Heliostat calibration method and device, storage medium, computer program product, and solar thermal power generation system

Abstract

A heliostat calibration method and device, storage medium, computer program product, and solar thermal power generation system, the method comprising: obtaining a first image shot for a target target, and determining a first pixel position corresponding to the target target in the first image; obtaining a second image shot for a mirror image in the heliostat, and determining a second pixel position corresponding to the center point of the mirror image of the sun in the second image based on the maximum brightness value in the brightness values ​​of each pixel in the second image and a preset target brightness range; judging whether the first pixel position and the second pixel position are symmetrical around a calibration point; if the judgment result is no, calibrating the heliostat based on the first pixel position and the second pixel position, and then obtaining a second image re-shot for the mirror image in the heliostat and determining the second pixel position, until the first pixel position and the re-determined second pixel position are symmetrical around the calibration point. The above scheme helps to improve the calibration accuracy of the heliostat.

Description

Technical Field

[0001] The present invention relates to the technical field of photothermal power generation, and in particular to a heliostat calibration method and device, a storage medium, a computer program product, and a photothermal power generation system. Background Art

[0002] With the continuous development of renewable energy, solar thermal power generation is an important direction of new energy utilization, mainly including three systems: trough, tower, and dish (disk). Among them, the tower solar thermal power generation system has higher tracking complexity and accuracy requirements than other systems such as trough and butterfly.

[0003] Heliostat is a component of a tower solar thermal power generation system. Its function is to reflect sunlight to a fixed position on a receiving tower to generate heat, which is then converted into electricity by the receiving tower. Since the sun's position in the sky changes constantly throughout the day, the heliostat also needs to adjust its angle constantly to reflect sunlight to the receiver on the receiving tower. The closer the sunlight reflected by the heliostat is to the center point of the receiver, the higher the power generation efficiency. Therefore, calibrating or adjusting the position of the heliostat is the key to a tower solar thermal power generation system.

[0004] However, the existing heliostat calibration method has limited calibration accuracy, which affects the power generation efficiency. Summary of the invention

[0005] The problem solved by the embodiments of the present invention is: how to effectively improve the calibration accuracy of the heliostat.

[0006] To solve the above problem, an embodiment of the present invention provides a heliostat calibration method, the heliostat calibration method comprising: acquiring a first image shot for a target point, and determining a first pixel position corresponding to the target point in the first image; acquiring a second image shot for a mirror image in the heliostat, and determining a second pixel position corresponding to a center point of the mirror image of the sun in the second image based on a maximum brightness value among brightness values ​​of pixels in the second image and a preset target brightness range, wherein the mirror image in the heliostat includes at least the mirror image of the sun, a first imaging plane to which the first image belongs and a second imaging plane to which the second image belongs are parallel to each other and have overlapping formats, and The method comprises the steps of: determining a first pixel position and a second pixel position, wherein the line between the center point of the first image and the center point of the second image is perpendicular to the first imaging plane and the second imaging plane; determining whether the first pixel position and the second pixel position are symmetrical around a calibration point, wherein the calibration point is a midpoint of the line between the center point of the first image and the center point of the second image; and if the determination result is no, calibrating the heliostat based on the first pixel position and the second pixel position, and then acquiring a second image retaken for the mirror image in the heliostat and determining a second pixel position corresponding to the center point of the mirror image of the sun in the second image, until the first pixel position and the re-determined second pixel position are symmetrical around the calibration point.

[0007] Optionally, based on the maximum brightness value among the brightness values ​​of each pixel in the second image and a preset target brightness range, the second pixel position corresponding to the center point of the sun's mirror image in the second image is determined, including: judging whether the maximum brightness value is within the target brightness range; if the maximum brightness value exceeds the target brightness range, adjusting the exposure time of shooting, and obtaining a second image retaken based on the adjusted exposure time, until the maximum brightness value among the brightness values ​​of each pixel of the retaken second image is within the target brightness range, and taking the position of the pixel to which the maximum brightness value among the brightness values ​​of each pixel of the most recently shot second image belongs as the second pixel position corresponding to the center point of the sun's mirror image in the second image.

