DE102018212539A1 - Method for operating an environment sensor device of a motor vehicle and motor vehicle - Google Patents

Abstract

Method for operating an environment sensor device of a motor vehicle (1), which has at least one environment sensor (4) which is arranged on or adjacent to an outer surface (8) of the motor vehicle (1), in an impact situation, characterized by the following steps
Monitoring of the fulfillment of a sensor protection criterion evaluating an impact object (11) describing sensor data, which describes an impending and / or occurring impact of the impact object (11) on the outer surface (8),
- when the sensor protection criterion is met, actuating a retraction device (6) to remove the environmental sensor (4) from the outer surface (8),
- when the sensor is withdrawn, monitoring a reset criterion that indicates the end of the impact situation,
- When the reset criterion is met, actuating the retraction device (6) to reset the environment sensor (4) in the direction of the outer surface (8).

Description

The invention relates to a method for operating an environment sensor device of a motor vehicle, which has at least one environment sensor, which is arranged on or adjacent to an outer surface of the motor vehicle, in an impact situation. In addition, the invention relates to a motor vehicle.

Modern motor vehicles often use environment sensors to collect sensor data relating to the environment of the motor vehicle, which can then be evaluated by corresponding downstream vehicle systems, for example by driver assistance systems, safety systems and the like. Such environment sensors include, for example, ultrasonic sensors, lidar sensors, cameras, laser scanners and radar sensors.

In particular, the use of radar sensors in motor vehicles is increasing more and more. Sensor data from radar sensors can be used, for example, in applications such as parking aids, blind spot monitoring, pre-crash sensing and / or stop-and-go functions. Radar sensors have the advantage of being able to be at least partially concealed behind components of the motor vehicle. For example, radar sensors can be installed inside bumpers of the motor vehicle and / or in some other way behind radar-permeable, over-painted windows. The corresponding component can then be understood as an external radome and, as a design element of the motor vehicle, is also intended to meet further requirements, for example UV resistance, degree of gloss, radar permeability and the like. Radar sensors of this type (and also other environmental sensors) are attached, for example, to vehicle components of the motor vehicle, for example body components.

Radar sensors generally have a high-frequency part and a low-frequency part, the high-frequency part generating high-frequency radar signals in the range from approximately 10 to 80 gigahertz. The radar signals are sent and received via an antenna arrangement of the radar sensor. The high-frequency, received radar signals are converted and mixed down to a low frequency, with the processing of the low-frequency radar signals taking place in the low-frequency part.

With regard to the fulfillment of security requirements, radar sensors make a not insignificant contribution due to their reliability and robustness.

In general, environmental sensors that provide sensor data for safety-relevant functions must withstand a number of specific tests. For example, it is known for radar sensors in legislation to subject them to a predefined pendulum swing, whereupon the radar sensors still have to remain sufficiently functional. Particularly with regard to long-range radar sensors, which are mounted open, and thus form part of the outer surface of the motor vehicle, problems can occur with the pendulum impact. Then the radar sensor would not meet the statutory requirements.

Another problem with environment sensors that are arranged as part of and / or adjacent to an outer surface of the motor vehicle is that even minor collisions, for example so-called parking bumps, can damage the environment sensors, so that corresponding associated functions can be lost.

DE 10 2010 030 415 A1 relates to a crash structure for installation in a vehicle, which has a crash-dependent adjustable stiffness. An elastic element as part of the crash structure will compress itself elastically under the action of the crash and is directly structurally connected to a sensor system for generating a signal characterizing the crash for determining the rigidity. In particular, the sensor can be arranged on the elastic element or in the elastic element, which compresses elastically under the action of a crash. This allows light parking bumpers and the like to be intercepted without causing damage to the crash structure, in particular the sensor.

DE 10 237 721 A1 relates to an installation device for vibration-damped installation of an ultrasonic transducer, which has an elastic decoupling device which is arranged between the sensor and the component receiving the sensor.

Known, passive, elastic fastening structures of this type for environment sensors can bring the environment sensor elastically back into its original position after an impact, but are not reliable and subject to great tolerances. Furthermore, such concepts cannot be controlled.

