CN109738163B

CN109738163B - Method for acquiring image rotation-out-of-target amount in photoelectric tracking equipment

Info

Publication number: CN109738163B
Application number: CN201910041940.8A
Authority: CN
Inventors: 史建亮; 王强; 杨涛; 于伟
Original assignee: Institute of Optics and Electronics of CAS
Current assignee: Institute of Optics and Electronics of CAS
Priority date: 2019-01-16
Filing date: 2019-01-16
Publication date: 2020-11-17
Anticipated expiration: 2039-01-16
Also published as: CN109738163A

Abstract

The invention provides an image rotation-out-of-target amount acquisition method applied to photoelectric tracking equipment. The reference laser is introduced into the photoelectric tracking equipment, the position of a reference light point image is extracted from a detector to obtain the image rotation angle of the system, and the effective miss distance of the image rotation is obtained by adopting a rotation coordinate method. The miss distance can be used as a tracking error control quantity of a photoelectric tracking system. The angle information quantity is provided in real time without an angle measuring device of the rotary platform, and the relative rotation quantity angle beta of the reference light image point and the reference zero point moment reference light image point is detected on the detector in real time. The rotation angle comprises rotation amount information of the multi-dimensional motion platform and relative rotation amount between the reflectors in the optical path of the system, a rotation matrix is generated by the rotation angle beta, and the matrix is multiplied by the original miss distance (gamma)_y,γ_z) Finally obtaining the racemization off-target amount (gamma)_y1,γ_z1). The method is simple and easy, the despin and miss distance precision is high, and the precision is not influenced by factors such as the installation precision of a rotary platform, the angle measuring precision of an angle measuring device and the like.

Description

Method for acquiring image rotation-out-of-target amount in photoelectric tracking equipment

Technical Field

The invention belongs to the technical fields of optical engineering, tracking control and the like, and particularly relates to an image rotation miss distance acquisition method applied to photoelectric tracking equipment.

Background

The method for acquiring the amount of the image-eliminating rotation-out-of-target is applied to the tracking control of a photoelectric tracking equipment system on a target. The imaging of the target light passing through the multi-dimensional motion platform and reaching the detector can generate rotation, so that the extracted target image point miss distance contains the rotation motion information of the motion platform, the motion characteristics of the target are not really reflected, the information of the miss distance without despinning cannot be used as the control error of the system, and otherwise the system tracking fails. In the prior art, two methods of measuring angle information by a hardware beam derotator or a software motion platform are generally adopted for beam derotation, wherein the beam derotator internally comprises a transmission mechanism such as a gear and the like, and the unstable motion of the transmission mechanism can influence the stability of a target image point; the method for measuring the angle information by adopting the motion platform is influenced by the angle measurement precision of the angle measurement sensor, only comprises the rotation angle information of the motion platform, does not comprise the rotation information between internal reflectors, is influenced by the orthogonality of the motion platform of system equipment to a certain extent, and has high requirements on the system installation and adjustment precision. The method of the invention is simple and easy to operate, does not need angle measurement information of a motion platform sensor, only needs a detector to provide position information, further improves the reliability, and has higher angle measurement precision than the prior method.

Disclosure of Invention

Aiming at the technical problem of the above image rotation eliminating method, an easy-to-realize method for acquiring the miss distance of the image rotation eliminating method applied to the photoelectric tracking equipment is provided, and the method can fundamentally solve the problem.

In order to achieve the purpose of the present invention, the present invention provides an image rotation off-target amount obtaining method which is easy to implement and is applied to photoelectric tracking equipment, and the technical scheme adopted to solve the technical problem comprises: a laser beam is emitted as reference light, and the collimated laser beam is coupled and introduced into a photoelectric tracking equipment system by a laser, a beam collimator and a pyramid lens at the front end of an entrance pupil of the system; before the tracking device begins to track the target, the image point position information of the reference laser beam on the target surface coordinate system of the detector is marked and recorded, and a vector OP is formed by the image point position information and the zero point of the target surface coordinate system of the detector₀(ii) a When the target image enters a system detector, the image processing system acquires the original miss distance information (gamma) of the target with image rotation under the target surface coordinate system of the detector_y,γ_z) Detecting the position of the reference laser image point from the moment, and forming a vector OP with the zero point of the target surface coordinate system of the detector₁Calculating a vector OP₀And vector OP₁The included angle beta of (a). Form a coordinate rotation matrix R from the angle beta_βLeft-hand multiplying the original miss distance information (gamma) of the target_y,γ_z) To obtain the information (gamma) of the amount of the stigmatic miss_y1,γ_z1)。

Wherein, the introduced laser beam needs to adjust the angle between the light beam and the visual axis of the system according to the visual field omega of the equipment system, so that the image point position P of the reference laser on the detector₀(y, z) is more than two-thirds of the field of view from the detector coordinate zero point O (0, 0).

