System and method for traffic monitoring

Abstract

The invention relates to a system (47) and a method for traffic monitoring, wherein the system comprises a sensor device (48), the sensor device comprising at least one, preferably three-dimensional, laser scanner, wherein at least one scan can be performed by means of the laser scanner, in which an environment (49) of the laser scanner, comprising at least one area extending from a front (43) of a moving first vehicle (39) to a rear (44) of a second vehicle (40) moving in front of the first vehicle, can be scanned and scan data describing the environment, preferably a point cloud describing the environment, can be generated, from which a distance (50) of the first vehicle to the second vehicle can be determined.

Description

[0001] The invention relates to a system and a method for traffic monitoring.

[0002] As part of traffic monitoring, the police and other authorities conduct distance and / or speed measurements on moving traffic. The German Road Traffic Regulations (StVO) stipulate, in particular, that a sufficient distance must be maintained from the vehicle in front. This distance must generally be large enough to allow the driver to stop behind the vehicle in front even if it brakes suddenly. A rule of thumb for passenger cars is that, within city limits, the distance should be at least as great as the distance traveled in one second or three car lengths, and that outside city limits, the distance should be at least as great as the distance traveled in two seconds or at least half the speedometer reading.For trucks with a permissible total mass exceeding 3.5 t and buses, a minimum distance of 50 m must be maintained on motorways when their speed exceeds 50 km / h. Similar traffic regulations apply in other countries.

[0003] In order to penalize a violation of the required distance, i.e., a failure to maintain the prescribed minimum distance, traffic monitoring must be carried out, including at least one distance measurement; various methods for this are known from practice.

[0004] One method involves measuring distances using stationary video surveillance. At least one video camera is installed on a bridge to record the flow of traffic. A computer then calculates potential distance violations from a recorded traffic grid. To create this grid, markings are placed on the roadway to serve as fixed measuring points. The computer can then calculate whether a driver has committed a distance violation. If a vehicle is detected that falls below the minimum distance, a speed camera installed under the bridge is manually triggered to take a picture of the vehicle, including the driver and the vehicle's license plate number. Because this method is not automated, it is prone to errors and inaccurate.Furthermore, it is complex to implement, as cameras and speed cameras need to be installed, and markings need to be put in place. Additionally, only stationary distance measurements, meaning measurements tied to a fixed location, are possible.

[0005] A second method involves measuring distances using mobile video surveillance. This involves installing a video camera in a surveillance vehicle disguised as a police car. A sensor records vehicles and certain fixed points, from which a computer can then calculate a distance violation, a process that is more complex and time-consuming. Furthermore, with mobile distance measurement, it is crucial to ensure that the angle between the sensor and the vehicle remains constant. Since this is often difficult to achieve in practice, this method frequently yields inaccurate results.

[0006] A third method is optical distance measurement without technical measuring devices. In this method, the distance between two vehicles is estimated by eye. This method is therefore very inaccurate.

[0007] The present invention is therefore based on the objective of proposing a system and a method for traffic monitoring which enables traffic monitoring that includes at least one mobile or stationary, simple and precise distance measurement.

[0008] This problem is solved by a system having the features of claim 1 and a method having the features of claim 9.

[0009] The traffic monitoring system according to the invention comprises a sensor device, wherein the sensor device comprises at least one, preferably three-dimensional, laser scanner, wherein at least one scan can be performed by means of the laser scanner, in which an environment of the laser scanner, comprising at least one area extending from the front of a moving first vehicle to the rear of a second vehicle moving in front of the first vehicle, can be scanned and scan data describing the environment, preferably a point cloud describing the environment, can be generated, from which a distance of the first vehicle to the second vehicle can be determined.

