DE3208550C2 - Vehicle, in particular industrial truck, for driverless steering on a guide wire - Google Patents

Abstract

A vehicle, in particular an industrial truck, for driverless steering on a guide wire, with a load axle and non-steerable load wheels and at least one steerable wheel at the other end of the vehicle as well as two sensors arranged in the area of an axle in the middle of the vehicle to record measured variables depending on the respective distance from the guide wire and a steering drive for the at least one steerable wheel with an actual value transmitter for the steering angle, has a third sensor (17) as far away as possible from the other two sensors. In a circuit arrangement for evaluating the measured variables and determining a steering target signal, a driving range selection circuit is provided, by means of which measured variables from the third sensor can be introduced into the circuit arrangement depending on the driving conditions. An additional curve target value can also be determined from the two first-mentioned probes as a function of a set steering angle value Θ ↓ i ↓ s ↓ t and a temporal change in the inclination of the vehicle center axis to the guide wire (20) and a steering angle target signal in Can be switched on depending on the travel range selection circuit.

Description

ai (like claim 3)

a2 (like claim 3)

aj are arranged the distance of the third sensor at the other end of the vehicle from the axis, in the vicinity of the ersteu and second sensors (8, 9) ι>, K \, K ₂ = constants.

11. Vehicle according to claim 6, characterized in that that a steering-soli-signal for the second branch is formed according to the formula - '"

OsU = Zl ■ - ^V v + * 2 · I fr! ■

where} ^ Y ₁ , m, O ₂ JiP, Isowie, 4 ^ and Y _{1 have} the meaning according to claim 3.

12. Vehicle according to claim 6, characterized in that that the steering target signal for the third Branch is formed according to the formula

«Sw / = K _u ■ Y _v + K ₁₂ - I _Ψγ \ ■ sign U Ώ

where the sizes have the meaning given above and K _n and K _{12 are} constants that are larger than K ₁ and K ₁ .

13. Vehicle according to claim 6, characterized in that that the steering target value for the branch of cornering is formed according to the formula

«Sw / =

Y, + K ₂₃ ■ I _Vv \ · sign {AY,) + K ₃ Tl

where the quantities stated correspond to the data in the claims 3-5 and K _13, K i and K ₃ are constants _3, which are optimized with respect to K, and K. ₂

14. Vehicle according to one of claims 1 - 13, characterized in that the driving range selection circuit is designed as a multiplexer (H5), in which the corresponding steering angle target signal 6w / for the respective area in the steering drive (2io; can be switched through.

The invention relates to a vehicle, in particular an industrial truck, for driverless steering on a guide wire, with a load axle and J5 non-steerable load wheels at one end of the load bearing and at least one steerable wheel at the other end of the vehicle and in particular consisting of coils three sensors for recording measured variables depending on the respective distance from the guide -40 wire and a steering drive for the steerable wheel with an actual value transmitter for the steering angle and further with a circuit arrangement for evaluating the measured variables and determining a steering target signal.

Three sensors, each consisting of two coils, are known from EP 00 01 504 on a vehicle. There are two, preferably one, axle, namely the axle with the non-steerable wheels, Associated sensors with coils on both sides of the center line and a third sensor, the coils of which in the> o essentially between the coils of the other two sensors are arranged on the center line. One Another arrangement of the sensor assembly, but based on the center of the vehicle, is included. Thereby the direction and the lateral displacement of the vehicle should be used for the development of the steering signals be recorded according to the vehicle steering geometry.

The three sensors are closely associated with one another. Through this anorcl- t> o The aim is to improve the steering of the vehicle even at higher speeds can be achieved.

According to DE-AS 18 01 967 are to improve the driving stability of vehicles while avoiding b5 taking into account many parameters and a great deal of effort, two sensors in the longitudinal direction one after the other angeorltiet. This is particularly the case Arrangement of a sensor on the front part, for example in the area of the bumpers and another Sensor on the rear part of the vehicle, also in the area of the bumpers there. at When cornering, however, steering signals can only be determined at low driving speeds, apart from that of considerable uncertainty with changing curvatures.

