Patent ID: 8818568

Claim:
A control system for a rubber-tired gantry (RTG) crane, comprising: a global navigation satellite system (GNSS) receiver mounted on a RTG crane; at least one transceiver for processing signals received from at least one GNSS receiver located at a base station associated with a known location; and a controller comprising at least one data processor configured to: generate, using the known position associated with the base station and signals received from the GNSS receiver located at the base station, a satellite observation error estimate; generate, using the satellite observation error estimate and a position of the RTG crane determined using signals received from the GNSS receiver mounted on the RTG crane, at least one control signal representing a navigation command executable by at least one control device of the RTG crane; in accordance with a determination that signals received from the GNSS receiver located at the base station are processed by the controller at a slower rate than signals received from the GNSS receiver mounted on the RTG crane, generate the control signal at least partly by performing at least one asynchronous process at the RTG crane, the at least one asynchronous process comprising, prior to receipt of real-time signals from the GNSS receiver located at the base station, processing previously received signals from the GNSS receiver located at the base station for interim navigation, the processing accounting for anticipated errors in the signals received from the GNSS receiver located at the base station; and to output the control signal for execution by the control device.