Method for calibrating a traffic monitoring system and traffic monitoring system

Abstract

Method for calibrating a traffic monitoring system. The traffic monitoring system can detect a monitoring area and at least one object located within the monitoring area. The traffic monitoring system has at least two sensors for monitoring the monitoring area and the at least one object, a communication unit for communicating with the at least one object, and a control unit connected to the sensors and the communication unit. The method comprises the following steps: a) collecting sensor information with at least one sensor, and b) receiving object information of the object by the communication unit, whereby the object information is determined by the object and transmitted to the traffic monitoring system, and c) Calibrating the sensor with the sensor information and the object information transmitted by the object.

Description

The invention relates to a method for calibrating a traffic monitoring system and to a traffic monitoring system.In known traffic monitoring systems, for example in automated valve parking (AVP) type 2 systems, the infrastructure assumes responsibility for driving the vehicle, wherein the vehicle itself does not have to have any environment sensor system. The traffic space and the vehicles are monitored via sensors installed in the traffic system. When installing the sensors for the infrastructure, a relatively complex calibration is necessary in order subsequently to achieve the necessary accuracy during productive operation, that is to say during the control of the vehicle or vehicles.If a sensor fails in these systems, it is damaged or its orientation is changed, recalibration must take place in order to achieve the necessary accuracy again. For this recalibration, an interruption of the productive operation is frequently required.The invention is based on the object of proposing a method for calibrating a sensor in a traffic monitoring system, which method makes possible simple calibration of a sensor. It is furthermore an object of the invention to provide a traffic monitoring system which can carry out such a method.To achieve the object, a method for calibrating a traffic monitoring system is provided. The traffic monitoring system can detect a monitoring area and at least one object located on the monitoring area. The traffic monitoring system has at least two sensors for monitoring the monitoring region and the at least one object, a communication unit for communication with the at least one object and a control unit connected to the sensors and the communication unit. The method comprises the following steps: a) detecting at least one object with at least one sensor and determining information of the object from the sensor information, and b) receiving object information of the object by the communication unit, wherein the object information is determined by the object and transmitted to the traffic monitoring system, and c) calibrating the sensor with the sensor information and the object information transmitted by the object.A traffic monitoring system is understood to mean, in particular, systems such as, for example, an AVP type 2 system, which is suitable for automated vehicle guidance and for which no sensors are required in the vehicle. The system receives the information about the vehicle, in particular about the position and the movements of the vehicle, via the sensors installed in the traffic monitoring system and controls the vehicle from a starting point to its defined destination, for example within a parking deck, on the basis of this information.The monitoring area is the area that is covered or detected by the sensors and in which objects can be detected.The sensors may be any type of instrument capable of detecting an object. This can be done, for example, optically or acoustically. The optical sensors include, for example, cameras, CCD sensors or photocells. However, other methods for detecting, such as radar or LIDAR, are also conceivable.The communication unit can be devices by means of which communication can take place between the traffic monitoring system, in particular the AVP type 2 system, and the object, in particular the vehicle. This is preferably configured wirelessly and can be realized, for example, by means of WIFI and / or Bluetooth or via a mobile radio network.The control unit evaluates the information generated by a sensor and transmitted to the control unit, in particular position information.The control unit is connected to the communication unit in a wired and / or wireless manner in order to be able to receive and / or transmit data from and / or to the object, in particular the vehicle. The received data may be object information about the object. The transmitted data may be control commands for controlling the object.The sensor information serves as a basis for a wide variety of calculations of the control unit, whereby, for example, a collision of a vehicle with an object located on its route can be avoided. Sensor information can be, for example, position information, speed information, or any object information, such as, for example, turn signals, steering angle, vehicle or person, for in particular vehicles and / or persons.The object information serves as a basis for a wide variety of calculations of the