Precise sun tracking system combining active tracking and passive tracking

Abstract

The invention relates to a precise sun tracking system combining active and passive tracking. The precise sun tracking system comprises an upper computer, a high-precision rotary tracking device, a folded light path device and a photoelectric detection compensation device, the high-precision rotary tracking device comprises a motor controller, an azimuth angle tracking mechanism and an elevation angle tracking mechanism, the motor controller is used for receiving an instruction of the upper computer, and the motor controller drives the azimuth angle tracking mechanism and the elevation angle tracking mechanism to act so as to realize accurate tracking of the sun; the folded light path device comprises a light inlet reflector, a fixed reflector and a light outlet reflector; the photoelectric detection compensation device captures solar facula information through the CMOS area-array camera, uploads the solar facula information to the image processing device, and transmits deviation information to the data processing module of the upper computer. According to the invention, real-time accurate tracking of sunlight can be realized, stable operation of equipment under various environmental conditions is ensured, and the requirements of high precision, miniaturization and real-time tracking of the sun to monitor the atmospheric environment are met.

Description

Technical Field

[0001] The present invention relates to the field of atmospheric environment observation, and more specifically, to a precise sun tracking system combining active and passive tracking. Background Art

[0002] High-resolution FTIR spectrometers have important applications in atmospheric pollutant monitoring and can accurately invert the composition and concentration of pollutants in the atmosphere. Existing domestic high-resolution FTIR equipment has the problem of being difficult to balance between miniaturization and high resolution. The equipment is large in size, which limits its application in space-constrained scenarios. The inversion algorithm for long-life atmospheric pollutants is imperfect and cannot meet the needs of long-term stable monitoring. In addition, the existing solar tracking system is not accurate enough to meet the requirements of high-resolution spectrometers for sunlight accuracy, resulting in reduced accuracy of observation data. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a precise solar tracking system combining active and passive tracking, which can realize real-time and precise tracking of sunlight and ensure stable operation of the equipment under various environmental conditions.

[0004] The technical solution adopted by the present invention to solve the technical problem is: constructing a precise sun tracking system combining active and passive tracking, including a host computer, a high-precision rotation tracking device, a folded optical path device and a photoelectric detection compensation device;

[0005] The high-precision rotation tracking device includes a motor controller, an azimuth tracking mechanism and an altitude tracking mechanism. The motor controller is used to receive instructions from a host computer. The motor controller drives the azimuth tracking mechanism and the altitude tracking mechanism to operate to achieve accurate tracking of the sun. The folded optical path device includes a light input reflector, a fixed reflector and a light output reflector. The photoelectric detection compensation device captures solar spot information through a CMOS area array camera and uploads it to an image processing device. The image processing device calculates the deviation between the center of mass coordinates of the spot and the center coordinates of the image in real time, and transmits the deviation information to a data processing module of the host computer.

[0006] According to the above scheme, the host computer includes a solar tracking algorithm module and a data processing module. The solar tracking algorithm module calculates the azimuth and altitude of the sun in real time based on the acquired time and space information. The data processing module performs data conversion based on the calculation results and sends instructions to the motor controller through serial communication to drive the high-precision rotation tracking device to track the sun in real time.

[0007] According to the above scheme, the solar tracking algorithm module obtains the current time, geographical location, altitude and other information, completes the calculation of Julian day and century number, calculates the heliocentric longitude, heliocentric latitude and the distance between the earth and the sun by summing the periodic terms; converts the heliocentric coordinates into geocentric coordinates to obtain the geocentric longitude and latitude of the sun, and calculates the altitude angle and azimuth of the sun through right ascension and declination corrections.

[0008] According to the above scheme, the image processing device uses the Otsu algorithm to process the image, and forms a grayscale histogram by analyzing the input image and counting the number of pixels of each grayscale level, normalizing the histogram so that the sum of the probabilities of each grayscale level is 1, calculating the cumulative probability and cumulative mean of pixels less than the current grayscale level, calculating the inter-class variance for each possible threshold, finding the optimal threshold that maximizes the inter-class variance, performing image segmentation according to the found optimal threshold, and outputting a binary image; calculating the deviation between the sun's center of mass coordinates and the image center, and sending the deviation data to the host computer, correcting the tracking error in real time, and ensuring that the light spot always remains in the center of the field of view.

