CN102929299A - Mechanical-error calibration method for heliostat - Google Patents

Abstract

The invention relates to a mechanical-error calibration method for a heliostat, which is based on the application of a heliostat real-time follow-up solar device of a tower type solar energy heat-collection system. The method comprises the following steps: judging the position of a light spot on a heat collector through images shot by a camera; comparing the mass centre position of the light spot with an appointed position, if deviation occurs, showing that mechanical error of the heliostat exists, at the moment, recording the elevation angle and azimuth angle of the sun, as well as those of the heliostat when light spot deviates, the height of a heliostat bracket and position coordinates of the heliostat bracket relative to the center spot of the heliostat heat collector; calculating the coordinates of the deviated heliostat mass centre relative to the mass centre position of the original heliostat through a computation module; converting the deviation amount of the heliostat center spot into deviation amount of the mass centre point of the heat collector through a coordinate system, and building a new heliostat center spot; determining the appointed position coordinates of the heat collector under a coordinate system taking the new heliostat center spot as an origin; and taking the heliostat having the mechanical error as a criteria, re-calculating and re-sending so as to realize the tracking of the heliostat, and projecting the light spot data, thereby achieving the purposes of high-efficiency tracking and sunlight spot projection.

Description

A kind of method of heliostat machine error calibration

Technical field

The present invention relates to tower type solar collecting system technical field, particularly a kind of method of heliostat machine error calibration.

Background technology

Heliostat is in During Process of Long-term Operation, because the external force factors such as wind-force, gravity deform the heliostat support frame structure, when causing heliostat tracking and projected spot error occurs, and this error is called machine error.In order to guarantee that heliostat can the high precision projected spot, the calibration steps of research and development machine error is necessary with device.

At present, heliostat and heat collector when prior art can realize the Jing Chang installation accurately align, and can be in service to proofreading and correct because of the error of mechanically deform and settlement of foundation generation to the mirror head phase.But weak point is: prior art is just proofreaied and correct for the machine error in a certain moment, but can not realize the machine error calibration function of arbitrary period tracking stroke, namely except the moment that machine error is calibrated, other constantly heliostats still exist machine error or projected spot time error larger, need to again calibrate it, required time is more, and cost increases.

Summary of the invention

The present invention has proposed a kind of method of heliostat machine error calibration in order to solve the defective of prior art machine error calibration.

The present invention realizes according to following proposal:

A kind of method of heliostat machine error calibration, be based on the application of tower type solar collecting system heliostat real-time follow-up sun device system, the picture that utilizes video camera to take is judged the position of hot spot on the heat collector, the centroid position of hot spot is compared with assigned address, if any deviation, illustrate that machine error has occured heliostat, record this moment elevation angle and the position angle of the sun, the height of the elevation angle of heliostat and position angle and heliostat support and with respect to the position coordinates of heliostat heat collector central point when forming the deviation hot spot, extrapolate center of mass point that heliostat after the deviation occurs by computation model with respect to the coordinate of former heliostat centroid position, side-play amount with the heliostat barycenter, be transformed into the side-play amount of heat collector center of mass point by coordinate system, set up new heliostat central point, and at the position coordinates of under the coordinate system of initial point, determining the heat collector appointment, heliostat after the machine error to occur as benchmark, again calculate the data that are sent to this heliostat tracking and projected spot, reach the purpose that solar facula was followed the tracks of and throwed to high-level efficiency;

The center of mass point of heliostat is obtained by following model inference with respect to the coordinate of former heliostat centroid position after the generation machine error:

$x_0=a_0-\frac{-b+\sqrt{b^2-4\&times;a\&times;\mathrm{<figure-callout\; id="2"\; label="c"\; filenames="HDA00002449805300021.png"\; state="\{\{state\}\}">c</figure-callout>}}}{2\&times;a}\&times;{\mathrm{\&omega;}}_1...\left(1\right)$

$y_0=b_0-\frac{-b+\sqrt{b^2-4\&times;a\&times;\mathrm{<figure-callout\; id="2"\; label="c"\; filenames="HDA00002449805300021.png"\; state="\{\{state\}\}">c</figure-callout>}}}{2\&times;a}\&times;{\mathrm{\&omega;}}_2...\left(2\right)$

$z_0=h_0-\frac{-b+\sqrt{b^2-4\&times;a\&times;\mathrm{<figure-callout\; id="2"\; label="c"\; filenames="HDA00002449805300021.png"\; state="\{\{state\}\}">c</figure-callout>}}}{2\&times;a}\&times;{\mathrm{\&omega;}}_3...\left(3\right)$