[0010] The system is used for traffic monitoring, including at least distance measurement. Distance measurement measures the distance between a moving first vehicle and a second vehicle ahead of it. This measurement is taken to detect a distance violation by the first vehicle. A distance violation by the first vehicle is defined as a situation where the distance between the first vehicle and the second vehicle ahead falls below the minimum distance prescribed by traffic regulations for the section of road on which the first and second vehicles are traveling. The first and / or second vehicle can be a motor vehicle, in particular a passenger car, truck, or bus. The system can be configured for mobile or stationary installation.If the system is designed for mobile deployment, it can be part of a mobile surveillance setup, in particular a surveillance vehicle. Specifically, the system can be mounted on a surveillance vehicle, enabling mobile distance measurements, i.e., independent of a fixed location. The surveillance vehicle can be a motor vehicle. The motor vehicle can be a police vehicle. The police vehicle, in turn, can be a patrol car or an unmarked vehicle. The surveillance vehicle can also be a trailer. Alternatively, the surveillance vehicle can be an aircraft. The aircraft can be an airplane, a helicopter, a balloon, an airship, or a drone. The aircraft can also be a model aircraft.The mobile surveillance system can also be configured with a tripod on which at least part of the system, in particular the laser scanner, can be mounted. The tripod can be set up at the roadside or on a bridge. If the system is configured for stationary use, it can be part of a surveillance system intended for fixed installation. The surveillance system intended for fixed installation can be configured with a column that can be permanently installed, in particular at the roadside. The system comprises a sensor device, wherein the sensor device includes at least one, preferably three-dimensional, preferably imaging, laser scanner, wherein at least one scan can be performed by means of the laser scanner, in which the area surrounding the laser scanner extends from the front of the first vehicle to the rear of the second vehicle.The scanning process involves the scanning of a surveillance vehicle and the generation of scan data describing the environment, preferably a point cloud describing the environment. In other words, the scan includes scanning at least the area of ​​the laser scanner or surveillance vehicle, encompassing at least the front of the first vehicle and the rear of the second vehicle, and thus at least the front of the first vehicle, a gap extending between the front of the first vehicle and the rear of the second vehicle, and the rear of the second vehicle. The scanning process also generates scan data, preferably a point cloud, which describes or depicts at least the front of the first vehicle, the gap extending between the front of the first vehicle and the rear of the second vehicle, and the rear of the second vehicle.The area extending from the front of the first vehicle to the rear of the second vehicle can include at least one first point on the front of the first vehicle, preferably the front of the first vehicle itself, and at least one second point on the rear of the second vehicle opposite the first point, preferably the rear of the second vehicle, and at least one connecting line between the first and second points, preferably the gap extending between the front of the first vehicle and the rear of the second vehicle. The scan can be a 180° scan. Alternatively, the scan can be a 360° scan, so that the entire area around the laser scanner or the monitoring vehicle can be scanned and described by the scan data. Preferably, the laser scanner can have a horizontal opening angle of at least 180°, and particularly preferably 360°.During scanning, at least one preferably rotating, preferably infrared laser beam, emitted by means of the laser scanner, rotating laser, or rotating lidar sensor, and which may in particular be configured as a fan beam, can scan or sweep the area surrounding the laser scanner or surveillance vehicle, which includes at least the area extending from the front of the first vehicle to the rear of the second vehicle. The laser beam, in particular fan-shaped, can have a vertical opening angle, for example, between 10° and 30°, preferably between 15° and 20°, and particularly preferably between 16° and 17°. Objects in the vicinity, in particular the front of the first vehicle and the rear of the second vehicle, can reflect the laser beam from scanning points on the objects, in particular the front of the first vehicle and the rear of the second vehicle, back to the laser scanner.The surface geometry of objects, particularly the front of the first vehicle and the rear of the second, can be captured using a laser scanner, specifically through a pulse-time-of-flight method, phase-difference method, or triangulation method. This process generates a discrete set of points corresponding to the scan points, a point cloud, which can represent the surroundings. The distance between the first and second vehicles can be precisely determined from this point cloud. Points contained within the three-dimensional point cloud can be described by three-dimensional coordinates. These coordinates can be determined from angles and distances relative to an origin, which can be defined by the position of the laser scanner. The front of the first vehicle and the rear of the second vehicle can be described by points within the point cloud.The distance between the first and second vehicles can then be determined, for example, as the distance between a first point in the point cloud, which describes the front of the first vehicle, and a second point in the point cloud, located opposite the first point and describing the rear of the second vehicle. Furthermore, it is possible to generate a three-dimensional model from the point cloud. The point cloud can also be output as an image, particularly a reflection image. Distance measurement can be performed in real time. The system therefore enables simple and precise traffic monitoring, including at least mobile or stationary distance measurement. Based on the scan data or point cloud, the dimensions of a part of the first vehicle, in particular its width, can be determined and compared with known dimensions of that part, especially its width.This allows for a plausibility check or determination of the precision of the distance measurement.

[0011] In a preferred embodiment of the system, the system may include a processing device. The processing device may be configured as a processor.

[0012] In a preferred embodiment of the system, the processing device can determine the distance between the first and second vehicles from the scan data. This allows for automated distance determination on-site. Alternatively, the distance between the first and second vehicles can be manually measured from the scan data. For this purpose, the point cloud can be output as an image, particularly a reflection image.

[0013] In a preferred embodiment of the system, the system can comprise a first speed measuring device for measuring the speed of a monitoring vehicle, on which the system can be mounted. The speed of the first vehicle can be inferred from the speed of the monitoring vehicle. The speed of the first vehicle can be taken into account when determining a threshold value, in particular a minimum distance to be maintained, against which the distance of the first vehicle to the second vehicle is to be compared in order to detect a following distance violation.

[0014] In a preferred embodiment of the system, the first speed measuring device can comprise at least one optical speed sensor. The optical speed sensor can be in the form of a laser velocimeter. The optical speed sensor can comprise a transmitter for emitting, preferably coherent, light, in particular laser light or radar light, towards a road surface and a receiver for receiving the light reflected from the road surface. The receiver can have an interference detector, which can be configured to detect a measurement describing the speed of the monitoring vehicle, characterized by interference between the reflected and emitted light.The optical speed sensor can be coupled to an evaluation unit of the speed measuring device, which can be configured to determine the speed of the monitoring vehicle from the measured value. Alternatively, the first speed measuring device can also be a speedometer or another device suitable for measuring the speed of the monitoring vehicle.

