CN113147607A

CN113147607A - Sensor device for a motor vehicle

Info

Publication number: CN113147607A
Application number: CN202110069605.6A
Authority: CN
Inventors: 塞巴斯蒂安·斯塔夫; 托比亚斯·里奇; 布鲁诺·阿尔维斯
Original assignee: Ford Global Technologies LLC
Current assignee: Ford Global Technologies LLC
Priority date: 2020-01-23
Filing date: 2021-01-19
Publication date: 2021-07-23
Also published as: DE102020101511A1

Abstract

The invention relates to a sensor device (1) for a motor vehicle (10), wherein the sensor device (1) has a sensor unit (2), wherein the sensor unit (2) protrudes outwards relative to an adjacent outer surface (12) of the motor vehicle (10) at least in a sensor-optimized position. In order to improve the aerodynamics of a motor vehicle with external sensors, according to the invention the sensor device (1) can be adjusted into an air-flow optimized position in which both the air resistance caused by the sensor device (1) and the acquisition range of the sensor unit (2) are reduced compared to the sensor optimized position.

Description

Sensor device for a motor vehicle

Technical Field

The invention relates to a sensor device for a motor vehicle.

Background

In motor vehicles, in particular in autonomous motor vehicles, it is essential for an accurate and reliable control that sufficiently up-to-date data about the surroundings of the motor vehicle are provided. The respective data can be collected by different sensors, including passive sensors (e.g. cameras for visible or infrared light) and also active sensors (e.g. ultrasonic, radar or lidar sensors). Some sensors may be arranged inside the vehicle cab, for example behind the windscreen, or may be integrated outside the vehicle (for example inside the radiator grille or behind it) in such a way that they are hardly visible from the outside. However, other sensors require, at least for optimal function, a measurement position that is clearly prominent with respect to the ideal shape of the panel, which is determined according to design and aerodynamics. This may also be due in part to the structure of the sensor being too large to be integrated into the panel in the area provided. Therefore, there is a conflict between the optimal efficiency of the sensor and the optimal aerodynamics of the positioning relative to the sensor.

US 4375898A discloses a wind guide assembly for reducing aerodynamic drag in a tractor-trailer. The assembly has a deflector plate which is substantially rectangular in plan view and is designed to be pivotably arranged on the roof of the tractor. The panel has a reinforcing element having a plurality of intersecting, diagonally extending segments. An adjustable strut connects the deflector plate to the roof. By adjusting the strut, the deflector plate can be adjusted between a retracted position and at least one extended position.

US 2009/0248242 a1 discloses a method for changing the aerodynamic resistance of a motor vehicle having at least one adjustable air deflection element. In this case, an air resistance sensor is provided on the outer surface of the motor vehicle, the air resistance is measured, and it is compared with a predetermined value. The air deflection elements are arranged differently depending on the result to achieve an advantageous air resistance. For example, one or more air deflecting elements may be disposed on a tractor of a tractor-trailer and alternately adjusted to minimize intermediate space relative to the trailer.

In view of the cited prior art, the aerodynamics of motor vehicles with external sensors still have room for improvement.

Disclosure of Invention

It is an object of the invention to improve the aerodynamics of a motor vehicle with external sensors.

According to the invention, this object is achieved by a sensor device having the features of claim 1, wherein the dependent claims relate to advantageous designs of the invention.

It is to be noted that the features and measures which are set forth separately in the following description may be combined with one another in any technically reasonable manner and may disclose further designs of the invention. The present invention is additionally characterized and described in the specification with particular reference to the accompanying drawings.

The invention provides a sensor device for a motor vehicle. The motor vehicle may be a passenger car, a minivan, a bus, or also a truck. In particular, it may be an autonomous motor vehicle, i.e. a motor vehicle which may at least optionally be controlled/driven by itself without driver intervention.

