CN105045270A - Rigid-flexible system attitude control method based on vibration compensation and state feedback - Google Patents

Abstract

Provided is a rigid-flexible system attitude control method based on vibration compensation and state feedback. According to the method, dynamic measuring information of flexible vibration is directly employed, compensation and feedback control of vibration influence is performed in an attitude controller of a central rigid body, and actuators do not need to be arranged on flexible accessories. Conventional PID control is difficult to adapt to the condition of inaccurate parameters or changing parameters of controlled objects, and general adaptive control has internal conflicts between the ensuring of the steady-state performance and the dependence on continuous excitation. According to the method, the state feedback control parameters change with the change of estimation states, good steady-state performance indexes can be maintained by variable system and environment, and the method is especially applicable to attitude control of satellites with large flexible influence and high-stability performance index.

Description

A kind of hard and soft posture control method based on vibration compensation and feedback of status

Technical field

The invention belongs to Spacecraft Attitude Control field, relate to a kind of hard and soft posture control method based on vibration compensation and feedback of status.

Background technology

Control main direction of studying for " Rigid Base+flexible appendage " system mainly contains two classes: one is on flexible structure, arrange that sensor and actuator carry out Active Vibration Control; Two is do not consider vibrational structure sensor and actuator, carries out passive suppression by the controller of Rigid Base to flexible vibration.

This method does not need to install actuator on flexible appendage, but utilizes the kinetic measurement information of flexible vibration, in the attitude controller of Rigid Base, carry out vibration compensation and FEEDBACK CONTROL to vibration effect.

In the vibration survey of flexible structure, various ways is proposed.Vibration survey is carried out at flexible appendage free end installation accelerometer as document " the full physical simulation research of flexible satellite large angle maneuver variable-structure control " (Zhou Jun etc., aerospace journal, the 1st phase in 1999) adopts; For the limitation that accelerometer measures exists, Chinese patent 01279070.2, " flexible model tester " proposes to adopt resistance-strain bridge circuit to carry out mode of oscillation measurement; Chinese patent 201010623825.0, the hybrid smart structure control device of flexible vibration " on the star " proposes to adopt piezoelectric ceramics (PZT) to carry out mode of oscillation measurement, and wherein strain sensitive device can be arranged on hinge place, has highly sensitive feature.

At the basic controller design aspect of rigid-body attitude, regulatory PID control is difficult to the situation that adaptation object parameters is forbidden or changed, and general adaptive control exists the internal conflict guaranteed steady-state behaviour and rely between Persistent Excitation, need the weak point for some Typical Controllers to carry out new exploration for this reason.

Summary of the invention

Technology of the present invention is dealt with problems and is: overcome the deficiencies in the prior art, propose a kind of hard and soft posture control method based on vibration compensation and feedback of status, solve and utilize the kinetic measurement information of flexible vibration in the attitude controller of Rigid Base to the problem of the gesture stability that vibration effect compensates.

Technical solution of the present invention is: a kind of hard and soft posture control method based on vibration compensation and feedback of status, and step is as follows:

(1) controlled hard and soft system comprises Rigid Base and flexible appendage, flexible appendage comprises one or more semi-girder, this controlled hard and soft system can be used as and be with the Rigid Base of one or more semi-girder to make Plane Rotation, and the kinetics equation of controlled hard and soft system is:

$\[J_r+\mathrm{\ρ}AL(R^2+RL+\frac{1}{3}{L}^2)\]\stackrel{\·\·}{\mathrm{\θ}}+2\mathrm{\ρ}A{\∫}_0^{L}v\stackrel{\·}{v}dl+\mathrm{\ρ}A{\∫}_0^L(R+l)\stackrel{\·\·}{v}dl=T_c+T_d---\left(1\right)$

$\mathrm{\ρ}A\stackrel{\·\·}{v}+{\mathrm{EIv}}_{llll}+\mathrm{\ρ}A(R+l)\stackrel{\·\·}{\mathrm{\θ}}=\mathrm{\ρ}A{\stackrel{\·}{\mathrm{\θ}}}^{2}v---\left(2\right)$

v(0,t)＝v _l(0,t)＝v _ll(L,t)＝v _lll(L,t)＝0(3)