Compared with the prior art, the invention has the following advantages:

1. the motion information of the system equipment multi-dimensional motion platform can be measured and obtained only by using the reference laser and the detector as angle measuring tools, and compared with the existing method for measuring the angle by adopting a beam derotator and an angle measuring device, the method is simple and easy to implement and has good economy;

2. the reference laser beam penetrates through the light path of the whole system, the motion information of the multi-dimensional motion platform is contained, the image rotation noise caused by external environment interference in the system is also contained, and the measured image rotation angle precision and the tracking precision are higher than those of the conventional method;

3. compared with the method of angle measurement and image rotation elimination by adopting an angle measurement device, the method only needs to calibrate the image rotation zero point of system equipment before use, does not need to calibrate the influence of the motion direction of each motion platform on the image rotation, and can greatly save time and cost and has high reliability in use.

Drawings

Fig. 1 is a schematic layout diagram of a method for acquiring a miss distance of a stigmator applied to a photoelectric tracking device, where 1 is a primary mirror, 2 is a laser, 3 is a beam collimator, 4 is a reference parallel light source, 5 is a pyramid mirror, 6 is a secondary mirror, and 7 is a detection system.

Fig. 2 is a schematic diagram of the telescope (pitch axis system) and detector coordinate system.

FIG. 3 is a schematic diagram of coordinate rotation solution of stigmation rotation target amount.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to specific embodiments and the accompanying drawings.

The invention provides a method for acquiring the miss distance of a stigmation spin applied to photoelectric tracking equipment, which comprises the following steps: in the systemThe front end of the entrance pupil couples the collimated laser beam into a photoelectric tracking device system through a laser 2, a beam collimator 3 and a pyramid 5; the laser 2 and the beam collimating mirror 3 form a reference parallel light source 4, before the tracking device starts to track the target, the image point position information of the reference laser beam on the detector target surface coordinate system of the detection system 7 is marked and recorded, and a vector OP is formed by the image point position information and the zero point of the detector target surface coordinate system₀(ii) a When the target image enters the detector of the detection system 7, the image processing system acquires the original miss distance information of the target with image rotation under the target surface coordinate system of the detector, detects the position of the reference laser image point from the moment, and forms a vector OP with the zero point of the target surface coordinate system of the detector₁Calculating a vector OP₀And vector OP₁The included angle beta of (a). Form a coordinate rotation matrix R from the angle beta_βLeft-hand multiplying the original miss distance information (gamma) of the target_y,γ_z) To obtain the information (gamma) of the amount of the stigmatic miss_y1,γ_z1)。

The method comprises the following specific steps:

the first step is as follows: according to fig. 1 and fig. 2, a schematic layout diagram of a reference laser light path and a schematic diagram of a telescope (i.e. a pitch axis system) and a detector coordinate system are provided for the method for acquiring the miss distance of the image rotation elimination in the photoelectric tracking device, wherein a reference parallel light source 4 composed of a small laser 2 and a beam collimator lens 3 is installed at the front end of the photoelectric tracking device, and the installation position is shown in fig. 2; the collimated laser light is redirected back into the tracking system by a pyramid 5 mounted above the electro-optical tracking device as shown in figure 1. Fig. 1 shows the overall layout of the reference laser light path. Figure 2 shows the coordinate systems of the telescope and detector, both using the right hand coordinate system.

The second step is that: according to fig. 2, a schematic diagram of the coordinate systems of the telescope (i.e. the pitch axis system) and the detector of the present invention is provided, and the motion platforms of the equipment system, such as the azimuth axis system and the pitch axis system, are rotated to keep the coordinate system of the telescope and the coordinate system of the detector consistent. Initially adjusting the angle between the collimated laser source and the system visual axis to enable the image point of the collimated laser to be located at the position of 1 point, namely the zero point position of the detector coordinate system, and indicating that the collimated laser beam is consistent with the system visual axis at the moment; adjustment alignmentThe angle between the straight laser source and the system visual axis makes the image point of the collimated laser move to the 2 o 'clock or 2' clock position. The 2 point and 2 'point positions are located outside the view field of the system 2/3, on one hand, the 2 point and the 2' point positions are far away from the target image point, the target imaging and the extraction of the miss distance are prevented from being influenced, on the other hand, the distance from the zero point O of the detector coordinate can improve the vector OP₀Sum vector OP₁The resolution accuracy of (2).

