WO2017016716A1

WO2017016716A1 - Driver assistance system for adapting the braking power of an electric recuperation brake of a motor vehicle

Info

Publication number: WO2017016716A1
Application number: PCT/EP2016/062540
Authority: WO
Inventors: Tobias Huber
Original assignee: Continental Automotive Gmbh
Priority date: 2015-07-30
Filing date: 2016-06-02
Publication date: 2017-02-02
Also published as: DE102015214538A1

Abstract

The invention relates to a driver assistance system for adapting an electric recuperation behaviour of a vehicle to a prospective route of the vehicle. Said driver assistance system comprises a prediction module, a control unit and an electric recuperation brake. Said prediction module is designed to calculate the prospective route of the vehicle and the control unit is designed to adapt the braking power of the electric recuperation brake to the expected route.

Description

description

Driver assistance system for adjusting the braking force of an electric recuperation brake of a vehicle

The invention relates to a driver assistance system for adapting an electrical recuperation brake of a vehicle to an anticipated trajectory of the vehicle, a vehicle having such a driver assistance system, a method for adjusting an electrical recuperation brake, a program element and a computer-readable medium.

Hybrid vehicles and also purely electric vehicles can be equipped with a generator function of the electric drive. An electric motor is used for energy recovery. In this way, it is possible that the friction brake is relieved during braking or not used at all. The electrical energy thus obtained can be stored, for example, in batteries or a capacitor, or can be directly available to other consumers in the vehicle.

It can be considered an object of the invention to reduce the power consumption of a vehicle.

This object is achieved by the subject matter of the independent claims to ^¬. Further developments of the invention will become apparent from the dependent claims and from the following description.

According to one aspect of the invention, a driver assistance system for adapting an electrical recuperation brake of a vehicle to an anticipated trajectory of the vehicle is specified. The driver assistance system has a prediction module and a control unit. The prediction module is designed to calculate the expected trajectory of the vehicle. In addition, the control unit is designed to adapt the braking force of an electric recuperation brake of the vehicle to the expected trajectory.

The vehicle is, for example, be a force ^¬ vehicle, such as car, bus or truck, or even a rail vehicle or a bicycle. In particular, the driver assistance system is suitable for passenger cars with hybrid drive or exclusively electric drive.

The estimated trajectory calculated by the system includes the vehicle's path and time information. Therefore, each place (future) is uniquely assigned a place. To this extent, the trajectory includes the information of the VELOCITY ^¬ ness of the vehicle at any time and at any place of the ektorie Traj. The expected trajectory is calculated by the prediction module is, for example, characterized by restrictions in the Be ^¬ calculation methods. Thus, a measure of the smoothness of the trajectory may be limited by an upper limit. This applies in particular to the partial derivation of the locus by location, if curvatures of curvature are to be restricted to a certain extent; The derivation of the locus curve over time can also be taken into account in the calculation of the probable trajectory, especially if the lateral acceleration of the vehicle is taken into account when the expected speed of the vehicle at the respective location of the trajectory is known or estimated. The expected trajectories may be derived, for example, from polynomials of at least third degree (cubic) obtained by interpolation or from ornamental curves, in particular from point clouds of geodesic coordinates. ^

dinaten, be calculated. A smoothing by, for example, by z-transformation discretized dynamic Übertra ^¬ tion functions is conceivable. Other sources of information may also be used, which will be discussed in more detail below.

The electrical recuperation is, for example, alternate ^¬ representative of an electric brake in the strict sense, or even in the generator mode of a vehicle with electric drive. The latter can refer both to a hybrid vehicle, which uses a combination of an internal combustion engine and an electric drive, or even to a purely electrically driven vehicle. In other words, the recuperation electric brake may be an electric motor configured to be operable in a generator mode so that kinetic energy of the vehicle may be converted into electric current at a negative acceleration with a decelerating effect. In this case, the electric current can be used to apply voltage to a capacitor and to store charge on the capacitor components. Also, a battery can be powered with this power.

