DE102007035905A1 - Sensor arrangement for motor vehicle, has capacitive sensor for detecting humidity, and evaluation device for common evaluation of information about presence of humidity and rain drop detected by radiation-sensitive and capacitive sensors - Google Patents

Abstract

The arrangement (SENS) has a rain sensor, a capacitive sensor for detecting humidity, and an evaluation device for common evaluation of information about the presence of humidity and rain drop detected by a radiation-sensitive sensor and the capacitive sensor. The radiation-sensitive sensor has a light detection and ranging sensor (LID) and a camera (K). The capacitive sensor has wires and conductive coatings and/or surfaces as capacitive elements (C1-C4). The capacitive elements are arranged such that a detection region of the capacitive sensor extends on a region outside the arrangement. Independent claims are also included for the following: (1) a method for operating a sensor arrangement for a vehicle (2) a computer program product for a sensor arrangement of a vehicle.

Description

The The invention relates to a sensor arrangement for a vehicle with one or several radiation-sensitive sensors.

Under the concept of driver assistance systems (English: ADAS, Advanced Driver Assistance Systems) functions are summarized which the support serve the driver of a motor vehicle. The aim of the driver assistance systems is often Increasing safety by avoiding dangerous situations before its creation and through the assistance of the driver to avoid accidents in critical situations. Other goals are the increase of Comfort through stress reduction and relieving the driver in standard situations, the facilitation of orientation by situationally prepared and driver-friendly conveyed environment information, as well as the increase of Driving pleasure.

Examples for driver assistance functions are traction control and traction control like ABS (Anti-lock Braking System), ASR (Traction Control), ESP (Electronic Traction Control) Stability Program) EDS (electronic differential lock), as well as adaptive cornering light, Up and dimming assistant for the driving lights, night vision systems, cruise control, Parking assistance, Brake Assist, ACC (Adaptive Cruise Control) or Adaptive Cruise Control, Distance warning, turn assistant, traffic jam assistant, lane detection system, lane departure warning, Lane Keeping Support, Lane Change Assistant, ISA (Intelligent Speed Adaptation), ANB (Automatic Emergency braking), curve assistant, tire pressure monitoring system, driver condition detection, Traffic sign recognition, Platooning.

Lots Driver assistance functions usually evaluate information from which one or more radiation-sensitive sensors be recorded. These sensors may, for. For example, radar sensors, optical cameras, ultrasonic sensors, Lidar sensors or infrared sensors act. For the applications ACC (Adaptive Cruise Control) and Traffic Jam Assist, for example, are Lidar sensors, for traffic Jam Assist, Traffic Sign Recognition and Lane Departure Warning optical cameras or video cameras, for blind spot detection and Lane Change Assistant Radar sensors, for Night Vision IR sensors for the near and / or far infrared, for Park Mate ultrasonic sensors, and for Sensitive Guidance optical Cameras and radar sensors.

Of the Invention is based on the object, an efficient sensor arrangement for a Vehicle with one or more radiation-sensitive sensors show, and a corresponding vehicle, a method for Operating a sensor array and a computer program product.

These The object is achieved by a sensor arrangement having the features of the claim 1, as well as by a vehicle, by a method and a computer program product solved with features of independent claims. Advantageous embodiments and further developments are the subject of dependent claims.

The inventive sensor arrangement comprises at least one radiation-sensitive sensor, at least one capacitive sensor for the detection of moisture, as well as an evaluation device for the common evaluation of the radiation-sensitive sensor and the capacitive sensor detected information.

The Sensor arrangement may be integrated in a common housing, which in this case z. B. the at least one radiation-sensitive Sensor and the evaluation device may include; furthermore, in this Case of at least one capacitive sensor attached to the surface of the housing be. It is also possible that the sensor arrangement consists of several individual parts, wherein the Evaluation device connects both to the at least one radiation sensitive sensor as well as to the at least one capacitive Sensor has.

The Sensor arrangement has various types of sensors. On the one hand If one or more radiation-sensitive sensors are present, such as B. a lidar sensor and / or a radar sensor and / or a Camera. For a radiation-sensitive sensor, the measurement is based that electromagnetic radiation of a certain wavelength or a certain wavelength range received and evaluated. Are several radiation sensitive Sensors available, can be sensitive in mutually different wavelength ranges. The type of detectable by the radiation-sensitive sensors Information can - depending on the type of radiation-sensitive sensors used - different be.

