CN102620687A - Transmission circular grating cradle head based on image processing and positioning detection method thereof - Google Patents

Abstract

The invention discloses a transmission circular grating cradle head based on image processing and a positioning detection method thereof. Transmission circular glass gratings are respectively and additionally arranged on a cradle head base and a cradle head rotary body, moire fringes are formed between two glass gratings by utilizing rotation process of the cradle head rotary body, and the method utilizing pixel numbers of the moire fringes in a target area to calculate the rotation angle of the cradle head is formed by collecting the images of the moire fringes and performing relative gray processing. The method is simple, convenient to implement, high in measurement accuracy, small in outside interference, good in stability of the whole device, high in reliability and especially suitable for the cradle head with high-accuracy control requirements in the rotation process.

Description

Transmission-type circle grating The Cloud Terrace and position finding and detection method thereof based on Flame Image Process

Technical field

The present invention relates to a kind of The Cloud Terrace position finding and detection method, particularly a kind of transmission-type circle grating The Cloud Terrace and position finding and detection method thereof based on Flame Image Process belong to security protection and industrial control field.

Background technology

The Cloud Terrace all has critical role in safety monitoring and commercial production manufacturing, wherein, realize that the High Accuracy Control of The Cloud Terrace and location are important contents of this area research, also is that The Cloud Terrace is used and development key.

For guaranteeing the High Accuracy Control and the location of The Cloud Terrace, it is effective a kind of means that high Precision Detection is carried out in The Cloud Terrace position in the operation process.Detection in the existing The Cloud Terrace generally is to measure with angular transducer; Measuring accuracy is more than 0.01 °, but this method receives the restriction and the influence of measurement error of angular transducer precision, and measuring accuracy is limited; Generally can't reach required more high precision, make troubles for actual the use.

How existing method is improved, improved measuring accuracy and measure accuracy, just become problem to be solved by this invention.

Summary of the invention

In view of the shortcoming and defect of above-mentioned prior art, the present invention aims to provide a kind of mode of utilizing transmission-type circle grating and image processing method to combine, the The Cloud Terrace rotational angle is accurately detected, to guarantee to rotate accuracy and reliability.

The present invention realizes through following technical scheme:

A kind of transmission-type circle grating The Cloud Terrace based on Flame Image Process; Comprise The Cloud Terrace pedestal, The Cloud Terrace rotor and control system; Also comprise two transmission-type Circular glass gratings, infrared light supply, lens, reflection unit and cameras, two transmission-type Circular glass grating pairs should be fixed on The Cloud Terrace pedestal and the The Cloud Terrace rotor; Lens and infrared light supply are separately fixed on the The Cloud Terrace pedestal, and the infrared light supply scioptics are corresponding with the glass raster on the The Cloud Terrace rotor; Reflection unit is corresponding to the glass raster below of The Cloud Terrace pedestal; Camera is corresponding with reflection unit, and the output terminal of camera is connected with control system, and camera and reflection unit are separately fixed on the The Cloud Terrace pedestal.

Said reflection unit is the prism of a 45, and camera is corresponding with the reflecting surface of prism.

A kind of position finding and detection method of the transmission-type circle grating The Cloud Terrace based on Flame Image Process comprises:

A), choose two blocks of transmission-type Circular glass gratings, one is fixed on the The Cloud Terrace pedestal as indication grating, another is fixed on the The Cloud Terrace rotor as the scale grating.

B), along with the rotation of The Cloud Terrace rotor, infrared light supply irradiation glass raster, camera utilizes reflection unit that the Moire fringe image between two glass rasters is gathered.

C), according to formula: Y=0.259R+0.588G+0.124B, the colored Moire fringe image that control system will collect changes into gray level image.

D), utilize the linear transformation mode gray level image to be carried out the grey level stretching of enhancing contrast ratio.

E), the image after the grey level stretching is converted into black white image.

