DE102019217006A1 - Method, device and computer program product for minimally stressful trajectory planning for vehicles - Google Patents

Abstract

The invention relates to a method, a device and a computer program product for the determination of trajectories with a minimum load for the route planning of, in particular, autonomously driving vehicles. The aim is to record and evaluate the loads acting on a vehicle and its occupants along a road section at the local level. As a result, the service life of the vehicle is extended and the risk of kinetosis for the occupants is significantly reduced. Subsequent vehicles can use the results to optimize their trajectories to be traveled. In order to achieve this, trajectories already traveled and / or known stress hotspots are retrieved when driving on a road section and a trajectory is searched based on which the stresses for the vehicle and occupants can be further reduced or avoided. While this trajectory with minimal stress is being traveled, it is recorded along this trajectory whether stress hotspots occur there.

Description

The invention relates to a method, a device and a computer program product in order to provide trajectory planning with minimal stress for the route planning of vehicles, in particular for the route planning of autonomously driving vehicles.

For the operation of automated or autonomously driving vehicles, the challenge is that the loads that occur when driving, i.e. above all forces and moments, should be as low as possible. There are two reasons for this: the durability of the vehicles and the comfort of the occupants of the vehicles.

It can be assumed that the intensity of use of automated or autonomously driving vehicles will increase compared to conventional vehicles. The reasons for this are the greater convenience, the wider group of users, which also includes children and senior citizens, and the particular suitability for car sharing and commercial use such as robot taxis. This means that such a vehicle is used longer and more frequently or has less downtime than a conventional vehicle in the same period of time. In relation to its service life, this means that more kilometers are covered overall. This is a challenge for the durability of the vehicle components, since with a higher mileage, more load cycles act on them and in turn lead to greater fatigue or wear.

In order to ensure the longevity and safety of the vehicle, it makes sense to keep the loads that occur during operation as low as possible. Although this generally also applies to conventional vehicles, it is particularly relevant for automatic or autonomously driving vehicles due to the increased lifetime performance. Since the components of conventional vehicles are optimized today for reasons of consumption in terms of lightweight construction, the components of automatic or autonomously driving vehicles would have to be designed to be more resilient or heavier. This would result in higher manufacturing costs and also increase the fuel or power consumption of the vehicle.

One of the strongest selling points for self-driving vehicles will be the particular comfort, as the occupants can pursue recreational activities such as reading, watching TV or sleeping while on the move. So that this comfort is not impaired, disruptive loads on the passengers should be as low as possible. Furthermore, the alternative pastime while driving harbors the fact that the eyes of the occupants no longer actively follow the course of the road and a disharmony arises between visual perception and the sense of balance. Therefore, an increased incidence of so-called motion sickness (kinetosis) is to be expected with automated driving. In order to prevent this motion sickness, the loads acting on the occupants, in particular the vibrating loads, must be kept as low as possible.

In order to avoid or at least reduce the occurrence of kinetosis, various solutions are proposed in the prior art: an optimized interior design, the creation of an artificial horizon, active vibration damping and a gentle driving style or route.

Of the known approaches, only the last point is suitable for positively influencing the operational stability. In principle, a gentle driving style can always be implemented by simply driving the vehicle very slowly. Since this is impractical in real road traffic, the prior art relates primarily to the selection of a route that is as gentle as possible from the starting point to the destination of the journey. A digital map of the road network is usually used as a basis, with route sections being evaluated on the basis of their properties with regard to the occurrence of vehicle accelerations and using this quantification to determine the route as the optimal combination of the road section parameters.

DE 10 2007 038 424 A1 discloses a method and a device in which a characteristic value for the curvature is calculated for each route section and assigned to it. The gentlest route is the one with the lowest overall characteristic value of the curves from a plurality of possible routes. However, only the transverse dynamics are considered, whereas longitudinal and vertical dynamics also play an essential role for the problems of kinetosis and operational stability described above.

The DE 10 2012 016 736 A1 describes a technique for determining gentle routes as part of a route calculation. A weighting is assigned to each street section and, if necessary, turning maneuvers at intersections. This weighting quantifies the vehicle accelerations to be expected on the road section, which are estimated using comprehensive map data from the properties of the road section (curves, inclines, stop signs, and the like). In addition, an influence of the driver's driving style can be taken into account here. Depending on whether the procedure is for the Careful transport of people or freight is to be used, the spatial directions of the accelerations are weighted differently. How the weighting should be calculated is not described, however. However, the estimation of acceleration profiles solely on the basis of map data is firstly very difficult and secondly imprecise. In this respect, the method disclosed here can only be a rough estimate of the accelerations that can be expected, which, however, causes a great deal of effort.

In DE 10 2017 206 435 A1 a method / driver assistance system is presented that specifically relates to the reduction of kinetosis through route selection. On the one hand, vehicle accelerations are calculated on the basis of map material, and on the other, kinetosis-relevant health data of the occupants are recorded via sensors. On the basis of the information, different routes to the destination are evaluated with regard to their risk of cinema, and the best route is selected. In addition, the occupant has the option of communicating his or her current kinetic state and thereby adapting the driving style of the automatic vehicle. However, the focus here is on expressly considering several potential routes and selecting the one with the lowest risk of kinetosis. How exactly this risk is quantified is not described.

DE 10 2017 214 823 A1 shows a method and a device with which a map for operating an automatic or autonomously driving vehicle can be created and provided. This is divided into three steps: receiving acceleration values along a route, creating the map and making the map available for the operation of the automatic vehicle. The acceleration values are recorded by sensors built into the vehicle and made available on a server or in a cloud. In addition, the occupant can use an input unit to evaluate his / her subjective comfort perception of the last section of the route. Thanks to the joint storage in the cloud, other vehicles can also benefit from the data collected and adapt their operations accordingly. This probably facilitates the updating and provision of map information with regard to acceleration values and thus the planning of gentle routes, but does not solve the problems described above.

DE 10 2014 213 522 A1 discloses a method for determining load profiles of vehicles. For this purpose, operating time, speed, engine speed as well as longitudinal and lateral acceleration are recorded using sensors. A stored evaluation profile is used to assign a numerical load parameter to the measured values, which quantifies the influence of the measured value on the wear and tear of the vehicle. The successive addition of the load parameters results in a continuously increasing wear index for the vehicle during operation, which can be compared with other vehicles in the fleet. However, the procedure is not for prevention. There is no differentiated consideration of components or specific forces and moments. Therefore, the key figures are only used for the relative comparison of several vehicles in a fleet.

