• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    Relative navigation system (200) and method for eliminating spurious signals which may be received by a relative navigation system (200) having a first object (202) and a second object (210), including the projection of polarized light at first orientation, from the first object (202), to form at least one grid line.
    公开号:FR3022353A1
    申请号:FR1555359
    申请日:2015-06-12
    公开日:2015-12-18
    发明作者:Jerry Lynne Page
    申请人:GE Aviation Systems LLC；
    IPC主号:
    专利说明:

    [0001] METHOD FOR REMOVING PARASITE SIGNALS AND RELATIVE NAVIGATION SYSTEM Relative navigation systems are useful for various applications such as the navigation of autonomous vehicles, particularly in the context of warehouses or factories, in-flight refueling and appointments space. In some applications, only the distance between two objects is necessary. In other applications, both the distance and the relative position (pitch, yaw and roll) between two objects are required. In such applications, high reliability, lightness and low cost may be desirable. In a first embodiment, the invention relates to a method for eliminating spurious signals received by a relative navigation system having a projection in space, from a grid generator in a first object, of polarized light at first. orientation in order to form at least one line of a grid, the detection in the second object of the polarized light having the first orientation and the filtering in the second object of polarized light at a second orientation, different from the first orientation .
    [0002] In another embodiment, the invention relates to a navigation system, comprising a grid generator adapted to project in the space of the first orientation polarized light to form a plurality of grid lines that create a grid defining a first relative reference frame and a detection module adapted to detect the polarized light having the first orientation and to filter second orientation polarized light. The invention will be better understood from the detailed study of some embodiments taken by way of nonlimiting examples and illustrated by the appended drawings in which: FIG. 1 is a diagrammatic representation of a first and a second objects, each having its relative reference frame and being able to navigate according to one embodiment of the invention; Figure 2 is a schematic representation of a direct signal; Figure 3 is a schematic representation of a spurious signal; Fig. 4 is a flowchart illustrating a method according to one embodiment of the invention for eliminating reflected interference signals; and FIG. 5 is a schematic representation of a relative navigation system according to one embodiment of the invention, capable of eliminating reflected interference signals. Figure 1 shows a relative navigation system 8 having a first grid object or generator 10, which projects a grid such as a plurality of intersecting lines into a space within a field of a signal. shown, the projected grid includes intersecting lines. At a certain distance from the grid generator 10, these intersecting lines appear in the form of a grid in space, the grid being all the larger as it is further away from the grid generator 10. For purposes of the description, the grid generator 10 can be envisaged as projecting intersecting lines substantially in the y direction of the coordinate system shown. If one were to observe the projection of intersecting lines in the xz plane at a distance R1 from the grid generator 10, a first grid 14 would be observed. If the same projection of intersecting lines was observed at a distance R2, larger than the distance R1 in the x - z plane, we observe a second grid 16, which appears relatively larger than the first grid 14.
    [0003] The first grid 14 at the distance R1 from the grid generator 10 is delimited in space in the horizontal direction by a first vertical line 18 and a second vertical line 20. There are a plurality of vertical lines created, in time and space. between the first vertical line 18 and the second vertical line 20. The first grid 14 at the distance R1 from the grid generator 10 is delimited in space in the vertical direction by a first horizontal line 22 and a second horizontal line 24. There is a plurality of horizontal lines created, in space and time, between the first horizontal line 22 and the second horizontal line 24. The distance R1 can be any distance between the first gate 14 and the generator 10 grids. For convenience, the distance is determined between a point 26 on the first gate 14 and the gate generator 10, as shown. The second gate 16 at the distance R2 of the gate generator 10 is identical to the first gate 14, but at a greater distance from the gate generator 10 than the first gate 14. The second gate 16 is delimited in the space in FIG. the horizontal direction by a first vertical line 28 of the second grid 16 and a second vertical line 30 of the second grid 16. There are a plurality of vertical lines created in space and time between the first vertical line 28 of the second gate 16 and the second vertical line 30 of the second gate 16. The second gate 16 at a distance R2 from the gate generator 10 is delimited in the space in the vertical direction by a first horizontal line 32 of the second gate 16 and a second horizontal line 34 of the second grid 16. There are a plurality of horizontal lines in space and time between the first horizontal line 32 of the second grid and the dry horizontal line wave 34 of the second gate 16. A point 36 on the second gate 16 is shown.