F), black white image is scanned; Completion is to the wherein mark and the intercepting in a white Moire fringe zone; Calculate the pixel count of the white pixel in the single marking fringe area; Utilize sum formula, extrapolate with the relational expression between Moire fringe marked region sum of all pixels and the marked region area A, that is:

$A=n\underset{i\≥T}{\mathrm{\Σ}}{v}_i$

Wherein, n is a total number of image pixels in the single Moire fringe marked region, v _iFor image gray levels is the frequency of the pixel appearance of i, T is a gray threshold.

G), according to the area A of marked region, the rotational angle θ that the definition inverse cosine function calculates The Cloud Terrace accomplishes the accurate demarcation to the The Cloud Terrace turned position,

$\mathrm{\θ}=\arccos \frac{A}{A_{\max }}$

A wherein _MaxBe the maximum area in single white Moire fringe zone, its computing formula is following:

$A_{\max }=n_{\max }\underset{i\≥T}{\mathrm{\Σ}}{v}_i$

N wherein _MaxTotal number of image pixels during for white Moire fringe zone maximum area.

A kind of transmission-type circle grating The Cloud Terrace and position finding and detection method thereof based on Flame Image Process of the present invention through on The Cloud Terrace pedestal and The Cloud Terrace rotor, setting up transmission-type Circular glass grating respectively, utilize the rotation process of The Cloud Terrace rotor; Between two glass rasters, form Moire fringe, after gathering the Moire fringe image and carrying out the gray scale processing, form a kind of method of calculating the The Cloud Terrace rotational angle with the pixel count of Moire fringe in the target area; Avoided carrying out the shortcoming that measurement of angle exists with angular transducer in the prior art, precision is high, receives external interference little; It is convenient to realize; Wherein, adopt the pixel count method to calculate, calculated amount is little; Algorithm is simple, can not receive the influence of irregular Moire fringe shape.Whole apparatus structure is simple, easy to use, good stability, reliability height, and testing result is quick, accurate, is particularly suitable on the The Cloud Terrace that rotation process has High Accuracy Control to require, using.

Description of drawings

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

Embodiment

1 couple of the present invention does further description below in conjunction with accompanying drawing:

A kind of transmission-type circle grating The Cloud Terrace based on Flame Image Process of the present invention comprises The Cloud Terrace pedestal, The Cloud Terrace rotor, two transmission-type Circular glass gratings, infrared light supply, lens, reflection unit, camera and control system.The Cloud Terrace rotor relative The Cloud Terrace pedestal under the control of control system rotates, images acquired information at any time, and the image information of gathering sent in the far-end server, to realize security or production monitoring process.The glass raster that increases newly, infrared light supply, lens, reflection unit and camera then are the detection and localization that is used for the The Cloud Terrace rotation process, to guarantee that The Cloud Terrace rotor rotational angle accurately, reliably.

Wherein, two transmission-type Circular glass grating pairs should be fixed on The Cloud Terrace pedestal and the The Cloud Terrace rotor, are fixed on the indication grating that is called on the The Cloud Terrace pedestal, are fixed on to be called the scale grating on the The Cloud Terrace rotor.When The Cloud Terrace rotated, the scale grating rotated with respect to indication grating, and striped radially moves, and can form the Moire fringe of image change, and the area size of Moire fringe just can reflect the angle that The Cloud Terrace rotates.

For forming apparent Moire fringe; Also order is equipped with lens and infrared light supply above the scale grating; Lens are fixedly connected with the The Cloud Terrace pedestal respectively with infrared light supply; The infrared light supply scioptics are corresponding with the scale grating on the The Cloud Terrace rotor, and scale grating and indication grating are crossed in the IR transmission.

For making cradle head structure more reasonable; Collection to Moire fringe is more effective, and reflection unit also is housed below indication grating, and reflection unit is the prism of a 45; Prism can be refracted to prism one side with incident image; Thereby photograph function image behind the birefringence of side is taken pictures, shortened the integrally-built axial distance of The Cloud Terrace, satisfied the collection needs of Moire fringe in the rotary course.Camera and prism are separately fixed on the The Cloud Terrace pedestal, and it is fixing that the mutual alignment of camera, prism, indication grating keeps.

