Detection device for detecting objects in at least one monitoring area by analyzing polarization components of electromagnetic waves reflected at the objects

Abstract

A detection device (16) for detecting objects in at least one monitoring area, a road condition detection system, a driver assistance system, a vehicle and a method for detecting at least one property of an object. The detection device (16) comprises at least one receiving device (24) designed for receiving electromagnetic receiving waves (34) and converting received electromagnetic receiving waves (34) into processable receive signals (46). The at least one receiving device (24) comprises at least one receiving unit (40) for receiving electromagnetic receiving waves (34) and at least one polarization filter unit (38) arranged in propagation direction (Xr) of the electromagnetic receiving waves (34) in front of the at least one receiving unit (40). The at least one polarization filter unit (38) is designed for defining four different transmission polarization directions (50) for the electromagnetic receiving waves (34). The at least one receiving device (24) is designed for converting polarization components of the electromagnetic receiving waves (34) with four different polarization directions (50) separately into respective receive signals (46).

Description

[0001]1 / 34 2023PF00717 Description Detection device for detecting objects in at least one monitoring area by analyz- ing at least two polarization components of electromagnetic waves reflected at the objects Technical Field The present invention relates to a detection device for detecting objects in at least one monitoring area, in particular a detection device for a road condition detection system, in particular for a vehicle, comprising at least one receiving device designed for receiving electromagnetic receiving waves and converting received electromagnetic receiving waves into processable receive signals, the at least one receiving device comprises at least one receiving unit for receiving elec- tromagnetic receiving waves and at least one polarization filter unit arranged in propaga- tion direction of the electromagnetic receiving waves in front of the at least one receiving unit, where the at least one polarization filter unit is designed for defining at least two trans- mission polarization directions for the electromagnetic receiving waves, so that only the polarization components of the electromagnetic receiving waves with the defined at least two transmission polarization directions can pass the at least one polarization filter unit, where the at least one polarization filter unit is designed for defining at least two different transmission polarization directions and the at least one receiving device is designed for converting polarization components of the electromagnetic receiving waves with at least two different polarization directions separately into respective receive signals. Further, the invention relates to a road condition detection system, in particular a road condition detection system for a vehicle, for identifying the condition of a road, comprising at least one detection device for detecting objects in at least one monitoring area, the at least one detection device comprising at least one receiving device designed for receiving electromagnetic receiving waves and converting received electromagnetic receiving waves into processable receive signals, where the road condition detection system com- prises at least one evaluation device for processing receive signals from the at least one detection device into data characterizing at least one property of the road. Furthermore, the invention relates to a driver assistance system for a vehicle, comprising at least one detection device for detecting objects in at least one monitoring area, the at 2 / 34 2023PF00717 least one detection device comprising at least one receiving device designed for receiving electromagnetic receiving waves and converting received electromagnetic receiving waves into processable receive signals, where the driver assistance system comprises at least one control unit for the semiautonomous or autonomous control of functions of the vehicle. Moreover, the invention relates to a vehicle comprising at least one detection device for detecting objects in at least one monitoring area, the at least one detection device com- prises at least one receiving device designed for receiving electromagnetic receiving waves and converting received electromagnetic receiving waves into processable receive signals. In addition, the invention relates to a method for detecting at least one property of an object, in particular for detecting a condition of a road, by use of at least one detection device, in particular by use of at least one detection device of a vehicle, at which electro- magnetic receiving waves are received by at least one receiving device of the at least one detection device and the received electromagnetic receiving waves are converted into processable receive signals, the received electromagnetic receiving waves are filtered with at least one polarization filter unit in such a way that only the polarization components of the electromagnetic re- ceiving waves with defined at least two transmission polarization direction can pass through the at least one polarization filter unit, where the at least two transmission polar- ization directions are defined with the at least one polarization filter unit, the polarization components of the electromagnetic receiving waves that pass through the at least one polarization filter unit are received with at least one receiving unit of the at least one receiving device, and the received polarization components of the at least one electromagnetic receiving wave are converted into receive signals, where the polarization components of the electromagnetic receiving waves with the at least two different transmission polarization directions are filtered and the polarization components with the at least two different transmission polarization di- rections are converted separately into respective receive signals. 3 / 34 2023PF00717 State of Technology From the JP2005043240 a sensor for detecting a road surface conditions, which can precisely distinguish the road surface conditions is known. The sensor for detecting the road surface conditions is composed of a light source having at least an infrared wave- length range; a first analyzer arranged on an optical path through which incident light emitted from the light source is projected onto the road surface and transmitting only polarized light with a first orientation in the incident light. A polarizing beam splitter (po- larization branching means) separates reflected light based on its polarization direction, transmitting polarized light (S-polarized light) having a polarization direction which is a first direction that is the same as the projected light, and reflecting polarized light (P- polarized light) having a polarization direction which is a second direction perpendicular to the projected light. Transmitted light (S-polarized light) passes through the polarizing beam splitter. Reflected light (P-polarized light) having a polarization direction, which is the second direction, is reflected by the polarizing beam splitter. A third photodetector receives the transmitted light and converts it into an electrical signal. A half mirror divides the reflected light in two. A fourth photodetector receives one of the lights separated by the half mirror. Third and fourth amplifiers amplify output signals from the third and fourth photodetectors, respectively. A comparator inputs output signals from the amplifiers, compares the intensity of each output signal, and identifies the road surface condition. It is an objective of the invention to provide a detection device, a road condition detection system, a driver assistance system, a vehicle and a method of the type mentioned above, in which the detection properties can be achieved more efficiently, in particular the detec- tion device can be made more compact. Disclosure of Invention The objective of the invention is solved in the detection device in that the at least one polarization filter unit is designed for defining four different transmission polarization directions and the at least one receiving device is designed for converting polarization components of the electromagnetic receiving waves with four different po- larization directions separately into respective receive signals and the detection device comprises at least one evaluation device that comprises a means to analyze the polarization of the electromagnetic receiving waves based on the 4 / 34 2023PF00717 receive signals of the polarization components with the four different polarization direc- tions. According to the invention, the detection device comprises at least one polarization filter unit. The polarization filter unit is arranged in propagation direction of the electromagnetic receiving waves in front of at least one receiving unit. With the polarization filter unit four different transmission polarization directions for the electromagnetic receiving waves can be defined. Only the polarization components of the electromagnetic receiving waves with the defined transmission polarization directions can pass through the at least one polari- zation filter unit. The at least one receiving device is designed for converting polarization components of the electromagnetic receiving waves with the four different polarization directions separately. The detection device comprises at least one evaluation device that comprises a means to analyze the polarization of the electromagnetic receiving waves based on the receive signals of the polarization components with the four different polarization directions. Based on the receive signals of the four different polarization directions, the properties of the materials, e.g. dry asphalt, wet asphalt, ice or snow, from which the electromagnetic receiving waves are reflected, can be determined very precisely. The detection device according to the invention can be used for polarimetry. In this way, the detection device can detect the presence of ice, water, snow or other substances on a road by analyzing the polarization of the receiving waves, in particular by analyzing changes of polarizations of the receiving waves, coming from the road. The detection device according to the invention can also analyze electromagnetic receiv- ing waves from the environment. The electromagnetic receiving waves are not neces- sarily reflected electromagnetic waves originating from electromagnetic illumination waves transmitted by a transmitter of the detection device. The detection device can also be a passive detection device without a transmitting device. The filter elements of the detection device are not limited to use as optical noise filters. The filter elements are not limited to selecting only the polarization of receiving waves originating from polarized il- lumination waves transmitted from the detection device. 