Petri net

About: Petri net is a research topic. Over the lifetime, 25039 publications have been published within this topic receiving 406994 citations.

A Petri-net coordination model for an intelligent mobile robot

Abstract: A Petri net model of the coordination level of an intelligent mobile robot system (IMRS) is presented. The purpose of this model is to specify the integration of the individual efforts on path planning, supervisory motion control, and vision system that are necessary for the autonomous operation of a mobile robot in a structured dynamic environment. This is achieved by analytically modeling the various units of the system as Petri net transducers and explicitly representing the task precedence and information dependence among them. The model can be used to simulate the task processing and evaluate the efficiency of operations and the responsibility of decisions in the coordination level of the intelligent mobile robot system. Some simulation results of the task processing and learning are presented. >

Autonomous And Timed Continous Petri Nets

Abstract: Since an autonomous continuous Petri net is presented as a limit case of autonomous discrete Petri nets, this new model thus preserves most of the properties of classical Petri nets.

Modeling and performance analysis of cluster tools using Petri nets

Abstract: The performance of cluster tools is gaining ever-increasing importance as the semiconductor industry migrates to larger wafer sizes, and smaller device geometries. Customers demand higher throughput-to-footprint ratios for semiconductor equipment. Cluster tool throughput is the outcome of complex interactions of various subsystems, and there is a critical need for appropriate tools that aid in understanding these interactions, and their effects on throughput. Current methods for throughput analysis are not very well oriented toward understanding the dynamics in cluster tool processing. In this paper we present a procedure to model cluster tools using Petri nets. These models help designers to comprehend the flow of wafers during processing. While Petri nets have been used extensively in the modeling and analysis of diverse manufacturing processes/systems, this to the best of our knowledge is the first attempt to specifically model cluster tools. A state cycle analysis is discussed next; this method enables equipment designers to extract steady state throughput information, as well as understand the interplay of subsystems during the wafer Row. Two example configurations are used to illustrate Petri net-based model building and analysts. These two examples encompass a variety of design features found in the industry today, e.g., sequential and parallel processing, single and dual end effector robots, anticipatory and simple scheduling.

Repairing process models to reflect reality

Abstract: Process mining techniques relate observed behavior (i.e., event logs) to modeled behavior (e.g., a BPMN model or a Petri net). Processes models can be discovered from event logs and conformance checking techniques can be used to detect and diagnose differences between observed and modeled behavior. Existing process mining techniques can only uncover these differences, but the actual repair of the model is left to the user and is not supported. In this paper we investigate the problem of repairing a process model w.r.t. a log such that the resulting model can replay the log (i.e., conforms to it) and is as similar as possible to the original model. To solve the problem, we use an existing conformance checker that aligns the runs of the given process model to the traces in the log. Based on this information, we decompose the log into several sublogs of non-fitting subtraces. For each sublog, a subprocess is derived that is then added to the original model at the appropriate location. The approach is implemented in the process mining toolkit ProM and has been validated on logs and models from Dutch municipalities.

Hierarchical reachability graph of bounded Petri nets for concurrent-software analysis

Abstract: Petri nets have been proposed as a promising tool for modeling and analyzing concurrent-software systems such as Ada programs and communication protocol software. Among analysis techniques available for Petri nets, the most general approach is to generate all possible states (markings) of the system in a form of a so-called reachability graph. However, this conventional reachability graph approach is inefficient or intractable, even for a bounded Petri net, due to state explosion in many practical applications. To cope with this problem, this paper proposes a method for constructing a hierarchically organized state space called the hierarchical reachability graph (HRG). Using the HRG, we obtain necessary and sufficient conditions for reachability and deadlock, as well as algorithms to test whether a given state or marking is reachable from the initial state and whether there is a deadlock state (a state with no successor states). >