The sensor device has a sensor unit which projects outwards relative to the adjacent outer surface of the motor vehicle at least in a sensor-optimized position. As will become clear hereinafter, the sensor device may have other components, in contrast to the sensor unit, which do not have a sensing function, but whose presence and function are related to the sensor unit. The sensor unit in turn has one or more sensors, wherein these sensors can be active sensors and/or passive sensors. In addition to the actual sensor(s), the sensor unit can have, in particular, a housing which protects the sensor from weather and mechanical influences and in some cases also ensures an aesthetic appearance. For example, the housing may be made in the same color as the body of the motor vehicle, so that it is better visually integrated. The sensor unit protrudes outwardly with respect to an adjacent outer surface of the motor vehicle. The outer surface is adjacent to the sensor unit and may particularly enclose it. It is usually formed by the body of a motor vehicle. At least in the sensor-optimized position, the sensor unit projects or extends outwardly with respect to the adjacent outer surface (i.e. with respect to the exterior of the motor vehicle). For example, if the outer surface extends horizontally, the sensor unit protrudes in a vertical direction (generally upward) with respect to the outer surface. It may also be mentioned that the sensor unit forms a protrusion in the outer surface. In this way, the air resistance of the motor vehicle is increased, at least in the sensor-optimized position, because the air flow flowing around the motor vehicle can flow relatively easily around a, usually aerodynamically optimized, outer surface, instead of around the protruding sensor unit. On the other hand, the outwardly protruding position of the sensor unit makes it possible to obtain a large acquisition range, which is only slightly limited by, for example, the vehicle body.

According to the invention, the sensor device can be adjusted to an air flow optimized position in which both the air resistance caused by the sensor device and the acquisition range of the sensor unit are reduced compared to the sensor optimized position. In other words, at least one component of the sensor device is adjustable between the above-mentioned sensor-optimized position and the air-flow-optimized position. Herein, "adjustable" generally means "motor adjustable" such that at least one motor or actuator acts on the respective component to effect adjustment thereof.

In this case, the acquisition range of the sensor unit is greater in the sensor-optimized position than in the air-flow-optimized position. The acquisition range is the spatial or solid angle range around which the sensor unit can acquire or provide sensor data. From the perspective of the sensor unit, if a particular area is covered by a vehicle component, that area is not part of the acquisition range. The acquisition range is greatest in the sensor optimized position, but at the expense of high air resistance. When reference is made herein to "air resistance", it does not strictly refer to air resistance-of course, it depends on speed-but rather to the air resistance coefficient or coefficient of resistance or c_wThe value is obtained. As an alternative to the "air resistance caused by the sensor device", this can therefore also be referred to as "c of the sensor device for the entire motor vehicle_wContribution of value ". Air resistance is reduced at an airflow optimization positionBut at the cost of reduced acquisition range. As will become clear below, this is because at least a part of the given acquisition range in the sensor-optimized position is covered by the vehicle component in the air-flow-optimized position and is therefore no longer able to be acquired by the sensor unit. On the other hand, improved flow behavior can be achieved by the mentioned vehicle component, for example, because the sensor unit is located at least partially in the wind shadow of the vehicle component. Depending on the circumstances here, an adjustment to the air flow-optimized position or the sensor-optimized position can be performed depending on whether a higher priority is given to the optimal function or the minimum air resistance of the sensor unit.

According to a preferred embodiment, the sensor device has at least one adjustable guide element which is arranged in the vehicle longitudinal direction relative to the sensor unit and extends relative to the outer surface in the air flow optimized position in order to guide the air flow in the sensor unit region and is retracted towards the outer surface in the sensor optimized position. The guide element is arranged in the vehicle longitudinal direction relative to the sensor unit, i.e. the guide element and the sensor unit are arranged offset relative to each other in the vehicle longitudinal direction (X-direction). Typically, the guiding element is arranged adjacent to the sensor unit, wherein the distance between the two elements is preferably less than 10cm, less than 5cm or less than 2 cm. The guide element may also be in contact with the sensor unit in a sensor-optimized position and/or an air-flow-optimized position. The guide element is adjustable, which obviously means that at least one motor or actuator is associated with the guide element in order to adjust it. In the air flow optimized position, the guide element extends relative to the outer surface, i.e. the guide element protrudes outwardly relative to the outer surface.

