  Empirical experiences have shown that simultaneous (rather than conventional
sequential) plant and controller design procedure leads to an improvement in
performance and saving of plant resources. Such a simultaneous synthesis
procedure is called as "co-design". In this letter we study the co-design
problem for a class of Lipschitz nonlinear dynamical systems having a quadratic
control objective and state-feedback controller. We propose a novel time
independent reformulation of the co-design optimization problem whose
constraints ensure stability of the system. We also present a gradient-based
co-design solution procedure which involves system coordinate transformation
and whose output is provably stable solution for the original system. We show
the efficacy of the solution procedure through co-design of a single-link
robot.