    [0004] The similarity of the grids 14 and 16 becomes apparent in the case of projected grid lines, the second grid 16 being composed of the same lines as those forming the first line 14, except that the second grid 16 is observed at a greater distance from the generator 10 grids, which makes the second grid 16 appear larger than the first grid 14. In this sense, the second grid 16 has the appearance of the grid lines created by the grid generator 10 at the distance R2, while the first grid 14 has the appearance of the grid lines at the distance R1. The grids 14 and 16 can have any number of lines. As illustrated, they consist of ten vertical lines on ten horizontal lines. A grid composed of a greater number of intersecting lines may have the effect of a better angular resolution of detection, for a fixed field of the signal 12 and a fixed distance relative to the grid generator 10, than that of a grid composed of a smaller number of intersecting lines.
    [0005] Grids 14 and 16 are shown in square form, but this is not mandatory for the methods and devices of the present invention. The grid may have any shape, including rectangular, oval or circular. In addition, the intersecting lines of the grids 14 and 16 are shown in orthogonal form; however, this is not mandatory for the methods and devices of the present invention. The angles between the intersecting lines may be right angles, acute angles or obtuse angles in different parts of the grid.
    [0006] Although illustrated examples use Cartesian coordinates, any suitable coordinate system can be used, such as polar, cylindrical, or spherical coordinate systems, to create the grids as well as to detect the grids. For example, to form a grid amenable to a representation in polar coordinates, a series of concentric circles and lines radiating from the center of these circles can be projected into space by the grid generator. A second object or detection module 38 may be in the field of signal 12 of the generator 10 grids, allowing the detection module 38 to "see" the grid. The detection module 38 may be designed in any suitable manner to "see" the grid. By way of non-limiting example, the grid generator 10 can use a scanning laser to create a two-dimensional grid in space. As shown in FIG. 2, the ideal context is that the emitted light propagates directly to the detection module 38 where the information of the transmitted gate is detected and decoded to provide the necessary spatial information. However, as illustrated in FIG. 3, there are situations where the light of the gates emitted does not propagate directly to the detection module 38. On the other hand, the light of the gates emitted is reflected by an object 50 which is also in the field of the grids issued. The reflected information is then "seen" by the detection module 38. These strayly reflected signals, or multipath signals, create erroneous information when received by the detection module 38. Signals reflected from a / object (s) 50 in the field of the transmitted gates, which reach the detection module 38, may appear to be valid signals. The detection module 38 can not identify the fact that these signals have followed a path other than direct from the grid generator 10. Since these signals represent the place where the reflective object 50 is placed on the two-dimensional grid, it misleads the relative navigation system 8 as to the position of the detection module 38, because it then seems to be in the same place that the reflective object 50. More particularly, the determination of the position is a function of the coordinates of the position on the grid, the object 50 reflects the transmitted signal on which is coded the position of the object. If the detection module 38 sees only the signal on which the position of the object is coded, it intercepts the code for the position of the object. Furthermore, a problem arises if the object 50 is sufficiently close to the detection module 38 for the reflected signal and the direct signal to hit the detection module 38 at moments that overlap a little. In such a case, the combined signal is not decodable because the transmitted reflected signal and the directly transmitted signal overlap in time and may be corrupted.
    [0007] The object 50 may be any object to which the transmitted signal may be reflected, the reflected signals may in particular be reflected as non-limiting examples, by the mechanical structures of a parachute-brake, a vehicle and a detector, vehicle surfaces, propellers, etc.