control unit, whereby, for example, a collision of a vehicle with an object located on its route can be avoided. Sensor information can be, for example, information about the speed of the object, the steering angle, the turn signal or distance information by means of in-vehicle sensor systems. This object information is generated by the object.If the calculation reveals that a dangerous situation, for example a collision, could take place for a vehicle, the control unit can intervene, for example by slowing, stopping or calculating a different driving route for the vehicle located in the traffic monitoring space by means of corresponding control signals. A control unit is, for example, a microcontroller or central processing units (CPU). However, server-based control units are also conceivable, for example.The orientation of a sensor may change during operation of the traffic monitoring system. This can be done, for example, by comparing the sensor information of the sensors or by comparing it with information stored in the controller. If the orientation of a sensor has changed, calibration of this sensor is necessary.For calibration, the position of an object, in particular of a vehicle, determined with the sensor is compared with the object information of the object transmitted from the object to the communication unit. If the information of the object determined from the sensor information deviates from the object information transmitted to the communication unit, a calibration of the sensor is carried out with the information received from the object. As a result, the sensor deviating from the original calibration can be re-calibrated automatically by the control unit without the personnel being necessary for a calibration. This may also avoid time in which the system must be put into the idle state for recalibration of a sensor.The information determined with the sensor is preferably compared with the object information transmitted by the object and the calibration of the sensor is carried out if the information of the object determined from the sensor information deviates from the object information transmitted by the object.Furthermore, the traffic monitoring system receives object information from a plurality of objects and transmits it for calibration for a sensor. By using different information, a greater accuracy in the calibration can be achieved. In particular, the object information can be compared with one another in order to verify it and / or in order to improve the accuracy of the calibration.In particular, the object information is provided by means of a sensor system, in particular a surroundings sensor system, attached to the object. This object information can be, for example, distance information to other objects monitoring area. This information can be determined by means of radar and / or LIDAR and / or ultrasonic sensors and / or cameras.Furthermore, for example, the sensor information and / or object information is movement information, position information, system information and / or vehicle information of the object. This information serves as a basis for calculation for calibrating the sensor. The more of this information is present, the more accurate the calibration of the sensor can be carried out. Movement information can be, for example, the speed of the object, in particular of the vehicle. Position information can be, for example, the position of the object, in particular of the vehicle, in the monitoring area or a distance or distance covered. Vehicle information can be, for example, speed, steering angle, distance information with respect to other objects, position information of the object, in particular of the vehicle, and / or indicator state. System information can be, for example, information of the activated flasher and the time delay of this information transmitted to the control unit. This allows the latency of the system to be calculated.During the calibration of the sensor, the traffic space is preferably monitored by means of the remaining sensors. Thus, the operation of the traffic monitoring system, in particular in a parking system, can be continued. The information of the sensor to be calibrated can be taken out of the calculations in particular during recalibration.The traffic monitoring system can preferably generate control commands for objects, in particular vehicles, which are located on the traffic surface, and send them to the vehicles, wherein the control commands are determined as a function of information determined by the sensors, wherein the control commands are adapted during the calibration of a sensor. The sensor information includes position and speed, for example. This allows an imminent collision with another object, for example a person who is located in the traffic space, or a point in time at which the vehicle has to turn at a branch to be determined. Depending on the prevailing situation, control commands for the brake, the throttle, the steering angle, or the flasher, for example, can be generated or changed. Thus, in particular a vehicle in a parking system can be driven safely from a starting position to a defined target position by means of the traffic monitoring system. However, other objects which cannot be controlled by the traffic monitoring system, in particular persons, are also advantageously