[0015] In a preferred embodiment of the system, the system can include a second speed measuring device for measuring the differential speed of a vehicle relative to the system or monitoring vehicle, or the vehicle's own speed. The vehicle can be the first vehicle, the second vehicle, or another or third vehicle. Using the processing device, the vehicle's speed can be determined from the differential speed of the vehicle relative to the monitoring vehicle and the speed of the monitoring vehicle measured by the first speed measuring device. Depending on the system's design or state of motion, the differential speed of the vehicle relative to the system or monitoring vehicle can correspond to the vehicle's own speed.The speed of the first vehicle can be taken into account when determining a threshold, in particular a minimum distance to be maintained, against which the distance of the first vehicle to the second vehicle is to be compared in order to determine a following distance violation. Alternatively or additionally, the system can thus serve for traffic monitoring that includes distance measurement and speed measurement. Speed ​​measurement measures the speed of a moving vehicle. The speed measurement of the first vehicle can therefore alternatively or additionally also serve to determine a speeding violation, that is, an exceedance of a maximum speed prescribed by traffic regulations on the section of road on which the first vehicle is traveling. Likewise, a speed measurement of the second vehicle or other...The third vehicle serves to detect a speeding violation by the second or other / third vehicle. The second speed measuring device can, in principle, be any device suitable for measuring the difference in speed between the vehicle and the system or monitoring vehicle, or the vehicle's own speed.

[0016] In a preferred embodiment of the system, which can be arranged on a surveillance vehicle, the second speed measuring device can be configured with at least one further sensor device, wherein at least two, preferably at least three, beams of, preferably pulsed, light can be emitted by means of the further sensor device, wherein the emitted beams can be spaced apart from each other when viewed laterally to the surveillance vehicle and along a longitudinal axis of the surveillance vehicle, wherein when the vehicle moves past the surveillance vehicle relative to the surveillance vehicle, the emitted beams can be traversed successively by at least a part of the vehicle, wherein when traversing the emitted beams, the emitted beams can be reflected by the vehicle, wherein reflected beams can be received by means of the sensor device and from the reflectedBeams can be used to generate received signals, from which the differential speed of the vehicle relative to the monitoring vehicle can be determined. The determination of the differential speed of the vehicle relative to the monitoring vehicle based on the received signals can be carried out using the processing device. The monitoring vehicle with the system mounted on it can be driven while the speed measurement is being performed. In other words, the system can be designed such that the speed measurement can be carried out, in particular, even when the system is moving alongside the moving monitoring vehicle. For this purpose, the system can include at least one further sensor device, wherein at least two, preferably at least three, beams of, preferably pulsed, light, i.e., light beams, can be emitted by means of the further sensor device, wherein the system mounted on the monitoring vehicleThe system considers the emitted beams as they extend laterally to the monitoring vehicle, i.e., on one side of the monitoring vehicle, and along a longitudinal axis of the monitoring vehicle, where they can be spaced apart from one another. The additional sensor device can include a transmitter for emitting the beams. The number of such beams that can be emitted by the additional sensor device can be at least two, i.e., for example, two, three, four, five, or more. The emitted beams can extend parallel to each other at fixed intervals. In this context, the term "light" is understood to mean electromagnetic radiation in any frequency range. In particular, the light can be visible light, infrared light, ultraviolet light, or electromagnetic radiation with a frequency in the radio frequency range, especially radar radiation.Preferably, the emitted beams or light can each be formed from light pulses. The vehicle can be detected by means of the additional sensor device. The emitted beams can serve as measuring beams. The emitted beams can define a detection range of the additional sensor device. Two outer beams of the emitted beams, viewed along the longitudinal direction, can limit the detection range in a longitudinal direction of the monitoring vehicle or along its longitudinal axis. A range of the additional sensor device or the emitted beams can limit the detection range in a transverse direction of the monitoring vehicle or along a transverse axis of the monitoring vehicle. The vehicle can be detected when it enters the detection range. When the vehicle moves past the monitoring vehicle relative to the monitoring vehicle, during which the relative to theIf a vehicle moving a surveillance vehicle can pass laterally by the surveillance vehicle, particularly when passing or overtaking the surveillance vehicle, the emitted beams or paths of the emitted beams can be traversed or driven through successively in one direction of travel by at least a part of the vehicle, especially a front or rear of the vehicle, preferably by the entire vehicle. It is possible that only the vehicle is moving, only the surveillance vehicle is moving, or both the vehicle and the surveillance vehicle are moving. Furthermore, it is possible that the vehicle and the surveillance vehicle are traveling in the same or opposite directions. In all of the aforementioned cases, the vehicle can pass the surveillance vehicle. The emitted beams are reflectable.When the emitted beams strike at least one surface or object(s), the beams are reflected by the surface or object(s). The objects can be vehicles, in particular the vehicle or other vehicles besides the vehicle being monitored for speed, or any other conceivable object, especially at the edge of a road or lane. When passing through the emitted beams or their paths, the emitted beams can be reflected by the vehicle. The additional sensor device can detect reflected beams resulting from these reflections, particularly from the vehicle or other objects. The additional sensor device can include a receiver for receiving the reflected beams. Furthermore, the additional sensor device, in particular the receiver, can be used to determine the speed of the emitted beams.Received signals can be generated from the reflected beams. A received signal can be generated from each reflected beam. The received signals can be electrical signals. The receiving device can include a detector for converting the reflected beams into electrical signals. The received signals can describe the intensities of the reflected beams or light, or the distances between the emitting points of the emitted beams on the further sensor device and the reflection points of the emitted beams, particularly on the vehicle or other objects. An emitting point is understood to be a point on the further sensor device where the respective beam is emitted; a reflection point is understood to be a point on the vehicle or other object where the respective emitted beam is reflected. The distances can be determined by the further sensor device or receiving device from the travel times of the emitted and reflected beams.The reflected rays or light are determined. The travel times can be determined based on the reception times of the reflected rays or light pulses and the transmission times of the emitted rays or light pulses. The received signals can change depending on whether or not rays reflected from the vehicle are received. Reflection of the emitted rays from objects other than the vehicle and the reception of corresponding reflected rays can lead to different received signals, particularly lower intensities or greater distances, than reflection of the emitted rays from the vehicle and the reception of corresponding reflected rays. Therefore, the presence of the vehicle within the emitted rays or paths can be inferred from the received signals. Thus, the vehicle can be detected using the received signals.The processing device can evaluate the received signals, particularly those describing intensities or distances, preferably continuously. From the received signals describing the distances, the processing device can determine the distance of the vehicle from the monitoring vehicle along the transverse axis, for example, as the average of the distances. If the received signals do not describe the distances, the processing device can determine the distances from the received signals by calculating the travel times. The processing device can determine whether the distances lie within a range, preferably definable or programmable, in order to detect the vehicle and, if applicable, a lane defined by the distance range in which the vehicle is located. Furthermore, the processing device can use the distances to...The system detects whether another vehicle moves between the vehicle being monitored and the monitoring vehicle during speed monitoring, thus distorting the speed measurement. Based on the received signals, the processing device can determine the differential speed of the vehicle relative to the monitoring vehicle. This differential speed is the vehicle's speed relative to the monitoring vehicle. If the vehicle traverses the emitted beams or paths sequentially, it can enter the emitted beams or paths with its front and exit them with its rear. Therefore, the beams reflected by the vehicle can reach the subsequent sensor device sequentially, and reflections of theThe emitted beams are interrupted sequentially. This can lead to changes in the received signals, particularly the spacing. The received signals, especially the spacing, can change sequentially, specifically decreasing and increasing. Based on the received signals, the times when the vehicle's front enters the emitted beams or paths and / or the times when the vehicle's rear exits the emitted beams or paths can be determined. This can be done by considering at least one time difference between two times when the vehicle's front enters the emitted beams or paths and at least one known distance along the longitudinal axis traversed within that time difference from the beginning or front, and / or at least one time difference between two times when the vehicle exits the beams or paths.By considering the emitted beams or paths from the rear of the vehicle and at least a known distance between emitted beams or paths traversed along the longitudinal axis within the time difference from the rear, the differential velocity can be determined. Alternatively or additionally, instead of determining the differential velocity by detecting the front or rear of the vehicle, it can also be determined by detecting the vehicle's contour. It would also be conceivable to determine the speed of the monitoring vehicle using the additional sensor device by correlating changes in the measured distances to the surroundings during travel.

