DE102021109496A1 - Method and device for monitoring the tracking of a vehicle - Google Patents

Abstract

A device for monitoring the tracking of a motor vehicle is described. The device is set up to determine a quality indicator for the cumulative quality of the tracking of the vehicle in a past time interval. Furthermore, the device is set up to determine on the basis of the quality indicator that the quality of the lane guidance is impaired and in response thereto to bring about an action with regard to the lane guidance of the vehicle.

Description

The invention relates to a method and a corresponding device for monitoring the lane guidance, in particular the automated lane guidance, of a vehicle.

A vehicle can have a driving function, in particular a driver assistance function according to SAE Level 2, in which the vehicle is automatically guided laterally in order to keep the vehicle within a lane. The driver of the vehicle can then, if necessary, take his hands off the steering wheel of the vehicle, at least for a certain period of time, but is still responsible for monitoring the driving operation of the vehicle.

If, during the operation of the driver assistance function, it is detected that the vehicle is crossing the lane marking of the lane currently being traveled in, the driver assistance function typically issues a warning to prompt the driver of the vehicle to put their hands on the steering wheel and, if necessary, the lateral guidance to take over the vehicle. The output of a warning when crossing the lane markings can be perceived by the driver of the vehicle as uncomfortable and possibly unsafe.

The present document deals with the technical task of increasing the comfort and feeling of safety of a driver during lane guidance, in particular with assisted lane guidance, of a vehicle. Furthermore, the present document deals with the technical task of increasing the functional reliability of an automated driving function, in particular a driving function according to SAE level 2 or more or according to SAE level 3 or more.

The object is solved by each of the independent claims. Advantageous embodiments are described inter alia in the dependent claims. It is pointed out that additional features of a patent claim dependent on an independent patent claim without the features of the independent patent claim or only in combination with a subset of the features of the independent patent claim can form a separate invention independent of the combination of all features of the independent patent claim, which can be made the subject of an independent claim, a divisional application or a subsequent application. This applies equally to the technical teachings described in the description, which can form an invention independent of the features of the independent patent claims.

According to one aspect, a device for monitoring the tracking of a motor vehicle is described. The lane guidance of the vehicle can be effected manually by the driver of the vehicle or (preferably) automatically by the vehicle. Lane guidance can be designed to guide the vehicle within a specific (current) lane, in particular to guide it transversely. The steering of the vehicle can be effected manually by the driver via a steering means (in particular via the steering wheel) of the vehicle or automatically by an (electric) steering device. The automated lane guidance can be carried out with a degree of automation according to SAE Level 2.

The device can be set up to determine a quality indicator for the cumulative and/or the average quality of the tracking of the vehicle in a past time interval. In particular, the quality indicator can show how well the vehicle was guided within the past time interval within the lane currently being traveled on. The quality of the lane guidance can be based on the lateral distance, in particular the minimum distance, of the vehicle from a lane boundary (e.g. to the right or left lane boundary) during the time interval and/or based on the lateral distance of the vehicle from the middle of the lane are evaluated during the time interval.

The quality indicator can be determined on the basis of the environmental data from one or more environmental sensors (e.g. cameras) of the vehicle. In particular, the distance from a lane boundary and/or from the center of the lane can be determined on the basis of the environmental data.

The device can be set up to determine the quality indicator on the basis of the instantaneous quality of the tracking of the vehicle at a plurality of different points in time (in particular at 5 or more or and 10 or more points in time) within the time interval under consideration. The instantaneous quality values for the different points in time can be cumulated and/or averaged in order to determine the quality indicator.

The device can be set up to determine the quality indicator for a specific (current) point in time. The time interval considered to determine the quality indicator can extend directly back into the past, starting from the specific (current) point in time. The time interval can have a duration of 5 seconds or more, in particular 10 seconds or more. For example, a time interval with a duration between 5 and 15 seconds can be considered. Alternatively or additionally, the Zeitinter wall have 5 or more, in particular 10 or more, consecutive points in time for which the (instantaneous) quality of the tracking is evaluated in each case in order to determine the quality indicator based on the individual (instantaneous) quality values. The individual points in time can, for example, follow one another with a temporal sampling rate of 1 Hz or more.