The invention is therefore based on the object of achieving an improved protection of environmental sensors near or as part of the outer surface of a motor vehicle.

• - Überwachung der Erfüllung eines ein Aufprallobjekt beschreibende Sensordaten auswertenden Sensorschutzkriteriums, welches einen bevorstehenden und/oder eingetretenen Aufprall des Aufprallobjekts auf die Außenfläche beschreibt,
• - bei Erfüllung des Sensorschutzkriteriums Ansteuern einer Rückzugseinrichtung zur Entfernung des Umfeldsensors von der Außenfläche,
• - bei zurückgezogenem Sensor Überwachung eines Rückstellkriteriums, welches die Beendigung der Aufprallsituation anzeigt,
• - bei erfülltem Rückstellkriterium Ansteuern der Rückzugseinrichtung zur Rückstellung des Umfeldsensors in Richtung zu der Außenfläche.

A method of the type mentioned at the outset is characterized according to the invention by the following steps:

• Monitoring of the fulfillment of a sensor protection criterion evaluating an impact object describing sensor data, which describes an impending and / or occurring impact of the impact object on the outer surface,
• - when the sensor protection criterion is met, actuating a retraction device to remove the environmental sensor from the outer surface,
• - when the sensor is withdrawn, monitoring a reset criterion that indicates the end of the impact situation,
• - If the reset criterion is met, actuating the retraction device to reset the environment sensor in the direction of the outer surface.

The reset criterion can expediently at least partially also evaluate sensor data of the same sensors (recorded later) that were also used to evaluate the sensor protection criterion. This will be discussed in more detail below.

The environment sensor device thus includes a retraction device, which can also be understood as an active reset device and / or active elastic device. This means that if there is a risk of damage to the environment sensor, and consequently an impact of an impact object takes place or is imminent, the environment sensor can be withdrawn into a safe position, namely a retreat position, which is further away from the outer surface of the motor vehicle and thus from the hazard. Shortly before or (in the case of environment sensors arranged behind the components forming the outer surface) during the impact, the environment sensor is actively reset so that the impact object (or the component) does not hit the environment sensor directly, or at least only weakly. An active, controllable concept is used which is less tolerant, robust, reliable and long-lasting than passive elastic concepts. In addition, elastic structures lose elasticity over time, which creates a tolerance and / or aging problem. Furthermore, passive elastic structures cannot be controlled or controlled, which means that the environment sensor is returned in the vicinity of the damage, which could impair the sensor functionality. An active or motorized resetting of the environment sensor, on the other hand, can be checked, in particular up to a certain distance from the damage, so that the functionality of the environment sensor is still guaranteed.

In other words, the present invention thus represents a reversible, active, at least temporary correction of the installation position of the environment sensor that protects the sensor.

A radar sensor can be used particularly expediently as the environment sensor. Furthermore, it is expedient if the environment sensor is concealed behind a component of the motor vehicle that defines the outer surface. Radar sensors in particular have proven to be relatively sensitive to even smaller external influences, from which they can therefore be better protected with the aid of the present invention. This applies in particular to concealed radar sensors, which can be located, for example, at an extremely short distance behind a component defining the outer surface, for example a bumper component, which can then be understood as an external radome, for example. The radar sensor is therefore also exposed to the corresponding reaction of the component to the impact in impact situations. However, the risk of damage can be significantly reduced within the scope of the present invention by removing the radar sensor from the component / the outer surface. It should be noted here that the concept described here can of course also be applied to open radar sensors that form part of the outer surface, so that, for example, an openly installed long-range radar sensor can be retracted into a bumper or the like by means of the retraction device and there better protected is.

The radar sensor can preferably be based on semiconductor technology, in particular CMOS technology, in particular thus have a semiconductor chip that implements at least one radar transceiver of the radar sensor. The semiconductor chip can also be used to implement a digital signal processing component and / or a control unit of the radar sensor, wherein the control unit can in particular also be designed to carry out the method according to the invention described here. The semiconductor chip and an antenna arrangement of the radar sensor can be realized as a package which is carried, for example, by a printed circuit board which is held in a housing of the radar sensor. Semiconductor radar sensors of this type have the advantage of excellent quality of their sensor data, in particular also in a close-up or ultra-close range, so that it is particularly preferred for radar sensors in particular to use sensor data of the radar sensor itself as sensor data to be evaluated by the sensor protection criterion and / or the reset criterion.

