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
  • G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
  • G01S17/66—Tracking systems using electromagnetic waves other than radio waves
• • 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
  • G01S17/86—Combinations of lidar systems with systems other than lidar, radar or sonar, e.g. with direction finders

Definitions

• the present invention relates to a method for determining the trajectory of an object, in particular of an object in space.
• Such methods are of particular relevance for the determination of the trajectory of so-called space debris, for example objects no longer needed, which are in orbit around the earth.
• space debris for example objects no longer needed, which are in orbit around the earth.
• the present invention has for its object to provide a method by which the trajectories of objects which have a small size and / or a low reflectance, with high
• a known approximate trajectory of an object can be specified. In particular, this can be an exact
• Tracking d. H. a fine tracking, an object done.
• a subregion in this description and the appended claims is to be understood as a subregion of the detection region detected by the detection device.
• a region is in particular a spatial region, for example a solid angle region, which is exposed to laser light by means of the laser device and / or in which light must be emitted or reflected so that it can be detected by the detection device.
• the solid angle regions have either a common origin or two mutually different origins.
• the tracking of the detection device takes place by means of a separate tracking device, which is preferably a tracking device different from the laser device.
• the detection device and the laser device comprise a common tracking device.
• the beam deflection device is controlled and / or regulated by means of the control device such that the detection region is scanned by means of the laser radiation, in particular of the laser pulses. Scanning in this description and in the appended claims is to be understood as meaning control and / or regulation of the beam deflection device in such a way that the subregions of the detection region are exposed to laser radiation in a structured manner in accordance with a predetermined search pattern.
• the beam deflection device is controlled and / or regulated by means of the control device in such a way that the detection region is scanned spirally and / or radially to the center of the detection region by means of the laser radiation.
• the beam deflection device is controlled and / or regulated by means of the control device in such a way that the detection region is scanned in a square pattern and / or in line, in particular line by line or column by column.
• laser light which is emitted by the laser device and which is applied in a sub-area. ordered object was reflected is detected by means of a non-spatially resolving detection device.
• the detection device can thereby have a much higher sensitivity.
• the detection device can be operated, in particular, in a single-photon mode in which a photon is already sufficient to generate a detection signal.
• a time difference between the emission of laser radiation, in particular a laser pulse, on the one hand and the detection of the partially reflected by the object laser light, in particular laser pulse, on the other hand is determined.
• the approximate trajectory of the object is determined by means of a radar device and / or by means of a passive detection device, i. H. without active artificial lighting.
• the approximate trajectory of the object is taken from a database and / or calculated.
• a database device may be provided, which is in particular coupled to at least one tracking device.
• an evaluation device is preferably the position and / or orientation of the beam deflection device when emitting the
• a relative position of the object relative to a center of the detection area is determined at a predetermined time.
• an assignment of detected laser light to emitted laser pulses in particular via an estimation of the transit time, can be carried out by means of the evaluation device is or is being carried out.
• such an assignment may be advantageous.
• the detection device is and / or is preferably deactivated and / or protected from reflected laser light while laser light is generated by means of the laser device and / or while laser light is on the way to the object.
• the detection device is and / or is preferably activated, in particular ready for the detection of reflected laser light, while laser light reflected from the object is on the return path from the object.
• the laser light is on the way to the object or on the way back from the object.
• the beam deflection device is preferably controlled and / or regulated by means of the control device such that the detection region is moved along a predetermined path by means of the laser radiation, in particular the laser pulses
• Raster is scanned and that by means of an evaluation device from a determined time, to which a reflection is carried out and / or to which by the detection device reflected laser radiation is detected, a relative position of the object is determined relative to a center of the detection area. In particular, in this case, it is concluded from a determined elapsed time during the execution of the method to a specific point of the grid in order to determine the relative position of the object relative to the center of the detection area.
• an actual trajectory of the object is determined, in particular using the determined angular positions of at least one tracking device.
• the determination of the actual trajectory can be done, for example, by calculating the Kepler track with the associated Kepler elements.
• the tracking of the laser device and the detection device is adapted to the actual trajectory of the object.
• Such an adaptation is also referred to as "fine tracking”. It may be favorable if the method is carried out several times in succession in order to gradually achieve a higher accuracy in determining the actual trajectory of the object.
• the actual trajectory of the object ascertained when the method is carried out for the first time is then the approximate trajectory of the object in the second execution of the method, etc.
• the tracking by means of the tracking device is thus preferably adjusted such that the laser device and the detection device for tracking the object are tracked along its actual trajectory.
• Do not move the detection device ie. stationary objects can be detected by means of the method according to the invention.
• the position of an object relative to the laser device and the detection device can be determined by means of the method according to the invention.