[0017] In a preferred embodiment of the system, laser light can be used. The further sensor device can then be designed as a lidar sensor device, that is, as a sensor device that operates according to the lidar method.

[0018] In a preferred embodiment of the system, the further sensor device can comprise at least two, preferably at least three, transmit / receive modules, preferably configured as lidar sensors, wherein each transmit / receive module can emit one of the beams, and each transmit / receive module can receive one of the reflected beams. The transmit / receive modules can be configured as distance sensors, in particular laser sensors, preferably lidar sensors or time-of-flight (ToF) sensors.

[0019] In a preferred embodiment of the system, the emitted beams can be perpendicular to the longitudinal axis and / or horizontal, preferably in a common horizontal plane. If the emitted beams are both perpendicular and horizontal, they can be parallel to the transverse axis of the surveillance vehicle.

[0020] In a preferred embodiment of the system, the system can comprise a receiver for a global navigation satellite system (GNSS) and / or an inertial measurement device with at least one accelerometer and / or at least one gyroscope (IMU). Using the receiver, the location and / or direction of travel of the monitoring vehicle can be determined from satellite signals. The location of the monitoring vehicle can correspond to the location of a distance or speed measurement, or the location of a distance or speed violation by the first vehicle, and the direction of travel of the monitoring vehicle can correspond to the direction of travel of the first vehicle.Furthermore, the location of the monitoring vehicle can be used to determine whether the monitoring vehicle, and thus also the first vehicle, is located within or outside of built-up areas, particularly on a motorway or rural road. This information can be taken into account when determining a threshold value, especially a minimum distance to be maintained, against which the measured distance between the first vehicle and the second vehicle is to be compared in order to establish a following distance violation. The first speed measuring device can comprise the inertial measuring device and / or the receiving device. Using the inertial measuring device and / or the receiving device, the speed of the monitoring vehicle can be measured alternatively or additionally to the measurement of the monitoring vehicle's speed by means of the optical speed sensor.When the optical speed sensor, the inertial measuring device, and the receiver are used together to determine the speed of the monitoring vehicle, measurement accuracy and reliability can be increased. Furthermore, the differential speed of the vehicle being monitored can be corrected using the inertial measuring device and / or the receiver. Since the speed measurement can be distorted as a result of the monitoring vehicle or the vehicle itself cornering, data from the inertial measuring device and / or the receiver can be taken into account when determining the differential speed, thus correcting the differential speed of the vehicle being monitored.

