Sighting system of heliostat

Abstract

A sighting system (200) of a heliostat. A light redirecting element (430) is provided on a first light path (410), and sunlight (440) reflected by a heliostat (132) passes through the light redirecting element (430) to obtain redirected sunlight (450) capable of being incident to an imaging module (214). Scattered light (460) of a heat absorber (110) travels through a second light path (420), maintains the original direction thereof, and is directly incident to the imaging module (214). The sighting system (200) realizes simultaneous imaging of the sunlight (440) reflected by the heliostat (132) and the scattered light (460) of the heat absorber (110) by means of the first light path (410) and the second light path (420), thereby converting the problem of controlling the rotation of the heliostat (132) into the problem of determining an angle difference between the sunlight (440) reflected by the heliostat (132) and the scattered light (460) of the heat absorber (110) by means of image comparison between the sunlight (440) reflected by the heliostat (132) and the scattered light (460) of the heat absorber (110).

Description

Heliostat aiming system Technical Field

[0001] The present invention relates to the field of solar thermal applications, and more particularly to a heliostat aiming system. This application claims priority to Chinese patent application number 202311361340.2, filed on October 20, 2023, entitled “A Heliostat Aiming System,” the entire contents of which are incorporated herein by reference. Background Art

[0002] The basic principle of CSP is to control heliostats to reflect sunlight onto the surface of a heat sink located atop a tower. The heat from the sunlight is absorbed by the heat sink, melting the molten salt inside. This molten salt is then transported by high-temperature pumps to a power station at the base of the tower, where it generates high-temperature electricity. Therefore, ensuring that the sunlight reflected by the heliostats accurately strikes the heat sink is a key technical challenge in CSP.

[0003] Summary of the Invention

[0004] The present invention aims to solve one of the technical problems in the related art at least to a certain extent. To this end, the present invention provides a heliostat aiming system.

[0005] The present invention provides a sighting system for a heliostat, the sighting system being suitable for the heliostat to reflect sunlight onto a heat absorber. The sighting system comprises an optical path module, an imaging module, and an adjustment module. The optical paths through which the sunlight reflected by the heliostat and the scattered light from the heat absorber pass include a first optical path and a second optical path. The optical path of the sunlight reflected by the heliostat before entering the imaging module is recorded as the first optical path, and the optical path of the scattered light from the heat absorber before entering the imaging module is recorded as the second optical path. The optical path module comprises a light deflection element, which is provided on the first optical path. The sunlight reflected by the heliostat passes through the light deflection element to be redirected so as to be incident on the imaging module. The solar light is redirected by the heat absorber and the scattered light from the heat absorber is directly incident on the imaging module while maintaining its original direction. The imaging module is configured to image the redirected solar light and the scattered light from the heat absorber to obtain imaging data of the imaging module. The imaging data includes an image of the sun and an image of the heat absorber. The adjustment module is configured to determine an imaging position of the sun and an imaging position of the heat absorber based on the imaging data of the imaging module, and adjust the posture of the heliostat based on the imaging position of the sun and the imaging position of the heat absorber so that the distance between the imaging position of the sun and the imaging position of the heat absorber is less than a preset distance threshold.

[0006] In the above embodiment, by providing a light redirecting element in the first optical path, sunlight reflected by the heliostat is redirected by the light redirecting element to be incident on the imaging module. Light scattered by the heat absorber is then incident directly on the imaging module while maintaining its original direction through the second optical path. Simultaneous imaging of the sunlight reflected by the heliostat and the light scattered by the heat absorber is achieved through the first and second optical paths, thereby transforming the problem of heliostat rotation control into a problem of comparing the angles of the sunlight reflected by the heliostat and the light scattered by the heat absorber through imaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] FIG1 is a schematic diagram of a heliostat system in the related art according to an embodiment of the present invention;

[0008] FIG2 a is a schematic diagram of a heliostat aiming system according to an example scenario of this specification;

[0009] FIG2 b is a schematic diagram of the optical path of the aiming system of the heliostat provided according to the example scenario of this specification;

[0010] FIG3 a is a schematic diagram of a heliostat aiming system according to an example scenario of this specification;

[0011] FIG3 b is a schematic diagram of a heliostat aiming system according to an example scenario of this specification;

[0012] FIG3c is a schematic diagram of a logo pattern provided according to an example scenario of this specification;

[0013] FIG4 a is a schematic diagram of a heliostat aiming system according to an embodiment of the present specification;

[0014] FIG4 b is a schematic diagram of an optical path of a sighting system according to an embodiment of the present specification;

[0015] FIG5a is a schematic diagram of an optical path according to an embodiment of the present specification;

[0016] FIG5 b is a schematic diagram of an optical path according to an embodiment of this specification;

[0017] FIG6 is a schematic diagram of a sighting system after tilting according to an embodiment of the present specification;

[0018] FIG7 is a schematic diagram of an optical path module provided according to an embodiment of this specification;

[0019] FIG8 is a schematic diagram of an optical path module provided according to an embodiment of this specification;

[0020] FIG9a is a schematic diagram of an optical path module provided according to an embodiment of this specification;

[0021] FIG9 b is a schematic diagram of an optical path module provided according to an embodiment of this specification;

[0022] FIG9c is a schematic diagram of an imaging module provided according to an embodiment of this specification;

[0023] FIG9 d is a schematic diagram of an imaging module provided according to an embodiment of this specification;

[0024] FIG9e is a schematic diagram of an optical path module provided according to an embodiment of this specification;

[0025] FIG9f is a schematic diagram of an optical path module provided according to an embodiment of this specification;

[0026] FIG10 is a flow chart of a method for determining a difference angle according to an example scenario of this specification;

[0027] FIG11 is a flow chart of a method for determining a difference angle according to an example scenario of this specification. DETAILED DESCRIPTION

[0028] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, but are not to be construed as limiting the present invention.

[0029] In the related art, referring to FIG1 , a heat absorber 110' is mounted on a tower 120'. A mirror field 130' is arranged around the tower 120'. The mirror field 130' includes multiple heliostats 132'. Each heliostat 132' is mounted on a heliostat column 134'. An image sensor 140' is mounted on the tower 120' and secured via a support member. The image sensor 140' is communicatively connected to an image controller 150', which in turn is communicatively connected to a heliostat controller 160'. Light reflected from a single heliostat 132' is reflected by the image sensor 140'. The image controller 150' coordinates with the heliostat controller 160' to fine-tune the heliostat's attitude based on the image of the reflected light spot obtained by the image sensor 140'. The heliostat's attitude can refer to its orientation and angle, such as the tilt angle of the heliostat's mirror surface. In other words, the heliostat posture may be the azimuth angle and pitch angle of the heliostat mirror relative to a reference object, such as the ground.

[0030] The calibration methods used in related art use the calibrated heliostat's geographic location relative to the Earth and its own attitude angle as a reference to derive the required operating attitude of other heliostats, rather than determining for each heliostat whether the actual reflection angle of the current sunlight is aimed at the heat absorber. Furthermore, these calibration methods fail to consider the impact of changes in the heliostat's attitude caused by sustained wind loads on its reflection efficiency. Furthermore, the reflection efficiency of a mirror field depends on the installation accuracy of the heliostat columns, the machining accuracy of the heliostats, and the transmission accuracy of the heliostats during operation. Therefore, during the actual operation of a mirror field, the reflection efficiency of the heliostats will decrease as the heliostats' attitude changes due to wind loads, the positional accuracy of the heliostat columns, the machining accuracy of the heliostats, and the tracking accuracy of the drive mechanism decrease.

[0031] Based on the above analysis, this specification provides a heliostat aiming system in a scenario example. A heliostat is suitable for reflecting sunlight onto a heat absorber. Referring to Figure 2a, the aiming system 200 includes a sight 210 and an adjustment module 220. The sight 210 includes an optical path module 212 and an imaging module 214. The adjustment module 220 is connected to the heliostat column 134. The adjustment module 220 includes a heliostat azimuth rotation axis assembly 222, a heliostat elevation rotation axis assembly 224, a transmission support, an image reading module 226, and an image processing module 228. It should be noted that the housing of the sight 210 is the housing of the optical path module, and the optical path elements in the optical path module 212 and the imaging module 214 are both disposed within the housing of the sight 210. The image reading module can be understood as an image reading program, which can be stored in a memory and executed by a processor. The image processing module can be understood as an image processing program, which can be stored in a memory and executed by a processor.

[0032] In this example scenario, the aimer 210 can be considered a device that determines whether two light beams (the sunlight reflected by the heliostat and the scattered light from the absorber) are parallel. The specific principle is: when the lens is focused at infinity, parallel light incident at the same angle will accurately converge at the same point on the image sensor located at the lens focal point. Conversely, light rays converging at the same point on the image sensor must be parallel before entering the imaging module 214. Furthermore, if the sunlight reflected by the heliostat strikes the absorber, the sunlight reflected by the heliostat and the scattered light from the absorber are parallel and 180 degrees opposite to each other. The sunlight reflected by the heliostat and the scattered light from the absorber can then be imaged separately. By comparing the image positions of the sunlight reflected by the heliostat and the scattered light from the absorber, it can be determined whether the sunlight reflected by the heliostat and the scattered light from the absorber are parallel. If they are determined to be non-parallel, a feedback control signal for the heliostat can be generated based on the image positions of the sunlight reflected by the heliostat and the scattered light from the absorber. The heliostat is adjusted in attitude by a feedback control signal of the heliostat so that the sunlight reflected by the heliostat is parallel to the scattered light of the heat absorber, that is, the sunlight reflected by the heliostat is irradiated on the heat absorber.

[0033] In this example scenario, the image processing module 228 is in communication with the image reading module 226, which is in communication with the imaging module 214. The housing of the sight 210 is connected to the heliostat's azimuth axis assembly 222 via an aiming connection rod 230. The heliostat's azimuth axis assembly 222 is mounted on the heliostat column 134, and the heliostat's elevation axis assembly 224 is mounted on the heliostat's azimuth axis assembly 222. Alternatively, the azimuth axis assembly 222 is mounted on the heliostat column 134, the transmission support is mounted on the azimuth axis assembly 222, the elevation axis assembly 224 connects the transmission support and the mirror frame, and the mirror frame is connected to the elevation axis assembly 224 and the transmission support. The azimuth axis assembly 222 drives the heliostat to rotate in an azimuth direction perpendicular to the ground, while the elevation axis assembly 224 drives the heliostat to rotate about the transmission support axis, which is parallel to the ground. It can be understood that the azimuth axis assembly corresponds to the azimuth drive mechanism, while the elevation axis assembly corresponds to the horizontal drive mechanism. The azimuth drive mechanism is mounted on the heliostat column, the transmission support is mounted on the azimuth drive mechanism, the horizontal drive mechanism connects the transmission support and the mirror frame, the mirror frame is connected to the horizontal drive structure and the transmission support, and the mirror is mounted on the mirror frame. The azimuth drive mechanism drives the heliostat to rotate in an azimuth direction perpendicular to the ground, while the horizontal drive mechanism drives the heliostat to rotate around the axis of the transmission support, which is parallel to the ground.

[0034] In some cases, to ensure that the sunlight reflected by the heliostats accurately hits the designated location on the receiver, the heliostat focusing angle deviation needs to be less than 1 mrad (approximately 0.0573 degrees). In actual tower-type solar thermal power plants, the receiver installation height can reach over 100 meters, and the distance between the heliostats and the central tower can reach 500 meters or even over 1000 meters. Under this precision requirement, even with a small angular error in controlling the heliostats, the spot distance deviation on the receiver for heliostats farther away can exceed 1 meter. For example, an angular error of 0.5° can result in a spot distance deviation of nearly 20 meters, so the angle control accuracy should be at least on the order of 0.1°.

[0035] It should be noted that the optical path module 212 and the imaging module 214 constitute the imaging instrument. The optical path module 212 is responsible for guiding and processing the scattered light from the heat absorber and the sunlight reflected by the heliostat, ensuring that these rays are accurately transmitted and focused to the imaging module 214. The imaging module 214 is responsible for converting the light processed by the optical path module 212 into electrical signals. The imaging module 214 consists of a photosensitive element (such as a CCD or CMOS sensor) and associated signal processing circuitry. Its primary function is to capture light and convert it into digital image data. As can be seen, the optical path module 212 determines the paths of the reflected sunlight and the scattered light from the heat absorber, playing a crucial role in the imaging process. In this example scenario, the heliostat's feedback control signal is determined based on the imaging position of the scattered light from the heat absorber and the imaging position of the sunlight reflected by the heliostat. Therefore, the design and composition of the optical path module 212 have a significant impact on the heliostat's feedback control signal.

[0036] Analysis revealed that assembly errors (or installation errors) in optical components, as well as changes in optical component characteristics caused by external factors such as temperature fluctuations and vibration, can affect the image positions of the scattered light from the absorber and the sunlight reflected by the heliostat, thereby affecting the accuracy of the heliostat's feedback control signal. Further analysis revealed that installation errors in the optical components within the common optical path have the same impact on the images of the scattered light from the absorber and the sunlight reflected by the heliostat, canceling out the effects and not affecting the relative position or distance between the two images. However, installation errors in the non-common optical path have different impacts on the images of the scattered light from the absorber and the sunlight reflected by the heliostat, potentially affecting the relative position and distance between the two images.

[0037] The optical paths of the sunlight reflected by the heliostat and the scattered light from the heat absorber are divided into a common optical path portion and a non-common optical path portion, based on whether the scattered light from the heat absorber and the sunlight reflected by the heliostat pass through them together. The common optical path portion may be the optical path that the scattered light from the heat absorber and the sunlight reflected by the heliostat pass through together. The non-common optical path portion may be the optical path that the scattered light from the heat absorber and the sunlight reflected by the heliostat pass through separately.

[0038] For the common optical path portion, the installation error of the optical device in the common optical path portion has the same impact on the scattered light from the absorber and the sunlight reflected by the heliostat. Therefore, the impact of the installation error of the optical device in the common optical path portion on the imaging of the scattered light from the absorber and the imaging of the sunlight reflected by the heliostat can be offset, that is, it will not affect the relative position and relative distance between the two images.