• the determination of the (stationary) position of an object is a special case of determining the trajectory of an object in which the trajectory has the zero vector as the motion vector.
• the laser device and the detection device are used to detect the position of an object in the region of an expected, approximate position of the object. This directing is thus also a special case of tracking, in which the motion vector is the zero vector.
• the present invention thus also relates to a method for determining the position of an object, in particular of an object in space, comprising:
• This method may comprise one or more of the features and / or advantages described in connection with the method for determining the trajectory of an object and / or the trajectory determination device.
• the present invention further relates to a trajectory determination device for determining the trajectory of an object.
• the invention is in this respect the task of providing a trajectory determination device, by means of which the trajectory of
• a trajectory determination device for determining the trajectory of an object, in particular of an object in space, which comprises the following:
• a laser device for generating laser radiation
• a detection device for detecting laser light emitted by the laser device and reflected in a detection area of the detection device
• a tracking device for tracking the laser device and the detection device for tracking the object along its approximate trajectory
• a beam deflection device for deflecting the laser radiation
• control device for controlling and / or regulating the beam deflection device in such a way that the laser radiation can be directed successively to different subregions of the detection range detected by the detection device.
• the trajectory determination device preferably has one or more features and / or advantages of the method according to the invention.
• the detection device is a non-spatially resolving detection device.
• the detection device may be a single detector, in particular a photomultiplier and / or a single photon avalanche diode (SPAD).
• the trajectory determination device comprises an evaluation device, by means of which the distance of the object from the laser device and the detection device can be determined by determining a time difference between the emission of a laser pulse on the one hand and the detection of the laser pulse partially reflected by the object.
• the trajectory determination device preferably comprises an evaluation device, by means of which an actual relative position of the object relative to the center of the detection area and the approximate trajectory of the object and / or from at least two temporally successively determined relative positions of the object relative to the center of the detection area Trajectory of the object is determinable.
• the control device of the trajectory determination device is preferably designed so that one or more steps of the method according to the invention can be carried out.
• a beam deflection device may, for example, be a so-called tip-tilt mirror.
• the beam deflection device is an optical element with high temporal dynamics and high angular resolution, so that the laser pulses can be directed in targeted manner into different subregions of the detection range detected by the detection device.
• stationary objects can also be detected by means of the trajectory determination device according to the invention for determining the trajectory of an object, in particular of an object in outer space.
• the trajectory determination device is then a position determination device for determining the position of an object, in particular of an object in space.
• the present invention thus also relates to a position determining device for determining the position of an object, in particular of an object in space, comprising:
• a laser device for generating laser radiation
• a detection device for detecting laser light emitted by the laser device and reflected in a detection area of the detection device
• an alignment device for aligning the laser device and the detection device to an expected, approximate position of the object
• a beam deflection device for deflecting the laser radiation
• control device for controlling and / or regulating the beam deflecting device in such a way that the laser radiation can be directed successively to different subregions of the detection range detected by the detection device.
• the position-determining device according to the invention preferably has one or more features of the method according to the invention and / or of the trajectory determination device according to the invention.
• objects can also be detected up to the geostationary orbit and their position determined.
• the method according to the invention and / or the trajectory determination device according to the invention may preferably furthermore have one or more of the features and / or advantages described below.
• the method according to the invention and / or the device according to the invention may be favorable if by means of the method according to the invention and / or the device according to the invention objects with a size of up to approximately 10 cm can be detected and their trajectories can be determined.
• the method according to the invention and the device according to the invention preferably take place without position-sensitive detectors, in particular without quadrant detectors, lateral effect diodes, focal plane arrays, etc.
• objects can also be detected and their trajectories can be determined, which are not provided with optical retouch reflectors like satellites.
• the object to be detected does not have to be permanently exposed to laser radiation. Rather, an approximately known spatial area can preferably be scanned by means of laser pulses.
• a laser tracking technique may be based on the measurement of positional deviations relative to an optical axis using position sensitive detectors which require a large number of reflected photons to operate. Especially for small objects, objects with a smaller reflectance or distant objects, this method is rather unsuitable.
• the detection device is operated in the breakdown mode (Geiger mode).
• the gain of the detection device is preferably set so high that even a single photon drives the detection device into saturation and thus is detected with high probability. In this way, a detection device with very high sensitivity can be provided, so that even very small objects can be detected reliably.
• objects are first detected in an ad hoc mode, or known trajectories of objects are measured until a so-called catalog accuracy is maintained (catalog mode).
• catalog accuracy is maintained (catalog mode).
• the trajectory of these objects thus obtainable is preferably the approximate trajectory of the objects.
• a search space is preferably defined in which the object can be expected, for example based on the precision of the original orbit determination or on the accuracy of a catalog used.
