CN203414078U - Sun position tracking sensor - Google Patents

Abstract

The utility model discloses a sun position sensor. The offset of a normal line between incident light and a heat collecting face is measured for the first time through four symmetric photodiodes outside a light shading cylinder, and a control signal is outputted after the offset is processed by a microcomputer, therefore, the sensor has a relatively large tracking viewing angle. After the first-time tracking, the sensitivity of the sensor is improved by an optical system; a signal of a four-quadrant detector is reprocessed by the microcomputer, control data is outputted, and the facing direction of the heat collecting surface is micro-adjusted to achieve the purpose of tracking the sun position with high accuracy. The sum of voltage values induced by the four photodiodes is detected, so that the sensor can be switched between the work state and the non-work state along with the change of the illumination intensity, does not work at night or in the rainy day, and only works under the condition that the illumination intensity is enough.

Description

A kind of position of sun tracing sensor

Technical field

The present invention relates to field of power electronics, relate in particular to a kind of position of sun tracing sensor.

Background technology

Sun power is a kind of clean, lasting energy, has very large potentiality to be exploited.In China, greatly develop under the Policy Background of novel energy research solar energy generation technology important in inhibiting.Sun power has the features such as energy density is low, the continuous variation in locus, so one of gordian technique of solar light-heat power-generation is for collecting sun power.In utilizing solar electrical energy generation process, utilize the accurate tracking position of sun of sensor, make solar energy collecting face all the time perpendicular to sun incident light, focused on some thermal-arrest generatings.Research shows to adopt the collecting system of position of sun real time technique for tracking, than hard-wired system sun power receptance, has improved 37.7%, follows the trail of accuracy affects energy and accepts efficiency.Therefore, in the process of sunlight heat power generation, the precision of sun-tracing position is an important indicator, and it is very necessary when design sun tracing system, improving tracking real-time accuracy.

The method that solar energy tracking technology adopts has track of sun tracing, photoelectric tracing method and mixes back tracking method.Track of sun tracing obtains the position of the sun according to solar orbit computing formula in uranology, with this Data Control follower to sun comprehensive trace.This method cost is low, and reliability is high, but cannot eliminate cumulative errors completely, and tracking accuracy is also only 1 ° of left and right.Utilize at present photoelectric tracing method or mix the sun position sensor general using pinhole imaging system principle of back tracking method, or precision is high but cost is also high, the precision that cost is low is low, and cost performance is not high, and has the little shortcoming in the visual angle of tracking.

Summary of the invention

For the shortcoming of prior art, the object of the present invention is to provide a kind of simple in structure, with low cost, there is larger tracking visual angle and the position of sun tracing sensor of precision.

For solving the problems of the technologies described above, the technology used in the present invention method is: a kind of position of sun tracing sensor, it comprises cone, optical system, 4 quadrant detector, photodiode, microcomputer signal-processing board.4 quadrant detector and microcomputer signal-processing board are arranged on the bottom in cone, and four photodiode symmetries are arranged on cone outside, and optical system is arranged on cone top.If four induced voltage signals corresponding to photodiode are respectively Ua, Ub, Uc, Ud.When Intensity of the sunlight does not reach generating during minimum value, be contained in the magnitude of voltage sum Ua+Ub+Uc+Ud that the photodiode of cone outside induces and be less than setting value, microcomputer judges that tracing system do not work.

When intensity of illumination reaches generating intensity, Ua+Ub+Uc+Ud is greater than setting value, and microcomputer judgement enters coarse adjustment track phase.When heat collector surface is not during perpendicular to sunshine, the suffered intensity of illumination of photodiode that outer symmetrical is installed is different, and the voltage signal inducing is also different.If the shifted signal of two vertical direction is respectively Δ m and Δ n.There is following formula:

$\left\{\begin{array}{c}\mathrm{\Δm}=\frac{U_a+U_d-U_b-U_c}{U_a+U_b+U_c+U_d}\\ \mathrm{\Δn}=\frac{U_a+U_b-U_c-U_d}{U_a+U_b+U_c+U_d}\end{array}\right.$

By microcomputer, shifted signal be converted into turning to of stepper motor and rotate the data such as step number, then exporting to topworks with max232, making heat collector surface tentatively perpendicular to sun incident light.Through previous step, to following the trail of after precision coarse adjustment, sunshine forms a small light spot on just focusing on a bit on the 4 quadrant detector of bottom through optical system.If four quadrants the corresponding different light area of light activated element produce respectively impedance current i 1, i2, i3, i4.The current value sum i1+i2+i3+i4 that now 4 quadrant detector induces has been greater than setting value, and microcomputer judgement enters the fine setting stage, and microcomputer is only processed signal the output motor of 4 quadrant detector output and controlled data.