The device can be set up to determine the quality indicator with a sliding window method (in order to determine a quality indicator for the immediately adjacent time interval). Alternatively or additionally, the device can be set up to determine the quality indicator taking into account a forgetting factor (to reduce the influence of the (instantaneous) quality of the vehicle's lane guidance from points in time that are increasingly in the past on the quality indicator). For example, the quality indicator can be determined on the basis of a weighted summation of the instantaneous tracking quality values for a sequence of past points in time. The weights can be reduced as the distance in time from the current time increases, in order to determine a quality indicator that is current in time.

Alternatively or additionally, the device can be set up to determine the quality indicator in such a way that the quality indicator is limited and/or normalized to a specific value range, e.g. between 0 and 1. This can be brought about, for example, by reducing or raising the quality indicator to the maximum value or to the minimum value of the value range if the determined quality indicator leaves the value range.

The above-mentioned measures can cause a quality indicator to be determined for a current point in time, which shows the cumulative and/or average quality of the track guidance (exclusively) for the directly preceding (time-limited) time interval.

The device is also set up to determine on the basis of the quality indicator that the quality of the tracking is impaired. In particular, the device can be set up to compare the quality indicator with a (predefined) quality threshold value. The quality threshold value can, for example, be a (mean) value within the possible value range of the quality indicator. It can then be precisely determined on the basis of the comparison whether the tracking performance is degraded or not.

The device can be set up to repeatedly, in particular periodically (for example with a frequency of 1 Hz or more), determine a current quality indicator for the previous time interval (starting from the current time). Furthermore, the device can be set up to check, on the basis of the current quality indicator, whether the tracking of the vehicle (at the current time) is impaired or not. The cumulative and/or average tracking quality can thus be checked repeatedly. In this way, a permanently comfortable and safe tracking of the vehicle can be effected.

The device is also set up (at the respective current point in time) to bring about a measure, in particular a safety measure, with regard to the lane guidance of the vehicle in response to a recognized impairment in the lane guidance of the vehicle. In particular, the measure may include issuing a notice to the driver of the vehicle (e.g. via a user interface of the vehicle).

By taking into account the cumulative and/or average quality of the lane guidance of the vehicle in a directly preceding time interval, an impairment of the lane guidance can be detected at an early stage. In this way, the comfort and safety of the (possibly automated) lane guidance of the vehicle can be increased.

The device can be set up, for the individual points in time of a sequence of consecutive points in time (e.g. 5 points in time or more, or 10 points in time or more) within the past time interval, to provide an assessment of the (instantaneous) quality of the tracking of the vehicle at the respective point in time determine. The quality indicator can then be determined in a precise and efficient manner on the basis of the ratings for the sequence of consecutive points in time, in particular on the basis of a possibly weighted summation of the ratings for the sequence of consecutive points in time.

The device can be set up, for example, to determine the (lateral) distance of the vehicle from the center of the lane or from the (left or right) lane boundary of the lane in which the vehicle is driving for a specific point in time from the sequence of successive points in time. The minimum distance to a lane boundary can be considered. The assessment of the (instantaneous) quality of the tracking of the vehicle at the specific point in time can then be determined in a precise manner on the basis of the determined distance.

The assessment of the (instantaneous) quality of the tracking of the vehicle at the specific point in time can be determined using an assessment function. The applicant can ment function for different values of the distance (to a lane boundary or to the middle of the lane) each display a value of the evaluation.

The evaluation function can be designed in such a way that a large distance to a lane boundary or a small distance to the center of the lane is rewarded (e.g. by a value with a first (e.g. positive) sign). Furthermore, the evaluation function can be designed in such a way that a small distance to a lane boundary or a large distance to the middle of the lane is penalized (e.g. by a value with a second (e.g. negative) sign).

In other words, the evaluation function can be designed in such a way that the value of the evaluation has a first (e.g. positive) sign if the distance to the lane boundary is greater than or equal to a first distance threshold value and/or if the distance to the Lane center is less than or equal to a second distance threshold. Furthermore, the evaluation function can be designed in such a way that the value of the evaluation has a second (e.g. negative) sign opposite to the first sign if the distance to the lane boundary is smaller than the first distance threshold value and/or if the distance to the Lane center is greater than the second distance threshold.

By considering an evaluation function for determining the quality indicator, the cumulative and/or average quality of the tracking can be determined in a particularly precise and robust manner. In this case, the evaluation function can be designed asymmetrically in order to penalize relatively small distances from a lane boundary more severely than to reward relatively large distances from a lane boundary. In this way, the sensitivity of detection of impaired tracking can be increased.

