阅读说明：本技术 一种机械光圈的加权控制方法 (Weighting control method for mechanical aperture ) 是由 杨社教 李学均 吕军锋 刘凯 乔如 王淑婷 刘永 陈永发 冯颖台 索学锋 路远 于 2020-12-03 设计创作，主要内容包括：本发明提供一种机械光圈的加权控制方法,该加权控制方法首先设定亮度的合理区间,确定合理区间亮度的上边界值和下边界值；然后执行以下步骤：取当前图像亮度与设置值域比较；根据比较结果,判断当前亮度所在的区间范围；判断选择当前应该使用的基本脉冲调整单位,选定基本脉冲调整单位的两个参数t-H和t-L,确定此次调整应该使用的基本脉冲调整单位的个数N；根据选定的加权控制系数组Kp(t-H,t-L,N),驱动光圈扩大或者关小；反复执行此步骤,实时调整光圈控制,直至视频图像的亮度合适、清晰、稳定。可以有效的解决现有技术在进行机械光圈控制时,出现的光圈调节缓慢、不实时,光圈过调节造成图像亮度忽明忽暗的问题。(The invention provides a weighting control method of a mechanical aperture, which comprises the steps of firstly setting a reasonable interval of brightness, and determining an upper boundary value and a lower boundary value of the brightness of the reasonable interval; the following steps are then performed: comparing the brightness of the current image with a set value range; judging the interval range of the current brightness according to the comparison result; judging and selecting the basic pulse adjusting unit to be used currently, and selecting two parameters t of the basic pulse adjusting unit H And t L Determining the number N of basic pulse adjustment units to be used in the adjustment; according to the selected weighting control coefficient group Kp (t) H ，t L N), driving the aperture to expand or close; and repeatedly executing the step, and adjusting the aperture control in real time until the brightness of the video image is proper, clear and stable. The method can effectively solve the problems that in the prior art, when mechanical aperture control is carried out, the aperture is slowly adjusted and is not real-time, and the aperture is over-adjusted to cause the brightness of an image to be suddenly changedThe problem of darkness is neglected.)

1. A method for controlling the weighting of a mechanical aperture, comprising the steps of:

s001, presetting a target brightness value range;

s002, dividing the region outside the target brightness value range into a plurality of sub-regions;

s003, giving each subregion a weighting coefficient group;

s004, obtaining the brightness of the currently shot image, judging whether the brightness of the image falls into a target brightness value range, and if so, keeping the opening of the mechanical aperture unchanged; if not, searching the sub-region to which the image brightness belongs and the corresponding sub-region weighting coefficient group, transmitting the sub-region weighting coefficient group to the motor by the processor, and driving the mechanical aperture to expand or contract by the motor according to the sub-region weighting coefficient group;

and S005, repeatedly executing the step S004 until the brightness of the currently shot image falls into the target brightness value range.

2. The method for controlling weighting of a mechanical aperture according to claim 1, wherein the step S001 of presetting the target brightness value range specifically comprises the following steps:

setting target brightness value ranges from Sv1 to Sv 2;

where Sv1 is the lower boundary luminance setting value, Sv2 is the upper boundary luminance setting value, and Sv1 > Sv 2.

3. The method for controlling the weighting of the mechanical aperture as claimed in claim 2, wherein the step S002 of dividing the region outside the target luminance value range into a plurality of sub-regions specifically comprises the following steps:

taking an area with the brightness value greater than Sv1 as a darker area, dividing the darker area into m sub-areas, sequentially marking the critical values of the sub-areas by taking Sv1 as a starting point as Sv1i, wherein i is 1 and 2 … … m, the value of Sv1i is positively correlated with the value of i, and each sub-area is endowed with a corresponding weighting coefficient which is marked as K1i, i is 1 and 2 … … m;

the area with the brightness value < Sv2 is taken as a highlight area, the highlight area is divided into n sub-areas, the critical values of the sub-areas are marked in sequence by taking Sv2 as a starting point, are Sv2i, i is 1 and 2 … … n, wherein Sv2i and i are in negative correlation, and each sub-area is assigned with a corresponding weighting coefficient, which is denoted as K2i, i is 1 and 2 … … n.

