This brief investigates the problem of robust sampled-
data H∞ control for active vehicle suspension systems. By
using an input delay approach, the active vehicle suspension
system with sampling measurements is transformed into a continuous-
time system with a delay in the state. The transformed
system contains non-differentiable time-varying state delay and
polytopic parameter uncertainties. A Lyapunov functional approach
is employed to establish the H∞ performance, and the
controller design is cast into a convex optimization problem with
linear matrix inequality (LMI) constraints. A quarter-car model
is considered in this brief and the effectiveness of the proposed
approach is illustrated by a realistic design example.