EP3857257A1 - Apparatus and method for determining the distance of an object by scanning - Google Patents
Apparatus and method for determining the distance of an object by scanningInfo
- Publication number
- EP3857257A1 EP3857257A1 EP19779764.0A EP19779764A EP3857257A1 EP 3857257 A1 EP3857257 A1 EP 3857257A1 EP 19779764 A EP19779764 A EP 19779764A EP 3857257 A1 EP3857257 A1 EP 3857257A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- frequency
- lasers
- awg
- light source
- source unit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
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- 230000035559 beat frequency Effects 0.000 description 2
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Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
- G01S7/481—Constructional features, e.g. arrangements of optical elements
- G01S7/4814—Constructional features, e.g. arrangements of optical elements of transmitters alone
- G01S7/4815—Constructional features, e.g. arrangements of optical elements of transmitters alone using multiple transmitters
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
- G01S17/02—Systems using the reflection of electromagnetic waves other than radio waves
- G01S17/06—Systems determining position data of a target
- G01S17/08—Systems determining position data of a target for measuring distance only
- G01S17/32—Systems determining position data of a target for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated
- G01S17/34—Systems determining position data of a target for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated using transmission of continuous, frequency-modulated waves while heterodyning the received signal, or a signal derived therefrom, with a locally-generated signal related to the contemporaneously transmitted signal
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
- G01S17/02—Systems using the reflection of electromagnetic waves other than radio waves
- G01S17/06—Systems determining position data of a target
- G01S17/42—Simultaneous measurement of distance and other co-ordinates
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
- G01S17/02—Systems using the reflection of electromagnetic waves other than radio waves
- G01S17/50—Systems of measurement based on relative movement of target
- G01S17/58—Velocity or trajectory determination systems; Sense-of-movement determination systems
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
- G01S7/481—Constructional features, e.g. arrangements of optical elements
- G01S7/4817—Constructional features, e.g. arrangements of optical elements relating to scanning
Definitions
- the invention relates to a device and a method for scanning the distance of an object.
- the device and the method can be used to determine distances of both moving and still objects and in particular to determine the topography or shape of a spatially extended three-dimensional object.
- LIDAR For optical distance measurement of objects, a measuring principle also known as LIDAR is known, in which an optical signal whose frequency has changed over time is transmitted to the object in question and is evaluated after back-reflection on the object.
- FIG 9a shows only a schematic representation of a basic structure known per se, in which a signal 911 emitted by a light source 910 with a frequency which changes over time (also referred to as “chirp”) in FIG two partial signals is split, this split taking place, for example, via a beam splitter, not shown (for example a partially transparent mirror or a fiber-optic splitter).
- the two partial signals are coupled via a signal coupler 950 and superimposed on one another at a detector 960, the first partial signal reaching the signal coupler 950 and the detector 960 as a reference signal 922 without reflection on the object labeled “940”.
- the second partial signal arriving at the signal coupler 950 or at the detector 960 runs as a measurement signal 921 via an optical circulator 920 and a scanner 930 to the object 940, is reflected back by the latter and thus arrives with a time delay and correspondingly changed compared to the reference signal 922 Frequency to signal coupler 950 and detector 960.
- the detector signal supplied by the detector 960 is evaluated relative to the measuring device or the light source 910 by means of an evaluation device (not shown), the difference frequency 931 between the measurement signal 921 and the reference signal 922, which is detected at a specific point in time and shown in the diagram in FIG. 9b, being characteristic of the Distance of the object 940 from the measuring device or the light source 910.
- the time-dependent frequency profile of the signal 911 emitted by the light source 910 can also be such that there are two sections in which the time derivative of the frequency generated by the light source 910 is opposite to one another.
- DFB lasers distributed feedback laser
- Have tuning range of the order of 500GHz
- a device according to the invention for scanning the distance of an object has:
- a light source unit for emitting a plurality of optical signals, each with a time-varying frequency, the light source unit having a plurality of lasers,
- an evaluation device for determining a distance of the object on the basis of measurement signals, each of which emerges from the optical signals, is reflected or scattered on the object and not reflected or scattered on the object, and
- a dispersive scan device which causes a frequency-selective deflection of the measurement signals directed to the object.
- the lasers of the light source unit differ with respect to the center frequencies in the time-dependent frequency course of each optical signal generated from each other.
- the lasers of the light source unit can have a frequency offset corresponding to the respective tuning range with regard to the center frequencies in the time-dependent frequency profile.