The output terminal of camera keeps being communicated with control system; The Moire fringe photo of taking is sent in the control system at any time; After the adjustment and simple operation of control system to image; Converse the angle of The Cloud Terrace rotor actual rotation at last through the pixel count of Moire fringe in the target area, this angle is used as feedback information and turns back in the control system, thereby finally accomplishes the correction of The Cloud Terrace rotor rotational angle.

Do further description in the face of position finding and detection method of the present invention down:

A kind of position finding and detection method of the transmission-type circle grating The Cloud Terrace based on Flame Image Process, concrete steps comprise:

Step 1, choose two blocks of transmission-type Circular glass gratings, one is fixed on the The Cloud Terrace pedestal as indication grating, and another is fixed on the The Cloud Terrace rotor as the scale grating.

Transmission-type Circular glass grating makes it still satisfying the condition that Moire fringe produces in the rotary course relatively mainly in order to cooperate the process that relatively rotates of The Cloud Terrace pedestal and The Cloud Terrace rotor, guarantees dependability and durability.

Step 2, along with the rotation process of The Cloud Terrace rotor, infrared light supply irradiation glass raster, camera utilizes reflection unit that the Moire fringe image between two glass rasters is gathered.

Wherein, infrared light supply is fixed on the The Cloud Terrace rotor, and it is fixing that the position of infrared light supply and target grating keeps.Reflection unit mainly plays the effect to a lateral reflection, and like this, the position of camera needn't be consistent with the incoming position of infrared light supply; Thereby dwindled the volume of The Cloud Terrace; Simultaneously, since the The Cloud Terrace rotor in continuous rotation, like this; The Moire fringe that reflection unit also can produce diverse location accurately, fully reflect away makes the process of taking pictures simpler, reliable.

Step 3, according to formula: Y=0.259R+0.588G+0.124B, the colored Moire fringe image that control system will collect changes into gray level image.

Because the image of gathering is a coloured image,, at first need convert coloured image to gray level image for ease of later image contrast, analysis.According to gray scale formula Y=0.259R+0.588G+0.124B, accomplish the conversion between Red Green Blue and the gray scale.

Step 4, utilize the linear transformation mode gray level image to be carried out the grey level stretching of enhancing contrast ratio.

If the gray scale of piece image concentrates on darker zone, cause the figure kine bias dark, then can stretch between the object gray area, to improve the image lightness with the grey level stretching function; Equally,, when causing the figure kine bias bright, then can come between the compressed objects gray area, to reduce the image lightness with the grey level stretching function if gradation of image concentrates on brighter zone.Adjusted gray level image, contrast obviously strengthens, for the mark and the intercepting of successive image provides convenience.

Step 5, the image after the grey level stretching is converted into black white image.Concrete steps comprise: at first, obtain the maximum gradation value and the minimum gradation value of image after the grey level stretching, be designated as Z respectively _MAXAnd Z _MIN, make initial threshold T _K=(Z _MAX+ Z _MIN)/2; Then, according to threshold value T _KWith image Segmentation is prospect and background, obtains prospect average gray value Z respectively _OWith background average gray value Z _B, calculate the threshold value T that makes new advances _K+1=(Z ₀+ Z _B); At last, repeat above process, with the method for iteration, until T _KConvergence, i.e. T _{K+ 1}=T _K, and press T _KValue is accomplished black white image and is transformed, and accomplishes binarization processing of images.

Step 6, black white image is scanned; Accomplish the wherein mark and the intercepting in a white Moire fringe zone; Calculate the pixel count of white pixel in this single marking fringe area; Utilize sum formula, extrapolate with the relational expression between Moire fringe marked region sum of all pixels and the marked region area A, that is:

$A=n\underset{i\≥T}{\mathrm{\Σ}}{v}_i$

Wherein, n is a total number of image pixels in the single Moire fringe marked region, v _iFor image gray levels is the frequency of the pixel appearance of i; T is a gray threshold.