5 / 34 2023PF00717 The detection device according to the invention can be used to analyze polarization prop- erties of electromagnetic receiving waves received by the detection device. The polariza- tion properties of the electromagnetic receiving waves depend on the properties of the object on which the electromagnetic receiving waves are reflected. Advantageously, the electromagnetic receiving waves can be electromagnetic illumina- tion waves that are generated by at least one transmitting device of the detection device and reflected by an object, in particular by the road. Alternatively or additionally, the elec- tromagnetic receiving waves can be natural or artificial electromagnetic waves from the environment, e.g. sunlight or artificial light, reflected by an object, in particular by the road. It is well known that the reflection property of an object depends on the material property of the object. In particular, the reflection property of water is different to the reflection property of ice and different to the reflection property of snow. In this way, by use of the detection device according to the invention, water, ice and snow, for example, can be distinguished. In this way, the properties of objects, that are detected with the by use of the detection device, can be determined more efficient. In particular, with the detection device the condition of a road in the monitoring area can be detected more accurate. By use of the detection device according to the invention, it can be discriminated between the materials of the road. Specifically it can be distinguished between dry asphalt, wet asphalt, icy road or snowy road, etc. By using the detection device according to the invention, the environment can be evalu- ated more efficiently in order to use the information for autonomous or semiautonomous driving, for example. Since the at least one receiving unit and the at least one polarization filter unit are part of the detection device, the detection device according to the invention can be formed more compact. Advantageously, the receive signals can be electrical receive signals. Electrical receive signals can be processed by use of electronic devices, such as electronic processors or the like. 6 / 34 2023PF00717 The invention can be used with vehicles. A key functional characteristic of a vehicle is its ability to move. Vehicles can be motor vehicles. Advantageously, the invention can be used in land vehicles, in particular passenger cars, trucks, buses, motorcycles, drones, mobile robots, mobile machines, in particular construction or transport machines, such as cranes, excavators or the like, aircraft, in particular flying drones, and / or water vehicles, in particular water drones. The invention can also be used with vehicles that can be op- erated autonomously or semiautonomously. However, the invention is not limited to ve- hicles. It can also be used in stationary operation. The detection device can be used to detect stationary or moving objects, in particular vehicles, persons, animals, obstacles, roads, road surfaces, road unevenness, in partic- ular potholes or stones, road limitations, open spaces, in particular parking spaces, pre- cipitations or the like. According to a favorable embodiment, the means to analyze the polarization of the elec- tromagnetic receiving waves can be designed to carry out a Stokes formalism to identify at least a part of the Stokes parameters for the electromagnetic receiving waves. The polarization state, the angle of linear polarization and / or the degree of linear polarization of the electromagnetic receiving waves can be derived from the Stokes parameters. The polarization state, the angle of linear polarization and / or the degree of linear polarization of the electromagnetic receiving waves depend on the properties of the material from which the electromagnetic receiving waves are coming. In this way, it can be discrimi- nated between the materials, in particular asphalt, wet asphalt, ice road or snowy road or the like. According to another favorable embodiment, at least one polarization filter unit can comprise four polarization filter elements, where each of the polarization filter elements is designed for defining an individual transmission polarization direction, where the individual transmission polarization directions of the four polarization filter elements are different, and / or at least one polarization filter unit can be adjustable for defining four different transmission polarization directions. 7 / 34 2023PF00717 Advantageously, at least one polarization filter unit can comprise four polarization filter elements. Each of the polarization filter elements can be designed for defining an individ- ual transmission polarization direction. In this way, four transmission polarization direc- tions can be defined by use of the polarization filter unit. The four different polarization components with four different transmission polarization directions can be received and converted separately. Polarization filter elements can easily be manufactured. Advantageously, the individual transmission polarization direction of the four polarization filter elements can be different. In this way, four different transmission polarization direc- tions can be defined by use of the polarization filter unit. In this way, changes of the po- larization of the receiving waves can be analyzed. The four individual polarization filter elements can be individually specified with regard to the polarization direction. In contrast, a polarizing beam splitter known from the state of technology allows only two perpendic- ular polarization directions. The specification of four individual, e.g. 45° different trans- mission polarization directions is not possible with a polarizing beam splitter. This is only possible with individual polarization filter elements according to the invention. Advantageously, the at least one polarization filter unit can be designed for defining four different transmission polarization directions with polarization angles of 0°, -45°, 45° and 90° with respect to a suitable coordinate system, in particular an orthogonal coordinate system. One axis of the coordinate system can be the propagation direction of the elec- tromagnetic receiving waves. The two other axes can be perpendicular to the propagation direction. Advantageously, one of the two other axes can lie in a horizontal plane. The third axis can lie in a vertical plane. In this way, the material properties of horizontal planes of an object and of vertical planes of an object can be identified more accurate. With four polarization filter elements, the four transmission polarization directions 0°, +45°, -45° and 90° can be defined. Alternatively or additionally, at least one polarization filter unit can be adjustable for de- fining four different transmission polarization directions. In this way, the different trans- mission polarization directions can easily be adjusted. An adjustable polarization filter can be switched between the four different transmission polarization directions. 8 / 34 2023PF00717 Advantageously, at least one polarization filter unit can be adjustable for four different transmission polarization directions. In this way, the four transmission polarization direc- tions of 0°, 45°, -45° and 90° can be defined. Advantageously, the at least one polarization filter unit can be adjusted automatically for defining four different transmission polarization directions. In this way, the at least one polarization filter unit can be controlled by use of a control unit. According to another favorable embodiment, at least one receiving unit can comprise four receiving elements, that are designed for converting electromagnetic receiving waves separately, and / or at least one receiving unit can be controllable for successive conversions of four electro- magnetic receiving waves. Advantageously, at least one receiving unit can comprise four receiving elements. With the four receiving elements, four filtered electromagnetic receiving waves filtered by the respective four polarization filter elements can be received and converted separately. In this way, the electromagnetic receiving waves can be analyzed for their respective polar- ization components. With four receiving elements, the polarization components of filtered electromagnetic receiving waves with four different transmission polarization directions can be analyzed. In this way, polarization components for the transmission polarization directions of 0°, 45°, -45° and 90° can be analyzed separately. Advantageously, the four polarization filter elements can be arranged next to each other when viewed in the propagation direction of the electromagnetic receiving waves. In this way, the polarization filter unit can be realized in a space-saving manner. Advantageously, the four receiving elements can be arranged next to each other when viewed in the propagation direction. In this way, the receiving device can be realized in a space-saving manner. Advantageously, the receiving elements can be arranged behind the corresponding po- 9 / 