CN101963665A - Laser radar geometric overlap factor automatic regulation system and regulation method - Google Patents

Abstract

The invention discloses a laser radar geometric overlap factor automatic regulation system which comprises an outgoing light path, a receiving light path and a data acquisition and control part. A regulation method comprises the following steps: a pulse laser sends out a pulse laser beam, the pulse laser beam is collimated and expanded by a collimating and expanding system and is reflected into the atmosphere so as to produce echoed signals after steering by a rotatable reflector and a fixed reflector, a telescope receives the echoed signals, and the echoed signals sequentially passes through a pinhole aperture, a lens and a light filter to be transferred to a photoelectric detector and the data acquisition and control system; and the echoed signals are processed according to equivalent criteria and an optimization algorithm to obtain control signals to control an X-axis executing mechanism and a Y-axis executing mechanism to regulate the angle of the rotatable reflector so as to enable the axial line of the outgoing laser beam reflected by the mixed reflector to coincide with the axial line of the telescope. The regulation system and the regulation method can automatically regulate the angle of the outgoing laser beam, reduce the influence of geometric factors on the atmospheric echoed signals and widen the effective detection range of the laser radar.

Description

How much overlap factor automatic adjustment systems of laser radar and method of adjustment

Technical field

The invention belongs to the atmospheric environment observation technical field, be specifically related to how much overlap factor automatic adjustment systems of a kind of laser radar, the invention still further relates to the method for utilizing this system to adjust.

Background technology

Laser radar has been widely used in research fields such as Laser Atmospheric Transmission, global climate prediction, gasoloid radiation effect and atmospheric environment as a kind of active remote sensing prospecting tools.

In laser radar system, telescopical field angle should be a bit larger tham the angle of divergence of laser beam.For coaxial laser radar, the outgoing laser beam axis will with the telescope dead in line; For non-coaxial laser radar, the outgoing laser beam axis will with the telescope parallel axes.Ideally begin echoed signal and just can enter range of telescope fully from ground.

But coaxial or parallel often being difficult between these two axis realized in practice.In addition, because blocking of shelters such as auxilliary mirror of telescope and associated mechanical mechanism, often can not receive echoed signal fully at the low latitude laser radar, have how much overlay regions this moment, in this overlay region, emission of lasering beam and telescopical visual field partially overlap, continuous increase along with height, the ratio of overlapping region area and facula area increases gradually, finally reaches a certain peak value, and how much overlap factors also reach maximal value at this moment.And in the high-altitude, since the existence of the angle of two optical axises, the very fast increase of distance meeting between range of telescope and the laser facula, and this may cause geometric factor to be decayed rapidly.Therefore, the existence of geometric factor is the key factor that the investigative range of laser radar is reduced.

At present, people mainly adopt the mode of manual adjustments, make this two axis coaxles or parallel as far as possible, thereby increase the effective detection range of radar; In addition, people also adopt the method for experiment or correction to program to reduce the influence of geometry overlap factor to the echoed signal of lower atmosphere layer.But these modes all can only reduce the influence of how much overlap factors to a certain extent, and can not fundamentally eliminate this problem.

Summary of the invention

The purpose of this invention is to provide how much overlap factor automatic adjustment systems of a kind of laser radar, solved the mode of existing employing manual adjustments, perhaps adopt the method for experiment, correction to program to reduce of the influence of geometry overlap factor to the echoed signal of lower atmosphere layer, effect is undesirable, the problem that automaticity is not high.

Another object of the present invention provides a kind of method of utilizing said system to adjust.

The technical solution adopted in the present invention is, how much overlap factor automatic adjustment systems of a kind of laser radar, comprise emitting light path, receiving light path and data acquisition and control section, emitting light path comprises pulsed laser, and the emergent light side of pulsed laser is disposed with collimating and beam expanding system, rotatable mirror, stationary mirror; Receiving light path comprises telescope, and telescopical emergent light side is disposed with aperture, lens, optical filter, photoelectricity testing part; Data acquisition and control section comprise Data Acquisition and Conversion System (DACS), the input end of Data Acquisition and Conversion System (DACS) is set to described photoelectricity testing part, the output terminal of Data Acquisition and Conversion System (DACS) is provided with two branch roads, article one, branch road is disposed with X-axis actuator drivers, X-axis topworks, be disposed with Y-axis actuator drivers, Y-axis topworks on another branch road, the output terminal of X-axis topworks and Y-axis topworks is set to described rotatable mirror.

Another technical scheme of the present invention is, how much overlap factor automatic adjusting method of a kind of laser radar, adopt how much overlap factor automatic adjustment systems of laser radar, the structure of this system is: comprise emitting light path, receiving light path and data acquisition and control section, emitting light path comprises pulsed laser, and the emergent light side of pulsed laser is disposed with collimating and beam expanding system, rotatable mirror, stationary mirror; Receiving light path comprises telescope, and telescopical emergent light side is disposed with aperture, lens, optical filter, photoelectricity testing part; Data acquisition and control section comprise Data Acquisition and Conversion System (DACS), the input end of Data Acquisition and Conversion System (DACS) is set to described photoelectricity testing part, the output terminal of Data Acquisition and Conversion System (DACS) is provided with two branch roads, article one, branch road is disposed with X-axis actuator drivers, X-axis topworks, be disposed with Y-axis actuator drivers, Y-axis topworks on another branch road, the output terminal of X-axis topworks and Y-axis topworks is set to described rotatable mirror

Specifically implement according to following steps:

Step 1: pulsed laser sends pulse laser beam, behind the collimating and beam expanding system collimator and extender, turn to back directive atmosphere by rotatable mirror, stationary mirror successively, produce echoed signal, telescope receives echoed signal, echoed signal by aperture, lens, optical filter, passes to photoelectricity testing part and Data Acquisition and Conversion System (DACS) successively;

Step 2: Data Acquisition and Conversion System (DACS) is handled echoed signal according to criterion of equal value and optimized Algorithm, controlled signal, angle by X-axis actuator drivers and Y-axis actuator drivers control X-axis topworks and Y-axis topworks adjusting rotatable mirror makes through outgoing laser beam axis and telescope dead in line after the fixation reflex mirror reflection.

