Global Dispatcher Interface - Initial Prototype Design

This paper presents an overview of the design and development of a prototype Global Dispatcher Interface (GDI) for the control of a group of lifts. The role of the dispatcher is to assign passenger calls to the optimal lift in a group, as decided by a dispatcher algorithm. The GDI is independent of the underlying algorithm, which may be distributed remotely, and provides a standard means through which all interactions with the dispatcher may occur. To warrant the “Global” appellation the GDI must support any of the currently available, as well as anticipated, call station modes, types and configurations of cars, topology of control equipment and buildings. The analysis and design process follows a recognised Systems Development Life-Cycle, centred on Use Cases in a UML model. Significant diagrams from the model are presented and discussed to illustrate the evolution of the prototype design. The requirements, resulting from analysis of the Use Cases, identify that the GDI design must be compatible with a publish-and-subscribe architecture and a RESTful interface is selected for this purpose. Where possible, the prototype design uses open standards with an emphasis on demonstrating those aspects that are specific to lift system dispatcher operation, while attempting to demonstrate independence from implementation details such as programming language, network protocols, etc. The Standard Elevator Information Schema is particularly relevant and fulfils these objectives. The working prototype, which operates in conjunction with simulated lifts and passengers, is presented as a validation of the design.