CN102052913A - Small hole imaging principle-based projector for measuring sun position information - Google Patents

Abstract

The invention discloses a small hole imaging principle-based projector for measuring sun position information, comprising a closed bottom tube, a projection screen, a sampling device and a processing unit, wherein the sampling device comprises a pick-up lens; a small hole is arranged in the middle of a top cover of the bottom tube; the projection screen is located in the tube body of the bottom tube, and a distance between the projection screen and the small hole is measured; the sampling device is located in the tube body of the bottom tube and below the projection screen and used for measuring a projection position of a light spot on the projection screen; the small hole, the pick-up lens and the center of the projection screen are located on the same straight line; the processing unit is connected with the sampling device; and the sun position information is calculated through the position information sampled by the sampling device and the distance between the projection screen and the small hole. The invention has the advantages of reasonable structure, low cost, high precision and strong scientificity.

Description

A kind of projection arrangement of the measurement position of sun information based on the pinhole imaging system principle

Technical field

The present invention relates to a kind of projection arrangement of the measurement position of sun information based on the pinhole imaging system principle.

Background technology

About the measurement of sun altitude and position angle, we just learnt the method for " shadow is seen in vertical rod " on the textbook of middle school, and this method need be measured the length of upright pole and shadow thereof, and will calculate by trigonometric function and just can obtain a result, and were very inconvenient.And when the height of the sun was very low, the shadow of upright pole was long oversize, and the length of founding the pole shadow can't be judged and measure at all to image fog.

In number of patent application is 200920044257.1 patent documentation, a kind of altitude of the sun measuring instrument is disclosed, mainly comprise base, horizontal adjustment screw, support, protractor, angle display, several parts such as ceiling hammer; At the base center support is installed, on support, is connect protractor and vertical line is hung in installation.Instrument is placed on the platform about 1 meter under the sunlight, over against the sun, makes bright spot drop on the angle display pattern center center pit on the angle display, at this moment can read the angle number of altitude of the sun at that time from the scale of angle display upward arrow indication protractor.Though this method has been avoided the trouble of shadow linear measure longimetry and calculating, the moving measurement of also main armrest, naked eyes are read scale, are not easily, and precision also is difficult to guarantee.

Number of patent application is in 200810242752.3 the patent documentation, to disclose a kind of intelligent sun angle detector, and it comprises three groups of photocell detectors and a series of match circuit.With one group be example, illustrate how above-mentioned intelligent detection instrument measures altitude of the sun.One group of photocell detectors is installed on the output shaft of one group of stepper motor, along with the rotation of stepper motor, photocell detectors is converted into short-circuit current with the radiation intensity of the sunshine that collects, and this short-circuit current is through current/voltage circuit, behind the voltage amplifier circuit, enter dsp chip; Dsp chip sends drive signal on the one hand, continues to drive above-mentioned stepper motor and is rotated, so that above-mentioned photocell detectors continues to gather intensity of solar radiation; On the other hand, above-mentioned dsp chip inserts PC by RS-232 communication level translation interface, the signal that there obtains from above-mentioned photocell detectors is sent into the above-mentioned PC calculated, and obtains the numerical value of solar azimuth and elevation angle.Though it is complicated that this method measuring accuracy height, project organization show slightly, and cost is not low, be not to be easy to realize.

Summary of the invention

For addressing the above problem, the present invention proposes a kind of projection arrangement of the measurement position of sun information based on the pinhole imaging system principle, comprise: airtight end tube, a projection screen, a sampling apparatus that comprises pick-up lens and a processing unit, the top cover middle part of tube of the described end is provided with an aperture; Projection screen is positioned at end tube cylindrical shell, measures the spacing between projection screen and the aperture; Sampling apparatus is positioned at the below of end tube cylindrical shell and projection screen, is used to measure the projected position of hot spot on projection screen; Aperture, pick-up lens, projection screen are centered close on same the straight line, and described processing unit connects sampling apparatus, by to the positional information of sampling apparatus sampling and the sunny positional information of distance computation between projection screen and the aperture.

Tube of the described end is a hermetically-sealed construction, and there is an aperture at its center, top cover upper end.

Described projection screen is made with thin fibrous material.

The method that the projection arrangement of described a kind of measurement position of sun information based on the pinhole imaging system principle is measured may further comprise the steps:

One projection arrangement is provided, and it comprises: airtight end tube, a projection screen, a sampling apparatus that comprises pick-up lens and a processing unit, and the top cover middle part of tube of the described end is provided with an aperture, and aperture, pick-up lens, projection screen are centered close to same straight line;

Sampling apparatus samples sunshine and injects the back forms hot spot at projection screen position from aperture;

Sampling apparatus reaches processing unit with the information of sampling;

Processing unit is to the positional information of sampling apparatus sampling and the sunny positional information of distance computation between projection screen and the aperture.