1. 1. Die schonende Route wird nur durch eine „globale“ Betrachtung ermittelt. Global heißt in diesem Zusammenhang, dass die Straßenabschnitte jeweils als Ganzes betrachtet werden und die Route als Aneinanderreihung von Straßenabschnitten entsteht. Für das Auftreten von Schwingungen ist jedoch auch die „lokale“ Streckenführung entscheidend. Lokal meint dabei, wo genau auf einem Straßenabschnitt, beispielsweise auf breiten Straßen eher links oder rechts und mit welcher Geschwindigkeit das Fahrzeug fährt. Mit anderen Worten, welche Trajektorie es zurücklegt. Üblicherweise werden autonom fahrende Fahrzeuge so programmiert, dass sie möglichst mittig auf einer Straße fahren, um einen weiten Abstand zu anderen Verkehrsteilnehmern zu haben. Liegt auf dieser Fahrkurve jedoch eine Bodenunebenheit wie ein Schlagloch vor, wird diese voll getroffen und erzeugt hohe Belastungen im Fahrzeug. Ein menschlicher Fahrer hingegen würde etwas seitlich versetzt zu der Bodenunebenheit fahren, um diese zu umgehen. Bei der globalen Betrachtung gemäß dem Stand der Technik wird nicht aufgelöst, wie und wo das Fahrzeug auf dem Straßenabschnitt fährt, sondern nur dass es ihn überhaupt befährt. Folglich ist die Belastungsabschätzung auf globaler Ebene höchst unpräzise und kann die genannten Probleme hinsichtlich Verschleiß und Kinetose nicht lösen.
2. 2. Es werden nur Beschleunigungen, und dies zum Teil auch nur als gemittelte Werte, und keine konkreten Kräfte beziehungsweise Momente betrachtet. Dabei unterscheiden die bekannten Lösungen auch nicht dezidiert nach den Raumrichtungen, in denen Beschleunigungen auftreten. Für den Anwendungsfall der Betriebsfestigkeit ist dies ein wesentlicher Nachteil, denn die Beschleunigungen geben nur mittelbar Aufschluss über die Kräfte und Momente. Dies liegt unter anderem daran, dass einige Bauteile nur durch bestimmte Beschleunigungsrichtungen belastet werden, zum Beispiel der Antriebsstrang hauptsächlich durch Längsdynamik und die Federung hauptsächlich durch Vertikaldynamik. Andere Bauteile reagieren zwar auf mehrere Belastungsrichtungen, jedoch unterschiedlich stark, sodass eine Gewichtung vorgenommen werden muss. Außerdem können sich je nach Zusammenwirken der Beschleunigungen aus unterschiedlichen Richtungen die dadurch erzeugten Kräfte und/oder Momente verstärken oder vermindern, beispielsweise wenn gleichzeitig durch Querdynamik eine Zugkraft und durch Vertikaldynamik eine Druckkraft in ein Bauteil eingeleitet wird, die sich gegenseitig eliminieren. Die bloße Betrachtung der Beschleunigungsintensitäten bildet diesen Effekt nicht ab.

All previously known solutions have the following essential disadvantages in common:

1. 1. The gentle route is only determined through a "global" view. In this context, global means that the road sections are viewed as a whole and the route is created as a series of road sections. For the occurrence of vibrations, however, the “local” routing is also decisive. Local means where exactly on a section of road, for example on wide roads, on the left or right and at what speed the vehicle is driving. In other words, what trajectory it covers. Usually, autonomously driving vehicles are programmed in such a way that they drive as centrally as possible on a road in order to have a long distance from other road users. However, if there is an unevenness in the ground such as a pothole on this driving curve, it will be hit completely and generate high loads in the vehicle. A human driver, on the other hand, would drive somewhat offset to the side of the unevenness in the ground in order to avoid it. In the global view according to the prior art, it is not resolved how and where the vehicle is traveling on the road section, but only that it is actually traveling on it. As a result, the stress assessment on a global level is extremely imprecise and cannot solve the problems mentioned with regard to wear and kinetosis.
2. 2. Only accelerations, and in some cases only as averaged values, and no concrete forces or moments are considered. The known solutions do not distinguish between the spatial directions in which accelerations occur. This is a major disadvantage for the operational stability application, because the accelerations only provide indirect information about the forces and moments. This is due, among other things, to the fact that some components are only loaded by certain directions of acceleration, for example the drive train mainly by longitudinal dynamics and the suspension mainly through vertical dynamics. Other components react to several directions of loading, but to different degrees, so that weighting must be carried out. In addition, depending on the interaction of the accelerations from different directions, the forces and / or torques generated thereby can increase or decrease, for example if a tensile force is introduced into a component simultaneously through transverse dynamics and a compressive force is introduced into a component through vertical dynamics, which mutually eliminate each other. The mere consideration of the acceleration intensities does not depict this effect.

The use of the accelerations to describe the forces acting on the occupants is only possible due to the linear relationship between force = mass * acceleration at constant mass. For vehicle components, on the other hand, the relationship between accelerations and the resulting forces is not linear in many cases. For the application of comfort and kinetosis prevention, the acceleration consideration may be sufficient as an approximate solution. However, the accelerations estimated or measured in the prior art are obviously those in the vehicle's center of gravity. It is not taken into account that resilient or damping elements can be interposed on the transmission path to the occupant and that the exact position of the occupants in the vehicle has an influence. Consequently, the mere use of the vehicle's center of gravity accelerations results in a deviation from the forces actually acting on an occupant.

Furthermore, the prior art does not take into account that the force acting on an occupant is supported by the seat depending on the spatial direction. For example, an occupant seated in the direction of travel is pressed against the seat when starting off, so that the seat dissipates the forces that arise. When cornering, however, the occupant is pushed to the side by centrifugal forces. Since these are not completely caught by the seat belt, he has to use his own muscle strength to hold himself in position. Therefore, depending on the spatial direction and seat geometry, there is a difference in comfort that cannot be mapped simply by looking at the amounts of the vehicle's center of gravity accelerations.

DE 10 2014 214 729 A1 discloses a method for detecting potholes in a vehicle. A pothole is detected using the level sensors of the wheels and assigned to a coordinate point by means of a position determination device. The information about the occurrence of the pothole is stored in a digital map and, if necessary, transmitted wirelessly to a central server so that other vehicles can also be warned of this. If a vehicle comes close to a known pothole, the driver is warned or the speed is reduced or an automatic evasive maneuver is carried out. However, the invention relates exclusively to potholes and only stores their coordinates, that is to say no further information about their dimensions and stress intensity. No details are given about the design of the implementation of the automatic evasive maneuver. Since there is no consideration of the proportionality of the evasive maneuver, the transverse loads generated thereby can be greater than the vertical loads of the only small pothole that has been bypassed. A holistic exposure assessment is therefore indispensable for fulfilling the aforementioned goals, but is not shown in this document.

In addition, it should be mentioned as a disadvantage that the methods described are not able to determine the oscillation frequency of the accelerations that occur. This has a significant influence on the driver's wellbeing or the risk of kinetosis and can also be relevant for the operational stability if natural frequencies are hit by components of the vehicle and resonance effects arise.

This results in the object of the invention to propose a solution as to how route planning can be improved in such a way that the risk of kinetosis for the occupants of the vehicle and the wear and tear of the vehicle and its parts are minimized, taking into account the actual conditions along the road sections at a local level Level.

The object of the invention is achieved with a method, a device and a computer program product according to the independent claims 1, 9 and 10 . Further preferred embodiments of the invention emerge from the other features mentioned in the subclaims.

