Patent ID: 7032763

Claim:
A method for guiding a land traveling straddle crane from a remote land station along a curved path, the method comprising the steps of: providing at least two GPS receivers, each of the GPS receivers having an antenna mounted to the vehicle so that the antennae are spaced apart from each other; defining a tracking line representing a desired travel direction at a current point along a desired land travel path that can include at least one curved portion, the tracking line intersecting a vehicle centerpoint; receiving signals from GPS satellites using a first GPS antenna fixed at a first position on the crane; receiving signals from GPS satellites using a second GPS antenna fixed at a second position on the crane that is spaced from the first GPS antenna in a horizontal direction; detecting a position of the first GPS antenna; detecting a position of the second GPS antenna; determining a rotational error as an angular difference between a vehicle centerline and the tracking line, the vehicle centerline extending in a front-rear direction through a vehicle center, the vehicle centerline having a fixed relationship relative to vehicle and the first and second GPS antennae; steering wheels of the crane to reduce the rotational error and to guide the crane along said land travel path.