AERODYNAMIC SYSTEM, AND METHOD FOR CONTROLLING AN ADJUSTABLE AERODYNAMIC ELEMENT

Abstract

An aerodynamic system may have at least one adjustable aerodynamic element on a leading vehicle. The system may include a sensor device, which is located on the trailing vehicle and is configured to detect status information for the leading vehicle. The system also may include an evaluation unit that is configured to determine a target setting for the aerodynamic element on the basis of respective available settings for the aerodynamic element, the obtained status information, and an optimizing variable. A control unit in the system may be configured to adjust the aerodynamic element to the target setting. A method for controlling the adjustable aerodynamic element may also be included.

Claims

1. An aerodynamic system for two vehicles travelling such that a trailing vehicle is trailing a leading vehicle, comprising: at least one adjustable aerodynamic element located on the leading vehicle; a sensor device, located on the trailing vehicle and configured to at least detect status information for the leading vehicle; a evaluation unit, configured to determine a target setting for the aerodynamic element on the basis of the respective available settings for the aerodynamic element, the detected status information, and an optimizing variable; and a control unit, configured to adjust the aerodynamic element to the target setting.

2. The aerodynamic system according to claim 1, wherein the evaluation unit is configured to select the optimizing variable on the basis of an energy storage level in at least one of the two vehicles.

3. The aerodynamic system according to claim 1, wherein the optimizing variable is selected from a list containing fuel consumption for the leading vehicle, fuel consumption for the trailing vehicle, and the combined fuel consumption for both vehicles.

4. The aerodynamic system according to claim 3, wherein if a level in the energy storage level falls below a minimum fuel supply level in one of the two vehicles, the fuel consumption for this vehicle is selected as the optimizing variable.

5. The aerodynamic system according to claim 1, wherein the sensor device is configured to detect at least one of the following values as status information for the leading vehicle: speed, distance to the trailing vehicle, height, width, silhouette, and alignment in relation to a driving lane.

6. The aerodynamic system according to claim 1, wherein the sensor device contains at least one of the following components: an ADAS sensor set, a camera facing forwards, a radar system, an ultrasonic sensor, or a lidar.

7. The aerodynamic system according to claim 1, wherein the evaluation unit is configured to determine the fuel consumption for the leading vehicle and the trailing vehicle resulting from the available settings on the basis of the status information and the respective available settings for the aerodynamic element.

8. The aerodynamic system according to claim 7, wherein the evaluation unit is configured to determine a wind shadow of the leading vehicle on the basis of the status information and the respective available settings for the aerodynamic element, and determine the fuel consumption for the trailing vehicle on the basis of the wind shadow.

9. The aerodynamic system according to claim 1, wherein the evaluation unit is configured to obtain a value for the optimizing variable, and to determine the target setting in an adaptive manner.

10. The aerodynamic system according to claim 1, wherein the aerodynamic element is formed by a rear spoiler, the angle of which can be adjusted.

11. A method for controlling an adjustable aerodynamic element when two vehicles are traveling together such that a trailing vehicle is trialing a leading vehicle, wherein the leading vehicle has the aerodynamic element, the method comprising at least the following steps: obtaining status information for the leading vehicle with a sensor device on the trailing vehicle; determining a target setting for the aerodynamic element on the basis of the respective available settings for the aerodynamic element, the detected status information, and an optimizing variable; and adjusting the aerodynamic element to the target setting.

12. The method according to claim 11, wherein the status information is sent to an evaluation unit, which determines the target setting for the aerodynamic element on the basis of the available settings and the optimizing variable.

13. The method according to claim 11, wherein the available settings for the aerodynamic element are sent to an evaluation unit, which determines the target value for the aerodynamic element on the basis of the available settings and the optimizing variable.

14. The method according to claim 11, wherein the optimizing variable is selected from a list, which contains the fuel consumption of the leading vehicle, fuel consumption of the trailing vehicle, and the combined fuel consumption for the two vehicles.

15. The method according to claim 14, wherein the optimizing variable is selected on the basis of an energy storage level in at least one of the two vehicles.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] FIG. 1 shows a schematic illustration of an aerodynamic system.