[0008] Optionally, the two endpoint brightness values ​​of the target brightness range are respectively recorded as a first brightness threshold and a second brightness threshold, and the first brightness threshold is less than the second brightness threshold; if the maximum brightness value exceeds the target brightness range, the exposure time of shooting is adjusted, including: if the maximum brightness value is greater than or equal to the second brightness threshold, reducing the exposure time of shooting; if the maximum brightness value is less than or equal to the first brightness threshold, increasing the exposure time of shooting.

[0009] Optionally, the first brightness threshold and / or the second brightness threshold is determined based on the bit width of the second image, and the larger the bit width of the second image is, the larger the first brightness threshold and / or the second brightness threshold is.

[0010] Optionally, the first brightness threshold is determined by the following formula: Y1=w1×(2 x -1); the second brightness threshold is determined by the following formula: Y2 = w2 × (2 x -1); wherein Y1 represents the first brightness threshold, Y2 represents the second brightness threshold, x represents the bit width of the second image, w1 represents a preset first adjustment coefficient, w2 represents a preset second adjustment coefficient, and w1<w2.

[0011] Optionally, calibrating the heliostat is achieved by controlling the movement of the heliostat; before calibrating the heliostat based on the first pixel position and the second pixel position, the method further includes: determining a distance between the second pixel position and a target symmetric position, recorded as a target distance, wherein the target symmetric position is a symmetric position of the first pixel position relative to the calibration point; if the target distance is less than or equal to a preset distance threshold, reducing a moving speed of the heliostat, and calibrating the heliostat using the reduced moving speed.

[0012] Optionally, the smaller the target distance is, the smaller the lowered moving speed of the heliostat is.

[0013] The embodiment of the present invention further provides a heliostat calibration device, comprising: a first pixel position determination module, used to obtain a first image shot for a target target point, and determine a first pixel position corresponding to the target target point in the first image; a second pixel position determination module, used to obtain a second image shot for a mirror image in the heliostat, and determine a second pixel position corresponding to a center point of the mirror image of the sun in the second image based on a maximum brightness value among brightness values ​​of pixels in the second image and a preset target brightness range, wherein the mirror image in the heliostat includes at least the mirror image of the sun, a first imaging plane to which the first image belongs and a second imaging plane to which the second image belongs are parallel to each other and have overlapping formats, and the second pixel position determination module is ... target target point in the first image and determine a second pixel position corresponding to a center point of the mirror image of the sun in the second image. A line between a center point of an image and a center point of the second image is perpendicular to the first imaging plane and the second imaging plane; a judgment module, used to judge whether the first pixel position and the second pixel position are symmetrical around a calibration point, wherein the calibration point is the midpoint of the line between the center point of the first image and the center point of the second image; and a calibration module, used to calibrate the heliostat based on the first pixel position and the second pixel position if the judgment result is no, and then obtain a second image re-taken for the mirror image in the heliostat and determine a second pixel position corresponding to the center point of the mirror image of the sun in the second image, until the first pixel position and the re-determined second pixel position are symmetrical around the calibration point.

[0014] An embodiment of the present invention further provides a storage medium having a computer program stored thereon, wherein the computer program executes the steps of the above heliostat calibration method when executed by a processor.

[0015] An embodiment of the present invention further provides a heliostat calibration device, comprising a memory and a processor, wherein the memory stores a computer program that can be run on the processor, and the processor executes the steps of the heliostat calibration method when running the computer program.

[0016] An embodiment of the present invention further provides a solar thermal power generation system, comprising the above-mentioned heliostat calibration device, and also comprising: a heliostat and a receiving tower; the heliostat calibration device corresponds one-to-one to the heliostat, and the receiving tower includes the above-mentioned target point.

[0017] An embodiment of the present invention further provides a computer program product, including a computer program, which executes the steps of the above heliostat calibration method when executed by a processor.

[0018] Compared with the prior art, the technical solution of the embodiment of the present invention has the following advantages:

[0019] In the calibration scheme provided by the embodiment of the present invention, after obtaining the second image shot for the mirror image in the heliostat, the second pixel position corresponding to the center point of the mirror image of the sun in the second image is determined based on the maximum brightness value among the brightness values ​​of each pixel in the second image and the preset target brightness interval. By appropriately setting the target brightness interval, it is possible to exclude the influence of other interfering targets in the second image other than the mirror image of the sun, and ensure that the brightest point in the second image (i.e., the pixel position with the largest brightness value) is the center point of the mirror image of the sun rather than other interfering targets in the environment. In this way, the accuracy of determining the second pixel position corresponding to the center point of the mirror image of the sun in the second image can be improved, thereby improving the efficiency and accuracy of subsequent heliostat calibration based on the first pixel position and the second pixel position.