For this reason, in DE-OS 25 21 571 except the> A third sensor in the central zone of the sensors located at the front and rear of the vehicle Arranged in the vehicle around the curve fin radius, which is determined by the course of the guide wire, in a better way to identify. Here v, but only a control influence is introduced, which depends on the Curve is changeable.

With the known designs, only a uniform steering target signal is determined.

Sensors of the embodiments discussed generally have suitable coil arrangements, either at a symmetrical distance to the central longitudinal axis of the vehicle or in a crossed arrangement aer longitudinal center line, so that signals are picked up by a field generated by the guide wire and from this, measured variables for representing the position of the vehicle relative to the guide wire were developed from which signals for the steering drive are derived

When a steerable wheel is mentioned above, it is implied that this expression is also a includes two-sided wheel arrangement on steering axles or a movable steering axle for two wheels.

It can be assumed that the concentrated anoidization of sensors on the rigid Load axis is favorable for a threading operation on a guide wire. There is also a curve guide

possible in both directions of travel.

When cornering, however, problems arise, especially at higher speeds and the Danger of so-called rolling movements, which also occur in particular when driving straight ahead can if the steerable wheel is also the drive wheel.

Basically it is included that by means of drive means or motors arranged on the vehicle either the steerable wheel or the unsteerable wheel load wheels are driven. Both are on vehicles of the type described known per se. However, the invention particularly preferably extends to a Vehicle in which the steerable wheel is also driven. If this is a With the end of the load bearing at the front of the vehicle, it is far from the direction of travel Sensors removed. This creates the swaying movements, which are a hindrance, especially in a narrow aisle, so that disadvantages must be accepted or in the known vehicles of this type the driving speed must be reduced so much that the economic utilization of the Vehicle is significantly impaired.

The invention is based on the object of providing a vehicle of the type specified at the beginning to improve that the driving characteristics under particular inductive guidance is improved, namely from one point of view in the area of a straight route and from another point of view jo even when cornering, this purpose by simple means, in particular circuit means, and simple arrangements on the vehicle should be achievable.

This object is achieved in that two r> sensors are combined on an axis and the third sensor is arranged at a distance from the axis, and that in the circuit arrangement a driving range selection circuit is provided which introduces w for different driving ranges various steering target signals derived from the first and second sensor on the one hand and in addition from the third sensor on the other hand provides and different Steering target signals are formed on the one hand from two sensors and on the other hand from three sensors and the Introduction of additional steering signal influences in deriving measured variables also from the third sensor in Depending on the driving range introduced by the driving range selection circuit is provided.

The distance of the third sensor can advantageously as large as ^Moegi: h are selected: i. The arrangement of the third sensor results in a division of the sensors, which is already advantageous for driving the vehicle of permissible sizes in the different driving areas under the prevailing conditions to enable an optimal drive. Control takes place in «> all driving areas, but under different conditions.

Another particularly preferred one also provides in connection with this solution Embodiment provides that an additional curve target value as a function of a set steering angle value and a temporal change in the inclination of the vehicle center axis relative to the guide wire Inclusion of the respective distance values from the first and second sensors in relation to the guide wire is determined and the steering angle target signal depending on the driving range selection circuit is switchable. This results in the advantage of a far more precise cornering, because in a special Evaluation also a speedometer can be saved.

This includes the fact that only the so-called first and second sensors in the area of an axle, namely in the area of the load axle or steering axle, preferably in the area of a load axle, are used during cornering, with an activation or deactivation depending on certain driving areas of the so-called third sensor is provided and then in each case the additional curve target value is introduced. In particular, it is to be assumed that the first and second sensors are used when cornering, while the third sensor is introduced into the control when driving straight ahead.

The additional curve target value introduced in this way is a particularly advantageous embodiment of the invention, especially in connection with the ability to switch to different route categories.

A particularly advantageous embodiment is that this curve setpoint value 72 according to the Information in claim 3 is formed. This design has the advantage that when used optimized constants the derivation is possible and also taking into account the center distance between the different edge axes.

