# Week 16: H_infinity Control

#### 10 February 2003

 Overview Reading FAQ Homework CDS 110b

### Overview

This weeks lectures are a review of some basic concepts from last term, but cast in the language of H_infty control theory. We define the norm of a signal and the induced norms of a system. Focusing on the H_infty norm, we define the notions of stability and performance for a system in terms of the sensitivity function and complementary sensitivity function.

\n" : "
\n"); # Loop through the filenames in order. \$getfnames = defined &GetFnames ? \&GetFnames : htdb::GetFnames; @filenames = &{\$getfnames}(\$DBPath); for (@filenames) { # Parse the filname and extract the ID and tag information (\$id, \$tag) = &{\$parsefname}(\$filename = \$_); next if not \$id; # Open the file and extract the contents \$contents = &htdb::readfile(\$filename); next if not \$contents; # Now see if this entry matches the criteria for a match next if not &{\$checkentry}(\$contents, %in); # Print out the information associated with this entry \$count += &{(\$in{_tight} ? \$tightentry : \$printentry)} (\$filename, \$contents, \$id, \$tag, \$DBURL."/".\$filename); \$num_found++; # See if we are counting and stop if needed last if (\$in{_count} && \$count > \$in{_count}); } # Close the list environment used for the results print (\$in{_tight} ? "
\n" : "\n"); return \$num_found; } # # Subroutine for alerting the user that no matches occured # sub PrintNoMatches { print "

## No matches found

\n"; print "Sorry, no entries match your request. "; print "Please choose some different parameters and try again.

\n"; print \$footer; }

• Doyle, Francis, Tannenbaum (DFT), Chapters 1-3

### Homework

The homework covers the basic definitions of signals and systems.

Homework #13