Ming Liang Lu

A G2 based MDOOM testbed for concurrent process engineering

A three life cycle dimensional concurrent process engineering (CPE) conceptual framework is presented, which is captured by a multi-dimensional object-oriented model (MDOOM) and implemented into a G2 based testbed. Emphasis is placed on the testbed configuration and implementation details. Finally, a distillation process design example is given to illustrate the way of using the testbed to carry out CPE.

A Multidimensional Design Framework and Its Implementation in an Engineering Design Environment

This paper describes a multidimensional design framework that distinguishes in an explicit way the role that control and opera tion play in the generation of the behavior of the device as a whole. This multidimensional framework that represents physical, behavioral, and operational aspects of the plant is intended to provide the means for consistency along the life-cycles of the enterprise, plant and prod uct, as well as, clear interactions between the plant structure and its associated behaviors. The design environment based on such frame work is being developed to support the increasing fidelity of the models that dictate the behavior associated to each piece of equipment, combined behaviors, inheritance of actions and interoperable life-cycle activity performers.

A Concurrent Engineering Environment for Chemical Manufacturing

Design and operation of process plants are now dominated by constraints imposed by safety, environmental impact, waste minimiza tion, cost effectiveness, controllability, and operability over the complete product and process life cycle including market analysis, conceptual and detailed design through to commissioning, operation, and disposal of products and decommissioning of the plant This means it inevitably in volves a large number of activities carried out by teams of engineers which draw on a variety of technologies that rely on diverse types of informa tion having complex data structures and relationships which must be shared by team members and integrated through computer based software packages Conflicting goals, uncertainty, and multiple solutions are crucial elements of these activities which are essentially about decision mak ing This paper describes the architectural and functional characteristics of a computer integrated concurrent engineering environment for life cy cle chemical manufacturing which allows project teams to work over a heterogeneous computer network Emphasis is placed on the key imple mentation issues with specific attention being paid to STEP-based chemical process data modelling, information sharing and communication, and distributed agent cooperation. The benefits this approach can bring are illustrated by considering the revamp design of a refinery fluid cata lytic cracking process, particularly in respect to the way the environment supports the project team

Operational design for start-up of chemical processes

Aiming at designing more operable chemical processes, this paper presents an operational design methodology for the case of process start-up which evaluates and improves a process flow diagram (PFD) into an operational flow diagram (OFD) by modifying the process structure, adjusting the process behavior and adding more facilities. An important controlled group unit (CGU) concept is introduced, which can be operated independently from other parts of the process. This CGU concept makes it convenient to decompose the whole process into CGUs so that the complicated design problem can be narrowed down and simplified. A multi-level blackboard architecture is used to implement such a design methodology which supports an interactive environment for engineers. Object orientation is used to implement the knowledge sources which improves the blackboard performance. Finally, the methodology is illustrated by a simple example and then is evaluated by an industrial hydrogen-desulfurization process design case study.

Fuzzy rule generation from data for process operational decision support

Neural networks and expert systems are now beginning to realise their potential in developing intelligent operational decision support systems. While neural networks are able to learn complex nonlinear functional relations between multiple inputs and outputs, there remains the important limitation that knowledge embedded in the neural network is opaque. This image of a black-box technology is a major factor influencing the acceptability of this approach because it does not improve the heuristic understanding of the domain problem. On the other hand, expert systems make use of logic rules to carry out heuristic reasoning. Knowledge used to reach a conclusion is transparent and can be displayed through HOW and WHY explanation facilities which are an integral part of well-founded expert systems. However, a critical problem with this approach is knowledge acquisition. This contribution introduces a fuzzy neural network to extract fuzzy rules automatically from numerical data. By changing fuzzy membership functions, three types of rules can be extracted, i.e. rules with and without fuzzy membership values and neuro-expert systems which overcome the problems described above.

A two-tier methodology for synthesis of operating procedures

To cope with the difficulties in synthesizing operating procedures for the process with complicated operational constraints, a two-tier planning methodology is presented in this paper in which the top-tier determines the operating path using optimization methods, and the bottom-tier synthesizes the primitive operations through a model based reasoning which is generic. The methodology is suitable for quantitative planning of operating procedures when operational constraints are more stringent. A case study is given to illustrate how the methodology is used in a case containing complex mixing constraints.

An agent-based environment for operational design

We provide the development up to date of P-DOSS (Plant Design and Operation Support System), an engineering support system that aims at assisting designers working in the detailed process design for creating a more safe, controllable and reliable plant. P-DOSS includes an integrated modeling environment for exploring multiple P&ID design alternatives together with the capability of analyzing each of them by means of simulating the operations carried out during the life-cycle of the plant. To this end, an experimental prototype has been constructed comprising a simulated multi-agent environment in which it becomes possible to concurrently carry out plans and actions. As a result a constant feedback of simulation agents is the key to produce more reliable design and operations. The object-oriented structure of P-DOSS distinguishes between the process component models and their physical counterparts which provides the possibility of selecting the adequate models fidelity, and sets the basis of a more flexible information model for both plant design and operations.

iGES — An intelligent graphical engineering system

Abstract To support plant operators to operate and manage the plant for better quality, safer, and less cost, this paper describes the design and implementation of an intelligent Graphical Engineering System — iGES. First, three types of functions, data management, problem solving and utilities, are designed to support the whole plant operation. Then, a distributed and integrated software system architecture is described. Within this architecture, a central platform manages the functional distributed components, in terms of data transfer and communication and interfacing. Finally, the implementation issues are discussed in two phases including technical and business decisions, current status and next step plans. Based on a few commercial packages, the first phase system has been implemented and installed into a project site for evaluation.

A hypermanager for a computer integrated concurrent process engineering environment

As one of the most important issues in the development of a computer integrated concurrent process engineering environment, this paper first draws the system requirements into data browsing and tool access management. A hyper-manager is then designed which introduces hyper-objects as front end. These hyper-objects are hyper-linked with system objects and support tools locally or remotely which are configured in a multi-dimensional object-oriented information model (MDOOM) and a concurrent tasking activity model. The MDOOM allows switching the information and support tools between different dimensions and the activity model maintains the tool availability to prevent conflicts. Integrated with WWW, the hyper-manager allows browsing both local and remote data and carrying out multiple tasks. A prototype system implemented in Tcl/Tk linking with Prolog has demonstrated a desirable functionality.