We explore the challenges and opportunities of shifting industrial control software from dedicated hardware to bare-metal servers or cloud computing platforms using off the shelf technologies. In particular, we demonstrate that executing time-critical applications on cloud platforms is viable based on a series of dedicated latency tests targeting relevant real-time configurations.
Programmable Logic Controllers (PLCs) are an established platform, widely used throughout industrial automation but poorly understood among researchers. This paper gives an overview of the state of the practice, explaining why this settled technology persists throughout industry and presenting a critical analysis of the strengths and weaknesses of the dominant programming styles for today's PLC-based automation systems. We describe the software execution patterns that are standardized loosely in IEC 61131-3. We identify opportunities for improvements that would enable increasingly complex industrial automation applications while strengthening safety and reliability. Specifically, we propose deterministic, distributed programming models that embrace explicit timing, event-triggered computation, and improved security.
The effects of realistic wireless communication are important for the modeling and evaluation of emerging connected and automated vehicle applications. This paper discusses the development of a novel closed-loop connected vehicle analysis system (CONVAS) interlinking Vissim microscopic traffic simulation and ns-3 wireless communication simulation. In CONVAS, ns-3 uses Vissim’s vehicle positions for wireless modeling and in turn Vissim uses the packet reception from ns-3 to modify vehicle behaviors. The authors propose an application for intelligent avoidance of the dilemma zone to demonstrate the use of the platform for modeling connected and automated vehicles and to illustrate the effects of communications on the application performance. A simulation experiment was conducted with a test bed for an isolated high-speed, fixed-time signalized intersection with different communication model configurations. The evaluation results showed that the effectiveness of the application as measured by successful clearing of vehicles from the dilemma zone depended greatly on performance of wireless communication.
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