DE102008043675A1 - Target-steering angle determining method for multi-part vehicle combination used as e.g. tractor-trailer combination, involves determining target-steering angle based on momentary driving speed of combination and effective length - Google Patents

Abstract

The method involves determining a target-steering angle over a path (4) and a steering angle (13) momentarily lying at a tractive unit (1) and a trailer (3) by a control device based on momentary driving speed of a multi-part vehicle combination and an effective length (6) of the tractive unit and the trailer. The path is predefined over a trajectory. A target-steering angle of the tractive unit is determined based on a difference between a function of a target-steering angle of the trailer and a function of deviation of the steering angle of the trailer from the target-steering angle. An independent claim is also included for a control device for determining a target-steering angle of a multi-part vehicle combination.

Description

The The invention relates to a method for determining desired steering angles a multi-unit vehicle combination according to claim 1 and the invention relates to a control device for implementation of the method according to claim 13.

The DE 198 06 655 A1 describes an electronic maneuvering aid of a vehicle combination consisting of the links truck, drawbar and trailer by means of which a desired steering angle can be determined, which is applied to a steering of the vehicle combination, steers the trailer along a predetermined circle radius. The target steering angle is applied via a servomotor to a steering wheel of a truck of the vehicle combination, whereby the trailer of the vehicle combination is automatically directed in a reverse drive along the predetermined circle radius.

The DE 103 22 828 B4 describes a return device for a vehicle combination, consisting of the articulated successively coupled members tractor, turntable and trailer. The return device is designed in such a way that it can determine a desired towing vehicle steering angle for a steering of the towing vehicle by means of which the trailer can be steered about the desired trailer steering angle from a predefined desired trailer steering angle and a measured actual trailer steering angle. The return device determines the target steering angle for the members of the vehicle combination starting at a rearmost link of the vehicle combination, the trailer, up to a frontmost member of the vehicle combination, the towing vehicle.

Other methods and devices for controlling vehicle combinations go from the writings DE 10 2005 043 470 A1 and DE 10 2006 035 021 A1 out.

task The invention is a method and a controller to provide, by means of which the target steering angle of the links a multi-unit vehicle combination, over which a Default member of the vehicle combination along a given trajectory is steerable, can be determined more precisely.

These The object is achieved by a method according to the patent claim 1 and by a control device according to the Claim 13 solved. The invention is based on a vehicle combination with at least one control unit, this is the nominal steering angle over a given trajectory and currently on the limbs applied actual steering angle determined.

According to the invention relates the controller here a current driving speed of the vehicle combination and effective lengths of the links of the Fahrzeuggespanns in the determination of the desired steering angle, thereby the target steering angle are much more accurately determined and thus less effort to readjust inaccurately determined target steering angle must be operated.

When Actual steering angle here are those steering angle designated, the at the time of determining the target steering angle on the links of the vehicle combination. The actual steering angle can be determined arbitrarily, but preferably over Angle sensors, which, for example, to clutches between the Limbs are arranged, or over between the limbs arranged camera systems, which the actual steering angle over determine an image analysis. As a target steering angle, however, are those steering angles designated at the time of investigation the desired steering angle to the limbs of the vehicle combination so that one of the Glie der, the so-called default member, is steered along the predetermined trajectory.

Each link of the vehicle combination here comprises at least one wheel, via which it is in contact with the ground and through which it is movable on the ground. Each member further has at least one coupling, by means of which it is articulated with other members of the vehicle combination. A member of a vehicle combination may therefore be a towing vehicle, a turntable, a dolly, a trailer or the like. Preferably, the vehicle combination is designed as a articulated train or a semitrailer. In an articulated train with serving as a default member trailer, a hinged coupled with this trailer and a hinged coupled to this towing vehicle while the desired steering angle of the trailer between the longitudinal axis of the trailer and the longitudinal axis of the fifth wheel must be present and the target steering angle of the fifth wheel must be present between the longitudinal axis of the fifth wheel and the longitudinal axis of the tractor to steer the trailer along the predetermined trajectory for him. In a two-link tractor with a towing vehicle and a hinged coupled with this and serving as Vorgabeglied trailer, the target steering angle of the trailer must zwi present the trailer longitudinal axis and the towing vehicle longitudinal axis to steer the trailer along the predetermined trajectory for him.

At least a member of the vehicle combination, the so-called steerable member, has a steering by means of which it is directly steerable to to specify the direction of travel of the vehicle combination and thereby the Target steering angle at the remaining links of the vehicle combination adjust. The steering comprises at least one steered wheel, the for generating a steering movement about a Radeinschlagwinkel the longitudinal axis of the steered member is rotatable. The means of the inventive method determined target steering angle for the steerable member applies to a one-track model of the steerable link and describes the angle about which one steered wheel of the single-track model has to be taken so that itself the desired steering angle at a movement of the vehicle combination to the Set limbs. If the steering is multi-lane and a steering type is, in which the wheels occupy different Radeinschlagwinkel need, so a low-wear steering movement is possible, for example, a steering knuckle, must the desired steering angle of the Einspurmodell in a known manner the kinematics of the steering on the different Radeinschlagwinkel the real steered wheels of the steerable member converted become. When running as a turntable or articulated steering multi-lane steering corresponds to the determined target steering angle, however usually directly to the Radeinschlagwinkel the steered wheels or a turning angle of the fifth wheel or articulated steering.

