DE102014215673A1 - Driver assistance system in a motor vehicle - Google Patents

Abstract

The invention relates to a driver assistance system in a motor vehicle having a detection system for detecting preceding events requiring a reduction of the current speed to a reduced target speed, and a functional unit for determining a deceleration strategy for reducing the speed from the current speed to the target speed at the location of the preceding event. The function unit first determines a first one-stage or multi-stage delay strategy when a forward event requiring a speed reduction is detected, wherein the delay stages of the first delay strategy are determined as a function of predetermined parameters. In addition, the driver assistance system includes a hinting system for issuing a prompt indication to the driver at a defined time prior to reaching the forward event requiring a speed reduction to allow automatic implementation of the delay strategy, the function unit then initiating the automatic implementation of the delay strategy upon confirmation by the driver of the prompt indication ,

Description

The invention relates to a driver assistance system in a motor vehicle for determining a delay strategy and for automatically implementing the deceleration strategy.

In principle, many driver assistance systems designed as a speed control system are already known, which regulate the speed of the motor vehicle to a predetermined desired or desired speed. In addition to these longitudinal control systems, longitudinal control systems, so-called distance-related longitudinal control systems or cruise control systems, which have been extended by a distance control, can already be purchased from some manufacturers today. Such systems - for example, the Applicant of the present patent application under the name "Active Cruise Control" - offered systems make it possible to automatically guide the motor vehicle while maintaining a desired distance to a preceding vehicle with a desired or a correspondingly lower speed. Detects a mounted on the motor vehicle distance sensor, which can work especially on radar, a preceding target or (power) vehicle in the own lane, the own speed - eg. By inducing a suitable braking torque - to the speed of the preceding vehicle or of the target object is adapted such that a distance control contained in the "active vehicle speed control" or in the corresponding longitudinal control system automatically adjusts and maintains a situation-appropriate distance to the vehicle or target object traveling in front of it.

Next are so-called. Speed limit systems are known which prevent exceeding the speed set by the driver.

The DE 10 2012 211 967 A1 describes a combination of a speed limit system and a speed control system, wherein the maximum speed of the speed limit system instead of the set speed setting is adopted as (new) set speed for the speed control.

Finally, in newer vehicles there are also driver assistance systems, which can either proactively recognize a speed limit from map data of a navigation system and / or image processing and display it to the driver so that the latter can automatically adapt his speed to the speed limit if necessary (eg BMW Speed limit info).

From the DE 10 2008 018 421 A1 a driver assistance system for transmitting and receiving speed data and / or traffic density data for controlling a cruise control system is known which determines based on the received data a maximum speed and this tells the driver by issuing a corresponding hint. The driver can accept this specification of the permissible speed by a simple operation for his speed control system.

Finally, out of the DE 10 2011 119 007 A1 a method for operating a vehicle and a corresponding ausgestalte control unit is known, wherein depending on the current speed and reduced due to a speed reduction target speed a Ausrollweg of the vehicle is determined, the Ausrollweg of the vehicle is determined either for a freewheeling operating state or a fuel cut-off operating state. Depending on the determined Ausrollwegs either an output to the driver can be generated, which should cause the driver to a certain driving style, or a corresponding control signal to be passed to an automatic cruise control function, ie either the driving style is left to the driver and issued only a hint or an automatic speed control independent of the driver takes place.

If only an indication is issued, the degree of support of the system is relatively low, but if an automatic control is carried out immediately, the driver is too severely limited in his management task.

The object of the invention is now to provide a driver assistance system, which supports the driver in a required speed reduction, without restricting the driver's management task too much.

This object is achieved by a driver assistance system according to claim 1. Advantageous developments emerge from the dependent claims.

The basic idea of the invention is to specify a deceleration strategy with a targeted control of a partial route in sails, in towing and / or braking. At least the sections sailing and tow should be applicatively adjustable in their length. The remaining distance should be slowed down, as only then a speed can be reached at a defined location.

