EP3652044A1

EP3652044A1 - Method and device for calculating a path of motion of a vehicle

Info

Publication number: EP3652044A1
Application number: EP18730710.3A
Authority: EP
Inventors: Holger Andreas Banzhaf
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2017-07-13
Filing date: 2018-06-06
Publication date: 2020-05-20
Also published as: CN110869266B; WO2019011537A1; US20210089036A1; DE102017212044A1; CN110869266A

Abstract

The invention relates to a method and a device for calculating a path of motion (3) of a vehicle (100). According to the invention, a start position (1) and a destination position (2) of the vehicle (100) are defined, a number of possible paths of motion (3) are generated which precisely connect the start position (1) and the destination position (2) to each other, wherein different path elements are linked to each other in different ways for each possible path of motion (3) in order to connect the start position (1) and the destination position (2) of the vehicle (100) to each other, wherein the path elements are linked to each other such that a possible path of motion (3) at a linkage point (13) between two path elements may only have a discontinuous curvature profile if the possible path of motion (3) at the linkage point (13) describes a directional change of the vehicle (100), and a path of motion (3) is selected from the possible paths of motion (3) on the basis of a property of the possible paths of motion (3).

Description

Description title

Method and device for calculating a trajectory of a

vehicle

State of the art

The present invention relates to a method and apparatus for calculating a trajectory of a vehicle.

The maneuvering of vehicles in narrow scenarios plays an especially important role in parking. First, the difficulty lies in generating a collision-free path with as few changes of direction as possible, as short a path length as possible and a small change in curvature over its course.

In the near future, automated vehicles will be parked highly compressed, i. Vehicles are parked closer and possibly parked so that

Displacement operations are necessary to another vehicle

auszuparken. This results in highly non-convex state spaces in which a path must be found for the maneuvering of a vehicle.

One possible approach to solving this path planning problem is sampling-based motion planners, such as Rapidly-Exploring Random Trees. Randomly sampling two configurations in the state space and connecting them exactly to a so-called "Steering / Extended Function." If the connected path is collision free, it is added to a tree (graph), so that the state space does not need to be discretized and converges probabilistically optimal solution, if

one exists. For vehicles with a minimum turning circle, the difficulty is to find a steering function to accurately connect two configurations while optimizing a given cost criterion (eg, length,

Curvature, number of direction changes ...). It is understood that vehicles that can turn on the spot (keyword omnisteer) are excluded.

The prior art includes Reeds-Shepp (RS) Steer and Continuous Curvature (CC) Steer. The advantage of Reeds-Shepp Steer (RS-Steer) is that the shortest path between two points is found. Disadvantage is, that the found path consists exclusively of curves and straights. The resulting discontinuous curvature of the curve means that you must stop while driving to adjust the new curvature, and then continue driving. Not practical in reality.

Continuous Curvature Steer (CC-Steer) addresses this problem by allowing only a continuous curvature. For this purpose, between straight lines and circles still clothoids are used to make the change in curvature steadily. Problem here is that through the

Clothoids the paths become longer and maneuvering in very tight

Scenarios becomes difficult to impossible.

FIG. 7 shows a representation of a movement path 3 calculated by means of a reeds-shepp steer, wherein the movement path 3 has a start position 1 with a movement path 3

Target position 2 connects. FIG. 8 shows a representation of this by means of

Continuous Curvature Steer calculated trajectory 3, which also connects a start position 1 with a target position 2. Disclosure of the invention

The inventive method for calculating a trajectory of a vehicle comprises defining a start position and a target position of the vehicle; generating a number of possible trajectories, wherein for each possible trajectory different trajectory elements are interlinked in different ways to interconnect the starting position and the target position of the vehicle, wherein the Railway elements are linked together so that a possible

Movement path may have a discontinuous curvature at a connection point between two orbital elements only if the possible trajectory at the point of connection describes a change of direction of the vehicle, and selecting a trajectory of the possible trajectories based on a property of the possible trajectories.

