DE102017207119A1 - Method for turning a vehicle - Google Patents

Abstract

In a method for turning a vehicle (F), wherein the vehicle (F) comprises a plurality of wheels (1, 2, 3, 4), wherein at least one rear wheel (3, 4) during turning a steering angle (β) is set, a Lenkpol (P) shifts during turning at most by a predefined maximum distance in the vehicle longitudinal direction of a suspension of the rear wheel (3, 4) in the direction of a vehicle front.

Description

The invention relates to a method for turning a vehicle according to the preamble of claim 1. The invention further relates to a control device, a steering system, a computer program product and a computer-readable medium according to the independent claims.

Turning over vehicles is often problematic, especially in urban areas. On the one hand there is typically little space available, eg. B. due to high traffic, parked vehicles or in parking garages. On the other hand, conventional motor vehicles typically have turning circles, often in the range of 10 meters and more. One reason for this is that such vehicles are usually equipped with steering systems, which can only provide a steering angle at the front axle, which is also mostly below 40 degrees.

For some time, however, individual wheel plates are known, by means of which an independent steering of the individual wheels of a vehicle is possible, in particular by means of so-called steer-by-wire systems. In particular, vehicles with such Einzelradstellern may thus be able to provide also at the rear axle steering angle, which then allows smaller turning circles. In addition, there are now opportunities for automobiles automated and / or autonomous driving.

These new technical possibilities open up new possibilities for turning vehicles. However, it may be important to not only want to achieve a minimum turning radius, but also not to neglect the comfort and well-being of the vehicle occupants. This problem has not been sufficiently addressed in the prior art.

The object of the invention is to eliminate or at least reduce the disadvantages of the prior art. In particular, it is the object of the invention to make the turning of a motor vehicle such that a good ride comfort for the vehicle occupants is achieved.

The object is achieved by a method for turning a vehicle, wherein the vehicle comprises a plurality of wheels, wherein at least one rear wheel during turning a steering angle is provided, wherein a steering pole during turning at most by a predefined maximum distance in the vehicle longitudinal direction of a Suspended suspension of the rear wheel in the direction of a vehicle front.

The turning of a vehicle here means a driving maneuver in which a direction of travel of the vehicle is significantly changed, for example by 180 degrees. However, in principle, such driving maneuvers should also fall under the term "turning", in which the direction of travel is changed by less than 180 degrees, for example only by 120 degrees or by 150 degrees. Also, a turn by more than 180 degrees - for example, 270 degrees - in principle conceivable, although such a turn then can also be described as a change in direction of travel by 90 degrees corresponding to an opposite direction of rotation. The vehicle is typically a motor vehicle z. As a car or commercial vehicle. The vehicle typically includes at least three wheels. The term steering pole is to be understood as meaning the instantaneous pole of the rotational movement of the vehicle during turning. In a vehicle, the steering pole is the point at which intersect the imaginary axes of rotation of all the wheels of the vehicle. Typically, during the process, individual wheel actuators of each of the wheels of the vehicle are controlled such that the individual wheels are pivoted to the desired positions and, if necessary, each individually driven in the desired direction.

Under a single wheel actuator is a device to understand, by means of which a steering angle of a single wheel of a vehicle can be adjusted independently of the steering angles of other wheels. The control is typically accomplished by means of a steer-by-wire concept.

A steering angle is to be understood as an angle by which a wheel is pivoted in relation to a vehicle longitudinal axis. When driving straight ahead, the steering angle thus amounts to 0 degrees; in the case of a curve, it assumes positive values, which become greater the smaller the radius of the respective driven curve becomes. The vehicle longitudinal axis defines the vehicle longitudinal direction.

Under the aforementioned displacement of the Lenkpols of a suspension of the rear wheel in the direction of the vehicle front is always to understand only a change in a position of the Lenkpols along the direction of a vehicle longitudinal axis. In other words, if the vehicle longitudinal axis is considered as the y-axis of a coordinate system, then the maximum distance is to be understood as a distance in the y-direction. The same applies to the following maximum distance and the following minimum distance: here too, it is always exclusively distances in the y direction, with the vehicle longitudinal axis being defined as the y direction.