• the search space is preferably scanned by means of a pulse laser, in which the angles at which the laser beam is emitted are changed gradually.
• the illuminated position in the search space can be changed after each laser pulse. In principle, however, all search strategies come into question.
• the object is illuminated by a laser pulse sometime during the scan cycle.
• a detection device designed, for example, as a ranging sensor is preferably used, so that reflected laser light can be reliably detected with high sensitivity. If a laser pulse strikes the object during the scanning process, reflected photons from the detection device can be detected by it. By determining the transit time, the distance of the object can also be determined. This distance is detected as well as the previously noted horizontal and vertical angular position and time. All data can be related to each other so that a data set is available from which a very accurate absolute position of the object in space (relative to the earth) can be determined. This method can preferably be carried out further along an assumed orbit, so that finally an actual trajectory of the object can be determined from the data records obtained. The accuracy of the method depends essentially on the laser beam diameter at the location of the target object and on the angular resolution of the beam deflection device.
• a laser device with a pulse repetition rate of about 1 kHz, a pulse energy of 1 J and a beam diameter of about 7 m at a distance of about 1,000 km and a search space in the form of an ellipse (large semi-axis, which preferably along the Trajectory is approximately 500 m, small semi-axis, which is preferably substantially perpendicular to the trajectory: approximately 100 m, which is approximately the current accuracy of the orbital catalog for low-earth orbit space debris equivalent) provided.
• ellipse large semi-axis, which preferably along the Trajectory is approximately 500 m, small semi-axis, which is preferably substantially perpendicular to the trajectory: approximately 100 m, which is approximately the current accuracy of the orbital catalog for low-earth orbit space debris equivalent
• Scan strategy can increase the number of hits of the object per second and thus the frequency of the position measurement.
• a traced detection area is preferably scanned or scanned by means of laser pulses.
• laser radiation is meant in particular continuous laser radiation or pulsed laser radiation (laser pulses).
• the accuracy in the position determination thus preferably depends on the beam diameter of the laser and not on a spatial resolution of the detection device. Furthermore, it can be provided that the accuracy in the position determination depends on the accuracy of the beam deflection device, the at least one tracking device and / or at least one recording and storage device for the laser device.
• a schematic representation of a trajectory determination device for determining the trajectory of an object in space
• a schematic representation of a laser device of the trajectory determination device for determining the trajectory of an object in space
• a schematic representation of a laser device of the trajectory determination device for determining the trajectory of an object in space
• a schematic representation of detectable by means of a Detektionsvor direction of the trajectory determination device detection area which is scanned spirally by means of laser pulses from the laser device
• a schematic representation of a detection range corresponding to Figure 3 wherein quadratic sub-areas of the detection area are successively applied line by line with laser pulses
• 6 shows a schematic illustration of the approximate trajectory and the actual trajectory of an object detectable by means of the trajectory determination device.
• a trajectory determination device 100 designated as a whole as 100 in FIGS. 1 and 2, comprises a laser device 102 and a detection device 104.
• the trajectory determination device 100 comprises at least one alignment device 108, which is designed, for example, as a tracking device 110.
• the laser device 102 and the detection device 104 can be aligned with the object 106.
• the position of the object 106 can be determined by means of the trajectory determination device 100 as a special case of determining a trajectory.
• the trajectory determination device 100 is therefore also a position determination device 111.
• the laser device 102 and the detection device 104 can be read by means of the tracking device 110. Tracking the object 106 along an approximate trajectory 112 of the object 106 tracked.
• the laser device 102 can be aligned by means of the alignment device 108 and / or can be tracked by the tracking device 110 in such a way that laser pulses 114 emitted by the laser device 102 can be directed into a spatial region in which the object 106 is arranged.
• the detection device 104 can be aligned by means of the alignment device 108 and / or so trackable by the tracking device 110 that a detection region 116 of the detection device 104, in which light must be emitted or reflected, so that it can be detected by the detection device 104, always an expected , approximate location of the object 106 and its surroundings.
• the trajectory determination device 100 further comprises a radar device 118, by means of which an object 106 can be detected and by means of which an approximate position and / or an approximate trajectory 112 of the object 106 can be determined.
• the trajectory determination device 100 further comprises a control device 120 and an evaluation device 122.
• the control device 120 the laser device 102, the detection device 104, the alignment device 108, the tracking device 110, the radar device 118 and / or a beam deflection device (to be described later) can be controlled and / or or controllable.
• the evaluation device 122 signals determined and / or generated by the laser device 102 and / or the detection device 104 and the radar device 118 can be evaluated for determining the position and / or the trajectory 112 of the object 106.
• the laser device 102 comprises a laser pulse generation device 124 and a beam deflection device 126.
