DE102019203369A1 - Device and method for adaptive speed control of a motor vehicle - Google Patents

Abstract

The invention relates to a device (1) for adaptive speed control of an ego motor vehicle (10). Such devices, or adaptive cruise control systems, comprise 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 of the relevant object from the ego motor vehicle (10). According to the invention, the device (1) also has an ACC control display (12) for displaying an object symbol (120), the appearance of which can be changed in steps as a function of a particular distance. This type of provision of driver information on the current functioning of the device (1) enables an improved user understanding of the interventions made by the device (1) on the driving behavior of the ego motor vehicle (1) and is thus able to increase the acceptance of driving with assistance systems , who in particular also monitor the driving environment. To this extent, the invention contributes to an improvement in road safety. The invention also relates to a method for adaptive speed control of a motor vehicle using the device according to the invention.

Description

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

For the purpose of reducing the burden on the driver, especially when driving on the motorway, motor vehicles have long been offered with devices for speed control. Such devices, also known as cruise control or cruise control, enable the driver to preset a desired speed which the vehicle then maintains until the driver cancels this setting, for example by pressing the foot brake. In systems of this type, the speed of the motor vehicle drive is automatically adapted to the desired speed set in each case via a mostly electronic control system.

A further development of these cruise 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, automatic control of the distance to a vehicle in front via the brake system using an ACC sensor Unit, comprising ACC radar sensors and antennas, enable.

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

The ACC function is therefore also of great 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 stages or levels for the different degrees of automation from conventional to fully automated movement of a motor vehicle, which therefore also define the requirements for the assistance systems used in each case Form accident prevention and occupant protection.

The levels are individually defined as follows: Level / level 0 - Driving without assistance system, level / level 1 - partially automated driving with an assistance system, level / level 2 - partially automated driving with several assistance systems, level / level 3 - Highly automated driving with several assistance systems, stage / level 4th - Fully automated driving with several assistance systems, stage / level 5 - autonomous or driverless driving. At level 0-2 The driver is responsible for monitoring the driving environment at level 3-5 the system.

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

Various visual representations of the ACC function are known from the prior art. In many vehicles, for example, 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 with increasing distance and decreases with decreasing distance. This object symbol is used to monitor the ACC function while driving.

Another example of a visual representation of the ACC function is from US 6226588 B1 refer to. The speed of a motor vehicle (ego vehicle) equipped with the ACC function and a vehicle driving ahead are then displayed in the usual way by means of a speedometer needle, the segment of a circle between the two speedometer needles being highlighted. In addition, another circle segment is visually highlighted on the speedometer surface, which is limited radially by the lowest and highest set control speed. By means of this visualization of the prevailing speed conditions, the driver should be able to easily understand the actual state of the distance control and thus changes in speed of the ego vehicle.

Out US 6226588 B1 It is also known to provide messages from the ACC system acoustically in the form of tones or voice instructions.

A driver assistance system that, in addition to visual and acoustic driver information, also allows haptic warning messages to the driver, for example in the event of overtiredness detected by the system sensors, is in US 6226588 B1 specified.

An ACC system and how it works are detailed in US 7974778 B2 disclosed.

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

The behavior of the ACC system is technically correct in these cases, 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 watch 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 way 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 as a whole and to a lack of user acceptance.

The present invention is intended to provide a device for adaptive speed control of a motor vehicle and a corresponding method which 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 of the invention is achieved by the subjects of the independent claims. Preferred further developments are the subject of the subclaims.

A first aspect of the present invention relates to a device for adaptive speed control of a motor vehicle or an adaptive cruise control. Such devices typically include an ACC sensor unit. For adaptive speed control of motor vehicles, a radar system with at least one ACC radar sensor and an ACC radar antenna is usually used as the ACC sensor unit. This enables, in a known manner, 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. A control unit, which is typically also provided as part of an adaptive cruise control device, is used to continuously calculate a relative distance between the vehicles in front and the ego vehicle from the signals from the ACC sensor unit. The distance values obtained in this way are then graphically represented in an object symbol, such an object symbol advantageously being arranged in the vehicle driver's field of vision, that is to say on the dashboard of the ego vehicle. A central arrangement, for example between a rev counter and a speedometer within a combination instrument, 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 comprised by an ACC control display, in which further operating parameters of the ACC system can usually be displayed.

While an object symbol of the known type essentially only changes the value for the relative distance to a relevant object, the inventive device for adaptive speed control of a motor vehicle is designed to display several object symbols, the appearance of which changes in steps depending on a particular distance is.

To this end, 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 to the driver of the ego vehicle that the device for adaptive speed control of a motor vehicle has “seen” objects.

