Method for detecting traffic participants

Abstract

The invention relates to a method for detecting traffic participants along at least one traffic route, wherein the method comprises the following steps: transmitting a transmission signal by means of at least one transmitting device for radar radiation; detecting a reception signal by means of at least one receiving device for radar radiation; mixing the transmission signal and the reception signal to form a baseband signal, calculating a detection matrix from the baseband signal, and evaluating the detection matrix in an evaluation module of an electronic data processing device, wherein peaks of the detection matrix are assigned to objects; checking in a diagnostic module whether an interference criterion is met; generating a signal from the evaluation result in the evaluation module and the check result in the diagnostic module; and transmitting the signal to a control module of the electronic data processing device.

Description

Technical Field

[0001] The invention relates to a method for detecting traffic participants along at least one traffic route. Background Art

[0002] Today, traffic participants are detected along various traffic routes on land, sea and air. This usually involves statistically evaluating the number and type of traffic participants and / or controlling the traffic flow along at least one traffic route.

[0003] Nowadays, traffic flows along traffic routes, in particular intersecting traffic routes, such as intersections or entrances, are usually controlled by electronically operated systems, which, for example, adapt traffic light switching, priority driving rules and / or speed limits to traffic conditions. To this end, it is necessary to detect the current traffic situation. This is often achieved by radar sensors, which emit radar radiation in the form of a transmission signal so that the transmission signal is reflected by a traffic participant, such as a motor vehicle. The reflected radar radiation is detected in the form of a reception signal. The reception signal contains information about the distance, radial speed, direction of movement and / or size of the traffic participant.

[0004] Various forms of transmission signals are known from the prior art. For example, frequency ramps can be used which are formed repeatedly and identically or differently and which are transmitted alternately or simultaneously. Corresponding transmission signals are known, for example, from DE 10 2013 008 607 A1 and DE 10 2017 105 783 A1. Signals produced by preferably digital PMCW (Phase Modulated Continuous Wave) modulation can also be used as transmission signals. In this case, the signal is modulated onto a carrier wave in a phase-modulated manner, which carrier wave can then be used as a transmission signal.

[0005] With current methods, different types of traffic participants (e.g. motor vehicles, motorcycles and trucks) can be distinguished from one another, but also pedestrians or cyclists, and the traffic flow can be controlled based on the data stored for the different types of traffic participants. This can include, for example, switching traffic light facilities and / or opening or closing additional lanes or issuing or cancelling speed limits.

[0006] For example, the use of radar sensors has the following advantages compared to the use of cameras operating in the visible light range: radar sensors function independently of daylight and can also function in fog and darkness. However, even when using radar sensors to monitor and control traffic flow, interference may occur, for example due to weather influences or interference with other radar radiation sources. In the case of interference, traffic participants cannot be detected or at least cannot be detected optimally. Interference can hinder or even prevent the smooth flow of traffic and also pose a danger to the relevant traffic participants. Summary of the invention

[0007] The object of the present invention is therefore to improve a method for controlling a traffic flow along at least one traffic route in such a way that disturbances are detected early when road users are detected and a response can be initiated, thereby increasing traffic safety.

[0008] The invention achieves the stated object by a method for detecting traffic participants along at least one traffic route, wherein the method comprises the following steps:

[0009] - transmitting a transmission signal by means of at least one transmission device for radar radiation;

[0010] - detecting a received signal by means of at least one receiving device for radar radiation;

[0011] - mixing the transmission signal and the reception signal to form a baseband signal and calculating a detection matrix from the baseband signal and evaluating the detection matrix in an evaluation module of the electronic data processing device, wherein peaks of the detection matrix are assigned to the objects;

[0012] - Check in the diagnostic module whether the interference criteria are met;

[0013] - generating a signal from the evaluation result in the evaluation module and the examination result in the diagnosis module; and

[0014] - A control module that transmits the signal to an electronic data processing device.

[0015] Therefore, according to the invention, radar radiation is emitted in the form of transmission signals by at least one transmitting device for radar radiation, which is advantageously part of a radar sensor. As mentioned above, these transmission signals can have different forms. These transmission signals are reflected with different intensities by different traffic participants located on a monitored subsection of at least one traffic route, wherein the intensity of the reflection depends in particular on the size of the traffic participant and the distance of the traffic participant from the transmitting device and the receiving device. A part of the reflected radar radiation is reflected back in the form of reception signals to a radar sensor, in particular a reception device for radar radiation, which is part of the radar sensor. The reception signals are detected by means of at least one receiving device for radar radiation, which is preferably also part of the at least one radar sensor. The transmission signals emitted by the at least one transmitting device for radar radiation and the reception signals detected by the at least one receiving device for radar radiation are mixed into a baseband signal, from which a detection matrix is ​​calculated. For example, the detection matrix is ​​a range Doppler matrix calculated from a double Fourier transform of the baseband signal. If the transmitted transmission signal is not a repeated frequency ramp, but is preferably a digital phase modulated signal, for example, the range-Doppler matrix can also be calculated by correlation (range) and Fourier transformation (Doppler). This method is known from the prior art and is well known to those skilled in the art. Other possible detection matrices are, for example, a range-time matrix or a range-angle matrix that has been Fourier transformed only once. Preferably, multiple detection matrices are calculated and used in one measurement cycle, preferably in each measurement cycle, for example in different angular ranges and / or angular directions.