- the invention is based in particular on the concept of connecting a laser array (in particular a DFB laser array, a DBR laser array, a WGMR laser array or a VCSEL laser array) as a light source in a LIDAR system with a dispersive scan device, which causes a frequency-selective deflection of the respective measurement signals to the object to be measured with regard to its distance.
- a laser array in particular a DFB laser array, a DBR laser array, a WGMR laser array or a VCSEL laser array
- laser array is intended to include an arrangement of at least two lasers.
- a suitable offset of the center frequencies of the individual lasers within the light source unit or the laser array used according to the invention (wherein this offset can in particular essentially correspond to the tuning range of the individual lasers), a correspondingly large tuning range (corresponding, for example, to a frequency response of the order of magnitude) can result 10THz or more) and thus an effective scanning process can be realized, whereby at the same time the high temporal coherence of the DFB lasers (for example relative to VCSEL lasers) can be used.
- the lasers within the light source unit or the laser array used according to the invention can be operated sequentially in embodiments of the invention, wherein only one of the lasers is active and the next laser is only switched on when the preceding laser is at the limit of its tuning range has arrived.
- the lasers of the light source unit can also be operated simultaneously, with the result that the respective measurement signals of all lasers are emitted simultaneously.
- a further dispersive element can be used to spatially divide the measurement signals reflected by the object as a function of the respective frequency range respectively.
- the detector arrangement can have a plurality of detector elements which can be operated independently of one another and which are in turn assigned to different angular ranges in the angular distribution of the measurement signals directed to the object.
- the dispersive scan device used according to the invention for frequency-selective deflection of the measurement signals directed to the object is designed as a two-dimensional dispersive scan device and, for this purpose, can in particular have at least one AWG in combination with a diffraction grating.
- the AWG present in the dispersive scanning device can work in a higher order and cause a comparatively rapid deflection in a first spatial direction, whereas the (decoupling) grating operated in a lower order causes a comparatively slow deflection in this vertical spatial direction.
- a laser array formed by the light source unit has a resulting tuning range of at least 1THz, in particular of at least 4THz, furthermore in particular at least 10THz.
- the lasers of the light source unit are each for obtaining additional information regarding the relative speed between the object and the measuring device or the light source unit for generating optical signals with a time-dependent frequency profile with two sections in which the time derivative of the frequency to one another is opposed.
- the light source unit has a first laser for generating a first optical signal with a first time-dependent frequency profile and a second laser for generating a second optical signal with a second time-dependent frequency profile, wherein the time derivatives of the frequency in the first and second frequency curve are opposite to each other.
- the invention thus includes the further concept of generating the optical signals which can be used to obtain additional information with regard to the relative speed between the object and the measuring device and which have an opposite frequency profile with separate lasers, with the result that in conjunction with a in a suitably designed dispersive scanning device and with a correspondingly synchronous operation of the two lasers, a significant reduction in measuring time (essentially by a factor of two) can be achieved.
- the design of the dispersive scan device “in a suitable manner” here means that — as explained in more detail below — the dispersive scan device depends on whether the frequency ranges of the optical signals generated by the lasers match or differ from one another are the dispersive scan device, for example can have two AWGs, only a single AWG or also a diffraction grating.
- the frequency ranges traversed by the first optical signal and by the second optical signal are different from one another.
- the dispersive scan device has at least one AWG.
- measurement signals which have arisen from the optical signals of the first or second laser are coupled into the same AWG.
- the dispersive scanning device has at least one diffraction grating.
- measurement signals which have arisen from the optical signals of the first or second laser are coupled into the same diffraction grating.
- the frequency ranges traversed by the first optical signal and by the second optical signal match.
- the dispersive scan device has a first AWG and a second AWG.
- the first optical signal is coupled into the first AWG and the second optical signal is coupled into the second AWG.
- the first AWG and the second AWG are arranged next to one another in a direction perpendicular to the signal path.
- a lateral distance between the first AWG and the second AWG has a value which is so small that the radiation beams emanating from the AWGs on the object (in the far field) have a lateral distance in the range from one to ten beam diameters.
- the invention also relates to a method for scanning the distance of an object, the method comprising the following steps:
- Emitting using a light source unit, at least one optical signal with a time-varying frequency; and Determining a distance of the object on the basis of in each case a measurement signal reflected on the object, resulting from the at least one optical signal, and a reference signal not reflected on the object;
- the measurement signals are directed frequency-selectively in different beam directions to the object via a dispersive scan device;
- a plurality of measurement signals are simultaneously fed to the dispersive scan device, these measurement signals differing from one another in their time-dependent frequency profile.
- the dispersive scan device simultaneously supplied measurement signals each have an opposite time-dependent frequency profile.