To the another is at least one capacitive sensor, by means of of which the presence of moisture can be detected. A capacitive sensor works based on the change in the capacity a single or multiple capacitors, which is measurable. The presence of moisture can be determined by this since these are unchanged Geometry of the capacitive sensor, a change in capacitance over the Condition without or with less moisture causes.

The from the at least one radiation-sensitive sensor and that of the information detected at least one capacitive sensor not separated, but evaluated together. This does not close from that also evaluation steps are present, in which the Information to be treated separately. The evaluation device determines a common evaluation result using both of information acquired by the at least one radiation-sensitive sensor as well as using at least one capacitive Sensor captured information.

In Development of the invention comprises the at least one capacitive Sensor as capacitive elements Wires and / or conductive surfaces and / or conductive coatings. The capacitive elements in this case form one or more capacitors; between They have a potential difference when using the sensor.

one Embodiment of the invention according to are capacitive Elements of the at least one capacitive sensor arranged such that the detection range of the at least one capacitive sensor yourself on an area outside the sensor arrangement extends. The capacitive sensor reacts in this Fall not just to moisture inside or on the surface of the Sensor arrangement, but also to moisture outside the sensor arrangement.

The capacitive elements of the at least one capacitive sensor can, for. B. be applied to a housing of the at least one radiation-sensitive Sensors, or on a lens of at least one radiation-sensitive Sensors, or on one of the at least one radiation-sensitive Sensor attached foil, or in a disc of the vehicle. The type of application or attachment of the capacitive elements can to be done differently, in particular depending on the type of capacitive elements.

In Development of the invention, the evaluation device is formed to decide on one to be carried out a device for the removal of moisture. After this The evaluation device can decide the decision Generate and output appropriate signal.

The Device for removing moisture can be z. B. a heater for the Include sensor arrangement. A decision in favor of the operation of a Heating device of the sensor arrangement falls the evaluation device preferably if, due to the common information evaluation it is determined that the sensor arrangement or parts of the sen soranordnung z. B. misted or iced. The heating of the sensor arrangement can be done using the at least one capacitive sensor. This allows a dual use of the capacitive sensor. Also another heating the sensor arrangement is possible.

The Device for removing moisture can be z. B. a wiper system and / or include a heater of a window of the vehicle. A Decision in favor of the operation a wiper system falls the evaluation device preferably when, due to the common Information evaluation is determined that the disc or parts the disc are moistened with moisture. By heating the Washer, optionally in combination with the wiper system, can Ice be removed from the disc.

The Device for removing moisture can be z. B. an air conditioner and / or include a heater of the vehicle. A decision in favor the operation an air conditioning and / or heating falls the evaluation device preferably if, due to the common information evaluation it is determined that the environment of the sensor arrangement too moist is.

In Development of the invention, the evaluation device is formed for the evaluation of the at least one radiation-sensitive sensor recorded information such that in the air and / or on a Disc of the vehicle located water droplets are detected. A drop of water can in this case from liquid water, or even out Water in solid state consist, for. B. in the form of hailstones or Snowflakes.

In Development of the invention, the evaluation device is formed for the evaluation of the detected by the at least one capacitive sensor Information such that on or outside the sensor array located water droplets are detected. A drop of water can here from liquid water, or also consist of water in solid state, z. In Shape of hailstones or snowflakes.

at the vehicle according to the invention is a sensor arrangement of the explained Kind in the proximity the windshield attached, z. B. in the foot of the rearview mirror.

In the method according to the invention for operating a sensor arrangement for a vehicle, information is acquired from at least one radiation-sensitive sensor, and In Formations detected by at least one capacitive sensor for detecting moisture. Furthermore, there is a joint evaluation of information acquired by the at least one radiation-sensitive sensor and by the at least one capacitive sensor. Furthermore, it is possible to decide on the basis of the evaluation of an operation to be carried out of a device for the removal of moisture.

The Computer program product according to the invention has the functionality an input for receiving information captured by at least a radiation-sensitive sensor, as well as the functionality of a Received for receiving information from at least one capacitive sensor for the detection of moisture, and over the functionality an evaluation component for the joint evaluation of the at least one radiation-sensitive sensor and of the at least a capacitive sensor detected information. Under a computer program product may be in the context of the present invention in addition to the actual computer program (with his over the normal physical interaction between program and arithmetic unit in particular a recording medium for the computer program, a file library, a configured arithmetic unit, as well For example, a storage device or server on or belonging to the computer program Files are stored, understood.

