CN102288133B - Installation deflection angle calibration method of gyro indirect stable system - Google Patents

Abstract

The invention relates to an installation deflection angle calibration method of a gyro indirect stable system, which comprises the steps that: an inertial measurement unit (IMU) and a video camera are simultaneously arranged on a carrier, the optical axis of the video camera aims at a fixed target, the carrier is controlled to swing regularly, the optical axis of the video camera is stabilized through an indirect stabilizing technology, then an image processing technology is adopted to estimate the deviation information of the optical axis of the video camera relative to the fixed target, the deviation information is used for measuring, and the installation deflection angle between an IMU coordinate system and a carrier coordinate system in the indirect stabilizing system as well as the installation deflection between a video camera coordinate system and the carrier coordinate system can be accurately estimated according to an installation deflection angle estimation model. The installation deflection angle calibration method of the gyro indirect stable system excites installation errors into view axis aiming errors through the regular swinging of the carrier, reverses the installation deflection angles by measuring the aiming errors, can estimate five installation deflection angles through one experiment, and has the characteristics of accuracy, high efficiency, easiness in operation, high universality and the like. After the installation deflection angles are estimated and corresponding errors are compensated through the method, the view axis stability and precision of the system can be greatly improved.

Description

A kind of installation deflection angle calibration method of gyro indirect stable system

Technical field

The present invention relates to a kind of mounting error calibration method, can be applicable to certainly demarcation, the self-correcting of various instruments and system, also can be applicable to test and the demarcation of inertia device and inertia assembly, belong to automatic control, inertia measurement field.

Technical background

Have that the optical axis is stable, the Photodetection system of following function is with a wide range of applications in fields such as Missile Terminal Guidance system, unmanned plane Reconnaissance systems.At present, most Photodetection systems all adopt traditional rate gyro stable platform scheme, and this scheme is with its higher lasting accuracy and have larger bandwidth and be widely applied in every field, but the volume of system, weight are larger, and cost is higher.Along with the development need of miniaturization, low-cost Photodetection system, directly adopt the stabilization technique of rate gyro to be restricted, propose to adopt the indirect stabilization mode to solve the stable problem of the optical axis for this reason.

Directly stationary mode is traditional gyrostabilized platform, two gyros are directly installed on the inner frame of two degrees of freedom servo turntable, rate gyro is directly measured the disturbance angle velocity of boresight, and form feedback moment for the disturbance torque of offsetting platform, thereby realize the spatial stability of optical axis, its principle as shown in Figure 2.This stationary mode can directly be measured the disturbance angle velocity of boresight, and disturbance torque is had preferably inhibition, and theory and practice proves that all the precision of the direct systems stabilisation of boresight can satisfy engineering demand.But this mode cost is high, volume is large, complex structure, for satisfying the growth requirement of miniaturization, low-cost target seeker, attempts to adopt the indirect stabilization mode to solve the stable problem of boresight.The indirect stabilization mode has been removed two gyros on the target seeker stable platform, utilizes the robot pilot connect firmly on carrier or the Inertial Measurement Unit (IMU) of navigational system, measures the angular velocity on three directions of carrier.The angular speed information of computing machine by carrier, and in conjunction with kinematics model and the kinetic model of Photodetection system framework is estimated and disturbance torque that the reconstruct Photodetection system is subject to, and is controlled motor and eliminate this disturbance torque.Its stability principle is illustrated in fig. 3 shown below.The compact mechanical structure of this stationary mode is small and exquisite, and expense is relatively reasonable, but because video camera has lost the ability of direct mensuration boresight angular speed, can only provide vehicle coordinate system interior measurement numerical value to the aiming line angle, and have larger measurement noise.In addition, by the principle of indirect stabilization as can be known, IMU and video camera can cause angular speed and the angle coupling error of system with respect to the mounting shift angle of vehicle coordinate system, the carrier disturbance is larger, the error that causes is also larger, therefore, need to analyse in depth high precision, the Fast Calibration problem of research and solution mounting shift angle.

Traditional mounting shift angle scaling scheme often adopts the separate calibration pattern, need to design a calibration experiment for a mounting shift angle, namely once experiment can only be demarcated a drift angle, this method clear concept, but complicated operation, simultaneously because the coupling that crosses one another between each alignment error is difficult to the stated accuracy that reaches higher.The present invention proposes a kind of mounting shift angle scaling scheme based on the optical measurement of optical axis steady state error, by giving the certain input angular velocity of carrier, can go out by an experimental calibration whole mounting shift angles of system, demarcating steps is simple, efficient is higher, and can reach higher stated accuracy.

Summary of the invention

Technology of the present invention is dealt with problems and is: at present domestic research to gyro indirect stabilization technology is still not deep enough, see from documents and materials and still the mounting shift angle calibration technique of gyro indirect stabilization system not to be studied at present, the present invention studies the scaling method of a kind of gyro indirect stabilization system mounting shift angle, the method can calibrate IMU coordinate system and the mounting shift angle of carrier coordinate system and the mounting shift angle of camera coordinate system and carrier coordinate system in the indirect stabilization system quickly and accurately, has the advantages such as accurate, efficient, easy to operate, high universalizable.

