Method for detecting energy distribution condition on heat absorber and mirror field control module

Abstract

The invention relates to the technical field of solar photo-thermal application, and discloses an aiming system of a heliostat, a light steering element is arranged on a first light path, and sunlight reflected by the heliostat passes through the light steering element to obtain redirected sunlight which can be incident to an imaging module. And scattered light of the heat absorber is directly incident to the imaging module through the second light path in the original direction. According to the sighting system, simultaneous imaging of solar rays reflected by the heliostat and scattered rays of the heat absorber is achieved through the first light path and the second light path; therefore, the rotation control problem of the heliostat is converted into the problem of comparing the angle difference between the sunlight reflected by the heliostat and the scattered light of the heat absorber through the imaging of the sunlight reflected by the heliostat and the scattered light of the heat absorber.

Description

Technical Field

[0001] The present invention relates to the field of solar thermal application technology, and in particular to a method for detecting energy distribution on a heat absorber and a mirror field control module. The present invention is a divisional application of a Chinese patent application with application number 202410918325.1 and title “Heliostat Aiming System” filed on July 10, 2024. Background Art

[0002] The basic principle of CSP is to control the heliostat to reflect sunlight to the surface of the absorber located on the tower. After the absorber absorbs the heat from the sunlight, it heats and melts the molten salt inside the absorber. The molten salt is transported by a high-temperature pump to the power station at the bottom of the tower for high-temperature power generation. Therefore, how to make the sunlight reflected by the heliostat accurately irradiate the surface of the absorber is a key technical difficulty in CSP. Summary of the invention

[0003] 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.

[0004] The present invention provides a sighting system of a heliostat, the sighting system is 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 path through which the sunlight reflected by the heliostat and the scattered light of the heat absorber pass comprises a first optical path and a second optical path; the optical path before the sunlight reflected by the heliostat enters the imaging module is recorded as the first optical path, and the optical path before the scattered light of the heat absorber enters the imaging module is recorded as the second optical path; the optical path module comprises a light deflection element, the light deflection element is arranged on the first optical path; the sunlight reflected by the heliostat passes through the light deflection element, and is redirected to be incident on the imaging module. The solar rays, the heat absorber is located within the field of view of the imaging module, and the scattered light of the heat absorber is directly incident on the imaging module while maintaining the original direction through the second optical path; the imaging module is used to image the redirected solar rays 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.

[0005] In the above embodiment, by providing a light redirecting element 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 scattered light from the heat absorber directly enters the imaging module while maintaining the original direction through the second optical path. The sunlight reflected by the heliostat and the scattered light from the heat absorber are imaged simultaneously through the first optical path and the second optical path, thereby converting the heliostat rotation control problem into the problem of the angle difference between the sunlight reflected by the heliostat and the scattered light from the heat absorber through imaging comparison of the sunlight reflected by the heliostat and the scattered light from the heat absorber.

[0006] In one of the embodiments, 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 imaging module is also used to image the scattered light of the identification object.

[0007] In the above embodiment, by setting an identification object on the mounting base of the heat absorber, the shape and position of the heat absorber can be indirectly determined and identified with the aid of the imaging data of the identification object. Specifically, 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 easy to be accurately identified. In particular, even in the case where the image of the heat absorber overlaps with the image of the sun, based on the position of the identified identification pattern and the relative position 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, thereby improving the accuracy of the imaging position of the heat absorber.

[0008] In one of the embodiments, 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 fuse the obtained multiple frames of image data to obtain a high dynamic range image; the adjustment module is also 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.

[0009] In the above embodiment, by controlling the exposure time of different lengths, a clear image of the heat absorber or the sun can be obtained. In this way, it is no longer necessary to set filters in the first optical path and the second optical path, which not only further reduces the number of optical devices used in the optical module, but also further reduces the assembly errors of the optical devices in the non-common optical path part and the influence of the change of the characteristics of the optical devices on the imaging position.

[0010] In one of the embodiments, 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 that can reflect sunlight to the heat absorption area; the mirror field control module is used to detect whether each heat absorption area meets the principle of uniform energy distribution according to the irradiation energy data of the target heliostat.

[0011] In one of the embodiments, the mirror field control module is used to further divide the heat absorption area to obtain multiple sub-areas if it is detected that each of the heat absorption areas meets 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.

[0012] In the above embodiment, the surface of the heat absorber is monitored by the principle of uniform energy distribution, which not only ensures the safety of the heat absorber, but also monitors the temperature of the heat absorber and can dynamically adjust the sunlight reflected on the heat absorber in real time based on the monitoring situation, so that the energy received by the surface of the heat absorber is uniform, reducing the heat loss caused by local overheating of the heat absorber and reducing the probability of damage to the heat absorber. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A schematic diagram of a heliostat system in the related art provided according to an embodiment of the present specification;

[0014] Figure 2a A schematic diagram of a heliostat aiming system provided according to an example scenario of the present specification;

[0015] Figure 2b A schematic diagram of an optical path of a heliostat aiming system provided according to a scenario example of this specification;

[0016] Figure 2c A schematic diagram of an optical path of a heliostat aiming system provided according to a scenario example of this specification;

[0017] Figure 3a A schematic diagram of a heliostat aiming system provided according to an example scenario of the present specification;

[0018] Figure 3b A schematic diagram of a heliostat aiming system provided according to an example scenario of the present specification;

[0019] Figure 3c A schematic diagram of a logo pattern provided according to an example scenario of this specification;

[0020] Figure 4a A schematic diagram of a heliostat aiming system according to an embodiment of the present specification;

[0021] Figure 4bA schematic diagram of an optical path of a sighting system provided according to an embodiment of this specification;

[0022] Figure 5a A schematic diagram of an optical path provided according to an embodiment of this specification;

[0023] Figure 5b A schematic diagram of an optical path provided according to an embodiment of this specification;

[0024] Figure 5c A schematic diagram of a sighting system after tilting according to an embodiment of the present specification;

[0025] Figure 6a A schematic diagram of an optical path module provided according to an embodiment of this specification;

[0026] Figure 6b A schematic diagram of an optical path module provided according to an embodiment of this specification;

[0027] Figure 7a A schematic diagram of an adjustment module provided according to an embodiment of the present specification;

[0028] Figure 7b A schematic diagram of the connection between the housing and the adjustment module provided according to the implementation mode of this specification;

[0029] Figure 7c A schematic diagram of an adjustment module provided according to an embodiment of the present specification;

[0030] Figure 7d A schematic diagram of an adjustment module provided according to an embodiment of the present specification;

[0031] Figure 8a A schematic diagram of an adjustment structure provided according to an embodiment of the present specification;

[0032] Figure 8b A schematic diagram of the connection between the adjustment structure and the adjustment module provided according to the implementation mode of this specification;

[0033] Figure 8c A schematic diagram of an adjustment structure provided according to an embodiment of the present specification;

[0034] Figure 9a A schematic diagram of an optical path module provided according to an embodiment of this specification;

[0035] Figure 9b A schematic diagram of an optical path module provided according to an embodiment of this specification;

[0036] Fig.9c A schematic diagram of an imaging module provided according to an embodiment of the present specification;

[0037] Figure 9d A schematic diagram of an imaging module provided according to an embodiment of the present specification;

[0038] Fig.9e A schematic diagram of an optical path module provided according to an embodiment of this specification;

[0039] Figure 9f A schematic diagram of an optical path module provided according to an embodiment of this specification;

[0040] Fig.10a A schematic diagram of a first housing installation method provided according to an embodiment of this specification;

[0041] Fig.10b A schematic diagram of a second housing installation method provided according to an embodiment of this specification;

[0042] Fig.11a A flowchart of a method for determining a difference angle provided according to an example scenario of this specification;

[0043] Fig.11b A flowchart of a method for determining a difference angle provided according to an example scenario of this specification. DETAILED DESCRIPTION

[0044] Embodiments of the present invention are described in detail below, examples of which 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 be used to explain the present invention, and should not be construed as limiting the present invention.

[0045] In the process of tower solar thermal power generation, thousands of heliostats are needed to reflect sunlight to the surface of the absorber at the top of the absorber tower. Since the position of the sun changes in real time, the heliostats also need to be adjusted in real time to ensure that the reflected light is always accurately reflected to the absorber surface.

[0046] For related technologies, see Figure 1, a heat absorber 110' is mounted on a tower 120', a mirror field 130' is arranged around the tower 120', and the mirror field 130' includes a plurality of heliostats 132'. The heliostat 132' is mounted on a heliostat column 134'. An image sensor 140' is disposed on the tower 120', and the image sensor 140' is fixed by a support member of the image sensor. The image sensor 140' is communicatively connected to an image controller 150', and the image controller 150' is communicatively connected to a heliostat controller 160'. The light of a single heliostat 132' is reflected onto the image sensor 140', and the image controller 150' coordinates the heliostat controller 160' to fine-tune the posture of the heliostat according to the processing result of the reflected light spot image obtained by the image sensor 140'.

[0047] Specifically, the brightness of the light spot received by the image sensor 140' is compared with the preset brightness threshold, and the posture of the heliostat is gradually adjusted so that the brightness of the light spot reflected by the heliostat received on the image sensor reaches the preset brightness threshold. At this point, the posture of the heliostat meets the correct posture of the operating conditions, that is, the reflected light of the heliostat to the sunlight can be accurately irradiated on the surface of the absorber. Further, the posture information of the heliostat at this time can also be recorded, and then, according to the geographical location of the mirror field, the location of the absorber, the system operation time and the sun angle, the posture required for the light spot of the heliostat in the mirror field and the area related to the calibration heliostat at any time on the designed position of the absorber can be calculated, and the same method can be used to achieve the calibration of the heliostats in the entire mirror field.

[0048] The calibration method in the related art uses the geographical location of the calibrated heliostat relative to the earth and its own attitude angle as a reference to deduce the attitude required for the operation of other heliostats, rather than judging whether the actual reflection angle of the current sunlight is aimed at the heat absorber for each heliostat. Moreover, on the one hand, the calibration method in the related art does not take into account the influence of the attitude change of the heliostat caused by the continuous wind load on the reflection efficiency of the heliostat; on the other hand, the reflection efficiency of the mirror field depends on the installation accuracy of the heliostat column, the processing accuracy of the heliostat and the transmission accuracy of the heliostat during operation. Therefore, in the actual operation of the mirror field, the reflection efficiency of the heliostat will decrease with the attitude change of the heliostat caused by the wind load, the position accuracy of the heliostat column, the processing accuracy of the heliostat, and the sun tracking accuracy of the driving mechanism.

[0049] Based on the above analysis, a heliostat aiming system is provided in a scenario example of this specification. The heliostat is suitable for reflecting sunlight onto a heat absorber. Figure 2aThe aiming system 200 includes an aimer 210 and an adjustment module 220. The aimer 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 an azimuth rotation axis assembly 222 of the heliostat, an elevation rotation axis assembly 224 of the heliostat, an image reading module 226 and an image processing module 228. It should be noted that the housing of the aimer 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 arranged in the housing of the aimer 210.

[0050] In this scenario example, the aimer 210 can be regarded as a device for determining whether two light beams (the sunlight reflected by the heliostat and the scattered light of the heat 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 focus of the lens. Conversely, the light rays converged at the same point on the image sensor must be parallel to each other before entering the imaging module 214. Further, if the sunlight reflected by the heliostat irradiates the heat absorber, the sunlight reflected by the heliostat is parallel to the scattered light of the heat absorber and is 180 degrees opposite. Then, the sunlight reflected by the heliostat and the scattered light of the heat absorber can be imaged respectively, and by comparing the imaging position of the sunlight reflected by the heliostat and the imaging position of the scattered light of the heat absorber, it can be determined whether the sunlight reflected by the heliostat and the scattered light of the heat absorber are parallel. If it is determined that they are not parallel, a feedback control signal of the heliostat can be generated based on the imaging position of the sunlight reflected by the heliostat and the imaging position of the scattered light of the heat 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.

[0051] In this scenario example, the image processing module 228 is connected to the image reading module 226 in communication, and the image reading module 226 is connected to the imaging module 214 in communication. The housing of the sight 210 is connected to the azimuth rotation axis assembly 222 of the heliostat through the sighting connecting rod 230. The azimuth rotation axis assembly 222 of the heliostat is arranged on the heliostat column 134, and the elevation rotation axis assembly 224 of the heliostat is arranged on the azimuth rotation axis assembly 222 of the heliostat. Alternatively, the azimuth rotation axis assembly 222 is installed on the heliostat column 134, the transmission support is installed on the azimuth rotation axis assembly 222, the elevation rotation axis assembly 224 connects the transmission support and the mirror frame, and the mirror frame is connected to the elevation rotation axis assembly 224 and the transmission support. The azimuth rotation axis assembly 222 drives the heliostat to rotate around the azimuth direction perpendicular to the ground, and the elevation rotation axis assembly 224 drives the heliostat to rotate around the axis of the transmission support, and the axis of the transmission support is parallel to the ground. It can be understood that the azimuth rotation axis assembly corresponds to the azimuth drive mechanism, the elevation rotation 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 surface is mounted on the mirror frame. The azimuth drive mechanism drives the heliostat to rotate around the azimuth direction perpendicular to the ground, and the horizontal drive mechanism drives the heliostat to rotate around the axis of the transmission support, and the axis of the transmission support is parallel to the ground.

[0052] In some cases, in order to ensure that the sunlight reflected by the heliostat can accurately illuminate the specified position of the absorber, the heliostat focusing angle deviation needs to be less than 1mrad (about 0.0573 degrees). In actual tower-type solar thermal power stations, the installation height of the absorber can reach more than 100m, and the distance between the heliostat and the center tower can reach 500m or even more than 1000m. Under this accuracy requirement, even if there is a small angle error when controlling the heliostat, the spot distance deviation of the farther heliostat on the absorber will exceed 1m. For example, an angle error value of 0.5° will 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°.

[0053] It should be noted that the optical path module 212 and the imaging module 214 constitute an imaging instrument. The optical path module 212 is responsible for guiding and processing the scattered light of the heat absorber and the sunlight reflected by the heliostat, ensuring that this part of the light can be 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 an electrical signal. The imaging module 214 is composed of a photosensitive element (such as a CCD or CMOS sensor) and a related signal processing circuit, and its main function is to capture light and convert it into digital image data. It can be seen that the optical path module 212 determines the path of the reflected sunlight and the scattered light of the heat absorber, and plays a vital role in the imaging process. In this scenario example, the feedback control signal of the heliostat is determined based on the imaging position of the scattered light of 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 an important influence on the feedback control signal of the heliostat.

[0054] After analysis, it is found that the assembly error (or installation error) of the optical device, as well as the change in the characteristics of the optical device caused by external factors such as temperature change and vibration, will affect the imaging position of the scattered light of the heat absorber and the imaging position of the sunlight reflected by the heliostat, thereby affecting the accuracy of the feedback control signal of the heliostat. Further analysis shows that the installation error of the optical device in the common optical path part has the same effect on the imaging of the scattered light of the heat absorber and the imaging of the sunlight reflected by the heliostat, which can be offset and will not affect the relative position and relative distance between the two images. The installation error of the optical device in the non-common optical path part has different effects on the imaging of the scattered light of the heat absorber and the imaging of the sunlight reflected by the heliostat, which can affect the relative position and relative distance between the two images.

