DE102019203369B4 - Device and method for adaptive cruise control of a motor vehicle - Google Patents

Abstract

Device (1) for adaptive cruise control of an ego motor vehicle (10), comprising an ACC sensor unit (11) for continuously detecting at least one preceding vehicle (20), selecting one of the detected preceding vehicles (20) as a relevant object and determining a distance between the ego motor vehicle (10) and the vehicle driving ahead (20) selected as the relevant object, and an ACC control display (12) with an object symbol (120) to represent a detected with the ACC sensor unit (11). Distance, characterized in that the device (1) for displaying the object symbol (120) in the ACC control display (12) is configured in such a way that the detection of at least one preceding vehicle (20) by a first object symbol (121) involves the perception of objects the device (1) signals, the selection of the relevant object by a second object symbol (122) recognition of a driving situation by the device (1) signals, determining the distance between the ego motor vehicle (10) and the relevant object using a third object symbol (123) signals that the device (1) can control a driving situation, and determining the distance between the ego motor vehicle (10) and the relevant object uses a fourth object symbol (124) to signal that the device (1) cannot control a driving situation, the first object symbol (121), the second object symbol (122), the third object symbol (123) and the fourth object symbol ( 124) are designed to be visually distinguishable.

Description

The invention relates to a device for adaptive cruise control of a motor vehicle and a method for adaptive cruise control of a motor vehicle using the device according to the invention.

For the purpose of relieving the driver, particularly when driving on the freeway, motor vehicles have long been available with speed control devices. Devices of this type, also known as cruise control or cruise control, allow the driver to preset a desired speed, which the vehicle then maintains until the driver cancels this setting, for example by actuating the foot brake. In systems of this type, the speed of the motor vehicle drive is automatically adjusted to the respectively set desired speed via a mostly electronic control system.

A further development of these speed control devices are adaptive cruise control, also known under the abbreviation ACC for Adaptive Cruise Control, which, in addition to automatic control of the vehicle speed via the engine speed, also automatically controls the distance to a vehicle driving ahead via the brake system using an ACC sensor Unit comprising ACC radar sensors and antennas allow.

With the adaptive cruise control or ACC function, a further significant relief and increase in comfort for the driver on motorway journeys, but also in city traffic, can be achieved. By defusing potentially dangerous situations, adaptive cruise control makes a direct contribution to traffic safety.

The ACC function is therefore also of essential importance in driverless motor vehicles or in autonomous driving.

With this in mind, the responsible government agencies in Europe and the USA have defined five steps or levels for the different degrees of automation from conventional to fully automated driving of a motor vehicle, which therefore also define the requirement framework for the assistance systems used in each case Accident prevention and occupant protection.

The stages or levels are defined as follows: Stage/level 0 - driving without an assistance system, stage/level 1 - partially automated driving with one assistance system, stage/level 2 - partially automated driving with several assistance systems, stage/level 3 - highly automated driving with several assistance systems, stage/level 4 - fully automated driving with several assistance systems, stage/level 5 - autonomous or driverless driving. At stage/level 0-2, the driver is responsible for monitoring the driving environment, at stage/level 3-5 the system.

The required driver information is usually provided via an ACC control display, a suitable visualization system on the dashboard in the vehicle, which represents a user interface or human-machine interface (HMI).

Various visual representations of the ACC function are known in the prior art. In many vehicles, the distance to a vehicle in front is displayed in the form of a white bar within the instrument cluster on the dashboard, the length of which increases as the distance increases and decreases as the distance decreases. This object symbol is used to monitor the ACC function while driving.

Another example of a visual representation of the ACC function is off US6226588B1 refer to. The speed of a motor vehicle (ego vehicle) equipped with the ACC function and of a vehicle driving ahead are then displayed in the usual way by means of a speedometer needle in each case, with the circular segment area between the two speedometer needles being highlighted visually. In addition, another circle segment is visually highlighted on the speedometer surface, which is radially delimited by the lowest and highest set control speed. By means of this visualization of the prevailing speed conditions, it should be possible for the driver to understand the actual state of the distance control and thus changes in the speed of the ego vehicle in a simple manner.