[0016] The detection matrix is ​​then evaluated in an evaluation module of an electronic data processing device. In the detection matrix, the spectral energy (signal energy) is assigned to different information. For example, the distance ("range") is plotted on one axis of a range-Doppler matrix, the Doppler frequency is plotted on another axis, and thus information about the radial velocity of the traffic participant that reflects the transmitted signal is plotted. Therefore, the presence of a signal energy that is preferably significantly higher than the matrix noise at the spectral position in the cell of the range-Doppler matrix, particularly preferably more than 20 dB higher than the matrix noise, means that the received signal is generated by the reflection of the transmitted signal on an object, especially a traffic participant, which has a certain distance ("range") and a certain radial velocity towards or away from the at least one receiving device, which is derived from the corresponding Doppler frequency. However, the assignment between the radial velocity and the Doppler frequency may be ambiguous, for which methods are known from the prior art to eliminate.

[0017] The signal energy in such an element of a detection matrix, in particular a range Doppler matrix, is called a "peak," wherein different peaks of the range Doppler matrix are assigned to different objects, in particular traffic participants. Here, a single peak or a range Doppler matrix range with multiple peaks can be assigned to an object.

[0018] According to the invention, a check is made in the diagnostic module to see whether the interference criterion is met. Signals are then generated based on the evaluation results of the detection matrix in the evaluation module and the check results in the diagnostic module, which are transmitted to the control module. Preferably, the evaluation results of the baseband signal in the time domain are also taken into account.

[0019] For example, the control module is provided for evaluating signals, for example statistically, and / or for controlling the traffic flow along at least one traffic route. In the latter case, a method for controlling the traffic flow along at least one traffic route is provided.

[0020] Preferably, the evaluation module and / or the diagnostic module is part of an electronic data processing device, which is part of a radar sensor, which also has a transmitting device and / or a receiving device. Preferably, the control module is not part of the sensor, but is part of a control computer, for example, for controlling the traffic flow. Of course, the control module can also be part of the sensor. It is also possible that the evaluation module and / or the diagnostic module is not part of the radar sensor, but is part of another electronic data processing device, preferably the control module also belongs to this other electronic data processing device.

[0021] In a preferred embodiment, the evaluated detection matrix, preferably the evaluated range-Doppler matrix and the baseband signal are used to check whether an interference criterion is met. Advantageously, the interference criterion is met, for example, if rain and / or snow and / or interference with the signals of other transmitting devices and / or a change in position and / or orientation of the corresponding sensor is detected in the evaluation of the detection matrix.

[0022] Precipitation in the form of rain and / or snow also reflects at least a portion of the transmitted transmission signal, and in this way results in a received signal of a certain type. In the evaluated detection matrix, this results in a characterizing effect. Therefore, for example, in the case of a range Doppler matrix, a large amount of signal energy occurs when the distance ("Range") is several meters, because most of the reflected transmission signal is reflected by a large number of precipitation elements, i.e., raindrops or snowflakes, within this range. Although raindrops and snowflakes with a larger distance will also reflect the transmission signal that penetrates thereto, the distance is too large and will not result in a noticeable intensity of the received signal. The radial velocity of precipitation is also typical, because raindrops and snowflakes usually fall to the ground at a characterizing speed. Depending on the wind conditions, the radial velocity toward or away from at least one radar sensor will of course be affected. In this way, rain and / or snow can be easily and reliably detected.

[0023] If this is the case, the interference criterion is deemed to be met, since it is no longer possible or at least no longer reliably possible for the sensor to reliably and unambiguously identify road users and, if necessary, assign them to different categories.

[0024] Preferably, a plurality of detection matrices, preferably range-Doppler matrices, of different, preferably consecutive measurement cycles are evaluated. These detection matrices are formed by baseband signals, which are mixed from transmission signals and reception signals of different measurement cycles. As a result, the objects determined when evaluating a plurality of detection matrices can be linked to one another and the movement of the objects can thus be tracked. As a result, a better distinction can be made between moving objects, in particular traffic participants, and static objects, such as buildings, signs or traffic lights, than can be achieved by evaluating radial velocities. Thus, an actual trajectory can be assigned to the moving object, which actual trajectory in particular contains the position of the respective object at different points in time. Advantageously, the interference criterion is considered to be met if a predetermined number of these actual trajectories, such as at least 10, at least 25 or at least 50, do not follow the course stored in the electronic database. Preferably, these predetermined number of actual trajectories that do not follow the stored course must occur within a predetermined time period, such as within 10 minutes, within 5 minutes or within 2 minutes, in order to meet the interference criterion.

