  This paper proposes a globally and exponentially convergent predictive
observer for attitude and position estimation based on landmark measurements
and velocity (angular and linear) readings. It is assumed that landmark
measurements are available with time-delay. The maximum value of the sensor
delay under which the estimation error converges to zero is calculated.
Synthesis of the observer is based on a representation of rigid-body kinematics
and sensor delay, formulated via ordinary and partial differential equations
(ODE-PDE). Observability condition specifies necessary and sufficient landmark
configuration for convergence of attitude and position estimation error to
zero. Finally, for implementation purposes, a PDE-free realization of the
predictive observer is proposed. Simulation results are presented to
demonstrate performance and convergence properties of the predictive observer
in case of a wheeled mobile robot.