[0021] In a preferred embodiment of the system, the system can include a radar device. The radar device allows approaching vehicles to be detected at an early stage. It can monitor the area behind and / or in front of the monitoring vehicle. The radar device can provide a rough estimate of the vehicle's speed before the actual speed measurement is carried out using the additional sensor device. Therefore, the radar device can be configured for the measurement, particularly a rough estimate, of the vehicle's speed or the differential speed between the vehicle and the monitoring vehicle.

[0022] In a preferred embodiment of the system, the system may include a camera device for recording at least one image containing at least one vehicle. The vehicle may be the first vehicle, second vehicle, or other or third vehicles. The camera device may include a plurality of cameras. For example, a first camera of the camera device may be configured for recording images or photographs, and a second camera of the camera device may be configured for recording videos. The recording may be an image or photograph or a video. The camera device may record at least one image or photograph and at least one video containing at least the first vehicle. In particular, the camera device may record an image or photograph containing the driver of the first vehicle, the driver's face, and / or the vehicle registration number of the first vehicle.A photograph is taken and / or a video is recorded that includes at least the first vehicle committing the following distance violation. The recording can include both the first and second vehicles. The recording can then be a wide-angle shot. A recording or wide-angle shot including both the first and second vehicles can be made in addition to a recording that includes the driver of the first vehicle, the driver's face, and / or the vehicle registration number of the first vehicle. Using the processing device, the vehicle registration number and / or the vehicle type of the first vehicle, in particular whether the first vehicle is a passenger car, a truck, or a bus, can be determined or identified from a recording, in particular an image or photograph, and / or from scan data, in particular an image of the point cloud, especially by means of image processing.The vehicle type can be taken into account when determining a threshold value, in particular a minimum distance to be maintained, against which the measured distance between the first vehicle and the second vehicle is to be compared in order to determine a violation of the distance requirement. The camera device can include an exposure unit, preferably a black flash unit, in order to be able to take pictures at night, for example.

[0023] In a preferred embodiment of the system, the system may include a storage device, in particular for storing scan data and / or data describing the distance between the first vehicle and the second vehicle and / or data describing the speed of a vehicle and / or data describing at least one recording containing at least one vehicle and / or data describing the location of a monitoring vehicle where the system may be installed and / or data describing the direction of travel of the monitoring vehicle. The storage device may further store the date of a distance measurement or a distance violation and / or the date of a speed measurement or a speed violation and / or the time of a distance measurement or a distance violation and / or the time of a speed measurement or a speed violation. All of the aforementioned data may be stored in encrypted form.Furthermore, the storage device can be used to store a function for determining a threshold value, in particular a minimum distance to be maintained, in accordance with the traffic regulations applicable in a given country. The function can assign a threshold value to a location parameter of the monitoring vehicle, which can describe whether the monitoring vehicle, and thus the first vehicle, is located within or outside of built-up areas, in particular on a motorway or a rural road; to the speed of the first vehicle; and to a vehicle type parameter, which can describe whether the first vehicle is a passenger car, truck, or bus. This threshold value is then used to compare the determined distance of the first vehicle from the second vehicle in order to establish a distance violation.For example, the function can assign a threshold of 50 m to a truck traveling on the motorway at a speed exceeding 50 km / h and a threshold of x / 2 m to a passenger car traveling on the motorway or rural road at a speed of x km / h. Furthermore, the data storage device can store a catalog of fines relating to following distance violations and / or speeding violations, based on which the processing device can automatically calculate any fine that may be imposed, depending on the determined distance between the first vehicle and the second vehicle or the determined speed of the vehicle.

[0024] In a preferred embodiment of the system, the system may include a display device. The display device can show the determined distance of the first vehicle from the second vehicle, and / or the measured speed of the second vehicle, and / or the location of the monitoring vehicle, particularly in map form, and / or the direction of travel of the monitoring vehicle, and / or the date and time of the distance or speed measurement, and / or the recording including at least the first vehicle, and / or any fine that may be imposed. The point cloud can also be displayed by means of the display device.

[0025] In a preferred embodiment of the system, the system may include a user interface device. The user interface device may, in particular, allow the function to be entered, programmed, or modified, and in particular, information relating to the function that is dependent on the traffic regulations of a particular country may be entered and / or modified.

[0026] Further advantageous embodiments of the system result from the feature descriptions of the dependent claims relating back to method claim 9.

[0027] The mobile monitoring arrangement according to the invention, in particular a monitoring vehicle, or a monitoring arrangement intended for stationary installation, comprises a system according to the invention.

[0028] The mobile surveillance system can be a surveillance vehicle. The surveillance vehicle can be a motor vehicle or an aircraft. The motor vehicle can be a police vehicle. The police vehicle, in turn, can be an emergency vehicle or an unmarked civilian vehicle. The aircraft can be an airplane, a helicopter, a balloon, an airship, or a drone. The aircraft can also be a model aircraft. The surveillance vehicle can also be a trailer. The mobile surveillance system can also be equipped with a tripod on which at least part of the system, in particular a laser scanner or a sensor device of the system, can be mounted. The tripod can be set up at the side of a road or on a bridge.The monitoring arrangement intended for fixed installation can be designed with a column that can be permanently installed, in particular at the side of a road.