• Laser pulses 114 can be generated by means of the laser pulse generation device 124 of the laser device 102.
• the laser pulses 114 can be deflected.
• the beam deflection device 126 is preferably designed as a mirror 128, for example as one or more tilting mirrors, in particular a tip-tilt mirror, and can be pivoted about, for example, two pivot axes 130.
• the laser pulses 114 generated by the laser pulse generating device 124 can be directly or indirectly directed to the beam deflection device 126 and deflected by means of the beam deflection device 126 relative to a central axis 132 of the laser device 102.
• the above-described trajectory determination apparatus 100 and thus also the position determination apparatus 111 function as follows.
• an approximate position and / or an approximate trajectory 112 of an object 106 in space is determined.
• the trajectory determination device 100 is used.
• the laser device 102 and the detection device 104 are directed by means of the alignment device 108 to a point in outer space in which, according to the measurement by means of the radar device 118, the object 106 is suspected.
• the central axis 132 of the laser device 102 is directed to this point.
• this point preferably forms a center 134 of the detection area 116 of the detection device 104.
• the laser device 102 and the detection device 104 are tracked by means of the tracking device 110 along the approximate trajectory 112 of the object 106.
• laser pulses 114 are generated by the laser pulse generating device 124, which are first directed along the central axis 132 of the laser device 102 into the center 134 of the detection region 116.
• the evaluation device 122 By means of the evaluation device 122 is thereby the current orientation of the laser device 102 and the detection device 104 and the
• the object 106 is arranged.
• all steps can be carried out by means of the evaluation device 122, so that the position of the object 106 relative to the laser device 102 and the detection device 104 can be determined automatically.
• the detection area 116 is subjected to laser pulse 114 in segments.
• the laser pulses 114 are deflected relative to the central axis 132 by means of the beam deflection device 126, so that successive different subregions 136 of the detection region 116 are exposed to laser light. It may be favorable in this case if adjacent subregions 136 overlap in sections.
• the detection region 116 is essentially spirally charged with laser pulses 114.
• the detection region 116 can be scanned by means of the laser pulses 114.
• a sub-area 136 is subjected to a laser pulse 114 and the object 106 is actually arranged in this sub-area 136, laser light is reflected by the object 106 and the reflected laser light is detected by means of the detection device 104.
• a positional deviation ⁇ , ⁇ of the object 106 from the center 134 of the detection region 116 can be closed.
• the trajectory 112 of the object 106 can be determined more closely, so that finally the actual trajectory 138 of the object 106 (see FIG ) is available.
• the laser pulses 114 are always directed only into a relatively small subarea 136 of the detection area 116 and a light reflection only occurs when the object 106 is arranged in the subareas 136 that are being exposed to laser light, a high spatial resolution of the trajectory determination device 100 is achieved the laser device 102 achieved.
• the detection device 104 only has to be able to receive light from any of the subareas 136 of the detection area 116.
• a position-sensitive detection by means of the detection device 104 is thus not necessary. Rather, the detection device 104 can be operated to exploit even very weak signals in a single-photon operation to detect even very small objects 106, which reflect only a small number of photons back to the detection device 104, and their position and / or trajectory 112 to determine with high accuracy.
• FIG. 4 shows an alternative search pattern for scanning the detection region 116 by means of the laser pulses 114.
• substantially square subregions 136 are provided which are successively exposed to laser pulses 114.
• the subregions 136 are thereby scanned along an angular spiral starting from the center 134 of the detection region 116.
• the detection of the object 106 in the search pattern shown in FIG. 4 takes place according to the detection of the object 106 in the search pattern shown in FIG. 3, so that reference is made to the description thereof.
• a search pattern shown in FIG. 5 differs from the search pattern illustrated in FIG. 4 essentially in that the subregions 136 are not scanned from the center 134 of the detection area 116 and spirally with laser pulses 114. Rather, in the search pattern shown in FIG. 5, scanning of the detection area 116 is provided line by line. This can be done, for example, along the trajectory or perpendicular to the trajectory. Incidentally, the detection of the object 106 in the detection area 116 is also carried out using the search pattern according to FIG. 5 as described in connection with the search pattern shown in FIG.

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• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Electromagnetism (AREA)
• Radar, Positioning & Navigation (AREA)
• Remote Sensing (AREA)
• Computer Networks & Wireless Communication (AREA)
• General Physics & Mathematics (AREA)
• Optical Radar Systems And Details Thereof (AREA)

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• 2012
  • 2012-05-21 DE DE102012104349A patent/DE102012104349A1/de not_active Ceased
• 2013
  • 2013-05-16 WO PCT/EP2013/060190 patent/WO2013174722A1/fr not_active Ceased

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