DE102022117407B3 - Method for operating a control unit for trajectory planning as well as a correspondingly operable control unit and motor vehicle - Google Patents

Abstract

The invention relates to a method for operating a control unit (20) for trajectory planning, wherein a respective current input control value (24) of a trajectory planner (24) connected upstream of the test module (30) is determined by a processor circuit of the control unit (20) in successive test cycles through a test module (30). 21) is received and by outputting a respective output control value (12), a vehicle movement control (13) is activated, which is connected downstream of the test module (30) and which guides the motor vehicle (10) automatically. The invention provides that the processor circuit checks the received current input control value (24) of the trajectory planner (21) to determine whether a future travel trajectory of the motor vehicle (10) results for the input control value (24) when it is used as an output control value (12). each of at least one predetermined admissibility condition (46, 47) is met, and only if each admissibility condition (46, 47) is met, the input control value (24) and otherwise a substitute control value (43) are output as the output control value (12) of the test cycle (42). becomes.

Description

The invention relates to a method for operating an electronic control unit (ECU - Electronic Control Unit) in connection with trajectory planning. Such trajectory planning is actually carried out by a trajectory planner. This plans a travel trajectory and cyclically outputs a current control value that specifies the steering angle and/or the travel speed according to the planned travel trajectory. The control value is intended for a vehicle motion control (VMM - Vehicle Motion Management), which automatically guides the motor vehicle on a road in accordance with this control value. A trajectory planner can be used, for example, to plan a driving trajectory in connection with lane keeping assistance. The invention also includes a control unit that can be operated according to the method, as well as a motor vehicle with such a control unit.

In a motor vehicle, an automated driving function can be used to drive or drive the motor vehicle using vehicle motion control, so that the driver can take his hands off the steering wheel (hands free driving). Which steering angle and/or which driving speed should currently be set by the vehicle movement control can be determined by a trajectory planner, which determines a travel trajectory for the motor vehicle. For example, the driving function can provide automated lane keeping assistance and/or parking assistance in this way.

The trajectory planner determines suitable travel trajectories accordingly. To implement the determined travel trajectory, the trajectory planner can output a control signal to the vehicle movement control. This control signal is digital or sampled, which means that a current signal value of the control signal is output by the trajectory planner in successive transmission cycles or control cycles. This control value is intended for the vehicle motion management (VMM) to set the steering angle and/or the vehicle speed for the current control cycle according to the signal value.

When developing or further developing a trajectory planner, one is interested in taking additional criteria, in particular driving comfort, into account when planning the trajectory. This can make a trajectory planner very complex in terms of its structure or functionality. In order for such a trajectory planner to still function reliably for a variety of possible driving situations, it must be ensured that the vehicle movement control always receives valid or acceptable control values that result in suitable driving behavior of the motor vehicle.

Accordingly, the development or further development of trajectory planners can be undesirably complex and/or time-consuming to test.

From the US 2019 / 0 317 505 A1 It is known that in a motor vehicle, on the basis of sensor data from at least one environment sensor, a course of road markings or lane markings can be recognized by means of computer vision processing of the sensor data and can be used to map the environment.

From the US 10 802 492 B2 A trajectory planner for a motor vehicle is known, which determines several potentially usable travel trajectories and uses a cost function to select the travel trajectory that best meets several different quality criteria in the sense of cost minimization.

Further state of the art regarding trajectory planners for motor vehicles can be found in the publications DE 10 2019 214 935 A1 , DE 10 2019 134 258 A1 and DE 10 2018 103 409 A1 known.

The invention is based on the object of being able to reliably operate a trajectory planner for controlling vehicle movement control even in unknown or new driving situations.

The task is solved by the subject matter of the independent patent claims. Advantageous further developments or further developments of the invention are described in the dependent claims, the following description and the figures.

As a solution, the invention includes a method for operating a control unit, which is also referred to as an ECU - Electronic Control Unit. This control unit is intended for trajectory planning. The control unit has a test module that couples a trajectory planner, as described at the beginning, with a vehicle movement control that automatically guides a motor vehicle. The trajectory planner can be implemented, for example, as software of the control unit itself or in an upstream control unit. The vehicle movement control can also be implemented as software of the control unit itself or a downstream control unit. Trajectory planner and vehicle movement control can be designed in a manner known from the prior art. Through the processor circuit of the control unit, the trajectory planner and the vehicle movement control are coupled to one another via a test module in order to check the control values cyclically output by the trajectory planner, as described at the beginning, before they are forwarded to the vehicle movement control or (according to the invention) by a Replacement tax value can be replaced. For better distinction, the control values cyclically output by the trajectory planner are referred to here as “input control values” because they represent an input for the method described below. Since the input control values are generated cyclically, the input control values are also checked cyclically, that is, in the method, a respective current input control value from the upstream trajectory planner is received in successive test cycles and the test module is controlled by outputting a respective control value to the vehicle movement control. This control value, which is output to the vehicle motion controller per test cycle, is referred to here as the “output control value”. In the manner described, this output control value can correspond to the input control value or a substitute control value. The method can be carried out by a software module or program module, referred to herein as a test module. This test module couples the trajectory planner with the vehicle movement control in the manner described. The test cycles correspond to the control cycles described above.