34 2023PF00717 larization filter elements when viewed in the propagation direction. In this way, the detec- tion device can be realized in a space-saving manner. Additionally or alternatively, at least one receiving unit can be controllable for successive conversions of the polarization components of four filtered electromagnetic receiving waves filtered by the respective four polarization filter elements. In this way, only one receiving element is required for the separate conversion of the polarization components of four filtered electromagnetic receiving waves. So, the number of required receiving elements can be reduced. Advantageously, at least one controllable receiving unit can be combined with at least one adjustable polarization filter unit. In this way, the four different transmission polariza- tion directions can be defined one after the other, e.g. by trigger signals, and the respec- tive polarization components of the electromagnetic receiving waves can be converted one after the other, e.g. by triggering the controllable at least one receiving unit. So, the detection device can be designed even more compact. According to another favorable embodiment, at least one polarization filter unit can com- prise at least one polarization filter element for defining an individual transmission polari- zation direction, and at least one receiving unit can comprise at least one receiving ele- ment for converting electromagnetic receiving waves, where at least one polarization filter element is assigned to at least one receiving element. In this way, the at least one polar- ization filter unit can filter the electromagnetic receiving waves so that only the defined polarization components can reach the at least one receiving element. Advantageously, at least one polarization filter unit can comprise four polarization filter elements and at least one receiving unit can comprise four receiving elements, where the four polarization filter elements are each be assigned to one of the four receiving ele- ments. In this way, four different polarization components can be received and converted separately at the same time. Advantageously, polarization filter elements of the at least one polarization filter unit each can be assigned to one respective receiving element of the at least one receiving unit. In 10 / 34 2023PF00717 this way, the polarization components each can be assigned directly to one of the receiv- ing elements. Advantageously, at least one polarization filter element can be designed as polarization layer on a respective receiving element. In this way, the at least one receiving device can be designed more compact. According to another favorable embodiment, the at least one receiving device can com- prise at least one assigning system for electromagnetic waves, in particular an optical system, that is arranged in front of the at least one polarization filter unit in propagation direction of the electromagnetic receiving waves and that is designed for assigning at least one monitoring area to the at least one polarization filter unit. In this way, electro- magnetic receiving waves coming from the at least one monitoring area can be assigned to the at least one polarization filter unit. The at least one polarization filter unit can be used to analyze the polarization compo- nents of the electromagnetic receiving waves. In this way, a predefined monitoring area can be monitored. The monitoring area can be an area on a road. In this way, the road condition can be identified by use of the detection device according to the invention. Advantageously, at least one assigning system can be set between at least two different monitoring areas. In this way, at least two different monitoring areas can be monitored with just one detection device. Advantageously at least one assigning system can consist of or comprise at least one optical component. In this way, optical electromagnetic receiving waves, such as light waves, can be received and processed by use of the detection device. Advantageously, at least one assigning system can be an optical system. In this way, the assignment of the at least one monitoring area to the at least one filter unit can be im- proved. According to another favorable embodiment, the detection device can comprise at least two receiving devices that are assigned to different individual monitoring areas. In this 11 / 34 2023PF00717 way, several individual monitoring areas can be monitored simultaneously with the at least two receiving devices. According to another favorable embodiment, the detection device can comprise at least one transmitting device for transmitting electromagnetic illumination waves, in particular linear polarized electromagnetic illumination waves, which may be reflected in at least one monitoring area, where the reflected electromagnetic illumination waves may be re- ceived as electromagnetic receiving waves by use of the at least one receiving device of the detection device. In this way, the at least one monitoring area can be actively illumi- nated. So, a defined illumination of the monitoring area can be realized. Further, a corre- lation between the transmitted electromagnetic illumination waves and the received elec- tromagnetic receiving waves can be used to obtain further information about a monitoring area. Advantageously, by transmitting electromagnetic illumination waves and receiving the re- flected electromagnetic receiving waves, time of flight measurements can be carried out. Advantageously, the detection device can be combined with a LiDAR system. In this way, distances of objects can be determined. Advantageously, the at least one transmitting device can be designed for transmitting linear polarized electromagnetic illumination waves. In this way, the analysis of the polar- ization components of the electromagnetic received receiving waves can be further im- proved. The linear polarized electromagnetic illumination waves can be polarized with the same polarization direction as at least one of the polarization directions of the at least one po- larization filter unit. In this way the efficiency of the detection device can be further im- proved. Advantageously, the at least one transmitting device can be designed for transmitting electromagnetic illumination waves that are polarized linearly at -40° or +45° with respect to the coordinate system of the receiving device. In this way, electromagnetic receiving waves coming from horizontal extended objects, such as a road, can be analyzed more exact. 12 / 34 2023PF00717 According to another favorable embodiment, the detection device can be designed as an optical detection device, in particular an optical sensor system, a camera system or a LiDAR system, or as a radar system. An optical detection device can use light as electro- magnetic receiving waves and, if so, as electromagnetic illumination waves. Advantageously, the detection device can be designed for the use of electromagnetic waves in near infrared. In this way, a disturbance from artificial ambient light, in particular vehicle headlights, can reduced. Advantageously, the detection device can be a camera system. The camera system can be used to generate an at least two-dimensional picture of the monitoring area. Alternatively, the detection device can be designed as a LiDAR system. In this way, dis- tances of objects, in particular a road, in the monitoring area can be determined. Alternatively, the detection device can be designed as a radar system. The radar system can use electromagnetic receiving waves and electromagnetic illumination waves in form of radar signals. According to another favorable embodiment, the at least one receiving unit can comprise at least one optical receiving element, in particular at least one photodiode, at least one pixel of an image sensor, a charge coupled device or an active pixel sensor or the like, or the at least one receiving unit can comprise at least one receiving element that is de- signed as a radar antenna or a radar antenna element. Optical receiving elements can be used for receiving optical waves as electromagnetic receiving waves, such as light, for example near infrared light. Radar antennas or radar antenna elements can be used for receiving radar waves as electromagnetic receiving waves. 13 / 34 2023PF00717 According to another favorable embodiment, the detection device can comprise at least one evaluation device that is designed for processing the receive signals into at least one data element, that characterizes the prop- erty of an object, in particular a condition of a road, from which the received at least one electromagnetic receiving wave is reflected, and / or the detection device can comprise at least one evaluation device that is designed for processing the receive signals, where the at least one evaluation device can comprise or use at least a part of the Stokes formalism, at least one lookup table, at least one deep learning method or the like. Advantageously, the detection device can comprise at least one evaluation device that is designed for processing the receive signals into at least one data element. The at least one data element can characterize the property of an object from which the received at least one electromagnetic receiving wave is reflected. In this way, the detection device can be used for characterizing objects. Advantageously, the at least one data element can characterize the condition of a road. A road can be an object, from which the at least one electromagnetic receiving wave is reflected. In this way, the detection device can be used for identifying the condition of the road. In particular, it is possible to detect whether the road is dry, wet, icy or snow-cov- ered. Advantageously, the at least one evaluation device can comprise or use at least a part of the Stokes formalism, at least one lookup table, deep learning methods or the like. The Stokes formalism can be used to process Stokes parameters based on the intensities of the received at least two polarization components of the electromagnetic receiving waves. Based on the