[0030] FIG. 2 shows a schematic illustration indicating the status information that can be obtained with the sensor device in the aerodynamic system shown in FIG. 1.

[0031] FIG. 3 shows a schematic illustration of a method for controlling an adjustable aerodynamic element in the aerodynamic system shown in FIG. 1.

DETAILED DESCRIPTION OF THE DRAWINGS

[0032] FIG. 1 shows a schematic illustration of an aerodynamic system. The illustration shows a leading vehicle 10 and a trailing vehicle 12, both of which are trucks. Both vehicles 10, 12 are traveling forwards. A wind shadow 16 is created by an airflow caused by the leading vehicle 10, indicated by the broken line 14, and a slipstream. The wind shadow 16 is an area with lower wind speed.

[0033] The two vehicles 10, 12 are traveling at a distance to one another the upper third of FIG. 1, in which the trailing vehicle 12 is outside the wind shadow 16. The front end of the trailing vehicle 12 is driving into the airflow, and thus subjected to a stronger air resistance. This results in a higher fuel consumption for the trailing vehicle 12.

[0034] The middle part of FIG. 1 shows the two vehicles 10, 12 traveling at a distance to one another in which the front end of the trailing vehicle 12 is largely within the wind shadow 16. As the broken line 14 illustrating the airflow indicates, the airflow is substantially above the trailing vehicle 12, and no longer impacts the front end for the most part. This results in a lower air resistance for the trailing vehicle 12, such that its fuel consumption is reduced.

[0035] This spacing between the vehicles 10, 12 can be obtained by “platooning,” also referred to as an “electronic drawbar.” The two vehicles 10, 12 are operated at least semiautonomously in this case. If the leading vehicle 12 has to slow down slightly, however, the trailing vehicle 12 needs to make larger speed adjustments due to the short distance between the two vehicles 10, 12, e.g. by braking strongly. This satisfies requirements regarding traffic safety, although platooning is still more risky.

[0036] It is therefore desirable to be able to obtain the aerodynamic advantages obtained with the spacing shown in the middle, but with a greater distance between the two vehicles 10, 12. The leading vehicle 10 therefore has an adjustable aerodynamic element 18 on top of its trailer for this. The aerodynamic element 18 forms a rear spoiler. When the aerodynamic element 18 is raised, it lifts the airflow at the rear of the leading vehicle 10, as indicated by the broken line 14 in the lower third of FIG. 1. In this embodiment, the aerodynamic element 18 is attached to the trailer with a hinge. In another embodiment, the aerodynamic element 18 can slide up and down.

[0037] It can be seen in the lower third of FIG. 3 that the airflow now lies largely above the trailing vehicle 12. This results in better airflow conditions than in the state shown in the middle of FIG. 1, in which the aerodynamic element 18 is retracted, and lies flat against the leading vehicle 10. Nearly all of the front end of the trailing vehicle 12 is now in the enlarged wind shadow 16 obtained with the aerodynamic element 16. The fuel consumption of the trailing vehicle 12 is substantially reduced in this manner. The savings in terms of fuel consumption are greater than the increase in fuel consumption caused by the deployment of the aerodynamic element 18 and the resulting air resistance for the leading vehicle 10, thus resulting in a greater overall efficiency for the two vehicles obtained with this form of platooning. The silhouette of the trailing vehicle 12 does not need to be altered to obtain these advantages. The increase in efficiency can be obtained by trailing at a defined distance, controlled in this case by the autonomous driving system in the trailing vehicle 12.

[0038] The aerodynamic element 18 is set with respect to the external dimensions of the two vehicles 10, 12. By way of example, if the trailing vehicle 12 is smaller than the leading vehicle 10, the aerodynamic element 18 does not have to be raised as far to obtain a beneficial airflow, so that the air resistance for the leading vehicle 10 does not need to be enlarged unnecessarily. If the trailing vehicle 12 is larger than the leading vehicle 10, the aerodynamic element is raised higher, in order to obtain a larger increase in efficiency. The distance between the two vehicles 10, 12 can also be taken into account. By way of example, the aerodynamic element 18 is first raised when the distance between the two vehicles 10, 12 falls below a minimum spacing, because the increase in efficiency an only be obtained if the vehicles are close enough together.

