CN104427253A - Camera light intensity automatic regulating apparatus - Google Patents

Camera light intensity automatic regulating apparatus Download PDF

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Publication number
CN104427253A
CN104427253A CN201310368326.5A CN201310368326A CN104427253A CN 104427253 A CN104427253 A CN 104427253A CN 201310368326 A CN201310368326 A CN 201310368326A CN 104427253 A CN104427253 A CN 104427253A
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circuit
hollow shaft
shaft motor
camera
motor
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CN201310368326.5A
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CN104427253B (en
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孙增玉
梁雅军
宋金城
郭磊
高越
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China Academy of Launch Vehicle Technology CALT
Beijing Aerospace Institute for Metrology and Measurement Technology
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China Academy of Launch Vehicle Technology CALT
Beijing Aerospace Institute for Metrology and Measurement Technology
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  • Investigating Materials By The Use Of Optical Means Adapted For Particular Applications (AREA)
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Abstract

The invention belongs to the technical field of photogrammetry, and specifically relates to a camera light intensity automatic regulating apparatus. The apparatus comprises a camera, a fixed polarizing disc, a velocity measurement machine, a hollow shaft motor, a rotation polarizing disc and a matched circuit. A figure acquisition and processing computer acquires image information and solves a background gray-scale value; a gray-scale signal acquisition acquires gray-scale signals and inputs the gray-scale signals into a second comparison circuit for comparison with a set object gray-scale value; a comparison value, after passing through a proportion regulating circuit, is taken as a speed ring set value; the velocity measurement machine obtains the rotation speed of a hollow shaft motor, the rotation speed, after acquisition by a velocity measurement machine signal acquisition circuit, is input to a first comparison circuit, a comparison is made between the speed value and the speed ring set value, and a motor speed deviation is solved; a control circuit solves deviation signals to form control signals, and the control signals, after passing through a power amplification circuit, are transmitted to a motor driving circuit to drive the hollow shaft motor; and such a process is carried out in a circulating mode so that the angle positions of the hollow shaft motor are continuously corrected, and the deflection angles of the polarizing discs are controlled.