[0039] Regarding the non-common optical path portion, the non-common optical path portion includes a first optical path and a second optical path. The optical path of the sunlight reflected by the heliostat before entering the imaging module 214 is denoted as the first optical path, and the optical path of the scattered light from the heat absorber before entering the imaging module 214 is denoted as the second optical path. Because assembly errors of optical components affect the imaging position of the scattered light from the heat absorber and the imaging position of the sunlight reflected by the heliostat, these assembly errors can have some impact on the feedback control signal of the heliostat. Similarly, changes in optical properties caused by external factors such as temperature changes and vibration can affect the imaging position of the scattered light from the heat absorber and the imaging position of the sunlight reflected by the heliostat, and can also have some impact on the feedback control signal of the heliostat.

[0040] As mentioned above, the heliostat's angle control accuracy should be at least on the order of 0.1°. Installation errors and variations in optical properties of the optical components in the common optical path will not affect the relative position and distance between the two images. However, installation errors and variations in optical properties of the optical components in the non-common optical path will affect the relative position and distance between the two images. Therefore, to improve angle control accuracy, the non-common optical path should be minimized as much as possible, and the number of optical components used in this non-common optical path should be minimized. This will reduce the impact of optical component assembly errors on the image position of the scattered light from the absorber and the image position of the sunlight reflected by the heliostat, as well as the impact of variations in optical properties on the image position of the scattered light from the absorber and the image position of the sunlight reflected by the heliostat.

[0041] To ensure that sunlight reflected from the heliostat reaches the heat absorber, the sunlight must be parallel to the scattered light from the heat absorber and 180° in the opposite direction. To minimize the non-common optical path and the number of optical components used in this non-common optical path, the scattered light from the heat absorber can be directed directly into the imaging module in the second optical path. This eliminates the need for optical devices for steering in the second optical path, and the sunlight reflected from the heliostat in the first optical path is redirected 180° before entering the imaging module. As shown in Figure 2b, the heat absorber 110 is located within the field of view of the imaging module 214. The difference between the second optical path and the first optical path is that the first optical path includes a light steering element that redirects the sunlight reflected from the heliostat 180°.

[0042] It should be noted that the sight is located within approximately 50 mm of the center of the heliostat's mirror surface. The sight's imaging module 214 continuously receives scattered light from the heat absorber and sunlight reflected from portions of the heliostat's mirror surface surrounding the sight's installation location. These reflected sunlight originates from the central region of the entire heliostat's mirror surface and can be used to represent sunlight reflected by the entire heliostat. In one example, the sight can be fixed to the heliostat column via a connecting rod, and the sight is located within approximately 50 mm of the center of the heliostat's mirror surface. For example, the connecting rod can pass through various components between the heliostat column and the central region of the heliostat's mirror surface. The sight's attitude does not change when the heliostat rotates in either the azimuth or horizontal dimensions. Therefore, the sight's attitude can be fixed after being adjusted during installation, reducing the sight's control logic and improving the accuracy of the heliostat's feedback control signals.

[0043] It should be noted that since the housing of the sight 210 is also connected to the heliostat's azimuth rotation axis assembly 222 via the sight connecting rod 230, the sight must rotate synchronously in the opposite direction as the heliostat rotates in azimuth to ensure that the heat absorber is always within the field of view of the sight's imaging module 214. When the heliostat is in horizontal motion, the sight remains above the mirror surface, allowing sunlight reflected by the mirror to continuously enter the sight.

[0044] In some cases, the heat absorber appears in the field of view of the imaging module, so the shape of the heat absorber can be identified based on the image output by the imaging module, and the center of the heat absorber can be determined. However, in actual operation, the inventors found that: 1) Since the heliostat reflects sunlight onto the heat absorber, the surface brightness of the heat absorber will vary greatly at different times; 2) The brightness of the heat absorber surface is uneven, and the heat absorber observed by the imaging module includes bright spots and dark spots. These two reasons lead to the direct identification of the shape and position of the heat absorber based on the image output by the imaging module, which may affect the accuracy of the heat absorber imaging position, and even make it difficult to successfully identify the heat absorber based on the image output by the imaging module. Therefore, the inventors proposed a new way to indirectly determine and identify the shape and position of the heat absorber, that is, to set an identification pattern on the support of the heat absorber and below the heat absorber. There is a fixed relative position relationship between the identification pattern and the heat absorber.

[0045] Based on the above analysis, the embodiment of this specification also provides another scenario example. In this scenario example, an identification pattern is provided on the support of the heat absorber (such as the tower mentioned above). The identification pattern is not directly illuminated by the sunlight reflected by the heliostat, and its brightness variation at different times is less than the brightness variation of the surface of the heat absorber, or the brightness distribution on the surface of the identification pattern is relatively uniform. In this way, the imaging of the identification pattern in the imaging module is easily recognized. Furthermore, based on the position of the identified identification pattern and the relative positional relationship between the identification pattern and the heat absorber, the position of the identification pattern is converted to the center position of the heat absorber.

[0046] Referring to Figure 3a, in this example scenario, the aiming system 200 includes a sight 210 and an adjustment module 220. The sight 210 includes an optical path module 212 and an imaging module 214. The adjustment module 220 includes a first image reading module 310 and a first image processing module 320. The first image processing module 320 includes a first angle comparison module 322 and a first position determination module 324. The optical path of sunlight reflected by the heliostat 132 before entering the imaging module 214 is referred to as the first optical path, and the optical path of light scattered by the heat absorber before entering the imaging module 214 is referred to as the second optical path. Different filters are provided on the first and second optical paths, respectively. It should be noted that the light passing through the filter on the first optical path can be any color of red, blue, or green, while the light passing through the filter on the second optical path can be any color of red, blue, or green except for the colors permitted by the first optical path. The red filter is designed to allow red light to pass while blocking or absorbing light of other colors. This means that when a red light filter is placed in the first optical path, only red light is able to pass through the filter, while light of other colors is blocked or absorbed. The blue light filter is designed to allow blue light to pass through, while blocking or absorbing light of other colors. This means that when a blue light filter is placed in the second optical path, only blue light is able to pass through the filter, while light of other colors is blocked or absorbed. The green light filter is designed to allow green light to pass through, while blocking or absorbing light of other colors. This means that when a green light filter is placed in the second optical path, only green light is able to pass through the filter, while light of other colors is blocked or absorbed.

[0047] Exemplarily, a red light filter is provided on the first optical path, and a blue light filter is provided on the second optical path. The first image reading module 310 obtains solar image data and identification image data from the imaging data of the imaging module according to preset colors. Specifically, it extracts red light data from the imaging data of the imaging module to obtain solar image data, and extracts blue light data from the imaging data of the imaging module to obtain identification image data. The first image processing module 320 determines an adjustment strategy for the heliostat based on the relative position data between the identification pattern and the heat absorber, the solar image data, and the identification image data. This adjustment strategy is used to indicate adjustments to the heliostat's posture. The relative position data between the identification pattern and the heat absorber can be used to characterize the relative spatial position between the identification pattern and the heat absorber. The first image reading module can be understood as an image reading program, which can be stored in a memory and executed by a processor. The first image processing module can be understood as an image processing program, which can be stored in a memory and executed by a processor.

[0048] In some cases, in order to achieve a heliostat focusing angle deviation of less than 1 mrad, it is necessary to minimize the number of optical devices used in the optical module. The inventors have discovered that by controlling the first exposure time, a high-quality image of the heat absorber can be obtained, and by controlling the second exposure time, a high-quality image of the sun can be obtained. In this way, there is no need to set filters in the first and second optical paths. It should be noted that the first exposure time is longer than the second exposure time, and the first and second exposure times can be set in combination with the actual imaging situation, and are not specifically limited here. Therefore, a multiple exposure method is used, and multiple frames of image data are obtained by controlling the exposure time. The image data obtained by the multiple exposures are fused to form a high dynamic range image. At this time, both the sun and the heat absorber appear on the high dynamic range image. The high dynamic range image can be obtained by fusion using an HDR (High Dynamic Range) synthesis algorithm, such as weighted averaging and tone mapping.

[0049] To illustrate the multiple exposure operation, in the first exposure, a first exposure time is used, resulting in an image of the heat sink, while the image of the sun is overexposed. In the second exposure, a second exposure time is used, resulting in an image of the sun, while the image of the heat sink is relatively dark. Multiple exposures are performed in this manner.

[0050] The multiple exposure operation is exemplarily described, in one portion of the multiple exposures, an exposure time of a first duration is performed to obtain an image of the heat absorber, and in another portion of the multiple exposures, an exposure time of a second duration is performed to obtain an image of the sun.

[0051] Based on the above analysis, the embodiments of this specification provide another example scenario, as shown in Figure 3b. In this example scenario, the aiming system 200 includes a sight 210 and an adjustment module 220. The sight 210 includes an optical path module 212 and an imaging module 214. The adjustment module 220 includes a second image reading module 330 and a first image processing module 320. The first image processing module 320 includes a second angle comparison module 326 and a second position determination module 328. In this example scenario, filters are not required on the first and second optical paths of the optical path module, reducing the number of optical components in the non-common optical path sections. This further reduces the impact of optical component assembly errors and optical property variations on the imaging position of the scattered light from the absorber and the imaging position of the sunlight reflected by the heliostat.

[0052] Specifically, the second image reading module 330 acquires multiple frames of image data from the imaging module's imaging data according to the exposure time and fuses the acquired multiple frames of image data to produce a high dynamic range image. The high dynamic range image includes images of the heat absorber and the sun. Based on the high dynamic range image, the second position determination module 328 determines a first imaging position of the sun on the imaging module's image sensor and a third imaging position of the heat absorber on the image sensor. The second angle comparison module 326 determines the difference angle between the sunlight reflected by the heliostat and the scattered light from the heat absorber based on the first and third imaging positions. This difference angle is used to indicate adjustments to the heliostat's posture. The second image reading module can be understood as an image reading program, which can be stored in memory and executed by a processor. The second position determination module can be understood as a position calculation program, which can be stored in memory and executed by a processor. The second angle comparison module can be understood as an angle comparison program, which can be stored in memory and executed by a processor.

[0053] Furthermore, in some cases, the image of the heat absorber and the image of the sun may overlap, making it impossible to accurately determine the imaging position of the sun and the imaging position of the heat absorber. Therefore, referring to Figure 3c, an identification pattern 340 can be set on the support of the heat absorber and below the heat absorber 110. There is a fixed relative position relationship between the identification pattern and the heat absorber. Accordingly, the second image reading module 330 obtains multiple frames of image data from the imaging data of the imaging module according to the exposure time, and fuses the obtained multiple frames of image data to obtain a high dynamic range image. The high dynamic range image includes the image of the heat absorber, the image of the sun, and the image of the identification pattern. The second position determination module 328 determines the first imaging position of the sun on the image sensor of the imaging module and the second imaging position of the identification object on the image sensor of the imaging module based on the high dynamic range image, and determines the third imaging position of the heat absorber on the image sensor based on the second imaging position and the relative position data between the identification object and the heat absorber. The second angle comparison module 326 determines the difference angle between the sunlight reflected by the heliostat and the scattered light from the absorber according to the first imaging position and the third imaging position; the difference angle is used to indicate the adjustment of the posture of the heliostat.

[0054] The embodiments of this specification also provide another example scenario. In this scenario, to ensure the safety of the heat absorber, the heat absorber temperature is monitored, and the amount of sunlight reflected onto the heat absorber is dynamically adjusted in real time to ensure uniform energy distribution across the heat absorber surface, reduce heat loss caused by localized overheating of the heat absorber, and minimize the likelihood of damage. Specifically, a mirror field includes numerous heliostats, each of which has a corresponding mirror field control module. After determining the relative position between the heliostats and the heat absorber, the spot area of ​​each heliostat on the heat absorber at each moment can be pre-calculated through simulation and experimental methods. The correspondence between the heliostats and spot areas is pre-stored in the mirror field control module. The mirror field control module uses an astronomical algorithm to calculate in real time the amount of sunlight energy P(i) reflected onto the heat absorber by each heliostat at each moment and the reflection target area. At the first level, the heat absorber is divided into N heat absorption areas, where N is greater than or equal to 4. At each moment, an identification set for each heat absorbing region is determined based on the relationship between the reflective target region corresponding to each heliostat and the N heat absorbing regions obtained by dividing the heat absorber. The identification set includes identification information for each of the multiple target heliostats. This identification information is used to uniquely identify the target heliostat. The identification information can be either the heliostat ID information or the heliostat serial number.

[0055] In this scenario, for each heliostat, the mirror field control module first determines the reflected power of each heliostat based on the relative position data between each heliostat and the heat absorber, the projected area of ​​each heliostat, the mirror reflectivity, and the solar irradiation data. Second, the mirror field control module determines the energy density of each heat absorption area based on the area of ​​each heat absorption area, the reflected power of the target heliostat, and the percentage of sunlight reflected by the target heliostat to each heat absorption area. Next, the reflected power of each heliostat in the mirror field is summed to obtain the aggregate reflected power, and the ratio of the aggregate reflected power to the area of ​​the heat absorber is used to obtain the total energy density. The energy density of each heat absorption region is averaged; then, the root mean square difference between the energy density of each heat absorption region and the average energy density of the entire heat absorption region is determined as the energy uniformity characterization data of each heat absorption region; finally, if the energy uniformity characterization data of each heat absorption region exceeds the energy uniformity allowable threshold corresponding to the first level, some target heliostats corresponding to each heat absorption region are rotated. After the heliostats are rotated, the energy uniformity characterization data of each heat absorption region is recalculated using the above method until the energy uniformity characterization data of each heat absorption region does not exceed the energy uniformity allowable threshold corresponding to the first level.

[0056] In this scenario, if the energy uniformity characterization data for each heat absorption region does not exceed the energy uniformity threshold corresponding to the first level, each heat absorption region is further subdivided at the second level to obtain multiple sub-regions. The energy uniformity characterization data for each sub-region is calculated using the same method. Similarly, if the energy uniformity characterization data for each sub-region exceeds the energy uniformity threshold corresponding to the second level, some of the target heliostats corresponding to each sub-region are rotated. After the heliostats are rotated, the energy uniformity characterization data for each sub-region is recalculated using the above method until the energy uniformity characterization data for each sub-region does not exceed the energy uniformity threshold corresponding to the second level.