The device according to the invention for calculating a trajectory of a vehicle, comprising an arithmetic unit which is adapted to-a

Start position and a target position of the vehicle to define; to generate a number of possible trajectories, for each possible

Movement path different track elements are linked in different ways with each other to connect the starting position and the target position of the vehicle with each other, the track elements are linked together so that a possible trajectory on a

Linking point between two track elements may only have a discontinuous curvature course, if the possible trajectory at the point of connection describes a change of direction of the vehicle, and a trajectory of the possible trajectories based on a

Select property of possible trajectories.

Thus, a trajectory of a vehicle is calculated from a start position to a target position. The method and apparatus are adapted to a trajectory of a vehicle with limited

Curvature / minimum turning circle to calculate. The trajectory is a path, which is a movement of a vehicle with minimal

Curvature / turning circle and thus also describes the necessary steering movements. The trajectory at maximum steering angle can

be mathematically described by a continuous curve. The

Trajectory of Hinterachsmittelpunkts or center of gravity is not necessarily identical to the path, which is traversed by a wheel of a vehicle. Thus, the movement path describes a movement of a point of the vehicle during a movement of the vehicle. From such a trajectory can be directly on a necessary

Close the steering movement. If the trajectory is represented mathematically as a function, for example, then the curvature, ie also the curvature Steering movement, for example, be determined by means of a derivation of the function.

Defining the start position and the target position is setting second positions of the vehicle. The starting position describes an orientation and a position of the vehicle with respect to a reference system. Accordingly, the target position describes an orientation and a position of the vehicle with respect to the reference system. The definition of the start position and the target position takes place in particular by means of a data record which is called

Basis for calculating the trajectory is provided. Such a data record is provided, for example, by a driver assistance system.

In generating a number of possible trajectories, multiple individual trajectories are generated, each of which is possible

Trajectories the starting position and the target position of the vehicle connects. Thus, different sequences of

Determines steering movements to be made by the vehicle to be moved from the start position to the target position. The vehicle is moved so that it reaches the target position in a desired orientation.

An orbital element is an element which mathematically describes a course of a part of the trajectory. For example, a track element defines a curve shape. In this case, a predefined set of track elements is accessed in order to link them together. In which

Generating a possible trajectory web members of the same or different kind are lined up to create a connection between the start position and the target position, which is to be traveled by the vehicle to get from the start position to the target position. The track elements can be adapted to be generated in the

Trajectory to fit. Thus, for example, a track element which describes a straight line, be adapted so that the straight line a

having desired length. In another example, a track member describing a curved path may be adjusted so that the

Curve track has a desired length, wherein a curve angle between a curve input and a curve output is changed accordingly, but the underlying shape of the curve is maintained. A railway element preferably defines a direction of movement in which the

Vehicle has to move in a departure of the trajectory in the region of the respective track element. The different track elements are linked together in different ways to create the possible trajectories. In this case, a possible movement path may comprise one or more of the different track elements. Different possible paths of movement may comprise different or the same track elements. Include two

Trajectories same orbital elements, so these are in a different

Order arranged.

The linking of the different track elements is based on at least one basic rule: The track elements are to be linked together so that a possible trajectory at a transition between two track elements only has a discontinuous curvature, if the trajectory at the transition also describes a change of direction of the vehicle , That means that such possible

Discarded motion paths or not generated only in which two track elements adjacent to each other, which define a same direction of movement and at the point of connection thus no change of direction is necessary, and at the same time at the point where these two

Railway elements adjacent to each other, there is a non-continuous curvature. In other words, this means that any possible trajectory between two track elements may only have a kink, if at the same time at this point of the trajectory, a change of direction of the vehicle takes place. A kink is a location on a possible trajectory at which the vehicle must turn the wheels in the stationary state to start the trajectory.

A discontinuous curvature profile means that a derivative of a trajectory shown as a curve at the junction of two successive orbital elements is not continuous, so has a jump.

