Summary of the invention
Technology of the present invention is dealt with problems and is: the deficiency that overcomes prior art; The moon heart adjustment in direction method of ground month navigation in a kind of day is provided; The integrated day ground month fan-shaped visual field scanning of navigation sensor revised to the pulse of the moon constantly; Thereby improved the precision of definite month heart direction, finally improved the precision of autonomous navigation system.
Technical solution of the present invention is: the moon heart adjustment in direction method performing step of ground month navigation in a kind of day is following:
(1) calculates the moon heart direction position angle φ in integrated day ground month navigation sensor measurement coordinate system revise
MWith angle of pitch δ
M, formula is following
δ
M=arctg(sinμ
Mctgβ
L) (23)
In the formula, ω
ROTThe sweep speed of integrated day ground month navigation sensor; t
L1-MOONMonth fan-shaped visual field 1 of navigation sensor, integrated day ground scans the pulse moment of the moon; t
L2-MOONMonth fan-shaped visual field 2 of navigation sensor, integrated day ground scans the pulse moment of the moon; t
M1-M2-REFThe integrated day ground month navigation sensor plane of symmetry is through the pulse moment of reference point on integrated day ground month navigation sensor equatorial plane;
D
L1-L2Month fan-shaped visual field 1 of navigation sensor, integrated day ground was ahead of the angle of month fan-shaped visual field 2 of navigation sensor, integrated day ground on the ground month navigation sensor equatorial plane on integrated; β
LFan-shaped visual field 1 of month navigation sensor, integrated day ground and fan-shaped visual field 2 are with respect to the angle of integrated day ground month navigation sensor scanning axes of rotation skew.
(2) the coordinate E of moon heart direction in integrated day ground month navigation sensor measurement coordinate system before calculate revising
Sm, formula is following
(3) calculate to revise vector that satellite before month heart direction points to the moon three component x in integrated day ground month navigation sensor measurement coordinate system
m, y
m, z
m, formula is following
In the formula, L
MsFor the moon arrives satellite distance.
(4) calculate to revise before month heart direction angle μ between the reference point on the projection of the integrated day ground month navigation sensor equatorial plane and the integrated day ground moon navigation sensor equatorial plane, formula is following
μ=arccos(z
m/L
ms) (26)
(5) calculate poor between maximum visual angle, moon clear zone and the actual angle of visibility.
γ=arccos(R
m/L
ms)-li (27)
In the formula, R
mBe the moon radius of a ball; Li is actual angle of visibility, is to obtain according to a day ground month ephemeris computation of storing on satellite orbit that forecasts on the star and the star.
(6) calculate offset angle λ, formula is following
λ=arccos[(L
ms 2-R
m 2+R
m 2cosγ)/L
ms 2] (28)
(7) calculate intermediate variable η, formula is following
η=arccos{[L
ms 2-R
m 2+R
m 2cos(li)]/L
ms 2}?(29)
(8) calculate to revise back month heart direction angle μ ' between the reference point on the projection of the integrated day ground month navigation sensor equatorial plane and the integrated day ground moon navigation sensor equatorial plane, formula is following
μ′=μ+[arccos(R
m/L
ms)-η-λ] (30)
(9) calculate satellite and point to the projection r of moon vector at the integrated day ground month navigation sensor equatorial plane
k, formula is following
(10) calculate intermediate variable Q, formula is following
(11) calculate intermediate variable T, formula is following
(12) calculate scanning corner ε, formula is following
(13) calculate the angle ε _ L1 and the ε _ L2 of the projection on integrated day ground month navigation sensor equatorial plane of the fan-shaped visual field of integrated day ground month navigation sensor 1, fan-shaped visual field 2 and month heart direction, be divided into following 4 kinds of situation
1. if y
m<0 and μ>=ε, then
2. if y
m<0 and μ<ε, then
3. if y
m>=0 and μ>=ε, then
4. if y
m>=0 and μ<ε, then
(14) the integrated day ground moon fan-shaped visual field 1 of navigation sensor and 2 after the calculating correction month heart direction scans the pulse moment t ' of the moon
L1-MOONAnd t '
L2-MOON, formula is following
(15) calculate revised month heart direction position angle φ ' in integrated day ground month navigation sensor measurement coordinate system
MWith angle of pitch δ '
M, formula is following
δ′
M=arctg(sinμ′
Mctgβ
L) (41)
In the formula,
(16) calculate revised month heart direction coordinate E ' in integrated day ground month navigation sensor measurement coordinate system
Sm, formula is following
Thereby accomplish moon heart adjustment in direction to day ground month navigation.