The evaluation function can be designed in such a way that the absolute value of the evaluation increases at least in a sub-range as the difference between the ascertained distance and the first and/or second distance threshold value increases. In this way, the cumulative and/or average quality of tracking can be determined with increased accuracy.

The device can be set up (in particular on the basis of environmental data from one or more environmental sensors (e.g. cameras) of the vehicle) to bring about automated lane guidance of the vehicle. Automated lane guidance can be carried out according to SAE Level 2, for example. As a measure (when it is detected that the lane guidance of the vehicle is impaired), the driver of the vehicle can be prompted (e.g. by issuing a message) to place his hands on the steering means of the vehicle and/or to carry out the lane guidance of the vehicle manually. In this way, comfortable and safe automated lane guidance can be enabled.

As an alternative or in addition, the device can be set up to output a message to the driver of the vehicle as a measure (when an impairment of the lane guidance of the vehicle is detected) in order to increase the attention of the driver of the vehicle during the manual lane guidance of the vehicle.

According to a further aspect, a (road) motor vehicle (in particular a passenger car or a truck or a bus) is described which comprises the device described in this document.

According to a further aspect, a method for monitoring the tracking of a motor vehicle is described. The method includes determining a quality indicator for the cumulative and/or the average quality of the lane guidance of the vehicle in a previous time interval (that is directly before the current time). Furthermore, the method includes determining, on the basis of the quality indicator, that the quality of the tracking is impaired. The method further includes, in response to the determining, effecting a measure, in particular a safety measure, related to the tracking of the vehicle.

According to a further aspect, a software (SW) program is described. The SW program can be set up to be executed on a processor (e.g. on a vehicle's control unit) and thereby to carry out the method described in this document.

According to a further aspect, a storage medium is described. The storage medium can comprise a SW program which is set up to be executed on a processor and thereby to carry out the method described in this document.

In the context of the document, the term "automated driving" can be understood as driving with automated longitudinal or lateral guidance or autonomous driving with automated longitudinal and lateral guidance. Automated driving can involve driving on the freeway for a longer period of time, for example act for a limited period of time while parking or manoeuvring. The term "automated driving" includes automated driving with any degree of automation. Exemplary degrees of automation are assisted, partially automated, highly automated or fully automated driving. These degrees of automation were defined by the Federal Highway Research Institute (BASt) (see BASt publication "Research compact", issue 11/2012). With assisted driving, the driver constantly performs longitudinal or lateral guidance, while the system takes over the other function within certain limits. With semi-automated driving (TAF), the system takes over longitudinal and lateral guidance for a certain period of time and/or in specific situations, whereby the driver has to constantly monitor the system, as with assisted driving. With highly automated driving (HAD), the system takes over longitudinal and lateral guidance for a certain period of time without the driver having to constantly monitor the system; however, the driver must be able to take control of the vehicle within a certain period of time. With fully automated driving (VAF), the system can automatically handle driving in all situations for a specific application; a driver is no longer required for this application. The four levels of automation mentioned above correspond to SAE levels 1 to 4 of the SAE J3016 standard (SAE - Society of Automotive Engineering). For example, highly automated driving (HAF) corresponds to level 3 of the SAE J3016 standard. Furthermore, SAE J3016 also provides SAE Level 5 as the highest degree of automation, which is not included in the BASt definition. SAE Level 5 corresponds to driverless driving, in which the system can automatically handle all situations like a human driver throughout the journey; a driver is generally no longer required. The aspects described in this document relate in particular to a system in accordance with SAE Level 2.

It should be noted that the methods, devices and systems described in this document can be used both alone and in combination with other methods, devices and systems described in this document. Furthermore, any aspects of the methods, devices and systems described in this document can be combined with one another in a variety of ways. In particular, the features of the claims can be combined with one another in many different ways.

• 1 ein beispielhaftes Fahrzeug mit einer Spurhalteassistenzfunktion;
• 2a eine beispielhafte Anordnung eines Fahrzeugs innerhalb einer Fahrspur;
• 2b eine beispielhafte Bewertungsfunktion; und
• 3 ein Ablaufdiagramm eines beispielhaften Verfahrens zur Überwachung der Spurführung eines Fahrzeugs.