4. The method for controlling weighting of a mechanical aperture according to claim 3, wherein the step S003 of assigning a weighting factor group to each sub-area specifically comprises the following steps:

each weighting coefficient K1i and each weighting coefficient K2i are correspondingly provided with a high level time t_HTime t of low level_LAnd the pulse number N, forming a subregion weighting coefficient group Kp (t)_H，t_L，N)。

5. The method for controlling weighting of a mechanical aperture according to claim 4, wherein step S004 is executed to obtain the brightness of the currently photographed image, determine whether the brightness of the image falls within a target brightness range, and if so, keep the opening of the mechanical aperture unchanged; if not, searching the sub-region to which the image brightness belongs and the corresponding sub-region weighting coefficient group, transmitting the sub-region weighting coefficient group to a motor by a processor, and driving the mechanical aperture to expand or contract by the motor according to the sub-region weighting coefficient group, wherein the specific steps are as follows:

s401, acquiring a brightness value L of a currently shot image through a photosensitive element;

s402, judging that the brightness value of the image falls into a target brightness value range, namely that Sv2 is more than or equal to L is more than or equal to Sv1, keeping the opening of the mechanical aperture unchanged, and otherwise executing S403 or S404;

s403, if the image brightness value is in a dark area, namely L is greater than Sv1, continuing comparison, confirming a sub-area in the dark area where the image brightness value L is located, then calling a weighting coefficient K1i corresponding to the sub-area, and then calling a sub-area weighting coefficient group Kp (t) corresponding to the weighting coefficient K1i_H，t_LN), the processor transmits the weighting coefficient group to the motor, the motor drives the mechanical aperture to expand, the brightness value of the image is collected again, the step is repeatedly executed until the brightness of the currently shot image falls into a target brightness value range, namely Sv2 is not less than L and not more than Sv1, and the brightness of the image is kept stable;

s404, if the image brightness value is in a bright area, namely L is less than Sv2, continuing comparison, and confirming a sub-area in the bright area where the image brightness value L isThen, the weighting coefficient K2i corresponding to the sub-region is called, and then the sub-region weighting coefficient group Kp (t) corresponding to the weighting coefficient K2i is called_H，t_LAnd N), the processor transmits the weighting coefficient group to the motor, the motor drives the mechanical aperture to be reduced, the image brightness value is collected again, the step is repeatedly executed until the brightness of the current shot image falls into a target brightness value range, namely Sv2 is not less than L and not more than Sv1, and the brightness of the image is kept stable.

6. The method of weighting control of a mechanical iris according to claim 5, further comprising the step S006. modifying the subregion weight coefficient set Kp (t)_H，t_LN), including the following:

if the mechanical diaphragm is adjusted in a mode that the environment is too bright and the size is small, calling a subregion weighting coefficient K1i recorded at the X-th time, reducing K1i if an overshoot phenomenon occurs in the process of adjusting the image brightness by using K1i, otherwise increasing K1i, and recording the K1i value at the moment as a subregion weighting coefficient K1i called at the X + 1-th time, wherein X is a positive integer larger than or equal to 0;

alternatively, the first and second electrodes may be,

if the mechanical diaphragm is adjusted in an excessively dark environment, the sub-region weighting coefficient K2i recorded at the X-th time is called, if an overshoot phenomenon occurs in the process of adjusting the image brightness by using K2i, K2i is reduced, otherwise, K2i is increased, and the value of K2i at the moment is recorded as the sub-region weighting coefficient K2i called at the X + 1-th time, wherein X is a positive integer larger than or equal to 0.

Technical Field

The invention belongs to the field of aviation onboard camera aperture control, and particularly relates to a weighting control method for a mechanical aperture.

Background

The mechanical aperture of the camera is a device for controlling the illumination flux entering the camera lens, and in some occasions with large illumination change, the electronic shutter can not obtain normal images, and the size of the mechanical aperture needs to be adjusted at any time according to the illumination intensity.

The existing mechanical aperture control of a camera usually adopts an image brightness reference point, the average brightness of the current video image is collected and then compared with the brightness reference point, and if the average brightness is higher than the reference point, the mechanical aperture is closed; if the average brightness is below the reference point, the mechanical aperture is opened up. The method is simple and quick, but for the aperture control near the reference point, the aperture jitter phenomenon exists, and the aperture jitter phenomenon is difficult to stabilize all the time, so that the video image has the phenomenon of brightness flickering near the reference point. If the phenomenon of image flickering is to be reduced, the control force of the aperture can be reduced, but the aperture is controlled in a non-real time manner.

Publication No. CN106973223A proposes a control strategy using proportional-integral-derivative to control the aperture. However, for the use scenes with severe changes of the external extremely bright environment and the extremely dark environment, the mutual reference and correction functions of the integral and differential control algorithms are not large, so that the calculation amount of the whole control process is greatly increased, and the control is easy to lose the real-time property.