• • Planen und/oder Befahren eines Straßenabschnittes,
• • Abfragen bereits gefahrener Trajektorien und/oder vorhandener Belastungshotspots entlang dieses Straßenabschnittes,
• • Analyse der bereits gefahrenen Trajektorien und/oder vorhandenen Belastungshotspots,
• • Bestimmung einer belastungsminimalen Trajektorie auf dem Straßenabschnitt, wobei o eine Standardtrajektorie gewählt wird, wenn keine Belastungshotspots vorhanden sind, und ◯ bei Vorhandensein von Belastungshotspots ▪ eine Trajektorie bestimmt wird, die in Bezug zu mindestens einer bereits gefahrenen Trajektorie zumindest im Bereich des oder der Belastungshotspots seitlich verlegt ist und/oder ▪ eine Verringerung der Geschwindigkeit des Fahrzeugs zumindest im Bereich des oder der Belastungshotspots ermittelt wird,
• • Befahren des Straßenabschnittes entlang der ermittelten belastungsminimalen Trajektorie auf dem Straßenabschnitt.

The method according to the invention for minimally stressful trajectory planning for vehicles comprises at least the following steps:

• • Planning and / or driving on a road section,
• • Query of already driven trajectories and / or existing stress hotspots along this road section,
• • Analysis of the already driven trajectories and / or existing stress hotspots,
• • Determination of a minimum load trajectory on the road section, whereby o a standard trajectory is selected if there are no load hotspots, and ◯ if there are load hotspots ▪ a trajectory is determined that is related to at least one trajectory already driven at least in the area of the load hotspot (s) is laid to the side and / or ▪ a reduction in the speed of the vehicle is determined at least in the area of the stress hotspot (s),
• • Driving on the road section along the determined minimum load trajectory on the road section.

The aim is to determine a trajectory along which the loads for the vehicle and the occupants are as low as possible and thus the wear and tear and the risk of kinetosis are minimized. A trajectory is the actual route taken by the vehicle. In this context, vehicles are primarily intended to mean autonomously driving or automated vehicles, but a trajectory with a minimum load can also be transmitted to a human driver as a driving recommendation in order to enable him to drive with minimum load.

At the beginning of the method and / or at the start of the method, driving on a road section is planned, for example because it is on a planned travel route or route, or it is being driven on. Road sections are parts of a road that is subdivided, for example, by intersections. A street can also be subdivided into street sections depending on the length or by means of suitable distinctive points.

As a result, a suitable device asks the vehicle whether one or more trajectories have already been traveled on this road section and / or whether stress hotspots are known on the road section. This information can be provided and retrieved, for example, via a server (for example as Car2X communication) and / or the communication between individual vehicles in the vicinity (for example by means of Car2Car communication). As an alternative or in addition, this information can also be stored on a storage unit in the vehicle. A stress hotspot should be understood as a specific influencing variable known at the local level, in particular with regard to type, size and position, which has a negative effect on the risk of kinetosis and / or the wear and tear of the vehicle. The characteristics of the stress hotspot can, as will be explained later, be further explored and specified in the course of the method according to the invention.

The known trajectories and / or stress hotspots are analyzed for their topicality and their suitability for determining the trajectory to be traveled. More recent information is preferably taken into account, since it is more up-to-date, and the information available can also be combined with other data, such as weather and / or traffic density, and pre-filtered, as will be explained below. The type, size and exact position of the existing stress hotspots as well as the course of the trajectories that have already been driven are analyzed. It is advantageous to determine that trajectory from the existing trajectories which has the lowest loads on the vehicle and / or occupants, that is to say makes the lowest contribution to wear and / or kinetosis.

From this, the trajectory with the minimum load that the vehicle should then drive can be determined. In this case, a standard trajectory is determined if no stress hotspot on the road section and / or no trajectory on the road section that has already been traveled is known. A standard trajectory can, for example, be a route that runs in the middle of a lane and can be driven at the maximum permissible speed.

If, however, one or more stress hotspots are known on the road section, a check is made as to whether a trajectory with minimal stress can be found that is laterally offset in relation to at least one known trajectory that has already been driven. In the previous analysis it was preferably already determined which of the known trajectories had the lowest loads for the vehicle and / or occupants and this was used as the starting trajectory for a lateral relocation. If only one trajectory is known, based on this, the laterally shifted trajectory is checked with regard to occurring loads.

In order to enable a comparison of the known trajectories, the loads that occur must have been quantified beforehand, for example the values of the relative excesses of load thresholds of vehicle parts can be added up. A weighting depending on the importance of the vehicle part (for example based on the safety relevance or the repair costs of the component) is useful.

On the basis of the trajectory with the lowest stress or, if applicable, only one known trajectory, it is checked whether a lateral relocation is possible at least in the area of the stress hotspot (s) without endangering safety, for example in the case of wide roads in the form of laterally offset driving or in multi-lane roads by changing lanes . There the laterally offset trajectory should be a predefined minimum distance away from all trajectories that have already been tried out. This prevents that there is only a minimal lateral installation, which however does not have any significant influence on the load level.

If this lateral displacement of the trajectory is possible and this trajectory has not yet been driven on, this trajectory is generated as the trajectory to be driven on. It can then be transmitted to the vehicle control and / or the driver of the vehicle and driven on.

Alternatively or additionally, a reduction in the speed can be checked while maintaining a known, low-stress trajectory at least in the area of the stress hotspot (s). It makes sense to set a lower limit for the speed, such as falling below the permissible maximum speed in km / h or in%, in order to avoid excessive braking, obstruction of the flow of traffic and a disproportionate increase in travel time.

If a reduction in speed is possible, this trajectory is determined with a reduced speed and transmitted to the vehicle control and / or the driver of the vehicle for the purpose of driving. Otherwise it will be driven on without reducing the speed.

Preferably, but not exclusively, the steps mentioned take place in a cascading sequence. In this advantageous embodiment, the lateral relocation is first checked in relation to a known and, in particular, the known trajectory with the lowest stress, as already stated. If this is possible, this laterally laid trajectory is used. If lateral relocation is not possible or sensible, a reduction in speed is checked on one of the known trajectories or on the trajectory with the lowest load to date. If this is again possible, the known trajectory is traveled at a lower speed. However, if it is not possible to reduce the speed, there is no further change, since in this case this is already the trajectory with the lowest load. This step-by-step, cascading procedure for determining the minimum load trajectory has the advantage that first the avoidance of load hotspots, which is more gentle on the flow of traffic and more favorable for the consumption of the vehicle, namely the sideways evasion by adapting the trajectory, is checked. The trajectory to be traveled can be determined in such a way that a smooth course of the journey is achieved and not just a short evasion. The speed reduction, which is usually associated with acceleration afterwards, is checked and, if necessary, selected only if it is not possible to move it sideways.

The vehicle now drives along the determined trajectory. It is advantageous that this can always be overridden by the general vehicle control, in particular when spontaneous emergency braking is required.

These method steps are expediently carried out for each road section along a route to be traveled in order to reduce the stress on the vehicle and the occupants and thus the risk of wear and tear and kinetosis on the entire route that the vehicle is traveling on.