[0029] In the traffic monitoring method according to the invention, at least one scan is carried out using at least one, preferably three-dimensional, laser scanner of a sensor device of the system, in which an environment of the laser scanner, comprising at least one area extending from the front of a moving first vehicle to the rear of a second vehicle moving in front of the first vehicle, is scanned and scan data describing the environment, preferably a point cloud describing the environment, is generated, on the basis of which a distance of the first vehicle to the second vehicle is determined.

[0030] For the advantageous effects of the method according to the invention, reference is made to the description of advantages of the system according to the invention.

[0031] The system can be mounted on a surveillance vehicle, particularly on its roof. The surveillance vehicle can be moving or flying during traffic monitoring, especially when measuring distances, performing scans, and / or measuring speeds. Distance and speed measurements are also possible when the surveillance vehicle is stationary. The system can be mobile or stationary in other ways.

[0032] In a preferred embodiment of the method, the scan can be performed when the moving surveillance vehicle, at least with its laser scanner, is positioned laterally adjacent to the area extending from the front of the first vehicle to the rear of the second vehicle, and in particular laterally adjacent to a gap between the first and second vehicles. The first and second vehicles can travel in a first lane in the same direction, with the surveillance vehicle traveling in a second lane parallel to the first lane. The second lane can run directly adjacent to the first lane. Alternatively, at least one further lane can run parallel to the first and second lanes, respectively, between the first and second lanes.The scan can be performed when the moving surveillance vehicle is positioned on the second lane, with its laser scanner at least laterally adjacent to the area extending from the front of the first vehicle to the rear of the second vehicle, and in particular laterally adjacent to the gap between the first and second vehicles. Preferably, the speed differential between the surveillance vehicle and the first and / or second vehicle can be relatively small.

[0033] In a preferred embodiment of the method, a sequence of scans can be performed using the laser scanner. By generating a sequence of scan data describing the environment, it can be determined whether the distance between the first vehicle and the second vehicle was only briefly too small. This can be the case, for example, if the second vehicle brakes suddenly.

[0034] Using the laser scanner, a sequence or multiple scans, for example 20 scans, can be performed per second.

[0035] Based on a sequence or multiple scans in which a suitable environment of the laser scanner, in particular the area extending from the front of the first vehicle to the rear of the second vehicle, can be scanned, or based on scan data describing the environment generated during the sequence or multiple scans, in particular point clouds, the speed of the monitoring vehicle and / or the speed of a vehicle, which may be the first vehicle, the second vehicle or another or third vehicle, can be determined.

[0036] In a preferred embodiment of the method, the distance between the first vehicle and the second vehicle can be determined from the scan data using a processing device of the system. The processing device can then compare the determined distance between the first and second vehicles, preferably after a tolerance deduction, with a threshold value, in particular a minimum distance to be maintained. The threshold value or minimum distance against which the determined distance between the first and second vehicles is to be compared can be determined by the processing device depending on the speed of the first vehicle and / or the type of vehicle and / or the location of the monitoring vehicle or first vehicle. The speed of the first vehicle can be measured using the second speed measuring device.The vehicle type of the first vehicle can be determined using the processing device, in particular by means of image processing, based on an image taken by the camera device. The location of the monitoring vehicle or first vehicle can be determined using the receiving device.

[0037] In a preferred embodiment of the method, if the threshold is not met, the scan data and / or data describing the distance between the first and second vehicles can be stored by means of a data storage device of the system. The scan data or data can initially be temporarily stored by means of a data buffer device of the system. If the threshold is not met, the temporarily stored scan data or data can be permanently saved by means of the data storage device. If the threshold is not met, the temporarily stored data or scan data can be deleted.

[0038] The processing device allows a vehicle speed measured using the second speed measuring device, preferably after a tolerance deduction, to be compared with a limit speed, preferably a permissible maximum speed. If the limit speed is exceeded, data describing the vehicle's speed can be stored using the system's data storage device. The data can initially be temporarily stored using the data buffer. If the limit speed is exceeded, the temporarily stored data can be permanently saved using the data storage device. If the limit speed is not reached, the temporarily stored data can be deleted.

[0039] In a preferred embodiment of the method, at least one recording including at least the first vehicle can be made using a camera device of the system and the recording can be stored using the data storage device and / or a location of a monitoring vehicle on which the system is arranged and / or a direction of travel of the monitoring vehicle can be determined using a receiver device for a global navigation satellite system of the system and data describing the location of the monitoring vehicle and / or data describing the direction of travel of the monitoring vehicle can be stored using the storage device.

[0040] Further advantageous embodiments of the method result from the feature descriptions of the dependent claims relating back to device claim 1.

[0041] Preferred embodiments of the invention are explained in more detail below with reference to the accompanying drawings.

[0042] They show: Fig. 1 a surveillance vehicle with a system in a first embodiment; Fig. 2 a surveillance vehicle with a system in a second embodiment.

