Cyber-physical systems (CPSs) are the next generation of engineered systems in which computing, communication, and control technologies are tightly integrated. Research on CPSs is fundamentally important for engineered systems in many important application domains such as transportation, energy, and medical systems. We overview CPS research from both a historical point of view in terms of technologies developed for early generations of control systems, as well as recent results on CPSs in many relevant research domains such as networked control, hybrid systems, real-time computing, real-time networking, wireless sensor networks, security, and model-driven development. We outline the potential for CPSs in many societally important application domains.

http://cesg.tamu.edu/wp-content/uploads/2012/03/ps_files/12-02-10-CPS-Centennial.pdf

Cyber–Physical Systems: A Perspective at the Centennial

Hardware multithreading is becoming a generally applied technique in the next generation of microprocessors. Several multithreaded processors are announced by industry or already into production in the areas of high-performance microprocessors, media, and network processors.A multithreaded processor is able to pursue two or more threads of control in parallel within the processor pipeline. The contexts of two or more threads of control are often stored in separate on-chip register sets. Unused instruction slots, which arise from latencies during the pipelined execution of single-threaded programs by a contemporary microprocessor, are filled by instructions of other threads within a multithreaded processor. The execution units are multiplexed between the thread contexts that are loaded in the register sets.Underutilization of a superscalar processor due to missing instruction-level parallelism can be overcome by simultaneous multithreading, where a processor can issue multiple instructions from multiple threads each cycle. Simultaneous multithreaded processors combine the multithreading technique with a wide-issue superscalar processor to utilize a larger part of the issue bandwidth by issuing instructions from different threads simultaneously.Explicit multithreaded processors are multithreaded processors that apply processes or operating system threads in their hardware thread slots. These processors optimize the throughput of multiprogramming workloads rather than single-thread performance. We distinguish these processors from implicit multithreaded processors that utilize thread-level speculation by speculatively executing compiler- or machine-generated threads of control that are part of a single sequential program.This survey paper explains and classifies the explicit multithreading techniques in research and in commercial microprocessors.

https://www.di.unipi.it/~vannesch/SPA%202010-11/ungerer%20-%20multithreading.pdf

A survey of processors with explicit multithreading

Cyber–physical systems: Extending pervasive sensing from control theory to the Internet of Things

Integration of Smoke Effect and Blind Evacuation Strategy (SEBES) within fire evacuation simulation

Future manufacturing is envisioned to be highly flexible and adaptable. New technologies for reconfigurable systems and their adaptations are preconditions for this vision. Without such solutions, engineering adaptations of Industrial Process Measurement and Control Systems (IPMCS) will exceed the costs of engineered systems by far and the reuse of equipment will become inefficient. Especially the reconfiguration of control applications is not sufficiently solved. This paper gives an overview of the use of reconfiguration applications for downtimeless system evolution of control applications on basis of the standard IEC 61499. A new approach for the reconfiguration of IEC 61499 based control application and the corresponding modeling is discussed. This new method significantly increases engineering efficiency and reuse in component-based IPMCS.

Zero Downtime Reconfiguration of Distributed Automation Systems: The εCEDAC Approach

Dynamic software reconfiguration is a useful tool to adapt and maintain software systems. In most approaches, the system has to be stopped while the reconfiguration is in progress. This is not suitable for real-time systems, even on small-embedded systems. Timing constraints must be met even while the system is reconfiguring. Our approach is based on the real-time middleware OSA+. Our main objective is to be able to reconfigure services during run-time, with a predictable and predefined blackout time (the time the systems does not react due to the reconfiguration). Three different approaches concerning the blocking or non-blocking state of a service are presented. These approaches can be used to realize a tradeoff between the reconfiguration time and the blackout time.

Dynamic real-time reconfiguration in distributed systems: timing issues and solutions

New applications introducing restrictions in power consumption, heat, costs and available space are leading to small microcontrollers becoming increasingly important in distributed real-time systems. Traditional real-time middleware architectures are insufficient for these small devices. The paper presents an ongoing approach of constructing middleware for small devices by adapting the microkernel concept from operating systems to middleware. This middleware called OSA+ is service oriented and consists of a small core, basic-, extension-, and user-services. The core provides only restricted functionality, while the basic and extension services adapt and scale the system according to the application environment. A first (quick and non-optimal) prototype implementation offers a core size of about 60 kBytes and an average size of about 10 kBytes for a basic service. We consider this as a basis for further optimizations leading to yet smaller sizes.

Distributed real-time computing for microcontrollers-the OSA+ approach

Today more and more embedded real-time systems are implemented in a distributed way. These distributed embedded systems consist of a few controllers up to several hundreds. Distribution and parallelism in the design of embedded real-time systems increase the engineering challenges and require new methodological framework based on middleware. Our research work focuses on the development of a middleware that supports the design of heterogeneous distributed real-time systems and allows the use of small microcontrollers as computation nodes. Our study is aimed to a new approach that led to the development of OSA+-a scalable service-oriented real-time middleware architecture. This middleware has been used as the basic platform for different domain applications: (i) conception of an autonomous guided vehicle system based on multithreaded Java microcontrollers and (ii) development of a permanent monitoring distributed system for an oil drilling application. This paper presents the basic architecture of OSA+ and its implementation for the distributed real-time embedded systems design.

http://behnam4209.persiangig.com/document/os/paper%202.pdf

A microkernel middleware architecture for distributed embedded real-time systems

This paper present the use of fuzzy if-then rules for a decision support system in stock trading. The three following linguistic variables well be the input for the rule : view from the expert, earning — per-share and price to earnings ratio. The purpose of this rule is to assist investors making a decision on their shares. The investors need to make a right decision to gain a high profit in stock trading. Stock market is a complex environment. Therefore by using this Artificial Intelligence (AI) application which is Fuzzy Logic (FL) can make it simpler as well as giving benefits to investors. Most of the earlier research works show that FL can work within stocks environment.

Decision making using fuzzy logic for stock trading

The technology shows more and more powerful computers and systems. On the other hand, the needs in small embedded systems increase too, for e.g. PDAs, cell phones, even household appliances have now embedded systems. All these systems have a potential to communicate with each other. For these requirements, we are working on a real-time Java-based middleware, OSA+ (Open System Architecture - PLatform for Universal Services). Our main objective is to have a small-footprint and scalable real-time middleware. Part of our research work focuses on the dynamic reconfiguration of the middleware during run-time. We will present in this paper the research, which is going to lead us to a true dynamic reconfigurable middleware.

Etienne Schneider

Papers

Dynamic real-time reconfiguration in distributed systems: timing issues and solutions

Distributed real-time computing for microcontrollers-the OSA+ approach

A microkernel middleware architecture for distributed embedded real-time systems

Decision making using fuzzy logic for stock trading

Dynamic reconfiguration through OSA+, a real-time middleware