- the method is carried out using a device with the features described above.
- 1a-1b are schematic representations to explain the structure of a device according to the invention in a first embodiment
- FIG. 2a-2c are diagrams for explaining the functioning of the device according to the invention from FIG. 1;
- FIG. 3-8 diagrams for explaining further embodiments of a device according to the invention.
- FIGS. 9a-9b are schematic representations to explain the structure and mode of operation of a conventional device for determining the distance.
- FIGS. 1 a-1 b The structure and mode of operation of a device according to the invention are described below in an exemplary embodiment with reference to the schematic illustration in FIGS. 1 a-1 b.
- the lasers can be DFB lasers, DBR lasers or WGMR lasers or VCSEL lasers. With regard to the principle of operation of a DFB laser array consisting of a plurality of DFB lasers, DiLazaro et al.
- this laser array 111 is combined according to the invention with the use of a dispersive scanning device 130, the mode of operation of which is illustrated in FIG. 1b.
- the laser array 111 used in accordance with the invention is part of a light source unit 110 which, as a result, generates optical signals with a frequency that varies with time in accordance with the frequency response indicated in FIG. 2 a.
- WDM wavelength division multiplexer
- the individual lasers of the laser array 111 are offset with respect to one another with respect to their center frequencies by approximately the tuning range, with the result that the frequency response shown in FIG. 2a is generated during sequential operation of the lasers of the laser array 111, the contributions of the individual Lasers are labeled "1.1", “1.2", “1.3”, ...
- the lasers of the laser array 111 can be operated simultaneously without the need for such a sequential control, so that in this case the optical signals of the lasers are offset simultaneously (but also with one another according to FIG. 4) Center frequencies) are transmitted.
- the optical signals generated by the light source unit 110 are split up via a beam splitter 118 (for example a partially transparent mirror or a fiber-optic splitter) in a manner known per se as partial signals serving as measuring signals and as partial signals serving as reference signals .
- the partial signals serving as the measuring signal are directed via an optical circulator 120 and the dispersive scanning device 130 to an object to be measured with respect to its distance from the device (not shown in FIG. 1 a), whereas the partial signals serving as reference signal are analogous to FIG. 9a-9b can be used for further evaluation.
- 1b is configured as a two-dimensional scanning device and has an AWG 131 in combination with a diffraction grating 132 for frequency-selective deflection in two mutually perpendicular directions.
- AWG 131 in combination with a diffraction grating 132 for frequency-selective deflection in two mutually perpendicular directions.
- the dispersion of the AWG 131 (which is defined by the order in which the AWG is operated) in the dispersive scanning device 130 is chosen to be substantially larger than the dispersion of the diffraction grating 132.
- the AWG 131 operated in a higher order thus effects a comparatively fast scanning process in the sense of a frequency-selective deflection by angle f in a first spatial direction on a comparatively short time scale, whereas the diffraction grating 132 performs a comparatively slow scanning process on a larger time scale frequency-selective beam deflection takes place in the direction perpendicular to this by an angle Q.
- the signal path runs back via the optical circulator 120 to a further dispersive element 150 (which can be designed as an AWG) for frequency-selective spatial division of the measurement signal reflected by the object. Due to the frequency-selective spatial division by the further dispersive element 150, the different frequency ranges, which correspond to the different deflections towards the object, are spatially separated from one another on a detector arrangement 160 designed as an array.
- a further dispersive element 150 which can be designed as an AWG
- the above-described two-dimensional scanning process with the two-dimensional dispersive scanning device 130 according to the invention with comparatively fast scan (by angle f) in the first spatial direction and a comparatively slow scan (by angle Q) in the second spatial direction basically has gaps without further measures in the scan area, which correspond to "unscanned" angular areas.
- This fact can be taken into account by the fact that, in embodiments of the invention and as indicated in the diagram in FIG. 3, by successively shifting the respective “start wavelength” in successive scans while simultaneously shifting the working frequency of the AWG 131 of the dispersive scan device 130 a displacement of the scan pattern is effectively effected in order to fill the above-mentioned gaps or non-scanned angular ranges.
- the tuning range of the laser array 111 is preferably chosen to be, for example, at least 10% larger than the minimum tuning range required to cover the desired scanning angle range by the dispersive scanning device 130.
- the frequency is increased from the value h to the value f 2 in accordance with the frequency range 501 passed through with a linear time dependency according to FIG. 5a, whereas for the second laser the frequency corresponding to the frequency range 502 passed through, also with a linear, however, the opposite time dependency is reduced from the value f 2 to the value h.