Description

A kind of camera light intensity automatic regulating equipment
Technical field
The invention belongs to photogrammetric technology field, be specifically related to a kind of camera light intensity automatic regulating equipment.
Background technology
Photogrammetric technology is widely used in science and technology and industrial production, but optical measurement requires relatively stricter to bias light, needs strictly to control bias light line strength or improve picture quality by adjustment lens aperture.But in bias light fast-changing occasion in time, in order to avoid crossing dark or crossing bright phenomenon, ensure IMAQ effect, need to design special light intensity automatic adjusting mechanism.Conventional control method is adjustment aperture method and polarizer adjustment method, but the change of aperture needs adjustment camera lens to realize, but photogrammetric all needs is demarcated the lens distortion of camera, and changing camera lens can affect demarcation effect, reduces certainty of measurement.
The light modulation structure of polarization theory is utilized to have good effect, and larger to the adjustable range of intensity of illumination.Polarizer constructions is close together by two polarizers and is formed, and wherein one maintains static, and during another Zhang Xuanzhuan, the angle of two polarizers will change.Natural daylight is a kind of electromagnetic wave, has the polarization characteristic of shear wave.Be located at the light vector A of plane vibration, be respectively A at the amplitude in x, y direction xwith A y, vibration phase difference is δ, if be θ through maximum direction PM and the x-axis angle of shaking of first polarizer rear polarizer, and sets Pm as the direction orthogonal with PM.As shown in Figure 1.
Suppose that ideal polarizer peak swing transmitance is 1, minimum amplitude transmitance is 0, then transmitted light intensity is: E ( θ ) = A x 2 cos 2 θ + A y 2 sin 2 θ + 2 A x A y cos θ sin θ cos δ
= E x cos 2 θ + E y sin 2 θ + 2 E x E y cos θ sin θ cos δ - - - ( 1 )
Put into polarizer P1 in the optical path as the polarizer, if Natural light intensity is E 0, now any direction projecting light intensity E becomes linearly polarized light, that is:
E = 1 2 E 0 - - - ( 2 )
Put into polarizer P2 in the optical path, as analyzer, its thoroughly shake direction P2 and P1 angle are θ, thus form quarter-wave plate, E (θ)=E in this up-to-date style (1) 2, A x=A1, A y=0, substitute into transmitted light intensity formula (1), obtain:
E 2 = A 1 2 cos 2 θ - - - ( 3 )
That is: E 2 = E 1 cos 2 θ = 1 2 E 0 cos 2 θ - - - ( 4 )
Wherein A1, E 1for light amplitude and light intensity after polarizer P1, E 2for light intensity after analyzer P2, as shown in Figure 2.
But in the application at present to polarizer light intensity regulating, the angle between polarizer is often relatively fixing, therefore cannot accomplishes the real-time adjustment of intensity of illumination and quantitatively regulate.
Summary of the invention
In order to the real-time of the Adjustment precision and adjustment that improve regulating system, the present invention proposes a kind of camera light intensity automatic regulating equipment, closed-loop automatic control technology based on speed and position feedback is incorporated in the light intensity regulating based on polarizer, achieve motor to respond fast and even running, reach the experiment effect that camera entrance light intensity is constant, test zone gradation of image is constant.
For achieving the above object, the technical solution used in the present invention is:
A kind of camera light intensity automatic regulating equipment comprises camera, fixing polarizer, tachometer, hollow shaft motor, rotatory polarization sheet and support circuit; Described fixing polarizer is arranged on the camera lens of camera, the interior axle of rotatory polarization sheet and hollow shaft motor is fixed, and hollow shaft motor is adjusted to coaxial with the optical axis of camera, when hollow shaft motor rotates, angle between rotatory polarization sheet and fixing polarizer changes, realize the incident intensity of adjustment camera, hollow shaft motor rotating speed measured in real time by tachometer, and is converted into analog electrical signal and is transferred to figure sampling and processing computer; Described support circuit comprises figure sampling and processing computer, grey scale signal Acquisition Circuit, comparison circuit 1, comparison circuit 2, proportion adjustment circuit, tachometer signal acquisition circuit, control circuit, power amplification circuit, motor-drive circuit; Described figure sampling and processing computer is connected with camera, gathers image information and resolves background gray levels; Described grey scale signal Acquisition Circuit is connected with figure sampling and processing computer, gathers grey scale signal and be input to comparison circuit 2 to compare with the target gray value of setting; As the set point of speed ring after comparison value passing ratio regulating circuit; Tachometer measurement obtains the rotary speed of hollow shaft motor, and after being gathered by tachometer signal acquisition circuit, be input to comparison circuit 1, this velocity amplitude and speed ring set point compare, and resolve and obtain motor speed deviation; By control circuit, deviation signal is resolved, formation control signal, after power amplification circuit, be transferred to motor-drive circuit and drive hollow shaft motor to rotate; The circulation of this process is carried out, the angle position of continuous modified spatial spindle motor, realizes the object controlling polarizer deflection angle.
Described tachometer signal acquisition circuit, comparison circuit 1, control circuit, power amplification circuit, motor-drive circuit form rate loop, for carrying out the feedback compensation of local to hollow shaft motor: suppress for the axle system friction in loop on the one hand, if allocated bandwidth is reasonable on the other hand, speed loop feedback can be designed to profound and negative feedbck, to improve characteristics of objects, reduce hollow shaft motor self-characteristic to the difficulty of major loop Control System Design, make system have certain robustness.
Described figure sampling and processing computer, grey scale signal Acquisition Circuit, comparison circuit 2, proportion adjustment circuit, comparison circuit 1, control circuit, power amplification circuit, motor-drive circuit form position loop, the calculating realizing departure is compared by the value of feedback of gray scale and set point, the departure of polarizer constructions is obtained according to result of calculation, send into the control system of hollow shaft motor, ensure the trace performance to setting gray value.