Due to the arrangement relative to the sensor unit, the air flow flowing through the motor vehicle is influenced jointly by the guide element and the sensor unit, wherein the guide element guides or guides the air flow. It should be understood that this means that the course of the gas flow is influenced by the guide element or is formed by the guide element in the region of the sensor unit. The detection range of the sensor unit is adversely affected or reduced, since the guide element extends in the air flow-optimized position. Sensory recording by means of the guide element is generally not possible or at best only possible in a limited manner. In the sensor-optimized position, the guide element is retracted, i.e. adjusted, relative to the outer surface, whereby at least a part of the guide element is moved towards the outer surface. In the sensor-optimized position, the guide element can be arranged above, at or below the outer surface level. In any case, the defects of the sensor unit are reduced or even counteracted in such a way that the acquisition range is enlarged compared to the optimal position of the gas flow.

Preferably, the at least one guide element is arranged in front of the sensor unit in the longitudinal direction of the vehicle. The vehicle longitudinal direction generally corresponds approximately to the flow direction of the air flow along the surface of the motor vehicle, although it may deviate therefrom due to the direction of travel, cross wind and formation of the surface. Typically, in such a design, the air first flows through the guiding element before reaching the sensor unit. The guide element can thus deflect or redirect the air flow before it passes onto the sensor unit. The sensor unit may be arranged at least partially in the wind shadow of the guiding element. In this embodiment, the guide element is offset relative to the sensor unit in the vehicle longitudinal direction toward the front of the vehicle. In this case, its position transverse to the longitudinal direction of the vehicle (i.e. the transverse direction and the vertical direction) usually corresponds at least partially to the position of the sensor unit.

In addition to or instead of the above-described embodiments, at least one guide element may be arranged behind the sensor unit in the longitudinal direction of the vehicle. In this embodiment, the guide element is offset with respect to the sensor unit in the vehicle longitudinal direction toward the rear of the vehicle. Such a guiding element may shape or guide the air flow behind the sensor unit and may thus, for example, reduce turbulence behind the sensor unit.

Independently of the arrangement of the guide elements, it is preferred if at least one guide element has a ramp section which, in the air flow optimized position in the longitudinal direction of the vehicle, rises relative to the outer surface toward the sensor unit. In the case of a guide element arranged in front of the sensor unit, the ramp section rises from front to back, and in the case of a guide element arranged behind the sensor unit, the ramp section rises from back to front or falls from front to back. In this case, the highest point of the ramp section is usually the point which is arranged closest to the sensor unit. The ramp segments may be straight, curved and/or angled. In other words, the slope of the ramp segment may be constant, may vary continuously, or may vary discontinuously.

During the adjustment to the optimal position of the sensor, the ramp section can be adjusted overall, for example linearly or rectilinearly. However, this results in a constant inclination thereof with respect to the adjacent outer surface, which is disadvantageous aerodynamically or aesthetically. According to a preferred embodiment, the ramp section is pivotable between a sensor-optimized position and an air-flow-optimized position. That is, the ramp segment is adjusted by pivotal movement between two positions. The pivot axis is preferably located in the region of that end of the ramp section which faces away from the sensor unit and is therefore arranged lowermost relative to the outer surface. Due to the pivoting, the opposite end facing the sensor unit is moved towards the outer surface when adjusted to the sensor optimized position or away from the outer surface when adjusted to the air flow optimized position. The position of the end facing away from the sensor unit changes little or not at all. In particular, in the sensor-optimized position, the entire ramp section can be arranged at the level of the adjacent outer surface. It is therefore integrated into the outer surface, which is particularly advantageous aesthetically.