[0055] Based on whether the scattered light of the heat absorber and the sunlight reflected by the heliostat pass through together, the optical path through which the sunlight reflected by the heliostat and the scattered light of the heat absorber pass is divided into a common optical path portion and a non-common optical path portion. The common optical path portion may be an optical path through which the scattered light of the heat absorber and the sunlight reflected by the heliostat pass through together. The non-common optical path portion may be an optical path through which the scattered light of the heat absorber and the sunlight reflected by the heliostat pass through separately.

[0056] For the common optical path portion, the installation error of the optical device in the common optical path portion has the same influence on the scattered light of the absorber and the sunlight reflected by the heliostat. Therefore, the influence of the installation error of the optical device in the common optical path portion on the imaging of the scattered light of the absorber and the imaging of the sunlight reflected by the heliostat can be offset, that is, the relative position and relative distance between the two images will not be affected.

[0057] For 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 before the sunlight reflected by the heliostat enters the imaging module 214 is recorded as the first optical path, and the optical path before the scattered light of the heat absorber enters the imaging module 214 is recorded as the second optical path. Because the assembly error of the optical device affects the imaging position of the scattered light of the heat absorber and the imaging position of the sunlight reflected by the heliostat, the assembly error of the optical device will have some influence on the feedback control signal of the heliostat. Similarly, changes in optical properties caused by external factors such as temperature changes and vibrations will affect the imaging position of the scattered light of the heat absorber and the imaging position of the sunlight reflected by the heliostat, and will also have some influence on the feedback control signal of the heliostat.

[0058] As mentioned above, the angle control accuracy of the heliostat should be at least 0.1°. The installation error and optical property change of the optical device in the common optical path part will not affect the relative position and relative distance between the two images. The installation error and optical property change of the optical device in the non-common optical path part will affect the relative position and relative distance between the two images. Therefore, in order to improve the angle control accuracy, firstly, the non-common optical path part should be reduced as much as possible, and secondly, the number of optical devices used in the non-common optical path part should be reduced as much as possible, so as to reduce the influence of the assembly error of the optical device on the imaging position of the scattered light of the absorber and the imaging position of the sunlight reflected by the heliostat, and reduce the influence of the change of optical properties on the imaging position of the scattered light of the absorber and the imaging position of the sunlight reflected by the heliostat.

[0059] If you want to ensure that the sunlight reflected by the heliostat hits the heat absorber, the sunlight reflected by the heliostat is parallel to the scattered light of the heat absorber and is 180° opposite. In order to minimize the non-common optical path and the number of optical devices used in the non-common optical path, you can choose to directly shoot the scattered light of the heat absorber into the imaging module on the second optical path. In this way, there is no need to set an optical device to achieve the steering function on the second optical path, and the sunlight reflected by the heliostat on the first optical path is shot into the imaging module after being turned 180°. As you can see, please refer to 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 a light redirecting element is provided on the first optical path to realize 180° redirection of the sunlight reflected by the heliostat.

[0060] It should be noted that the sight is located within a range of about 50 mm from the center of the heliostat mirror surface, and the imaging module 214 of the sight always receives the scattered light from the heat absorber and the sunlight reflected by the partial mirror surface of the heliostat around the installation position of the sight. These reflected sunlight rays come from the central area of ​​the entire heliostat mirror surface and can be used to represent the sunlight reflected by the entire heliostat. In one example, the sight can be fixed on the heliostat column by a connecting rod, and the sight is located within a range of about 50 mm from the center of the heliostat mirror surface. For example, the connecting rod can pass through the components between the heliostat column and the central area of ​​the heliostat mirror surface. Whether the heliostat rotates in the azimuth dimension or the horizontal dimension, the posture of the sight will not change. Therefore, the posture of the sight can be fixed after adjusting it during the installation stage, reducing the control logic of the sight and improving the accuracy of the feedback control signal of the heliostat.

[0061] It should be noted that, since the housing of the sight 210 can also be connected to the azimuth rotation shaft assembly 222 of the heliostat through the sight connecting rod 230, when the heliostat rotates in the azimuth dimension, the sight needs to rotate synchronously in the opposite direction so that the heat absorber is always located within the field of view of the imaging module 214 of the sight. When the heliostat is driven horizontally, the sight is always located above the mirror surface, and the sunlight reflected by the mirror surface can always enter the sight.

[0062] It is understandable that the scattered light from the heat absorber on the second optical path may be directed 180° before entering the imaging module, and the sunlight reflected by the heliostat on the first optical path may be directed directly into the imaging module. Figure 2c , part of the heliostat is located within the field of view of the imaging module, and the difference between the second optical path and the first optical path is that a light redirection element for realizing 180° redirection of the scattered light of the heat absorber is arranged on the second optical path. Similarly, the sight is located within a range of about 50 mm from the center of the heliostat mirror surface, and the imaging module 214 of the sight always receives the scattered light on the heat absorber and the sunlight reflected by the partial mirror surface of the heliostat around the installation position of the sight. These reflected sunlight rays come from the central area of ​​the entire heliostat mirror surface and can be used to represent the sunlight reflected by the entire heliostat. Since the housing of the sight 210 is connected to the azimuth rotation shaft assembly 222 of the heliostat through the sight connecting rod 230, when the heliostat rotates in the azimuth dimension, the sight needs to rotate synchronously in the opposite direction so that the scattered light of the heat absorber can enter the sight after passing through the light redirection element. When the heliostat is driven horizontally, the sight is always located above the mirror surface, and the sunlight reflected by the mirror surface can always enter the sight.

[0063] 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 surface of the heat absorber 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 imaging position of the heat absorber, 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.

[0064] Based on the above analysis, the implementation mode of this specification also provides another scenario example. In this scenario example, an identification pattern is provided on the support member 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 position 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.

[0065] See also Figure 3aIn this scenario example, the aiming system 200 includes an aimer 210 and an adjustment module 220. The aimer 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 the sunlight reflected by the heliostat before entering the imaging module 214 is recorded as the first optical path, and the optical path of the scattered light from the heat absorber before entering the imaging module 214 is recorded as the second optical path. Different filters are respectively arranged on the first optical path and the second optical path. It should be noted that the light passing through the filter on the first optical path can be any color of red light, blue light, and green light, and the light passing through the filter on the second optical path is any color of red light, blue light, and green light except the color light allowed by the first optical path. The design of the red light filter is to allow red light to pass through while blocking or absorbing light of other colors. This means that when a red light filter is placed in the first light path, only red light is able to pass through the filter, while other colors of light are blocked or absorbed. The blue light filter is designed to allow blue light to pass through, while blocking or absorbing other colors of light. This means that when a blue light filter is placed in the second light path, only blue light is able to pass through the filter, while other colors of light are blocked or absorbed. The green light filter is designed to allow green light to pass through, while blocking or absorbing other colors of light. This means that when a green light filter is placed in the second light path, only green light is able to pass through the filter, while other colors of light are blocked or absorbed.

[0066] 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, that is, extracts red light data from the imaging data of the imaging module to obtain solar image data; extracts blue light data from the imaging data of the imaging module to obtain identification image data. The first image processing module 320 determines the adjustment strategy of 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, and the adjustment strategy is used to indicate the adjustment of the posture of the heliostat.

[0067] In this example, the first position determination module 324 determines the first imaging position of the sun on the image sensor of the imaging module based on the solar image data. The second imaging position of the identification element on the image sensor is determined based on the identification image data; the third imaging position of the heat absorber on the image sensor is calculated based on the relative position data between the identification element and the heat absorber and the second imaging position. The first angle comparison module 322 determines the difference angle between the sunlight reflected by the heliostat and the scattered light of the heat absorber based on the first imaging position and the third imaging position; the difference angle is used to indicate the adjustment of the posture of the heliostat.

[0068] In some cases, in order to achieve a heliostat focusing angle deviation of less than 1 mrad, it is necessary to minimize the optical devices used in the optical module. The inventors have found that 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. In this way, it is no longer necessary to set filters in the first optical path and the second optical path. It should be noted that the first duration is longer than the second duration, and the first duration and the second duration can be set in combination with the actual imaging situation, and 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, and the image data obtained by multiple exposures are fused to form a high dynamic range image. At this time, both the sun and the heat absorber will appear on the high dynamic range image.

[0069] To illustrate the multiple exposure operation, in the first exposure, the first exposure time is performed, and the image of the heat absorber is obtained, while the image of the sun is overexposed. In the second exposure, the second exposure time is performed, and the image of the sun is obtained, while the image of the heat absorber is relatively dark. Multiple exposures are performed in this way.

[0070] The multiple exposure operation is exemplarily described, in one part of the multiple exposures, an exposure time of a first duration is performed to obtain an image of the heat absorber. In another part of the multiple exposures, an exposure time of a second duration is performed to obtain an image of the sun.

[0071] Based on the above analysis, this specification also provides another scenario example. Figure 3b In this scenario example, the aiming system 200 includes an aimer 210 and an adjustment module 220. The aimer 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 scenario example, it is not necessary to set filters on the first optical path and the second optical path in the optical path module, which reduces the number of optical devices in the non-common optical path part, and further reduces the influence of optical device assembly errors and optical property changes on the imaging position of the scattered light of the absorber and the imaging position of the sunlight reflected by the heliostat.

[0072] Specifically, 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 and the image of the sun. The second position determination module 328 determines the first imaging position of the sun on the image sensor of the imaging module and the third imaging position of the heat absorber on the image sensor based on the high dynamic range image. The second angle comparison module 326 determines the difference angle between the sunlight reflected by the heliostat and the scattered light of the heat 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.

[0073] Furthermore, in some cases, the image of the receiver and the image of the sun will overlap, making it impossible to accurately determine the image position of the sun and the image position of the receiver. 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 of the heat 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.

[0074] The implementation method of this specification also provides another scenario example. In this scenario example, in order to ensure the safety of the heat absorber, the temperature of the heat absorber is monitored, and the sunlight reflected on the heat absorber is adjusted dynamically in real time to make the energy received by the heat absorber surface uniform, reduce the heat loss caused by local overheating of the heat absorber, and reduce the probability of damage to the heat absorber. Specifically, the mirror field includes many heliostats, and the mirror field corresponds to a mirror field control module. After determining the relative position between the heliostat and the heat absorber, the spot area of ​​each heliostat on the heat absorber at each moment can be pre-calculated by simulation and experimental methods, and the corresponding relationship between the heliostat and the spot area can be pre-saved in the mirror field control module. The mirror field control module can calculate the sunlight energy P(i) and the reflection target area reflected by each heliostat on the heat absorber at each moment in real time through an astronomical algorithm. At the first level, the heat absorber is divided into N heat absorption areas. Among them, N is greater than or equal to 4. At each moment, an identification set of each heat absorbing region is determined according to the relationship between the reflection target region corresponding to each heliostat and the N heat absorbing regions obtained by dividing the heat absorber. The identification set includes identification information of each of the multiple target heliostats, and the identification information is used to uniquely identify the target heliostat. The identification information may be the ID information of the heliostat or the number of the heliostat.

[0075] In this scenario example, for each heliostat, first, the mirror field control module can determine the reflection power of each heliostat based on the relative position data between each heliostat and the absorber, the projection area of ​​each heliostat, the mirror reflectivity, and the solar irradiation data; secondly, the mirror field control module can determine the energy density of each heat absorption area based on the area of ​​each heat absorption area, the reflection power of the target heliostat, and the percentage of sunlight reflected to each heat absorption area by the target heliostat; then, the reflection power of each heliostat in the mirror field is summed to obtain the aggregate reflection power, and the ratio of the aggregate reflection power to the area of ​​the absorber is used to obtain the integral The energy density average of each heat absorbing area is calculated; then, the root mean square difference between the energy density of each heat absorbing area and the energy density average of the entire heat absorber is determined as the energy uniformity characterization data of each heat absorbing area; finally, if the energy uniformity characterization data of each heat absorbing area exceeds the energy uniformity allowable threshold value corresponding to the first level, the part of the target heliostats corresponding to each heat absorbing area is rotated, and after the heliostats are rotated, the energy uniformity characterization data of each heat absorbing area is recalculated using the above method until the energy uniformity characterization data of each heat absorbing area does not exceed the energy uniformity allowable threshold value corresponding to the first level.

[0076] In this scenario example, if the energy uniformity characterization data of each heat absorption area does not exceed the energy uniformity allowable threshold corresponding to the first level, each heat absorption area is further subdivided on the second level to obtain multiple sub-areas. The energy uniformity characterization data of each sub-area is calculated using the same method. Similarly, if the energy uniformity characterization data of each sub-area exceeds the energy uniformity allowable threshold corresponding to the second level, the partial target heliostat corresponding to each sub-area is rotated, and after the heliostat is rotated, the energy uniformity characterization data of each sub-area is recalculated using the above method until the energy uniformity characterization data of each sub-area does not exceed the energy uniformity allowable threshold corresponding to the second level.

[0077] In this scenario example, if the energy uniformity characterization data of each sub-area does not exceed the energy uniformity allowable threshold corresponding to the second level, each sub-area is further subdivided at the third level to obtain the corresponding subdivided area, and the energy uniformity characterization data of each subdivided area is calculated. It should be noted that the energy uniformity allowable threshold corresponding to the first level, the energy uniformity allowable threshold corresponding to the second level, and the energy uniformity allowable threshold corresponding to the third level are successively reduced, and the energy uniformity allowable threshold corresponding to the last level is the smallest.

[0078] In this scenario example, the above steps at different levels are executed cyclically until the last level. It can be 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.

[0079] How to rotate the heliostat to meet the principle of uniform energy distribution is exemplified. When performing regional subdivision at the current level, when a certain heliostat (denoted as SD) needs to be transferred from subdivision area A1 to subdivision area A2, the heliostat SD can be rotated by the controller of the heliostat SD so that more than 50% of the light spots of the heliostat SD can fall in the subdivision area A2, and the center of the light spot of the heliostat SD coincides with the center of the subdivision area A2. The energy uniformity characterization data of each subdivision area is recalculated by the above method. If the recalculated energy uniformity characterization data exceeds the energy uniformity allowable threshold corresponding to the current level, it indicates that further adjustment is required. The area distribution of the light spot area of ​​the heliostat SD in the subdivision area A1 and the subdivision area A2 can be recalculated by the mirror field control module, that is, the area of ​​the light spot of the heliostat SD falling in the subdivision area A1 and the subdivision area A2 is adjusted. At this time, the center of the light spot of the heliostat and the center of the subdivision area A2 do not coincide, and then the energy density of each subdivision area is recalculated until the energy uniformity characterization data of each subdivision area does not exceed the energy uniformity allowable threshold corresponding to the current level.

