초록 ▼

In order to permit digital processing of the alternating signals induced in a pair of perpendicular detecting coils mounted on a trackless vehicle which is guided over a buried guide cable carrying alternating current, one of the induced signals is phase shifted and applied to one input of a compara

In order to permit digital processing of the alternating signals induced in a pair of perpendicular detecting coils mounted on a trackless vehicle which is guided over a buried guide cable carrying alternating current, one of the induced signals is phase shifted and applied to one input of a comparator whose other input receives the other signal. At the same time, the other signal is also fed to a comparator which produces a rectangular output signal in phase with the original signal. The outputs of the two comparators are fed to a microprocessor which generates an error signal related to the time interval between the occurrence of periodic features of the two input signals. The error signal is used to engage the steering gear of the vehicle to return it to its path over the guide cable. In further embodiments, the frequency of the input signals is lowered to facilitate digital processing and a separate counter is used to uncouple the microprocessor from the detection apparatus, permitting it to process the data at a lower frequency of operation.

대표청구항 ▼

An apparatus for guiding a trackless vehicle along a path defined by a guide cable disposed in the road surfce, said guide cable carrying an alternating current, thereby generating an alternating electromagnetic field in the space surrounding the guide cable, said apparatus having detector means for

An apparatus for guiding a trackless vehicle along a path defined by a guide cable disposed in the road surfce, said guide cable carrying an alternating current, thereby generating an alternating electromagnetic field in the space surrounding the guide cable, said apparatus having detector means for detecting the direction and magnitude of the alternating magnetic field, said detector means including a first detecting coil (13) disposed substantially horizontally on said vehicle and a second detecting coil (14) disposed substantially perpendicular to said first detecting coil, for generating from the alternating magnetic field first and second alternating signals, respectively, and comprising, in accordance with the invention, phase shifting means (24) connected to the second detecting coil (14) and receiving the second signal to shift the phase of said second signal and thereby form a third signal; and computer means (21, 22; 25) connected to the first coil for receiving said first signal and to the phase shifting means (24) for receiving the third signal, said computer means including clock means (25t; 31, 25t′) and comparator means (21, 22) comparing the relative phase of the first signal representative of the phase of the alternating magnetic field with the phase of the third signal, said computer deriving a digital error signal as a function of the phase difference between the first and third signals to thereby obtain a control signal to steer said vehicle in the sense of reducing the phase difference between the first and third signals, resulting in guiding said vehicle (10) in a path over said guide cable (12).