Characteristics of the present invention also are,

Data Acquisition and Conversion System (DACS) is wherein handled echoed signal according to criterion of equal value and optimized Algorithm, specifically implements according to following steps:

A. the current location with rotatable mirror is designated as W ₀, detection of echoes signal intensity P (z) is 0 to z ₂Echoed signal P (z) is carried out integration in the distance range, promptly ask for echoed signal (z) with time shaft from 0 to z ₂The area that is surrounded:

$C={\∫}_0^{z_2}P\left(z\right)\mathrm{dz},$

In the formula, z ₂For P (z) distance near P (∞) in certain error range, be designated as C ₀

B. rotatable mirror is rotated to negative direction, detection of echoes signal intensity P (z) is 0 to z ₂Echoed signal P (z) is carried out integration in the distance range, promptly ask for echoed signal P (z) with time shaft from 0 to z ₂The area that is surrounded:

$C={\∫}_0^{z_2}P\left(z\right)\mathrm{dz},$

In the formula, z ₂For P (z) distance near P (∞) in certain error range, be designated as C ₁, current location is designated as W ₁

C. rotatable mirror is rotated to positive dirction, detection of echoes signal intensity P (z) is 0 to z ₂Echoed signal P (z) is carried out integration in the distance range, promptly ask for echoed signal P (z) with time shaft from 0 to z ₂The area that is surrounded:

$C={\∫}_0^{z_2}P\left(z\right)\mathrm{dz},$

In the formula, z ₂For P (z) distance near P (∞) in certain error range, be designated as C ₂, current location is designated as W ₂

D. criterion value C more of equal value ₀, C ₁And C ₂Size, judge W ₀Whether be in the optimum position: work as C ₁, C ₂Value all less than C ₀The time, show W this moment ₀Be in the optimum position, rotatable mirror is adjusted back to W again ₀, regulate and finish; Work as C ₁, C ₂Value all be not less than C ₀The time, show W this moment ₀Be not in the optimum position, according to C ₁And C ₂Size, control X-axis topworks or Y-axis topworks rotate to above-mentioned W with rotatable mirror ₁Or W ₂The position;

E. current location is designated as W` ₀, detect atmosphere echoed signal intensity P (z), 0 to z ₂Echoed signal P (z) is carried out integration in the distance range, promptly ask for echoed signal P (z) with time shaft from 0 to z ₂The area that is surrounded:

$C={\∫}_0^{z_2}P\left(z\right)\mathrm{dz},$

In the formula, z ₂For P (z) distance near P (∞) in certain error range, be designated as C` ₀

F. rotate the θ angle with respect to current location to positive dirction or negative direction, detect atmosphere echoed signal intensity P (z), 0 to z ₂Echoed signal P (z) is carried out integration in the distance range, promptly ask for echoed signal P (z) with time shaft from 0 to z ₂The area that is surrounded:

$C={\∫}_0^{z_2}P\left(z\right)\mathrm{dz},$

In the formula, z ₂For P (z) distance near P (∞) in certain error range, be designated as C` <sub>1</sub>, this moment, the position was designated as W` ₁, rotation angle value is last time 1.618 times of the adjusting angle value; After this time regulating, if criterion value C` of equal value <sub>1</sub>＞C` ₀, then return step e and continue to carry out; If criterion value C` of equal value <sub>1</sub>＜C` ₀, then enter step g and continue to carry out;

G. again rotatable mirror is adjusted back to W ₀The ` position is returned step a and is carried out.

Data Acquisition and Conversion System (DACS) is wherein handled echoed signal according to criterion of equal value and optimized Algorithm, specifically implements according to following steps:

A. the current location with rotatable mirror is designated as W ₀, detection of echoes signal intensity P (z), definition square distance correction signal is as follows:

S(z)＝P(z)z ²，

Criterion of equal value is defined as follows:

$C={\&Integral;}_0^{z_2}S\left(z\right)\mathrm{dz},$

In the formula, z ₂For P (z) distance near P (∞) in certain error range, be designated as C ₀

B. rotatable mirror is rotated to negative direction, detection of echoes signal intensity P (z), definition square distance correction signal is as follows:

S(z)＝P(z)z ²，

Criterion of equal value is defined as follows:

$C={\&Integral;}_0^{z_2}S\left(z\right)\mathrm{dz},$

In the formula, z ₂For P (z) distance near P (∞) in certain error range, be designated as C ₁, current location is designated as W ₁

C. rotatable mirror is rotated to positive dirction, detection of echoes signal intensity P (z), definition square distance correction signal is as follows:

S(z)＝P(z)z ²，

Criterion of equal value is defined as follows:

$C={\&Integral;}_0^{z_2}S\left(z\right)\mathrm{dz},$

In the formula, z ₂For P (z) distance near P (∞) in certain error range, be designated as C ₂, current location is designated as W ₂

D. criterion value C more of equal value ₀, C ₁And C ₂Size, judge W ₀Whether be in the optimum position: work as C ₁, C ₂Value all less than C ₀The time, show W this moment ₀Be in the optimum position, rotatable mirror is adjusted back to W again ₀, regulate and finish; Work as C ₁, C ₂Value all be not less than C ₀The time, show W this moment ₀Be not in the optimum position, according to C ₁And C ₂Size, control X-axis topworks or Y-axis topworks rotate to above-mentioned W with rotatable mirror ₁Or W ₂The position;