[0080] If the spot area of ​​a heliostat is large and covers more than two subdivided areas, the energy density of each subdivided area at the current moment can be calculated by the above method. When further adjustment is needed, the distribution of the spot area in multiple subdivided areas can be recalculated by the mirror field control module until the adjusted energy density meets the principle of uniform energy distribution.

[0081] 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 energy density mean of the absorber. It should be noted that at a certain moment, if any heliostat can reflect the sunlight that exceeds the percentage threshold to any heat absorption area of ​​the 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.

[0082] It is understandable that since the energy density, the angle between the sun's azimuth vector and the surface normal vector of the heliostat, and the reflection target area corresponding to the heliostat all change dynamically over time, the above parameters in this scenario example are for a certain moment.

[0083] See also Figure 4a The embodiment of the present specification provides a sighting system 200 of a heliostat, and the sighting system is suitable for the heliostat to reflect sunlight onto a heat absorber. The sighting system 200 includes an optical path module 212, an imaging module 214, and an adjustment module 220. The optical path module 212 includes a light redirecting element 430, and the sighting system has a first optical path 410 and a second optical path 420. A light redirecting element 430 is provided on the first optical path 410; the sunlight 440 reflected by the heliostat passes through the light redirecting element 430 to obtain redirected sunlight 450 that can be incident on the imaging module 214. The heat absorber is located within the field of view of the imaging module, and the scattered light 460 of the heat absorber passes through the second optical path 420 and directly incidents on the imaging module 214 while maintaining the original direction. The optical paths through which the sunlight reflected by the heliostat and the scattered light of the heat absorber pass include the first optical path and the second optical path.

[0084] 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.

[0085] The adjustment module 220 is used to determine the imaging position of the sun and the imaging position of the 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 absorber so that the distance between the imaging position of the sun and the imaging position of the absorber is less than a preset distance threshold.

[0086] In this embodiment, in order to bypass the acquisition of the solar azimuth vector and the zero calibration of the heliostat itself, whether the sunlight 440 reflected by the heliostat and the scattered light 460 of the heat absorber are parallel in the propagation direction is used as an evaluation standard for whether the sunlight 440 reflected by the heliostat points to the heat absorber. For example, the angle of the sunlight 440 reflected by the heliostat and the scattered light 460 of the heat absorber can be compared by imaging, and whether the two beams of light are parallel can be determined according to the angle comparison result. In actual situations, the sunlight 440 reflected by the heliostat and the scattered light 460 of the heat absorber are in opposite directions, so the two beams of light need to be converted into light of the same direction. Furthermore, in order to reduce the influence of the assembly error of the optical device and the change of the characteristics of the optical device on the imaging position, in this embodiment, the heat absorber is arranged to be located within the field of view of the imaging module, so that the scattered light 460 of the heat absorber directly enters the imaging module 214 of the aiming system 200. The sunlight 440 reflected by the heliostat needs to be displaced for a certain period of time so that the sunlight 440 reflected by the heliostat can indirectly enter the imaging module 214 of the aiming system 200 .

[0087] Specifically, in order to image the sunlight 440 reflected by the heliostat and the scattered light 460 of the heat absorber, it is necessary to set the optical path module 212 and the imaging module 214. The optical path of the sunlight reflected by the heliostat before entering the imaging module is recorded as the first optical path 410, and the optical path of the scattered light of the heat absorber before entering the imaging module is recorded as the second optical path 420. The first optical path 410 needs to be provided with a light redirecting element 430 capable of redirecting the sunlight 440 reflected by the heliostat, so that the redirected sunlight 450 obtained after the sunlight 440 reflected by the heliostat passes through the light redirecting element 430 can be incident on the imaging module 214. The second optical path 420 does not need to be provided with a light redirecting element, and the scattered light 460 of the heat absorber passes through the second optical path 420 and directly incidents on the imaging module 214 while maintaining the original propagation direction. In other words, the heat absorber appears within the field of view of the imaging module 214, and the imaging module 214 can 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 can be understood 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.

[0088] After the imaging module 214 receives the redirected solar light 450 and the scattered light 460 of the heat absorber, the imaging module 214 images the redirected solar light 450 and the scattered light 460 of the heat absorber to obtain imaging data. Since the imaging data of the imaging module includes the image of the sun and the image of the heat absorber, the positional relationship between the image of the sun and the image of the heat absorber can be determined based on the imaging data of the imaging module, so that the angle of the solar light 440 reflected by the heliostat and the scattered light 460 of the heat absorber can be compared according to the positional relationship to obtain the adjustment strategy of the heliostat, and the attitude of the heliostat can be adjusted by the adjustment strategy of the heliostat. After the attitude of the heliostat is adjusted, the redirected solar light and the scattered light 460 of the heat absorber can be re-imaged, and the imaging data obtained by the re-imaging can be used to continue to determine whether the solar light 440 reflected by the heliostat and the scattered light 460 of the heat absorber are parallel, until the imaging of the sun and the imaging of the heat absorber are roughly overlapped or tend to overlap, that is, the distance between the imaging position of the sun and the imaging position of the heat absorber is less than the preset distance threshold. The preset distance threshold can be set to N pixels in combination with actual conditions. The value of N can be set in combination with specific conditions and is not specifically limited here. It should be noted that the value of N can be less than 3 (for example, N is equal to 1 or 2), less than 10 (for example, N is equal to 5 or 7), and less than 20 (for example, N is equal to 12 or 16). For example, if the resolution of the image sensor in the imaging module 214 is 1280*1024, the horizontal field of view of the aiming device is 10 degrees, and the angle corresponding to each pixel is the quotient between 10 and 1280, which is the minimum angular resolution that the aiming device can achieve. Since the intensity of the reflected sunlight and the intensity of the scattered light of the heat absorber can guarantee the signal-to-noise ratio of the imaging data in most cases, N can also be equal to 1. N is related to the minimum angular resolution that the aiming device can achieve, that is, it can be set according to the minimum angular resolution that the aiming device can achieve. It can be understood that this example is exemplified with 1280*1024, and the resolution of the image sensor in the imaging module 214 can also be 2K or 4K.

[0089] In this implementation, please refer to Figure 4b The light path through which the sunlight reflected by the heliostat and the scattered light from the absorber pass includes a non-common light path portion 412 and a common light path portion 414. The non-common light path portion 412 includes a first light path 410 and a second light path 420. The common light path portion 414 includes the objective lens in the imaging module.

[0090] It should be noted that if the redirected sunlight 450 and the scattered light 460 of the heat absorber are parallel to each other, when the lens of the imaging module is focused at infinity, the redirected sunlight 450 and the scattered light 460 of the heat absorber as parallel light incident at the same angle will accurately converge at the same point on the image sensor located at the focus of the lens. Conversely, the two beams of light that converge at the same point on the image sensor must be parallel to each other before entering the imaging module.

[0091] In the above embodiment, by providing a light redirecting element 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 scattered light of the heat absorber directly enters the imaging module while maintaining the original direction through the second optical path. The aiming system realizes simultaneous imaging of the sunlight reflected by the heliostat and the scattered light of the heat absorber through the first optical path and the second optical path, thereby converting the heliostat rotation control problem into the problem of the angle difference between the sunlight reflected by the heliostat and the scattered light of the heat absorber through the imaging comparison of the sunlight reflected by the heliostat and the scattered light of the heat absorber. Furthermore, by using a smaller number of optical devices (light redirecting elements are provided on the first optical path, and there are no light redirecting elements on the second optical path), not only the sunlight reflected by the heliostat is displaced by a certain distance, but also the assembly error of the optical device and the influence of the change of the characteristics of the optical device on the imaging position are reduced. It should be noted that, compared with the related art in which the deviation between the sunlight reflected by the mirror and the scattered light of the heat absorber is determined by determining the position of the sun's image off the center, the related art uses a static reference (such as the axis of the mirror tube). When the heliostat system is offset in angle due to foundation settlement, wind force, etc., the angle offset cannot be corrected, and eventually the direction error of the light reflected by the mirror will be formed, so it needs to be recalibrated and maintained frequently. In the above embodiment, the sunlight reflected by the heliostat and the scattered light of the heat absorber are imaged at the same time. Since the relative angle between the heliostat and the heat absorber is "fixed", it is no longer necessary to adjust the static reference as in the related art.

[0092] In another embodiment, the sunlight 440 reflected by the heliostat can also be set to directly enter the imaging module 214 of the aiming system 200, and the scattered light 460 of the heat absorber needs to be displaced so that the scattered light 460 of the heat absorber can indirectly enter the imaging module 214 of the aiming system 200. Specifically, the optical path module 212 includes a first optical path 410 and a second optical path 420. A light redirecting element 430 is provided on the second optical path 420; the scattered light 460 of the heat absorber passes through the light redirecting element 430 to obtain redirected scattered light that can be incident on the imaging module 214. The sunlight 440 reflected by the heliostat passes through the first optical path 410 and directly enters the imaging module 214 while maintaining the original direction. The imaging module 214 images the redirected scattered light and the sunlight 440 reflected by the heliostat. The adjustment module 220 adjusts the posture of the heliostat according to the imaging data of the imaging module 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. It should be noted that if the redirected scattered light and the sunlight 440 reflected by the heliostat are parallel to each other, when the lens of the imaging module is focused at infinity, the redirected scattered light and the sunlight 440 reflected by the heliostat as parallel light incident at the same angle will accurately converge at the same point on the image sensor located at the focus of the lens.

[0093] In the above embodiment, by providing a light redirecting element on the second optical path, the scattered light of the heat absorber passes through the light redirecting element to obtain redirected scattered light that can be incident on the imaging module. The sunlight reflected by the heliostat passes through the first optical path and directly enters the imaging module while maintaining the original direction, and the rotation control problem of the heliostat is converted into the problem of the angle difference between the sunlight reflected by the heliostat and the scattered light of the heat absorber through the imaging comparison of the sunlight reflected by the heliostat and the scattered light of the heat absorber. Furthermore, by using a smaller number of optical devices (light redirecting elements are provided on the second optical path, and there are no light redirecting elements on the first optical path), not only the scattered light of the heat absorber is displaced by a certain distance, but also the assembly error of the optical device and the influence of the change of the characteristics of the optical device on the imaging position are reduced.

[0094] In another embodiment, when the heliostat is working under the permissible constant wind load, the elastic deformation of the heliostat after being stressed causes the heliostat to have an angle deviation in both the azimuth direction and the height direction, so that the reflected light of the heliostat will deviate from the initial heat absorption area. At this time, the difference between the direction vector of the sunlight 440 reflected by the heliostat and the direction vector of the scattered light scattered by the initial heat absorption area can be obtained through the aiming system 200, and the angle deviation of the heliostat in the azimuth direction and the height direction can be obtained, which are α and β respectively. Then, the angle deviations α and β in the two dimensions of the azimuth direction and the height direction are corrected by the heliostat controller, and the sunlight 440 reflected by the heliostat is realigned to the initial heat absorption area.

[0095] 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.

[0096] In some embodiments, the sunlight reflected by the heliostat is reflected twice by the light redirecting element 430 and then incident on the imaging module, and the redirected sunlight is 180 degrees opposite to the sunlight reflected by the heliostat.

[0097] In some embodiments, the light redirecting element is configured as a corner cube prism. Figure 5a , the sunlight 440 reflected by the heliostat is incident on the imaging module 214 after being reversed by 180 degrees by the corner cube prism 520; the scattered light 460 of the heat absorber keeps the original direction and directly incident on the imaging module 214. Or, see Figure 5b The scattered light 460 from the heat absorber is incident on the imaging module 214 after being reversed by 180 degrees by the corner cube prism 520 ; the sunlight 440 reflected by the heliostat maintains the original direction and directly incident on the imaging module 214 .

[0098] It should be noted that the above-mentioned embodiments are intended to image the sunlight reflected by the heliostat and the scattered light of the heat absorber on the image sensor at the same time. Since it is necessary to meet the requirement that the focusing angle deviation of the heliostat is less than 1 mrad (about 0.0573 degrees), the impact of the assembly error of the optical device and the change of the characteristics of the optical device on the control accuracy of the heliostat cannot be ignored, so the number of optical devices in the optical module is minimized in the above-mentioned embodiments. If a beam splitter (a half-reflective and half-mirror) is used, after using the beam splitter, the two beams of light will overlap at the position of the beam splitter, and finally form an overlapping image on the image sensor. However, the assembly error and optical device characteristics of the beam splitter itself will affect the control accuracy of the heliostat. Furthermore, the light path passed by the two beams of light (the sunlight reflected by the heliostat and the scattered light of the heat absorber) can be divided into a non-common light path part and a common light path part. In addition, the assembly errors and characteristic changes of the optical devices in the two light beams in the common light path portion can offset each other, while the assembly errors and characteristic changes of the optical devices in the two light beams in the non-common light path portion cannot offset each other, so the number of optical devices in the two light beams in the non-common light path portion should be minimized. When using two light beams to determine the angle error, the non-common light path method using a beam splitter requires at least a lens and a beam splitter, and the two light beams in each light path include at least two optical devices, and this part of the non-common light path will introduce a relatively large error. Under the premise of minimizing the error introduced in the non-common light path portion, the solar light reflected by the heliostat in this embodiment is designed to be incident on the imaging module after being reflected twice by the light deflection element, while the scattered light from the heat absorber is directly incident on the imaging module.

[0099] If the light redirection element uses a corner cube, only one optical device (corner cube) is involved in the non-common optical path of the sunlight reflected by the heliostat and the scattered light of the absorber. It should be emphasized that the corner cube also has the characteristic of being insensitive to installation accuracy. In particular, if the corner cube is installed with eccentricity and tilt, it will not affect its high accuracy (commercial grade typical value 8 arc seconds, about 0.002°) to reversely reflect the incident light in a 180° parallel manner.

[0100] It should be noted that during the operation of the heliostat, if the aiming system 200 is tilted due to at least one of the reasons such as foundation settlement, wind force, gravity, etc., the angle between the aiming optical axis and the scattered light of the heat absorber will change, that is, the image of the heat absorber on the image sensor of the imaging module will move, but at this time, the light that overlaps with the image of the heat absorber on the image sensor is still a beam parallel to the scattered light of the heat absorber, and this light will still accurately point to the heat absorber and intersect with it. Please refer to Figure 5c , Figure 5c It is used to simulate the aiming system 200 after tilting. When the foundation settlement, wind, gravity and other conditions occur during the operation of the heliostat, the aiming system 200 as a whole rotates at a large angle, causing the imaging position of the scattered light from the heat absorber to move. However, as long as the scattered light from the heat absorber and the sunlight reflected by the heliostat meet the conditions of parallelism and opposite propagation directions, the two beams of light will still converge at the same point on the image sensor. It can be seen that since the tilt of the aiming system 200 will have the same impact on the scattered light from the heat absorber and the sunlight reflected by the heliostat, that is, the movement of the imaging position, even if the foundation settlement, wind, gravity and other conditions occur during the operation of the heliostat, the accurate operation of the aiming system 200 will not be affected. It is understandable that the static reference used in the related art needs to be readjusted when an angle deviation occurs due to foundation settlement, wind influence, etc., while the direction of the scattered light from the heat absorber in the above embodiment is acquired "dynamically", and the aiming system in the above embodiment has the ability of dynamic tracking and self-calibration. This feature makes the aiming system in the above embodiment do not need to be adjusted frequently.