There is thus provided a method and apparatus for calculating a new steering function that lives between the two worlds RS-Steer and CC-Steer. Non-continuous curvature changes are only at Change of direction of the vehicle allowed. For this purpose, the maneuverability is increased while ensuring that the paths described by the trajectory can be traversed directly. When driving forwards or backwards are only continuous

Curvature curves allowed, which is made possible in particular by using circles, lines, and clothoids as orbital elements, with clothoids in particular represent a possibility of curvature continuous connection between the circle and straight. At a change of direction of

Vehicle is allowed to have the curvature by e.g. full left turn after full legal turn may be changed and thus here has a non-continuous course. This steering function is called Hybrid Curvature Steer (HC-Steer). It is inspired by human maneuvering in tight scenarios, where we humans are also turning the steering wheel to a standstill to better read e.g. to get into a parking space.

Trajectories produced according to the invention have the advantage that they can be traversed immediately. In comparison to CC-Steer, HC-Steer increases the maneuverability of the vehicle. A computing time for the connection of two configurations, here a start position and a target position, lies in

Microsecond range and is therefore very low.

The dependent claims show preferred developments of the invention. Preferably, the number of possible trajectories is generated by the fact that the different track elements are combined in different ways with each other. It is thus ensured that different possible paths of movement differ from each other. It is advantageous if each of the possible trajectories is a predetermined combination of the different track elements. In particular, a number of sets of track elements are provided, each set comprising a sequence of particular track elements, and in particular also instructions for changing direction between the track elements. Such a set of orbit elements is also called a family. The sets of track elements may comprise a mutually different number of track elements. There are thus a number of possible Trajectories, which can be generated in principle from the track elements limited because not all theoretically possible combinations of track elements must be considered. Thus, the generation of the possible trajectories takes place, in particular, by the fact that the track elements are linked together in accordance with the order defined in the sentences.

Preferably, the different track elements comprise a curve element, and in generating the number of possible trajectories, the curve element is selected from one of the following: an RS curve element describing a constant curve radius curve, an HC curve element comprising a combination of a curve with a constant radius and a curve with a radius increasing or decreasing over a distance with the property of minimum radius on one side and infinite radius on the other side, and a CC

Curve element, which is a combination of a curve with constant radius and in front of it and behind each with a curve with one over one

Distance is rising or falling radius. The RS curve element is a Reeds Shepp curve element. The CC Curve is a Continuous Curvature Curve. The curve with the over a distance

rising or falling radius in the RS curve element and / or the CC curve element is in particular a curve with a linearly increasing or decreasing over a distance radius and is referred to in this case as a clothoid. Thus, based on a very small number of web elements, a trajectory can be calculated which meet the required requirements, whereby a computational effort is limited. The HC curve element is preferably defined by two concentric circles, the continuous radius curve being along an inner one of the concentric circles, and the rising or falling radius path connecting the inner and outer concentric circles. In particular, the HC curve element is a combination of a clothoid and a constant radius curve. A selection is made from a number of possible curve elements. In this case, different one of the possible curve elements can be selected in a single possible trajectory. Minimum radius means that one

Curvature of the curve is zero because curvature = 1 / radius. Preferably, the different track elements comprise a cam element and a straight line element. Thus, a high flexibility in calculating the possible trajectories is achieved. Detours in trajectories can be avoided.

It is also advantageous if, during the selection of a movement path from the possible movement paths, a length of the possible movement paths and / or a minimum number of direction changes of the movement paths and / or a minimal change in curvature is the property of the possible movement paths on which the selection is based. In particular, the trajectory is selected from the possible trajectories, which is the shortest of the possible trajectories. Alternatively, in particular the trajectory is selected from the possible trajectories, which comprises the fewest changes of direction. Alternatively, in particular the trajectory is selected from the possible trajectories, which has a minimum change in curvature. A trajectory with minimal curvature change is in particular such a

Trajectories, in total the least change in a

Steering of the vehicle must be made to start the trajectory. Also, a weighting of several properties can be made to select the trajectory. It is thus selected the trajectory, which is particularly pleasant for a driver. Will the