The fact that the steering pole is allowed to travel at most by a predefined maximum distance from the wheel suspension of the rear wheel in the direction of the vehicle front, the ride comfort for the vehicle occupants can be improved, which can also have a positive effect on traffic safety. In conventional vehicles, in which at the rear wheels no steering angle can be made, the steering pole is always equal to the height of the rear wheels. Only by a steering position on the rear wheels, it is even possible that the steering pole shifts in the direction of the vehicle front. Among other things, the invention is based on the recognition that a forwardly displaced steering pole can have a negative effect on the ride comfort of vehicle occupants.

In advantageous embodiments, during steering a steering angle of at least one front wheel and / or the steering angle of the at least one rear wheel is / are limited such that the predefined maximum distance is maintained. A limitation of the steering angle is therefore particularly advantageous because it is particularly easy for a given vehicle geometry too far advancing the steering pole can be prevented. In principle, however, this could also be accomplished in other ways, for example by the fact that the vehicle occupant always sits far enough forward.

In advantageous embodiments, the steering pole shifts at most by a predefined maximum distance in the vehicle longitudinal direction in front of a vehicle occupant.

This has the advantage that such a relatively tight turning circle is guaranteed with still acceptable ride comfort. It should be noted that the maximum distance is typically measured from a body center of the vehicle occupant.

In advantageous embodiments, the predefined maximum distance is 0 cm. In this way, a good compromise between tight turning circle and ride comfort is achieved.

In advantageous embodiments, the steering pole migrates at most up to a predefined minimum distance in the vehicle longitudinal direction to a vehicle occupant. This has the advantage that such a relatively good ride comfort is guaranteed at a still acceptable turning circle.

In advantageous embodiments, the vehicle occupant is a back seat occupant, in particular a rear seat back occupant of the vehicle. Such an alignment of the procedure on a back seat occupant has the advantage that for all persons in the vehicle - ie z. B. for both the driver, as well as for people in the rear - an acceptable ride comfort is guaranteed.

In typical embodiments, the vehicle occupant is a cockpit occupant, particularly a driver or passenger, of the vehicle. Such an alignment of the method on a cockpit occupant has the advantage that a relatively tight turning circle is made possible, but always sufficient driving comfort for the cockpit passengers, especially for the driver, is ensured.

In advantageous embodiments, it is determined by means of at least one seat sensor signal who should be considered the vehicle occupant. In particular, it is determined by means of seat sensor signals from all available vehicle seats, where in the vehicle is the person sitting furthest back - so for example on the driver's seat when the driver is alone in the vehicle, or in the back seat, if this at least in part is occupied. This is a particularly simple way to always ensure a sufficiently great ride comfort for all persons in the vehicle and at the same time to be able to drive as tight as possible in turning circles. Such use of seat sensor signals is advantageous because seat sensors are already installed in many vehicles in order to issue warning messages when a seat belt is not worn when the seat is occupied.

A control device for controlling a turning of a vehicle comprises means which are suitable for carrying out the steps of a method according to one of the previously described embodiments of the invention. Advantageously, the control device comprises computer program code for carrying out the method. The control device is advantageously part of a vehicle control or a separate control device. Advantageously, the control device comprises a digital control unit.

In advantageous embodiments, the control device is suitable for carrying out a method for turning a vehicle according to at least one of the aforementioned embodiments. For this purpose, the control device comprises suitable means, for example a Radwinkelerfassungseinrichtung for detecting current steering angles of the wheels of the vehicle and / or a Radwinkeleinstelleinrichtung for sending control commands to the Einzelradsteller and / or a steering angle limiting means for limiting the steering angle of the wheels during turning and / or a Radantriebseinrichtung for preferably separate control of wheel drives and / or at least one seat sensor, preferably in each case one seat sensor per seat, and / or a seat sensor signal Evaluation. Advantageously, at least some of the aforementioned components are implemented in the control device by means of the computer program code.