Wherein, the variable a in (1), (2) and (3) formula, b, c is calculated by following formula

a=ω ₁ ²+ω ₂ ²-ω ₃ ²…………………………………………………(4)

b=(2×l+2×h ₀)×ω ₃-2×a ₀×ω ₁-2×b ₀×ω ₂…………………………(5)

c=a ₀ ²+b ₀ ²-h ₀ ²-2×l×h ₀…………………………………………(6)

Wherein, the variable ω in (4), (5) and (6) formula ₁, ω ₂, ω ₃Calculated by following formula

Wherein, the variable in (7), (8) and (9) formula

Calculated by following formula

In the above formula (1), (2), (3), (4), (5), (6), (7), (8), (9), (10) symbol explain as follows:

HS: the elevation angle of the expression sun, i.e. angle between sunray and the surface level (ground) (or 90 ° of angles between sunray and the vertical direction-HS), unit degree of being (°), span is 0 ° to 90 °;

AS: the position angle of the expression sun, the angle that is sunray between the vertical projecting line on the surface level (ground) and Zheng Bei (or due south, Zheng Xi, due east) direction, unit degree of being (°), span is 0 ° to 360 ° (or-180 ° to 180 °);

G: the elevation angle of expression heliostat, i.e. the angle of the normal of heliostat and surface level (ground) (or the angle of settled date minute surface and surface level (90 °-G)), unit degree of being (°), span is 0 ° to 90 °;

F: the position angle of expression heliostat, the angle that is heliostat normal (or settled date minute surface) between the vertical projecting line on the surface level (ground) and Zheng Bei (or due south, Zheng Xi, due east) direction, unit degree of being (°), span is 0 ° to 360 ° or (180 ° to 180 °);

L: the height of expression heliostat support, i.e. vertical range (bee-line) between heliostat central point and the surface level (ground), unit is meter (m);

ω ₁, ω ₂, ω ₃,

The intermediate variable that relates in the expression computation process does not have practical significance;

a ₀, b ₀, h ₀: the expression video camera is taken the center of mass point coordinate of skew hot spot, and namely barycenter of light spots is with respect to the coordinate in the rectangular coordinate system in space of true origin of heliostat center of mass point before the machine error to occur as (a ₀, b ₀, h ₀), unit is rice (m);

x ₀, y ₀, z ₀: expression is with respect to the position of the central point that heliostat is new under the original coordinate system, and unit is rice.

The error that the present invention can high-precision calibration heliostat machinery causes is calibrated the required time short, has improved the work efficiency of heliostat; Mathematical model has guaranteed the precision of calibration; The error that the heliostat that the present invention can absolute calibration machinery causes is followed the tracks of.

Description of drawings

Fig. 1 is the inventive method process flow diagram;

Fig. 2 is disposal route schematic diagram of the present invention.Among the figure: heliostat centroid position after the 1-generation machine error; 2-does not calibrate the front heliostat centroid position of machine error; Actual facula position on the 3-alignment surface; 4-heat collector central point; The central point of 5-alignment surface; The 6-computing machine; 7-camera (or video camera).

Embodiment

As shown in Figure 1 and Figure 2, step of the present invention is: the first step: based on the heliostat real-time follow-up sun, utilize the picture of camera to judge the position of hot spot on the heat collector:

One, the centroid position of observing hot spot by video camera coincide (coincidence) with assigned address, and illustrating does not have error;

Its two, the centroid position of observing hot spot by video camera is equipped with deviation (not overlapping) with specific bit, illustrates to have occurred error in the tracing process, this source of error is in machine error.

Second step: take actual hot spot on the heat collector with video camera, record the height of the elevation angle of the elevation angle of the sun this moment and position angle, formation deviation hot spot heliostat and position angle, heliostat support and with respect to the position coordinates of heliostat heat collector central point;

The 3rd step: graphical analysis.Utilize the method for graphical analysis to calculate actual barycenter of light spots coordinate on the heat collector that second step takes;

The 4th step: utilize the position coordinates of following formula calculating heliostat virtual center point, as follows:

$x_0=a_0-\frac{-b+\sqrt{b^2-4\&times;a\&times;\mathrm{<figure-callout\; id="2"\; label="c"\; filenames="HDA00002449805300021.png"\; state="\{\{state\}\}">c</figure-callout>}}}{2\&times;a}\&times;{\mathrm{\&omega;}}_1...\left(1\right)$