protected from the vehicles as a result. In addition, the absence of the sensor information can be reacted during the recalibration of the one sensor, since, for example, less information could be present in this monitoring area. Thus, the vehicle would be able to be guided at reduced speed or brought to a standstill completely, for example. This additionally increases the safety of the traffic monitoring system.Furthermore, the sensor is checked and calibrated automatically, in particular as soon as an object is located in the monitoring region of the traffic monitoring system. This means that during the ongoing operation, the objects in the monitoring region are detected permanently, for example cyclically, and the calibration of the sensors is checked. Alternatively, the check and calibration may be performed once with each object being passed to the traffic monitoring system. Furthermore, the checking and in particular the calibration of the sensor changed from its original calibration can be started manually. This ensures that the traffic monitoring system does not automatically switch back to the productive mode, although, for example, auxiliary means required for assembly work, such as a ladder, a frame or measurement setups, would be located in the traffic space. Thus, after the work is finished, the person can manually enable and start the traffic monitoring system.To achieve the object, a traffic monitoring system is furthermore provided. The traffic monitoring system can detect a monitoring area and at least one object located on the monitoring area. The traffic monitoring system has at least two sensors for monitoring the monitoring region and the at least one object, a communication unit for communication with the at least one object and a control unit connected to the sensors and the communication unit. A sensor may be calibrated with a method according to any preceding claim.In particular, the traffic monitoring system has a plurality of sensors, wherein each region is monitored by at least two sensors.In addition, the traffic monitoring system can generate control commands for objects, in particular vehicles, which are located on the traffic surface and can transmit them to the objects, in particular vehicles, wherein the control commands are determined as a function of information determined by the sensors, and wherein the control commands are adapted during the calibration of a sensor.Preferably, the calibration of the sensor changed from its original calibration can be started manually.Further advantages and features will become apparent from the following description in conjunction with the accompanying drawings. In this figure: FIG. 1 shows a schematic structure of a traffic monitoring system; FIG. 2 shows a schematic sequence of the process steps of the initial calibration of a sensor of the traffic monitoring system by means of an object; and FIG. 3 shows a schematic sequence as in FIG. 2 with detection of the position deviation of a sensor from the original calibration.Referring to FIG. 1, a traffic monitoring system 1 is shown. The traffic monitoring system 1 has a plurality of sensors 3 and a control unit 13. The sensors 3 each have a detection area 11, which sensors 3 at least partially detect the same areas of a monitoring area 10, which is a traffic space here. Further sensors are preferably provided in the monitoring area 10, so that the entire traffic space can be detected or monitored by sensors. In particular, the sensors 3 are positioned such that each region of the traffic space is redundantly monitored.In addition, static objects 5, also referred to below as columns 5, are present in the detection regions 11 of the sensors 3. These can be used as additional reference points in the traffic monitoring system 1.If an object 7, also called vehicle 7, is transferred to the traffic monitoring system 1 in a starting zone, for example by the driver thereof, the traffic monitoring system 1 establishes a connection with the vehicle 7 via wireless communication by means of the communication unit 15. Subsequently, a defined target 9, referred to as parking space 9 below, is defined by the control unit 13, and the vehicle 7 is controlled to this target 9.Control commands transmitted from the control unit 13 to the vehicle 7 control the latter in the direction of the parking space 9 defined as the target. Here, control commands are generated in order to move the vehicle forwards or backwards accordingly or to set the corresponding steering angle of the wheels in order to control the vehicle to the parking space 9. The vehicle 7 can implement these control commands independently, i.e. without a driver, so that the vehicle 7 moves within the traffic area remotely by the traffic monitoring system 1.If a hazardous situation occurs during the movement of the vehicle 7 to the parking space 9, for example because a person is located in the monitoring area 10 in the vicinity of the controlled vehicle 7, the control unit 13 can generate correspondingly adapted control commands and transmit them to the vehicle 7 by means of the communication unit 15 in order to avoid the hazardous situation. For example, the speed of the vehicle can be reduced or the vehicle can be brought completely to a standstill or a different route can be created.The sensors must be aligned or