Rapid installation and adjustment method for large-aperture schlieren light path

Abstract

The invention relates to the field of optical system installation and adjustment, and provides a rapid installation and adjustment method for a large-aperture schlieren optical path in order to solve the problems that an existing schlieren optical path is long in installation and adjustment period, low in precision, poor in stability and the like, and the rapid installation and adjustment method comprises the following steps that the schlieren optical path is preliminarily set up according to the theoretical angle of system design; a first eight-line instrument is arranged on a light path between the transmitting end primary mirror and the imaging end primary mirror; adjusting the spatial positions of the transmitting-end primary mirror and the imaging-end primary mirror through a first eight-line instrument, so that the centers of the two primary mirrors are located on the same horizontal plane; adjusting the postures of the transmitting end primary mirror and the transmitting end secondary mirror through the second eight-line instrument, so that the image of the first eight-line instrument is overlapped with the image of the second eight-line instrument; the postures of the imaging end primary mirror and the imaging end secondary mirror are adjusted through the third eight-line instrument, so that the image of the first eight-line instrument coincides with the image of the third eight-line instrument; the clearest image of the resolution plate is found by moving the camera, the spatial position of the camera is determined, and rapid adjustment of the large-aperture schlieren optical path is completed.

Description

Technical Field

[0001] The invention relates to the field of optical system adjustment, and in particular to a rapid adjustment method for a large-aperture schlieren optical path. Background Art

[0002] The Schlieren imaging system uses the fact that the refractive index gradient of light in the measured flow field is proportional to the airflow density of the flow field for imaging testing. It has the characteristics of high sensitivity, good imaging quality, and fast measurement speed. Usually, the imaging optical path of the Schlieren imaging system is a "Z"-shaped optical path. In the process of assembling and adjusting the Schlieren imaging system, the difficulty of the installation and adjustment mainly lies in the rapid penetration of multiple sections of the optical path.

[0003] The current adjustment method of the Schlieren imaging system is: by placing a cross-grained plate at the center of the light inlet of the primary mirror, passing the cross-grained plate through the center of the primary mirror, and then using a theodolite to observe the image of the cross-grained plate in the emission direction of the secondary mirror; when using the theodolite for observation, it is also necessary to initially locate the position and posture of the theodolite. This step will cause the existing Schlieren optical path adjustment method to waste more time and energy in systems with large aperture primary mirrors and large adjustment space, resulting in problems such as long adjustment cycle, low adjustment accuracy, and poor stability of the adjustment equipment, thereby failing to ensure that the various optical index parameters in the Schlieren imaging system can meet the system requirements. Summary of the invention

[0004] The present invention proposes a rapid adjustment method for a large-aperture Schlieren optical path to solve the technical problems of the existing Schlieren imaging system adjustment method, such as a long adjustment period, low adjustment accuracy, and poor stability of the adjustment equipment.

[0005] To achieve the above objectives, the technical solution proposed by the present invention is:

[0006] A fast adjustment method for a large-aperture Schlieren optical path, which is special in that it includes the following steps:

[0007] S1. Preliminarily build a large-aperture Schlieren optical path according to the theoretical perspective of system design; set up the first eight-line instrument on the optical path between the primary mirror at the transmitting end and the primary mirror at the imaging end;

[0008] S2, adjusting the spatial position of the imaging end primary mirror so that the centers of the transmitting end primary mirror, the first eight-line instrument and the imaging end primary mirror are located on the same horizontal optical axis;

[0009] S3, installing the second eight-ray instrument on the optical axis between the light source and the slit, adjusting the postures of the primary mirror at the transmitting end and the secondary mirror at the transmitting end, so that the outgoing light of the second eight-ray instrument coincides with the outgoing light of the first eight-ray instrument after being imaged by the secondary mirror at the transmitting end;

[0010] S4, installing the third eight-line instrument on the optical axis between the imaging objective lens and the knife edge, adjusting the postures of the imaging end primary mirror and the imaging end secondary mirror, so that the outgoing light of the third eight-line instrument coincides with the outgoing light of the first eight-line instrument after being imaged by the imaging end secondary mirror;

[0011] S5. Place a resolution board on the optical path between the transmitting end and the imaging end. After turning on the light source, move the camera to find the clearest image of the resolution board received, so as to determine the spatial position of the camera and complete the rapid adjustment of the large-aperture Schlieren optical path.

