  This paper studies control synthesis for a general class of nonlinear,
control-affine dynamical systems under additive disturbances and
state-estimation errors. We enforce forward invariance of static and dynamic
safe sets and convergence to a given goal set within a user-defined time in the
presence of input constraints. We use robust variants of control barrier
functions (CBF) and fixed-time control Lyapunov functions (FxT-CLF) to
incorporate a class of additive disturbances in the system dynamics, and
state-estimation errors. To solve the underlying constrained control problem,
we formulate a quadratic program and use the proposed robust CBF-FxT-CLF
conditions to compute the control input. We showcase the efficacy of the
proposed method on a numerical case study involving multiple underactuated
marine vehicles.