[0020] Furthermore, by judging whether the maximum brightness value among the brightness values ​​of each pixel in the second image is within the preset target brightness range, and based on the comparison result between the maximum brightness value and the brightness values ​​at both ends of the target brightness range, starting from the level of improving image quality, by appropriately increasing or decreasing the exposure time of the image sensor, the quality of the captured second image is optimized, the influence of other interfering targets in the heliostat is avoided as much as possible, and the maximum brightness value of each pixel in the second image is ensured to always be within the target brightness range. Thus, it is helpful to realize that the brightest pixel position in the second image is the pixel position corresponding to the mirror image of the sun, rather than the pixel position corresponding to other interfering targets in the heliostat, thereby improving the positioning accuracy of the second pixel position, and further improving the efficiency and accuracy of subsequent calibration of the heliostat. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a flow chart of a heliostat calibration method in an embodiment of the present invention;

[0022] Figure 2 is a schematic diagram of calibrating a heliostat using a heliostat calibration device in a typical application scenario of an embodiment of the present invention;

[0023] Figure 3 yes Figure 1 A flowchart of a specific implementation of step S14;

[0024] Figure 4 It is a structural schematic diagram of a heliostat calibration device in an embodiment of the present invention. DETAILED DESCRIPTION

[0025] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0026] Reference Figure 1 , Figure 1is a flow chart of a heliostat calibration method in an embodiment of the present invention. Specifically, the method may include:

[0027] Step S11: Acquire a first image shot for a target point, and determine a first pixel position corresponding to the target point in the first image.

[0028] Step S12: acquiring a second image shot for the mirror image in the heliostat, and determining a second pixel position corresponding to the center point of the mirror image of the sun in the second image based on a maximum brightness value among brightness values ​​of pixels in the second image and a preset target brightness range, wherein the mirror image in the heliostat includes at least the mirror image of the sun, a first imaging plane to which the first image belongs and a second imaging plane to which the second image belongs are parallel to each other and have overlapping formats, and a line between the center point of the first image and the center point of the second image is perpendicular to the first imaging plane and the second imaging plane.

[0029] Step S13: determining whether the first pixel position and the second pixel position are symmetrical around a calibration point, where the calibration point is the midpoint of a line between a center point of the first image and a center point of the second image.

[0030] If the judgment result of step S13 is no, that is, the first pixel position and the second pixel position are not symmetrical around the calibration point, step S14 is executed.

[0031] Step S14: calibrating the heliostat based on the first pixel position and the second pixel position.

[0032] After the heliostat is calibrated, the step S12 is returned and re-executed until the first pixel position and the re-determined second pixel position are symmetrical about the calibration point. In the process of re-executing the step S12, the second image obtained is a second image re-photographed for the mirror image in the calibrated heliostat.

[0033] Further, if the judgment result of step S13 is yes, that is, the first pixel position and the second pixel position are symmetrical around the calibration point, then there is no need to calibrate the heliostat. Further, since the position of the sun changes in real time in actual applications, and the heliostat calibration device used to perform the heliostat calibration method may also be slightly offset, it is possible to directly return to step S11 without calibrating the heliostat to continue the next round of calibration. In other words, the heliostat calibration method of the embodiment of the present invention can be executed cyclically.

[0034] In a specific implementation, the above heliostat calibration method can be Figure 2 The heliostat calibration device shown is implemented. Figure 2 , the specific implementation process, relevant principles and technical effects of the above-mentioned heliostat calibration method are described in detail.

[0035] like Figure 2 As shown, a schematic diagram of using a heliostat calibration device 20 to calibrate a heliostat in a typical application scenario of an embodiment of the present invention is provided. It should be pointed out that the heliostat calibration device 20 does not constitute a limitation on the specific implementation process of the heliostat calibration method of the present application. In other words, the heliostat calibration method of the present application, in addition to using Figure 2 The heliostat calibration device 20 shown is implemented, and may also be implemented based on other appropriate calibration devices or structures having the same or similar calibration principles.

