Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01C—MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY
  • G01C21/00—Navigation; Navigational instruments not provided for in groups G01C1/00 - G01C19/00
  • G01C21/10—Navigation; Navigational instruments not provided for in groups G01C1/00 - G01C19/00 by using measurements of speed or acceleration
  • G01C21/12—Navigation; Navigational instruments not provided for in groups G01C1/00 - G01C19/00 by using measurements of speed or acceleration executed aboard the object being navigated; Dead reckoning
  • G01C21/16—Navigation; Navigational instruments not provided for in groups G01C1/00 - G01C19/00 by using measurements of speed or acceleration executed aboard the object being navigated; Dead reckoning by integrating acceleration or speed, i.e. inertial navigation
  • G01C21/165—Navigation; Navigational instruments not provided for in groups G01C1/00 - G01C19/00 by using measurements of speed or acceleration executed aboard the object being navigated; Dead reckoning by integrating acceleration or speed, i.e. inertial navigation combined with non-inertial navigation instruments
  • G01C21/1656—Navigation; Navigational instruments not provided for in groups G01C1/00 - G01C19/00 by using measurements of speed or acceleration executed aboard the object being navigated; Dead reckoning by integrating acceleration or speed, i.e. inertial navigation combined with non-inertial navigation instruments with passive imaging devices, e.g. cameras
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01C—MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY
  • G01C5/00—Measuring height; Measuring distances transverse to line of sight; Levelling between separated points; Surveyors' levels
  • G01C5/06—Measuring height; Measuring distances transverse to line of sight; Levelling between separated points; Surveyors' levels by using barometric means

Definitions

• the present invention relates to the fields of navigation and positioning.
• the present invention relates to a navigation method and device for a vehicle, a system, a vehicle, a computer program and an associated information medium.
• the present invention finds a particularly advantageous application, although in no way limiting, for the implementation of navigation systems for aircraft.
• inertial navigation As a navigation solution using data from an inertial measurement unit (i.e. specific force and angular speed).
• inertial data to implement a navigation solution requires solving the well-known problem of drift over time in inertial navigation. Indeed, small errors in measuring the specific force and angular velocity are integrated over time by inertial navigation and thus lead to increasingly larger errors in velocity and position.
• hybrid inertia-GPS navigation solutions do not make it possible to reliably and precisely locate a vehicle while guaranteeing a high level of integrity. Integrity is defined as the ability to provide, in addition to an estimated quantity (eg the position, speed, heading of a vehicle), a protection radius associated with this quantity, that is to say a bound increasing the estimation error with a defined probability, in particular very close to 1.
• the present invention aims to remedy all or part of the disadvantages of the prior art, in particular those explained above.
• a navigation method for a vehicle, said method comprising steps of: determination by a first navigation module of first navigation data of said vehicle from data from an inertial measurement unit and a satellite positioning module; and determination by a second navigation module of second navigation data of said vehicle from: data from the inertial measurement unit and images acquired by said vehicle; and furthermore from data from said satellite positioning module and/or an altimeter.
• a “position” can designate an absolute position defined with respect to the terrestrial reference frame, or a relative position defined with respect to a reference position.
• inertial measurement unit reference is made to a measuring device providing, for a plurality of measurement instants, data relating to the specific force (ie the sum external forces other than gravitational divided by the mass) and the angular speed of the vehicle.
• inertial unit hereinafter designates a navigation device integrating over time the specific force and angular velocity data produced by an inertial measurement unit and making it possible to determine vehicle navigation data.
• the proposed method makes it possible to precisely determine the navigation data of a vehicle (e.g. the position and movement data of the vehicle as well as the associated protection radii) while guaranteeing a level of integrity and availability high of the navigation system.
• the step of determining navigation data by the first navigation module and the step of determining navigation data by the second navigation module are carried out concomitantly (i.e. in parallel, or simultaneously).
• the parallel use of two distinct navigation modules i.e. said first and second navigation modules
• makes it possible to improve the resilience of the vehicle's navigation system with regard to failures of the sensors used for navigation e.g. satellite positioning module, image acquisition device
• failures of the sensors used for navigation e.g. satellite positioning module, image acquisition device
• the sensors used for navigation e.g. satellite positioning module, image acquisition device
• the use of a satellite and image positioning module makes it possible to compensate for inertial navigation drift and thus to precisely determine the vehicle's navigation data.
