Utilize the three-dimensional posture fixing method of atmospheric polarization light
Technical field
The present invention relates to the autonomous measuring method of bionic three-dimensional attitude, specifically a kind of polarization mode that utilizes atmosphere natural light extracts a kind of method of the 3 d pose information of endoatmosphere motion carrier.
Background technology
At present, utilize the bionic navigation research that atmospheric polarization type carries out to be considered to a kind of new direction that has prospect, be prevalent in natural most of invertabrate and part vertebrate, particularly there is the insect of compound eye structural.Atmospheric polarization type is that sunshine enters after atmospheric envelope with atmospheric molecule ion scattering forms and a kind ofly has a stable form distributing, it is the natural quality of the earth, the directional information that wherein contained can be insect course information is provided, and has pure independently, is not vulnerable to the feature of external disturbance.
Research shows, in compound eye, the ommatidium of polarization sensitive is concentrated on into fan-shaped distribution back edge district, and the ommatidium in sky all directions can detect the polarization mode of sky bulk zone.Insect utilizes the polarization information perception sun meridian in detected this region and the angle of axon to determine course.To flying insect, realize three-dimensional navigation and not only will solve course problem, also to solve aloft attitude problem.Bionical behaviouristics is tested and is shown, the method for utilizing atmospheric polarization type information to carry out three-dimensional navigation is feasible.Crawling insect utilizes polarized light and odometer location, and flying insect utilizes polarized light and light stream perception to locate.
The regularity of distribution of atmospheric polarization type: the light that solar radiation goes out is through atmospheric scattering, and the light that arrives earth surface has become the stack of natural light and linearly polarized light, has formed and has had the stable polarization state distributing.Because the stable polarization state distributing is the radiation spectrum for whole sunshine, its distribution has electromagnetism/artificial interference, the round-the-clock feature of not being subject to, and distribute along the surface of the whole earth, relative position between its atmospheric polarization state eigenvector information and the sun has extremely strong regularity, can be polarized light detection reliable information carrier in a global range is provided.Through research, find, there is a kind of metastable polarization mode in the atmosphere under observation position arbitrarily, it shows as two stable line of symmetries that distribute, article one, be sun meridian and contrary sun meridian SM-ASM, the degree of polarization of atmospheric polarization type is symmetrical about SM-ASM, E-vector about SM-ASM against symmetrical; Another is to be the maximum polarized line of 90 ° with solar angle distance, and atmospheric polarization type is symmetrical about maximum polarized line, the position at polarized line place, and degree of polarization is maximum, and far away apart from line of symmetry, degree of polarization is less.
At present, for endoatmospheric motion carrier, especially unmanned autonomous platform is as unmanned plane, robot etc., and in its navigation procedure, the measurement of 3 d pose is very crucial.There is the defect of accumulated error in traditional inertial navigation, and GPS needs a large amount of satellite supports, is vulnerable to external electromagnetic wave interference.
Summary of the invention
The problems referred to above that the present invention exists in order to solve the existing air navigation aid for space motion body, provide a kind of three-dimensional posture fixing method of utilizing atmospheric polarization light.
The present invention adopts following technical scheme to realize:
A three-dimensional posture fixing method of utilizing atmospheric polarization light, comprises the steps:
(1), build three-dimensional coordinate system, the center of gravity of carrier of take is initial point O ', the axon of carrier is X ' axle, pointing to carrier top is Z ' axle, Y ' axle meets right hand rectangular coordinate system regulation; Be that X ' O ' Y ' plane is the flight dip plane of carrier;
Foundation, with reference to rectangular coordinate system, be take ground detection point as initial point O, and pointing to due east direction is X-axis, is Z axis vertically upward, and sensing direct north is Y-axis; Take XOY plane as reference level surface;
The center of gravity O ' that bionic compound eyes sphere sensor array is arranged on to carrier locates.
(2), utilize the sunshine E-Vector Message in bionic compound eyes sensor array Real-time Collection all directions, and determine the ommatidium array of the E-vector that horizontal direction detected and the geometric position on sphere thereof;
Then after initial point O ' and O being overlapped, the projection of the ommatidium array of determining the E-vector that horizontal direction detected in reference level surface, i.e. the projection CD of sun meridian in reference level surface; The intersection of certain moment X ' O ' Y ' plane and XOY plane is AB;
In reference level surface, the angle σ between CD and AB is determined by formula (1)
Wherein, α is the angle between sun subpoint S and dip plane normal; β is the angle between dip plane normal and Z axis; α and β all can be measured by bionic compound eyes sphere sensor array; θ
sfor sun polar angle, can be calculated by solar calendar theory.