Trajectory selected from the possible trajectories, which is the shortest of the possible trajectories, so there is a quasi-optimal, apart from the direction changes also curvature, connection between the starting position and the target position. Quasi-optimal because it is not analytically possible to prove this, but this can be demonstrated experimentally or by simulation. Furthermore, it is advantageous if the track elements are linked to one another in such a way that a possible trajectory at a transition between two track elements, ie at a linking point, always exhibits a continuous curvature when the trajectory at the transition describes a movement of the vehicle in the same direction. It is therefore excluded that the vehicle is stopped only because of a steering angle can be changed. It is also advantageous if each of the track elements has a starting point and an end point, wherein the track elements by a relative

Moving the starting point and the end point are adapted to each other for use within a possible trajectory. It is thus changed a position of the two points to each other. For example, a curve angle of a curve element can be defined by a relative position of the starting point relative to the end point. Also, a length of a straight line element can be defined by a relative position of the starting point relative to the end point. It is thus ensured that a small number of track elements is sufficient to the

To generate trajectory.

It is also advantageous if, in addition to the start position and the target position of the vehicle, at least one intermediate target position is defined. Defining the intermediate target position takes place in the same way as is done by a sampling-based motion planner. An intermediate target position is a position that lies on at least one of the possible trajectories.

In particular, different intermediate target positions are defined for different possible trajectories.

Furthermore, it is advantageous if the method further comprises a collision detection, wherein an envelope of the vehicle along the possible

Movement paths is calculated and such possible trajectories are discarded, whose associated envelope indicates a collision with an object. Thus, the method can be used particularly advantageously in the field of highly compacted parking.

Brief description of the drawings

Hereinafter, embodiments of the invention will be described in detail with reference to the accompanying drawings. In the drawing is:

Figure 1 is a representation of an inventively calculated

Trajectory,

FIG. 2 a representation of the possible curve elements, FIG. 3 shows a representation of interconnected web elements which are linked to a possible trajectory,

FIG. 4 shows a representation of a first HC curve element,

FIG. 5 shows a representation of a second HC curve element,

Figure 6 is an illustration of a vehicle with a device for

Calculating a trajectory of the vehicle,

FIG. 7 shows a representation of a reeds-shepper calculated

Trajectory,

FIG. 8 shows a representation of a trajectory calculated using a continuous curvature steer.

Embodiments of the invention

FIG. 1 shows a representation of a calculated according to the invention

Trajectory 3. The trajectory 3 connects a starting position 1 with a target position. The movement path 3 is a movement path calculated for a movement of a vehicle 100.

The method described below is also referred to as a Hybrid Curvature (HC) Steer and simulates human behavior when steering a vehicle 100 in confined spaces. Thereby, trajectories 3 with continuous curvatures are computed while the vehicle 100 is moving in one direction, but non-continuous curvatures are allowed when a direction change occurs. This will be a high

Agility of the vehicle 100 allows for short travel distances.

When calculating the movement path 3, the start position 1 and the target position 2 of the vehicle 100 are first defined. The start position 1 and the target position 2 are defined, for example, by being provided by an external driving assistance system. For example, the start position 1 is a current position of the vehicle 100, and the target position 2 describes a position in an environment of the vehicle 100 to which Vehicle 100 is to be moved, for example one by means of a

Parking sensor detected parking space or a generated configuration of the motion planner. The necessary calculations are based on a mathematical vehicle model, by which, for example, a dimension of the vehicle 100 and other vehicle characteristics, for example a maximum

Steering angle, the track width, the center distance are defined. The trajectory 3, as shown in Figure 1, describes a

Movement of a point of the vehicle 100. The point may be any point that moves with a movement of the vehicle 100. This point is exemplified in FIG. 1 at a point located in the center of a rear axle of the vehicle 100. It is a steering movement of the

Vehicle 100 is to move the point along the movement path 3, derived directly from the movement path 3. The movement path 3 could thus also be described by a tire track 5, which is also shown by way of example in FIG. The depicted in Figure 1

Tire track 5 is the movement path 3 associated and it is represented by both the same movement of the vehicle 100.