• the proposed navigation solution by exploiting a plurality of navigation modules, makes it possible to improve the level of integrity and availability of the vehicle's navigation system while precisely determining the vehicle navigation data.
• the proposed navigation solution presents: a higher level of availability than existing hybrid inertia-GPS navigation systems; and a higher level of integrity than existing hybrid inertia-vision navigation systems.
• the proposed method comprises steps of: if said satellite positioning module is functional, supplying said first navigation data to a guidance module of said vehicle; and otherwise, supplying said second navigation data to said guidance module of said vehicle.
• This embodiment makes it possible to guide a vehicle with precision. It should be noted that this embodiment benefits from the technical advantages of the proposed navigation solution. Indeed, precise guidance of the vehicle is enabled because the navigation data is precisely determined.
• the proposed solution uses images for navigation to compensate for inertial navigation drift.
• the use of navigation data determined from images by the second navigation module for vehicle guidance is conditioned on unavailability of the satellite positioning module (e.g. faulty module, or unusable ).
• this embodiment makes it possible to significantly relax the constraints on the reliability (i.e. the hourly risk of integrity) of the image acquisition device and the associated image processing algorithms.
• the proposed navigation solution makes it possible to precisely determine the navigation data of a vehicle while guaranteeing a high level of integrity, even for an image acquisition device and image processing algorithms. associated images of low maturity.
• the second navigation module uses, according to this embodiment, data from the satellite positioning module or the altimeter in addition to the acquired images. This makes it possible to compensate with better precision the inertial navigation drift of the second navigation module when the satellite positioning module or the altimeter are usable. Thus, this embodiment makes it possible to maintain a precise location chain by exploiting the different sensors when they are available.
• This embodiment makes it possible to use data from independent sensors of different types to determine the vehicle's navigation data in an efficient manner, particularly in terms of precision of the navigation data obtained and the necessary hardware and software resources. (e.g. processing resources, memory resources, etc.).
• hardware and software resources e.g. processing resources, memory resources, etc.
• this embodiment makes it possible to implement multi-sensor data fusion to determine vehicle navigation data.
• the use of an inertial unit makes it possible to determine navigation data from inertial data; and the use of a Kalman filter makes it possible to correct this navigation data using data from other sensors (i.e. realignment of the inertial navigation to compensate for the drift).
• the combination of an inertial unit and a Kalman filter makes it possible to implement multi-sensor data fusion to precisely determine the vehicle's navigation data from independent sensors of different types.
• the proposed method comprises steps of: detection of at least one terrestrial reference point in said acquired images; determination of an observed relative position of said at least one terrestrial reference point detected relative to said vehicle from said acquired images; determination of an estimated relative position of said at least one terrestrial reference point detected relative to said vehicle from a position of said vehicle determined by the second navigation module and a known position of said at least one terrestrial reference point; and determining said second navigation data from the difference between the observed and estimated relative positions of said at least one terrestrial reference point relative to said vehicle.
• a “terrestrial reference point” is a terrestrial point whose position (e.g. the geographic coordinates) is known.
• a terrestrial reference point is also referred to as “landmark”.
• This embodiment makes it possible to compensate for the drift of the inertial navigation of the second navigation module from images acquired by the vehicle.
• navigation data are determined from acquired images, for example by using navigation techniques. visual odometry, cartographic registration techniques, machine learning algorithms, etc.
• said step of detecting at least one terrestrial reference point in the acquired images comprises steps of: selecting a portion of at least one acquired image, the coordinates of said portion being determined from a known position of said at least one terrestrial reference point, a position of said vehicle determined by the second navigation module and information relating to the precision of said determined position of said vehicle provided by the second module navigation; and detection of said at least one terrestrial reference point in said portion of said at least one acquired image.
• This embodiment is advantageous in that it makes it possible to use only a portion of the image (i.e. a region of interest) to detect a terrestrial reference point and thus to restrict the portion of the image to be processed. . More generally, this embodiment makes it possible to reduce the hardware and software resources (e.g. processing resources, memory resources, etc.) necessary for the detection of a terrestrial reference point in acquired images and therefore for the determination of data of navigation from acquired images.
• a portion of the image i.e. a region of interest
• this embodiment makes it possible to reduce the hardware and software resources (e.g. processing resources, memory resources, etc.) necessary for the detection of a terrestrial reference point in acquired images and therefore for the determination of data of navigation from acquired images.