The driver assistance system generally comprises a detection system for detecting preceding events requiring reduction of the current speed to a reduced target speed, a functional unit for determining an appropriate deceleration strategy for reducing the speed from the current speed to the target speed at the location of the preceding event, and A hint system for issuing a prompt indication to the driver at a defined time prior to reaching the forward event requiring a speed reduction to allow automatic implementation of the delay strategy. Only when the driver permits the automatic implementation of the deceleration strategy by a corresponding confirmation of the prompt, the functional unit causes the automatic implementation of the deceleration strategy by sending appropriate control signals to the drive and / or brake unit.

The relevant preceding events which require a reduction in speed can either be from map data of a navigation system and / or by means of image processing of a forward-looking sensor system and / or by means of a car-to-X communication unit by receiving relevant data from other vehicles or traffic signs or traffic guidance systems be recognized. The preceding events may therefore be, for example, temporary or permanent speed limits, which are either indicated directly on a traffic sign, or derive therefrom on the basis of the general traffic rules (for example, a speed limit applies in Germany in the case of a local transit 50 km / h). The decisive target speed for the deceleration strategy at the location of the preceding event may be either the actual preset speed limit or a speed deviating upwards or downwards from the preset speed limit by a predetermined amount, wherein the amount and direction of the deviation, for example, by the driver in a central vehicle menu can be adjustable.

Alternatively or additionally, it is also possible for the driver to determine his own speed limits on a route known to him via a vehicle-internal or vehicle-external interface. When driving on the route with active longitudinal guidance system, these speed limits can be taken into account accordingly. In this case, the driver in advance z. For example, you can also choose whether you want to have the speed limit always set yourself, or selected speed limits according to a rule (for example, only on a certain route, for certain street classes, at a specific time, depending on weather conditions, etc.). , It is also possible to create several speed profiles for a certain section of track, which are then active according to predefined rules (speed profile for good road conditions, speed profile for wet roads and / or speed profile for snow-covered roads).

The driver assistance system according to the invention is further distinguished by the fact that the functional unit initially determines a first deceleration strategy upon detection of a forward event which requires a speed reduction, wherein the deceleration stage of the first deceleration strategy to be adopted is determined as a function of predetermined parameters. In the sense of the given parameters, current operating conditions of the vehicle and / or current system settings and / or driver specifications and / or relevant ambient conditions can be evaluated. The first delay strategy can be one-level or multi-level. As delay stages all modes of the motor vehicle can be defined, which cause a deceleration of the vehicle, such as. B. Sail operation (traction interruption, for example, by opening the connection unit between the gearbox and engine), coasting and braking operation. A single-stage delay strategy is understood to mean that only a single delay stage (eg overrun operation) is used to decelerate the vehicle during the entire deceleration strategy. A multi-stage delay strategy consists of more than one stage in a row (eg overrun followed by brakes).

In principle, in determining the delay strategy in addition to the relevant framework conditions such. B. differential speed between the current speed and the target speed and distance to the location of the relevant leading events also other criteria are taken into account, which have an influence on the deceleration effect of the vehicle. The influencing factors may in particular be current influencing factors, but it is also possible to take into account already known influencing factors which will occur in the future and influence the delay, which will occur up to the location of the preceding event. For example. it can be the road inclination, wind and other weather conditions, the current load of the vehicle or the like. Likewise, in the choice of the delay stages to be considered, the first delay strategy (and in the case of several Delay stages of the respective portion of the delay stage in the total delay) depending on the above parameters are set.

