This monograph develops a framework for time-optimal control problems,
focusing on minimal and maximal time-optimal controls for
linear-controlled evolution equations. Its use in optimal control
provides a welcome update to Fattorini's work on time-optimal and
norm-optimal control problems. By discussing the best way of
representing various control problems and equivalence among them, this
systematic study gives readers the tools they need to solve practical
problems in control.
After introducing preliminaries in functional analysis, evolution
equations, and controllability and observability estimates, the authors
present their time-optimal control framework, which consists of four
elements: a controlled system, a control constraint set, a starting set,
and an ending set. From there, they use their framework to address areas
of recent development in time-optimal control, including the existence
of admissible controls and optimal controls, Pontryagin's maximum
principle for optimal controls, the equivalence of different optimal
control problems, and bang-bang properties.
This monograph will appeal to researchers and graduate students in
time-optimal control theory, as well as related areas of controllability
and dynamic programming. For ease of reference, the text itself is
self-contained on the topic of time-optimal control. Frequent examples
throughout clarify the applications of theorems and definitions,
although experience with functional analysis and differential equations
will be useful.