It may be that the electric recuperation brake

can be parameterized and thus the braking force on the vehicle is adjustable. "Adjust" can mean in this context that the control unit determines what braking force ^¬ running exercises the electrical recuperation over time. In other words, the timing of the Be ^¬ acceleration can be adjusted. "Adjust" can also mean that different variables be weighted differently. In particular, the accelerator pedal position (or that of another input device, for example a sidestick) and the time derivative of the accelerator pedal position can be weighted differently. Also different settings, like "Sport mode", can be used, for example, to ensure a comfortable cornering speed. Tells the calculation of the estimated trajectory cornering in Example ^¬, 200 m with a 90 ° turn with a curvature radius of 20 m ahead, it might, for example, in non-operation of the accelerator pedal by the vehicle driver, the control unit a constant negative acceleration of the vehicle to achieve the commanded speed difference to the electric recuperation brake. A progressively increasing commanded amount of acceleration is also conceivable, which allows a shorter travel time than with constant decelerating acceleration. The temporal course of the adaptation can be determined, for example, by optimization algorithms, numerical averaging or extrapolations.

For this, the prediction module comprises a position determination ^¬ unit, or communicates with an external position determination ^¬ unit in conjunction to determine the current position of the vehicle. This can be, for example, the existing navigation device of the vehicle. It should continue to hinge ^¬ reported that the positioning of the vehicle can also be made via a cell positioning. This is particularly useful when using GSM or UMTS networks. It may be an advantageous effect of the invention that the fuel consumption of a hybrid vehicle can be reduced, or the range of a purely electric vehicle can be increased by more energy can be recovered by optimized electrical recuperation.

According to one embodiment of the invention, the prediction module is executed, the estimated trajectory of the vehicle from the path planned by the navigation device Vehicle and other parameters, in particular to determine the current vehicle speed.

In this embodiment, the route calculated by the navigation device is used to determine the prospective trajectory of the vehicle. For example, the navigation device is satellite-based (for example, by global satellite navigation systems, GPS) and supported by inertial sensors. It should be noted that in the context of the present invention GPS stands for all navigation satellite systems, such as e.g. NAVSTAR, Galileo, GLONASS (Russia), Compass (China), IRNSS (India).

According to another embodiment of the invention, the prediction module is adapted to predict future turning of the vehicle and the control unit is adapted to adjust the expected trajectory of the vehicle accordingly.

If a turn of the vehicle is predicted, for example, the braking force of the electric recuperation brake can be set accordingly. Thus, in directly be ^¬ projecting and sharp turns a higher braking force can be set as in soft curves that are passable at high speed Ge ^¬ .

According to another embodiment of the invention, the control unit is adapted to adjust the braking force of the electric recuperation brake depending on whether the prospective trajectory of the vehicle has a right or left turn.

If, for example, a left turn is expected, then the vehicle could slow down more, as through oncoming traffic a further reduction in speed may be necessary. Right- Turns often allow for a higher turn-off speed, especially when driving on federal roads or highways that have a delay line. According to a further embodiment of the invention, the driver assistance system has a feedback device, which is designed to transmit information to an operator to adjust the electric recuperation brake. It may be useful to alert the vehicle operator to the adapted braking action of the electric recuperation brake so that it can adapt to it. For example, it may be indicated to the driver that in an upcoming turn the vehicle will assume a certain and comfortable speed for the driver, which will also be achieved without his intervention, in particular without the driver applying the (friction) brakes. The driver can be informed of this information, for example via an acoustic signal, a visual signal, a haptic signal or combinations of these signals. For example, the accelerator pedal itself has a haptic output module that tells the vehicle driver by vibration that there is no need to operate the accelerator pedal with the actual starting of the calculated trajectory. In this case, the driver can take the foot off the accelerator and let the vehicle itself an op ^¬ timiertes braking with the respectively adapted energy ^¬ recovery. The driver can continue to be rewarded by positive signals perceived by humans, thus reducing the energy consumption of the vehicle.

According to another embodiment of the invention, the prediction module is further configured to detect pedestrians, traffic lights or other vehicles and is the control unit designed to adjust the probable trajectory of the vehicle accordingly.

Accordingly, pedestrians, traffic lights or other vehicles are detected by corresponding sensors on the vehicle. This can be done in particular by cameras, stereo cameras, laser sensors, Ult ^¬ raschallsensoren or other sensors and corresponding algorithms, such as image processing algorithms. Be detected pedestrian on a pedestrian crossing, the prediction module may set the way to the pedestrian crossing with the current position and speed of the vehicle in United ^¬ bond and determine an optimum braking force for the electric recuperation. Subsequently, the control unit ^¬ command a corresponding braking force to the electric recuperation brake. It should be noted that the term "adjustment of the trajectory of the vehicle" also includes a pure speed change, without affecting the locus of the vehicle.