Now, by solar calendar theory, calculated the angle of CD and Y-axis in reference level surface
axon O ' X ' is projected as OU ' on surface level, is measured the angle of CD and OU ' by bionic compound eyes sphere sensor array
ρ is the angle of Y-axis and AB in reference level surface, by formula (2), is determined
Be known α, β, θ
s, σ, ρ,
(3), determine crab angle Ψ
Crab angle Ψ is the angle of Y-axis and OU ' in reference level surface, by formula (3), is determined:
(4), determine pitching angle theta and roll angle φ
The angle ω of X ' axle and X-axis, is determined by formula (4):
cosω=cos
2ρcosβ+sin
2ρ..................................(4)
Pitching angle theta is determined by formula (5):
cosω=cosψcosθ................................................(5)
The angle δ of Y ' axle and Y-axis, is determined by formula (6):
cosδ=sin
2ρcosβ+cos
2ρ.................................(6)
Roll angle φ is determined by formula (7):
cosδ=cosψcosφ-sinψsinθsinφ..............................(7)
Calculate crab angle ψ, pitching angle theta and roll angle φ, complete carrier and determine in the attitude in space.
The directional information that said method utilizes atmospheric polarization type to contain, for aircraft (carrier) flight attitude provides reference, its principle of work is: utilize the E-Vector Message in bionic compound eyes sensor array Real-time Collection all directions, determine the ommatidium array of E-vector of detection level direction and the geometric position on sphere thereof; Then according to the angle that the projection of the meridianal ommatidium array of the sun in reference level surface and aircraft axon detected, crab angle is determined in the projection in reference level surface; Finally, according to detecting the angle of meridian center (zenith) with sphere centre, utilize formula (5), (7) to calculate respectively the angle of pitch and roll angle.
The present invention is reasonable in design, utilize the entrained polarized light detection array detection of aircraft to present mode mate with the polarization mode under horizontality, calculate the angle of pitch and roll angle; Utilize sun meridian and axon angle to determine crab angle.Adopt atmospheric polarization type to carry out three-dimensional posture fixing, a kind of good technological means is provided, have completely from principal characteristic, by the detection in real time atmospheric polarization type being distributed, just can calculate the 3 d pose of self, simple possible does not have cumulative errors, and polarization information is present in endoatmospheric visible ray simultaneously, is difficult to by artificial large area, disturbed and destroy.
Accompanying drawing explanation
Fig. 1 is the schematic diagram with α, β, γ, σ angle.
Fig. 2 is the schematic diagram with crab angle.
Fig. 3 is the schematic diagram with ω and δ angle
Embodiment
Below in conjunction with accompanying drawing, the specific embodiment of the present invention is elaborated.
A three-dimensional posture fixing method of utilizing atmospheric polarization light, comprises the steps:
(1), build three-dimensional coordinate system, the center of gravity of carrier of take is initial point O ', the axon of carrier is X ' axle, pointing to carrier top is Z ' axle, Y ' axle meets right hand rectangular coordinate system regulation; Be that X ' O ' Y ' plane is the flight dip plane of carrier;
Foundation, with reference to rectangular coordinate system, be take ground detection point as initial point O, and pointing to due east direction is X-axis, is Z axis vertically upward, and pointing to geographical direct north is Y-axis; Take XOY plane as reference level surface;
The center of gravity O ' that bionic compound eyes sphere sensor array is arranged on to carrier locates.
Described bionic compound eyes sphere sensor array, those skilled in the art can be based on husky ant living model independent design or customize the existing matured product of domestic and international scientific research institution voluntarily.