[0036] Specifically, the heliostat calibration device 20 may include: a calibration body 30, a first image sensor 31, and a second image sensor 32, and may also include a calibration body bracket 37. Wherein:

[0037] The calibration body 30 includes a first optical surface 34 and a second optical surface 35 which are arranged opposite to each other, and may also include a light shielding surface 33. The first optical surface 34 may be provided by a first lens, and the second optical surface 35 may be provided by a second lens. In a specific implementation, the calibration body 30 may have a variety of shapes, for example, Figure 2 The calibration body 30 may be a cylinder. In this case, the first optical surface 34 and the second optical surface 35 are equivalent to the upper and lower surfaces of the cylinder, and the light shielding surface 33 is equivalent to the cylindrical surface of the cylinder.

[0038] In some embodiments, the calibration body may also be in other shapes, such as a cuboid, a cube, etc., with a first optical surface 34 and a second optical surface 35, which are not limited here. Specifically, the first optical surface 34 and the second optical surface 35 may be arranged to be parallel to each other.

[0039] The first image sensor 31 and the second image sensor 32 are located on the calibration body 30; the first image sensor 31 has a first imaging plane 301 facing the first optical surface 34, and the second image sensor 32 has a second imaging plane 302 facing the second optical surface 35; the first imaging plane 301 and the second imaging plane 302 are parallel and overlap in size. Specifically, the first image sensor 31 and the second image sensor 32 can be arranged back to back or with a certain gap, and the specific size of the gap can be set according to actual conditions.

[0040] The first image sensor 31 is used to capture a first image of a target point A of the receiving tower 50, and the second image sensor 32 is used to capture a second image of a mirror image in the heliostat 60, wherein the mirror image in the heliostat 60 includes at least a mirror image of the sun 40 (also called a "sun image"); wherein a line between a center point of the first image and a center point of the second image is perpendicular to the first imaging plane 301 and the second imaging plane 302.

[0041] In a specific implementation, a receiver 51 may be provided on the receiving tower 50, and the receiver 51 is used to receive the reflected light of the sun during the actual light-to-heat conversion process. A target plate 52 may also be provided on the receiving tower 50, and a plurality of target points may be provided on the target plate 52, and a target point may be arbitrarily selected from the plurality of target points as the target point A for calibrating the heliostat. In order to obtain higher power generation efficiency, the target point A may be set as the center point of the receiver 51.

[0042] In the embodiment of the present invention, the midpoint of the line between the center point of the first image and the center point of the second image may be used as a calibration point to implement calibration of the heliostat.

[0043] After acquiring the first image, the first pixel position corresponding to the target point A in the first image can be determined; after acquiring the second image, the second pixel position corresponding to the center point of the mirror image of the sun 40 in the second image can be determined.

[0044] Since the first imaging plane 301 and the second imaging plane 302 are parallel and overlap in width, the heliostat can be calibrated so that the first pixel position corresponding to the mirror image of the sun 40 in the heliostat 60 in the first image and the first pixel position corresponding to the target point A on the receiving tower 50 in the second image are symmetrical around the calibration point (that is, the midpoint of the line between the center point of the first image and the center point of the second image), so that the sunlight reflected by the heliostat 60 is parallel to the light that passes through the target point A of the receiving tower 50 and reaches the second imaging plane 302. In this way, in actual application, the incident position of the sunlight reflected by the heliostat 60 on the receiving tower 50 is close to or overlaps with the position of the target point A on the receiving tower 50, so that the sunlight reflected by the heliostat 60 can be reflected to the receiver 51 of the receiving tower 50 to achieve light-to-heat conversion.

[0045] In a specific implementation, in order to improve the calibration efficiency and calibration accuracy, the heliostat calibration device 20 may further include a control component (not shown) for determining whether the first pixel position and the second pixel position are symmetrical around a calibration point, and if the first pixel position and the second pixel position are not symmetrical around the calibration point, calibrating the heliostat based on the first pixel position and the second pixel position until the first pixel position and the re-determined second pixel position are symmetrical around the calibration point.

[0046] The control component may be in communication connection with the heliostat support 601 , and the heliostat support 601 moves (eg, moves in a horizontal direction, a vertical direction, or other appropriate directions) the heliostat 60 under the control of the control component to achieve calibration of the heliostat 60 .