[0043] The Fig. 1 Figure 10 shows a surveillance vehicle 10, designed as a motor vehicle, comprising a traffic monitoring system 11. The system 11 includes a sensor device (not shown), which comprises a laser scanner (not shown). Using the sensor device or the laser scanner, a distance measurement between two vehicles can be performed. The system 11 includes two further sensor devices 14 and 15 for detecting vehicles 12 and 13 on both sides of the surveillance vehicle 10. Using the further sensor devices 14 and 15, a speed measurement of a vehicle can be performed. By means of the further sensor device 14 or 15, three beams 16, 17, 18 or 19, 20, 21 of pulsed laser light can be emitted, wherein the emitted beams 16, 17, 18 or 19, 20, 21 run perpendicular to a longitudinal axis 22 of the monitoring vehicle 10, horizontally and at equal distances 23, 24 from each other.The monitoring vehicle 10 and the vehicles 12, 13 travel in the same direction 25 of the monitoring vehicle 10 and 26, 27 of the vehicles 12, 13 on a roadway 28, whereby the vehicle 12 travels on a lane 29 of the roadway 28, the vehicle 13 on a lane 30 of the roadway 28 and the monitoring vehicle 10 on a lane 31 of the roadway 28 arranged between the lane 29 and the lane 30. When the monitoring vehicle 10 is overtaken by the vehicle 12 or 13, the emitted beams 16, 17, 18 or 19, 20, 21 can be traversed by the vehicle 12 or 13 in succession, whereby when traversing the emitted beams 16, 17, 18 or 19, 20, 21, the emitted beams 16, 17, 18 or 19, 20, 21 can be reflected by the vehicle 12 or 13, whereby by means of the further sensor device 14 or 13, the emitted beams 16, 17, 18 or 19, 20, 21 can be reflected by the vehicle 12 or 13.15 reflected rays not shown here can be received from the light and received signals can be generated from the reflected rays, whereby a differential speed of the vehicle 12 or 13 to the monitoring vehicle 10 can be determined on the basis of the received signals by means of a processing device of the system 11 not shown here. Using the processing device, three times of entry of the vehicle 12 or 13 with a front 32 or 33 of the vehicle 12 or 13 into the emitted beams 16, 17, 18 or 19, 20, 21 and three times of exit of the vehicle 12 or 13 with a rear 34 or 35 of the vehicle 12 or 13 from the emitted beams 16, 17, 18 or 19, 20, 21 are determined from the received signals, whereby the processing device uses three time differences from each pair of times of entry of the vehicle 12 or 13 with the beginning 32 or 33 into the emitted beams 16, 17, 18 or 19, 20, 21.The differential velocity is determined from the emitted rays 16, 17, 18 and 19, 20, 21 traversed within the three time differences from the beginning 32 and 33, respectively, and from three time differences from each of the two times of exit of the vehicle 12 and 13 with the end 34 and 35, respectively, and from the emitted rays 16, 17, 18 and 19, 20, 21 traversed within the three time differences from the end 34 and 35, respectively. System 11 further comprises a speed measuring device (not shown) with at least one optical speed sensor, an inertial measurement unit (IMU) (not shown) with at least one accelerometer and at least one gyroscope, and a receiver (not shown) for a global navigation satellite system (GNSS). The speed measuring device, or...The speed of the monitoring vehicle 10 is measured by the speed sensor, the inertial measuring device, and the receiving device. The difference in speed between vehicle 12 or 13 and the speed of the monitoring vehicle 10 is added to the speed of vehicle 12 or 13. If the monitoring vehicle 10 is traveling in lane 29 or 30, vehicles in lanes 30 and 31 or 29 and 31 can be speed-monitored using the additional sensor device 14 or 15.

[0044] If another vehicle is ahead of vehicle 12 or 13 in lane 29 or 30, a scan can be performed using the laser scanner, in which an area (not shown here) extending from the front 32 or 33 of vehicle 12 or 13 to the rear of the respective other vehicle is scanned and scan data describing the environment is generated, based on which, in particular by means of the processing device, a distance of vehicle 12 or 13 to the respective other vehicle can be determined.

[0045] System 11 is used for traffic monitoring, including distance measurement and speed measurement.

[0046] The Fig. 2 Figure 3 shows a first vehicle 39 traveling in a first lane 37 of a carriageway 38 and a second vehicle 40 preceding the first vehicle 39 in the same first lane 37. A surveillance vehicle 42, designed as a motor vehicle, is traveling in a second lane 41 of the carriageway 38 adjacent to the first lane 37. The surveillance vehicle 42 is positioned laterally adjacent to a gap 45 extending between the front 43 of the first vehicle 39 and the rear 44 of the second vehicle 40. The first vehicle 39, the second vehicle 40, and the surveillance vehicle 42 are traveling in a common direction 46.The surveillance vehicle 42 comprises a traffic monitoring system 47, wherein the system 47 comprises a sensor device 48, the sensor device 48 comprising a laser scanner (not shown here) by means of which at least one scan can be performed, in which a lateral environment 49 of the surveillance vehicle 42, which is indicated here by a dashed boundary line and includes an area extending from the front 43 of the first vehicle 39 to the rear 44 of the second vehicle 40, can be scanned and scan data describing the environment 49 can be generated, wherein the system 47 comprises a processing device (not shown here) by means of which a distance 50 of the first vehicle 39 to the second vehicle 40 can be determined on the basis of the scan data.The system 47 further comprises a receiver (not shown) for a global navigation satellite system for determining the location and direction of travel 46 of the monitoring vehicle 42, a camera device (not shown) for recording at least one image including at least the first vehicle 39, and a data storage device (not shown). To detect a distance violation, the processing device compares the determined distance 50 between the first vehicle 39 and the second vehicle 40, preferably after a tolerance deduction, with a minimum distance. If the determined distance 50 between the first vehicle 39 and the second vehicle 40 is less than the minimum distance, a distance violation has occurred. In the event of a distance violation, data describing the determined distance 50 between the first vehicle 39 and the second vehicle 40 is stored by the data storage device.Furthermore, a recording containing the first vehicle 39 is made using the camera device, from which a driver of the first vehicle 39 and a vehicle registration number of the first vehicle 39 can be identified, and stored using the data storage device. Additionally, data describing the location of the monitoring vehicle 42 corresponding to the location of the distance violation and data describing the direction of travel 46 of the monitoring vehicle 42 are stored using the data storage device, whereby the location of the monitoring vehicle 42 and the direction of travel of the monitoring vehicle 46 are determined using the receiving device.