Described support circuit all adopts single-chip microcomputer to realize in digital form; described tachometer signal acquisition circuit is made up of A/D; described grey scale signal Acquisition Circuit is made up of serial ports; the arithmetic element of described comparison circuit 1, comparison circuit 2 and control circuit is made up of single-chip microcomputer; the control signal that control circuit exports is defeated by drive circuit by D/A; all kinds of status data enters single-chip microcomputer by DIO, the calculating of various function and the differentiations of state such as single-chip microcomputer completes speed acquisition, gradation data receives, the anglec of rotation is resolved, Digital Signal Processing, abnormal signal protection.
Beneficial effect acquired by the present invention is:
Camera light intensity automatic regulating equipment based on double loop automatic control system of the present invention realizes based on polarizer principle, by camera perception tested region light intensity, adjusting device is jointly formed by tachometer, hollow shaft motor, camera, image acquisition computer and adjusting control circuit etc., automatic control technology based on speed and position feedback is incorporated in the adjustment of polarizer, realize the automatic adjustment to camera entrance light intensity, keep gathering image brightness constant, do not affect by background light intensity.Experimental result shows, when testee background light intensity generation acute variation, can fast automatic adjustment camera entrance light intensity, realize light intensity constant, camera image can all-the-time stable at setting gray value, fast response time, gray scale bias is not more than 1.
Accompanying drawing explanation
Fig. 1 is polarization theory schematic diagram I;
Fig. 2 is polarization theory schematic diagram II;
Fig. 3 is camera light intensity automatic regulating equipment schematic diagram of the present invention;
In figure: 1, camera; 2, the incident ray after overregulating; 3, camera lens; 4, fixing polarizer; 5, tachometer; 6, hollow shaft motor; 7, rotatory polarization sheet; 8, original incident light.
Embodiment
Below in conjunction with the drawings and specific embodiments, the present invention is described in detail.
As shown in Figure 3, camera light intensity automatic regulating equipment of the present invention comprises camera 1, fixing polarizer 4, tachometer 5, hollow shaft motor 6, rotatory polarization sheet 7 and support circuit; Described fixing polarizer 4 is arranged on the camera lens 3 of camera 1, rotatory polarization sheet 7 is fixed with the interior axle of hollow shaft motor 6, and hollow shaft motor 6 is adjusted to coaxial with the optical axis of camera 1, when hollow shaft motor 6 rotates, angle between rotatory polarization sheet 7 and fixing polarizer 4 changes, realize the incident intensity of adjustment camera 1, tachometer 5 in real time measures hollow shaft motor 6 rotating speed, and is converted into analog electrical signal and is transferred to figure sampling and processing computer; Described support circuit comprises figure sampling and processing computer, grey scale signal Acquisition Circuit, comparison circuit 1, comparison circuit 2, proportion adjustment circuit, tachometer signal acquisition circuit, control circuit, power amplification circuit, motor-drive circuit; Described figure sampling and processing computer is connected with camera, gathers image information and resolves background gray levels; Described grey scale signal Acquisition Circuit is connected with figure sampling and processing computer, gathers grey scale signal and be input to comparison circuit 2 to compare with the target gray value of setting; As the set point of speed ring after comparison value passing ratio regulating circuit; The rotary speed obtaining hollow shaft motor 6 measured by tachometer 5, and after being gathered by tachometer signal acquisition circuit, be input to comparison circuit 1, this velocity amplitude and speed ring set point compare, and resolve and obtain motor speed deviation; By control circuit, deviation signal is resolved, formation control signal, after power amplification circuit, be transferred to motor-drive circuit and drive hollow shaft motor 6 to rotate; The circulation of this process is carried out, the angle position of continuous modified spatial spindle motor 6, realizes the object controlling polarizer deflection angle.
The basic role in each loop is as follows:
Rate loop: be made up of tachometer signal acquisition circuit, comparison circuit 1, control circuit, power amplification circuit, motor-drive circuit successively; Be mainly used in feedback compensation hollow shaft motor 6 being carried out to local.On the one hand the axle system friction in loop is suppressed, on the other hand, if allocated bandwidth is reasonable in design, speed loop feedback can be designed to profound and negative feedbck, LOCAL FEEDBACK is carried out for loop and has improved characteristics of objects, reduce hollow shaft motor 6 self-characteristic to the difficulty of major loop Control System Design, make system have certain robustness.
Position loop: be made up of figure sampling and processing computer, grey scale signal Acquisition Circuit, comparison circuit 2, proportion adjustment circuit, comparison circuit 1, control circuit, power amplification circuit, motor-drive circuit successively; Compare by the value of feedback of gray scale and set point the calculating realizing departure, obtain the departure of polarizer constructions according to result of calculation, send into the control system of hollow shaft motor 6, ensure the trace performance to setting gray value.
Described support circuit all adopts single-chip microcomputer to realize in digital form.Described tachometer signal acquisition circuit is made up of A/D; described grey scale signal Acquisition Circuit is made up of serial ports; the arithmetic element of described comparison circuit 1, comparison circuit 2 and control circuit is made up of single-chip microcomputer; the control signal that control circuit exports is defeated by drive circuit by D/A; all kinds of status data enters single-chip microcomputer by DIO, the calculating of various function and the differentiations of state such as single-chip microcomputer completes speed acquisition, gradation data receives, the anglec of rotation is resolved, Digital Signal Processing, abnormal signal protection.