The Computer program product according to the invention and the method of the invention are suitable especially for the sensor arrangement according to the invention, this also applies to the embodiments and developments can. You can do this they include further suitable steps or functionalities.

in the The invention will be explained in more detail with reference to an embodiment. there demonstrate:

1 a sensor arrangement,

2 : an evaluation device for the sensor arrangement.

at Motor vehicles it is common Use rain sensors to automatically control the windscreen wiper. A rain sensor is usually in the foot of the rearview mirror in the upper area the windshield integrated or on the edge of the field of view the disc glued. The operation of a conventional Rain sensor based on an optoelectronic measurement by a IR emitting light emitting diode (LED) and IR radiation receiving and detecting photodiode. The LED sends IR radiation at a certain angle through the disc, taking this angle is set such that when the disc is dry almost the entire amount of light is reflected by total reflection. The photodiode measures the intensity the incident radiation. Rain on the outer surface of the disc changes the refraction behavior: if the disc is wet, it changes The relationship the refractive indexes on the disk surface and thus the light no longer totally reflected, but emerges from the disc, so that only part of the emitted radiation reaches the photodiode. The rain sensor determines in this way the wetting of a small one Part of the disc and allows to estimate the wetting of the entire disk and activate the wiper, when adequate wetting is achieved.

Should the driver driver assistance functions such. B. ACC or traffic sign recognition for disposal be made often forward-facing radiation-sensitive sensors needed, such as z. B. Lidar sensors, radar sensors, cameras. These sensors have to be like that be installed inside the vehicle so that they "see" through the windscreen, without losing sight for the Restrict driver. Thus, in particular, the positioning between the headliner is suitable and the rearview mirror, d. H. the installation location of the conventional Rain sensor. The radiation-sensitive sensor and the rain sensor must therefore in terms of their dimensions and Installation matched to each other.

1 shows a sensor SENS in a housing G, which includes a Lidar sensor LID and a camera K as radiation-sensitive sensors. The housing G consists of a permeable to IR radiation plastic. In the center of the sensor SENS, the camera K is arranged with its lens L; it can be a single camera or a stereo camera arrangement. Under the plastic of the housing G on the right and left side of the camera K are the lenses, as well as transmitter and receiver of the Lidar sensor LID. In order to have sufficient space for the installation of a conventional rain sensor, the lower part of the sensor SENS should have a recess, in 1 shown in dashed lines, which is tailored to the size of the conventional rain sensor.

On the housing G of the sensor SENS capacitive elements C1 and C2, C3 and C4 are applied. In 1 and the following embodiments, the capacitive elements C1 and C2, C3 and C4 are realized by parallel-guided wires, wherein the wires C1 and C2 are parallel to each other and the wires C3 and C4 are parallel to each other. Alternatively to the embodiment of the wires, the capacitive elements C1 and C2, C3 and C4 may be conductive surfaces or coatings. It is the case in each case that the shortest Ver connecting line between the respective mutually belonging capacitive elements lies approximately in the plane of the housing.

The Capacitive elements C1 and C2, C3 and C4 are part of a Capacitive sensor whose operation is the following: the Voltage levels of the individual capacitive elements C1 and C2, C3 and C4 are set so that in each case between the wires C1 and C2 and between the wires C3 and C4 an electric field is present. The electric field is strongest in the plane of the capacitive elements C1 and C2, C3 and C4, d. H. in the plane of the housing G; however, it is not limited to this level, but is also an area outside of the housing G penetrated by the electric field. Are the capacitive elements C1 and C2, C3 and C4 nearby the windscreen, so penetrates the electric field and the disc and the nearby outdoor area in front of the disc. Due to the presence of moisture, z. B. by drops of water on the disk, the electric field is affected. The capacity of the capacitive Elements C1 and C2, C3 and C4 changes thus by the presence of moisture on the disc.

by virtue of the high dielectric constant of Water opposite that of air is the effect of capacity change due to the present of water drops, snowflakes or the like measurable. Here you can different measurement principles are used, for. B. can the change the resonant frequency of the capacitive elements C1 and C2, C3 and C4 resonant circuits can be detected, or it can comparative measurements done with other capacitors.

