DE102014010381A1 - Method for operating a vehicle system of a motor vehicle for protection against damage caused by unevenness of the ground and motor vehicle - Google Patents

Abstract

Method for operating a vehicle system (2) of a motor vehicle (1) for protection against damage to the body (9) and / or the chassis and / or the wheels (10) of the motor vehicle (1), in particular also by objects resulting, unevenness of the Underground (20) on which the motor vehicle (1) is operated, wherein depending on a height for at least a portion of the substrate (20) indicating height information on fulfillment of at least one risk criterion that evaluates the height information, a collision avoiding and / or Kollollfolgenmündde and or a driver warning action takes place, wherein to determine the height information radar data at least one of the underbody (4) of the motor vehicle (1) arranged radar sensor (5) of the motor vehicle (1) on the ground (20) under the motor vehicle (1) addressed.

Description

The invention relates to a method for operating a vehicle system of a motor vehicle for protection against damage to the body and / or the chassis and / or the wheels of the motor vehicle, in particular by objects resulting, unevenness of the ground on which the motor vehicle is operated, wherein in Dependence of altitude information indicative of the altitude for at least a portion of the ground upon satisfaction of at least one hazard criterion evaluating the altitude information, performing a collision avoiding and / or collision sequence mitigation and / or a driver warning action. In addition, the invention relates to a motor vehicle.

In the prior art, vehicle systems, in particular suspension systems, have already been proposed for motor vehicles, which make it possible to change the height of the body and possibly also of the chassis itself relative to the road, possibly also in different ways over the horizontal extent of the motor vehicle. In this case, for example, electromechanical and / or hydraulic actuators can be used to adjust the chassis in height.

Such an actuator can be used in the context of a vehicle system to protect against damage, which can also occur in particular by unevenness of the road, especially on the road. In the context of the present description of unevenness of the roadway, possible collision objects are also arranged on the roadway. In the presence of such unevenness of the road, it may happen that the chassis and / or the body come into contact with the road, so that damage may occur. For example, if there is a massive, small obstacle on the road, it can lead to collisions with the lower edge of the vehicle, which can lead to any damage to the chassis. An evasive maneuver at higher speeds can be very critical for the driver and possibly have further damage consequences.

Consequently, vehicle systems have already been proposed which evaluate height information for at least part of the traveled subsoil, in particular the roadway, for example on the basis of a risk criterion, and can perform various actions when the risk criterion occurs. It can be provided that as an action warning information is output to a driver of the motor vehicle and / or a driving engagement to avoid a collision with the ground, it is preferred, however, if there are already actuators on the height of the chassis and / or the body can be changed if as an action on at least one actuator, the height of the chassis and / or the body is adapted to avoid collision with the ground.

Such a method is for example from the DE 10 2009 040 170 A1 which discloses an intelligent sensor chassis system which uses a chassis actuator unit to lower or raise the vehicle chassis to maintain or undercut maximum headroom or to achieve or exceed required ground clearance. In addition, there is proposed to use laser range sensor elements which are arranged in the region of the front and rear bumper and measure the distance between the vehicle underbody and the road surface. In this way, a height information is thus obtained when driving over the subsurface. Another possibility determination of a height information is given by predictive sensors that measure the background in the environment of the motor vehicle.

Thus, a vehicle system for protection against damage to the body and / or the chassis and / or the wheels of the motor vehicle by unevenness of the substrate ultimately hardly useful information about the ground below the motor vehicle available, but can be materially damaging. This is due, in particular, to the fact that a height of the underbody of the motor vehicle can only be measured over the ground at certain points via a laser distance sensor. In particular, in the case of distributed unevenness of the ground, such a punctual measurement is therefore not sufficient.

The invention is therefore based on the object to provide an improved way to obtain altitude information of the ground below the motor vehicle.

To solve this problem, it is provided according to the invention in a method of the type mentioned that radar data of at least one arranged on the underbody of the motor vehicle radar sensor of the motor vehicle, which is directed to the ground under the motor vehicle, are taken into account.

The invention therefore proposes to install at least one radar sensor in the lower area of the motor vehicle, which constantly monitors the distance between the underbody of the motor vehicle, for example the lower edge of the body, and the ground over a larger area of the ground. Send the radar sensors Radar signals in the direction of the ground, the ground below the motor vehicle reflects the radar signals back to the radar sensor and the transmitted and reflected radar signals are evaluated together to accurately evaluate the distance between the underbody of the motor vehicle and the ground.

