Cnj : subtitle a visual programming environment for constraint nets

• Main Author: Song, Fengguang
• Language: English
• Published: 2009
• Online Access: http://hdl.handle.net/2429/13068

The Constraint Nets model (CN) proves to be useful for a wide variety of purposes, ranging from intelligent agent systems, and real-time embedded systems, to integrated hybrid systems with various time structures: discrete, continuous, and time-based. This thesis describes a new visual programming environment called CNJ (Constraint Nets in Java) which utilizes component-based technology. CNJ uses JavaBeans, Bean Introspection, drag-and-drop, and Java Swing MDI (Multiple Document Interface) technologies, as well as XML-based CNML as its standard interchange format. The environment supports constraint net modeling, simulation, and animation for hybrid systems. Furthermore, it provides support for a topdown design, middle-out design, and bottom-up design where the module bean can be reused anywhere in any other CN model, saving designers time and effort. As an experiment, a hybrid dynamic elevator system is developed successfully, and test results confirm the effectiveness of the tool for hybrid system modeling and real-time simulation.