Although the existing mechanical diaphragm control is debugged under a certain condition to reach a stable state, the friction force of transmission machinery is changed due to the influence of temperature or long-time work and the like, the problem that the originally set parameters are not suitable exists, and the phenomenon of light and shade flicker also occurs.

Disclosure of Invention

An object of an embodiment of the present invention is to provide a method for controlling weighting of a mechanical aperture, so as to overcome the above technical drawbacks.

In order to solve the technical problem, the invention provides a weighting control method of a mechanical aperture, which comprises the following steps:

s001, presetting a target brightness value range;

s002, dividing the region outside the target brightness value range into a plurality of sub-regions;

s003, giving each subregion a weighting coefficient group;

s004, obtaining the brightness of the currently shot image, judging whether the brightness of the image falls into a target brightness value range, and if so, keeping the opening of the mechanical aperture unchanged; if not, searching the sub-region to which the image brightness belongs and the corresponding sub-region weighting coefficient group, transmitting the sub-region weighting coefficient group to the motor by the processor, and driving the mechanical aperture to expand or contract by the motor according to the sub-region weighting coefficient group;

and S005, repeatedly executing the step S004 until the brightness of the currently shot image falls into the target brightness value range.

Further, the step S001 of presetting the target brightness value range specifically includes the following steps:

setting target brightness value ranges from Sv1 to Sv 2;

where Sv1 is the lower boundary luminance setting value, Sv2 is the upper boundary luminance setting value, and Sv1 > Sv 2.

Further, in step S002, dividing the region outside the target luminance value range into a plurality of sub-regions specifically includes the following steps:

taking an area with the brightness value greater than Sv1 as a darker area, dividing the darker area into m sub-areas, sequentially marking the critical values of the sub-areas by taking Sv1 as a starting point as Sv1i, wherein i is 1 and 2 … … m, the value of Sv1i is positively correlated with the value of i, and each sub-area is endowed with a corresponding weighting coefficient which is marked as K1i, i is 1 and 2 … … m;

the area with the brightness value < Sv2 is taken as a highlight area, the highlight area is divided into n sub-areas, the critical values of the sub-areas are marked in sequence by taking Sv2 as a starting point, are Sv2i, i is 1 and 2 … … n, wherein Sv2i and i are in negative correlation, and each sub-area is assigned with a corresponding weighting coefficient, which is denoted as K2i, i is 1 and 2 … … n.

Preferably, the step S003 of giving each sub-region a weighting coefficient group specifically includes the following steps:

each weighting coefficient K1i and each weighting coefficient K2i are correspondingly provided with a high level time t_HTime t of low level_LAnd the pulse number N, forming a subregion weighting coefficient group Kp (t)_H，t_L，N)。

Further, in step S004, the brightness of the currently photographed image is obtained, whether the brightness of the image falls into the target brightness value range is determined, and if yes, the opening of the mechanical aperture is kept unchanged; if not, searching the sub-region to which the image brightness belongs and the corresponding sub-region weighting coefficient group, transmitting the sub-region weighting coefficient group to a motor by a processor, and driving the mechanical aperture to expand or contract by the motor according to the sub-region weighting coefficient group, wherein the specific steps are as follows:

s401, acquiring a brightness value L of a currently shot image through a photosensitive element;

s402, judging that the brightness value of the image falls into a target brightness value range, namely that Sv2 is more than or equal to L is more than or equal to Sv1, keeping the opening of the mechanical aperture unchanged, and otherwise executing S403 or S404;

s403, if the image brightness value is in a dark area, namely L is greater than Sv1, continuing comparison, confirming a sub-area in the dark area where the image brightness value L is located, then calling a weighting coefficient K1i corresponding to the sub-area, and then calling a sub-area weighting coefficient group Kp (t) corresponding to the weighting coefficient K1i_H，t_LN), the processor transmits the weighting coefficient group to the motor, the motor drives the mechanical aperture to expand, the brightness value of the image is collected again, and the step is repeatedly executed until the brightness of the currently shot image falls into a target brightness value range, namely that Sv2 is not less than L and not more than Sv1 maintains the brightness stability of the image;

s404, if the image brightness value is in a bright area, namely L is less than Sv2, continuing comparison, confirming a sub-area in the bright area where the image brightness value L is located, then calling a weighting coefficient K2i corresponding to the sub-area, and then calling a sub-area weighting coefficient group Kp (t) corresponding to the weighting coefficient K2i_H，t_LAnd N), the processor transmits the weighting coefficient group to the motor, the motor drives the mechanical aperture to be reduced, the image brightness value is collected again, and the step is repeatedly executed until the brightness of the currently shot image falls into a target brightness value range, namely that Sv2 is not less than L and not more than Sv1 maintains the image brightness to be stable.