In order to determine which output control value should be output to the vehicle motion control in the current test cycle, it is provided according to the method that for the respective test cycle the test module of the processor circuit generates a current substitute control value on the basis of its own planning module, i.e. a backup planning module or a backup -Trajectory planning. The planning module therefore plans independently of the trajectory planner. The planning module provides a planning strategy that is conservative or prioritizes maintaining the roadway in that it provides for maintaining the current output value (from the previous test cycle) and / or steering towards a center of the roadway currently traveled by the motor vehicle. In other words, the test module's own planning module prioritizes or prefers not to deflect more from the center of the road, i.e. it corresponds to the previous output control value, but rather to at least maintain the previous output control value or even steer it further towards the center of the road. This can differ from the input control value of the trajectory planner in that, for example, for reasons of comfort, it provides for cutting a curve and for this purpose plans a travel trajectory that remains on the road but points towards the edge of the road.

The processor circuit (with its test module) checks the received current input value of the trajectory planner to see whether a future travel trajectory of the motor vehicle results from at least one predetermined one for the input control value when it is used as an output control value (i.e. if the input control value were passed through to the vehicle movement control). Each admissibility condition is met. The resulting future travel trajectory must therefore fulfill all specified admissibility conditions (one or more than one). Only if each eligibility condition is satisfied, the input control value (of the trajectory planner) is output as the output control value of the current test cycle. Otherwise, the replacement tax value is issued as an output tax value, i.e. if at least one admissibility condition is unfulfilled or violated.

The invention has the advantage that the test module of the processor circuit represents a filter or a limiter, which ensures that the trajectory planning cannot cause the vehicle movement control to be activated that lies outside the at least one permissibility condition. The trajectory planning can therefore be optimized for comfort and/or designed experimentally, for example. Whenever this contradicts at least one admissibility condition, this is recognized by the intermediate test module of the processor circuit and then, instead of the input control value of the trajectory planner, the substitute control value from the planning module is used, which implements the “more conservative” planning strategy in the sense mentioned above.

The invention has the advantage that the trajectory planner can carry out more complex optimizations and these can also be used in previously unknown or new driving situations, since no undesirable vehicle guidance behavior of the vehicle movement control can arise due to the interposed test module.

In order to determine a “conservative” or restrictive substitute control value for a test cycle in the planning module, the invention provides that the planning module receives at least one dynamic parameter that describes a movement of the motor vehicle on this road. In this way, the at least one dynamic parameter can describe a driving speed and/or yaw rate and/or a position of the motor vehicle on the road (for example distance to the center line) and/or an orientation of the motor vehicle with respect to the course of the center of the road. The planning module can determine the substitute control value using a controller, for example a so-called PID controller (PID - proportional integral differential). A PI controller can also be used as an alternative. The controller is set or configured in such a way that its control target or setpoint is set to minimize a distance of the motor vehicle from the center of the road (track). The substitute control value is therefore determined in such a way that the motor vehicle is guided towards the center of the road when using the substitute control values in the test cycles. The distance of the motor vehicle from the center of the road can be based, for example, on the center of gravity and/or the geometric center of the motor vehicle or its contour. A reference point along a center line of the motor vehicle is preferably used. The curvature or change in curvature of the driving line with which the controller returns the vehicle to the center of the road or guides it onto this depends on the time constant, which can control or determine the control behavior in the controller in a manner known per se. Here, by setting a corresponding time constant in a configuration memory of the controller, the person skilled in the art can determine the time interval within which the controller attempts to regulate the distance of the motor vehicle to the center of the road to 0. For example, time constants can range from 4 seconds to 30 seconds, just to give examples.

A time constant can be provided for the controller, which indicates the time interval within which the distance to the center of the road is, for example, halved or adjusted to 0. This time constant or generally a control behavior of the controller is preferably set or designed depending on the speed, since different steering maneuvers can be made at lower speeds than at a relatively high speed. In this context, the invention includes that a first parameter data set for driving speed values in a first value interval (for example low driving speeds) and a second parameter data set for driving speed values in a second value interval (for example relatively higher driving speeds) are provided in the controller. In a third value interval lying between the first and the second value interval, i.e. an intermediate interval, a fade function for controller outputs of the controller is used, which is based on the first parameter set and the second parameter set. In other words, a fade is carried out between a controller for low speeds and a controller for high speeds proportionally depending on the distance between the speed value and the interval limits, for example by means of a linear fade. This has the advantage that no jerky or hard changes in the controller behavior are caused when changing between low and high speeds. The first value interval can range, for example, for speeds from 0 km/h to 60 km/h and the second value interval for speeds in a range from 80 km/h to the maximum speed, to name just one example.

