Angle lag control methods and apparatus for long ground vehicles

Abstract

An automatic control system for articulated vehicles including leading and trailing wheeled supports each having steerable wheels and each pivotally connected to, and supporting, a center frame, and where the leading support may be manually controlled; wherein: (i) a parameter indicative of distance traveled by the vehicle is continuously measured; (ii) the leading angle .alpha..sub.1 between the longitudinal centerlines of the lead support and the frame is continuously measured and averaged over time and as a function of distance traveled to produce a delayed first signal representative of the time average of the leading angle .alpha..sub.1 ; (iii) the trailing angle .alpha..sub.2 between the longitudinal centerlines of the trailing support and the frame is measured to produce a signal representative of the trailing angle .alpha..sub.2 ; (iv) the delayed first signal is compared with the second signal to produce a third signal representative of the angular difference between the trailing angle .alpha..sub.2 and the time average of the leading angle .alpha..sub.1 ; and (v) the third signal is input to an automatic control system for steering the trailing support through a steering angle .beta. sufficient to maintain the trailing angle .alpha..sub.2 substantialy equal to the time average of the leading angle .alpha..sub.1, thus permitting the trailing support to move along substantially the same path as the leading support.