[0047] It can be understood that, in the process of calibrating the heliostat 60 using the heliostat calibration device 20, the positioning accuracy of the two pixel positions, namely, the first pixel position corresponding to the target point A in the first image and the second pixel position corresponding to the center point of the mirror image of the sun 40 in the second image, can directly affect the accuracy of calibrating the heliostat 60.

[0048] However, it should be pointed out that during the image acquisition process of the image sensor, specifically taking the acquisition of the second image by the second image sensor 32 for the mirror image in the heliostat 60 as an example, due to factors such as light and the surrounding environment, the second image may contain other interference targets in addition to the mirror image of the sun 40. These interference targets may cause the result of positioning the second pixel position in the second image to be biased or even completely wrong, thereby greatly reducing the calibration accuracy of the heliostat.

[0049] To solve the above technical problems, in the calibration scheme provided by the embodiment of the present invention, after obtaining the second image shot for the mirror image in the heliostat, the second pixel position corresponding to the center point of the mirror image of the sun in the second image is determined based on the maximum brightness value among the brightness values ​​of each pixel in the second image and the preset target brightness interval. By appropriately setting the target brightness interval, it is possible to exclude the influence of other interfering targets in the second image other than the mirror image of the sun, and ensure that the brightest point in the second image (i.e., the pixel position with the largest brightness value) is the center point of the mirror image of the sun rather than other interfering targets in the environment. In this way, the accuracy of determining the second pixel position corresponding to the center point of the mirror image of the sun in the second image can be improved, thereby improving the efficiency and accuracy of subsequent heliostat calibration based on the first pixel position and the second pixel position.

[0050] Further, in step S12, based on the maximum brightness value among the brightness values ​​of each pixel in the second image and a preset target brightness range, the second pixel position corresponding to the center point of the sun's mirror image in the second image is determined, which can specifically include: judging whether the maximum brightness value is within the target brightness range; if the maximum brightness value exceeds the target brightness range, adjusting the exposure time of shooting, and obtaining a second image retaken based on the adjusted exposure time, until the maximum brightness value among the brightness values ​​of each pixel of the retaken second image is within the target brightness range, and taking the position of the pixel to which the maximum brightness value among the brightness values ​​of each pixel of the most recently shot second image belongs as the second pixel position corresponding to the center point of the sun's mirror image in the second image.

[0051] Furthermore, the brightness values ​​of the two endpoints of the target brightness range are respectively recorded as a first brightness threshold and a second brightness threshold, and the first brightness threshold is less than the second brightness threshold; if the maximum brightness value exceeds the target brightness range, the exposure time of shooting is adjusted (specifically, the exposure time of the image sensor for shooting the second image is adjusted), including: if the maximum brightness value is greater than or equal to the second brightness threshold, reducing the exposure time of shooting; if the maximum brightness value is less than or equal to the first brightness threshold, increasing the exposure time of shooting.

[0052] It can be understood that, in the process of capturing an image, the longer the exposure time of the image sensor is, the greater the brightness value of each pixel in the captured image is, and when the exposure time is too long, in addition to the sun image in the heliostat, the mirror images of other objects in the heliostat will also be brighter in the second image, thereby interfering with the accurate positioning of the pixel position corresponding to the mirror image of the sun in the second image (i.e., the second pixel position); on the contrary, the shorter the exposure time of the image sensor is, the smaller the brightness value of each pixel in the captured image is, and when the exposure time is too short, both the sun image in the heliostat and the mirror images of other objects will be darker in the second image, and at this time, the mirror images of other objects will also interfere with the accurate positioning of the pixel position corresponding to the mirror image of the sun in the second image (i.e., the second pixel position).

[0053] To solve the above problem, in an embodiment of the present invention, the target brightness interval is appropriately set, and it is determined whether the maximum brightness value among the brightness values ​​of each pixel in the second image is within the target brightness interval; and based on the comparison result between the maximum brightness value and the brightness values ​​at both end points of the target brightness interval, starting from the aspect of improving image quality, the exposure time of the image sensor is appropriately increased or decreased to optimize the quality of the captured second image, avoid the influence of other interfering targets in the heliostat as much as possible, and ensure that the maximum brightness value of each pixel in the second image is always within the target brightness interval.

