Solid-state long-range target pose detection device and detection method

Abstract

This invention provides a solid-state long-range target pose detection device, comprising: a laser, a grating, an optical system, and a surface detector; the laser beam emitted is split by the grating to effectively illuminate the target; the beam reflected from the illuminated target is imaged by the optical system and then incident on the surface detector to obtain the target information; based on the target information, an albedo model of the target is calculated, and pose data is obtained based on the albedo model. This invention utilizes prior distribution to perform statistical analysis on the photon distribution obtained from reflection, ultimately achieving simultaneous detection of system contour, attitude, and unknowns. It effectively improves the system's detection throughput and efficiency, overcoming the shortcomings of traditional methods such as low efficiency and high inertia caused by the need for scanning mirrors, while also enabling the measurement of unknown targets.

Description

Technical Field

[0001] This invention relates to the field of optical technology, and in particular to a solid-state long-distance target pose detection device and its detection method. Background Technology

[0002] Long-baseline optics and infrared interferometers can achieve extremely high angular resolution. Currently, only the CHARA interferometer array at Mount Wilson Observatory in the United States and the VLTI interferometer array at the European Southern Observatory in Chile can perform interferometric imaging of more than four 1-meter telescopes. Traditional interferometer arrays are limited by the number of telescopes and the degrees of freedom in baseline configuration, and their subsequent data processing relies heavily on prior physics and cosmological models. At the same time, the insufficient light-gathering area also prevents further improvement in the sensitivity of the back-end instruments. Summary of the Invention

[0003] In view of the above problems, the purpose of this invention is to propose a solid-state long-range target pose detection device and its detection method, which can make full use of existing telescopes for flexible baseline configuration, and achieve more refined imaging and geometric measurement by improving spatial resolution.

[0004] To achieve the above objectives, the present invention adopts the following specific technical solution:

[0005] This invention provides a solid-state long-range target pose detection device, comprising: a laser, a grating, an optical system, and a surface detector;

[0006] The laser beam is split by a grating to effectively illuminate the target being measured.

[0007] After the target is illuminated, the light beam reflected by the optical system is imaged and then incident on the surface detector to obtain the information of the target.

[0008] The albedo model of the target is calculated based on the information of the target. The calculation process includes:

[0009] The photon count rate function is:

[0010]

[0011] in,

[0012] c is the speed of light; t is time; (i, j) are pixel coordinates;

[0013] η q Quantum efficiency for surface detectors;

[0014] For target reflectivity;

[0015] s is the laser photon flux that varies with time;

[0016] z is the target distance;

[0017] b is the background photon flux, and d is the dark count rate;

[0018] The probability mass function of the number of photons M(t1,t2) detected by the surface detector within the time interval (t1,t2) is:

[0019]

[0020]

[0021] Where k is the number of successes;

[0022] Because surface detectors have a dead time, i.e., in the range [0, T] r Only one photon was detected within T. r Given the pulse period, the detection probability of a single laser pulse is:

[0023]

[0024] Where S is the number of signal photons in one pulse repetition period;

[0025] B is the number of background photons in one pulse repetition period;

[0026] In low-light-flux scenarios, the probability of a single laser pulse returning multiple signal photons is negligible, and the number of photons detected by N laser pulses is K. i,j The probability mass function follows a binomial distribution:

[0027]

[0028] Where N is the number of laser pulses emitted;

[0029] Find the reflectivity The secondary log-likelihood function:

[0030]

[0031]

[0032] To ensure smoothness, a TV regularization term was added.

[0033] Pose data is obtained based on the albedo model of the target object.

[0034] Preferably, the position of the surface detector is calibrated according to the emission relative relationship to ensure that the light spot of the laser beam emitted by the laser corresponds one-to-one with the surface detector.

[0035] This invention also provides a solid-state long-range target pose detection method, comprising the following steps:

[0036] Preprocessing step S0: Track and observe the target under test to obtain the prior data of the target under test, namely the background reflectance model;

[0037] S1. Calculate the albedo model of the target at the current moment based on the target information obtained by the surface detector;

[0038] S2. The albedo model of the target under test and the background albedo model of the prior data are sequentially correlated using the correlation function to obtain the correlation coefficient;

[0039] S3. When the correlation coefficient is less than the preset value, the albedo model of the target under test is determined to be the same as the background albedo model in the prior data at this time, that is, the pose of the target under test at the current time is obtained.

[0040] Preferably, step S1 includes the following calculation steps:

[0041] The photon count rate function is:

[0042]

[0043] in,

[0044] c is the speed of light; t is time; (i, j) are pixel coordinates;

[0045] η q Quantum efficiency for surface detectors;

[0046] For target reflectivity;

[0047] s is the laser photon flux that varies with time;

[0048] z is the target distance;

[0049] b is the background photon flux, and d is the dark count rate;

[0050] The probability mass function of the number of photons M(t1,t2) detected by the surface detector within the time interval (t1,t2) is:

[0051]

[0052]

[0053] Where k is the number of successes;

[0054] Because surface detectors have a dead time, i.e., in the range [0, T] r Only one photon was detected within T. rGiven the pulse period, the detection probability of a single laser pulse is:

[0055]

[0056] Where S represents the number of signal photons in one pulse repetition period;

[0057] B represents the number of background photons within one pulse repetition cycle;

[0058] In low-light-flux scenarios, the probability of a single laser pulse returning multiple signal photons is negligible, and the number of photons detected by N laser pulses is K. i,j The probability mass function follows a binomial distribution:

[0059]

[0060] Where N is the number of laser pulses emitted;

[0061] Find the reflectivity The secondary log-likelihood function:

[0062]

[0063]

[0064] To ensure smoothness, a TV regularization term was added.