Further, the weighting control method of the mechanical diaphragm also comprises the step S006. the sub-region weighting coefficient group Kp (t) is corrected_H，t_LN), including the following:

if the mechanical diaphragm is adjusted in a mode that the environment is too bright and the size is small, calling a subregion weighting coefficient K1i recorded at the X-th time, reducing K1i if an overshoot phenomenon occurs in the process of adjusting the image brightness by using K1i, otherwise increasing K1i, and recording the K1i value at the moment as a subregion weighting coefficient K1i called at the X + 1-th time, wherein X is a positive integer larger than or equal to 0;

alternatively, the first and second electrodes may be,

if the mechanical diaphragm is adjusted in an excessively dark environment, the sub-region weighting coefficient K2i recorded at the X-th time is called, if an overshoot phenomenon occurs in the process of adjusting the image brightness by using K2i, K2i is reduced, otherwise, K2i is increased, and the value of K2i at the moment is recorded as the sub-region weighting coefficient K2i called at the X + 1-th time, wherein X is a positive integer larger than or equal to 0.

The invention has the following beneficial effects:

according to the invention, by setting a reasonable brightness interval and controlling the brightness in different ranges by adopting different weighting coefficients, the problems that the aperture is slowly adjusted and is not real-time and the image brightness is dim and bright due to the over-adjustment of the aperture in the prior art when the mechanical aperture control is carried out can be effectively solved.

In order to make the aforementioned and other objects of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

Fig. 1 is a flowchart of a method of weighting control of a mechanical aperture.

Fig. 2 is a diagram of a target luminance range.

Fig. 3 is a weighting coefficient setting diagram for a dark ambient brightness area.

Fig. 4 is a weighting coefficient setting diagram of an ambient brightness highlight region.

FIG. 5 is a waveform diagram of a mechanical iris drive basic pulse;

FIG. 6 is a mechanical aperture drive PWM waveform diagram;

fig. 7 is a flowchart of the calling of the sub-region weighting coefficient group Kp.

Detailed Description

The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will become apparent to those skilled in the art from the present disclosure.

In the present invention, the upper, lower, left, and right in the drawings are regarded as the upper, lower, left, and right of the weighting control method for the mechanical aperture described in the present specification.

The exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, however, the present invention may be embodied in many different forms and is not limited to the embodiments described herein, which are provided for complete and complete disclosure of the present invention and to fully convey the scope of the present invention to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the accompanying drawings is not intended to be limiting of the invention. In the drawings, the same units/elements are denoted by the same reference numerals.

Unless otherwise defined, terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Further, it will be understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense.

The first embodiment:

the embodiment relates to a method for controlling the weighting of a mechanical aperture, comprising the steps of:

s001, presetting a target brightness value range;

s002, dividing the region outside the target brightness value range into a plurality of sub-regions;

s003, giving each subregion a weighting coefficient group;

s004, obtaining the brightness of the currently shot image, judging whether the brightness of the image falls into a target brightness value range, and if so, keeping the opening of the mechanical aperture unchanged; if not, searching the sub-region to which the image brightness belongs and the corresponding sub-region weighting coefficient group, transmitting the sub-region weighting coefficient group to the motor by the processor, and driving the mechanical aperture to expand or contract by the motor according to the sub-region weighting coefficient group;

and S005, repeatedly executing the step S004 until the brightness of the currently shot image falls into the target brightness value range.

Specifically, referring to fig. 1, after the camera is powered on, initialization is performed first; then closing an electronic shutter of the camera; then, collecting the video brightness signal, sending the video brightness signal to an A/D conversion module for conversion, comparing the converted current brightness information with a target brightness value range, and judging whether the image brightness is too bright or too dark, specifically as follows:

judging whether the image brightness falls into a target brightness value range, if so, keeping the opening of the mechanical aperture unchanged; if not, searching the sub-region to which the image brightness belongs and the corresponding sub-region weighting coefficient group, transmitting the sub-region weighting coefficient group to the motor by the processor, and driving the mechanical aperture to expand or contract by the motor according to the sub-region weighting coefficient group.

According to the invention, by setting a reasonable brightness interval and controlling the brightness in different ranges by adopting different weighting coefficients, the problems that the aperture is slowly adjusted and is not real-time and the image brightness is dim and bright due to the over-adjustment of the aperture in the prior art when the mechanical aperture control is carried out can be effectively solved.