Because the precision that previous step is adjusted is limited, luminous point may be on the central point of 4 quadrant detector, and the area of hot spot on each light activated element is not identical, thereby four impedance electric currents that produce also will be not identical.If spot center deviation detector center is respectively Δ x and Δ y in the side-play amount of x direction and y direction.The photocurrent i producing due to photodiode is fainter, so need to be converted into larger voltage signal U by operational amplifier.The size of considering photocurrent when intensity of illumination is different can change, therefore also result will be compared to value.As shown in the formula:

$\left\{\begin{array}{c}\mathrm{\&Delta;x}=\frac{{\mathrm{<figure-callout\; id="1"\; label="U"\; filenames="HDA00003207213600011.png"\; state="\{\{state\}\}">U</figure-callout>}}_1+U_4-U_2-U_3}{{\mathrm{<figure-callout\; id="1"\; label="U"\; filenames="HDA00003207213600011.png"\; state="\{\{state\}\}">U</figure-callout>}}_1+U_2+{\mathrm{<figure-callout\; id="3"\; label="U"\; filenames="HDA00003207213600011.png"\; state="\{\{state\}\}">U</figure-callout>}}_3+{\mathrm{<figure-callout\; id="4"\; label="U"\; filenames="HDA00003207213600011.png"\; state="\{\{state\}\}">U</figure-callout>}}_4}\\ \mathrm{\&Delta;y}=\frac{{\mathrm{<figure-callout\; id="1"\; label="U"\; filenames="HDA00003207213600011.png"\; state="\{\{state\}\}">U</figure-callout>}}_1+U_2-U_3-U_4}{{\mathrm{<figure-callout\; id="1"\; label="U"\; filenames="HDA00003207213600011.png"\; state="\{\{state\}\}">U</figure-callout>}}_1+U_2+{\mathrm{<figure-callout\; id="3"\; label="U"\; filenames="HDA00003207213600011.png"\; state="\{\{state\}\}">U</figure-callout>}}_3+{\mathrm{<figure-callout\; id="4"\; label="U"\; filenames="HDA00003207213600011.png"\; state="\{\{state\}\}">U</figure-callout>}}_4}\end{array}\right.$

Wherein U1, U2, U3, U4 correspond respectively to the voltage signal that in I, II, III, four quadrants of IV, light activated element produces.Can record the distance of facula deviation photodetector central point thus, and then by microcomputer, shifted signal is converted into turning to of stepper motor and rotates the data such as step number, then export to topworks with max232.Stepper motor is corresponding to rotate, and makes Δ x and Δ y trend towards zero, reaches the object that position of sun high precision is followed the trail of.

Meanwhile, from above formula, hot spot is far away apart from central point skew, and Δ x and Δ y are just larger, and just more easily measure hot spot departs from central point to controller.The present invention has added optical system, utilizes the refraction principle of light, and when angle of incidence of sunlight skew certain angle, the distance of deflection of optical point central point is much larger than other designs that do not adopt at present optical system.The expansion of deflection of optical point central point distance has in fact just improved the sensitivity that sensor changes sun angle, both can reduce the requirement to 4 quadrant detector performance, thereby adopt cheap detector to reduce costs, also can meet high-precision requirement, so just improved the cost performance of sensor simultaneously.Meanwhile, because sensor has coarse adjustment and two stages of accurate adjustment, can guarantee the high precision of tracking, also greatly expand the tracking visual angle of sensor.

The invention has the beneficial effects as follows: by adopting optical system can improve position of sun, follow the trail of precision, also reduced sensor production cost simultaneously.Adopt coarse adjustment, two steps of accurate adjustment, comparing traditional sensors has increased tracking visual angle greatly.

Accompanying drawing explanation

Below in conjunction with accompanying drawing, the invention will be further described.

Fig. 1 is that position of sun photoelectric tracing sensor forms structural drawing;

Fig. 2 is four-quadrant tracing system schematic diagram;

Fig. 3 is that two schemes forms hot spot contrast schematic diagram;

Fig. 1: 1, optical system 2, cone 3, photodiode 4,4 quadrant detector 5, MICROCOMPUTER PROCESSING plate

Fig. 3: a, optical system principle schematic b, pinhole imaging system schematic diagram

Embodiment

Below in conjunction with accompanying drawing, further illustrate the present invention.

The present invention is a kind of position of sun tracing sensor, comprises lighttight cone, photodiode, 4 quadrant detector, MICROCOMPUTER PROCESSING plate; Wherein, 4 quadrant detector is contained on MICROCOMPUTER PROCESSING plate and is arranged on cone bottom, and photodiode is contained in cone external port; It is characterized in that: also comprise the optical system that is arranged on cone top.