[0012] Further, S1.1, preliminarily construct the Schlieren optical path according to the theoretical perspective of system design; the large-aperture Schlieren optical path includes a light source, a lens, a slit, a transmitting end, an imaging end, a knife edge, an imaging objective lens and a camera arranged in sequence along the light source emission light path;

[0013] S1.2. Install the first eight-line instrument on a two-dimensional lifting platform, and then place the two-dimensional lifting platform between the main mirror at the transmitting end and the main mirror at the imaging end, and the first eight-line instrument is located on the optical path between the main mirror at the transmitting end and the main mirror at the imaging end.

[0014] Further, S2.1, adjusting the posture of the first eight-line instrument so that the horizontal line of the first eight-line instrument is parallel to the ground;

[0015] S2.2, adjust the height of the first eight-line instrument so that the cross beam emitted by the first eight-line instrument coincides with the center of the primary mirror at the transmitting end;

[0016] S2.3. Adjust the spatial position of the imaging end main mirror so that the center of the imaging end main mirror coincides with the outgoing light beam of the first eight-line instrument, and finally the centers of the transmitting end main mirror, the first eight-line instrument and the imaging end main mirror are located on the same horizontal optical axis.

[0017] Further, S3.1, adjusting the installation position of the slit so that it is located at the focus of the light source, and installing the second eight-line instrument on the optical axis between the light source and the slit;

[0018] S3.2, adjust the posture of the primary mirror at the transmitting end so that the outgoing light of the first eight-line instrument is located at the center position of the secondary mirror at the transmitting end;

[0019] S3.3. Adjust the posture of the secondary mirror at the transmitting end so that the outgoing light of the second eight-line instrument coincides with the outgoing light of the first eight-line instrument after being imaged by the secondary mirror at the transmitting end, thereby completing the adjustment of the optical path at the transmitting end.

[0020] Furthermore, in step S3, the angle α1 between the incident light beam of the second eight-line instrument and the outgoing light beam of the first eight-line instrument, the angle α2 between the optical axis of the light source and the primary mirror at the transmitting end, and the angle α3 between the optical axis of the imaging objective lens and the primary mirror at the imaging end satisfy the following formula:

[0021] α1=α2=α3.

[0022] Further, S4.1, adjusting the installation position of the knife edge to be conjugate with the slit position, and installing the third eight-line instrument on the optical axis between the imaging objective lens and the knife edge;

[0023] S4.2, adjust the optical axis of the primary mirror at the imaging end so that the outgoing light of the first eight-ray instrument is located at the center of the secondary mirror at the imaging end;

[0024] S4.3. Adjust the optical axis of the secondary mirror at the imaging end so that the outgoing light of the third eight-line instrument coincides with the outgoing light of the first eight-line instrument after being imaged by the secondary mirror at the imaging end, thereby completing the optical path adjustment at the imaging end.

[0025] Further, S5.1, remove the first eight-wire instrument, the second eight-wire instrument, and the third eight-wire instrument;

[0026] S5.2. Place a resolution plate on the optical path between the emission end and the imaging end, and turn on the light source;

[0027] S5.3. Move the camera back and forth along the optical axis of the knife edge and the imaging objective lens, observe the image of the resolution plate received by the camera, and find the clearest image received, so as to determine the spatial position of the camera and complete the rapid adjustment of the large-aperture Schlieren optical path.

[0028] Furthermore, the transmitting end primary mirror, the transmitting end secondary mirror, the imaging end primary mirror, the imaging end secondary mirror, the first eight-line instrument, the second eight-line instrument and the third eight-line instrument can all be adjusted in azimuth and pitch to achieve adjustment of pitch, yaw and front and rear position movement.

[0029] Beneficial effects of the present invention:

[0030] [1] The invention discloses a rapid adjustment method for large-aperture schlieren optical path. The operation process is simple and easy to implement. The entire optical system is adjusted by two eight-line instruments and a two-dimensional lifting platform, which effectively reduces the problems of poor adjustment stability caused by the diversity of adjustment and measurement equipment, effectively shortens the adjustment cycle, improves the adjustment accuracy, and makes the adjustment process of the entire optical system simpler and more efficient. It also ensures that the optical index parameters after adjustment meet the system requirements, and has strong practicality and reliability.

