US-20260126514-A1 - METHOD, DEVICE AND SYSTEM FOR DETERMINING AN ELEVATION OF A ROAD PORTION USED BY A VEHICLE

Abstract

Described is a method for determining an elevation of a road portion used by a vehicle. The method includes detecting signals emitted by two respective ground-based transmitters positioned at distinct elevations. The detected signals are compared to determine signal having the highest power, and the elevation of the road portion is determined based the comparison.

Inventors

• Sebastian Strunck
• Kansheng Yang

Assignees

• VALEO COMFORT AND DRIVING ASSISTANCE

Dates

Publication Date

20260507

Application Date

20251031

Priority Date

20241107

Claims (15)

1. 1 . A method for determining an elevation of a road portion used by a vehicle, the method comprising: detecting signals emitted by at least two respective ground-based transmitters the ground-based transceivers being each positioned at distinct elevations; comparing the detected signals to determine a signal having a highest power; and determining the elevation of the road portion based on the comparison.
2. 2 . The method according to claim 1 , wherein each detected signal comprises data relative to a position of a given ground-based transmitter the determined elevation being further based on data relative to the position.
3. 3 . The method according to claim 2 , wherein, before the step of comparing, the method comprises a step of selecting detected signals having at least one spatial coordinate in common, the step of comparing being carried out on the signals selected in the step of selecting.
4. 4 . The method according to claim 1 , wherein the method further comprises, before the step of comparing, checking each detected signal for transmission errors or loss of data and selecting detected signals that are free from transmission error or loss of data, the step of comparing being carried out on the signals selected in the step of selecting.
5. 5 . The method according to claim 4 , wherein the method further comprises: recording non-selected signals in a library; and discarding each current received signal that matches with one of the signals recorded in the library.
6. 6 . The method according to claim 1 , wherein the elevation of the road portion is shared with a network.
7. 7 . The method according to claim 1 , wherein the different ground-based transmitters are each comprised in a road side unit.
8. 8 . A device for detecting an elevation of a road portion used by a vehicle, the device comprising: a receiver configured to: detect signals respectively emitted by different ground-based transmitters, and compare the detected signals to determine a signal having the highest power; and a controller configured to determine the elevation of the road portion based on the comparison.
9. 9 . The device according to claim 8 , wherein each detected signal comprises data relative to a position of a given ground-based transmitter, the elevation of the road portion being further based on the data relative to the position.
10. 10 . The device according to claim 8 , comprising a radio transmitter configured to emit a signal, the transmitter comprising at least one dipole antenna.
11. 11 . The device according to claim 10 , wherein the at least one dipole antenna is configured to operate in reception, to receive the signals from the ground-based transmitters, and in transmission, to transmit the signal emitted by the transmitter of the device.
12. 12 . The device according to claim 10 , wherein the at least one dipole antenna has a first dimension higher than a second dimension, the first dimension being oriented along a vertical direction.
13. 13 . The device according to claim 8 , wherein the device is an on-board device of the vehicle, and the ground-based transmitters are road side units.
14. 14 . A system for determining an elevation of a road used by a vehicle, the system comprising: at least two ground-based transmitters, each ground-based transmitter being arranged to emit a signal; and an on-board device according to claim 8 and comprised in the vehicle.
15. 15 . The system according to claim 14 , wherein each ground-based transmitter comprises at least one dipole antenna having a first dimension higher than a second dimension, the first dimension being oriented along a vertical direction, the first dimension being higher than or equal to λ/2, where λ corresponds to a wavelength of an operating frequency of the at least dipole one antenna.

Description

TECHNICAL FIELD OF THE INVENTION The invention relates to a method for determining an elevation of a road portion used by a vehicle. The invention also relates to a device and a system for determining an elevation of a road portion used by a vehicle. BACKGROUND INFORMATION AND PRIOR ART Methods are known for determining an elevation of a road portion on which a vehicle is driving. These methods often use the road portion position as determined by a receiver receiving signals from satellites in a satellite positioning system and then use data from a map to determine the altitude associated to this road portion. These methods are functional, but they do not work very well when the vehicle is driving under a bridge or on a bottom layer of a multi-layer road. Thus, these methods are not accurate. In addition, these methods use several data and measurements from additional sensors and thus can demand extra cost and are not easy to implement. The invention is intended to remedy at least one of the aforementioned drawbacks. SUMMARY OF THE INVENTION In an embodiment, the invention provides a method for determining an elevation of a road portion used by a vehicle, said method comprising the following steps: detecting signals emitted by at least two respective ground-based transmitters, said ground-based transceivers being each positioned at distinct elevations,comparing the detected signals to determine the signal having the highest power,determining the elevation of the road portion based on the comparison. By using the signal having the highest power, it is possible to differentiate between situations (e.g. to assess whether the vehicle is driving under a bridge or on a bottom layer of a multi-road layer) and determine the elevation of the road The method according to the invention is thus easy to implement and does not demand extra cost. In addition, it allows easily determining which road portion is followed by the vehicle in a multi-layer road. According to an embodiment, each detected signal comprises data relative to the position of the given ground-based transmitter, the determined elevation being further based on the data relative to the position. Thus, the elevation may be determined (in practice) by using the data recorded in the signal having the highest power. Therefore, the method is easily implemented and does not need a lot of processing to determine the elevation of the road portion used by the vehicle. According to this embodiment, before the step of comparing, the method may comprise a step of selecting the detected signals having at least one spatial coordinate in common, preferably two spatial coordinates in common, said step of comparing being carried out on the signals selected in this step of selecting. According to an embodiment, the method further comprises, before the step of comparing, checking each detected signal for transmission errors and/or loss of data and selecting the detected signals that are free from transmission error or loss of data, said step of comparing being carried out on the signals selected in this step of selecting. According to this embodiment, the method may further comprise: recording the non-selected signals in a library, anddiscarding each current received signal that matches with one of the signals recorded in the library. According to an embodiment, wherein the elevation of the road portion is shared with a network. According to an embodiment, the different ground-based transmitters are each comprised in a road side unit and/or the device is an on-board device. According to an embodiment, the different ground-based transmitters are each comprised in an on-board device and/or the device is a road side unit. A further object of the invention is to provide a device for detecting an elevation of road portion used by a vehicle, said device comprising: a receiver configured to:i) detect signals respectively emitted by different ground-based transmitters,ii) compare the detected signals to determine the signal having the highest power,a controller configured to determine the elevation of the road portion based on the comparison. According to an embodiment, each detected signal comprises data relative to the position of the given ground-based transmitter, said elevation of the road portion being further based on the data relative to the position. According to an embodiment, the device comprises a radio transmitter configured to emit signal, said transmitter comprising at least one dipole antenna. According to this embodiment, the at least one dipole antenna may be configured to operate on the one hand, in reception, to receive the signals from the ground-based transmitter, and, on the other hand, in transmission to transmit the signal emitted by the transmitter of the device. According to an embodiment, the at least one-half wave dipole antenna has a first dimension higher than a second dimension, said first dimension being oriented along a vertical direction. Accordin