Technical solution of the present invention is: a kind of installation deflection angle calibration method of gyro indirect stable system, and implementation step is as follows:

The first step is set up video camera optical axis steady state error and IMU mounting shift angle in the gyro indirect stabilization system And video camera mounting shift angle

Between model;

(1) the definition carrier coordinate system is o-x _by _bz _b, it is o-x that IMU measures coordinate _my _mz _m, video camera optical axis coordinate system o-x _py _pz _p, definition I M U measures coordinate system with respect to the mounting shift angle of carrier coordinate system ${\stackrel{\‾}{\mathrm{\δ}}}_g={\left[\begin{array}{ccc}{\mathrm{\δ}}_{\mathrm{gx}}& {\mathrm{\δ}}_{\mathrm{gy}}& {\mathrm{\δ}}_{\mathrm{gz}}\end{array}\right]}^T,$ Definition video camera optical axis coordinate system is with respect to the mounting shift angle of carrier coordinate system ${\stackrel{\‾}{\mathrm{\δ}}}_p={\left[\begin{array}{ccc}{\mathrm{\δ}}_{\mathrm{px}}& {\mathrm{\δ}}_{\mathrm{py}}& {\mathrm{\δ}}_{\mathrm{pz}}\end{array}\right]}^T,$ The carrier movement angular speed ${\stackrel{\‾}{\mathrm{\ω}}}_b={\left[\begin{array}{ccc}{\mathrm{\ω}}_{\mathrm{bx}}& {\mathrm{\ω}}_{\mathrm{by}}& {\mathrm{\ω}}_{\mathrm{bz}}\end{array}\right]}^T,$ Can obtain IMU measured angular speed

With the carrier movement angular speed

Between the pass be:

${\stackrel{\‾}{\mathrm{\ω}}}_{\mathrm{bm}}={\stackrel{\‾}{R}}_y\left({\mathrm{\δ}}_{\mathrm{gy}}\right){\stackrel{\‾}{R}}_x\left({\mathrm{\δ}}_{\mathrm{gx}}\right){\stackrel{\‾}{R}}_z\left({\mathrm{\δ}}_{\mathrm{gz}}\right){\stackrel{\‾}{\mathrm{\ω}}}_b---\left(1\right)$

In the following formula (1) Be respectively the Eulerian angle rotation matrix around x, y, z axle, and have: ${\stackrel{\&OverBar;}{R}}_y\left({\mathrm{\&delta;}}_{\mathrm{gy}}\right)=\left[\begin{array}{ccc}1& 0& -{\mathrm{\&delta;}}_{\mathrm{<figure-callout\; id="0"\; label="gy"\; filenames="HSB00001011003500021.png"\; state="\{\{state\}\}">gy</figure-callout>}}\\ 0& 1& 0\\ {\mathrm{\&delta;}}_{\mathrm{<figure-callout\; id="0"\; label="gy"\; filenames="HSB00001011003500021.png"\; state="\{\{state\}\}">gy</figure-callout>}}& 0& 1\end{array}\right],{\stackrel{\&OverBar;}{R}}_x\left({\mathrm{\&delta;}}_{\mathrm{gx}}\right)=\left[\begin{array}{ccc}1& 0& 0\\ 0& 1& {\mathrm{\&delta;}}_{\mathrm{gx}}\\ 0& -{\mathrm{\&delta;}}_{\mathrm{<figure-callout\; id="1"\; label="gx"\; filenames="HSB00001011003500022.png"\; state="\{\{state\}\}">gx</figure-callout>}}& 1\end{array}\right],{\stackrel{\&OverBar;}{R}}_z\left({\mathrm{\&delta;}}_{\mathrm{gz}}\right)=\left[\begin{array}{ccc}1& {\mathrm{\&delta;}}_{\mathrm{gz}}& 0\\ -{\mathrm{\&delta;}}_{\mathrm{<figure-callout\; id="1"\; label="gz"\; filenames="HSB00001011003500022.png"\; state="\{\{state\}\}">gz</figure-callout>}}& 1& 0\\ 0& 0& 1\end{array}\right]$

(2) video camera adopts the two framework control models of twin shaft, definition o-x _oy _oz _oBe video camera outside framework coordinate system (orientation framework); O-x _iy _iz _iBe inner frame coordinate system (pitching frame) that η, ε are respectively orientation corner and the pitching corner of camera framework.According to framed structure and compound motion principle, the motion of inner frame is rotated by inside casing displacement and housing and is caused that jointly the motion of housing is rotated by housing self and base motion causes jointly, thereby the motion of the optical axis is synthesizing of inside casing, housing, base motion.

If the angular velocity vector of carrier motion is

The motion angular velocity vector of outside framework then

Can be expressed as:

${\stackrel{\&OverBar;}{\mathrm{\&omega;}}}_o={\stackrel{\&OverBar;}{R}}_z\left(\mathrm{\&eta;}\right){\stackrel{\&OverBar;}{\mathrm{\&omega;}}}_b+\stackrel{\&OverBar;}{\stackrel{\&CenterDot;}{\mathrm{\&eta;}}}---\left(2\right)$

Wherein,

Be the rotation matrix of vehicle coordinate system to video camera outside framework coordinate system,

Tracking angular rate vector for the video camera outside framework.Can be expressed as respectively:

${\stackrel{\&OverBar;}{R}}_z\left(\mathrm{\&eta;}\right)=\left[\begin{array}{ccc}{c}_{\mathrm{\&eta;}}& s_{\mathrm{\&eta;}}& 0\\ -s_{\mathrm{\&eta;}}& c_{\mathrm{\&eta;}}& 0\\ 0& 0& 1\end{array}\right];$ c _η＝cos(η)；s _η＝sin(η)； $\stackrel{\&OverBar;}{\stackrel{\&CenterDot;}{\mathrm{\&eta;}}}\left(t\right)={\left[\begin{array}{ccc}0& 0& \stackrel{\&CenterDot;}{\mathrm{\&eta;}}\left(t\right)\end{array}\right]}^T$

Be the outside framework tracking angular rate.

