CN203414078U - Sun position tracking sensor - Google Patents

Abstract

The utility model discloses a sun position tracking sensor, which initially measures the offset between the sun's incident light and the normal line of the heat-collecting surface through four photodiodes arranged symmetrically outside the shading tube, and outputs a control signal after being processed by a microcomputer. This method has a larger tracking angle of view. After the initial tracking is achieved, the optical system is used to improve the sensitivity of the sensor, and the microcomputer processes the signal of the four-quadrant detector, outputs control data, and fine-tunes the orientation of the heat collecting surface to achieve the purpose of high-precision tracking of the sun's position. By detecting the sum of the voltage values induced by the four photodiodes, the sensor can switch between working and not working with the change of light intensity, so as to realize that it does not work at night and in rainy weather, and only works when the light intensity is sufficient. Work.

Description

A solar position tracking sensor

technical field

The invention relates to the field of power electronics, in particular to a sun position tracking sensor.

Background technique

Solar energy is a clean and durable energy with great development potential. Under the background of my country's policy of vigorously developing new energy sources, it is of great significance to study solar power generation technology. Solar energy has the characteristics of low energy density and constantly changing spatial position, so one of the key technologies for solar thermal power generation is to collect solar energy. In the process of using solar power to generate electricity, the sensor is used to accurately track the position of the sun, so that the solar energy collecting surface is always perpendicular to the incident light of the sun, and it is focused to a point to collect heat for power generation. Studies have shown that the heat collection system using real-time tracking technology of the sun position has a 37.7% higher solar energy acceptance rate than the fixed installation system, and the tracking accuracy directly affects the energy acceptance efficiency. Therefore, in the process of solar thermal power generation, the accuracy of tracking the sun's position is an important indicator, and it is very necessary to improve the real-time tracking accuracy when designing a solar tracking system.

The methods used in solar tracking technology include sun trajectory tracking method, photoelectric tracking method and hybrid tracking method. The sun trajectory tracking method obtains the position of the sun according to the solar orbit calculation formula in astronomy, and uses this data to control the tracking mechanism to fully track the sun. This method has low cost and high reliability, but it cannot completely eliminate the cumulative error, and the tracking accuracy is only about 1°. At present, the sun position sensor using the photoelectric tracking method or the hybrid tracking method generally uses the pinhole imaging principle, which is either high in precision but high in cost, or low in cost but low in precision, not cost-effective, and has the disadvantage of small tracking angle of view.

Contents of the invention

Aiming at the shortcomings of the prior art, the purpose of the present invention is to provide a sun position tracking sensor with simple structure, low cost, large tracking viewing angle and precision.

In order to solve the above-mentioned technical problems, the technical method adopted in the present invention is: a sun position tracking sensor, which includes a shading tube, an optical system, a four-quadrant detector, a photodiode, and a microcomputer signal processing board. The four-quadrant detector and the microcomputer signal processing board are installed at the bottom of the shading tube, the four photodiodes are symmetrically installed outside the shading tube, and the optical system is installed on the top of the shading tube. Let the induced voltage signals corresponding to the four photodiodes be Ua, Ub, Uc, and Ud respectively. When the sunlight intensity does not reach the minimum value of power generation, the sum of the voltage values Ua+Ub+Uc+Ud induced by the photodiodes installed outside the shading tube is less than the set value, and the microcomputer determines that the tracking system does not work.

When the light intensity reaches the power generation intensity, Ua+Ub+Uc+Ud is greater than the set value, and the microcomputer determines to enter the rough adjustment tracking stage. When the heat collecting surface is not perpendicular to the sunlight, the intensity of light received by the symmetrically installed photodiodes is different, and the induced voltage signals are also different. Let the offset signals in two vertical directions be Δm and Δn respectively. Has the following formula:

$\left\{\begin{array}{c}\mathrm{<span\; class="notranslate">\; \&Delta;m</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; b</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}}{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; b</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}}\\ \mathrm{<span\; class="notranslate">\; \&Delta;n</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; b</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}}{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; b</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}}\end{array}\right.$

