DE102016221440A1 - Method for diagnosing environmental sensor systems in vehicles - Google Patents

Abstract

Method for diagnosing a sensor system (10) installed in a vehicle (A) for detecting objects in the vicinity of said vehicle, characterized in that data characterizing a reference object (18) are transmitted to the vehicle via an ITS communication system (14) ( A), in the vehicle (A) on the basis of the data transmitted expected detection data for the reference object (18) are calculated, and the expected detection data compared with actual detection data obtained upon detection of the reference object (18) by the sensor system (10) become.

Description

The invention relates to a method for diagnosing a sensor system installed in a vehicle for detecting objects in the surroundings of this vehicle.

In the context of driver assistance systems for motor vehicles and even more so in the course of the development of autonomously driving vehicles, an increasingly complex environment sensor system is needed in the vehicles. The sensor systems, such as radar sensors, which detect objects around the vehicle are of high relevance for traffic safety, since the function of the driver assistance systems and the autonomous vehicle guidance systems decisively depends on the reliability and accuracy of these sensor systems. These sensor systems should therefore be subjected to a diagnosis as close as possible, so that any malfunctions or errors can be detected immediately.

So far, special test setups are used to diagnose the sensor systems, especially after the initial installation. In the daily use of vehicles, however, a diagnosis is usually only possible to a limited extent, for example by plausibility of the detection data supplied by the sensor system based on realistic assumptions about the traffic environment and / or by comparison of acquisition data obtained from different sensor systems on the same object.

In order to improve traffic safety and the flow of traffic, there are also efforts to network traffic-related vehicles and institutions responsible for transport infrastructure through a communication network known as an Intelligent Transportation System (ITS) so that relevant traffic density information, Disturbances and potential dangers can be exchanged in real time among the participants. For the construction of these ITS systems existing mobile data networks are used as well as the GPS systems currently available in most vehicles.

The object of the invention is to provide a method for improved diagnosis of environment sensors in vehicles.

Disclosure of the invention

This object is achieved according to the invention in that data which characterize a reference object are transmitted to the vehicle via an ITS communication system, expected detection data for the reference object are calculated in the vehicle on the basis of the transmitted data, and the expected acquisition data are compared with actual acquisition data, obtained upon detection of the reference object by the sensor system.

If a significant deviation results in the comparison of the expected detection data with the data actually obtained, this indicates a malfunction of the relevant sensor system, so that a warning to the driver or in the case of autonomous vehicles a message to the vehicle owner and / or commissioned workshops can be generated.

In this way, with sufficient density of the reference objects, a practically continuous diagnosis of the sensor systems during driving operation can be realized.

Advantageous embodiments and further developments of the invention are specified in the subclaims.

The reference objects can be objects which are set up specifically for diagnostic purposes on the traffic routes, for example, radar reflectors as reference objects for radar sensors in the vehicles. The information about the relevant properties of the reference objects, such as the site, the orientation, size and reflectivity can be recorded for a larger number of reference objects in a database and then made available to the vehicles via the ITS system. Specifically, this information is transmitted to a computer installed on board the vehicle, for example the computer on which the software for the driver assistance system or the autonomous vehicle guidance system also runs. Based on the data of a GPS system, the current location of the vehicle is known in this computer, so that it can be determined whether one or more reference objects are currently in the detection range of the sensor system. In the simplest case, it is then simply checked whether the reference objects were actually located by the sensor system.

According to one embodiment of the invention, however, a much more sophisticated diagnosis is possible. For example, the detection data provided by a radar sensor for a specific object usually not only include the distance of the object, but also its relative velocity and the direction angle at which the object is "seen". In addition, information about the strength of the received radar echo is also available. Based on the known properties of the reference object, it is possible to calculate which values would be expected for the acquisition data, and it can be checked whether these expected values agree within certain tolerance limits with the values actually obtained by the sensor system. If, for example, it shows that the directional angle of the reference objects measured by the radar sensor always deviates from the expected directional angle by approximately the same amount in the same direction, this indicates a misalignment of the radar sensor, which can then be corrected automatically by a corresponding recalibration , Similarly, the strength of the received radar echo can be used to check whether the radar sensor still has sufficient sensitivity and range and whether the distances and relative speeds are measured correctly.

In addition to stationary reference objects, it is also possible to use movable reference objects, for example radar reflectors, which are installed on or in vehicles.