After defining the starting position 1 and the target position 2 of the vehicle 100, a number of possible trajectories 3 are generated. Each of the possible trajectories 3 connects the starting position 1 and the target position 2 of the vehicle 100. It is understood that the vehicle 100 is typically on different way from the start position 1 to the target position 2 can be moved. The possible trajectories 3 describe a selection of trajectories 3 which the vehicle 100 can drive to get from the start position 1 to the destination position 2.

In order to generate the possible trajectories 3, different orbital elements are linked to each other in different ways

Start position 1 and the target position 2 of the vehicle 100 to connect with each other. In this case, the possible trajectories 3 are composed of a number of available different track elements. The available different track elements are for example a

Curve element 1 1 and a straight line element. The curve element 1 1 describes a curve. The straight line element describes a path with a straight course. Each of the track elements connects a starting point 30 with an end point 32. The cam element 11 becomes possible from one of the following

Curve elements 20, 21, 22 selected: an RS curve element 20, an HC curve element 21 and a CC curve element 22. The curve element 10 thus describes that the associated possible movement path 3 comprises a curve. The exact shape of the curve is still open and depends on whether the RS curve element 20, the HC curve element 21 or the

CC curve element 22 is selected.

The possible curve elements 20, 21, 22 are shown in FIG. The RS curve element 20 describes a constant curve radius curve, with the RS curve element 20 maximum at its beginning and end

Have curvature. The constant curve radius corresponds to the maximum steering angle of the vehicle 100. The path described by the RS curve element 20 thus lies on a first circle 23. The starting point 30 and the end point 32 of the RS curve element 20 lie on the first circle 23.

Correspondingly, the RS curve element 20 defines a course of a possible movement path 3 along a circular path over a curve angle 25. The first circle 23 in this case has a minimum radius 24, which corresponds to the constant radius of curvature and corresponding to the maximum steering angle of the vehicle 100.

The CC curve element 22 describes a combination of a curve with a constant radius of curvature and two curves with an over a distance increasing or decreasing radius with the property of minimum radius on the one hand and infinite radius on the other hand, the

Curve with constant radius of curvature between the two curves is arranged with non-constant radius of curvature. The CC curve element 22 has a curvature of zero at its beginning and end. In this case, the radius increases in particular linearly over a distance or drops linearly over the distance. The curve with constant curve radius lies on an inner circle 28. The constant curve radius corresponds to the maximum

Steering angle of the vehicle 100. The portion of the CC curve element 22 with constant radius of curvature begins at a first transition point 31 and ends at a second transition point 27. The starting point 30 and the end point 32 of the CC curve element 22 lie on an outer circle 29. The inner circle 28 has an inner radius 36. The outer circle 29 has an outer radius 37. The outer radius 37 is larger than the inner one

Radius 36. The path described by the CC curve element 22 has a radius falling over a distance between the starting point 30 and the first transition point 31. The path described by the CC curve element 22 has a radius increasing over a distance between the second transition point 27 and the end point 32. The

Curve radius is chosen so that it is at the first transition point 31 and at the second transition point 27 equal to the constant radius of curvature of the curve with constant radius and thus equal to the inner radius 36 and the outer radius is selected so that the vehicle with steering angle 0 / no curvature is at start 30 and end position 32.

The HC curve element 21 describes a combination of a curve with a constant radius and a curve with a radius increasing or decreasing over a distance. The HC curve element 21 has a curvature of zero at its beginning or end. The HC curve element

21 substantially corresponds to the CC curve element 22, but the HC curve element 21 ends at the second transition point 27. Thus, the constant radius curve lies on the inner circle 28. The constant radius of curvature corresponds to the maximum steering angle of the vehicle 100. The portion of the constant radius HC curve element 21 begins at a first transition point 31 and terminates at the end point 32. The starting point 30 of the HC curve element 21 thus lies on the outer circle 29, where the vehicle has 0 ° steering angle and the end point 32 of the HC curve element 21 lies on the inner circle 28. The inner circle 28 knows the inner radius 36. The outer circle 29 has the outer radius 37.