[0054] From the above, compared with adopting other methods to determine the second pixel position (for example, when the maximum brightness value exceeds the target brightness range, without changing the exposure time, selecting a pixel position from a plurality of pixel positions with larger brightness values ​​in the second image as the second pixel position), adopting this embodiment helps to achieve that the brightest pixel position in the second image is the pixel position corresponding to the mirror image of the sun, rather than the pixel position corresponding to other interference targets in the heliostat, thereby improving the positioning accuracy of the second pixel position, and further improving the efficiency and accuracy of subsequent calibration of the heliostat.

[0055] In a specific implementation, the first brightness threshold and / or the second brightness threshold is determined based on the bit width of the second image. The larger the bit width of the second image, the larger the first brightness threshold and / or the second brightness threshold.

[0056] Specifically, the first brightness threshold is determined by the following formula:

[0057] Y1=w1×(2 x -1);

[0058] The second brightness threshold is determined by the following formula:

[0059] Y2=w2×(2 x -1);

[0060] Among them, Y1 represents the first brightness threshold, Y2 represents the second brightness threshold, x represents the bit width of the second image, w1 represents a preset first adjustment coefficient, w2 represents a preset second adjustment coefficient, and w1<w2.

[0061] In some non-limiting embodiments, the bit width of the second image may be 8 bits, the first adjustment coefficient may be selected from the interval [0.8, 0.92], and the second adjustment coefficient may be selected from the interval [0.95, 1]. For example, the first brightness threshold may be set to 230, and the second brightness threshold may be set to 255.

[0062] Further, refer to Figure 3 , Figure 3 yes Figure 1 Flow chart of a specific implementation of step S14 in FIG. In this implementation, the heliostat is calibrated by controlling the movement of the heliostat; the step S14 may specifically include the following steps S141 to S143.

[0063] In step S141, the distance between the second pixel position and the target symmetric position is determined, which is recorded as the target distance, wherein the target symmetric position is the symmetric position of the first pixel position relative to the calibration point.

[0064] In step S142, it is determined whether the target distance is less than or equal to a preset distance threshold.

[0065] If the target distance is less than or equal to the distance threshold, step S143 is executed; further, if the target distance is greater than the distance threshold, the moving speed of the heliostat may be kept unchanged (i.e., the heliostat is continued to be moved at the original moving speed) to calibrate the heliostat.

[0066] In step S143, the moving speed of the heliostat is reduced, and the heliostat is calibrated using the reduced moving speed.

[0067] Furthermore, the smaller the target distance is, the smaller the lowered moving speed of the heliostat is.

[0068] It can be understood that the goal of calibrating the heliostat may be to make the second pixel position as close to or even coincide with the target symmetric position as possible (that is, the target distance is as small as possible or even 0). Therefore, in the embodiment of the present invention, when the target distance gradually decreases to less than or equal to a preset distance threshold as the calibration process progresses, the moving speed of the heliostat is reduced, which helps to further improve the calibration accuracy.

[0069] Further, Figure 1 In step S11 of the illustrated embodiment, a light source may be set at the position of the target point (the brightness of the light source may be close to the brightness of the mirror image of the sun in the heliostat), and a first pixel position corresponding to the light source in the first image is determined, that is, the first pixel position corresponding to the target point in the first image.

[0070] In an embodiment of the present invention, regarding the specific implementation plan for determining the first pixel position corresponding to the light source at the target point in the first image, it can be executed by referring to the solution for determining the second pixel position corresponding to the center point of the sun's mirror image in the second image in step S12, which will not be repeated here.

[0071] Reference Figure 4 , Figure 4 : is a schematic diagram of the structure of a heliostat calibration device in an embodiment of the present invention. The device may include:

[0072] A first pixel position determination module 41 is used to obtain a first image shot for a target point, and determine a first pixel position corresponding to the target point in the first image;

[0073] A second pixel position determination module 42 is used to obtain a second image shot for a mirror image in a heliostat, and determine a second pixel position corresponding to a center point of the mirror image of the sun in the second image based on a maximum brightness value among brightness values ​​of pixels in the second image and a preset target brightness range, wherein the mirror image in the heliostat includes at least the mirror image of the sun, a first imaging plane to which the first image belongs and a second imaging plane to which the second image belongs are parallel to each other and have overlapping formats, and a line between a center point of the first image and a center point of the second image is perpendicular to the first imaging plane and the second imaging plane;

[0074] A determination module 43, configured to determine whether the first pixel position and the second pixel position are symmetrical around a calibration point, wherein the calibration point is a midpoint of a line between a center point of the first image and a center point of the second image;

[0075] The calibration module 44 is configured to calibrate the heliostat based on the first pixel position and the second pixel position if the judgment result of the judgment module 43 is no, and then obtain a second image re-photographed for the mirror image in the heliostat and determine a second pixel position corresponding to the center point of the mirror image of the sun in the second image, until the first pixel position and the re-determined second pixel position are symmetrical around the calibration point.