[0025] Usually, the monitoring area of ​​at least one traffic route is known, in which there may be traffic participants who can reflect the transmitted transmission signal in the direction of at least one receiving device. For example, the at least one traffic route has multiple lanes, in which a certain driving direction is dominant and these lanes follow a predetermined direction. This direction can be stored in an electronic database. The emission of the transmission signal, the reception of the reception signal, the mixing of the signal into a baseband signal and a detection matrix, the determination of the preferred range Doppler matrix and the evaluation of the detection matrix are usually not only implemented once as described above, but multiple times and one after another. These method steps can be implemented, for example, hundreds of times per second. Therefore, a single object can be tracked over a long period of time. Here, the velocity vector and / or the location where the corresponding object is detected may change. In this way, the actual trajectory of the object can be determined, and therefore the trajectory of the traffic participant can be determined.

[0026] Preferably, the determined actual trajectory is compared with trajectories stored, for example, for different lanes of at least one traffic route. If the actual trajectory calculated from the different detection matrices deviates from the desired trajectory stored in the electronic database, for example in terms of azimuth or elevation, this is a clear sign that "the orientation and / or position of at least one radar sensor has shifted" or "the position and / or orientation of at least one receiving device for radar radiation has shifted". The monitoring area of ​​the traffic route is changed in this way, so that reliable data can no longer be determined or this can at least not be ensured. Preferably, the interference criterion is met in this case.

[0027] Advantageously, the maximum signal-to-noise ratio, the minimum signal-to-noise ratio, the average signal-to-noise ratio and / or the median of the signal-to-noise ratio are determined from the signal-to-noise ratio of the selected peaks of the detection matrix. If the maximum signal-to-noise ratio, the minimum signal-to-noise ratio, the average signal-to-noise ratio and / or the median of the signal-to-noise ratio are below a predetermined limit value, it is considered that the interference criterion is met. The predetermined limit value is, for example, 100 dB, preferably 50 dB, and particularly preferably 20 dB. Therefore, the corresponding signal-to-noise ratio is determined by the selected peaks of the detection matrix, for example the range-Doppler matrix. The maximum, minimum, average and / or median of these ratios are then determined and compared with the predetermined limit value. If the corresponding signal-to-noise ratio is less than the predetermined limit value, it is considered that reliable object recognition of a single traffic participant cannot be or cannot be reliably ensured to meet the interference criterion.

[0028] Preferably, the selected peaks of the detection matrix are all peaks that can be assigned to one object or to a plurality of moving objects. Particularly preferably, they are all peaks that can be assigned to one moving object. Alternatively, the selected peaks are all peaks of the detection matrix used.

[0029] Preferably, in the evaluation of the detection matrix, for example the range Doppler matrix, the radar cross section of the object, preferably the moving object, is determined. For example, this can be determined from the strength of the received receive signal and the strength of the emitted transmit signal, wherein preferably the distance and / or one or more angles of the corresponding object determined by the detection matrix are also taken into account. In this configuration of the method, the interference criterion is met if the maximum radar cross section, the minimum radar cross section and / or the average radar cross section and / or the median of the determined radar cross sections are less than a predetermined limit value. For example, a typical value of the radar cross section for a human is about 1 m 2 For passenger cars, it is about 10m 2 、For trucks, about 100m 2 Depending on the monitoring cross section, a predetermined limit value is selected for the average radar cross section. If the corresponding limit value is undershot, a fault criterion is present in a medium embodiment of the method.

[0030] Preferably, the radar cross section of all objects is determined, particularly preferably the radar cross section of all moving objects. Alternatively or in addition thereto, the radar cross section of a certain class of objects, for example the radar cross section of all passenger cars and / or all trucks, can also be determined and used for the evaluation. In this case, different limit values ​​can be used for the radar cross sections of different classes of objects.

[0031] In a preferred configuration of the method, the at least one receiving device has multiple, preferably at least three, particularly preferably at least four, and further particularly preferably at least eight receiving antennas. The received signals reflected by the object arrive at these multiple receiving antennas at different time points. The received signals of different receiving antennas are mixed with the transmitted transmit signals, and a detection matrix, such as a range Doppler matrix, is formed by the baseband signals generated in this way. Since the received signals arrive at different receiving antennas at different time points, a phase shift occurs between different received signals, and therefore different baseband signals are obtained for different detection matrices. Complex value inputs with complex phases are generated in the Fourier transform implemented when calculating the detection matrix, especially the range Doppler matrix. Here, the phase difference of these phases between two receiving antennas depends only on their spacing. Receiving antenna pairs with the same spacing also have the same phase difference.