The ACC control display of the ACC system, on the other hand, shows a second object symbol when a relevant object is selected by the device. The driver of the ego vehicle is thereby signaled 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 is being determined, that is, that the device can “control” a driving situation.

A fourth object symbol is finally displayed in the ACC control display of the ACC system in order 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 shown in such a way that a driver of the ego vehicle ensures that they can be visually differentiated.

The provision according to the invention of driver information on the current mode of operation of the device for adaptive speed 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. This not only increases trust in the reliability of such assistance systems and consequently user acceptance of partially or fully automated driving, so that the obvious advantages of the assistance systems of partially or fully automated driving over driving without assistance systems with regard to accident avoidance and occupant protection can increasingly come into their own. In other words, the invention per se enables road safety to be improved.

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

In principle, however, the invention can be used advantageously not only in ACC systems, but more generally in all driver assistance systems in which user information relating to the proper functioning of a system is directly relevant to a user's sense of security. With the provision of 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 various “levels of situation controllability” or “risk levels”, this is advantageously taken into account.

In the case of instrument clusters in which certain display fields are designed for the alternating display of different driver information, such as navigation information and ACC information, it is preferred to give the driver a risk level change, and therefore a change of object symbol for the ACC To signal control display even if other driver information is currently displayed in the display field instead of the ACC control display. For this purpose, the ACC control display in the instrument cluster is advantageously configured in such a way that the new object symbol can be displayed briefly in the driver information currently displayed.

A further aspect of the present invention relates to a method for adaptive speed control of a motor vehicle using the device according to the invention, which method 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 a relevant object and means for determining a distance between the ego motor vehicle and the preceding vehicle selected as the relevant object Vehicle on. In addition, the device comprises an ACC control display with an object symbol for displaying a distance between the ego vehicle and the relevant object determined by the ACC system on the basis of 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 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 traveling ahead is then selected as the relevant object and the distance between the ego motor vehicle and the vehicle traveling ahead selected as the relevant object is determined. Once the relative distance between the two vehicles has been determined, this is signaled to the driver in the ACC control display with a second object symbol, which stands for recognition of a driving situation, the second and first object symbols differing visually.

In a third step, based on the detected distance between the ego motor vehicle and the relevant object, it is checked whether a current driving situation can be controlled by the adaptive speed control of an ego motor vehicle. If so, this is communicated to the driver of the ego vehicle using a third Object symbol in the ACC control display signaled, the third, second and first object symbols differing visually.

In a fourth step it is finally checked on the basis of the detected distance between the ego motor vehicle and the relevant object whether a current driving situation cannot be controlled by the adaptive speed 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, the fourth, third, second and first object symbols differing visually.

Further preferred embodiments of the invention result from the other features mentioned in the subclaims.

In a preferred embodiment of the invention it is provided that the first, second, third and fourth object symbols are displayed in a different color in the ACC control display. A display of 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 is particularly advantageous. Such a color sequence based on the familiar signal colors of traffic lights enables the driver to intuitively assign a respectively 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 a color intensity increasing 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 directed specifically with regard to a risk associated with a particular driving situation.

Since the two aforementioned embodiments necessarily require the user to have intact color vision for proper use of the ACC system, it is particularly advantageous if, in the two aforementioned embodiments, a monochrome raster is also provided for the purpose of clearly distinguishing the individual object symbols.

Of course, as an alternative, color differentiation or its additional use can also be completely dispensed with, since the raster representation of the object symbols clearly ensures that they can be visually distinguished.

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 in front each include a bar symbol, the bar symbol of the first, second, third and fourth Object symbol 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 in each case from the first to the fourth object symbol so that it can be visually distinguished. 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 indicates 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 shortened by three sections. The respective bar symbol is preferably provided as a light bar.

To display the functional state of the inventive device for adaptive speed control of an ego motor vehicle, it can also be advantageous, in addition to the visually distinguishable display of the first, second, third and fourth object symbols, to provide an acoustic warning signal for the driver, which is preferred in In the form of a short acoustic signal.

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

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

• 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 speed control according to the prior art;
• 2 an instrument cluster with an ACC control display, comprising an object symbol for displaying a distance between an ego motor vehicle and a vehicle traveling ahead, according to the prior art, recorded by an ACC sensor unit;
• 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 Instrument cluster of an ego motor vehicle according to the invention;
• 4th 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 flow diagram 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 used in the ego vehicle 10 from the ACC system 1 in connection with the ACC sensor unit 11 provided, with the ACC control display 12 acts as a user interface.

The ACC control display 12 is in 2 shown. As usual, this is 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 arranged on the dashboard.