Stokes parameters, the polarization state, the angle of linear polarization and / or the degree of linear polarization of the received electromagnetic receiving waves can be determined. The polarization state, the angle of linear polarization and the degree of linear polarization depend on the material properties of the object from which the elec- tromagnetic receiving waves are reflected. It is known, that the Stokes parameters S0, S1, S2, S3 are a set of values that describe the 14 / 34 2023PF00717 polarization state of electromagnetic radiation. The Stokes formalism describes the po- larization state of the wave (PS) based on the Stokes parameters. The Stokes parameters S1, S2 and S3 can be parameterized one a so-called Poincaré sphere in spherical coor- dinates. The Stokes parameters can be determined from the intensities I of the four polarization components of the electromagnetic receiving wave with polarization directions of 0°, 45°, -45° and 90°. Therefore, the following, well known relationship can be used: ^^ ≡ ^^0°^ + ^^90°^^^ ≡ ^^0°^ − ^^90°^^^ ≡ ^^45°^ + ^^−45°^^^ ≡ ^^^^^^ + ^^^^^^The intensities I(0°) , I(-45°), I(45°) and I(90°) can be determined based on the receive signals for the respective linear polarization directions of 0°, 45°, -45° and 90°. The fourth Stokes parameter S3 can be determined from the intensity of the right-hand circularly polarized component I(RHC) and the intensity of the left-hand circularly polarized com- ponent I(LHC). The intensities I can be values that characterize the power energy of the respective polarization component. Further, following relationship is known for partially polarized waves: ^^ ^ ^ ^^ ≥ ^^ + ^^ + ^^For well polarized waves, e.g. coherent light, it is: ^^ = ^ ^ ^ ^^ ^ + ^^ + ^^Thus, by determining the first three Stokes parameters S0, S1, S2 , that are based on the 15 / 34 2023PF00717 measured intensities I(0°), I(-45°), I(45°) and I(90°), the Stokes parameter S3 can be de- termined, if the receiving wave is polarized. Otherwise, the value of the Stokes parameter S3 can be roughly estimated. The Stokes parameters S0, S1, S2, S3 can be used for determining the polarization state of light PS, the angle of linear polarization AP and the degree of linear polarization DP using the following relationships: The Stokes parameters S0, S1, S2, S3, the polarization state of light PS, the angle of linear polarization AP and the degree of linear polarization DP depend on material properties of the object, from which the electromagnetic receiving waves are reflected. Thus, according to the invention the Stokes parameters S0, S1, S2, S3, the polarization state of light PS, the angle of linear polarization AP and the degree of linear polarization DP can be used to differentiate between the materials of the object. Advantageously, it can be determined whether a road is dry, wet, icy or snow-covered. Advantageously, the at least one evaluation device can use at least one lookup table. In this way, the intensity is of the polarization components of the received electromagnetic receiving waves can be directly compared with data elements in the lookup table. By use of deep learning methods, the at least one evaluation means can be further im- proved. Further, the objective of the invention is achieved with the road condition detection system 16 / 34 2023PF00717 by that the at least one detection device is a detection device according to the invention. According to the invention, the road condition detection system comprises at least one detection device. The at least one detection device can be used for analyzing the polari- zation components of electromagnetic receiving waves, that are reflected at objects in at least one monitoring area of the at least one detection device. The intensities of the po- larization components depend on the material properties of the reflecting object. In this way, it can be determined for example, whether the road is dry, wet, icy or snow-covered. The road condition detection system according to the invention can be designed very compact. Further, the road condition detection system is extremely accurate. Advantageously, the at least one detection device can comprise at least one receiving device designed for receiving electromagnetic receiving waves and converting received electromagnetic receiving waves into processable receive signals. Advantageously, the at least one receiving device can comprise at least one receiving unit for receiving elec- tromagnetic receiving waves and at least one polarization filter unit arranged in propaga- tion direction of the electromagnetic receiving waves in front of the at least one receiving unit. Advantageously, the at least one polarization filter unit can be designed for defining four transmission polarization directions for the electromagnetic receiving waves, so that only the polarization components of the electromagnetic receiving waves with the defined four transmission polarization direction can pass the at least one polarization filter unit. Advantageously, the at least one polarization filter unit can be designed for defining four different transmission polarization directions. Advantageously, the at least one receiving device can be designed for converting polarization components of the electromagnetic receiving waves with four different polarization directions separately into respective re- ceive signals. Furthermore, the objective of the invention can be achieved with the driver assistance system by that the at least one detection device is a detection device according to the invention. With the driver assistance system according to the invention functions of a vehicle, in particular driving functions, can be controlled autonomously or semiautonomously based on information about objects, that are detected by use of the at least one detection device. 17 / 34 2023PF00717 In this way, the autonomous or semiautonomous operation of the vehicle can be im- proved. Advantageously, the driver assistance system can comprise at least one road condition detection system, in particular at least one road condition detection system according to the invention. In this way, the information obtained with the road condition detection sys- tem about the condition of a road on which the vehicle is driving can be used for autono- mous or semiautonomous control of vehicle functions. Moreover, the objective of the invention can be achieved by the vehicle by that the at least one detection device is a detection device according to the invention. Advantageously, the vehicle can comprise at least one driver assistance system, in par- ticular at least one driver assistance system according to the invention. With the driver assistance system functions of a vehicle, in particular driving functions, can be controlled autonomously or semiautonomously based on information about objects, that are de- tected by use of the at least one detection device, in particular the at least one detection device according to the invention. In this way, the autonomous or semiautonomous oper- ation of the vehicle can be improved. Advantageously, the vehicle can comprise at least one road condition detection system, in particular at least one road condition detection system according to the invention. In this way, the information obtained with the road condition detection system about the condition of a road on which the vehicle is driving can be used for autonomous or semi- autonomous control of vehicle functions. In addition, the objective of the invention is achieved with the method by that four different transmission polarization directions are designed by use of the at least one filter unit, the polarization components of the electromagnetic receiving waves with four different polarization directions filtered by the at least one polarization filter unit are converted separately into respective receive signals by use of the at least one receiving device, and the polarization of the electromagnetic receiving waves is analyzed based on the receive 18 / 34 2023PF00717 signals from the polarization components with the four different polarization directions. According to invention, the polarization components of electromagnetic receiving waves reflected at objects, e.g. a road, are analyzed. The analyzed polarization components are received by at least one receiving unit and converted into respective receive signals. The receive signals can be processed into data elements. The data elements can characterize the property, in particular the material, of the object that reflects the electromagnetic re- ceiving waves. Advantageously, a road condition of a road can be identified based on the determined receive signals. Thus, the method according to the invention can be carried out in combination with or by a road condition detection system, in particular a road con- dition detection system according to the invention. Advantageously, at least parts of the method for detecting a property of an object can be formed by software means, in particular by algorithms or the like. Advantageously, at least parts of the method can be integrated into at least one detection device, in particular at least one detection device according to the invention, a road con- dition detection system, in particular a road condition detection system according to the invention, a driver assistance system, in particular a driver assistance system according to invention, and / or a vehicle, in particular a vehicle according to the invention. According to a favorable embodiment, the Stokes formalism can be carried out to identify at least one of the Stokes parameters for the electromagnetic receiving waves. The po- larization state, the angle of linear polarization and / or the degree of linear polarization of the electromagnetic receiving waves can be derived from the Stokes parameters. According to another favorable embodiment, the received polarization components of the electromagnetic receiving wave can be converted into receive signals that characterize the signal intensities of the received polarization components. In this