[0032] Preferably, a measure for the dispersion of the phase differences is determined, for example, the standard deviation of the phase differences is determined. The interference criterion is met if the maximum standard deviation, the minimum standard deviation and / or the average standard deviation and / or the median of the determined standard deviations exceeds a predetermined limit value, for example, 60°, preferably 30°, particularly preferably 5°.

[0033] The standard deviation is preferably calculated for all peaks of the detection matrix, particularly preferably for peaks that can be assigned to an object. In a particularly preferred configuration, the standard deviation of the phase difference is calculated for all peaks of the detection matrix that can be assigned to a moving object. Preferably, the calculation is performed in the azimuth direction and / or in the elevation direction. Here, the azimuth extends on a plane perpendicular to the direction of gravity. The elevation angle describes the angle relative to the direction of gravity.

[0034] Preferably, the number of objects to which at least one peak of the detection matrix is ​​assigned is determined. Preferably, the number of static objects is determined. In this case, the interference criterion is considered to be met if this number exceeds a predetermined upper limit value, wherein the upper limit value is, for example, 150, preferably 100, particularly preferably 75, or if this number is below a predetermined lower limit value, which is preferably 10, preferably 20, particularly preferably 30. If the number of ascertained objects to which at least one peak of the detection matrix can be assigned is greater than the predetermined upper limit value or less than the predetermined lower limit value, it is considered that either this is a very unusual traffic situation for which there is no optimal control signal for controlling the traffic flow, or that the sensor emitting the radar beam and receiving the received signal is operating in a disrupted manner. Of course, these limit values ​​are selected depending on the traffic route, whose traffic flow is controlled. In the case of rural roads that are likely to be seldom traveled, the predetermined upper limit value can be smaller, for example 50, 40 or 30, while in the case of large intersections of multiple traffic routes (for example multiple multi-lane roads), larger upper limit values ​​can be suitable, for example 200, 250 or 300. Likewise, in the case of country roads that are likely to be traveled less frequently, the predetermined lower limit value may be small, for example 5 or even 0. In the case of large intersections of multiple traffic lanes, a predetermined lower limit value of 40, 50 or 60 may also be suitable and may be selected.

[0035] If only or also static objects are counted, the corresponding limit value can be selected depending on the number of objects actually present (eg signs or buildings).

[0036] Advantageously, the characteristics of the baseband signal that characterize the interference disturbance are also investigated before the calculation of the detection matrix, for example the range-Doppler matrix. Preferably, in order to identify these characteristic characteristics, it is checked whether the signal energy and / or the signal amplitude exceeds a predetermined or adaptively changed limit value. If an adaptively selected limit value is used, the limit value is advantageously adapted to the prevailing traffic situation, for example by deriving an average signal energy or an average signal amplitude from the history (for this purpose, for example, a mean value calculation or a median calculation can be used) and determining the limit value, for example, by multiplying this value by 8, 10 or 12. Advantageously, a measure for determining the interference intensity and / or the frequency band occupied by the interfering object can be derived from an optional subsequent analysis of the exceeding of the limit value, for example in terms of position, width and / or change over time. However, it is also possible to determine the interference intensity, for example, by observing an increased noise level after the Fourier transformation or the first stage of the correlation or in the detection matrix. A sufficiently high interference intensity is then a criterion for interference.

[0037] Advantageously, the interference criterion in the form of a total interference criterion is met if the weighted sum of the maximum signal-to-noise ratio, the minimum signal-to-noise ratio, the average signal-to-noise ratio and / or the median of the signal-to-noise ratio, the maximum radar cross section, the minimum radar cross section and / or the average radar cross section and / or the median of the calculated radar cross section, the minimum standard deviation, the maximum standard deviation and / or the average standard deviation and / or the median of the calculated standard deviations and / or the number of objects and / or the interference strength exceeds a predetermined limit value. This limit value is almost freely selectable and can be offset by suitable weighting of the individual summands. The predetermined limit value is, for example, -15, 10 or 100. In order to simplify the calculation, individual summands or all summands of the weighted sum can be set to the limit value or can be scaled individually if they exceed or fall below the limit value.