[0031] [2] The present invention adjusts the main mirror at the transmitting end and the main mirror at the imaging end to the same horizontal plane through the first eight-line instrument, and now pierces the center of the entire system together in space, thereby reducing the accumulation of subsequent penetration errors of each component causing the entire system to tilt; at the same time, it also improves the assembly efficiency. The main mirrors at the transmitting end and the imaging end share a reference, which can effectively reduce system errors, improve installation accuracy, and shorten installation time. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1A schematic diagram of an optical path of an embodiment of a method for quickly adjusting a large-aperture schlieren optical path according to the present invention;

[0033] Figure 2 It is a schematic diagram of the positions of the transmitting end, the first eight-line instrument and the imaging end in step 1 of an embodiment of a method for rapid adjustment of a large-aperture schlieren optical path of the present invention;

[0034] Figure 3 This is a schematic diagram of the assembly structure of the transmitter in an embodiment of the present invention;

[0035] Figure 4 This is a schematic diagram of the assembly structure of the transmitting end and the imaging end in an embodiment of the present invention;

[0036] Figure 5 Schematic diagram of optical path imaging of the emitting end and the imaging end in an embodiment of the present invention;

[0037] Reference numerals:

[0038] 1-primary mirror at the transmitting end, 2-secondary mirror at the transmitting end, 3-two-dimensional lifting platform, 4-first octet, 5-second octet, 6-primary mirror at the imaging end, 7-secondary mirror at the imaging end, 8-resolution board, 9-light source, 10-imaging objective lens, 11-slit, 12-knife edge, 13-camera, 14-lens, 15-third octet. DETAILED DESCRIPTION

[0039] like Figure 1 As shown, the large-aperture schlieren optical path includes a light source 9, a lens 14, a slit 11, a transmitting end, an imaging end, a knife edge 12, an imaging objective lens 10 and a camera 13 arranged in sequence along the transmitting light path of the light source 9; wherein the transmitting end includes a transmitting end primary mirror 1 and a transmitting end secondary mirror 2, and the imaging end includes an imaging end primary mirror 6 and an imaging end secondary mirror 7; the transmitting end primary mirror 1 and the imaging end primary mirror 6 are arranged relative to the same optical axis, and the knife edge 12 and the slit 11 are conjugate in position.

[0040] A fast adjustment method for a large-aperture Schlieren optical path comprises the following steps:

[0041] S1. Preliminarily build a large-aperture Schlieren optical path according to the theoretical perspective of system design; set up a first eight-line instrument 4 on the optical path between the transmitting end primary mirror 1 and the imaging end primary mirror 6; Figure 2 As shown, the first eight-line instrument 4 is installed on the two-dimensional lifting platform 3, and then the two-dimensional lifting platform 3 is placed between the transmitting end main mirror 1 and the imaging end main mirror 6, and the first eight-line instrument 4 is located on the optical path between the transmitting end main mirror 1 and the imaging end main mirror 6;

[0042] S2, determine the positions of the transmitting end primary mirror 1 and the imaging end primary mirror 6 to ensure that the heights of the transmitting end and the imaging end are on the same horizontal plane;

[0043] S2.1. Adjust the posture of the first eight-line instrument 4 so that the horizontal line of the first eight-line instrument 4 is parallel to the ground;

[0044] S2.2, adjusting the height of the first eight-line instrument 4 so that the cross beam emitted by the first eight-line instrument 4 coincides with the center of the primary mirror 1 at the transmitting end;

[0045] S2.3. Adjust the spatial position of the imaging end main mirror 6 so that the center of the imaging end main mirror 6 coincides with the outgoing light beam of the first eight-line instrument 4, and finally the centers of the transmitting end main mirror 1, the first eight-line instrument 4 and the imaging end main mirror 6 are located on the same horizontal optical axis.