In particular, to determine the delay element (s) or stage (s) for the first-time delay strategy, it can first be determined based on the predetermined parameters which delay stages are fundamentally permitted at the current time. Advantageously, then at least that delay stage is determined as (to be used) delay stage for the first-time delay strategy, which causes the lowest delay of the vehicle from all permitted delay stages. So z. B. due to a driving mode selected by the driver (eg., "Sporty") basically the sailing mode be prevented, so that it can not be allowed as a deceleration for the first time delay strategy also. In this case, as the sole delay stage or as the first delay stage of the multi-stage delay strategy for the first deceleration strategy, the overrun operation can be defined, since this has a lower deceleration effect than a braking operation. However, if the sailing operation is permitted, the sailing operation would be set as the sole delay stage or as the first delay stage of the multi-stage delay strategy for the first delay strategy, as this in turn causes a lower delay than the overrun operation. However, the sailing operation can also be due to existing transmission parameters, eg. B. a too low transmission oil temperature not be approved as a delay stage. However, the mere fact that the transmission is currently not in neutral position, ie there is no frictional interruption between transmission and drive, does not affect the permissibility of the sailing operation as a type of deceleration for the first-time single-stage deceleration strategy.

For better driveability, a multi-stage delay strategy can advantageously be determined as a first delay strategy, wherein the strategy is configured in the multi-stage first delay strategy that connect the further delay stages to a first long delay stage with low delay effect, with the intended duration of the delay stage with increasing delay effect of the delay stage Delay stages is further shortened. In a particularly advantageous embodiment, a combination of a long sailing phase followed by a short boost phase and again followed by a very short braking phase can be selected for the first deceleration strategy as a multi-stage deceleration strategy. The number of stages, as well as their lengths can be influenced by various factors such. As the position of the driving experience switch, the current speed, the speed difference between current speed and target speed, the topology and existing targets and, where appropriate, their position dependent.

Advantageously, depending on the first delay strategy via the notification system, the functional unit, at least approximately at the time, initiates the prompt for the first delay strategy to be implemented so that the target speed is reached (approximately) at the location of the preceding event. If, for example, the functional unit determines that the first deceleration strategy would have to be implemented at the latest 500 m before the occurring event due to the speed difference to be overcome and possibly further criteria (such as roadway inclination, wind, loading), the functional unit causes the notification system to transmit Reaching the 500 m distance to the relevant event issues a corresponding prompt to the driver to allow the automatic implementation of the deceleration strategy. The request indication can be output as acoustically, optically and / or haptically perceptible signal. Premature issuance of the prompts would therefore not be advantageous because, with immediate confirmation of the prompts by the driver and immediate implementation of the deceleration strategy (which the operator expects to operate as well), the target speed will be at the location of the event ahead with the least amount of deceleration not reached, but possibly even would fall below.

In order to take into account the problem that the driver does not immediately confirm the request notification and thus does not immediately implement the delay strategy at the time of the prompt message issue, it is ensured that the automatic implementation of the local delay strategy is also ensured later the target speed is reached, preferably continuously, but at the latest from the time from which the driver confirms the prompt, adapts or redetermines the deceleration strategy and then implements it accordingly after allowing the automatic conversion.

Since, after the time at which the prompt is issued, reaching the target speed at the location of the event occurring with the previously determined first delay strategy (with the lowest delay effect) can no longer be achieved, is advantageously at the earliest from the date, from which has been initiated but at the latest from the date on which the Driver has allowed the automatic implementation of the deceleration strategy, the function unit in response to the approved delay stages determine a new deceleration strategy, which can also consist of other or more stages or types of deceleration, the deceleration strategy can be based on the normal deceleration behavior of a driver.

Specifically, the functional unit can thereby determine an adapted one-, two- or three-stage delay strategy, taking into account the permitted types of deceleration and at least as a function of the differential speed between the current speed and target speed and / or depending on the distance to the event ahead, preferably with As delay requirements increase, at least those delay stages are included in the one-, two-, or three-stage delay strategy, which can achieve greater delay. In other words, with only a small delay requirement for the target speed at the location of the occurring event (eg, due to a small difference speed to be overcome and / or an even greater distance to the preceding event), those permitted delay stages preferably flow into the adapted delay strategy, which cause a lower delay, with a high delay requirement preceded (or only) the braking operation is considered as the sole delay stage in the determination of the delay strategy.