Second embodiment:

the embodiment relates to a method for controlling the weighting of a mechanical aperture, comprising the steps of:

s001, presetting a target brightness value range, which specifically comprises the following steps:

setting target brightness value ranges from Sv1 to Sv 2;

where Sv1 is the lower boundary luminance setting value, see fig. 2, Sv2 is the upper boundary luminance setting value.

Sv1 > Sv2 because the darker the image brightness, the greater the value of Sv.

The above Sv1 and Sv2 are set according to actual image needs, and their values are not unique or fixed.

Fig. 2 shows the target luminance value range:

when the image brightness changes from bright to dark, the image brightness is not adjusted as long as the image brightness reaches the upper boundary set value Sv2, the motor does not stop immediately due to inertia of the motor and continues to rotate, and the aperture can be continuously closed as long as the image brightness does not exceed the set lower boundary set value Sv 1.

When the image brightness changes from dark to bright, the adjustment is not carried out as long as the image brightness reaches the lower boundary set value Sv1, the motor does not stop immediately due to inertia of the motor, the motor can still rotate, the aperture can still be opened continuously, and the image brightness can be changed to be larger as long as the image brightness does not exceed the set upper boundary set value Sv 2.

In the actual diaphragm control, the arrangement of the Sv1 and the Sv2 not only ensures the stability of the diaphragm control, but also ensures that when the images are within the brightness range of the Sv1 and the Sv2, the visual interpretation has no obvious brightness and shade difference, and the subsequent image processing is not influenced.

S002, dividing the region outside the target brightness value domain into a plurality of sub-regions, and specifically comprising the following steps:

as shown in fig. 3, a region with a brightness value > Sv1 is taken as a dark region, the dark region is divided into m sub-regions, the critical values of the sub-regions are marked in sequence by using Sv1 as a starting point, which are Sv1i, i is 1 and 2 … … m, wherein Sv1i value is positively correlated with i value, and each sub-region is assigned with a corresponding weighting coefficient, which is K1i, i is 1 and 2 … … m;

as shown in fig. 4, a region having a luminance value < Sv2 is defined as a highlight region, the highlight region is divided into n sub-regions, threshold values of the sub-regions are Sv2i and i is 1 and 2 … … n, where Sv2i is negatively correlated with i, and a corresponding weighting coefficient is assigned to each sub-region and is denoted as K2i, i is 1 and 2 … … n, with Sv2 being a starting point.

The aperture control is real-time sampling control, calculates the control quantity according to the brightness deviation value at the sampling moment, and adopts a numerical calculation method to carry out successive approximation; in the aperture control, the partial brightness range of the upper boundary setting value of the ambient brightness is divided into m areas, and each area adopts a proportional control coefficient K1 i; the dark range of the lower boundary setting value of the ambient brightness is divided into n regions, and each region employs a proportional control coefficient K2 i.

The proportional control coefficients are weighting coefficients, the force required by the mechanical diaphragm to open and the force required by the mechanical diaphragm to close are not necessarily the same, and the weighting control coefficients K1i and K2i are set according to the respective requirements.

In the aperture control, the more the brightness area is divided, the more the control is accurate, the more the weighting control coefficient is set, the larger the calculated amount is, the proportional control coefficient is obtained according to the product requirement and the actual test, and the intelligent correction is carried out according to the actual situation.

S003, endowing each sub-area with a weighting coefficient group, which specifically comprises the following steps:

each weighting coefficient K1i and each weighting coefficient K2i are correspondingly provided with a high level time t_HTime t of low level_LAnd the pulse number N, forming a subregion weighting coefficient group Kp (t)_H，t_LN), specifically as follows:

referring to fig. 5, in the aperture control, a basic pwm (pulse width modulation) waveform is used as a minimum adjustment unit, and the high level time t can be changed in different brightness regions_HAnd time t of low level_LUsing different minimum pulse waveform adjusting units;

referring to fig. 6, in driving the diaphragm, the high level time t of different basic pulse adjustment units is used in different brightness setting value ranges by driving using the pulse width modulation waveform set_HAnd time t of low level_LAnd using different numbers of basic pulses N1 × t1, … Ni × ti, … Ns × ts, the whole driving process is completed by a series of pulse width modulation waveform groups, wherein N1 × t1 represents the adjustment time of the first group of pulse width modulation waveform groups, Ni × ti represents the adjustment time of the ith group of pulse width modulation waveform groups, and Ns × ts represents the adjustment time of the ith group of pulse width modulation waveform groups.

