DE102017205134A1 - Delay assistance system in a motor vehicle and method for controlling a corresponding deceleration assistance system - Google Patents

Abstract

The invention relates to a deceleration assistance system and to a method for controlling a deceleration assistance system in a motor vehicle. The delay system according to the invention comprises the following components:
- an electronically controlled automated transmission,
an electronic control unit for controlling upshifts and downshifts in the transmission,
a detection system for detecting preceding events requiring a reduction in the current speed to a reduced target speed,
a functional unit for determining a deceleration strategy for reducing the speed to the target speed, in particular at the location of the preceding event, and for executing the deceleration strategy even without the operator actuating a control element, the deceleration strategy comprising performing an automatic downshift.

Description

The invention relates to a deceleration assistance system in a motor vehicle for determining and implementing a deceleration strategy, and to a corresponding method for controlling a deceleration assistance system.

In the sense of a delay assistant, so-called foresight assistants are already known which can use navigation data to recognize and point out certain sections of the route which require a reduction in speed, so that the driver can reduce his speed early by means of a suitable operator action.

For example, the DE 10 2014 215 673 A a driver assistance system for determining a delay strategy and for automatically implementing the deceleration strategy, wherein upon detection of a forward event that requires a speed reduction, a single or multi-stage delay strategy is determined and depending on the determined delay strategy at a defined time before reaching the relevant event an indication is issued. If the driver confirms the indication by actuating a corresponding operating element, an automatic implementation of the delay strategy is initiated. Such an implementation of the deceleration is particularly suitable for use in active or switched speed control systems, since in active speed control systems, the driver expects an automatic speed control without an active manual influence on the acceleration or the deceleration.

The basic idea of the object of DE 10 2015 205 371 A1 is to recognize a speed-reducing event and specify a deceleration strategy with a targeted control of a leg in sails and a leg in overrun mode, so that a corresponding speed reduction is achieved comfortably and energy efficient.

The object of the invention is to provide a deceleration assistance system for vehicles, which is further improved in terms of energy efficiency, comfort and component protection.

This object is achieved by a delay assist system according to claim 1 and by a corresponding method according to claim 3. Advantageous developments emerge from the dependent claims.

• - ein elektronisch steuerbares automatisiertes Getriebe,
• - eine elektronische Steuereinheit zur Steuerung von Hoch- und Rückschaltvorgängen im Getriebe,
• - ein Erfassungssystem zum Erkennen vorausliegender Ereignisse, die eine Reduzierung der aktuellen Geschwindigkeit auf eine reduzierte Zielgeschwindigkeit erfordern,
• - eine Funktionseinheit zum Ermitteln einer Verzögerungsstrategie zur Reduzierung der Geschwindigkeit auf die Zielgeschwindigkeit insbesondere am Ort des vorausliegenden Ereignisses und zum Ausführen der Verzögerungsstrategie auch ohne Betätigung eines Bedienelements durch den Fahrer, wobei die Verzögerungsstrategie das Ausführen eines automatischen Rückschaltvorganges umfasst. Eine Rückschaltung bzw. Verzögerung sollte vorzugsweise nur dann gemacht werden, wenn der Fahrer das Fahrpedal nicht mehr betätigt; denn damit kann der Fahrer den Willen „auszurollen“ anzeigen.

The invention relates to a deceleration assistance system and to a method for controlling a deceleration assistance system in a motor vehicle. The delay system according to the invention comprises the following components:

• - an electronically controlled automated transmission,
• an electronic control unit for controlling upshifts and downshifts in the transmission,
• a detection system for detecting preceding events requiring a reduction in the current speed to a reduced target speed,
• a functional unit for determining a deceleration strategy for reducing the speed to the target speed, in particular at the location of the preceding event, and for executing the deceleration strategy even without the operator actuating a control element, the deceleration strategy comprising performing an automatic downshift. A downshift or deceleration should preferably be made only when the driver no longer actuates the accelerator pedal; because with it the driver can show the will to "roll out".

Preferably, the functional unit for executing a deceleration strategy, which comprises not only an automatic downshift but also an additional deceleration contribution, is designed such that the additional deceleration contribution can be made in a motor vehicle with recuperation capability (eg with a generator drive electric motor) and with a braking system is at least partially applied by the brake system, if only the Rekuperationsmöglichkeit was previously used for a predetermined time and / or for a predetermined number of deceleration processes.