• a navigation device for a vehicle comprising: a first navigation module configured to determine first navigation data of said vehicle from data coming from a measurement unit inertial and a satellite positioning module; and a second navigation module configured to determine second navigation data of said vehicle from data from the inertial measurement unit and images acquired by said vehicle; and furthermore from data from said satellite positioning module and/or an altimeter.
• the proposed navigation device has the advantages described above in connection with the proposed navigation method. According to one embodiment, the navigation device implements all or part of the steps of the proposed navigation method.
• the proposed device comprises a control module configured to: if said satellite positioning module is functional, providing said first navigation data to a guidance module of said vehicle; and otherwise, providing said second navigation data to said guidance module of said vehicle
• a navigation system for a vehicle comprising: a navigation device according to the invention; an inertial measurement unit; a satellite positioning module; and an image acquisition device.
• the proposed navigation system has the advantages described above in connection with the proposed navigation method. According to one embodiment, the proposed navigation system implements all or part of the steps of the proposed navigation method.
• the navigation system comprises a computer vision device configured to determine at least one position of the vehicle from the images acquired by said image acquisition device.
• the navigation system comprises a guidance module configured to guide said vehicle based on navigation data determined by said navigation device according to the invention.
• a vehicle comprising a navigation system according to the invention.
• a computer program comprising instructions for implementing the steps of a method according to the invention, when the computer program is executed by at least a processor or computer.
• the present invention relates to a navigation method and device for a vehicle, as well as an associated system, vehicle, computer program and information medium.
• the SYS navigation system proposed for a vehicle comprises at least the following elements: a set of SENS sensors; an APP navigation device; and a CMD guidance module.
• the navigation device APP is configured to determine, from the data coming from the set of SENS sensors, IN_NAV_CMD navigation data of the vehicle.
• the CMD guidance module is configured to guide the vehicle based on the IN_NAV_CMD navigation data provided by the APP device.
• the SYS system is on board a vehicle, for example in a land vehicle: car, truck, train, etc., or in a marine vehicle: boat, frigate, or even in an air vehicle: an aircraft, a helicopter, a plane, a drone, etc.
• the SYS system is, according to a variant embodiment, embedded in an aircraft.
• the set of SENS sensors comprises at least one of the following sensors: at least one inertial measurement unit IMU; at least one GPS satellite positioning module; at least one BARO altimeter; a VISION sensor (hereinafter referred to as a computer vision device or sensor); at least one odometer; a Pitot probe; and a magnetometer.
• the GPS satellite positioning module provides OUT_GPS navigation data.
• the OUT_GPS navigation data includes, for a plurality of measurement instants, a position Pos and a speed Vel of the vehicle.
• the GPS satellite positioning module provides an absolute Pos position relative to the terrestrial reference frame comprising one or more coordinates from the following set: latitude, longitude; and altitude.
• the satellite positioning module complies with the “Global Positioning System”, more commonly referred to by the acronym GPS.
• GPS Global Positioning System
• the BARO altimeter provides OUT_BARO so-called altimeter data as output.
• the BARO altimeter is, according to one embodiment, a barometric altimeter.
• the altimeter data OUT_BARO are, for a plurality of measurement instants, representative of the altitude Alt of the vehicle or variations in altitude of said vehicle.
• the computer vision sensor VISION (also referred to as “computer vision device”) provides OUT_VIS data as output.
• the VISION sensor comprises or is configured to communicate with: a DB recording medium; and a CAM image acquisition device.
• the recording medium DB for example a database, includes the positions (i.e. geographical coordinates) of a plurality of terrestrial reference points AMER (hereinafter called bitters) as well as information relating to the graphic representations of the terrestrial points reference AMER.
• the terrestrial reference points may be a landing strip, a navigation light, a Precision Approach Path Indicator, etc.
• the OUT_VIS data provided by the VISION sensor include, for a plurality of measurement instants, differences ox, oy between the observed and estimated relative positions of the terrestrial reference points AMER relative to the vehicle.
• the relative position (observed or estimated) of a landmark relative to the vehicle is defined by two angles - a lateral angle and a vertical angle - characterizing the axis of sight of the landmark relative to the longitudinal axis of the landmark. vehicle.
• the VISION sensor is configured to select in this image a region of interest (i.e. a portion of this image) and detect the terrestrial reference point in this region of interest.