In like manner as can be known, the angular velocity vector of target seeker inner frame Can represent becomes:

${\stackrel{\&OverBar;}{\mathrm{\&omega;}}}_i={\stackrel{\&OverBar;}{R}}_x\left(\mathrm{\&epsiv;}\right){\stackrel{\&OverBar;}{\mathrm{\&omega;}}}_o+\stackrel{\&OverBar;}{\stackrel{\&CenterDot;}{\mathrm{\&epsiv;}}}---\left(3\right)$

Wherein, Be the rotation matrix of video camera outside framework coordinate system to the inner frame coordinate system,

Tracking angular rate vector for the video camera inner frame.Can be expressed as respectively:

${\stackrel{\&OverBar;}{R}}_x\left(\mathrm{\&epsiv;}\right)=\left[\begin{array}{ccc}1& 0& 0\\ 0& c_{\mathrm{\&epsiv;}}& s_{\mathrm{\&epsiv;}}\\ 0& -s_{\mathrm{\&epsiv;}}& c_{\mathrm{\&epsiv;}}\end{array}\right];$ c _ε＝cos(ε)；s _ε＝sin(ε)； $\stackrel{\&OverBar;}{\stackrel{\&CenterDot;}{\mathrm{\&epsiv;}}}\left(t\right)={\left[\begin{array}{ccc}\stackrel{\&CenterDot;}{\mathrm{\&epsiv;}}\left(t\right)& 0& 0\end{array}\right]}^T$

Be the inner frame tracking angular rate.

Formula (3) substitution formula (2) can be got:

${\stackrel{\&OverBar;}{\mathrm{\&omega;}}}_i={\stackrel{\&OverBar;}{R}}_x\left(\mathrm{\&epsiv;}\right){\stackrel{\&OverBar;}{R}}_z\left(\mathrm{\&eta;}\right){\stackrel{\&OverBar;}{\mathrm{\&omega;}}}_b+{\stackrel{\&OverBar;}{R}}_x\left(\mathrm{\&epsiv;}\right)\stackrel{\&OverBar;}{\stackrel{\&CenterDot;}{\mathrm{\&eta;}}}+\stackrel{\&OverBar;}{\stackrel{\&CenterDot;}{\mathrm{\&epsiv;}}}\left(t\right)---\left(4\right)$

Expansion (4) can get:

$\left[\begin{array}{c}{\mathrm{\&omega;}}_{\mathrm{ix}}\\ {\mathrm{\&omega;}}_{\mathrm{iy}}\\ {\mathrm{\&omega;}}_{\mathrm{iz}}\end{array}\right]=\left[\begin{array}{c}{\mathrm{\&omega;}}_{\mathrm{bx}}\cos \left(\mathrm{\&eta;}\right)+{\mathrm{\&omega;}}_{\mathrm{by}}\sin \left(\mathrm{\&eta;}\right)\\ -{\mathrm{\&omega;}}_{\mathrm{bx}}\sin \left(\mathrm{\&eta;}\right)\cos \left(\mathrm{\&epsiv;}\right)+{\mathrm{\&omega;}}_{\mathrm{by}}\cos \left(\mathrm{\&eta;}\right)\cos \left(\mathrm{\&epsiv;}\right)+{\mathrm{\&omega;}}_{\mathrm{bz}}\sin \left(\mathrm{\&epsiv;}\right)\\ {\mathrm{\&omega;}}_{\mathrm{bx}}\sin \left(\mathrm{\&eta;}\right)\sin \left(\mathrm{\&epsiv;}\right)-{\mathrm{\&omega;}}_{\mathrm{by}}\cos \left(\mathrm{\&eta;}\right)\sin \left(\mathrm{\&epsiv;}\right)+{\mathrm{\&omega;}}_{\mathrm{bz}}\cos \left(\mathrm{\&epsiv;}\right)\end{array}\right]+\left[\begin{array}{c}\stackrel{\&CenterDot;}{\mathrm{\&epsiv;}}\\ \sin \left(\mathrm{\&epsiv;}\right)\stackrel{\&CenterDot;}{\mathrm{\&eta;}}\\ \cos \left(\mathrm{\&epsiv;}\right)\stackrel{\&CenterDot;}{\mathrm{\&eta;}}\end{array}\right]---\left(5\right)$

According to the indirect stabilization principle as can be known, for guaranteeing stable in order to ensure the optical axis, namely

Need the motion angular speed of control pitching and azimuth-drive motor to be:

$\stackrel{\&CenterDot;}{\mathrm{\&epsiv;}}\left(t\right)=-{\mathrm{\&omega;}}_{\mathrm{bx}}\cos \left(\mathrm{\&eta;}\right){-\mathrm{\&omega;}}_{\mathrm{by}}\sin \left(\mathrm{\&eta;}\right)$ $\left(6\right)$

$\stackrel{\&CenterDot;}{\mathrm{\&eta;}}\left(t\right)=-{\mathrm{\&omega;}}_{\mathrm{bx}}\sin \left(\mathrm{\&eta;}\right)\tan \left(\mathrm{\&epsiv;}\right)+{\mathrm{\&omega;}}_{\mathrm{by}}\cos \left(\mathrm{\&eta;}\right)\tan \left(\mathrm{\&epsiv;}\right)-{\mathrm{\&omega;}}_{\mathrm{bz}}$

When there is mounting shift angle in video camera optical axis coordinate system with respect to carrier coordinate system

The time, formula (4) can be rewritten as:

${\stackrel{\&OverBar;}{\mathrm{\&omega;}}}_i={\stackrel{\&OverBar;}{R}}_x(\mathrm{\&epsiv;}+{\mathrm{\&delta;}}_{\mathrm{px}})({\stackrel{\&OverBar;}{R}}_z(\mathrm{\&eta;}+{\mathrm{\&delta;}}_{\mathrm{pz}}){\stackrel{\&OverBar;}{\mathrm{\&omega;}}}_b+\stackrel{\&OverBar;}{\stackrel{\&CenterDot;}{\mathrm{\&eta;}}})+\stackrel{\&OverBar;}{\stackrel{\&CenterDot;}{\mathrm{\&epsiv;}}}---\left(7\right)$

(3) because the motion angular velocity of carrier Obtained by gyro to measure, therefore, in the formula (7)

Need to by

Substitute, with formula (1) and formula (6) substitution formula (7), can obtain the steady state error of the optical axis with respect to mounting shift angle ${\stackrel{\&OverBar;}{\mathrm{\&delta;}}}_g={\left[\begin{array}{ccc}{\mathrm{\&delta;}}_{\mathrm{gx}}& {\mathrm{\&delta;}}_{\mathrm{gy}}& {\mathrm{\&delta;}}_{\mathrm{gz}}\end{array}\right]}^T$ And ${\stackrel{\&OverBar;}{\mathrm{\&delta;}}}_p={\left[\begin{array}{ccc}{\mathrm{\&delta;}}_{\mathrm{px}}& {\mathrm{\&delta;}}_{\mathrm{py}}& {\mathrm{\&delta;}}_{\mathrm{pz}}\end{array}\right]}^T$ Relational expression as follows:

${\stackrel{\&OverBar;}{\mathrm{\&omega;}}}_i=A{\left[\begin{array}{ccc}{\mathrm{\&omega;}}_{\mathrm{bx}}& {\mathrm{\&omega;}}_{\mathrm{by}}& {\mathrm{\&omega;}}_{\mathrm{bz}}\end{array}\right]}^T---\left(8\right)$

Wherein,

$A=\left[\begin{array}{ccc}({\mathrm{\&delta;}}_{\mathrm{gz}}-{\mathrm{\&delta;}}_{\mathrm{pz}})s_{\mathrm{\&eta;}}& -({\mathrm{\&delta;}}_{\mathrm{gz}}-{\mathrm{\&delta;}}_{\mathrm{pz}})c_{\mathrm{\&eta;}}& {\mathrm{\&delta;}}_{\mathrm{gy}}{c}_{\mathrm{\&eta;}}-{\mathrm{\&delta;}}_{\mathrm{gx}}{s}_{\mathrm{\&eta;}}\\ ({\mathrm{\&delta;}}_{\mathrm{gz}}-{\mathrm{\&delta;}}_{\mathrm{pz}})c_{\mathrm{\&epsiv;}}{c}_{\mathrm{\&eta;}}+{\mathrm{\&delta;}}_{\mathrm{px}}{s}_{\mathrm{\&epsiv;}}{s}_{\mathrm{\&eta;}}-{\mathrm{\&delta;}}_{\mathrm{gy}}{s}_{\mathrm{\&epsiv;}}& ({\mathrm{\&delta;}}_{\mathrm{gz}}-{\mathrm{\&delta;}}_{\mathrm{pz}})c_{\mathrm{\&epsiv;}}{s}_{\mathrm{\&eta;}}-{\mathrm{\&delta;}}_{\mathrm{px}}{s}_{\mathrm{\&epsiv;}}{c}_{\mathrm{\&eta;}}+{\mathrm{\&delta;}}_{\mathrm{gx}}{s}_{\mathrm{\&epsiv;}}& {\mathrm{\&delta;}}_{\mathrm{px}}{c}_{\mathrm{\&epsiv;}}-{\mathrm{\&delta;}}_{\mathrm{gy}}{c}_{\mathrm{\&epsiv;}}{s}_{\mathrm{\&eta;}}-{\mathrm{\&delta;}}_{\mathrm{gx}}{c}_{\mathrm{\&epsiv;}}{c}_{\mathrm{\&eta;}}\\ ({\mathrm{\&delta;}}_{\mathrm{pz}}-{\mathrm{\&delta;}}_{\mathrm{gz}})s_{\mathrm{\&epsiv;}}{c}_{\mathrm{\&eta;}}+{\mathrm{\&delta;}}_{\mathrm{px}}{c}_{\mathrm{\&epsiv;}}{s}_{\mathrm{\&eta;}}-{\mathrm{\&delta;}}_{\mathrm{gy}}{c}_{\mathrm{\&epsiv;}}& ({\mathrm{\&delta;}}_{\mathrm{pz}}-{\mathrm{\&delta;}}_{\mathrm{gz}})s_{\mathrm{\&epsiv;}}{s}_{\mathrm{\&eta;}}-{\mathrm{\&delta;}}_{\mathrm{px}}{c}_{\mathrm{\&epsiv;}}{c}_{\mathrm{\&eta;}}+{\mathrm{\&delta;}}_{\mathrm{gx}}{c}_{\mathrm{\&epsiv;}}& -{\mathrm{\&delta;}}_{\mathrm{px}}{s}_{\mathrm{\&epsiv;}}+{\mathrm{\&delta;}}_{\mathrm{gy}}{s}_{\mathrm{\&epsiv;}}{s}_{\mathrm{\&eta;}}+{\mathrm{\&delta;}}_{\mathrm{gx}}{s}_{\mathrm{\&epsiv;}}{c}_{\mathrm{\&eta;}}\end{array}\right]$

s _ε＝sinε，c _ε＝cosε，s _η＝sin?η，c _η＝cos?η

(4) only consider the optical axis in the Mach angle speed of pitching and azimuth direction, ignore second order in a small amount, arrangement formula (8) can get:

$\left[\begin{array}{c}\mathrm{\&Delta;}{\mathrm{\&omega;}}_x\\ \mathrm{\&Delta;}{\mathrm{\&omega;}}_z\end{array}\right]=\left[\begin{array}{cccc}{\mathrm{<figure-callout\; id="1"\; label="H"\; filenames="HSB00001011003500022.png"\; state="\{\{state\}\}">H</figure-callout>}}_{\mathrm{1,1}}& {\mathrm{<figure-callout\; id="1"\; label="H"\; filenames="HSB00001011003500022.png"\; state="\{\{state\}\}">H</figure-callout>}}_{\mathrm{1,2}}& {\mathrm{<figure-callout\; id="1"\; label="H"\; filenames="HSB00001011003500022.png"\; state="\{\{state\}\}">H</figure-callout>}}_{\mathrm{1,3}}& {\mathrm{<figure-callout\; id="1"\; label="H"\; filenames="HSB00001011003500022.png"\; state="\{\{state\}\}">H</figure-callout>}}_{\mathrm{1,4}}\\ {\mathrm{<figure-callout\; id="2"\; label="H"\; filenames="HSB00001011003500022.png"\; state="\{\{state\}\}">H</figure-callout>}}_{\mathrm{2,1}}& {\mathrm{<figure-callout\; id="2"\; label="H"\; filenames="HSB00001011003500022.png"\; state="\{\{state\}\}">H</figure-callout>}}_{\mathrm{2,2}}& {\mathrm{<figure-callout\; id="2"\; label="H"\; filenames="HSB00001011003500022.png"\; state="\{\{state\}\}">H</figure-callout>}}_{\mathrm{2,3}}& {\mathrm{<figure-callout\; id="2"\; label="H"\; filenames="HSB00001011003500022.png"\; state="\{\{state\}\}">H</figure-callout>}}_{\mathrm{2,4}}\end{array}\right]X---\left(9\right)$

Wherein,

H _1，1＝0，H _1，2＝-sinηω _bz，H _1，3＝cosηω _bz，H _1，4＝cosηω _by-sinηω _bx

H _2，1＝cosεsinηω _bx-cosεcosηω _by-sinεω _bz，H _2，2＝sinεcosηω _bz+cosεω _by

H _2，3＝-cosεω _bx+sinεsinηω _bz，H _2，4＝sinεcosηω _bx+sinεsinηω _by

X=[δ _Pxδ _Gxδ _Gyδ _z] ^T, because δ _PzAnd δ _GzImpact effect with respect to steady state error is identical, so get δ _z=δ _Pz-δ _Gz

Δ ω _x, Δ ω _zBe the fleet angle speed of the video camera optical axis at pitching and course both direction, namely optical axis steady state error can obtain by the means that image is processed.

Second step, with fixing target of video camera optical axis aiming, the control carrier waves by following rule:

Carrier deviate from voyage route respectively to axle (Z axis), pitch axis (X-axis), roll axle (Y-axis) do three times motor-driven, three times motor-driven rule is sinusoidal rule: course angle ψ=A ₁Sin (ω ₁T), pitching angle theta=A ₂Sin (ω ₂T), roll angle γ=A ₃Sin (ω ₃And A t), ₁≠ A ₂≠ A ₃, ω ₁≠ ω ₂≠ ω ₃

Utilize image processing techniques to estimate in the carrier movement process video camera optical axis with respect to the error delta ω of initial aiming point _X, Δ ω _Z, be also referred to as optical axis steady state error;

The 3rd step, utilize the optical axis steady state error that measures as measurement information, in conjunction with the error model that the first step is set up, utilize Recursive Least Squares can estimate the mounting shift angle of system; Get state variable X=[δ _Pzδ _Gxδ _Gyδ _z] ^T, measurement amount Z=[Δ ω _xΔ ω _z] ^T, the estimation formulas of least square method of recursion is as follows:

${\hat{X}}_{k+1}={\hat{X}}_k+P_{k+1}{H}_{k+1}^T(Z_{k+1}-H_{k+1}{\hat{X}}_k)$ $\left(10\right)$

$P_{k+1}=P_k-P_k{H}_{k+1}^T{(I+H_{k+1}{P}_k{H}_{k+1}^T)}^{-1}{H}_{k+1}{P}_k$

The 4th step, the 3rd step was estimated that the mounting shift angle that obtains compensated, repeat second step, observe the optical axis steady state error in the carrier movement process, the estimation effect of checking mounting shift angle.

The present invention's advantage compared with prior art is:

(1) domestic less to the systematic research of gyro indirect stabilization, have not yet to see the research to the process alignment error calibration of gyro indirect stabilization system, therefore method of the present invention has larger novelty.

(2) traditional mounting shift angle scaling scheme often adopts the separate calibration pattern, need to design a calibration experiment for a mounting shift angle, namely once experiment can only be demarcated a drift angle, this method clear concept, but complicated operation, simultaneously because the coupling that crosses one another between each alignment error is difficult to the stated accuracy that reaches higher.The present invention proposes a kind of mounting shift angle scaling scheme based on the optical measurement of optical axis steady state error, by giving the certain input angular velocity of carrier, can go out by an experimental calibration whole mounting shift angles of system, demarcating steps is simple, efficient is higher, and can reach higher stated accuracy.