According to a further advantageous embodiment of the invention, the additional curve setpoint value 72 approximated in a method and composition according to claim 4. This leads to another Simplification, which, however, also has good results compared to known designs

In connection with the formation of the target curve value 72, there is a further advantageous embodiment in the formation according to claim 5. This can be achieved in particular that this additional Curve setpoint value 72 does not have a vibrational effect on the control loop.

By the embodiment described, a vehicle is created with a control arrangement whose Variability significantly increases the accuracy of following a guide wire depending on the driving conditions

In an advantageous embodiment, the driving range selection circuit is designed with at least two driving range branches for delivering a steering target signal, with one driving range for straight travel on the guide wire and another driving range for cornering, and the driving ranges can be determined by predetermined Limit values for Θ «,, Y _v and \ Ψ _ν \ as well as TZ This results in automatic switching and rapid adaptation to the route. It is particularly preferred that four driving area branches are provided, a first of which is for guidance within a straight aisle , a second for guidance along straight lines outside of rack aisles, a third branch for guidance along straight lines for the driving state in which the vehicle is not exactly in the middle of the guide wire and a fourth driving area

branch is intended for cornering. This enables a much more precise adjustment. With regard to the The arrangement of the third sensor is in an embodiment of the vehicle, in which the first and second Sensor in the area of the load axis are provided that the third sensor with respect to the load axis beyond the at least one steerable wheel is arranged. Here"! is an expedient embodiment of the Invention for the greatest possible distance between the third sensor and the other two sensors in the Relation to the accuracy of the control.

In the solution according to the invention, the connection of vehicle-dependent and measured variables from the third sensor are included as a function of the driving range. This is a particularly advantageous embodiment of the invention.

An expedient embodiment provides the formation in connection with the four branches of the driving area a steering target signal according to claim 10. Here it is the solution with particularly precise control when driving in a straight line using all three Sensors. For the second branch, in which sufficient straight-ahead travel is possible with less effort is to be achieved, in an advantageous embodiment, it is sufficient to generate the target steering signal according to FIG Claim 11, while in one for the third branch in In the event of a discrepancy, a switchover is advantageously provided, in which the steering target signal is adjusted Claim 12 is formed. This results in a gradation that allows the vehicle to be used optimally based on distance and speed.

The additional curve target values are already at the top addressed. For the so-called fourth branch, the branch of cornering in the driving range selection circuit, taking the value 72 into account, the A particularly preferred embodiment has a target steering value in accordance with the information in claim 13 Before, so that optimal capabilities are required, in particular can also be achieved while saving a tachometer generator.

The driving range selection circuit is expediently designed as a multiplexer in which the corresponding steering angle target signal Θ »» for the respective Area can be switched through in the steering drive.

The invention will be described in more detail below going described, with a summary also given of the control equations according to the claims is, but the execution is also explained with reference to a drawing. In the drawing shows

F i g. 1 is a plan view of the outline of a vehicle to explain the influencing variables in Scope of the invention,

Fig.2 is a block diagram for the principal Control relationships,

Fig.3-9 block diagrams for the control and Control circuits, which can be assembled in the manner described, show in detail

Fig. 3-7 representations for the signal processing with the measured variables recorded by the vehicle through the sensors,

F i g. 8 a block diagram for a driving range switch,

9 is a block diagram to explain the Setpoint value switching for the four different driving ranges.

First, to explain the formulas given in the rule equations, reference is made to F i g. 1 Referenced. The outline 1 of a vehicle has a Load-bearing end 2, at which by a mast or another guide arrangement 3, for example a load carrying fork 4, is guided. In this end 2 is the Load axle 5 with unguided load wheels 6, 7 angeord net. At this end of the load 2 are related to Load axis 5 has two sensors, a first sensor 8 and a second load sensor 9, for example each with two Coils, arranged symmetrically to the longitudinal axis 10 of the vehicle. The first sensor 8 is between the

ίο Load pick-up end 2 and the load axis 5 with one

Distance 11 in size a \ and the second sensor 9 on

the other side of the load axis 5 at a distance \ 2a ₂ arranged.

With a center distance 13 corresponding to b is in the

Near the other end of the vehicle 14 with a vertical steering axis 15 a steerable wheel 16 intended. And behind this steerable wheel in relation to the load axle 5 is the so-called third wheel Sensor 17, which can be switched on or off. The distance 18 this third sensor 17 from the load axis 5 is denoted by a ₃ .

