阅读说明：本技术 快门集成装置、控制系统及时序控制方法 (Shutter integrated device, control system and time sequence control method ) 是由 黄振新 陈植 李腾骥 邓吉龙 熊贵天 李阳 于 2021-03-31 设计创作，主要内容包括：本发明公开了快门集成装置、控制系统及时序控制方法,快门集成装置包括集成装置底板、第一CCD相机、第二CCD相机、第一快门开关、第二快门开关和分光装置；第一CCD相机、第二CCD相机和分光装置均安装在集成装置底板上；第一快门开关设置在第一CCD相机上,第二快门开关设置在第二CCD相机上；第一快门开关、第二快门开关分别与控制系统连接等。本发明避免了因相机位置及状态差异导致的调试困难,提升了效率,消除了系统误差,实现了MHz曝光,且曝光图像之间互不干扰和影响,提升了系统整体精度及稳定性。(The invention discloses a shutter integrated device, a control system and a time sequence control method, wherein the shutter integrated device comprises an integrated device bottom plate, a first CCD camera, a second CCD camera, a first shutter switch, a second shutter switch and a light splitting device; the first CCD camera, the second CCD camera and the light splitting device are all arranged on the integrated device bottom plate; the first shutter switch is arranged on the first CCD camera, and the second shutter switch is arranged on the second CCD camera; the first shutter switch and the second shutter switch are respectively connected with the control system and the like. The invention avoids the debugging difficulty caused by the position and state difference of the camera, improves the efficiency, eliminates the system error, realizes the MHz exposure, does not interfere and influence the exposure images, and improves the integral precision and stability of the system.)

1. A shutter integrated device is characterized by comprising an integrated device bottom plate (3), a first CCD camera (4), a second CCD camera (5), a first shutter switch (6), a second shutter switch (7) and a light splitting device (8); the first CCD camera (4), the second CCD camera (5) and the light splitting device (8) are all arranged on the integrated device bottom plate (3); the first shutter switch (6) is arranged on the first CCD camera (4), and the second shutter switch (7) is arranged on the second CCD camera (5); the first shutter switch (6) and the second shutter switch (7) are respectively electrically connected with the camera control system.

2. The shutter integrated device according to claim 1, wherein the integrated device base plate (3) comprises a six-degree-of-freedom adjustable optical positioning structure for assisting in fixing the position of the first CCD camera (4) and the second CCD camera (5).

3. A control system for a camera, comprising the shutter integrated device as claimed in any one of claims 1 or 2, further comprising a synchronization controller, an interface device and a computer, wherein the shutter integrated device is electrically connected to the synchronization controller, the synchronization controller is electrically connected to the interface device, and the interface device is electrically connected to the computer.

4. The control system of camera of claim 3, wherein the synchronization controller comprises a DG645 synchronization controller.

5. The control system of the camera according to claim 3, wherein the interface means includes any one or more of an ethernet interface, a GPIB interface, and an RS-232 interface.

6. A timing control method based on the shutter integrated device of any one of claims 1 or 2 or the control system of the camera of any one of claims 3, 4 or 5, and further comprising a control program for executing the steps of: controlling the first shutter switch (6) so that the first shutter switch (6) is in an open state when the first pulse laser light and the second pulse laser light are emitted, and the first shutter switch (6) is in a closed state when the third pulse laser light and the fourth pulse laser light are emitted; and controlling the second shutter switch (7) to be in a normally open state.

Technical Field

The invention relates to the field of laser speed measurement, in particular to a shutter integrated device, a control system and a time sequence control method.

Background

In the conventional Particle Image Velocimetry (PIV) technology in the technical field of laser Velocimetry, generally, only the velocity value of the Particle can be obtained, and it is difficult to obtain the Particle acceleration value with higher precision. The four pulse lasers can sequentially emit four pulse laser beams, tracking particle images illuminated by the four pulse laser beams are respectively shot by using 2 double-exposure Charge Coupled Device (CCD) cameras, the speed of tracking particles is calculated according to the obtained cross-frame tracking particle images, and the acceleration is further calculated.

However, since the time interval between the four pulse laser beams is short, and the time of the second exposure of the conventional double-exposure CCD camera is long, the CCD camera can simultaneously capture the trace particle images irradiated by the third pulse laser beam and the fourth pulse laser beam when capturing the trace particle image irradiated by the second pulse laser beam, which causes inaccuracy of the acquired cross-frame particle pair, and affects the accuracy and/or precision of the particle velocity calculated based on the cross-frame particle pair. And because at least two double-exposure CCD cameras are required to work synchronously, if the positions of the optical centers of the two CCD cameras are not set, displacement errors exist between tracing particle image pairs directly, and calculation results are influenced.

