CN201653554U - Infrared thermogragh calibrating device - Google Patents

Abstract

The utility model discloses an infrared thermogragh calibrating device. The calibrating device is connected with an infrared thermogragh, and comprises an infrared surface radiation source, a rotary driving mechanism, a driving control mechanism, a temperature sensor and a central processor. The calibrating device provides constant and uniform surface radiating infrared rays through rotating the infrared surface radiation source, uses the infrared thermogragh to collect the infrared images and calculate the average measuring value of the pixel corresponding to each image in the infrared thermogragh plane array, uses the temperature sensor to collect the current ambient temperature and calculate the theoretical value of the infrared radiation, and compares the average measuring value and the theoretical value to calculate the calibrating defection value of the traditional infrared thermogragh, thereby calibrating the nonuniform time defect of the infrared thermogragh on line.

Description

The thermal infrared imager means for correcting

Technical field

The utility model relates to the thermal infrared imager alignment technique, more particularly, relates to a kind of thermal infrared imager means for correcting.

Background technology

Along with the high speed development of infrared imagery technique, thermal infrared imager uses more and more in metallurgy industry, and the slag detection system utilizes infrared imagery technique to come following slag situation in the converter tapping process is detected exactly under the converter infrared image.At present, thermal infrared imager all is to adopt un-cooled infrared focal plane array (IRFPA) as photodetector components basically, and it is made up of many pixels, a pixel in the corresponding infrared image of each pixel.And causing the heteropical factor of thermal infrared imager can be divided into two classes: a class is a space heterogeneity factor: owing to form the difference of each pixel on material, size and manufacturing process of infrared focus plane, make its characteristic meeting different, therefore inconsistent to the response characteristic of infrared radiation, thus make thermal imaging system spatially have heterogeneity; Another kind of is time heterogeneity factor: because each pixel of focal plane all is a photoelectric sensor, same pixel is owing to constantly receive the excitation of infrared radiation, As time goes on its response characteristic can create a difference, cause exporting the result and drift about, thereby make thermal imaging system have heterogeneity in time.

At present, bearing calibration at thermal infrared imager mainly is at the heterogeneity problem on the space both at home and abroad, generally all adopt thermal imaging system is carried out the blackbody temperature calibration, promptly before thermal imaging system dispatches from the factory, thermal imaging system is calibrated, thereby drawn each pixel of infrared focus plane response curve and correlation parameter separately by the experiment of standard black matrix.And relatively be short of at the correlation technique of thermal infrared imager heterogeneity problem in time, the on-line correction technology of particularly carrying out in the thermal imaging system use also is in blank at present.Therefore, in the application that measuring accuracy is had relatively high expectations, thermal imaging system is difficult to satisfy actual request for utilization, thereby has directly limited its usable range.

The utility model content

At the above-mentioned shortcoming that exists in the prior art, the purpose of this utility model provides a kind of thermal infrared imager means for correcting, the temporal heterogeneity defective that this means for correcting can the on-line correction thermal infrared imager exists.

For achieving the above object, the utility model adopts following technical scheme:

This thermal infrared imager means for correcting links to each other with thermal infrared imager, comprising: infrared area radiation source, be located at the place ahead of thermal infrared imager camera lens; Rotary drive mechanism, output terminal links to each other with infrared area radiation source; Drive controlling mechanism, output terminal links to each other with rotary drive mechanism; Temperature sensor is located near the infrared area radiation source; Central processing unit, input end links to each other with the output terminal of thermal infrared imager, temperature sensor, and output terminal links to each other with the input end of drive controlling mechanism.

Described rotary drive mechanism comprises reducing motor, and the output shaft of reducing motor links to each other with infrared area radiation source, and is provided with spacing push rod on output shaft.

Described drive controlling mechanism comprises a control circuit, control circuit comprise two be used to control infrared area radiation source position of rotation near switch.

Described infrared area radiation source is circular ferrous metal baffle plate.