Claims (4)

1. a camera light intensity automatic regulating equipment, is characterized in that: this device comprises camera (1), fixing polarizer (4), tachometer (5), hollow shaft motor (6), rotatory polarization sheet (7) and support circuit; Described fixing polarizer (4) is arranged on the camera lens (3) of camera (1), rotatory polarization sheet (7) is fixed with the interior axle of hollow shaft motor (6), and hollow shaft motor (6) is adjusted to coaxial with the optical axis of camera (1), when hollow shaft motor (6) rotates, angle between rotatory polarization sheet (7) and fixing polarizer (4) changes, realize the incident intensity of adjustment camera (1), hollow shaft motor (6) rotating speed measured in real time by tachometer (5), and is converted into analog electrical signal and is transferred to figure sampling and processing computer; Described support circuit comprises figure sampling and processing computer, grey scale signal Acquisition Circuit, comparison circuit 1, comparison circuit 2, proportion adjustment circuit, tachometer signal acquisition circuit, control circuit, power amplification circuit, motor-drive circuit; Described figure sampling and processing computer is connected with camera, gathers image information and resolves background gray levels; Described grey scale signal Acquisition Circuit is connected with figure sampling and processing computer, gathers grey scale signal and be input to comparison circuit 2 to compare with the target gray value of setting; As the set point of speed ring after comparison value passing ratio regulating circuit; The rotary speed obtaining hollow shaft motor (6) measured by tachometer (5), and after being gathered by tachometer signal acquisition circuit, be input to comparison circuit 1, this velocity amplitude and speed ring set point compare, and resolve and obtain motor speed deviation; By control circuit, deviation signal is resolved, formation control signal, after power amplification circuit, be transferred to motor-drive circuit and drive hollow shaft motor (6) to rotate; The circulation of this process is carried out, the angle position of continuous modified spatial spindle motor (6), realizes the object controlling polarizer deflection angle.
2. camera light intensity automatic regulating equipment according to claim 1, it is characterized in that: described tachometer signal acquisition circuit, comparison circuit 1, control circuit, power amplification circuit, motor-drive circuit forms rate loop, for carrying out the feedback compensation of local to hollow shaft motor (6): suppress for the axle system friction in loop on the one hand, if allocated bandwidth is reasonable on the other hand, speed loop feedback can be designed to profound and negative feedbck, to improve characteristics of objects, reduce hollow shaft motor (6) self-characteristic to the difficulty of major loop Control System Design, system is made to have certain robustness.
3. camera light intensity automatic regulating equipment according to claim 1, it is characterized in that: described figure sampling and processing computer, grey scale signal Acquisition Circuit, comparison circuit 2, proportion adjustment circuit, comparison circuit 1, control circuit, power amplification circuit, motor-drive circuit form position loop, the calculating realizing departure is compared by the value of feedback of gray scale and set point, the departure of polarizer constructions is obtained according to result of calculation, send into the control system of hollow shaft motor (6), ensure the trace performance to setting gray value.
4. camera light intensity automatic regulating equipment according to claim 1, it is characterized in that: described support circuit all adopts single-chip microcomputer to realize in digital form, described tachometer signal acquisition circuit is made up of A/D, described grey scale signal Acquisition Circuit is made up of serial ports, described comparison circuit 1, the arithmetic element of comparison circuit 2 and control circuit is made up of single-chip microcomputer, the control signal that control circuit exports is defeated by drive circuit by D/A, all kinds of status data enters single-chip microcomputer by DIO, single-chip microcomputer completes speed acquisition, gradation data receives, the anglec of rotation is resolved, Digital Signal Processing, the calculating of various function and the differentiations of state such as abnormal signal protection.
CN201310368326.5A 2013-08-22 2013-08-22 A kind of camera light intensity self-checking device Active CN104427253B (en)