[0046] S3, transmitter optical path adjustment

[0047] S3.1, if Figure 3 As shown, the installation position of the slit 11 is adjusted so that it is located at the focus of the light source 9, and the second eight-line instrument 5 is installed on the optical axis between the light source 9 and the slit 11;

[0048] S3.2, adjusting the posture of the primary mirror 1 at the transmitting end so that the outgoing light of the first eight-line instrument 4 is located at the center position of the secondary mirror 2 at the transmitting end;

[0049] S3.3. Adjust the posture of the secondary mirror 2 at the transmitting end so that the outgoing light of the second eight-line instrument 5 coincides with the outgoing light of the first eight-line instrument 4 after being imaged by the secondary mirror 2 at the transmitting end, thereby completing the adjustment of the optical path at the transmitting end.

[0050] Among them, the angle α1 between the outgoing light beam of the first eight-line instrument 4 and the incident light beam of the second eight-line instrument 5 = the angle α2 between the optical axis between the light source 9 and the transmitting end main mirror 1 = the angle α3 between the optical axis between the imaging objective lens 10 and the imaging end main mirror 6.

[0051] S4, Imaging end optical path adjustment

[0052] S4.1, if Figure 4 As shown, the installation position of the knife edge 12 is adjusted to be conjugate with the position of the slit 11, and the third eight-line instrument 15 is installed on the optical axis between the imaging objective lens 10 and the knife edge 12;

[0053] S4.2, adjusting the posture of the primary mirror 6 at the imaging end so that the outgoing light of the first eight-line instrument 4 is located at the center position of the secondary mirror 7 at the imaging end;

[0054] S4.3, adjusting the posture of the imaging end secondary mirror 7, so that the outgoing light of the third eight-line instrument 15 coincides with the outgoing light of the first eight-line instrument 4 after being imaged by the imaging end secondary mirror 7, thereby completing the optical path adjustment of the imaging end;

[0055] S5. System optical path adjustment

[0056] S5.1, remove the first eight-wire instrument 4, the second eight-wire instrument 5 and the third eight-wire instrument 15;

[0057] S5.2. Place a resolution plate 8 on the optical path between the emitting end and the imaging end, turn on the light source 9, and the optical path between the emitting end and the imaging end is as follows: Figure 5 As shown;

[0058] S5.3, move the camera 13 back and forth along the optical axis of the knife edge 12 and the imaging objective lens 10, observe the image of the resolution plate 8 received by the camera 13, and find the clearest image received, so as to determine the spatial position of the camera 13 and complete the rapid adjustment of the large-aperture Schlieren optical path.

Claims

1. A fast adjustment method for a large-aperture Schlieren optical path, characterized in that: The following steps are involved: S1. Preliminarily construct a large-aperture Schlieren optical path according to the theoretical perspective of system design; set up a first eight-line instrument (4) on the optical path between the transmitting end primary mirror (1) and the imaging end primary mirror (6); S2, adjusting the spatial position of the imaging end primary mirror (6) so that the centers of the transmitting end primary mirror (1), the first eight-line instrument (4) and the imaging end primary mirror (6) are located on the same horizontal optical axis; S3, installing the second eight-line instrument (5) on the optical axis between the light source (9) and the slit (11), adjusting the postures of the primary mirror (1) at the transmitting end and the secondary mirror (2) at the transmitting end, so that the outgoing light of the second eight-line instrument (5) is imaged by the secondary mirror (2) at the transmitting end and coincides with the outgoing light of the first eight-line instrument (4); S4, installing the third eight-line instrument (15) on the optical axis between the imaging objective lens (10) and the knife edge (12), adjusting the postures of the imaging end primary mirror (6) and the imaging end secondary mirror (7), so that the outgoing light of the third eight-line instrument (15) coincides with the outgoing light of the first eight-line instrument (4) after being imaged by the imaging end secondary mirror (7); S5. Place a resolution plate (8) on the optical path between the transmitting end and the imaging end, turn on the light source (9), and then move the camera (13) to find the clearest image of the received resolution plate (8), thereby determining the spatial position of the camera (13) and completing the rapid adjustment of the large-aperture Schlieren optical path.

2. According to claim 1, a rapid adjustment method for a large-aperture Schlieren optical path is characterized in that: Step S1 is specifically as follows: S1.

1. Preliminarily constructing a Schlieren light path according to the theoretical perspective of system design; the large-aperture Schlieren light path includes a light source (9), a lens (14) arranged in sequence along the emission light path of the light source (9), a slit (11), an emission end, an imaging end, a knife edge (12), an imaging objective lens (10) and a camera (13); S1.