Disclosure of Invention

The invention aims to overcome the defects of the prior art, provides a shutter integrated device, a control system and a time sequence control method, avoids the debugging difficulty caused by the position and state difference of cameras, improves the efficiency, ensures that four laser pulses with the same energy pass through the light transmittance of the two cameras to be consistent, eliminates the system error, realizes the MHz exposure, does not interfere and influence each other among the exposed images, and improves the overall precision and stability of the system.

The purpose of the invention is realized by the following scheme:

a shutter integrated device comprises an integrated device bottom plate, a first CCD camera, a second CCD camera, a first shutter switch, a second shutter switch and a light splitting device; the first CCD camera, the second CCD camera and the light splitting device are all arranged on the integrated device bottom plate; the first shutter switch is arranged on the first CCD camera, and the second shutter switch is arranged on the second CCD camera; the first shutter switch and the second shutter switch are respectively electrically connected with the camera control system.

Furthermore, the integrated device bottom plate comprises a six-degree-of-freedom adjustable optical positioning structure for assisting in fixing the positions of the first CCD camera and the second CCD camera.

A control system of a camera comprises the shutter integrated device, a synchronous controller, an interface device and a computer, wherein the shutter integrated device is electrically connected with the synchronous controller, the synchronous controller is electrically connected with the interface device, and the interface device is electrically connected with the computer.

Further, the synchronization controller comprises a DG645 synchronization controller.

Further, the interface means comprises any one or more of an ethernet interface, a GPIB interface and an RS-232 interface.

A timing control method based on the shutter integrated device or the control system based on the camera, and further comprising a control program for executing the steps of: controlling the first shutter switch to be in an open state when the first pulse laser and the second pulse laser emit light, and to be in a closed state when the third pulse laser and the fourth pulse laser emit light; and controlling the second shutter switch to be in a normally open state.

The invention has the beneficial effects that:

(1) the integrated device is designed in the embodiment of the invention, the angles of the reflecting mirrors of the light splitting devices and the positions of the CCD cameras can be reasonably designed, so that the fields of view of the laser pulse light reaching the cameras after entering the device are basically consistent, and the six-degree-of-freedom adjustable precision mechanism is used for fine adjustment, thereby avoiding the debugging difficulty caused by the difference of the positions and the states of the cameras and improving the efficiency;

(2) in the embodiment of the invention, two shutter switches are integrated at the same time, so that the light transmittance of the quartic laser pulses with the same energy passing through the two cameras is ensured to be consistent, and the system error is eliminated;

(3) according to the embodiment of the invention, the synchronous controller is combined with the time sequence control, the MHz exposure of the two cameras is realized, and the exposure images are not interfered and influenced mutually.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic structural diagram of an embodiment of the present invention;

FIG. 2 is a timing control diagram according to an embodiment of the present invention;

in the figure, 1-four pulse laser, 2-light guide arm, 3-integration device bottom plate, 4-first CCD camera, 5-second CCD camera, 6-first shutter switch, 7-second shutter switch and 8-light splitting device.

Detailed Description

All features disclosed in all embodiments in this specification, or all methods or process steps implicitly disclosed, may be combined and/or expanded, or substituted, in any way, except for mutually exclusive features and/or steps.

In the invention, MHz describes the exposure frequency of the camera, namely the time interval between camera frames is microsecond order, so the frame frequency is MHz.

As shown in fig. 1-2, a shutter integrated device includes an integrated device bottom plate 3, a first CCD camera 4, a second CCD camera 5, a first shutter switch 6, a second shutter switch 7 and a light splitting device 8; the first CCD camera 4, the second CCD camera 5 and the light splitting device 8 are all arranged on the integrated device bottom plate 3; a first shutter switch 6 is provided on the first CCD camera 4, and a second shutter switch 7 is provided on the second CCD camera 5; the first shutter switch 6 and the second shutter switch 7 are respectively electrically connected with the camera control system.

Further, the integrated device bottom plate 3 includes a six-degree-of-freedom adjustable optical positioning structure for assisting in fixing the positions of the first CCD camera 4 and the second CCD camera 5.

A control system of a camera comprises the shutter integrated device, a synchronous controller, an interface device and a computer, wherein the shutter integrated device is electrically connected with the synchronous controller, the synchronous controller is electrically connected with the interface device, and the interface device is electrically connected with the computer.

Further, the synchronization controller comprises a DG645 synchronization controller.

Further, the interface means comprises any one or more of an ethernet interface, a GPIB interface and an RS-232 interface.

A timing control method based on the shutter integrated device or the control system based on the camera, and further comprising a control program for executing the steps of: controlling the first shutter switch 6 so that the first shutter switch 6 is in an open state when the first pulse laser light and the second pulse laser light are emitted, and the first shutter switch 6 is in a closed state when the third and fourth pulse laser light are emitted; the second shutter switch 7 is controlled to be in a normally open state.

