Page 21 - DCAP608_REAL TIME SYSTEMS

Real Time Systems

Notes 2.2 High Level Controls

Controllers are usually systematized in a hierarchy. Higher level controllers and multiple
control loops supervise the behaviour of low-level controllers. Decision making complexity
and time-scale increases as go up hierarchy. Move from control to planning. Higher level
planning must still be done in real-time, although deadlines are less tight.
Figure 2.2: High Level Controls

Self Assessment

Fill in the blanks:
1. Real-time systems have found applications in ……………… ranging areas.
2. Errors arises due to A/D and D/A conversion as well as due to ………………
3. It is not meaningful to talk about guarantying real-time ………………
4. Software developing is ……………… to errors.

5. Controllers are usually ……………… in a hierarchy.
6. Higher level controllers and multiple control loops supervise the behaviour of ………………
controllers.

2.3 Signal Processing

The term real-time “refers to systems in which the correctness of the system depends not only on
the logical result of computation, but also on the time at which the results are produced”.

16 LOVELY PROFESSIONAL UNIVERSITY