The invention also includes further developments that result in additional advantages.

A further development takes into account that after receiving the input control value from the trajectory planner, the decision as to whether this input control value of the trajectory planner or the substitute control value of the own planning module should be forwarded or output as the output control value should advantageously only be able to be carried out with a short delay. A further development provides for the replacement control value of the respective test cycle to be calculated in advance, i.e. generated before this test cycle. For this purpose, the planning module is operated with dynamic data from the motor vehicle, which is projected into the future. It can therefore already be calculated during the last or previous test cycle which substitute control value should be used for the next test cycle. For this purpose, dynamic data of the motor vehicle, for example the driving speed and/or yaw rate, can be used in the previous test cycle, which are projected into the future at the time that corresponds to the beginning of the subsequent test cycle or the time of the decision between input control value and substitute control value. Here Of course, it can also be taken into account which output control value was generated or used as a basis in the previous test cycle, so that a changed or newly set steering angle and / or a changed or newly set driving speed is also taken into account when projecting into the future. This means that no time is lost in the current test cycle in first calculating the replacement control value for this test cycle, since this has already been calculated in advance at the beginning of the test cycle by means of the projection of the dynamic data into the future.

Several further developments address the question of which admissibility condition should be used in order to recognize a travel trajectory planned by the trajectory planner as unsuitable.

A further development takes into account that it should always be ensured that if the automated driving function is canceled, at least a predetermined takeover time period should be available to take over control of the vehicle. Such a takeover time can range from 1.5 seconds to 10 seconds, to give just examples. In the method, at least one road edge course and/or at least one road edge course (in the case of a multi-lane road) can therefore be determined in a digital area map and/or entered into the area map. In addition, a contour of the motor vehicle is entered into the surrounding map. Such an environment map can include a graphical representation of the environment and the contour of the motor vehicle and/or a representation based, for example, on mathematical graphs with nodes and edges. An environment map can be used, as is known from the prior art. The environment map is used to check the period of time within which the motor vehicle would reach or intersect the edge of the road and/or road if the current input control value were output as the output control value for all future test cycles. In other words, a forecast or projection into the future is made based on the input control value received from the trajectory planning. It is checked how much time or what period of time would remain until the motor vehicle reaches the edge of the road or road. In this case, the admissibility condition that would classify the input control value as permissible or usable states that the time period is greater than the said takeover time period for handing over control of the vehicle to the driver. So only an input control value is recognized as permissible that always provides the driver with the takeover time period in order to take over control of the vehicle again. Here, the current input control value is taken into account in such a way that, for example, a curvature of the currently driven travel trajectory, i.e. a current steering angle, is maintained, i.e. the input control value is also used as a basis for all future test cycles.

If the trajectory planner plans a travel trajectory that would result in contact with the edge of the road or road in less than the takeover time, the replacement control value should be used. A further development of this provides that, in the event that it is recognized that the time period is smaller than the takeover time period, the processor circuit checks which of the input control value of the trajectory planner and the substitute control value of the planning module in its hypothetical use for the future planning cycles a longer period of time until the edge of the road is reached. It is therefore checked which of the two usable control values (input control value and replacement control value) allows more time for the transfer or leaves more time. This control value is then used as the output control value. This maximizes the available or remaining transfer time.

An additional or alternative admissibility condition includes that the input control value must result in a curvature and/or a change in curvature of the driving line of the motor vehicle that lies within a respective predetermined value interval. In other words, the person skilled in the art can specify value intervals within which the curvature and/or change in curvature should lie. The driving line of the vehicle used here can, for example, relate to the movement or trajectory of the vehicle's center of gravity and/or a geometric center of the motor vehicle. When determining which curvature and/or change in curvature results depending on the input control value, a mechanics of the steering linkage (for example torsional behavior) and/or chassis dynamics (for example the behavior or a characteristic of the vibration dampers) is preferably also taken into account in order to determine what effect the input control value has on the actually resulting driving line with respect to the road. For this purpose, a model of the motor vehicle, for example the known single-track model, can be used as a basis. The value intervals can be stored in a respective memory in the processor circuit. Thus, by defining or adjusting the value intervals in the processor circuit through the test module, a person skilled in the art can determine or ensure that when using the trajectory planner, no driving lines arise that are Curvature and/or change in curvature results outside the permissible values given by the value intervals.

