DE2064839A1 - Vehicle guidance system - Google Patents

Description

IBERLlN 33 β MUNICH Augurta-Vlktorla-Straßa 65 DlV-I ΠΟ. HANS RUSCHKE Planzenauar Straß. 2

Pat. Dr. Ruichka _, ~ ,, -, », -,. —.... »-, Pat. Attorney Agular

Dipl.-Ing. HEINZ AGULAR

T »l« _fl ramm-Adr · «··: PATENTANWÄLTE Talagraph-Adr ·» ·: Quadrature Berlin Quadrature Munich

M 2940

Minnesota iuining and! Manufacturing Company, Saint Paul, Minnesota 55101, V.St.A.

Kraftwa ^ eix control system

The wish to drive on the country roads safer and making it easier has led to various proposals for the automatic guidance of automobiles. Several of these Proposals have included the formation of a path of single, short, alternating polarity magnetic fields just above the surface of the road, a motor vehicle to be guided is equipped with flow sensors, and when driving along On the street, the flow sensors cross the fields and Generates / eri an electrical signal, which with regard to the The frequency of the distance between the fields and the speed aes "xiraftwagens depends,! laughs a general suggestion that in a frequency discriminator due to some difference between the frequency of the derived from the flow sensors iJi; -; xia ± G and the frequency to which the discriminator is set ict, oiibwicf.elte Strom used to control the throttle of the power

20 * 029 / 0208-

to operate. Often there is a pair of flow sensors in the transverse direction attached to the vehicle at a distance from each other, so that they sit on either side of the fields, and each-amplitude difference the signals in the two sensors are used to control or steer the car.

In some proposed systems, the consequence of the magnetic fields is made along and just above the road surface by one or more electrical conductors that run into the Road embedded and looped so that they reverse the polarity of the fields created by the current in the conductor (see e.g. U.S. Patents 2,493,755 and 3,029,893). It · it has also been suggested that the fields be formed by a series of permanent bar magnets embedded in the street should (see U.S. Patent 2,493,755), or by magnetization a rail of a track system (see USA patent 2 576 4-24), or by magnetizing a metal wire or a metal band laid along the road (see U.S. Patent 2,661,070).

In a similar proposed system, ferromagnetic strips are embedded in the road, in dense, regular intervals. The car to be managed has a transformer, and when driving over the one at a distance The following strip causes the reduced reluctance for the field of the transformer Frequency depends on the distance between the strips and the speed of travel. Any difference between the frequency of this developed Signal and a standard frequency is from one Frequency discriminator determined and to adjust the drug of the car (see e.g. USA patent specification 3 üö5 b4-6).

A fundamental disadvantage of these proposed systems. Be -... is that the devices in the street that generate cause an electrical signal, which the driving

209829/028 «bad omqinai.

speed of the car, are expensive to install and maintain. Embedding is expensive and also generally limited to new roads or roads being re-paved. aside from that For example, the embedded materials are expensive, and moreover, the electrical power is used for supply in the pus system of the electricity needed.

Most of these systems also provide an unalterable control from Hagnebfeidern and therefore only allow adjustment a single standard GB speed. if "weather," Road or traffic conditions are temporary or permanent ^ Change in the speed at which the cars drive over the Drive the road, make it necessary, there is no way the cars automatically guide at the new speed.

The present invention provides a new system for creating a series of magnetic signals along a road to control the speed and direction of a vehicle traveling on the road. In this system, an organic, polymeric, magnetizable marking, preferably a practically continuously painted line or strip, is applied to the surface of the road. In general, it is applied μ in the middle of each track in which the speed and direction are to be controlled. The strip is magnetized at a row of closely spaced points or areas which are arranged according to a predetermined frequency which can either be constant or can vary along the strip, the magnetization points having alternating polarity. The magnetic field or flow sensors in the car moving over the strip develop an alternating signal, the frequency of which is compared with a standard frequency. Each difference is used to change the speed of the car. A vehicle traveling on this road preferably contains two laterally spaced apart flow sensors which "ride" over the mametized strip, and

209829/0298

Each amplitude difference between the two developed signals becomes used to steer the vehicle.