- the tuning rate (B / T) is chosen to be the same for both lasers, but with opposite signs.
- the measurement signal resulting from the optical signal of the first laser is coupled into a first AWG 510
- the measurement signal resulting from the optical signal of the second laser is coupled into a second AWG 520.
- the second AWG 520 arranged upside down to the first AWG 510.
- the AWGs 510 and 520 have a free-radiation area behind the waveguides, so that they act like line spectrometers.
- the beams of rays emanating from the AWGs migrate side by side simultaneously over the object.
- the two AWGs 510, 520 are arranged such that the measuring radiation of the first AWG 510 and the measuring radiation of the second AWG 520 are in sufficient spatial proximity, but with a negligible overlap of the laser spots (typically each having a Gaussian intensity distribution) hit the object.
- the distance between the measurement radiation of the first AWG 510 and the measurement radiation of the second AWG 520 can be in the range from one to ten beam diameters.
- the two AWGs 510, 520 can in particular (but without being limited to this) be produced monolithically.
- the radiation from both lasers can be separated again during the detection and fed to two independent, balanced detectors.
- the distance and speed of the object can be calculated on the basis of the sum and the difference of the beat frequencies determined with the detectors.
- the light source unit has two tunable lasers with different frequency ranges [fi ... or [f 3 ... f 4 ] (where h ⁇ f4 applies).
- the frequency corresponding to the frequency range 601 passed through with linear time dependence according to FIG. 6b is increased from the value fi to the value f 2
- the frequency corresponding to the frequency passed Frequency range 602 with likewise linear, but opposite time dependence according to FIG. 6a is reduced from the value f 4 to the value f 3 .
- the tuning rate (B / T) for both lasers is chosen to be the same, but with the opposite sign.
- the optical signals of both lasers are superimposed and coupled into a single AWG 610 (or one AWG per row of pixels) according to FIG. 6c.
- the frequencies h and f 3 are a whole number multiple of the free spectral range (FSR) of this AWG 610 apart.
- the two lasers use different AWG orders, taking advantage of the fact that the laser radiation generated by the lasers is periodically assigned to the same AWG output channels at a distance from the free spectral range (FSR). The radiation from both lasers thus emerges from one and the same AWG location or pixel at all times.
- the two laser spots (typically each having a Gaussian intensity distribution) overlap spatially completely on the object. Due to the non-overlapping frequency ranges, however, the radiation from the two lasers can be spectrally separated again during the detection and fed to two mutually independent, balanced FMCW detectors. The distance and speed of the object can be calculated from the sum and the difference of the beat frequencies determined with the detectors.
- FIGS. 7a-7b several rows of pixels can also be measured in parallel if a stack arrangement of (a number M) AWGs or AWG pairs (analogous to FIG. 5c or 6c) is used.
- Can transition channels ve through the dispersive effect of this AWG 's due to the frequency-selective distribution of the measuring signals generated plurality of spatially separated off via an imaging system on its waste stands ready to be object to be measured with respect to.
- the image can also be infinite, so that a largely collimated measuring beam is emitted for each AWG output channel.
- a matrix-like array of M * N output channels wherein the individual, each belonging to an AWG groups of N output channels in Fig. 7b "710a", “710b ",” 710c ", ... are designated.
- FIG. 7a shows, in a highly simplified schematic representation, the structure of an individual AWG, to which electromagnetic radiation with a time-varying frequency is supplied via an input light guide 701 from a light source (not shown in FIGS. 7a-7b).
- the radiation enters the AWG waveguide 703 of different lengths via a first free radiation area 702 and interferes constructively at different locations at the end of a second free radiation area 704 due to the different phase delays caused in the waveguides 703.
- N is, for example, may be at least 10 or even at least 100).
- the distance between the output channels generated by one AWG each can be increased by an additional spreading element before they are projected onto the object via an imaging system.
- Such an expansion element 720 can have a stack of N planar individual elements for channel expansion, the optical fibers of the expansion element 720 being optically coupled to the output channels of the AWG arrangement.
- Each individual AWG in a monolithic production method is preferably directly assigned an element for channel expansion.
- the use of the spreading element 720 makes it possible, on the one hand, to cover a larger solid angle range and, on the other hand, also to reduce the angular velocity of the measuring beam on the object during the individual distance measurements, which in turn reduces phase fluctuations and the achievable Depth resolution increased or peak widths in the measured distance spectrum can be reduced.