[0065] Compared with existing technologies, this method uses a target and background albedo model for detection and performs statistical analysis of the photon distribution obtained from reflection based on prior distributions, ultimately achieving simultaneous detection of the system's outline, attitude, and unknowns. This effectively improves the system's detection throughput and efficiency, overcoming the shortcomings of traditional methods such as low efficiency and high inertia caused by the need for physical methods like scanning mirrors, while also enabling the measurement of unknown targets. Attached Figure Description

[0066] Figure 1 This is a schematic diagram of the structure of a solid-state long-range target pose detection device provided in an embodiment of the present invention.

[0067] Figure 2 This is a schematic diagram of the pose of the target being measured in the solidified long-range target pose detection device provided according to an embodiment of the present invention.

[0068] Figure 3 This is a flowchart illustrating a solid-state long-range target pose detection method provided in an embodiment of the present invention.

[0069] The accompanying reference numerals include: laser 1, grating 2, target under test 3, optical system 4, and surface detector 5. Detailed Implementation

[0070] In the following description, embodiments of the invention will be described with reference to the accompanying drawings. In the description below, the same modules are denoted by the same reference numerals. Where the same reference numerals are used, their names and functions are also the same. Therefore, their detailed description will not be repeated.

[0071] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not constitute a limitation thereof.

[0072] Figure 1 A schematic diagram of the solid-state long-range target pose detection device provided according to an embodiment of the present invention is shown.

[0073] Figure 2 A schematic diagram of the pose of the target being measured in a solidified long-range target pose detection device provided according to an embodiment of the present invention is shown.

[0074] like Figure 1-2 As shown, the solid-state long-range target pose detection device provided in this embodiment of the invention includes: a laser 1, a grating 2, an optical system 4, and a surface detector 5.

[0075] The laser beam is split into multiple paths by grating 2, and through the efficient equal-splitting optical path, it provides large-area, high-throughput effective illumination to the target 3.

[0076] After being illuminated, the light beam reflected from the target 3 is imaged by the optical system 4 and then incident on the surface detector 5 to obtain the information of the target 3. Based on the emission relative relationship, the position of the surface detector 5 is calibrated to ensure a one-to-one correspondence between the light spot and the point detector, so as to achieve the highest efficiency of coupling and detection.

[0077] The reflectance model of the measured target 3 is calculated based on the information of the measured target 3. The calculation process includes:

[0078] The photon count rate function is:

[0079]

[0080] in,

[0081] c is the speed of light; t is time; (i, j) are pixel coordinates;

[0082] η q Quantum efficiency for surface detectors;

[0083] For target reflectivity;

[0084] s is the laser photon flux that varies with time;

[0085] z is the target distance;

[0086] b is the background photon flux, and d is the dark count rate;

[0087] The probability mass function of the number of photons M(t1,t2) detected by the surface detector within the time interval (t1,t2) is:

[0088]

[0089]

[0090] Where k is the number of successes;

[0091] Because surface detectors have a dead time, i.e., in the range [0, T] r Only one photon was detected within T. r Given the pulse period, the detection probability of a single laser pulse is:

[0092]

[0093] Where S represents the number of signal photons in one pulse repetition period;

[0094] B represents the number of background photons within one pulse repetition cycle.

[0095] In low-light-flux scenarios, the probability of a single laser pulse returning multiple signal photons is negligible, and the number of photons detected by N laser pulses is K. i,j The probability mass function follows a binomial distribution:

[0096]

[0097] Where N is the number of laser pulses emitted;

[0098] Find the reflectivity The secondary log-likelihood function:

[0099]

[0100]

[0101] To ensure smoothness, a TV regularization term was added.

[0102] Figure 3 A schematic flowchart of a solid-state long-range target pose detection method provided according to an embodiment of the present invention is shown.

[0103] like Figure 3As shown, the solid-state long-range target pose detection method provided in this embodiment of the invention includes the following steps:

[0104] Preprocessing step S0: Track and observe the target under test to obtain the prior data of the target under test, namely the background reflectance model.

[0105] The aforementioned prior data consists of pose data of the target object obtained from various angles.

[0106] S1. Based on the target information detected by the surface detector, image reconstruction is performed to obtain the albedo model of the target at the current moment.