Described photodiode is at least four.Described MICROCOMPUTER PROCESSING plate is the circuit board identical with cone radius, embeds cone bottom, seals light tight.Describedly be at least four photodiodes and be attached to cone outer wall and install symmetrically along excircle; The signal wire that they are drawn is connected on MICROCOMPUTER PROCESSING plate, by microcomputer, photodiode input signal is processed, and topworks sends according to the signal after processing the order that position of sun is followed the trail of again; When intensity of illumination is inadequate, the magnitude of voltage sum of photodiode induction does not reach setting value, and microcomputer judgement topworks does not work; When intensity of illumination is enough, the magnitude of voltage sum of photodiode induction is greater than setting value, and microcomputer judgement sensor enters preliminary track phase;

Further, described microcomputer is converted into shifted signal turning to of stepper motor and rotates step count data, then exports to topworks with max232.

Further, described position of sun photoelectric tracing sensor has coarse adjustment and two stages of accurate adjustment.

When in night or rainy weather, light intensity is inadequate, is contained in the magnitude of voltage sum Ua+Ub+Uc+Ud that four photodiodes of cone outside induce and is less than setting value, and microcomputer is judged in tracking mode not, output stepper motor rotates step number Wei Ling， topworks and remains static.

When enough in daytime and light intensity, the magnitude of voltage sum Ua+Ub+Uc+Ud that four photodiodes induce is greater than setting value.First microcomputer enters coarse adjustment state, and microcomputer is only processed the voltage signal that four photodiodes induce, and these four signals become Ua, Ub, Uc, Ud after operational amplifier amplifies.If these four magnitudes of voltage are unequal, Δ m and Δ n will be not equal to zero, and wherein Δ m and Δ n refer to respectively the variation value of two vertical direction.Its computing formula is:

$\left\{\begin{array}{c}\mathrm{\&Delta;m}=\frac{U_a+U_d-U_b-U_c}{U_a+U_b+U_c+U_d}\\ \mathrm{\&Delta;n}=\frac{U_a+U_b-U_c-U_d}{U_a+U_b+U_c+U_d}\end{array}\right.$

Microcomputer is sampled after Ua, Ub, Uc, tetra-magnitudes of voltage of Ud by AD, and the value of calculating Δ m and Δ n by program is translated into direction and the rotation step number that stepper motor rotates, and these data are passed to topworks with MAX232.After topworks carries out, heat collector surface is turned towards vertical sun direction of light, the intensity of illumination that now four photodiodes receive can change, and Ua, Ub, Uc, Ud trend towards equating.Now microcomputer is again to this four voltage AD sampling, and controls topworks and make heat collector surface continue to turn towards vertical sun direction of light.So circulation, finally can reach the mobile equilibrium of Ua=Ub=Uc=Ud, reaches the object of preliminary sun-tracing position.Because the preliminary precision of following the trail of is not high, also need to continue fine setting.

Preliminary tracking while reaching certain precision, sunshine focuses on through optical system the hot spot forming and just can drop on 4 quadrant detector.Light activated element on 4 quadrant detector just can induce electric current, this current signal is converted into 0 to 5v voltage signal U1, U2, U3, U4 after operational amplifier.When the value of U1+U2+U3+U4 is greater than setting value, microcomputer judgement enters the fine setting stage, and microcomputer is only processed the voltage signal that 4 quadrant detector is corresponding.As Fig. 2, facula deviation 4 quadrant detector central point Δ x and Δ y, have:

$\left\{\begin{array}{c}\mathrm{\&Delta;x}=\frac{{\mathrm{<figure-callout\; id="1"\; label="U"\; filenames="HDA00003207213600011.png"\; state="\{\{state\}\}">U</figure-callout>}}_1+U_4-U_2-U_3}{{\mathrm{<figure-callout\; id="1"\; label="U"\; filenames="HDA00003207213600011.png"\; state="\{\{state\}\}">U</figure-callout>}}_1+U_2+{\mathrm{<figure-callout\; id="3"\; label="U"\; filenames="HDA00003207213600011.png"\; state="\{\{state\}\}">U</figure-callout>}}_3+{\mathrm{<figure-callout\; id="4"\; label="U"\; filenames="HDA00003207213600011.png"\; state="\{\{state\}\}">U</figure-callout>}}_4}\\ \mathrm{\&Delta;y}=\frac{{\mathrm{<figure-callout\; id="1"\; label="U"\; filenames="HDA00003207213600011.png"\; state="\{\{state\}\}">U</figure-callout>}}_1+U_2-U_3-U_4}{{\mathrm{<figure-callout\; id="1"\; label="U"\; filenames="HDA00003207213600011.png"\; state="\{\{state\}\}">U</figure-callout>}}_1+U_2+{\mathrm{<figure-callout\; id="3"\; label="U"\; filenames="HDA00003207213600011.png"\; state="\{\{state\}\}">U</figure-callout>}}_3+{\mathrm{<figure-callout\; id="4"\; label="U"\; filenames="HDA00003207213600011.png"\; state="\{\{state\}\}">U</figure-callout>}}_4}\end{array}\right.$