[0038] Thus, for example, if the maximum signal-to-noise ratio is below this value, the maximum signal-to-noise ratio can be increased to 5 dB, 10 dB or 20 dB or other appropriate values. If the maximum signal-to-noise ratio exceeds this value, respectively, the maximum signal-to-noise ratio can also be set to 40 dB, 50 dB or 60 dB. Preferably, the signal-to-noise ratio can also be limited to a range, such as 14 dB to 50 dB. If a linear scale is used, the scale can be limited to 5 to 300. If the parameters are scaled individually, the range thus limited is scaled to a scaling range of 0 to 100. Of course, other ranges and scaling ranges can also be used.

[0039] In this way the calculations are simplified and errors due to values ​​that are too large or too small are less likely to occur.

[0040] For example, the value of the minimum standard deviation can be set to 0 rad, 0.1 rad or 0.2 rad, or limited to a maximum of 0.75 rad, 0.5 rad or 0.4 rad. Such a range can also be scaled to a scaled range of 0 to 100 for the weighted sum.

[0041] The number of possible objects can also be determined as a value, for example up to 60 and at least 0, wherein the range can also be scaled to a scaled range, for example 0 to 100. Advantageously, the variable is set to the predetermined limit value if it exceeds or falls below the corresponding predetermined limit value.

[0042] In the weighted sum, the sign of the corresponding weighting can vary. Thus, for example, the minimum standard deviation is provided with a positive factor, and the target number and the maximum signal-to-noise ratio are provided with a negative factor. Of course, alternatively, these factors can also have opposite signs.

[0043] Regardless of whether the individual variables form the interference criterion individually or in the form of a weighted sum, these variables are preferably filtered over time so that an evaluation result from a single detection matrix or a single measurement cycle does not immediately lead to a interference report or to the interference criterion being considered to be met. This can be achieved, for example, by a possibly weighted, time-varying average value, i.e., by the results of a plurality of preferably consecutive measurement cycles.

[0044] In a preferred configuration, at least one transmitting device for radar radiation and at least one receiving device for radar radiation are respectively part of a radar sensor, wherein the position and / or orientation and / or speed and / or acceleration of the radar sensor are advantageously determined by at least one additional (on-board) sensor. In order to obtain reliable measured values, it is necessary that at least one radar sensor maintains its set position and advantageously also maintains its set orientation. If the position changes, for example because a pole or signboard to which the sensor is fastened suffers a traffic accident and, for example, falls over, it is no longer possible to ensure that the sensor monitors the desired area of ​​at least one traffic route. This can be determined by a position sensor and / or an orientation sensor. Radar sensors are usually arranged above and / or beside the lane, for example on poles, signboards or traffic light facilities. In particular, traffic lights are often also arranged to be suspended above intersections, so that the traffic lights will swing due to the wind. Therefore, it can be advantageous to use a speed sensor and / or an acceleration sensor in order to determine the speed and / or acceleration of the radar sensor and to regard the interference criterion as being met when a predetermined limit value is exceeded. Advantageously, position sensors, orientation sensors, speed sensors and / or acceleration sensors are present for at least two, preferably all three, independent spatial directions.

[0045] Preferably, the interference criterion is met if the position and / or orientation and / or velocity and / or acceleration of the radar sensor deviates from a setpoint value by more than a predetermined limit value.

[0046] Advantageously, the control signal transmitted to the control module of the electronic data processing device is a number, position, velocity vector, dimension (spatial extension scale) and / or classification of traffic participants (objects) that can be detected and determined from the peak of the detection matrix, for example, the range Doppler matrix, or a preliminary stage with information about distance, angle, radial velocity and / or other characteristics. The interference signal to be transmitted, if necessary, can contain the following information, for example: at least one radar sensor is not working or is not working reliably. In this case, the control module of the electronic data processing device responsible for controlling the traffic flow will call a model of another possible time control of traffic guidance and traffic flow control. However, instead of this, the control signal can also contain information about the occupation of all lanes of at least one traffic route to be monitored. In this case, it is advantageous that the number of traffic participants and the number of data of these traffic participants transmitted to the control module are overestimated, that is, more traffic participants are reported than are actually present. Therefore, for the situation where the interference criterion is considered to be met, as many traffic participants as possible in as many lanes and directions as possible will be reported.

[0047] Preferably, the signal generated from the evaluation results in the evaluation module and the check results in the diagnosis module and then transmitted to the control module contains an evaluation signal, which contains information about the objects determined when evaluating the range Doppler matrix when the interference criterion is not met. Preferably, when the interference criterion is not met, the signal consists of the evaluation signal. For example, the evaluation signal contains, for example, a list of all peaks when evaluating the range Doppler matrix, which list contains, for example, radial speeds and distances to the radar sensor and, if necessary, properties of the corresponding object or objects. The evaluation signal can also contain an occupancy signal of the virtual induction loop, by which the control module of the control computer is informed whether a certain lane is occupied, the control computer being used, for example, to control the switching of traffic light facilities at intersections. The evaluation signal can also contain a trigger signal, which, for example, warns of a fast approaching traffic participant.