way, the polarization state of the received electromagnetic receiving waves can be determined based on the signal intensities. According to another favorable embodiment, 19 / 34 2023PF00717 based on receive signals belonging to the four polarization components with the four po- larization directions at least one property information that characterizes a property of an object, in particular a condition of a road, at which the electromagnetic receiving waves are reflected, can be determined and / or based on a relation between the receive signals belonging to the four polarization com- ponents with the four polarization directions at least one property information can be de- termined and / or based on the receive signals belonging to the four polarization components with the four polarization directions at least one property information that characterizes a property of an object, in particular a condition of a road, at which the electromagnetic receiving waves are reflected, can be determined using the Stokes formalism and / or based on the receive signals belonging to the four polarization components with the four polarization directions at least one Stokes parameter and / or a polarization state and / or an angle of linear polarization and / or a degree of linear polarization of the at least one electromagnetic receiving wave can be processed and based on at least one Stokes pa- rameter and / or a polarization state and / or an angle of linear polarization and / or a degree of linear polarization at least one property information that characterizes a property of an object, in particular a condition of a road, at which the electromagnetic receiving waves are reflected, can be determined. Advantageously, based on the receive signals at least one property information of an object can be determined. In this way, a direct and fast correlation between the receive signals and the material properties can be determined. Advantageously, based on a relation between the receive signals at least one property information of an object can be determined. In this way, a further information, namely the relation between the receive signals, can be used for determining the property infor- mation. In this way, the at least one property information can be determined more accu- rately. 20 / 34 2023PF00717 Advantageously, based on receive signals at least one property information can be de- termined using the Stokes formalism. The Stokes formalism describes the polarization state of electromagnetic waves, like light, for a wave propagating along a propagation direction. Using the Stokes formalism, four Stokes parameters can be calculated based on the intensities of polarization components with polarization directions of 0°, -45°, 45° and 90°. The Stokes parameters can be used as indicators for the properties of the object. Advantageously, the Stokes parameters can directly be used as property information. In this way, no further calculation is required. Advantageously, based on the receive signals at least one Stokes parameter and / or a polarization state and / or an angle of linear polarization and / or a degree of linear polariza- tion of the received at least one electromagnetic receiving wave can be processed and based on at least one of these values the at least one property information can be deter- mined. In this way, the at least one property information can be determined very efficiently from the at least two receive signals. Advantageously, the polarization state and / or angle of linear polarization and / or a degree of linear polarization can be determined based on at least one of the Stokes parameters. Since the Stokes parameters depend on the material properties, in particular the road condition, also the polarization state of electromagnetic waves, the angle of linear polari- zation and the degree of linear polarization depend on the material properties, in particular the road condition. Advantageously, the material property information can be the deter- mined based on the polarization state of light and / or the angle of linear polarization and / or the degree of linear polarization. In this way, the at least one property information can be determined more accurate. Advantageously, the property information can be represented by at least one data ele- ment. Data elements can efficiently be stored and processed. Otherwise, the features and advantages shown in connection with the detection device according to the invention, the road condition detection system according to the invention, the driver assistance system according to the invention, the vehicle according to the in- vention and the method according to the invention and their respective advantageous configurations shall apply mutatis mutandis to each other and vice versa. The individual 21 / 34 2023PF00717 features and advantages can, of course, be combined with each other, whereby further advantageous effects can occur which go beyond the sum of the individual effects. Brief Description of Drawings The present invention together with the above-mentioned and other objects and ad- vantages may best be understood from the following detailed description of the embodi- ments, but not restricted to the embodiments, wherein is shown schematically Figure 1 a top view of a vehicle comprising a driver assistance system with two de- tection devices for monitoring a road according to a first embodiment; Figure 2 a side view of the vehicle of Figure 1; Figure 3 a detail view of one of the detection devices of the vehicle of Figures 1 and 2; Figure 4 a front view of a receiving unit of the detection device of Figure 3; Figure 5 a front view of a polarization filter unit of the detection device of Figure 3; Figure 6 a top view of a vehicle comprising a driver assistance system with two de- tection devices for monitoring a road according to a second embodiment; Figure 7 a side view of the vehicle of Figure 6; Figure 8 the detection device of the vehicle of Figures 6 and 7; Figure 9 a detail view of a detection device according to a third embodiment that can be used with the vehicle of Figure 6 and 7; Figure 10 the detection device of Figure 9 monitoring a road; Figure 11 a detail view of a detection device according to a third embodiment that can be used with the vehicle of figures number 1 and 2. In the drawings, equal or similar elements are referred to by equal reference numerals. The drawings are merely schematic representations, not intended to portray specific pa- rameters of the invention. Moreover, the drawings are intended to depict only typical embodiments of the invention and therefore should not be considered as limiting the scope of the invention. Embodiment(s) of Invention Figure 1 shows a top view of a vehicle 10 in form of a passenger car. Figure 2 shows a side view of the vehicle 10. 22 / 34 2023PF00717 The vehicle 10 comprises a driver assistance system 12. The driver assistance system can be used for operating functions of the vehicle 10, for example driving functions, au- tonomously or semiautonomously. The driver assistance system 12 comprises a control unit 14 and two detection devices 16. The detection device 16 are identical in in terms of form and function. The detection devices 16 are each connected to the control unit 14 for data transfer. With each detection device 16 a respective monitoring area 18 can be monitored. The detection devices 16 can be used to detect objects, e.g. a road 20, in the monitoring area 18. The detection devices 16 comprise means for identifying the condition of the road 20. The detection devices 16 comprising the means for identifying the condition of the road 20 are road condition detection systems. The detection devices 16 each are located in one of the headlights of the vehicle 10. The detection devices 16 each are directed in driving direction of the vehicle 10. The monitor- ing areas 18 are in driving direction in front of the vehicle 10. Each monitoring area 18 covers a part of the surface of the road 20. The detection devices 16 can also be located elsewhere on the vehicle 10 and can be orientated differently. The vehicle 10 also can comprise more or less than two detection devices 16 and / or can comprise detection devices 16 of a different type. Figures 3 to 5 show one of the detection devices 16 as an example in different views. The detection device 16 comprises a housing 22, receiving device 24, a transmitting de- vice 26 and a control and evaluation device 28. The receiving device 24, the transmitting device 26 and the control and evaluation device 28 are located in the housing 22. One side of the housing 22 has a window for the receiving device 24 and the transmitting device 26. The transmitting device 26 comprises a light source for electromagnetic illumination waves 30, for example near infrared light. The light source is a laser diode, for example. Further, the transmitting device 26 comprises means, for example a polarization filter or 23 / 34 2023PF00717 the like, for linear polarization of the electromagnetic illumination waves 30. The transmitting device 26 can be used to send electromagnetic illumination waves 30 with a linear polarization into the monitoring area 18. The polarization direction 32 defined for the illumination waves 30 is 45° with respect to an orthogonal illumination coordinate system 33, for example. The illumination coordinate system 33 is defined by a propagation direction Xi of the illu- mination waves 30, a Yi-axis and a Zi-axis. The axes of the illumination coordinate system 33 are assigned to the axes of a vehicle coordinate system of the vehicle 10, for example. In the shown embodiment, the propagation direction Xi of the illumination waves 30 runs parallel to a vehicle longitudinal axis VL in direction of travel of the vehicle 10. The Yi-axis runs parallel to a vehicle transverse axis VT. The Zi-axis runs parallel to a vehicle vertical axis VV. Under normal operating conditions of the vehicle 10, the vehicle vertical axis VV and the Zi-axis run approximately vertically. The vehicle transverse axis VT and the Yi- axis run approximately horizontally. The polarization direction 32 is specified by an angle, in the example 45°, to the Yi-axis. Under normal operating conditions of the vehicle 10, the polarization direction 32 is indi- cated in relation to the horizontal. The electromagnetic illumination waves 30 that hit the road 20 are reflected. The electro- magnetic illumination waves 30 that are reflected towards the detection device 16 are referred to as electromagnetic receiving waves 34 for ease of differentiation. The material properties of the road 20, e.g. the condition of the road 20, influence the polarization state of the electromagnetic receiving waves 34. For example, dry asphalt, wet asphalt, ice on the road 20 or snow on the road 20 have different influence on the polarization state of the electromagnetic receiving waves 34. The polarization state of electromagnetic receiving waves 34 can be analyzed by use of the receiving device 24. The condition of the road 20 can be deduced from the polarization state of the electro- magnetic receiving waves 34. 