According to a further embodiment of the invention, the control unit is designed to increase the braking force of the electric recuperation brake upon detection of a measure justifying the situation, caused, for example, by pedestrians, traffic lights, sharp bends or by other vehicles. According to a further embodiment of the invention, the control unit is designed to adapt the braking force of the electrical recuperation brake in consideration of topology data stored in a digital map. According to this embodiment, a digital map may be consulted as another source of information to optimize the trajectory of the vehicle. The "topology data" can eg height profiles of the road, curves in the road, bottlenecks, construction sites, other danger spots such as narrow Bridges, potholes, deciduous forests, entry lanes, wind-prone areas, and the like. Especially in digital maps has seen places that give reduced Ge ^¬ speed event, the expected trajectory can therefore be included in the calculation.

According to a further aspect of the invention, a vehicle with an electric regenerative braking and a Fahreras ^¬ sistenzsystem as indicated above and described below.

According to a further aspect of the invention, a method for adjusting the braking force of an electric recuperation brake of a vehicle is provided, in which first the probable trajectory of the vehicle is calculated by the prediction module and then the braking force of the electric recuperation brake of the vehicle is adapted to the expected trajectory.

In accordance with another aspect of the invention, there is provided a program element that, when executed on a driver assistance system processor, directs the processor to perform the steps described above and below.

According to a further aspect of the invention, a computer- readable medium is provided, on which a program element is ge ^¬ stores which, when executed on a processor of a Fah ^¬ rerassistenzsystems, instructs the processor to perform the steps described above and below. In the following, the invention will be described with reference to the figures execution ^¬ examples.

Fig. 1 shows a vehicle with a driver assistance system for adjusting the braking force of an electric Recuperation of the vehicle according to an exporting ^¬ approximately example of the invention.

Fig. 2 shows a vehicle in a turning situation according to an embodiment of the invention.

Fig. 3 shows a vehicle at an intersection according to another embodiment of the invention.

4 shows a schematic representation of a method according to a further exemplary embodiment of the invention.

The representation in the figures is schematic and not to scale. If the same reference numerals are used in the various figures, these designate the same or similar elements.

1 shows a vehicle 1 with a driver assistance system 100 having a prediction module 20 and a control unit 30. The vehicle has an electrical recuperation brake 40 and a navigation device 50.

2 shows the vehicle 1 of FIG. 1 at a fork 110. With the aid of the navigation device, which outputs the current position of the vehicle 1, the prediction module determines the vo ^¬ prospective trajectory 300, the vehicle 1 is driven. The navigation device supplies the current position of the vehicle 1 and possibly the speed of the vehicle 1. This position can then be used in a digital map, so that the prediction module 20 receives information about the road. Also, the planned route, as it determines the navigation device is, Hérange ^¬ subjected in this example, to determine the expected trajectory of the vehicle 300. 1 The expected trajectory 300 in this case is a turn to the right into an exit without delay. streaks. The vehicle 1 is provided the pre ^¬ clear trajectory is traveled 300 taking a slower speed to take one for the driver of the vehicle 1 is still comfortable lateral acceleration. The driver is accordingly recorded by a notification unit 60, a signal that the vehicle 1 is about to take a slower speed. In this case, the drive switches to its generator mode, which delays the vehicle 1 with optimized braking force.

FIG. 3 shows the vehicle 1 in front of an intersection 110 with another vehicle 140, a traffic light system 130 and a pedestrian 120. With the aid of the navigation device that outputs the current position of the vehicle 1, the prediction module determines the prospective trajectory 300 similarly to the previous example that the vehicle 1 is being driven on. Further, the prediction module of the vehicle 1 detects the intersection 110, the turning ^¬ gespuren the junction 110 and the traffic situation at the intersection 110. More specifically, another vehicle 140, the AM pelanlage 130 and the pedestrian 120 are part of this Ver ^¬ traffic situation. Thus, detailed information about the traffic situation is available to the prediction module 20. It is also conceivable that the traffic light 130 communicates with the vehicle 1 and notifies the prediction module of an impending red phase. The wireless transmission or the wireless reception of the data can be done via Bluetooth, WLAN (eg WLAN 802.1 la / b / g / n or WLAN 802.11p), ZigBee or WiMax or even cellular radio systems such as GPRS, UMTS or LTE , It is also possible to use other transmission protocols. The protocols mentioned offer the advantage of standardization that has already taken place. A C2X communication may also be provided in order to provide the prediction module with at least part of the information needed to calculate the prospective trajectory. A C2X communication includes a communication cation between a vehicle 1 and another device that is not a vehicle, such as a traffic light 130. Accordingly, the prediction module could determine whether the intersection 110 in the existing green phase with the mo ^¬ mentaneous speed of the vehicle 1 and the maximum speed allowed can be crossed, or whether the vehicle 1 will be brought to a halt in the red phase. If the forecast ^¬ say module determine that the vehicle will stop 1, the electrical recovery brake could be controlled such that the vehicle 1 with optimum efficiency of the