The outer radius 37 is greater than the inner radius 36. The path described by the HC curve element 21 has a falling off over a distance between the starting point 30 and the first transition point 31

Curve radius on. The sloping curve radius is chosen so that it at the first transition point 31 equal to the constant radius of curvature of

Curve with constant radius of curvature and thus equal to the inner radius 36. The sloping radius has the property that this at the Starting point 30 is infinitely large and thus a curvature of the HC curve element 21 at this point is zero. Moreover, the falling radius has the property that it is minimal at the first transition point 31, here equal to the inner radius 36.

All of the possible curve elements 20, 21, 22 can be traversed in both possible directions, thus also from the end point 32 to the starting point 30. Each of the path elements and thus also each of the possible curve elements

20, 21, 22 has a continuous over its full course

Curvature on, except when the web element defines a change of direction of the vehicle 100 at the corresponding position. Mathematically, the continuous curve means that the first derivative of the

Railway elements is steady after the way. With regard to the CC curve element

This means that there is no kink between the curve with continuous radius and the curve with the radius rising or falling over the distance. In order to calculate the possible trajectories 3, the track elements are linked together according to predetermined combinations. Thus, each of the possible trajectories is a predetermined combination of

different railway elements. In this case, each path element is also assigned a direction of movement of the vehicle 100. Accordingly, at a point of connection of two adjoining web elements

Change of direction of the vehicle 100 done. Also such

Change of direction is defined in the given combinations.

Thus, the predetermined combination is composed in particular of the orbital elements and an indicator for a change of direction. The possible

Trajectories 3 are given from different

Combinations of the track elements and the indicator for a change of direction composed. At a node 13 between two

Web elements is an end point 32 of a web element at a starting point 30 of a subsequent web element. The combinations are predefined. Thus, in the following, the straight line element 11 is represented by an "S", the curve element 1 1 is represented by a "C" and the direction change is represented by a "." For example, one possible combinations could be formulated as follows: "C | C | C ". This means that the starting position 1 and the target position 2 in the given order are to be connected by three curve elements 10 with intervening changes of direction. The resulting possible movement path 3 is shown by way of example in FIG. If one follows the trajectory 3 shown there from the start position 1 to the target position 2, one passes through the web elements according to the above-described

exemplary possible combinations. One is in the first order

Web element a curve element 1 1, wherein the HC curve element 21 has been selected as a curve element 1 1. One in order second

Web element is again a curve element 1 1, wherein the RS curve element 20 has been selected as a curve element 11. One in the order third

Web element is again a curve element 11, wherein the HC curve element 21 has been selected as a curve element 1 1.

The exemplary possible combination "C | C | C" is only one of several possible combinations. <br/> <br/> The several possible combinations preferably advantageously comprise the following combinations: "C | C | C", "C | CC", "CC | C",

"CSC", "CC | CC", "C | CC | C", "C | CSC", "CSC | C", "C | CSC | C", "CCC", "C | SC", "CS | C "," C | S | C ". Particularly preferably, the several possible combinations comprise exclusively the aforementioned combinations. From each of the combinations, a possible motion path 3 is generated.

When generating the number of possible trajectories, the track elements are linked together at the linking points 13 such that a possible trajectory at a linking point 13 between two track elements may only have a discontinuous curvature when the possible trajectory at the transition a change of direction of the vehicle 100th describes. This is achieved, for example, by connecting points between two track elements in which a

Change of direction, the sequence of an HC curve element 21 to another HC curve element 21, the sequence of an HC curve element 21 to an RS curve element 20, the sequence of an RS curve element 20 to an HC

Curve element 21, or the sequence of an RS curve element 20 is allowed to an RS curve element 20. A CC curve element is at a Change of direction preferably not allowed to keep the trajectory 3 as short as possible. Thus, the movement path 3 at the connection point 13 between two web elements, in which there is a change of direction, have a discontinuous curvature. This is the case, for example, at a turning point 8, 9 of the trajectory 3 shown in FIG. 1, or the case at the two linking point 13 shown in FIG.