The invention is based on the following considerations and findings:

With a focus on the lowest possible wear of the brake components, it makes sense to use the engine braking effect during braking. For vehicles with manual transmissions, this is determined by the driver's shift behavior. In vehicles with automatic transmissions, the engine braking effect should also be used, which is why there are different approaches to detect the driver's braking request and adjust the gear shift behavior accordingly

Disadvantages of the prior art:

• - So far, a manual action of the driver is always provided to notify the vehicle or the transmission control unit the braking request.
• - Uncomfortable for the driver as he always has to apply the brake to a stop.
• - Only low utilization of the engine braking effect in current automatic vehicles.
• - Increased brake wear.
• - Monitoring the vehicle environment is currently not included in the automatic transmission control.
• - Partly unfavorable switching operations, as future actions are not anticipated.

Therefore, the invention proposes to make better use of the engine braking effect of automatic vehicles during the braking process. This should be dependent on external parameters and not exclusively on the action of the driver. For this purpose, suitable sensors, e.g. a camera or intelligent navigation systems, which are already used in principle for known deceleration assistance systems, monitors the vehicle environment. Depending on the equipment of the vehicle, alternative systems for detecting the vehicle environment may also be radar, laser scanner or the iCam system.

In the vehicle environment, different goals are relevant, e.g. red traffic lights or traffic in the immediate vicinity of the vehicle.

In particular, one's own speed situation, the distance to the destination and the speed of the destination are taken into account for monitoring. The information is transferred to a function logic (functional unit) of the control unit, which calculates the optimum delay and the optimal delay time from this. This can be done according to the transmission concept. To detect the driver's request should also preferably be made a coupling to the accelerator pedal position.

Subsequently, the transmission is controlled via the electronic transmission control so that the engine braking effect is used for the braking process. The goal is that the driver does not have to press the brake pedal. For this purpose, a prediction of the vehicle in front can also be used.

An automatic braking to the front vehicle is already used in the context of ACC (Active Cruise Control). Thus, both the technology and the sensors are present in these vehicles. However, this also affects the braking system, which should not necessarily be the case in the solution proposed here according to the invention. Nevertheless, a coupling to the driver assistance system is conceivable.

In electric vehicles, there is a special advantageous application. Here it happens regularly that the brakes rust, as it is hardly braked manually. This can be attributed to the fact that as much energy as possible should be recovered, which is why the existing recuperation system is designed accordingly. This has the consequence that the braking effect of the recuperation system is usually strong enough to reduce the vehicle speed without manual braking is required. Here, the proposed solution could, for example, engage in an advantageous manner in the recuperation system and reduce its braking effect something to prevent rusting of the brakes. Furthermore, the Rekuperationsstärke can be adapted to the braking target to further relieve the driver. Because with electric vehicles, it may even be that they delay too much for the braking target and the driver must therefore remain on the accelerator pedal.

Advantages of the invention:

• - Better utilization of the motor braking effect
• - Less wear of the brakes
• - Less driver action necessary
• - More meaningful, situation-adapted switching operations
• - Prevention of rusting brakes in electric vehicles

The invention will be explained in more detail with reference to an embodiment. For this purpose, an overview of an advantageous for the invention overall arrangement is shown in the drawing.

It shows a device for controlling an automated transmission, such as an automatic transmission 4, for a motor vehicle with a selector 1 in the form of a selector lever, not shown, in at least one lane (first lane) for determining the adjustable in an automatic mode A driving steps P, R. , N, and D is movable. The selection device 1 can also be designed as an electronic transmission switch. In the example shown, to switch to a manual mode M, the selector device 1 can be moved at least into a second lane, in which the gears of the transmission can be stepped up or down manually in stages using a upshift and downshift button. The Invention is preferably applicable in position D of the automatic mode A.

Furthermore, a detection system 2 is provided for detecting preceding events S1, S2 and S3 which require a reduction of the current speed v to a reduced target speed v1, v2 or v3. An event S1 may, for example, be a changeover of an approaching traffic light to red. An event S2 may be, for example, an approaching reduction in the maximum permitted speed. An event S3 may, for example, be an approaching following run behind a preceding vehicle of lower speed v3.

The relevant events lying ahead, which require a reduction of the speed, can for example consist of 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. For example, the preceding events may be 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 (eg in Germany, a speed limit of 50 km applies to a local transit /H). These may also be turn-off situations (eg at intersections or motorway exits), roundabouts or curves. The target speed for the deceleration strategy at the location of the preceding event may be either the speed limit actually imposed or due to the situation, or a speed limit imposed by the given or the situation, up or down by a predetermined amount.