Formula (1) is attitude dynamic equations, formula (2) is semi-girder flexural vibrations equation, formula (3) is boundary condition, ρ, A, L, R are respectively the distance of the sectional density of flexible cantilever beam, sectional area, length, semi-girder rigid body barycenter relative to Rigid Base tie point, v is the bending displacement at semi-girder arbitrfary point place for the first order derivative of bending displacement, for the second derivative of bending displacement, v _l, v _ll, v _lllthe bending displacement v being respectively semi-girder arbitrfary point place to the single order of the distance l of opposed cantilevered beams when arbitrfary point is not out of shape on semi-girder and Rigid Base tie point, second order and three rank partial derivatives, θ, be respectively the attitude angle acceleration of the attitude angle of Rigid Base, the attitude angular velocity of Rigid Base and Rigid Base, t represents system time, T _c, T _dbe respectively and act on control moment in Rigid Base and disturbance torque, J _r, be respectively the inertia of Rigid Base and the rotating shaft of semi-girder relative system attitude, remember that total inertia is

(2) to the controlled hard and soft system described in step (1), build attitude control system, comprise sensor, topworks and controller, sensor comprises attitude sensor, gyro and displacement transducer, attitude sensor, gyro installation are in Rigid Base, and displacement transducer is installed on a cantilever beam; Controller is arranged in Rigid Base, for the control moment needed for the hard and soft system of real-time resolving; Topworks is arranged in Rigid Base, is applied to Rigid Base for the control moment calculated by controller.

(3) adopt the sensor described in step (2) to measure the controlled hard and soft system described in step (1), namely recorded the measured value θ of Rigid Base attitude angle θ by attitude sensor _m, record Rigid Base attitude angular velocity by gyro measured value the dynamic coordinate q of n rank mode before semi-girder is recorded by displacement transducer _i(t) (i=1,2 ... n) measured value q _mi(t) (i=1,2 ... n), n gets the non-zero positive integer being less than or equal to 4;

(4) the measured value q of the dynamic coordinate of n rank mode before the semi-girder obtained according to step (3) _mi(t) (i=1,2 ... n), the flexural vibrations displacement of semi-girder arbitrfary point is calculated (0≤l≤L), and to v _m(l, t) carries out difference and obtains flexural vibrations speed right again carry out difference and obtain flexural vibrations acceleration

In formula,

Φ _i(l)=sin (β _il)-sh (β _il)-σ _i[cos (β _il)-ch (β _il)], σ _i=(sin β _il+sinh β _il)/(cos β _il+cosh β _iand β L), ₁l ≈ 1.8751, β ₂l ≈ 4.6941, β ₃l ≈ 7.8548, β ₄l ≈ 10.9955.

According to calculated semi-girder flexural vibrations displacement v _m(l, t), flexural vibrations speed with flexural vibrations acceleration carry out flexible vibration feedforward control u _v, formula is as follows:

$u_v=2\mathrm{\ρ}A{\∫}_0^L{v}_m(l,t){\stackrel{\·}{v}}_m(l,t)dl+\mathrm{\ρ}A{\∫}_0^L(R+l){\stackrel{\·\·}{v}}_m(l,t)dl---\left(4\right)$

(5) the measured value q of the dynamic coordinate of n rank mode before the semi-girder obtained according to step (3) _mi(t) (i=1,2 ... n), the measured value that difference obtains speed is carried out to displacement measurement (i=1,2 ... n), modal coordinate feedback control amount u is calculated _q, formula is as follows:

$u_q=\underset{i=1}{\overset{n}{\Σ}}\[K_{qi}{q}_{mi}\left(t\right)+K_{\stackrel{\·}{q}i}{\stackrel{\·}{q}}_{mi}\left(t\right)\]---\left(5\right)$

K in formula _qi>0,

(6) the attitude angle θ of the Rigid Base obtained according to step (4) and attitude angular velocity measured value θ _mwith obtain the attitude error θ of attitude feedback control _ewith attitude angular velocity error be respectively:

θ _e＝θ _d-θ _m(6)

${\stackrel{\·}{\mathrm{\θ}}}_e={\stackrel{\·}{\mathrm{\θ}}}_d-{\stackrel{\·}{\mathrm{\θ}}}_m---\left(7\right)$

θ in formula _dwith be respectively the instruction input of attitude angle and attitude angular velocity;

Attitude feedback control rule is:

$u_{\mathrm{\&theta;}}=J\&CenterDot;K_{\mathrm{\&theta;D}}\&CenterDot;[{\stackrel{\&CenterDot;}{\mathrm{\&theta;}}}_e+K_{\mathrm{\&theta;P}}\&CenterDot;{\mathrm{\&theta;}}_e]+K_{\mathrm{\&theta;I}}\&CenterDot;{\&Integral;\mathrm{\&theta;}}_e{|}_{|\&CenterDot;|<\mathrm{\&gamma;}}\&CenterDot;\mathrm{dt},(0.1>\mathrm{\&gamma;}>0)---\left(8\right)$

In formula, K _{θ P}, K _{θ I}, K _{θ D}for controling parameters;

(7) flexible vibration feedforward control moment u step (4) calculated _v, the modal coordinate FEEDBACK CONTROL moment u that calculates of step (5) _qwith the attitude feedback control moment u that step (6) calculates _θbe added, and carry out amplitude limit, obtain comprehensive control moment T _c:

T _c＝mlf(u _θ+u _v+u _q,T _max)(9)

T in formula _maxfor the upper limit of the real system control moment amplitude of setting, T _max>0, mlf (the 1st parameter, the 2nd parameter) is two-parameter clip functions, namely when the absolute value of the 1st parameter is more than or equal to the 2nd parameter, clip functions under the prerequisite of the symbol of maintenance the 1st parameter, comprehensive control moment T _csize just gets the 2nd parameter T _max, when the absolute value of the 1st parameter is less than the 2nd parameter, Comprehensive Control moment T _csize directly gets the 1st parameter;

(8) final control moment T step (7) calculated _cexport to execution architecture, and be applied in the system described in step (1), complete the gesture stability of hard and soft system.

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

(1) the present invention is by step (4), by the disturbance torque of theory calculate flexible vibration to attitude motion, obtain feedforward compensation moment during gesture stability, achieve the feedforward compensation of gesture stability to flexible vibration, reduce the impact of flexible vibration on attitude motion.

(2) the present invention is by step (5), the speed that the modal vibration coordinate utilizing the measurement of displacement sensor to obtain and difference obtain, by increasing the method for modal vibration damping, achieving flexible vibration and suppressing, flexible mode is vibrated and can decay to zero rapidly.

(3) the present invention proposes a kind of attitude feedback control rule with Intelligent adjustment ability by step (6), and controller architecture is consistent with conventional PID controller structure, but controller parameter all carries out on-line control according to the characteristic of system.Controller parameter changes with the change of estimated state, makes the inventive method still can keep good steady-state behaviour index to the system of change and environment.

Accompanying drawing explanation

Fig. 1 is that the rigid body of band semi-girder makes Plane Rotation schematic diagram;

Fig. 2 is the system chart of the inventive method;

Fig. 3 is vibration suppressioning effect curve when adopting regulatory PID control method;

Fig. 4 is vibration suppressioning effect curve when adopting attitude control method of the present invention.