[0057] In this scenario, if the energy uniformity characterization data for each sub-region does not exceed the energy uniformity threshold corresponding to the second level, each sub-region is further subdivided at the third level to obtain the corresponding subdivided regions, and the energy uniformity characterization data for each subdivided region is calculated. It should be noted that the energy uniformity threshold corresponding to the first level, the energy uniformity threshold corresponding to the second level, and the energy uniformity threshold corresponding to the third level decrease in sequence, and the energy uniformity threshold corresponding to the last level is the smallest.

[0058] In this scenario example, the above steps at different levels are executed cyclically until the last level. It is understood that it is determined whether the energy uniformity characterization data of the subdivided area at the last level exceeds the energy uniformity allowable threshold corresponding to the last level.

[0059] This example illustrates how to rotate heliostats to ensure uniform energy distribution. When performing regional segmentation at the current level, if a heliostat (denoted as SD) needs to be moved from segment A1 to segment A2, the heliostat's controller can rotate the heliostat so that at least 50% of the heliostat's light spot falls within segment A2, and the center of the heliostat's light spot coincides with the center of segment A2. The energy uniformity data for each segment is recalculated using the aforementioned method. If the recalculated energy uniformity data exceeds the energy uniformity threshold corresponding to the current level, further adjustment is required. The mirror field control module can then recalculate the area distribution of the heliostat's light spot in segments A1 and A2. Specifically, the area of ​​the heliostat's light spot falling within segments A1 and A2 is adjusted so that the center of the heliostat's light spot does not coincide with the center of segment A2. The energy density of each segment is then recalculated until the energy uniformity data for each segment does not exceed the energy uniformity threshold corresponding to the current level.

[0060] If the spot area of ​​a heliostat is large and covers more than two subdivisions, the above method can be used to calculate the energy density of each subdivision at the current moment. When further adjustment is required, the mirror field control module can recalculate the distribution of the spot area in multiple subdivisions until the adjusted energy density meets the principle of uniform energy distribution.

[0061] It should be noted that the principle of uniform energy distribution requires that the energy uniformity characterization data of the subdivided area does not exceed the energy uniformity allowable threshold corresponding to the current level. The energy uniformity characterization data can be understood as the energy difference data between the energy density of any subdivided area and the average energy density of the heat absorber. It should be noted that at a certain moment, if any heliostat can reflect the sunlight that exceeds the proportion threshold to any heat absorption area of ​​the heat absorber, the any heliostat can be regarded as the target heliostat corresponding to the any heat absorption area, and the identification information of the target heliostat is included in the identification set of the any heat absorption area. The value range of the energy uniformity allowable threshold can be a value between 5-200. The energy uniformity allowable thresholds of different levels are set according to actual conditions and are not specifically limited here. The unit of the energy uniformity allowable threshold is the same as the unit of energy density, both of which are watts per square meter (W / m 2 ).

[0062] It is understandable that since the energy density, the angle between the sun's azimuth vector and the heliostat's surface normal vector, and the reflective target area corresponding to the heliostat all change dynamically over time, the above parameters in this scenario example are for a certain moment.

[0063] Referring to Figure 4a, an embodiment of this specification provides a heliostat aiming system 200 suitable for reflecting sunlight onto a heat absorber. Aiming system 200 includes an optical path module 212, an imaging module 214, and an adjustment module 220. Optical path module 212 includes a light redirecting element 430, and the aiming system has a first optical path 410 and a second optical path 420. Light redirecting element 430 is provided on first optical path 410. Sunlight 440 reflected by the heliostat passes through light redirecting element 430 to produce redirected sunlight 450 that is incident on imaging module 214. The heat absorber is within the field of view of the imaging module, and scattered light 460 from the heat absorber passes through second optical path 420, maintaining its original direction and directly incident on imaging module 214. The optical paths traveled by the sunlight reflected by the heliostat and the scattered light from the heat absorber include the first optical path and the second optical path.

[0064] The imaging module 214 is used to image the redirected sunlight 450 and the scattered light 460 of the heat absorber to obtain imaging data of the imaging module; wherein the imaging data includes the image of the sun and the image of the heat absorber.

[0065] Adjustment module 220 is configured to determine the imaging position of the sun and the imaging position of the heat absorber based on the imaging data from the imaging module, and adjust the posture of the heliostat based on the imaging position of the sun and the imaging position of the heat absorber so that the distance between the imaging position of the sun and the imaging position of the heat absorber is less than a preset distance threshold.

[0066] In this embodiment, to bypass the need to obtain the solar azimuth vector and zero-calibrate the heliostat itself, the parallelism of the propagation directions of the sunlight 440 reflected by the heliostat and the scattered light 460 from the heat absorber is used as a criterion for evaluating whether the sunlight 440 reflected by the heliostat is directed toward the heat absorber. For example, the angles of the sunlight 440 reflected by the heliostat and the scattered light 460 from the heat absorber can be compared through imaging, and the parallelism of the two beams can be determined based on the angle comparison result. In practice, the sunlight 440 reflected by the heliostat and the scattered light 460 from the heat absorber travel in opposite directions, necessitating the conversion of the two beams into light traveling in the same direction. Furthermore, to minimize the impact of optical device assembly errors and variations in optical device characteristics on the imaging position, in this embodiment, the heat absorber is positioned within the field of view of the imaging module, allowing the scattered light 460 from the heat absorber to directly enter the imaging module 214 of the aiming system 200. The sunlight 440 reflected by the heliostat needs to be displaced a certain distance so that the sunlight 440 reflected by the heliostat can indirectly enter the imaging module 214 of the aiming system 200 .

[0067] Specifically, to image the sunlight 440 reflected by the heliostat and the scattered light 460 from the heat absorber, an optical path module 212 and an imaging module 214 are required. The optical path of the sunlight reflected by the heliostat before entering the imaging module is referred to as the first optical path 410, and the optical path of the scattered light from the heat absorber before entering the imaging module is referred to as the second optical path 420. A light redirecting element 430 is required on the first optical path 410 to redirect the sunlight 440 reflected by the heliostat. This allows the redirected sunlight 450 generated by the sunlight 440 reflected by the heliostat after passing through the light redirecting element 430 to enter the imaging module 214. However, the second optical path 420 does not require a light redirecting element. The scattered light 460 from the heat absorber passes through the second optical path 420 and directly enters the imaging module 214 while maintaining its original propagation direction. In other words, the heat absorber appears within the field of view of the imaging module 214, allowing the imaging module 214 to directly image the heat absorber. For example, the scattered light 460 of the heat absorber can be focused on the central area of ​​the image sensor of the imaging module 214. It is understandable that the scattered light 460 of the heat absorber can also be focused on other areas of the image sensor of the imaging module 214.

[0068] After the imaging module 214 receives the redirected sunlight 450 and the scattered light 460 from the heat absorber, it images the redirected sunlight 450 and the scattered light 460 from the heat absorber to obtain imaging data. Since the imaging module's imaging data includes an image of the sun and an image of the heat absorber, the positional relationship between the sun's image and the heat absorber's image can be determined based on the imaging module's imaging data. Based on this positional relationship, the angles of the sunlight 440 reflected by the heliostat and the scattered light 460 from the heat absorber are compared to determine an adjustment strategy for the heliostat. The heliostat's attitude is then adjusted based on the adjustment strategy. After the heliostat's attitude is adjusted, the redirected sunlight and the scattered light 460 from the heat absorber can be re-imaged. Based on the re-imaged imaging data, it is further determined whether the sunlight 440 reflected by the heliostat and the scattered light 460 from the heat absorber are parallel until the sun's image and the heat absorber image substantially overlap or approach overlap, i.e., the distance between the sun's image position and the heat absorber image position is less than a preset distance threshold. The preset distance threshold can be set to N pixels based on actual circumstances. The value of N can be set based on specific circumstances and is not specifically limited here. It should be noted that the value of N can be less than 3 (e.g., N is equal to 1 or 2), less than 10 (e.g., N is equal to 5 or 7), or less than 20 (e.g., N is equal to 12 or 16). For example, if the resolution of the image sensor in imaging module 214 is 1280*1024 and the horizontal field of view of the aiming device is 10 degrees, the angle corresponding to each pixel is the quotient between 10 and 1280, which is the minimum angular resolution achievable by the aiming device. Because the intensity of reflected sunlight and the intensity of scattered light from the heat absorber can generally ensure the signal-to-noise ratio of the imaging data, N can also be equal to 1. N is related to the minimum angular resolution achievable by the aiming device, that is, it can be set based on the minimum angular resolution achievable by the aiming device. It will be understood that while this example uses 1280*1024 for illustration, the resolution of the image sensor in imaging module 214 can also be 2K or 4K.

[0069] In this embodiment, referring to FIG. 4 b , the optical paths of the sunlight reflected by the heliostat and the scattered light from the absorber include a non-common optical path portion 412 and a common optical path portion 414 . The non-common optical path portion 412 includes a first optical path 410 and a second optical path 420 . The common optical path portion 414 includes the objective lens in the imaging module.

[0070] It should be noted that if the redirected sunlight 450 and the scattered light 460 from the heat absorber are parallel to each other, when the imaging module's lens is focused at infinity, the redirected sunlight 450 and the scattered light 460 from the heat absorber, as parallel light incident at the same angle, will precisely converge at the same point on the image sensor located at the lens's focal point. Conversely, two light beams converging at the same point on the image sensor must be parallel before entering the imaging module.

[0071] In the above embodiment, the use of a smaller number of optical components (light deflection elements are provided on the first optical path, and no light deflection elements are provided on the second optical path) not only causes the sunlight reflected by the heliostat to shift a certain distance, but also reduces the impact of optical component assembly errors and variations in optical component characteristics on the imaging position. It should be noted that, in contrast to the related art method of determining the deviation between the sunlight reflected by the mirror and the scattered light from the absorber by determining the position of the sun's image off-center, the related art uses a static reference (such as the axis of the barrel). When the heliostat system experiences angular deviation due to foundation settlement, wind effects, etc., the resulting angular deviation cannot be corrected, ultimately resulting in directional errors in the mirror-reflected light, necessitating frequent recalibration and maintenance. In contrast, the above embodiment simultaneously images the sunlight reflected by the heliostat and the scattered light from the absorber. Because the relative angle between the heliostat and the absorber is fixed, the static reference adjustment required in the related art is no longer necessary.

[0072] In another embodiment, when a heliostat operates under a constant permissible wind load, the elastic deformation of the heliostat after being subjected to the force causes angular deviation in both azimuth and elevation. This causes the reflected light from the heliostat to deviate from the initial heat absorption region. In this case, the aiming system 200 calculates the difference between the direction vector of the sunlight 440 reflected by the heliostat and the direction vector of the scattered light from the initial heat absorption region to obtain the angular deviations α and β in azimuth and elevation, respectively. The heliostat controller then corrects the angular deviations α and β in both azimuth and elevation, realigning the sunlight 440 reflected by the heliostat to the initial heat absorption region.

[0073] In some embodiments, the sunlight reflected by the heliostat is reflected multiple times by the light redirecting element 430 and then enters the imaging module.

[0074] In some embodiments, the sunlight reflected by the heliostat is reflected twice by the light redirecting element 430 and then enters the imaging module, and the redirected sunlight is 180 degrees opposite to the sunlight reflected by the heliostat.

[0075] In some embodiments, the light redirecting element is configured as a corner cube prism. Specifically, as shown in Figure 5a, sunlight 440 reflected by the heliostat is redirected 180 degrees by the corner cube prism 520 before entering the imaging module 214. Light 460 scattered by the heat absorber remains directly incident on the imaging module 214 in its original direction. Alternatively, as shown in Figure 5b, sunlight 460 scattered by the heat absorber is redirected 180 degrees by the corner cube prism 520 before entering the imaging module 214. Light 440 reflected by the heliostat remains directly incident on the imaging module 214 in its original direction.

[0076] It should be noted that the above-described embodiment aims to image the sunlight reflected by the heliostat and the scattered light from the heat absorber simultaneously on the image sensor. Since the heliostat's focusing angle deviation must be less than 1 mrad (approximately 0.0573 degrees), the impact of optical component assembly errors and variations in optical component characteristics on the heliostat's control accuracy cannot be ignored. Therefore, the above-described embodiment minimizes the number of optical components in the optical module. If a beam splitter (a half-reflecting, half-mirror device) is used, the two beams of light will overlap at the beam splitter's location, ultimately forming an overlapping image on the image sensor. However, the beam splitter's own assembly errors and optical component characteristics can affect the heliostat's control accuracy. Furthermore, the optical paths traversed by the two beams of light (the sunlight reflected by the heliostat and the scattered light from the heat absorber) can be divided into a non-common optical path portion and a common optical path portion. As mentioned above, it's necessary to minimize the number of optical components in each of the two beams' non-common optical paths. Therefore, when determining angular error using two beams, the method using a beam splitter requires at least a lens and a beam splitter. Each of the two beams' paths includes at least two optical components, which can introduce significant error. To minimize the error introduced by the non-common optical path, this embodiment designs a system in which sunlight reflected from the heliostat is reflected twice by a light deflection element before entering the imaging module, while scattered light from the absorber enters the imaging module directly.

[0077] If a corner cube is used as the light redirecting element, only one optical component (the corner cube) is involved in the non-co-path portion between the sunlight reflected by the heliostat and the scattered light from the absorber. Corner cubes are also insensitive to installation accuracy. Even if the corner cube is mounted eccentrically or tilted, it still accurately reflects the incident light 180° parallel to the ground (typical commercial-grade value: 8 arc seconds, approximately 0.002°).