When effective length of a limb is in the invention Process any geometric length of the limb denotes, for example, the total length or a distance between two axes of the limb. Preferred is the effective length the distance between a first and a second point on one Longitudinal axis of the member, wherein at the first point a Force attacks which the limb during a movement of the vehicle combination in the direction of the actual steering angle and in the second point Fulcrum of the limb perpendicular to the longitudinal axis of the limb Is projected limb. The fulcrum is the one point around which the member under a movement of the vehicle combination under The applied actual steering angle is rotated. The first point, on which the force acts to guide the limb, lies here either in a coupling, with which the member with a front Link articulated coupled, if the member is not the steerable Limb is, or the first point lies in an intersection of a Steering axle with the longitudinal axis of the limb, if the limb the steerable link is and via a steering of the type one Axle steering has. When the steerable limb over has a kink or turntable steering, is the second point in the break point of the articulated steering or in the Support point of the fifth wheel. If the steerable member several Steering axles, the first point is at the intersection of those Steering axle, for which the desired steering angle are determined should. With this target steering angle can then over the distances between the steering axles and the steering kinematics known manner all required Radeinschlagwinkel the steered wheels of the steerable member are determined.

When Default member can be selected any member of the vehicle combination be, for which then given the trajectory to be traveled becomes. However, it is appropriate that in the vehicle team farthest from the steerable member to choose, since this when following the vehicle combination of Trajectory traverses the tightest curve radius and thus most likely to get in contact with obstacles. A drive to move the vehicle combination is not necessarily but appropriately integrated into the steerable member. Especially when the vehicle combination a plurality of links or particularly heavy limbs may also have several Members have their own drive.

In a particularly preferred embodiment of the invention Method, the vehicle combination a front member and a rear member directly coupled to the front member, wherein the controller the desired steering angle of the front member depending on a difference between a function the target steering angle of the rear member and a function of Deviation of the actual steering angle of the rear member from its desired steering angle determined. This adds to the accuracy of the process elevated. There is a function in the mathematical sense to understand what that means to calculate the target steering angle of the anterior limb involves the difference between two values is, wherein the one value of the target steering angle of the rear member is dependent and the other value of a deviation of Actual steering angle of the target steering angle of the rear member dependent is.

In this case, the term "front member" refers to any member of the vehicle combination which is arranged closer to the steerable member in the vehicle combination than a further member coupled directly to the front member, which is referred to as a rear member in the method according to the invention. The rear member is thus closer to the default member in the vehicle combination than the front member. The front member can also serve directly as a steerable member and the rear member can serve directly as a default member. For example, in a tractor-trailer with a towing vehicle and a trailer, the front link is the towing vehicle and the rear link of the trailers if the trailer serves as the default link and the towing vehicle serves as the steerable link. In an articulated train with a towing vehicle, a turntable and a trailer is, if the trailer as a default member and the towing vehicle as a steerable member, for determining the target steering angle of the fifth wheel, the front member of the fifth wheel and the rear member of the trailer. For determining the desired steering angle of the towing vehicle, however, the front member is the towing vehicle and the rear member of the turntable.

Prefers the trajectory is given over a nominal steering angle, which must be present at the default member, so that this along the trajectory is steered. If the rear member is the default member is, is therefore on the target steering angle, the trajectory given along which it is to be steered. A target steering angle a further member coupled directly to the default member, arranged between the Vorgabeglied and the steered member is and thus the front member opposite the Vorgabeglied can thus be determined directly.

wobei
α_{soll_n+1} in dem Verfahren für den Soll-Lenkwinkel steht, welcher an dem vorderen Glied des Fahrzeuggespanns anliegen muss, damit das Vorgabeglied entlang der Bahnkurve gelenkt wird und
α_{soll_n} für den Soll-Lenkwinkel steht, welcher an dem unmittelbar mit dem vorderen Glied gelenkig gekoppelten hinteren Glied des Fahrzeuggespanns anliegen muss, damit das Vorgabeglied entlang der Bahnkurve gelenkt wird und
α_{ist_n} in dem Verfahren für den Ist-Lenkwinkel des hinteren Gliedes zum Zeitpunkt der Bestimmung des Soll-Lenkwinkels des vorderen Gliedes steht,
l_n+1 für die effektive Länge des vorderen Gliedes und l_n für die effektive Länge des hinteren Gliedes steht, sowie
ν in dem Verfahren für die Fahrgeschwindigkeit steht, welche das Fahrzeuggespann zum Zeitpunkt der Ermittlung der Soll-Lenkwinkel aufweist. Diese kann in bekannter Weise über geeignete Vorrichtungen ermittelt werden.In a further particularly preferred embodiment, the control unit determines the desired steering angle of the members of the vehicle combination by means of the equation