A steering system for a vehicle in an embodiment of the invention comprises an aforementioned control device.

In one embodiment of the invention, a computer program product comprises commands which cause the control device according to the invention to carry out the method steps according to the invention.

A computer-readable medium in one embodiment of the invention comprises a computer program product according to the invention. The term computer-readable medium is to be understood in particular but not exclusively hard disks and / or servers and / or memory sticks and / or flash memory and / or DVDs and / or bluerays and / or CDs.

• 1: eine schematische Darstellung einer Ausführungsform der Erfindung,
• 2: eine schematische Darstellung einer Ausführungsform der Erfindung, in welcher der Fahrzeuginsasse ein Rückbankinsasse ist, und
• 3: eine schematische Darstellung einer Ausführungsform der Erfindung, in welcher der Fahrzeuginsasse ein Cockpitinsasse ist.

In the following the invention will be briefly explained with reference to drawings, in which:

• 1 : a schematic representation of an embodiment of the invention,
• 2 a schematic representation of an embodiment of the invention in which the vehicle occupant is a rear seat occupant, and
• 3 : A schematic representation of an embodiment of the invention in which the vehicle occupant is a cockpit occupant.

1 shows a schematic representation of an embodiment of the invention. It is a vehicle F shown, which among other things a first front wheel 1 , a second front wheel 2 , a first rear wheel 3 and a second rear wheel 4 includes. The front wheels 1 . 2 are suspended at the same height near a vehicle front, and the rear wheels 3 . 4 , are suspended at the same height near a rear of the vehicle. In the vehicle are four people, which are shown as circles. The two persons closer to the front of the vehicle are referred to as cockpit passengers, and the two persons closer to the rear of the vehicle are referred to as rear seat occupants. One of the back seat occupants is with the reference number 5 provided: in this embodiment, this is the vehicle occupant 5 in the sense of the invention.

In 1 is also a vehicle longitudinal axis L plotted the vehicle F goes through in length. Moreover, in 1 a steering pole P drawn, which is the point in which the axes of rotation of all four wheels 1 . 2 . 3 . 4 to cut. To this steering pole P turns the vehicle F when the wheels 1 . 2 . 3 . 4 are driven.

In 1 is also a predefined maximum distance m in the vehicle longitudinal direction L from the vehicle occupant 5 drawn from. At the in 1 illustrated embodiment, the steering pole shifts P at most by the predefined maximum distance m in the vehicle longitudinal direction L in front of the vehicle occupants 5 , In 1 has the steering pole 1 this maximum distance m not yet reached, ie the steering pole P is still within a permissible range. In other words: the steering pole P is still an acceptable distance from the vehicle occupants 5 slipped. When the steering pole P the maximum distance m not reached during the turning, then this also means that the steering pole P during turning at most by a predefined maximum distance from the wheel suspensions of the rear wheels 3 . 4 in the direction of the vehicle front.

2 shows a schematic representation of an embodiment of the invention, in which the vehicle occupant 5 a backseat is. It's the wheels again 1 . 2 . 3 . 4 of the vehicle F shown. Additionally are in 2 a steering angle α of the first front wheel 1 and a steering angle β of the first rear wheel 3 located. In 2 are also a distance a between wheel suspensions of the rear wheels 3 . 4 and a backseat inmate and a gap x between the wheel suspensions of the rear wheels 3 . 4 and suspension of the front wheels 1 . 2 located.