In technique scheme, thermal infrared imager means for correcting of the present utility model links to each other with thermal infrared imager, comprise infrared area radiation source, rotary drive mechanism, drive controlling mechanism, temperature sensor and central processing unit, this means for correcting is by rotating infrared area radiation source in order to provide constant uniform infrared surface radiation, by control thermal infrared imager continuous acquisition infrared image and calculate the average measurement value of infrared focal plane array pixel institute respective pixel, gather current environmental temperature and calculate the theoretical value of infrared radiation by temperature sensor, by average measurement value and theoretical value are compared, calculate the correction offset that is used for current thermal infrared imager, thereby realize the existing temporal heterogeneity defective of on-line correction thermal infrared imager.

Description of drawings

Fig. 1 is the structure principle chart of thermal infrared imager means for correcting of the present utility model;

Fig. 2 is control circuit figure of the present utility model.

Embodiment

Further specify the technical solution of the utility model below in conjunction with drawings and Examples.

See also shown in Figure 1, thermal infrared imager means for correcting of the present utility model links to each other with thermal infrared imager 8, comprise: infrared area radiation source 1, rotary drive mechanism, drive controlling mechanism, temperature sensor 6 and central processing unit 7, infrared area radiation source 1 is located at the place ahead of thermal infrared imager 8 camera lenses; Rotary drive mechanism, output terminal links to each other with infrared area radiation source 1; Drive controlling mechanism, output terminal links to each other with rotary drive mechanism; Temperature sensor 6 is located near the infrared area radiation source 1; Central processing unit 7, input end links to each other with the output terminal of thermal infrared imager 8, temperature sensor 6, and output terminal links to each other with the input end of drive controlling mechanism.Wherein, drive controlling mechanism comprises reducing motor 3, and the output shaft of reducing motor 3 links to each other with infrared area radiation source 1, and is provided with spacing push rod 2 on output shaft, and this spacing push rod 2 is selected the magnetic metal material for use, is used to trigger limit switch; Please in conjunction with shown in Figure 2, drive controlling mechanism comprises a control circuit 5, this control circuit 5 comprise two be used to control infrared area radiation source 1 position of rotation near switch 4, respectively with near switch 4 mutually and the diode D1, the D2 that connect, A among Fig. 2, B termination power supply (providing) by central processing unit 7, control the switch of reducing motor 3 by the position of responding to spacing push rod 2 near switch 4, thereby control the position of rotation of infrared area radiation source 1.This infrared area radiation source 1 can be selected a circular ferrous metal baffle plate for use, as a constant infrared area radiation source 1, in trimming process, provide constant and uniform infrared radiation for thermal imaging system, be installed on the axle of reducing motor 3, when starting, reducing motor 3 can drive the baffle plate rotation, sheltering from thermal infrared imager 8 camera lenses for closed, is the on-line correction state, is opened for the state that works online of thermal infrared imager 8.The temperature that temperature sensor 6 measures is the environment temperature at infrared area radiation source 1 place, the temperature of just infrared area radiation source 1.Central processing unit 7 mainly is to be made of the computing machine that data collecting card, image pick-up card, control card are housed, be used for automatic control to rotary drive mechanism, and the heat picture and the temperature signal that receive thermal infrared imager 8 and temperature sensor 6 collections, and signal handled, finish calculating and analytical work to thermal infrared imager 8 temporal Nonuniformity Corrections.

Below, in conjunction with Fig. 1, Fig. 2, the principle of work of this means for correcting is illustrated:

Thermal infrared imager 8 among Fig. 1 is used under the converter slag and detects, and the heterogeneity defective of this thermal infrared imager 8 in use for some time can time of origin needs timing, adopts following steps to proofread and correct:

1, starts by central processing unit 7 control reducing motors 3 earlier, drive the camera lens that infrared area radiation source is changeed and blocked thermal infrared imager 8 for 1 time, provide constant uniform infrared surface radiation for thermal infrared imager 8;

2, control thermal infrared imager 8 continuous acquisition N frame infrared images;

3, adopt temperature sensor 6 to gather the environment temperature at current radiation source place;

4, by computing machine according to N frame infrared image, calculate the average measurement value of each pixel institute respective pixel of infrared focal plane array;

5, calculate the theoretical value of the pairing gradation of image of current infrared radiation according to the survey environment temperature;

6, the time offset that calculates current each pixel of infra-red thermal imaging instrument according to the average measurement value and the theoretical value of pixel grey scale, and proofread and correct according to side-play amount;

7, change on the infrared area radiation source 1 of control, finish correction, thermal infrared imager 8 can be proceeded slag detection under the converter.

