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EP-4741761-A1 - METHOD, DEVICE AND SYSTEM FOR DETERMINING AN ELEVATION OF A ROAD PORTION USED BY A VEHICLE

EP4741761A1EP 4741761 A1EP4741761 A1EP 4741761A1EP-4741761-A1

Abstract

A method (200) for determining an elevation of a road portion used by a vehicle, said method (200) comprising the following steps: - detecting (201) signals emitted by at least two respective ground-based transmitters, said ground-based transceivers being each positioned at distinct elevations, - comparing (206) the detected signals to determine the signal having the highest power, - determining (208) the elevation of the road portion based on the comparison

Inventors

  • STRUNCK, SEBASTIAN
  • YANG, KANSHENG

Assignees

  • Valeo Comfort and Driving Assistance

Dates

Publication Date
20260513
Application Date
20241107

Claims (15)

  1. A method (200) for determining an elevation of a road portion (2a, 2b) used by a vehicle (1), said method (200) comprising the following steps: - detecting (201) signals (21, 31) emitted by at least two respective ground-based transmitters (231, 331), said ground-based transceivers (231, 331) being each positioned at distinct elevations, - comparing (206) the detected signals (21, 31) to determine the signal (21) having the highest power, - determining (208) the elevation of the road portion (2a, 2b) based on the comparison.
  2. Method (200) according to claim 1, wherein each detected signal (21, 31) comprises data relative to the position of the given ground-based transmitter (231, 331), the determined elevation being further based on the data relative to the position.
  3. Method (200) according to claim 2, wherein, before the step of comparing (206), the method (200) comprises a step of selecting (205) the detected signals (21, 31) having at least one spatial coordinate in common, said step of comparing (206) being carried out on the signals (21, 31) selected in this step of selecting (205).
  4. Method (200) according to any one of claims 1 to 3, wherein the method (200) further comprises, before the step of comparing (206), checking (203) each detected signal (21, 31) for transmission errors or loss of data and selecting the detected signals (21, 31) that are free from transmission error or loss of data, said step of comparing (206) being carried out on the signals (21, 31) selected in this step of selecting (205).
  5. Method (200) according to claim 4, wherein the method (200) further comprises: - recording the non-selected signals in a library, and - discarding (202) each current received signal that matches with one of the signals recorded in the library.
  6. Method (200) according to any one of the 1 to 6, wherein the elevation of the road portion is shared with a network.
  7. Method (200) according to any one of claims 1 to 5, wherein the different ground-based transmitters (231, 331) are each comprised in a road side unit (20, 30).
  8. Device (10) for detecting an elevation of road portion used by a vehicle, said device comprising: - a receiver (130) configured to: i) detect signals respectively emitted by different ground-based transmitters (231, 331), ii) compare the detected signals to determine the signal having the highest power, - a controller (13) configured to determine the elevation of the road portion based on the comparison.
  9. Device (10) according to claim 8, wherein each detected signal comprises data relative to the position of the given ground-based transmitter (231, 331), said elevation of the road portion being further based on the data relative to the position.
  10. Device (10) according to any one of claim 8 or 9, comprising a radio transmitter (131) configured to emit signal, said transmitter (131) comprising at least one dipole antenna.
  11. Device (10) according to claim 10, wherein the at least one dipole antenna is configured to operate on the one hand, in reception, to receive the signals from the ground-based transmitter (231, 331), and, on the other hand, in transmission to transmit the signal emitted by the transmitter (131) of the device (10).
  12. Device according to claim 10 or 11, wherein 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.
  13. Device (10) according to any one of claims 8 to 12, wherein the device (10) is an on-board device of the vehicle, and the ground-based transmitter are road side unit (20, 30).
  14. System (100) for determining an elevation of a road used by a vehicle, said system comprising: - at least two ground-based transmitters (231, 331), each ground-based transmitters (231, 331) being arranged to emit a signal, - an on-board device (10) according to any one of claims 8 to 13 and comprised in the vehicle.
  15. System (100) according to claim 14, wherein each ground-based transmitters (231, 331) comprises at least one dipole antenna having a first dimension higher than a second dimension, said first dimension being oriented along a vertical direction, said first dimension being higher than or equal to λ/2, where λ corresponding to the wavelength of the operating frequency of the at least 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 portion used by the vehicle. 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