Abstract: A method for identifying an elevation misalignment angle of a radar sensor of a vehicle, including: identifying elevation angles of radar object localizations with reference to a coordinate system of the radar sensor, an elevation angle of a radar object localization being respectively identified based on radar echoes that are obtained with at least two antenna directional characteristics that differ in an elevation direction; and identifying an elevation misalignment angle based on an occurrence frequency distribution of the elevation angles of at least some of the radar object localizations; and a radar sensor for vehicles having an evaluation device embodied to carry out the method.

Abstract: A method for identifying an elevation misalignment angle of a radar sensor of a vehicle, including: identifying elevation angles of radar object localizations with reference to a coordinate system of the radar sensor, an elevation angle of a radar object localization being respectively identified based on radar echoes that are obtained with at least two antenna directional characteristics that differ in an elevation direction; and identifying an elevation misalignment angle based on an occurrence frequency distribution of the elevation angles of at least some of the radar object localizations; and a radar sensor for vehicles having an evaluation device embodied to carry out the method.

Abstract: A radar sensor having a corresponding evaluation and control device, which has a measuring mode for locating radar targets and a blindness detection device, which is configured to detect blinding of the radar sensor with the aid of the signals received by the radar sensor itself; wherein the evaluation and control device has a test mode, in which the radar sensor is controlled on the basis of parameters that are different from the parameters for the measuring mode and optimized for the blindness detection device, and the evaluation and control device has a switching device for switching over between the measuring mode and the testing mode.

Abstract: In the method for detecting precipitation using a radar sensor, the radar sensor emits a transmission signal, whose frequency is varied periodically in successive modulation ramps. Signals received by the radar sensor are analyzed to determine precipitation on the basis of two different criteria. In the method, a first criterion relates to signals which are received during a pass-through of a modulation ramp, and a second criterion relates to a comparison of signals which are received during a pass-through of at least two successive modulation ramps.

Abstract: An apparatus for testing a cable or other capacitive load object with a VLF alternating cosine square, rectangular or trapezoidal test voltage, includes one or two DC voltage sources and a switching arrangement controlled by a measuring and control unit, to produce the test voltage with alternating switched polarity. The apparatus further includes a choke coil serving as an energy store, which is controlled by a switching element to be activated if the voltage/time slope arising during the switch-over after a respective half-wave of the test voltage falls below a defined threshold value.

Abstract: A method for detecting precipitation using a radar sensor system for motor vehicles designed for locating objects in the surroundings of the vehicle, in which method a locating signal that is a measure of the received power density as a function of the distance is integrated across a specific distance range lying below a limit distance for detecting precipitation. The locating signal is subjected to a filtering procedure before being integrated, the filtering procedure suppressing the peaks caused by located objects so that the filtered signal forms a measure of the noise level as a function of the distance.

Abstract: An FMCW radar sensor system is described having an antenna covered by a radome, a mixer for mixing a frequency-modulated transmission signal with a signal received by the antenna, a device for recording the mixed product of the mixer as a time-dependent signal, a device for calculating the spectrum of the time-dependent signal, and a device for detecting a reflecting coating on the radome, characterized in that the device for detecting the reflecting coating is configured for analyzing the time-dependent signal and for determining the extent of reflection on the radome based on the amplitude of this signal.

Abstract: A method for detecting icing at an angle-resolving radar sensor in a driver assistance system for motor vehicles, in which signals of a plurality of antenna elements each having a specific angle characteristic are compared with the corresponding angle characteristics, and the azimuth angle of a located object is determined on the basis of an angle fit quality which indicates how well the signals of the antenna elements correspond to the angle characteristics for a given azimuth angle, wherein an indicator for icing is formed which is a monotonically falling function of the angle fit qualities of the located objects, with objects having a low signal-to-noise ratio being included in the indicator at the most with a reduced weighting.

Abstract: A method for the detection of sensitivity losses of an FMCW radar locating device due to diffuse sources of loss, in which the radar locating device emits a transmit signal whose frequency is periodically modulated in successive modulation ramps, and at least one power characteristic of at least one frequency portion of a signal received by the radar locating device is evaluated, wherein the power of the transmit signal is varied cyclically, in each case after the completion of a modulation ramp, and the sensitivity losses are determined on the basis of differences in the power characteristics of signals received during successive modulation ramps having identical modulation.

Abstract: A method for detecting precipitation using a radar locating device for motor vehicles, that is designed to locate objects in the surroundings of the vehicle, in which method a locating signal (42), which is an index for the received power density as a function of the distance (R), is integrated over a first distance range (INT1), which is below a limit distance (Rlim) for the detection of precipitation, wherein the locating signal (42) is additionally integrated over a second distance range (INT2), which is above limit distance (Rlim), and for the detection of precipitation, the integrals over the first and second distance range are compared with each other.