24 / 34 2023PF00717 The receiving device 24 comprises an electromagnetic system in form of an optical sys- tem 36, a polarization filter unit 38, a receiving unit 40 and a carrier 42. The receiving unit 40 comprises four receiving elements 44. The receiving elements 44 each are photodiodes. The photodiodes are realized as layers on the carrier 42. The receiving elements 44 are arranged as a 2x2 array. Figure 4 shows a front view of the receiving unit 40 with the four receiving elements 44. Each receiving element 44 can receive parts of the electromagnetic receiving waves 34 and convert them into receive signals 46. The receive signals 46 are electrical signals, for example. The receive signals 46 can be transmitted to the control and evaluation device 28. The control and evaluation device 28 can be used to process the receive signals 46. The polarization filter unit 38 comprises four polarization filter elements 48. The polariza- tion filter elements 48 are located in propagation direction Xr of the receiving waves 34 in front of the respective receiving elements 44. Each polarization filter element 48 is de- signed as a polarization layer on top of one of the receiving elements 44. Each of the polarization elements 48 is assigned to one of the receiving elements 44. Figure 5 shows a front view of the polarization filter unit 38 with the four polarization filter elements 48. The polarization filter elements 48 are arranged as a 2x2 array similar to the 2x2 array of the receiving unit 40 that is shown in Figure 4. Each of the polarization filter elements 48 is designed for defining an individual transmis- sion polarization direction 50 for the passing electromagnetic receiving waves 34. The four different polarization directions 50 are 0°, -45°, +45° and 90°. The polarization direc- tions 50 are defined with respect to an orthogonal receiving coordinate system 52. The receiving coordinate system 52 is defined by a propagation direction Xr of the receiv- ing waves 34, an Yr-axis and an Zr-axis. The axis of the receiving coordinate system 52 are assigned to axis of the vehicle coordinate system of the vehicle 10, for example. In the shown embodiment, the propagation direction Xr of the illumination waves 30 runs parallel to a vehicle longitudinal axis VL against direction of travel of the vehicle 10. The Yr-axis runs parallel to a vehicle transverse axis VT. The Zr-axis runs parallel to a vehicle vertical axis VV. 25 / 34 2023PF00717 The polarization directions 50 are specified by a respective angle, in the example 0°, - 45°, +45° and 90°, to the Yr-axis. Under normal operating conditions of the vehicle 10, the polarization directions 50 are indicated in relation to the horizontal. Then the polari- zation direction 50 with 0° corresponds to the horizontal. The polarization direction 50 with 90° then corresponds to the vertical. The optical system 36 is placed in propagation direction Xr of the electromagnetic receiv- ing waves 34 in front of the polarization filter unit 38. The optical system 36 can be used to direct the receiving waves 34 coming from the part of the road 20 in the monitoring area 18 to the polarization filter unit 38. The optical system 36 is used to define the mon- itoring area 18. The polarization filter elements 48 define the respective transmission polarization direc- tion 50 of the electromagnetic receiving waves 34. Only the polarization components of the electromagnetic receiving wave 34 with the defined respective transmission polariza- tion direction 50 can pass the respective polarization filter elements 48. The receiving elements 44 receive the respective polarization components with the respective different polarization directions 50 separately and convert them separately into corresponding re- ceive signals 46. The four receive signals 46 of the four receiving elements 44 are transferred to the control and evaluation device 28. Based on the receive signals 46 the intensities I of the polarization components of the received electromagnetic receiving waves 34 can be determined. The intensities are val- ues that characterize the power or energy of the respective polarization component of the receiving wave 34. The receive signals 46 measured by the four receiving elements 44 deliver intensities I(0°) for the polarization direction 50 with 0°, I(-45°) for the polarization direction 50 with -45°, I(45°) for the polarization direction 50 with 45° and I(90°) for the polarization 50 with 90°. It is known, that Stokes formalism can be used for describing the polarization state of light PS. By use of the intensities I, four Stokes parameters S0, S1, S2, S3 are determined using the following formalism: 26 / 34 2023PF00717 ^^ ≡ ^^0°^ + ^^90°^^^ ≡ ^^0°^ − ^^90°^^^ ≡ ^^45°^ + ^^−45°^^^ ≡ ^^^^^^ + ^^^^^^The intensities I(0°) , I(-45°), I(45°) and I(90°) can be determined based on the receive signals for the respective linear polarization directions of 0°, 45°, -45° and 90°. The fourth Stokes parameter S3 can be determined from the intensity of the right-hand circularly polarized component I(RHC) and the intensity of the left-hand circularly polarized com- ponent I(LHC). The intensities I can be values that characterize the power energy of the respective polarization component. Further, following relationship is known: By determining the first three Stokes parameters S0, S1, S2, that are based on the meas- ured intensities I(0°), I(-45°), I(45°) and I(90°), the Stokes parameter S3 is determined. The Stokes parameters S0, S1, S2, S3 are then used for determining the polarization state of light PS, the angle of linear polarization AP and the degree of linear polarization DP using the following relationships: 27 / 34 2023PF00717 The Stokes parameters S0, S1, S2, S3, the polarization state of light PS, the angle of linear polarization AP and the degree of linear polarization DP depend on material properties of the road 20, from which the electromagnetic receiving waves 34 are reflected. The Stokes parameters S0, S1, S2, S3, the polarization state of light PS, the angle of linear polarization AP and the degree of linear polarization DP are used to differentiate between the condi- tions of the road 20. It can be determined whether the road 20 is dry, wet, icy or snow- covered. A lookup table can be used in which various values for polarization state of light PS, angle of linear polarization AP, degree of linear polarization DP and / or the Stokes parameters S0, S1, S2, S3 are compared with the respective conditions of the road 20, for example dry asphalt, wet asphalt, icy road or snow-covered road. Additionally or alternatively, deep learning methods can be used for determining the con- dition of the road 20 based on polarization state of light PS, angle of linear polarization AP, degree of linear polarization DP and / or the Stokes parameters S0, S1, S2, S3. Figures 6 to 8 show a detection device 16 according to a second embodiment. Those elements that are similar to those of the first embodiment in Figures 1 to 5 are provided with the same reference signs. The second embodiment differs from the first embodiment in that the optical system 36 is adjustable. By changing the setting of the optical system 36, the monitoring area 18 monitored by the detection device 16 can be varied. The de- tection device 16 according to the second embodiment can be used, for example, to mon- itor four monitoring areas 18 in different ranges relative to the vehicle 10. Figures 9 and 10 show a detection device 16 according to a third embodiment. Those elements that are similar to those of the first embodiment in Figures 1 to 5 are provided with the same reference signs. The third embodiment differs from the first embodiment in that it comprises four receiving devices 24. The receiving devices 24 are arranged verti- cally one above the other. The receiving devices 24 are inclined towards each other. Each receiving device 24 is aimed at a different monitoring area 18. The detection device 16 28 / 34 2023PF00717 according to the third embodiment can be used, for example, to monitor four monitoring areas 18 in different ranges relative to the vehicle 10. Figure 11 shows a detection device 16 according to a fourth embodiment. Those ele- ments that are similar to those of the first embodiment in Figures 1 to 5 are provided with the same reference signs. The fourth embodiment differs from the first embodiment in that the receiving unit 40 comprises only one receiving element 44 and the polarization filter unit 38 comprises only one polarization filter element 48. The polarization filter ele- ment 48 is adjustable. By changing the setting of the polarization filter element 48, the four different polarization directions 50 are 0°, -45°, +45° and 90° can be defined. The respective polarization components are analyzed in a measurement sequence in which the polarization filter elements 48 is set to the four different polarization directions 50 one after the other. In an embodiment not shown, some features of the described embodiments from Figures 1 to 11 can be combined.