[0009] According to the above scheme, the high-precision rotation tracking device includes a motor controller, an azimuth tracking mechanism and an altitude tracking mechanism. The motor controller is used to control the azimuth tracking mechanism and the altitude tracking mechanism. The azimuth tracking mechanism is horizontally fixed on the support frame, the rotating platform is fixedly connected to the bracket through a first connecting member, the altitude tracking mechanism is vertically installed on the side wall of the frame, and the rotating table is fixedly connected to the light incident reflector and rotates around the same central axis.

[0010] According to the above solution, the azimuth tracking mechanism is driven by a second stepper motor, the second stepper motor is connected to the worm gear transmission mechanism, and the worm gear is fixedly connected to the rotating platform.

[0011] According to the above solution, the altitude angle tracking mechanism is driven by a third stepper motor, the third stepper motor is connected to the worm gear transmission mechanism, the worm gear is fixedly connected to the rotating table, and the rotating table supports the light incident reflector.

[0012] According to the above scheme, the altitude angle tracking mechanism is fixed on the side wall of the frame and its rotation center is colinear with the rotation center of the incident reflector and the rotation center of the fixed reflector. The azimuth angle tracking mechanism is fixed on the support frame in a horizontal state and its rotation center is perpendicular to the rotation center of the fixed reflector.

[0013] According to the above scheme, it also includes an automatic rain shelter device, which includes a rain sensor, a rain shelter cover, a slide rail, a slider and a first stepper motor. The first stepper motor is installed at the bottom of the frame, the rain shelter cover is sleeved on the outside of the frame and is fixedly connected to the slider at the bottom, two slide rails are horizontally fixed to the bottom of the frame and connected to the slider at the same time, the first stepper motor includes a T-shaped screw rod installed at the bottom of the frame, and the right side of the bottom end of the rain shelter cover is fixedly connected to the screw rod nut through a second connecting piece.

[0014] According to the above scheme, when the rain sensor detects that the humidity exceeds the set threshold, the first stepper motor starts, driving the rain shelter to move along the slide rail, covering the entire device to prevent rain from invading; after the humidity returns to normal, the rain shelter is automatically retracted.

[0015] The precise sun tracking system combining active and passive tracking of the present invention has the following beneficial effects:

[0016] 1. The present invention combines a high-precision rotation tracking device with an automatic control program of a host computer to accurately adjust the azimuth and altitude angles to achieve real-time tracking of sunlight. Combined with a photoelectric detection compensation device, it can automatically capture and correct the error of the solar spot, ensuring that the system continues to operate stably in a complex environment and ensures efficient and accurate tracking of the sun.

[0017] 2. The compact mechanical structure design of the present invention not only meets the high-precision requirements of the solar tracking system, but also realizes the miniaturization of the system, which is suitable for application scenarios with limited space, such as the supporting equipment of the self-developed miniaturized high-resolution FTIR spectrometer;

[0018] 3. The present invention integrates a rain sensor and an automatic rain shelter device, which can automatically start the rain shelter device in bad weather, effectively protect the equipment, extend the service life of the equipment, and improve the reliability and durability of the equipment in different environments;

[0019] 4. The present invention detects the position of the sun spot in real time through a CMOS image sensor and an image processing device, eliminates the tracking deviation caused by the cumulative error of the rotating platform, and ensures the long-term high-precision operation of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0021] Figure 1 It is a structural schematic diagram of the active and passive tracking combined precision sun tracking system of the present invention;

[0022] Figure 2 is a side view of the azimuth tracking mechanism of the present invention;

[0023] Figure 3 is a top view of the azimuth tracking mechanism of the present invention;

[0024] Figure 4 is a side view of the altitude angle tracking mechanism of the present invention;

[0025] Figure 5 is a top view of the altitude angle tracking mechanism of the present invention;

[0026] Figure 6It is a schematic diagram of the structure of the folded optical path device of the present invention;

[0027] Figure 7 is a side view of the automatic rain shelter device of the present invention;

[0028] Figure 8 is a top view of the automatic rain shelter device of the present invention;

