CN103712597A

CN103712597A - High-speed linear array CCD signal measuring method

Info

Publication number: CN103712597A
Application number: CN201210371499.8A
Authority: CN
Inventors: 王小军; 王岩; 宋顺利; 姜华; 刘潇雨; 贺永喜; 王学根
Original assignee: China Academy of Launch Vehicle Technology CALT; Beijing Institute of Space Launch Technology
Current assignee: China Academy of Launch Vehicle Technology CALT; Beijing Institute of Space Launch Technology
Priority date: 2012-09-28
Filing date: 2012-09-28
Publication date: 2014-04-09
Anticipated expiration: 2032-09-28
Also published as: CN103712597B

Abstract

The invention belongs to the technical field of aiming, and concretely relates to a high-speed linear array CCD signal measuring method. The method comprises the following steps: a slit is utilized by a light source to form a light slit, and aiming parallel light beams are generated through an optical system composed of a cubic prism and an object lens and irradiate a target prism; the target prism reflects the parallel beams, the parallel beams are reflected by the object lens and the prism and are focused on the focal plane of the optical system; CCD is positioned on the focal plane of the optical system, receives a light slit signal and converts the light slit signal to a pixel voltage signal representing the intensity and the position of the light slit signal, and the pixel voltage signal output by the CCD is received and processed to obtain the relative corner information of the target prism and the object lens in order to realize the target azimuth measurement. The method realizes the identification and subdivision processing of 1024 pixel data within 2ms, realizes the CCD processing precision of 0.1 pixel, and makes it possible to realize the 10ms control period and the 15'' measurement precision of a movable aiming system.

Description

A kind of measuring method of high speed linear array CCD signal

Technical field

The invention belongs to point technique field, be specifically related to a kind of measuring method of high speed linear array CCD signal.

Background technology

CCD(Charge Coupled Device) claim again charge-coupled image sensor, to be made with lsi technology, there is opto-electronic conversion, storage and optoelectronic scanning function, have that volume is little, anti-vibration, the life-span is long, power consumption is little, highly sensitive and without advantages such as preheatings under the low light level.As the sensor of photoelectronic collimating instrument, improved photoelectricity collimation performance, realize high precision angle-measuring.

But the interface requirement of CCD is comparatively strict, not only need multipath clock to drive signal, and multipath clock signal must be strict synchronous, and CCD generally take the mode of bit stream output, require take over party to possess quick conversion and signal handling capacity.In application in the past, due to the special interface requirement of CCD, limited the conversion speed of optoelectronic device, the line array CCD of 1024 pixels of routine of take is example, the processing time of one frame signal often needs tens milliseconds to a few tens of milliseconds, has limited the ability of photoelectronic collimating instrument processing high speed signal.

Summary of the invention

The object of the present invention is to provide a kind of measuring method of high speed linear array CCD signal, to realize the high speed of ccd signal, accurately to gather.

For achieving the above object, the technical solution used in the present invention is:

A measuring method for high speed linear array CCD signal, it is achieved as follows: light source, by slit, forms an optical slits, and the optical system consisting of block prism, object lens, produces the parallel beam aiming at, and is irradiated to target prism; Target prism returns penetrates parallel beam, by object lens, block prism, focuses on the focal plane of optical system after turning back; CCD is positioned at the focal plane place of optical system, receive optical slits signal, be converted to the pixel voltage signal that represents optical slits signal intensity and position, by receiving and process the pixel voltage signal of CCD output, obtain the relative rotation information of target prism and objective lens optical axis, realize target measurement of azimuth.

Described CCD selects the line array CCD of 1024 pixels as the switching device of photosignal, the master clock frequency of CCD work is 1.25MHz/ dutycycle 1:1, the field synchronization clock of CCD work is 500Hz/ dutycycle 1:1250, the pixel clock frequency of CCD output is 312.5kHz/ dutycycle 1:1, and the synchronous requirement of clock hopping edge is 20ns.

Select the A/D converter of 12 to change fast each pixel voltage signal, the work clock of A/D converter is identical with the pixel clock frequency of CCD, and be 19ns lock in time.

Select dsp chip to realize the field synchronization clock of the major clock of CCD work, CCD work, the pixel clock of CCD output, the work clock of A/D converter is strictly synchronous.