However, it is also extremely advantageous in general if the sensor data are recorded by the environment sensor itself, which is particularly sensitive in an ultra-close range, and / or another sensor, in particular a crash sensor. Particularly with modern radar sensors based on semiconductor technology, detection and tracking of objects in the ultra-close range, i.e. in particular up to a distance of 2-4 cm, in particular 3 cm, from the radar sensor is still possible, the radar sensor preferably having a frequency bandwidth of more than one gigahertz, preferably four gigahertz, is operated. Due to the higher frequency bandwidth, the radar sensor can detect and track obstacles or impact objects up to the ultra-close range, in particular up to a distance of about 3 cm, and thus provide useful sensor data that can be evaluated by the sensor protection criterion and / or the reset criterion. Of course, this is of course also possible with other types of environment sensors, for example with ultrasonic sensors. Alternatively or in addition, sensor data from other sensors, in particular from crash sensors, can of course also be used in order to be able to determine the triggering point of the retraction device, and consequently the point in time at which the sensor protection criterion has been met, as precisely as possible.

In a specific embodiment, the sensor protection criterion can be met if the impact object falls below a minimum distance and / or if the time falls until the impact object and / or if the impact object, and / or the component, impacts the target. Specific values for the minimum distance and / or the minimum time can, for example, be selected depending on the time period for the withdrawal process, for example in the range of a few centimeters and / or milliseconds. It may be expedient to keep the environment sensor in its operating position for as long as possible in order to be able to measure the impact process as precisely as possible. If the environment sensor is arranged behind a component that defines the outer surface, it may already be sufficient to trigger the retraction process as soon as the impact object contacts the component, which can also be determined, for example, by a further sensor, in particular a crash sensor.

As far as the reset criterion is concerned, it should first be noted that sensor data does not necessarily have to be evaluated here, but that in many cases it is sufficient for the typical impact processes, for example, to wait for a predetermined period of time after the impact is at least imminent if the sensor protection criterion is met or collision processes continue. For example, the reset criterion can check whether a predetermined waiting time, for example in the range of 0.5-3 seconds, has expired. Of course, however, it is also possible to use sensor data from the environment sensor and / or further sensors in order to determine as securely as possible whether the impact process and thus the hazard situation for the environment sensor has ended. For example, it is possible here to wait until the motor vehicle and / or vehicle components surrounding the environment sensor have come to a standstill and / or the impact object and / or a relative movement of the impact object is no longer detected.

The withdrawal process can expediently be carried out by a motor of the withdrawal device. Such an engine can expediently also have its own energy source so as not to be influenced by damage in other parts of the motor vehicle. For example, in order to retract the environment sensor, an engagement element of the motor, which is designed in particular as a linear motor, can latch with a corresponding engagement element of the environment sensor and / or a carrier for the environment sensor and thus enable the environment sensor to be withdrawn. Of course, other configurations known to the person skilled in the art are also conceivable.

In a particularly advantageous embodiment of the present invention, it can be provided that the environment sensor is withdrawn against an elastic force of a reset element of the retraction device, which is released when the reset criterion is met. In this way, a specifically driven movement of the environment sensor is only necessary in one direction after the kinetic energy for the return movement is provided by the elastic return element. The elastic restoring element can be, for example, a spring and / or an elastic material, the elastic restoring element being biased by the withdrawal movement. Such a restoring movement driven by a restoring element is preferably carried out in a controlled manner, in particular, therefore, using suitable guide elements.

However, especially when greater control over the positioning of the environment sensor is to be given and / or greater robustness and less tolerance tolerance, it is expedient to also provide the resetting movement by the motor of the retraction device.

The environment sensor can preferably be withdrawn from an original operating position and at least when one is met sufficient free space at the original operating position indicating free space criterion to be reset to the original operating position. The free space criterion, if it is used, which is preferably the case when the resetting movement takes place automatically by means of a motor, also evaluates sensor data of the environment sensor itself, after it can be determined, for example, in the case of radar sensors in the ultra-close range, whether there are obstacles or the like. Of course, sensor data from other sensors can also be used here if necessary and useful. By using the free space criterion, it is ensured that no damage to the sensor threatens during the reset process. The free space criterion can of course also check the way to the original operating position.