Description of drawings

Fig. 1 is the realization flow figure of the inventive method;

Fig. 2 is the direct systems stabilisation schematic diagram of gyro;

Fig. 3 is gyro indirect stabilization systematic schematic diagram;

Fig. 4 is the steady state error curve of the optical axis when having mounting shift angle in the embodiment of the invention;

Fig. 5 is the real-time estimation curve of mounting shift angle in the embodiment of the invention;

Fig. 6 is compensation mounting shift angle backsight stabilizer shaft graph of errors in the embodiment of the invention;

Embodiment

The below sets forth specific implementation process of the present invention as an example of the demarcation of unmanned plane twin shaft opto-electric stabilization detection system mounting shift angle example.

Airborne Electro-optical Detecting System adopts two framework mode (can rotate around pitch axis and azimuth axis), Photodetection system and airborne IMU (being used for robot pilot) are installed in unmanned plane, and definition IMU measures coordinate system with respect to the mounting shift angle of carrier coordinate system ${\stackrel{\&OverBar;}{\mathrm{\&delta;}}}_g={\left[\begin{array}{ccc}{\mathrm{\&delta;}}_{\mathrm{gx}}& {\mathrm{\&delta;}}_{\mathrm{gy}}& {\mathrm{\&delta;}}_{\mathrm{gz}}\end{array}\right]}^T,$ Definition video camera optical axis coordinate system is with respect to the mounting shift angle of carrier coordinate system ${\stackrel{\&OverBar;}{\mathrm{\&omega;}}}_b={\left[\begin{array}{ccc}{\mathrm{\&omega;}}_{\mathrm{bx}}& {\mathrm{\&omega;}}_{\mathrm{by}}& {\mathrm{\&omega;}}_{\mathrm{bz}}\end{array}\right]}^T,$ Video camera adopts the indirect stabilization control mode, and the model between optical axis steady state error and the system's mounting shift angle is suc as formula shown in (9).

The hypothesis video camera optical axis locks a fixed target in the emulation, unmanned plane deviate from voyage route respectively to axle, pitch axis, roll axle do three times motor-driven, three motor-driven rules be respectively (°): course angle ψ=20sin (0.1 π t), pitching angle theta=10sin (0.2 π t), roll angle γ=15sin (0.3 π t).The angle mistake association amount output error of supposing image processing system is 2 pixels, camera field of view angle 3 degree, and image resolution ratio 512 * 512, the maximum error of measuring that can obtain thus Declination angle of sight axis is ± 4.2 ".

Ignore second order in the emulation in a small amount, in the measurement matrix Use the gyro to measure value

Replace; Suppose that the relative carrier of IMU is that the alignment error of X, Y, Z axis is respectively 1 °, 0.5 °, 2 °, target seeker is that the alignment error of X, Z axis is respectively 1.5 °, 0 ° with respect to carrier; Get original state X ₀=[1 ° 1 ° 1 ° 1 °].Fig. 4 is the steady state error curve of the optical axis when having mounting shift angle; Fig. 5 is the real-time estimation curve of mounting shift angle.As shown in Figure 5, behind 30s, utilize the photoelectric tracking technology to estimate that the alignment error angle that obtains will approach actual alignment error greatly, after this error angle compensation, the Systems balanth precision will improve greatly, as shown in Figure 6.

The content that is not described in detail in the instructions of the present invention belongs to the known prior art of this area professional and technical personnel.

It should be noted last that: above embodiment is the unrestricted technical scheme of the present invention in order to explanation only, and all modifications that does not break away from the spirit and scope of the present invention or local the replacement all should be encompassed in the middle of the claim scope of the present invention.

Claims (2)

1. installation deflection angle calibration method of gyro indirect stable system is characterised in that performing step is as follows:

The first step is set up video camera optical axis steady state error and IMU mounting shift angle in the gyro indirect stabilization system

And video camera mounting shift angle Between model, the modeling procedure of described model is as follows:

Step 1: definition IMU is with respect to the mounting shift angle of carrier coordinate system ${\stackrel{\&OverBar;}{\mathrm{\&delta;}}}_g={\left[\begin{array}{ccc}{\mathrm{\&delta;}}_{\mathrm{gx}}& {\mathrm{\&delta;}}_{\mathrm{gy}}& {\mathrm{\&delta;}}_{\mathrm{gz}}\end{array}\right]}^T,$ The carrier movement angular speed ${\stackrel{\&OverBar;}{\mathrm{\&omega;}}}_b={\left[\begin{array}{ccc}{\mathrm{\&omega;}}_{\mathrm{bx}}& {\mathrm{\&omega;}}_{\mathrm{by}}& {\mathrm{\&omega;}}_{\mathrm{bz}}\end{array}\right]}^T,$ Obtain IMU measured angular speed With the carrier movement angular speed

Between the pass be:

${\stackrel{\&OverBar;}{\mathrm{\&omega;}}}_{\mathrm{bm}}={\stackrel{\&OverBar;}{R}}_y\left({\mathrm{\&delta;}}_{\mathrm{gy}}\right){\stackrel{\&OverBar;}{R}}_x\left({\mathrm{\&delta;}}_{\mathrm{gx}}\right){\stackrel{\&OverBar;}{R}}_z\left({\mathrm{\&delta;}}_{\mathrm{gz}}\right){\stackrel{\&OverBar;}{\mathrm{\&omega;}}}_b---\left(1\right)$

In the following formula (1)