Out of US6226588B1 it is also known to provide acoustic messages from the ACC system in the form of tones or spoken instructions.

A driving assistance system that, in addition to visual and acoustic driver information, also allows haptic warning messages to be sent to the driver, for example in the event of drowsiness detected by the system sensors, is in US6226588B1 specified.

An ACC system and how it works is described in detail in US7974778B2 disclosed.

As practice has shown, however, errors that result in critical driving situations occur again and again in all current ACC systems. Such occur in particular when a vehicle drives ahead in the lane of the ego vehicle (ego lane) and the ego vehicle continues to follow it at high speed, although the vehicle in front has been recognized by the ACC system, without - visible to the driver - reacting to his presence.

In these cases, the behavior of the ACC system is technically correct, since there is no objective risk situation. However, since situations occur again and again in which a vehicle driving ahead is detected too late or even not at all by the ACC sensor, a driver of a motor vehicle equipped with an ACC system is forced to look at the control displays used to monitor the ACC function mistrust.

As a result, many drivers, despite having an ACC system, prefer to control their vehicle in a conventional manner and thus consciously forego the advantages of adaptive cruise control - also with regard to avoiding dangerous situations. Errors of the type mentioned thus lead to a justified loss of trust in the reliability of ACC systems overall and to a lack of user acceptance.

DE 10 2013 015 371 A1 discloses a method for operating a vehicle with adaptive cruise control, the speed of the vehicle being regulated as a function of a detected distance from a vehicle driving ahead. When the vehicle approaches the vehicle in front, before the speed of the vehicle is automatically reduced, a message about the forthcoming reduction in speed is output to a driver of the vehicle.

The aim of the present invention is to provide a device for adaptive cruise control of a motor vehicle and a corresponding method that are suitable for overcoming the disadvantages of the prior art and, in particular, for improving user acceptance of ACC systems and their reliability.

The object according to the invention is achieved by the subject matter of the independent patent claims. Preferred developments are the subject of the dependent claims.

A first aspect of the present invention relates to a device for adaptive cruise control of a motor vehicle or a distance control cruise control. Such devices typically include an ACC sensor unit. A radar system with at least one ACC radar sensor and one ACC radar antenna is usually used as the ACC sensor unit for adaptive speed control of motor vehicles. In a known manner, such enables a continuous detection of moving objects within the emission range of the ACC radar antenna and thus a measurement of a relative distance between a vehicle equipped with the adaptive cruise control (ego motor vehicle) and at least one vehicle driving ahead. Using a control unit, which is typically also provided as part of an adaptive cruise control device, a relative distance between the vehicles ahead and the ego vehicle is continuously calculated from the signals of the ACC sensor unit. The distance values obtained in this way are then graphically represented in an object symbol, with such an object symbol advantageously being arranged in the driver's field of vision, ie on the dashboard of the ego vehicle. A central arrangement, for example between a tachometer and a speedometer within an instrument cluster, is particularly preferred. A vehicle driving ahead, whose relative distance to the ego vehicle is determined in this way, can also be referred to as a relevant object. The object symbol for continuous distance display, or for providing visual driver information about the relative position of an ego vehicle to a relevant object, is surrounded by an ACC control display, in which other operating parameters of the ACC system can usually be displayed.

While with an object symbol of the known type essentially only the value for the relative distance to a relevant object changes, the device according to the invention for adaptive cruise control of a motor vehicle is designed to display a number of object symbols, the appearance of which changes in stages depending on a particular distance is.

For this purpose, the ACC control display of the ACC system is configured in such a way that the detection of at least one vehicle driving ahead is signaled by a first object symbol in the ACC control display. In other words, the first object symbol signals the driver of the Ego vehicle that the device for adaptive cruise control of a motor vehicle has "seen" objects.