As an alternative or in addition to the adjustable guide element, the sensor unit can be adjusted in such a way that the sensor unit projects less with respect to the outer surface in the air-flow-optimized position than in the sensor-optimized position. In other words, in the sensor optimized position the sensor unit may extend relative to the adjacent outer surface, whereas in the air flow optimized position it is retracted towards the outer surface. Here, it may optionally be able to sink completely into the adjacent outer surface. Of course, the scope of use of this option, compared to the installation space available below the outer surface, also depends on how the size of the sensor unit is formed. For example, in the case of a sensor unit arranged on the roof of a motor vehicle, it can be problematic to retract it down into the roof, since only a relatively small installation space is available in the roof region without adversely affecting the space of the passenger compartment.

The sensor unit can in particular have an active sensor, in particular a lidar sensor. Lidar sensors require a free line of sight of the acquisition range, i.e. opaque objects cannot be located within the line of sight. Therefore, there is often a conflict between optimal acquisition range and optimal aerodynamics. This also applies to all optical sensors (e.g. cameras) which only passively record images of the surroundings of the motor vehicle. However, within the scope of the invention, non-optical sensors (e.g. radar sensors or ultrasonic sensors) may also be highlighted in the above-described manner to ensure optimal function, depending on the acquisition range provided, in the case of adjacent outer surfaces. The adjustable guide element may impair the acquisition range of such a sensor in the air flow optimized position, since the sensor unit itself may be retracted in the direction of the adjacent outer surface.

In principle, it is conceivable for the adjustment of the sensor device to be carried out manually by the driver or passenger of the motor vehicle. However, this is often disadvantageous even in conventional motor vehicles, since on the one hand it requires the attention of the occupant and on the other hand it is difficult to make an estimate for the occupant when the full functionality of the sensor unit is required depending on the sensor optimization position and when the functionality of the sensor unit needs to be limited to improve the aerodynamics depending on the air flow optimization position. This is particularly true in autonomous motor vehicles, where the occupant should be released from the control of the motor vehicle. The control unit is therefore preferably designed to automatically adjust the sensor device between the sensor-optimized position and the air-flow-optimized position in dependence on the current driving conditions of the motor vehicle. The driving situation can be described by means of widely varying parameters, some of which relate to the motor vehicle itself (for example its speed, acceleration, road position, etc.), and others of which relate to the surroundings of the motor vehicle (for example the course of a provided route, stationary objects, other vehicles or pedestrians). When the full functionality of the sensor unit is required, the control unit may make a decision on widely varying criteria, for example, that a motor vehicle may collide with it if it has been determined or possibly other road users are located nearby. Conversely, if no other road users are currently nearby, the full functionality of the sensor unit may be abandoned in favor of improved aerodynamics. These criteria should be understood as examples only, and other criteria of great variation may also be used instead or in addition.

In particular, the control unit may be designed to adjust the sensor device into the sensor-optimized position if the speed of the motor vehicle falls below a predetermined threshold value. At low speeds, the improved aerodynamics have no significant effect, so that in principle an optimum functioning of the sensor unit can be prioritized.

Drawings

Further advantageous details and effects of the invention are explained in more detail below on the basis of different exemplary embodiments which are shown in the drawing, wherein

FIG. 1 shows a side view of a motor vehicle having a first embodiment of a sensor assembly according to the present invention in a sensor optimized position;

FIG. 2 shows a detail view of FIG. 1;

FIG. 3 shows a detail view corresponding to FIG. 2 with the sensor assembly in an airflow optimized position;

FIG. 4 shows a detail view corresponding to FIG. 3 with a second embodiment of the sensor assembly according to the invention in an air flow optimized position;

fig. 5 shows a detail corresponding to fig. 3 with a third embodiment of the sensor assembly according to the invention in an air flow optimized position.

Detailed Description

In the different figures, identical components are always provided with the same reference numerals and are therefore generally described only once.