This new system of creating a series of magnetic fields along a road is much cheaper than the known systems, and yet it has superior properties. Magnetizable paint itself is cheap and can be done quickly as well can be easily applied with conventional devices. In addition, it can be used both on existing and on new roads are applied. No power source is required to maintain the signal generated by the strip. The speed at which traffic is controlled can be changed in a convenient way daily or more often to keep up with the changing weather, road or road conditions Match traffic conditions by simply placing a vehicle with a magnetizing device near the road surface moves along the strip, or the pattern can be maintained for a long period of time. While the previous systems for controlling the speed and direction of a vehicle were quite impractical and their implementation unlikely, the system of this invention is extremely practical and provides a basis for developing one widespread automotive wire.

Magnetizable strips on roads that carry information Patterns of polarity magnetized are useful for delivering other types of control signals to one on the Vehicle moving on the road. For example, there are magnetisable strips in or on the edge of the lane, with a sequence being more magnetic Poles of alternating polarity are magnetized or opposite with continuous adjacent lines Polarity are provided along the strip, useful for warning the driver when approaching the edge dangerously the lane, whereby e.g. a magnetometer in the vehicle indicates when the vehicle is no longer over a strip

209829/0298

BATH ORIGINAL

is in the middle of the track or is in a strip off the Edge of the track approaching.

In the accompanying drawings is

-U ¹ Ig. 1 is a plan view of one half of a six-lane, split motorway,

Fig. 2 is a schematic side view of a vehicle for magnetizing a magnetizable strip on a road according to this invention, λ

Fig. 3 is a schematic representation of a part of a vehicle, which is automatically directed according to the invention,

! • 'ic- 4- a view of the vehicle of FIG. 3 along the line 4-4 of Fig. J,

Fip · :. t> is a schematic perspective view of a frequency differential accumulator of this invention by which the frequency of the developed signal is compared to a standard frequency and the speed of the vehicle is varied; and

Fig. 6 is a schematic diagram of an electrical Circuit that is the automatic control system of a Vehicle can operate which is directed according to the present invention.

Fig. 1 shows the top view of one half of a six-lane, divided highway according to this invention * Mur a the three lanes that form the right-hand side of the motorway are controlled. This track 10c has a continuous,> Strip 11 .bus magnetizable a material along the middle, strip 11 can be applied in various ways. : With the most convenient and cheapest method of application ϊ as stated above, the strip of / one-magnetic i

r - 20Ö8 2 9/0 2 tf S θ _: /; \ - ·.: ■ baoorigjnal-

prepared sable paint, the magnetizable particles, such as ferromagnetic oxides or iron filings, in dispersion in a paint vehicle, which generally contains an organic, polymeric, film-forming binder material in a volatile solvent. A wide variety of binding materials can be used including resin modified drying oils and alkyd, polyurethane, urea, allyl and epoxy resins. To address the need _v to avoid a high gain, it is convenient if a strip of intermediate thickness containing at least 30 and preferably 40 volume percent of magnetizable particles, although a rather thick strip may contain less magnetizable particles, such as 20 volume percent. In order for the paint to flow well and form a tough, adherent film, the percentage by volume of the particles, including any pigments and fillers, should generally not exceed 75 percent by volume.