gilt, dann ist sichergestellt, dass der Lenkpol P nicht vor den Fahrzeuginsassen 5 rutscht, insbesondere nicht vor eine Körpermitte des Fahrzeuginsassen 5.If at the in 2 shown vehicle F the relationship $$a-\frac{x}{\left(\frac{\text{tan}\alpha }{\text{tan}\beta }+1\right)}\ge 0$$

applies, then it is ensured that the steering pole P not in front of the vehicle occupants 5 slips, especially not in front of a body center of the vehicle occupant 5 ,

und $$y<0$$

gelten, dann liegt der Lenkpol P in Fahrzeuglängsrichtung L um den Abstand y vor der Körpermitte des Fahrzeuginsassen 5. Wenn der Abstand y dann kleiner ist, als die vordefinierte Maximaldistanz m, dann entspricht dies dem in 1 gezeigten Ausführungsbeispiel: Der Lenkpol P ist dann um eine akzeptable Distanz y vor den Fahrzeuginsassen 5 gewandert.If at the in 2 shown vehicle F the relationships $$a-\frac{x}{\left(\frac{\text{tan}\alpha }{\text{tan}\beta }+1\right)}\ge y$$

and $$y<0$$

apply, then lies the steering pole P in the vehicle longitudinal direction L by the distance y in front of the body center of the vehicle occupant 5 , If the distance y is then smaller than the predefined maximum distance m , then this corresponds to the in 1 shown embodiment: The steering pole P is then an acceptable distance y in front of the vehicle occupants 5 hiked.

$$y>0$$

gelten, dann liegt der Lenkpol P in Fahrzeuglängsrichtung L um den Abstand y hinter der Körpermitte des Fahrzeuginsassen 5. Wenn der Abstand y dabei grösser als die Minimaldistanz gewählt ist, die bei einem Ausführungsbeispiel der Erfindung mindestens zwischen dem Lenkpol P und dem Fahrzeuginsassen 5 eingehalten werden muss, dann entspricht diese Wertekonfiguration genau diesem Ausführungsbeispiel.If at the in 2 shown vehicle F the relationships $$\frac{x}{\left(\frac{\text{tan}\alpha }{\text{tan}\beta }+1\right)}\ge y$$

$$y>0$$

apply, then lies the steering pole P in the vehicle longitudinal direction L by the distance y behind the body center of the vehicle occupant 5 , If the distance y is chosen to be greater than the minimum distance, which in one embodiment of the invention at least between the Lenkpol P and the vehicle occupant 5 must be complied with, then this value configuration corresponds exactly to this embodiment.

3 shows a further schematic representation of an embodiment of the invention. The representation in 3 is essentially the same as in 2 but with the difference that the vehicle occupant 5 a cockpit occupant is. Accordingly, in 3 instead of the distance a between the wheel suspensions of the rear wheels 3 . 4 and a backseat occupant a gap b between the wheel suspensions of the rear wheels 3 . 4 and the cockpit occupants.

gilt, dann ist sichergestellt, dass der Lenkpol P nicht vor den Fahrzeuginsassen 5 rutscht, insbesondere nicht vor eine Körpermitte des Fahrzeuginsassen 5.If at the in 3 shown vehicle F now the relationship $$b-\frac{x}{\left(\frac{\text{tan}\alpha }{\text{tan}\beta }+1\right)}\ge 0$$

applies, then it is ensured that the steering pole P not in front of the vehicle occupants 5 slips, especially not in front of a body center of the vehicle occupant 5 ,

und $$y<0$$

gelten, dann liegt der Lenkpol P in Fahrzeuglängsrichtung L um den Abstand y vor der Körpermitte des Fahrzeuginsassen 5. Wenn der Abstand y dabei kleiner als die Maximaldistanz m gewählt ist, die bei einem Ausführungsbeispiel der Erfindung höchstens zwischen dem Lenkpol P und dem Fahrzeuginsassen 5 erreicht werden darf, dann entspricht die gewählte Wertekonfiguration genau diesem Ausführungsbeispiel.If at the in 3 shown vehicle F the relationships $$b-\frac{x}{\left(\frac{\text{tan}\alpha }{\text{tan}\beta }+1\right)}\ge y$$

and $$y<0$$

apply, then lies the steering pole P in the vehicle longitudinal direction L by the distance y in front of the body center of the vehicle occupant 5 , If the distance y is smaller than the maximum distance m is selected, which in one embodiment of the invention at most between the Lenkpol P and the vehicle occupant 5 can be achieved, then the selected value configuration corresponds exactly to this embodiment.