On the other hand, the ACC control display of the ACC system displays a second object symbol when a relevant object is selected by the device. This signals to the driver of the ego vehicle that the device has recognized a driving situation, or that the device can “perceive a given driving situation”.

A third object symbol in the ACC control display of the ACC system, on the other hand, signals to the driver of the ego vehicle that a distance between the ego vehicle and the relevant object has been determined, i.e. that the device “can control” a driving situation.

Finally, a fourth object symbol is displayed in the ACC control display of the ACC system to signal to the driver that the device cannot control a driving situation, or that the device "can no longer control" a driving situation.

The first, second, third and fourth object symbols are depicted in such a way that they can be visually distinguished by a driver of the ego vehicle.

The inventive provision of driver information on the current functioning of the device for adaptive cruise control of an ego motor vehicle enables an improved user understanding of the interventions made by the device in the driving behavior of the ego motor vehicle. As a result, not only does the trust in the reliability of such assistance systems increase and consequently the user acceptance of partially or fully automated driving, so that the obvious advantages that assistance systems have with partially or fully automated driving compared to driving without assistance systems with regard to accident prevention and occupant protection, can increasingly come into play. In other words, the invention per se enables traffic safety to be improved.

The invention is of particular advantage for all those assistance systems in motor vehicles that also monitor the driving environment, which is the case from level 3 onwards.

In principle, however, the invention can advantageously be used not only in ACC systems, but more generally in all driver assistance systems in which user information regarding the proper functioning of a system is directly relevant to a user's sense of security. This is advantageously taken into account by providing unambiguous system information that can be quickly and easily grasped by a user in the form of the object symbols according to the invention for visually signaling different “levels of situation controllability” or “risk levels”.

In the case of instrument clusters, in which certain display fields are designed to alternately display different driver information, such as navigation information and ACC information, it is preferable to give the driver a risk level change, and thus a change in the object symbol of the ACC Control display to signal even if other driver information is currently displayed in the display field instead of the ACC control display. The ACC control display in the instrument cluster is advantageously configured in such a way that the new object symbol can be briefly superimposed on the driver information currently being displayed.

A further aspect of the present invention relates to a method for adaptive cruise control of a motor vehicle using the device according to the invention, which has the method steps described below. The device used here has an ACC sensor unit for continuously detecting at least one preceding vehicle, means for selecting one of the detected preceding vehicles as the relevant object, and means for determining a distance between the ego motor vehicle and the preceding vehicle selected as the relevant object vehicle up. In addition, the device includes an ACC control display with an object symbol for representing a distance between the ego vehicle and the relevant object determined by the ACC system using the ACC sensor unit.

In a first step, according to the method, at least one vehicle driving ahead is detected by an ego motor vehicle using the device and is signaled to the driver of the ego motor vehicle by displaying a first object symbol in the ACC control display of the device.

In a second step, one of the detected vehicles driving ahead is then selected as the relevant object and the distance between the ego motor vehicle and the vehicle driving ahead selected as the relevant object is determined. Once the relative distance between the two vehicles has been determined, the driver is shown this in the ACC control display with a second object symbol that stands for recognizing a driving situation. signaled, whereby the second and first object symbol differ visually.

In a third step, the detected distance between the ego motor vehicle and the relevant object is used to check whether a current driving situation can be controlled by the adaptive cruise control of an ego motor vehicle. If so, this is signaled to the driver of the ego vehicle using a third object symbol in the ACC control display, with the third, second and first object symbol being visually different.

Finally, in a fourth step, based on the detected distance between the ego motor vehicle and the relevant object, it is checked whether a current driving situation cannot be controlled by the adaptive cruise control of an ego motor vehicle. If so, this is signaled to the driver of the ego vehicle using a fourth object symbol in the ACC control display, with the fourth, third, second and first object symbol being visually different.