Furthermore, an electronic control unit 3 is provided which receives various input signals, such. As the position of the accelerator pedal FP, the position of the brake pedal BP, the current vehicle speed v, information of the detection system 2 and signals of the selector 1. Depending on these input signals, the control elements of the automatic transmission 4 are controlled for changing and inserting predetermined gears by means of a programmed switching logic , The gear change control basically takes place in a manner known per se by a computer program stored in the control unit 3. Additionally or alternatively, recuperation options could also be used with electric drives.

The motor vehicle equipped with the invention further comprises a per se known electronically controllable brake system 6 and an electric motor which can be operated as a generator as recuperation possibility 5.

• - Erkennen vorausliegender Ereignisse S1, S2 oder S3, die eine Reduzierung der aktuellen Geschwindigkeit v auf eine reduzierte Zielgeschwindigkeit v1, v2 oder v3 erfordern,
• - Ermitteln einer Verzögerungsstrategie zur Reduzierung der Geschwindigkeit v auf die Zielgeschwindigkeit v1, v2 oder v3 und Ausführen der Verzögerungsstrategie auch ohne Betätigung zumindest des Bremspedals BP durch den Fahrer, wobei die Verzögerungsstrategie das Ausführen eines automatischen Rückschaltvorganges durch Ansteuerung des elektronisch steuerbaren automatisierten Getriebes 4 umfasst und
• - im Falle einer Verzögerungsstrategie, die nicht nur einen automatischen Rückschaltvorgang sondern auch einen zusätzlichen Verzögerungsbeitrag da erfordert, Aufbringen des zusätzlichen Verzögerungsbeitrags da zumindest zum Teil durch das Bremssystem 6, wenn zuvor für eine vorgegebene Zeit und/oder für eine vorgegebene Anzahl von Verzögerungsvorgängen ausschließlich die Rekuperationsmöglichkeit 5 eingesetzt wurde.

According to the invention, the following steps are carried out in particular by suitable programming of a functional unit 3.1, which is preferably integrated in the control unit 3:

• Detecting preceding events S1, S2 or S3 which require a reduction of the current speed v to a reduced target speed v1, v2 or v3,
• Determining a deceleration strategy for reducing the speed v to the target speed v1, v2 or v3 and executing the deceleration strategy even without operating at least the brake pedal BP by the driver, the deceleration strategy comprising performing an automatic downshift by driving the electronically controllable automated transmission 4 and
• in the case of a delay strategy which requires not only an automatic downshift but also an additional delay contribution thereto, applying the additional deceleration contribution there at least in part by the brake system 6, if only for a given time and / or for a predetermined number of deceleration processes Rekuperationsmöglichkeit 5 was used.

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 102014215673 A [0003]
• DE 102015205371 A1 [0004]

Claims (5)

Delay assistance system in a motor vehicle with an electronically controllable automated transmission (4), an electronic control unit (3) for controlling upshifts and downshifts in the transmission (4), a detection system (2) for detecting preceding events (S1, S2, S3) which require a reduction of the current speed (v) to a reduced target speed (v1, v2, v3), a functional unit (3.1) for determining a deceleration strategy for reducing the speed (v) to the target speed (v1, v2, v3) and for executing the deceleration strategy even without the operator actuating a control element (BP, FP), the deceleration strategy comprising Performing an automatic downshift includes. Delay assistance system after Claim 1 , characterized in that the functional unit (3.1) for executing a deceleration strategy, which comprises not only an automatic downshifting operation but also an additional deceleration contribution (da), is designed such that the additional deceleration contribution (da) in a motor vehicle with recuperation possibility (5) and with a brake system (6) is applied at least in part by the brake system (6), if only the Rekuperationsmöglichkeit (5) was previously used for a predetermined time and / or for a predetermined number of delay operations. Method for controlling a deceleration assistance system in a motor vehicle with the following steps: Detecting preceding events (S1, S2, S3) which require a reduction of the current speed (v) to a reduced target speed (v1, v2, v3), Determining a deceleration strategy for reducing the speed (v) to the target speed (v1, v2, v3) and executing the deceleration strategy even without operation of an operating element (BP, FP) by the driver, wherein the deceleration strategy to perform an automatic downshift by driving a electronically controllable automated transmission (4). Method according to the preceding claim with the step Execution of a deceleration strategy which comprises not only an automatic downshift but also an additional deceleration contribution (da), the additional deceleration contribution (da) in a motor vehicle with recuperation possibility (5) and with a brake system (6) at least in part by the braking system ( 6) is applied, if only the Rekuperationsmöglichkeit (5) was previously used for a predetermined time and / or for a predetermined number of delay operations. Electronic control unit (3) with a functional unit (3.1) for use in a deceleration assistance system and for carrying out the method by means of the deceleration system according to one of the preceding claims.

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