Furthermore, it is ensured that at node points 13 between two track elements, in which there is no change of direction, for none of the track elements, an RS curve element 20 may be selected as a curve element 1 1. Rather, it must be adjacent to each such connection point

Curve element 10, the HC curve element 21 or the CC curve element 22 are selected. In this case, a curve with an increasing or decreasing over a distance radius to the node 13 is adjacent.

The orbital elements are to be aligned so that the possible path of motion to be generated at a transition between the two

Railway elements, ie at the node 13, a steady

Curvature has, if the possible trajectory 3 at the node 13, a movement of the vehicle 100 in a constant

Direction describes what is the case when there is no change of direction at the considered node 13. This is done by a

corresponding alignment of the web elements, in particular of the respectively selected possible curve element 20, 21, 22. The web elements are thus linked together so that a possible trajectory on a

Junction point 13 between two track elements always has a continuous curvature when the possible trajectory on the

Junction point 13 describes a movement of the vehicle 100 in the same direction.

Since each combination defines a predetermined number of orbit elements, but the relative position of the start position 1 to the target position 2 is initially unknown, the orbit elements have a variable start point 30 and end point 32. Thus, a curve angle described by a possible curve element 20, 21, 22 can be changed by moving the starting point 30 relative to the end point 32 on the respectively associated circular path. This is shown in FIGS. 4 and 5 for the HC curve element 21. For this purpose, a first HC curve element 21 a is shown in Figure 4, which is a regular HC curve element 21 b. FIG. 5 shows a second HC curve element 21, which is an irregular HC curve element 21.

It can be seen that the starting point 30 for the first HC curve element 21a and the second HC curve element 21b are selected to be identical. However, the end point 32 for the first HC curve element 21 a and the second HC curve element 21 b is selected differently. The first HC curve element 21a and the second HC curve element 21b therefore describe different

Curve angle 33. The curve angle 33 is composed of one by a first partial angle 34 and a second partial angle 35. The first partial angle 24 is thereby described by the region of the HC curve element 21 with the radius decreasing linearly over the path. The second

Partial angle 35 is described by the range of the HC curve element 21 with the constant radius of curvature.

The second curve element 21 b has at the first transition point 31 on a direction change with continuous curvature transition.

It can be seen that the second HC curve element 21b would then also connect the starting point 30 shown in FIG. 5 to the end point 32 if the fraction with a constant radius of movement were guided in the direction shown in FIG. However, this would lead to a different direction of movement of the vehicle at the end point 32.

It can also be seen that it may happen that the end point 32 falls on the first transition point 31 of the HC curve element 21. In this case, the range with the constant turning radius of the HC curve element 21 has the length zero. This is for example the case shown in FIG

Trajectory 3 for the beginning of the starting position 1 HC curve element 21 of the case. Alternatively, in a calculation of the movement path 3 shown in FIG. 3, the area with the constant radius of curvature may have been very short, so that it is not recognizable in the illustration.

It is in a corresponding manner a variety of possible

Trajectories generated, with each of the possible trajectories of a own predetermined combination of railway elements is associated. The number of possible trajectories is thus generated by combining the different track elements in different ways. Each of the possible trajectories is a predetermined combination of different track elements.

From the possible trajectories 3, a trajectory 3 should be selected. This selected trajectory 3 is provided for movement of the vehicle 100. For this purpose, the movement path 3 is selected from the possible movement paths 3 based on a property of the possible movement paths 3.

In order to avoid that the selected trajectory 3 leads to a collision of the vehicle 100 with an obstacle, a first takes place

Collision detection. For this purpose, a track element (shortest path) is selected.

It is then checked whether the web element would lead to a collision at the corresponding position in a possible movement path 3. If there is a collision, the solution is discarded and depending on the scheduling algorithm

for example, a new configuration sampled. It is thus calculated which points around the vehicle from the vehicle 100 at its

Movement are crossed along the respective possible trajectory 3. It has been found that an object is located on one of the points which, as the vehicle 100 moves, move along the respective possible one

Trajectory 3 are crossed, the corresponding possible trajectory 3 is discarded, since their associated envelope 4 indicates a collision with an object. This is the case when a point on which the object is located lies within the envelope.