[0029] In the figure: 1. motor controller, 2. light guide tube, 3. support frame, 4. azimuth tracking mechanism, 5. rack, 6. altitude tracking mechanism, 7. light input reflector, 8. fixed reflector, 9. rain shelter, 10. slide rail and slider, 11. first stepper motor, 12. first connecting piece, 13. light output reflector, 14. FTIR spectrometer, 15. CMOS area array camera, 16. second stepper motor, 17. rotating platform, 18. light input port of FTIR spectrometer, 19. slide rail, 20. slider, 21. lead screw, 22. second connecting piece, 23. third stepper motor, 24. rotating table, 30. sun tracking algorithm module, 31. data processing module, 32. image processing system, 33. rain sensor. DETAILED DESCRIPTION

[0030] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0031] like Figure 1-4 As shown, the active and passive tracking combined precision solar tracking system of the present invention comprises a host computer, a high-precision rotation tracking device, a folded optical path device, a photoelectric detection compensation device and an automatic rain shelter device. The embodiment of the present invention is a solar tracking system equipped with a miniaturized high-resolution Fourier transform infrared spectrometer FTIR.

[0032] The upper computer includes a sun tracking algorithm module 30 and a data processing module 31, both of which are stored in the computer. The sun tracking algorithm module 30 calculates the azimuth and altitude of the sun in real time based on the acquired time and space information. The data processing module 31 performs data conversion based on the calculation results and sends instructions to the lower computer motor controller through serial communication to drive the high-precision rotation tracking device to track the sun in real time. Specifically, the data processing module 31 receives the deviation between the sun's mass center coordinates and the image center provided by the image processing device 32 to perform angle compensation and correct the tracking error in real time.

[0033] The high-precision rotation tracking device includes a motor controller 1, an azimuth tracking mechanism 4 and an altitude tracking mechanism 6. The motor controller 1 is installed indoors and is used to control the drive motors of the azimuth tracking mechanism 4, the altitude tracking mechanism 6 and the automatic rain shelter. The azimuth tracking mechanism 4 is horizontally fixed on the support frame 3, and has a light hole with a diameter of 150 mm in the center. The rotating platform 17 is fixedly connected to the bracket through the first connecting member 12, supporting the entire mechanical structure to rotate horizontally to achieve azimuth tracking. The altitude tracking mechanism 6 is vertically installed on the side wall of the frame 5, and the rotating table 24 is fixedly connected to the light input reflector 7, rotating around the same central axis to complete the altitude tracking.

[0034] The folded optical path device is composed of an incident light reflector 7, a fixed reflector 8 and an output light reflector 13. These reflectors are installed at designated positions to ensure that sunlight is accurately transmitted to the light inlet 18 of the FTIR spectrometer through multiple reflections of the optical path system. The incident light reflector 7 is fixed on the rotating table 24 of the altitude tracking mechanism 6 at an initial 45° angle, and its horizontal projection coincides with the fixed reflector 8. When the sunlight signal is received, it is reflected to the fixed reflector 8 at 90°. The fixed reflector 8 is fixed on the bracket of the rotating platform 17 at an angle of 45° and coincides with the hole in the azimuth tracking mechanism 4 and the vertical projection of the output light reflector 13, further reflecting the light spot to the output light reflector 13. The output light reflector 13 is fixed indoors at an angle of 45 degrees and fixed on the indoor rack to coincide with the horizontal projection of the light inlet 18 of the FTIR spectrometer, and finally reflects the sunlight spot to the light inlet 18 of the FTIR spectrometer.

[0035] The photoelectric detection compensation device includes a CMOS area array camera 15 and an image processing device 32. The CMOS area array camera 15 is installed on an indoor fixed rack, overlaps with the vertical projection of the light-emitting reflector 12, captures the sun spot and uploads the data to the image processing device 32.

[0036] The automatic rain shelter device is composed of a rain shelter cover 9, a rain sensor 33, a slide rail 19, a slider 20 and a first stepper motor 11. The first stepper motor 11 is installed at the bottom of the frame 5. The cylindrical rain shelter cover 9 is sleeved on the outside of the frame 5 and fixedly connected to the slider 20 at the bottom. Two slide rails 19 are horizontally fixed to the bottom of the frame 5 and connected to the slider 20 at the same time. The first stepper motor 11 includes a T-shaped screw rod 21 installed at the bottom of the frame 5. The right side of the bottom end of the rain shelter cover 9 is fixedly connected to the screw rod nut through the second connecting piece 22. When the rain sensor 33 detects that the humidity exceeds the set threshold, the first stepper motor 11 starts, driving the rain shelter cover 9 to move along the slide rail 19, covering the entire device to prevent rainwater from intruding. After the humidity returns to normal, the rain shelter cover 9 will automatically retract and the normal working state of the device will be restored.