The thickness of a color film on the highway is typically between 0.25 and 0.75 rom. Thicker magnetizable strips are also applicable, but if the strip is much thicker than 4 mm then magnetizing the entire thickness is much less convenient. The thicker the magnetized strip, the lower the necessary amplification of the signals developed in the flow sensors of the controlled vehicle and the longer the life of the strip. The strip also has a longer life if a tough film containing no magnetizable particles is painted over the strip with the magnetizable particles and if a channel xn is cut in the road surface and the strip is applied in the channel. Instead of a painted Jtreifens can eleventh Daetallfölie or an organic polym§i? It, pre-formed sheet, embedded in from the magnetizable particles, or on which they are applied can be used as a magnetizable strip 11, and may be such a film or a sheet such ^ be magnetized prior to application to the street. ',

. . ".., '" BADORjGiNAL

'; 201829/0211

Figure 2 shows one form of vehicle 13 for magnetizing a magnetizable strip in accordance with this invention a street. This vehicle has an electromagnet on a bracket 15 under the vehicle near the surface of the Road 10. The solenoid-to-road distance is preferably less than an inch, although larger distances are used when high power is supplied to the winding of the electromagnet. Where pretty thick magnetizable Strips are used and the entire thickness of the strip is to be magnetized, because the electromagricity can be are in contact with the strip. The carrier 15 may have wheels 16 that run on the road. From one Battery 19 to the electromagnet 14 · supplied current chopped at a constant rate by a device 20 with slip ring and commutator in pulses in alternating directions to im To form spaced apart magnetized surfaces or magnetic poles along the strip 11. The frequency of the current pulses can be chosen so that those formed at an equal distance from the rear arm 14a of the electromagnet Poles remain on the strip and the poles formed by the front arm 14b are canceled. The frequency of the pulses can also be such that when the arms 14a and 14b are energized they do not overlap the previously formed magnetic poles, whereby successive sets of north-south poles along the strip lag behind. In this case, this can be generated in the flow sensors Signals can be modified by circuitry in the controlled vehicle so that they have a constant wavelength. Instead of magnetizing, successive Dots of the strip 11 can have a sinusoidal pattern in the Strips are magnetized by applying a sinusoidal signal to the ■ electromagnet, or the electromagnet can fed by a capacitive discharge device.

For. the most practical way of working of the system should be the surface induction produced at the magnetized points Intensity of at least two Gauss and preferably of min-

209829/0296

have at least ten Gauss. The landmarks should be some distance apart so that the field between them is of a good height, but also not too far apart that the recovery mechanism does not respond quickly enough. Preferably, the adjacent points of opposite orientation along the strip are spaced V ₅ 5 "to 40 or $ 0 cm from one another. The vehicle 13 may have a demagnetizing electromagnet a'2. To remove any previous magnetization on the strip Demagnetizing the strip, the magnetizing vehicle 13 itself can be controlled automatically using the earlier magnetization of the strip.

An automobile or other vehicle that is used for the Control according to the invention is suitable, such as the vehicle 25 in Figures 3 and 4, contains at least one magnetic field bait Flow sensor near the surface of the road 10 to limit the strength of the field supplied by the strip and to limit the gain required for the signal developed by the flow sensor. The flow sensor is preferably movable and can be up to a distance of 20 cm from a smooth road surface & be lowered. That in the figures. 3 and 4 vehicle shown has two flow sensors 26 and 2'7 in a lateral arrangement according to FIG. 4 for use in steering. The flow sensors should be placed as far forward as possible, preferably in front of the front axle, so that they can quickly change any seal the vehicles can determine. i; ie flow sensors can have different shapes, but the embodiments shown each contain two large wings 20 and 29 of the same Plate or a plate layer structure made of ferromagnetic Material. The wings that collect the magnetic field they pass through and concentrate, are through a narrow intermediate portion 30 of the plate or plate laminate connected, and surrounding a conductive coil 31; this connecting intermediate part of the plates.