The method according to the invention is made possible, in particular, by the fact that in the meantime high-resolution radar sensors, which are also suitable for shorter ranges, exist with which excellent separation of individual targets, thus individual unevenness of the ground, and thus in particular certain characteristics of the ground, is possible. Such radar sensors can also, since they are usually based on a semiconductor technology, be realized extremely small construction, which makes a shoring on the underbody of the motor vehicle makes sense only. In this respect, the method according to the invention thus exploits the latest developments for the application of a radar sensor which has hitherto not been considered.

Thus, a significantly improved, more accurate, on a large areas of the ground below the motor vehicle, preferably the entire surface below the motor vehicle, related height information is determined, in particular by using multiple radar sensors that can be configured as wide-angle radar sensors. In contrast to the known punctual measurements a virtually complete scanning of the ground is also possible below the motor vehicle, which is an excellent complement to already known sampling techniques for areas around the motor vehicle. It follows, in turn, that even below the motor vehicle a constant monitoring of the distance between the subfloor and the substrate, in particular the road, is present, so that damage to the motor vehicle can be avoided even more than was previously the case. If, for example, a distance value between the underbody and the ground, as can be derived from the height information, falls below a certain threshold value, then at least one actuator can be actuated in order to lift the chassis and / or the body and thus avoid damage.

A particularly advantageous embodiment of the present invention provides that a radar sensor with an antenna arrangement permitting an angular resolution in at least two mutually perpendicular planes is used. The radar sensor can therefore not only determine in one plane the angle at which the reflection arrives by means of a clever arrangement of antenna elements of the antenna arrangement, but also output angle information in a plane perpendicular thereto, so that a planar detection area with respect to the ground is given. in which the height information, which follow from the measured distances, can be assigned as accurately as possible. For example, it can be provided that a radar sensor is used which has an opening angle of the detection area with respect to both planes in the range of 80 ° to 180 °, for example in one plane an opening angle of 160 °, in the other plane an opening angle of 90 ° Already by a single radar sensor an extremely extensive scanning of the ground below the motor vehicle can take place. Reflection sources can be accurately assigned by the three-dimensional measurement, for example, in spatial polar coordinates. Thus, an excellent measurement of the entire subsurface beneath the motor vehicle in three dimensions is possible, so that ideally for each position below the motor vehicle there is a height value as height information.

Excellent resolution of the radar sensor may be further facilitated by operating the radar sensor at a frequency bandwidth greater than 2 GHz. The larger the bandwidth that is used, the larger the pitch-separation capability, so that small unevenness of the ground can be better distinguished when a higher frequency bandwidth, for example of 4 GHz, has been selected. The structures of the underground can therefore be better distinguished. The radar sensor can be suitably operated in a frequency band which is in the range of 77 GHz to 81 GHz.

It is also advantageous if the radar sensor is operated so that a small cycle time is given. For example, it may be provided that the radar sensor is operated with a cycle time that is less than 30 ms. Such fast cycle times, for example, in a specific case of 10 ms, can be achieved in particular despite a high frequency bandwidth when working in semiconductor technology, in particular CMOS technology, with such radar sensors being available more cheaply in recent times.

As has already been mentioned, the method makes use of the availability of high-resolution, small-scale radar sensors, whereby in particular it is exploited that components in semiconductor techniques can now also be produced.

The realization of semiconductor-based radar components has long proved difficult, as expensive specialty semiconductors, particularly GaAs, have been required. There were smaller ones Radar sensors have been proposed, whose entire radar front-end is realized on a single chip in SiGe technology, before solutions in the CMOS technology were known. Such solutions are the result of extending CMOS technology to high frequency applications, often referred to as RF CMOS. Such a CMOS radar chip is realized extremely compact and does not use expensive special semiconductors, thus offers significant advantages over other semiconductor technologies, especially in the production. An exemplary implementation of a 77 GHz radar transceiver as a CMOS chip is described in the article by Jri Lee et al., "A Fully Integrated 77GHz FMCW Radar Transceiver in 65nm CMOS Technology", IEEE Journal of Solid State Circuits 45 (2010), pp. 2746-2755 , described.

After it has also been proposed to realize the chip and the antenna in a common package, a very low cost small radar sensor is possible, which can meet the space requirements significantly better and due to the short signal paths also has a very low signal-to-noise ratio and for high frequencies and larger, variable frequency bandwidths is suitable. Therefore, such small-sized radar sensors can also be used for short-range applications, for example in the range of 30 cm to 10 m.

It has also been proposed to provide such a CMOS transceiver chip and / or a package with CMOS transceiver chip and antenna on a common circuit board with a digital signal processing processor (DSP processor) or the functions of the signal processing processor in the CMOS Integrate transceiver chip. Similar integration is possible for control functions.

