  Stability is arguably one of the core concepts upon which our understanding
of dynamical and control systems has been built. The related notion of
incremental stability, however, has received much less attention until
recently, when it was successfully used as a tool for the analysis and design
of intrinsic observers, output regulation of nonlinear systems, frequency
estimators, synchronization of coupled identical dynamical systems, symbolic
models for nonlinear control systems, and bio-molecular systems. However, most
of the existing controller design techniques provide controllers enforcing
stability rather than incremental stability. Hence, there is a growing need to
extend existing methods or develop new ones for the purpose of designing
incrementally stabilizing controllers. In this paper, we develop a backstepping
design approach for incremental stability. The effectiveness of the proposed
method is illustrated by synthesizing a controller rendering a synchronous
generator incrementally stable.