$y_0=b_0-\frac{-b+\sqrt{b^2-4\&times;a\&times;\mathrm{<figure-callout\; id="2"\; label="c"\; filenames="HDA00002449805300021.png"\; state="\{\{state\}\}">c</figure-callout>}}}{2\&times;a}\&times;{\mathrm{\&omega;}}_2...\left(2\right)$

$z_0=h_0-\frac{-b+\sqrt{b^2-4\&times;a\&times;\mathrm{<figure-callout\; id="2"\; label="c"\; filenames="HDA00002449805300021.png"\; state="\{\{state\}\}">c</figure-callout>}}}{2\&times;a}\&times;{\mathrm{\&omega;}}_3...\left(3\right)$

Wherein, the variable a in (1), (2) and (3) formula, b, c is calculated by following formula

a=ω ₁ ²+ω ₂ ²-ω ₃ ²……………………………………………………(4)

b=(2×l+2×h ₀)×ω ₃-2×a ₀×ω ₁-2×b ₀×ω ₂……………………(5)

c=a ₀ ²+b ₀ ²-h ₀ ²-2×l×h ₀…………………………………………(6)

Wherein, the variable ω in (4), (5) and (6) formula ₁, ω ₂, ω ₃Calculated by following formula

Wherein, the variable in (7), (8) and (9) formula

Calculated by following formula

In the above formula (1), (2), (3), (4), (5), (6), (7), (8), (9), (10) symbol explain as follows:

HS: expression be the elevation angle of the sun, i.e. angle between sunray and the surface level (ground) (or 90 ° of angles between sunray and the vertical direction-HS), unit degree of being (°), span is 0 ° to 90 °;

AS: the position angle of the expression sun, the angle that is sunray between the vertical projecting line on the surface level (ground) and Zheng Bei (or due south, Zheng Xi, due east) direction, unit degree of being (°), span is 0 ° to 360 ° (or-180 ° to 180 °);

G: the elevation angle of expression heliostat, i.e. the angle of the normal of heliostat and surface level (ground) (or the angle of settled date minute surface and surface level (90 °-G)), unit degree of being (°), span is 0 ° to 90 °;

F: the position angle of expression heliostat, the angle that is heliostat normal (or settled date minute surface) between the vertical projecting line on the surface level (ground) and Zheng Bei (or due south, Zheng Xi, due east) direction, unit degree of being (°), span is 0 ° to 360 ° or (180 ° to 180 °);

L: the height of expression heliostat support, i.e. vertical range (bee-line) between heliostat central point and the surface level (ground), unit is meter (m);

ω ₁, ω ₂, ω ₃,

The intermediate variable that relates in the expression computation process does not have practical significance;

a ₀, b ₀, h ₀: the expression video camera is taken the center of mass point coordinate of skew hot spot, and namely barycenter of light spots is with respect to the coordinate in the rectangular coordinate system in space of true origin of heliostat center of mass point before the machine error to occur as (a ₀, b ₀, h ₀), unit is rice (m);

x ₀, y ₀, z ₀: expression is with respect to the position of the central point that heliostat is new under the original coordinate system, and unit is rice (m).

The 5th step: coordinate system conversion.The side-play amount of heliostat barycenter is transformed into the side-play amount of heat collector center of mass point by coordinate system, based on the position coordinates of determining the heat collector center under take new heliostat central point as the coordinate system of initial point;

The 6th step: based on new heliostat center point coordinate, continue the real-time follow-up sun.

Above process as shown in Figure 1.

Embodiment:

1) take the heat collector position with video camera, whether the hot spot that check is reflected through heliostat beats the assigned address at heat collector, if beat the position that is in impact point at hot spot, then machine error does not occur proof; Otherwise, take hot spot physical location image on heat collector, as shown in Figure 2;

2) with the center of finding the border hot spot that makes real of the method for graphical analysis as the known conditions that utilizes above mathematical model;

Record data: the elevation angle and position angle, the position coordinates of specified point and the position coordinates of actual point that comprise the elevation angle of heliostat and position angle, the sun; With these data equally as the known conditions of mathematical model;

4) use mathematical model to carry out the calculating of new specified point position:

Suppose heliostat barycenter generation machine error, utilize the actual hot spot of taking to calculate new centroid position, and obtain the actual position coordinate of new specified point by coordinate transform, look for again chance to take the image of hot spot after the calibration, if dot projection is to the specified point place, machine error is calibrated, otherwise the repetition 1 of again taking pictures), 2), 3) step, until dot projection is at the specified point place;

5) if the complete hot spot of finding afterwards of above calibration is not still beaten at the specified point place, illustrate that machine error does not occur heliostat, the reason that causes this phenomenon may be other reasons.