Consequently, the use of such radar sensors or radar frontends is also particularly advantageous in the context of the present invention. A particularly preferred embodiment of the present invention therefore provides that a radar sensor with a radar transceiver realized as a semiconductor chip, in particular a CMOS chip, is used. It is particularly preferred if a digital signal processing component and / or a control unit of the radar sensor are further realized by the semiconductor chip, so that a highly integrated solution is given. Moreover, it is particularly advantageous if an antenna arrangement of the radar sensor and the semiconductor chip are realized as a package, as just described. Such a high integration and controlled signal paths in the semiconductor chip mean that the noise level is lower, so that a high signal-to-noise ratio can be achieved. In this way it is possible to detect even smaller unevenness and less reflective structures of the background in the spectrum, since the integration lowers the noise level and thus the detection sensitivity can be increased.

In particular, the use of said semiconductor technologies, in particular CMOS technologies, in the manner already described above, allows the spacing capabilities and angular resolutions of the radar sensors to be realized by using larger frequency bandwidths, certain modulation techniques, and the like while still maintaining fast cycle times.

It should also be noted at this point that the use of semiconductor technologies, in particular CMOS technologies, not only makes it possible to provide suitable radar sensors due to the detection sensitivity for the method according to the invention, but that these radar sensors, in particular in the case of antenna arrangement and semiconductor chip in the package , can also be realized extremely compact and thus are particularly suitable for installation on or in the underbody of the motor vehicle. For example, CMOS chip packages have already been proposed whose extension along the long sides is smaller than 15 mm × 15 mm.

As already mentioned, it may be expedient if more than one radar sensor arranged on the underbody of the motor vehicle is used. In particular, the radar sensors and their detection ranges are selected so that the complete background underneath the motor vehicle is covered by the detection ranges of the plurality of radar sensors, so that in particular a complete description of the ground beneath the motor vehicle can be derived as height information.

A particularly expedient embodiment is also provided if a background map is determined as height information from the radar data of the at least one radar sensor arranged on the underbody of the motor vehicle. By measuring by the radar sensor, which, as already mentioned, ideally three-dimensional sources of reflections can identify and assign, it is therefore possible to map the ground below the motor vehicle, so as to generate a high-quality map of the ground, in particular the road , This underground map covers all relevant areas below the motor vehicle, ideally the entire underground of the motor vehicle. In a particularly advantageous embodiment, it can supplement an environmental model of the motor vehicle, as is often the case in motor vehicles by fusion of the sensor data of a plurality of sensors. Then, then, an environment model Added information that was previously unavailable.

Preferably, the height information is also determined for areas of the subsoil not lying beneath the motor vehicle as a function of radar data of at least one further radar sensor of the motor vehicle directed towards the surroundings of the motor vehicle and / or the radar data of the further radar sensor, in particular together with movement data of the motor vehicle (odometry data), are taken into account when determining the height information for the ground under the motor vehicle. The motor vehicle can therefore also have other radar sensors, which are directed to the environment of the motor vehicle and where appropriate also information about the ground, which is traveled by the motor vehicle, collect. Thus, a background map can also be supplemented for areas adjacent to the areas covered by the radar sensors arranged on the underbody of the motor vehicle. At the same time, of course, if it is known that the motor vehicle has moved to a location that was initially only detected at a remote location, a stored altitude information about this location is included in the evaluation of the current radar data of the radar sensor arranged on the underbody of the motor vehicle.

This extension, which relates to the use of further radar sensors, in particular 360 ° around the motor vehicle, also makes it possible to detect unevenness of the ground, in particular smaller obstacles, by means of radar on the road, so that, for example, the chassis and / or the vehicles can also be anticipated Body can be raised to prevent collision with the obstacle. Ideally, the entire environment is scanned, so that an extension of the method according to the invention with regard to collisions of the roof of the motor vehicle, for example at low bridges, is possible. Then, for example, the chassis and / or the body can be lowered down to avoid a collision and to reduce the severity of the accident. In other words, the method according to the invention is thus useful with previously known possibilities for scanning the environment in terms of unevenness of the road or other collision hazards that can be influenced by a height adjustment of the motor vehicle connectable.