und $$y>0$$

gelten, dann liegt der Lenkpol P in Fahrzeuglängsrichtung L um den Abstand y hinter einer Körpermitte des Fahrzeuginsassen 5. Wenn der Abstand y dabei grösser als die Minimaldistanz gewählt ist, die bei einem Ausführungsbeispiel der Erfindung mindestens zwischen dem Lenkpol P und dem Fahrzeuginsassen 5 eingehalten werden muss, dann entspricht die gewählte Wertekonfiguration genau diesem Ausführungsbeispiel.If at the in 3 shown vehicle F the relationships $$b-\frac{x}{\left(\frac{\text{tan}\alpha }{\text{tan}\beta }+1\right)}\ge y$$

and $$y>0$$

apply, then lies the steering pole P in the vehicle longitudinal direction L by the distance y behind a body center of the vehicle occupant 5 , If the distance y is chosen to be greater than the minimum distance, which in one embodiment of the invention at least between the Lenkpol P and the vehicle occupant 5 must be complied with, then the selected value configuration corresponds exactly to this embodiment.

In advantageous embodiments, the steering angle α and / or the steering angle β so limited that at least one of the aforementioned relationships and / or pairs of relationships always apply during the turning.

LIST OF REFERENCE NUMBERS

1, 2

front wheels

3, 4

rear wheels

5

passenger

F

vehicle

L

vehicle longitudinal axis

P

steering pole

a

Distance between rear wheel suspensions and a rear seat occupant

b

Distance between rear wheel suspensions and a cockpit occupant

m

predefined maximum distance between vehicle occupant and steering pole

x

Distance between the rear wheel suspensions and the front wheel suspensions

α

Steering angle of the first front wheel

β

Steering angle of the first rear wheel

Claims (11)

Method for turning a vehicle (F), wherein the vehicle (F) comprises a plurality of wheels (1, 2, 3, 4), wherein a steering angle (β) is set on at least one rear wheel (3, 4) during turning , characterized in that a Lenkpol (P) shifts during turning at most by a predefined maximum distance in the vehicle longitudinal direction of a wheel suspension of the rear wheel (3, 4) in the direction of a vehicle front. Method according to Claim 1 , characterized in that during turning a steering angle (α) at least one front wheel and / or the steering angle (β) of the at least one rear wheel (3, 4) are limited such that the predefined maximum distance is maintained. Method according to one of the preceding claims, characterized in that the steering pole (P) at most by a predefined maximum distance (m) in the vehicle longitudinal direction (L) in front of a vehicle occupant (5) shifts. Method according to Claim 3 , characterized in that the predefined maximum distance (m) is 0 cm. Method according to one of the preceding claims, characterized in that the steering pole (P) approaches the vehicle occupant (5) at most up to a predefined minimum distance in the vehicle longitudinal direction (L). Method according to one of Claims 3 to 5 , characterized in that the vehicle occupant (5) is a rear seat occupant, in particular a rear seat back passenger, or a cockpit occupant, in particular a driver or passenger, of the vehicle (F). Method according to Claim 6 , characterized in that it is determined by means of at least one seat sensor signal, who should apply as a vehicle occupant (5). Control device for controlling a turning of a vehicle (F), characterized in that the control device comprises means adapted to carry out the steps of a method according to one of the preceding claims. Steering system for a vehicle (F), characterized in that the steering system according to a control device Claim 8 includes. A computer program product comprising instructions that cause the controller of the Claim 8 the method steps according to one of Claims 1 to 7 performs. Computer-readable medium, characterized in that the computer-readable medium after the computer program product Claim 10 includes.

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