in which
α _{soll_n + 1 is} in the process for the target steering angle, which must be applied to the front member of the vehicle combination, so that the default member is steered along the trajectory and
α _{soll_n stands} for the desired steering angle, which must be applied to the articulated directly coupled to the front member rear member of the vehicle combination, so that the default member is steered along the trajectory and
α _{ist_n is} in the process for the actual steering angle of the rear member at the time of determining the target steering angle of the front member,
l _{n + 1 stands} for the effective length of the anterior limb and l _{n stands} for the effective length of the posterior limb, as well
ν is in the process for the driving speed, which has the vehicle combination at the time of determining the target steering angle. This can be determined in a known manner via suitable devices.

k ₁ , k ₂ , k ₃ stand for arbitrary correction factors, which are used to determine the desired steering angle. These can have a regulatory background and, for example, have an integrating or differentiating influence. The correction factors are specified or determined from any parameters. For example, the correction factors may be dependent on the desired or actual steering angles, or be dependent on the effective lengths of the links or on the speed of the vehicle combination.

For example used in a two-part vehicle combination that in a forward drive in the direction of travel behind lying member as Vorgabeglied, for which the trajectory to be traveled is specified and the front Limb serves as a steerable limb. The front member has accordingly the steering, by means of which the default member along the trajectory is steerable. For the rear link then the target steering angle predetermined by the trajectory and the voltage applied to the rear member Actual steering angle is determined via at least one angle sensor, which is preferably arranged in a coupling between the two members is. The instantaneous speed of the vehicle combination is determined by a speed sensor measured. The effective lengths of the anterior and posterior members are due to the geometry of the limbs predetermined and preferably in the control unit of the vehicle combination deposited. Thus, all sizes are for determination the desired steering angle of the front member known, from which optionally about a well-known steering kinematics Radeinschlagwinkel the steered wheels of the steerable member are calculated can.

For vehicle combinations with more than two links articulated in series, for example, a train with a towing vehicle coupled to the towing vehicle turntable and coupled to the turntable trailer, the target steering angle of the links are determined from the default member up to the steerable member. For this purpose, the desired steering angle of that member is first determined, which is coupled in the direction of the steerable member directly to the default member. The determined target steering angle then serves as the basis for the calculation of that member in Direction of the steerable member is directly coupled to this member. This is also done with the following Glie countries until the target steering angle of the steerable member is determined, from which, if necessary, the Radeinschlagwinkel the steered wheels can be determined.

to Steering the Vorgabegliedes along the trajectory during a movement of the vehicle combination is the determination of the desired steering angle preferably continuously, to disturbing influences such as a To correct inclination of a road surface. The determined Target steering angle of the steerable member, or the thereof determined Radeinschlagwinkel be either automatically to the Steering or the steered wheels of the steerable Link created to the vehicle combination regardless of to be able to steer a human driver of the vehicle combination, for example, in automatic in-house freight transport, or the determined target steering angle of the steerable member, or the resulting wheel steering angles are sent to the driver of the vehicle combination transmitted to this from a demanding cognitive determination to relieve the target steering angle. This can for example via a screen or via a support or inhibition of the driver during an operation steering or other haptic feedback to the driver. The method can in this case during a forward drive or a reverse drive of the vehicle combination be applied, whereby the vehicle combination in any direction of travel along the trajectory is steerable.

wobei l_K eine effektive Kupplungslänge des vorderen Gliedes ist. Die effektive Kupplungslänge ist hierbei eine beliebige, die Kupplung geometrisch bestim mende Länge, beispielsweise ein Abstand zwischen einer hinteren Achse des vorderen Gliedes und einem Verriegelungsbolzen der Kupplung oder der Abstand zwischen einem Rahmenelement des vorderen Gliedes und einem anderen Bauteil der Kupplung. Bevorzugt entspricht die effektive Kupplungslänge jedoch einem Abstand zwischen dem genannten zweiten Punkt des Gliedes, in welchen der Drehpunkt des vorderen Gliedes senkrecht auf die Längsachse des vorderen Gliedes projiziert ist und einem dritten Punkt auf der Längsachse des vorderen Gliedes, in welchem das vordere Glied mit dem hinteren Glied gelenkig gekoppelt ist. Durch die derartige Ermittlung des dritten Korrekturfaktors kann die Länge einer Kupplung des vorderen Gliedes, miteinbezogen werden, wodurch die Soll-Lenkwinkel feiner ermittelbar sind und das Vorgabeglied des Fahrzeuggespanns genauer auf der Bahnkurve lenkbar ist.In a preferred further embodiment of the invention, the control unit determines the third correction factor k ₃ via the equation

where l _{K is} an effective coupling length of the front member. The effective coupling length is in this case any, the coupling geometrically determin ing length, for example, a distance between a rear axis of the front member and a locking pin of the clutch or the distance between a frame member of the front member and another component of the clutch. Preferably, however, the effective coupling length corresponds to a distance between said second point of the member, in which the pivot point of the front member is projected perpendicular to the longitudinal axis of the front member and a third point on the longitudinal axis of the front member, in which the front member with the rear link is hinged. By thus determining the third correction factor, the length of a clutch of the front member, be included, whereby the target steering angle finer be determined and the default member of the vehicle combination is more precisely steered on the trajectory.