Fig. 1 shows a side view of a motor vehicle 10, in particular an autonomous motor vehicle 10, more precisely a passenger carUsing a side view of the vehicle. In all the figures, the X-axis (vehicle longitudinal axis) and the Z-axis (vehicle vertical axis) for orientation are shown. The motor vehicle 10 has a sensor device 1, the sensor device 1 having a sensor unit 2 arranged on the upper side of the motor vehicle 10 (more precisely on the roof). The sensor unit 2 has one or more lidar sensors that can provide sensor data about the surroundings of the motor vehicle 10. Although the body 11 of the motor vehicle 10 is usually aerodynamically optimized, this is not suitable for the sensor unit 2. For example, it may have a cylindrical shape and protrude outwardly with respect to the adjacent outer surface 12 of the vehicle body 11. It can also be said that the sensor unit 2 forms a protrusion with respect to the outer surface 12. In this way, an optimal acquisition range of the sensor unit 2 is provided, which makes it possible in particular to detect the region in front of the motor vehicle 10 above the roof of the motor vehicle 10. The sensor data provided by the sensor unit 2 substantially contribute to enabling the autonomous motor vehicle 10 to control/drive itself according to the current surroundings without the involvement of the driver. However, the projecting position of the sensor unit 2 also causes a relatively high air resistance or c_wThe value is obtained. Fig. 1 and 2 show the sensor device 1 in a sensor optimized position in which an increased air resistance is accepted in favor of an optimal acquisition range. However, the sensor device 1 also has a control unit 5, schematically shown in fig. 1, which control unit 5 is configured to automatically adjust the sensor device 1 to the air flow optimized position shown in fig. 3 as the case may be.

In the air flow optimized position, the first guide element 3 is arranged in front of the sensor unit 2 in the longitudinal direction of the vehicle and in such a way that overall a lower air resistance or a lower c is produced_wThe airflow is directed in such a manner. The guide element 3 has a ramp section 3.1, the ramp section 3.1 rising from a first end 3.2 facing away from the sensor unit 2 to a second end 3.3 facing the sensor unit 2. Thus, the air flow does not have an abrupt transition between the outer surface 12 and the ramp section 3.1, thereby reducing, for example, congestion or turbulence in the air flow. In short, it can be said that the air flow is guided over the sensor unit 2 by the ramp section 3.1. On the other hand, guideThe element 3 prevents the sensor unit 2 from being able to acquire the area located in front of the motor vehicle 10, thereby reducing its acquisition range as a whole. The control unit 5 is therefore designed to adjust the sensor device 1 to an air flow-optimized position or a sensor-optimized position depending on the respective driving situation. In particular, a sensor-optimized location may be selected if it is determined, based on the most recently obtained sensor data, or possibly other road users, are located nearby with which the motor vehicle 10 may collide. Furthermore, if the speed of the motor vehicle 10 falls below a certain threshold value, the sensor-optimized position can always be selected independently of the surroundings of the motor vehicle 10. Below a certain speed, the air resistance caused by the sensor unit 2 can be neglected, so that the guide element 3 is retracted towards the outer surface 12. In this case, the adjustment can be made by pivoting the guide element 3 about a pivot axis located in the region of the first end 3.2. After pivoting, the ramp section 3.1 is arranged at the level of the outer surface 12 (or even slightly below it) and is therefore not visible in fig. 2.

Fig. 4 shows a second embodiment of a sensor device 1 according to the invention, the appearance of which corresponds to fig. 2 in a sensor-optimized position. In fig. 4, the airflow optimization position is shown. In this case, in addition to the first guide element 3, a second guide element 4 is provided, which is arranged behind the sensor unit 2 in the vehicle longitudinal direction. It also has a ramp section 4.1, the ramp section 4.1 rising from a first end 4.2 facing away from the sensor unit 2 to a second end 4.3 facing the sensor unit 2 or falling from front to back. In this case, a pivot axis is also provided in the region of the first end 4.2. The air flow can be deflected or guided by the second guide element 4 behind the sensor unit 2, whereby possible turbulence behind the sensor unit 2 can be reduced. In some cases, the use of the second guide element 4 can already lead to an improvement in the air resistance without the first guide element 3.