[0076] For the principle, specific implementation and beneficial effects of the heliostat calibration device, please refer to the previous article and Figures 1 to 3 The related description about the heliostat calibration method shown is not repeated here.

[0077] The embodiment of the present invention further provides a storage medium, such as a computer-readable storage medium, on which a computer program is stored, and the computer program is executed by a processor. Figures 1 to 3 The steps of the heliostat calibration method shown in any embodiment. The computer-readable storage medium may include a non-volatile memory or a non-transitory memory, and may also include an optical disk, a mechanical hard disk, a solid-state hard disk, and the like.

[0078] Specifically, in the embodiment of the present invention, the processor may be a central processing unit (CPU), and the processor may also be other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0079] It should also be understood that the memory in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example but not limitation, many forms of random access memory (RAM) are available, such as static RAM (SRAM), dynamic random access memory (DRAM), synchronous DRAM (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link DRAM (SLDRAM) and direct rambus RAM (DR RAM).

[0080] The embodiment of the present invention further provides a heliostat calibration device, comprising a memory and a processor, wherein the memory stores a computer program that can be run on the processor, and the processor executes the above-mentioned Figures 1 to 3Any of the embodiments shows steps related to the heliostat calibration method.

[0081] The embodiment of the present invention further provides a solar thermal power generation system, which may include the above-mentioned heliostat calibration device, and may also include a heliostat and a receiving tower; the heliostat calibration device corresponds to the heliostat one by one, and the receiving tower includes Figures 1 to 3 The target site of any embodiment.

[0082] In a specific implementation, a heliostat calibration device may be arranged to correspond to a heliostat one by one, so that each heliostat calibration device can calibrate a unique heliostat to prevent interference between sunlight reflected by the heliostats, thereby improving the parallelism of calibration.

[0083] For more details about the solar thermal power generation system, please refer to Figure 2 The related descriptions in the previous article will not be repeated here.

[0084] The embodiment of the present invention also provides a computer program product, including a computer program, wherein the computer program is executed when the processor is running. Figures 1 to 3 The steps of the heliostat calibration method described in any embodiment.

[0085] The "plurality" appearing in the embodiments of the present application refers to two or more.

[0086] The first, second, etc. descriptions appearing in the embodiments of the present application are only used for illustration and distinction of the description objects. There is no order, nor do they indicate any special limitation on the number of devices in the embodiments of the present application, and cannot constitute any limitation on the embodiments of the present application.

[0087] It should be pointed out that the serial numbers of the steps in this embodiment do not limit the execution order of the steps.

[0088] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A heliostat calibration method, characterized in that: include: Acquire a first image captured for a target point, and determine a first pixel position corresponding to the target point in the first image; Acquire a second image shot for a mirror in a heliostat, and determine a second pixel position corresponding to a center point of the mirror image of the sun in the second image based on a maximum brightness value among brightness values ​​of pixels in the second image and a preset target brightness range, wherein the mirror image in the heliostat includes at least the mirror image of the sun, a first imaging plane to which the first image belongs and a second imaging plane to which the second image belongs are parallel to each other and have overlapping formats, and a line between a center point of the first image and a center point of the second image are perpendicular to the first imaging plane and the second imaging plane; determine whether the first pixel position and the second pixel position are symmetrical around a calibration point, wherein the calibration point is the midpoint of a line between a center point of the first image and a center point of the second image; If the judgment result is no, the heliostat is calibrated based on the first pixel position and the second pixel position, and then a second image re-photographed for the mirror image in the heliostat is obtained, and a second pixel position corresponding to the center point of the mirror image of the sun in the second image is determined, until the first pixel position and the re-determined second pixel position are symmetrical around the calibration point.