E. current location is designated as W` ₀, detecting atmosphere echoed signal intensity P (z), definition square distance correction signal is as follows:

S(z)＝P(z)z ²，

Criterion of equal value is defined as follows:

$C={\&Integral;}_0^{z_2}S\left(z\right)\mathrm{dz},$

In the formula, z ₂For P (z) distance near P (∞) in certain error range, be designated as C` ₀

F. rotate the θ angle with respect to current location to positive dirction or negative direction, detect atmosphere echoed signal intensity P (z), definition square distance correction signal is as follows:

S(z)＝P(z)z ²，

Criterion of equal value is defined as follows:

$C={\&Integral;}_0^{z_2}S\left(z\right)\mathrm{dz},$

In the formula, z ₂For P (z) distance near P (∞) in certain error range, be designated as C` <sub>1</sub>, this moment, the position was designated as W` ₁, rotation angle value is last time 1.618 times of the adjusting angle value; After this time regulating, if criterion value C` of equal value <sub>1</sub>＞C` ₀, then return step e and continue to carry out; If criterion value C` of equal value <sub>1</sub>＜C` ₀, then enter step g and continue to carry out;

G. again rotatable mirror is adjusted back to W ₀The ` position is returned step a and is carried out.

Data Acquisition and Conversion System (DACS) is wherein handled echoed signal according to criterion of equal value and optimized Algorithm, specifically implements according to following steps:

A. the current location with rotatable mirror is designated as W ₀, detection of echoes signal intensity P (z) searches out maximum of intensity P _MaxSecondly, carry out normalized, with the intensity level of each point divided by this maximal value, i.e. P (z)/P _Max(z); Then, with distance z ²As weights, to normalized value P (z)/P _MaxCarry out integration, promptly take following criterion:

$C={\&Integral;}_0^{z_2}\frac{P\left(z\right)}{{\mathrm{<figure-callout\; id="2"\; label="P\; max\; z"\; filenames="HSA00000238735000011.png"\; state="\{\{state\}\}">P</figure-callout>}}_{\max }}{z}^{}{}^2\mathrm{dz},$

In the formula, z ₂For P (z) distance near P (∞) in certain error range, be designated as C ₀

B. rotatable mirror is rotated to negative direction, detection of echoes signal intensity P (z) searches out maximum of intensity P _MaxSecondly, carry out normalized, with the intensity level of each point divided by this maximal value, i.e. P (z)/P _Max(z); Then, with distance z ²As weights, to normalized value P (z)/P _MaxCarry out integration, promptly take following criterion:

$C={\&Integral;}_0^{z_2}\frac{P\left(z\right)}{{\mathrm{<figure-callout\; id="2"\; label="P\; max\; z"\; filenames="HSA00000238735000011.png"\; state="\{\{state\}\}">P</figure-callout>}}_{\max }}{z}^{}{}^2\mathrm{dz},$

In the formula, z ₂For P (z) distance near P (∞) in certain error range, be designated as C ₁, current location is designated as W ₁

C. rotatable mirror is rotated to positive dirction, detection of echoes signal intensity P (z) searches out maximum of intensity P _MaxSecondly, carry out normalized, with the intensity level of each point divided by this maximal value, i.e. P (z)/P _Max(z); Then, with distance z ²As weights, to normalized value P (z)/P _MaxCarry out integration, promptly take following criterion:

$C={\&Integral;}_0^{z_2}\frac{P\left(z\right)}{{\mathrm{<figure-callout\; id="2"\; label="P\; max\; z"\; filenames="HSA00000238735000011.png"\; state="\{\{state\}\}">P</figure-callout>}}_{\max }}{z}^{}{}^2\mathrm{dz},$

In the formula, z ₂For P (z) distance near P (∞) in certain error range, be designated as C ₂, current location is designated as W ₂

D. criterion value C more of equal value ₀, C ₁And C ₂Size, judge W ₀Whether be in the optimum position: work as C ₁, C ₂Value all less than C ₀The time, show W this moment ₀Be in the optimum position, rotatable mirror is adjusted back to W again ₀, regulate and finish; Work as C ₁, C ₂Value all be not less than C ₀The time, show W this moment ₀Be not in the optimum position, according to C ₁And C ₂Size, control X-axis topworks or Y-axis topworks rotate to above-mentioned W with rotatable mirror ₁Or W ₂The position;

E. current location is designated as W` ₀, detect atmosphere echoed signal intensity P (z), search out maximum of intensity P _MaxSecondly, carry out normalized, with the intensity level of each point divided by this maximal value, i.e. P (z)/P _Max(z); Then, with distance z ²As weights, to normalized value P (z)/P _MaxCarry out integration, promptly take following criterion:

$C={\&Integral;}_0^{z_2}\frac{P\left(z\right)}{{\mathrm{<figure-callout\; id="2"\; label="P\; max\; z"\; filenames="HSA00000238735000011.png"\; state="\{\{state\}\}">P</figure-callout>}}_{\max }}{z}^{}{}^2\mathrm{dz},$

In the formula, z ₂For P (z) distance near P (∞) in certain error range, be designated as C` ₀

F. rotate the θ angle with respect to current location to positive dirction or negative direction, detect atmosphere echoed signal intensity P (z), search out maximum of intensity P _MaxSecondly, carry out normalized, with the intensity level of each point divided by this maximal value, i.e. P (z)/P _Max(z); Then, with distance z ²As weights, to normalized value P (z)/P _MaxCarry out integration, promptly take following criterion:

$C={\&Integral;}_0^{z_2}\frac{P\left(z\right)}{{\mathrm{<figure-callout\; id="2"\; label="P\; max\; z"\; filenames="HSA00000238735000011.png"\; state="\{\{state\}\}">P</figure-callout>}}_{\max }}{z}^{}{}^2\mathrm{dz},$