[0101] In some embodiments, the light redirecting element is configured as a reflector, wherein the reflector includes a plurality of mirror glasses, the plurality of mirror glasses are connected in a coordinated manner, and the sunlight reflected by the heliostat is reflected by the reflector in turn and then incident on the imaging module.

[0102] In some embodiments, the reflector portion includes a prism. There are multiple prisms, and the multiple prisms are used together to make the sunlight reflected by the heliostat enter the imaging module after being reflected by the mirror glass.

[0103] In some embodiments, the aiming system includes a housing. The imaging module and the optical path module are both disposed in the housing, and the housing has a first optical path and a second optical path. The housing is formed with a first light window and a second light window, and the sunlight reflected by the heliostat enters the first optical path through the first light window, and the scattered light of the heat absorber enters the second optical path through the second light window.

[0104] Specifically, see Figure 6a The aiming system includes a housing 610. The optical path module 212 includes a light redirecting element 430. The imaging module 214 and the optical path module 212 are both disposed in the housing 610, and the housing 610 has a first light path and a second light path. The housing 610 is formed with a first light window 620 and a second light window 630. The sunlight 440 reflected by the heliostat enters the first light path through the first light window 620. The light redirecting element 430 is disposed in the first light path. The sunlight reflected by the heliostat entering through the first light window 620 is redirected by the light redirecting element 430. The scattered light 460 of the heat absorber enters the second light path through the second light window 630.

[0105] In another embodiment, see Figure 6b The aiming system includes a housing 610. The optical path module 212 includes a light redirecting element 430. The imaging module 214 and the optical path module 212 are both disposed in the housing 610, and the housing 610 has a first light path and a second light path. The housing 610 is formed with a first light window 620 and a second light window 630, and the scattered light 460 of the heat absorber is incident into the second light path through the second light window 630, and the light redirecting element 430 is disposed in the second light path, and the scattered light 460 of the heat absorber incident into the second light window 630 is redirected by the light redirecting element 430. The sunlight 440 reflected by the heliostat is incident into the first light path through the first light window 620.

[0106] In some embodiments, the aiming system includes a first mounting base and an adjustment module. The adjustment module is connected to the first mounting base, and the housing is connected to one of the first mounting base and the adjustment module; the adjustment module can drive the heliostat to rotate.

[0107] The first mounting base can be understood as the mounting column of the heliostat, and the adjustment module can drive the heliostat to rotate. Figure 2a The aiming system includes a mounting column 134 of the heliostat and an adjustment module 220. The mounting column 134 is connected to the adjustment module 220. The housing 610 may be connected to the mounting column 134. Alternatively, the housing 610 may be connected to the adjustment module 220. Further, the aiming system may include a first connector, and the housing 610 is connected to the adjustment module 220 via the first connector.

[0108] In some embodiments, the housing is connected to the adjustment module. Figure 7a , the adjustment module includes a shaft assembly 710 and a driving member (not shown in the figure), and the housing 610 is connected to the shaft assembly 710 of the adjustment module. The driving member is connected to the shaft assembly 710 to drive the shaft to rotate. When the shaft assembly 710 of the adjustment module rotates, the heliostat 132 rotates to adjust the posture of the heliostat 132. Exemplarily, the heliostat system includes a lens, a mirror frame, a horizontal driving mechanism, an azimuth driving mechanism, a transmission support, a heliostat column, etc. (the driving member includes an azimuth driving mechanism and a horizontal driving mechanism). The azimuth driving mechanism is installed on the heliostat column, the transmission support is installed on the azimuth driving mechanism, the horizontal driving mechanism connects the transmission support and the mirror frame, the mirror frame is connected to the horizontal driving structure and the transmission support, and the mirror surface is installed on the mirror frame. The azimuth driving mechanism drives the heliostat to rotate around the azimuth direction perpendicular to the ground, and the horizontal driving mechanism drives the heliostat to rotate around the axis of the transmission support, and the axis of the transmission support is parallel to the ground. It should be noted that the housing is connected to the transmission support. If the azimuth driving mechanism drives the heliostat to rotate, since the transmission support is installed on the azimuth driving mechanism and the housing is connected to the transmission support, the housing rotates when the azimuth driving mechanism drives the heliostat to rotate. The imaging module needs to face the heat absorber in real time, so after the azimuth driving mechanism drives the heliostat to rotate, the housing 610 can be adjusted in posture so that the imaging module needs to face the heat absorber in real time, that is, the heat absorber is located within the field of view of the imaging module.

[0109] In the above embodiment, the housing of the sight is connected to the adjustment module to fix the housing of the sight on the mirror surface, thereby improving the firmness of the installation of the sight and making it easy to implement. When the sight rotates together with the mirror surface, the sight can be simply and quickly controlled to rotate in the opposite direction accurately in combination with the rotation of the mirror surface.

[0110] In some embodiments, the aiming system includes a first connecting member, and the housing is connected to the adjustment module via the first connecting member.

[0111] Specifically, see Figure 7b , one end of the first connecting member 720 is connected to the housing, and the other end of the first connecting member 720 is connected to the adjustment module. It should be noted that as the adjustment module drives the heliostat to rotate, the field of view of the imaging module changes, and the imaging module needs to be oriented toward the heat absorber in real time. Therefore, after the adjustment module drives the heliostat to rotate, the housing can be adjusted in posture so that the heat absorber is located within the field of view of the imaging module or even in the central imaging area of ​​the imaging module.

[0112] In the above embodiment, one end of the first connecting member is connected to the outer shell of the sight, and the other end is connected to the adjustment module, so that the outer shell of the sight is fixed on the adjustment module, and the outer shell of the sight is fixed on the mirror surface, which is beneficial to improve the firmness of the installation of the sight and is easy to implement.

[0113] In some embodiments, the adjustment module includes a first adjustment module, a transmission support, and a second adjustment module. The first adjustment module is connected to the first mounting base and the transmission support. The second adjustment module includes a rotating shaft and a brake. The rotating shaft can be rotatably mounted on the transmission support, the brake connects the transmission support and the rotating shaft, and the rotating shaft is connected and fixed to the frame of the heliostat. For details, please refer to Figure 7c , the first adjustment module 790 connects the first mounting base 730 and the transmission support 750. The second adjustment module includes a rotating shaft 760 and a brake 770. The rotating shaft 760 can be rotatably mounted on the transmission support 750, the brake 770 connects the transmission support 750 and the rotating shaft 760, and the rotating shaft 760 is connected and fixed to the mirror frame 780 of the heliostat. In this embodiment, one end of the first connecting member can be connected to the housing, and the other end of the first connecting member can be connected to the first mounting base. In another embodiment, one end of the first connecting member can be connected to the housing, and the other end of the first connecting member can be connected to the first adjustment module. In another embodiment, one end of the first connecting member can be connected to the housing, and the other end of the first connecting member can be connected to the transmission support.

[0114] In some embodiments, the rotation center axis of the first adjustment module is not parallel to the center axis of the rotating shaft. It is understandable that the rotation center axis of the first adjustment module is the center axis around which the first adjustment module drives the heliostat to rotate. The center axis of the rotating shaft is the center axis around which the second adjustment module drives the heliostat to rotate. Exemplarily, the first adjustment module drives the heliostat to rotate in the azimuth direction, and the second adjustment module drives the heliostat to rotate in the horizontal direction. The rotation center axis of the first adjustment module tends to be perpendicular to the horizontal plane, and the center axis of the rotating shaft tends to be parallel to the horizontal plane.

[0115] In some embodiments, the first adjustment module includes a fixed seat and an output end, the output end can rotate relative to the fixed seat, the fixed seat is connected and fixed to the first mounting base, and the output end is connected and fixed to the transmission support.

[0116] The first adjustment module may be a reducer. Figure 7d, the first adjustment module includes a fixed seat 740 and an output end (not shown in the figure). The first mounting base 730 can be understood as a mounting column of the heliostat. A fixed seat 740 is set on the first mounting base 730, and the fixed seat 740 is connected and fixed to the first mounting base 730. The output end can rotate relative to the fixed seat 740, and the output end can rotate on the first mounting base 730. When the output end rotates, it drives the heliostat to rotate. The output end is connected and fixed to the transmission support. In this embodiment, the first adjustment module also includes a first driving member (not shown in the figure), and the first driving member is transmission-connected to the output end to drive the output end to rotate. Exemplarily, the first driving member is configured as a driving motor, and the output shaft of the first driving member is fixed or transmission-connected to the output end. It should be noted that the output end can be understood as the output end of the azimuth rotating shaft assembly. The first driving member can be understood as an azimuth driving structure, and the azimuth driving structure drives the heliostat to rotate around the azimuth direction perpendicular to the ground.

[0117] In some embodiments, the second adjustment module includes a rotating shaft. The rotating shaft is fixedly connected to the heliostat, and the rotating shaft can be rotatably mounted on a transmission support. The transmission support is fixedly connected to the output end, and when the rotating shaft rotates, the heliostat is driven to rotate. Exemplarily, when the rotating shaft rotates, the heliostat is driven to rotate in the pitch direction. In this embodiment, the central axis of the output end and the central axis of the rotating shaft are not parallel. In some embodiments, the central axes of the two are perpendicular.

[0118] Specifically, a transmission support is provided on the driving structure of the output end, and the transmission support is fixedly connected to the output end. The rotating shaft is provided on the transmission support, and the heliostat is fixedly connected. When the rotating shaft rotates, the heliostat is driven to rotate, wherein the central axis of the output end and the central axis of the rotating shaft are not parallel. In this embodiment, the second adjustment module may include a second driving member, which is connected to the rotating shaft in a transmission manner to drive the rotating shaft to rotate. Exemplarily, the transmission support can be understood as a supporting mechanism of the rotating shaft. The second driving member is configured as a driving motor, and the second driving member is fixedly provided on the transmission support. It should be noted that the rotating shaft can be understood as a horizontal angle rotating shaft. The second driving member can be understood as a horizontal driving structure, which drives the heliostat to rotate around the axis of the transmission support, and the axis of the transmission support is parallel to the ground.

[0119] It can be understood that the azimuth drive mechanism is installed on the column of the heliostat, the transmission support is installed on the azimuth drive mechanism, the horizontal drive mechanism connects the transmission support and the mirror frame, the mirror frame connects the horizontal drive structure and the transmission support, and the mirror surface of the heliostat is installed on the mirror frame.

[0120] In some embodiments, the first connector is connected to a support mechanism of the output end. Specifically, the output end has a support mechanism, and the housing 610 can be connected to the support mechanism of the output end through the first connector 720 .

[0121] In some embodiments, the first connecting member is connected to the transmission support. The transmission support can be understood as a support structure of the rotating shaft, and the housing 610 can be connected to the support structure of the rotating shaft, that is, connected to the transmission support, through the first connecting member 720.

[0122] In some embodiments, if the housing is connected to the transmission support through a first connection member, when the first adjustment module drives the heliostat to rotate, the housing rotates in the opposite direction to adjust the postures of the optical path module and the imaging module, so that the heat absorber is located within the field of view of the imaging module. In some other embodiments, if the housing is connected to the output end of the first adjustment module through a first connection member, when the first adjustment module drives the heliostat to rotate, since the transmission support is fixedly connected to the output end, the housing needs to rotate in the opposite direction to adjust the postures of the optical path module and the imaging module, so that the heat absorber is located within the field of view of the imaging module; when the shaft drives the heliostat to rotate, the posture of the housing remains unchanged.

[0123] Specifically, when the heliostat is driven to rotate in azimuth, the housing also rotates in azimuth, and the heat absorber may have deviated from the field of view of the imaging module. Therefore, in order for the heat absorber to always be within the field of view of the imaging module, the housing can be controlled to rotate in the opposite direction to adjust the posture of the optical path module and the imaging module, so that the heat absorber is within the field of view of the imaging module. When the shaft drives the heliostat to rotate horizontally or pitch, since the posture of the optical path module and the imaging module is still relative to the heat absorber, that is, the heat absorber remains within the field of view of the imaging module, the posture of the housing can remain unchanged.

[0124] In this embodiment, after the heliostat rotates, the housing is promptly controlled to rotate in the opposite direction to adjust the postures of the optical path module and the imaging module, so that the heat absorber is always kept within the field of view of the imaging module. Therefore, there is no need to deploy optical devices with steering or redirection functions in the optical path through which the scattered light of the heat absorber passes, thereby reducing the assembly errors of the optical devices and the impact of changes in optical characteristics on the imaging position of the heat absorber.

[0125] In some embodiments, the aiming system further comprises an adjustment mechanism, and the housing is disposed on the adjustment mechanism. The adjustment mechanism is used to drive the housing to move to adjust the posture of the optical path module and the imaging module so that the heat absorber is located within the field of view of the imaging module.

[0126] Since the postures of the optical path module and the imaging module need to be adjusted, an adjustment mechanism is provided for the housing. Figure 8aThe housing 610 is disposed on the adjustment mechanism 810. The adjustment mechanism 810 can drive the housing to rotate in the azimuth direction and the horizontal direction, thereby driving the sight to rotate to adjust the posture of the optical path module and the imaging module, and always keep the heat absorber within the field of view of the imaging module.

[0127] In some embodiments, the adjustment mechanism is connected to the transmission support of the adjustment module through a first connecting member. Figure 8b , the housing 610 is disposed on the adjustment mechanism 810. The adjustment mechanism 810 is connected to the transmission support of the adjustment module through the first connection member 720. In some other embodiments, the adjustment mechanism is connected to the output end of the first adjustment module through the first connection member.

[0128] In some embodiments, the adjustment mechanism is configured to drive the housing to rotate about at least one of the first axis and the second axis.

[0129] In some embodiments, the adjustment mechanism includes a vertical adjustment mechanism and a horizontal adjustment mechanism. The vertical adjustment mechanism is used to drive the housing to rotate around a first axis. The horizontal adjustment mechanism is used to drive the housing to rotate around a second axis.

[0130] Specifically, see Figure 8c , the adjustment mechanism 810 includes a vertical adjustment mechanism 812 and a horizontal adjustment mechanism 814. The horizontal adjustment mechanism 814 is connected to the first connecting member, and the vertical adjustment mechanism 812 is arranged above the horizontal adjustment mechanism 814. The vertical adjustment mechanism 812 can drive the housing to rotate around a first axis. The horizontal adjustment mechanism 814 can drive the housing to rotate around a second axis. The first axis and the second axis are perpendicular. Exemplarily, the first axis is perpendicular to the horizontal plane, and the second axis is parallel to the horizontal plane.

