CN102564343B - Detection device for surface-shape errors of solar trench type curved surface reflector - Google Patents

Abstract

The solar trough-type curved surface reflective mirror surface shape error detection device relates to the field of mirror surface detection. It solves the problems that the detection process is cumbersome and time-consuming in the existing detection of the trough-type curved surface reflective mirror surface shape error, and it is not suitable for fast and online detection. At the same time, there are For the complex problem of subsequent image processing, this device includes a light source device, a self-calibration device, and an image acquisition and processing device; the light source device includes a laser, a beam expander and a beam splitter group; the beam emitted by the laser is expanded by the beam expander Then the beam is divided into beams and reflected by the beam splitter, and the test beam beamed by the beam splitter is projected onto the measured curved surface mirror, and the self-calibration beam reflected by the beam splitter is incident on the self-calibration device, and the self-calibration device Calibrate the parallelism of the test beam projected onto the tested curved mirror; the image acquisition and processing device receives the light spot information reflected by the tested curved mirror and judges the surface shape error of the tested curved mirror. The invention is easy to operate and has low cost.

Description

Surface error detection device of solar trough curved surface mirror

technical field

The invention relates to the field of mirror surface detection, in particular to a surface shape error detection device for a solar trough type curved surface reflector.

Background technique

In the field of solar energy utilization, in order to increase the flux density of solar radiation, solar concentrators are required. The trough concentrator is a widely used concentrating method in the field of solar energy utilization. It has been commercialized in some countries (such as Germany and Spain), but it is still in its infancy in my country. The trough concentrator is composed of multiple curved mirrors. The surface shape accuracy of the curved mirror determines the light concentrating performance of the trough concentrator, so it is very important to detect the surface error of the curved mirror. In order to realize batch and standardized production of trough-type curved surface reflectors, it is necessary to provide a detection method and device capable of quickly and on-line detection of surface shape errors of trough-type curved surface reflectors. The surface shape error of the trough curved mirror is expressed by the declination angle between the normal direction of a certain point on the mirror surface and the ideal normal direction of the point, and the error is generally on the order of milliradians.

At present, the detection methods of the surface shape error of the trough curved mirror mainly include laser point-by-point scanning method, photogrammetry method, reflection grid moiré fringe detection method and so on. The laser point-by-point scanning method is to use the laser beam to irradiate the measured curved mirror. After the laser beam is reflected by the curved mirror, it is projected on the receiving screen located at about 2 times the focal length of the curved mirror. By recording the laser beam on the receiving screen The projected position reverses the normal direction of the measured point. This method has high accuracy, but it requires a large number of point data collection, which is very time-consuming and is not suitable for fast and online detection of grooved curved surface mirrors. The photogrammetry method is to first paste a large number of marker points on the measured surface mirror, use the camera to image these marker points at different angles, solve the coordinates of the marker points through the spatial position relationship of the image point and the object point, and fit the surface The three-dimensional graphics of the reflector, the device is relatively simple, but it needs to paste a large number of mark points on the surface of the reflector, which is cumbersome and time-consuming, and is not suitable for fast and online detection of grooved curved surface reflectors. The reflective grid Moore fringe detection method is to use the camera to capture the image of the grid stripe reflected by the measured curved surface mirror. The grid stripe image carries the modulation information of the measured curved surface mirror, and the image of the grid stripe is imaged Processing, and then inverting the surface shape information of the measured curved mirror, this method is a good way to achieve rapid detection, but the positioning accuracy of the curved mirror is high, and the subsequent image processing is more complicated.

Contents of the invention

The present invention provides a solar trough in order to solve the problem that the detection process is cumbersome and time-consuming in the detection of the surface shape error of the trough-type curved surface mirror, and it is not suitable for fast and on-line detection. At the same time, there is the problem of complicated subsequent image processing. Type curved surface mirror surface shape error detection device.