In order to determine the distance of the motor vehicle to the center of the road, for example, the geoposition of the motor vehicle can be determined on the one hand and the center of the road from a digital road map on the other hand. The geoposition of the motor vehicle can be determined in a manner known per se based on a receiver of a position signal from a GNSS (Global Navigation Satellite System), for example the GPS (Global Positioning System). An additional or alternative development to this provides that the center of the road is determined or signaled by environmental sensor data. In the manner described above, environmental sensor data, for example camera data, can be used to determine where road markings and/or road edges are located in relation to the motor vehicle using computer vision processing of these environmental sensor data. This requires that the road markings are visible using the surrounding sensor data. This can be unsafe, for example, in heavy rain or fog or in snow. In the event that the signaling of the road center profile is interrupted for one of the test cycles, i.e. no road edges can be detected in the surrounding sensor data from which the road center profile could be calculated, an output control value from one of the previous test cycles or from the immediately preceding test cycle is output again. If there is no signaling of the course of the road or the center of the road, the last valid output control value is output again. This ensures that a replacement control value is available even in the case described where there is no signaling of the center of the road.

If the substitute control value is used instead of the input control value to obtain an output control value for the vehicle motion control, this means that the trajectory planner has provided an input control value that leaves the at least one admissibility condition. In this case, according to a further development, it is provided that a takeover notice is issued to the driver of the motor vehicle, i.e. the driver is asked to take over the vehicle control instead of the trajectory planner and the vehicle movement control. Additionally or alternatively, a takeover procedure for handing over control of the vehicle to the driver is started. In other words, an automatism or logic is executed or triggered that ensures or causes the driver to take over control of the vehicle. Since it is ensured by then that the takeover time period is available, this is the most favorable time to hand over control of the vehicle, since a sufficiently large time interval or a sufficiently large period of time is still available without, for example, an emergency stopping maneuver having to be initiated.

For use cases or application situations that may arise with the method and that are not explicitly described here, it can be provided that an error message and/or a request to enter user feedback and/or a standard setting and/or a predetermined one can be issued according to the method Initial state is set.

In order to carry out the method, the invention also provides a control unit or a control device for a motor vehicle. This control unit has said processor circuit, which is set up to carry out an embodiment of the method according to the invention. For this purpose, the processor circuit can have at least one microprocessor and/or at least one microcontroller and/or at least one FPGA (Field Programmable Gate Array) and/or at least one DSP (Digital Signal Processor). Furthermore, the processor circuit can have program code that is designed to carry out the embodiment of the method according to the invention when executed by the processor device. The program code can be stored in a data memory of the processor circuit.

As a further solution, the invention finally includes the described motor vehicle with the trajectory planner for generating input control values and the vehicle movement control for automated driving of the motor vehicle. However, the trajectory planner does not directly control the vehicle movement control using the input control values, but rather the trajectory planner is coupled to the vehicle movement control via an embodiment of the control unit according to the invention. The trajectory planner and/or the motion control can also be implemented on the same processor circuit as the described test module of the control unit. In other words, the trajectory planner is then coupled to the vehicle movement control via the test module of the control unit. The motor vehicle according to the invention is preferably designed as a motor vehicle, in particular as a passenger car or truck, or as a passenger bus or motorcycle.

As a further solution, the invention also includes a computer-readable storage medium comprising program code which, when executed by a computer or a computer network, causes it to carry out an embodiment of the method according to the invention. The storage medium can, for example, be provided at least partially as a non-volatile data storage (e.g. as a flash memory and/or as an SSD - solid state drive) and/or at least partially as a volatile data storage (e.g. as a RAM - random access memory). . The storage medium can be implemented in the processor circuit in its data memory. The storage medium can also be operated on the Internet as a so-called app store server, for example. The computer or computer network can provide a processor circuit with at least one microprocessor. The program code can be provided as binary code or assembler and/or as source code of a programming language (e.g. C) and/or as a program script (e.g. Python).

The invention also includes the combinations of the features of the described embodiments. The invention therefore also includes implementations that each have a combination of the features of several of the described embodiments, provided that the embodiments have not been described as mutually exclusive.

• 1 eine schematische Darstellung einer Ausführungsform des erfindungsgemäßen Kraftfahrzeugs;
• 2 eine Steuereinheit, wie sie in dem Kraftfahrzeug von 1 bereitgestellt sein kann;
• 3 eine Skizze zur Veranschaulichung einer Umgebungskarte, in welcher ein Fahrbahnrandverlauf und eine Kontur des Kraftfahrzeugs kartographiert sind;
• 4 ein Diagramm mit schematisierten Verläufen einer Abfolge von Eingabesteuerwerten und Ersatzsteuerwerten für mehrere Prüfzyklen;
• 5 eine Skizze zur Veranschaulichung von Parametern eines Reglers der Steuereinheit von 2;
• 6 ein Diagramm mit einem schematisierten Verlauf eines Gewichtungsfaktors für eine Überblendfunktion des Reglers.