[0131] In the above embodiment, by providing a vertical adjustment mechanism and a horizontal adjustment mechanism, and the vertical adjustment mechanism drives the shell to rotate around the first axis, and the horizontal adjustment mechanism drives the shell to rotate around the second axis, the orientation of the shell can be flexibly controlled, which is beneficial for ensuring that the heat absorber is always within the field of view of the imaging module, and is beneficial for simplifying the optical path of the scattered light of the heat absorber.

[0132] In some embodiments, when the posture of the heliostat is adjusted by the first adjustment module of the adjustment modules, the adjustment mechanism is adapted to drive the housing to rotate in the opposite direction.

[0133] Specifically, when the first adjustment module drives the heliostat to rotate in azimuth, the housing rotates accordingly, and the heat absorber may have deviated from the field of view of the imaging module. Therefore, in order to ensure that the heat absorber is always located within the field of view of the imaging module, the housing can be controlled to rotate in the opposite direction to adjust the posture of the optical path module and the imaging module, so that the heat absorber is located within the field of view of the imaging module.

[0134] In the above embodiment, the heat absorber is kept within the field of view of the imaging module so that the scattered light from the heat absorber can be imaged on the image sensor of the imaging module, thereby simplifying the optical devices on the optical path through which the scattered light from the heat absorber passes, thereby reducing the impact of optical device assembly errors and changes in optical properties on the imaging position of the heat absorber.

[0135] In some embodiments, 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 redirecting element, and the scattered light of the absorber can be focused on the central area of ​​the image sensor.

[0136] Specifically, the posture of the housing is determined based on the relative position between the heliostat and the absorber, so that the imaging module in the housing can face the absorber, and the scattered light from the absorber can be focused on the central area of ​​the image sensor. The sunlight reflected by the heliostat can also be focused on the image sensor of the imaging module after passing through the light redirection element. It should be noted that the preferred method for making the sunlight reflected by the heliostat enter the aiming field of view is to use an astronomical algorithm to calculate the azimuth and elevation angles of the heliostat mirror, and then rotate it to the position given by the astronomical algorithm. As long as the comprehensive angle error of the aiming system is less than the aiming field of view angle, the mirror reflected light is incident on the image sensor.

[0137] In another embodiment, the posture of the housing can also be determined based on the relative position between the heliostat and the heat absorber, so that the imaging module in the housing can face the heliostat, and the sunlight reflected by the heliostat can be focused on the image sensor of the imaging module. The scattered light of the heat absorber can also be focused on the central area of ​​the image sensor after passing through the light redirecting element.

[0138] In some embodiments, the housing is suitable for being arranged in the middle of the heliostat. It should be noted that the housing can be located within a range of about 50 mm from the center of the heliostat mirror surface, and the optical instrument in the housing always receives the scattered light on the heat absorber and the reflected light of the heliostat mirror surface around the housing installation position, and these reflected lights come from the central area of ​​the reflected light of the entire heliostat mirror surface, which can indicate the position of the reflected light of the entire heliostat.

[0139] In some embodiments, the optical path module also includes: a first attenuation plate, which is disposed in the shell; a first attenuation plate is disposed on the first optical path, and along the propagation direction of the light in the first optical path, the first attenuation plate is located on the upstream side of the light redirecting element.

[0140] In some cases, because the sunlight reflected by the heliostat is strong, it is necessary to add an attenuator in the first optical path. For details, please refer to Figure 9a The optical path module further includes a first attenuation sheet 910 , which is located in the housing 610 and disposed on the first optical path. The first attenuation sheet 910 is located on the upstream side of the light redirecting element 430 along the propagation direction of the light in the first optical path.

[0141] It should be noted that the attenuation sheet is used to reduce the brightness of the sun in the image. It is understandable that the attenuation sheet can also be replaced by a filter with a lower transmittance. When designing an optical coating filter, a filter with a low transmittance can be artificially designed, which can reduce the brightness of the sun in the image. The attenuation sheet can also be replaced by a smaller aperture. By reducing the aperture, the amount of light entering is reduced, thereby reducing the brightness of the sun in the image.

[0142] 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 the light in the first optical path, the first filter is located between the first attenuation plate and the light redirecting element, or the first filter is located on the upstream side of the first attenuation plate.

[0143] Specifically, the color channel corresponding to the first light path imaging can be preset, so that the corresponding first filter can be set on the first light path in combination with the color channel corresponding to the first light path imaging. Figure 9b The first optical filter 920 is located in the housing 610. Along the propagation direction of the light in the first optical path, the first optical filter 920 can be located between the first attenuation plate 910 and the light redirection element 430. It can be understood that along the propagation direction of the light in the first optical path, the first optical filter can also be located on the upstream side of the first attenuation plate.

[0144] In the above implementation, 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 subsequently, which helps to improve the accuracy of solar imaging position recognition.

[0145] 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 the sunlight reflected by the heliostat can be incident on the imaging module after passing through the light deflection element.

[0146] Specifically, see Fig.9c The imaging module 214 includes a lens barrel 940, which has a light incident end 930, and the central axis of the lens barrel 940 serves as the optical axis of the imaging module. A light deflection element 430 is provided at the light incident end 930, so that the sunlight 440 reflected by the heliostat can be incident on the imaging module located in the lens barrel 940 after passing through the light deflection element 430. The number of light deflection elements may be one; or the number of light deflection elements may be multiple. Exemplarily, the multiple light deflection elements may be arranged in a ring relative to the central axis of the lens barrel 940, preferably symmetrically. In this embodiment, multiple may be understood as more than two.

[0147] In the above implementation, the lens barrel is provided to improve the installation stability of the light redirecting element and reduce the assembly error of the light redirecting element, thereby improving the imaging quality of the sun and further improving the accuracy of identifying the sun's imaging position.

[0148] In some embodiments, the imaging module includes 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.

[0149] Specifically, see Figure 9d The imaging module 214 further includes an objective lens 950 and an image sensor 960. The objective lens 950 and the image sensor 960 are disposed in the lens barrel 940. The objective lens 950 is located between the image sensor 960 and the light incident end 930. The objective lens 950 is used to focus the sunlight reflected by the heliostat on the image sensor 960, and to focus the scattered light of the heat absorber on the image sensor 960.

[0150] In some embodiments, a second filter is disposed on the second optical path, and a second filter is disposed at the incident end of the light.

[0151] Specifically, the color channel corresponding to the second light path imaging can be preset, so that the corresponding second filter can be set on the second light path in combination with the color channel corresponding to the second light path imaging. Fig.9e A second filter 970 is arranged on the second optical path, and a second filter 970 is arranged at the light incident end 930 .

[0152] In the above embodiment, by providing 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.

[0153] 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.

[0154] Specifically, see Figure 9f , a second attenuation plate 980 is disposed on the second optical path. Located in the light propagation direction in the second optical path, the second filter 970 is located on the upstream side of the second attenuation plate 980. Alternatively, located in the light propagation direction in the second optical path, the second attenuation plate 980 is located on the upstream side of the second filter 970.

[0155] It should be noted that the attenuation plate is used to reduce the brightness of the heat absorber in the image. It is understandable that the attenuation plate can also be replaced by a filter with a lower transmittance. When designing an optical coating filter, a filter with a low transmittance can be artificially designed, which can reduce the brightness of the heat absorber in the image. The attenuation plate can also be replaced by a smaller aperture. By reducing the aperture, the amount of light entering is reduced, thereby reducing the brightness of the heat absorber in the image.

[0156] In some embodiments, the adjustment module includes a first adjustment module, a transmission support, and a second adjustment module. The first adjustment module includes a fixed seat and an output end. The output end can rotate relative to the fixed seat, and the fixed seat is connected and fixed to the first mounting base. The output end is connected and fixed to the transmission support, and the second adjustment module connects the transmission support and the frame of the heliostat. The aiming system includes a second connecting member, and the housing is connected to the first mounting base through the second connecting member.

[0157] Specifically, see Fig.10a , the first mounting base 730 can be understood as a mounting column of the heliostat. A fixing base 740 is arranged on the first mounting base 730, and the fixing base 740 of the first adjustment module is connected and fixed to the first mounting base 730. The output end can rotate relative to the fixing base, and the heliostat is driven to rotate when the output end rotates. The housing 610 can be connected to the first mounting base 730 through the second connecting member 1010. It should be noted that, compared with the manner in which the housing 610 is connected to the transmission support through the first connecting member in the foregoing text (it can be considered that the heliostat and the housing are in an integrated design form), the housing 610 can be connected to the first mounting base 730 through the second connecting member 1010, and it can be considered that the heliostat and the housing are in a separated design form. In order for the housing not to affect the rotation process of the heliostat, the housing needs to be arranged outside the avoidance area of ​​the heliostat. The avoidance area is the area passed by the heliostat when it rotates. In some other embodiments, the aiming system includes a second connecting member, and the housing is connected to the fixing base of the first adjustment module through the second connecting member.

[0158] In some embodiments, the adjustment module includes a first adjustment module, a transmission support, and a second adjustment module, the first adjustment module includes a fixed base and an output end, the output end can rotate relative to the fixed base, the fixed base is connected and fixed to the first mounting base, the output end is connected and fixed to the transmission support, and the second adjustment module connects the transmission support and a mirror frame of the heliostat. The second mounting base is arranged in the surrounding area of ​​the first mounting base, and the housing is arranged on the second mounting base.

[0159] Specifically, see Fig.10b , the first mounting base 730 can be understood as a mounting column of the heliostat. A fixing base 740 is arranged on the first mounting base 730, and the fixing base 740 is connected and fixed to the first mounting base 730. The output end (not shown in the figure) of the first adjustment module can rotate relative to the fixing base 740, and the heliostat is driven to rotate when the output end rotates. A second mounting base 1020 is arranged in the surrounding area of ​​the first mounting base 730, and the housing 610 is arranged on the second mounting base 1020. It should be noted that, compared with the manner in which the housing 610 is connected to the transmission support through the first connecting member in the foregoing text (it can be considered that the heliostat and the housing are in an integrated design form), the housing 610 is arranged on the second mounting base 1020, and it can be considered that the heliostat and the housing are in a separated design form. In order for the housing not to affect the rotation process of the heliostat, the housing needs to be arranged outside the avoidance area of ​​the heliostat. The avoidance area is the area passed by the heliostat when it rotates.

[0160] It should be noted that the housing 610 of the sight is connected to the first mounting base 730 or the second mounting base 1020 through the second connecting member. Since the sight is in the avoidance area of ​​the heliostat, and the sight and the heliostat are installed and fixed in an independent manner, the rotation of the heliostat will not change the posture of the sight. It can be seen that, on the one hand, the independent installation method can simplify the rotation control logic of the sight, and the control is simple. On the other hand, the sight does not need to be equipped with a corresponding adjustment mechanism and a corresponding motor, which can simplify the structure of the sight. During the installation stage, the posture of the sight is manually adjusted by a technician. When the heat absorber appears at the center of the image, the sight can be fixed to keep the sight always aligned with the heat absorber.

[0161] In some embodiments, the housing is suitable for being arranged in the middle of the heliostat. The aiming system includes a third connecting member, and the housing is connected to the first mounting base of the heliostat through the third connecting member. Specifically, a through hole is provided in the central area of ​​the heliostat, and the third connecting rod is passed through the through hole, one end of the third connecting rod is connected to the housing, and the other end is connected to the first mounting base of the heliostat. In some other embodiments, the housing is suitable for being arranged in the middle of the heliostat. The aiming system includes a third connecting member, and the housing is connected to the fixing seat of the first adjustment module through the third connecting member. Specifically, a through hole is provided in the central area of ​​the heliostat, and the third connecting rod is passed through the through hole, one end of the third connecting rod is connected to the housing, and the other end is connected to the fixing seat of the first adjustment module. In the above embodiments, whether the housing is connected to the first mounting base of the heliostat or the fixing seat of the first adjustment module through the third connecting member, it can be regarded as an integrated design form of the heliostat and the housing. In this integrated design, since the third connecting rod passes through the central area of ​​the heliostat or the gap area in the center of the heliostat, when the posture of the heliostat is adjusted, the housing no longer rotates, that is, the posture of the housing remains unchanged, and the postures of the optical path module and the imaging module are always maintained so that the heat absorber is located within the field of view of the imaging module. Under this premise, the housing no longer needs to be provided with an adjustment mechanism, and the control logic of the housing can be simplified.

[0162] In some embodiments, when the housing of the sight is connected to the first mounting base or the second mounting base via the second connecting member, when the posture of the heliostat is adjusted, the posture of the housing remains unchanged to maintain the posture of the optical path module and the imaging module so that the heat absorber is located within the field of view of the imaging module.

[0163] Specifically, since the shell of the sight is connected to the first mounting base or the second mounting base through the second connecting member, the heliostat and the shell are designed to be separated, and the rotation of the heliostat does not drive the rotation of the shell. Then, when the posture of the heliostat is adjusted, the posture of the shell does not change, that is, the posture of the shell remains unchanged, thereby maintaining the posture of the optical path module and the imaging module so that the heat absorber is always located within the field of view of the imaging module.

[0164] The embodiment of the present specification provides a heliostat aiming system, wherein a marking object is arranged on the mounting base of the heat absorber, and the marking 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 marking object.

[0165] The identification object may be an object, symbol or mark used to identify the heat sink. For example, the identification object may be a checkered identification pattern or a striped identification image (see Figure 3c), 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 there is a fixed relative position between the identification object and 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.

[0166] Normally, 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, an indirect method is provided in the embodiment of the present specification. 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 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 elevation error value are used to correct the azimuth and elevation 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.

[0167] It should be noted that when locating the position of the image of the heat absorber, it can be indirectly obtained by calculating the position and shape of the identification pattern in the image. In some cases, the image of the sun overlaps with the image of the heat absorber. Due to the "crosstalk" between the RGB channels of the image sensor, there is a "residual image" of the sun's image on the channel where the image of the heat absorber is located. This residual image will affect the recognition of the heat absorber image. If a reference object far away from the sun's image is used to indirectly calculate the imaging position of the heat absorber, there will be no such problem.

[0168] In the above-mentioned embodiment, by setting a marking object on the mounting base of the heat absorber, and the marking object and the heat absorber are located together within the field of view of the imaging module, the scattered light of the marking object is imaged by the imaging module to obtain an image of the marking object with better imaging quality than the image of the heat absorber, and the high-quality image of the marking object is recognized by the image algorithm, which is not only conducive to improving the accuracy of the angle error of the heliostat, but also can reduce the amount of calculation. For example, when the mirror field is not working, the heat absorber is a low-brightness black object, and when the mirror field starts to work and the heliostats in the mirror field focus the sunlight on the surface of the heat absorber, the heat absorber is an object with extremely high brightness, and the brightness distribution on its surface is not uniform. For the surface of the heat absorber whose brightness changes greatly in different time periods and is in a high-brightness state, it is equivalent to an object with uneven brightness distribution, and the difficulty of correctly identifying it using an image algorithm is much greater than identifying the marking object.

[0169] In some embodiments, the adjustment module includes a first image processing module. The first image processing module is used 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.