[0037] The operation process of the present invention is as follows:

[0038] The data processing module 31 of the host computer performs data processing and position calculation. After the system is started, the solar tracking algorithm SPA module 30 obtains the current time, geographical location, altitude and other information, completes the calculation of Julian day and century number, and calculates the heliocentric longitude, heliocentric latitude and the distance between the earth and the sun by summing the periodic terms. The heliocentric coordinates are converted into geocentric coordinates to obtain the geocentric longitude and latitude of the sun. In order to correct the viewing angle of the observation point on the surface of the earth, through a series of right ascension and declination corrections, the algorithm finally calculates the altitude angle and azimuth of the sun, and the calculation results are saved in the spa_data structure. The results obtained by the data processing of the host computer are sent to the motor controller 1 of the lower computer through the serial port.

[0039] The high-precision rotation tracking device works. After receiving the command from the host computer, the motor controller 1 drives the azimuth tracking mechanism 4 and the altitude tracking mechanism 6. The azimuth tracking mechanism 4 uses the second stepper motor 11 as the power source. After the worm gear transmission with a transmission ratio of 1 / 288, the worm gear is fixedly connected to the rotating platform 17 and supports the entire mechanical structure. The altitude tracking mechanism 6 uses the third stepper motor 23 as the power source. After the worm gear transmission with a transmission ratio of 1 / 90, the worm gear is fixedly connected to the rotating table 24 and supports the light-entering reflector, and coordinately adjusts the azimuth and altitude angles of the rotating platform to ensure that the sun spot is aligned with the optical path system. The horizontal motion accuracy of the azimuth tracking mechanism can reach 0.000625°, and the vertical motion accuracy of the altitude tracking mechanism can reach 0.00125°, ensuring that the tracking error of the system is less than 0.01°.

[0040] The photoelectric detection compensation device performs error correction, and the CMOS array camera 15 captures the sun spot at regular intervals and transmits the data to the image processing device 32. The image processing device 32 uses the Otsu algorithm to process the image, and forms a grayscale histogram by analyzing the number of pixels at each grayscale level in the input image. The histogram is normalized so that the sum of the probability of each grayscale level is 1, and the cumulative probability and cumulative mean of pixels less than the current grayscale level are calculated. For each possible threshold, the inter-class variance is calculated, and the optimal threshold that maximizes the inter-class variance is found. The image is segmented according to the found optimal threshold, and a binary image is output. The deviation between the sun's centroid coordinates and the image center is calculated, and the deviation data is sent to the host computer 31 to correct the tracking error in real time to ensure that the light spot always remains in the center of the field of view.

[0041] The sunlight is transmitted to the FTIR spectrometer. Through the folded optical path device, the sunlight is reflected multiple times by the light input reflector 7, the fixed reflector 8 and the light output reflector 13, and finally enters the light input port 16 of the FTIR spectrometer 14. The system maintains the parallelism of the sunlight to ensure that the FTIR spectrometer can obtain high-precision signal light.

[0042] The system monitors the environmental humidity in real time through the rain sensor 33 and transmits the data to the host computer 31. When the humidity exceeds the set safety threshold, the host computer sends the data to the lower computer motor controller 1 through the serial port, controls the first stepper motor 11 to operate the rain cover 9 to slide along the slide rail 19, and completely covers the device to prevent rain from entering and damaging the device. When the weather improves, the rain cover 9 is automatically retracted, and the device resumes normal tracking operation.

[0043] The mechanical structure of the present invention is compact. Through the cooperation of the high-precision rotation tracking device and the photoelectric detection compensation device, the device can accurately track the sun under different environmental conditions. Combined with the host computer program, the system can correct errors in real time and automatically avoid rain, which greatly improves the stability and reliability of the equipment and ensures its stable operation in atmospheric environment monitoring.

[0044] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A precision solar tracking system combining active and passive tracking, characterized in that: It includes a host computer, a high-precision rotation tracking device, a folded optical path device and a photoelectric detection compensation device; The high-precision rotation tracking device includes a motor controller, an azimuth tracking mechanism and an altitude tracking mechanism. The motor controller is used to receive instructions from a host computer. The motor controller drives the azimuth tracking mechanism and the altitude tracking mechanism to operate to achieve accurate tracking of the sun. The folded optical path device includes a light input reflector, a fixed reflector and a light output reflector. The photoelectric detection compensation device captures solar spot information through a CMOS area array camera and uploads it to an image processing device. The image processing device calculates the deviation between the center of mass coordinates of the spot and the center coordinates of the image in real time, and transmits the deviation information to a data processing module of the host computer.