The present invention utilizes optical system to increase precision, and it consists of two convex lens and two right-angle prism erecting system, and enlargement ratio can be arranged to a plurality of numerical value, take 8 times as example.As shown in Figure 3 a, establishing angle of incidence of sunlight is α, and it is β that light penetrates angle between rear and normal through optical system., by the refraction principle of light, there is β=k α (k >=1).If optical system end-to-end distance 4 quadrant detector distance is d, hot spot apart from central point apart from f.Contrast pinhole imaging system principle measurement scheme, as shown in Figure 3 b, light from aperture through and cone axis between angle be γ, have γ=α.If small pitch 4 quadrant detector distance is h, the hot spot of pinhole imaging system is g apart from central point distance.As shown in Figure 2.Refraction principle and geometric knowledge by light are released f=8d*tg α, by pinhole imaging system principle, are released and can be released g=h*tg α.General h is set to 35mm, establishes d=20mm.Known through computing, compare traditional pinhole imaging system scheme, by optical system, strengthen facula deviation distance, thereby strengthened the difference between U1, U2, U3, U4.So just, reduce the requirement to 4 quadrant detector degree of accuracy, when adopting the 4 quadrant detector of lower accuracy, can measure Δ x and Δ y in the same old way, so just when guaranteeing high precision tracking, reduced cost.

Microcomputer is measured after Δ x and Δ y, controls topworks and rotates towards the trend that reduces Δ x and Δ y, finally makes Δ x=Δ y=0.

Now just reached the object of Dynamic High-accuracy sun-tracing position.

If intensity of illumination, by a little less than turning by force, does not reach the requirement of generating, the Ua+Ub+Uc+Ud that now outer four photodiodes of cone induce can be less than setting value, and microcomputer enters the interruption that stops tracking, controls topworks and keeps static, keeps lowest energy consumption.Until light intensity reaches generating intensity once again, reenter the stage that position of sun is followed the trail of.

The preferred embodiment that this invention has been described at this, comprises that inventor is for implementing known optimal mode of the present invention.The change of preferred embodiment is apparent for those of ordinary skills after reading above-mentioned explanation.Inventor wishes the rationally such change of application of those of ordinary skill, and inventor thinks and at this, clearly states different application and also can realize the present invention.Therefore, the present invention includes all modifications and the equivalents of the purport of quoting in the claim of enclosing, this allows in applicable law.In addition, any combination of all possible change of above-mentioned key element is also comprised by the present invention, unless pointed out in addition or obvious contradiction in context at this.

Claims (5)

1. a position of sun tracing sensor, comprises lighttight cone, photodiode, 4 quadrant detector, MICROCOMPUTER PROCESSING plate; Wherein, 4 quadrant detector is contained on MICROCOMPUTER PROCESSING plate and is arranged on cone bottom, and photodiode is contained in cone external port; It is characterized in that: also comprise the optical system that is arranged on cone top.

2. position of sun tracing sensor according to claim 1, is characterized in that: described photodiode is at least four.

3. position of sun tracing sensor according to claim 1, is characterized in that: described MICROCOMPUTER PROCESSING plate is the circuit board identical with cone radius, embeds cone bottom, seals light tight.

4. position of sun tracing sensor according to claim 1, is characterized in that: described in be at least four photodiodes and be attached to cone outer wall and install symmetrically along excircle; The signal wire that they are drawn is connected on MICROCOMPUTER PROCESSING plate, by microcomputer, photodiode input signal is processed, and topworks sends according to the signal after processing the order that position of sun is followed the trail of again; When intensity of illumination is inadequate, the magnitude of voltage sum of photodiode induction does not reach setting value, and microcomputer judgement topworks does not work; When intensity of illumination is enough, the magnitude of voltage sum of photodiode induction is greater than setting value, and microcomputer judgement sensor enters preliminary track phase.

5. position of sun tracing sensor according to claim 1, is characterized in that: described microcomputer is converted into shifted signal turning to of stepper motor and rotates step count data, then exports to topworks with max232.

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