[0047] System 47 is used for traffic monitoring that includes distance measurement.

[0048] All of the aforementioned features of systems 11 and 47, or all those in the Fig. 1 and 2 The features shown can be combined in any meaningful way.

Claims

1. System (11, 47) for traffic monitoring, wherein the system comprises a sensor device (48), the sensor device comprising at least one, preferably three-dimensional, laser scanner, wherein at least one scan can be performed by means of the laser scanner, in which an environment (49) of the laser scanner, comprising at least one area extending from a front (32, 33, 43) of a moving first vehicle (12, 13, 39) to a rear (44) of a second vehicle (40) moving ahead of the first vehicle, can be scanned and scan data describing the environment, preferably a point cloud describing the environment, can be generated, from which a distance (50) of the first vehicle to the second vehicle can be determined.

2. System according to claim 1, characterized by that the system (11, 47) includes a processing device by means of which the distance (50) of the first vehicle (12, 13, 39) to the second vehicle (40) can be determined on the basis of the scan data.

3. System according to claim 1 or 2, characterized by that the system (11, 47) comprises a first speed measuring device for measuring the speed of a monitoring vehicle (10, 42) on which the system can be arranged.

4. System according to any of the preceding claims, characterized by that the system (11, 47) includes a second speed measuring device for measuring a differential speed of a vehicle (12, 13, 39, 40) to the system.

5. System according to any of the preceding claims, characterized by that the system (11, 47) comprises a receiving device for a global navigation satellite system and / or an inertial measuring device with at least one accelerometer and / or at least one gyroscope.

6. System according to any of the preceding claims, characterized by thatthe system (11, 47) comprises a camera device for making at least one recording including at least one vehicle (12, 13, 39, 40).

7. System according to any of the preceding claims, characterized by that the system (11, 47) includes a data storage device, in particular for storing the scan data and / or data describing the distance (50) of the first vehicle (12, 13, 39) to the second vehicle (40) and / or data describing the speed of a vehicle (12, 13, 39, 40) and / or at least a recording including at least one vehicle (12, 13, 39, 40) and / or data describing the location of a monitoring vehicle (10, 42) where the system can be arranged and / or data describing the direction of travel (25, 46) of the monitoring vehicle.

8. Mobile surveillance arrangement, in particular surveillance vehicle (10, 42), or surveillance arrangement intended for stationary installation, comprising a system (11, 47) according to one of the preceding claims.

9. Method for traffic monitoring, wherein at least one, preferably three-dimensional, laser scanner of a sensor device (48) of the system is used to perform at least one scan, in which an environment (49) of the laser scanner, comprising at least one area extending from a front (32, 33, 43) of a moving first vehicle (12, 13, 39) to a rear (44) of a second vehicle (40) moving ahead of the first vehicle, is scanned and scan data describing the environment, preferably a point cloud describing the environment, is generated, on the basis of which a distance (50) of the first vehicle to the second vehicle is determined.

10. Method according to claim 9, characterized by thatthe system (11, 47) is arranged on a surveillance vehicle (10, 42), preferably the scan is carried out when the moving surveillance vehicle (10, 42) is at least laterally adjacent with the laser scanner to the area extending from the front (32, 33, 43) of the first vehicle (12, 13, 39) to the rear (44) of the second vehicle (40).

11. Method according to claim 9 or 10, characterized by that A sequence of scans is performed using the laser scanner.

12. Method according to any one of claims 9 to 11, characterized by thatBy means of a processing device of the system (11, 47) the distance (50) of the first vehicle (12, 13, 39) to the second vehicle (40) is determined on the basis of the scan data, wherein the distance (50) of the first vehicle to the second vehicle is compared with a threshold value, in particular a minimum distance to be maintained, by means of the processing device.

13. Method according to claim 12, characterized by that If the threshold is undershot, the scan data and / or data describing the distance (50) of the first vehicle (12, 13, 39) to the second vehicle (40) are stored by means of a data storage device of the system (11, 47).

14. Method according to claim 13, characterized by thatby means of a camera device of the system (11, 47) at least one recording including at least the first vehicle (12, 13, 39) is made and the recording is stored by means of the data storage device and / or that by means of a receiving device for a global navigation satellite system of the system a location of a monitoring vehicle (10, 42) on which the system is arranged and / or a direction of travel (25, 46) of the monitoring vehicle is determined and data describing the location of the monitoring vehicle and / or data describing the direction of travel of the monitoring vehicle are stored by means of the data storage device.

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