2. Install the first eight-line instrument (4) on the two-dimensional lifting platform (3), and then place the two-dimensional lifting platform (3) between the main mirror (1) at the transmitting end and the main mirror (6) at the imaging end, and the first eight-line instrument (4) is located on the optical path between the main mirror (1) at the transmitting end and the main mirror (6) at the imaging end.

3. According to claim 2, a fast adjustment method for a large-aperture Schlieren optical path is characterized in that: Step S2 is specifically as follows: S2.

1. Adjust the posture of the first eight-line instrument (4) so ​​that the horizontal line of the first eight-line instrument (4) is parallel to the ground; S2.2, adjusting the height of the first eight-line instrument (4) so ​​that the cross beam emitted by the first eight-line instrument (4) coincides with the center of the primary mirror (1) at the transmitting end; S2.

3. Adjust the spatial position of the imaging end main mirror (6) so that the center of the imaging end main mirror (6) coincides with the outgoing light beam of the first eight-line instrument (4), and finally the centers of the transmitting end main mirror (1), the first eight-line instrument (4) and the imaging end main mirror (6) are located on the same horizontal optical axis.

4. According to claim 3, a fast adjustment method for a large-aperture Schlieren optical path is characterized in that: Step S3 is specifically as follows: S3.

1. Adjust the installation position of the slit (11) so that it is located at the focus of the light source (9), and install the second eight-line instrument (5) on the optical axis between the light source (9) and the slit (11); S3.2, adjusting the posture of the primary mirror (1) at the transmitting end so that the outgoing light of the first eight-line instrument (4) is located at the center position of the secondary mirror (2) at the transmitting end; S3.

3. Adjust the posture of the secondary mirror (2) at the transmitting end so that the outgoing light of the second eight-line instrument (5) coincides with the outgoing light of the first eight-line instrument (4) after being imaged by the secondary mirror (2) at the transmitting end, thereby completing the adjustment of the optical path at the transmitting end.

5. According to claim 3, a fast adjustment method for a large-aperture Schlieren optical path is characterized in that: In step S3, the angle α1 between the incident light beam of the second eight-line instrument (5) and the outgoing light beam of the first eight-line instrument (4), the angle α2 between the optical axis of the light source (9) and the transmitting end primary mirror (1), and the angle α3 between the optical axis of the imaging objective lens (10) and the imaging end primary mirror (6) satisfy the following formula: α1＝α2＝α3。 6. A fast adjustment method for a large-aperture Schlieren optical path according to claim 3, characterized in that: Step S4 is specifically as follows: S4.

1. Adjust the installation position of the knife edge (12) so that it is conjugate with the position of the slit (11), and install the third eight-line instrument (15) on the optical axis between the imaging objective lens (10) and the knife edge (12); S4.2, adjusting the posture of the primary mirror (6) at the imaging end so that the outgoing light of the first eight-line instrument (4) is located at the center of the secondary mirror (7) at the imaging end; S4.

3. Adjust the posture of the imaging end secondary mirror (7) so that the outgoing light of the third eight-line instrument (15) coincides with the outgoing light of the first eight-line instrument (4) after being imaged by the imaging end secondary mirror (7), thereby completing the imaging end optical path adjustment.

7. A fast adjustment method for a large-aperture Schlieren optical path according to claim 6, characterized in that: Step S5 is specifically as follows: S5.1, remove the first eight-wire instrument (4), the second eight-wire instrument (5) and the third eight-wire instrument (15); S5.2, place a resolution plate (8) on the optical path between the emission end and the imaging end, and turn on the light source; S5.3, move the camera (13) back and forth along the optical axis of the knife edge (12) and the imaging objective lens (10), observe the image of the resolution plate (8) received by the camera (13), and find the clearest image received, thereby determining the spatial position of the camera (13) and completing the rapid adjustment of the large-aperture Schlieren optical path.

8. A fast adjustment method for a large-aperture Schlieren optical path according to claim 7, characterized in that: The transmitting end primary mirror (1), the transmitting end secondary mirror (2), the imaging end primary mirror (6), the imaging end secondary mirror (7), the first eight-line instrument (4), the second eight-line instrument (5) and the third eight-line instrument (15) can all be adjusted in azimuth and elevation.

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