A solar trough-type curved surface reflective mirror surface shape error detection device, the device includes a light source device, a self-calibration device and an image acquisition and processing device; the light source device includes a laser, a beam expander and a beam splitter mirror group; the image acquisition and processing device including light screens, cameras and computers;

The beam emitted by the laser is expanded by the beam expander and then reflected by the beam splitter group, and the test beam beamed by the beam splitter group is projected onto the curved surface mirror under test and reflected by the beam splitter group. The self-calibration beam is incident on the self-calibration device, and the self-calibration device calibrates the parallelism of the test beam projected onto the measured curved surface reflector; the light screen receives the spot information reflected by the measured curved surface reflector, and the camera collects the light The spot information on the screen and the spot information is transmitted to the computer, and the computer judges the surface error of the measured curved surface mirror by the received spot information, and the self-calibration device includes a self-calibration device including an f-theta lens and a CCD detector; The self-calibrating light beam is converged on the CCD detector through the f-θ lens.

Beneficial effects of the present invention: The surface shape error detection device of the solar trough curved reflective mirror of the present invention can quickly and accurately detect the surface shape of the solar trough curved reflective mirror online; the device uses an optical system to simulate parallel sunlight incident on the On the curved mirror, use the camera to shoot the light spot projected on the focal plane by the curved mirror, and perform image processing on the light spot, and then judge whether the surface shape error of the tested curved mirror meets the requirements for use. The device has low requirements on the positioning accuracy of the measured curved surface mirror, simple image processing, high detection accuracy, and fast detection speed. Combined with the scanning and adjustment mechanism, the online detection of the measured curved surface mirror can be realized, which is easy to operate and low in cost. .

Description of drawings

Fig. 1 is the structural diagram of Embodiment 1 of the solar trough type curved surface reflector surface error detection device of the present invention;

Fig. 2 is a structural view of Embodiment 2 of the surface error detection device of the solar trough curved surface mirror of the present invention.

In the figure, 1. Laser, 2. Beam expander, 3. Beam splitter group, 4. Inclined beam splitter, 5. Horizontal beam splitter, 6. Beam splitter unit, 7. Self-calibrating beam, 8. Test Beam, 9, f-θ lens, 10, CCD detector, 11, sliding beam, 12, guide rail, 13, measured curved surface mirror, 14, lifting rod, 15, baffle, 16, camera, 17, tripod , 18, light screen, 19, data line one, 20, data line two, 21, computer, 22, transmission device, 23, shutter.

Detailed ways

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 1. This embodiment will be described with reference to FIG. 1 . The surface error detection device of the solar trough curved reflector includes a light source device, a self-calibration device, and an image acquisition and processing device.

Described light source device comprises laser 1, beam expander mirror 2 and beam splitting mirror group 3; Described beam splitting mirror group 3 is made up of a series of beam splitting mirror units 6, and each beam splitting mirror unit 6 is made up of two pieces Beam mirror composition (tilt beam splitter 4 and horizontal beam splitter 5), the angle between the two beam splitters is 45°.

The beam expander 2 expands and collimates the laser beam emitted by the laser 1, divides it into a series of test beams 8 with approximately equal energy and parallel to each other through the beam splitter group 3, and projects them onto the curved mirror 13 under test. The position and inclination of each beam splitter unit 6 in the beam splitter group 3 are adjusted so that the beams projected onto the measured curved mirror 13 are parallel to each other. The number of beam splitter units 6 in the beam splitter group 3 is determined by the opening size of the measured curved mirror 13 and the measurement accuracy requirements. The self-calibration device receives the light beam reflected by the beam splitter group 3. The data acquisition and processing part includes a light screen, a camera and a computer. At a certain angle, the camera is used to shoot the light spots on the light screen. The camera is connected to the computer through the data line. The computer is used to process the image captured by the camera and the image acquisition and processing device of the self-calibration device, and calculate the measured curved surface reflector. surface error.