[0107] The steps include the following calculation steps:

[0108] The photon count rate function is:

[0109]

[0110] in,

[0111] c is the speed of light; t is time; (i, j) are pixel coordinates;

[0112] η q Quantum efficiency for surface detectors;

[0113] For target reflectivity;

[0114] s is the laser photon flux that varies with time;

[0115] z is the target distance;

[0116] b is the background photon flux, and d is the dark count rate;

[0117] The probability mass function of the number of photons M(t1,t2) detected by the surface detector within the time interval (t1,t2) is:

[0118]

[0119]

[0120] Where k is the number of successful detections, i.e., the desired number of detected photons, and the photon detection follows a Poisson distribution.

[0121] Because surface detectors have a dead time, i.e., in the range [0, T] r Only one photon was detected within T. r Given the pulse period, the probability of 0 detection for a single laser pulse is:

[0122]

[0123] Where S represents the number of signal photons in one pulse repetition period;

[0124] B represents the number of background photons within one pulse repetition cycle.

[0125] In low-light-flux scenarios, the probability of a single laser pulse returning multiple signal photons is negligible, and the number of photons detected by N laser pulses is K. i,j The probability mass function follows a binomial distribution:

[0126]

[0127] Where N is the number of laser pulses emitted;

[0128] Find the reflectivity The secondary log-likelihood function:

[0129]

[0130]

[0131] To ensure smoothness, a TV regularization term was added.

[0132] S2. The albedo model of the target under test and the albedo model of the prior data are sequentially correlated using the correlation function to obtain the correlation coefficient.

[0133] S3. When the above correlation coefficient is less than the preset value, it is determined that the albedo model of the target under test is the same as the albedo model in the prior data at this time, that is, the pose of the target under test at the above current time is obtained.

[0134] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

[0135] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A solid-state device for remote target pose detection, characterized in that The application relates to a laser radar system, which comprises a laser, a grating, an optical system and a plane detector. The laser emits a light beam, which is split by the grating to effectively illuminate a measured target. The light beam reflected by the measured target after being irradiated is imaged by the optical system and then enters the plane detector to obtain information of the measured target. A retroreflective model of the measured target is calculated according to the information of the measured target, and the calculation process comprises the following steps. A photon counting rate function is as follows: Wherein, c is the speed of light; t is time; (i, j) is pixel coordinates; s is a time-varying laser photon flux; η q quantum efficiency of the area detector; Target reflectance; z is target distance; b is background photon flux, and d is dark counting rate; A probability mass function of the photon number M(t1, t2) detected by the plane detector within a time period (t1, t2) is as follows: Wherein, k is the number of successes; Wherein, S represents the signal photon number within one pulse repetition period; Since the facet detector has a dead time, i.e. there is only one photon detected within [0, T r ) and T r is the pulse period, the single laser pulse detection probability is: B represents the background photon number within one pulse repetition period; Wherein, N is the number of emitted laser pulses; In the low light flux context, the probability of a single laser pulse returning multiple signal photons is negligible, and the number of photons K detected by N laser pulses i,j The probability mass function of K is binomially distributed: Pose data is obtained according to the retroreflective model of the measured target. log-likelihood function of the reflectivity R(ω) = 1 - exp(-2Re{S(ω)}) To ensure smoothness, a TV regularizer is added The position of the plane detector is calibrated according to the emission relative relationship, so that the light spot of the light beam emitted by the laser corresponds to the plane detector one by one.

2. The solid-state remote target pose detection device of claim 1, wherein The application further relates to a method for tracking a measured target, which comprises the following steps:

3. A method of detecting a position of a remote object using the solid-state remote object position detecting apparatus according to any one of claims 1 to 2, characterized by, A pretreatment step S0 is performed to track and observe the measured target, and prior data, i.e. a background retroreflective model, of the measured target is obtained; S1, a retroreflective model of the measured target at a current time is calculated according to the information of the measured target detected by the plane detector; S2, the retroreflective model of the measured target and the background retroreflective model of the prior data are sequentially subjected to correlation operation through a correlation function to obtain a correlation coefficient; S3, when the correlation coefficient is less than a preset value, it is determined that the retroreflective model of the measured target is the same as the background retroreflective model in the prior data at this time, i.e. the pose of the measured target at the current time is obtained. The step S1 comprises the following calculation steps:

4. The solid-state method of remote target pose detection according to claim 3, characterized in that A photon counting rate function is as follows: Wherein, c is the speed of light; t is time; (i, j) is pixel coordinates; s is a time-varying laser photon flux; η q Quantum efficiency for area detector; Target reflectance; z is target distance; b is background photon flux, and d is dark counting rate; A probability mass function of the photon number M(t1, t2) detected by the plane detector within a time period (t1, t2) is as follows: Wherein, k is the number of successes; Wherein, S represents the signal photon number within one pulse repetition period; Since the facet detector has a dead time, i.e. there is only one photon detected within [0, T r ) and T r is the pulse period, the single laser pulse detection probability is: B represents the background photon number within one pulse repetition period; Wherein, N is the number of emitted laser pulses; In the low light flux context, the probability of a single laser pulse returning multiple signal photons is negligible, and the number of photons K detected by N laser pulses i,j The probability mass function of K is binomially distributed: ​ Finding the reflectivity of the log-likelihood function: To ensure smoothness, a TV regularizer is added

Images