The offset signal is converted into data such as the steering and rotation steps of the stepping motor through the microcomputer, and then output to the actuator by max232, so that the heat collecting surface is initially perpendicular to the incident light of the sun. After roughly adjusting the tracking accuracy in the previous step, the sunlight can pass through the optical system and focus on a point on the four-quadrant detector at the bottom to form a small spot. Let the photosensitive elements in the four quadrants generate impedance currents i1, i2, i3, and i4 corresponding to different illuminated areas. At this time, the sum of the current values i1+i2+i3+i4 induced by the four-quadrant detector is greater than the set value, and the microcomputer determines that it enters the fine-tuning stage, and the microcomputer only processes the signal output by the four-quadrant detector and outputs motor control data.

Due to the limited accuracy of the previous step adjustment, the light spot may not be on the center point of the four-quadrant detector, and the area of the light spot on each photosensitive element is different, so the four impedance currents generated will also be different. Assume that the offsets of the center of the light spot from the center of the detector in the x direction and the y direction are Δx and Δy, respectively. Since the photocurrent i generated by the photodiode is relatively weak, it needs to be converted into a larger voltage signal U by an operational amplifier. Considering that the size of the photocurrent will change with different light intensities, the results should be ratioed. as follows:

$\left\{\begin{array}{c}\mathrm{<span\; class="notranslate">\; \&Delta;x</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}}{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}}\\ \mathrm{<span\; class="notranslate">\; \&Delta;y</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}}{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}}\end{array}\right.$

Among them, U1, U2, U3, and U4 correspond to the voltage signals generated by the photosensitive elements in the four quadrants Ⅰ, Ⅱ, Ⅲ, and Ⅳ respectively. From this, the distance of the light spot offset from the center point of the photodetector can be measured, and then the microcomputer converts the offset signal into data such as the steering and rotation steps of the stepping motor, and then outputs it to the actuator with max232. The stepper motor rotates correspondingly, so that Δx and Δy tend to zero, so as to achieve the purpose of high-precision tracking of the sun position.

At the same time, it can be seen from the above formula that the farther the light spot deviates from the center point, the larger the Δx and Δy, and the easier it is for the controller to measure the light spot deviation from the center point. The present invention adds an optical system, and utilizes the refraction principle of light. When the incident angle of sunlight deviates by a certain angle, the distance from the center point of the light spot is far greater than other designs that do not use the optical system at present. The expansion of the center point distance of the light point offset actually improves the sensitivity of the sensor to the change of the sun angle, which can not only reduce the performance requirements of the four-quadrant detector, thereby reducing the cost by using a cheap detector, but also can meet the requirements of high precision. Requirements, thus improving the cost performance of the sensor. At the same time, since the sensor has two stages of coarse adjustment and fine adjustment, it can not only ensure the high precision of tracking, but also greatly expand the tracking angle of the sensor.

The beneficial effect of the invention is that the tracking accuracy of the sun position can be improved by adopting the optical system, and the manufacturing cost of the sensor is also reduced. Using two steps of coarse adjustment and fine adjustment, the tracking angle of view is greatly increased compared with traditional sensors.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings.

Figure 1 is a structural diagram of the sun position photoelectric tracking sensor;

Figure 2 is a schematic diagram of a four-quadrant tracking system;

Figure 3 is a schematic diagram of the comparison of light spots formed by two schemes;

Figure 1: 1. Optical system 2. Shading tube 3. Photodiode 4. Four-quadrant detector 5. Microcomputer processing board

Figure 3: a. Schematic diagram of optical system principle b. Schematic diagram of pinhole imaging

Detailed ways

Further illustrate the present invention below in conjunction with accompanying drawing.

The present invention is a sun position tracking sensor, which includes an opaque shading tube, a photodiode, a four-quadrant detector, and a microcomputer processing board; The diode is installed at the outer port of the light-shielding cylinder; the feature is that it also includes an optical system installed on the top of the light-shielding cylinder.