Abstract: In operating a radar sensor, a modulation sequence having a number n of successive linear frequency ramps having different slopes an is cyclically repeated. A received radar signal reflected from an object is mixed with the emitted radar signal to form an intermediate frequency signal, which is analyzed for each frequency ramp with respect to its frequency spectrum. Peaks occurring in the frequency spectra of the intermediate frequency signal correspond to ambiguity lines in a distance/velocity space. Possible objects are assumed at intersection points of the ambiguity lines. The expected position which the possible objects would have at the point in time of the repetition of the modulation sequence is precalculated. The slope an of at least one of the frequency ramps is established for a subsequent modulation sequence in such a way that none of the expected positions of a possible object in the distance/velocity space is at an intersection point of precalculated ambiguity lines of the other possible objects.

Abstract: An apparatus for testing a cable or other capacitive load object with a VLF alternating cosine square, rectangular or trapezoidal test voltage, includes one or two DC voltage sources and a switching arrangement controlled by a measuring and control unit, to produce the test voltage with alternating switched polarity. The apparatus further includes a choke coil serving as an energy store, which is controlled by a switching element to be activated if the voltage/time slope arising during the switch-over after a respective half-wave of the test voltage falls below a defined threshold value.

Abstract: An FMCW radar sensor system is described having an antenna covered by a radome, a mixer for mixing a frequency-modulated transmission signal with a signal received by the antenna, a device for recording the mixed product of the mixer as a time-dependent signal, a device for calculating the spectrum of the time-dependent signal, and a device for detecting a reflecting coating on the radome, characterized in that the device for detecting the reflecting coating is configured for analyzing the time-dependent signal and for determining the extent of reflection on the radome based on the amplitude of this signal.

Abstract: A method for detecting icing at an angle-resolving radar sensor in a driver assistance system for motor vehicles, in which signals of a plurality of antenna elements each having a specific angle characteristic are compared with the corresponding angle characteristics, and the azimuth angle of a located object is determined on the basis of an angle fit quality which indicates how well the signals of the antenna elements correspond to the angle characteristics for a given azimuth angle, wherein an indicator for icing is formed which is a monotonically falling function of the angle fit qualities of the located objects, with objects having a low signal-to-noise ratio being included in the indicator at the most with a reduced weighting.

Abstract: A radar sensor having a corresponding evaluation and control device, which has a measuring mode for locating radar targets and a blindness detection device, which is configured to detect blinding of the radar sensor with the aid of the signals received by the radar sensor itself; wherein the evaluation and control device has a test mode, in which the radar sensor is controlled on the basis of parameters that are different from the parameters for the measuring mode and optimized for the blindness detection device, and the evaluation and control device has a switching device for switching over between the measuring mode and the testing mode.

Abstract: A method for detecting precipitation using a radar sensor system for motor vehicles designed for locating objects in the surroundings of the vehicle, in which method a locating signal that is a measure of the received power density as a function of the distance is integrated across a specific distance range lying below a limit distance for detecting precipitation. The locating signal is subjected to a filtering procedure before being integrated, the filtering procedure suppressing the peaks caused by located objects so that the filtered signal forms a measure of the noise level as a function of the distance.

Abstract: A method for the detection of sensitivity losses of an FMCW radar locating device due to diffuse sources of loss, in which the radar locating device emits a transmit signal whose frequency is periodically modulated in successive modulation ramps, and at least one power characteristic of at least one frequency portion of a signal received by the radar locating device is evaluated, wherein the power of the transmit signal is varied cyclically, in each case after the completion of a modulation ramp, and the sensitivity losses are determined on the basis of differences in the power characteristics of signals received during successive modulation ramps having identical modulation.

Abstract: A method for detecting precipitation using a radar locating device for motor vehicles, that is designed to locate objects in the surroundings of the vehicle, in which method a locating signal (42), which is an index for the received power density as a function of the distance (R), is integrated over a first distance range (INT1), which is below a limit distance (Rlim) for the detection of precipitation, wherein the locating signal (42) is additionally integrated over a second distance range (INT2), which is above limit distance (Rlim), and for the detection of precipitation, the integrals over the first and second distance range are compared with each other.

Abstract: In operating a radar sensor, a modulation sequence having a number n of successive linear frequency ramps having different slopes an is cyclically repeated. A received radar signal reflected from an object is mixed with the emitted radar signal to form an intermediate frequency signal, which is analyzed for each frequency ramp with respect to its frequency spectrum. Peaks occurring in the frequency spectra of the intermediate frequency signal correspond to ambiguity lines in a distance/velocity space. Possible objects are assumed at intersection points of the ambiguity lines. The expected position which the possible objects would have at the point in time of the repetition of the modulation sequence is precalculated. The slope an of at least one of the frequency ramps is established for a subsequent modulation sequence in such a way that none of the expected positions of a possible object in the distance/velocity space is at an intersection point of precalculated ambiguity lines of the other possible objects.

Abstract: In the method for detecting precipitation using a radar sensor, the radar sensor emits a transmission signal, whose frequency is varied periodically in successive modulation ramps. Signals received by the radar sensor are analyzed to determine precipitation on the basis of two different criteria. In the method, a first criterion relates to signals which are received during a pass-through of a modulation ramp, and a second criterion relates to a comparison of signals which are received during a pass-through of at least two successive modulation ramps.