A continuous longitudinal control signal for automated transportation systems via the low-frequency excitation of helical transmission lines

A method of generating continuous position information for use in the longitudinal control of automated ground transport systems is presented. The technique utilizes two specially excited four-wire helically wound transmission lines. The method of excitation, the signal detection, and processing schemes necessary to obtain the control signal, and the results of laboratory tests are presented. The technique should provide accurate, easily implementable, and environmentally impervious means of generating information for longitudinal control.