The method that the projection arrangement of described a kind of measurement position of sun information based on the pinhole imaging system principle is measured also comprises:

Take pictures the in advance projection screen of hot spot of sampling apparatus, and those information are sent to processing unit;

The projection arrangement of described measurement position of sun information based on the pinhole imaging system principle is characterized in that described processing unit is a basis:

Calculate position of sun information, wherein, H be between projection screen center and the aperture distance, (x, the y) coordinate of fastening at reference coordinate for hot spot,

Be sun altitude, ψ is a solar azimuth.

Compared with prior art, the invention has the advantages that apparatus structure is reasonable, cheap, it is easier to build; And the present invention is removable, steadiness is good, is difficult for deformation.Whole gatherer process does not have artificial participation, has reduced artificial error, more science, accurate.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Fig. 2 is the position view of projection screen;

Fig. 3 is the projection screen vertical view;

The reference frame synoptic diagram that Fig. 4 simulates for processing unit;

Fig. 5 is the relative position synoptic diagram of hot spot in Fig. 4 reference frame.

Fig. 6 is the Matlab figure of the variation of sun altitude and its deviation.

Embodiment

As Fig. 1, shown in Figure 2, a kind of projection arrangement of the measurement position of sun information based on the pinhole imaging system principle comprises: airtight end tube 1, a projection screen 2, a sampling apparatus 3 that comprises pick-up lens and a processing unit 4, and top cover 1 middle part of tube of the described end is provided with an aperture 5; Projection screen 2 is positioned at end tube 1 cylindrical shell, measures the spacing between projection screen 2 and the aperture 5; Sampling apparatus is positioned at the below of end tube 1 cylindrical shell and projection screen 2, is used to gather the projected position information of hot spot on projection screen 2; Aperture 5, pick-up lens, projection screen 2 are centered close on same the straight line; Described processing unit 4 connects sampling apparatus 3, by the positional information of sampling apparatus 3 samplings and the sunny positional information of distance computation between projection screen 2 and the aperture 5.

The method that a kind of projection arrangement of the measurement position of sun information based on the pinhole imaging system principle is measured may further comprise the steps:

One projection arrangement is provided, it comprises: airtight end tube 1, a projection screen 2, a sampling apparatus 3 that comprises pick-up lens and a processing unit 4, the top cover middle part of tube of the described end is provided with an aperture 5, and aperture 5, pick-up lens, projection screen 2 are centered close to same straight line.

Wherein,, utilize the GPS survey instrument earlier, make true bearing, on projection screen 2, make mark according to true bearing then, and projection screen 2 is set by the true bearing correspondence markings as Fig. 3.Take pictures the in advance projection screen 2 of hot spot of sampling apparatus 3, and those information are sent to processing unit 4; See Fig. 4 again, processing unit 4 on the basis of above-mentioned image information, according on the projection screen 2 the target orientation set up coordinate system, this coordinate system is reference frame.

Sunray is injected from the aperture at end tube 1 top, forms hot spot on projection screen 2; Sampling apparatus 3 samples sunshine and injects the position of back at projection screen 2 formation hot spots from aperture, and this positional information is reached processing unit 4; Processing unit 4 is the basis with the above-mentioned reference coordinate of setting up in advance, determines the coordinate of hot spot, and as Fig. 5, the point of black is the coordinate of the hot spot that samples of correspondence, Elevation angle for the sun.

Processing unit 4 draws position of sun information by the positional information of sampling apparatus 3 samplings and the spacing between projection screen 2 and the aperture 5 are calculated.

Wherein,, H be between projection screen 2 centers and the aperture 5 distance, (x, the y) coordinate of fastening at reference coordinate for hot spot, Be sun altitude, ψ is the position of sun angle.

The measured value of the aerial absolute index of refraction of normal light is 1.0002926, is no more than 1.0003.Suppose that incident angle is

Drift angle in the time of can obtaining the generation refraction according to the algorithm of refractive index is about:

When

The time, Δ θ=1.4 °; When

The time, Δ θ=0.017 °

When theoretical sun altitude When changing from 0 ° to 90 °, corresponding elevation angle deviation delta θ also changes, and the variation of its correspondence is mapped with Matlab; As Fig. 6, horizontal ordinate is a sun altitude

Ordinate is corresponding elevation angle deviation delta θ.Have only when cumulative errorss such as manufacturing installation during less than this deviation, the method just has practical meaning.