[0078] It should be noted that during heliostat operation, if the aiming system 200 tilts due to at least one of the following factors, such as ground settlement, wind, or gravity, the angle between the aiming optical axis and the scattered light from the absorber will change. This means that the image of the absorber on the imaging module's image sensor will shift. However, the light beam that overlaps with the absorber image on the image sensor remains parallel to the scattered light from the absorber and will continue to accurately point toward and intersect the absorber. See Figure 6, which simulates the aiming system 200 after tilting. When the heliostat experiences tilting due to ground settlement, wind, or gravity, the aiming system 200 rotates significantly, shifting the image position of the scattered light from the absorber. However, as long as the scattered light from the absorber and the sunlight reflected by the heliostat are parallel and propagate in opposite directions, the two beams will continue to converge at the same point on the image sensor. As can be seen, since the tilt of aiming system 200 has the same impact on the scattered light from the heat absorber and the sunlight reflected by the heliostat, namely, the shift in the imaging position, even if the heliostat column tilts due to foundation settlement, wind, or gravity during operation, it will not affect the accurate operation of aiming system 200. It is understandable that the static reference used in related art requires readjustment when angular deviation occurs due to foundation settlement, wind effects, etc., while the direction of the scattered light from the heat absorber in the above embodiment is determined "dynamically." The aiming system in this embodiment has dynamic tracking and self-calibration capabilities, which makes the aiming system in this embodiment unnecessary to adjust frequently.

[0079] In some embodiments, the aiming system includes a housing. The imaging module and the optical path module are both disposed within the housing, and the housing defines a first optical path and a second optical path. The housing is formed with a first light window and a second light window. Sunlight reflected by the heliostat enters the first optical path through the first light window, and light scattered by the heat absorber enters the second optical path through the second light window.

[0080] Specifically, referring to Figure 7 , the aiming system includes a housing 610. The optical path module 212 includes a light redirecting element 430. Both the imaging module 214 and the optical path module 212 are disposed within the housing 610, which defines a first optical path and a second optical path. The housing 610 is formed with a first light window 620 and a second light window 630. Sunlight 440 reflected from the heliostat enters the first optical path through the first light window 620. The light redirecting element 430 is disposed within the first optical path, redirecting the sunlight reflected from the heliostat entering through the first light window 620. Light scattered from the absorber 460 enters the second optical path through the second light window 630.

[0081] In another embodiment, referring to FIG8 , the aiming system includes a housing 610 . The optical path module 212 includes a light redirecting element 430 . Both the imaging module 214 and the optical path module 212 are disposed within the housing 610 , which defines a first optical path and a second optical path. The housing 610 is formed with a first light window 620 and a second light window 630 . Scattered light 460 from the heat absorber enters the second optical path through the second light window 630 . The light redirecting element 430 is disposed within the second optical path and redirects the scattered light 460 from the heat absorber entering through the second light window 630 . Sunlight 440 reflected by the heliostat enters the first optical path through the first light window 620 .

[0082] In some embodiments, the aiming system includes a heliostat column 134 serving as a first mounting base and an adjustment module. The adjustment module is connected to the first mounting base, and a housing is connected to either the first mounting base or the adjustment module. The adjustment module is capable of rotating the heliostat to adjust its azimuth and elevation angles.

[0083] In some embodiments, the housing is adapted to be located in the center of the heliostat. It should be noted that the housing can be located within approximately 50 mm of the center of the heliostat's mirror surface. The optical instrument within the housing continuously receives scattered light from the heat absorber and reflected light from the heliostat's mirror surface around the housing's installation location. This reflected light originates from the center of the heliostat's reflected light and can indicate the location of the entire heliostat's reflected light.

[0084] In some embodiments, the optical path module further includes: a first attenuation plate, which is disposed in the housing; a first attenuation plate is disposed on the first optical path, and along the propagation direction of light in the first optical path, the first attenuation plate is located on the upstream side of the light redirecting element.

[0085] In some cases, due to the strong sunlight reflected by the heliostats, it may be necessary to add an attenuation plate to the first optical path. Specifically, referring to Figure 9a , the optical path module also includes a first attenuation plate 910, which is located within the housing 610 and disposed on the first optical path. Along the propagation direction of light within the first optical path, the first attenuation plate 910 is located upstream of the light deflection element 430.

[0086] It should be noted that the function of the first attenuation plate is to reduce the brightness of the sun in the image. It is understood that the first attenuation plate can also be replaced with a filter with lower transmittance. When designing optical coating filters, a low transmittance filter can be artificially designed to reduce the brightness of the sun in the image. The first attenuation plate can also be replaced with a smaller clear aperture. By reducing the clear aperture, the amount of light entering is reduced, thereby reducing the brightness of the sun in the image.

[0087] In some embodiments, the optical path module also includes: a first filter, which is disposed in the housing; a first filter is disposed on the first optical path, and along the propagation direction of light in the first optical path, the first filter is located between the first attenuation plate and the light deflection element, or the first filter is located on the upstream side of the first attenuation plate.

[0088] Specifically, the color channel corresponding to the imaging of the first optical path can be pre-set, so that a corresponding first filter can be set on the first optical path in conjunction with the color channel corresponding to the imaging of the first optical path. Referring to Figure 9b, the first filter 920 is located within the housing 610. Along the propagation direction of the light within the first optical path, the first filter 920 can be located between the first attenuation plate 910 and the light deflection element 430. It is understood that the first filter can also be located upstream of the first attenuation plate along the propagation direction of the light within the first optical path.

[0089] In the above embodiment, by providing the first filter on the first optical path, the solar image data can be accurately read from the imaging data of the imaging module, which helps to improve the accuracy of solar imaging position recognition.

[0090] In some embodiments, the imaging module includes a lens barrel having a light incident end, and the central axis of the lens barrel serves as the optical axis of the imaging module; a light deflection element is provided at the light incident end so that sunlight reflected by the heliostat can be incident on the imaging module after passing through the light deflection element.

[0091] Specifically, referring to Figure 9c, the imaging module 214 includes a lens barrel 940 having a light incident end 930, with the central axis of the lens barrel 940 serving as the optical axis of the imaging module. A light deflection element 430 is provided at the light incident end 930 to allow sunlight 440 reflected from the heliostat to enter the imaging module within the lens barrel 940 after passing through the light deflection element 430. The number of light deflection elements can be one, or multiple. For example, the multiple light deflection elements can be arranged in a ring, preferably symmetrically, relative to the central axis of the lens barrel 940. In this embodiment, the term "multiple" can be understood as meaning more than two.

[0092] In the above embodiment, the provision of the lens barrel is conducive to improving the installation stability of the light deflection element and reducing the assembly error of the light deflection element, thereby improving the imaging quality of the sun and further improving the accuracy of the sun imaging position recognition.

[0093] In some embodiments, the imaging module includes an objective lens and an image sensor. The objective lens and the image sensor are disposed in a lens barrel, with the objective lens located between the image sensor and the light incident end.

[0094] Specifically, referring to FIG. 9 d , imaging module 214 further includes an objective lens 950 and an image sensor 960. Objective lens 950 and image sensor 960 are disposed within lens barrel 940. Objective lens 950 is positioned between image sensor 960 and light incident end 930. Objective lens 950 is used to focus sunlight reflected by the heliostat onto image sensor 960 and to focus scattered light from the heat absorber onto image sensor 960.

[0095] In some embodiments, a second filter is provided on the second optical path, and the second filter is provided at the incident end of the light.

[0096] Specifically, the color channel corresponding to the second optical path imaging can be pre-set, so that a corresponding second filter can be set on the second optical path in combination with the color channel corresponding to the second optical path imaging. Referring to Figure 9e, a second filter 970 is set on the second optical path, and the second filter 970 is set at the light incident end 930.

[0097] In the above embodiment, by arranging a second filter on the second optical path, the identification image data or the image data of the heat absorber can be accurately read from the imaging data of the imaging module, which is beneficial to improving the accuracy of the heat absorber imaging position recognition.

[0098] In some embodiments, a second attenuation plate is provided on the second optical path, wherein the second filter is located on the upstream side of the light propagation direction in the second optical path, and the second attenuation plate is located on the downstream side of the light propagation direction in the second optical path, or the second attenuation plate is located on the upstream side of the light propagation direction in the second optical path, and the second filter is located on the downstream side of the light propagation direction in the second optical path.

[0099] Specifically, referring to Figure 9f, a second attenuation plate 980 is provided on the second optical path. The second optical filter 970 is located upstream of the second attenuation plate 980 in the direction of light propagation within the second optical path. Alternatively, the second attenuation plate 980 is located upstream of the second optical filter 970 in the direction of light propagation within the second optical path.

[0100] It should be noted that the second attenuation plate is used to reduce the brightness of the heat absorber in the image. It is understood that the second attenuation plate can also be replaced with a filter with lower transmittance. When designing optical coating filters, a low transmittance filter can be artificially designed to reduce the brightness of the heat absorber in the image. The second attenuation plate can also be replaced with a smaller clear aperture. By reducing the clear aperture, the amount of light entering is reduced, thereby reducing the brightness of the heat absorber in the image.

[0101] In some embodiments, the heliostat's azimuth axis assembly 222 is used to adjust the azimuth angle of the heliostat's reflector assembly, such as with a reducer. The heliostat's elevation axis assembly 224 is used to adjust the elevation angle of the heliostat's reflector assembly, such as with an electric push rod. At least one of the transmission support and the reducer's output flange is connected to the housing 610. When the reducer drives the heliostat to rotate, the housing rotates in the opposite direction to adjust the position of the optical path module and the imaging module, so that the heat absorber is within the imaging module's field of view.

[0102] Of course, the housing 610 may also be arranged to maintain a constant posture relative to the heliostat column 134. When the posture of the heliostat is adjusted, the posture of the housing remains unchanged, so that the heat absorber is always located within the field of view of the imaging module.

[0103] The embodiments of this specification provide a heliostat aiming system, wherein a marking object is provided on a mounting base of a heat absorber, and the marking object and the heat absorber are both located within the field of view of an imaging module. The imaging module is further configured to image scattered light from the marking object.

[0104] Among them, the identification object can be an object, symbol or mark used to identify the heat absorber. For example, the identification object can adopt a checkered identification pattern, or a striped identification image (see Figure 3c), and the identification pattern can be set around the mounting base of the heat absorber. For another example, the identification object can also be an identification object set on the mounting base of the heat absorber. It should be noted that the size of the identification object itself is fixed, and the identification object has a fixed relative position with the heat absorber. The size of the identification object itself and the relative position between the identification object and the heat absorber can be set according to actual conditions, and no specific limitation is made here.

[0105] Under normal circumstances, since the brightness of the heat absorber surface is uneven and the brightness of the heat absorber surface changes significantly over time, the direct method of determining the imaging position of the heat absorber based on the image data output by the imaging module needs to be improved. Therefore, the embodiment of this specification provides an indirect method. Specifically, an identification object is provided on the mounting base of the heat absorber, and the identification object and the heat absorber are located together within the field of view of the imaging module. The scattered light of the identification object and the scattered light of the heat absorber are directly incident on the imaging module. Although the imaging module images the scattered light of the identification object and the scattered light of the heat absorber respectively, the imaging position of the identification object is determined by using the imaging data of the identification object; then, the imaging position of the heat absorber is inferred based on the relative position between the identification object and the heat absorber and the imaging position of the identification object. In addition, the position of the sun image is determined based on the imaging data of the sun, and the azimuth error value and the pitch error value are determined based on the imaging position of the heat absorber and the position of the sun image. The azimuth error value and the pitch error value are used to correct the azimuth and pitch angles of the heliostat so that the sunlight reflected by the heliostat is parallel to the scattered light of the absorber, so that the image of the absorber roughly coincides with the image of the sun.

[0106] It should be noted that the position of the heat sink image can be indirectly determined by calculating the position and shape of the marker pattern in the image. In some cases, the image of the sun and the heat sink overlap. Due to crosstalk between the RGB channels of the image sensor, an afterimage of the sun's image can be left on the channel where the heat sink image resides, affecting the recognition of the heat sink image. Indirectly calculating the heat sink image position using a reference object far from the sun's image avoids this problem.

[0107] In the above-described embodiment, an identification object is placed on the mounting base of the heat absorber, and both the identification object and the heat absorber are located within the field of view of the imaging module. The imaging module then uses this imaging module to image the scattered light from the identification object, resulting in an image of the identification object of superior quality compared to the image of the heat absorber. This high-quality image of the identification object is then recognized using an image algorithm. This not only improves the accuracy of the heliostat angular error but also reduces the computational effort. For example, when the heliostat field is not operating, the heat absorber is a low-brightness, black object. However, when the field begins operating and the heliostats in the field focus sunlight on the heat absorber surface, the heat absorber becomes an extremely bright object with a non-uniform brightness distribution. A heat absorber surface with a high brightness state that varies significantly over time is equivalent to an object with a non-uniform brightness distribution. Correctly identifying the identification object using an image algorithm is much more difficult than identifying the identification object.

[0108] In some embodiments, the adjustment module includes a first image processing module configured to adjust the posture of the heliostat according to the relative position data between the identification object and the heat absorber and the imaging data.

[0109] Specifically, because the marker object is within the imaging module's field of view, the imaging module can image the scattered light from the marker object. Consequently, the imaging data from the imaging module includes image data of the marker object. The imaging position of the marker object can then be determined based on the imaging data from the imaging module. The image position of the heat absorber can then be inferred using the relative position data between the marker object and the heat absorber and the marker object's image position. The heliostat's attitude adjustment strategy is determined based on the number of pixels that differ between the heat absorber's image position and the position of the sun's image.

[0110] In some embodiments, the adjustment module further includes a first image reading module. The first image reading module is configured to obtain solar image data and identification image data from the imaging data according to preset colors. The solar image data includes an image of the sun, and the identification image data includes an image of the heat absorber and an image of the identification object. The adjustment module is further configured to adjust the heliostat's posture based on the relative position data between the identification object and the heat absorber, the solar image data, and the identification image data.