From the remaining possible trajectories 3 is the

Movement path 3 is selected, which has the smallest length of all remaining possible trajectories 3, which has the least number of changes of direction of all remaining possible trajectories 3 or which has the least curvature change. The possible

Trajectories 3 with the shortest length has the lowest

Probability of a collision. However, if there is a collision, this solution is discarded and, for example, next shorter of the possible trajectories 3 selected. The selection can also be made on a combination of the length and the number of direction changes. Thus, selecting the

Trajectory 3 from the possible trajectories 3 to a length of the possible trajectories 3 and / or on a number of

Change of direction of the trajectories 3.

FIG. 6 shows an illustration of the vehicle 100 with a device 101 for calculating the movement path 3 of the vehicle 100

Vehicle 100 arranged a computing unit 102 which is adapted to carry out the method described above.

In addition to the above written disclosure, reference is explicitly made to the disclosure of Figures 1 to 8.

Claims

claims

A method of calculating a trajectory (3) of a vehicle (100) comprising:

Defining a start position (1) and a target position (2) of the vehicle (100),

Generating a number of possible trajectories (3) which exactly connect the starting position (1) and the target position (2),

• for each possible trajectory (3) different

Railway elements are linked together in different ways, in order to connect the starting position (1) and the target position (2) of the vehicle (100),

• wherein the track elements are linked together so that a possible trajectory (3) at a connection point (13) between two track elements may only have a discontinuous curvature course, if the possible

Movement path (3) at the connection point (13) describes a change of direction of the vehicle (100), and selecting a trajectory (3) from the possible

Trajectories (3) based on a property of the possible trajectories (3).

2. The method according to claim 1, characterized in that the number of possible trajectories (3) is generated by the fact that the different track elements are combined in different ways with each other.

3. The method according to claim 2, characterized in that each of the possible trajectories (3) is a predetermined combination of the different track elements.

4. The method according to any one of the preceding claims, characterized

characterized in that the different track elements a Curve element (10), and in generating the number of possible trajectories (3) the curve element (10) is selected from one of the following:

An RS curve element (20) which describes a curve with a constant curve radius,

An HC curve element (21) which is a combination of a constant radius curve and a curve with a radius increasing or decreasing over a distance with the minimum radius property on one side and infinite radius on the other side;

• a CC curve element (22), which is a combination of a curve with a constant radius and before and behind each with a curve with a radius increasing or decreasing over a distance.

Method according to one of the preceding claims, characterized in that the different web elements a

Curve element (10) and a straight line element (1 1) include.

Method according to one of the preceding claims, characterized in that when selecting a movement path (3) from the possible movement paths (3) a length of the possible

Trajectories (3) and / or a minimum number of

Directional changes of the trajectories (3) and / or a minimum curvature change is the property of the possible trajectories (3) on which the selection is based.

Method according to one of the preceding claims, characterized in that the web elements are linked to each other so that a possible trajectory (3) at a node (13) between two web elements always has a continuous curvature when the possible trajectory (3) on the

Link point (13) describes a movement of the vehicle (100) in the same direction.

Method according to one of the preceding claims, characterized in that each of the track elements has a starting point (30). and an endpoint (32), the orbital elements being displaced relative to one another for relative use by one of the starting point (30) and the endpoint (32)

Movement path (3) to be adjusted.

Method according to one of the preceding claims, characterized in that in addition to the start position (1) and the target position (2) of the vehicle (100) at least one intermediate target position is defined. 10. Device (101) for calculating a movement path (3) of a

Vehicle (100), comprising a computing unit (102), which is adapted to:

define a start position (1) and a destination position (2) of the vehicle (100),

to generate a number of possible trajectories (3) which are the

Start position (1) and the target position (2) connect exactly,

• for each possible trajectory (3) different

Movement path (3) at the connection point (13) a

Change of direction of the vehicle (100) describes, and to select a trajectory (3) from the possible trajectories (3) based on a property of the possible trajectories (3).