Petri nets based approach to software development for real-time control

1991 ◽  
Vol 138 (5) ◽  
pp. 474 ◽  
Author(s):  
P. Cofrancesco ◽  
A. Cristoforetti ◽  
R. Scattolini
Keyword(s):  
Software Development ◽  
Petri Nets ◽  
Real Time ◽  
Real Time Control ◽  
Time Control

Modeling and Simulation of Discrete Event Robotic Systems Using Extended Petri Nets

2012 ◽  
pp. 51-69
Author(s):  
Gen’ichi Yasuda
Keyword(s):  
Petri Nets ◽  
Real Time ◽  
Discrete Event ◽  
Control Flow ◽  
Coordination Mechanism ◽  
Robotic Systems ◽  
Real Time Control ◽  
Time Control ◽  
Extended Petri Nets ◽  
Implementation Problems

This chapter deals with modeling, simulation, and implementation problems encountered in robotic manufacturing control systems. Extended Petri nets are adopted as a prototyping tool for expressing real-time control of robotic systems and a systematic method based on hierarchical Petri nets is described for their direct implementation. A coordination mechanism is introduced to coordinate the event activities of the distributed machine controllers through friability tests of shared global transitions. The proposed prototyping method allows a direct coding of the inter-task cooperation by robots and intelligent machines from the conceptual Petri net specification, so that it increases the traceability and the understanding of the control flow of a parallel application specified by a net model. This approach can be integrated with off-the-shelf real-time executives. Control software using multithreaded programming is demonstrated to show the effectiveness of the proposed method.

scholarly journals Modelling and Control of Mechatronics Lines Served by Complex Autonomous Systems

Sensors ◽  
2019 ◽  
Vol 19 (15) ◽  
pp. 3266 ◽  
Author(s):  
Dragomir ◽  
Mincă ◽  
Dragomir ◽  
Filipescu
Keyword(s):  
Petri Nets ◽  
Real Time ◽  
Autonomous Systems ◽  
The Other ◽  
Added Value ◽  
Control Procedure ◽  
Real Time Control ◽  
Planning And Scheduling ◽  
Time Control ◽  
Wide Range

The aim of this paper is to reverse an assembly line, to be able to perform disassembly, using two complex autonomous systems (CASs). The disassembly is functioning only in case of quality default identified in the final product. The CASs are wheeled mobile robots (WMRs) equipped with robotic manipulators (RMs), working in parallel or collaboratively. The reversible assembly/disassembly mechatronics line (A/DML) assisted by CASs has a specific typology and is modelled by specialized hybrid instruments belonging to the Petri nets class, precisely synchronized hybrid Petri nets (SHPN). The need of this type of models is justified by the necessity of collaboration between the A/DML and CASs, both having characteristics and physical constraints that should be considered and to make all systems compatible. Firstly, the paper proposes the planning and scheduling of tasks necessary in modelling stage as well as in real time control. Secondly, two different approaches are proposed, related to CASs collaboration: a parallel approach with two CASs have simultaneous actions: one is equipped with robotic manipulator, used for manipulation, and the other is used for transporting. This approach is correlated with industrial A/D manufacturing lines where have to transport and handle weights in a wide range of variation. The other is a collaborative approach, A/DML is served by two CASs used for manipulation and transporting, both having simultaneous movements, following their own trajectories. One will assist the disassembly in even, while the other in odd workstations. The added value of this second approach consists in the optimization of a complete disassembly cycle. Thirdly, it is proposed in the paper the real time control of mechatronics line served by CASs working in parallel, based on the SHPN model. The novelty of the control procedure consists in the use of the synchronization signals, in absence of the visual servoing systems, for a precise positioning of the CASs serving the reversible mechatronics line.

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