In a particularly preferred further embodiment of the method according to the invention, the trajectory is given by a trajectory, which is composed of at least one trajectory and based on which the control unit determines the target steering angle of the default member, whereby the default member along complex routes is steerable. To determine the desired steering angle of the vehicle combination, the default member then serves as a rear member, whereby the target steering angle of a directly coupled to the default member and arranged between the default member and the steered member front member can be determined. The determination of the desired steering angle of the default member serving as the rear member is preferably carried out via the equation α soll_vorg = D · k 4 + K · k 5 + W · k 6 + k 7 . in which
α _{soll_vorg is} the target steering angle of the default member or the rear member,
D is a perpendicular deviation of the default member or the rear member to the trajectory,
K is a curvature of the trajectory in a solder penetration point,
W is an angle between the longitudinal axis of the default member and rear member and a tangent of the trajectory in a Vorhaltepunkt. The solder penetration point is that point on the trajectory at which an orthogonal of the trajectory passes through the second point of the default element, and the lead point is a point distant from the solder penetration point on the trajectory.

The correction factors k ₄ , k ₅ , k ₆ , k ₇ are preferably used to adapt the different sizes D, K and W to each other and can be factorized as desired. By k ₇ other influencing factors can be included. Thus, the default member is moved along the trajectory and the target steering angle Vorgabegliedes predetermined by the trajectory trajectories.

In Another embodiment of the invention determines the control unit by means of sensors an instantaneous actual position of the default member opposite the trajectory from which subsequently the Target steering angle of the default member is determined. Determined from this the control unit all desired steering angle, which must be present at the other links of the vehicle combination, so that the default member along the predetermined by the trajectory Trajectory is steered. The determined target steering angles are checked if they are within limits. These limits can be chosen such that, for example a collision or wedging of the links of the vehicle combination in a forward or reverse drive not possible. If a determined target steering angle exceeds a limit is used for the determination the further target steering angle for this target steering angle preferably the exceeded limit value is assumed.

On the basis of the thus determined desired steering angle and on the basis of geometric dimensions of the vehicle combination, the control unit determines a travel space within which the vehicle combination is during a forward or reverse drive, wherein it is checked whether there are obstacles within the driving range. The required geometric dimensions, such as widths, heights and lengths of the members of the vehicle combination are preferably stored in the control unit. It can also be arranged in each member of the vehicle combination, a control or storage device in which the specific geometric dimensions of this member are deposited, wherein the coupling of the members, the control or storage devices are interconnected, whereby a preferred central control unit on all control or memory devices of the links can access and perform the determinations of the desired steering angle and the driving range. The testing for obstacles preferably takes place with the aid of suitable sensors, for example radar or ultrasonic sensors, or with the aid of geographic data and sensors stored in the control unit for determining the position and orientation of the vehicle combination with respect to the stored geographical data. For example, the determination of the driving distance and the check for obstacles by those in the Scriptures DE 101 28 792 B4 , in the paragraphs [0019] to [0031] mentioned apparatus and the method mentioned therein.

In a preferred embodiment of the invention determines the controller upon detecting an obstacle in the driving compartment, an evasion trajectory, there are no obstacles within the driving range. The vehicle combination is thus along the trajectory without interference along the evasion trajectory directed. The end point of the trajectory is here preferably set as a fixed point, the default member must reach, thereby ending the original Trajectory is also the end point of evasion trajectory. It can also be given a final state of the vehicle combination, in which this must be on reaching the end point. This final state is preferred over target steering angle, which is the limbs of the Vehicle combination should have on reaching the end point and over a desired position in which the vehicle combination opposite geographic objects when reaching the endpoint Are defined. As a result, the final state of the vehicle combination such be defined that this is near any Object is directed, for example, a loading dock, and opposite This object is aligned, for example by a loading opening of the vehicle combination is aligned parallel to the loading dock.

The Determination of the evasion trajectory can take place in such a way that the vehicle combination virtually in a computer model along the trajectory is moved, each detected in the computer model Obstacle is involved. If the driving space determined herein of the vehicle combination in the computer model in the region of a detected Obstruction, the trajectory is moved and the Vehicle combination in the computer model along the so shifted Trajectory moves whereby in turn is checked whether the driving distance reaches the area of the detected obstacles. This is repeated until the driving space in the computer model no longer gets into the area of the obstacle, where corresponds to the last shifted trajectory of the evasion trajectory.

Another suitable method and apparatus for determining the evasion trajectory are, for example, in the Scriptures DE 10 2004 048 530 A1 described.