In the formula, z ₂For P (z) distance near P (∞) in certain error range, be designated as C` <sub>1</sub>, this moment, the position was designated as W` ₁, rotation angle value is last time 1.618 times of the adjusting angle value; After this time regulating, if criterion value C` of equal value <sub>1</sub>＞C` ₀, then return step e and continue to carry out; If criterion value C` of equal value <sub>1</sub>＜C` ₀, then enter step g and continue to carry out;

G. again rotatable mirror is adjusted back to W ₀The ` position is returned step a and is carried out.

The invention has the beneficial effects as follows, propose a kind of atmosphere remote measurement with geometric factor automatic adjustment system, the corresponding criterion of equal value of laser radar and optimize and revise method.This system can regulate the angle of outgoing laser beam automatically, and according to certain optimized Algorithm, automatically realize adjustment to geometric factor, make between emission of lasering beam axis and the telescopical axis coaxial or parallel as far as possible, reduce the influence of geometric factor, thereby increase effective investigative range of laser radar the atmosphere echoed signal.This system can be widely used in all kinds of radar systems, therefore, has crucial actual application value.

Description of drawings

Fig. 1 is the structural representation of how much overlap factor automatic adjustment systems of laser radar of the present invention;

Fig. 2 is the algorithm flow chart of how much overlap factor automatic adjustment systems of laser radar of the present invention;

Fig. 3 is the control principle figure of how much overlap factor automatic adjustment systems of laser radar of the present invention;

Fig. 4 is the graph of a relation of laser radar echo signal and distance in how much overlap factor automatic adjustment systems of laser radar of the present invention;

Fig. 5 is emission coefficient and a receiving system light path synoptic diagram in how much overlap factor automatic adjustment systems of laser radar of the present invention.

Among the figure, 1. pulsed laser, 2. collimating and beam expanding system, 3. rotatable mirror, 4. stationary mirror, 5. telescope, 6 apertures, 7. lens, 8. optical filter, 9. photoelectricity testing part, 10. Data Acquisition and Conversion System (DACS), 11.X the axle actuator drivers, 12.X axle topworks, 13.Y axle actuator drivers, 14.Y axle topworks, 15. photoelectric detector receiving areas, the hot spot on 16. rotatable mirrors, 17. objective plane, 18. laser beam axis, 19. telescope axis.

Embodiment

The present invention is described in detail below in conjunction with the drawings and specific embodiments.

The structure of how much overlap factor automatic adjustment systems of laser radar of the present invention, as shown in Figure 1, comprise emitting light path, receiving light path and data acquisition and control section, emitting light path comprises pulsed laser 1, and the emergent light side of pulsed laser 1 is disposed with collimating and beam expanding system 2, rotatable mirror 3, stationary mirror 4; Receiving light path comprises telescope 5, and the emergent light side of telescope 5 is disposed with aperture 6, lens 7, optical filter 8, photoelectricity testing part 9; Data acquisition and control section comprise Data Acquisition and Conversion System (DACS) 10, the input end of Data Acquisition and Conversion System (DACS) 10 is set to above-mentioned photoelectricity testing part 9, the output terminal of Data Acquisition and Conversion System (DACS) 10 is provided with two branch roads, article one, branch road is disposed with X-axis actuator drivers 11, X-axis topworks 12, be disposed with Y-axis actuator drivers 13, Y-axis topworks 14 on another branch road, the output terminal of X-axis topworks 12 and Y-axis topworks 14 is set to above-mentioned rotatable mirror 3.

The method that adopts how much overlap factor automatic adjustment systems of above-mentioned laser radar to adjust, specifically implement according to following steps:

Step 1: pulsed laser 1 sends the pulse laser beam of fixed wave length, behind collimating and beam expanding system 2 collimator and extenders, turn to back directive atmosphere by rotatable mirror 3, stationary mirror 4 successively, produce atmosphere backward scattered light echoed signal behind molecule in pulse laser beam and the atmosphere and the particle interaction, after this echoed signal is received by telescope 5, successively by aperture 6, lens 7, optical filter 8, be placed near the photoelectricity testing part of telescope focus 9 and receive, send into subsequently and carry out analyzing and processing in the Data Acquisition and Conversion System (DACS) 10.

Step 2: Data Acquisition and Conversion System (DACS) 10 is with the echoed signal that receives, handle according to criterion of equal value and optimized Algorithm, obtain comprising the control signal of rotatable mirror 3 positional informations, angle by X-axis actuator drivers 11 and Y-axis actuator drivers 13 control X-axis topworkies 12 and Y-axis topworks 14 adjusting rotatable mirrors 3 finally makes through outgoing laser beam axis and telescope 5 deads in line after stationary mirror 4 reflections.

In Data Acquisition and Conversion System (DACS) 10, criterion of equal value and optimized Algorithm are taked the strategy of substep optimizing, promptly earlier to the X-axis optimizing, again to the Y-axis optimizing; Perhaps earlier to the Y-axis optimizing, again to the X-axis optimizing.In independent searching process to diaxon, the criterion of equal value of employing is the same with optimized Algorithm.

In actual applications, owing to be difficult to directly judge whether telescope 4 axis overlap with the outgoing laser beam axis, therefore need to introduce the basis for estimation that can reflect rotatable mirror 3 positional informations indirectly.Can make criterion value of equal value reach maximal value by regulating the anglec of rotation of rotatable mirror 3, just can make outgoing laser beam axis and telescope dead in line degree good more.The present invention has introduced following several criterion of equal value:

(1) echoed signal is carried out integration

Detect atmosphere echoed signal intensity P (z), 0 to z ₂Echoed signal P (z) is carried out integration in the distance range, promptly ask for echoed signal P (z) with time shaft from 0 to z ₂The area that is surrounded:

$C={\&Integral;}_0^{z_2}P\left(z\right)\mathrm{dz}---\left(1\right)$

In the formula, z ₂Be P (z) distance near P (∞) in certain error range.