calibrated very accurately in order to be able to detect the objects 5, 7 very accurately in the monitored zone. Should a sensor 3 be changed from its original calibration position, this would have an effect on the calculation to control the vehicle 7.If the traffic monitoring system 1 is initialized for the first time, the sensors 3 are initially calibrated.FIG. 2 shows the steps of the initial calibration of a sensor 3 as part of the initialization of the traffic monitoring system 1. If the traffic monitoring system 1 is started up for the first time, the sensors 3 must be initially calibrated in order to be able to ensure an accurate production mode of the traffic monitoring system 1. The steps are listed below and executed in this order: 1. step: acquiring sensor information with at least one sensor 3, and 2. step: receiving object information from the object 7 by the communication unit, wherein the object information is acquired from the object and transmitted to the traffic monitoring system, and 3. step: calibrating the sensor with the sensor information and the object information transmitted by the object.The sensor information and the object information may be, for example, information on the object 7 itself. Alternatively or additionally, the sensor information can be information that can be detected both with the sensors 3 and with the sensors of the object 7.For example, the position of the vehicle 7 is detected by the sensors 3. After the object 5, 7 has been detected by the sensor 3, its position is generated as sensor information and transmitted to the control unit 13. The transmission from the sensor 3 to the control unit 13 can be effected both by cable and wirelessly.The control unit 13 then determines the sensor position from the transmitted sensor information by the position of the object 5, 7 in the detection region 11 of the sensor 3.For example, a map of the entire traffic space is generated and stored in the control unit, the determined positions of the objects 5, 7 being stored in this map. In particular, the information of the static objects, i.e. also their position, is available for the entire traffic monitoring system. The static objects 5 can likewise be detected by the vehicle 7 and this information can be sent as object information to the control unit 13 in order to compare this with the sensor information relating to this object. Similarly, the sensor information and the object information may be information on other traveling objects 7 within the monitoring area.In FIG. 3, the steps, as explained with reference to FIG. 2, are extended by the step of comparing the sensor information of the sensor 3 with the object information of the object 7 transmitted to the control unit 13. This makes it possible to detect a misalignment of a sensor 3 or the need for recalibration of the sensor 3.The steps are listed below: 1. step: acquisition of sensor information with at least one sensor 3, and 2. step: reception of object information of the object by the communication unit, wherein the object information is ascertained by the object and transmitted to the traffic monitoring system, and 3. step: comparison of the sensor information ascertained with the sensor with the object information transmitted by the object 4. step: calibration of the sensor with the sensor information and the object information transmitted by the object.Step 1 will not be discussed in detail, since this is identical to that of the explanation of FIG. 1.During productive operation of the traffic monitoring system 1, the sensor 3 generates sensor information. These can be effected both continuously and at more temporally definite intervals. If the sensor 3 is moved from its originally calibrated position, for example by a vehicle driving a mast on which the sensor 3 is mounted, the new sensor information is transmitted to the control unit 13. Subsequently, the control unit 13 compares the new sensor information with the object information of the vehicle 7 transmitted to the control unit 13.If a deviation is determined between the determined sensor information and the transmitted object information, the sensor 3 is recalibration, which recalibration can include, for example, automatic or manual readjustment of the sensor 3. Furthermore, correction factors can be determined for the sensor data or the sensor image, so that the positions detected with the sensor, in particular the positions of the vehicles, correspond to the real positions in the monitored zone.The object information is provided by the vehicle 7 and transmitted by wireless communication to the communication unit 15 which is connected to the control unit 13.If no deviation is detected, step 1 is started again and a new comparison of the sensor information and object information takes place.During this time, the traffic monitoring system 1 can no longer be in productive mode, but in a sleep mode.Preferably, however, the traffic monitoring system 1 is still in productive mode, wherein the monitoring of the monitoring region 10 takes place without the sensor 3 to be calibrated. This is only used again for monitoring the monitoring region 10 when the recalibration is concluded and, in the case of a renewed check, the sensor information of the vehicle 7 determined with the sensor 3 corresponds to the transmitted object information of