Examples of embodiments of the invention are described below. This shows:

• 1 a schematic representation of an embodiment of the motor vehicle according to the invention;
• 2 a control unit as found in the motor vehicle 1 can be provided;
• 3 a sketch to illustrate an area map in which a road edge and a contour of the motor vehicle are mapped;
• 4 a diagram with schematic progressions of a sequence of input control values and substitute control values for several test cycles;
• 5 a sketch to illustrate parameters of a controller of the control unit 2 ;
• 6 a diagram with a schematic progression of a weighting factor for a fade function of the controller.

The exemplary embodiments explained below are preferred embodiments of the invention. In the exemplary embodiments, the described components of the embodiments each represent individual features of the invention that are to be considered independently of one another and which also further develop the invention independently of one another. Therefore, the disclosure is intended to include combinations of the features of the embodiments other than those shown. Furthermore, the described embodiments can also be supplemented by further features of the invention that have already been described.

In the figures, the same reference numerals designate functionally identical elements.

1 shows a motor vehicle 10, which can be a motor vehicle, in particular a passenger car or truck.

An automated driving function 11 can be provided in the motor vehicle 10, which can generate output control values 12 without a driver's intervention, which control a vehicle movement control 13 so that it controls an actuator 14 of the motor vehicle in such a way that lateral guidance (steering) and/or longitudinal guidance ( Acceleration and / or braking) of the motor vehicle 10 is carried out by the vehicle movement control 13. Another name for vehicle motion control is VMM (Vehicle Motion Management).

The output control values 12 can be generated cyclically by the driving function 11, for example in a period in a range of 5 milliseconds to 50 milliseconds, to name just examples. This results in individual control cycles, each of which corresponds to a period of the periodic output of the output control values 12.

The driving function 11 can determine the output control values 12 based on at least one environmental sensor or environment sensor 16 of the motor vehicle 10. The at least one environment sensor 16 can have an output layer 17 through which output interfaces 18, 19 can be implemented. Different output interfaces 18, 19 can have different levels of reliability be implemented in accordance with the ASIL standard (Automotive Safety Integrity Level). It is shown that one output interface 18 can have the lowest integrity level QM, another output interface 19 can have the integrity level B (ASIL B).

The driving function 11 can be provided by a processor circuit P. The processor circuit P can be part of a control unit 20, which can be implemented, for example, as an ECU (Electronic Control Unit). Within the driving function 11, a trajectory planner 21 can be provided, which can generate control values for the vehicle movement control 13 based on environmental sensor data 22 from the output interface 18 by means of a processing layer 23, which are shown here as input control values 24. The environment sensor data 22 can be received via an input layer 25 through an input interface 26 of the trajectory planner 21, the input control values 24 can be output via an output layer 27 at an output interface 28. The trajectory planner 21 can use a planning algorithm 29, which can also take driving comfort into account, for example. Overall, the planning algorithm 29 only needs to meet the integrity level QM.

The trajectory planner 21 and the vehicle movement control 13 can be coupled in the motor vehicle 10 via the control unit 20 by means of a test module 30. The test module 30 can receive the input control values 24 at a reception interface 31. In addition, environment sensor data 33 can be received at an input interface 32, which can be received from the output interface 19 with the higher integrity level B from the at least one environment sensor 16.

Overall, the test module 30 can be implemented with integrity level B (ASIL-B). In order to ensure this level of integrity for the output control values 12 as well, the checking module 30 can provide a check of the input control value 24 from the trajectory planner 21 with the lower integrity level QM.

For this purpose, the test module 30 can have its own planning module 40, which provides a substitute control value 43 in a processing layer or processing layer 41 with program instructions 44 for each control cycle as part of a test, which results in a test cycle 42 for each input control value 24 (test cycle 42), which is kept ready in a check by the test module 30 as a replacement for the input control value 24. For this purpose, in the example shown, the input control value 24 must fulfill two admissibility conditions 46, 47, which will be explained below.

In order to ensure integrity level B, a security logic 50 can also be provided, which does not need to be described here in order to understand the idea described here.

Based on the environment sensor data 33, a signaling of a road center profile 51 can be provided, which signals a course or a geometry of the road center line of the road currently traveled by the motor vehicle 10.

For each test cycle 42, the test module 30 can decide whether the received input control value 24 or the substitute control value 43 determined by its own planning module 40 is output as the output control value 12. The selected control value (input control value 24 or substitute control value 43) can be output via an output layer 52 to an output interface 53, via which the control unit 20 can be coupled to the vehicle movement controller 13.

The test module 30 with its own planning module 40 is described in more detail below.

It is shown how the input control value 24 can be received by the test module 30. In addition, the environment sensor data 33 and the evaluation 60 of the road center profile 51 can be provided in the manner described.