Fig. 5 shows a third exemplary embodiment of a sensor device 1 according to the invention, the appearance of which again corresponds to fig. 2 in the sensor-optimized position. In the air flow optimized position shown in fig. 5, the sensor unit 2 is retracted in a direction towards the outer surface 12, i.e. the sensor unit 2 protrudes to a lesser extent than in the sensor optimized position (shown in dashed lines in fig. 5). It is clear that in this way the acquisition range of the sensor unit 2 is greatly limited, wherein in particular it is no longer possible to acquire the region in front of the motor vehicle 10. On the other hand, the air resistance is of course also considerably reduced by this measure. In some cases, the adjustability of the sensor unit 2 according to the third embodiment can also be advantageously combined with one or both adjustable guide elements 3, 4 corresponding to the first or second embodiment.

List of reference numerals:

1 sensor device

2 sensor unit

3. 4 guide element

3.1, 4.1 slope segment

3.2, 4.2 first end

3.3, 4.3 second end

5 control unit

10 Motor vehicle

11 vehicle body

12 outer surface

X X axle

Z Z axle

Claims

1. A sensor device (1) for a motor vehicle (10), the sensor device (1) having a sensor unit (2), the sensor unit (2) projecting outwardly relative to an adjacent outer surface (12) of the motor vehicle (10) at least in a sensor-optimized position,

it is characterized in that the preparation method is characterized in that,

the sensor device (1) can be adjusted into an air flow optimization position, in which both the air resistance caused by the sensor device (1) and the acquisition range of the sensor unit (2) are reduced compared to the sensor optimization position.

2. The sensor device according to claim 1, wherein,

it is characterized in that the preparation method is characterized in that,

it has at least one adjustable guide element (3, 4), which guide element (3, 4) is arranged in the longitudinal direction (ex) of the vehicle relative to the sensor unit (2) and extends in the air-flow-optimized position relative to the outer surface (12) to guide the air flow in the region of the sensor unit (2) and is retracted in the sensor-optimized position towards the outer surface (12).

3. The sensor device according to claim 2, wherein,

it is characterized in that the preparation method is characterized in that,

at least one guide element (3, 4) is arranged in front of the sensor unit (2) in the longitudinal direction (X) of the vehicle.

4. The sensor device according to claim 2 or 3,

it is characterized in that the preparation method is characterized in that,

at least one guide element (3, 4) is arranged behind the sensor unit (2) in the longitudinal direction (X) of the vehicle.

5. The sensor device according to any one of claims 2-4,

it is characterized in that the preparation method is characterized in that,

at least one guide element (3, 4) has a ramp section (3.1, 4.1), which ramp section (3.1, 4.1) in the air flow optimized position is raised relative to the outer surface (12) in the longitudinal direction (X) of the vehicle toward the sensor unit (2).

6. The sensor device according to claim 5, wherein,

it is characterized in that the preparation method is characterized in that,

the ramp sections (3.1, 4.1) are pivotable between the sensor-optimized position and the air-flow-optimized position.

7. The sensor device of any one of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the sensor unit (2) is adjustable such that the sensor unit (2) protrudes less with respect to the outer surface (12) in the air flow optimized position than in the sensor optimized position.

8. The sensor device of any one of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the sensor unit (2) has an active sensor, in particular a lidar sensor.

9. The sensor device of any one of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the control unit (5) is designed to automatically adjust the sensor device (1) between the sensor-optimized position and the air-flow-optimized position as a function of the current driving conditions of the motor vehicle (10).

10. The sensor device according to claim 9, wherein,

it is characterized in that the preparation method is characterized in that,

the control unit (5) is designed to: -adjusting the sensor device (1) to the sensor-optimized position if the speed of the motor vehicle (10) falls below a predetermined threshold value.