209829/0290 ° «G / nal

The signals developed in the two flow sensors 26 and 27 when passing through axial magnetic fields over a magnetized strip 11 are amplified and combined and then sent to a speed control mechanism which contains a so-called frequency differential accumulator. This device includes two synchronous electric motors, a "reference" - and a "Betutigungs ^ Hotor, wherein the windings of the reference engine can be powered by an AC power source with a standard reference frequency and the 'Jicklungen of the actuating motor to be fed g with the derived from i'lußsensor signal. It is to be ensured that the speeds at which the rotating parts of the motors are driven correspond to each other if the sequence of the derived signal corresponds to that of the standard signal on either the armature or the stator of the reference motor. The other non-fixed part of the actuating motor is free to rotate, and its speed of rotation differs from that of the free 'files des Bezu ^ smofcors (which may be jnuII) proportional to the difference in correspondence between the Drive speeds of the actuating and reference motors.

In the illustrated i'reouenzdifferentialakkumulator 33 f the armatures of the reference and actuating motors 34 and 35, respectively their shafts 36 and 37 with each other by a rigid coupling 38 tied together. The outer housing or body 40 of the Reference synchronous motor 3 ^ is fixed to the body 41 of the vehicle 25 attached, and the windings of the reference motor are Via conductor 39 from an alternating current source with a standard reference frequency (e.g. from a reference oscillator with a precision timing fork). The actuation synchronous motor 35 is supported only by its V / elle 37, and the windings this ho bore are fed with a signal which is developed in the flow sensors 2b and 27. The wave of jJt'Zu ^ G synchronous motor is running at a constant speed angotrioben, fed by the reference frequency of the

0 9 8 2 9/0298 ^BAD

Signais is determined. If the frequency of the signal derived from the flow sensor differs from the frequency of the standard signal, then the frequency of the EM developed in the stator of the actuating synchronous motor 35 does not correspond to the speed at which the shaft of the actuating motor is actually driven by the connection with the reference motor . As a result, the body 42 rotates the actuator motor 35> ^ur maintain a proper relationship with his Vjeile 37th

A lever 44, which serves as an output link, is on the body 4 ^ of the actuating synchronous motor attached and drent with the body. A link 45 including an electromagnetic clutch 65 (not shown) which are de-energized can, if the vehicle is not being controlled by the automatic guidance system, 'extends from the lever 44 to the throttle valve 46 of a carburetor so that the rotation of the body 42 of the actuation synchronous motor $ 5 sin opening or closing of the carburetor throttle valve. If the vehicle is traveling at a speed below the standard speed for the particular The speed of the road being driven is driving, then the frequency is that generated by the flow sensors 26 and 27 Signal lower than the standard frequency, and the body of the actuating synchronous motor rotates counterclockwise in Fig. 5> to open the throttle valve. The speed of the vehicle then increases until the frequency of the derived Signal is slightly above the standard frequency, causing the body to rotate clockwise in Fig. 5 and that The throttle valve closes somewhat. JFor a short time, the The body of the actuating synchronous motor has found its correct position to match the speed of the vehicle on the Maintain the standard speed, whereupon the lever and the carburetor throttle valve strive for it at a fixed speed for as long To remain in position as the standard highway speed remains constant.

BAD ORiGINAL

203823/0293

Other speed control mechanisms can be used to change the machine performance of a controlled vehicle in the event of changes the frequency of the derived signal can be used. To the Examples are frequency discriminators in vehicle control systems eier invention provided that generate a direct current when the derived signal differs in frequency from that to which the discriminators are tuned. This method the comparison of a signal derived from a flow sensor with a standard signal is only satisfactory, if it is not necessary to specify an "exact distance, to be maintained between closely spaced vehicles. ™ Since frequency discriminators can only provide DC outputs to operate the throttle valve actuating device, is a cumulative error "or slippage in these systems impossible to avoid.

