Examples of Real-Time and Embedded Systems Albert M. K. Cheng Real-Time Systems Laboratory Department of Computer Science University of Houston, TX 77204, USA
An Embedded System or Realtime System ¢ ¢ ¢ Real-time system l Produces correct results in a timely manner. Embedded system l computer hardware and software embedded as part of complete device to perform one or a few dedicated functions; often with real-time requirements. Examples: l MMDs, PDAs, Cell phones, GPS, etc.
Motivations and Applications: Automotive Control, Avionics, Medical Systems, and Many Embedded Systems
More Applications: Oil Exploration and Production
Control Systems: Old and New ¢ ¢ Old: Entire control process is done by mechanical hardware, governed by the mathematics of feedback control. Examples: Mastered cam grinder, Watt governor, Pneumatic process controller. ¢ ¢ New: Advances in electronics and computer systems lead to energetically isolate components of a controlled mechanical system. Masterless cam grinder, Digital oil production control of pump systems, Fly-bywire airplane, Drive-by -wire automobile.
Components of a Modern Control and Monitoring System M Monitor/Instruments: Signal processing, Energy conversion User(s)/Operator(s) UI User Interface N D T Decision and Control System: Computer Hardware, Software, Electronics Target System Under Control: Chemical/Fluid, Electrical, Mechanical, Thermal Networking and Communication A Other Components Actuation: Energy conversion, Power modulation
Cyber-Physical System (CPS) ¢ ¢ ¢ Tight conjoining of and coordination between computational and physical resources. Significantly enhance the adaptability, autonomy, efficiency, functionality, reliability, safety, and usability of current control systems. Example: An aerospace CPS will respond more quickly (e. g. , automatic aircraft collision avoidance), are more precise (e. g. , multiple landings in small airports), work in inaccessible environments (e. g. , autonomous space exploration), provide large-scale, distributed coordination (e. g. , automated air traffic control), are highly efficient (e. g. , long-duration space travel), and augment human capabilities (e. g. , tele-robotics).
Correctness of Real-Time Control and Monitoring Systems Satisfaction of logical correctness constraints ¢ Satisfaction of timing constraints ¢
Design and Implementation Issues ¢ ¢ ¢ ¢ Control and monitoring systems: old and new Model of an embedded/real-time system Scheduling real-time tasks Rate-monotonic scheduler, EDF, LLF Scheduling constraints Multiprocessor scheduling Identical, uniform, heterogeneous multiprocessors Specification, verification, and debugging
Скачать презентацию Examples of Real-Time and Embedded Systems Albert M
7d43808217549cd3379fb94cbe309ae1.ppt