[0170] Specifically, since the identification object is located within the field of view of the imaging module, the imaging module can image the scattered light of the identification object, and the imaging data of the imaging module includes the image data of the identification object. Then, the imaging position of the identification object can be determined based on the imaging data of the imaging module, and then the imaging position of the heat absorber can be inferred using the relative position data between the identification object and the heat absorber and the imaging position of the identification object. Based on the number of difference pixels between the imaging position of the heat absorber and the position of the sun image, the attitude adjustment strategy of the heliostat is determined according to the number of difference pixels.

[0171] In some embodiments, the adjustment module further includes 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 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, the solar image data, and the identification image data.

[0172] Specifically, a first filter can be configured in advance for the sunlight reflected by the heliostat, and a second filter can be configured for the scattered light of the heat absorber and the scattered light of the identification object. The first filter and the second filter are respectively used to retain light of different colors (such as one color in RGB). In this way, the imaging data of the sunlight reflected by the heliostat, the scattered light of the heat absorber and the scattered light of the identification object in the imaging module can be read according to the preset color. Exemplarily, the first filter corresponds to the first color, the second filter corresponds to the second color, the solar image data is read from the imaging data according to the first color, and the identification image data is read from the imaging data according to the second color. Although the identification image data includes the image of the heat absorber and the image of the identification object, the quality of the image of the heat absorber is unstable, so firstly, the imaging position of the identification object is determined based on the identification image data; secondly, the imaging position of the heat absorber is determined based on the imaging position of the identification object and the relative position number between the identification object and the heat absorber; finally, the posture of the heliostat is adjusted based on the imaging position of the heat absorber and the position of the solar image, so that the imaging of the sun and the imaging of the heat absorber are roughly overlapped.

[0173] In some embodiments, the first image processing module includes a first angle comparison module. The first angle comparison 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.

[0174] Among them, the imaging module can be regarded as an imaging system (or lens) with an infinite focal length. The scattered light of the heat absorber is imaged by the lens with an infinite focal length, and the scattered light scattered by the heat absorber into the lens with an infinite focal length corresponds to the first direction vector. After the sunlight reflected by the mirror passes through the light deflection element, the redirected sunlight passes through the imaging system with an infinite focal length, and its image is a sun. The redirected sunlight corresponds to the second direction vector. If the first direction vector and the second direction vector are parallel to each other, 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 calculate the difference angle between the sunlight reflected by the heliostat and the scattered light of the heat absorber. Specifically, since the quality of the image of the heat absorber is unstable, the difference angle between the sunlight reflected by the heliostat and the scattered light of the heat absorber is determined according to the relative position data between the heat absorbers of the identification object, the solar image data and the identification image data. Among them, the difference angle includes at least one of the azimuth error value and the pitch angle error value. The difference angle is used as an error signal of a closed-loop control system to indicate adjustment of the posture of the heliostat, thereby achieving high-precision closed-loop control of the heliostat.

[0175] In some embodiments, the first image processing module further includes a first position determination 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 used to determine a difference angle based on the first imaging position and the third imaging position.

[0176] Specifically, after the first image reading module obtains the sun image data and the identification image data from the imaging data according to the preset color, the first position determination module processes the sun image data to obtain the 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, but uses an indirect method to determine the third imaging position of the heat absorber on the image sensor according to the identification image data and the relative position data between the identification object and the heat absorber, so as to convert the difference pixel number into the difference angle between the sun light reflected by the heliostat and the scattered light of the heat absorber by comparing the difference pixel number between the first imaging position and the third imaging position.

[0177] 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.

[0178] Specifically, the identification image data is obtained from the imaging data according to a preset color through the first image reading module, and the identification image data includes the image of the heat absorber and the image of the identification object. Since the imaging quality of the heat absorber is unstable, the first position determination module uses the identification image data 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.

[0179] In some embodiments, the first imaging position is obtained by processing the solar image data through a template matching method or a deep learning method. The second imaging position is obtained by processing the identification image data based on a template matching method or a deep learning method. It should be noted that the first imaging position can also be obtained by processing the solar image data through edge detection, binarization processing, etc. The second imaging position can also be obtained by processing the identification image data through edge detection, binarization processing, etc.

[0180] See also Fig.11aThe present specification provides a method for determining the difference angle between the sunlight reflected by a heliostat and the scattered light of a heat absorber, the method comprising the following steps:

[0181] S1102, obtaining solar image data and identification image data from imaging data according to preset colors.

[0182] 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.

[0183] S1104. Determine a first imaging position of the sun on the image sensor of the imaging module based on the solar image data.

[0184] Specifically, the first imaging position is obtained by processing solar image data through a template matching method or a deep learning method.

[0185] S1106 . Determine a second imaging position of the identification object on the image sensor based on the identification image data.

[0186] Specifically, the second imaging position is obtained by processing the identification image data based on a template matching method or a deep learning method.

[0187] S1108. Determine 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.

[0188] S1110. Determine a difference angle between the sunlight reflected by the heliostat and the scattered light of the heat absorber according to the first imaging position and the third imaging position.

[0189] The difference angle is used to indicate the adjustment of the attitude of the heliostat.

[0190] In some embodiments, the adjustment module further 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 fuse the obtained multiple frames of image data to obtain a high dynamic range image. The adjustment module is also 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.

[0191] In some cases, the installation error of the optical device and the change of the optical characteristics affect the imaging position of the scattered light of the absorber and the imaging position of the sunlight reflected by the heliostat. Therefore, it is necessary to minimize the number of optical devices in the optical module. Specifically, by controlling the exposure time of the first duration, a clear image of the absorber can be obtained, and by controlling the exposure time of the second duration, a clear image of the sun can be obtained. By controlling the exposure time of the third duration, a clear image of the identification object can be obtained. It should be noted that 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. The exposure time is not specifically limited here. Therefore, a multiple exposure method is used, and multiple frames of image data are obtained by controlling the exposure time, and the image data obtained by multiple exposures are fused to form a high dynamic range image. At this time, the sun, the 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 frames corresponding to the first exposure time, the images of the heat absorber and the identification object are not clear in the image data frames corresponding to the second exposure time, and the images of the heat absorber and the sun are not clear in the image data frames corresponding to the third exposure time, after fusing the image data obtained by multiple exposures, the sun, the heat absorber and the identification object can all appear relatively clearly in the fused high dynamic range image.

[0192] However, the quality of the image of the heat absorber is unstable. Even if the heat absorber can appear relatively clearly on the fused high dynamic range image, an indirect method with the help of the identification object is adopted. First, multiple frames of image data are obtained from the imaging data according to the exposure time, and the acquired multiple frames of image data are fused to obtain a high dynamic range image. Secondly, the imaging position of the identification object is identified from the high dynamic range image, and then the imaging position of the heat absorber is determined based on the imaging position of the identification object and the relative position number between the identification object and the heat absorber; finally, the posture of the heliostat is adjusted based on the imaging position of the heat absorber and the position of the sun image, so that the image of the sun and the image of the heat absorber roughly overlap.

[0193] In some embodiments, 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 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 the adjustment of the posture of the heliostat.

[0194] Specifically, the imaging module can be regarded as an imaging system (or lens) with an infinite focal length. The scattered light of the heat absorber is imaged by the lens with an infinite focal length, and the scattered light scattered by the heat absorber into the lens with an infinite focal length corresponds to the first direction vector. After the sunlight reflected by the mirror passes through the light redirecting element, the redirected sunlight passes through the imaging system with an infinite focal length, and its image is a sun. The redirected sunlight corresponds to the second direction vector. If the first direction vector and the second direction vector are parallel to each other, 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 calculate the difference angle between the sunlight reflected by the heliostat and the scattered light of the heat absorber. Specifically, since the quality of the image of the heat absorber is unstable, the difference angle between the sunlight reflected by the heliostat and the scattered light of the heat absorber is determined indirectly based on the relative position data between the identification object and the heat absorber and the high dynamic range image. Among them, the difference angle includes at least one of the azimuth error value and the pitch angle error value. The difference angle is used as an error signal of a closed-loop control system to indicate adjustment of the posture of the heliostat, thereby achieving high-precision closed-loop control of the heliostat.

[0195] In some embodiments, the first image processing module further 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 used to determine a difference angle based on the first imaging position and the third imaging position.

[0196] Specifically, the second image reading module obtains multiple frames of image data from the imaging data according to the exposure time, fuses the obtained multiple frames of image data to obtain a high dynamic range image, and the second position determination module performs sun recognition on the high dynamic range image to obtain 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 image of the heat absorber overlaps with the image of the sun, the second position determination module does not directly determine the imaging position of the heat absorber on the image sensor, but uses an indirect method to determine the third imaging position of the heat absorber on the image sensor according to the high dynamic range image and the relative position data between the identification object and the heat absorber, thereby converting the number of difference pixels into the difference angle between the sunlight reflected by the heliostat and the scattered light of the heat absorber by comparing the number of difference pixels seen at the first imaging position and the third imaging position.

[0197] 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 according to the relative position data between the identification object and the heat absorber and the second imaging position.

[0198] Specifically, a second image reading module acquires multiple frames of image data from the imaging data according to the exposure time, and fuses the acquired multiple frames of image data 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.

[0199] In some embodiments, the first imaging position and the second imaging position are obtained by processing the high dynamic range image based on a template matching method or a deep learning method. It should be noted that the first imaging position can also be obtained by processing the sun image data by edge detection, binarization processing, etc. The second imaging position can also be obtained by processing the identification image data by edge detection, binarization processing, etc.

[0200] See also Fig.11b The present specification provides a method for determining the difference angle between the sunlight reflected by a heliostat and the scattered light of a heat absorber, the method comprising the following steps:

[0201] S1101 . Acquire multiple frames of image data from imaging data according to exposure time, and fuse the acquired multiple frames of image data to obtain a high dynamic range image.

[0202] S1103 . Determine a first imaging position of the sun on the image sensor of the imaging module based on the high dynamic range image.

[0203] The first imaging position is obtained by processing the high dynamic range image based on a template matching method or a deep learning method.

[0204] 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.

[0205] The second imaging position is obtained by processing the high dynamic range image based on a template matching method or a deep learning method.

[0206] S1107, determining a third imaging position according to the relative position data between the identification object and the heat absorber and the second imaging position.

[0207] S1109: Determine the difference angle between the sunlight reflected by the heliostat and the scattered light of the heat absorber according to the first imaging position and the third imaging position.

[0208] The difference angle is used to indicate the adjustment of the attitude of the heliostat.

[0209] In some embodiments, the adjustment module includes a second image processing module, which is used to determine the center distance data between the center point of the image of the absorber and the center point of the image of the sun according to the imaging data, and the center distance data is used to indicate the adjustment of the posture of the heliostat.

[0210] Specifically, the imaging module images the redirected sunlight and the scattered light of the heat absorber to obtain imaging data. The imaging data includes the image data of the heat absorber and the image data of the sun. The center point of the image of the heat absorber is determined based on the image data of the heat absorber. The center point of the image of the sun is determined based on the image data of the sun. The center distance data between the image of the heat absorber and the image of the sun is calculated based on the center point coordinates of the image of the heat absorber and the center point coordinates of the image of the sun. The adjustment strategy of the heliostat is generated based on the center distance data so that the image of the sun and the image of the heat absorber are roughly overlapped.

[0211] In some embodiments, the second image processing module is further used 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 posture of the heliostat.

[0212] 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 dimension of the horizontal dimension and the azimuth dimension, and the attitude of the heliostat is adjusted by the adjustment data in the at least one dimension. It should be noted that a center distance error threshold can be set in advance in combination with actual conditions, and the center distance data between the image of the heat absorber and the image of the sun is compared to see whether it is less than the center distance error threshold. If it is less than, it indicates that the heliostat does not need to be adjusted and can continue to chase the sun. If it is not less than, it indicates that 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 the azimuth angle adjustment data are transmitted to the heliostat controller to adjust the attitude of the heliostat.

[0213] The embodiment of the present specification also 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 designated position of the image sensor of the imaging module.

[0214] Specifically, the aiming system can be regarded as a system including an aimer, which includes an optical path module and an imaging module. The main control object of the aiming control module includes an aimer, which is used to perform posture control on the optical path module and the imaging module so that the identification object can be imaged at the specified position of the image sensor of the imaging module. For example, the identification object and the heat absorber are located together within the field of view of the imaging module; the imaging module images the scattered light of the heat absorber and the scattered light of the identification object. The heat absorber is pre-set to be imaged in the central area of ​​the image sensor, and because the relative position between the identification object and the heat absorber is fixed, the specified position of the identification object imaging on the image sensor can be determined based on the relative position between the identification object and the heat absorber and the central area of ​​the heat absorber imaging. It should be noted that if the heat absorber is pre-set to be imaged at the central position of the image sensor, the specified position of the identification object imaging on the image sensor can be determined based on the relative position of the heat absorber and the identification object and the central position of the image sensor.

[0215] In some embodiments, the aiming control module includes an attitude calculation module, which is used to calculate the attitude adjustment data of the aiming system according to the relative position data between the heliostat and the heat absorber and the current attitude data of the heliostat, wherein the attitude adjustment data is used to indicate the control of the attitude of the aiming system.

[0216] Specifically, first read the information of the configuration file, and then perform a self-test of the system motor and imaging module. If the self-test fails, send an error message to the mirror field control module and end the process. If the self-test passes, request the relative position data between the heliostat and the absorber and the current posture data of the heliostat from the mirror field control module. Calculate the posture adjustment data of the aiming system based on the relative position data between the heliostat and the absorber and the current posture data of the heliostat. Use the posture adjustment data to control the posture 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 mode, and the second locking control strategy is the real-time target recognition mode. When it is determined to adopt the mirror field control module control mode, send a data request to the mirror field control module to obtain the relative position data between the heliostat and the absorber and the current posture data of the heliostat, so as to determine the posture adjustment data of the aiming system.

[0217] Exemplarily, in the mirror field, a geodetic coordinate system of the mirror field is established with the tower as the coordinate origin, so that each heliostat has unique coordinate data. The coordinate data of each heliostat is measured by geodetic mapping or satellite positioning when the heliostat is installed, and is stored in the heliostat control module. For any heliostat, a certain direction can be selected in the geodetic coordinate system to locate the zero position of the heliostat, for example, setting due north as the zero position of the heliostat mirror surface. After determining the coordinate system, the direction vector of the line between the center of each heliostat and the heat absorber can be determined. When any heliostat rotates, the sight of the aiming system will rotate with it. At this time, the angle difference (denoted as α and γ) between the normal direction vector of the current heliostat surface and the direction vector of the line between the center of the heliostat and the heat absorber in the horizontal and pitch directions can be calculated by the rotation angle of the heliostat relative to the zero position in the horizontal and pitch directions and the direction vector of the line between the center of the heliostat and the heat absorber. In the mirror field control module control mode, the aimer and the heliostat rotate together in the horizontal and elevation directions, and the normal direction of the heliostat surface can be set as the zero position of the aimer. Under this premise, after the angle differences α and γ are known, the aimer can be controlled to rotate in the opposite direction of α and γ, and the aimer will point to the direction of the absorber.