Embodiment

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

Be illustrated in figure 1 the controlled hard and soft system comprising Rigid Base and flexible appendage, flexible appendage comprises one or more semi-girder, this controlled hard and soft system can be used as and be with the Rigid Base of one or more semi-girder to make Plane Rotation, and the kinetics equation of controlled hard and soft system is:

$\&lsqb;J_r+\mathrm{\&rho;}AL(R^2+RL+\frac{1}{3}{L}^2)\&rsqb;\stackrel{\&CenterDot;\&CenterDot;}{\mathrm{\&theta;}}+2\mathrm{\&rho;}A{\&Integral;}_0^{L}v\stackrel{\&CenterDot;}{v}dl+\mathrm{\&rho;}A{\&Integral;}_0^L(R+l)\stackrel{\&CenterDot;\&CenterDot;}{v}dl=T_c+T_d---\left(1\right)$

$\mathrm{\&rho;}A\stackrel{\&CenterDot;\&CenterDot;}{v}+{\mathrm{EIv}}_{llll}+\mathrm{\&rho;}A(R+l)\stackrel{\&CenterDot;\&CenterDot;}{\mathrm{\&theta;}}=\mathrm{\&rho;}A{\stackrel{\&CenterDot;}{\mathrm{\&theta;}}}^{2}v---\left(2\right)$

v(0,t)＝v _l(0,t)＝v _ll(L,t)＝v _lll(L,t)＝0(3)

Formula (1) is attitude dynamic equations, formula (2) is semi-girder flexural vibrations equation, formula (3) is boundary condition, ρ, A, L, R are respectively the distance of the sectional density of flexible cantilever beam, sectional area, length, semi-girder rigid body barycenter relative to Rigid Base tie point, v is the bending displacement at semi-girder arbitrfary point place for the first order derivative of bending displacement, for the second derivative of bending displacement, v _l, v _ll, v _lllthe bending displacement v being respectively semi-girder arbitrfary point place to the single order of the distance l of opposed cantilevered beams when arbitrfary point is not out of shape on semi-girder and Rigid Base tie point, second order and three rank partial derivatives, θ, be respectively the attitude angle acceleration of the attitude angle of Rigid Base, the attitude angular velocity of Rigid Base and Rigid Base, t represents system time, T _c, T _dbe respectively and act on control moment in Rigid Base and disturbance torque, J _r, be respectively the inertia of Rigid Base and the rotating shaft of semi-girder relative system attitude, remember that total inertia is

(2) for hard and soft system controlled shown in Fig. 1, build attitude control system as shown in Figure 2, comprise sensor, topworks and controller, sensor comprises attitude sensor, gyro and displacement transducer, attitude sensor, gyro installation are in Rigid Base, and displacement transducer is installed on a cantilever beam; Controller is arranged in Rigid Base, for the control moment needed for the hard and soft system of real-time resolving; Topworks is arranged in Rigid Base, is applied to Rigid Base for the control moment calculated by controller.

(3) the measured value θ of Rigid Base attitude angle θ is recorded by attitude sensor _m, record Rigid Base attitude angular velocity by gyro measured value the dynamic coordinate q of n rank mode before semi-girder is recorded by displacement transducer _i(t) (i=1,2 ... n) measured value q _mi(t) (i=1,2 ... n), n gets the non-zero positive integer being less than or equal to 4, and concerning the satellite attitude control system of routine, the mainly vibration effect of single order flexible mode, therefore n gets 1.

(4) according to the measured value q of the dynamic coordinate of n rank mode before semi-girder _mi(t) (i=1,2 ... n), the flexural vibrations displacement of semi-girder arbitrfary point is calculated (0≤l≤L), and to v _m(l, t) carries out difference and obtains flexural vibrations speed right again carry out difference and obtain flexural vibrations acceleration

In formula, Φ _i(l)=sin (β _il)-sh (β _il)-σ _i[cos (β _il)-ch (β _il)],

σ _i=(sin β _il+sinh β _il)/(cos β _il+cosh β _iand β L), ₁l ≈ 1.8751, β ₂l ≈ 4.6941, β ₃l ≈ 7.8548, β ₄l ≈ 10.9955.