The invention is described in more detail below using exemplary embodiments. show it

• 1 an example vehicle with a lane departure warning feature;
• 2a an example placement of a vehicle within a lane;
• 2 B an example scoring function; and
• 3 FIG. 12 is a flowchart of an example method for monitoring vehicle tracking.

As explained at the outset, the present document deals with increasing the comfort and safety of lane guidance, in particular automated lane guidance, of a vehicle. In this context shows 1 a vehicle 100 that includes one or more environment sensors 102 that are set up to capture environment data (ie sensor data) in relation to the environment of vehicle 100 . Exemplary surroundings sensors 102 are a radar sensor, a lidar sensor, a camera, etc. A (control) device 101 of the vehicle 100 can be set up to recognize lane markings on the roadway traveled by the vehicle 100 on the basis of the surroundings data. Device 101 can also be set up to control one or more longitudinal and/or lateral guidance actuators 103 (e.g. a steering device, a drive motor, a braking device, etc.) of vehicle 100 on the basis of the environmental data, in particular on the basis of the one or more recognized lane markings. longitudinally and/or transversely. In particular, device 101 can be set up to automatically guide vehicle 100 within a specific lane (eg as part of a lane departure warning function according to SAE Level 2).

The vehicle 100 can also include one or more steering means sensors 104 which are set up to detect whether the driver of the vehicle 100 is touching the steering means, in particular the steering wheel, of the vehicle 100 with one or two hands. In particular, a so-called hands-on detection (HOD) can be carried out on the basis of the sensor data from the one or more steering means sensors 104 .

Furthermore, the vehicle 100 may include a user interface 105 for interaction with the driver of the vehicle 100 . Device 101 may be set up to output an (acoustic, visual and/or haptic) indication to the driver of vehicle 100 via user interface 105, e.g. to prompt the driver of vehicle 100 to place one or two hands on the steering means of vehicle 100 to lay, and / or to cause the driver of the vehicle 100 to take over the lateral control of the vehicle 100.

The device 101 can be set up to check during the manual or automated lane guidance of the vehicle 100 within a specific lane whether the vehicle 100 is approaching the edge of the lane and/or whether the vehicle 100 is leaving the lane. If such a situation is detected, a warning can be issued to the driver of the vehicle 100 via the user interface 105, eg to prompt the driver of the vehicle 100 to guide the vehicle 100 back into the lane and/or back to the lane center . The output of a warning as a result of a detected crossing of a lane boundary can be perceived by the driver of the vehicle as too late and as uncomfortable.

2a illustrates the (lateral) positioning of a vehicle 100 within a lane 210 . The lane 210 can have a lane center 211 between two lane boundaries 212 . In this case, the lane boundaries 212 can each be indicated by a lane marking on the roadway. The lane markings can be recognized on the basis of the surroundings data from one or more surroundings sensors 102 of the vehicle 100 .

For the safest possible journey, the vehicle 100 should be guided manually by the driver or automatically in the middle of the lane 211 so that the (lateral) distance 201 of the vehicle 100 from the lane boundaries 212 has a maximum possible value. During the operation of the vehicle 100, there may be deviations from the ideal lane center guidance, e.g. due to an unconcentrated manual driving style on the part of the driver or due to insufficient recognition quality of the lane markings. Such deviations from the ideal lane center guidance can gradually lead to a departure from the lane currently being traveled on, and can thus be used as an early indicator for possible departure from the lane.

The device 101 can be set up to determine an (instantaneous) quality value in relation to the quality of the lateral positioning of the vehicle 100 within the lane 210 currently being traveled on at a sequence of successive points in time. The (instantaneous) quality or the (instantaneous) quality value can depend, for example, on the (minimum) distance 201 of the vehicle 100 from a lane boundary 212 of the lane 210 . The (instantaneous) quality or the (instantaneous) quality value can be determined on the basis of the surroundings data from one or more surroundings sensors 102 .

Furthermore, the device 101 can be set up to determine a quality indicator for the time-cumulated and/or average quality of the tracking of the vehicle 100 on the basis of the (instantaneous) quality values for the sequence of successive points in time. The indicator can depend on the (minimum) distance 201 from a lane boundary 212 that vehicle 100 maintained at the individual points in time of the sequence of points in time. In particular, the indicator may indicate how well the vehicle 100 was guided along the lane center 211 within the time interval corresponding to the sequence of times. The quality indicator can be determined on the basis of a (weighted) summation of the (instantaneous) quality values for the sequence of points in time.

