Method and system for compensating for a time discrepancy
A method and system for compensating for a time discrepancy. A first and a second vehicle-to-X communication system resort to an external time base. The first vehicle-to-X communication system determines a first internal time base from the external time base and the second vehicle-to-X communication system determines a second internal time base from the external time base. The first vehicle-to-X communication system sends vehicle-to-X data and the second vehicle-to-X communication system receives vehicle-to-X data. The vehicle-to-X data to be sent include a time stamp generated from the first internal time base and captured ambient sensor data include a first time stamp generated from the second internal time base. Alignment of the captured ambient sensor data with the received vehicle-to-X data is used to determine the time discrepancy between the first internal time base and the second internal time base and to compensate for it using a correction value.
1. A method for compensating for a time discrepancy,
in which a first and a second vehicle-to-X communication system resort to an external time base,
wherein the first vehicle-to-X communication system determines a first internal time base from the external time base and the second vehicle-to-X communication system determines a second internal time base from the external time base,
wherein the first vehicle-to-X communication system sends vehicle-to-X data and the second vehicle-to-X communication system receives vehicle-to-X data,
wherein vehicle-to-X data to be sent are denoted using a first time stamp created from the first internal time base, and
wherein captured ambient sensor data are denoted using a first time stamp created from the second internal time base, wherein
temporal consistency checking between the captured ambient sensor data and the received vehicle-to-X data is used to determine the time discrepancy between the first internal time base and the second internal time base and to compensate for said time discrepancy using a correction value.
2. The method as claimed in claim 1 , wherein the first and second vehicle-to-X communication systems resort to a time base of a global navigation satellite system as the external time base.
3. The method as claimed in claim 1 , wherein
the consistency checking involves the use of a first data curve created by means of temporal interpolation and/or extrapolation of the ambient sensor data and/or a second data curve created by temporal interpolation and/or extrapolation of the received vehicle-to-X data.
4. The method as claimed in claim 1 , wherein
the consistency checking involves the use of a piece of speed information from captured Doppler effect data from a radar sensor and a piece of speed information from received vehicle-to-X data.
5. The method as claimed in claim 1 , wherein
the consistency checking involves the use of a piece of state change information for a traffic signal installation from captured image data from a camera sensor and a piece of state change information for the traffic signal installation from received vehicle-to-X data.
6. The method as claimed in claim 1 , wherein
the consistency checking involves the use of a piece of position information from captured distance data from a distance sensor and a piece of position information from received vehicle-to-X data.
7. The method as claimed in claim 1 , wherein
the consistency checking is based on a multiplicity of ambient sensor data records averaged using one or more statistical averaging methods.
8. The method as claimed in claim 1 , wherein
the correction value is taken from a data fusion process, wherein the data fusion process is used to fuse ambient sensor data and vehicle-to-X data.
9. The method as claimed in claim 1 , wherein
the correction value is determined for each first and each second vehicle-to-X communication system individually.
10. A system for compensating for a time discrepancy, comprising an external timer and at least a first and a second communication subscriber, wherein the first communication subscriber comprises a first vehicle-to-X communication system having a first internal timer and the second communication subscriber comprises a second vehicle-to-X communication system having a second internal timer and ambient sensors and electronic consistency checking means, wherein the first and second vehicle-to-X communication systems resort to an external time base of the external timer, wherein the first vehicle-to-X communication system uses the first internal timer to determine a first internal time base and the second vehicle-to-X communication system uses the second internal timer to determine a second internal time base,
wherein the first vehicle-to-X communication system sends vehicle-to-X data and the second vehicle-to-X communication system receives vehicle-to-X data,
wherein the first internal timer denotes vehicle-to-X data to be sent using a time stamp created from the first internal time base and
wherein the second internal timer denotes captured ambient sensor data using a first time stamp created from the second internal time base,
wherein the electronic consistency checking means use temporal consistency checking between captured ambient sensor data and received vehicle-to-X data to determine the time discrepancy between the first timer and the second timer and to compensate for said time discrepancy using a correction value.
11. The system as claimed in claim 10 , wherein the ambient sensors are one or more elements selected from the group consisting of
a radar sensor,
an optical camera sensor,
a lidar sensor,
a laser sensor and
an ultrasonic sensor.
12. The system as claimed in claim 10 , wherein
the vehicle-to-X communication systems send and/or receive vehicle-to-X data on the basis of one or more connection classes selected from the group consisting of
a WLAN connection, based on IEEE 802.11,
an ISM (Industrial, Scientific, Medical Band) connection,
a Bluetooth® connection,
a ZigBee connection,
a UWB (Ultra Wide Band) connection,
a WiMax® (Worldwide Interoperability for Microwave Access) connection,
an Infrared connection,
a mobile radio connection and
a radar-based communication.
13. The system as claimed in claim 10 , wherein
the system carries out a method for compensating for a time discrepancy,
in which a first and a second vehicle-to-X communication system resort to an external time base
wherein the first vehicle-to-X communication system determines a first internal time base from the external time base and the second vehicle-to-X communication system determines a second internal time base from the external time base,
wherein the first vehicle-to-X communication system sends vehicle-to-X data and the second vehicle-to-X communication system receives vehicle-to-X data,
wherein vehicle-to-X data to be sent are denoted using a first time stamp created from the first internal time base, and
wherein captured ambient sensor data are denoted using a first time stamp created from the second internal time base, wherein temporal consistency checking between the captured ambient sensor data and the received vehicle-to-X data is used to determine the time discrepancy between the first internal time base and the second internal time base and to compensate for said time discrepancy using a correction value.
14. The use of the system as claimed in claim 10 in a motor vehicle.
15. The method as claimed in claim 2 , wherein
the consistency checking involves the use of a first data curve created by temporal interpolation and/or extrapolation of the ambient sensor data and/or a second data curve created by temporal interpolation and/or extrapolation of the received vehicle-to-X data.
16. The system as claimed in claim 11 , wherein
the vehicle-to-X communication systems send and/or receive vehicle-to-X data on the basis of one or more connection classes selected from the group consisting of
a WLAN connection, based on IEEE 802.11,
an ISM (Industrial, Scientific, Medical Band) connection,
a Bluetooth® connection,
a ZigBee connection,
a UWB (Ultra Wide Band) connection,
a WiMax® (Worldwide Interoperability for Microwave Access) connection,
an Infrared connection,
a mobile radio connection and
a radar-based communication.