This embodiment also includes a scanning and adjusting mechanism, which includes a sliding beam 11, a guide rail 12, a lifting pole 14 and a baffle plate 15, the sliding beam 11 is used to install a light source device and a self-calibration device, and the guide rail 12 is used to install the sliding beam 11. The laser 1, the beam expander 2 and the beam splitter group 3 are fixed on the sliding beam 11 on the guide rail 12 and arranged in a line. The lifting rod 14 is used to reflect light on the measured curved surface The position and posture of the mirror 13 are adjusted, and the baffle 15 is used to fix the position of the measured curved surface mirror 13 . Wherein, the relative positions of the guide rail 12, the lifting pole 14 and the baffle plate 15 are fixed in advance, and are determined by the geometric parameters of the measured curved surface reflector 13. The baffle plate 15 is used to support one end of the measured curved surface reflector 13, and the lifting pole 14 The lifting height is calculated in advance by the geometric parameters of the measured curved surface reflector 13, so that the direction of the parallel scanning laser beam is consistent with the optical axis direction of the measured curved surface reflector 13, and the sliding beam 11 is along the measured curved surface reflective mirror 13. The movement in the direction of the focal line ensures that the scanning laser beam scans the measured curved mirror 13 .

The self-calibration device described in this embodiment consists of an f-θ lens 9, a CCD detector 10 and a data line 220. After the laser beam passes through the beam splitter mirror group 3, the partially reflected self-calibration beam 7 passes through the f-θ lens 9 are converged on the CCD detector 10, if the beam spots reflected by all beam splitter mirror units 6 on the CCD detector are coincident, it proves that the test beams 8 projected on the mirror 13 to be tested are parallel to each other; otherwise, the splitter must be adjusted. The position and inclination of the beam mirror unit 6 until the spots of the light beams reflected by all the beam splitter mirror units 6 coincide on the CCD detector 10 .

The image acquisition and processing part is composed of a light screen 18 , a camera 16 , a tripod 17 , a data line 19 and a computer 21 . The light screen 18 is placed at the standard focal line of the tested curved mirror 13, and forms a certain angle (0-90°) with the optical axis direction of the tested curved mirror 13 to receive the light reflected by the tested curved mirror 13. The size and inclination angle of the light screen 18 need to be designed according to the geometric parameters of the measured curved mirror 13, so as to ensure that all reflected light spots of the tested curved mirror 13 can be obtained. The camera 16 is used to collect light spot information on the light screen 18, and is supported by a tripod 17 to adjust its position and angle. When the sliding crossbeam 11 scans along the focal line direction of the curved surface reflector 13 under test, the camera 16 can take a series of images, and the image information is transmitted to the calculation 21 through the data line one 19, and the computer 21 processes the image information Then it is judged whether the measured curved surface reflector 13 is qualified.

In this embodiment, a conveying device 22 is also included. The measured curved surface mirror 13 is placed on the conveying device 22 of the production line, and is transported to a predetermined position by the conveying device 22 and then stops. The lifting rod 14 supports one end of the curved mirror 13 to be tested, and the rising height of the lifting rod 14 can be calculated according to the geometric parameters of the curved mirror 13 to ensure that the test beam 6 emitted by the beam splitter group 3 It is consistent with the optical axis direction of the curved surface reflector 13 under test. The other end of the tested curved mirror 13 is stuck on the baffle 15, and the test beam 8 is incident on the tested curved mirror 13 along the optical axis direction of the tested curved mirror 13, and is reflected and converged by the tested curved mirror 13. On the light screen 18. Because there is a certain surface error in the curved mirror 13 to be tested, the light spots on the light screen 18 have a certain stray distribution. The test beam 8 scans the measured curved surface reflector 13 along with the movement of the sliding beam 11, and the camera 16 captures the light spot information on the light screen 18 and transmits it to the computer 21 through the data line 19, and the computer 21 judges the measured curved surface through image processing. Whether the reflector is qualified, so as to achieve the purpose of online rapid detection.