Claims (2)

1. the method for heliostat machine error calibration, be based on the application of tower type solar collecting system heliostat real-time follow-up sun device system, the picture that utilizes video camera to take is judged the position of hot spot on the heat collector, the centroid position of hot spot is compared with assigned address, if any deviation, illustrate that machine error has occured heliostat, record this moment elevation angle and the position angle of the sun, the height of the elevation angle of heliostat and position angle and heliostat support and with respect to the position coordinates of heliostat heat collector central point when forming the deviation hot spot, extrapolate center of mass point that heliostat after the deviation occurs by computation model with respect to the coordinate of former heliostat centroid position, side-play amount with the heliostat barycenter, be transformed into the side-play amount of heat collector center of mass point by coordinate system, set up new heliostat central point, and at the position coordinates of under the coordinate system of initial point, determining the heat collector appointment, heliostat after the machine error to occur as benchmark, again calculate the data that are sent to this heliostat tracking and projected spot, reach the purpose that solar facula was followed the tracks of and throwed to high-level efficiency.

2. according to claims 1 described method, it is characterized in that, the center of mass point of heliostat is obtained by following model inference with respect to the coordinate of former heliostat centroid position after the generation machine error:

$x_0=a_0-\frac{-b+\sqrt{b^2-4\&times;a\&times;c}}{2\&times;a}\&times;{\mathrm{\&omega;}}_1...\left(1\right)$

$y_0=b_0-\frac{-b+\sqrt{b^2-4\&times;a\&times;c}}{2\&times;a}\&times;{\mathrm{\&omega;}}_2...\left(2\right)$

$z_0=h_0-\frac{-b+\sqrt{b^2-4\&times;a\&times;c}}{2\&times;a}\&times;{\mathrm{\&omega;}}_3...\left(3\right)$

Wherein, the variable a in (1), (2) and (3) formula, b, c is calculated by following formula

a=ω ₁ ²+ω ₂ ²-ω ₃ ²…………………………………………………(4)

b=(2×l+2×h ₀)×ω ₃-2×a ₀×ω ₁-2×b ₀×ω ₂…………………………(5)

c=a ₀ ²+b ₀ ²-h ₀ ²-2×l×h ₀…………………………………………(6)

Wherein, the variable ω in (4), (5) and (6) formula ₁, ω ₂, ω ₃Calculated by following formula

Wherein, the variable in (7), (8) and (9) formula Calculated by following formula

In the above formula (1), (2), (3), (4), (5), (6), (7), (8), (9), (10) symbol explain as follows:

HS: the elevation angle of the expression sun, i.e. angle between sunray and the surface level (ground) (or 90 ° of angles between sunray and the vertical direction-HS), unit degree of being (°), span is 0 ° to 90 °;

AS: the position angle of the expression sun, the angle that is sunray between the vertical projecting line on the surface level (ground) and Zheng Bei (or due south, Zheng Xi, due east) direction, unit degree of being (°), span is 0 ° to 360 ° (or-180 ° to 180 °);

G: the elevation angle of expression heliostat, i.e. the angle of the normal of heliostat and surface level (ground) (or the angle of settled date minute surface and surface level (90 °-G)), unit degree of being (°), span is 0 ° to 90 °;

F: the position angle of expression heliostat, the angle that is heliostat normal (or settled date minute surface) between the vertical projecting line on the surface level (ground) and Zheng Bei (or due south, Zheng Xi, due east) direction, unit degree of being (°), span is 0 ° to 360 ° or (180 ° to 180 °);

L: the height of expression heliostat support, i.e. vertical range (bee-line) between heliostat central point and the surface level (ground), unit is meter (m);

ω ₁, ω ₂, ω ₃,

The intermediate variable that relates in the expression computation process does not have practical significance;

a ₀, b ₀, h ₀: the expression video camera is taken the center of mass point coordinate of skew hot spot, and namely barycenter of light spots is with respect to the coordinate in the rectangular coordinate system in space of true origin of heliostat center of mass point before the machine error to occur as (a ₀, b ₀, h ₀), unit is rice (m);

x ₀, y ₀, z ₀: expression is with respect to the position of the central point that heliostat is new under the original coordinate system, and unit is rice.

Images