Pace program 15 ms per day

Question 4 2day

1. What is Petri net?

2. Why to use PN algorithm for prediction the process control system?

3. The advantages used PN for your system?

4. Type of PN?

Answer
Q1

Petri net is a graphical and mathematical modelling tools applicable for many systems. They are promising tools for describing and studying information that are characterized as being concurrent asynchronous, distributed, parallel, non deterministic, and or stochastic. As a graphical tool, Petri net can be used as a visual communication aid similar to flow charts, block diagrams, and network. Analysis of the Petri net then will be revealed important of the structure and dynamic behavior of the modelling system. This information can be used to evaluate the model system and in suggesting improvement or changing the design. Thus, the development of Petri nets theory based on the application of the Petri nets such as in modelling and design of the systems. Petri net is an abstract, formal model of information flow.

 In general, Petri net is a graphic, mathematical and process-modelling tool for engineers in automatic control and computer science and which applicable to many systems. Moreover, Petri net can be applied to event related process control in simulating, checking, debugging and starting, the quantitative deviations from the ideal solutions of any given continuous or discrete process as well as providing formal checking at all development stage from specification via design to implement.

Q2 

A Petri net is a graphical and mathematical modelling tool. As a graphical tool, Petri net can be used as a visual communication aid similar to the flow charts, block diagrams, and networks. Basically Petri net can be divided to two major techniques. First technique is a Classical Method and second technique is a High Level Method. 

The Petri net approach provides an effective way of translating the constraints into software and allowing a computer to play a bigger role. The procedures must first be drawn up the Petri net. This is not the extra stage involving further scope for error, rather, it is obliging the designer to adopt the formalism that makes checking and error detection must simpler.

The implementation involves the use of the Petri net interpreter. This is not particularly large or complicated pieces of code (like a Basic interpreter, for example) and can be used repeatedly so that extra development cost associated with especially rigorous checking can be justified. 

 Q3

With respect to modeling and analysis, Petri nets offer the following advantages:-

1. Using Petri nets to model feature like precedence relation, concurrency, conflict and mutual exclusion of real-time system is simple and straightforward.
2. The formal graphic representation provides a medium of visualizing the complex system under modeling for both modelers and users.
3. Having a well-developed mathematical foundation, analysis can be carried out to detect deadlock, overflow and irreversible situation, etc.
4. Performance evaluation is possible through mathematical analysis of the model of the system (using deterministic timed Petri net or stochastic timed Petri nets).

Q4

   Flow chart below is a description of the fundamental theory of Petri net Algorithm.