    [0008] Embodiments of the invention relate to distinguishing and eliminating unwanted parasitic or multipath signals from those propagated directly from the gate generator to the detection module. According to one embodiment of the invention, Figure 4 illustrates a method, which can be used to project a grid into space and to eliminate spurious signals. The term "space" is not limited to the outdoor space and the grid can be projected into any appropriate space, including both indoors and outdoors. Method 100 begins at 102 by projecting polarized light having a first orientation to form at least one grid line projecting into space from the first object or grid generator. In this way, the relative navigation system 8 creates a signal with a defined state of polarization. This may include projecting a non-polarized light beam by a light source. The single beam of unpolarized light can be passed through a beamformer. The unpolarized light beam can be polarized by passing the unpolarized light beam through a polarizer. Alternatively, the first orientation polarized light projection may include projecting a light beam polarized by a light source. In this case, the light source may comprise a highly polarized laser. As the term polarization is used in the present description, it serves to evoke the state of polarization of light defined by the orientation of its electric field as the light wave propagates. Light polarization states can vary from any desired degree of polarization in both orientations. However, for ease of use, two different orientations may be chosen in the form of orthogonal pairs so that a first polarized light may be filtered using a polarization filter or a properly designed polarizer and still allow the emission of the corresponding orthogonal polarization light. For example, the electric field of a linearly polarized light can be polarized vertically or horizontally. Since both electric field vectors are perpendicular or orthogonal, they can not interfere with each other. A polarization filter or polarizer can pass light in a first polarization state and filter the orthogonally polarized light. For linearly polarized light, the polarizer must be aligned with the electric field vector to pass a first linearly polarized light and to filter the orthogonally polarized light. A disadvantage of the use of linear polarization and polarizers is that the proper orientation must be maintained in order to preserve the separation of the polarizations. For example, if the first object emits horizontally polarized light and the second object has two linear polarizers / detectors, one for horizontally polarized light and one for vertically polarized light, and if the second object rolled around the optical axis, the two polarizers / detectors "would" each see a component of the emitted beam with horizontal and vertical polarization and the separation of the two beams would be lost. Thus, while the light emitted at 102 may have linear polarization, it is contemplated that in many applications circular polarizations, rather than linear polarizations, may be more useful because circular polarizations are insensitive to rotations around an optical axis. Circularly polarized light has an electric field vector that rotates around the axis of light propagation. Orthogonal polarization states have electric field vectors that rotate in a clockwise and anti-clockwise direction and are respectively referred to as right circular polarization (PCD) and left circular polarization (PCG). On the other hand, when polarized light is reflected, the angular orientation of the major axis of polarization with respect to a perpendicular to the plane of incidence changes sign. In addition, the direction of rotation of the electric field or the right or left side is reversed. In the case of circularly polarized light, there is no major axis defined, because the major and minor axes are equal to each other, which is not the case with polarized light elliptical. Therefore, the only effect of circular polarized light reflection is the change for the right or left side. Thus, if the light emitted at 102 is at PCD, any reflected light will be at PCG. At 104, the method may be continued by detecting, in the second object or detection module 38, the polarized light having the first orientation. This may include allowing polarized light at the first orientation to pass through a corresponding polarizer in the second object. At 106, the method comprises filtering, in the second object or detection module, second orientation polarized light. For example, the filtering may comprise optical filtering, and a polarizing filter that corresponds to the predefined polarization state of the light emitted at 102 may be included in the detection module. Such a polarizing filter can pass light propagating directly from the gate generator and reject unwanted light reflected by objects in the gate emitting field, which can also hit the detection module. In this way, the detection module can receive signals that do not correspond to the predefined polarization state. In this way, the parasitic signals can be limited. The filtering of the polarized light having the second orientation may comprise the total elimination of the light having the second orientation or the reduction of the amount of light detected having the second orientation. The method for eliminating spurious signals is flexible and the illustrated method 100 has only an illustrative function. For example, the sequence of steps presented only has an illustrative function and is in no way intended to limit the method 100, it being understood that the steps can take place in a different logical order, in particular the detection and the Filtering can take place at the same time, or additional or intermediate steps can be included without departing from the embodiments of the invention. For example, the method 100 may include a modulation of the projected light to route a first grid word composed of a number of modulated bits to identify the grid line (s) in a grid by the first grid word. module. The method 100 may include projecting polarized light at a first orientation to form a plurality of grid lines, including spatially projecting a horizontal grid line and a vertical grid line that intersect to form part of the grid. Still further, additional intersecting grid horizontal and vertical lines may be projected to form additional portions of the grid. The additional intersecting horizontal and vertical grid lines can be physically spaced from each other in space. These additional lines can also be modulated.