According to calculated semi-girder flexural vibrations displacement v _m(l, t), flexural vibrations speed v & _m(l, t) and flexural vibrations acceleration carry out flexible vibration feedforward control u _v, formula is as follows:

$u_v=2\mathrm{\&rho;}A{\&Integral;}_0^L{v}_m(l,t){\stackrel{\&CenterDot;}{v}}_m(l,t)dl+\mathrm{\&rho;}A{\&Integral;}_0^L(R+l){\stackrel{\&CenterDot;\&CenterDot;}{v}}_m(l,t)dl---\left(4\right)$

Wherein formula (4) is according to the disturbance torque of the flexible vibration of theory calculate to attitude motion, and flexible vibration displacement, vibration velocity and vibration acceleration survey calculation value is replaced.By introducing feedforward compensation moment in gesture stability, achieving the feedforward compensation of gesture stability to flexible vibration, reducing the impact of flexible vibration on attitude motion, make the Rigid Base when flexible vibration still have higher attitude stability.

(5) according to the measured value q of the dynamic coordinate of n rank mode before semi-girder _mi(t) (i=1,2 ... n), the measured value that difference obtains speed is carried out to displacement measurement (i=1,2 ... n), modal coordinate feedback control amount u is calculated _q, formula is as follows:

$u_q=\underset{i=1}{\overset{n}{\&Sigma;}}\&lsqb;K_{qi}{q}_{mi}\left(t\right)+K_{\stackrel{\&CenterDot;}{q}i}{\stackrel{\&CenterDot;}{q}}_{mi}\left(t\right)\&rsqb;---\left(5\right)$

K in formula _qi>0, concerning real system, because the damping of modal vibration is less, after making flexible mode starting of oscillation, need the longer time just can decay to zero, this for Rigid Base gesture stability be disadvantageous, need to make flexible mode vibration damping as early as possible, therefore in the gesture stability of Rigid Base, modal coordinate FEEDBACK CONTROL is introduced, the speed that the modal vibration coordinate utilizing the measurement of displacement sensor to obtain and difference obtain, by increasing the method for modal vibration damping, achieve flexible vibration to suppress, flexible mode is vibrated and can decay to zero rapidly, Rigid Base also can be stablized as early as possible.

(6) the attitude angle θ of the Rigid Base obtained according to step (4) and attitude angular velocity measured value θ _mwith obtain the attitude error θ of attitude feedback control _ewith attitude angular velocity error be respectively:

θ _e＝θ _d-θ _m(6)

${\stackrel{\&CenterDot;}{\mathrm{\&theta;}}}_e={\stackrel{\&CenterDot;}{\mathrm{\&theta;}}}_d-{\stackrel{\&CenterDot;}{\mathrm{\&theta;}}}_m---\left(7\right)$

θ in formula _dwith be respectively the instruction input of attitude angle and attitude angular velocity;

Attitude feedback control rule is:

$u_{\mathrm{\&theta;}}=J\&CenterDot;K_{\mathrm{\&theta;}D}\&CenterDot;\&lsqb;{\stackrel{\&CenterDot;}{\mathrm{\&theta;}}}_e+K_{\mathrm{\&theta;}P}\&CenterDot;{\mathrm{\&theta;}}_e\&rsqb;+K_{\mathrm{\&theta;}I}\&CenterDot;\&Integral;{\mathrm{\&theta;}}_e{|}_{|\&CenterDot;|<\mathrm{\&gamma;}}\&CenterDot;dt,(1>>\mathrm{\&gamma;}>0)---\left(8\right)$

In formula, K _{θ P}, K _{θ I}, K _{θ D}for controling parameters; Controling parameters K _{θ P}, K _{θ I}, K _{θ D}according to attitude error θ _ewith attitude angular velocity error determine, wherein $K_{\mathrm{\&theta;}P}=\frac{|n_{\stackrel{\&CenterDot;}{\mathrm{\&theta;}}}{|}_{max}+K_{\mathrm{\&theta;}D}^{-1}\&CenterDot;J^{-1}|T_d{|}_{max}}{|n_{\mathrm{\&theta;}}{|}_{\max }},K_{\mathrm{\&theta;}I}={\mathrm{\&lambda;}}_i\&lsqb;1+sgn({\mathrm{\&theta;}}_e\&CenterDot;{\stackrel{\&CenterDot;}{\mathrm{\&theta;}}}_e)\&rsqb;\left|{\mathrm{\&theta;}}_e\right|.$ In formula, with 1> λ _i>0,1> λ _d>0; 10≤t ₀≤ 100, desirable t ₀=50.