Claims

29 / 34 2023PF00717 Claims 1. Detection device (16) for detecting objects (20) in at least one monitoring area (18), in particular a detection device (16) for a road condition detection system, in particular for a vehicle (10), comprising at least one receiving device (24) designed for receiving elec- tromagnetic receiving waves (34) and converting received electromagnetic receiving waves (34) into processable receive signals (46), the at least one receiving device (24) comprises at least one receiving unit (40) for re- ceiving electromagnetic receiving waves (34) and at least one polarization filter unit (38) arranged in propagation direction (Xr) of the electromagnetic receiving waves (34) in front of the at least one receiving unit (40), where the at least one polarization filter unit (38) is designed for defining at least two transmission polarization directions (50) for the electromagnetic receiving waves (34), so that only the polarization components of the electromagnetic receiving waves (34) with the defined at least two transmission polarization directions (50) can pass the at least one polarization filter unit (38), where the at least one polarization filter unit (38) is designed for defining at least two different transmission polarization directions (50) and the at least one receiving device (24) is designed for converting polarization components of the electromagnetic receiving waves (34) with at least two different polarization directions (50) separately into respec- tive receive signals (46), characterized in that the at least one polarization filter unit (38) is designed for defining four different trans- mission polarization directions (50) and the at least one receiving device (24) is de- signed for converting polarization components of the electromagnetic receiving waves (34) with four different polarization directions (50) separately into respective receive sig- nals (46) and the detection device (16) comprises at least one evaluation device (28) that com- prises a means to analyze the polarization of the electromagnetic receiving waves (34) based on the receive signals (46) of the polarization components with the four different polarization directions (50).

2. Detection device according to claim 1, characterized in that the means to analyze the polarization of the electromagnetic receiving waves (34) is designed to carry out a30 / 34 2023PF00717 Stokes formalism to identify at least a part of the Stokes parameters for the electromag- netic receiving waves (34).

3. Detection device according to claim 1 or 2, characterized in that at least one polarization filter unit (38) comprises four polarization filter elements (48), where each of the polarization filter elements (48) is designed for defining an individual transmission polarization direction (50), where the individual transmission polarization di- rections (50) of the four polarization filter elements (48) are different, and / or at least one polarization filter unit (38) is adjustable for defining four different transmission polarization directions (50).

4. Detection device according to one of the previous claims, characterized in that at least one receiving unit (40) comprises four receiving elements (44), that are de- signed for converting electromagnetic receiving waves (34) separately, and / or at least one receiving unit (40) is controllable for successive conversions of four electro- magnetic receiving waves (34).

5. Detection device according to one of the previous claims, characterized in that at least one polarization filter unit (38) comprises at least one polarization filter element (48) for defining an individual transmission polarization direction (50), and at least one receiv- ing unit (40) comprises at least one receiving element (44) for converting electromagnetic receiving waves (34), where at least one polarization filter element (48) is assigned to at least one receiving element (44).

