DE3001718A1 - Automatic guidance system for trackless vehicles - has circuit to generate phase difference signals to control system steering along AC cable in road surface - Google Patents

Abstract

An automatic guidance system utilises signal phase shift to control the steering of a trackless vehicle, which has a horizontally positioned coil together with a vertical coil in which voltage signals are induced as the vehicle passes over a cable in-set into the road surface. The cable carries an a.c. signal. The coil (13,14) signals are amplified (20,23) and are mixed (26,27) with signal generated by an oscillator driven (28) one out of four bit counter (30). Comparator stage (21,22) monitor the phase differences of the signals to generate a command for the steering unit using a microprocessor control unit (25).

Description

Arrangement for tracking of track-free vehicles

(Addition to P 27 52 027.7) The invention relates to an arrangement for Tracking of track-free vehicles according to P 27 52 027.7.

In such arrangements, a phase rotator is provided which makes an individual adjustment to 900 necessary because of the component tolerance. Temperature influences can cause changes in phase angle and gain.

The invention is based on the above-mentioned arrangements to be trained in such a way that a phase turner can be dispensed with. For this the invention provides that a) the mixing stages after a phase lock Method, for example working according to the sampling method, b) the oscillator vibrates at a frequency that corresponds to four times the superposition frequency, c) the superposition frequency is divided down in a one-of-four divider and d) the sampling pulses for the mixer stages at different, neighboring outputs of the divider (for example at outputs 1 and 2).

The invention is described in more detail below using an exemplary embodiment described and explained, which is shown in the drawing.

In Figure 1, 10 denotes a track-free vehicle; under the. about ft, lg a Leltdr ah 12 laid in the guideway 11 near the surface runs. A horizontal coil 13 and a vertical coil 14 are attached to the vehicle 10.

Horizontal "and vertical" denotes the direction of the coil axis or the coil core. An alternating current flows through the guide wire 12, which, in an undisturbed state, forms a circular field around the guide wire 12, by the evaluable in the coils 13 and 14 for the tracking of the vehicle 10 Stresses are induced.

The ones for tracking the track-free vehicle shown in FIG. 1 The arrangement serving 10 corresponds largely to the exemplary embodiment according to FIG der P 27 52 027.7, and has the following structure: The one from the alternating magnetic field of the guide cable 12 interspersed, horizontal coil 13 is via an amplifier 20 to a converter 26, the vertical coil 14 is fed to a converter 27 via an amplifier 23. Both converters are converted from an oscillator 28 via a one-out-of-one counter 30 fed, which oscillates at a frequency which is four times the superposition frequency the two mixing stages 26 and 27 corresponds. The sampling impulses for the niche levels 26th and 27 are at different, adjacent outputs of the divider 30 in the illustrated Embodiment tapped at outputs 1 and 2.

In Figure 3, the top, meandering line shows that of the oscillator 28 output frequency supplied; of the two liner 32 below and 33 gives 32 the superposition frequency at output 1 for the mixer 26 and the line 33 the output voltage at the output 2 of the divider 30 again.

The intermediate frequency voltages arise in the mixing stages 26 and 27 with a rigid phase difference. -L ~.

Adjustment of the phase rotation is not necessary. Temperature influences on the phase angles are not present.

The evaluation: the niche stage 26 is connected to a first comparator 21 connected, the other input is grounded, and also with an input of a second comparator 22, at the other input of which the output voltage of the mixer 27 is. The outputs of the two compressor pumps kl and 22 are connected to a computing stage 25, preferably a microprocessor. the Calculation stage 25 determined from the time interval between the rising edges of the pulse trains 32 and 33 by counting the deviation of the vehicle from the predetermined one Lane correspond to 3röf? -. E, the manipulated variable is not one in the drawing dargeteliten steering member of the vehicle is supplied.

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Claims (1)

Claim: Arrangement for tracking a track-free vehicle: ages mlt-effi of an electromagnetic alternating field that surrounds one of the driveway of the vehicle, built with alternating current flowing through the guide wire and can be scanned by at least two coils, which are vertical and horizontal in the same Height are arranged on the vehicle, the phase difference between that in the first coil induced first signal and one of the induced in the second coil The third signal obtained from the second signal is used to form a time interval which is used to generate a manipulated variable for a steering element of the vehicle, according to P 27 52 027.0, characterized in that a) two ischstufe (26 and 27) after a phase-locked process, for example a sampling process, b) an oscillator (28) oscillates at a frequency in which four times the superposition frequency corresponds to the mixing rate, c) the superposition frequency in a one-off four-divider (30) is divided down and d) the sampling pulses for the mixer stages (26, 27) at different., adjacent outputs (for example 1 and 2) of the divider (30) be tapped.