    [0009] 5 represents a relative navigation system 200 able to operate according to an embodiment of the method 100. The relative navigation system 200 is similar to the relative navigation system 8, described above, it being understood that, unless otherwise mentioned, the description of the like parts applies to the relative navigation system 200. A first object of the relative navigation system 200 or the grid generator 202 of the relative navigation system 200 may comprise a beam generator 204 such as a laser or any which light source is adequate A horizontal grid line and / or a vertical grid line can be projected from the beam generator 204. The light emerging from the beam generator 204 can be strongly polarized. Alternatively, a polarizer 206 may be inserted somewhere after the beam generator 204 so that the light beam can be polarized as it passes through the polarizer 206.
    [0010] Regardless of the fact that a separate polarizer is used, it will be considered that the gate generator 202 projects into the first orientation polarized light space to form a plurality of gate lines that create a gate defining a first relative reference frame. .
    [0011] A second object of the relative navigation system 200 or a detection module 210 is also included in the relative navigation system 200. The detection module 210 is designed to detect polarized light and to filter polarized light at second orientation, different from the first orientation. For example, the detection module 210 has been shown including a polarizer 212 which allows light at the first orientation to pass through the polarizer 212 so that it can be detected. The polarizer 212 also filters light having the second orientation. The polarizer 212 can completely eliminate the light having the second orientation so that it is not detected at all by the detection module. It is envisaged that the polarizer 212 may not eliminate all of the light of the second orientation, but reduce the possible effects of any reflected light reaching the detection module 210.
    [0012] Thus, depending on the polarization of the light, either the light passes through the polarizer 212 and reaches the remainder of the detection module 210, or it is filtered. In the relative navigation system 200, the polarizer 212 is a polarizer corresponding to the light having the first orientation so as to allow the light having the first orientation to pass through the polarizer 212 so as to form a portion of the gate. In the illustrated example, the light 230 projected by the gate generator 202 is PCD. As explained above, the only effect of circularly polarized light reflection is the side change. When the PCD light is reflected, as illustrated by the light 230 reflected by the object 222, the side changes. Thus, any light reflected by a single surface of the object 222 will become the orthogonally polarized light shown at 232. For example, in the figure, the PCD signal becomes a PCG signal, at 232, at the instant it is reflected by the object 222. The unreflected PCD signal remains a PCD signal. In the illustrated example, the matched polarizer 212 is a PCD polarizer, which allows the direct signal to pass through the polarizer 212 so that light can be detected by the detection module 210. However, the reflected light 232, which is then to PCG, is filtered by the polarizer 212 to PCD. In this way, the polarized light beam, which has been reflected and therefore has a second orientation, will be filtered by the polarizer 212 from the detection module 210. The corresponding filter may be any suitable optical filter taking into account the light emitted by the grid generator. For example, if the grid generator emits light to PCG, the corresponding filter can then be a PCG polarizer, and so on. In addition, the filtering of signals reflected with an optical filter is an example of how the polarized light having the second orientation can be filtered. It is contemplated that the polarized light having the second orientation can be filtered in any suitable manner. For example, a sensor can detect the polarization and electronically filter or process the signal having the second orientation. Furthermore, the signals can be filtered by a process, in particular by using likelihood criteria in the software in order to ignore certain signals reflected as a function of their rate or unrealistic positional jumps. The embodiments described above have provided various advantages, including the fact that the embodiments eliminate or reduce the possible effect of any reflected light that reaches the detection module thereby reducing noise and positional errors. in the relative navigation system. The embodiments described above may include the use of commercial circular polarizers, which allow, for a small fee, to ensure that the relative navigation system operates smoothly in congested environments.
    权利要求:
    Claims (15)
    [0001]
    REVENDICATIONS1. A method (100) for eliminating spurious signals received by a relative navigation system (200), the method (100) comprising: projecting into space on a first object, from a generator (202) of grids, a first orientation light (230) for forming at least one gate line; detecting, in a second object (210), light having the first orientation (230); and filtering, in the second object (210), polarized second orientation light (232), different from the first orientation.