It is particularly expedient for the method that the vehicle can be precisely localized on a digital map, since an algorithm for controlling the vehicle calculates the vehicle guidance on the basis of the road parameters stored in the map. There should therefore be a highly accurate map of the streets by means of which the vehicle can determine its current position to within a few centimeters using location information such as GPS data and sensor data from the environment recognition.

In a preferred embodiment of the invention, it is provided that while driving on the road section along the determined minimal stress trajectory stress hotspots are determined and transmitted to vehicles in the vicinity and / or a central storage device. After the trajectory with the minimum load and thus the trajectory to be driven on a road section has been determined and the vehicle is driving on it, it should be monitored and recorded along this trajectory as to whether there are any load hotspots. If this is the case, these stress hotspots should be transmitted to vehicles in the immediate vicinity, for example with the known Car2Car communication.

Alternatively or additionally, the transmission to a central storage device should take place. Thus, when planning and / or driving on the route section, other vehicles can use the current information regarding possible loads in order to determine a current, optimized for them minimal load trajectory. This successively results in a more precise picture of the stress hotspots and an iterative optimization of the local routing with regard to the load input into the vehicle. As soon as all possibilities for relocating trajectories for a stress hotspot have been determined and tried out, the optimal trajectory has been found. The vehicles that have traveled different trajectories, have "sacrificed" themselves in a certain way in order to enable a large number of following vehicles to have a trajectory with a minimum load. The fact that older data is regularly deleted from the server on the basis of the acquisition date ensures that it is up-to-date, since obstacles that cause stress hotspots may have been removed or newly created in the meantime. Depending on the type of obstacle, the deletion period should be variable, since, for example, a blockade of one's own lane by a stopping vehicle will clear up again more quickly than an unevenness in the ground.

• • Erfassung von Referenzgrößen während des Befahrens des Straßenabschnittes entlang der ermittelten belastungsminimalen Trajektorie,
• • Umrechnen der erfassten Referenzgrößen in jeweils mindestens eine korrespondierende Belastungsgröße mittels mindestens einer hinterlegten Übertragungsfunktion,
• • Korrelation der korrespondierenden Belastungsgrößen entlang der gefahrenen Trajektorie,
• • Analyse der korrespondierenden Belastungsgrößen entlang der gefahrenen Trajektorie und Bestimmung von Belastungshotspots.

In particular, existing stress hotspots on a route section are determined using at least the following steps:

• • Acquisition of reference values while driving on the road section along the determined minimum load trajectory,
• • Conversion of the recorded reference variables into at least one corresponding load variable using at least one stored transfer function,
• • Correlation of the corresponding load variables along the trajectory driven,
• • Analysis of the corresponding stress levels along the trajectory and determination of stress hotspots.

So first of all, so-called reference variables are recorded while driving on the road section. Reference variables are variables that are easy to measure in the vehicle, such as accelerations and speeds, from which the resulting load variables such as forces and / or moments that act on individual components of the vehicle or on the occupant (s) can be calculated or determined. The detection of the reference variables can preferably be carried out by sensors already present in the vehicle.

The reference values are recorded continuously. The recorded values are preferably stored in a buffer memory. The acquisition takes place until the end of the route section is reached. So that the capacity of the buffer is sufficient, it makes sense when creating the map or dividing the road sections to divide very long route sections into shorter sections.

The recorded reference variables are converted into at least one corresponding load variable, the conversion taking place on the basis of a stored transfer function. It is therefore possible that several load values can be derived from one reference value. For the conversion, each recorded reference variable is used in a transfer function that is available for the stress variable in question, and at least one stress time signal is thus calculated.

The transfer function is known in advance and is usually model-specific for a vehicle. It should be stored in the processing unit that carries out the steps for determining exposure hotspots.

Since it is known from the traveled trajectory at what point in time the vehicle was at which location, the load variables can be locally correlated, that is, the exact position of the load variables and thus also of the load hotspots can be determined based on the time and the location information.

• • Bodenunebenheiten, insbesondere Schlaglöcher, Bahnübergänge, Bremsschwellen und/oder Kanaldeckel,
• • Bremssituationen, insbesondere an Ampeln, Stopp-Schildern, Zebrastreifen, Verkehrsstau und dergleichen,
• • Lenksituationen, insbesondere bei engen Kurven, Schikanen zur Verkehrsberuhigung oder durch Ausweichmanöver, beispielsweise wenn die Müllabfuhr, ein Bus, ein Taxi, eine Baustelle oder ein Unfall einen Fahrstreifen blockiert.

The load variables are examined or analyzed. For this purpose, barriers are preferably stored for each type of exposure in which the intensity of exposure should usually be. If the signal exceeds or falls below a limit at a certain point in time, this is detected and, for example, quantified on the basis of a relative indication (“exceeded by x%”). In particular, if several stress signals exceed the limits at the same time, this is an indication of the occurrence of a stress hotspot. Noticeably high deflections along the driven trajectory are correlated with a specific location, as explained. Examples of such hotspots can be:

• • Uneven ground, in particular potholes, level crossings, speed bumps and / or manhole covers,
• • braking situations, especially at traffic lights, stop signs, zebra crossings, traffic jams and the like,
• • Steering situations, especially in tight bends, harassment to calm the traffic or by evasive maneuvers, for example when the garbage disposal, a bus, a taxi, a construction site or an accident blocks a lane.

• • Bei Bodenunebenheiten ist unter anderem relevant, in welchem Winkel sie getroffen werden, also ob ein Schlagloch nur am Rand gestreift oder voll durchfahren wird, ob eine Schwelle schräg oder im rechten Winkel angefahren wird, oder ob die Unebenheit gegebenenfalls sogar ganz umfahren wird.
• • Bei Bremssituationen ist unter anderem relevant, wie stark gebremst wird, also ob zuvor schnell oder langsam gefahren wurde, ob die verbliebene Distanz zum Hindernis eine hohe Verzögerung erforderlich macht oder ob durch den Untergrund an den von der Trajektorie befahrenen Stellen ein hoher oder niedriger Reibwert zum Reifen vorliegt.
• • Bei Lenksituationen ist unter anderem relevant, wie eng die Krümmung der Trajektorie ist, welche Geschwindigkeit gefahren wird, wie stark das Lenkrad eingeschlagen wird, welcher Reibwert entlang der Trajektorie zwischen Reifen und Untergrund vorliegt.

Depending on how such a hotspot is traveled, i.e. which specific trajectory has been covered, this has a considerable influence on the loads. The following is an example:

• • In the case of uneven floors, the angle at which they are hit is relevant, i.e. whether a pothole is only grazed on the edge or driven through, whether a threshold is approached at an angle or at a right angle, or whether the unevenness is possibly even bypassed completely.
• • In braking situations, it is relevant, among other things, how hard the brakes are applied, i.e. whether the vehicle has been driven quickly or slowly, whether the remaining distance to the obstacle requires a high degree of deceleration or whether the ground at the points traveled by the trajectory has a high or low coefficient of friction to mature.
• • In steering situations, it is relevant, among other things, how tight the curvature of the trajectory is, what speed is driven, how much the steering wheel is turned, what coefficient of friction exists along the trajectory between the tires and the ground.