The steerable wheel 16 is inclined to the longitudinal center line of the vehicle. The angle 19 denotes the value θύ (.

In FIG. 1, the guide wire 20 is located on one side of the longitudinal center line 10 of the vehicle. In the area of the three sensors 8, 9, 17 the distances to the center of the sensors or to the longitudinal center line of the vehicle are denoted by 21 = y ₁ , 22-Y 2, 23 = Y ₃ .

The vehicle speed ν according to the arrow 24 in front of the steerable wheel 16 is used in this explanation as the peripheral speed of this steerable drive wheel. For this purpose, a tachometer is arranged, its Output variable with the diameter of the steerable Wheel is related.

From the three distances Y ₁ , Y ₂ and Y ₃ as well as the set steering angle! β, «and the speed ν become the target value of a steering angle to be set e »/; determined.

In the exemplary embodiment shown, the steerable wheel 16 is on the one hand a drive motor 25 and a steering drive 26 assigned. Via a functional connection 27, this steering drive provides a steering

* 5 actual value in a circuit arrangement 28 from which about a further functional connection 29 a steering target value θ «* / is given in the steering drive.

In the circuit arrangement, the above are via an input bus designated as a whole by 30

so-called measured values fed in, which result from the Sensors, the steering drive and the speed result, while at the same time the vehicle-specific Sizes 11, 12 and 18 are taken into account. This serves for formal explanation only.

In this input bus 30 store the input signals that are shown in FIGS. 3 and 4 are shown as well the output signal of the mentioned tachometer for evaluation in the amplifier in FIG. 4, in which the Amount of speed in relation to the center distance 13 is evaluated.

When the load-bearing end 2 of the vehicle is in front, and the vehicle, as in FIG. 1, to the left of the guide wire 20, the respective values Y are counted as positive for the following description The steering angle 19 is also positive to the left in the direction shown.

If four driving areas are mentioned, then are these by the criteria given above

certainly. The first travel area applies to guidance within a straight aisle. At this precise control will be signals from the sensors

»Se, = K ₁ - Y, with

sign \ AY _h )

introduced. For this
the formulas apply

so-called first area

(D

+ O ₂

O ₃

^ ₁ , K ₂ α constants

(3)

(4)

In the simplified application, the conditions apply to the second travel area along straight stretches outside of rack aisles

= K ₁ - Y, + Κ ₂ - \ ψΑ sign U Y,) (5)

with

AYy

For the third area, just like the second area, only with the first and second sensor works, the control equation applies

»Se, = K ₁₂ · Y, + K ₂₂ · I _Ψν \ ■ sign {AY,) (9)

The constants K ₁₂ and K ₂₂ must be optimized for threading.

For the so-called fourth driving area, for cornering, only the first and applies second sensor, but taking into account the center distance, the control equation

"may be = K ₁₃ · Y, + K ₂₃ ■ I ψ, \ ■ sign U Υ,} + K ₃ ■ TL

(10) with

TL = aresin j sin 0 _iJf + -A- ■ -i- (| ψ, \ ■ sign {A Y,)) \

(H)

Kj ₃ , K ₂₃ and K ₃ are optimized constants.

In this regard, it is also generally stated that the approximation of the quantity Ti can be determined by the equation

TL = β, «+ K ₁ - £ ■ (! *, I-sign U Ig) (12)

a ₃ +

(2)

and in a further embodiment when only discrete values are used by the determination

Tl

for A ₁ < TL < A _{1 M} / = 1.2

(13)

· Discrete level values

The speed ν is expediently indicated by the peripheral speed of a in the equations Drive wheel expressed. It is also noted that from this value of the driving speed ι and the three distances ΥΊ, V :, Vj in connection with the set steering angle Θ,., the target value θ.,., ·. -determined will.