    [0002]
    The method (100) of claim 1, wherein the polarized light projection having the first orientation (230) comprises projecting a non-polarized light beam from a light source (204).
    [0003]
    The method (100) of claim 1, wherein the polarized light projection having the first orientation (230) comprises polarizing the light beam by passing the light beam through a polarizer (206).
    [0004]
    The method (100) of claim 1, wherein the polarized light projection having the first orientation (230) comprises projecting a polarized light beam from a light source (204).
    [0005]
    The method (100) of claim 1, wherein the filtering comprises optical filtering of the polarized light.
    [0006]
    The method (100) of claim 5, wherein the detection of the polarized light having the first orientation (230) comprises allowing the polarized light having the first orientation (230) to pass through a suitable polarizer (212). in the second object (210).
    [0007]
    The method (100) of claim 6, wherein filtering the polarized light having the second orientation includes blocking, by the matched polarizer (212), the light having the second orientation.
    [0008]
    The method (100) of claim 6, wherein filtering the polarized light having the second orientation comprises reducing a detected amount of light having the second orientation.
    [0009]
    The method (100) of claim 1, wherein the polarized light projection having the first orientation (230) for forming at least one gate line comprises the polarized light projection having the first orientation (230) to form a plurality of grid lines.
    [0010]
    The method (100) of claim 9, wherein the plurality of grid lines comprises a horizontal grid line and a vertical grid line that intersect to form a portion of the grid.
    [0011]
    The method (100) of claim 10, further comprising spatially projecting additional intersecting grid and horizontal lines to form additional portions of the grid.
    [0012]
    A relative navigation system (200), comprising: a generator (202) for projecting into the space of the first orientation polarized light (230) to form a plurality of grid lines that create a grid defining a first relative reference frame; and a detection module (210) for detecting the polarized light and for filtering second orientation polarized light (232) different from the first orientation. 25
    [0013]
    The relative navigation system (200) according to claim 12, wherein the detection module (210) comprises a polarizer (212) which allows the light having the first orientation (230) to pass through the polarizer (212) to to be detected and blocks the light having the second orientation. 30
    [0014]
    The relative navigation system (200) of claim 13, wherein the polarizer (212) completely eliminates the undetected light having the second orientation.
    [0015]
    The relative navigation system (200) of claim 12, wherein the polarizer (212) is a right circular polarizer.
    类似技术:
    公开号 | 公开日 | 专利标题
    FR3003347A1|2014-09-19|GRID FORMING METHOD DEFINING A FIRST RELATIVE REFERENCE FRAMEWORK
    FR3003348A1|2014-09-19|GRID FORMING METHOD DEFINING A FIRST RELATIVE REFERENCE FRAMEWORK
    FR3022353A1|2015-12-18|METHOD FOR REMOVING PARASITE SIGNALS AND RELATIVE NAVIGATION SYSTEM
    CN106597414B|2020-01-10|Method for calibrating gain ratio of polarization laser radar
    US20160314336A1|2016-10-27|Bathymetric techniques using satellite imagery
    EP2839297A1|2015-02-25|Device for determining wind speed comprising a plurality of laser sources
    JP3578214B2|2004-10-20|Retro-reflective photoelectric sensor
    EP3152593B1|2020-07-22|Device for detecting an obstacle by means of intersecting planes and detection method using such a device
    EP2611169A1|2013-07-03|Device for the acquisition of stereoscopic images