In order to be able to map the deceleration behavior of an average, predictive driver as well as possible, the functional unit is advantageously constructed in such a way that, if possible and meaningful, a multi-stage, ie a two-stage or three-stage deceleration strategy is determined in the continuous adaptation of the deceleration strategy a control of the delay by initiating a sail operation and / or an overrun operation is to take place, and only then a control of the deceleration is carried out by a braking operation, so that the target speed is achieved. In other words, a controllable delay stage with a low delay effect is therefore selected as the first delay stage, and a delay stage with a large, advantageously adjustable delay is selected as the last delay stage. Ideally, the adapted delay strategy is determined in such a way that each delay stage is used approximately for an equal distance or the ratio of the delay stages used is approximately identical for all route sections.

As already mentioned, there are basically three relevant delay stages which can be taken into account when determining the deceleration strategy: Sail operation, overrun operation and braking operation. Advantageously, assuming that all delay stages are permitted in principle, all three delay stages can be taken into account in the one-, two-, or three-stage delay strategy, wherein in determining and implementing the delay strategy during overrun operation, regulation of the deceleration is dependent on the deceleration strategy Soll-thrust torque and / or during braking operation, a regulation of the delay can be made to a dependent of the deceleration strategy target braking torque. In other words, in the overrun operation and / or braking operation within the selected deceleration stage, the extent of the deceleration to be effected can be regulated by appropriate setpoint specifications. A corresponding regulation is not possible in sail operation, since no corresponding influence on the drive unit is possible here due to the frictional connection interruption.

The invention will now be explained in more detail with reference to the following embodiment. It shows

1 an exemplary structure of a driver assistance system in a motor vehicle for determining a delay strategy and automatic implementation of the deceleration strategy,

2 a first example of a determined and automatically implemented delay strategy, and

3 a second example of a determined and automatically implemented delay strategy.

In detail shows the 1 as a central element of the driver assistance system, a functional unit FE, which receives input signals e1 of a first detection unit E1, input signals e2 of a second detection unit E2, a speed signal v, a status signal s of a driving experience switch and an approval signal z for allowing automatic conversion of a determined deceleration strategy.

The first detection unit E1 may be, for example, a vehicle-mounted and forward-facing (eg, video) sensor that detects leading speed-limiting events that may require reducing the current speed to a reduced target speed. In the second detection unit E2 it can For example, be an in-vehicle navigation system, which also recognizes depending on the known position of the vehicle and a track section lying ahead, speed-limiting events. Both the first detection unit E1 and the second detection unit E2 are configured in such a way that, on the one hand, they can recognize the location of the preceding, speed-limiting event, and thus also the actual speed limit, and forward it to the functional unit FE.

Furthermore, the functional unit FE receives a signal +/- Δv from a central menu unit ZME arranged in the vehicle, which indicates with which deviation the driver has set up or down to determine the target speed from the actual speed limit. This specification can be changed by the driver at any time.

Finally, the functional unit FE receives further relevant data s, from which it can determine which types of delay are currently permitted in principle. As an example, here the functional unit FE is connected to a so-called driving experience switch FES, by means of which the driver can select an operating mode of the vehicle. If, for example, the driver has selected the sport mode, then in principle no sailing operation is permitted, which is fundamentally to be taken into account by the functional unit FE during the determination of the deceleration strategy.

As soon as the functional unit FE has relevant data e1 and / or e2 about a speed limit event which precedes the event, the functional unit FE can first determine the target speed at the location of the event lying ahead, taking into account the driver specification from the central menu unit ZME, and then depending on of the approved delay stages, plan a first delay strategy, in which case the delay stage which has the least delay effect is used as the sole delay stage in this example. Alternatively, the first deceleration strategy may also be constructed such that for the first deceleration strategy a combination of a long sailing phase followed by a short thrust phase and again followed by a very short braking phase is selected.