There are at least four photodiodes. The microcomputer processing board is a circuit board with the same radius as the light-shielding cylinder, embedded in the bottom of the light-shielding cylinder, sealed and opaque. The at least four photodiodes are attached to the outer wall of the light-shielding cylinder and installed evenly and symmetrically along the outer circumference; the signal lines drawn from them are connected to the microcomputer processing board, and the microcomputer processes the input signal of the photodiode, and the actuator then processes the signal according to the processed signal. Issue a command to track the sun position; when the light intensity is not enough, the sum of the voltage values induced by the photodiodes does not reach the set value, and the microcomputer judges that the actuator does not work; when the light intensity is sufficient, the sum of the voltage values induced by the photodiodes is greater than Set the value, and the microcomputer judges that the sensor has entered the preliminary tracking stage;

Further, the microcomputer converts the offset signal into the steering and rotation step data of the stepping motor, and then outputs it to the actuator through max232.

Further, the sun position photoelectric tracking sensor has two stages of rough adjustment and fine adjustment.

At night or in rainy weather, the light intensity is not enough, and the sum of the voltage values Ua+Ub+Uc+Ud induced by the four photodiodes installed outside the shading tube is less than the set value, the microcomputer determines that it is in the non-tracking state, and the output step The number of rotation steps of the feeder motor is zero, and the actuator remains stationary.

When it is daytime and the light intensity is sufficient, the sum of the voltage values Ua+Ub+Uc+Ud induced by the four photodiodes is greater than the set value. The microcomputer first enters the coarse adjustment state, and the microcomputer only processes the voltage signals induced by the four photodiodes, and these four signals are amplified by the operational amplifier and become Ua, Ub, Uc, Ud. If these four voltage values are not equal, Δm and Δn will not be equal to zero, where Δm and Δn refer to voltage offset values in two vertical directions respectively. Its calculation formula is:

$\left\{\begin{array}{c}\mathrm{<span\; class="notranslate">\; \&Delta;m</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; b</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}}{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; b</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}}\\ \mathrm{<span\; class="notranslate">\; \&Delta;\; n</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; b</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}}{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; b</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}}\end{array}\right.$

After the microcomputer samples the four voltage values of Ua, Ub, Uc, and Ud through AD, the value of Δm and Δn is calculated by the program and converted into the direction of rotation of the stepping motor and the number of steps of rotation, and this data is transmitted to the actuator by MAX232 . After the execution mechanism is executed, the heat collecting surface is turned to the direction perpendicular to the sunlight. At this time, the light intensity received by the four photodiodes will change, and Ua, Ub, Uc, and Ud tend to be equal. At this time, the microcomputer re-samples the four voltages AD, and controls the actuator so that the heat collecting surface continues to turn in the direction perpendicular to the sunlight. Such a cycle can finally reach the dynamic balance of Ua=Ub=Uc=Ud, that is, to achieve the purpose of initially tracking the position of the sun. Since the initial tracking accuracy is not high, further fine-tuning is required.

When the preliminary tracking reaches a certain accuracy, the light spot formed by the focusing of sunlight by the optical system can fall on the four-quadrant detector. The photosensitive element on the four-quadrant detector can induce current, and the current signal is converted into voltage signals U1, U2, U3, U4 from 0 to 5v after the operational amplifier. When the value of U1+U2+U3+U4 is greater than the set value, the microcomputer determines to enter the fine-tuning stage, and the microcomputer only processes the voltage signal corresponding to the four-quadrant detector. As shown in Figure 2, the light spot shifts the center point Δx and Δy of the four-quadrant detector, and there are:

$\left\{\begin{array}{c}\mathrm{<span\; class="notranslate">\; \&Delta;x</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="u"\; filenames="HDA00003207213600011.png"\; state="\{\{state\}\}">u</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}}{{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="u"\; filenames="HDA00003207213600011.png"\; state="\{\{state\}\}">u</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="3"\; label="u"\; filenames="HDA00003207213600011.png"\; state="\{\{state\}\}">u</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="4"\; label="u"\; filenames="HDA00003207213600011.png"\; state="\{\{state\}\}">u</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}}\\ \mathrm{<span\; class="notranslate">\; \&Delta;y</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="u"\; filenames="HDA00003207213600011.png"\; state="\{\{state\}\}">u</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}}{{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="u"\; filenames="HDA00003207213600011.png"\; state="\{\{state\}\}">u</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="3"\; label="u"\; filenames="HDA00003207213600011.png"\; state="\{\{state\}\}">u</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="4"\; label="u"\; filenames="HDA00003207213600011.png"\; state="\{\{state\}\}">u</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}}\end{array}\right.$