Further preferred configurations of the invention result from the remaining features mentioned in the dependent claims.

In a preferred embodiment of the invention, it is provided that the first, second, third and fourth object symbol are each displayed in a different color in the ACC control display. In this case, it is particularly advantageous to display the first object symbol in white, the second object symbol in green, the third object symbol in yellow and the fourth object symbol in red. Such a color sequence, based on the familiar signal colors of traffic lights, enables the driver to intuitively assign a displayed object symbol to a driving situation and an associated risk level.

Alternatively, it is preferred to provide the object symbols according to the invention in one color, in particular in red, with an increasing color intensity from the first to the fourth object symbol. This embodiment of the object symbols according to the invention also ensures that the driver's attention is specifically drawn to a risk associated with a particular driving situation.

Since the two aforementioned embodiments necessarily require intact color vision on the part of the user for the intended use of the ACC system according to the invention, it is particularly advantageous if, in the two aforementioned embodiments, monochrome screening is also provided for the purpose of clearly distinguishing the individual object symbols.

Of course, as an alternative, a color differentiation or its additional use can also be completely dispensed with, since the visual distinguishability of the object symbols is clearly ensured by the grid display.

In a further preferred embodiment of the invention, it is provided that the object symbols in the control display of the ACC system for the representation of a relative distance between the ego motor vehicle and a vehicle driving ahead each comprise a bar symbol, the bar symbol of the first, second, third and fourth Object symbols are in turn designed to be visually distinguishable by a first, second, third and fourth color, color intensity and/or grid.

Alternatively, it is also preferred to provide the bar symbol of the first, second, third and fourth object symbol with a length that decreases from the first to the fourth object symbol in a visually distinguishable manner. In this alternative, a reduced distance and an associated higher risk level of the ego vehicle to a vehicle driving ahead are indicated by a shorter bar length, while a longer bar symbol signals a greater distance and therefore a lower risk level. The bar symbol is advantageously divided into ten equidistant sections, the bar symbol of the first object symbol for signaling the lowest risk level extending over all ten sections and the bar lengths from the first object symbol to the fourth object symbol being reduced by three sections in each case. In this case, the respective bar symbol is preferably provided as a light bar.

To display the functional state of the device according to the invention for adaptive cruise control of an ego motor vehicle, it can also be advantageous, in order to increase attention, to provide an acoustic warning signal for the driver in addition to the visually distinguishable representation of the first, second, third and fourth object symbols, which is preferably takes the form of a short audio signal.

In addition, or as an alternative to an acoustic warning signal, it is preferable to increase the driver's attention by means of a haptic warning signal. This is preferably done by generating a short vibration of the steering wheel of the ego motor vehicle.

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

• 1 eine schematische Darstellung eines Ego-Kraftfahrzeugs mit einer Vorrichtung zur adaptiven Geschwindigkeitsregelung gemäß dem Stand der Technik;
• 2 ein Kombi-Instrument mit einer ACC-Kontrollanzeige, umfassend ein Objektsymbol zur Darstellung eines mit einer ACC-Sensor-Einheit erfassten Abstandes zwischen einem Ego-Kraftfahrzeug und einem vorausfahrenden Fahrzeug gemäß dem Stand der Technik;
• 3 ein erstes bis viertes Objektsymbol zum Signalisieren eines ersten bis vierten Betriebszustandes eines ACC-Systems als Objektsymbol in einer ACC-Kontrollanzeige eines Kombi-Instruments eines Ego-Kraftfahrzeugs gemäß der Erfindung;
• 4 ein zweites Objektsymbol zum Signalisieren eines zweiten Betriebszustandes eines ACC-Systems als Objektsymbol in einer ACC-Kontrollanzeige eines Kombi-Instruments eines Ego-Kraftfahrzeugs und als akustisches und haptisches Warnsignal gemäß der Erfindung;
• 5 ein schematisches Ablaufdiagramm des erfindungsgemäßen Verfahrens.