Be respectively the Eulerian angle rotation matrix around x, y, z axle, and have: ${\stackrel{\&OverBar;}{R}}_y\left({\mathrm{\&delta;}}_{\mathrm{gy}}\right)=\left[\begin{array}{ccc}1& 0& -{\mathrm{\&delta;}}_{\mathrm{gy}}\\ 0& 1& 0\\ {\mathrm{\&delta;}}_{\mathrm{gy}}& 0& 1\end{array}\right],$ ${\stackrel{\&OverBar;}{R}}_x\left({\mathrm{\&delta;}}_{\mathrm{gx}}\right)=\left[\begin{array}{ccc}1& 0& 0\\ 0& 1& {\mathrm{\&delta;}}_{\mathrm{gx}}\\ 0& -{\mathrm{\&delta;}}_{\mathrm{gx}}& 1\end{array}\right],$ ${\stackrel{\&OverBar;}{R}}_z\left({\mathrm{\&delta;}}_{\mathrm{gz}}\right)=\left[\begin{array}{ccc}1& {\mathrm{\&delta;}}_{\mathrm{gz}}& 0\\ -{\mathrm{\&delta;}}_{\mathrm{gz}}& 1& 0\\ 0& 0& 1\end{array}\right]$

Step 2: according to the principle of gyro indirect stabilization technology, the Mach angle rate representation of the video camera optical axis is:

${\stackrel{\&OverBar;}{\mathrm{\&omega;}}}_i={\stackrel{\&OverBar;}{R}}_x(\mathrm{\&epsiv;}+{\mathrm{\&delta;}}_{\mathrm{px}})({\stackrel{\&OverBar;}{R}}_z(\mathrm{\&eta;}+{\mathrm{\&delta;}}_{\mathrm{pz}}){\stackrel{\&OverBar;}{\mathrm{\&omega;}}}_b+\stackrel{\&OverBar;}{\stackrel{\&CenterDot;}{\mathrm{\&eta;}}})+\stackrel{\&OverBar;}{\stackrel{\&CenterDot;}{\mathrm{\&epsiv;}}}---\left(2\right)$

In the following formula

And

Be respectively the framework pilot angle speed that the indirect stabilization algorithm calculates, ε represents the pitching corner of camera framework, and η represents the orientation corner of camera framework,

The motion angular speed of expression carrier, wherein

$\stackrel{\&OverBar;}{\stackrel{\&CenterDot;}{\mathrm{\&eta;}}}={\left[\begin{array}{ccc}0& 0& \stackrel{\&CenterDot;}{\mathrm{\&eta;}}\end{array}\right]}^T,\stackrel{\&OverBar;}{\stackrel{\&CenterDot;}{\mathrm{\&epsiv;}}}={\left[\begin{array}{ccc}0& 0& \stackrel{\&CenterDot;}{\mathrm{\&epsiv;}}\end{array}\right]}^T---\left(3\right)$

$\stackrel{\&CenterDot;}{\mathrm{\&epsiv;}}=-\cos \mathrm{\&eta;}{\mathrm{\&omega;}}_{\mathrm{bx}}-\sin \mathrm{\&eta;}{\mathrm{\&omega;}}_{\mathrm{by}}$ $\left(4\right)$

$\stackrel{\&CenterDot;}{\mathrm{\&eta;}}=\sec \mathrm{\&epsiv;}(-\sin \mathrm{\&epsiv;}\sin \mathrm{\&eta;}{\mathrm{\&omega;}}_{\mathrm{bx}}+\sin \mathrm{\&epsiv;}\cos \mathrm{\&eta;}{\mathrm{\&omega;}}_{\mathrm{by}}-\cos \mathrm{\&epsiv;}{\mathrm{\&omega;}}_{\mathrm{bz}})$

Step 3: because the motion angular velocity of carrier

Obtained by gyro to measure, therefore, in the formula (2)

Need to by

Substitute, with formula (1), formula (3), formula (4) substitution formula (2), obtain the steady state error of the optical axis with respect to mounting shift angle ${\stackrel{\&OverBar;}{\mathrm{\&delta;}}}_g={\left[\begin{array}{ccc}{\mathrm{\&delta;}}_{\mathrm{gx}}& {\mathrm{\&delta;}}_{\mathrm{gy}}& {\mathrm{\&delta;}}_{\mathrm{gz}}\end{array}\right]}^T$ And ${\stackrel{\&OverBar;}{\mathrm{\&delta;}}}_p={\left[\begin{array}{ccc}{\mathrm{\&delta;}}_{\mathrm{px}}& {\mathrm{\&delta;}}_{\mathrm{py}}& {\mathrm{\&delta;}}_{\mathrm{pz}}\end{array}\right]}^T$ Relational expression as follows:

${\stackrel{\&OverBar;}{\mathrm{\&omega;}}}_i=A{\left[\begin{array}{ccc}{\mathrm{\&omega;}}_{\mathrm{bx}}& {\mathrm{\&omega;}}_{\mathrm{by}}& {\mathrm{\&omega;}}_{\mathrm{bz}}\end{array}\right]}^T---\left(5\right)$