Visible, although the structure of the controller of this method proposition is consistent with conventional PID controller structure, the controller parameter that the inventive method proposes all carries out on-line control according to the characteristic of system, for having the attitude controller of Intelligent adjustment ability.Controller parameter changes with the change of estimated state, wherein the change of system state is got to the monitor value of a period of time, as by t ₀get 50 seconds, i.e. K _{θ D}value and current time 50 seconds backward in all states relevant, make the optimum configurations of controller can the change of responding system state, and good steady-state behaviour index can be kept.。

(7) flexible vibration feedforward control moment u step (4) calculated _v, the modal coordinate FEEDBACK CONTROL moment u that calculates of step (5) _qwith the attitude feedback control moment u that step (6) calculates _θbe added, and carry out amplitude limit, obtain comprehensive control moment T _c:

T _c＝mlf(u _θ+u _v+u _q,T _max)(9)

T in formula _maxfor the upper limit of the real system control moment amplitude of setting, wherein T _max>0, mlf (the 1st parameter, the 2nd parameter) are two-parameter clip functions, namely when the absolute value of the 1st parameter is more than the 2nd parameter, clip functions under the prerequisite of the symbol of maintenance the 1st parameter, comprehensive control moment T _csize just gets the 2nd parameter T _max, otherwise Comprehensive Control moment T _csize directly gets the 1st parameter;

(8) final control moment T step (7) calculated _cexport to execution architecture, and be applied in the system described in step (1), complete the gesture stability of hard and soft system.

Carried out simulation comparison based on the attitude feedback control device designed by the present invention to hard and soft systems such as the Large Spacecraft of moonlet, general applied satellite, large-scale application platform and similar Hubble in described step (6), result is as shown in table 1.Visible, attitude control accuracy during employing the inventive method and Attitude control stability are all less than regulatory PID control method, wherein in Attitude control stability the inventive method result comparatively regulatory PID control method improve 3 ~ 5 times, attitude control accuracy improves 30% ~ 80%.Concerning embody rule as satellite gravity anomaly, adopt the inventive method can realize higher control accuracy compared with regulatory PID control method, make satellite have better performance.

This controller of table 1 and regulatory PID control results contrast

Vibration suppression correlation curve time as shown in Figure 3, Figure 4 for adopting regulatory PID control method and adopting attitude control method of the present invention, wherein Fig. 3 adopts regulatory PID control method, do not introduce vibrational feedback to compensate, although visible flexible vibration is decayed gradually, speed of convergence is slower.Fig. 4 have employed attitude control method of the present invention, carries out FEEDBACK CONTROL to vibration, and the time making vibration damping used greatly reduces.

The content be not described in detail in instructions of the present invention belongs to the known technology of those skilled in the art.

Claims (2)

1., based on a hard and soft posture control method for vibration compensation and feedback of status, it is characterized in that step is as follows:

(1) controlled hard and soft system comprises Rigid Base and flexible appendage, flexible appendage comprises one or more semi-girder, this controlled hard and soft system can be used as and be with the Rigid Base of one or more semi-girder to make Plane Rotation, and the kinetics equation of controlled hard and soft system is:

$\&lsqb;J_r+\mathrm{\&rho;}AL(R^2+RL+\frac{1}{3}{L}^2)\&rsqb;\stackrel{\&CenterDot;\&CenterDot;}{\mathrm{\&theta;}}+2\mathrm{\&rho;}A{\&Integral;}_0^{L}v\stackrel{\&CenterDot;}{v}dl+\mathrm{\&rho;}A{\&Integral;}_0^L(R+l)\stackrel{\&CenterDot;\&CenterDot;}{v}dl=T_c+T_d---\left(1\right)$