[0111] Specifically, a first filter can be pre-configured for sunlight reflected by the heliostat, and a second filter can be pre-configured for scattered light from the heat absorber and the marker object. The first and second filters are each configured to retain light of a different color (e.g., one color from the RGB spectrum). In this way, the imaging data from the sunlight reflected by the heliostat, the scattered light from the heat absorber, and the scattered light from the marker object can be read in the imaging module according to the preset color. For example, the first filter corresponds to a first color, and the second filter corresponds to a second color. The solar image data is read from the imaging data according to the first color, and the marker image data is read from the imaging data according to the second color. Although the marker image data includes images of both the heat absorber and the marker object, the quality of the absorber image is unstable. Therefore, the imaging position of the marker object is first determined based on the marker image data. Secondly, the imaging position of the marker object is determined based on the imaging position of the marker object and the relative position between the marker object and the absorber. Finally, the heliostat's posture is adjusted based on the absorber image position and the position of the solar image so that the solar image and the absorber image approximately overlap.

[0112] In some embodiments, the first image processing module includes a first angle comparison module. The first angle comparison module is configured to determine a difference angle between sunlight reflected by the heliostat and light scattered by the heat absorber based on relative position data between the identification object and the heat absorber, the solar image data, and the identification image data; the difference angle is used to indicate whether to adjust the heliostat's posture.

[0113] The imaging module can be considered an imaging system (or lens) with an infinite focal length. The lens with an infinite focal length images the scattered light from the heat absorber. The scattered light from the heat absorber that enters the lens with an infinite focal length corresponds to a first direction vector. Sunlight reflected by the mirror passes through the light redirecting element and then, after passing through the imaging system with an infinite focal length, forms an image of the sun. The redirected sunlight corresponds to a second direction vector. If the first direction vector and the second direction vector are parallel, the image of the sun and the image of the heat absorber should roughly overlap. Therefore, in this embodiment, the difference between the image of the sun and the image of the heat absorber is compared to infer the difference angle between the sunlight reflected by the heliostat and the scattered light from the heat absorber. Specifically, because the quality of the heat absorber image is unstable, the difference angle between the sunlight reflected by the heliostat and the scattered light from the heat absorber is determined based on the relative position data between the target heat absorbers, the solar image data, and the marker image data. The difference angle includes at least one of an azimuth error value and a pitch error value. The difference angle is used as an error signal of a closed-loop control system to indicate adjustment of the heliostat's posture, thereby achieving high-precision closed-loop control of the heliostat.

[0114] In some embodiments, the first image processing module further includes a first position determination module. The first position determination module is configured to determine a first imaging position of the sun on the image sensor of the imaging module based on the solar image data, and to determine a third imaging position of the heat absorber on the image sensor based on the identification image data and the relative position data between the identification object and the heat absorber. The first angle comparison module is further configured to determine a difference angle between the first and third imaging positions.

[0115] Specifically, after the first image reading module acquires solar image data and identification image data from the imaging data according to a preset color scheme, the first position determination module processes the solar image data to determine a first imaging position of the sun on the image sensor of the imaging module. Due to the unstable imaging quality of the heat absorber, the first position determination module does not directly determine the imaging position of the heat absorber on the image sensor. Instead, it indirectly determines a third imaging position of the heat absorber on the image sensor based on the identification image data and the relative position data between the identification object and the heat absorber. By comparing the number of pixels that differ between the first and third imaging positions, the difference in pixels is converted into the difference in angle between the sunlight reflected by the heliostat and the scattered light from the heat absorber.

[0116] In some embodiments, the first position determination module is further used to determine a second imaging position of the identification object on the image sensor based on the identification image data; and determine a third imaging position based on the relative position data between the identification object and the heat absorber and the second imaging position.

[0117] In some embodiments, the first imaging position is obtained by processing solar image data using a template matching method or a deep learning method. The second imaging position is obtained by processing marker image data using a template matching method or a deep learning method. It should be noted that the first imaging position can also be obtained by processing solar image data using edge detection, binarization, or the like. The second imaging position can also be obtained by processing marker image data using edge detection, binarization, or the like.

[0118] Referring to FIG. 10 , an embodiment of the present specification provides a method for determining the difference angle between sunlight reflected by a heliostat and scattered light from a heat absorber. The method includes the following steps:

[0119] S1102: Obtain sun image data and logo image data from imaging data according to preset colors.

[0120] The solar image data includes an image of the sun, and the identification image data includes an image of the heat absorber and an image of the identification object.

[0121] S1104 : Determine a first imaging position of the sun on the image sensor of the imaging module based on the solar image data.

[0122] Specifically, the first imaging position is obtained by processing solar image data using a template matching method or a deep learning method. The template matching method compares the solar image data with a pre-prepared solar template image to determine the first imaging position. The deep learning method is a deep learning model that inputs the solar image data into the deep learning model, which then outputs the first imaging position.

[0123] S1106 : Determine a second imaging position of the identification object on the image sensor based on the identification image data.

[0124] Specifically, the second imaging position is obtained by processing the identification image data based on a template matching method or a deep learning method. The method for determining the second imaging position is similar to the method for determining the first imaging position, and will not be repeated here.

[0125] S1108 , determining a third imaging position of the heat absorber on the image sensor according to the relative position data between the identification object and the heat absorber and the second imaging position.

[0126] S1110 : Determine a difference angle between sunlight reflected by the heliostat and scattered light from the heat absorber according to the first imaging position and the third imaging position.

[0127] The difference angle is used to indicate adjustment of the heliostat's attitude.

[0128] In some embodiments, the adjustment module further includes a second image reading module. The second image reading module is configured to acquire multiple frames of image data from the imaging data according to the exposure time and fuse the acquired multiple frames of image data to generate a high dynamic range image. The adjustment module is further configured to adjust the heliostat's posture based on the relative position data between the identification object and the heat sink and the high dynamic range image.

[0129] Specifically, by controlling the exposure time of the first duration, a high-quality image of the heat absorber can be obtained, and by controlling the exposure time of the second duration, a high-quality image of the sun can be obtained. By controlling the exposure time of the third duration, a high-quality image of the identification object can be obtained. The third duration is longer than the first duration, and the first duration is longer than the second duration. The first duration, the second duration, and the third duration can be set in combination with the actual imaging situation. No specific limitation is made here. Therefore, a multiple exposure method is used, and multiple frames of image data are obtained by controlling the exposure time. The image data obtained by the multiple exposures are fused to form a high dynamic range image. At this time, the sun, the heat absorber, and the identification object will all appear on the high dynamic range image. Exemplarily, multiple frames of image data are obtained from the imaging data according to the first duration, the second duration, and the third duration, and the obtained multiple frames of image data are fused to obtain a high dynamic range image. Although the images of the sun and the identification object are not clear in the image data frame corresponding to the first exposure time, the images of the heat absorber and the identification object are not clear in the image data frame corresponding to the second exposure time, and the images of the heat absorber and the sun are not clear in the image data frame corresponding to the third exposure time, after fusing the image data obtained by multiple exposures, the sun, heat absorber and identification object can all appear relatively clearly in the fused high dynamic range image.

[0130] However, the image quality of the heat sink is unstable. Even if the heat sink appears relatively clearly in the fused high-dynamic-range image, an indirect method using a marker object is used. First, multiple frames of image data are acquired from the imaging data according to the exposure time and fused to produce a high-dynamic-range image. Second, the imaging position of the marker object is identified from the high-dynamic-range image. The image position of the heat sink is then determined based on the marker object's imaging position and the relative position between the marker object and the heat sink. Finally, the heliostat's attitude is adjusted based on the absorber's imaging position and the position of the sun's image, so that the sun's image and the absorber's image roughly overlap.

[0131] In some embodiments, the first image processing module includes a second angle comparison module. The second angle comparison module is configured to determine a difference angle between sunlight reflected by the heliostat and light scattered by the heat absorber based on the relative position data between the identification object and the heat absorber and the high dynamic range image; the difference angle is used to indicate an adjustment to the heliostat's posture.

[0132] Specifically, because the image quality of the heat sink is unstable, the difference angle between the sunlight reflected by the heliostat and the scattered light from the heat sink is indirectly determined based on the relative position data between the marker object and the heat sink and the high dynamic range image. This difference angle includes at least one of an azimuth error and an elevation error. This difference angle serves as an error signal in a closed-loop control system, instructing adjustments to the heliostat's posture, thereby achieving high-precision closed-loop control of the heliostat.

[0133] In some embodiments, the first image processing module further includes a second position determination module. The second position determination module is configured to determine a first imaging position of the sun on the image sensor of the imaging module based on the high dynamic range image, and to determine a third imaging position of the heat absorber on the image sensor based on the relative position data between the identification object and the heat absorber and the high dynamic range image; and the second angle comparison module is further configured to determine a difference angle between the first imaging position and the third imaging position.

[0134] Specifically, a second image reading module acquires multiple frames of image data from the imaging data according to the exposure time, fuses the acquired multiple frames of image data to generate a high dynamic range image, and then performs sun recognition on the high dynamic range image to determine a first imaging position of the sun on the image sensor of the imaging module. Due to the unstable imaging quality of the heat absorber and the possibility that the heat absorber image overlaps with the sun's image, the second position determination module does not directly determine the heat absorber's imaging position on the image sensor. Instead, it indirectly determines a third imaging position of the heat absorber on the image sensor based on the high dynamic range image and the relative position data between the identification object and the heat absorber. By comparing the number of pixels difference between the first and third imaging positions, the difference is converted into the difference in angle between the sunlight reflected by the heliostat and the scattered light from the heat absorber.

[0135] In some embodiments, the second position determination module is also used to determine the second imaging position of the identification object on the image sensor of the imaging module based on the high dynamic range image, and determine the third imaging position based on the relative position data between the identification object and the heat absorber and the second imaging position.

[0136] Specifically, the second image reading module obtains multiple frames of image data from the imaging data according to the exposure time, and the obtained multiple frames of image data are fused to obtain a high dynamic range image, and the high dynamic range image includes the image of the heat absorber and the image of the identification object. Since the imaging quality of the heat absorber is unstable and the image of the heat absorber may overlap with the image of the sun, the second position determination module uses the high dynamic range image to determine the second imaging position of the identification object on the image sensor, and then determines the third imaging position of the heat absorber on the image sensor in combination with the relative position data between the identification object and the heat absorber and the second imaging position.

[0137] In some embodiments, the first imaging position and the second imaging position are each obtained by processing a high dynamic range image using a template matching method or a deep learning method. It should be noted that the first imaging position can also be obtained by processing solar image data using edge detection, binarization, or the like. The second imaging position can also be obtained by processing marker image data using edge detection, binarization, or the like.

[0138] Referring to FIG. 11 , an embodiment of this specification provides a method for determining the difference angle between sunlight reflected by a heliostat and scattered light from a heat absorber. The method includes the following steps:

[0139] S1101 , acquiring multiple frames of image data from imaging data according to exposure time, and fusing the acquired multiple frames of image data to obtain a high dynamic range image.

[0140] S1103 : Determine a first imaging position of the sun on the image sensor of the imaging module based on the high dynamic range image.

[0141] The first imaging position is obtained by processing the high dynamic range image based on a template matching method or a deep learning method.

[0142] S1105 . Determine a second imaging position of the identification object on the image sensor of the imaging module based on the high dynamic range image.

[0143] The second imaging position is obtained by processing the high dynamic range image based on a template matching method or a deep learning method.

[0144] S1107: Determine a third imaging position according to the relative position data between the identification object and the heat absorber and the second imaging position.

[0145] S1109: Determine the difference angle between the sunlight reflected by the heliostat and the scattered light from the heat absorber according to the first imaging position and the third imaging position.

[0146] The difference angle is used to indicate adjustment of the heliostat's attitude.

[0147] In some embodiments, the adjustment module includes a second image processing module configured to determine a center distance between a center point of the image of the heat absorber and a center point of the image of the sun based on the imaging data, the center distance data being used to indicate adjustment of the heliostat's posture.

[0148] Specifically, the imaging module images the redirected sunlight and scattered light from the absorber to generate imaging data. The imaging data includes image data of the absorber and image data of the sun. The center point of the absorber image is determined based on the absorber image data. The center point of the sun image is determined based on the sun image data. The center distance data between the absorber image and the sun image is calculated based on the center point coordinates of the absorber image and the sun image. Based on this center distance data, an adjustment strategy for the heliostat is generated to ensure that the sun image and the absorber image approximately overlap.

[0149] In some embodiments, the second image processing module is further configured to convert the center distance data into horizontal angle adjustment data in the horizontal dimension and azimuth angle adjustment data in the azimuth dimension; the horizontal angle adjustment data and the azimuth angle adjustment data are used to indicate adjustment of the heliostat's posture.

[0150] The horizontal angle adjustment data may be the horizontal angle of the heliostat that needs to be changed, and the azimuth angle adjustment data may be the azimuth angle of the heliostat that needs to be changed. Specifically, the center distance data between the image of the heat absorber and the image of the sun is converted into adjustment data in at least one of the horizontal and azimuth dimensions, and the heliostat's posture is adjusted using the adjustment data in at least one dimension. It should be noted that a center distance error threshold can be pre-set based on actual conditions, and the center distance data between the image of the heat absorber and the image of the sun is compared to see if it is less than the center distance error threshold. If it is less than the center distance error threshold, the heliostat does not need to be adjusted and can continue tracking the sun. If it is not less than the center distance error threshold, the heliostat needs to be adjusted, so the center distance data between the image of the heat absorber and the image of the sun is converted into horizontal angle adjustment data and azimuth angle adjustment data. The horizontal angle adjustment data and azimuth angle adjustment data are transmitted to the heliostat controller to adjust the heliostat's posture. It should be noted that the second image processing module, second position determination module, second angle comparison module, etc. in this specification can be understood as corresponding software programs, which can be stored in a memory and executed by a processor.

[0151] The embodiment of the present specification further provides a sighting system, which further includes a sighting control module. The sighting control module is used to control the posture of the sighting system so that the marked object can be imaged at a specified position of the image sensor of the imaging module.

[0152] Specifically, the aiming system can be considered a system that includes an aimer, which includes an optical path module and an imaging module. The aiming control module primarily controls the aimer, which is used to control the posture of the optical path module and the imaging module so that the marker object is imaged at a specified location on the imaging module's image sensor. For example, the marker object and the heat absorber are both located within the imaging module's field of view; the imaging module images the scattered light from the heat absorber and the marker object. The heat absorber is pre-set to image at the center of the image sensor. Since the relative position between the marker object and the heat absorber is fixed, the specified location of the marker object on the image sensor can be determined based on the relative position between the marker object and the heat absorber and the center of the image sensor. It should be noted that if the heat absorber is pre-set to image at the center of the image sensor, the specified location of the marker object on the image sensor can be determined based on the relative position between the heat absorber and the marker object and the center of the image sensor. The aiming control module can be understood as an aiming control program, which can be stored in memory and executed by a processor.

