  We present a suboptimal control design algorithm for a family of
continuous-time parameter-dependent linear systems that are composed of
interconnected subsystems. We are interested in designing the controller for
each subsystem such that it only utilizes partial state measurements
(characterized by a directed graph called the control graph) and limited model
parameter information (characterized by the design graph). The algorithm is
based on successive local minimizations and maximizations (using the
subgradients) of the $H_\infty$--norm of the closed-loop transfer function with
respect to the controller gains and the system parameters. We use a vehicle
platooning example to illustrate the applicability of the results.