Likewise, "normal" vehicles can also be used as reference objects. In particular, each networked via the ITS system vehicle can serve as a reference object for all other vehicles. For this purpose, it is only necessary that the vehicle, which is to serve as a reference object, has a location system for determining the own position and preferably also a system for determining the current orientation or direction and this information then the other via the ITS system Vehicles are provided.

Likewise, two vehicles that are networked together via the ITS system can also serve as reference objects alternately or mutually match their acquisition data for a third object, which then temporarily forms a reference object.

In addition to the raw data supplied directly by the sensor systems, it is also possible to compare derived quantities, such as object classifications, which are calculated by attached systems from the raw data.

In the case of a fleet consisting of several vehicles, preferably of vehicles of the same type, a statistical evaluation of the acquisition data obtained for one or more reference objects can also be carried out, whereby the diagnoses, plausibility checks and auto-calibrations of the sensor systems can be further improved.

In the following embodiments are explained in detail with reference to the drawing.

• 1 ein Diagramm eines Fahrzeugs und eines Referenzobjekts, die über ein ITS-System miteinander vernetzt sind;
• 2 ein Flussdiagramm zur Illustration eines typischen Ablaufs eines erfindungsgemäßen Diagnoseverfahrens;
• 3 in einem Diagramm ähnlich 1 ein Beispiel für ein Diagnoseverfahren, bei dem ein anderes Fahrzeug als Referenzobjekt dient;
• 4 ein Diagramm für ein Beispiel, bei dem zwei Fahrzeuge einander gegenseitig als Referenzobjekt dienen;
• 5 ein Diagramm für ein Verfahren, bei dem zwei miteinander vernetzte Fahrzeuge Daten über ein als Referenzobjekt dienendes drittes Fahrzeug abgleichen; und
• 6 ein Flussdiagramm für das Verfahren nach 5.

Show it:

• 1 a diagram of a vehicle and a reference object, which are networked together via an ITS system;
• 2 a flowchart illustrating a typical flow of a diagnostic method according to the invention;
• 3 similar in a diagram 1 an example of a diagnostic method in which another vehicle serves as a reference object;
• 4 a diagram for an example in which two vehicles mutually serve as a reference object;
• 5 a diagram for a method in which two interconnected vehicles match data about serving as a reference object third vehicle; and
• 6 a flowchart for the method according to 5 ,

In 1 schematically a plan view of a vehicle A is shown as a sensor system 10 a radar sensor, which is installed in the front of the vehicle and provides, for example, location data on vehicles ahead for a distance control system.

On board the vehicle A is a calculator 12 which runs, among other things, the software for a driver assistance system, in this example the distance control system. To the periphery of the computer 12 also includes a wireless communication interface, which provides a bidirectional connection to an ITS communication system 14 can be built. About this communication system is the calculator 12 in the vehicle A also with a server 16 which maintains a database in which traffic infrastructure data for the region traveled by the vehicle A is stored.

In the example shown, the traffic infrastructure also includes a reference object 18 in the form of a fixed radar reflector, which is placed on the traveled by the vehicle A route on the roadside. The relevant properties of the reference object 18 , in this example, the exact location coordinates, the orientation and dimensions of the radar reflector and the reflectivity of the surface for radar radiation in that of the radar sensor 10 used frequency band, are stored in the database.

In the example shown is the reference object 18 an ITS client 20 assigned via the ITS communication system 14 wireless with the server 16 can communicate. For example, the ITS client 20 Be part of a weather station, with the weather conditions, especially rain or snowfall at the site of the reference object 18 measured and sent to the server 16 can be reported.

In the in 1 As shown, the vehicle A is near the location of the reference object 18 to happen so that the reference object in the radar locating range of the sensor system 10 lies. This allows the reference object 18 for a diagnosis of the sensor system 10 to use. The computer receives this 12 via the ITS communication system 14 in the database of the server 16 stored data about the reference object 18 , One in the calculator 12 Implemented testing software then calculates the acquisition data that the sensor system 10 with perfect function over the reference object 18 and compares this expected acquisition data with that actually from the sensor system 10 supplied data.