A system such as the frequency differential accumulator 33 is preferred. This accumulator has a memory for Jileine cumulative frequency deviations, which at any moment relates the position of the vehicle on the road to the position which the vehicle should actually have at that moment. This memory is located in the angle that the lever 44- in each particular moment one ä decreases. As an example, it is assumed that the synchronous motors 3 ^ - and 3p each have 72 poles. For each polarity reversal of the electrical signals, the motors rotate 5 degrees. It is assumed that the magnetic poles aur the b "& raßenstreifen lie at a distance of ^ 2.5 cm. If the vehicle for some reason, such as when driving uphill, GeschwiiidigKeit loses, it dan 67.5 cm remains (3 UmJiehrungen) against the position it should be at that moment, the body of the i-iotOiS 35 fed with the derived signal rotates 15 degrees less than that of the reference motor, which opens the throttle valve to increase the speed The speed increases until the three missing i-oj.uiu ^ ehi ^ unrjen have been fetched again, so that the

209829/029 » ^8AD ■

Lever 44 resumes its previous position .. The "memory" was satisfied with regard to the three missing Pο! reversals ".

(Of course, the body 42 of the actuation motor 35 ^and the lever 44 attached to it should be able to rotate freely for a satisfactory operation of the frequency differential accumulator 33 · stops 4 '/ are provided on both sides of the fog 44 in the fog path, Instead of being directly connected to the body 42 of the synchronous motor 35, the lever 44 may be connected by a gear train which reduces the angular movement of the lever 44 for a given angle of rotation of the body 42. This "reduction in lever movement is particularly useful when using synchronous motors with a small number of poles. In the normal operating sequence of the frequency differential accumulator 33, the" lever should never reach these stops ". Electrical switches are attached near each stop and they operate devices for Warning the driver - switch off the automatic guidance system The return spring brings the throttle valve into a free position when the automatic control system is switched off.

If, instead of the body, the shaft of the first synchronous motor is fixed with respect to the vehicle and the bodies of the two Motors are coupled to one another, then the shaft of the second synchronous motor carries the lever that controls the carburetor throttle valve controls. But if the body of the first motor is attached to the automobile body, but the shaft of the first Motor is coupled to the body of the second motor, then the lever 44 is carried by the shaft of the second motor. In another arrangement, the bodies of both are synchronous motors attached to the automobile body, and the lever 44 is attached to a shaft which is connected to the two shafts of the motors is connected via a differential gear. Other arrangements

. ;., "2-0 9 8 23/029 8

BATH ORIGINAL

for coupling the frequency differential accumulator with the carburetor throttle valve are provided. For example, the üebel 44 operate the valve of a vacuum actuator, which "in turn moves the carburetor throttle valve. Such an arrangement requires less power from the synchronous motor and amplifiers. '

ei is a vehicle which is driven under control of a constant-ii'requens Differentialakkur.iulators] / t>, the number of revolutions of the coupled waves is directly propor- ä tionai the number of traversed by the vehicle lOlaritätsänderunden, and this number is directly proportional to the distance traveled by the aurus, provided that the standard speed does not change along the way. Odometer or devices for displaying the AnJtcunft of a vehicle can be at a particular destination point are driven by the coupled wave dor i-xotore as zh the number of revolutions of a base to Kessung the traveled distance is, which is independent of the air pressure and UEM slip of help if the frequency of the .otandardstromes by an electrically uefcrieberieu tuning fork Ainet accuracy of ¹ U ₁ ÜÜ1 percent is derived, which is lcictit be reached, should two consecutively fahrenue u'ahr tools its distance by no more aln f ^ 5j3 to 160 , S * km change. Instead of a uial of the above-standard frequency in a vehicle, the standard frequency can be broadcast by the customer radio and received in the vehicle, whereby even this small deviation is eliminated.