Determine as follows about the error of related physical quantity:

H is the height of aperture 5 apart from projection screen 2, and Δ H is the deviation that can guarantee in the machining; R is the projection screen radius; (x y) is recorded by processing unit 4; Δ X, Δ Y correspondence be the cumulative errors of central shaft deviation and Flame Image Process error; Make projection screen be parallel to pick-up lens with level meter, therefore the level meter deviation delta θ that causes ₁The GPS survey instrument carries out the North and South direction location, therefore causes north and south positive dirction deviations Δ θ ₂

According to

:

The elevation angle deviation is:

Azimuth angle deviation is:

$\mathrm{\Δ\ψ}:=\mathrm{\Δx}\·\frac{\∂}{\∂x}\mathrm{\ψ}+\mathrm{\Δy}\frac{\∂}{\∂y}\mathrm{\ψ}+\mathrm{\Δ}{\mathrm{\θ}}_2$

$=-\frac{\mathrm{\Δxy}}{x^2(1+\frac{y^2}{x^2})}+\frac{\mathrm{\Δy}}{x(1+\frac{y^2}{x^2})}+{\mathrm{\Δ\θ}}_2$

In above-mentioned two formulas of the error substitution of each value that records and each value, can obtain the error at elevation angle and phasing degree.

Now suppose height error 0.01mm, height H=30mm; 1,000,000 pixel camera machines, R=60mm; Think optical correction's central shaft roughly, facula position is precisely located, then horizontal x deflection error 0.06mm, vertically y deflection error 0.06mm.Its directional error is with x, and y changes and changes.

Get north latitude 30 and spend height at high noon, x=0, y=4mm.This time error maximum, for-0.001921397380+ Δ θ ₁

As can be seen, under the situation of device existence than mistake, the measured deviation of this device is less, the degree of accuracy height.

That the present invention has is rational in infrastructure, cheap, degree of accuracy is high, scientific strong advantage.

More than disclosed only be several specific embodiments of the application, but the application is not limited thereto, any those skilled in the art can think variation, all should drop in the application's the protection domain.

Claims (6)

1. the projection arrangement based on the measurement position of sun information of pinhole imaging system principle is characterized in that, comprising: airtight end tube, a projection screen, a sampling apparatus that comprises pick-up lens and a processing unit, and the top cover middle part of tube of the described end is provided with an aperture;

Projection screen is positioned at end tube cylindrical shell, measures the spacing between projection screen and the aperture;

Sampling apparatus is positioned at the below of end tube cylindrical shell and projection screen, is used to measure the projected position of hot spot on projection screen; Aperture, pick-up lens, projection screen are centered close on same the straight line,

Described processing unit connects sampling apparatus, by the positional information of sampling apparatus sampling and the sunny positional information of distance computation between projection screen and the aperture.

2. the projection arrangement of a kind of measurement position of sun information based on the pinhole imaging system principle as claimed in claim 1 is characterized in that end tube is a hermetically-sealed construction, and there is an aperture at its center, top cover upper end.

3. the projection arrangement of a kind of measurement position of sun information based on the pinhole imaging system principle according to claim 1 is characterized in that, projection screen is made with thin fibrous material.

4. a method of measuring based on the projection arrangement of the measurement position of sun information of pinhole imaging system principle is characterized in that, may further comprise the steps:

One projection arrangement is provided, and it comprises: airtight end tube, a projection screen, a sampling apparatus that comprises pick-up lens and a processing unit, and the top cover middle part of tube of the described end is provided with an aperture, and aperture, pick-up lens, projection screen are centered close to same straight line;

Sampling apparatus samples sunshine and injects the back forms hot spot at projection screen position from aperture;

Sampling apparatus reaches processing unit with the information of sampling;

Processing unit is to the positional information of sampling apparatus sampling and the sunny positional information of distance computation between projection screen and the aperture.

5. method as claimed in claim 4 is characterized in that, also comprises:

Utilize the GPS survey instrument earlier, make true bearing, on projection screen, make mark according to true bearing then, and projection screen is set by the true bearing correspondence markings;

Take pictures the in advance projection screen of hot spot of sampling apparatus, and those information are sent to processing unit;

Processing unit on the basis of above-mentioned image information, according on the projection screen the target orientation set up coordinate system, this coordinate is a reference frame.

6. method as claimed in claim 5 is characterized in that:

Described processing unit is a basis

Calculate position of sun information, wherein, H be between projection screen center and the aperture distance, (x, the y) coordinate of fastening at reference coordinate for hot spot,

Be sun altitude, ψ is a solar azimuth.

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