In addition to the method, the present invention also relates to a motor vehicle with a vehicle system for protection against damage to the body and / or the chassis and / or the wheels of the motor vehicle, in particular by objects resulting, unevenness of the ground on which the motor vehicle is operated, wherein a control unit of the vehicle system is designed to perform a collision avoiding and / or collision tracking and / or a driver warning action in response to at least one hazard criterion evaluating the height information for at least a portion of the ground indicating altitude information characterized in that for determining the height information at least one arranged on the underbody of the motor vehicle radar sensor which is directed to the ground under the motor vehicle, is provided. In particular, the control unit can therefore be designed to carry out the method according to the invention. All statements relating to the method according to the invention can be analogously transferred to the motor vehicle according to the invention, with which therefore also the already mentioned advantages can be obtained. In particular, at least two radar sensors may also be provided on the underbody of the motor vehicle, directed at the ground, so that their detection areas cover the entire underground beneath the motor vehicle.

Further advantages and details of the present invention will become apparent from the embodiments described below and with reference to the drawing. Showing:

1 a schematic diagram of a motor vehicle according to the invention,

2 the structure of the underbody of the motor vehicle according to 1 arranged radar sensor,

3 the antenna arrangement of the radar sensor 2 .

4 the scanning of the ground beneath the motor vehicle by the arranged on the underbody of the motor vehicle radar sensors, and

5 the scanning of the environment by other radar sensors.

1 shows a schematic diagram of a motor vehicle according to the invention 1 , This has a vehicle system 2 To protect against damage to unevenness of the ground on which the motor vehicle 1 is operated on. The control unit receives this 3 of the vehicle system 2 , Which is incidentally designed for carrying out the method according to the invention, sensor data of various sensors of the motor vehicle, in particular radar data of the underbody 4 of the motor vehicle 1 arranged radar sensors 5 lying on the ground beneath the motor vehicle 1 are directed. In this way, unevenness of the ground beneath the motor vehicle 1 be detected. As further possible sensors in the present case, a forward-looking further radar sensor 6 and a camera 7 , which can be designed as a 3D camera, shown. From the sensor data of the different sensors 5 . 6 and 7 determines the control unit 3 a the ground on which the motor vehicle 1 operated, describing the underground map as height information, according to which at least one hazard criterion based on the height information, ie the underground map, is evaluated, which of course can also enter more data, in particular Ego data on the operating condition of the motor vehicle 1 and the same. Ultimately, it is checked whether there is too high a probability of collision with an unevenness of the background. If this is the case, then a risk criterion is met by the control unit 3 actuators 8th , About the height adjustment of the suspension and / or the body not shown here 9 is possible, controlled in order to avoid a collision or to reduce the collision sequences.

In other embodiments, other actions may be provided by the control unit 3 can be triggered, for example, warnings to the driver or driving interventions, for example, to damage the wheels 10 to avoid.

It should be noted that it is particularly preferred within the scope of the invention if the other radar sensors 6 the entire environment of the motor vehicle 1 , ie 360 °, cover. For example, eight other radar sensors can do this 6 are provided, of which two at each corner of the motor vehicle 1 are arranged.

Below are the underbody radar sensors 5 shown in detail, which are manufactured in this case in CMOS technology kleinbauend. Each of the radar sensors 5 is according to 2 through a package 11 formed the in 2 not shown antenna arrangement of the radar sensor 5 and a semiconductor chip 12 , here a CMOS chip, includes. In the CMOS chip 12 are the radar transceivers 13 , a digital signal processing component 14 (DSP) and a control unit 15 realized so that the radar data equal as an object list or partial underground map to an im 1 indicated bus system 16 of the motor vehicle 1 can be passed on.

The structure of the antenna arrangement 17 of the underground radar sensor 5 is in 3 shown in more detail. As can be seen, the antenna arrangement 17 four antenna elements 18 on, wherein one of the antenna elements 18 in a different direction than the three remaining antenna elements 18 connected to this, so that an education is given, which allows a determination of angle information in two mutually perpendicular planes. The present embodiment is the radar sensor 5 overall selected so that an opening angle of the detection range in the two said levels of 160 ° or 90 ° is given, thus a very large area of the ground by the radar sensor 5 can be detected. Overall, the number and arrangement of radar sensors 5 so chosen that the entire underground below the motor vehicle 1 can be detected.

The high integration in CMOS technology used in the radar sensor 5 allows a very high signal-to-noise ratio, since the internal signal noise is minimized, so that relevant unevennesses on the ground can be distinguished from the so-called "ground clutter", which is a source of interference. To further improve the separation capability, the radar sensors become 5 operated at a frequency bandwidth of 4 GHz in a frequency band of 77 GHz to 81 GHz. However, due to the use of CMOS technology and high integration, very low cycle times are still possible, for example in the range of 10 ms.