The third step: according to the invention, a coordinate system schematic diagram of a telescope (namely a pitching axis system) and a detector and a coordinate rotation solving schematic diagram of a de-imaging rotation miss amount are respectively provided according to the figure 2 and the figure 3, a detector image processing system extracts, calibrates and records the 2 point or 2' point position (shown in the figure 2) of a collimated laser image, and the image point is equal to the collimated laser image point P in the figure 3₀(y, z) as shown in FIG. 3, forms a vector OP with the zero point O (0,0) of the probe target surface coordinate system₀. Fig. 3 shows the position miss information of the reference laser and the target image point on the target surface of the system detector.

The fourth step: according to the schematic diagram of the coordinate rotation solving of the image rotation miss distance provided by the invention in fig. 3, when the target image enters the system detector, the image processing system acquires the original miss distance information (gamma) of the target with image rotation in the target surface coordinate system of the detector_y,γ_z) Detecting the position P of the reference laser image point from the time₁(y ', z') forming a vector OP with the zero O of the coordinate system of the target surface of the detector₁。

The fifth step: FIG. 3 is a schematic diagram of the coordinate rotation solution of the stigmatic miss distance of the present invention, which is represented by the angle equation β ═ acos (OP)₀,OP₁)＝(OP₀·OP₁)/(|OP₀|·|OP₁I) calculating the vector OP₀And vector OP₁The included angle beta of (a). Judging whether the included angle beta is clockwise or anticlockwise by cross multiplication of two vectors, and setting a vector OP₀Two elements in the sequence are (y, z), vector OP₁The two elements are (y ', z'), and the cross product of the two vectors is calculated to be OP₀×OP₁(y · z ') - (y' · z). If cross product OP₀×OP₁>0, the included angle beta is anticlockwise, the coordinate rotation matrix is R_β＝[cosβ,sinβ；-sinβ,cosβ]. If cross product OP₀×OP₁<0, indicating that the included angle beta is clockwise, the coordinate rotation matrix is R_β＝[cos(-β),sin(-β)；-sin(-β),cos(-β)]。

And a sixth step: according to FIG. 3, a schematic diagram of solving the coordinate rotation of the stigmation target amount of the present invention, a coordinate rotation matrix R is provided_βLeft-hand multiplication of original miss distance information (gamma) of target_y,γ_z) Obtaining the miss distance information (gamma) of the stigmation_y1,γ_z1)＝R_β·(γ_y,γ_z)。

The embodiments described above are only for explaining the present invention, the scope of protection of the present invention shall include the whole contents of the claims, and the whole contents of the claims of the present invention shall be realized by those skilled in the art of the embodiments.

Claims

1. An image rotation-miss amount acquisition method applied to photoelectric tracking equipment is characterized by comprising the following steps: a laser beam is emitted as reference light, and the collimated laser beam is coupled and introduced into a photoelectric tracking equipment system by a laser, a beam collimator and a pyramid lens at the front end of an entrance pupil of the system; before the tracking device begins to track the target, calibrating and recording the image point position information P of the reference laser beam on the coordinate system of the target surface of the detector₀(y, z) and zero point O (0,0) of the coordinate system of the target surface of the detector form a vector OP₀(ii) a The target image enters a system detector, and an image processing system acquires the original miss distance information (gamma) of the target with image rotation under a target surface coordinate system of the detector_y,γ_z) Detecting the position P of the reference laser image point from the time₁(y ', z') forming a vector OP with the zero O of the coordinate system of the target surface of the detector₁Calculating a vector OP₀And vector OP₁The included angle beta of; form a coordinate rotation matrix R from the angle beta_βFrom a matrix R_βLeft-hand multiplication of original miss distance information (gamma) of target_y,γ_z) To obtain the information (gamma) of the amount of the stigmatic miss_y1,γ_z1)；

The introduced laser beam needs to adjust the angle between the beam and the visual axis of the system according to the visual field omega of the equipment system, so that the image point position P of the reference laser on the detector₀(y, z) is more than two-thirds of the field of view from the detector coordinate zero point O (0, 0).