On the basis of the determined first delay strategy, the functional unit FE causes by a corresponding signal af to a display operation unit ABE, which includes a hint system HS and a control element BE, the output of a request signal at about the time at which the determined single-stage delay strategy would have to be implemented so that the determined target speed is reached at the location of the preceding event. At the same time, the functional unit FE continuously adapts the deceleration strategy from the moment the prompt is issued, so that the target speed at the location of the preceding event can be achieved even with continuously decreasing distance or changing actual speed v.

As soon as the driver confirms the request signal by actuating the operating element BE, the display operating unit ABE sends back a corresponding "approval" signal z to the functional unit FE. The functional unit FE then begins to initiate the automatic conversion of the (last determined) deceleration strategy by causing corresponding control signals "sailing", "thrust" or "MBr" to the drive unit AE and / or brake unit BrE. During the activation, the deceleration strategy is further adapted to the current situation and implemented accordingly, so that the target speed is reached at the location of the preceding event.

Based on the following two descriptions 2 and 3 Two different examples of different implemented delay strategies will now be presented. Both 2 and 3 show a distance d, where at the location vE applies a speed limit of 50 km / h, which is also assumed below as the target speed. It is further assumed that the vehicle approaching the speed limit moves at a constant speed of 80 km / h. For the sake of completeness, it should be noted that at this point in time, the vehicle is either at an initial speed of 80 km / h due to an active cruise control (eg cruise control) or due to a corresponding "manual"driver's command by operating the accelerator pedal at this speed emotional. Furthermore, in both examples, it is assumed that a sailing operation is generally admissible as a deceleration stage and this sailing operation has the lowest deceleration effect of all permitted deceleration stages. Due to the difference in speed between the current speed and the target speed to be achieved, it follows that the sailing operation would have to be initiated at the location Ah, so that the target speed would only be achieved by the sailing operation and its deceleration effect a1 at location vE (dashed line). On the basis of this knowledge, an appealing request for information to the driver thus becomes available at location Ah If this is confirmed, an automatic conversion of a (last) determined delay strategy is implemented. If a multi-stage delay strategy were to be selected as the first delay strategy, the request for information would only be made at a later point in time.

In the 2 The authorization of the automatic implementation of the deceleration strategy now takes place at location Z1 by means of a corresponding control element actuation. Since a certain amount of time has already elapsed since the issuing of the prompting instruction at the location Ah and the automatic implementation of the deceleration strategy at the location Z1, and thus the distance to the location vE of the speed-limiting event has become smaller, the target speed can no longer be achieved by a sole sailing operation become. The mitterlweile adapted delay strategy is now constructed as a three-stage delay strategy, being first switched to the sailing mode in which the vehicle is delayed with a first delay a1 is changed at the location dü1 from sailing to overrun, in which the vehicle with a second Delay a2 is delayed, and only in place dü2 is changed from the overrun in a braking operation in which the vehicle is decelerated by controlling the delay a3. In order to make the deceleration strategy appear as pleasant as possible to the driver, the three successive deceleration stages are implemented for a respective same distance d.

In the 3 the automatic implementation of the deceleration strategy is only permitted at a later time Z2, so that the distance to the speed-limiting event is only very small. Since a three-stage delay strategy no longer makes sense because of the short distance, a one-step delay strategy adapted in the meantime is implemented here, with the braking mode which can cause the greatest deceleration being selected as the deceleration stage. In this case, the braking torque Mbr effecting a corresponding deceleration a4 is regulated so that the target speed can still be reached at the location vE of the preceding event.

The two examples show that even with initially identical basic requirements, a constant adjustment of the delay stage is required, so that after allowing the automatic implementation of the deceleration strategy, the target speed is reached at the location of the speed-reducing event.