Recuperation brake is slowed down to the traffic light 130.

4 shows a method for adjusting an electrical recuperation brake. In a first step, a determination Sl of a position of the vehicle 1 takes place. This can be carried out, for example, by means of satellite navigation. In a second step, the determining S2 of the current speed of the vehicle takes place. The speed can be from the vehicle's tachometer or via satellite navigation. In a further step, the detection S3 of the environment is carried out, whereupon the calculation S4 of the prospective trajectory 300 of the vehicle 1 and the adaptation S5 of the braking force of the electric recuperation brake to the prospective trajectory 300 follows.

In other words, an optimized adaptation of a

Rekuperationsleistung or a Rekuperationsfunktion done in a vehicle, if it is detected that at a junction a turn lane is driven on or a turn exists. There are different "use cases", depending on whether there is a right or left turn, or a different weighting of the input signals and their derivatives must be provided in. Basically, the electric motor of the vehicle is adapted so that a certain Rekuperationsleistung is achieved, in turn, the vehicle slows down so that it bends with an ideal (comfort) speed at the intersection ^¬ . The friction brake should be used as little as possible - ideally the friction brake is not used at all.

This functionality can be made possible due to different environmental ^¬ information. Key information comes from offboard / onboard sensors and connectivity services, which are then merged and rated.

The following steps may therefore be necessary for the overall function:

Recognition of lanes / turning teams / turn-off conditions based on evaluation of various sensors (especially traffic light recognition, distance measurement to other traffic and navigation data),

- recognition of the curve radius based on "eHorizon" data (topology data from navigation device or cloud server) or recorded radius data,

- detection of pedestrian lights / pedestrians / cyclists / oncoming traffic by turn-assistants;

Thus, the recuperation performance in the vehicle, for example, adapted to full power when braking due to pedestrians or oncoming traffic is detected, or if a very tight curve ahead.

Different sensors are used and different information is used to analyze the situation and to predict that there is one

Turning situation exists:

- Influence of curves on the velocity profile:

Basically, the driver reduces his speed to a certain level to get into a corner with some To change direction. For the system curves and turning maneuvers are predictive analyzed for their change of direction and be at a maximum speed ^¬ upgraded. The greater the turn, the more intense the impact on the braking maneuver.

Analysis of the crossing topology:

For each intersection, the topology is determined using the "Most Likely Path" and all alternative paths supplied by the navigation system / "cloud service" and assigned to one of several classes. For each intersection, the following attributes can also be identified as the main attributes in the current "eHorizon": the road classes of the "Most Likely Path" before and after the intersection, the road classes of all alternative paths and the turn-off angle of the "Most Likely Path".

Navigation input:

A route input may help to detect turn situations, especially if the driver has actively entered a destination - but in principle, he is expected to reach the destination and follow the route.

Camera systems, radar or lidar systems:

These recognize the environment, especially the traffic and traffic light signs and circuits. In addition, it can be recognized on which lane the vehicle is standing or turning. It is possible to determine the relationships between topology data, GPS data and camera data. You can also determine if you are on a left or right turn lane. These situations are evaluated differently, since for the left turning process the oncoming traffic must be taken into account via different sensors. The system can also accommodate pedestrians, Recognize cyclists or similar road users who might have an impact during the turn. The turn-off can bend to the right in particular a foot ^¬ predecessor on reasonably straight on to capture on the einzubiegende street from the walkway to the right of the vehicle and its imaginary extension over the crossing the area at a forthcoming waste.