• the coordinates of the region of interest are determined from: the known position of the terrestrial reference point; the position of the vehicle determined by the LOC_VISION navigation module; and information provided by the LOC_VISION navigation module relating to the protection radius of the determined position of the vehicle (i.e. the probability that the position error is less than the protection radius is greater than a defined value, in particular very close to 1).
• the LOC_GPS navigation module determines the OUT_LOC_GPS navigation data from data from the IMU inertial measurement unit, the GPS satellite positioning module, and the BARO altimeter.
• the navigation module LOC_VISION determines the navigation data OUT_LOC_VIS from data from the inertial measurement unit IMU, the GPS satellite positioning module, the BARO altimeter and the VISION sensor.
• the navigation module LOC_VISION uses, to realign the NAV_IMU_VIS inertial unit, data from other GPS, BARO, VISION sensors when these data are available.
• the VISION sensor can only be used by the LOC_VISION navigation module to realign the NAV_IMU_VIS inertial unit following the detection of a landmark.
• the LOC_VISION navigation module does not use the data from the GPS satellite positioning module, when the GPS module is faulty or unusable.
• the navigation data determined at a given time is a function of the navigation data determined at previous times.
• the NAV_IMU_GPS and NAV_IMU_VIS inertial units integrate over time the specific force Fs and angular velocity data produced by the inertial measurement unit IMU to determine navigation data OUT_LOC_GPS and OUT_LOC_VIS.
• small errors in measuring the specific force Fs and the angular speed are integrated over time by the inertial units and thus lead to errors in speed and position increasing over time (i.e. drift of inertial navigation). . Consequently, the fact of using a sensor at a given moment to realign an inertial unit makes it possible to improve the precision of the navigation data determined at subsequent moments.
• the navigation module LOC_VISION uses the data from the GPS module to compensate for the drift of the NAV_IMU_VIS inertial unit. Then, during a second subsequent period, the GPS satellite positioning module is no longer available. During the second period, although the GPS module is no longer available, the LOC_VISION navigation module determines OUT_LOC_VIS navigation data that is more precise than a navigation module that never uses the data from a GPS module. Indeed, the LOC_VISION navigation module benefits during the second period from the alignment of the inertial unit during the first period.
• the SWITCH control module receives the navigation data OUT_LOC_GPS and OUT_LOC_VIS respectively produced by the navigation modules LOC_GPS and LOC_VISION and provides the guidance module CMD with navigation data IN_NAV_CMD.
• the SWITCH control module provides the CMD guidance module with either the OUT_LOC_GPS navigation data or the OUT_LOC_VIS navigation data.
• the SWITCH control module is configured to select the navigation data to be provided depending on the availability (ie functional or non-functional) of the GPS satellite positioning module, this embodiment being detailed below with reference in Figures 2A and 2B.
• the proposed navigation method comprises at least one of the following steps S10 to S50 implemented by the proposed SYS navigation system .
• steps S10 to S50 are implemented in chronological order as described below.
• the LOC_GPS navigation module determines OUT_LOC_GPS navigation data of the vehicle from the data from the inertial measurement unit IMU, the GPS satellite positioning module, and the BARO altimeter.
• step S20 the navigation module LOC_VISION determines OUT_LOC_VISION navigation data of the vehicle from data from the inertial measurement unit IMU, the GPS satellite positioning module, the altimeter BARO, and the VISION computer vision sensor.
• step S20 comprises substeps S21 to S24 detailed below with reference to Figure 2B.
• Steps S10 and S20 can be carried out simultaneously, one before the other or vice versa. According to a particular embodiment, steps S10 and S20 are carried out in parallel.
• the navigation modules LOC_GPS and LOC_VISION continue to output the navigation data OUT_LOC_GPS and OUT_LOC_VIS.
• the LOC_GPS and LOC_VISION navigation modules cannot use the data from the non-functional sensor to compensate for the drift (i.e. readjust) of the NAV_IMU_GPS and NAV_IMU_VIS inertial units.
• step S40 if and only if it has been determined in step S30 that the GPS satellite positioning module is functional, the SWITCH control module provides the OUT_LOC_GPS navigation data to the module. CMD guidance of the vehicle.
• step S50 if it was determined in step S30 that the GPS satellite positioning module is not functional (the GPS module being unavailable, faulty, broken down or not usable) , the SWITCH control module provides the OUT_LOC_VIS navigation data to the vehicle's CMD guidance module.
• the navigation system implements, according to one embodiment, the steps S10 and S20 previously detailed.