• • die gefahrene Trajektorie,
• • die genaue Position des Belastungshotspots auf dem Straßenabschnitt,
• • Art(en) und Intensität(en) der Belastungen an dem Belastungshotspot, dies können Belastungs-Spitzenwerte oder kleine Ausschnitte aus den Belastungszeitsignalen sein,
• • Datum und Uhrzeit der Befahrung,
• • Verkehrsdichte und/oder
• • Witterungsbedingungen.

As already explained, the determined stress hotspots are transmitted to vehicles in the vicinity (for example using Car2Car communication) and / or a central storage device (for example using Car2X communication to a central server). In order to characterize the stress hotspots, the following information about a stress hotspot is preferably transmitted:

• • the trajectory driven,
• • the exact position of the stress hotspot on the road section,
• • Type (s) and intensity (s) of the stress at the stress hotspot, these can be stress peak values or small excerpts from the stress time signals,
• • Date and time of the visit,
• • Traffic density and / or
• • weather conditions.

The transmission to other vehicles in the vicinity is based on the assumption that they may also be driving on the same route section shortly and could be affected by the stress hotspots.

The named information can be stored in an organized manner on a central server and later transmitted to other autonomous vehicles or to the same vehicle again upon request. Ordered in this case means that the information is assigned to the associated street section. For example, a vehicle that is planning to drive on a certain road section can simply query all empirical values and thus stress hotspots for this section.

After the information has been passed on, the data can be deleted from the buffer so that the storage space can be used for other purposes.

• • Mehrkörpersimulation des Fahrzeugs mit Referenzmanövern,
• • Korrelation der Referenzgrößen aus den Referenzmanövern mit resultierenden Belastungsgrößen.

According to the invention, at least the following steps should be carried out to determine a transfer function:

• • Multi-body simulation of the vehicle with reference maneuvers,
• • Correlation of the reference values from the reference maneuvers with the resulting load values.

These steps should preferably be carried out once as part of the vehicle development.

So that the vehicles do not have to be equipped with complex, heavy and expensive measurement technology for forces and torques, variables should be used that correlate to the loads, but are easier to measure or are already recorded by the sensors installed in the vehicle, such as the reference variables, which have already been explained. Examples of such reference variables can be: longitudinal, lateral and vertical acceleration, speed, steering angle, brake pressure, engine speed / torque, spring travel, gear position and the like.

• • Für Längsbeschleunigung und Geschwindigkeit: Anfahren und Bremsen auf gerader, ebener Strecke.
• • Für Querbeschleunigung: Kurvenfahrt konstanter Geschwindigkeit bei variablen Kurvenradien auf ebener Strecke.
• • Für Vertikalbeschleunigung: Gerades Überfahren unterschiedlich intensiver Bodenhindernisse mit konstanter Geschwindigkeit.

In order to be able to draw conclusions about the load values from these reference values, a connection between the reference values and the load values must be established. For example, a vehicle and its driving environment can be virtually modeled true to detail and with high quality results by means of numerical simulation. So-called multi-body simulations are often used for this. These can be coupled with finite element simulations to take into account the deformation of individual components. So-called reference maneuvers are used in the simulation in order to achieve a usable coupling between reference and load values. Reference maneuvers are standardized driving maneuvers in which mainly a variable that can be easily measured in real operation changes, while other influencing variables remain constant, for example:

• • For longitudinal acceleration and speed: moving off and braking on a straight, level route.
• • For lateral acceleration: cornering at constant speed with variable curve radii on a level route.
• • For vertical acceleration: Drive straight over obstacles of different intensity at a constant speed.

Since only one reference variable is continuously varied in each of the reference maneuvers, while the others remain largely constant, the resulting influence on the component or occupant loads can be assigned to it, i.e. correlated. By plotting a load variable over a reference variable, a characteristic curve or a characteristic field is obtained which represents the transfer function between the two variables and is suitable for converting them. The correlation is ideally carried out for individual vehicle parts or for the occupants.

In order to enable the conversion of reference values into load values while driving on a minimal exposure trajectory, the determined transfer function is stored in a memory of the computing unit that carries out the steps for determining exposure hotspots. It should be noted that transfer functions only apply to the vehicle variant or vehicle model with which or for which the simulation was carried out.

It is also advantageous if the same load values are superimposed from different reference values. In doing so, signals of the same load values that result from different reference values, such as those resulting from a force on a chassis component from longitudinal, transverse and vertical dynamics, are to be superimposed. Since a large number of vehicle components and also human occupants are sensitive to stimuli from several spatial directions, the time signals of a load variable that result from various reference variables are added up. This takes into account the effects of amplification and weakening. As an example, reference is made to the normal force of a handlebar in the chassis: From the time profiles of the longitudinal, lateral and vertical acceleration, three time profiles of the normal force are calculated using three transfer functions. These three time courses depict the case if an acceleration would have occurred in only one of the three spatial directions. Since the three signals have the same time axis, they can be added. As a result, for example, the normal force is reduced at points in time when the different directions of acceleration simultaneously generate compressive and tensile forces.

In a further preferred embodiment, reference values are stored in a memory device in the vehicle while driving on the road section along the determined minimum load trajectory, the determined load hotspots and / or the at least one stored transfer function and / or the conversion of the recorded reference values into load values, the analysis of the Load variables and / or the determination of the minimum load trajectory carried out in a computing unit in the vehicle.

• • Die Übertragungsfunktion wird nach jedem Straßenabschnitt zur Umrechnung benötigt. Wenn sie zentral an einem anderen Ort gespeichert wären, müssten sie jedes Mal abgefragt und versendet werden. Dies wäre sehr aufwendig, sodass eine lokale Speicherung im Fahrzeug deutlich weniger Kommunikationsaufwand verursacht.
• • Das Speichern der Referenzgrößen im Fahrzeug erlaubt auch das Umrechnen und Analysieren der Belastungen direkt im Fahrzeug ohne vorher notwendigen Datentransfer.
• • Liegen die Belastungshotspots in einem Speicher im Fahrzeug vor, kann ein Fahrzeug beim erneuten Befahren eines Straßenabschnittes auf diese Informationen zugreifen. Es ist dabei unabhängig von einer Verbindung zu einem Server und das Verfahren kann beschleunigt werden.

The local storage of reference variables while driving on the road section, the determined stress hotspots and / or the transfer function on a local memory in the vehicle has various advantages:

• • The transfer function is required for conversion after each road section. If they were stored centrally in a different location, they would have to be queried and sent every time. This would be very complex, so that local storage in the vehicle causes significantly less communication effort.
• • Saving the reference values in the vehicle also allows the loads to be converted and analyzed directly in the vehicle without the need to transfer data beforehand.
• • If the stress hotspots are stored in a memory in the vehicle, a vehicle can access this information when it drives on a section of road again. It is independent of a connection to a server and the process can be accelerated.

This embodiment should be understood to the effect that the transfer function (s) and / or the determined stress hotspots are stored in the memory device in the vehicle even before driving on a road section.