[0218] 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.

[0219] Specifically, in the case of determining to adopt the real-time target recognition method, the motor is controlled to rotate according to the preset rotation angle, and a photo is taken after each rotation. Based on the image data obtained by the photo, it is detected whether the target moves to the specified area of ​​the image. For example, the target can be a heat absorber, and it is detected whether the heat absorber moves to the central area of ​​the image. The target can also be an identification object, and it is detected whether the identification object moves to the peripheral area of ​​the central area of ​​the image. The target can also be a heat absorber and an identification object, and it is detected whether the heat absorber and the identification object are respectively located in their respective corresponding areas. Exemplarily, the preset rotation angle can be any one of 1 degree, 2 degrees, 3 degrees, and 5 degrees. For example, the aiming system is controlled by the motor to rotate 1 degree, and a photo is taken after rotating 1 degree, and it is detected whether the target moves to the specified area of ​​the image based on the image data obtained by the photo. If not, the aiming system is controlled by the motor to rotate 1 degree, and the above-mentioned photo taking and detection of whether the target moves to the specified area of ​​the image are repeated until it is detected that the target moves to the specified area of ​​the image.

[0220] 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.

[0221] Specifically, in the case of determining to adopt the real-time target recognition method, after each rotation according to the preset rotation angle, the rotation angle is counted to obtain the statistical rotation angle of the aiming system. If the target is not detected in the image obtained by taking pictures, the statistical rotation angle of the aiming system is compared with the preset angle threshold. If the statistical rotation angle of the aiming system exceeds the preset angle threshold, it indicates that an operation error occurs, triggering an error message to be sent to the mirror field control module. If the statistical rotation angle of the aiming system does not exceed the preset angle threshold, the posture of the aiming system is adjusted according to the preset rotation angle, and the process of taking pictures and target recognition is repeated until the target is detected to move to the specified area of ​​the image. It can be understood that the target in this embodiment can be a heat absorber or an identification object. Exemplarily, the preset angle threshold can be any one of 90 degrees, 180 degrees, 270 degrees, and 360 degrees. For example, the aiming system has been rotated 360 degrees by motor control, and no target has been detected in the image obtained by taking pictures during the rotation process, indicating that an operation error occurs, triggering an error message to be sent to the mirror field control module.

[0222] In some embodiments, the aiming control module further includes an identification module and a position determination module.

[0223] 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.

[0224] The identification recognition module is used to recognize the identification object based on the adjusted identification image and obtain the position data of the identification object in the adjusted identification image.

[0225] The position judgment module is used to judge whether the posture of the aiming system needs to be adjusted again according to 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.

[0226] Specifically, after the posture of the aiming system is adjusted, the scattered light of the identification object enters the imaging module, and the scattered light of the identification object is imaged to obtain the adjusted identification image. The identification recognition module can be understood as an identification recognition program. By running the identification recognition program, the adjusted identification image is subjected to target recognition to obtain the position data of the identification object in the adjusted identification image. Since the preset position of the identification object in the image has been set in advance, the actual position data of the identification object in the adjusted identification image is compared with the preset position of the identification object in the image to determine whether the posture of the aiming system needs to be adjusted again. If it is determined that the image of the identification object is already located at the specified position of the image sensor according to the comparison result of the actual position data and the preset position, it indicates that no further adjustment is required. If it is determined that the image of the identification object is not located at the specified position of the image sensor according to the comparison result of the actual position data and the preset position, it indicates that further adjustment is required so that the identification object can be imaged at the specified position of the image sensor. The preset position of the identification object in the image is exemplarily described, and the preset position of the identification object in the image can be determined according to the imaging position of the heat absorber and the relative position data between the heat absorber and the identification object.

[0227] In some implementations, 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.

[0228] 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.

[0229] 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.

[0230] Specifically, if it is detected that the identification object moves to the specified area of ​​the image, the process of taking pictures and collecting images is triggered and interrupted, and the optical path module and imaging module of the aiming system are controlled to enter the locked state. At this time, it indicates that the scattered light from the heat absorber and the identification object can directly enter the imaging module, and the aiming system can be started to measure the difference angle between the sunlight reflected by the heliostat and the scattered light from the heat absorber. If it is determined that the identification object is not imaged at the specified position based on the comparison result of the actual position data and the preset position, it indicates that it needs to be adjusted again so that the identification object can be imaged at the specified position of the image sensor.

[0231] In some embodiments, the aiming system further includes an aiming control module, which is used to control the posture of the aiming system so that the heat absorber can be imaged at the center area of ​​the image sensor of the imaging module.

[0232] Specifically, the main control object of the aiming control module includes an 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.

[0233] In some embodiments, the aiming system includes a heliostat control module communicatively connected to the adjustment module, and the heliostat control module is communicatively connected to a mirror field control module. The mirror field control module is used to correct the time 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.

[0234] Among them, the reflection spot area and shape of each heliostat in the mirror field at each time period of the year are calculated in advance through simulation and experimental methods and stored in the mirror field control module. The mirror field control module uses astronomical algorithms to calculate the reflection power of each heliostat at each time period of the year in real time. The time period value interval is consistent with the heliostat control interval time.

[0235] As mentioned above, in order to ensure that the sunlight reflected by the heliostat can accurately illuminate the absorber, the heliostat focusing angle deviation needs to be less than 1mrad. Therefore, in some cases, various factors that affect the posture of the heliostat are comprehensively considered, such as the heliostat being continuously affected by the variable wind load. Therefore, the frequency of wind speed changes needs to be considered when controlling the heliostat. Specifically, an instrument (such as an anemometer) for measuring wind speed conditions can be deployed in the mirror field. The wind speed conditions of the mirror field can be monitored by the instrument, which is connected to the mirror field control module for communication and transmits the monitored wind speed conditions to the mirror field control module. The mirror field control module determines whether the heliostat is continuously affected by the variable wind load based on the received wind speed conditions. If it is determined that the heliostat is continuously affected by the variable wind load, the wind speed change frequency is determined according to the wind speed condition, and the time interval of the time period and the heliostat control time interval are corrected according to the determined wind speed change frequency. It should be noted that if the heliostat is 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.

[0236] Exemplarily, the time interval is recorded as t1, and the heliostat control interval is recorded as t2. After the mirror field control module determines the wind speed change frequency, since the relationship data between the wind speed change frequency and the correction coefficient is pre-stored in the mirror field control module, the corresponding correction coefficient θ is obtained by searching in the pre-stored relationship data based on the determined wind speed change frequency. 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 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.

[0237] The embodiment of the present specification also provides a sighting system, which also includes a heliostat control module communicatively connected to the adjustment module; the heliostat control module is used to receive adjustment posture data determined according to the imaging data, and control the adjustment module to rotate the heliostat according to the adjustment posture data.

[0238] Among them, the heliostat control module can be understood as the controller of the heliostat. The heliostat controller can be installed on the rotation drive input end or the mirror surface of the heliostat, and control the rotation of the horizontal drive motor and the azimuth drive motor by wired or wireless means. The heliostat controller receives the adjustment posture data by wired or wireless means. It can be understood that the adjustment posture data can enable the aiming control module of the aiming system (which can be understood as the aiming controller) to be transmitted to the heliostat control module. The aiming controller can be a controller for controlling the posture of the optical path module and the imaging module so that the heat absorber and / or the identification object appear within the field of view of the imaging module, that is, the aiming controller can be understood as a controller for controlling the aiming of the aiming device including the optical path module and the imaging module to aim at the heat absorber and / or the identification object.

[0239] The attitude adjustment data may include at least one of azimuth data and elevation data for indicating the rotation of the heliostat obtained by processing the imaging data of the imaging module. The azimuth data may include an azimuth error value, and the elevation data may include a elevation error value.

[0240] Specifically, the attitude adjustment data can be used to modify the azimuth and pitch angle of the heliostat. The adjustment module controls the heliostat to rotate according to the modified azimuth and pitch angle 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 overlaps with the image of the sun.

[0241] Exemplarily, the heliostat controller can calculate the altitude angle and azimuth of the sun at the current moment according to the longitude, latitude, altitude and time of the center point of the heliostat. Then, according to the coordinate difference between the center point of the heliostat mirror and the center point of the absorber in three-dimensional space, the target azimuth and target pitch angle of the mirror required to reflect the sunlight to the absorber are calculated, and the heliostat controller controls the horizontal rotation drive motor at the drive output end and the pitch rotation drive motor of the drive shaft to operate so that the mirror azimuth and the mirror pitch angle are as close as possible to the theoretically calculated target azimuth and target pitch angle. In order to ensure the control accuracy, the heliostat controller will also calculate the optimal speed that the horizontal rotation drive motor and the pitch rotation drive motor should maintain when the sunlight is reflected to the absorber, and the heliostat controller will keep the motor speed running at this speed.

[0242] Mechanical errors and other reasons may cause the sunlight reflected by the heliostat to not irradiate the heat absorber. The heliostat controller will read the azimuth deviation value and the elevation deviation value measured by the aiming system in real time. The heliostat controller will use the measured azimuth deviation value and the elevation deviation value for correction based on the current target azimuth and target elevation, and calculate the optimal speed and rotation direction of the horizontal rotation drive motor and the elevation rotation drive motor accordingly, and control the rotation of the drive motor accordingly, so that the azimuth deviation value and the elevation deviation value measured by the aiming system are as close to zero as possible, thereby ensuring that the sunlight reflected by the heliostat irradiates the heat absorber as much as possible.

[0243] In some embodiments, the heliostat control module is communicatively connected to the mirror field control module. The heliostat control module is used to feed back the current posture data of the heliostat to the mirror field control module.

[0244] Specifically, the mirror field control module can be understood as the host computer of the controller of each heliostat. 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 adjustment posture data, the heliostat control module sends the current posture data of the heliostat to the mirror field control module, and the mirror field control module records the current posture data of the heliostat.

[0245] In some embodiments, the heat absorber is divided into a plurality of heat absorption regions. Each heat absorption region corresponds to a target heliostat, and the target heliostat corresponding to any heat absorption region is a heliostat that can reflect sunlight to the any heat absorption region. The mirror field control module is used to detect whether the any heat absorption region meets the principle of uniform energy distribution according to the irradiation energy data of the target heliostat.

[0246] In some cases, not all heliostats that can reflect sunlight to the heat absorption region X are target heliostats for the heat absorption region X. When the ratio of sunlight reflected by heliostat Y to the heat absorption region X to the total sunlight reflected by heliostat Y exceeds a preset ratio threshold, heliostat Y is determined as the target heliostat for the heat absorption region X. When the ratio of sunlight reflected by heliostat Y to the heat absorption region X to the total sunlight reflected by heliostat Y does not exceed a preset ratio threshold, heliostat Y cannot be considered as the target heliostat for the heat absorption region X. Exemplarily, the preset ratio threshold may be equal to any one of 3%, 5%, and 10%. For example, if heliostat Y can reflect more than 5% of the total sunlight reflected by it to the heat absorption region X at all times throughout the year, heliostat Y is determined as the target heliostat for the heat absorption region X. In some cases, any heliostat that can reflect sunlight to the heat absorption region X can be used as the target heliostat for the heat absorption region X.

[0247] The irradiation energy data may be energy data related to the reflection power of the heliostat. For example, the irradiation energy data may be the reflection power of the heliostat. The irradiation energy data may be the irradiation data of the sun on the heliostat, such as the radiation flux falling on the heliostat. The purpose of the uniform energy distribution principle is to ensure that the temperature of the area on the absorber is relatively uniform to reduce the probability of the absorber malfunctioning or reducing the working efficiency of the absorber due to uneven temperature.

[0248] Specifically, the heat absorber is divided into multiple heat absorption areas, and each of the divided heat absorption areas is detected to prevent the heat absorber from being locally overheated. For any heat absorption area (denoted as X), although there are multiple heliostats in the mirror field, not every heliostat in the mirror field can reflect sunlight to the heat absorption area X, so it is necessary to configure a target heliostat that can reflect sunlight to the heat absorption area X for the heat absorption area X. By analogy, a corresponding target heliostat is configured for each heat absorption area.

[0249] After configuring a corresponding target heliostat for each heat absorption area, the irradiation condition of sunlight on each heat absorption area can be determined according to the irradiation energy data of the target heliostat, so that the irradiation condition of sunlight on each heat absorption area can be used to detect whether each heat absorption area meets the principle of uniform energy distribution.

[0250] In some embodiments, the mirror field control module is further used to determine the irradiation energy data of the target heliostat based on the relative position data between the target heliostat and the absorber, the projection area of ​​the target heliostat, the mirror reflectivity, and the solar irradiation data.

[0251] Specifically, first, determine the direction vector corresponding to the sun's position where the target heliostat is located, recorded as the sun's azimuth vector; secondly, determine the azimuth vector of the heat absorber based on the relative position data between the target heliostat and the heat absorber; then, based on the principle that the surface normal direction of the target heliostat, the sun's azimuth vector, and the heat absorber's azimuth vector satisfy the reflection theorem, determine the azimuth and elevation angle that the target heliostat needs to be at at the current moment. On this basis, determine the projection area of ​​the target heliostat; finally, determine the irradiation energy data of the target heliostat based on the projection area, mirror reflectivity, and solar irradiation data of the target heliostat.

[0252] Exemplarily, 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 position of the sun where the heliostat is located according to the astronomical algorithm; 3) Convert the position of the sun where the heliostat is located 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 azimuth vector of the sun and the surface normal vector of the heliostat. The angle a between them; 6) The area of ​​the heliostat is denoted as S, and the projection area on the sun is equal to the product of S and cos(a); 7) Assume that the maximum ground irradiance is E (the maximum ground irradiance E can be the irradiance measured by the irradiance meter facing the sun, rather than the horizontal irradiance of the ground), 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.

[0253] In some embodiments, the mirror field control module is communicatively connected to a radiometer; the radiometer is used to collect solar irradiation data.

[0254] The mirror field can be divided into regions, each region is equipped with a irradiance meter, and the irradiance meter equipped in each region is connected to the mirror field control module in communication. Specifically, the irradiance meter in the mirror field region where the target heliostat is located is first determined, and then the solar irradiance data is collected by the irradiance meter, so that the irradiation energy data of the target heliostat can be determined.

[0255] 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 principle of uniform energy distribution according to the energy density of each heat absorption area.

[0256] Specifically, each heat absorption region corresponds to a plurality of target heliostats, each target heliostat has irradiation energy data, statistics are performed based on the irradiation energy data of each target heliostat, the sum of irradiation energy of each heat absorption region is obtained, and the energy density of each heat absorption region is calculated based on the sum of irradiation energy and the area of ​​each heat absorption region. According to the energy density of each heat absorption region, it is detected whether each heat absorption region meets the principle of uniform energy distribution. Exemplarily, the energy density difference between the energy densities of each heat absorption region can be detected, and it is judged whether each heat absorption region is overheated by the detected energy density difference.