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

An additional use of an acoustic warning signal 3 and a haptic warning signal 4th one by the second object symbol 122 signaled driving situation is in 4th represented symbolically. The acoustic warning signal 3 is a short acoustic signal, the haptic warning signal 4th a brief vibration of the steering wheel. In the present case, the driver of the ego vehicle 10 signals recognition of a driving situation by the ACC system in this threefold way.

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

In a first process step 100 are from the ACC sensor unit 11 of the ego vehicle 10 several vehicles ahead 20th detected. This is shown in the ACC control display 12 by displaying the first object icon 121 signals. The driver of the ego vehicle 10 recognizes that the ACC system 1 is active.

In a second process step 200 selects the ACC system 1 from the vehicles in front 20th that as a relevant object that is in the ego lane of the ego vehicle 10 emotional. This process is shown in the ACC control display 12 by displaying the second object icon 122 signals to which the driver of the ego vehicle 10 recognizes that the ACC system 1 has recognized a driving situation.

In a third process step 300 determines the ACC system 1 the distance between the ego motor vehicle 10 and the vehicle in front selected as the relevant object 20th and evaluated based on the from the ACC sensor unit 11 determined measured values the controllability of the current driving situation by the ACC system 1 . If this is the case, the ACC control display shows 12 the third object symbol 123 displayed to the driver of the ego vehicle 10 signals that the ACC system 1 can control the driving situation.

In a fourth process step 400 determines the ACC system 1 again the distance between the ego motor vehicle 10 and the vehicle in front selected as the relevant object 20th and evaluated based on the from the ACC sensor unit 11 determined measured values the controllability of the current driving situation by the ACC system 1 . In the event that this is not the case, the ACC control display shows 12 the fourth object symbol 124 displayed to the driver of the ego vehicle 10 signals that the ACC system 1 cannot control the driving situation.

List of reference symbols

1

ACC system / adaptive cruise control

11

ACC sensor unit

12

ACC control display

120

Object icon

121

first object symbol

122

second object symbol

123

third object symbol

124

fourth object symbol

2

Instrument cluster

3

acoustic warning signal

4th

haptic warning signal

10

Ego motor vehicle

20th

Vehicle ahead / moving object

100

first procedural step

200

second process step

300

third process step

400

fourth procedural step

QUOTES INCLUDED IN THE DESCRIPTION

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

Patent literature cited

• US 6226588 B1 [0010, 0011, 0012]
• US 7974778 B2 [0013]

Claims (9)

Device (1) for adaptive speed 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 preceding vehicle (20) selected as the relevant object, and an ACC control display (12) with an object symbol (120) for displaying a signal with 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 vehicle (20) ahead is a first object symbol (121) Perception of objects by the device (1) signals, the selection of the relevant object by a second object symbol (122) signals a detection of a driving situation by the device g (1) signals, the determination of the distance between the ego motor vehicle (10) and the relevant object by a third object symbol (123) signals that a driving situation can be controlled by the device (1), and the determination of the distance between the ego -Motor vehicle (10) and the relevant object by a fourth object symbol (124) signals a lack of controllability of a driving situation by the device (1), 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) according to 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 raster. Device (1) according to Claim 1 or 2 , wherein the object symbols (120, 121, 122, 123, 124) of the ACC control display (12) include a bar symbol to represent a distance between the ego motor vehicle (10) and a vehicle driving ahead (20). Device (1) according to Claim 3 , wherein the bar symbols of the first, second, third and fourth object symbols (121, 122, 123, 124) are represented visually distinguishable by a first, second, third and fourth color, color intensity and / or grid. Device (1) according to Claim 1 , characterized in that the first, second, third and fourth object symbols (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 a length that decreases in each case from the first to the fourth object symbol (121, 122, 123, 124) are shown in a visually distinguishable manner. Device (1) according to Claim 1 , characterized in that the device (1) is configured in such a way 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 a driver of the ego motor vehicle (10) can be generated. Device (1) according to Claim 6 wherein the audible warning signal comprises a short sound signal. Device (1) according to Claim 6 wherein the haptic warning signal comprises a short vibration, in particular 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 FIG Claim 1 , having an ACC sensor unit (11) for the continuous detection of 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) for displaying a distance detected with the ACC sensor unit (11), characterized by the steps of: detecting (100) at least a preceding vehicle (20) by an ego motor vehicle (10) and signaling that objects are perceived 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 that as a relevant object selected preceding vehicle (20) and signaling that a driving situation has been recognized by displaying a second object symbol (122); Determining (300) a distance between the ego motor vehicle (10) and the preceding vehicle (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 a lack of controllability of a driving situation by displaying a fourth object symbol (124); the first, second, third and fourth object symbols (121, 122, 123, 124) each being displayed in the ACC control display (12) of the device (1).

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