(2) square correction signal of adjusting the distance is carried out integration

Detect atmosphere echoed signal intensity P (z), and definition square distance correction signal is as follows:

S(z)＝P(z)z ² (2)

Therefore, criterion of equal value can be defined as follows:

$C={\&Integral;}_0^{z_2}S\left(z\right)\mathrm{dz}---\left(3\right)$

In the formula, z ₂Be P (z) distance near P (∞) in certain error range.

(3) normalized signal is carried out integration

Detect atmosphere echoed signal intensity P (z), search out maximum of intensity P _MaxSecondly, carry out normalized, with the intensity level of each point divided by this maximal value, i.e. P (z)/P _Max(z); Then, with distance z ²As weights, to normalized value P (z)/P _MaxCarry out integration, promptly take following criterion:

$C={\&Integral;}_0^{z_2}\frac{P\left(z\right)}{{\mathrm{<figure-callout\; id="2"\; label="P\; max\; z"\; filenames="HSA00000238735000011.png"\; state="\{\{state\}\}">P</figure-callout>}}_{\max }}{z}^{}{}^2\mathrm{dz}---\left(4\right)$

In the formula, z ₂Be P (z) distance near P (∞) in certain error range.

As shown in Figure 2, optimized Algorithm is specifically implemented according to following steps:

A. the current location with rotatable mirror 3 is designated as W ₀, detection of echoes signal intensity P (z) calculates criterion value of equal value according to formula (1) or formula (3) or formula (4), is designated as C ₀

B. with rotatable mirror 3 to low-angle of negative direction rotation, detection of echoes signal intensity P (z) calculates criterion value of equal value according to formula (1) or formula (3) or formula (4), is designated as C ₁, current location is designated as W ₁

C. with rotatable mirror 3 to low-angle of positive dirction rotation, detection of echoes signal intensity P (z) calculates criterion value of equal value according to formula (1) or formula (3) or formula (4), is designated as C ₂, current location is designated as W ₂

D. criterion value C more of equal value ₀, C ₁And C ₂Size, judge W ₀Whether be in the optimum position: work as C ₁, C ₂Value all less than C ₀The time, show W this moment ₀Be in the optimum position, then rotatable mirror 3 adjusted back to W again ₀, regulate and finish; Work as C ₁, C ₂Value all be not less than C ₀The time, show W this moment ₀Be not in the optimum position, so according to C ₁And C ₂Size, control X-axis topworks 12 or Y-axis topworks 14 rotate to above-mentioned W with rotatable mirror 3 ₁Or W ₂The position.

E. current location is designated as W` <sub>0</sub>, and calculate criterion value C` of equal value ₀

F. rotate the θ angle with respect to current location to positive dirction or negative direction, calculate the criterion C` of this moment <sub>1</sub>, this moment, the position was designated as W` ₁, but rotation angle value becomes 1.618 times of adjusting angle value last time; After this time regulating, if criterion value C` of equal value <sub>1</sub>＞C` ₀, then return step e and continue to carry out; If criterion value C` of equal value <sub>1</sub>＜C` ₀, then enter step g and continue to carry out.

G. again rotatable mirror 3 is adjusted back to W ₀The ` position is returned step a and is carried out.

By above analysis as can be known, this is one and is worth optimization problem most, in practice, can make criterion value of equal value reach maximal value by regulating the anglec of rotation of rotatable mirror 3.The self-regulating control system structure of this geometry overlap factor as shown in Figure 3.

Below from the principle aspect automatic adjustment system of the present invention and method of adjustment are described:

Usually, the atmosphere remote measurement is as follows with laser radar equation:

$P\left(z\right)=P_o{C}_1\frac{{\mathrm{<figure-callout\; id="2"\; label="A\; r\; Z"\; filenames="HSA00000238735000011.png"\; state="\{\{state\}\}">A</figure-callout>}}_r}{Z^{}}\mathrm{\&beta;}\left(z\right)\mathrm{\&epsiv;}\left(z\right)e^{-{\&Integral;}_0^{\mathrm{<figure-callout\; id="2"\; label="z"\; filenames="HSA00000238735000011.png"\; state="\{\{state\}\}">z</figure-callout>}}2\mathrm{\&alpha;}\left(z\right)\mathrm{dz}}---\left(5\right)$

In the formula, the echoed signal power (W) that P (z) receives for laser radar; P ₀Emissive power (W) for laser instrument; Z represents to survey height (m), and in formula, surveying height z is with 1/z ²Form occur, shown that the laser radar signal will be along with the increase of height square decaying with height; A _rBe telescopical receiving area (m ²); ε (z) is how much overlap factors, the degree that overlaps of its expression emitted laser bundle and receiving telescope visual field, and when incomplete coincidence, it is worth less than 1, and when reaching when overlapping fully, its value is 1; C ₁Be the system compensation constant, comprise the efficient of detector and the light path transmissivity of system; β (z) is certain backscattering coefficient (m that is detected component in the atmosphere ^-1Sr ^-1); α (z) is the total extinction coefficient of atmosphere, is made up of atmospheric molecule and Aerosol Extinction two parts usually, i.e. α (z)=α _M(z)+α _A(z).

The atmosphere remote measurement with the echoed signal waveform of laser radar as shown in Figure 4, in the figure:

(1) from 0 to z _a, echoed signal strengthens gradually, and this mainly causes owing to the near field geometric factor increases gradually.

(2) from z _aTo z _b, signal reduces gradually, and this mainly is because the effect of the square distance factor, transmission factor, the scattering coefficient factor and far field geometric factor causes.

(3) from z _bTo the infinite distance, it is constant that signal keeps, and this signal can be thought system noise.