the vehicle 7. In particular, the at least redundant monitoring of the traffic area by the sensors 3 always ensures complete monitoring of the traffic area, that is to say that at least two sensors 3 monitor a monitoring region 11. Advantageously, three sensors 3 monitor a monitoring area 11 so that during a calibration of a sensor 3 two sensors remain for monitoring the monitoring area 11. Optionally, the control commands for the vehicles 7 may be adjusted until recalibration is complete, for example by controlling the vehicle 7 through the traffic space at a reduced speed.In order to increase the accuracy of the sensors 3, a plurality of sensors 3 can be combined to form a sensor group or sensor fusion.In addition, the traffic monitoring system 1 can perform a latency calibration, wherein the delay between the transmission of the control command of the vehicle 7 and the performance of the control command of the vehicle 7 can be calculated in order for the traffic monitoring system 1 to guide the vehicle 7 even more precisely, which is advantageous in narrow ranges of a parking system.List of reference characters1 Traffic monitoring system 3 Sensor / s 5 Static objects / pillars 7 Object / vehicle 9 Parking lot 10 Monitoring area 11 Detection area 13 Control unit 15 Communication unit

Claims

Method for calibrating a traffic monitoring system (1), wherein the traffic monitoring system (1) can capture a monitoring area and at least one object located on the monitoring area, wherein the traffic monitoring system has at least two sensors (3) for monitoring the monitoring area (11) and the at least one object, a communication unit for communication with the at least one object and a control unit connected to the sensors (3) and the communication unit, having the following steps: a) capturing sensor information with at least one sensor 3, and b) receiving object information of the object by the communication unit, wherein the object information is determined by the object and transmitted to the traffic monitoring system, and c) calibrating the sensor (3) with the sensor information and the object information transmitted by the object (7).Method according to Claim 1, characterized in that the information determined with the sensor (3) is compared with the object information transmitted by the object, and the calibration of the sensor (3) is carried out if the information of the object (7) determined from the sensor information deviates from the object information transmitted by the object (7).The method of claim 1 or 2, wherein the traffic monitoring system receives object information from multiple objects and transmits it for calibration for a sensor.Method according to one of the preceding claims, characterized in that the object information is carried out by means of a sensor system, in particular a surroundings sensor system, which is attached to the object (7).Method according to one of the preceding claims, characterized in that the sensor information and / or object information is movement information, position information, system information and / or vehicle information of the object.Method according to one of the preceding claims, characterized in that during the calibration of the sensor (3) the traffic space is monitored by means of the remaining sensors (3).Method according to one of the preceding claims, characterized in that the traffic monitoring system (1) can generate control commands for objects, in particular vehicles (7) which are located on the traffic surface, and transmit them to the vehicles (7), wherein the control commands are determined as a function of information determined by the sensors, wherein the control commands are adapted during the calibration of a sensor (3).Method according to one of the preceding claims, characterized in that the calibration of the sensor (3) which has been changed from its original calibration can be started manually.Traffic monitoring system (1), wherein the traffic monitoring system (1) can detect a monitoring area and at least one object located on the monitoring area, wherein the traffic monitoring system has at least two sensors (3) for monitoring the monitoring area (11) and the at least one object, a communication unit for communication with the at least one object and a control unit connected to the sensors (3) and the communication unit, wherein a sensor can be calibrated with a method according to one of the preceding claims.Traffic monitoring system according to claim 9, characterized in that the traffic monitoring system comprises a plurality of sensors (3), each area being monitored by at least two sensors (3).Traffic monitoring system according to Claim 9 or 10, characterized in that the traffic monitoring system can generate control commands for objects, in particular vehicles (7) which are located on the traffic surface and transmit them to the objects, in particular vehicles (7), wherein the control commands are determined as a function of information determined by the sensors (3), and wherein the control commands are adapted during the calibration of a sensor (3).Traffic monitoring system according to one of Claims 9 to 11, characterized in that the calibration of the sensor (3) which has been changed from its original calibration can be started manually.

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