Alternatively or additionally, the recorded reference variables can be converted into load variables, the analysis of the load variables and / or the determination of the minimum load trajectory can be carried out in a computing unit in the vehicle. This is particularly useful if the transfer functions and / or the reference variables are stored in the vehicle, since this avoids complex data traffic between the vehicle and a server on which these processes can alternatively take place. When converting, analyzing and calculating the minimum load trajectory on a server, the time-continuous reference variables and, if necessary, environmental information would have to be transmitted to a server and the trajectory to be traveled that was determined therefrom would have to be transmitted back.

A next embodiment provides that the weather, the traffic density, information from vehicles in the immediate vicinity, the position of the occupant (s) of the vehicle, the approximate weight of the occupant (s) of the vehicle, Wöhler lines for the components of the vehicle and / or frequencies of the load

The weather can be obtained through the sensors built into the vehicle, in particular based on data from a rain sensor or the windshield wiper intensity, external data sources such as servers that provide weather data (weather stations / precipitation radar), or from vehicles in the vicinity and used to determine the trajectory with the minimum load become. The weather has a direct influence on the drivability of roads, for example because the coefficient of friction between tires and road changes or visibility deteriorates. Such information is advantageously also passed on with the transmission of the determined stress hotspots, so that in the analysis of known stress hotspots before the determination of a new trajectory to be traveled, the information that was recorded under the same weather conditions can be filtered out and preferably used.

The same applies to traffic density. This can be quantified, for example in the form of a deviation between the normally drivable, desired speed and the actually realized speed. In addition to the vehicle's own sensors, the traffic density can also be carried out using external sources, such as a traffic density determination using mobile phones by external providers or Car2Car communication. Even in the case of traffic density, this information can be transmitted with determined stress hotspots for further use.

Further or other information, such as accidents, temporary closures or obstacles and the like, can also be received by vehicles from the immediate vicinity and the determination of the trajectory with the minimum load can be included and make it possible to determine the trajectory with even more up-to-date data. Such data can also be contained in the data of a central server, but the Car2Car communication results in advantages: Firstly, a time advantage, since the direct sending and receiving of the data is faster than the detour with intermediate storage on a server. This allows you to react better to spontaneous obstacles. Second, there is a redundancy advantage, for example if communication with the server is hindered, it fails or is overloaded.

When calculating the forces on the occupants, what is relevant is what position they are in the vehicle, i.e. what seat they are sitting on. This can be determined, for example, by the occupancy sensors, which originally serve to warn if the seat belt is forgotten, and can be taken into account in the conversion or selection of the transfer function. It is also advantageous that the transfer functions for the occupant forces were determined and stored not only for people of average body mass and size, but in each case for different body weights. The occupancy sensor system should be so pronounced that it not only recognizes whether the seat is occupied or not, but also determines the approximate body mass of the occupant. As a result, a more suitable transfer function can be used and an increase in accuracy can be achieved. Another advantage arises if the transfer functions are also differentiated according to whether the seat is currently in an upright or in a lying position.

With a focus on the operational stability of the vehicle, Wöhler lines for the vehicle components can also be included in the determination of the trajectory with the minimum load. Using a Wöhler curve, linear damage accumulation in the form of a miner's sum can be used to quantify the influence of the level and frequency of stress on the fatigue of a vehicle component. By applying a counting method of the fatigue strength to the load time signals occurring along a trajectory and calculating the Miner's sum from this, a key figure is obtained that specifically relates to component fatigue due to the loads. This is much more suitable for assessing how gentle a trajectory is than simply adding up threshold values for individual loads. In addition, a miner's sum can be continuously accumulated over the vehicle's service life in order to estimate information about the absolute fatigue state of the component. The vehicle owner can be warned that the component should be replaced shortly. If Miner sums are counted for the components, it can be determined whether, for example, component A. is much closer to its theoretical end of life than a component B. . In this case, when choosing between several potential trajectories, it is advantageous if such trajectories are preferred, the component A. Load only a little and therefor component B. more. This results in a uniform fatigue of all components, which increases the overall service life of the vehicle.

With regard to the prevention of kinetosis, the assessment of the stress on the occupant can be carried out on a frequency-related basis. It is known that certain stimulation frequencies are particularly conducive to malaise and nausea, for example the natural frequency of the stomach. To do this take into account, the occupant loads are weighted with frequency-dependent factors. The weights can be based, for example, on the ISO 2631-1 standard "Mechanical vibration and shock - Evaluation of human exposure to wholebody vibration".

In a further embodiment, obstacles along the driven trajectory are determined and measured by means of the environment recognition of the vehicle. The sensors that vehicles are equipped with in order to be able to drive autonomously or to monitor the environment to increase safety while driving, for example cameras, laser scanners, radar and the like, are used to detect, classify and monitor obstacles measured. It is no longer just recorded and transmitted that there is an obstacle, but also details about the obstacle itself, such as its type or its dimensions (for example by means of corner coordinates of a polyhedron that describes an envelope of the obstacle).

• • eine Sende- und Empfangseinrichtung, die ausgebildet und eingerichtet ist, bereits gefahrene Trajektorien und/oder vorhandene Belastungshotspots entlang eines Straßenabschnittes abzufragen, die zu befahrende belastungsminimale Trajektorie an eine zentrale Speichereinrichtung und/oder Fahrzeuge in der Umgebung zu übertragen und/oder ermittelte Belastungshotspots an eine zentrale Speichereinrichtung und/oder Fahrzeuge in der Umgebung zu übertragen,
• • eine Recheneinheit, die ausgebildet und eingerichtet ist, bereits gefahrene Trajektorien und/oder bekannte Belastungshotspots zu analysieren, eine belastungsminimale Trajektorie zu bestimmen und/oder erfasste Referenzgrößen in jeweils mindestens eine korrespondierende Belastungsgröße mittels mindestens einer hinterlegten Übertragungsfunktionen umzurechnen,
• • eine Verbindung mit einer fahrzeugeigenen Umfelderkennung, und/oder
• • eine Speichereinheit zum Hinterlegen von erfassten Referenzgrößen und/oder Übertragungsfunktionen

auf. Details dazu wurden in der Beschreibung des Verfahrens bereits erläutert.According to the invention, a device is also claimed which carries out the method disclosed here. Such a device has at least

• A transmitting and receiving device which is designed and set up to query trajectories already driven and / or existing stress hotspots along a road section, to transmit the minimal stress trajectory to be driven to a central storage device and / or vehicles in the area and / or to determined stress hotspots to transfer a central storage device and / or vehicles in the vicinity,
• • a computing unit that is designed and set up to analyze trajectories that have already been driven and / or known stress hotspots, to determine a minimal stress trajectory and / or to convert recorded reference variables into at least one corresponding stress variable using at least one stored transfer function,
• • a connection with a vehicle's own environment recognition, and / or
• • a storage unit for storing recorded reference variables and / or transfer functions

on. Details on this have already been explained in the description of the method.

A computer program product is also claimed which calculates a low-stress trajectory using the disclosed method when it is executed in a computing unit.