In a further development of the invention, the control unit triggers a reorientation of the vehicle if necessary. Such Neuausrich device is preferably a straightening of the vehicle combination, in which the vehicle combination is moved under a very low or zero going target steering angle of the steered link of the vehicle combination in one direction until the target steering angle of the other members of the towing vehicle sufficient are low. The members in a wedged vehicle combination are thereby aligned so that they are again steerable along the predetermined trajectory. The reorientation is preferably triggered when an actual steering angle applied to a link is very large, or when a determined target steering angle exceeds a limit value by a specific difference value exceeds.

The Task is also solved by a control unit, by means of which the method according to claim 1 is feasible. This can be a single central controller or it can be spatially distinct from each other separate and functionally combined control units exist, which are wired or wirelessly connected are, with these individual control units then over the members of the vehicle combination can be arranged distributed.

in the The invention will be described below with reference to examples and drawings explained in more detail, from which further advantageous Embodiments can be removed. Each show in a schematic representation,

1 a semitrailer in the sense of a vehicle combination with two members;

2 an articulated train in the sense of a vehicle combination with three links, wherein the towing vehicle has four axes, three of which are steering axles;

3 a vehicle combination with four links, consisting of a traction vehicle with articulated steering and three trailers;

4 a two-unit vehicle combination which is to be moved along trajectories to an end point, which are combined to form a trajectory;

5 another two-unit vehicle combination, which is moved along a trajectory.

The two-part vehicle combination in 1 has a towing vehicle 1 with a steering 2 in the sense of a steered member and a trailer 3 of the type of semi-trailer. The trailer 3 serves as default element, which along the given trajectory 4 should be led. For this purpose, the vehicle combination on at least one control unit, not shown, which determines the target steering angle, the at the members 1 . 3 must be present, so that the trailer 3 is directed along the trajectory. The target steering angle of the rear link, that is the trailer 3 , must be between the longitudinal axis 5 of the posterior member and the longitudinal axis 5 the front link, that is the train train 1 , issue. The nominal steering angle of the towing vehicle 1 applies to a steered wheel of a single-track model of the towing vehicle 1 , which is represented by the filled with italic lines wheels. Because the steering 2 however, is a type of axle pivot steering in which the steered wheels of the steering axle 10 assume different Radeinschlagwinkel to produce a low-friction steering movement is from the target steering angle of the towing vehicle 1 about the kinematics of the steering 2 determines the different wheel steering angle of the steered wheels. The determined target steering angle are valid for any direction of travel of the vehicle combination, the trailer 2 can thus during a forward or reverse travel along the trajectory 4 be guided.

The determination of the nominal steering angle of the links 1 . 3 of the vehicle combination thus begins at the default member, that is at the trailer 3 , whose nominal steering angle through the trajectory 4 is predetermined. Starting from the target steering angle of the default member, the target steering angle of the steered member, that is the towing vehicle 1 determined.

The effective lengths 6 the limbs 1 . 3 of the vehicle combination are the distances between the first points 7 at which a steering force on the longitudinal axis 5 of the respective member 1 . 3 acts and the second points 8th on which the fulcrum 9 of the respective member 1 . 3 perpendicular to its longitudinal axis 5 is projected. At the towing vehicle 1 is therefore the first point 7 the one point where the steering axle is 10 with the longitudinal axis 5 of the towing vehicle 1 cuts and the second point 8th is the point in which the non-steered axle 11 with the longitudinal axis 5 cuts, At the trailer 2 is the first point 7 in the clutch 12 with the towing vehicle 1 and the second point 8th in the intersection of the longitudinal axis 5 of the trailer 3 with the non-steered axle 11 of the trailer 3 , The determination of the actual steering angle 13 of the trailer 3 Preferably takes place via an angle sensor, not shown, which is connected to the clutch 12 is arranged. Optionally, the geometric dimensions of the links 1 . 3 So also the effective lengths 6 , in a control unit of the respective member 1 . 3 deposited, which are connected to each other when assembling the vehicle combination, which can be done via cable or light or radio waves and may exist permanently or only to transfer the required data. Preferred is in the towing vehicle 1 arranged a control unit, which takes over the determination of all desired steering angle.

The vehicle combination in 2 has opposite the vehicle combination 1 for another link, the turntable 14 and thus sits down from a towing vehicle 1 , the turntable rotatably coupled to the towing vehicle 14 and one with the turntable 14 rotatably coupled trailer 3 together. The towing vehicle 1 has four axes 10 . 11 of which three steering axles 10 are and an unsteered axis 11 is. The wheels of the towing model of the towing vehicle 1 are shown hatched. The trailer 3 has two non-steered axles combined into a double axle 11 ,