2. The active and passive tracking combined precision sun tracking system according to claim 1, characterized in that: The host computer includes a solar tracking algorithm module and a data processing module. The solar tracking algorithm module calculates the azimuth and altitude of the sun in real time based on the acquired time and space information. The data processing module performs data conversion based on the calculation results and sends instructions to the motor controller through serial port communication to drive the high-precision rotation tracking device to track the sun in real time.

3. The active and passive tracking combined precision solar tracking system according to claim 2, characterized in that: The solar tracking algorithm module obtains the current time, geographic location, altitude and other information, completes the calculation of Julian day and century number, calculates the heliocentric longitude, heliocentric latitude and the distance between the earth and the sun by summing the periodic terms; converts the heliocentric coordinates into geocentric coordinates to obtain the geocentric longitude and latitude of the sun, and calculates the altitude and azimuth of the sun through right ascension and declination corrections.

4. The active and passive tracking combined precision sun tracking system according to claim 1, characterized in that: The image processing device uses the Otsu algorithm to process images, analyzes the input image and counts the number of pixels at each gray level to form a gray histogram, normalizes the histogram so that the sum of the probabilities of each gray level is 1, calculates the cumulative probability and cumulative mean of pixels less than the current gray level, calculates the inter-class variance for each possible threshold, finds the optimal threshold that maximizes the inter-class variance, performs image segmentation according to the found optimal threshold, and outputs a binary image; calculates the deviation between the sun's center of mass coordinates and the image center, sends the deviation data to a host computer, corrects the tracking error in real time, and ensures that the light spot always remains at the center of the field of view.

5. The active and passive tracking combined precision sun tracking system according to claim 1, characterized in that: The high-precision rotation tracking device includes a motor controller, an azimuth tracking mechanism and an altitude tracking mechanism. The motor controller is used to control the azimuth tracking mechanism and the altitude tracking mechanism. The azimuth tracking mechanism is horizontally fixed on a support frame. The rotating platform is fixedly connected to the support through a first connecting piece. The altitude tracking mechanism is vertically installed on the side wall of the frame. The rotating table is fixedly connected to the light incident reflector and rotates around the same central axis.

6. The active and passive tracking combined precision sun tracking system according to claim 5, characterized in that: The azimuth tracking mechanism is driven by a second stepping motor, the second stepping motor is connected to a worm gear transmission mechanism, and the worm gear is fixedly connected to the rotating platform.

7. The active and passive tracking combined precision sun tracking system according to claim 5, characterized in that: The altitude angle tracking mechanism is driven by a third stepping motor, the third stepping motor is connected to a worm gear transmission mechanism, the worm gear is fixedly connected to a rotating table, and the rotating table supports a light incident reflector.

8. The active and passive tracking combined precision sun tracking system according to claim 5, characterized in that: The elevation angle tracking mechanism is fixed on the side wall of the frame and its rotation center is colinear with the rotation center of the incident reflector and the rotation center of the fixed reflector. The azimuth angle tracking mechanism is fixed on the support frame in a horizontal state and its rotation center is perpendicular to the rotation center of the fixed reflector.

9. The active and passive tracking combined precision sun tracking system according to claim 8, characterized in that: It also includes an automatic rain shelter device, which includes a rain sensor, a rain shelter cover, a slide rail, a slider and a first stepper motor. The first stepper motor is installed at the bottom of the frame. The rain shelter cover is sleeved on the outside of the frame and is fixedly connected to the slider at the bottom. Two slide rails are horizontally fixed to the bottom of the frame and connected to the slider at the same time. The first stepper motor includes a T-shaped screw rod installed at the bottom of the frame. The right side of the bottom end of the rain shelter cover is fixedly connected to the screw rod nut through a second connecting piece.

10. The active and passive tracking combined precision sun tracking system according to claim 9, characterized in that: When the rain sensor detects that the humidity exceeds the set threshold, the first stepper motor starts, driving the rain shelter to move along the slide rail, covering the entire device to prevent rain from invading; when the humidity returns to normal, the rain shelter is automatically retracted.

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