[0048] Preferably, in addition to the evaluation signal, the signal also contains a diagnostic signal which contains the information that the interference criterion is not met.

[0049] Preferably, the signal contains a diagnostic signal, which contains the following information when the interference criterion is met: the interference criterion is met. The diagnostic signal can consist only of this information. Alternatively, the diagnostic signal contains information about the cause of the interference. This is possible in particular when there are different interference criteria, of which only one or a small number of interference criteria are met. In this way, different interference causes can be distinguished, such as rain, snow, storms or movement of the sensor. In addition, the diagnostic signal can include the proportion of the interference. Thus, for example, the field of view of the radar sensor may be limited by rain, so that although reliable data can still be generated and transmitted to the control module, these data are only reliable for a limited distance from the radar sensor. For example, the diagnostic signal can contain the following information: the field of view of the radar sensor is limited to a certain proportion by rain or snow, such as 75%, 50% or 25%.

[0050] Preferably, the signal contains an evaluation signal about a fictitious target when the interference criterion is met. Thus, for example, the evaluation signal can contain the information that all lanes are occupied, although this cannot be derived from the evaluation of the range Doppler matrix due to the interference. This is particularly advantageous when the control module is part of a control computer that can control, for example, traffic guidance or traffic flow on at least one traffic route using only the corresponding evaluation signals. In particular, older control computers are not configured to receive diagnostic signals in addition to these evaluation signals in order to detect functional disturbances of the radar sensor.

[0051] Preferably, a plurality of radar sensors, for example four radar sensors, are used in the method. These radar sensors are preferably arranged at an intersection where at least two traffic routes intersect or cross. Here, the four sensors monitor different parts of a traffic route or monitor different traffic routes, for example. The transmission signals and reception signals of all radar sensors are processed into a range Doppler matrix and evaluated. The evaluation signal is transmitted to an intersection computer including a control module. If necessary, a diagnostic module is also part of the intersection computer. However, this is not necessary, because the diagnostic module can also be arranged in one or each radar sensor.

[0052] In a particularly preferred embodiment, a plurality of sensors are used in the method. As a result, different parts of a traffic route and / or different traffic routes can be monitored and traffic participants located thereon can be detected. Preferably, in this case, the transmission signal is emitted by each of the sensors and the reception signal is received by each of the sensors. Preferably, in this case, the control module is part of the control computer. Preferably, this also applies to the diagnostic module, which preferably evaluates the detection matrix generated and provided by all sensors and the corresponding signals.

[0053] In the evaluation module, a list of all objects is preferably created to which at least one peak of the detection matrix can be assigned. Additionally or alternatively, an occupancy signal for the virtual induction loop or other trigger signals that are necessary or at least helpful for controlling the traffic flow are generated. These include signals that contain information about rapidly approaching objects and the like.

[0054] Preferably, the diagnostic module generates a diagnostic signal which can contain, for example, the following information: one of the sensors used or all of the sensors is disturbed. In addition, the extent of the disturbance and / or the cause of the disturbance can be indicated. This information can include, for example, that the sensors are disturbed by 35% due to a first disturbance cause, such as rain.

[0055] The invention also solves the problem by a sensor for detecting road users along at least one road route, wherein the sensor is configured to carry out a method according to one of the embodiments described herein. The sensor preferably has an electronic data processing device having an evaluation module and preferably a diagnostic module. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Embodiments of the present invention are described in detail below with reference to the accompanying drawings. The accompanying drawings show:

[0057] Figure 1 A schematic diagram of an apparatus according to an embodiment of the present invention;

[0058] Figure 2 Schematic evaluation based on distance from the object;

[0059] Figure 3 Schematic evaluation based on radial velocity and reflectivity of the object;

[0060] Figure 4 Schematic diagram of the inspection interference standard. DETAILED DESCRIPTION

[0061] Figure 1 A radar sensor 2 is schematically shown, which has a transmitting device 4. The transmitting device 4 is configured to emit a transmit signal 6. Figure 1 In the embodiment of the present invention, these transmission signals are reflected by road users 8 and reflected in the form of reception signals 10 in the direction of radar sensor 2. Road users 8 can be pedestrians, cyclists, passenger cars, trucks or other road users, for example.

[0062] Radar sensor 2 has a receiving device 12 which is configured to detect received signal 10. Figure 1In the exemplary embodiment shown in , the radar sensor also has an electronic data processing device 14. The electronic data processing device has an evaluation module 16 and a diagnostic module 18. It is advantageous, but not absolutely necessary, for the evaluation module 16 and the diagnostic module 18 to be part of the same electronic data processing device 14, or for the electronic data processing device 14 to be part of the radar sensor 2.