A particularly advantageous embodiment in this context provides that if the free space criterion is not met, a new operating position in the direction of the outer surface is determined and the environment sensor is only reset to this new operating position. This means that depending on a measurement of the free space in the direction of the outer surface of the motor vehicle, a type of correction of the operating position can be used, in particular and preferably based on sensor data of the environmental sensor then operated in the retracted position. If, for example, a component behind which the environment sensor was installed and which defines the outer surface has been pressed in, a return to the original operating position could damage the environment sensor due to a collision with the component. However, the environment sensor can still be moved back at least part of the way in the direction of the outer surface, so that a new operating position can be found and used in order to be able to continue to record useful sensor data from the environment sensor.

An expedient development of the present invention provides that the retraction device has a partial housing that partially protects the environment sensor in the retracted position. For example, the environment sensor can be shielded laterally in the retracted position, for example by other vehicle components or components moved by the impact. In this way, a further improved protection of the environment sensor is allowed.

In addition to the method, the present invention also relates to a motor vehicle having at least one environment sensor which is attached to at least one vehicle component via a retraction device and is arranged on or adjacent to an outer surface of the motor vehicle, and a control device designed to carry out the method according to the invention. The environment sensor and the retraction device form an environment sensor device. All statements relating to the method according to the invention can be transferred analogously to the motor vehicle according to the invention, with which the advantages already mentioned can also be obtained. In particular, the control device can be a control unit of the environment sensor itself or can comprise this.

• 1 eine Prinzipskizze eines erfindungsgemäßen Kraftfahrzeugs,
• 2 eine Umfeldsensoreinrichtung zu einem ersten Zeitpunkt einer Aufprallsituation, und
• 3 eine Umfeldsensoreinrichtung zu einem zweiten Zeitpunkt einer Aufprallsituation.

Further advantages and details of the present invention result from the exemplary embodiments described below and from the drawing. Show:

• 1 a schematic diagram of a motor vehicle according to the invention,
• 2 an environment sensor device at a first point in time of an impact situation, and
• 3 an environment sensor device at a second point in time of an impact situation.

1 shows a schematic diagram of a motor vehicle according to the invention 1 , It is in a front bumper 2 of the motor vehicle 1 one as a radar sensor 3 trained environment sensor 4 installed, which is shown enlarged for the sake of illustration. The radar sensor 3 has a semiconductor chip, here specifically a CMOS chip, which in addition to a radar transceiver also a digital signal processing component and a control unit 5 of the radar sensor 3 realized. The semiconductor chip is with an antenna arrangement of the radar sensor 3 realized in one package. For example, the semiconductor chip can be carried in a housing, supported by a printed circuit board. After the radar sensor 3 with a high frequency bandwidth, for example a frequency bandwidth of 4 gigahertz in the frequency range from 87 to 91 gigahertz, it also delivers in the ultra-close range, i.e. at distances up to 3 cm in front of the radar sensor 3 , useful sensor data on existing objects or obstacles. The radar sensor 4 is about a retreat facility 6 with one by the control unit 5 controllable motor, here a linear motor, with a fixed vehicle component 7 , for example a body part, connected. The control unit 5 is designed as a control device for performing the method according to the invention.

2 shows the through the retraction device 6 and the environment sensor 4 formed sensor device again more precisely. The radar sensor is located here 3 in an operating position adjacent to an outer surface 8th of the motor vehicle 1 defining component 9 , here a plastic bumper component, which is in this Area therefore an external radome for the radar sensor 3 forms. The retreat facility 6 includes an engine 10 , here a linear motor, over which the position of the radar sensor 3 and thus the distance of the radar sensor 3 from the outside surface 8th can be changed.

2 refers to a first point in time during an impact situation. An impact object approaches 11 according to the arrow 12 on a collision course with the component 9 and thus also the outer surface 8th , From sensor data from the radar sensor 3 itself, which, as described, also provides useful data in the ultra-close range, can be concluded that the current distance 13 of the impact object 11 to the outside surface 8th still exceeds a minimum distance.