The advantages of the proposed determination of minimum load trajectories are obvious: reference values that are easy to measure can be recorded and converted into load values. The transfer functions required for this can be determined completely virtually. The acquisition of the reference variables while driving on a route section takes place continuously instead of just being estimated on the basis of map data, as was customary up to now. Obstacles or loads for the vehicle and occupants are recorded in terms of their type, position and size, without being limited to road damage or curves. The data is up-to-date and very accurate at the local level, so that the trajectory planning can be optimized. At the same time, the route can be evaluated on the basis of specific component or occupant loads, taking into account directional, superposition and non-linearity effects. Using Car2Car communication, the information obtained can be quickly transmitted to other vehicles in the vicinity.

The various embodiments of the invention mentioned in this application can advantageously be combined with one another, unless stated otherwise in the individual case.

• 1 ein beispielhaftes Schema des Verfahrensablaufs,
• 2 Ausführungsbeispiel der erfindungsgemäßen Vorrichtung, und
• 3 Beispiele für seitliche Trajektorienverlegungen.

The invention is explained below in exemplary embodiments with reference to the accompanying drawings. Show it:

• 1 an exemplary scheme of the process flow,
• 2 Embodiment of the device according to the invention, and
• 3 Examples of lateral trajectory relocations.

1 shows an exemplary embodiment of the method according to the invention. To make it easier to read, 1 only the process steps are marked with reference symbols.

First of all, this is done in a first block A. determines the transfer function for later converting the reference values into load values. This is done in step 1 a multi-body simulation of a vehicle F. created and the loads from reference maneuvers determined. In step 2 the reference variables determined by the simulation are correlated with the resulting load variables, so that characteristic curves or maps are obtained that represent the transfer function. The transfer functions are done in one step 3 stored in a memory of a computing unit, which calculates trajectories with minimal stress at a later point in time. This sequence A. and from it The resulting transfer functions are model- or vehicle-specific.

In the block B. are the steps 4th to 9 summarized for the recording and determination of stress hotspots. This detection takes place when driving on a road section. This can be driving on after determining a trajectory with a minimum load, but also driving on a road section for the first time.

In step 4th reference values are recorded while driving on a road section and stored in a buffer. This intermediate memory is preferably part of a computing unit in the vehicle, by means of which the reference values are subsequently converted into load values and the load hotspots are determined.

Using the transfer functions stored in the memory of the processing unit, the reference variables are converted into the desired or necessary load variables in step 5. Load values resulting from various reference values are superimposed in step 6 in order to take reinforcements and weakenings into account.

On the basis of the calculated load variables, an evaluation can take place in step 7 as to whether previously defined limits for these load variables have been exceeded and by how much. Alternatively, it can be determined whether limit values for the load variables have been reached. Exceeding these barriers, especially crossing several barriers, is an indication of the presence of a stress hotspot.

The determined stress hotspots are then transmitted (step 8) together with other relevant information, such as weather conditions or traffic density, to vehicles in the area and / or a central server, so that other vehicles always have up-to-date information to determine minimal stress trajectories stand.

After the information has been transmitted, the cache is deleted (step 9 ).

The third block C. shows the sequence for determining the minimal exposure trajectory: While planning a route and / or while driving, known, i.e. already driven, trajectories on the road sections and / or known exposure hotspots (step 10 ). The actual trajectory planning (step 11 ). It is checked whether stress hotspots are known on the road section (step 11.0). If not, in the 1 marked with "N", a standard trajectory is determined (step 11.1). However, stress hotspots are known to exist in 1 marked with "Y", a lateral shifting of the trajectory is checked (step 11.2).

If a lateral relocation is possible, which is marked with “Y”, a laterally relocated trajectory is determined (step 11.2.1). If it is not possible to move to the side without impairing traffic and / or the safety of the vehicle and occupants, as marked with an "N", a check is made as to whether the speed can be reduced (step 11.2.2). If yes (“Y”), a trajectory with a lower speed to be driven is determined (step 11.2.2.1). If not (“N”), the trajectory is determined without reducing the speed (step 11.2.2.2).

After the trajectory has been determined, the minimum load trajectory determined is used as a step 12th drive on. While driving on the trajectory with the minimum load, the steps from Block B. carried out for the determination of stress hotspots, like the arrow from step 12th to step 4th to illustrate. This ensures that any further existing stress hotspots are determined along the determined trajectory and the resulting information can be made available to other vehicles.

2 shows an embodiment of the device according to the invention as a schematic sketch. A vehicle F1 is with a vehicle controller 42 equipped for autonomous driving. In addition, the vehicle F1 has an environment recognition U which includes various sensors, radar, cameras and the like to detect the surroundings of the vehicle F1 and other road users. The vehicle F1 also has a transmitting and receiving device 36 on, by means of which a wireless communication 37 between the vehicle F1 and other vehicles F2 by means of Car2Car communication and with a central storage device, in particular a server 28 can be implemented using Car2X communication.

Also are a storage device 30th and an arithmetic unit 32 provided in vehicle F1. In the storage device 30th are the reference values when driving on a road section 38 as well as the transfer function (s) 40 saved. This includes saving the reference values 38 realized with a buffer, from which after the end of a street section and transmission of the determined stress hotspots to the central server 28 and / or other vehicles F2 use the reference variables recorded for this purpose 38 to be deleted.

In the arithmetic unit 32 are made in 1 in the blocks B. and C. illustrated method steps for determining a minimum load trajectory and for determining the load hotspots along a trajectory driven. The data of the environment detection U and the minimum load trajectory determined are then sent to the vehicle control system 42 transmitted, which controls the driving on the determined trajectory.

In 3 examples of lateral trajectory relocations are shown. Each of the 3a to 3h shows a street section 20th by a vehicle F. should be driven on. On every stretch of road 20th is at least one obstacle 34 shown that as a result of the determination of reference and exposure variables as exposure hotspot 22nd is classified.

In 3a protrudes a bump in the floor 34 in the street section 20th into it. When querying trajectories that have already been driven and known stress hotspots, it is transmitted that some trajectories have already been taken 24 along the road section 20th where the unevenness of the ground 34 was recorded as exposure hotspot 22a. As with each of the already driven trajectories 24 the unevenness of the ground 22a was detected, as well as its exact position on or along the road section 20th , the position and size can be at a local level, namely in relation to the road section 20th very precisely determined and in the determination of a minimum load trajectory 26th must be taken into account.

It is now known that a stress hotspot 22a in the form of a bump in the floor 34 is present, as in 1 already shown, checked a lateral installation. As it is known from previous journeys that the unevenness of the ground 34 to the outer edge of the road section 20th is only a detour in the direction of the middle of the road to avoid loads on the vehicle F. and its occupants make sense. Since a sufficient distance to the center line can still be maintained, the trajectory to be driven on becomes the minimum load 26th determined by laying it sideways towards the center of the street.

While driving on the minimum load trajectory 26th can by means of the environment recognition U of the vehicle F. (not shown) the obstacle can be detected and classified more precisely. Using the in the vehicle F. Built-in sensors, cameras, radar, laser scanners and the like can change the size, shape, exact position and type of the obstacle 34 are recorded and evaluated, so that this characterizing information about the obstacle 34 can also be made available to other road users in order to determine trajectories with the minimum load.