The effective length 6 of the towing vehicle 1 Here is the distance between the first point 7 of the towing vehicle 1 in which is the foremost steering axle 10 with the longitudinal axis 5 of the towing vehicle 1 cuts and the second point 8th in which the fulcrum 9 of the towing vehicle 1 perpendicular to its longitudinal axis 5 is projected. The effective length 6 of the fifth wheel 14 Here is the distance of the first point 7 of the fifth wheel 14 in which the coupling is 12 of the fifth wheel 14 with the towing vehicle 1 located and the second point of the fifth wheel 8th in which the fulcrum 9 of the fifth wheel perpendicular to its longitudinal axis 5 is projected. The effective length 6 of the trailer 3 Here is the distance between the first point 7 of the trailer 3 which is on the clutch 12 of the trailer 3 with the turntable 14 lies and the second point 8th of the trailer 3 in which the fulcrum 9 of the trailer 3 perpendicular to its longitudinal axis 5 is projected. Thus, the first point corresponds 7 of the trailer 3 the second point 8th of the fifth wheel 14 , The effective coupling length 15 of the towing vehicle 1 Here is the distance between the second point 8th of the towing vehicle 1 and a third point 16 in which the towing vehicle 1 with the turntable 14 is coupled.

The default member is in 2 the trailer 3 for which the target steering angle over the trajectory 4 is given. The speed of the vehicle combination is determined via a speed sensor, not shown, and the actual steering angle 13 the links are determined by angle sensors (not shown). The effective lengths 6 of the trailer, the towing vehicle 1 and the fifth wheel 14 , as well as the effective coupling length 15 of the towing vehicle 1 are preferably stored in the control unit, also not shown. Because the second point 8th of the fifth wheel 14 in the clutch 12 with the trailer 3 lies, has the turntable 14 over no effective coupling length. Thus, all variables for determining the desired steering angle of the fifth wheel 14 known, the turntable 14 the front member forms, as this closer to the steerable member, the towing vehicle 1 , in which vehicle combination is arranged as the trailer 3 , which consequently forms the rear member.

When the target steering angle of the fifth wheel 14 is known, are all sizes for determining the desired steering angle of the towing vehicle 1 known, which hereby forms the front member, since it is the steerable member. The turntable 14 thus forms the back link.

The determined target steering angle applies to the wheel of the single-track model of the towing vehicle 1 which is on the steering axle 10 which determines the effective length of the towing vehicle 1 is used, which here on the foremost steering axle 10 true. Based on this target steering angle, are about the kinematics of the steering 2 and about the distances of the steering axles 10 the individual Radeinschlagwinkel the at the steering axles 10 arranged steered wheels determinable.

3 shows a four-unit vehicle combination with a towing vehicle 1 and three trailers linked in a row 3 where the towing vehicle 1 is driven and as a steerable member via a designed as articulated steering 2 has, by means of which the third supporter serving as Vorgabeglied 3 along the trajectory 4 is steerable. The first trailer 3 is directly with the towing vehicle 1 hinged coupled, the second trailer 3 is immediately with the first trailer 3 articulated coupled and the third trailer 3 is directly with the second trailer 3 coupled. The towing vehicle 1 can be, for example, a wheel loader, and the free hitch be 12 of the third trailer 3 If necessary, additional trailers can be coupled. The effective length 6 of the towing vehicle 1 is the distance between the first point 7 , which is the break point 17 the steering 2 is and the second point 8th in which the fulcrum 9 of the towing vehicle 1 on its longitudinal axis 5 projected vertically. The effective coupling length 15 of the towing vehicle 1 is the distance between the second point 8th and the third point 16 in which the towing vehicle 1 with the first trailer 3 is coupled. The effective length 6 of the first trailer 3 is the distance of the first point 7 of the trailer 3 in which this with the towing vehicle 1 is coupled and the second point 8th of the trailer 3 in which the fulcrum 9 of the trailer 3 on its longitudinal axis 5 is projected. The effective coupling length 15 of the first trailer 3 is the distance of the second point 8th and the third point 16 this trailer 3 in which he is with the second trailer 3 is coupled. Because the trailer 3 have the same geometric dimensions, correspond to the effective lengths 6 and effective clutch lengths 15 the second and third trailer 3 those of the first trailer 3 ,

The third trailer 3 serves as the default member of the vehicle combination, whereby the target steering angle of the third trailer 3 over the trajectory 4 is specified directly. This must be between the longitudinal axes 5 the second and third trailer 3 present, thus the third trailer 3 along the trajectory 4 during a forward or backward movement of the vehicle combination is steered. By means not shown angle sensors are currently between members 1 . 3 adjacent actual steering angle 13 determined, and by means of a speed sensor, not shown, the speed of the vehicle combination is determined, whereby all sizes for determining the target steering angle of the second trailer 3 are known. The second trailer forms 3 the front link and the third trailer 3 the rear link, since the latter serves as default element, or since the second trailer 3 is arranged closer to the steerable member in the vehicle combination.

When the target steering angle of the second trailer 3 is known, are with the actual steering angle 13 and the speed of the vehicle combination all sizes for determining the desired steering angle of the first trailer 3 known. This must be on the first trailer 3 abut, so that the target steering angle of the second trailer 3 upon movement of the vehicle combination to the second trailer 3 is created and the predetermined target steering angle of the third trailer 3 to the third trailer 3 is created. In determining the target steering angle of the first trailer 3 now serves the first trailer 3 as a front link and the second trailer 3 as a rear link, since the last in the vehicle combination is arranged closer to the default link.