For the problems mentioned in the background, optionally, two CCD cameras may be respectively arranged on two sides of the shooting area along a direction perpendicular to the light plane of the laser sheet, and the magnifications of the two CCD cameras are made to be the same by adjusting the central points of the mirror surfaces of the two CCD cameras to be located on a straight line and adjusting the size of the field of view. And then, a shutter switch device is added on one camera, and the shutter switch is controlled to be closed at the third pulse and the fourth pulse, so that the second image of the first camera only captures the second pulse. However, the above solution has the following disadvantages: the two CCD cameras are respectively arranged on the tripod, the flexibility is poor, the speed measurement technology requires that the central point of the mirror surface is positioned on a straight line, and the size of the view field, namely the magnification, is required to be consistent, so that great difficulty is brought to the adjustment of the position of the cameras, the efficiency is low and the precision is poor; the shutter switch has dead weight, the installation of the shutter switch causes the visual field and the focal plane of the camera to deviate, the overall stability of the system is poor, meanwhile, the light switch has certain influence on the transmittance of light, and the light transmittance error of the two CCD cameras is also caused.

In the embodiment of the invention, as shown in fig. 1, a four-pulse laser 1 sequentially emits four pulse laser beams, a light guide arm 2 irradiates the pulse laser beams on an observation area in a sheet light mode, and an integrated device bottom plate 3 comprises a six-degree-of-freedom adjustable precise optical positioning structure and can assist in fixing the positions of 2 CCD cameras; the first CCD camera 4 is responsible for shooting the first and second laser pulses; the second CCD camera 5 is responsible for shooting the third and fourth laser pulses; the first shutter switch 6 is closed under the control of the control device so that the pulsed light does not enter the first CCD camera 4 any more; the second shutter switch 7 is in a normally open state under the control of the control device; the spectroscopic device 8 outputs the received pulsed light information to the first CCD camera 4 and the second CCD camera 5, respectively.

In the working process, a large number of trace particles in an observation area move along with a flow field, scattering occurs under the action of pulse laser, scattered light enters a shutter integrated device, firstly enters a first CCD camera 4 and a second CCD camera 5 respectively under the action of a light splitting device 8, at the moment, the second CCD camera 5 does not respond, the first CCD camera 4 starts to work, 2 exposures are carried out to shoot trace particle images under the irradiation of a first pulse and a second pulse of the laser respectively, and before a third pulse of the laser, a first shutter switch 6 responds and is closed under a signal of a control device, so that the trace particle images irradiated by the third pulse and a fourth pulse laser beam cannot be shot by the first CCD camera 4.

In other embodiments of the present invention, a control apparatus for controlling four laser pulses emitted by a four-pulse laser to irradiate a trace particle at a time and to be photographed by 2 CCD cameras includes two DG645 synchronous controllers, DG645 is an eight-channel digital delay pulse generator, generates pulses of TTL amplitude through a high-precision circuit and digitally controls delay time thereof to output, and provides four independently controlled pulse outputs, up to eight delay logic conversions, delay resolutions of all channels are 5ps, jitter between each channel is less than 25ps, and a pulse frequency is 10MHz high. The DG645 can be connected to the computer through Ethernet, General Purpose Interface Bus (GPIB), and RS-232 interfaces. Since DG645 can provide lower jitter, higher accuracy, faster trigger frequency and more outputs, it is well suited for simultaneous timing control of the pulsed laser of a four-pulse laser, CCD camera exposure time and shutter switch in embodiments of the present invention.

The specific timing control is shown in fig. 2, where t0 is the system start time, t1 and t2 are the times when the first CCD camera 4 and the second CCD camera 5 start the first exposure, respectively, and t3, t4, t5, and t6 are the times of four pulses of the four-pulse laser, respectively, and the 6 time parameters are adjusted by the control program so that the four pulses fall into the four exposures, respectively. Without the shutter switch, it is obvious that the third and fourth pulsed lasers would appear together in the second exposure of the first CCD camera 4, obviously detrimental to the subsequent calculations. Therefore, the shutter switch 1 is controlled by t7 and t8 to be in an open state when the first and second pulses emit light, and in a closed state when the third and fourth pulses emit light, and the shutter switch 2 is in a normally open state, which is used to ensure that the laser pulses with the same capacity have the same light transmittance in both cameras.

In the acceleration measuring process, two eight-channel digital delay pulse generators are adopted to respectively control the double-exposure CCD camera and the four-pulse laser, so that the double-exposure CCD camera and the four-pulse laser are mutually matched, trace particle images under the irradiation of pulse laser with extremely short time intervals (usually microsecond level) can be obtained, four MHz-exposure particle images are further obtained, and then three trace particle speed values and two trace particle acceleration values are obtained. The embodiment of the invention has been preliminarily debugged and verified by tests, the scheme is feasible, and the result reaches the expected target.

The functionality of the present invention, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium, and all or part of the steps of the method according to the embodiments of the present invention are executed in a computer device (which may be a personal computer, a server, or a network device) and corresponding software. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, or an optical disk, exist in a read-only Memory (RAM), a Random Access Memory (RAM), and the like, for performing a test or actual data in a program implementation.