In the control unit 5 a sensor protection criterion is now used to continuously check whether the distance 13 of the impact object 12 falls below the minimum distance. Alternatively, a time until a collision can be compared with a minimum time and / or the actual contact of the impact object 11 with the outside surface 8th and thus the component 9 be monitored.

The control unit controls if the sensor protection criterion is met 5 the engine 10 on, the radar sensor 3 increasing the distance from the outer surface 8th in an in 3 withdrawal position shown. The radar sensor is there 3 significantly better from damage caused by an impact of the impact object 11 protected, what effect by an optional, partial dash housing indicated here by dashed lines 14 for the retreat position can still be improved.

In a simple embodiment, it can then be provided in the following to wait for a certain waiting period to expire, in order then for the radar sensor 3 by means of the engine 10 (or a less preferred elastic return element of the retractor 6 ) back to the original operating position of the 2 cut back. Alternatively, the reset criterion can also check whether the impact situation has actually ended, in particular using sensor data from the radar sensor 3 ,

Furthermore, the radar sensor 3 not necessarily in the original operating position of the 2 be retracted, but it can, preferably based on sensor data from the radar sensor 3 , are checked whether there is sufficient free space, which can also be checked for the way to this original operating position. If such a free space criterion is met, there is nothing to prevent a return to the original operating position. However, if the free space criterion is not met, a new, corrected operating position is determined as an intermediate position between the retreat position and the original operating position into which the radar sensor is located 3 can be moved without damage, whereupon it is moved into this new operating position.

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included 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.

Patent literature cited

• DE 102010030415 A1 [0008]
• DE 10237721 A1 [0009]

Claims (10)

Method for operating an environment sensor device of a motor vehicle (1), which has at least one environment sensor (4), which is arranged on or adjacent to an outer surface (8) of the motor vehicle (1), in an impact situation, characterized by the following steps - monitoring the fulfillment of a a sensor protection criterion evaluating impact object (11) describing an impending and / or occurring impact of the impact object (11) on the outer surface (8), - when the sensor protection criterion is met, actuating a retraction device (6) to remove the environmental sensor (4) from the outer surface (8), - when the sensor is withdrawn, monitoring a reset criterion that indicates the end of the impact situation, - when the reset criterion is met, actuating the retraction device (6) to reset the environmental sensor (4) in the direction of the outer surface (8). Procedure according to Claim 1 , characterized in that a radar sensor (3) is used as the environment sensor (4) and / or that the environment sensor (4) is concealed behind a component (9) of the motor vehicle (1) that defines the outer surface (8). Procedure according to Claim 1 or 2 , characterized in that the sensor data are recorded by the environment sensor (4) itself, which is particularly sensitive in an ultra-close range, and / or another sensor, in particular a crash sensor. Method according to one of the preceding claims, characterized in that the sensor protection criterion if the impact object (11) falls below a minimum distance and / or if the impact object (11) falls short of a minimum time until the impact and / or if the impact object (11 ), in particular on the component (9). Method according to one of the preceding claims, characterized in that at least the withdrawal process, in particular also the reset process, is carried out by a motor (10) of the withdrawal device (6). Method according to one of the preceding claims, characterized in that the environment sensor (4) is withdrawn against an elastic force of a reset element of the retraction device (6), which is released when the reset criterion is met. Method according to one of the preceding claims, characterized in that the environment sensor (4) is withdrawn from an original operating position and is reset to the original operating position at least when a sufficient free space criterion indicating the original operating position is met. Procedure according to Claim 7 , characterized in that if the free space criterion is not met, a new operating position is determined in the direction of the outer surface (8) and the environment sensor (4) is only reset to this new operating position. Method according to one of the preceding claims, characterized in that the retraction device (6) has a partial housing (14) which partially surrounds the environment sensor (4) in the retracted position. Motor vehicle (1), comprising at least one environment sensor (4), which is attached to at least one vehicle component (7) via a retraction device (6) and is arranged on or adjacent to an outer surface (8) of the motor vehicle (1), and one for carrying it out a method according to one of the preceding claims formed control device.

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