Once the target steering angle of the first trailer 3 is known, can with the actual steering angle 13 and the speed of the vehicle combination of the desired steering angle of the towing vehicle 1 be determined, the towing vehicle 1 as a front link and the first trailer 3 rear link serves as the towing vehicle 1 forms the steerable member. The steering 2 of the towing vehicle 1 is designed as articulated steering, whereby the target steering angle of the towing vehicle 1 directly at the steering 2 can be applied so that the target steering angle for steering the third trailer 3 along the trajectory 4 between the tractor 1 and the first trailer 3 as well as between the followers 3 to adjust.

4 shows a two-unit vehicle combination consisting of a tractor serving as a steerable member 1 and a supporter serving as defaulting member 3 a type of semi-trailer which travels backwards along a number of predetermined trajectories to an endpoint 18 to be moved. The trajectories are here to a trajectory 19 summarized, and the position of the end point 18 is through the fixed loading ramp 20 Are defined. The final state of the vehicle combination is also given, which is indicated by the outline of one at the end point 18 located Fahrzeugge spanns is illustrated. It includes the position and location of the trailer 3 opposite the loading ramp 20 and the location of the towing vehicle 1 opposite the trailer 3 ,

The determination of the nominal steering angle of the links 1 . 3 of the vehicle combination 4 takes place in accordance with the determination of the desired steering angle of the links 1 . 3 of the vehicle combination 1 , In this case, the control unit (not shown) of the vehicle combination determines on the basis of the trajectory 19 and the geometrical dimensions of the vehicle combination a driving space 21 , within which the vehicle combination during a journey along the trajectory 20 located. About obstacle sensors 22 the control unit scans the environment and checks whether it is within the driving range 21 obstacles 23 are located. About this obstacle detection is also the loading dock 20 detectable, whereby the position of the vehicle combination opposite the loading ramp 20 and thus the position of the end point 18 is determinable. If inside the train 21 obstacles 23 are detected, the controller determines an evasion trajectory 24 for which then also the desired steering angle of the vehicle combination and from it a not shown new driving space is determined and it is checked whether there are still obstacles 23 are located. If this is the case, then further evasion trajectories can continue 24 be determined until no obstacles 23 are more present in each newly designated driving space.

When determining the desired steering angle, the control unit checks whether the determined target steering angle exceed predetermined limits. If this is the case, the value of the relevant target steering angle is replaced by the value of the limit value and the determination of the further target steering angle dependent on this target steering angle is based on the limit value. In this case, if a difference value between the target steering angle and the limit value is too large, the control unit preferably initiates a realignment of the vehicle combination, in which the vehicle combination is moved forward at very small Radeinschlagwinkeln so long, either through the obstacle sensors 22 an obstacle 23 in front of the towing vehicle 1 is detected or until the actual steering angle 13 of the trailer 3 fall below a predetermined further limit.

5 shows another two-unit vehicle combination with a powered towing vehicle 1 as a steerable link and with a trailer 3 as a default member, which along several to a trajectory 19 summarized trajectories should be steered. This is the target steering angle of the trailer 3 based on a vertical distance of the trailer 3 from the trajectory 19 , based on a curvature of the trajectory 19 with a radius of curvature 28 in a solder penetration point 25 and by an angle 29 between the longitudinal axis 5 of the trailer 3 and a tangent to the trajectory 19 in a preview point 26 certainly. Subsequently, the determination of the desired steering angle of the towing vehicle 1 analogous to the determination of the desired steering angle of the towing vehicle 1 out 1 respectively.

The vertical distance of the default member to the trajectory, here is the distance between the solder penetration point 25 and the second point 8th on the longitudinal axis of the default link, in this case the trailer 3 in which the fulcrum 9 of the trailer 3 projected vertically. The solder penetration point 25 is the point on the trajectory 19 through which an orthogonal of the trajectory 19 runs, which is the second point 8th of the default member intersects. The preview point 26 is a given distance 27 on the trajectory from the solder penetration point 25 spaced.

Preferred is in the 1 to 5 the control unit in the towing vehicle 1 arranged, however, can basically be in any term 1 . 3 . 14 of the vehicle combination. It can also have multiple controllers in one link 1 . 3 . 14 or in the limbs 1 . 3 . 14 the vehicle combination can be arranged ver shares, which determine the desired steering angle of the vehicle combination together, preferably division of labor.

As a general rule the desired steering angle of the steerable member, as described, by determining the individual target steering angle between the steerable member and the default member arranged members, why for each of the members proposed in claim 3 Equation with the values specific to this member, such as the effective length or the actual steering angle, is solved. As the target steering angle of the limbs thereby directly are dependent on each other, which can be in Mathematically differentiating the specific values also be summarized into a single equation, for example by using the specific equation to calculate the target steering angle of the posterior member into the specific equation for calculation the target steering angle of the front member is used. through this summarized equation is then the desired steering angle the steered member directly from the predetermined target steering angle of the default element and determinable from the specific values of the terms. But this is just a mathematical summary of the represents equations given in the proposed method, this is expressly also in the sense of the invention.