Thus, the capacitive sensor comprising the capacitive elements C1 and C2, C3 and C4 can be used to detect moisture on the windshield. A conventional rain sensor is thereby unnecessary. Therefore, the adaptation of the outer shape of the sensor SENS, by the dashed recess in 1 indicated, omitted. Thus, more space is available for the lidar sensor LID and the camera K within the housing G, whereby higher-quality lidar sensors LID and the cameras K can be used. Furthermore, it is advantageous that the visual restriction of the driver is reduced because the additional rain sensor can be dispensed with.

Alternatively to the representation of 1 the sensor SENS without housing G can be realized. For this purpose, the sensor SENS is arranged behind the windshield so that the lenses of the lidar sensor LID and the lens L of the camera K are in the immediate vicinity of the windshield. The capacitive elements C1 and C2, C3 and C4 can in this case be applied directly to the lenses of lidar sensor LID and / or camera K.

Instead of the capacitive elements C1 and C2, C3 and C4 directly on the sensor SENS can raise these first on an intermediate layer between the sensor SENS and the disc are applied, for. B. a slide. In the installation of the sensor SENS is the intermediate layer in direct contact to the sensor SENS, so that the effect of this embodiment after the installation of the sensor SENS equal to that of the direct application the capacitive elements C1 and C2, C3 and C4 to the sensor SENS is. One more way is the capacitive elements C1 and C2, C3 and C4 within the To install disc. In general, the disc consists of two layers, which are interconnected by means of an adhesive layer. Between These two layers can be the capacitive elements C1 and C2, C3 and C4 may be arranged.

The Capacitive elements C1 and C2, C3 and C4 may be within the beam range of the lidar sensor LID and / or the camera K run. by virtue of the small distance between the lenses and the capacitive elements C1 and C2, C3 and C4 and the thinness the wires C1 and C2, C3 and C4 become the capacitive elements C1 and C2, C3 and C4 from the lidar sensor LID and the camera K did not notice. Should nevertheless a disturbance of the Radiation detection of Lidar sensor LID and / or camera K through the capacitive elements C1 and C2, C3 and C4 occur, they can of course outside or at the edge of the beam areas.

As already explained, the capacitive sensor detects moisture on the disc. Farther The capacitive sensor also reacts when moisture directly between the capacitive elements C1 and C2, C3 and C4 or precipitate. In this case, it can be assumed that the lens L is the Camera K and possibly also the lens of the lidar sensor LID or the housing G is fogged. Because at unfavorable weather conditions can be the optically effective surface fogged by lidar sensor LID and camera K or at very low Temperatures even freeze, allowing the functioning of Lidar sensor Limited LID and camera K or impossible is.

It is thus possible that the use of Camera K and Lidar sensor LID is limited possible, even if the windshield wiper, the drops are removed on the disc. Therefore, the sensor SENS should be heated. In this case, it is advantageous to use the capacitive elements C1 and C2, C3 and C4 as a heating element. By connecting the ends of the capacitive elements C1 and C2 together, and correspondingly also of the capacitive elements C3 and C4, a current flow through the capacitive elements C1 and C2, C3 and C4 can be established which leads to heating of the capacitive elements C1 and C2 , C3 and C4 and thus also the sensor SENS leads. The capacitive elements C1 and C2, C3 and C4 are used in this case secondarily as heating elements. This is particularly advantageous because the sensor SENS is usually not or only poorly ventilated, so that defrosting or evaporation of moisture on the surfaces of the sensor SENS without heating may take a long time. The heating of the sensor SENS is also useful if there is ice on the disk in the field of view of the sensor SENS, because by heating the sensor SENS this ice can be defrosted.

In 2 an evaluation device S is shown, which represents a part of the sensor SENS. The evaluation device S receives from the capacitive sensor information IN1 about the presence of moisture, which are evaluated by the evaluation device S.

Farther receives the evaluation device S of lidar sensor LID and / or camera K captured data as information IN2. In the air and / or on the Windshield located drops, such. B. raindrops, fog or also snow or hail, are detected by the lidar sensor LID. These structures reflect the light emitted by the Lidar sensor LID Radiation, allowing detection of the reflected radiation the presence of the respective structures can be concluded. Also, the pictures taken by the camera K can be See if rain, snow or fog is present in the outside air and / or on the windshield is.

The Evaluation device S evaluates the information IN1 and IN2 together out. The capacitive sensor indicates moisture and shows the Information IN2 water drops or similar, so should the windshield wiper actuated become. The decision about that and to what extent the To operate windscreen wipers is, is hit by the evaluation device S. About the Interface I will issue a corresponding instruction to one for the actuation of the Windscreen wiper responsible Unit spent.