The internal operation clock frequency of described dsp chip is 20MHz, and there are three independently timers inside, by the mode that programming is set to timer, makes the frequency range of the PWM mouth output that DSP is corresponding adjustable at 1Hz～10MHz; Respectively the period counter of two timers is set as to 500Hz and numerical value corresponding to 1.25MHz, according to the requirement of different duty, set respectively two relatively numerical value corresponding to counter, two timers are set as to synchronous Starting mode simultaneously, thereby two clocks that obtained 500Hz/ dutycycle 1:1250 and 1.25MHz/ dutycycle 1:1 at PWM1, PWM2 delivery outlet, and two clock synchronous are better than 5ns; For obtaining another two clock signals, the clock of 1.25MHz is input to a scale-of-two synchronous counter, after two divided-frequency and four frequency divisions by counter, can obtain the square-wave signal of two strict synchronous 625kHz and 312.5kHz.

Described DSP adopts assembly language, utilizes the high speed instruction of DSP, completes reading, judge, storing of CCD pixel data in 1.6us; In 2ms, realize processing, the identification of hot spot signal, the Subdividing Processing of 1024 pixel data, realize the CCD processing accuracy of 0.1 pixel.

The obtained beneficial effect of the present invention is:

The measuring method of high speed linear array CCD signal of the present invention, three kinds of clock signals that CCD is needed and the clock signal of signal conversion, realize by clock division circuits, sequential translation circuit, realized good synchronization and the high speed acquisition of signal; Adopt DSP assembly language, utilize the high speed instruction of DSP, in 1.6us, complete reading, judge, storing of CCD pixel data; In 2ms, realizing processing, the identification of hot spot signal, the Subdividing Processing of 1024 pixel data, realize the CCD processing accuracy of 0.1 pixel, for realizing the control cycle, 15 of sighting system 10ms " angle measurement accuracy provides possibility:

(1) select the line array CCD of 1024 pixels as the switching device of photosignal, the master clock frequency of CCD work is 1.25MHz, the field synchronization clock of CCD work is 500Hz, and the collection clock frequency of A/D converter part is 625kHz, and three kinds of clocks must guarantee strict sequential requirement;

(2) adopt digital signal processor (DSP) as the CPU of ccd signal collection, processing, utilize the built-in clock of DSP, width modulation delivery outlet, be aided with peripheral logical circuit, realize CCD clock and gather strictly synchronizeing of clock with A/D;

(3) adopt DSP assembly language, utilize the high speed instruction of DSP, in 1.6us, complete reading, judge, storing of CCD pixel data; In 2ms, realize processing, the identification of hot spot signal, the Subdividing Processing of 1024 pixel data, realize the CCD processing accuracy of 0.1 pixel.

Accompanying drawing explanation

Fig. 1 is CCD angle measuring principle figure;

Fig. 2 is the sequential chart of CCD clock and A/D clock;

Fig. 3 is CCD clock synchronous, signal acquisition circuit schematic diagram;

In figure: 1, target prism; 2, object lens; 3, block prism; 4, slit; 5, light source; 6, CCD.

Embodiment

Below in conjunction with the drawings and specific embodiments, the present invention is described in detail.

As shown in Figure 1, the measuring method of a kind of high speed linear array CCD signal of the present invention is achieved as follows: light source 5, by slit 4, forms an optical slits, the optical system consisting of block prism 3, object lens 2 etc., produce the parallel beam aiming at, be irradiated to target prism 1; Target prism 1 returns penetrates parallel beam, by object lens 2, block prism 3, focuses on the focal plane of optical system after turning back; CCD6 is positioned at the focal plane place of optical system, receive optical slits signal, be converted to the pixel voltage signal that represents optical slits signal intensity and position, by receiving and process the pixel voltage signal of CCD6 output, obtain the relative rotation information of target prism 1 and object lens 2 optical axises, realize target measurement of azimuth.

Described CCD6 selects the line array CCD of 1024 pixels as the switching device of photosignal, as shown in Figure 2, the master clock frequency of CCD work is 1.25MHz/ dutycycle 1:1, the field synchronization clock of CCD work is 500Hz/ dutycycle 1:1250, the pixel clock frequency of CCD output is 312.5kHz/ dutycycle 1:1, the frequency of three kinds of clocks, dutycycle difference are very large, and the synchronous requirement of clock hopping edge is 20ns, and sequential requires strict; In order to change fast the signal of each pixel, selected the A/D converter of a 12, the work clock of A/D converter is identical with the pixel clock frequency of CCD, and be 19ns lock in time.

