1. 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

2. An Embedded System or Real-time System
Produces correct results in a timely manner.
Embedded system
computer hardware and software embedded as part of complete device to perform one or a few dedicated functions; often with real-time requirements.
Examples:
MMDs, PDAs, Cell phones, GPS, etc.
What is a real-time system? In a real-time system, the tasks have deadline. Each task is required to finish correctly before its deadline. 2

3. Motivations and Applications: Automotive Control, Avionics, Medical Systems, and Many Embedded Systems

4. More Applications: Oil Exploration and Production

5. 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-by-wire airplane, Drive-by-wire automobile.

6. Components of a Modern Control and Monitoring System
Monitor/Instruments:
Signal processing,
Energy conversion
User(s)/Operator(s) UI D T
User Interface
Decision and
Control System:
Computer
Hardware,
Software,
Electronics
Target System
Under Control:
Chemical/Fluid,
Electrical,
Mechanical,
Thermal N
Networking and
Communication A
Actuation:
Energy conversion,
Power modulation
Other Components

7. 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).

8. Correctness of Real-Time Control and Monitoring Systems
Satisfaction of logical correctness constraints
Satisfaction of timing constraints

9. 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