$\mathrm{\&rho;}A\stackrel{\&CenterDot;\&CenterDot;}{v}+{\mathrm{EIv}}_{llll}+\mathrm{\&rho;}A(R+l)\stackrel{\&CenterDot;\&CenterDot;}{\mathrm{\&theta;}}=\mathrm{\&rho;}A{\stackrel{\&CenterDot;}{\mathrm{\&theta;}}}^{2}v---\left(2\right)$

v(0,t)＝v _l(0,t)＝v _ll(L,t)＝v _lll(L,t)＝0(3)

Formula (1) is attitude dynamic equations, formula (2) is semi-girder flexural vibrations equation, formula (3) is boundary condition, ρ, A, L, R are respectively the distance of the sectional density of flexible cantilever beam, sectional area, length, semi-girder rigid body barycenter relative to Rigid Base tie point, v is the bending displacement at semi-girder arbitrfary point place for the first order derivative of bending displacement, for the second derivative of bending displacement, v _l, v _ll, v _lllthe bending displacement v being respectively semi-girder arbitrfary point place to the single order of the distance l of opposed cantilevered beams when arbitrfary point is not out of shape on semi-girder and Rigid Base tie point, second order and three rank partial derivatives, θ, be respectively the attitude angle acceleration of the attitude angle of Rigid Base, the attitude angular velocity of Rigid Base and Rigid Base, t represents system time, T _c, T _dbe respectively and act on control moment in Rigid Base and disturbance torque, J _r, be respectively the inertia of Rigid Base and the rotating shaft of semi-girder relative system attitude, remember that total inertia is

(2) to the controlled hard and soft system described in step (1), build attitude control system, comprise sensor, topworks and controller, sensor comprises attitude sensor, gyro and displacement transducer, attitude sensor, gyro installation are in Rigid Base, and displacement transducer is installed on a cantilever beam; Controller is arranged in Rigid Base, for the control moment needed for the hard and soft system of real-time resolving; Topworks is arranged in Rigid Base, is applied to Rigid Base for the control moment calculated by controller.

(3) adopt the sensor described in step (2) to measure the controlled hard and soft system described in step (1), namely recorded the measured value θ of Rigid Base attitude angle θ by attitude sensor _m, record Rigid Base attitude angular velocity by gyro measured value the dynamic coordinate q of n rank mode before semi-girder is recorded by displacement transducer _i(t) (i=1,2 ... n) measured value q _mi(t) (i=1,2 ... n), n gets the non-zero positive integer being less than or equal to 4;

(4) the measured value q of the dynamic coordinate of n rank mode before the semi-girder obtained according to step (3) _mi(t) (i=1,2 ... n), the flexural vibrations displacement of semi-girder arbitrfary point is calculated (0≤l≤L), and to v _m(l, t) carries out difference and obtains flexural vibrations speed right again carry out difference and obtain flexural vibrations acceleration

In formula,

Φ _i(l)＝sin(β _il)-sh(β _il)-σ _i[cos(β _il)-ch(β _il)],σ _i＝(sinβ _iL+sinhβ _iL)/(cosβ _iL+coshβ _iL)，

And β ₁l ≈ 1.8751, β ₂l ≈ 4.6941, β ₃l ≈ 7.8548, β ₄l ≈ 10.9955.

According to calculated semi-girder flexural vibrations displacement v _m(l, t), flexural vibrations speed with flexural vibrations acceleration carry out flexible vibration feedforward control u _v, formula is as follows:

$u_v=2\mathrm{\&rho;}A{\&Integral;}_0^L{v}_m(l,t){\stackrel{\&CenterDot;}{v}}_m(l,t)dl+\mathrm{\&rho;}A{\&Integral;}_0^L(R+l){\stackrel{\&CenterDot;\&CenterDot;}{v}}_m(l,t)dl---\left(4\right)$

(5) the measured value q of the dynamic coordinate of n rank mode before the semi-girder obtained according to step (3) _mi(t) (i=1,2 ... n), the measured value that difference obtains speed is carried out to displacement measurement calculate modal coordinate feedback control amount u _q, formula is as follows:

$u_q=\underset{i=1}{\overset{n}{\&Sigma;}}\&lsqb;K_{qi}{q}_{mi}\left(t\right)+K_{\stackrel{\&CenterDot;}{q}i}{\stackrel{\&CenterDot;}{q}}_{mi}\left(t\right)\&rsqb;---\left(5\right)$