Coaxial laser radar geometric factor synoptic diagram as shown in Figure 5.Among Fig. 5, R _dBe the radius of photoelectricity testing part receiving area 15, f is the equivalent focal length of telescope 5, R ₀Be effective reception radius of telescope 5, R` <sub>0</sub>Be hot spot 16 radiuses of outgoing beam on rotatable mirror, A is the angle between the axis 19 of outgoing laser beam axis 18 and telescope 5, A <sub>1</sub>Be the angle of half field-of view of telescope 5, A <sub>2</sub>The angle of divergence for outgoing beam, z is a detection range, R (z) is the visual field radius of telescope at distance z place objective plane 17 places, and R` (z) is the spot radius at objective plane 17 places, and d (z) is the distance between objective plane 17 place's telescopes, 5 optical axis and the laser beam axis 18.

Adjusting to rotatable mirror 3 need be regulated X-axis and Y-axis simultaneously, and X-axis is with respect to the anglec of rotation θ of optimum position _xAnd Y-axis is with respect to the anglec of rotation θ of optimum position _yAnd be the funtcional relationship of a dullness between the included angle A, this funtcional relationship can be expressed as through deriving:

A＝arccos(cos(θ _x)cos(θ _y)) (6)

In fact, the adjusting of included angle A will directly determine the adjusting of the how much overlap factor ε in far field (z).Obviously, under the identical situation of other parameters, the value of how much overlap factor ε (z) is big more, and the value of the correction echoed signal S (z) that z highly locates is just big more.And ε (z) has certain relation with detection height and diaxon included angle A: near field range, owing to blocking of shelters such as stationary mirror, geometric factor is always 0 in a bit of scope of beginning, increases to maximal value then gradually; In this segment distance scope, the laser radar echo signal is increased to a peak value gradually along with the increase of surveying height.This height can think that shelter no longer plays the minimum altitude of bigger effect to geometric factor.When A changed among a small circle, this minimum altitude changed little, depended primarily on the radius of opening of the telescope and shelter.

In far-field range, how much overlap factors no longer are subjected to the influence of shelter; Under the identical situation of other parameter, the value of A is more little, and the distance of equal height place range of telescope central point and spot center point is just more little, and the overlapping region of range of telescope and hot spot is just big more, and the value of geometric factor is also just big more.The value of A is more little in addition, and the effective range of laser radar also can increase.And when A changed among a small circle, the variation of β (z), α (z) was also less relatively, can think to remain unchanged.

In fact, aforementioned (2), (3) plant in the criterion z ²Can be regarded as weights, therefore these two kinds of methods can be eliminated the problem of near field echoes overflow effectively, increase the proportion of far-field signal in criterion, thereby improve the registration of outgoing laser beam axis and telescope axis, increase the effective detection range of laser radar.Obviously the included angle A of diaxon is big more, and criterion value of equal value is more little; The angle of diaxon is more little, and criterion value of equal value is big more; When diaxon overlaps, criterion of equal value will reach maximal value.Therefore,, obtain the maximal value of C, just can make outgoing laser beam axis and telescope dead in line degree good more by automatic adjusting angle A.At this moment, problem also is converted into value and optimizes.This method has been considered the amplitude and the detection range of actual ghosts signal, combines closely with the actual detection of laser radar, therefore has more practicality and operability.

Claims (5)

1. how much overlap factor automatic adjustment systems of a laser radar, it is characterized in that, comprise emitting light path, receiving light path and data acquisition and control section, emitting light path comprises pulsed laser (1), and the emergent light side of pulsed laser (1) is disposed with collimating and beam expanding system (2), rotatable mirror (3), stationary mirror (4); Receiving light path comprises telescope (5), and the emergent light side of telescope (5) is disposed with aperture (6), lens (7), optical filter (8), photoelectricity testing part (9); Data acquisition and control section comprise Data Acquisition and Conversion System (DACS) (10), the input end of Data Acquisition and Conversion System (DACS) (10) is set to described photoelectricity testing part (9), the output terminal of Data Acquisition and Conversion System (DACS) (10) is provided with two branch roads, article one, branch road is disposed with X-axis actuator drivers (11), X-axis topworks (12), be disposed with Y-axis actuator drivers (13) on another branch road, Y-axis topworks (14), the output terminal of X-axis topworks (12) and Y-axis topworks (14) is set to described rotatable mirror (3).

2. how much overlap factor automatic adjusting method of a laser radar, it is characterized in that, adopt how much overlap factor automatic adjustment systems of laser radar, the structure of this system is: comprise emitting light path, receiving light path and data acquisition and control section, emitting light path comprises pulsed laser (1), and the emergent light side of pulsed laser (1) is disposed with collimating and beam expanding system (2), rotatable mirror (3), stationary mirror (4); Receiving light path comprises telescope (5), and the emergent light side of telescope (5) is disposed with aperture (6), lens (7), optical filter (8), photoelectricity testing part (9); Data acquisition and control section comprise Data Acquisition and Conversion System (DACS) (10), the input end of Data Acquisition and Conversion System (DACS) (10) is set to described photoelectricity testing part (9), the output terminal of Data Acquisition and Conversion System (DACS) (10) is provided with two branch roads, article one, branch road is disposed with X-axis actuator drivers (11), X-axis topworks (12), be disposed with Y-axis actuator drivers (13) on another branch road, Y-axis topworks (14), the output terminal of X-axis topworks (12) and Y-axis topworks (14) is set to described rotatable mirror (3)

Specifically implement according to following steps:

Step 1: pulsed laser (1) sends pulse laser beam, behind collimating and beam expanding system (2) collimator and extender, turn to back directive atmosphere by rotatable mirror (3), stationary mirror (4) successively, produce echoed signal, telescope (5) receives echoed signal, echoed signal by aperture (6), lens (7), optical filter (8), passes to photoelectricity testing part (9) and Data Acquisition and Conversion System (DACS) (10) successively;

Step 2: Data Acquisition and Conversion System (DACS) (10) is handled echoed signal according to criterion of equal value and optimized Algorithm, controlled signal, angle by X-axis actuator drivers (11) and Y-axis actuator drivers (13) control X-axis topworks (12) and Y-axis topworks (14) adjusting rotatable mirror (3) makes through outgoing laser beam axis and telescope (5) dead in line after stationary mirror (4) reflection.