The steering of a vehicle 25 is controlled by comparing the signals developed in the flow sensors Z6 and d '/. ; Eggs in the illustrated embodiment, the signal from each Jj'lußsonsor Zi> 2 and ^r / amplified and then on opposite Lioktromij is emergency valves in the hydraulic steering system of the l' ^r ahrze'.geo, "fromn the!" ahr ^ eug is too far to the left of the strip, then the voltage developed by the left flow sensor is less than that of the right ! "flow sensor 27" and

209829/0298 bathroom original

the force of the left electromagnet becomes less than that of the right electromagnet. As a result, the left steering valve will be suppressed by the right steering valve and the vehicle will turn right. The vehicle thus returns over the strip until the voltage developed by the left flow sensor is greater than that of the right flow sensor, at which point the vehicle returns to the left again. This oscillation of the vehicle to place e _v s above the center will take place continuously, but only very little.

^ In other embodiments of the invention v / ground by the Signals derived from flow sensors are fed to a polarized relay (balanced armature relay) with two windings, which Direct current from an electric battery in the vehicle only switches to a steering valve controlled by an electromagnet at each time. In other embodiments Switch the polarized Kelais power for two electric motors which are coupled to the steering axle, or such electric motors or a single one, reversible in the direction of rotation hotor can be obtained directly through the derived from the flow sensors Signals are operated.

p Fig. 6 shows an electrical circuit which is connected to that for the Vehicle 25 shown device of the vehicle control system used can be. The two flow sensors 26 and 27 are connected to amplifiers 51 and 52, respectively. The reinforced Signals are sent to a local amplifier 53 »where they are combined and further amplified, and then sent to the second synchronous motor 35 of the frequency differential accumulator 33 given to will. The signals are also sent to threshold relays 5 ^ resp. 55j and when the signals are large enough, they bring these threshold relays to the position shown in FIG.

Accordingly, if a vehicle 25 on a freeway 10 is appropriate drives close to the strip to receive control signals of useful amplitude, then the flow sensors 26 and 27 develop

209829/0291

BAD ORfGSNAL

.Ö signal actuating the threshold relay ". In all likelihood according to, when a vehicle starts driving on a controlled motorway, the lever on one of the stop would be and switch 4ö. The driver was about the required Speed of travel on this road is informed by signs, maps or in any other way, and he accelerates or decelerates his vehicle to this speed. When the vehicle reaches the speed and is a little above or below, the difference in frequency causes between that derived from the flow sensors signal and the standard signal that the fog 44 is moving away from the ' Stop 4? triggers and actuates the switch 48, whereupon a ! Area lamp 57 in the dashboard of the vehicle and in electrical Connection from threshold relay 55 via the switch to hasse lights up. (In another possible arrangement the driver can operate a switch on the dashboard trigger a mechanism, the lever 44 between the stop 4 '/ arranges.)

The lighting up of the lamp 57 indicates to the driver of the vehicle that he can switch on his automatic control system. This is done by actuating the push button switch 50, which is also attached to the dashboard. The actuation of the push button & switch 5ö closes a circuit from an electric battery via the line 59 and the switches 60, 61 and 62 and then through various parts of the vehicle control system to earth: the coil 64 of a magnetic coupling 65 with an electromagnet, which connects the lever 44 of the frequency differential accumulator 53 to the throttle valve of the carburetor, two external lamps 67 and 6ö, which indicate to other vehicles that the vehicle is being controlled by an automatic vehicle control system, the coil 69 of a double-pole relay 70 for closing the circuit, which connects the flow sensors 26 and 27 to auxiliary steering valves 49 and 50, and the coil 71 of an electromagnet that holds the switch 5ö in the closed position.

209829/029 &

^ß AD ORIGINAL

With the system thus excited, the signals developed in the flow sensors 26 and 26 are accumulated by means of the frequency differential accumulator compared to the standard frequency to operate the lever 44 and control the speed of the vehicle.

The vehicle can be removed from control by the guidance system in several different ways. When the driver of the car either presses the brake or accelerator pedal or moves the steering wheel, he opens one of the switches 60, 62 or 61 -6 released (whereby the return spring 72 brings the throttle valve into the free position), the electromagnet 69 for the relay 70 is de-energized, so that the flow sensors 26 and d7 no longer operate the auxiliary steering valves, and the coil 71 w: Lrd de-energizes, whereby the switch 58 is released.