Embodiment 2. This embodiment is described in conjunction with FIG. 2. The difference between this embodiment and Embodiment 1 is that, on the basis of Embodiment 1, a shutter 23 is added in each beam splitter unit 6 in this embodiment, in order to be able to To quantitatively test the surface error of the measured curved mirror 13, it is necessary to add a shutter 23 to each beam splitter unit. When the light spot deviates from the ideal position, all the shutters 23 can be closed, and the shutters 23 can be opened sequentially from left to right, that is, the measured point corresponding to the deviated light spot can be found, and can be obtained from the deviation amount of the light spot and the coordinate information of the measured point. The deviation between the normal direction of the measured point and the ideal normal direction is obtained.

Claims (8)

1. solar groove type optical reflector of curved surface face shape error pick-up unit, this device comprises light supply apparatus, self-calibrating device and image acquisition and treating apparatus; It is characterized in that;

Described light supply apparatus comprises laser instrument (1), beam expanding lens (2) and beam splitter group (3); Image acquisition and treating apparatus comprise optical screen (18), camera (16) and computing machine (21);

The light beam that described laser instrument (1) sends also reflects through beam splitter group (3) beam splitting after beam expanding lens (2) expands again, test beams after beam splitter group (3) beam splitting is projected on tested optical reflector of curved surface (13), self calibration light beam through beam splitter group (3) reflection is incident to self-calibrating device, and described self-calibrating device is to being projected to the depth of parallelism calibration of the test beams on tested optical reflector of curved surface (13); Described optical screen (18) receives the facula information of tested optical reflector of curved surface (13) reflection, camera (16) gathers the facula information on optical screen (18) and facula information is transferred in computing machine (21), and computing machine (21) judges the face shape error of tested optical reflector of curved surface (13) by the facula information receiving; Described self-calibrating device comprises that self-calibrating device comprises f-θ lens (9) and ccd detector (10); Described self calibration light beam converges on ccd detector (10) through f-θ lens (9).

2. solar groove type optical reflector of curved surface face shape error pick-up unit according to claim 1, it is characterized in that, this device also comprises scanning and governor motion, described scanning and governor motion comprise sliding beam (11), guide rail (12), lifting pole (14) and baffle plate (15), described sliding beam (11) is for installing light supply apparatus and self-calibrating device, guide rail (12) is for installing sliding beam (11), lifting pole (14) is for adjusting position and the attitude of tested optical reflector of curved surface (13), baffle plate (15) is for the position of fixing tested optical reflector of curved surface (13).

3. solar groove type optical reflector of curved surface face shape error pick-up unit according to claim 1 and 2, it is characterized in that, described laser instrument (1), beam expanding lens (2) and beam splitter group (3) are fixed on sliding beam (11) successively, described beam splitter group (3) is comprised of a plurality of beam splitters unit (6), and each beam splitter unit (6) is comprised of two beam splitter groups (3).

4. solar groove type optical reflector of curved surface face shape error pick-up unit according to claim 3, it is characterized in that, described two beam splitters are respectively inclination beam splitter (4) and horizontal beam splitter (5), and the angle of inclination beam splitter (4) and horizontal beam splitter (5) is 45 °.

5. solar groove type optical reflector of curved surface face shape error pick-up unit according to claim 3, is characterized in that, the quantity of described beam splitter unit (6) is determined by opening size and the measuring accuracy of tested optical reflector of curved surface (13).

6. solar groove type optical reflector of curved surface face shape error pick-up unit according to claim 3, it is characterized in that, in each beam splitter unit (6), shutter (23) is set, when tested optical reflector of curved surface (13) being carried out to face shape error detection, when the facula information of the upper tested optical reflector of curved surface (13) obtaining of optical screen (18) departs from normal place, by shutter (23) Close All, and open successively from left to right shutter (23), obtain and depart from the corresponding measured point of hot spot.

7. solar groove type optical reflector of curved surface face shape error pick-up unit according to claim 1, it is characterized in that, described image acquisition and treating apparatus also comprise tripod (17), and described camera (16) supports the adjustment of go forward side by side line position and angle by tripod (17).

8. solar groove type optical reflector of curved surface face shape error pick-up unit according to claim 1, is characterized in that, the optical axis angle scope of optical screen in described image acquisition and treating apparatus (18) and tested optical reflector of curved surface (13) is at 0～90 °.

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