstrate that, where the design of an observer plays a major role involving output feedback, there may be advantages in formulating a control system as a differential-algebraic equation (DAE), especially in the case of interconnected subsystems. An implicit system of interconnected DAE observers is considered and shown implementable using an existing DAE solver, whose resolution allows one the capability of computing input and output bounds. This is based on fixed or variable timesteps within the operating interval of each subsystem to ensure input-output stability (IOS) and the observability property of the interconnected observer system. The observer design method is based on the extended linearization approach. The basic background is provided for the design process of an interconnected observer system using DAE. Note, the application of the new approach has not been considered previously for the case of an interconnected DAE observer system

GeoBlockchain: The Analysis, Design, and Evaluation of a Spatially Enabled Blockchain

Land ownership and supply chain use cases are an enormous business challenge for both the public and private sectors. Every organization has different needs and wants, and they are researching and exploring ways to add value and impact their ownership tracing processes. Geospatial and Blockchain technologies are two emerging trends that could help an organization add value in this manner. The combination of blockchain and geospatial technologies would result in the new concept of GeoBlockchain, defined here as an artifact that could be used to study the trends and behaviours of participants (users) geographically and spatially, based on distributed nodes, transactions, and geo-locations through the blockchain technology. GeoBlockchain can also be used to visually display geo-ownership tracing processes (points, lines, and polygons) demonstrating the importance of geography. The result of this research was the design, development, implementation, and evaluation of a Spatially Enabled Blockchain ICT artifacts. Each prototype artifact was built using ArcGIS Enterprise and Hyperledger Fabric. The architecture designs were implemented with on-premises and cloud environments and evaluated based on users’ usability and sociotechnical metrics. This research indicates that blockchain technology can be integrated with geospatial technology, resulting in the GeoBlockchain framework along with its attendant implementation criteria in the age of GeoBlockchain