The driver can remove the vehicle from the system at his own request, or he may have been asked to do so. If, for example, the system malfunctions in any way, so that the second synchronous motor 35 because of the first; lagging, Wk then strikes the lever 4-4- on one of the switches 4b and switches this to a position which is not shown in FIG. Thereupon the light 57 in the dashboard goes out, and a flashing lamp 73, the rear light 74 of the vehicle 25, a lamp "take over control!" 75 in the dashboard and a warning buzzer 76 switched on. The driver can then take control of the car himself and possibly take it out of the}: controlled lane.

Claims

2 0 9 8 2 9/0298 _BAD original

Claims (1)

Claims 1. Procedure for delivering tax information to a vehicle, which travels on a road and both a magnetic flux detection device to generate electrical signals according to a pattern of both magnetic signals above the Road as well as a mechanism which is operated by the electrical signals received from the magnetic flux detection device be developed, characterized in that the l-iuster magnebischer! '' elder above the road is created in that 1) a color scheme is applied to the street, consisting of an organic, polymeric binder, which forms a durable, adhesive paint film, and made of a magnetizable, small-part material which is dispersed in the binder, and 2) the applied paint composition is magnetized with an information providing pattern of polarities, the magnetic induction About surface having at each magnetic pole has an intensity of at least "ll Gauss. 2. The method according to claim 1, characterized in that the magriotizable strip has a thickness between 0.25 and 4 mm and at least 40 percent by volume magnetizable Has particles and the surface magnetic induction at each pole is at least 10 Gauss. 5. Method for controlling the speed of a vehicle, driving on a road and a magnetic flux detection device and a speed control device which is connected to the Magrietfluss-Ermittlungsvorrichbung which, if the vehicle is a series of magnetic 209829/0298 bathroom original fields from the magnetic poles along the Road exit according to a predetermined distance, with adjacent poles having opposite polarity, the Magnetic flux detection device generates a pulsating electrical signal, the frequency of which depends on the distance of the magnetic poles and the vehicle speed is determined, and the developed signal in the speed control device can be compared with a standard frequency and changes the vehicle speed can be, so that .von the Magnetfluß-Ermittlungsvor-P direction generated signal with the standard frequency in accordance is brought, characterized in that the magnetic poles are generated by 1) a practically continuous strip of a magrietisable. Material is created that extends in the direction of travel along the road by you put a color scheme on the street, an organic, polymeric binder that forms a permanently adhesive film, and contains magnetizable, fine-grained material dispersed in the binder, and ™ 2) the strip with a sequence of magnetic poles like described magnetized, the surface magnetic induction each magnetic pole has an intensity of at least 2 Gauss " 4 ·. Method for controlling the speed of a vehicle on a street where you can 1) creates a sequence of magnetic poles that extend in the direction of travel along the road and in are arranged at a certain distance, with adjacent poles having different i-olarities, 209829/029 8 bad origsnal 2) the vehicle with a main flow detection device at a point where it crosses the magnetic fields above the magnetic poles and a pulsating one electrical signal developed, its frequency depends on the distance between the magnetic poles and on the vehicle speed, and 5) equips the vehicle with a speed control device to the of the hagnetf1uß-investigation - to receive device-developed signals to compare the frequency with a ötandardfrequenz and {to change the vehicle speed so that the signal generated in the iiagnetfluß-Eriiiittlungsvorrichtung with the standard frequency matches, characterized in that the speed control device a memory device containing an output signal provides which is the accumulated difference between the number of pulses in the magnetic flux detection device generated bignals and the number of pulsations that the signal generated in the luagnetfluss-Detection device were "brought into agreement with the standard frequency, and that the speed control device seeks to keep the speed of the vehicle as long as " 'Z.U change until the accumulated difference is balanced. Hp / Iie ^BATH 20982 9/029 8