The total adjustment time T is expressed as:

as shown in fig. 1, after the camera is powered on, initialization is performed first; then closing an electronic shutter of the camera; and then collecting video brightness signals, sending the video brightness signals to an A/D conversion module for conversion, comparing the converted current brightness information with a target brightness value range, judging whether the image brightness is too bright or too dark, comparing the image brightness with the previous brightness information, and determining the area where the image brightness is located. If the image brightness is far from the brightness setting value range, selecting a weighting coefficient group Kp with a larger value, if the image brightness is near to the brightness setting value range, selecting a weighting coefficient group Kp with a smaller value, sending the weighting coefficient group to a function of the driving motor, and outputting a PWM waveform rotating by the driving motor until the image brightness is adjusted to the setting value range.

S004, obtaining the brightness of the currently shot image, judging whether the brightness of the image falls into a target brightness value range, and if so, keeping the opening of the mechanical aperture unchanged; if not, searching the sub-region to which the image brightness belongs and the corresponding sub-region weighting coefficient group, transmitting the sub-region weighting coefficient group to a motor by a processor, and driving the mechanical aperture to expand or contract by the motor according to the sub-region weighting coefficient group, wherein the specific steps are as follows:

s401, acquiring a brightness value L of a currently shot image through a photosensitive element;

s402, judging that the brightness value of the image falls into a target brightness value range, namely that Sv2 is more than or equal to L is more than or equal to Sv1, keeping the opening of the mechanical aperture unchanged, and otherwise executing S403 or S404;

s403, if the image brightness value is in a dark area, namely L is greater than Sv1, continuing comparison, confirming a sub-area in the dark area where the image brightness value L is located, then calling a weighting coefficient K1i corresponding to the sub-area, and then calling a sub-area weighting coefficient group Kp (t) corresponding to the weighting coefficient K1i_H，t_LN), the processor transmits the weighting coefficient group to the motor, the motor drives the mechanical aperture to expand, the brightness value of the image is collected again, and the step is repeatedly executed until the brightness of the currently shot image falls into a target brightness value range, namely that Sv2 is not less than L and not more than Sv1 maintains the brightness stability of the image;

s404, if the image brightness value is in a bright area, namely L is less than Sv2, continuing comparison, confirming a sub-area in the bright area where the image brightness value L is located, then calling a weighting coefficient K2i corresponding to the sub-area, and then calling a sub-area weighting coefficient group Kp (t) corresponding to the weighting coefficient K2i_H，t_LN), the processor transmits the weighting coefficient group to the motor, the motor drives the mechanical aperture to be reduced, the brightness value of the image is collected again, and the method is repeatedly executedAnd step (3) until the brightness of the currently shot image falls into a target brightness value range, namely that Sv2 is not less than L and not more than Sv1 maintains the stability of the image brightness.

The steps of the flow chart using the set of weighting control coefficients Kp are shown in fig. 7:

step S101, comparing the current image brightness with a target brightness value range, and starting the current aperture control adjustment according to the comparison result;

step S102, judging the current brightness in which interval range of the figure 3 or the figure 4 is according to the comparison result;

step S103, judging and selecting the basic pulse adjusting unit which should be used currently according to the interval range of the current brightness, and selecting two parameters t of the basic pulse adjusting unit_HAnd t_L；

t_HThe larger the initial driving force for driving the aperture, and the smaller the initial driving force for driving the aperture;

step S104, determining the number N of basic pulse adjusting units to be used in the current adjustment according to the interval range of the current brightness, wherein the more the number N is, the faster the rotating speed of the aperture is, and otherwise, the smaller the rotating speed is;

step S105, selecting a weighting control coefficient group Kp (t) according to S103 and S104_H，t_LN), driving the aperture to expand or close;

in step S106, the single-use weighting control coefficient group driving the aperture ends.

The adjustment of the camera iris control is returned to the state of the sampled video luminance value of fig. 1, and the next adjustment is performed.

And S005, repeatedly executing the step S004 until the brightness of the currently shot image falls into the target brightness value range.

The third embodiment:

the embodiment provides a weighting control method of a mechanical aperture, which comprises the following steps:

s001, presetting a target brightness value range, which specifically comprises the following steps:

setting target brightness value ranges from Sv1 to Sv 2;

where Sv1 is the lower boundary luminance setting value, Sv2 is the upper boundary luminance setting value, and Sv1 > Sv 2.