As shown in Figure 3, select dsp chip to realize above four kinds of clocks strictly synchronous, the internal operation clock frequency of dsp chip is 20MHz, and there are three independently timers inside, by the mode that programming is set to timer, make the frequency range of the PWM mouth output that DSP is corresponding adjustable at 1Hz～10MHz.Respectively the period counter of two timers is set as to 500Hz and numerical value corresponding to 1.25MHz, according to the requirement of different duty, set respectively two relatively numerical value corresponding to counter, two timers are set as to synchronous Starting mode simultaneously, thereby two clocks that obtained 500Hz/ dutycycle 1:1250 and 1.25MHz/ dutycycle 1:1 at PWM1, PWM2 delivery outlet, and two clock synchronous are better than 5ns.For obtaining another two clock signals, the clock of 1.25MHz is input to a scale-of-two synchronous counter, after two divided-frequency and four frequency divisions by counter, can obtain the square-wave signal of two strict synchronous 625kHz and 312.5kHz.Under which, utilize DSP internal clocking, programmable counter and a peripheral scale-of-two synchronous counter, realized four kinds of frequencies, dutycycle difference is large, synchronously requires strict clock signal, may for what realize that high-speed CCD collection provides.

Adopt DSP assembly language, utilize the high speed instruction of DSP, in 1.6us, complete reading, judge, storing of CCD pixel data; In 2ms, realize processing, the identification of hot spot signal, the Subdividing Processing of 1024 pixel data, realize the CCD processing accuracy of 0.1 pixel.

Claims

1. the measuring method of a high speed linear array CCD signal, it is characterized in that: it is achieved as follows: light source (5), by slit (4), forms an optical slits optical system forming by block prism (3), object lens (2), produce the parallel beam aiming at, be irradiated to target prism (1); Target prism (1) returns penetrates parallel beam, by object lens (2), block prism (3), focuses on the focal plane of optical system after turning back; CCD(6) be positioned at the focal plane place of optical system, receive optical slits signal, be converted to the pixel voltage signal that represents optical slits signal intensity and position, by receiving and process CCD(6) output pixel voltage signal, obtain the relative rotation information of target prism (1) and object lens (2) optical axis, realize target measurement of azimuth.

2. the measuring method of high speed linear array CCD signal according to claim 1, it is characterized in that: described CCD(6) select the line array CCD of 1024 pixels as the switching device of photosignal, the master clock frequency that CCD does is 1.25MHz/ dutycycle 1:1, the field synchronization clock of CCD work is 500Hz/ dutycycle 1:1250, the pixel clock frequency of CCD output is 312.5kHz/ dutycycle 1:1, and the synchronous requirement of clock hopping edge is 20ns.

3. the measuring method of high speed linear array CCD signal according to claim 2, it is characterized in that: select the A/D converter of 12 to change fast each pixel voltage signal, the work clock of A/D converter and CCD(6) pixel clock frequency identical, be 19ns lock in time.

4. the measuring method of high speed linear array CCD signal according to claim 3, is characterized in that: select dsp chip to realize the field synchronization clock of the major clock of CCD work, CCD work, the pixel clock of CCD output, the work clock of A/D converter is strictly synchronous.

5. the measuring method of high speed linear array CCD signal according to claim 4, it is characterized in that: the internal operation clock frequency of described dsp chip is 20MHz, there are three independently timers inside, by the mode that programming is set to timer, make the frequency range of the PWM mouth output that DSP is corresponding adjustable at 1Hz～10MHz; Respectively the period counter of two timers is set as to 500Hz and numerical value corresponding to 1.25MHz, according to the requirement of different duty, set respectively two relatively numerical value corresponding to counter, two timers are set as to synchronous Starting mode simultaneously, thereby two clocks that obtained 500Hz/ dutycycle 1:1250 and 1.25MHz/ dutycycle 1:1 at PWM1, PWM2 delivery outlet, and two clock synchronous are better than 5ns; For obtaining another two clock signals, the clock of 1.25MHz is input to a scale-of-two synchronous counter, after two divided-frequency and four frequency divisions by counter, can obtain the square-wave signal of two strict synchronous 625kHz and 312.5kHz.

6. the measuring method of high speed linear array CCD signal according to claim 5, is characterized in that: described DSP adopts assembly language, utilizes the high speed instruction of DSP, completes reading, judge, storing of CCD pixel data in 1.6us; In 2ms, realize processing, the identification of hot spot signal, the Subdividing Processing of 1024 pixel data, realize the CCD processing accuracy of 0.1 pixel.