2. The method according to claim 1, characterized in that Determining a second pixel position corresponding to a center point of the sun's mirror image in the second image based on a maximum brightness value among brightness values ​​of pixels in the second image and a preset target brightness range includes: Determining whether the maximum brightness value is within the target brightness range; If the maximum brightness value exceeds the target brightness range, the exposure time of the shooting is adjusted, and a second image retaken based on the adjusted exposure time is obtained, until the maximum brightness value among the brightness values ​​of each pixel of the retaken second image is within the target brightness range, and the position of the pixel to which the maximum brightness value among the brightness values ​​of each pixel of the second image taken most recently belongs is used as the second pixel position corresponding to the center point of the sun's mirror image in the second image.

3. The method according to claim 2, characterized in that The two endpoint brightness values ​​of the target brightness interval are respectively recorded as a first brightness threshold and a second brightness threshold, and the first brightness threshold is smaller than the second brightness threshold; If the maximum brightness value exceeds the target brightness range, the exposure time of shooting is adjusted, including: If the maximum brightness value is greater than or equal to the second brightness threshold, reducing the exposure time of shooting; If the maximum brightness value is less than or equal to the first brightness threshold, the exposure time of shooting is increased.

4. The method according to claim 3, characterized in that The first brightness threshold and / or the second brightness threshold are determined based on the bit width of the second image. The larger the bit width of the second image, the larger the first brightness threshold and / or the second brightness threshold.

5. The method according to claim 4, characterized in that The first brightness threshold is determined by the following formula: Y1=w1×(2 x -1); The second brightness threshold is determined by the following formula: Y2=w2×(2 x -1); Among them, Y1 represents the first brightness threshold, Y2 represents the second brightness threshold, x represents the bit width of the second image, w1 represents a preset first adjustment coefficient, w2 represents a preset second adjustment coefficient, and w1<w2.

6. The method according to claim 1, characterized in that Calibration of the heliostat is achieved by controlling the movement of the heliostat; Based on the first pixel position and the second pixel position, calibrating the heliostat includes: Determine a distance between the second pixel position and a target symmetric position, recorded as a target distance, wherein the target symmetric position is a symmetric position of the first pixel position relative to the calibration point; If the target distance is less than or equal to a preset distance threshold, the moving speed of the heliostat is reduced, and the heliostat is calibrated using the reduced moving speed.

7. The method according to claim 6, characterized in that The smaller the target distance is, the smaller the lowered moving speed of the heliostat is.

8. A heliostat calibration device, characterized in that: include: A first pixel position determination module, used to obtain a first image shot for a target point, and determine a first pixel position corresponding to the target point in the first image; a second pixel position determination module, configured to obtain a second image shot for a mirror image in a heliostat, and determine a second pixel position corresponding to a center point of the mirror image of the sun in the second image based on a maximum brightness value among brightness values ​​of pixels in the second image and a preset target brightness range, wherein the mirror image in the heliostat includes at least the mirror image of the sun, a first imaging plane to which the first image belongs and a second imaging plane to which the second image belongs are parallel to each other and have overlapping formats, and a line between a center point of the first image and a center point of the second image is perpendicular to the first imaging plane and the second imaging plane; a determination module, configured to determine whether the first pixel position and the second pixel position are symmetrical about a calibration point, wherein the calibration point is a midpoint of a line between a center point of the first image and a center point of the second image; and a calibration module, configured to calibrate the heliostat based on the first pixel position and the second pixel position if the judgment result is no, and then obtain a second image re-photographed for the mirror image in the heliostat and determine a second pixel position corresponding to the center point of the mirror image of the sun in the second image, until the first pixel position and the re-determined second pixel position are symmetrical around the calibration point.

9. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the heliostat calibration method according to any one of claims 1 to 7 are executed.

10. A heliostat calibration device, comprising a memory and a processor, wherein the memory stores a computer program that can be run on the processor, wherein: When the processor runs the computer program, the processor performs the steps of the heliostat calibration method according to any one of claims 1 to 7.

11. A solar thermal power generation system, characterized in that: The heliostat calibration device comprises the heliostat according to claim 10, and further comprises: a heliostat and a receiving tower; the heliostat calibration device corresponds to the heliostat one-to-one, and the receiving tower comprises the target point according to any one of claims 1 to 7.

12. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the heliostat calibration method according to any one of claims 1 to 7 are executed.

Images