S002, dividing the region outside the target brightness value domain into a plurality of sub-regions, and specifically comprising the following steps:

taking an area with the brightness value greater than Sv1 as a darker area, dividing the darker area into m sub-areas, sequentially marking the critical values of the sub-areas by taking Sv1 as a starting point as Sv1i, wherein i is 1 and 2 … … m, the value of Sv1i is positively correlated with the value of i, and each sub-area is endowed with a corresponding weighting coefficient which is marked as K1i, i is 1 and 2 … … m;

the area with the brightness value < Sv2 is taken as a highlight area, the highlight area is divided into n sub-areas, the critical values of the sub-areas are marked in sequence by taking Sv2 as a starting point, are Sv2i, i is 1 and 2 … … n, wherein Sv2i and i are in negative correlation, and each sub-area is assigned with a corresponding weighting coefficient, which is denoted as K2i, i is 1 and 2 … … n.

S003, endowing each sub-area with a weighting coefficient group, which specifically comprises the following steps:

each weighting coefficient K1i and each weighting coefficient K2i are correspondingly provided with a high level time t_HTime t of low level_LAnd the pulse number N, forming a subregion weighting coefficient group Kp (t)_H，t_L，N)。

S004, obtaining the brightness of the currently shot image, judging whether the brightness of the image falls into a target brightness value range, and if so, keeping the opening of the mechanical aperture unchanged; if not, searching the sub-region to which the image brightness belongs and the corresponding sub-region weighting coefficient group, transmitting the sub-region weighting coefficient group to a motor by a processor, and driving the mechanical aperture to expand or contract by the motor according to the sub-region weighting coefficient group, wherein the specific steps are as follows:

s401, acquiring a brightness value L of a currently shot image through a photosensitive element;

s402, judging that the brightness value of the image falls into a target brightness value range, namely that Sv2 is more than or equal to L is more than or equal to Sv1, keeping the opening of the mechanical aperture unchanged, and otherwise executing S403 or S404;

s403, if the image brightness value is in a dark area, namely L is more than Sv1, continuing comparison, confirming a sub-area in the dark area where the image brightness value L is located, then calling a weighting coefficient K1i corresponding to the sub-area, and then calling the weighting coefficient K1i corresponding to the sub-areaThe sub-region weighting coefficient group Kp (t) corresponding to the weighting coefficient K1i is retrieved_H，t_LN), the processor transmits the weighting coefficient group to the motor, the motor drives the mechanical aperture to expand, the brightness value of the image is collected again, and the step is repeatedly executed until the brightness of the currently shot image falls into a target brightness value range, namely that Sv2 is not less than L and not more than Sv1 maintains the brightness stability of the image;

s404, if the image brightness value is in a bright area, namely L is less than Sv2, continuing comparison, confirming a sub-area in the bright area where the image brightness value L is located, then calling a weighting coefficient K2i corresponding to the sub-area, and then calling a sub-area weighting coefficient group Kp (t) corresponding to the weighting coefficient K2i_H，t_LAnd N), the processor transmits the weighting coefficient group to the motor, the motor drives the mechanical aperture to be reduced, the image brightness value is collected again, and the step is repeatedly executed until the brightness of the currently shot image falls into a target brightness value range, namely that Sv2 is not less than L and not more than Sv1 maintains the image brightness to be stable.

And S005, repeatedly executing the step S004 until the brightness of the currently shot image falls into the target brightness value range.

Step S006, modifying the subregion weighting coefficient group Kp (t)_H，t_LN), including the following:

if the mechanical diaphragm is adjusted in a mode that the environment is too bright and the size is small, calling a subregion weighting coefficient K1i recorded at the X-th time, reducing K1i if an overshoot phenomenon occurs in the process of adjusting the image brightness by using K1i, otherwise increasing K1i, and recording the K1i value at the moment as a subregion weighting coefficient K1i called at the X + 1-th time, wherein X is a positive integer larger than or equal to 0;

alternatively, the first and second electrodes may be,

if the mechanical diaphragm is adjusted in an excessively dark environment, the sub-region weighting coefficient K2i recorded at the X-th time is called, if an overshoot phenomenon occurs in the process of adjusting the image brightness by using K2i, K2i is reduced, otherwise, K2i is increased, and the value of K2i at the moment is recorded as the sub-region weighting coefficient K2i called at the X + 1-th time, wherein X is a positive integer larger than or equal to 0.

And driving the aperture to be enlarged or reduced by using the weighting control coefficient group for multiple times until the image brightness of the whole camera is stabilized within a range of a reasonable interval.

