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EP-4187278-B1 - SYSTEM FOR LOCALIZING OBJECTS IN AN INDOOR ENVIRONMENT USING A WIRELESS COMMUNICATION NETWORK

EP4187278B1EP 4187278 B1EP4187278 B1EP 4187278B1EP-4187278-B1

Inventors

  • Geyer, Fabien
  • Multerer, Thomas
  • SCHUPKE, DOMINIC

Dates

Publication Date
20260506
Application Date
20211130

Claims (14)

  1. System (10) for localizing an object (9) in an indoor environment (20), the system (10) comprising: a wireless communication infrastructure, configured to enable wireless communication inside the indoor environment (20) via a wireless communication network (4), the wireless communication infrastructure comprising: a plurality of wireless access points (1), configured to provide mobile network devices (2, 3) with access to the wireless communication network (4); at least one cooperative mobile network device (2) in communication with at least one of the plurality of wireless access points (1); and a processing device (5); wherein each of the wireless access points (1) is configured to sense first signal propagation data of wireless signals (6) transmitted via the wireless communication network (4); wherein the cooperative mobile network device (2) is configured to sense second signal propagation data of wireless signals (6) transmitted via the wireless communication network (4); wherein the cooperative mobile network device (2) is configured to evaluate the second signal propagation data and to determine its own position based on the evaluated second signal propagation data and positions of the wireless access points (1); and wherein the processing device (5) is configured to evaluate the first signal propagation data and to extract localization data indicative of the position of an object (9) located in the indoor environment (20) based on the evaluated first signal propagation data, on the evaluated second signal propagation data, on the determined position of the cooperative mobile network device (2), and on the positions of the wireless access points (1).
  2. The system (10) of claim 1, wherein the at least one cooperative mobile network device (2) is configured to simultaneously establish and/or utilize connections to at least two wireless access points (1).
  3. The system (10) of any one of the preceding claims, wherein the first signal propagation data and/or the second signal propagation data comprises correlation data of the wireless access points (1) and/or of the cooperative mobile network device (2).
  4. The system (10) of any one of the preceding claims, wherein the first signal propagation data sensed by the wireless access points (1) and/or the second signal propagation data sensed by the at least one cooperative mobile network device (2) comprises channel state information, CSI.
  5. The system (10) of any one of the preceding claims, wherein the first signal propagation data sensed by the wireless access points (1) and/or the second signal propagation data sensed by the cooperative mobile network device (2) comprises at least one of a spatial, a frequency related, an amplitude related or a time related variation of wireless signals within the indoor environment (20).
  6. The system (10) of any one of the preceding claims, wherein the wireless access points (1) and/or the cooperative mobile network device (2) are Wifi enabled devices according to one of the Wifi standards IEEE 802.11.
  7. The system (10) of any one of the preceding claims, wherein the processing device (5) is configured to execute a machine learning algorithm on the first signal propagation data and the second signal propagation data, the machine learning algorithm being configured to extract the localization data based on training data; wherein the training data are obtained by an object position measurement system and/or predetermined test object arrangement within the indoor environment (20).
  8. The system (10) of claim 7, wherein the machine learning algorithm is configured to extract the positions of static objects (9) within the indoor environment (20).
  9. The system (10) of any one of the preceding claims, wherein the extraction of localization data comprises the evaluation of time series and a spectral analysis in order to detect moving objects (9).
  10. The system (10) of any one of the preceding claims, wherein the first signal propagation data sensed by the wireless access points (1) and/or the second signal propagation data sensed by the cooperative mobile network device (2) is obtained from wireless signals reflected from a passive object (9), the passive object (9) not sending any wireless signals, wherein the localization data is indicative of the position of the passive object (9).
  11. The system (10) of any one of claims 1 to 9, wherein the first signal propagation data sensed by the wireless access points (1) and/or the second signal propagation data sensed by the cooperative mobile network device (2) is obtained by the wireless access points (1) and/or the cooperative mobile network device passively capturing wireless signals exchanged between a non-cooperative mobile network device (3) and the wireless access point (1) to which the non-cooperative mobile network device (3) is connected; wherein the localization data is indicative of the position of the non-cooperative wireless network device (3).
  12. The system (10) of any one of the preceding claims, wherein the first signal propagation data and/or the second signal propagation data is provided as raw data from the physical layer of the wireless communication infrastructure.
  13. The system (10) of any one of the preceding claims, wherein the indoor environment (20) is a passenger cabin (20) of an aircraft.
  14. An aircraft (100), comprising: a passenger cabin (20); and a system (10) according to any one of claims 1 to 12.