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111131724A (en) * 2019-12-31 2020-05-08 浙江大华技术股份有限公司 Vehicle window colorful pattern eliminating system, method and device, controller and storage medium
CN114199527A (en) * 2021-12-22 2022-03-18 长沙麓邦光电科技有限公司 OD value detection method and system of graded filter and storage medium
CN114236866A (en) * 2022-02-12 2022-03-25 南京工程学院 Terahertz polarization adjusting system based on metal wire grid terahertz wire polarizer
CN114440081A (en) * 2022-04-11 2022-05-06 西南交通大学 Vehicle-mounted positioning speed measuring device for urban rail train

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US6028303A (en) * 1996-11-14 2000-02-22 Nikon Corporation Polarizing filter control mechanism to reduce reflected light
US20060291075A1 (en) * 2005-06-27 2006-12-28 Pentax Corporation An imaging device having a polarizing filter, and a method of controlling rotation of a polarizing filter of an imaging device
CN102540531A (en) * 2012-01-11 2012-07-04 中国科学院长春光学精密机械与物理研究所 Transitional grey level driving method for increasing response speed of liquid crystal wave-front corrector
CN103048798A (en) * 2012-12-29 2013-04-17 深圳市时代华影科技开发有限公司 High-light-efficiency light modulation device and high-light-efficiency (3-dimensional) 3D projection system

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6028303A (en) * 1996-11-14 2000-02-22 Nikon Corporation Polarizing filter control mechanism to reduce reflected light
US20060291075A1 (en) * 2005-06-27 2006-12-28 Pentax Corporation An imaging device having a polarizing filter, and a method of controlling rotation of a polarizing filter of an imaging device
CN102540531A (en) * 2012-01-11 2012-07-04 中国科学院长春光学精密机械与物理研究所 Transitional grey level driving method for increasing response speed of liquid crystal wave-front corrector
CN103048798A (en) * 2012-12-29 2013-04-17 深圳市时代华影科技开发有限公司 High-light-efficiency light modulation device and high-light-efficiency (3-dimensional) 3D projection system

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111131724A (en) * 2019-12-31 2020-05-08 浙江大华技术股份有限公司 Vehicle window colorful pattern eliminating system, method and device, controller and storage medium
CN114199527A (en) * 2021-12-22 2022-03-18 长沙麓邦光电科技有限公司 OD value detection method and system of graded filter and storage medium
CN114199527B (en) * 2021-12-22 2023-11-17 长沙麓邦光电科技有限公司 OD value detection method, system and storage medium of graded optical filter
CN114236866A (en) * 2022-02-12 2022-03-25 南京工程学院 Terahertz polarization adjusting system based on metal wire grid terahertz wire polarizer
CN114440081A (en) * 2022-04-11 2022-05-06 西南交通大学 Vehicle-mounted positioning speed measuring device for urban rail train

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