The present invention's advantage compared with prior art: the shape that prior art is ignored the moon clear zone that can observe on the star is the actual conditions that constantly change, and the moon heart direction that obtains through integrated day ground month navigation sensor scanning survey information has certain angular deviation with an actual moon heart direction.The present invention introduces a month heart direction with the visible moon clear zone of the satellite of predicting on star information and confirms algorithm; The integrated day ground month fan-shaped visual field scanning of navigation sensor revised to the pulse of the moon constantly; Thereby improved the precision of definite month heart direction, finally improved the precision of autonomous navigation system.
Embodiment
A ground month navigation sensor comprised two double cone scanning type earth sensors and two sector display formula life sensors in integrated day.Integrated day ground month navigation sensor can be responsive to earth heat radiation, again can be responsive to day, month visible light.
In Fig. 1, the visual field that infrared visual field 1 and infrared visual field 2 are double cone scanning type earth sensors, the fan-shaped visual field of visible light is the visual field of sector display formula life sensor.
What the present invention mainly adopted is the integrated day sector display formula life sensor in the ground month sensor; They utilize the si-photodiode detector can be responsive to the sun and the moon, and the moment that in fan-shaped visual field, occurs according to the sun and the moon can calculate the orientation of its direction vector with respect to satellite.The visual field of each visible light sensor is that 72 degree are long, the wide fan-shaped shape of slit of 2.5 degree, and it is with respect to scanning axes of rotation skew 16 degree angles.In the optical head scanning process, fan-shaped visual field scanning cross the space for and scanning rotating shaft angle spend to the spherical zone zone between 87 degree 23.
As shown in Figure 2, the measurement coordinate system of integrated day ground month navigation sensor.Initial point O
sThe intersection point of the scanning rotating shaft of integrated day ground month navigation sensor and integrated day ground month sensor equatorial plane, X
sAlong scanning rotor shaft direction, Z
sIn the sensor equatorial plane, and make the reference point that is fixed on sensor be positioned at O
s-Z
sX
sIn the plane, Y
sMake O
s-X
sY
sZ
sConstitute right hand orthonormal system.
The fan-shaped visual field of two sector display formula life sensors shown in Fig. 3 is designated as fan-shaped visual field 1 and fan-shaped visual field 2 respectively, the symmetrical plane of fan-shaped visual field 1 and 2 is designated as the M1-M2 face.Fan-shaped visual field 1 was ahead of fan-shaped visual field 2 on the ground month navigation sensor equatorial plane on integrated angle is designated as D
L1-L2, see Fig. 3.Fan-shaped visual field 1 and 2 angles with respect to the scanning axes of rotation skew are designated as β
L, see Fig. 3.Here D
L1-L2=4 degree, β
L=16 degree.
Integrated day ground month navigation sensor mainly contains three times to the basic observed quantity of the moon: the pulse that the moon is swept in fan-shaped visual field 1 is t constantly
L1-MOON, the fan-shaped visual field 2 pulse t constantly that sweeps to the moon
L2-MOON, the pulse of plane of symmetry M1-M2 through reference point t constantly
M1-M2-REFCan obtain position angle and the elevation angle of moon heart direction according to these three observed quantities with respect to integrated day ground month navigation sensor measurement coordinate system, and the coordinate of the satellite vector that points to the moon in integrated day ground month navigation sensor measurement coordinate system.
The sweep speed of integrated day ground month navigation sensor is designated as ω
ROT, ω
ROT=240 rev/mins=8 π radian per seconds, getting sensor can only be rotated counterclockwise.
In Fig. 4, provided the principle of the correction moon of the present invention heart direction.Wherein, solid line representes that partly dotted portion is represented the edge, clear zone under the situation that the moon of simulating after the over-compensation be not blocked from the edge, the actual clear zone of the moon that satellite is seen.
Known integrated day ground month navigation sensor scanning survey information t
L1-MOON, t
L2-MOON, t
M1-M2-REF, then the present invention calculates the moon heart direction E ' that contains compensation rate
SmMethod step following:
(1) calculates the moon heart direction position angle φ in integrated day ground month navigation sensor measurement coordinate system revise
MWith angle of pitch δ
M, formula is following
δ
M=arctg(sinμ
Mctgβ
L) (44)
In the formula,
(2) the coordinate E of moon heart direction in integrated day ground month navigation sensor measurement coordinate system before calculate revising
Sm, formula is following
(3) calculate to revise vector that satellite before month heart direction points to the moon three component x in integrated day ground month navigation sensor measurement coordinate system
m, y
m, z
m, formula is following
In the formula, L
MsFor the moon arrives satellite distance.