The differences and peculiarities of the others are given priority below 3b to 3h worked out. In 3b is on the street section 20th a traffic island 34 , 22b arranged by the vehicle F. must be bypassed. Here, too, is based on the trajectories that have already been traveled 24 Checked a lateral installation in order to achieve the trajectory with the minimum load 26th to determine.

The determination of the minimum load trajectories 26th can also be temporary stress hotspots 22nd such as a puddle 34 in a curve ( 3c , Stress hotspot 22c) or a stationary vehicle 34 ( 3d , Exposure hotspot 22d) and provide. If other vehicles use this stretch of road 20th drive on and thereby no longer detect a puddle 22c or a stationary vehicle 22d, these stress hotspots can be deleted again from the server or the puddle 22c can be classified as a stress hotspot in the aftermath of rain events, so that a vehicle F. this exposure hotspot 22c is only transmitted when it is raining or has rained.

In 3e is a street section 20th shown on which a speed bump 34 is arranged across the entire lane. It is recorded as stress hotspot 22e. Parts of the speed bump 22e have already broken out in the areas 22x, so that there are no longer any obstacles and no increased load on a vehicle F. can act, its trajectory 24 , 26th is guided so that the wheels of the vehicle F. roll through the imperfections 22x. Alternatively, the trajectory to be traveled 26th also a bypass 26th provide the speed bump 22e.

Another influence on the determination of the minimum load trajectory 26th may be the position and distance of staggered stop lines 22f on traffic lights and the like. The offset stop lines do not necessarily have to be of structural origin, but can also be created in the sense of a virtual stop line when another waiting vehicle is already standing on a lane. In the 3f The two lanes shown both lead straight ahead. Unless the vehicle F. should drive straight ahead, the method according to the invention is used to determine whether the lateral offset to the right lane with the longer braking distance and, as a result, a lower deceleration despite the lane change, a lower load on the vehicle F. represents.

In the case of multiple obstacles 34 as in 3g need to follow along previously driven trajectories 24 and the reference variables recorded in the process, the stress variables are analyzed and from this it is determined whether the stress caused by a manhole cover as a stress hotspot 22g or a gutter made of cobblestone as a stress hotspot 22h is more stressful for the vehicle and occupants. If there is no trajectory without contact with one of the two stress hotspots 22g and 22h, the trajectory to be traveled is then guided over that of the two stress hotspots 22g or 22h which showed the lower stress magnitudes.

3h shows a level crossing 22i in a curve 22k. Here, too, must be based on the load values along the trajectories driven 24 determine which of them has the least impact on the vehicle F. and occupant means and whether a lateral transfer is still possible.

List of reference symbols

1 to 12

Procedural steps

20th

Street section

22nd

Stress hotspot

24

traveled trajectories

26th

minimum load trajectory

28

central storage facility

30th

Storage device in the vehicle

32

Arithmetic unit

34

obstacle

36

Transmitting and receiving device

37

wireless communication

38

Reference variable (s)

40

Transfer function (s)

42

Vehicle control

A.

Determination of the transfer function (s)

B.

Identification and determination of stress hotspots

C.

Determination of a minimum load trajectory

F.

vehicle

U

Environment recognition

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 102007038424 A1 [0008]
• DE 102012016736 A1 [0009]
• DE 102017206435 A1 [0010]
• DE 102017214823 A1 [0011]
• DE 102014213522 A1 [0012]
• DE 102014214729 A1 [0016]

Claims (10)

Method for minimally stressful trajectory planning (26) for vehicles (F) with at least the following steps: • Planning and / or driving on a road section (20), • Query of already driven trajectories (24) and / or existing stress hotspots (22) along this road section (20), • Analysis of the already driven trajectories (24) and / or existing stress hotspots (22), • Determination of a minimum load trajectory (26) on the road section (20), wherein ◯ a standard trajectory (26a) is selected if there are no stress hotspots (22), and ◯ in the presence of stress hotspots (22) ▪ a trajectory (26b) is determined which is moved laterally in relation to at least one trajectory that has already been driven at least in the area of the stress hotspot (s) (22) and / or ▪ a reduction in the speed of the vehicle (F) is determined at least in the area of the stress hotspot (s) (22), • Driving on the road section (20) along the determined minimum load trajectory (26) on the road section (20). Procedure according to Claim 1 , characterized in that while driving on the road section (20) along the determined minimal stress trajectory (26) stress hotspots (22) are determined and _{transmitted to vehicles (F x} ) in the vicinity and / or a central storage device (28). Procedure according to Claim 2 , characterized in that the stress hotspots (22) are determined with at least the following steps: • acquisition of reference variables (38) while driving on the road section (20) along the determined minimum stress trajectory (26), • conversion of the recorded reference variables (38) in at least one corresponding load size by means of at least one stored transfer function (40), • Correlation of the corresponding load sizes along the driven trajectory (24), • Analysis of the corresponding load sizes along the driven trajectory (24) and determination of stress hotspots (22). Procedure according to Claim 3 , characterized in that at least the following steps are carried out to determine a transfer function: • multi-body simulation of the vehicle (F) with reference maneuvers, • correlation of the reference variables (38) from the reference maneuvers with resulting load variables. Method according to one of the preceding claims, characterized in that the same load variables are superimposed from different reference variables (38). Method according to one of the preceding claims, characterized in that • reference variables (38) while driving on the road section (20) along the determined minimum stress trajectory (26), the determined stress hotspots (22) and / or the at least one stored transfer function (40) are stored in a storage device (30) in the vehicle (F) and / or • the conversion of the recorded reference variables (38) into load values, the analysis of the load values and / or the determination of the minimum load trajectory (26) in a computing unit (32) is carried out in the vehicle (F). Method according to one of the preceding claims, characterized in that to determine the minimum load trajectory (26) the weather, the traffic density, information from vehicles (F _x ) from the immediate vicinity, the position of the occupant (s) of the vehicle (F), the Approximate weight of the occupant (s) of the vehicle (F), Wöhler lines for the components of the vehicle (F) and / or frequencies of the load are included. Method according to one of the preceding claims, characterized in that obstacles (34) along the driven trajectory (24, 26) are determined and measured by means of the environment recognition (U) of the vehicle (F). Device for low-stress trajectory planning with a method according to one of the preceding claims, with at least • one transmitting and receiving device (36) which is designed and set up, trajectories (24) already driven and / or existing stress hotspots (22) along a road section (20) ) to query the minimal exposure trajectory (26) to be traveled to a central storage device (28) and / or vehicles (Fx) in the vicinity and / or determined exposure hotspots (22) to a central storage device (28) and / or vehicles ( Fx) in the environment, • to a computing unit (32) which is designed and set up to analyze trajectories (24) and / or known stress hotspots (22), to determine and / or record a minimal stress trajectory (26) Reference quantities (38) in each case in at least one corresponding load quantity by means of at least one stored transmission point ion (40) to convert, • a connection with a vehicle's own environment recognition (U), and / or • a memory unit for storing recorded reference variables (38) and / or transfer functions (40). Computer program product for low-stress trajectory planning with a method according to one of the preceding Claims 1 to 8th .

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