For the input control value 24 received in the test cycle 42, the first admissibility condition 46 can be provided that a curvature of a driving line of the motor vehicle 10 on the road resulting from the input control value 24 and / or a change in curvature of the driving line lies in a respective predetermined value interval 61, 62. If it turns out for the current input control value 24 that the resulting curvature of the driving line is in the value interval 61 or the change in curvature is in the value interval 62, then the admissibility condition 46 is fulfilled (symbolized by a plus symbol), Otherwise, if at least one value interval 61, 62 is not reached, the admissibility condition 46 is violated (symbolized by a minus sign).

If admissibility condition 46 is met, admissibility condition 47 can be checked. The admissibility condition 47 can indicate that a time period T until a road edge is reached must be greater than a predetermined handover time period 64, as will be discussed below in connection with 3 is explained. If this admissibility condition 47 is also met (symbolized by a plus symbol), the input control value 24 can be output to the vehicle movement control 13 as an output control value 12. The time period T results from the length of the future driving line 87 up to the intersection 88 divided by the current driving speed of the motor vehicle 10.

For the current test cycle 42, the planning module 40 can provide a substitute control value 43 and additionally a further substitute control value 43', which can be seen overall as substitute control values, since only one of the two substitute control values 43, 43' is available per test cycle 42.

The substitute control value 43 can be calculated by a controller 66 in the event that the road center profile 51 could be determined from the surroundings sensor data 33 (symbolized by a plus sign). If, on the other hand, no road center profile 51 is available for the current test cycle 42 (symbolized by a minus sign), the output control value 12' of the previous test cycle can be selected as the substitute control value 43 '.

If, on the other hand, the center of the road 51 is available for the operation of the controller 66, the controller 66, for example as a PID controller, can carry out regulation using the substitute control value 43, as described in the further context 5 is explained in more detail.

In the event that the admissibility condition 46 is violated by the input control value 24, a decision can be made in a block 67 that the replacement control value 43 is to be used as the output control value 12. In addition, an indication signal 68 can be generated, which initiates the driver to take over the driving task and/or a corresponding handover procedure.

If the admissibility condition 47 is violated, a comparison 70 of the input control value 24 on the one hand and the substitute control value 43 on the other hand can be carried out in a block 69 to determine which of the two control values results in the longer time until the edge of the road or the roadside is reached. This control value is then output to the vehicle motion controller 13 as an output control value 12. Furthermore, said indication signal 68 can be generated.

If no road center profile 51 is available, the last output control value 12 'from the previous test cycle can be output to the vehicle movement control 13 as an output control value 12 in a block 71. In addition, the advisory signal 68 can be generated.

3 illustrates how in an environment map 80, for example by means of a vehicle-related coordinate system 81 with an axis S along the vehicle's longitudinal axis and a transverse axis Y transverse to the vehicle's longitudinal axis, on the one hand a road edge course 82 and on the other hand a vehicle contour 83 of the motor vehicle 10 can be mapped. Starting from a current position 84 of the motor vehicle, it can be determined, for example, for a vehicle center 85 and/or for a vehicle edge 86 on the basis of the current input control value 24 for a future driving movement according to the driving line 87 of the motor vehicle 10, when there is a contact or an intersection 88 with the edge of the road 82 results. The resulting shorter time period T can be compared with the handover time period 64 in connection with the second admissibility condition 47 in the manner described. If the time period T is less than the transfer time period 64 for one of the two intersection points 88, the admissibility condition 47 is violated in the manner described.

4 illustrates how the output control value A (output control value 12) is output over time T for different test cycles 42 at times t _k , t _k+1 . In the current test cycle 42 at time t _k it must be ensured that there is no cutting of the road edge 82 (see 3 ) is given or results at a time closer than the handover period 64. For this purpose, the input control value 24 is used in an extrapolation 90 in the in 3 described manner for determining the future route course 87 is taken as a basis. 4 further illustrates that for the current test cycle 42 at time t _k the replacement control value 43 for the next test cycle 42 'is calculated by driving dynamics data (for example the driving speed and / or yaw rate and / or spatial orientation of the motor vehicle, to name just examples) on the basis of the currently valid input control value 24 or substitute control value 43 is calculated in advance by means of a temporal extrapolation 93 for the position of the motor vehicle 10 and/or the driving dynamics of the motor vehicle 10 at time t _k+1 of the next test cycle 42', so that the substitute control value 43 is calculated in advance for the next test cycle 42' from that point on t _k+1 is available and, for example, comparison 70 can be carried out.

5 illustrates how, starting from a center of the road 51, a current distance 100 of the motor vehicle 10 to a parallel point P on the center of the road 51 can be determined and the controller 66 calculates the substitute control value 43 in such a way that the distance 100 is regulated to 0, i.e. the motor vehicle 10 is guided to the middle of the road 51.

It is shown here that the so-called single-track model 101 can be used as a basis for the motor vehicle 10.