(4) calculate to revise before month heart direction angle μ between the reference point on the projection of the integrated day ground month navigation sensor equatorial plane and the integrated day ground moon navigation sensor equatorial plane, formula is following
μ=arccos(z
m/L
ms) (47)
(5) calculate poor between maximum visual angle, moon clear zone and the actual angle of visibility.
γ=arccos(R
m/L
ms)-li (48)
In the formula, R
mBe the moon radius of a ball; Li is actual angle of visibility, is to obtain according to a day ground month ephemeris computation of storing on satellite orbit that forecasts on the star and the star.
(6) calculate offset angle λ, formula is following
λ=arccos[(L
ms 2-R
m 2+R
m 2cosγ)/L
ms 2] (49)
(7) calculate intermediate variable η, formula is following
η=arccos{[L
ms 2-R
m 2+R
m 2cos(li)]/L
ms 2} (50)
(8) calculate to revise back month heart direction angle μ ' between the reference point on the projection of the integrated day ground month navigation sensor equatorial plane and the integrated day ground moon navigation sensor equatorial plane, formula is following
μ′=μ+[arccos(R
m/L
ms)-η-λ] (51)
(9) calculate satellite and point to the projection r of moon vector at the integrated day ground month navigation sensor equatorial plane
k, formula is following
(10) calculate intermediate variable Q, formula is following
(11) calculate intermediate variable T, formula is following
(12) calculate scanning corner ε, formula is following
(13) calculate the angle ε _ L1 and the ε _ L2 of the projection on integrated day ground month navigation sensor equatorial plane of the fan-shaped visual field of integrated day ground month navigation sensor 1, fan-shaped visual field 2 and month heart direction, be divided into following 4 kinds of situation
1. if y
m<0 and μ>=ε, then
2. if y
m<0 and μ<ε, then
3. if y
m>=0 and μ>=ε, then
4. if y
m>=0 and μ<ε, then
(14) the integrated day ground moon fan-shaped visual field 1 of navigation sensor and 2 after the calculating correction month heart direction scans the pulse moment t ' of the moon
L1-MOONAnd t '
L2-MOON, formula is following
(15) calculate revised month heart direction position angle φ ' in integrated day ground month navigation sensor measurement coordinate system
MWith angle of pitch δ '
M, formula is following
δ′
M=arctg(sinμ′
Mctgβ
L) (62)
In the formula,
(16) calculate revised month heart direction coordinate E ' in integrated day ground month navigation sensor measurement coordinate system
Sm, formula is following
So far, calculated revised month heart direction E '
Sm, compare the moon heart direction E before revising
Sm, its precision is higher.
Simulation example: the flying height of satellite is the near-circular orbit of 500km, and three attitude angle are zero, and the nominal orbit parameter is a=6878.14km, e=0.001, i=97.4 °, Ω=157.5 °, ω=90 °, M=0 °.
Attitude misalignment, the random measurement noise mean square deviation of the moon is taken as 0.05 ° (3 σ).Track condition is estimated initial value: there is the 10km error in semi-major axis a, the same nominal value of other state initial value.
The emulation initial time is got 0 o'clock on the 1st January in 2010, simulation time 3600s, step-length 60s.Simulation result shown in Fig. 5~7, wherein position angle and height angular unit degree of being.
Fig. 5 has provided the error of position angle and the elevation angle in integrated day ground month navigation sensor measurement coordinate system of month heart direction vector before the compensation; Fig. 6 has provided position angle and the elevation angle error after the compensation.
Can find out by Fig. 5 and Fig. 6; Compensation forward angle error is about 0.06 °~0.4 °; The elevation angle error is between-0.08 °~0.08 °, and compensation back bearing error is about-0.09 °~0.13 °, and the elevation angle error is between-0.045 °~0.045 °.It is thus clear that the moon clear zone shape through satellite is seen compensates, and can improve definite precision of moon heart direction greatly, especially azimuthal definite precision is more than doubled.
The content of not doing to describe in detail in the instructions of the present invention belongs to those skilled in the art's known technology.