Data analysis, evaluation of recuperation data:

All data are fused in a control unit provided in such a way that o a turn-off probability is calculated for the respective turn-off situation,

o an optimal speed trajectory is calculated for the turn. The Be ^¬ bill can be divided into different small sections containing an optimal Geschwin ^¬ speed of the vehicle as a main component, or

o an optimal Rekuperationsleistung the vehicle is set to guide the vehicle at the time in the desired direction.

"Human Machine Interface" - information transfer to humans:

Basically, the driver can be informed early on a display about the reaction due to various signals that he should no longer press the accelerator pedal, as there is a curvy turn. This can be done via an active accelerator pedal, which has the ability to provide haptic impulses. For example, it is determined in an experiment that every second intersection is used in a city driving for bending by ^¬ average. The typical journey time between two intersections is 40 to 80 seconds. Accordingly, there is a high potential in such a journey in order to drive a vehicle in an energy-efficient manner in a city center.

The invention may also be used in connection with automated driving or automated starting.

_{Λ rΛ r}

16

Reference sign list

100 driver assistance system

1 vehicle

20 predictive module

30 control unit

40 electrical recuperation brake

50 navigation device

60 return device

110 intersection

120 pedestrians

130 traffic lights

140 Other vehicle

300 Expected Trajectory

Determine

S2 Determine

S3 capture

S4 Calculate

S5 Customize

Claims

claims

A driver assistance system (100) for adjusting the braking force of an electrical recuperation brake (40) of a vehicle (1) to an anticipated trajectory (300) of the vehicle (1), comprising:

a prediction module (20), and

a control unit (30),

wherein the prediction module (20) is adapted to calculate the expected trajectory (300) of the vehicle (1), and

wherein the control unit (30) is designed to adjust the braking force of the electrical recovery brake (40) to the advance ^¬ time trajectory (300).

2. driver assistance system (100) according to claim 1,

wherein the prediction module (20) is further configured to determine the prospective trajectory (300) of the vehicle (1) from the planned path of a navigation device (50) of the vehicle (1).

3. Driver assistance system (100) according to one of the preceding claims,

wherein the prediction module (20) is further carried out, a future turning of the vehicle (1) to predict and control unit (30) is executed, the estimated time Tra ^¬ jektorie (300) of the vehicle (1) adapted accordingly.

4. driver assistance system (100) according to claim 3,

wherein the control unit (30) is further executed, the

Adjust the braking force of the electrical recovery brake (40) in Ab ^¬ dependence of whether the anticipated trajectory (300) of the vehicle (1) has a right or left turn.

5. Driver assistance system (100) according to one of the preceding claims, further comprising:

a feedback device (60) configured to communicate to a vehicle operator information for adjusting the recuperation electric brake (40).

6. driver assistance system (100) according to any one of the preceding claims,

wherein the prediction module (20) is further carried out, pedestrian (120), lights (130) to detect or other vehicles (140) and the control unit (30) is executed, the estimated trajectory (300) of the vehicle (1) ent ^¬ speaking adapt.

7. driver assistance system (100) according to claim 6,

wherein the control unit (30) is further configured, upon detection of pedestrians (120), traffic lights (130), sharp curves or other vehicles (140), to increase the braking force of the electric recuperation brake (40).

8. driver assistance system (100) according to any one of the preceding claims,

wherein the control unit (30) is further adapted to adjust the braking force of the electrical Rekuperationsbremse (40) taking into account topology data stored in a digital map.

9. vehicle (1) with an electric recuperation brake (40) and a driver assistance system (100) according to one of the preceding claims.

10. A method for adjusting the braking force of an electric recuperation brake (40), comprising the steps of: Calculating (S4) the prospective trajectory (300) of the vehicle (1), and

Adjusting (S5) the braking force of the electric

Rekuperationsbremse (40) to the prospective trajectory (300).

11. A program element which, when run on a processor (a driver assistance system) is carried out, directs the processor to ^¬ perform the following steps:

Calculating (S4) the prospective trajectory of the vehicle (1), and

Adjusting (S5) the braking force of the electric

Rekuperationsbremse (40) to the prospective trajectory (300).

12. The computer-readable medium on which a program element is ge ^¬ stores, which, when executed on a processor (a Fah ^¬ rerassistenzsystems), instructs the processor to perform the steps of:

Calculating (S4) the prospective trajectory of the vehicle (1), and

Adjusting (S5) the braking force of the electric

Rekuperationsbremse (40) to the prospective trajectory (300).