3. method of adjustment according to claim 2 is characterized in that, described Data Acquisition and Conversion System (DACS) (10) is handled echoed signal according to criterion of equal value and optimized Algorithm, specifically implements according to following steps:

A. the current location with rotatable mirror (3) is designated as W ₀, detection of echoes signal intensity P (z) is 0 to z ₂Echoed signal P (z) is carried out integration in the distance range, promptly ask for echoed signal P (z) with time shaft from 0 to z ₂The area that is surrounded:

$C={\&Integral;}_0^{z_2}P\left(z\right)\mathrm{dz},$

In the formula, z ₂For P (z) distance near P (∞) in certain error range, be designated as C ₀

B. rotatable mirror (3) is rotated to negative direction, detection of echoes signal intensity P (z) is 0 to z ₂Echoed signal P (z) is carried out integration in the distance range, promptly ask for echoed signal P (z) with time shaft from 0 to z ₂The area that is surrounded:

$C={\&Integral;}_0^{z_2}P\left(z\right)\mathrm{dz},$

In the formula, z ₂For P (z) distance near P (∞) in certain error range, be designated as C ₁, current location is designated as W ₁

C. rotatable mirror (3) is rotated to positive dirction, detection of echoes signal intensity P (z) is 0 to z ₂Echoed signal P (z) is carried out integration in the distance range, promptly ask for echoed signal P (z) with time shaft from 0 to z ₂The area that is surrounded:

$C={\&Integral;}_0^{z_2}P\left(z\right)\mathrm{dz},$

In the formula, z ₂For P (z) distance near P (∞) in certain error range, be designated as C ₂, current location is designated as W ₂

D. criterion value C more of equal value ₀, C ₁And C ₂Size, judge W ₀Whether be in the optimum position: work as C ₁, C ₂Value all less than C ₀The time, show W this moment ₀Be in the optimum position, with rotatable mirror

(3) adjust back to W again ₀, regulate and finish; Work as C ₁, C ₂Value all be not less than C ₀The time, show W this moment ₀Be not in the optimum position, according to C ₁And C ₂Size, control X-axis topworks (12) or Y-axis topworks (14) rotate to above-mentioned W with rotatable mirror (3) ₁Or W ₂The position;

E. current location is designated as W` ₀, detect atmosphere echoed signal intensity P (z), 0 to z ₂Echoed signal P (z) is carried out integration in the distance range, promptly ask for echoed signal P (z) with time shaft from 0 to z ₂The area that is surrounded:

$C={\&Integral;}_0^{z_2}P\left(z\right)\mathrm{dz},$

In the formula, z ₂For P (z) distance near P (∞) in certain error range, be designated as C` ₀

F. rotate the θ angle with respect to current location to positive dirction or negative direction, detect atmosphere echoed signal intensity P (z), 0 to z ₂Echoed signal P (z) is carried out integration in the distance range, promptly ask for echoed signal P (z) with time shaft from 0 to z ₂The area that is surrounded:

$C={\&Integral;}_0^{z_2}P\left(z\right)\mathrm{dz},$

In the formula, z ₂For P (z) distance near P (∞) in certain error range, be designated as C` <sub>1</sub>, this moment, the position was designated as W` ₁, rotation angle value is last time 1.618 times of the adjusting angle value; After this time regulating, if criterion value C` of equal value <sub>1</sub>＞C` ₀, then return step e and continue to carry out; If criterion value C` of equal value <sub>1</sub>＜C` ₀, then enter step g and continue to carry out;

G. again rotatable mirror (3) is adjusted back to W ₀The position is returned step a and is carried out.

4. method of adjustment according to claim 2 is characterized in that, described Data Acquisition and Conversion System (DACS) (10) is handled echoed signal according to criterion of equal value and optimized Algorithm, specifically implements according to following steps:

A. the current location with rotatable mirror (3) is designated as W ₀, detection of echoes signal intensity P (z), definition square distance correction signal is as follows:

S(z)＝P(z)z ²，

Criterion of equal value is defined as follows:

$C={\&Integral;}_0^{z_2}S\left(z\right)\mathrm{dz},$

In the formula, z ₂For P (z) distance near P (∞) in certain error range, be designated as C ₀

B. rotatable mirror (3) is rotated to negative direction, detection of echoes signal intensity P (z), definition square distance correction signal is as follows:

S(z)＝P(z)z ²，

Criterion of equal value is defined as follows:

$C={\&Integral;}_0^{z_2}S\left(z\right)\mathrm{dz},$

In the formula, z ₂For P (z) distance near P (∞) in certain error range, be designated as C ₁, current location is designated as W ₁

C. rotatable mirror (3) is rotated to positive dirction, detection of echoes signal intensity P (z), definition square distance correction signal is as follows:

S(z)＝P(z)z ²，

Criterion of equal value is defined as follows:

$C={\&Integral;}_0^{z_2}S\left(z\right)\mathrm{dz},$

In the formula, z ₂For P (z) distance near P (∞) in certain error range, be designated as C ₂, current location is designated as W ₂