[0153] In some embodiments, the aiming control module includes a posture calculation module. The posture calculation module is configured to calculate posture adjustment data for the aiming system based on the relative position data between the heliostat and the heat sink and the current posture data of the heliostat. The posture adjustment data is used to indicate how to control the posture of the aiming system.

[0154] Among them, the current attitude data can be used to describe the current attitude of the heliostat. The attitude adjustment data can be the angle that the heliostat needs to change, such as the pitch angle that needs to be changed or the azimuth angle that needs to be changed. Specifically, the information in the configuration file is first read, and then the system motor and imaging module self-test is performed. If the self-test fails, an error message is sent to the mirror field control module and the process ends. If the self-test passes, the mirror field control module is requested to obtain the relative position data between the heliostat and the heat absorber and the current attitude data of the heliostat. The attitude adjustment data of the aiming system is calculated based on the relative position data between the heliostat and the heat absorber and the current attitude data of the heliostat. The attitude adjustment data is used to control the attitude of the aiming system. It should be noted that two locking control strategies for the aiming system can be pre-configured. The first locking control strategy is the mirror field control module control method, and the second locking control strategy is the real-time target recognition method. If the field control module is used, a data request is sent to the field control module to obtain the relative position data between the heliostat and the receiver, as well as the heliostat's current attitude data, thereby determining the attitude adjustment data for the aiming system. The field control module can be understood as the host computer of the heliostat controller, which is a computer device. The attitude calculation module can be understood as the corresponding attitude calculation program, which can be stored in memory and executed by the processor.

[0155] For example, a geodetic coordinate system is established within the mirror field with the tower as the coordinate origin. This way, each heliostat has unique coordinate data. The coordinate data for each heliostat is measured during installation using geodetic mapping or satellite positioning and stored in the heliostat control module. For any heliostat, a specific direction can be selected within the geodetic coordinate system to locate the zero position of the heliostat, for example, setting true north as the zero position of the heliostat's mirror surface. After determining the coordinate system, the direction vector of the line connecting the center of each heliostat and the heat sink can be determined. When any heliostat rotates, the sight of the aiming system rotates with it. At this point, the angular difference (denoted as α and γ) between the normal direction vector of the current heliostat surface and the direction vector of the line connecting the center of the heliostat and the heat sink in the horizontal and elevation directions can be calculated using the rotation angle of the heliostat relative to the zero position in both the horizontal and elevation directions and the direction vector of the line connecting the center of the heliostat and the heat sink. In the field control module, the collimator and heliostat rotate together in both horizontal and elevation directions. The collimator's zero position can be set to the direction normal to the heliostat's surface. With these angle differences α and γ known, the collimator can be controlled to rotate in opposite directions by α and γ, thereby pointing toward the receiver.

[0156] In some embodiments, the aiming control module includes a posture adjustment module; the posture adjustment module is used to adjust the posture of the aiming system according to a preset rotation angle.

[0157] Specifically, if real-time target recognition is determined, the motor controls the rotation according to a preset angle. After each rotation, a photo is taken. Based on the image data obtained, it is detected whether the target has moved into a designated area of ​​the image. For example, if the target is a heat sink, the heat sink is detected to see if it has moved into the center area of ​​the image. Alternatively, the target is an identifier, and the identifier is detected to see if it has moved into an area surrounding the center area of ​​the image. Alternatively, if the target is a heat sink and an identifier, the heat sink and the identifier are detected to see if they are located in their respective corresponding areas. For example, the preset rotation angle may be any of 1, 2, 3, or 5 degrees. For example, the motor controls the aiming system to rotate 1 degree, and after that, a photo is taken. Based on the image data obtained, it is detected whether the target has moved into the designated area of ​​the image. If not, the motor controls the aiming system to rotate 1 degree again, and the above steps of taking photos and detecting whether the target has moved into the designated area of ​​the image are repeated until the target is detected to have moved into the designated area of ​​the image. The posture adjustment module can be understood as a corresponding posture adjustment program, which can be stored in memory and executed by the processor.

[0158] In some embodiments, the posture adjustment module is further configured to trigger sending an error message to the scope control module if it is determined that the statistical rotation angle of the aiming system has exceeded a preset angle threshold.

[0159] Specifically, if real-time target recognition is used, after each rotation according to a preset angle, the rotation angle is statistically calculated to obtain a statistical rotation angle of the aiming system. If the target is not detected in the captured image, the statistical rotation angle of the aiming system is compared with a preset angle threshold. If the statistical rotation angle of the aiming system exceeds the preset angle threshold, an operational error has occurred, triggering the transmission of an error message to the field of view control module. If the statistical rotation angle of the aiming system does not exceed the preset angle threshold, the aiming system posture is adjusted according to the preset rotation angle, and the capture and target recognition process is repeated until the target is detected moving to a specified area of ​​the image. It is understood that the target in this embodiment can be a heat sink or a marking object. For example, the preset angle threshold can be any of 90 degrees, 180 degrees, 270 degrees, or 360 degrees. For example, if the aiming system has rotated 360 degrees under motor control and no target is detected in the captured image during the rotation, an operational error has occurred, triggering the transmission of an error message to the field of view control module.

[0160] In some embodiments, the aiming control module further includes an identification module and a position determination module.

[0161] The imaging module is also used to image the scattered light of the identification object after the posture of the aiming system is adjusted to obtain an adjusted identification image.

[0162] The identification recognition module is used to recognize the identification object based on the adjusted identification image and obtain position data of the identification object in the adjusted identification image.

[0163] The position judgment module is used to judge whether the posture of the aiming system needs to be adjusted again based on the position data of the marked object in the adjusted marked image, so that the marked object can be imaged at the specified position of the image sensor.

[0164] Specifically, after the aiming system's posture is adjusted, scattered light from the marker object enters the imaging module, where it is imaged to obtain an adjusted marker image. The marker recognition module can be understood as a marker recognition program. By running the marker recognition program, target recognition is performed on the adjusted marker image to obtain position data of the marker object in the adjusted marker image. The marker recognition program can be stored in a memory and executed by a processor. Because a preset position of the marker object in the image is already set, the actual position data of the marker object in the adjusted marker image is compared with the preset position of the marker object in the image to determine whether the aiming system's posture needs to be adjusted again. If the comparison between the actual position data and the preset position determines that the marker object's image is already at the designated position of the image sensor, then no further adjustment is required. If the comparison between the actual position data and the preset position determines that the marker object's image is not at the designated position of the image sensor, then further adjustment is required to ensure that the marker object is imaged at the designated position of the image sensor. By way of example, the preset position of the marker object in the image can be determined based on the imaging position of the heat absorber and the relative position data between the heat absorber and the marker object. The position determination module can be understood as a corresponding position determination program, which can be stored in a memory and executed by a processor.

[0165] In some embodiments, the identification recognition module is further configured to trigger sending an error message to the mirror field control module if it is recognized that the identification object does not exist in the adjusted identification image.

[0166] Specifically, target recognition is performed on the adjusted identification image. If the identification object cannot be recognized in the adjusted identification image, an error message is triggered to be sent to the mirror field control module.

[0167] In some embodiments, the aiming control module is further used to control the aiming system to enter a locked state when the identification object has been imaged at the specified position; or to readjust the posture of the aiming system when the identification object has not been imaged at the specified position.

[0168] Specifically, if the marker object is detected moving into a designated area of ​​the image, the image capture process is interrupted, and the aiming system's optical path module and imaging module enter a locked state. This indicates that scattered light from the heat absorber and the marker object can directly enter the imaging module, and the aiming system is activated to measure the difference angle between sunlight reflected from the heliostat and scattered light from the heat absorber. If the comparison of the actual position data with the preset position determines that the marker object is not imaged at the designated location, further adjustment is required to ensure that the marker object is imaged at the designated location on the image sensor.

[0169] In some embodiments, the aiming system further includes an aiming control module, which is configured to control the posture of the aiming system so that the heat absorber can be imaged at the center of the image sensor of the imaging module.

[0170] Specifically, the main control object of the aiming control module includes the aimer, which is used to perform posture control on the optical path module and the imaging module so that the heat absorber can be imaged at the central area of ​​the image sensor of the imaging module.

[0171] In some embodiments, the aiming system includes a heliostat control module communicatively coupled to the adjustment module, which is in turn communicatively coupled to a mirror field control module. The mirror field control module is configured to modify the time interval and the heliostat control time interval based on the frequency of wind speed fluctuations when the heliostats are continuously subjected to variable wind loads.

[0172] The reflected light spot area and shape of each heliostat in the field at various times of the year are calculated in advance through simulation and experimentation and stored in the field control module. The field control module uses astronomical algorithms to calculate the reflected power of each heliostat in real time at various times of the year. The interval between time intervals matches the heliostat control interval.

[0173] As mentioned above, to ensure that the sunlight reflected by the heliostats accurately strikes the absorber, the heliostat's focusing angle deviation must be less than 1 mrad. Therefore, in some cases, it's necessary to comprehensively consider various factors affecting the heliostat's posture. For example, heliostats are continuously affected by variable wind loads. Therefore, the frequency of wind speed fluctuations must be considered when controlling the heliostats. Specifically, an instrument (such as an anemometer) can be deployed in the mirror field to measure wind speed conditions. This instrument monitors the wind speed conditions in the mirror field. The instrument communicates with the mirror field control module and transmits the monitored wind speed conditions to the mirror field control module. Based on the received wind speed conditions, the mirror field control module determines whether the heliostats are continuously affected by the variable wind load. If the heliostats are determined to be continuously affected by the variable wind load, the wind speed fluctuation frequency is determined based on the wind speed conditions. The time interval and the heliostat control time interval are adjusted based on the determined wind speed fluctuation frequency. It should be noted that if the heliostats are continuously affected by the variable wind load, it is also necessary to determine whether the maximum wind load exceeds the allowable value. When the maximum wind load does not exceed the allowable value, the time interval and the heliostat control time interval are corrected. It should be noted that the variable wind load can be understood as the variable wind load on the heliostat, such as the variable wind load caused by wind speed changes.

[0174] For example, the time interval is denoted as t1, and the heliostat control interval is denoted as t2. After the mirror field control module determines the wind speed variation frequency, it searches the pre-stored relationship data between the wind speed variation frequency and the correction coefficient based on the determined wind speed variation frequency to obtain the corresponding correction coefficient θ. The mirror field control module uses the correction coefficient θ to adjust the time interval t1. For example, the adjusted time interval is θ*t1. The mirror field control module also uses the correction coefficient θ to adjust the time interval t2. For example, the adjusted time interval is θ*t2. It should be noted that θ can be a preset reduction percentage.

[0175] The embodiments of the present specification further provide a sighting system, which further includes a heliostat control module communicatively connected to the adjustment module; the heliostat control module is configured to receive attitude adjustment data determined based on the imaging data and control the adjustment module to rotate the heliostat based on the attitude adjustment data.

[0176] The heliostat control module can be understood as the heliostat controller. The heliostat controller can be installed at the heliostat's rotation drive input or on the mirror surface, controlling the rotation of the horizontal drive motor and azimuth drive motor via wired or wireless communication. The heliostat controller receives attitude adjustment data via wired or wireless communication. It is understood that the attitude adjustment data can be transmitted from the aiming control module (which can be understood as the aiming controller) of the aiming system to the heliostat control module. The aiming controller can be a controller for controlling the attitude of the optical path module and imaging module so that the heat absorber and / or the identification object appear within the imaging module's field of view. In other words, the aiming controller can be understood as a controller that controls the aiming system, including the optical path module and imaging module, to aim at the heat absorber and / or the identification object. The heliostat controller can be understood as an electronic device that includes a CPU or MCU.

[0177] The attitude adjustment data may include at least one of azimuth angle data and pitch angle data obtained by processing imaging data from the imaging module and used to indicate the rotation of the heliostat. The azimuth angle data may include an azimuth angle error value, and the pitch angle data may include a pitch angle error value.

[0178] Specifically, the attitude adjustment data can be used to modify the azimuth and pitch angles of the heliostat. The adjustment module controls the heliostat to rotate according to the modified azimuth and pitch angles so that the sunlight reflected by the heliostat is parallel to the scattered light from the absorber, so that the image of the absorber and the image of the sun roughly overlap.

[0179] For example, the heliostat controller can calculate the current solar altitude and azimuth based on the longitude, latitude, altitude, and time of day of the heliostat's center point. Then, based on the three-dimensional coordinate difference between the heliostat's mirror center point and the receiver's center point, it calculates the target azimuth and pitch angles of the mirror required to reflect sunlight onto the receiver. The heliostat controller controls the horizontal rotation drive motor at the drive output and the pitch rotation drive motor at the drive shaft to operate so that the mirror's azimuth and pitch angles are as close as possible to the theoretically calculated target azimuth and pitch angles. To ensure control accuracy, the heliostat controller also calculates the optimal speeds for the horizontal and pitch rotation drive motors to maintain sunlight reflection onto the receiver, and maintains these motor speeds.

[0180] Mechanical errors and other factors may cause sunlight reflected by the heliostat to not reach the heat sink. The heliostat controller reads the azimuth and elevation deviation values ​​measured by the aiming system in real time. Based on the current target azimuth and elevation angles, the heliostat controller uses these values ​​to make corrections. It calculates the optimal speed and direction for the pan and tilt drive motors and controls the motors accordingly, keeping the azimuth and elevation deviation values ​​measured by the aiming system as close to zero as possible. This ensures that sunlight reflected by the heliostat reaches the heat sink as closely as possible.

[0181] In some embodiments, the heliostat control module is communicatively connected to the mirror field control module. The heliostat control module is configured to feed back current posture data of the heliostat to the mirror field control module.