1

towing vehicle

2

steering

3

pendant

4

trajectory

5

longitudinal axis

6

effective length

7

first Point

8th

second Point

9

pivot point

10

steering axle

11

Not steered axle

12

clutch

13

Actual steering angle

14

turntable

15

effective coupling length

16

third Point

17

inflection point

18

endpoint

19

Trajektion

20

loading ramp

21

driving space

22

obstacle sensor

23

obstacle

24

Ausweichtrajektion

25

Lotdurchstoßpunkt

26

Preview point

27

path

28

radius of curvature

29

angle

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 19806655 A1 [0002]
• - DE 10322828 B4 [0003]
• - DE 102005043470 A1 [0004]
• DE 102006035021 A1 [0004]
• - DE 10128792 B4 [0025]
• DE 102004048530 A1 [0028]

Claims (13)

Method for determining the desired steering angle of a multi-unit vehicle combination, which on the links ( 1 . 3 ) of the vehicle combination to a default member of the vehicle combination along a predetermined trajectory ( 4 ), wherein the vehicle combination comprises at least one control unit which controls the desired steering angles via the trajectory (FIG. 4 ) and currently on the links ( 1 . 3 ) applied actual steering angle ( 13 ), characterized in that the control unit, the target steering angle including a current vehicle speed of the vehicle combination and including effective lengths ( 6 . 15 ) of the limbs ( 1 . 3 ) of the vehicle combination. A method according to claim 1, characterized in that the vehicle combination comprises a front link and a rear link coupled directly to the front link, the controller controlling the target steering angle of the front link in response to a difference between a function of the target steering angle of the rear link and a function of the deviation of the actual steering angle ( 13 ) of the rear member of the target steering angle determined. A method according to claim 2, characterized in that the controller the desired steering angle of the front member by means of the equation

where α _{soll_n + 1 is} the target steering angle that must be applied to the front link of the vehicle combination to steer the default member along the trajectory l _{n + 1 is} the effective length (6) of the front link of the vehicle combination, l _n the effective length (6) of the rear link of the vehicle combination directly linked to the front link is ν the instantaneous vehicle speed of the vehicle _combination , k _{1 is} a first correction factor, k _{2 is} a second correction factor, k _{3 is} a third correction factor, α _{soll_n} der Target steering angle, which must be applied to the rear member, so that the default member along the trajectory is steerable, α _{ist_n} the actual steering angle ( 13 ) abutting against the rear member at the time of determining the target steering angle of the front member. A method according to claim 1, characterized in that a foremost member of the vehicle combination a towing vehicle ( 1 ) with a drive and a steering ( 2 ). Method according to claim 1, characterized in that that in the direction of travel rearmost member of the vehicle combination is the default member. A method according to claim 3, characterized in that the controller the third correction factor on the equation

where l _{K is} an effective coupling length ( 15 ) of the anterior limb. Method according to claim 2, characterized in that that the target steering angle of the front member during a Forward drive or reverse drive of the vehicle combination is determined. Method according to claim 1, characterized in that the trajectory ( 4 ) via a trajectory ( 19 ) is given. A method according to claim 3 and 8, characterized in that the default member serves as a rear member, wherein the controller the desired steering angle of the rear member via the equation α soll_n = D · k 4 + K · k 5 + W · k 6 + k 7 determined, where α _{soll_n is} the target steering angle, which must be applied to the rear member so that it is steerable along the trajectory, D is a vertical deviation between the rear member and the trajectory ( 19 ), K is a curvature of the trajectory ( 19 ) in a solder penetration point ( 25 ) W is an angle ( 29 ) between a longitudinal axis ( 5 ) of the posterior member and a tangent of the trajectory ( 19 ) in a preview point ( 26 ), k _{4 is} a fourth correction factor, k _{5 is} a fifth correction factor, k _{6 is} a sixth correction factor, k _{7 is} a seventh correction factor. A method according to claim 9, characterized in that the control device - a current actual position of the default member of the vehicle combination with respect to the trajectory ( 19 ) determines, - determines the target steering angle of the default member - the target steering angle of the other members ( 1 . 3 ) determines the vehicle combination, - checks whether the determined target steering angle are within limits, - a driving space ( 21 ), within which the vehicle combination during a movement along the trajectory ( 19 ) checks whether there are obstacles ( 23 ) are located. A method according to claim 10, characterized in that the control device an evasion trajectory ( 24 ), which runs in such a way that within the driving range ( 21 ) no obstacles ( 23 ) are located. Method according to claim 10, characterized in that if necessary, the control unit is a reorienter of the vehicle combination triggers. Control unit for carrying out the Method according to claim 1.