For setting the travel range with an inductive

In accordance with the above rule equations, it is assumed that the first and second areas are the Provide guidance with accuracy along a straight guidewire. Thereby the areas determined by the fact that the lateral deviation V of the

si load axis center of the guide wire, the angle Ψ of the vehicle inclination between the vehicle longitudinal axis and guide wire and the set steering angle θ «are smaller in terms of amount than the limit values V'i _mjv , (P _{1 mj>} and βι _mJ . These limit values

mi are set in a circuit arrangement, so that the prerequisite for automatic connection to the optimal guidance takes place.

The first travel range is only switched on when both | θ, «|, | V, | and | Φ, | each less than

4-, predetermined limit values θι ™ ,. Vi _mjl , Ψ \ _m j. are. If the area 1 is reached, this area can only be left again when the amounts of | θ «, |. IV, | and | fP _t | each greater than specified limit values θ _{2 mj>} . Y ₂ «, j, and <P: _mjT are.

If the conditions for the first and second driving range are not met, the conditions for the third or fourth driving range, which can be switched on by monitoring circuits as a function of incoming measured variables, apply. The condition that a switchover takes place when Tl is greater than a predetermined limit T2 _m i " applies in particular to the fourth driving range when cornering, also for the special switchable variable T2. This suppresses disturbances that can occur when values are approaching.

It is known from the prior art that the values Vi-Vj and θά, as well as the angle Φ of the vehicle steering center axis to the guide wire from the values Y are known or can be determined.

b5 The F i g. 3 shows the formation of the signals Yi, and Ψ ^ The inputs Yi, Y ₂ , Yi are fed to amplifiers 31-33. The amplifier constants can be taken from the above formula 2, whereby in this context

hir.g all dre. Sensors 8, 9, 17 are used. The amplifiers 31-33 feed a summer 37 via lines 34-36 in accordance with the above formula, so that the signal Yh is produced on the output line at the output 38. From the line to the output 318, behind the adder 37, a branch 40 to a second subtractor 39 is tapped, which is also fed _{via a line 143 from the input K 3.} This difference generator 39 has the special circuit of a difference generator. The differentiator 39, which is connected in the manner of an inverted summer, forms the difference Yh minus Yi, which is an influencing variable for the development for ¹ Ph (formula 3). The difference calculator 39 is followed by an amount calculator 41 and an amplifier 42, which as a gain factor has the relevant amount from the formula 3 May , and this is followed by a multiplier 43. A branch line 44 feeds into this from the branch 40. A differentiator 45 and a sign identifier 46 for determining the sign of Ψ are connected in series in the branch line. Thus, in the multiplier 43, the quantity Ψ * = | <Ρ _Λ | · Sign (Δ Y _h ) is formed.

The signal <P * is thus present at output 47.

4 is provided for the development of the signals Y _v at the output 48 and Ψ at the output 49. Here only the values Y \ and Yj are fed into the inputs, namely into amplifiers 50, 51, the constants of which are derived from formula 6 above, namely the factor for this variable with regard to input Y \ or the factor for amplifier 51 to Y ₂ from the formula 6. The outputs are connected by lines shown to the summer 52, which supplies the output 48.

Two function lines 58, 59 are taken from the inputs Y \ and Yi and feed into a subtracter 60, according to formula 7. An amount builder 61 and an amplifier §2 with a gain factor corresponding to the constants are connected to this subtractor 60 of the formula 7 to a multiplexer 63. A branch 64 feeds this from the line to the output 48 with a series-connected differentiator 65 and a sign identifier 66. This results in the signal for <P _V according to formula 7 at output 49.

The developments of the various quantities for 7 "2 are explained schematically in FIGS. 5-7. Referring first to FIG is used on the input 67, and there is also an input 68 for a measured variable θ "coming from the steering drive. A differentiator 69 connects to the input 67, which is followed by an amplifier 70 multiplied by the gain factor b / \ v \ in the amplifier according to formula 11, so that after being fed into a downstream adder 71, the signal θα, which is converted into a sine function in a circuit block 72, is fed in from input 68. This is done by adding up The output from the summer 71 is connected to a circuit assembly 73 in which the arc sin characteristic element is formed according to equation 11, so that at the output ng 74 the value T2 determined according to this equation is obtained.