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

• 1 a schematic representation of an ego motor vehicle with a device for adaptive cruise control according to the prior art;
• 2 an instrument cluster with an ACC control display, comprising an object symbol for representing a distance between an ego motor vehicle and a vehicle driving ahead, which is detected by an ACC sensor unit, according to the prior art;
• 3 a first to fourth object symbol for signaling a first to fourth operating state of an ACC system as an object symbol in an ACC control display of an instrument cluster of an ego motor vehicle according to the invention;
• 4 a second object symbol for signaling a second operating state of an ACC system as an object symbol in an ACC control display of an instrument cluster of an ego motor vehicle and as an acoustic and haptic warning signal according to the invention;
• 5 a schematic flowchart of the method according to the invention.

1 shows a schematic representation of an ego motor vehicle 10 with a device 1 for adaptive cruise control, as is known from the prior art. The ACC function is provided in the ego vehicle 10 by the ACC system 1 in connection with the ACC sensor unit 11, with the ACC control display 12 acting as a user interface.

The ACC indicator 12 is in 2 shown. As usual, this is arranged in the instrument cluster 2 between the rev counter and the speedometer in the central field of vision of the driver of the host vehicle 10 on the dashboard.

3 shows the different forms of representation of the object symbol 120 of the ACC control display 12. The first object symbol 121 is shown in white as a bar symbol in a perspective plan view. The representation of the second object symbol 122 differs from that of the first object symbol 121 only in the color of the bar, which is green in the case of the latter. In the same way, the third object symbol 123 is provided with a bar symbol in yellow and the fourth object symbol 124 with a bar symbol in red.

An additional use of an acoustic warning signal 3 and a haptic warning signal 4 in a driving situation signaled by the second object symbol 122 is in 4 represented symbolically. The acoustic warning signal 3 is a short acoustic signal, and the haptic warning signal 4 is a brief vibration of the steering wheel. In the present case, the driver of ego vehicle 10 is signaled in this three ways by the ACC system that a driving situation has been recognized.

5 finally illustrates the individual steps of the method to be carried out using the ACC system 1 according to the invention.

In a first method step 100 , multiple vehicles 20 driving ahead are detected by the ACC sensor unit 11 of the ego vehicle 10 . This is signaled in the ACC control display 12 by displaying the first object symbol 121 . The driver of ego vehicle 10 recognizes from this that ACC system 1 is active.

In a second method step 200, the ACC system 1 selects the relevant object from the vehicles 20 driving in front that is moving in the ego vehicle's 10 lane. This process is signaled in ACC control display 12 by displaying second object symbol 122, from which the driver of ego vehicle 10 recognizes that ACC system 1 has recognized a driving situation.

In a third method step 300, the ACC system 1 determines the distance between the ego motor vehicle 10 and the preceding vehicle 20 selected as the relevant object and uses the measured values determined by the ACC sensor unit 11 to evaluate the ability of the vehicle to control the current driving situation ACC system 1. If this is the case, the third object symbol 123 is displayed in the ACC control display 12, which signals to the driver of the ego vehicle 10 that the ACC system 1 can control the driving situation.

In a fourth method step 400, the ACC system 1 again determines the distance between the ego motor vehicle 10 and the vehicle 20 driving ahead selected as the relevant object and uses the measured values determined by the ACC sensor unit 11 to evaluate the controllability of the current driving situation the ACC system 1. If this is not the case, the fourth object symbol 124 is displayed in the ACC control display 12, which the driver of ego vehicle 10 signals that ACC system 1 cannot control the driving situation.