Shows the capacitive sensor humidity and show the information IN2 no water drops o. Ä. On, the sensor SENS should be heated. The decision about that a heater of the sensor SENS is to be operated by the evaluation device S met. about the interface I will issue a corresponding instruction to one for the actuation of Heating competent Unit spent. The heater can be as above explained to act on the capacitive elements C1 and C2, C3 and C4, or a different kind of heating. Instead of or in addition to direct heating of the sensor SENS it is possible to Purposes of removing moisture from the sensor SENS the heating, optionally in combination with the air conditioning system of the vehicle to press.

The The invention has been described above with reference to an exemplary embodiment. It is understood that numerous changes and modifications are possible, without departing from the scope of the invention.

Claims (16)

Sensor arrangement (SENS) for a vehicle, comprising at least a radiation-sensitive sensor (LID, K), at least one capacitive sensor for the detection of moisture, and an evaluation device (S) for the common evaluation of the at least one radiation-sensitive Sensor (LID, K) and the at least one capacitive sensor detected Information (IN1, IN2). Sensor arrangement (SENS) according to claim 1, wherein the at least one radiation-sensitive sensor (LID, K) a Lidar sensor (LID) and / or a radar sensor and / or a camera (K) includes. Sensor arrangement (SENS) according to claim 1 or 2, at which is the at least one capacitive sensor as capacitive elements (C1, C2, C3, C4) wires and / or conductive surfaces and / or conductive Coating includes. Sensor arrangement (SENS) according to one of claims 1 to 3, wherein capacitive elements (C1, C2, C3, C4) of at least a capacitive sensor are arranged such that the detection area of the at least one capacitive sensor extends to an area outside the sensor array (SENS) extends. Sensor arrangement (SENS) according to one of claims 1 to 4, wherein capacitive elements (C1, C2, C3, C4) of the at least one capacitive sensor are applied • on a housing (G) of the at least one strah sensor (LID, K), or • on a lens (L) of the at least one radiation-sensitive sensor (LID, K), or • on a film attached to the at least one radiation-sensitive sensor (LID, K), or • in a disk of the vehicle. Sensor arrangement (SENS) according to one of claims 1 to 5, in which the evaluation device (S) is designed to decide on a to be carried out a device for the removal of moisture. Sensor arrangement (SENS) according to claim 6, wherein the moisture removal device is a heating device for the Sensor arrangement (SENS) includes. Sensor arrangement (SENS) according to claim 7, wherein the heating of the sensor assembly (SENS) by the heater is done using the at least one capacitive sensor. Sensor arrangement (SENS) according to one of claims 6 to 8, in which the device for removing moisture a wiper system and / or a heating of a window of the vehicle. Sensor arrangement (SENS) according to one of claims 6 to 9, in which the device for removing moisture includes air conditioning and / or heating of the vehicle. Sensor arrangement (SENS) according to one of claims 1 to 10, in which the evaluation device (S) is designed for Evaluation of the at least one radiation-sensitive sensor (LID, K) recorded information (IN2) such that in the air and / or detected on a slice of the vehicle water drops detected become. Sensor arrangement (SENS) according to one of claims 1 to 11, in which the evaluation device (S) is designed for Evaluation of the detected by the at least one capacitive sensor Information (IN1) such that on or outside the sensor array (SENS) water drops are detected. Vehicle with a sensor arrangement (SENS) after a the claims 1 to 12, wherein the sensor assembly (SENS) in the vicinity of the windshield is appropriate. Method for operating a sensor arrangement (SENS) for a Vehicle, being of at least one radiation sensitive Sensor (LID, K) information (IN2) can be detected of at least a capacitive sensor for the detection of moisture information (IN1) are detected, a joint evaluation of the at least one radiation-sensitive sensor (LID, K) and the at least one capacitive sensor detected information (IN1, IN2). The method of claim 14, wherein due to the evaluation of a to take place an operation Device for eliminating moisture is decided. Computer program product for a sensor arrangement (SENS) for a Vehicle, with an input for receiving information (IN2) detected by at least one radiation-sensitive sensor (LID, K) an input for receiving information (IN1) at least one capacitive sensor for detecting moisture, one Evaluation component for the joint evaluation of at least a radiation-sensitive sensor (LID, K) and the at least a capacitive sensor detected information (IN1, IN2).