The Fi g. 6 shows with corresponding inputs and using a differentiator 69 'corresponding to assembly 69, the determination of T2 according to the above form! 12, wherein an amplifier 75 with an amplifier constant K * is used after the differentiator 69 '. At the output 77 of the adder 76, which is fed directly from the input 68 with the measured variable θ ,,, the signal 7 * 2 for cornering, which is approximated in this regard, is obtained.

Either the signal T2 at the output 74 or at the output 77 is shown in FIG. 7 in terms of the solution

to according to equation 13 above into an assembly 7f> fed in, which binds the signal 72 to the determined level values, so that a level discrete Conversion arises and the signal at output 79, insofar as it is used further, such as the Signals at output 74 or 77, does not induce oscillation on downstream control loops.

In Figure 8, the range circuit is shown to the extent that input signals as they are by the previous circuit arrangements are determined, Output signals are generated as control signals for the first to fourth travel ranges can be fed into the steering drive as θ «, // value.

In Fig. 8 are the inputs 80 for <P "81 for Y _n 82 for Θ" ,, 80 ', 81' and 82 'for the corresponding Input values and 83 for Yi before. All inputs feed comparators 84-90 in the arrangement shown from top to bottom, of which comparators 85-89 are window comparators. The window comparators 85 and 86 form the threshold values, the must be undercut in order to get into driving areas 1 and 2. A downstream AND element 91 controls the set input 92 of a downstream AES-FIip-flop circuit 93, the other input 94 of which by an output signal from the AND gate 95 is fed, with which the window comparators 87-89 are connected on the input side. This resets the S flip-flop circuit. Such RS flip-flop circuits are known the zero state, d. H. in erased state, but a 1 at the S input and a 0 at the Ä input to the starting position 1. It is assumed that the input two one signals do not occur at the same time, while zero signals at both inputs change the state

«Let change. This creates the prerequisite for distinguishing between the first and second driving range. For this purpose the input 83 with Y _{3 is} used, which is followed by the window comparator 90 and an AND element 96 in this AND element 96

Via a second input 97, a so-called aisle signal "Vehicle is in the rack aisle", introduced additively and the output signal is via a connection 98 once in a negation or Inverse circuit 99 and over another Connection 100 fed into an AND element 101 that on the other hand also with output 5 of the ÄS-FHp-FIop is connected As a result, a signal is variable for the first at the output 102 of the AND element 101 Area formed

The negation circuit 99 feeds into a further AND element 103, into which a feed 104 also feeds the connection 105 between 93 and 101 opens so that at the output 106 a vanable signal for the second Driving range

If the first and second areas are not switched because of the upstream threshold values, an additional input 107 for the variable T2 results in the determination according to one of the above

given formulas under review by the downstream window comparators 108 a feed into the AND elements 109 with the output 110 for the third area or into an AND element 111 another AND element 112 with the output 113 for the fourth driving range. A connection 114 feeds into both AND elements 109, 112 from the negated output desflS flip-flop93.

In this context, reference is also made to the above control equations 1, 5, 9, 10. That’s the Requirements for the signaling for driving in different driving areas created.

These outputs so described are in accordance with Figure 9 in a multiplexing circuit 115 with the used as starting designation extent already inputs 102, 106, 113 and 110 fed This is the passage in response to the inputs 116, Y _h, 117 <Pa, 118, Y _n 119,9 ,, 118 ', Yv, 119', Φν, 118 ", Y _t , 119", <P, and 107 TI instead, the sizes according to the above information with reference to FIGS. 3-7

are determined.

The inputs are followed by amplifiers 120-128, of which the amplifiers each have the above-mentioned steering parameters or amplifier constants K _u K ₂ or optimized constants Kn, K ₂ I and also Ki ₃ , Ka and K ₃ . The amplifiers 120, 121 are in a summer 129, the amplifiers 122, 123 in a summer 130 and the amplifiers 124, 125 in a summer 131 and the amplifiers 126, 128

ίο summarized in a summer 132, so that the Above mentioned dependencies for the adjustment for the purpose of passing a variable signal into the respective driving range can be detected. Here the summers are connected by connections 133, 134, 135, 136 each with an input to be scanned 137,138,139, 140 for the first to fourth travel ranges, so that the signal θ »// at output 141 of the multiplexer is output as given by equations above for the various conditions.