During adjustment, if the difference value between the brightness of the current image and the reasonable interval is large, a relatively large weighting control coefficient group Kp is used, the speed of enlarging and reducing the aperture is ensured, and the real-time performance of the whole aperture control adjustment process is ensured; if the difference value between the brightness of the current image and the reasonable interval is small, the relatively small weighting control coefficient group Kp is used, the image brightness shake caused by the diaphragm over-adjustment can be effectively eliminated, the image brightness is kept stable, and the middle weighting control coefficient group Kp ensures the continuous change of the image brightness and prevents the sudden change of the brightness of the image.

The proportional control coefficient Kp is intelligently corrected according to the technical operation condition, and specifically comprises the following steps:

if the aperture is closed and adjusted in the process of over-bright environment, the weighting scale coefficient K1i recorded in the last time is utilized, the overshoot phenomenon in the adjustment process is judged after adjustment, the K1i is properly reduced, otherwise, the K1i is properly increased, and the coefficient K1i is stored and recorded; if the diaphragm is adjusted by the weighting scale factor K2i of the last recording during the adjustment process when the diaphragm is too dark, if it is judged that there is an overshoot phenomenon during the adjustment process, K2i is appropriately decreased, and this factor K2i is kept recorded. The intelligent optimization weighting control coefficient group Kp of the camera can ensure that the friction coefficient of a transmission mechanism is reduced after the camera is used for a long time, the aperture is flexibly adjusted, and the condition of light and shade jitter of image brightness caused in the aperture adjusting process is set by experience under the condition that Kp is not suitable, so that the display of the light and shade jitter is automatically eliminated.

Fourth embodiment:

the method for controlling the weighting of the mechanical aperture is particularly suitable for an airborne camera, the airborne camera is mainly used for irradiating pictures of plane display and external field superposition, the aperture is controlled to be used for clearly seeing characters on a screen display of an airplane, and the method is applied to a certain airborne camera and specifically comprises the following steps:

it should be noted that the following parameters are brightness values obtained by sampling and converting the brightness values by using a 12-bit a/D converter built in the MSP430 single-chip microcomputer, and may be different if different a/D converters are used.

Presetting target brightness value ranges Sv 1-Sv 2, wherein Sv1 is 3860, and Sv2 is 3840;

the critical values of the sub-regions in the darker region are:

Sv11	Sv12	Sv13	Sv14	Sv15
					3870	3890	3930	3990	4070

the weighting coefficient group corresponding to each sub-area of the partial dark area is respectively as follows:

the critical values of the sub-regions in the highlight region are respectively:

Sv21	Sv22	Sv23	Sv24	Sv25
					3830	3780	3680	3480	3080

the weighting coefficient group corresponding to each sub-area of the partial bright area is respectively as follows:

	tH/us	tL/us	N
				K21	30	70	5
K22	40	60	10
				K23	50	50	15
K24	60	40	20
				K25	70	30	25
K26	80	20	30

it can be seen that:

the method is mainly used for adjusting the external environment brightness far away from a target brightness value range and when the external brightness changes violently, the adjusting speed is high, and the time of the whole adjusting process is shortened.

K14(60, 20, 25) and K13(40, 20, 15), and K24(60, 40, 20) and K23(50, 50, 15) all belong to medium-speed regulation in respective areas, and are mainly used for regulation when the external environment brightness is close to a target brightness value range and the external brightness changes slowly, and the regulation process ensures continuity and smoothness of image brightness change, so that the phenomenon of light and shade abrupt change of the image brightness cannot occur in the regulation process of the image brightness.

③ K12(20, 10, 10) and K11(10, 10, 5), and K22(40, 60, 10) and K21(30, 70, 5) all belong to low-speed regulation in respective areas, and are mainly used for regulating the brightness of the external environment near a target brightness value area.

The drastic change of the external environment causes the aperture to be adjusted from the maximum aperture to the minimum aperture or from the minimum aperture to the maximum aperture, and the method provided by the invention is adopted in the whole adjusting process:

the aperture size of about 60% is adjusted at high speed, and the time is about 1 s;

the aperture size of about 30% is adjusted at medium speed, and the time is about 2 s;

the aperture size of about 10% is adjusted at low speed, and the time is about 1 s.

The time required by the whole adjusting process does not exceed 4s, and after the aperture is adjusted, the image is clear, the brightness is stable, and the brightness does not shake. Even if the external environment is slightly changed, the aperture adjustment is also responded, and the image brightness is adjusted in real time.

It will be understood by those of ordinary skill in the art that the foregoing embodiments are specific examples for carrying out the invention, and that various changes in form and details may be made therein without departing from the spirit and scope of the invention in practice.