[0257] How to calculate the energy density is explained by way of example. It is understandable that the sunlight reflected by the target heliostat to the heat absorption area may be all the sunlight reflected by the target heliostat or part of the sunlight reflected by the target heliostat. The ratio between the sunlight reflected by the target heliostat to the heat absorption area and the total sunlight reflected by the target heliostat is defined as the percentage of sunlight reflected by the target heliostat to the heat absorption area. The percentage of sunlight is related to the energy density of the heat absorption area. Therefore, the irradiation energy of the target heliostat in the heat absorption area is determined based on the percentage of sunlight and the irradiation energy data of the target heliostat. The irradiation energy of each target heliostat in the heat absorption area is summed to obtain the total irradiation energy of the heat absorption area. The energy density of each heat absorption area is obtained by dividing the total irradiation energy of the heat absorption area by the area of ​​the heat absorption area.

[0258] In some embodiments, the heat absorber corresponds to an average energy density. The energy uniform distribution principle requires that the energy difference data between the energy density of any heat absorbing region and the average energy density of the heat absorber is within the allowable energy difference range.

[0259] The energy density mean pm of the absorber is determined according to the following formula:

[0260]

[0261] Where pi is the energy density of the ith heat absorption area, x is the number of heliostats in the entire field, and A is the area of ​​the absorber.

[0262] Specifically, the energy density p of any heat absorption area is i and the mean energy density p of the absorber m Compare and obtain energy difference data. If the energy difference data is within the allowable range of energy difference, any heat absorption area meets the requirement of energy uniform distribution principle. If the energy difference data is not within the allowable range of energy difference, any heat absorption area does not meet the requirement of energy uniform distribution principle, and it is necessary to rotate part of the target heliostat in any heat absorption area to meet the requirement of energy uniform distribution principle.

[0263] 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.

[0264] For example, for each heat absorption region, the energy density of the heat absorption region is calculated according to the following formula:

[0265]

[0266] Among them, p i is the energy density of the i-th heat absorption area, i is the number of the target heliostat, x i is the number of target heliostats corresponding to the ith heat absorption area. η is the percentage of sunlight from the target heliostat to the ith 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 absorber, which is related to the reflection power of the target heliostat.

[0267] In some embodiments, the mirror field control module is used to continue dividing 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.

[0268] 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 of regions. Exemplarily, the multiple levels include the first level, the second level, the third level... 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 dividing on the first level continue to be 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 dividing on the second level continue to be divided on the third level, and so on, until each subdivided area on the heat absorber meets the energy uniform distribution requirements corresponding to the last level.

[0269] 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 of the following processing methods or a combination of multiple methods can be selected:

[0270] 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.

[0271] 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 requirement corresponding to the first level.

[0272] 3) Adjust at least part of the target heliostats corresponding to each heat absorption area to change the sunlight received by the heat absorption area. For example, rotate part of the target heliostats corresponding to the heat absorption area with higher energy density so that the part of the target heliostats reflects the sunlight to the heat absorption area with lower energy density. After rotating the part of the target heliostats, recalculate the energy density of each heat absorption area to determine whether each heat absorption area on the first level meets the new energy uniform distribution requirement corresponding to the first level.

[0273] 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.

[0274] 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.

[0275] In some implementations, the second allowed threshold is less than the first allowed threshold.

[0276] 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... 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... 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.

[0277] In some embodiments, the mirror field control module stores current posture data of the faulty heliostat; the mirror field control module 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.

[0278] The area to be evaluated is the area on the heat absorber that can be illuminated by the sunlight reflected by the faulty heliostat. When some heliostats cannot work due to strong winds or control failures, these heliostats are identified as faulty heliostats. Before they cannot work, the faulty heliostats can reflect sunlight on some areas of the heat absorber. Since the faulty heliostats cannot work at present, the sunlight received by these areas is reduced. It is necessary to re-judge these areas as areas to be evaluated to see whether they meet the principle of uniform energy distribution.

[0279] Specifically, the controller of the faulty heliostat sends the number of the faulty heliostat to the mirror field control module, and the mirror field control module records the current posture data of each heliostat, and the current posture data of the faulty heliostat is determined according to the number of the faulty heliostat. The energy density of the area to be evaluated is recalculated according to the number of the faulty heliostat and the current posture data. It is judged whether the area to be evaluated meets the principle of uniform energy distribution according to the energy density on the area to be evaluated.

[0280] For example, the energy density on the area to be evaluated can be compared with the average energy density of the heat absorber to determine whether the difference energy data between the energy density on the area to be evaluated and the average energy density of the heat absorber is within the allowable range required by the energy uniform distribution principle. If so, no adjustment is required. If not, it is necessary to determine the heat absorption area around the area to be evaluated, and rotate part of the target heliostats corresponding to the heat absorption area so that the energy density on the area to be evaluated meets the energy uniform distribution principle.

[0281] Exemplarily, a heat absorption region around the region to be evaluated is determined, and the energy density on the region to be evaluated is compared with the energy density of the heat absorption region to determine whether the difference energy data between the region to be evaluated and the heat absorption region is within the allowable range required by the energy uniform distribution principle. If so, no adjustment is required. If not, some of the target heliostats corresponding to the heat absorption region are rotated so that the energy density on the region to be evaluated meets the energy uniform distribution principle.

[0282] In some embodiments, the heat absorber is divided into a plurality of heat absorption regions. The mirror field control module is communicatively connected to a temperature meter, such as an infrared thermal imaging temperature meter, for monitoring the temperature of the heat absorption region; the mirror field control module is used to determine whether there is an uneven region in the plurality of heat absorption regions that does not meet the principle of uniform energy distribution based on the temperature data monitored by the infrared thermal imaging temperature meter.

[0283] Specifically, the temperature of each heat absorption area is monitored by 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 monitored by the infrared thermal imaging thermometer and determines whether there are uneven areas in the multiple heat absorption areas that do not meet the principle of uniform energy distribution based on the received temperature data.

[0284] For example, when there is partial obstruction by clouds over the mirror field, it is necessary to adjust the energy balance on the heat absorber. When there is cloud obstruction over the mirror field, the mirror field control module cannot know 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 regions. When there is cloud obstruction, the irradiance E value in the mirror field varies greatly, and the energy density difference in the target area is also large, which makes it difficult to meet the set threshold. Therefore, the heliostats in the area with large irradiance value E and 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 closing some heliostats to make them horizontal.

[0285] In some embodiments, the heat absorber is divided into a plurality of heat absorption regions. The adjustment module is further used to adjust the posture of a portion of the plurality of heliostats corresponding to the uneven region if there is an uneven region that does not satisfy the principle of uniform energy distribution among the plurality of heat absorption regions, so as to change the sunlight reflected on the uneven region.

[0286] Among them, the multiple heliostats corresponding to the uneven area are heliostats that can reflect sunlight to the uneven area. Specifically, the mirror field control module receives the temperature data monitored by the infrared thermal imaging thermometer, and determines whether there is an uneven area that does not meet the principle of uniform energy distribution in the multiple heat absorption areas according to the received temperature data. If there is an uneven area in the multiple heat absorption areas, the multiple heliostats corresponding to the uneven area are determined, and the postures of some of these heliostats are adjusted to change the sunlight reflected on the uneven area.

[0287] In the above embodiment, by adjusting the posture of a portion of the plurality of 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.

[0288] In some embodiments, the energy density of the uneven region is higher than the energy density of other heat absorbing regions. The plurality of heliostats corresponding to the uneven region include a first heliostat and a second heliostat. The distance between the first heliostat and the heat absorber is less than the distance between the second heliostat and the heat absorber. The adjustment module is further used to remove the sunlight reflected by the first heliostat from the uneven region and retain the sunlight reflected by the second heliostat to reduce the sunlight reflected on the uneven region.

[0289] Specifically, since 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 the spot area of ​​the second heliostat on the absorber. Sometimes, the sunlight reflected by the second heliostat can illuminate multiple heat absorption areas on the absorber. If the second heliostat is adjusted, it will not only affect the uneven area, but also other heat absorption areas, that is, adjusting the second heliostat will greatly affect the energy distribution of the absorber. Therefore, the first heliostat is adjusted first to move the sunlight reflected by the first heliostat from the uneven area, and the posture of the second heliostat is maintained unchanged to reduce the sunlight reflected on the uneven area.

[0290] The embodiment of the present specification also provides a method for aiming a heliostat, which is implemented by a sight configured for the heliostat. The sight includes an optical path module, an imaging module, and a controller. The optical path module includes a first optical path and a second optical path, and a light steering element is provided on the first optical path. The sunlight reflected by the heliostat passes through the light steering element to obtain redirected sunlight that can be incident on the imaging module, and the scattered light of the heat absorber passes through the second optical path and directly incident on the imaging module while maintaining the original direction. The imaging module is used to image the redirected sunlight and the scattered light of the heat absorber; the controller can calculate the angle difference between the sunlight reflected by the heliostat and the scattered light of the heat absorber according to the imaging data of the imaging module. And based on the angle difference between the sunlight reflected by the heliostat and the scattered light of the heat absorber, the angular displacement value that the heliostat needs to aim in the horizontal and azimuth directions is determined. The controller of the sight is communicatively connected to the mirror field control module. The aiming method of the heliostat includes the following steps:

[0291] 1) The mirror field control module calculates the target area reflected by each heliostat in the mirror field onto the absorber.

[0292] 2) The aimer collects the image of the sun reflected by the heliostat.

[0293] 3) The aimer collects the image of the target area reflected by the heliostat onto the absorber.

[0294] 4) The controller calculates the pixel difference between the image of the sun and the image of the target area, and the pixel difference may be a pixel difference value obtained by pixel comparison calculation.

[0295] 5) When the difference is greater than the set threshold, the aimer control system calculates the angular displacement values ​​of the heliostat that need to be aimed in both horizontal and azimuth directions;

[0296] 6) The aiming control system transmits the angular displacement value to be aimed to the heliostat controller by wire or wireless means;

[0297] 7) The heliostat controller adjusts the attitude according to the angular displacement value;

[0298] 8) After adjustment, the heliostat controller uploads the current posture data of the heliostat to the mirror field control module;

[0299] 9) Repeat steps 1) to 8) several times until the pixel difference between the image of the sun calculated in 5) and the image of the target area on the absorber is less than the threshold.

[0300] It is understandable that if the pixel difference is less than the set threshold, the heliostat continues to track the sun without adjusting the angle of the heliostat, and the current posture data of the heliostat is fed back to the mirror field control module.

[0301] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection portion with one or more wirings (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, 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 processing in other suitable ways if necessary, and then stored in a computer memory.

[0302] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0303] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0304] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0305] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0306] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for detecting energy distribution on a heat absorber, characterized in that: Applied in a mirror field control module, the absorber is divided into multiple levels of regions; each region corresponds to a target heliostat, and the target heliostat is a heliostat that can reflect sunlight to the region; the method includes: Determining the energy density of each area of ​​the first level according to the irradiation energy data of the target heliostat; Detecting whether each area of ​​the corresponding level meets the principle of uniform energy distribution according to the energy density of each area; if it is detected that all the divided areas meet the principle of uniform energy distribution, then continue to detect the energy density of the areas divided at the next level until the areas divided at the last level meet the principle of uniform energy distribution; Among them, different levels correspond to different energy uniformity allowable thresholds, and the energy uniformity allowable threshold corresponding to the first level to the energy uniformity allowable threshold corresponding to the last level decreases successively. The energy uniform distribution principle requires that the energy difference data between the energy density of each area of ​​the first level and the average energy density of the heat absorber is less than the energy uniformity allowable threshold corresponding to the first level, and the energy difference data between the energy density of each area of ​​the last level and the average energy density of the heat absorber is less than the energy uniformity threshold corresponding to the last level.

2. The method according to claim 1, characterized in that The energy density of each region is determined according to the area of ​​each region and the reflection power of the target heliostat.

3. The method according to claim 1, characterized in that The mirror field control module stores current posture data of the faulty heliostat; the method further includes: Record the serial number of the faulty heliostat; Recalculating the energy density of the area to be evaluated according to the serial number and current posture data of the faulty heliostat; wherein the area to be evaluated is the area on the absorber that can be irradiated by the sunlight reflected by the faulty heliostat; Whether the area to be evaluated satisfies the energy uniform distribution principle is detected according to the energy density on the area to be evaluated.

4. The method according to claim 1, characterized in that: The mirror field control module is communicatively connected to a temperature measuring instrument for monitoring the temperature of the heat absorber; the method further comprises: According to the temperature data monitored by the temperature measuring instrument, it is determined whether there is an uneven area that does not meet the principle of uniform energy distribution among the multiple areas obtained by dividing the heat absorber.

5. The method according to claim 1, characterized in that If there is an uneven area on the absorber that does not meet the principle of uniform energy distribution, some of the multiple heliostats corresponding to the uneven area are adjusted in posture to change the sunlight reflected on the uneven area; wherein the multiple heliostats corresponding to the uneven area are heliostats that can reflect sunlight to the uneven area.

6. The method according to claim 5, characterized in that The energy density of the uneven area is higher than the energy density of other areas; the plurality of heliostats corresponding to the uneven area 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 solar rays reflected by the first heliostat are removed from the uneven area, and the solar rays reflected by the second heliostat are retained to reduce the solar rays reflected on the uneven area.

7. The method according to any one of claims 1 to 6, characterized in that: The method further comprises: Monitor wind speed in the mirror field; If it is determined according to the wind speed condition that the heliostats in the mirror field are continuously affected by the variable wind load, determining the wind speed change frequency; The time period value interval and the heliostat control time interval are corrected according to the wind speed change frequency.

8. The method according to claim 7, characterized in that The mirror field control module pre-stores the relationship data between the wind speed change frequency and the correction coefficient; the correction of the time interval and the heliostat control time interval according to the wind speed change frequency includes: Based on the wind speed change frequency, the pre-stored relationship data is searched to obtain a corresponding correction coefficient, and the time interval and the heliostat control time interval are adjusted using the correction coefficient.

9. The method according to any one of claims 1 to 6, characterized in that: The mirror field control module is communicatively connected to a radiometer; the irradiation energy data of the target heliostat is determined by: Collecting solar irradiance data by means of the radiometer; The irradiation energy data of the target heliostat is determined according to the relative position data between the target heliostat and the heat absorber, the projection area and mirror reflectivity of the target heliostat, and the solar irradiation data.

10. The method according to any one of claims 1 to 6, characterized in that: The method further comprises: If the energy difference data between the energy density of any area of ​​any level and the average energy density of the absorber exceeds the energy uniformity allowable threshold value corresponding to the any level, some of the target heliostats corresponding to the any area are rotated, and the energy density of each area of ​​the any level is recalculated until the energy difference data between the energy density of each area of ​​the any level and the average energy density of the absorber does not exceed the energy uniformity allowable threshold value corresponding to the any level.

11. A mirror field control module, characterized in that: The invention comprises a memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the method according to any one of claims 1 to 10 by executing the computer instructions.

Images