• the proposed navigation method comprises, according to this embodiment, several iterations of steps S10 to S50 described above.
• the VISION sensor detects at least one terrestrial reference point AMER in images acquired by the image acquisition device CAM.
• the VISION sensor to detect an AMER terrestrial reference point in an image, implements the following steps.
• the VISION sensor selects a portion of this image (ie a region of interest), the coordinates of the image portion being determined from: the known position (eg geographical coordinates) of the terrestrial reference point AMER; the position of the vehicle determined by the LOC_VISION navigation module; and information relating to the precision of the vehicle position provided by the LOC_VISION navigation system (ie the protection radius).
• the VISION sensor detects the terrestrial reference point AMER in the image portion.
• the VISION sensor determines an estimated relative position POS_AMER_EST of the detected terrestrial reference point AMER relative to the vehicle from a position of the vehicle provided by the navigation module LOC_VISION and a known position of the terrestrial reference point AMER.
• the VISION sensor provides the navigation module LOC_VISION with the difference ox, oy between the observed relative position POS_AMER_OBS and the estimated relative position POS_AMER_EST of the terrestrial reference point AMER relative to the vehicle; and the navigation module LOV_VISION determines navigation data OUT_LOC_VIS in particular from this difference ox, oy.
• the proposed APP navigation device comprises: at least one PROC processing unit or processor; and at least one MEM memory.
• the APP device has, according to one embodiment, the hardware architecture of a computer and comprises, as such, a PROC processor, a RAM, a MEM read-only memory, and a non-volatile memory.
• the memory MEM associated with the device APP constitutes an information or recording medium in accordance with the invention, readable by computer and by the processor PROC, on which a computer program PROG in accordance with the invention is recorded.
• the computer program PROG comprises instructions for carrying out steps of a method according to the invention and implemented by the device APP, when the computer program PROG is executed by the processor PROC.
• the APP device has a COM communication module configured to communicate with at least one of the following elements: one or more sensors from the set of sensors SENSE ; and the CMD guidance module.
• the VISION sensor also known as computer vision device
• the VISION sensor has the hardware architecture of a computer and comprises, as such, a processor, a RAM, a read only memory, and non-volatile memory.
• the memory associated with the VISION sensor constitutes an information medium, readable by computer and on which a computer program is recorded.
• This computer program includes instructions for carrying out steps of a method according to the invention and implemented by the VISION sensor, when this computer program is executed by a processor.
• the proposed SYS navigation system makes it possible to ensure a high level of integrity while significantly relaxing the hourly integrity risk constraints on the VISION computer vision sensor.
• the proposed SYS navigation system ensures a high level of integrity, even with a low maturity VISION computer vision sensor.
• a reference navigation system comprising a single navigation module using data from an inertial measurement unit, a satellite positioning module and a computer vision sensor.
• a navigation system does not ensure a high level of integrity and could not be integrated into a critical system. Indeed, the hourly integrity risk conditions to be verified for the computer vision sensor are not achievable with this reference system, due to the lack of maturity of the computer vision sensor and computer vision techniques.
• the proposed navigation system SYS has two navigation modules LOC_GPS and LOC_VISION and conditions the use of the computer vision sensor VISION to situations for which the GPS satellite positioning module n is not available.
• the proposed SYS navigation system and, more particularly, the architecture of the APP navigation device make it possible to significantly relax the constraints on the hourly integrity risk to be verified for the VISION computer vision sensor.
• the term module can correspond as well to a software component as to a hardware component or a set of hardware and software components, a software component itself corresponding to one or more computer or computer programs or subprograms. more generally to any element of a program capable of implementing a function or a set of functions as described for the modules concerned.
• a hardware component corresponds to any element of a hardware assembly capable of implementing a function or a set of functions for the module concerned (integrated circuit, smart card, memory card, etc. .).

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• Engineering & Computer Science (AREA)
• Radar, Positioning & Navigation (AREA)
• Remote Sensing (AREA)
• Automation & Control Theory (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Navigation (AREA)
• Position Fixing By Use Of Radio Waves (AREA)

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• 2022
  • 2022-09-13 FR FR2209165A patent/FR3139653B1/fr active Active
• 2023
  • 2023-09-12 WO PCT/FR2023/051388 patent/WO2024056973A1/fr not_active Ceased
  • 2023-09-12 EP EP23793415.3A patent/EP4587793A1/de active Pending

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