The following variables are also shown, which can be measured if necessary using the sensors available in the motor vehicle or read out from a road map and which can be taken, for example, from the known single-lane model, which is shown in the 5 is symbolically represented:

$$\dot{r}=vsin\left(\theta \right)r\left(0\right)=r_0$$

$$\dot{\theta }=\dot{\beta }+\omega -\frac{v\kappa cos\left(\theta \right)}{1-\kappa T}\theta \left(0\right)={\theta }_0$$

$$z=r$$

$$\dot{z}=\dot{r}=vsin\left(\theta \right)$$

$$\ddot{z}=vcos\left(\theta \right)\dot{\theta }=vcos\left(\theta \right)\left(\dot{\beta }+\omega -\frac{v\kappa cos\left(\theta \right)}{1-\kappa T}\right)$$

From this, the controller 66 can be provided as an exemplary implementation with the following kinematics equations: $$\dot{s}=\frac{vcOs\left(\theta \right)}{1-\kappa T}s\left(0\right)={\mathrm{<figure-callout\; id="0"\; label="s"\; filenames="DE102022117407B3\_0019.png"\; state="\{\{state\}\}">s</figure-callout>}}_0$$

$$\dot{r}=vsin\left(\theta \right)r\left(0\right)={\mathrm{<figure-callout\; id="0"\; label="r"\; filenames="DE102022117407B3\_0019.png"\; state="\{\{state\}\}">r</figure-callout>}}_0$$

$$\dot{\theta }=\dot{\beta }+\omega -\frac{v\kappa cOs\left(\theta \right)}{1-\kappa T}\theta \left(0\right)={\mathrm{<figure-callout\; id="0"\; label="\theta "\; filenames="DE102022117407B3\_0019.png"\; state="\{\{state\}\}">\theta </figure-callout>}}_0$$

$$\mathrm{e.g}=r$$

$$\dot{\mathrm{e.g}}=\dot{r}=vsin\left(\theta \right)$$

$$\ddot{\mathrm{e.g}}=vcOs\left(\theta \right)\dot{\theta }=vcOs\left(\theta \right)\left(\dot{\beta }+\omega -\frac{v\kappa cOs\left(\theta \right)}{1-\kappa T}\right)$$

$$=v^{2}cos\theta \left({\kappa }_{\text{in}}-\frac{\kappa cos\left(\theta \right)}{1-\kappa r}\right)=\underset{\text{virtual input}}{\underbrace{\eta }}$$

mit der virtuellen Input-Größe: $$\eta =-k_{0}z-k_1\dot{z}$$

$$k_0={\omega }_0^2$$

$$k_1=2\zeta {\omega }_0$$

If you neglect the slip angle, you can write: $$\ddot{\mathrm{e.g}}=vcOs\left(\theta \right)\left(\omega -\frac{v\kappa cOs\left(\theta \right)}{1-\kappa T}\right)=vcOs\left(\theta \right)\left(v{\kappa }_{\text{in}}-\frac{v\kappa cOs\left(\theta \right)}{1-\kappa T}\right)$$

$$=v^{2}cOs\theta \left({\kappa }_{\text{in}}-\frac{\kappa cOs\left(\theta \right)}{1-\kappa r}\right)=\underset{\text{virtual input}}{\underbrace{\eta }}$$

with the virtual input size: $$\eta =-{\mathrm{<figure-callout\; id="0"\; label="k"\; filenames="DE102022117407B3\_0019.png"\; state="\{\{state\}\}">k</figure-callout>}}_0\mathrm{e.g}-{\mathrm{<figure-callout\; id="1"\; label="k"\; filenames="DE102022117407B3\_0018.png,DE102022117407B3\_0020.png"\; state="\{\{state\}\}">k</figure-callout>}}_1\dot{\mathrm{e.g}}$$

$${\mathrm{<figure-callout\; id="0"\; label="k"\; filenames="DE102022117407B3\_0019.png"\; state="\{\{state\}\}">k</figure-callout>}}_0={\mathrm{<figure-callout\; id="0"\; label="\omega "\; filenames="DE102022117407B3\_0019.png"\; state="\{\{state\}\}">\omega </figure-callout>}}_0^2$$

$${\mathrm{<figure-callout\; id="1"\; label="k"\; filenames="DE102022117407B3\_0018.png,DE102022117407B3\_0020.png"\; state="\{\{state\}\}">k</figure-callout>}}_1=2\mathrm{<figure-callout\; id="0"\; label="\zeta \; \omega "\; filenames="DE102022117407B3\_0019.png"\; state="\{\{state\}\}">\zeta </figure-callout>}{\omega }_{}{}_0$$

$$\omega =\frac{4}{t_{\text{settling}}}={\omega }_0$$

wobei t_settling in einem Bereich von 1s bis 20s liegen kann, z.B. 4s betragen kann.The following have proven to be exemplary, suitable values: $$\zeta =1$$

$$\omega =\frac{4}{t_{\text{settling}}}={\mathrm{<figure-callout\; id="0"\; label="\omega "\; filenames="DE102022117407B3\_0019.png"\; state="\{\{state\}\}">\omega </figure-callout>}}_0$$

where t _settling can be in a range from 1s to 20s, for example 4s.