Need to prove that at this in step 1, the purpose of closing infrared area radiation source 1 is to provide an infrared surface radiation of constant uniform to thermal infrared imager 8, guarantee that as far as possible the infrared radiation that each pixel of infrared focal plane array is received equates;

In step 2, the infrared chart that collects similarly is a gray level image, and the size of gray-scale value has reflected the height of testee temperature, and gray shade scale is by the precision decision of thermal imaging system and image collecting device, gathering the N two field picture is in order to prevent the influence of undesired signal to picture quality, to improve stability;

In step 3, the temperature that measures is the temperature of infrared area radiation source 1 place environment, the temperature of just infrared area radiation source 1, because infrared radiation and temperature are directly related, in order to obtain infrared intensity accurately, must know the temperature of current radiation source, and be revised;

In step 4, calculate the average measurement value of each pixel institute respective pixel of focal plane arrays (FPA) according to the N frame infrared picture data that collects, adopt formula $\stackrel{\‾}{x(i,j)}=\frac{\underset{k=1}{\overset{N}{\mathrm{\Σ}}}{x}_k(i,j)}{N}$ Calculate x in the formula _k(i, j) be k two field picture pixel (i, gray-scale value j),

For the focal plane arrays (FPA) pixel (i, measurement average j) is actual measured value, N is measured number of image frames;

In step 5, computing machine is calculated the gradation of image theoretical value of thermal imaging system to this infrared radiation response according to the relation between thermal infrared imager gradation of image value and the testee temperature value with counter the pushing off of the source temperature that measures;

In step 6, after measured value that obtains each pixel of infrared focal plane array and theoretical value, by relatively calculating the time offset of current each pixel, just heterogeneity is in time passed through formula $\mathrm{\Δx}(i,j)=x^{\′}-\stackrel{\‾}{x(i,j)}$ Calculate, x ' is the gray scale theoretical value of thermal imaging system to constant radiation source response in the formula, Be that ((i j) is focal plane arrays (FPA) pixel (i, time heterogeneity correction j) to Δ x to the focal plane arrays (FPA) pixel for i, actual measured value j).

Those of ordinary skill in the art will be appreciated that, above embodiment is used for illustrating the utility model, and be not to be used as qualification of the present utility model, as long as in connotation scope of the present utility model, all will drop in claims scope of the present utility model variation, the modification of the above embodiment.

Claims (4)

1. a thermal infrared imager means for correcting links to each other with thermal infrared imager, it is characterized in that:

This means for correcting comprises:

Infrared area radiation source is located at the place ahead of thermal infrared imager camera lens;

Rotary drive mechanism, output terminal links to each other with infrared area radiation source;

Drive controlling mechanism, output terminal links to each other with rotary drive mechanism;

Temperature sensor is located near the infrared area radiation source;

Central processing unit, input end links to each other with the output terminal of thermal infrared imager, temperature sensor, and output terminal links to each other with the input end of drive controlling mechanism.

2. thermal infrared imager means for correcting as claimed in claim 1 is characterized in that:

Described rotary drive mechanism comprises reducing motor, and the output shaft of reducing motor links to each other with infrared area radiation source, and is provided with spacing push rod on output shaft.

3. thermal infrared imager means for correcting as claimed in claim 1 is characterized in that:

Described drive controlling mechanism comprises a control circuit, control circuit comprise two be used to control infrared area radiation source position of rotation near switch.

4. thermal infrared imager means for correcting as claimed in claim 1 is characterized in that:

Described infrared area radiation source is circular ferrous metal baffle plate.

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