D. criterion value C more of equal value ₀, C ₁And C ₂Size, judge W ₀Whether be in the optimum position: work as C ₁, C ₂Value all less than C ₀The time, show W this moment ₀Be in the optimum position, rotatable mirror (3) is adjusted back to W again ₀, regulate and finish; Work as C ₁, C ₂Value all be not less than C ₀The time, show W this moment ₀Be not in the optimum position, according to C ₁And C ₂Size, control X-axis topworks (12) or Y-axis topworks (14) rotate to above-mentioned W with rotatable mirror (3) ₁Or W ₂The position;

E. current location is designated as W` ₀, detecting atmosphere echoed signal intensity P (z), definition square distance correction signal is as follows:

S(z)＝P(z)z ²，

Criterion of equal value is defined as follows:

$C={\&Integral;}_0^{z_2}S\left(z\right)\mathrm{dz},$

In the formula, z ₂For P (z) distance near P (∞) in certain error range, be designated as C` ₀

F. rotate the θ angle with respect to current location to positive dirction or negative direction, detect atmosphere echoed signal intensity P (z), definition square distance correction signal is as follows:

S(z)＝P(z)z ²，

Criterion of equal value is defined as follows:

$C={\&Integral;}_0^{z_2}S\left(z\right)\mathrm{dz},$

In the formula, z ₂For P (z) distance near P (∞) in certain error range, be designated as C` <sub>1</sub>, this moment, the position was designated as W` ₁, rotation angle value is last time 1.618 times of the adjusting angle value; After this time regulating, if criterion value C` of equal value <sub>1</sub>＞C` ₀, then return step e and continue to carry out; If criterion value C` of equal value <sub>1</sub>＜C` ₀, then enter step g and continue to carry out;

G. again rotatable mirror (3) is adjusted back to W ₀The ` position is returned step a and is carried out.

5. method of adjustment according to claim 2 is characterized in that, described Data Acquisition and Conversion System (DACS) (10) is handled echoed signal according to criterion of equal value and optimized Algorithm, specifically implements according to following steps:

A. the current location with rotatable mirror (3) is designated as W ₀, detection of echoes signal intensity P (z) searches out maximum of intensity P _MaxSecondly, carry out normalized, with the intensity level of each point divided by this maximal value, i.e. P (z)/P _Max(z); Then, with distance z ²As weights, to normalized value P (z)/P _MaxCarry out integration, promptly take following criterion:

$C={\&Integral;}_0^{z_2}\frac{P\left(z\right)}{P_{\max }}{z}^2\mathrm{dz},$

In the formula, z ₂For P (z) distance near P (∞) in certain error range, be designated as C ₀

B. rotatable mirror (3) is rotated to negative direction, detection of echoes signal intensity P (z) searches out maximum of intensity P _MaxSecondly, carry out normalized, with the intensity level of each point divided by this maximal value, i.e. P (z)/P _Max(z); Then, with distance z ²As weights, to normalized value P (z)/P _MaxCarry out integration, promptly take following criterion:

$C={\&Integral;}_0^{z_2}\frac{P\left(z\right)}{P_{\max }}{z}^2\mathrm{dz},$

In the formula, z ₂For P (z) distance near P (∞) in certain error range, be designated as C ₁, current location is designated as W ₁

C. rotatable mirror (3) is rotated to positive dirction, detection of echoes signal intensity P (z) searches out maximum of intensity P _MaxSecondly, carry out normalized, with the intensity level of each point divided by this maximal value, i.e. P (z)/P _Max(z); Then, with distance z ²As weights, to normalized value P (z)/P _MaxCarry out integration, promptly take following criterion:

$C={\&Integral;}_0^{z_2}\frac{P\left(z\right)}{P_{\max }}{z}^2\mathrm{dz},$

In the formula, z ₂For P (z) distance near P (∞) in certain error range, be designated as C ₂, current location is designated as W ₂

D. criterion value C more of equal value ₀, C ₁And C ₂Size, judge W ₀Whether be in the optimum position: work as C ₁, C ₂Value all less than C ₀The time, show W this moment ₀Be in the optimum position, rotatable mirror (3) is adjusted back to W again ₀, regulate and finish; Work as C ₁, C ₂Value all be not less than C ₀The time, show W this moment ₀Be not in the optimum position, according to C ₁And C ₂Size, control X-axis topworks (12) or Y-axis topworks (14) rotate to above-mentioned W with rotatable mirror (3) ₁Or W ₂The position;

E. current location is designated as W` ₀, detect atmosphere echoed signal intensity P (z), search out maximum of intensity P _MaxSecondly, carry out normalized, with the intensity level of each point divided by this maximal value, i.e. P (z)/P _Max(z); Then, with distance z ²As weights, to normalized value P (z)/P _MaxCarry out integration, promptly take following criterion:

$C={\&Integral;}_0^{z_2}\frac{P\left(z\right)}{P_{\max }}{z}^2\mathrm{dz},$

In the formula, z ₂For P (z) distance near P (∞) in certain error range, be designated as C` ₀

F. rotate the θ angle with respect to current location to positive dirction or negative direction, detect atmosphere echoed signal intensity P (z), search out maximum of intensity P _MaxSecondly, carry out normalized, with the intensity level of each point divided by this maximal value, i.e. P (z)/P _Max(z); Then, with distance z ²As weights, to normalized value P (z)/P _MaxCarry out integration, promptly take following criterion:

$C={\&Integral;}_0^{z_2}\frac{P\left(z\right)}{P_{\max }}{z}^2\mathrm{dz},$

In the formula, z ₂For P (z) distance near P (∞) in certain error range, be designated as C` <sub>1</sub>, this moment, the position was designated as W` ₁, rotation angle value is last time 1.618 times of the adjusting angle value; After this time regulating, if criterion value C` of equal value <sub>1</sub>＞C` ₀, then return step e and continue to carry out; If criterion value C` of equal value <sub>1</sub>＜C` ₀, then enter step g and continue to carry out;

G. again rotatable mirror (3) is adjusted back to W ₀The ` position is returned step a and is carried out.

Images