To determine the quality indicator, as exemplified in 2 B shown, an evaluation function 220 can be used, which evaluates the (instantaneous) quality of the tracking at a specific point in time, for example rewarding it with a (positive) reward or punishing it with a (negative) punishment. In the 2 B The evaluation function 220 shown is designed to assign an evaluation 231 to different (minimum) distances 201 of the vehicle 100 from a lane boundary 212 . The evaluation 231 can be increasingly more positive as the distance 201 increases (in particular it can have an increasingly higher positive value or reward). On the other hand, the evaluation 231 can be increasingly negative as the distance 201 decreases (in particular, have an increasingly higher negative value or punishment). in the in 2 B In the example shown, the evaluation function 220 has a limited positive evaluation 231 for distances 201 and above a maximum limit distance 222 and/or a limited negative evaluation 231 for distances 201 and below a minimum limit distance 221 .

wobei Δt die Zeitdauer zwischen zwei direkt aufeinanderfolgenden Zeitpunkten ist.The device 101 can be set up to determine the quality indicator by cumulating the assessments 231 of the (instantaneous) quality of the tracking at the individual points in time of the sequence of points in time. In particular, iteratively, starting from a value x(n-1) of the quality indicator for a previous time n-1 based on the (instantaneous) evaluation b(n) 231 at the current time n, the value x(n) of the quality indicator for the current time n are determined, for example as $$\text{x}\left(\text{n}\right)=\text{x}\left(\text{n}-1\right)+\text{b}\left(\text{n}\right)\ast \Delta \text{t}$$

where Δt is the length of time between two directly consecutive points in time.

If necessary, the quality indicator x(n) can be limited to a specific value range, for example between 0 and 1. Alternatively or additionally, a discounting or forgetting factor can be applied to the quality indicator x(n). In this way it can be brought about that the quality indicator displays the quality of the tracking within a relatively current time interval from the past.

The quality indicator x(n) ascertained for a current point in time n can be compared with a quality threshold value in order to ascertain whether the cumulative quality of tracking within the previous time interval was impaired. When it is determined based on the comparison that the cumulative tracking performance was degraded, a safety measure related to the tracking of the vehicle 100 can be effected. For example, when operating an automated lane guidance, the driver of the vehicle 100 can be prompted via the user interface 105 to take over the lateral guidance of the vehicle 100 manually. Alternatively, in the case of manual lane guidance, the attention of the driver of vehicle 100 can be increased by a warning.

3 12 shows a flow chart of an exemplary (possibly computer-implemented) method 300 for monitoring the (possibly automated) lane guidance of a motor vehicle 100 . The method 300 can be executed by the vehicle 100 .

The method 300 includes determining 301 a quality indicator for the cumulative and/or average quality of the tracking of the vehicle 100 in a past time interval. The (instantaneous, i.e. point-in-time-specific) quality of tracking can be evaluated at several (e.g. at 5 or more or at 10 or more) different points in time within the time interval. The quality indicator can then reflect the cumulative and/or the average quality at the different points in time. The quality indicator can indicate how well the vehicle 100 was guided within the lane 210 currently being traveled within the past time interval (on average). The quality indicator can depend on the (average) distance 201 of the vehicle 100 from a lane boundary 212 and/or on the lane center 211 of the lane 210 currently being traveled on.

Furthermore, the method 300 includes determining 302, on the basis of the quality indicator, that the quality of the tracking is impaired. For this purpose, the quality indicator can be compared to a quality threshold value, and on the basis of the comparison it can be recognized that the quality of lane guidance is impaired (e.g. because vehicle 100 was too close to lane boundary 212 or drove too far away from the center of the lane 211).

The method 300 also includes, in response to the detected impairment of the quality of the lane guidance, effecting 303 a (safety) measure in relation to the lane guidance of the vehicle 100. For example, a message can be output to the driver of the vehicle 100 as a measure, to cause the driver of the vehicle 100 to put his hands on the steering means of the vehicle 100, to cause the driver to take over the lane guidance of the vehicle 100 manually and/or to increase the driver's attention when lane guiding the vehicle 100.

The measures described in this document can increase the convenience and safety of lane guidance, in particular automated lane guidance, of a vehicle 100 .