4 shows more exactly how the radar sensors 5 with their likewise indicated coverage areas 19 the underground 20 below the subfloor 4 can scan. Due to the distance measurements and the good angular resolution, the height of bumps like the wave can be 21 and the object 22 be determined so that the extremely accurate altitude information from below the motor vehicle 1 result.

These are, as already described, summarized by a background map.

The through the underbody radar sensors 5 determined underground map of the underground 20 can supplement other information, which are stored for example in an environment model, for example, as in 5 shown is information about the underground 20 by the other radar sensor 6 but also information about obstacles 23 For example, with the roof of the motor vehicle 1 can collide. Even such obstacles 23 can in the control unit 3 be taken into account and to a corresponding control of the actuators 8th to lead. The detection of the underground 20 through the other radar sensors 6 enables a predictive assessment of collision hazards in the control unit 3 ,

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102009040170 A1 [0005]

Cited non-patent literature

• Jri Lee et al., "A Fully Integrated 77GHz FMCW Radar Transceiver in 65nm CMOS Technology", IEEE Journal of Solid State Circuits 45 (2010), pp. 2746-2755 [0016]

Claims (9)

Method for operating a vehicle system ( 2 ) of a motor vehicle ( 1 ) to protect against damage to the body ( 9 ) and / or the chassis and / or the wheels ( 10 ) of the motor vehicle ( 1 ), in particular by objects resulting, unevenness of the ground ( 20 ) on which the motor vehicle ( 1 ), depending on a height for at least a part of the subsoil ( 20 ) in which at least one hazard criterion evaluates the altitude information, a collision-avoiding and / or collision-sequence- reducing and / or a driver-warning action takes place, characterized in that for determining the altitude information, radar data of at least one on the underbody ( 4 ) of the motor vehicle ( 1 ) arranged radar sensor ( 5 ) of the motor vehicle ( 1 ), to the underground ( 20 ) under the motor vehicle ( 1 ). Method according to claim 1, characterized in that a radar sensor ( 5 ) with an antenna arrangement allowing an angular resolution in at least two mutually perpendicular planes ( 17 ) is used. Method according to claim 1 or 2, characterized in that the radar sensor ( 5 ) at a frequency bandwidth greater than 2 GHz and / or in a frequency band between 77 and 81 GHz and / or with a cycle time less than 30 ms. Method according to one of the preceding claims, characterized in that a radar sensor ( 5 ) with a semiconductor chip ( 12 ), in particular a CMOS chip, by which the radar transceiver ( 13 ) is realized. Method according to claim 4, characterized in that by the semiconductor chip ( 12 ) further comprises a digital signal processing component ( 14 ) and / or a control unit ( 15 ) of the radar sensor ( 5 ) and / or an antenna arrangement ( 17 ) of the radar sensor ( 5 ) and the semiconductor chip ( 12 ) as a package ( 11 ) are realized. Method according to one of the preceding claims, characterized in that more than one on the underbody ( 4 ) of the motor vehicle ( 1 ) arranged radar sensor ( 5 ) is used. Method according to one of the preceding claims, characterized in that from the radar data of at least one of the underbody ( 4 ) of the motor vehicle ( 1 ) arranged radar sensor ( 5 ) one in particular an environmental model of the motor vehicle ( 1 ) supplementary background map is determined as height information. Method according to one of the preceding claims, characterized in that the height information is also not for below the motor vehicle ( 1 ) lying areas of the underground ( 20 ) depending on radar data at least one on the environment of the motor vehicle ( 1 ) further radar sensor ( 6 ) of the motor vehicle ( 1 ) is determined and / or the radar data of the other radar sensor ( 6 ), in particular together with movement data of the motor vehicle ( 1 ), in the determination of the height information for the underground ( 20 ) below the motor vehicle ( 1 ). Motor vehicle ( 1 ) with a vehicle system ( 2 ) to protect against damage to the body ( 9 ) and / or the chassis and / or the wheels ( 10 ) of the motor vehicle ( 1 ), in particular by objects resulting, unevenness of the ground ( 20 ) on which the motor vehicle ( 1 ), wherein a control device ( 3 ) of the vehicle system ( 2 ) is formed, depending on a height for at least a part of the ground ( 20 ) at least one risk criterion, which evaluates the altitude information to carry out a collision avoiding and / or collision sequence mitigating and / or a driver warning action, characterized in that for determining the height information at least one of the underbody ( 4 ) of the motor vehicle ( 1 ) arranged radar sensor ( 5 ), to the underground ( 20 ) under the motor vehicle ( 1 ) is provided.

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