Reference List

1

ACC system / adaptive cruise control

11

ACC sensor unit

12

ACC indicator

120

object icon

121

first object icon

122

second object icon

123

third object icon

124

fourth object icon

2

instrument cluster

3

acoustic warning signal

4

haptic warning signal

10

ego motor vehicle

20

vehicle ahead / moving object

100

first step in the process

200

second process step

300

third step

400

fourth step

Claims (9)

Device (1) for adaptive cruise control of an ego motor vehicle (10), comprising an ACC sensor unit (11) for continuously detecting at least one preceding vehicle (20), selecting one of the detected preceding vehicles (20) as the relevant object and Determination of a distance between the ego motor vehicle (10) and the vehicle driving ahead (20) selected as the relevant object, and an ACC control display (12) with an object symbol (120) to represent a signal connected to the ACC sensor unit (11 ) detected distance, characterized in that the device (1) for displaying the object symbol (120) in the ACC control display (12) is configured such that the detection of at least one preceding vehicle (20) by a first object symbol (121). Perception of objects by the device (1) signals that the selection of the relevant object by a second object symbol (122) recognizes a driving situation by the device g (1) signals, determining the distance between the ego motor vehicle (10) and the relevant object using a third object symbol (123) signals that the device (1) can control a driving situation, and determining the distance between the ego - The motor vehicle (10) and the relevant object use a fourth object symbol (124) to signal that the device (1) cannot control a driving situation, the first object symbol (121), the second object symbol (122), the third object symbol (123 ) and the fourth object symbol (124) are designed to be visually distinguishable. Device (1) after claim 1 , wherein the first, second, third and fourth object symbol (121, 122, 123, 124) are represented visually distinguishable by a first, second, third and fourth color, color intensity and/or screening. Device (1) after claim 1 or 2 , wherein the object symbols (120, 121, 122, 123, 124) of the ACC control display (12) comprise a bar symbol for representing a distance between the ego motor vehicle (10) and a vehicle driving ahead (20). Device (1) after claim 3 , wherein the bar symbol of the first, second, third and fourth object symbol (121, 122, 123, 124) are represented visually distinguishable by a first, second, third and fourth color, color intensity and/or screening. Device (1) after claim 1 , characterized in that the first, second, third and fourth object symbol (121, 122, 123, 124) each comprise a bar symbol, the bar symbol of the first, second, third and fourth object symbol (121, 122, 123, 124) with of a length that decreases from the first to the fourth object symbol (121, 122, 123, 124). Device (1) after claim 1 , characterized in that the device (1) is configured such that in addition to the visually distinguishable representation of the first, second, third and / or fourth object symbol (121, 122, 123, 124) an acoustic and / or haptic warning signal for perception by a driver of the ego motor vehicle (10). Device (1) after claim 6 , wherein the audible warning signal comprises a short beep. Device (1) after claim 6 , The haptic warning signal is a short vibration, esp Special includes a short vibration of the steering wheel of the ego motor vehicle (10). Method for adaptive cruise control of a motor vehicle using the device according to claim 1 , having an ACC sensor unit (11) for continuously detecting at least one preceding vehicle (20), selecting one of the detected preceding vehicles (20) as a relevant object and determining a distance between the ego motor vehicle (10) and the as Relevant object selected preceding vehicle (20), and an ACC control display (12) with an object symbol (120) to represent a with the ACC sensor unit (11) detected distance, characterized by the steps: detecting (100) at least a preceding vehicle (20) by an ego motor vehicle (10) and signaling a perception of objects by displaying a first object symbol (121); Selecting (200) one of the detected preceding vehicles (20) as a relevant object, determining a distance between the ego motor vehicle (10) and the preceding vehicle (20) selected as a relevant object and signaling recognition of a driving situation by displaying a second object icon (122); determining (300) a distance between the ego motor vehicle (10) and the vehicle driving ahead (20) selected as the relevant object and signaling that a driving situation can be controlled by displaying a third object symbol (123); determining (400) a distance between the ego motor vehicle (10) and the preceding vehicle (20) selected as the relevant object and signaling that a driving situation cannot be controlled by displaying a fourth object symbol (124); wherein the first, second, third and fourth object symbols (121, 122, 123, 124) are respectively displayed in the ACC control display (12) of the device (1).

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