    EP2405399A1|2012-01-11|Method for calibrating the orientation of an on-board video camera
    EP3152592A1|2017-04-12|Device for detection of obstacles in a horizontal plane and detection method implementing such a device
    FR3007832A1|2015-01-02|NAVIGATION AND POINTING SYSTEM AND METHOD OF CALIBRATING A NAVIGATION AND POINTING SYSTEM
    JP4482603B2|2010-06-16|Polarization coupling cube corner retroreflector
    FR3025642B1|2019-07-05|MONITORING SYSTEM WITH POSITION DETECTION
    EP3680615A1|2020-07-15|Method for determining a radius of protection for a vision-based navigation system
    FR2979428A1|2013-03-01|METHOD OF LOCATING AN OBJECT USING A REFERENCE GRID
    FR3069692B1|2019-08-23|METHOD AND DEVICE FOR MANAGING THE DISPLAY OF VIRTUAL REALITY IMAGES
    CA3130973A1|2016-10-06|Imaging device and corresponding imaging method
    CN107870041A|2018-04-03|It is a kind of to divide amplitude polarized imaging system simultaneously without wave plate and polarizer
    FR3038118A1|2016-12-30|DEVICE AND METHOD FOR DETECTING OBJECTS
    EP2775318B1|2015-08-19|Method and system for image acquisition
    WO2018073528A1|2018-04-26|Windscreen for driving assistance
    EP3726246A1|2020-10-21|Polarization sensitive lidar system
    FR2903781A1|2008-01-18|POLARIZATION DETECTOR
    Freudenthaler2016|Supplement of About the effects of polarising optics on lidar signals and the∆ 90 calibration
    同族专利:
    公开号 | 公开日
    US9383261B2|2016-07-05|
    FR3022353B1|2018-08-17|
    GB2529043A|2016-02-10|
    GB2529043B|2017-04-05|
    US20150362369A1|2015-12-17|
    GB201510411D0|2015-07-29|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    JP2004239886A|2002-12-11|2004-08-26|Fuji Xerox Co Ltd|Three-dimensional image imaging apparatus and method|
    US7756614B2|2004-02-27|2010-07-13|Hewlett-Packard Development Company, L.P.|Mobile device control system|
    US7681839B2|2005-02-25|2010-03-23|Smiths Aerospace Llc|Optical tracking system for refueling|
    US7817087B2|2008-05-07|2010-10-19|The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration|Method and apparatus for relative navigation using reflected GPS signals|
    US8386096B2|2009-12-22|2013-02-26|General Electric Company|Relative navigation system|
    DE102011003803A1|2011-02-08|2012-08-09|Robert Bosch Gmbh|Method and device for determining a clarity of a pane of a vehicle|
    WO2012156915A2|2011-05-15|2012-11-22|Carbofix Orthopedics Ltd.|Guiding system|
    CN103857982A|2011-08-15|2014-06-11|纽约市哥伦比亚大学理事会|Systems and methods for performing machine vision using diffuse structured light|
    EP2955788A1|2012-07-03|2015-12-16|Lisa Dräxlmaier GmbH|Antenna system for broadband satellite communication in the ghz frequency range with dielectrically filled horn radiators|
    US9121709B2|2013-03-12|2015-09-01|Ge Aviation Systems, Llc|Method of forming a grid defining a first relative reference frame|US9823755B2|2015-02-26|2017-11-21|Konica Minolta Laboratory U.S.A., Inc.|Method and apparatus for interactive user interface with wearable device|
    CN105606089B|2016-02-03|2019-02-22|曲阜师范大学|Based on the polarotactic navigation sensor and working method for improving imitative husky ant POL neuron|
    CN108225336B|2018-01-24|2021-06-25|北京航空航天大学|Polarization autonomous combined navigation method based on confidence|
    法律状态:
    2016-06-28| PLFP| Fee payment|Year of fee payment: 2 |
    2017-06-27| PLFP| Fee payment|Year of fee payment: 3 |
    2017-09-22| PLSC| Search report ready|Effective date: 20170922 |
    2018-06-26| PLFP| Fee payment|Year of fee payment: 4 |
    2019-05-22| PLFP| Fee payment|Year of fee payment: 5 |
    2020-05-20| PLFP| Fee payment|Year of fee payment: 6 |
    2021-05-19| PLFP| Fee payment|Year of fee payment: 7 |
    优先权:
    申请号 | 申请日 | 专利标题
    US14303639|2014-06-13|
    US14/303,639|US9383261B2|2014-06-13|2014-06-13|Method of eliminating spurious signals and a relative navigation system|
    [返回顶部]