[0182] Specifically, the mirror field control module can be understood as the host computer for each heliostat's controller. The mirror field control module communicates with the heliostat control module of each heliostat. After the heliostat control module controls the adjustment module to rotate the heliostat according to the posture adjustment data, the heliostat control module sends the current posture data of the heliostat to the mirror field control module, which then records the current posture data. The host computer of the heliostat controller can be understood as a computer device.

[0183] In some embodiments, the heat absorber is divided into multiple heat absorption regions. Each heat absorption region corresponds to a target heliostat. The target heliostat corresponding to any heat absorption region is a heliostat capable of reflecting sunlight toward that heat absorption region. The mirror field control module is configured to detect whether any heat absorption region satisfies the principle of uniform energy distribution based on the irradiation energy data of the target heliostat.

[0184] In some cases, not all heliostats capable of reflecting sunlight toward heat absorption region X are considered target heliostats for heat absorption region X. If the ratio of sunlight reflected by heliostat Y toward heat absorption region X to the total sunlight reflected by heliostat Y exceeds a preset threshold, heliostat Y is determined to be the target heliostat for heat absorption region X. If the ratio of sunlight reflected by heliostat Y toward heat absorption region X to the total sunlight reflected by heliostat Y does not exceed the preset threshold, heliostat Y is not considered the target heliostat for heat absorption region X. For example, the preset threshold can be 3%, 5%, or 10%. For example, if heliostat Y can reflect more than 5% of its total sunlight toward heat absorption region X at all times throughout the year, heliostat Y is determined to be the target heliostat for heat absorption region X. In some cases, any heliostat capable of reflecting sunlight toward heat absorption region X can be considered the target heliostat for heat absorption region X.

[0185] The irradiation energy data may be energy data related to the heliostat's reflected power. For example, the irradiation energy data may be the heliostat's reflected power. The irradiation energy data may be data on the solar irradiation on the heliostat, such as the radiant flux falling on the heliostat. The principle of uniform energy distribution aims to ensure relatively uniform temperature across the heat sink, thereby reducing the likelihood of heat sink failure or reduced efficiency due to uneven temperatures.

[0186] Specifically, the heat absorber is divided into multiple heat absorption regions, and each of these regions is inspected to prevent local overheating. For any heat absorption region (denoted as X), although there are multiple heliostats in the field, not every heliostat in the field can reflect sunlight to that region. Therefore, a target heliostat that can reflect sunlight to that region is required. Similarly, each heat absorption region is assigned its own target heliostat.

[0187] After configuring a corresponding target heliostat for each heat absorption area, the illumination condition of sunlight on each heat absorption area can be determined based on the illumination energy data of the target heliostat, thereby detecting whether each heat absorption area meets the principle of uniform energy distribution.

[0188] In some embodiments, the mirror field control module is further configured to determine the irradiation energy data of the target heliostat based on the relative position data between the target heliostat and the absorber, the projected area of ​​the target heliostat, the mirror reflectivity, and the solar irradiation data.

[0189] Specifically, the direction vector corresponding to the sun's position at the target heliostat is first determined, denoted as the solar azimuth vector. Secondly, the azimuth vector of the heat absorber is determined based on the relative position data between the target heliostat and the heat absorber. Next, the azimuth and elevation angles of the target heliostat at the current moment are determined based on the principle that the target heliostat's surface normal, the sun's azimuth vector, and the heat absorber's azimuth vector satisfy the reflection theorem. Based on this, the target heliostat's projected area is determined. Finally, the target heliostat's irradiation energy data is determined based on the target heliostat's projected area, mirror reflectivity, and solar irradiance data.

[0190] For example, the irradiation energy data of the target heliostat is the reflected power of the heliostat at a certain moment. 1) Establish a geodetic coordinate system with the heliostat as the origin, due north as y+, and due east as x+; 2) Calculate the sun's position at the heliostat according to the astronomical algorithm; 3) Convert the sun's position at the heliostat into a direction vector in the geodetic coordinate system; 4) Calculate the azimuth and elevation angle of the heliostat at the current moment, so that the surface normal direction of the heliostat, the azimuth vector of the sun, and the azimuth vector of the heat absorber satisfy the reflection theorem; 5) Calculate the two directions of the sun's azimuth vector and the surface normal vector of the heliostat. 6) Let the area of ​​the heliostat be S. The area of ​​its projection onto the sun is equal to the product of S and cos(a). 7) Let the maximum ground irradiance be E (the maximum ground irradiance E can be the irradiance measured by a radiometer facing the sun, not the horizontal irradiance at ground level). Then the radiation flux falling on the heliostat is equal to E*S*cos(a) watts. If the reflectivity of the mirror is R, then the reflected power of the heliostat is equal to R*E*S*cos(a) watts.

[0191] In some embodiments, the mirror field control module is communicatively connected to a radiometer; the radiometer is used to collect solar irradiation data.

[0192] The mirror field can be divided into regions, each equipped with a radiometer. Each radiometer is connected to the mirror field control module. Specifically, the radiometer in the mirror field where the target heliostat is located is first identified. This radiometer then collects solar irradiance data, thereby determining the target heliostat's irradiance energy data.

[0193] In some embodiments, the mirror field control module is used to determine the energy density of each heat absorption area according to the irradiation energy data of the target heliostat, and detect whether each heat absorption area meets the energy uniform distribution principle according to the energy density of each heat absorption area.

[0194] Specifically, each heat absorption region corresponds to multiple target heliostats, each of which has irradiation energy data. Based on the irradiation energy data of each target heliostat, statistics are collected to obtain the total irradiation energy of each heat absorption region. Based on the total irradiation energy and the area of ​​each heat absorption region, the energy density of each heat absorption region is calculated. Based on the energy density of each heat absorption region, it is determined whether each heat absorption region meets the principle of uniform energy distribution. For example, the energy density differences between the energy densities of the heat absorption regions can be detected, and the detected energy density differences can be used to determine whether each heat absorption region is overheated.

[0195] The following example illustrates how to calculate energy density. It is understood that the sunlight reflected by the target heliostat onto the heat absorption region may be all of the sunlight reflected by the target heliostat, or it may be a portion of the sunlight reflected by the target heliostat. The ratio of the sunlight reflected by the target heliostat onto the heat absorption region to the total sunlight reflected by the target heliostat is defined as the percentage of sunlight reflected by the target heliostat onto the heat absorption region. This percentage of sunlight is related to the energy density of the heat absorption region. Therefore, the irradiation energy of the target heliostat in the heat absorption region is determined based on this percentage of sunlight and the irradiation energy data of the target heliostat. The irradiation energy of each target heliostat in the heat absorption region is summed to obtain the total irradiation energy of the heat absorption region. The energy density of each heat absorption region is obtained by dividing the total irradiation energy of the heat absorption region by the area of ​​the heat absorption region.

[0196] In some embodiments, the heat absorber has an average energy density. The principle of uniform energy distribution requires that the energy difference between the energy density of any heat absorbing region and the average energy density of the heat absorber is within an allowable energy difference range.

[0197] The energy density mean value p of the heat absorber is determined according to the following formula: m :

[0198] Among them, p i is the energy density of the ith absorption region, x is the number of heliostats in the entire field, and A is the area of ​​the absorber.

[0199] Specifically, the energy density p in any heat absorption area is i and the mean energy density p of the absorber m A comparison is performed to obtain energy difference data. If the energy difference data is within the allowable energy difference range, the heat absorption region satisfies the energy uniformity principle requirement. If the energy difference data is not within the allowable energy difference range, the heat absorption region does not meet the energy uniformity principle requirement, and the portion of the heliostat targeted in the heat absorption region needs to be rotated to meet the energy uniformity principle requirement.

[0200] In some embodiments, the energy density is determined based on the area of ​​the heat absorption region and the reflected power of the target heliostat.

[0201] For example, for each heat absorption region, the energy density of the heat absorption region is calculated according to the following formula:

[0202] Among them, p i is the energy density of the ith heat absorption area, i is the number of the target heliostat, x i is the number of target heliostats corresponding to the i-th heat absorption area. η is the percentage of sunlight from the target heliostat to the i-th heat absorption area, A i is the area of ​​the i-th heat absorption region. P(i) is the sunlight energy (or irradiation energy) reflected by the target heliostat to the heat absorber, which is related to the reflection power of the target heliostat.

[0203] In some embodiments, the mirror field control module is used to further divide the divided heat absorption area to obtain multiple sub-areas if it is detected that the divided heat absorption areas all meet the principle of uniform energy distribution, and further detect whether each sub-area meets the principle of uniform energy distribution based on the energy density of each sub-area.

[0204] Exemplarily, in order to ensure that the energy received by the surface of the heat absorber is uniform, the heat absorber is divided into multiple levels. Exemplarily, the multiple levels include the first level, the second level, the third level... and the last level. The heat absorber is divided into regions on the first level to obtain multiple heat absorption regions on the first level. If the individual heat absorption regions on the first level meet the energy uniform distribution requirements corresponding to the first level, the heat absorption regions obtained by the division on the first level are further divided on the second level to obtain multiple heat absorption regions on the second level. If the individual heat absorption regions on the second level meet the energy uniform distribution requirements corresponding to the second level, the heat absorption regions obtained by the division on the second level are further divided on the third level, and so on, until each subdivided region on the heat absorber meets the energy uniform distribution requirements corresponding to the last level.

[0205] It should be noted that the heat absorber is divided into regions on the first level to obtain multiple heat absorption regions on the first level. If the heat absorption regions on the first level do not meet the energy uniform distribution requirements corresponding to the first level, any one or a combination of the following treatment methods can be selected:

[0206] 1) The energy uniform distribution requirement corresponding to the first level can be adjusted to determine whether each heat absorption area on the first level meets the new energy uniform distribution requirement corresponding to the first level.

[0207] 2) The heat absorber can be re-divided at the first level to obtain multiple new heat absorption areas on the first level, and then it is determined whether each new heat absorption area on the first level meets the energy uniform distribution requirements corresponding to the first level.

[0208] 3) Adjusting at least a portion of the target heliostats corresponding to each heat absorption region changes the amount of sunlight received by the heat absorption region. For example, rotating a portion of the target heliostats corresponding to a heat absorption region with higher energy density causes these heliostats to reflect sunlight toward a heat absorption region with lower energy density. After rotating these target heliostats, recalculating the energy density of each heat absorption region to determine whether each heat absorption region on the first level meets the new uniform energy distribution requirement for the first level.

[0209] It is understandable that the processing method at the first level mentioned above can also be applied to other levels, and the processing methods at other levels will not be described in detail here.

[0210] In some embodiments, the principle of uniform energy distribution requires that the energy difference data between the energy density of any heat absorption area and the average energy density of the heat absorber is less than a first allowable threshold, and the energy difference data between the energy density of any sub-area and the average energy density of the heat absorber is less than a second allowable threshold.

[0211] In some embodiments, the second allowed threshold is less than the first allowed threshold.

[0212] Specifically, in order to ensure that the energy received by the surface of the heat absorber is uniform, the heat absorber is divided into multiple levels. Different levels are pre-set with corresponding first allowable thresholds. Exemplarily, the multiple levels include the first level, the second level, the third level... and the last level. The first level corresponds to the first allowable threshold, the second level corresponds to the second allowable threshold, the third level corresponds to the third allowable threshold... and the last level corresponds to the last allowable threshold. Among them, the first allowable threshold > the second allowable threshold > the third allowable threshold... > the last allowable threshold. It should be noted that for the first allowable threshold, the second allowable threshold, the third allowable threshold... and the last allowable threshold, the units of these allowable thresholds are the same as the units of energy density, which are watts per square meter (W / m 2 The value range of these allowable thresholds can be between 5-200, for example, the value range of the first allowable threshold is 100 to 200, and the value range of the last allowable threshold is 5 to 15. The second allowable threshold and the third allowable threshold in between can be set according to actual conditions and are not specifically limited here.

[0213] In some embodiments, the mirror field control module stores current posture data of the faulty heliostat; the mirror field control module is configured to record the number of the faulty heliostat, recalculate the energy density of the area to be evaluated based on the number of the faulty heliostat and the current posture data, and detect whether the area to be evaluated satisfies a principle of uniform energy distribution based on the energy density in the area to be evaluated.

[0214] The area to be evaluated is the area of ​​the heat sink that sunlight reflected by the faulty heliostat can reach. If some heliostats are inoperable due to strong winds or a control failure, these heliostats are identified as faulty. Before becoming inoperable, the faulty heliostats were able to reflect sunlight onto a portion of the heat sink. Since the faulty heliostats are currently inoperable, this area receives less sunlight, making it necessary to reassess whether it meets the principle of uniform energy distribution.

[0215] Specifically, the controller of the faulty heliostat sends the faulty heliostat's number to the mirror field control module, which stores the current posture data of each heliostat. The controller then determines the faulty heliostat's current posture data based on the faulty heliostat's number. The energy density of the area to be evaluated is recalculated based on the faulty heliostat's number and current posture data. The energy density in the area to be evaluated is then used to determine whether the area meets the principle of uniform energy distribution.

[0216] For example, the energy density of the area to be evaluated can be compared with the average energy density of the heat absorber to determine whether the difference in energy density between the two is within the allowable range required by the principle of uniform energy distribution. If so, no adjustment is required. If not, a heat absorbing region surrounding the area to be evaluated must be identified and the portion of the target heliostats corresponding to that region must be rotated to ensure that the energy density of the area to be evaluated meets the principle of uniform energy distribution.

[0217] For example, a heat-absorbing region surrounding the region to be evaluated is identified, and the energy density in the region to be evaluated is compared with the energy density of the heat-absorbing region to determine whether the energy difference between the region to be evaluated and the heat-absorbing region is within the allowable range required by the principle of uniform energy distribution. If so, no adjustment is required. If not, the portion of the target heliostats corresponding to the heat-absorbing region is rotated so that the energy density in the region to be evaluated meets the principle of uniform energy distribution.

[0218] In some embodiments, the heat absorber is divided into multiple heat absorption regions. The mirror field control module is communicatively connected to a temperature meter, such as an infrared thermal imaging thermometer, for monitoring the temperature of the heat absorption regions. The mirror field control module is configured to determine, based on temperature data monitored by the infrared thermal imaging thermometer, whether there are any uneven regions within the multiple heat absorption regions that do not meet the principle of uniform energy distribution.