The present invention utilizes an optical system to increase precision, which is composed of two convex lenses and a double rectangular prism erect system, and the magnification can be set to multiple values, taking 8 times as an example. As shown in Figure 3a, assume that the incident angle of sunlight is α, and the angle between the light after it passes through the optical system and the normal line is β. According to the refraction principle of light, there is β=kα (k≥1). Let the distance between the end of the optical system and the four-quadrant detector be d, and the distance between the light spot and the center point be f. Compared with the measurement scheme of the pinhole imaging principle, as shown in Figure 3b, the angle between the light passing through the pinhole and the central axis of the shading tube is γ, and γ=α. Assuming that the distance between the pinhole and the four-quadrant detector is h, the distance between the spot of the pinhole imaging and the center point is g. as shown in picture 2. f=8d*tgα can be deduced from the principle of refraction of light and geometric knowledge, and g=h*tgα can be deduced from the principle of pinhole imaging. Generally, h is set to 35mm, and d=20mm. After calculation, it can be seen that compared with the traditional pinhole imaging scheme, the spot offset distance is increased through the optical system, thereby increasing the difference between U1, U2, U3, and U4. In this way, the requirement for the accuracy of the four-quadrant detector is reduced. When a lower-precision four-quadrant detector is used, Δx and Δy can still be measured, which reduces the cost while ensuring high-precision tracking.

After the microcomputer measures Δx and Δy, the control actuator will turn towards the trend of reducing Δx and Δy, and finally make Δx=Δy=0.

At this time, the purpose of high-precision dynamic tracking of the sun's position has been achieved.

If the light intensity changes from strong to weak and fails to meet the requirements of power generation, the Ua+Ub+Uc+Ud sensed by the four photodiodes outside the shading tube will be less than the set value, and the microcomputer enters the interruption of stop tracking, and the control execution The mechanism remains stationary, keeping energy consumption to a minimum. Until the light intensity reaches the power generation intensity again, it will re-enter the stage of tracking the sun's position.

Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of the preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled practitioners to employ such modifications appropriately, and the inventors believe that the invention may be practiced otherwise than as expressly described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of all possible variations of the above-described elements is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.

Claims (5)

1. A solar position tracking sensor, comprising a light-tight shading tube, a photodiode, a four-quadrant detector, and a microcomputer processing board; wherein, the four-quadrant detector is mounted on a microcomputer processing board and installed at the bottom of the shading tube, and the photodiode Installed at the outer port of the shading tube; the feature is that it also includes an optical system installed on the top of the shading tube. the 2. The sun position tracking sensor according to claim 1, characterized in that: there are at least four photodiodes. 3. The sun position tracking sensor according to claim 1, characterized in that: the microcomputer processing board is a circuit board with the same radius as the shading cylinder, embedded in the bottom of the shading cylinder, sealed and opaque. 4. The solar position tracking sensor according to claim 1, characterized in that: said at least four photodiodes are attached to the outer wall of the shading cylinder and installed uniformly and symmetrically along the outer circumference; the signal lines drawn from them are connected to the microcomputer processing board, The microcomputer processes the input signal of the photodiode, and the actuator sends out a command to track the sun position according to the processed signal; when the light intensity is not enough, the sum of the voltage values induced by the photodiode does not reach the set value, and the microcomputer judges the actuator Does not work; when the light intensity is sufficient, the sum of the voltage values induced by the photodiodes is greater than the set value, and the microcomputer judges that the sensor enters the preliminary tracking stage. 5. The sun position tracking sensor according to claim 1, characterized in that: the microcomputer converts the offset signal into the steering and rotation step data of the stepping motor, and then outputs it to the actuator through max232.

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