[0039] The efficiency can be further increased by this means. The trailing vehicle 12 has a sensor device 20 for this. The detection region of the sensor device 20 is pointing forwards. The sensor device 20 makes use of the same sensors that are also used for generating the data necessary for the autonomous driving system in the trailing vehicle 12.

[0040] FIG. 2 shows a schematic illustration indicating the status information that can be obtained with the sensor device 20. The sensor device measures the height 22 and width of the leading vehicle 10. In one embodiment, the overall shape or silhouette thereof is detected. The distance between the two vehicles 10, 12 is also detected, as well as their positions on the road. These values form the status information, although other embodiments may contain more or fewer values.

[0041] This status information is sent to an evaluation unit 24. In the present case, the evaluation unit 24 is in the leading vehicle 10. The data transfer is made with a radio signal connection for this reason, using a signal transmission system, which is not indicated in the drawing. In another embodiment, the evaluation unit is in the trailing vehicle 12, in which case the data transfer can take place with a hard-wired connection, and the signal transmission system simply sends a target setting to the leading vehicle 10, or its control unit 26. In yet another embodiment, the evaluation unit is in the form of a central server, to which the status information is sent via a cellular telephone network, for example.

[0042] Available settings for the aerodynamic element 18 are stored in the evaluation unit 24, or are sent thereto. The respective data for the trailing vehicle 12, such as its height, width and shape, are also stored in the evaluation unit 24, or sent thereto. The data can also contain information from the autonomous driving system, such as the next driving maneuver, a traffic strategy, and information regarding other road users. A target stetting for the aerodynamic element 18 is then determined by the evaluation unit 24 on the basis of this data, the detected status information, and the available settings for the aerodynamic element 18, as well as an optimizing variable. The optimizing variable is selected in this case on the basis of the fuel consumption of the trailing vehicle 12, the fuel consumption of the leading vehicle 10, or a combined fuel consumption of the two vehicles 10, 12. One of these fuel consumption values can then be optimized by an optimized setting of the angle of the aerodynamic element 18 for a specific situation. This is accomplished with the control unit 26, which is configured to adjust the aerodynamic element 18 to the target setting.

[0043] Certain driving situations can also be taken into account by the aerodynamic system when setting the aerodynamic element 18. If the leading vehicle is tilting from side to side, or hydroplaning, the aerodynamic element 18 is not raised. Otherwise, the leading vehicle 10 would be slowed down by the increased air resistance. The trailing vehicle 12 would then have to slow down in order to maintain its distance and reduced air resistance obtained with the improved airflow.

[0044] The method for controlling the adjustable aerodynamic element 18 when two vehicles 10, 12 are travelling together, with one trailing the other. The respective status information for the leading vehicle 10 is obtained by a sensor device 20 on the trailing vehicle 12 in the first step 30. The optimizing variable is selected on the basis of an energy storage level in the two vehicles 10, 12 in the second step 32. This selection can also be made by the evaluation unit 24. If the energy storage level in the trailing vehicle 12 lies below a threshold value, and that in the leading vehicle 12 is above a threshold level, the fuel consumption of the trailing vehicle 12 is selected as the optimizing variable. As a result, it is possible to still reach a target destination with limited energy reserves, e.g. in the form of fuel or electricity, through fuel consumption optimization. If the energy storage levels in both vehicles 10, 12 are above a threshold value, the combined fuel consumption of both vehicles 10, 12 is selected as the optimizing variable. The makes it possible to travel particularly efficiently, as long as both energy storage levels are sufficient for reaching a desired target destination. The target setting of the aerodynamic element 18 is determined in the third step 34 on the basis of the respective available settings for the aerodynamic element 18, the detected status information, and the selected optimizing variable. The aerodynamic element 18 is adjusted to the target setting in the fourth step 36.

REFERENCE SYMBOLS

[0045] 10 leading vehicle [0046] 12 trailing vehicle [0047] 14 line/airflow [0048] 16 wind shadow [0049] 18 aerodynamic element [0050] 20 sensor device [0051] 22 height [0052] 24 evaluation unit [0053] 26 control unit [0054] 28 width [0055] 30 step [0056] 32 step [0057] 34 step [0058] 36 step