[0063] The received reception signal 10 is supplied by the receiving device 12 to an evaluation module 16. A detection matrix is ​​calculated and evaluated there. In the diagnosis module 18, a check is made as to whether the interference criterion is met. Subsequently, signals are generated from the evaluation results in the evaluation module 16 and the check results in the diagnosis module 18, which are transmitted to another electronic data processing device 20. The other electronic data processing device has a control module 22, to which the signals are transmitted along a data connection 24. The control module 22 of the electronic data processing device 20 is configured to control, for example, a traffic flow along a traffic route, for example by switching traffic light facilities, traffic signs or taking other measures that influence the traffic flow.

[0064] In a preferred embodiment, electronic data processing device 20 is also part of radar sensor 2. Particularly preferably, electronic data processing device 14 and electronic data processing device 20 are the same electronic data processing device, so that evaluation module 16, diagnosis module 18 and control module 22 are part of a single data processing device.

[0065] Figure 2 The results of the evaluation of the detection matrix are shown, wherein the distances (Range) are plotted for different measuring cycles. A large number of detected objects can be seen in a small distance range of up to 25 meters from the sensor, which are shown in black for better clarity. The white boxes shown with dashed lines mark these objects. It can therefore be seen from the evaluation of the distances that in the exemplary embodiment shown there are a large number of objects at very small distances from the actual sensor.

[0066] exist Figure 3 Another evaluation of the detection matrix or another part of the evaluation of the detection matrix is ​​shown. The radial velocity, i.e. the speed of the object towards or away from the sensor, is shown in the upper area. Here, there are also a large number of objects in the low speed range. The relevant speed range for objects with radial speeds of less than 10 m / s, for example, is again highlighted by the dashed box shown in white.

[0067] exist Figure 3 In the lower area of ​​the graph, the reflectivity, which is a direct measure of the radar cross section for an object, is plotted for a number of different measurement cycles. Here, too, it can be seen that objects have a radar cross section of less than 0 dBm. 2 Therefore, Figure 2 and Figure 3The results of the three diagrams in allow identification of a plurality of objects with very small radar cross sections, which are located at a small distance from the sensor and have a small radial velocity. In the embodiment shown, the objects can be identified as rain.

[0068] However, it is decisive for the functioning of the sensor that the rain has a certain intensity. This can be determined by Figure 2 and Figure 3 The individual "rain objects" are counted from the evaluation. If the number of rain objects thus determined exceeds a predefined limit, the rain is considered to be so heavy that the sensor's functional capacity is impaired. This can be seen from Figure 4 In the example shown, the limit value set is 100 objects. If more objects are detected, the line shown in blue is above the set limit value and the functional capacity of the sensor must be considered to be limited. In the exemplary embodiment shown, this is the case, for example, up to measuring cycle 2450. If the count number of rain objects is below the limit value, the functional capacity of the sensor is not limited and the interference criterion is not met. Figure 4 In the embodiment shown in , the interference criterion is met between measurement periods 72 to 2450 and between 3054 to 3267, but not in between and thereafter.

[0069] Reference numerals list

[0070] 2 Radar Sensor

[0071] 4 Transmitter

[0072] 6 Sending a signal

[0073] 8 Traffic Participants

[0074] 10. Receiving Signals

[0075] 12 Receiving device

[0076] 14 Electronic data processing equipment

[0077] 16 Evaluation Module

[0078] 18 Diagnostic module

[0079] 20 Electronic data processing equipment

[0080] 22 Control module

[0081] 24 Data Connections

Claims

1. A method for detecting traffic participants along at least one traffic route by means of at least one radar sensor, the at least one radar sensor having at least one transmitting device for radar radiation and at least one receiving device for radar radiation, and the at least one radar sensor being arranged above and / or beside the traffic route, wherein: The method comprises the following steps: - transmitting a transmission signal by means of the at least one transmission device for radar radiation; - detecting a received signal by means of the at least one receiving device for radar radiation; - mixing the transmission signal and the reception signal to form a baseband signal and calculating a detection matrix from the baseband signal and evaluating the detection matrix in an evaluation module of an electronic data processing device, wherein peaks of the detection matrix are assigned to objects; - Check in the diagnostic module whether the interference criteria are met; - generating a signal from the evaluation result in the evaluation module and the examination result in the diagnosis module; and - transmitting said signal to a control module of an electronic data processing device, Therein, the interference criterion is met if rain and / or snow is detected during the evaluation of the detection matrix, wherein the detection matrix is ​​a range-Doppler matrix.

2. The method according to claim 1, characterized in that A plurality of detection matrices are evaluated in succession so that an actual trajectory can be assigned to an object and a fault criterion is met if a predetermined number of the actual trajectories do not follow the course stored in the electronic database.