- the device can also have at least one deflection element, by means of which the respective angle at which light is directed from the AWGs of the AWG arrangement to the object can be varied, without restricting the field of vision (FOV), which is 20 ° * 20 ° can, for example, a remaining spatial dis- dance between each AWG 's of the AWG array in the optical imaging of the output channels to bridge onto the object.
- the deflection element thus serves to increase the angular resolution.
- the deflection element can be a mechanically movable optical element, wherein both reflective elements (for example a mirror that can be adjusted via at least one solid-state joint) and refractive optical elements (for example lenses or prisms) can be used.
- Optical phase arrays OPA
- LCPG liquid crystal polarization gratings
- LCPG Liquid Crystal Polarization Grätings
- the light source unit in turn has two tunable lasers with different frequency ranges 801, 802 (ranges [T ... f 2 ] and [f 3 .. . f 4 ]) with fi ⁇ f 2 ⁇ f 3 ⁇ f 4 ).
- the frequency is increased from the value T to the value f 2 in accordance with the frequency range 801 passed through with linear time dependency according to FIG. 8b, whereas for the second laser the frequency with the likewise linear but opposite time dependence according to FIG. 8a is increased from the value f 4 is reduced to the value f 3 .
- the tuning rate (B / T) is chosen to be the same for both lasers, but with the opposite sign.
- the optical signals of both lasers are superimposed and, according to FIG. 8c, formed with an anamorphic optics, for example cylinder optics, into a laser line 810 and coupled into a diffraction grating 820.
- a vertical row of pixels is generated via the laser line 810 formed with the cylinder optics during the spectral tuning.
- the frequencies zen fi and f 3 are an integer multiple of the free spectral range (FSR) of the diffraction grating 820 apart, so that the radiation from both lasers is deflected by the same grating deflection angle at all times.
- the two lasers use different diffraction grating orders.
- the two laser spots (typically each having a Gaussian intensity distribution) overlap spatially completely. Due to the non-overlapping frequency ranges, however, the radiation from the two lasers can be spectrally separated again during the detection and fed to two independent, balanced detectors.
- several rows of pixels can be measured in parallel by forming a plurality of parallel laser lines 810 from the cylinder optics and coupling them into the diffraction grating 820 next to one another.
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- Computer Networks & Wireless Communication (AREA)
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- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- Electromagnetism (AREA)
- Optical Radar Systems And Details Thereof (AREA)
Abstract
Description
Claims
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE102018216632.3A DE102018216632B4 (en) | 2018-09-27 | 2018-09-27 | Device for scanning the distance of an object |
DE102019209933.5A DE102019209933A1 (en) | 2019-07-05 | 2019-07-05 | Device and method for the scanning distance determination of an object |
PCT/EP2019/074879 WO2020064437A1 (en) | 2018-09-27 | 2019-09-17 | Apparatus and method for determining the distance of an object by scanning |
Publications (1)
Publication Number | Publication Date |
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EP3857257A1 true EP3857257A1 (en) | 2021-08-04 |
Family
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Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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EP19779764.0A Pending EP3857257A1 (en) | 2018-09-27 | 2019-09-17 | Apparatus and method for determining the distance of an object by scanning |
Country Status (3)
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US (1) | US20210231778A1 (en) |
EP (1) | EP3857257A1 (en) |
WO (1) | WO2020064437A1 (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
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DE102020215663A1 (en) | 2020-12-10 | 2022-06-15 | Peter Westphal | Device for spatially resolved distance and speed measurement |
DE102020134851A1 (en) * | 2020-12-23 | 2022-06-23 | OSRAM Opto Semiconductors Gesellschaft mit beschränkter Haftung | LIDAR SYSTEM, VEHICLE AND OPERATING PROCEDURE |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
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EP3281033B1 (en) | 2015-04-07 | 2022-01-12 | GM Global Technology Operations LLC | Compact lidar system |
WO2017054036A1 (en) * | 2015-09-28 | 2017-04-06 | Baraja Pty Ltd | Spatial profiling system and method |
KR101877388B1 (en) * | 2016-07-21 | 2018-07-11 | 엘지전자 주식회사 | Lidar apparatus for Vehicle |
KR20180013598A (en) * | 2016-07-29 | 2018-02-07 | 삼성전자주식회사 | Beam steering device and optical apparatus including the same |
-
2019
- 2019-09-17 WO PCT/EP2019/074879 patent/WO2020064437A1/en unknown
- 2019-09-17 EP EP19779764.0A patent/EP3857257A1/en active Pending
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2021
- 2021-03-24 US US17/211,401 patent/US20210231778A1/en active Pending
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US20210231778A1 (en) | 2021-07-29 |
WO2020064437A1 (en) | 2020-04-02 |
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