A control algorithm can be implemented in a known manner using these differential equations.

Another controller 66, which regulates the distance r to zero, can be found in the prior art.

Compensation for the case that v=0 can be done in a manner known per se, for example by deactivating the controller.

6 illustrates how two parameter sets 110, 111 can be used as a basis for the controller 66 when generating the substitute control value 43 as the output control value A, so that two substitute control values A _low and A _high result. The respective parameter data set 101, 111 applies to different value intervals 112, 113 of the driving speed v. In an intermediate area or transition area, which results in a third value interval 114 for the driving speed v, the outputs as they result for the two parameter data sets 110, 111 can be blended, for which purpose the in 6 linear blending function 115 shown can be used, in which a weighting factor f is selected or set depending on the driving speed v and the in 6 The formula shown can be used for blending.

Overall, the examples show how automated, hands-free driving can be provided while ensuring a minimum handover time.

Claims (9)

Method for operating a control unit (20) for trajectory planning, wherein a respective current input control value (24) of a trajectory planner (21) connected upstream of the test module (30) is received by a processor circuit of the control unit (20) in successive test cycles by a test module (30). and by outputting a respective output control value (12), a vehicle movement control (13) is controlled, which is connected downstream of the test module (30) and which automatically guides the motor vehicle (10), the test module (30) being the test module (30) for the respective test cycle (42). Processor circuit generates a replacement control value (43) on the basis of its own planning module (40), the own planning module (40) providing a planning strategy that maintains the current output control value (12) and / or a Steering towards the middle of a roadway currently traveled by the motor vehicle (10), and the processor circuit checks the received current input control value (24) of the trajectory planner (21) as to whether the input control value (24) is used as an output control value (12) a future travel trajectory of the motor vehicle (10) which satisfies each of at least one predetermined admissibility condition (46, 47), and only if each admissibility condition (46, 47) is met, the input control value (24) and otherwise the substitute control value (43) as the output control value (12) of the test cycle (42) is output, characterized in that the planning module (40) receives at least one dynamic parameter that describes a movement of the motor vehicle (10) on the road and the substitute control value (43) by means of a controller ( 66). Vehicle speed values in a first value interval (112) and - a second parameter data set (111) for vehicle speed values (v) in a second value interval (113) and - in a third value interval lying between the first value interval (112) and the second value interval (113) ( 114) a crossfade function (115) is used for controller outputs of the first parameter data set (110) and the second parameter data set (111). Procedure according to Claim 1 , wherein the substitute control value (43) of the respective test cycle (42) is generated before the respective test cycle (42) by operating the planning module (40) with dynamic data of the motor vehicle (10), which are projected into the future. Method according to one of the preceding claims, wherein at least one road edge course and/or at least one road edge course (82) on the one hand and a contour of the motor vehicle (10) on the other hand are entered in a digital environment map (80) and the period of time within which the motor vehicle (10) is checked is checked ) would reach or intersect a roadside or road edge if the current input control value (24) were output as an output control value (12) for all future test cycles, and the admissibility condition (46, 47) requires that the time period be greater than a predetermined takeover time period for handover the vehicle is driven by a driver. Procedure according to Claim 3 , whereby the processor circuit checks in the event that it is recognized that the time period is smaller than the takeover time period, which of the input control value (24) and the substitute control value (43) is a longer period of time when hypothetically used for the future test cycles leads, and this is used as the output control value (12). Method according to one of the preceding claims, wherein the road center profile (51) is signaled by environmental sensor data (22, 33) and, in the event that the signaling of the road center profile (51) is interrupted for one of the test cycles, an output control value (12) from a previous test cycle (42) is issued again. Method according to one of the preceding claims, wherein one of the at least one admissibility condition (46, 47) includes that the input control value (24) results in a curvature and/or a change in curvature of a driving line of the motor vehicle (10) which is in a respective predetermined one Value interval (61, 62). Method according to one of the preceding claims, wherein in the event that the replacement control value (43) is output as an output control value (12), a takeover notice is issued to a driver of the motor vehicle (10) and / or a takeover procedure for handing over vehicle control to the driver is started. Control unit (20) for a motor vehicle (10), wherein the control unit (20) has a processor circuit which is set up to carry out a method according to one of the preceding claims. Motor vehicle (10) having a trajectory planner (21) for generating input control values (24) and a vehicle movement control (13) for automatically guiding the motor vehicle (10), characterized in that the trajectory planner communicates with the vehicle movement control (13) via a test module (30) to a control unit (20). Claim 8 is coupled.

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