For this purpose 4 sheets of drawings

Claims (3)

Patent claims: 1. Vehicle, in particular P.urförderzeug, for driverless steering on a guide wire, with a load axle and non-steerable load wheels at one end of the load and at least one steerable wheel at the other end of the vehicle and, in particular, three sensors consisting of coils for picking up measured variables depending on the respective distance from the guide wire and a steering drive for the steerable wheel with an actual value transmitter for the steering angle and also with a circuit arrangement for evaluating the measured variables and determining a steering target signal, characterized in that two sensors (8, 9) combined on one axle (5,15) and the third sensor (17) is arranged at a distance (18) from the axis (5, 15), and that a driving range selection circuit is provided in the circuit arrangement (28), which the introduction for different driving ranges different steering soil signals derived from the first and second sensor on the one hand and also from the third th sensor on the other hand provides and different steering target signals are formed on the one hand from two sensors (8,9) and on the other hand from three sensors (8,9,17) and the introduction of additional steering signal influences derived from measured variables also from the third sensor ( 17) is provided as a function of the m driving range introduced by the driving range selection circuit. 2. Driving time? according to claim 1, characterized in that that an additional curve target value as a function of a set steering angle value Θ ,, γ and a z «itlicb« * n change of the so Inclination of the vehicle vertical axis to the guide wire (20) taking into account the respective distance values (11, 12) from the first and second Sensors (8, 9) is determined in relation to the guide wire (20) and the steering angle target signal in ■ »< > Can be switched on depending on the travel range selection circuit. 3. Vehicle according to claim 2, characterized in that the additional curve target value T2 is formed according to the formula Tl = arc sin (sin θ, _α + - £ - ■ -f (| ψ, \ ■ sign
{ | v | at {A where mean: a, • \ Y \ -YA 30th 0, "the actual steering angle value, b the distance between the load axis and the vertical axis of rotation of the steerable wheel
ν is the vehicle speed b0 seen from the guide wire, Y _{2 is} the distance of the center of the second sensor from the end of the load bearing behind the load axis to the guide wire, ai is the distance of the first sensor at the end of the load bearing of the vehicle to the load axle, 32 the distance of the second sensor on the other side of the load axis to the load axis. 4. Vehicle according to claim 2, characterized in that the additional curve target value Tl is formed according to the formula Tl ■■ £ ■ (| *. | -Sign in which the sizes mentioned each have the meaning as in claim 3. 5. Vehicle according to claim 2, characterized in that the additional curve SoU value Tl is formed according to the formula l for Ai U ... η where A, ■ «■ discrete level values. 6. Vehicle according to one of claims 1-5, characterized in that the driving range selection circuit is designed with at least two driving range branches for delivering a steering target signal, one driving range for straight travel on the guide wire and another driving range for curves -Drive is provided. and the driving ranges can be determined by given limit values for Θ, ». V ₁ and | Φ, | as well as T2. 7. Vehicle according to claim 6, characterized in that four driving area branches (102, 10b, 110, 113) are provided, of which a first (102) for a guide within a straight shelf aisle, a second (106) for a guide along straight Routes outside of aisles, a third branch (110) is provided for guidance along straight stretches for the driving state in which the vehicle is not exactly in the middle above the guide wire (20) and a fourth branch (113) is provided for cornering is. 8. Vehicle according to claim 1. in which the first and second sensors are arranged in the area of the load axis, characterized in that the third sensor (17) with respect to the load axis (5) beyond the at least one steerable wheel (16) is arranged. 9. Vehicle according to claim 1, 8 or 7, characterized by the connection of vehicle-dependent and measured variables from the third sensor (17) as a function of the driving range. 10. Vehicle according to claim 7, characterized in that that a steering target = signal is formed for the first branch (102) according to the formula Y, -Yi = AT ₁ sign ul V, the distance from the center of the sensor of the first sensor to the end of the vehicle load bearing where three sensors are used and mean: = L 3 V Υ — 5— ft -V « Y ° 1 _ V a ₃ + a, «2