Wherein,

$A=\left[\begin{array}{ccc}({\mathrm{\&delta;}}_{\mathrm{gz}}-{\mathrm{\&delta;}}_{\mathrm{pz}})s_{\mathrm{\&eta;}}& -({\mathrm{\&delta;}}_{\mathrm{gz}}-{\mathrm{\&delta;}}_{\mathrm{pz}})c_{\mathrm{\&eta;}}& {\mathrm{\&delta;}}_{\mathrm{gy}}{c}_{\mathrm{\&eta;}}-{\mathrm{\&delta;}}_{\mathrm{gx}}{s}_{\mathrm{\&eta;}}\\ ({\mathrm{\&delta;}}_{\mathrm{gz}}-{\mathrm{\&delta;}}_{\mathrm{pz}})c_{\mathrm{\&epsiv;}}{c}_{\mathrm{\&eta;}}+{\mathrm{\&delta;}}_{\mathrm{px}}{s}_{\mathrm{\&epsiv;}}{s}_{\mathrm{\&eta;}}-{\mathrm{\&delta;}}_{\mathrm{gy}}{s}_{\mathrm{\&epsiv;}}& ({\mathrm{\&delta;}}_{\mathrm{gz}}-{\mathrm{\&delta;}}_{\mathrm{pz}})c_{\mathrm{\&epsiv;}}{s}_{\mathrm{\&eta;}}-{\mathrm{\&delta;}}_{\mathrm{px}}{s}_{\mathrm{\&epsiv;}}{c}_{\mathrm{\&eta;}}+{\mathrm{\&delta;}}_{\mathrm{gx}}{s}_{\mathrm{\&epsiv;}}& {\mathrm{\&delta;}}_{\mathrm{px}}{c}_{\mathrm{\&epsiv;}}-{\mathrm{\&delta;}}_{\mathrm{gy}}{c}_{\mathrm{\&epsiv;}}{s}_{\mathrm{\&eta;}}-{\mathrm{\&delta;}}_{\mathrm{gx}}{c}_{\mathrm{\&epsiv;}}{c}_{\mathrm{\&eta;}}\\ ({\mathrm{\&delta;}}_{\mathrm{pz}}-{\mathrm{\&delta;}}_{\mathrm{gz}})s_{\mathrm{\&epsiv;}}{c}_{\mathrm{\&eta;}}+{\mathrm{\&delta;}}_{\mathrm{px}}{c}_{\mathrm{\&epsiv;}}{s}_{\mathrm{\&eta;}}-{\mathrm{\&delta;}}_{\mathrm{gy}}{c}_{\mathrm{\&epsiv;}}& ({\mathrm{\&delta;}}_{\mathrm{pz}}-{\mathrm{\&delta;}}_{\mathrm{gz}})s_{\mathrm{\&epsiv;}}{s}_{\mathrm{\&eta;}}-{\mathrm{\&delta;}}_{\mathrm{px}}{c}_{\mathrm{\&epsiv;}}{c}_{\mathrm{\&eta;}}+{\mathrm{\&delta;}}_{\mathrm{gx}}{c}_{\mathrm{\&epsiv;}}& -{\mathrm{\&delta;}}_{\mathrm{px}}{s}_{\mathrm{\&epsiv;}}+{\mathrm{\&delta;}}_{\mathrm{gy}}{s}_{\mathrm{\&epsiv;}}{s}_{\mathrm{\&eta;}}+{\mathrm{\&delta;}}_{\mathrm{gx}}{s}_{\mathrm{\&epsiv;}}{c}_{\mathrm{\&eta;}}\end{array}\right]$

s _ε＝sinε，c _ε＝cosε，s _η＝sinη，c _η＝cosη

Step 4: only consider the optical axis in the Mach angle speed of pitching and azimuth direction, ignore second order in a small amount, arrangement formula (5) can get:

$\left[\begin{array}{c}\mathrm{\&Delta;}{\mathrm{\&omega;}}_x\\ \mathrm{\&Delta;}{\mathrm{\&omega;}}_z\end{array}\right]=\left[\begin{array}{cccc}{H}_{\mathrm{1,1}}& H_{\mathrm{1,2}}& H_{\mathrm{1,3}}& H_{\mathrm{1,4}}\\ H_{\mathrm{2,1}}& H_{\mathrm{2,2}}& H_{\mathrm{2,3}}& H_{\mathrm{2,4}}\end{array}\right]X---\left(6\right)$

Wherein,

H _1，1＝0，H _1，2＝-sinηω _bz，H _1，3＝cosηω _bz，H _1，4＝cosηω _by-sin?ηω _bx

H _2，1＝cosεsinηω _bx-cosεcosηω _by-sinεω _bz，H _2，2＝sinεcosηεω _bz+cosεω _by

H _2，3＝-cosεω _bx+sinεsinηω _bz，H _2，4＝sinεcosηω _bx+sinεsinηω _by

X=[δ _Pxδ _Gxδ _Gyδ _z] ^T, because δ _PzAnd δ _GzImpact effect with respect to steady state error is identical, so get δ _z=δ _Pz-δ _Gz

Δ ω _x, Δ ω _zBe the fleet angle speed of the video camera optical axis at pitching and course both direction, i.e. optical axis steady state error;

Second step, with fixing target of video camera optical axis aiming, the control carrier waves with certain rule, utilizes image processing techniques to estimate that the video camera optical axis is also referred to as optical axis steady state error with respect to the error of initial aiming point in the carrier movement process;

The 3rd step, utilize the optical axis steady state error that measures as measurement information, in conjunction with the error model that the first step is set up, utilize Recursive Least Squares to estimate the mounting shift angle of system;

The 4th step, the 3rd step was estimated that the mounting shift angle that obtains compensated, repeat second step, observe the optical axis steady state error in the carrier movement process, the estimation effect of checking mounting shift angle.

2. a kind of installation deflection angle calibration method of gyro indirect stable system according to claim 1, it is characterized in that: the characteristics of motion of described carrier is:

Carrier is deviated from voyage route respectively to axle, i.e. Z axis, pitch axis, i.e. X-axis, roll axle, namely Y-axis do three times motor-driven, three times motor-driven rule is sinusoidal rule: course angle ψ=A ₁Sin (ω ₁T), pitching angle theta=A ₂Sin (ω ₂T), roll angle γ=A ₃Sin (ω ₃And A t), ₁≠ A ₂≠ A ₃, ω ₁≠ ω ₂≠ ω ₃

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