Description

TECHNICAL FIELD The present invention relates to a system for object localization, particularly in the passenger cabin of a vehicle, especially an aircraft. TECHNICAL BACKGROUND In civil air traffic, huge amounts of passengers are regularly transported. After every flight, the cabin crew has to ensure the cabin of the aircraft is empty. In order to recognize, for example, people or forgotten luggage or other objects, the cabin crew has to manually check the passenger cabin, e.g., the overhead departments. In order to improve and speed up the workflow of the cabin crew, automatic recognition of such persons or objects by sensing technologies may be advantageous. The vast majority of indoor localization methods currently on the market require the installation of additional equipment in the area where the localization is being performed. This can be considered a disadvantage in object localization inside a vehicle cabin, as additional equipment usually means additional weight as well as the need for additional certification. WO 2018/094502 A1 describes a device-free localization method in smart indoor spaces, such as an apartment or other living area, covered by wireless networks with active commercially available devices. The method uses existing wireless communication signals and machine learning techniques to automatically detect entry into the area and track the position of a moving individual within the coverage area. The paper Ma et al, "WiFi Sensing with Channel State Information: A Survey," ACM Computer Survey, 2019, provides an overview of signal processing techniques, algorithms, applications, and performance results of WiFi sensing with channel state information (CSI). CSI represents how wireless signals propagate from a transmitter to a receiver at specific carrier frequencies along one or multiple paths. For example, CSI can be represented as a matrix of complex values representing the amplitude attenuation and phase shift of (multipath) WiFi channels. A time series of CSI measurements captures, how wireless signals interact with surrounding objects and people in time, frequency, and space domains, and can therefore be used for various wireless measurement applications. DE 10 2019 220 630 A1 discloses a system for object localization in an indoor environment. The system comprises a wireless communication infrastructure configured to enable wireless communication within the indoor environment via a wireless communication network. The system further comprises at least one wireless access point, wherein the wireless access point is further configured to acquire signal propagation data of wireless signals transmitted over the wireless communication network along a plurality of propagation paths. The system further includes a processing device configured to analyze the signal propagation data and extract localization data from the signal propagation data, wherein the localization data specifies the location of objects located within the indoor environment. US 2017 / 086 202 A1 describes a system and method for object detection in a wireless network. A wireless communications device receives a first set of wireless signals on a first frequency band, and generates a first interference profile for the wireless network based on signal interference in the first set of wireless signals. The wireless communications device further receives a second set of wireless signals on a second frequency band, and generates a second interference profile for the wireless network based on signal interference in the second set of wireless signals. The wireless communications device then detects the presence of an object in the wireless network based at least in part on the first interference profile and the second interference profile. KR 2010 0 073 744 A describes an RF-based indoor location estimation method and apparatus, which identifies the location of an indoor moving object by utilizing a signal attenuation model in an indoor environment generated based on signal strength information according to an obstacle property in a non line of sight (NLOS) environment where an obstacle exists, and a relationship information of the signal transmission time of an RF signal according to a distance. By applying a location estimation technique utilizing a signal attenuation model based on the received signal strength and a ranging model based on the round-trip transmission time to consider NLOS environmental factors that generate multiple paths due to reflection or diffraction, it is as being advantageous to estimate the location of a node moving in an indoor environment more precisely. DESCRIPTION It is an objective of the invention to provide more accurate solutions for indoor localization of active and passive objects that are compatible with the specific requirements of vehicle cabins. This objective is solved by the subject matter of the independent claims. Further embodiments are described in the dependent claims as well as i