The present invention is not limited to the exemplary embodiments shown. In particular, it should be noted that the description and the figures are only intended to illustrate the principle of the proposed methods, devices and systems by way of example.

Claims (12)

Device (101) for monitoring the tracking of a motor vehicle (100); wherein the device (101) is set up - to determine a quality indicator for a cumulative quality of the tracking of the vehicle (100) in a past time interval; - determine on the basis of the quality indicator that the quality of the tracking is impaired; and - in response thereto effecting an action related to the tracking of the vehicle (100). Device (101) according to claim 1 , wherein the device (101) is set up - for the individual points in time of a sequence of successive points in time within the past time interval to determine an evaluation (231) of the quality of the tracking of the vehicle (100) at the respective point in time; and - to determine the quality indicator on the basis of the evaluations (231) for the sequence of consecutive points in time, in particular on the basis of an optionally weighted summation of the evaluations (231) for the sequence of consecutive points in time. Device (101) according to claim 2 , wherein the device (101) is set up, - for a specific point in time from the sequence of successive points in time, a distance (201), in particular a lateral distance, of the vehicle (100) from a lane center (211) or from a lane boundary (212) to determine a lane (210) traveled by the vehicle (100); and - to determine the evaluation (231) of the quality of the tracking of the vehicle (100) at the specific point in time on the basis of the determined distance (201). Device (101) according to claim 3 , wherein - the device (101) is set up to determine the evaluation (231) of the quality of the tracking of the vehicle (100) at the specific point in time on the basis of the determined distance (201) using an evaluation function (220); - the evaluation function (220) indicates a value of the evaluation (231) for different values of the distance (201); and - the evaluation function (220) is designed in particular in such a way that - the value of the evaluation (231) has a first sign if the distance (201) to the lane boundary (212) is greater than or equal to a first distance threshold value and /or if the distance to the lane center (211) is less than or equal to a second distance threshold value, and/or - the value of the evaluation (231) has a second sign opposite to the first sign if the distance (201) to the lane boundary (212) is less than the first distance threshold value and/or if the distance to the lane center (211) is greater than the second distance threshold value. Device (101) according to claim 4 , wherein the evaluation function (220) is designed such that the absolute value of the evaluation (231) increases at least in a sub-area with increasing difference of the determined distance (201) from the first and/or second distance threshold value. Device (101) according to one of the preceding claims, wherein the device (101) is set up - compare the goodness indicator to a goodness threshold; and - to determine on the basis of the comparison whether the tracking performance is impaired or not. Device (101) according to one of the preceding claims, wherein the device (101) is set up - to determine the quality indicator using a sliding window method and/or taking into account a forgetting factor to reduce an influence of the quality of the lane guidance of the vehicle (100) from points in time that are increasingly in the past on the quality indicator; and or - to determine the quality indicator in such a way that the quality indicator is limited and/or normalized to a specific value range. Device (101) according to one of the preceding claims, wherein the device (101) is set up - In particular on the basis of environmental data from one or more environmental sensors (102) of the vehicle (100) to bring about automated tracking of the vehicle (100); and - as a measure to cause a driver of the vehicle (100) via a user interface (105) of the vehicle (100) to put his hands on a steering means of the vehicle (100) and / or to carry out the lane guidance of the vehicle (100) manually. Device (101) according to one of the preceding claims, wherein the device (101) is set up to output a message to a driver of the vehicle (100) as a measure to draw the attention of the driver of the vehicle (100) to the manual lane guidance of the vehicle ( 100) to increase. Device (101) according to any one of the preceding claims, wherein - the time interval has a duration of 5 seconds or more, in particular 10 seconds or more; and or - The time interval has 5 or more, in particular 10 or more, consecutive points in time for which the quality of the tracking is evaluated in order to determine the quality indicator. Device (101) according to one of the preceding claims, wherein the device (101) is set up to repeatedly, in particular periodically, - to determine a current quality indicator for the previous time interval; and - to check on the basis of the current quality indicator whether the tracking of the vehicle (100) is impaired or not. Method (300) for monitoring the tracking of a motor vehicle (100); wherein the method (300) comprises, - determining (301) a quality indicator for a cumulative quality of the tracking of the vehicle (100) in a past time interval; - determining (302), based on the quality indicator, that the tracking quality is impaired; and - in response thereto, effecting (303) a measure take in relation to the tracking of the vehicle (100).

Images