Abstract
This paper investigates a modified modeling of networked control systems (NCSs) with programmable logic controller (PLC). First, the controller-to-actuator and sensor-to-controller network-induced delays are investigated by a modeling tactics based on hierarchical coloured petri net (HCPN) in a structure-conserving way. Comparing with the recent result, the signal transmission delay is set in a random interval instead of a fixed mode; moreover, the data packet drop out and disorder are also taken into consideration. Second, delays captured form CPN tools are analyzed with a strategy based on Baum–Welch algorithm and statistics science. Besides, time delays are modeled as a Markov chain and the transition probabilities is calculated using the consequent from the previous operation. Finally, a comparison verification illustrates the equivalence property between proposed models.
Highlights
As a kind of control system [1,2,3,4,5,6], networked control systems (NCSs) have motivated a lot of research studies in the control field during recent years [7,8,9,10] by many advantages it shares; for example, reduced weight, high flexibility, simple installation and maintenance, and low cost
Contrasting with delays obtained from the hierarchical coloured petri net (HCPN) model in [32], it can be clearly see that because of the indeterminacy transmission phenomenon and the random transmission time delay the periodicity of Tca and Tsc is broken
Using the data from those two matrices, the stationary distribution of the Markov model λsc and λca can be estimated by those two time delays (Tca and Tsc) with the Matlab statics toolbox. e probability density function(PDF) can be calculated by sample arrays which can be obtained from HCPN consecutive time delay sequence
Summary
As a kind of control system [1,2,3,4,5,6], NCSs have motivated a lot of research studies in the control field during recent years [7,8,9,10] by many advantages it shares; for example, reduced weight, high flexibility, simple installation and maintenance, and low cost. E insertion of this performance condition, with a finite bandwidth, brings serial challenging and undesirable issues on account of data packet loss, scheduling, and latency in the process of communication signal’s transmission to remote analog input/output unit Affected by these cases, the communication channel, which takes the place of traditional signal transmission technologies, brings hard-to-solve problems in the stability analysis and controller synthesis because of transmission time delays. (i) First, considering the potential cause for the deteriorating performance or instability on NCSs, this paper sets network band delay in an interval instead of the definite transmission delay in [32] to make the model more realistic In this method, it is supported by the HCPN model to simulate some challenging issues on account of network information propagation.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