[0219] Specifically, the temperature of each heat-absorbing area is monitored using an infrared thermal imaging thermometer. The infrared thermal imaging thermometer sends the detected temperature data to the mirror field control module, which receives the temperature data and determines whether there are any uneven areas in the multiple heat-absorbing areas that do not meet the principle of uniform energy distribution based on the received temperature data.

[0220] For example, when clouds partially block the view above the mirror field, it is necessary to adjust the energy balance on the heat absorber. When clouds block the view above the mirror field, the mirror field control module cannot determine whether the temperature of each area of ​​the heat absorber is uniform from the state of the heliostat itself. At this time, the temperature difference of each area of ​​the heat absorber can be monitored by an infrared thermal imaging thermometer, and the difference value can be uploaded to the mirror field control module. The mirror field control module can also re-divide the heat absorber into different areas. When there is cloud cover, the irradiance E value in the mirror field varies greatly, and the energy density difference in the target area is also large, making it difficult to meet the set threshold. Therefore, the heliostats in areas with large irradiance values ​​E and that cannot be adjusted across multiple target areas are reversed. That is, the angle between the azimuth vector of the sun and the surface normal vector of the heliostat is increased to be greater than the actual calculated theoretical value, thereby reducing the reflected power of the heliostat, or some heliostats are closed to make them horizontal.

[0221] In some embodiments, the heat absorber is divided into a plurality of heat absorption regions. The adjustment module is further configured to, if a non-uniform region exists among the plurality of heat absorption regions that does not satisfy the principle of uniform energy distribution, adjust the attitude of a portion of the plurality of heliostats corresponding to the non-uniform region to change the amount of sunlight reflected onto the non-uniform region.

[0222] The heliostats corresponding to the uneven regions are capable of reflecting sunlight toward the uneven regions. Specifically, the mirror field control module receives temperature data monitored by the infrared thermal imaging thermometer and, based on the received temperature data, determines whether any uneven regions within the multiple heat absorption regions satisfy the principle of uniform energy distribution. If any uneven regions exist within the multiple heat absorption regions, the heliostats corresponding to the uneven regions are identified and the positions of some of these heliostats are adjusted to alter the sunlight reflected toward the uneven regions.

[0223] In the above embodiment, by adjusting the postures of some of the heliostats corresponding to the uneven area, the sunlight reflected on the uneven area is reduced, thereby improving the uniformity of energy distribution on the surface of the absorber.

[0224] In some embodiments, the energy density of the non-uniform region is higher than the energy density of other heat-absorbing regions. The plurality of heliostats corresponding to the non-uniform region include a first heliostat and a second heliostat. The distance between the first heliostat and the heat absorber is smaller than the distance between the second heliostat and the heat absorber. The adjustment module is further configured to remove sunlight reflected by the first heliostat from the non-uniform region and retain sunlight reflected by the second heliostat to reduce sunlight reflected on the non-uniform region.

[0225] Specifically, because the distance between the first heliostat and the absorber is smaller than the distance between the second heliostat and the absorber, the spot area of ​​the first heliostat on the absorber is smaller than that of the second heliostat. Sometimes, sunlight reflected by the second heliostat can illuminate multiple heat-absorbing areas on the absorber. Adjusting the second heliostat affects not only the uneven area but also other areas. In other words, adjusting the second heliostat can significantly affect the energy distribution of the absorber. Therefore, prioritizing adjustment of the first heliostat to shift sunlight reflected from the uneven area while maintaining the position of the second heliostat unchanged can reduce the amount of sunlight reflected on the uneven area.

[0226] It should be noted that the logic and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing the logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (e.g., a computer-based system, a system including a processor, or other system that can fetch and execute instructions from an instruction execution system, apparatus, or device). For purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (non-exhaustive list) of computer-readable media include the following: an electrical connection with one or more wires (electronic device), a portable computer disk cartridge (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and programmable read-only memory (EPROM or flash memory), fiber optic devices, and portable compact disc read-only memory (CDROM). Furthermore, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or otherwise processing it in a suitable manner if necessary, and then storing it in a computer memory.

[0227] It should be understood that various parts of the present invention can be implemented using hardware, software, firmware, or a combination thereof. In the above-described embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0228] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0229] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0230] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0231] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A heliostat aiming system, characterized in that: The aiming system is suitable for the heliostat to reflect sunlight onto the heat absorber, and the aiming system includes an optical path module, an imaging module and an adjustment module; the optical path through which the sunlight reflected by the heliostat and the scattered light of the heat absorber pass includes a first optical path and a second optical path; the optical path of the sunlight reflected by the heliostat before entering the imaging module is recorded as the first optical path, and the optical path of the scattered light of the heat absorber before entering the imaging module is recorded as the second optical path; The optical path module includes a light redirecting element, and the light redirecting element is arranged on the first optical path; the sunlight reflected by the heliostat passes through the light redirecting element to obtain redirected sunlight that can be incident on the imaging module, the heat absorber is located within the field of view of the imaging module, and the scattered light of the heat absorber passes through the second optical path and keeps the original direction to be directly incident on the imaging module; The imaging module is used to image the redirected sunlight and the scattered light of the heat absorber to obtain imaging data of the imaging module; wherein the imaging data includes an image of the sun and an image of the heat absorber; The adjustment module is used to determine the imaging position of the sun and the imaging position of the heat absorber according to the imaging data of the imaging module, and adjust the posture of the heliostat according to the imaging position of the sun and the imaging position of the heat absorber so that the distance between the imaging position of the sun and the imaging position of the heat absorber is less than a preset distance threshold.

2. The aiming system according to claim 1, characterized in that: The sunlight reflected by the heliostat is incident on the imaging module after being reflected multiple times by the light redirecting element; The sunlight reflected by the heliostat is reflected twice by the light redirecting element and then incident on the imaging module, and the redirected sunlight is 180 degrees opposite to the sunlight reflected by the heliostat; The light deflection element is configured as a corner cube prism.

3. The aiming system according to claim 1, characterized in that: The aiming system includes a housing; The imaging module and the optical path module are both arranged in the housing, and the housing has the first optical path and the second optical path; The housing is formed with a first light window and a second light window. Sunlight reflected by the heliostat is incident on the first light path through the first light window, and scattered light from the heat absorber is incident on the second light path through the second light window.

4. The aiming system according to claim 3, characterized in that: The housing is suitable for being arranged at the middle position of the heliostat; The posture of the housing depends on the relative position between the heliostat and the absorber, so that the sunlight reflected by the heliostat can be focused on the image sensor of the imaging module after passing through the light deflection element, and the scattered light of the absorber can be focused on the central area of ​​the image sensor.

5. The aiming system according to claim 3, characterized in that: The optical path module further includes: a first attenuation sheet, which is disposed in the housing; the first attenuation sheet is disposed on the first optical path, and along the propagation direction of the light in the first optical path, the first attenuation sheet is located on the upstream side of the light redirecting element; Wherein, the optical path module also includes: a first optical filter, which is arranged in the housing; the first optical filter is arranged on the first optical path, and along the propagation direction of the light in the first optical path, the first optical filter is located between the first attenuation plate and the light deflection element, or the first optical filter is located on the upstream side of the first attenuation plate.

6. The aiming system according to claim 5, characterized in that: The imaging module includes a lens barrel, which is formed with a light incident end, and the central axis of the lens barrel serves as the optical axis of the imaging module; the light deflection element is arranged at the light incident end, so that the sunlight reflected by the heliostat can be incident on the imaging module after passing through the light deflection element; wherein the number of the light deflection elements is 1; or the number of the light deflection elements is multiple.

7. The aiming system according to claim 6, characterized in that: The imaging module comprises an objective lens and an image sensor; the objective lens and the image sensor are arranged in the lens barrel, and the objective lens is located between the image sensor and the light incident end; a second filter is arranged on the second optical path, and the second filter is arranged at the light incident end; Among them, a second attenuation plate is arranged on the second optical path, the second filter is located on the upstream side of the light propagation direction in the second optical path, and the second attenuation plate is located on the downstream side of the light propagation direction in the second optical path; or, the second attenuation plate is located on the upstream side of the light propagation direction in the second optical path, and the second filter is located on the downstream side of the light propagation direction in the second optical path.

8. The aiming system according to claim 1, characterized in that: An identification object is arranged on the mounting base of the heat absorber, and the identification object and the heat absorber are located together within the field of view of the imaging module; the imaging module is also used to image the scattered light of the identification object.

9. The aiming system according to claim 8, characterized in that: The adjustment module includes a first image processing module and a first image reading module; The first image reading module is used to obtain solar image data and identification image data from the imaging data according to a preset color; wherein the solar image data includes an image of the sun, and the identification image data includes an image of the heat absorber and an image of the identification object; The first image processing module is used to determine the difference angle between the sunlight reflected by the heliostat and the scattered light of the heat absorber according to the relative position data between the identification object and the heat absorber, the solar image data and the identification image data; the difference angle is used to indicate the adjustment of the posture of the heliostat.

10. The aiming system according to claim 9, characterized in that: The first image processing module includes a first position determination module and a first angle comparison module; The first position determination module is used to determine a first imaging position of the sun on the image sensor of the imaging module based on the sun image data, and to determine a third imaging position of the heat absorber on the image sensor based on the identification image data and the relative position data between the identification object and the heat absorber; The first angle comparison module is further configured to determine the difference angle according to the first imaging position and the third imaging position.

11. The aiming system according to claim 9, characterized in that: The adjustment module also includes a second image reading module; The second image reading module is used to obtain multiple frames of image data from the imaging data according to the exposure time, and to obtain the multiple frames of image data. Image data is fused to obtain a high dynamic range image; The adjustment module is further used to adjust the posture of the heliostat according to the relative position data between the identification object and the heat absorber and the high dynamic range image.

12. The aiming system according to claim 11, characterized in that The first image processing module includes a second angle comparison module; The second angle comparison module is used to determine the difference angle between the sunlight reflected by the heliostat and the scattered light of the absorber based on the relative position data between the identification object and the absorber and the high dynamic range image; the difference angle is used to indicate the adjustment of the posture of the heliostat.

13. The aiming system according to claim 12, characterized in that: The first image processing module also includes a second position determination module; The second position determination module is used to determine a first imaging position of the sun on the image sensor of the imaging module based on the high dynamic range image, and to determine a third imaging position of the heat absorber on the image sensor based on the relative position data between the identification object and the heat absorber and the high dynamic range image; The second angle comparison module is further configured to determine the difference angle according to the first imaging position and the third imaging position.

14. The aiming system according to claim 8, characterized in that: The aiming system also includes an aiming control module; The aiming control module is used to control the posture of the aiming system so that the identification object can be imaged at a specified position of the image sensor of the imaging module; Alternatively, it is used to control the posture of the aiming system so that the heat absorber can be imaged at the central area of ​​the image sensor of the imaging module.

15. The aiming system according to claim 14, characterized in that The aiming control module includes a posture calculation module and a posture adjustment module; The attitude calculation module is used to calculate according to the relative position data between the heliostat and the heat absorber and the current attitude data of the heliostat to obtain attitude adjustment data of the aiming system, wherein the attitude adjustment data is used to indicate control of the attitude of the aiming system; The posture adjustment module is used to adjust the posture of the aiming system according to a preset rotation angle; if it is determined that the statistical rotation angle of the aiming system has exceeded a preset angle threshold, it triggers the sending of an error message to the upper computer.

16. The aiming system according to claim 15, characterized in that The aiming control module also includes a mark recognition module and a position determination module; The imaging module is further used to image the scattered light of the identification object after adjusting the posture of the aiming system to obtain an adjusted identification image; The identification recognition module is used to identify the identification object based on the adjusted identification image and obtain the position data of the identification object in the adjusted identification image; or, if it is recognized that the identification object does not exist in the adjusted identification image, trigger an error message to be sent to the upper computer; The position determination module is used to determine whether the posture of the aiming system needs to be adjusted again according to the position data of the identification object in the adjusted identification image, so that the identification object can be imaged at the specified position of the image sensor.

17. The aiming system according to claim 1, characterized in that: The aiming system further comprises a heliostat controller communicatively connected to the adjustment module, and the heliostat controller is communicatively connected to a host computer; The host computer is used to correct the time period value interval and the heliostat control time interval according to the wind speed change frequency when the heliostat is continuously affected by the variable wind load.

18. The aiming system according to claim 1, characterized in that: The aiming system further comprises a heliostat controller communicatively connected to the adjustment module, and the heliostat controller is communicatively connected to a host computer; The heat absorber is divided into a plurality of heat absorption areas; each heat absorption area corresponds to a target heliostat, and the target heliostat is a heliostat capable of reflecting sunlight to the heat absorption area; The host computer is used to further divide the divided heat absorption area to obtain multiple sub-areas if it is detected that the divided heat absorption areas all meet the principle of uniform energy distribution, and continue to detect whether each sub-area meets the principle of uniform energy distribution according to the energy density of each sub-area, and the number of levels of the heat absorption area divided by the heat absorber is limited; Among them, the principle of uniform energy distribution requires that: the energy difference data between the energy density of any heat absorption area and the average energy density of the heat absorber is less than a first allowable threshold, and the energy difference data between the energy density of any sub-area and the average energy density of the heat absorber is less than a second allowable threshold; the second allowable threshold is less than the first allowable threshold.

19. The aiming system according to claim 18, characterized in that The host computer stores the current posture data of the faulty heliostat; the host computer is used to record the number of the faulty heliostat, recalculate the energy density of the area to be evaluated according to the number of the faulty heliostat and the current posture data, and detect whether the area to be evaluated meets the principle of uniform energy distribution according to the energy density on the area to be evaluated; the area to be evaluated is the area on the absorber that can be irradiated by the sunlight reflected by the faulty heliostat.

20. The aiming system according to claim 18, characterized in that If there is an uneven region that does not satisfy the principle of uniform energy distribution among the multiple heat absorption regions, and the energy density of the uneven region is higher than the energy density of other heat absorption regions, part of the sunlight reflected by the heliostats is removed from the multiple heliostats corresponding to the uneven region.

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