In this way, not only can be checked, whether the reference object 18 really from the sensor system 10 is located, but also whether the object distance was measured correctly. Since it is known that the reference object 18 is a stationary object, the coincidence of the measured relative velocity with the absolute velocity of the vehicle A can also be checked. Likewise, the direction angle can be calculated, below which the reference object 18 is located by the sensor system and also this angle can be compared with the actually measured direction angle. Likewise, depending on the distance between the sensor system 10 and the reference object 18 an expected value for the strength of the received radar echo can be calculated. If the weather station is at the location of the reference object 18 Rain or snow reports, these weather conditions can also be included in the calculation of the strength of the radar echo, so that a realistic value for the expected sensitivity of the sensor system 10 receives. Even without direct measurement of the signal strength, the sensitivity of the radar sensor can be checked by comparing the distance between radar sensor and reference object 18 at the time it measures to which the reference object 18 is first detected by the radar sensor when approaching the vehicle A.

When along the route traveled by the vehicle A more reference objects 18 are set up, the above-described diagnosis can be repeated as each reference object passes. One possible procedure is in 2 represented in the form of a flow chart.

In step S1, the vehicle A (more precisely its computer reports 12 ) the position of the vehicle A to the server 16 , Likewise, the type of sensor for which a diagnosis is to be performed is also reported. In this example, the sensor type "radar sensor" would be reported.

The server then searches in step S2 16 in its local database for reference objects suitable for the sensor type reported (in this example, radar reflectors) and located near the reported position of the vehicle A. If no suitable reference objects are found (result "no" in step S3), the server reports in step S4 to the vehicle that a diagnosis of the radar sensor is currently not possible.

If, on the other hand, at least one suitable reference object is found, for example the reference object 18 , so the server transmits 16 in step S5, the relevant properties of this reference object to the computer 12 in the vehicle A.

In step S6 then calculates the test software that is on the computer 12 runs, based on the properties of the reference object transmitted by the server, in particular its position, orientation and reflection properties, the detection data, the sensor system 10 with correct function over the reference object 18 would have to deliver. In step S7, the calculated acquisition data is then compared with the acquisition data actually received from the sensor system. If these data match within given tolerance limits, it can be concluded that the sensor system 10 works perfectly. If, on the other hand, significant deviations in the acquisition data are detected, an error message is output or, if the error can be corrected by a recalibration of the sensor system, an appropriate correction is automatically made.

In order for the diagnosis to be repeated when further reference objects pass, step S1 is preferably carried out automatically at regular time intervals, so that a new diagnosis can be made in each case if the result in step S3 is positive.

In a modified embodiment, instead of the current position of the vehicle or in addition to it, also a possibly programmed in the navigation system of the vehicle route can be reported in step S1, so that the server 16 then search for reference objects placed along this route in step S2.

3 illustrates a situation in which in front of the vehicle A, another vehicle B runs, as a reference object 18 ' is being used. The vehicle B does not necessarily have its own Sensor system, however, has a computer as an ITS client 20 ' and over the ITS communication system 14 wireless with the server 16 can communicate.

The procedure is essentially the same as in 2 , except that in this case also the vehicle B at regular intervals its current position to the server 16 reports. Then, when the request from the vehicle A arrives at step S1, the server finds instead of the stationary reference object 18 (or in addition to this) the moving reference object 18 ' in the form of the vehicle B. The current orientation or direction of travel of the vehicle B and preferably also its speed and the vehicle type are sent to the server 16 reported so that the testing software in the calculator 12 of the vehicle A based on this information can calculate the detection data, the sensor system 10 about the vehicle B should deliver.

In the database of the server 16 For example, for different vehicle types and different orientations of the vehicle (and thus for different directions of incidence of the radar radiation), the respective radar reflection cross sections can be stored, so that the ITS client only needs to report the vehicle type and the position and direction, while all other information, the the test software required in vehicle A can be obtained from the database.

4 illustrates a situation in which the two vehicles A and B ride side by side at approximately the same height and each with sensor systems 10 ' equipped, the dead-angle sensors for monitoring the rooms have the right and left side of each vehicle. In this case, the sensor systems of the two vehicles thus "see each other" so that the vehicles can reciprocally serve as reference objects. In this case, those of the sensor system 10 ' Each vehicle received detection data via the ITS communication system 14 directly or indirectly via the server 16 be transmitted to the respective other vehicle, so that the detection data can be compared with each other. In this way, for example, it can be checked whether the two sensor systems measure the same lateral distance between the two vehicles.

To the properties of the reference objects, in the database in the server 16 are stored or transmitted to this, in each case for each type of vehicle include the exact installation locations of the radar sensors that the sensor systems 10 ' form. This makes it possible to also match the angle information obtained from the sensor systems.