6. Detection device according to one of the previous claims, characterized in that the at least one receiving device (24) comprises at least one assigning system (36) for electromagnetic waves, in particular an optical system (36), that is arranged in front of the at least one polarization filter unit (38) in propagation direction (Xr) of the electromag- netic receiving waves (34) and that is designed for assigning at least one monitoring area (18) to the at least one polarization filter unit (38).

7. Detection device according to one of the previous claims, characterized in that31 / 34 2023PF00717 the detection device (16) comprises at least two receiving devices (24) that are assigned to different individual monitoring areas (18).

8. Detection device according to one of the previous claims, characterized in that the detection device (16) comprises at least one transmitting device (26) for transmitting electromagnetic illumination waves (30), in particular linear polarized electromagnetic il- lumination waves (30), which may be reflected in at least one monitoring area (18), where the reflected electromagnetic illumination waves (30) may be received as electromagnetic receiving waves (34) by use of the at least one receiving device (24) of the detection device (16).

9. Detection device according to one of the previous claims, characterized in that the detection device (16) is designed as an optical detection device (16), in particular an optical sensor system a camera system or a LiDAR system, or as a radar system.

10. Detection device according to one of the previous claims, characterized in that the at least one receiving unit (40) comprises at least one optical receiving element (44), in particular at least one photodiode, at least one pixel of an image sensor, a charge coupled device or an active pixel sensor or the like, or the at least one receiving unit comprises at least one receiving element that is designed as a radar antenna or a radar antenna element.

11. Detection device according to one of the previous claims, characterized in that the detection device (16) comprises at least one evaluation device (28) that is designed for processing the receive signals (46) into at least one data element, that characterizes the property of an object (20), in particular a condition of a road (20), from which the received at least one electromagnetic receiving wave (34) is reflected, and / or the detection device (16) comprises at least one evaluation device (28) that is designed for processing the receive signals (46), where the at least one evaluation device (28) comprises or uses at least a part of the Stokes formalism, at least one lookup table, at least one deep learning method or the like.32 / 34 2023PF00717 12. Road condition detection system, in particular a road condition detection system for a vehicle (10), for identifying the condition of a road (20), comprising at least one detection device (16) for detecting objects (20) in at least one monitoring area (18), the at least one detection device (16) comprising at least one receiving device (24) designed for receiving electromagnetic receiving waves (34) and converting received electromag- netic receiving waves (34) into processable receive signals (46), where the road condition detection system comprises at least one evaluation device (28) for processing receive signals (46) from the at least one detection device (16) into data characterizing at least one property of the road (20), characterized in that the at least one detection device (16) is a detection device according to one of the claims 1 to 11.

13. Driver assistance system (12) for a vehicle (10), comprising at least one detection device (16) for detecting objects (20) in at least one monitoring area (18), the at least one detection device (16) comprising at least one receiving device (24) designed for receiving electromagnetic receiving waves (34) and converting received electromagnetic receiving waves (34) into processable receive signals (46), where the driver assistance system comprises at least one control unit (14) for the semiautonomous or autonomous control of functions of the vehicle (10), characterized in that the at least one detection device (16) is a detection device according to one of the claims 1 to 11.

14. Vehicle (10) comprising at least one detection device (16) for detecting objects (20) in at least one monitoring area (18), the at least one detection device (16) comprises at least one receiving device (24) designed for receiving electromagnetic receiving waves (34) and converting received electromagnetic receiving waves (34) into processable re- ceive signals (46), characterized in that the at least one detection device (16) is a de- tection device according to one of the claims 1 to 11.

15. Method for detecting at least one property of an object (20), in particular for detect- ing a condition of a road (20), by use of at least one detection device (16), in particular by use of at least one detection device (16) according to one of the claims 1 to 11, in partic- ular by use of at least one detection device (16) of a vehicle (10), at which electromagnetic receiving waves (34) are received by at least one receiving device (24) of the at least one detection device (16) and the received electromagnetic receiving waves (34) are con- verted into processable receive signals (46),33 / 34 2023PF00717 the received electromagnetic receiving waves (34) are filtered with at least one polariza- tion filter unit (38) in such a way that only the polarization components of the electromag- netic receiving waves (34) with defined at least two transmission polarization direction (50) can pass through the at least one polarization filter unit (38), where the at least two transmission polarization directions (50) are defined with the at least one polarization filter unit (38), the polarization components of the electromagnetic receiving waves (34) that pass through the at least one polarization filter unit (38) are received with at least one receiving unit (40) of the at least one receiving device (24), and the received polarization components of the at least one electromagnetic receiving wave (34) are converted into receive signals (46), where the polarization components of the electromagnetic receiving waves (34) with the at least two different transmission polarization directions (50) are filtered and the polarization components with the at least two different transmission polarization di- rections (50) are converted separately into respective receive signals (46), characterized in that four different transmission polarization directions (50) are de- signed by use of the at least one filter unit (38), the polarization components of the electromagnetic receiving waves (34) with four differ- ent polarization directions (50) filtered by the at least one polarization filter unit (38) are converted separately into respective receive signals (46) by use of the at least one re- ceiving device (24), and the polarization of the electromagnetic receiving waves (34) is analyzed based on the receive signals (46) from the polarization components with the four different polarization directions (50).

16. Method according to claim 15, characterized in that a Stokes formalism is carried out to identify at least one of the Stokes parameters for the electromagnetic receiving waves (34).

17. Method according to claim 15 or 16, characterized in that the received polariza- tion components of the electromagnetic receiving wave (34) are converted into receive34 / 34 2023PF00717 signals (46) that characterize the signal intensities of the received polarization compo- nents.

18. Method according to one of the claims 15 to 17, characterized in that based on the receive signals (46) belonging to the four polarization components with the four polarization directions (50) at least one property information that characterizes a property of an object (20), in particular a condition of a road (20), at which the electro- magnetic receiving waves (34) are reflected, is determined and / or based on a relation between the receive signals (46) belonging to the four polarization components with the four polarization directions (50) at least one property information is determined and / or based on the receive signals (46) belonging to the four polarization components with the four polarization directions (50) at least one property information that characterizes a property of an object (20), in particular a condition of a road (20), at which the electro- magnetic receiving waves (34) are reflected, is determined using the Stokes formalism and / or based on the receive signals (46) belonging to the four polarization components with the four polarization directions (50) at least one Stokes parameter and / or a polarization state and / or an angle of linear polarization and / or a degree of linear polarization of the at least one electromagnetic receiving wave (34) is processed and based on at least one Stokes parameter and / or a polarization state and / or an angle of linear polarization and / or a de- gree of linear polarization at least one property information that characterizes a property of an object (20), in particular a condition of a road (20), at which the electromagnetic receiving waves (34) are reflected, is determined.

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