The targeted initial activation of a sailing operation and / or a pushing operation during the automatic deceleration brings a customer-like behavior, whereby the acceptance of such systems can be substantially increased. But this alone can not ensure that the desired speed is achieved at the desired location, since it is a control and can not compensate for external disturbances (eg slopes, wind resistance). The remaining distance in braking operation via a corresponding regulation of the deceleration or the braking torque ensures that the target speed can be achieved at the predetermined location.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been 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.

Cited patent literature

• DE 102012211967 A1 [0004]
• DE 102008018421 A1 [0006]
• DE 102011119007 A1 [0007]

Claims (10)

Driver assistance system in a motor vehicle having a detection system (E1, E2) for detecting preceding events (vE) that require a reduction of the current speed to a reduced target speed, a functional unit (FE) for determining a deceleration strategy for reducing the speed from the current speed (VE) v) to the target speed at the location of the preceding event (vE), wherein the functional unit (FE) first detects a first single or multi-stage delay strategy upon detection of a forward event (vE) requiring a speed reduction, the delay stages of the first delay strategy in response to predetermined parameters (s), and with a notification system (ABE) for issuing a request indication (Ah) to the driver at a defined time prior to reaching the forward events requiring a speed reduction s (vE) for allowing automatic implementation of the deceleration strategy, wherein the functional unit (FE) causes the automatic implementation of the deceleration strategy upon confirmation (z) of the request indication (Ah) by the driver. Driver assistance system according to claim 1, characterized in that as first or sole delay stage of the first delay strategy that delay stage is set, which causes the lowest delay (a1) of the vehicle from all the allowed delay stages, and wherein advantageously in a multi-stage first delay strategy, the strategy is constructed in that the further delay stages are connected to a first long delay stage with a low delay effect (a1), the further duration of the delay stages being further shortened as the delay effect (a2, a3) of the delay stage increases. Driver assistance system according to one of the preceding claims, characterized in that as the first deceleration stage of the first deceleration strategy in approved sailing operation of sailing (sailing), otherwise the thrust operation (thrust) is. Driver assistance system according to one of the preceding claims, characterized in that the functional unit (FE) in response to the first delay strategy at that time via the hint system (HS) the prompt hint (Ah), to which the first delay strategy would have to be implemented, so that on Place of the preceding event (vE) is reached in about the target speed. Driver assistance system according to one of the preceding claims, characterized in that continuously, but in particular at the earliest from the time from which the request instructions (Ah) was initiated or at the latest from the time from which the driver has allowed the automatic implementation of the delay strategy, the functional unit ( FE) determines an adapted one-stage or multi-stage delay strategy as a function of the permitted types of delay. Driver assistance system according to claim 5, characterized in that the functional unit (FE), taking into account the permitted delay stages and as a function of the differential speed between the current speed (v) and target speed and / or depending on the distance to the preceding event (vE) a adapted one, two or three-stage delay strategy determined, which advantageously should first take place a control of the delay, and only then a control of the delay is made so that the target speed is reached. Driver assistance system according to claim 5 or 6, characterized in that the adapted two- or three-stage delay strategy is constructed such that is selected as the first delay stage, a delay stage with a low delay and / or a delay stage with the larger delay is selected as the last delay stage, the at the last delay stage advantageously a delay control is possible. Driver assistance system according to one of claims 5 to 6, characterized in that when determining an adapted two- or three-stage delay strategy, the delay strategy is determined such that each delay stage is used approximately for an equal distance (d). Driver assistance system according to one of claims 5 to 8, characterized in that as a delay stages of the adjusted one, two or three-stage deceleration strategy a sailing (sailing) and / or a pushing operation (thrust) and / or a braking operation (MBr) of the vehicle is set , wherein advantageously in the implementation of the deceleration strategy during the thrust operation (thrust), a regulation of the deceleration to a dependent on the deceleration strategy target thrust torque and / or during braking operation (MBr), a regulation of the deceleration to a dependent of the deceleration strategy target braking torque , Driver assistance system according to one of the preceding claims, characterized characterized in that the functional unit (FE) in the determination of the delay strategy takes into account present and / or future occurring environment information.

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