It is not mandatory that the sensor systems 10 ' the two vehicles simultaneously locate the other vehicle. Dead-angle radar sensors are often directed slightly obliquely to the rear, so that in an overtaking first the outdated vehicle (here vehicle B) locates the overtaking vehicle A, and only with some delay then the overtaking vehicle A locates the outdated vehicle B. This time offset can be taken into account in the data comparison on the basis of the transmitted information about the vehicle positions and speeds.

5 illustrates an example in which the two vehicles A and B do not use each other mutually as a reference object, but rather both a third vehicle C as a temporary reference object 18 " use. The reference object 18 " is temporary in that it is only available as long as the sensor systems 10 the two vehicles A and B locate this reference object simultaneously. Via the ITS communication system 14 The two vehicles A and B can then exchange their registration data and compare with each other. Since the vehicle B also from the sensor system 10 of the vehicle A can also be the information about the distance and the relative speed of the vehicles A and B in the computers 12 these two vehicles are made available, whereby an adjustment of the distance and angle data of the vehicle C is made possible. The vehicle C does not need to have a sensor system nor with the ITS communication system 14 to be networked. As a temporary reference object 18 " Therefore, instead of the vehicle C, for example, a stationary object such as a traffic sign or the like could serve.

One possible procedure is in 6 shown in a flow chart.

In step S11, the vehicle A sends a request for a sensor adjustment to the preceding vehicle B (or possibly also to several vehicles in the environment). In step S12, the vehicle B responds by reporting its detection data for the vehicle C to the vehicle A. In step S13, the vehicle A reports its detection data for the vehicle B and also for the vehicle C to the vehicle B. In step S14, then test algorithms run in both the vehicle A and in the vehicle B, with which on the basis of the detection data reported by the other vehicle for the vehicle C, the detection data for this vehicle C, which is the own sensor system, is calculated 10 would have to deliver with correct function. In step S15, the calculated acquisition data is then compared with the data actually supplied by the own sensor system.

At least in cases where the reference object 18 " is not a vehicle, but a fixed object, that can be in 5 and 6 generalize the illustrated concept to drop the condition that the object must be located by two or more vehicles simultaneously. It is sufficient for the participating vehicles to exchange acquisition data which specifies the location of the reference object in absolute coordinates in a global coordinate system. The data exchange can be done directly from vehicle to vehicle or via the server 16 respectively. In the latter case, the acquisition data can also be stored permanently in the database of the server, so that the database constantly "learns" new reference objects. Statistical averaging over the acquisition data reported by different vehicles for the same object can improve accuracy.

Claims (9)

Method for diagnosing a sensor system (10, 10 ') installed in a vehicle (A) for detecting objects in the vicinity of said vehicle, characterized in that data characterizing a reference object (18; 18'; 18 ") are transmitted via an ITS Communication system (14) are transmitted to the vehicle (A), in the vehicle (A) on the basis of the data transmitted expected detection data for the reference object (18; 18 '; 18 ") are calculated, and the expected detection data are compared with actual detection data, obtained upon detection of the reference object by the sensor system (10; 10 '). Method according to Claim 1 in which the reference object (18) is a stationary object. Method according to Claim 1 in which the reference object (18 ') is another vehicle (B) which at least reports its position data via the ITS communication system (14). Method according to one of Claims 1 to 3 in which data on the reference object (18; 18 ') are stored on a server (16) which communicates with the vehicle (A) via the ITS communication system (14), for the sensor system (10; 10') of which Diagnosis is performed. Method according to Claim 4 in which the reference object (18, 18 ') is assigned an ITS client (20, 20') for the transmission of data to the server (16). Method according to Claim 4 or 5 in which a diagnostic operation in the vehicle (A) is triggered by reporting the position of this vehicle and the type of sensor system (10) to be diagnosed via the ITS communication system (14) to the server (16), which then searches for reference objects (18; 18 ') in the vicinity of the vehicle (A) searches. Method according to Claim 1 in which the reference object (18 ") is a temporary reference object which is detected simultaneously by sensor systems (10) of two vehicles (A, B) which are networked with one another via the ITS communication system (14). Method according to Claim 7 in which a diagnostic operation in the vehicle (A) is triggered by the fact that, if from the sensor system of this vehicle (A) another vehicle (B), with which it is networked via the ITS communication system (14), and a temporary reference object ( 18 "), a request for a sensor adjustment is sent to the other vehicle (B). Method according to one of the preceding claims, in which new reference objects (18 ") are created by detection data for a stationary object measured by the sensor system (10) of a vehicle via the ITS communication system (14) to another vehicle and / or server (16).

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