(2), utilize the sunshine E-Vector Message in bionic compound eyes sensor array Real-time Collection all directions, and determine the ommatidium array of the E-vector that horizontal direction detected and the geometric position on sphere thereof;
Carrier 3 d pose determine location-independent with center of gravity O ' of carrier, for convenience of initial point O ' and initial point O are overlapped, the projection of the ommatidium array of determining E-vector that horizontal direction detected in reference level surface, i.e. the projection CD of sun meridian in reference level surface; The intersection of certain moment X ' O ' Y ' plane and XOY plane is AB;
In reference level surface, the angle σ between CD and AB is determined by formula (1)
Wherein, as shown in Figure 1, α is the angle between sun subpoint S and dip plane normal; β is the angle between dip plane normal and Z axis; α and β all can be measured by bionic compound eyes sphere sensor array; θ
sfor sun polar angle, those skilled in the art calculate according to solar calendar theory, do not have technical difficulty.
Now, those skilled in the art calculate the angle of CD and Y-axis in reference level surface according to solar calendar theory
axon O ' X ' is projected as OU ' in reference level surface, is measured the angle of CD and OU ' by bionic compound eyes sphere sensor array (arranging according to the simple eye geometry of sensor array)
ρ is the angle of Y-axis and two sides intersection AB on surface level, by formula (2), is determined
Be known α, β, θ
s, σ, ρ,
Principle is as follows: according to existing achievement in research, atmospheric polarization type has stable symmetry, the ommatidium listing towards sky different directions due to bionic compound eyes sphere sensor array detects polarization information and the intensity signal making progress from the party simultaneously, in order to determine the relation between sky polarization mode and flight attitude.First, as shown in Figure 1, on the sphere of bionic compound eyes sphere sensor array, the position of those ommatidiums of all polarization angle χ=90 that detect ° on sphere forms a curve, this curve is with the interior sun meridian of hemisphere is corresponding on high, sun meridian must pass through sun subpoint S(check point and the line of position of sun and the intersection point of sky hemisphere) with the intersection point of zenith point M(Y axle and sky hemisphere), sun meridian is about zenith point M symmetry; Then, measure sun subpoint S and the position of zenith point M on spherical array, theoretical according to Rayleigh scattering, in sun subpoint S direction, there are several like this features: (1) degree of polarization P=0; (2) E-direction vector level; (3) light intensity is maximum.And M is in sun meridian central point.Can determine like this intersection point of a M, N(dip plane normal and sky hemisphere) and the position of S on spherical array; Finally, according to these 3 geometric positions on spherical array, naturally just can determine angle α and β, and γ can be calculated by theory.As shown in Figure 2, the direct north of take in reference level surface is coordinate basis direction, any time anywhere sun meridian ASM-SM and the angle of direct north be

those skilled in the art can be drawn by calculation of parameter such as geographic coordinate information and time references
because the E-direction vector of any point on sun meridian has like this, that is: along sun meridian E-direction vector level.Therefore, when measuring, only need to pay close attention to all those ommatidium positions that polarization angle χ=90 ° detected, their projections in reference level surface are consistent with the projection of sun meridian in reference level surface, measure the angle between the projection OU ' of O ' X ' axle in reference level surface on this projection line and dip plane and are
like this, by the measurement of bionic compound eyes sphere sensor array and theoretical calculating, can directly obtain seven basic angular distance: α, β, θ
s, σ, ρ,
(3), determine crab angle
Crab angle ψ is the angle of Z axis and OU ' in reference level surface, by formula (3), is determined:
(4), determine the angle of pitch and roll angle
Determined after crab angle, the polarization mode that can further detect by spherical array changes the angle of pitch and the roll angle of determining carrier.Suppose the state of flight of a certain place carrier of a certain moment, as shown in Figure 3.Now, aircraft dip plane can be regarded as by take again AB after reference surface surface level rotation ψ angle and obtain after axle flip angle β.
The angle ω of X ' axle and X-axis, is determined by formula (4):
cosω=cos
2ρcosβ+sin
2ρ..................................(4)
Pitching angle theta is determined by formula (5):
cosω=cosψcosθ................................................(5)
The angle δ of Y ' axle and Y-axis, is determined by formula (6):
cosδ=sin
2ρcosβ+cos
2ρ.................................(6)
Roll angle φ is determined by formula (7):
cosδ=cosψcosφ-sinψsinθsinφ..............................(7)
Calculate crab angle ψ, pitching angle theta and roll angle φ, complete carrier and determine in the attitude in space.