In formula $K_{qi}>0,K_{\stackrel{\&CenterDot;}{q}i}>5K_{qi}$

(6) the attitude angle θ of the Rigid Base obtained according to step (4) and attitude angular velocity measured value θ _mwith obtain the attitude error θ of attitude feedback control _ewith attitude angular velocity error be respectively:

θ _e＝θ _d-θ _m(6)

${\stackrel{\&CenterDot;}{\mathrm{\&theta;}}}_e={\stackrel{\&CenterDot;}{\mathrm{\&theta;}}}_d-{\stackrel{\&CenterDot;}{\mathrm{\&theta;}}}_m---\left(7\right)$

θ in formula _dwith be respectively the instruction input of attitude angle and attitude angular velocity;

Attitude feedback control rule is:

$\begin{array}{cc}{u}_{\mathrm{\&theta;}}=J\&CenterDot;K_{\mathrm{\&theta;}D}\&CenterDot;\&lsqb;{\stackrel{\&CenterDot;}{\mathrm{\&theta;}}}_e+K_{\mathrm{\&theta;}P}\&CenterDot;{\mathrm{\&theta;}}_e\&rsqb;+K_{\mathrm{\&theta;}I}\&CenterDot;\&Integral;{\mathrm{\&theta;}}_e{|}_{|\&CenterDot;|<\mathrm{\&gamma;}}\&CenterDot;dt& (0.1>\mathrm{\&gamma;}>0)\end{array}---\left(8\right)$

In formula, K _{θ P}, K _{θ I}, K _{θ D}for controling parameters;

(7) flexible vibration feedforward control moment u step (4) calculated _v, the modal coordinate FEEDBACK CONTROL moment u that calculates of step (5) _qwith the attitude feedback control moment u that step (6) calculates _θbe added, and carry out amplitude limit, obtain comprehensive control moment T _c:

T _c＝mlf(u _θ+u _v+u _q,T _max)(9)

T in formula _maxfor the upper limit of the real system control moment amplitude of setting, T _max>0, mlf (the 1st parameter, the 2nd parameter) is two-parameter clip functions, namely when the absolute value of the 1st parameter is more than or equal to the 2nd parameter, clip functions under the prerequisite of the symbol of maintenance the 1st parameter, comprehensive control moment T _csize just gets the 2nd parameter T _max, when the absolute value of the 1st parameter is less than the 2nd parameter, Comprehensive Control moment T _csize directly gets the 1st parameter;

(8) final control moment T step (7) calculated _cexport to execution architecture, and be applied in the system described in step (1), complete the gesture stability of hard and soft system.

2. a kind of hard and soft posture control method based on vibration compensation and feedback of status according to claim 1, is characterized in that: controling parameters K in described step (6) _{θ P}, K _{θ I}, K _{θ D}according to attitude error θ _ewith attitude angular velocity error determine, namely $K_{\mathrm{\&theta;}P}=\frac{|n_{\stackrel{\&CenterDot;}{\mathrm{\&theta;}}}{|}_{max}+K_{\mathrm{\&theta;}D}^{-1}\&CenterDot;J^{-1}|T_d{|}_{max}}{|\mathrm{\&theta;}{|}_{\max }},K_{\mathrm{\&theta;}I}={\mathrm{\&lambda;}}_i\&lsqb;1+\mathrm{sgn}({\mathrm{\&theta;}}_e\&CenterDot;{\stackrel{\&CenterDot;}{\mathrm{\&theta;}}}_e)\&rsqb;\left|{\mathrm{\&theta;}}_e\right|,$ In formula, with | n _θ| _maxbe respectively the maximal value of angular velocity and the measurement of angle noise arranged according to sensor performance, value be 1 × 10 ^-5~ 1 × 10 ^{-2 °}/ s and | n _θ| _maxspan be 1 × 10 ^-4~ 0.1 °, 1> λ _i>0,1> λ _d>0,10≤t ₀≤ 100.