3. The method according to claim 1 or 2, characterized in that: The maximum signal-to-noise ratio, the minimum signal-to-noise ratio, the average signal-to-noise ratio and / or the median of the signal-to-noise ratio are obtained from the signal-to-noise ratio of the selected peak of the detection matrix, and if the maximum signal-to-noise ratio, the minimum signal-to-noise ratio, the average signal-to-noise ratio and / or the median of the signal-to-noise ratio are lower than a predetermined limit value, the interference standard is met, wherein the predetermined limit value is 100dB or 50dB or 20dB.

4. The method according to claim 1 or 2, characterized in that: When evaluating the detection matrix, a radar cross section of the selected object is ascertained, and a interference criterion is met if a maximum radar cross section, a minimum radar cross section and / or an average radar cross section and / or a median of the ascertained radar cross sections is less than a predefined limit value.

5. The method according to claim 1 or 2, characterized in that: The at least one receiving device has multiple receiving antennas and calculates the standard deviation of the phase difference between each two receiving antennas for a selected peak or a selected object, and if the maximum standard deviation, the minimum standard deviation and / or the average standard deviation and / or the median of the obtained standard deviations exceed a predetermined limit value, the interference criterion is met, wherein the predetermined limit value is 60° or 30° or 5°.

6. The method according to claim 1 or 2, characterized in that: The number of objects to which at least one peak of the detection matrix is ​​assigned is determined, and the interference criterion is met if the number exceeds a predetermined upper limit value, wherein the predetermined upper limit value is 150 or 100 or 75, or if the number is below a predetermined lower limit value, wherein the predetermined lower limit value is 10 or 20 or 30.

7. The method according to claim 1 or 2, characterized in that: If the interference intensity of the received signal, which is not composed of reflected transmitted signals, exceeds a predetermined limit value, the interference criterion is met.

8. The method according to claim 1 or 2, characterized in that: obtaining a maximum signal-to-noise ratio, a minimum signal-to-noise ratio, an average signal-to-noise ratio and / or a median signal-to-noise ratio from the signal-to-noise ratio of the selected peak of the detection matrix, Find the radar cross section of the selected object, and / or The at least one receiving device has a plurality of receiving antennas, and a standard deviation of a phase difference between every two receiving antennas is calculated for a selected peak or a selected object. if - the maximum signal-to-noise ratio, the minimum signal-to-noise ratio, the average signal-to-noise ratio and / or the median of the signal-to-noise ratio, - maximum radar cross section, minimum radar cross section, average radar cross section and / or median radar cross section, - maximum standard deviation, minimum standard deviation, mean standard deviation and / or median standard deviation, - the deviation of the actual trajectory of the object from the desired trajectory, - the interference intensity and / or If the weighted sum of the number of objects exceeds or falls below a predetermined limit value, the interference criterion is met.

9. The method according to claim 1 or 2, characterized in that: The at least one transmitting device and the at least one receiving device are parts of a radar sensor and a position and / or an orientation and / or a speed and / or an acceleration of the radar sensor is determined by means of at least one sensor.

10. The method according to claim 9, characterized in that The interference criterion is met if the position and / or orientation and / or velocity and / or acceleration of the radar sensor deviates from a setpoint value by more than a predetermined limit value.

11. The method according to claim 1 or 2, characterized in that: The signal contains an evaluation signal which contains information about the object ascertained during the evaluation of the detection matrix if the interference criterion is not met.

12. The method according to claim 11, characterized in that In addition to the evaluation signal, the signal also contains a diagnostic signal, which contains the information that the interference criterion is not met.

13. The method according to claim 1 or 2, characterized in that: The signal comprises a diagnostic signal, which, when a disturbance criterion is met, comprises the following information: the disturbance criterion is met, wherein the signal comprises no information about the object.

14. The method according to claim 1 or 2, characterized in that: When the interference criterion is met, the signal contains an evaluation signal regarding the fictitious object.

15. The method according to claim 4, characterized in that When evaluating the detection matrix, a radar cross section of the selected moving object is ascertained, and a interference criterion is met if a maximum radar cross section, a minimum radar cross section and / or an average radar cross section and / or a median of the ascertained radar cross sections is less than a predefined limit value.

16. The method according to claim 5, characterized in that The at least one receiving device has at least three receiving antennas.

17. The method according to claim 5, characterized in that The standard deviation of the phase difference in the azimuth direction and / or the elevation direction between each two receiving antennas is calculated for the selected peak or the selected object.

18. A radar sensor for detecting traffic participants along at least one traffic route, wherein: The radar sensor is configured to carry out a method according to any of the preceding claims.

19. The radar sensor according to claim 18, characterized in that: The radar sensor has an electronic data processing system having an evaluation module and having a diagnostic module.

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