Because Moire fringe is very dull on background, is the black background and the white Moire fringe of sheet, therefore is easy to obtain through scan method the intercepting and the mark of a Moire fringe.

Step 7, according to the area A of marked region, the rotational angle θ that the definition inverse cosine function calculates The Cloud Terrace accomplishes the accurate demarcation to the The Cloud Terrace turned position,

$\mathrm{\θ}=\arccos \frac{A}{A_{\max }}$

A wherein _MaxBe the maximum area in single white Moire fringe zone, its computing formula is following:

$A_{\max }=n_{\max }\underset{i\≥T}{\mathrm{\Σ}}{v}_i$

N wherein _MaxTotal number of image pixels during for white Moire fringe zone maximum area.

So far, The Cloud Terrace actual rotation angle is calculated at any time, according to this angle, can carry out position compensation to the required rotational angle of The Cloud Terrace, has guaranteed that The Cloud Terrace rotates result's accuracy and reliability, has improved rotation precision greatly.

Claims (3)

1. the transmission-type based on Flame Image Process is justified the grating The Cloud Terrace; Comprise The Cloud Terrace pedestal, The Cloud Terrace rotor and control system; It is characterized in that; Also comprise two transmission-type Circular glass gratings, infrared light supply, lens, reflection unit and cameras, said two transmission-type Circular glass grating pairs should be fixed on The Cloud Terrace pedestal and the The Cloud Terrace rotor; Said lens and infrared light supply are separately fixed on the The Cloud Terrace pedestal, and the infrared light supply scioptics are corresponding with the glass raster on the The Cloud Terrace rotor; Said reflection unit is corresponding to the glass raster below of The Cloud Terrace pedestal; Said camera is corresponding with reflection unit, and the output terminal of camera is connected with control system, and camera and reflection unit are separately fixed on the The Cloud Terrace pedestal.

2. the transmission-type circle grating The Cloud Terrace based on Flame Image Process according to claim 1 is characterized in that said reflection unit is the prism of a 45, and camera is corresponding with the reflecting surface of prism.

3. the position finding and detection method based on the transmission-type circle grating The Cloud Terrace of Flame Image Process is characterized in that, comprising:

A), choose two blocks of transmission-type Circular glass gratings, one is fixed on the The Cloud Terrace pedestal as indication grating, another is fixed on the The Cloud Terrace rotor as the scale grating;

B), along with the rotation of The Cloud Terrace rotor, infrared light supply irradiation glass raster, camera utilizes reflection unit that the Moire fringe image between two glass rasters is gathered;

C), according to formula: Y=0.259R+0.588G+0.124B, the colored Moire fringe image that control system will collect changes into gray level image;

D), utilize the linear transformation mode gray level image to be carried out the grey level stretching of enhancing contrast ratio;

E), the image after the grey level stretching is converted into black white image,

F), black white image is scanned; Completion is to the wherein mark and the intercepting in a white Moire fringe zone; Calculate the pixel count of the white pixel in the single marking fringe area; Utilize sum formula, extrapolate with the relational expression between Moire fringe marked region sum of all pixels and the marked region area A, that is:

$A=n\underset{i\≥T}{\mathrm{\Σ}}{v}_i$

Wherein, n is a total number of image pixels in the single Moire fringe marked region, v _iFor image gray levels is the frequency of the pixel appearance of i, T is a gray threshold;

G), according to the area A of marked region, the rotational angle θ that the definition inverse cosine function calculates The Cloud Terrace accomplishes the accurate demarcation to the The Cloud Terrace turned position,

$\mathrm{\θ}=\arccos \frac{A}{A_{\max }}$

A wherein _MaxThe maximum area in single white Moire fringe zone, its computing formula is following:

$A_{\max }=n_{\max }\underset{i\≥T}{\mathrm{\Σ}}{v}_i$

N wherein _MaxTotal number of image pixels during for white Moire fringe zone maximum area.

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