CN106379558A - Sliding mode variable structure composite control method based on angle acceleration feedforward - Google Patents

Abstract

The invention relates to a sliding mode variable structure composite control method based on angle acceleration feedforward. The method comprises the following steps of calculating a linear error sliding mode surface function; then, calculating the boundary layer thickness; next, calculating the control moment based on the angle acceleration feedforward; and finally, calculating a control instruction of a corresponding execution mechanism according to a control moment. The linear error sliding mode surface consisting of quaternion deviation and attitude angle velocity deviation is designed; a system is enabled to normally move along the sliding mode surface; a processing method of boundary layer function with a sign function is used, so that the system buffet can be effectively reduced; the single machine service life is prolonged; the good electrical and mechanical stability of a system is improved; the coupling moment and the angular momentum in the maneuvered process are compensated; and the control precision is improved.

Description

A kind of sliding moding structure composite control method based on angular acceleration feedforward

Technical field

The present invention relates to a kind of sliding moding structure composite control method based on angular acceleration feedforward.

Background technology

Strengthen with satellite function, the flexible appendage area size that star carries is increasing, and the impact bringing is annex Flexible fundamental frequency become lower, coupling becomes big.With satellite, platform stance maneuverability demand is improved, star configures big The execution structure of moment, such as control-moment gyro group.This high-torque actuator stem force square is big, during attitude maneuver Easily evoke the vibration of flexible appendage so that fast settling time is elongated.

Content of the invention

The present invention provide a kind of sliding moding structure composite control method based on angular acceleration feedforward, be capable of satellite by Carry out rapid attitude maneuver according to the process footprint designing, can effectively suppress the flexible vibration of flexible appendage, significantly shorten attitude The time of fast and stable, simple and reliable, operand is little, and engineering is easily achieved.

In order to achieve the above object, the present invention provides a kind of sliding moding structure complex controll side based on angular acceleration feedforward Method, comprises the steps of：

Step S1, calculating linearity error sliding-mode surface function；

Step S2, calculating boundary layer thickness；

Step S3, the control moment based on angular acceleration feedforward for the calculating；

Step S4, calculate the control instruction of corresponding executing agency according to control moment.

In described step S1, the step calculating linearity error sliding-mode surface function comprises：

Step S1.1, calculating sliding-mode surface coefficient；

$K_i=\frac{k_{bi}{\mathrm{\ω}}_{f\_\min }}{2\×1.5538{\mathrm{\ζ}}_i},i=x,y,z$

Wherein, k_biIt is the isolation multiple of system bandwidth and flexible appendage fundamental frequency；ω_{f_min}It is flexible appendage fundamental frequency；ζ_iIt is to be System damped coefficient；

Step S1.2, calculating sliding-mode surface function；

The form of three direction design sliding-mode surfaces is as follows：

S_i=K_iq_e+Ω_e, i=x, y, z

Wherein, q_e=q_v-q_vdIt is quaternary number vector error, q_vIt is the celestial body quaternary number obtaining when pre-testVector portion Point, q_vdIt is the attitude maneuver quaternary number Q of planning_dVector section；It is attitude angular velocity error,It is current survey The celestial body attitude angular velocity measuring, ω_dIt is the attitude maneuver angular speed of planning.

In described step S2, the step calculating boundary layer thickness comprises：

${\mathrm{\ϵ}}_i=\frac{T_{res\_i}}{4{\mathrm{\ζ}}_i^2{I}_{ii}{K}_i},i=x,y,z$

Wherein, T_{res_i}It is the moment that system is reserved；ζ_iIt is system damping coefficient；I_iiIt is the principal moments in three directions of system； K_iIt is sliding-mode surface coefficient.

In described step S3, the step calculating the control moment based on angular acceleration feedforward comprises：

Step S3.1, calculating control moment：

${T_{ci}}^{\&prime;}=\left\{\begin{array}{cc}{T}_{res\_i}& S_i>{\mathrm{\&epsiv;}}_i\\ T_{res\_i}\frac{S_i}{{\mathrm{\&epsiv;}}_i}& \left|S_i\right|<{\mathrm{\&epsiv;}}_i\\ -T_{res\_i}& S_i<-{\mathrm{\&epsiv;}}_i\end{array}\right.,i=x,y,z$

Angular acceleration feedforward is added in step S3.2, control moment：

T_ci'=T_ci'-I_iα_di, i=x, y, z

Wherein, α_diIt is the attitude maneuver angular acceleration instruction of planning；

Step S3.3, carry out torque compensation：

$T_c={T_c}^{\&prime;}-I\left({\widehat{\mathrm{\&omega;}}}_r\&times;R\left({\hat{q}}_{ao}\right)\left[\begin{array}{c}0\\ -{\mathrm{\&omega;}}_0\\ 0\end{array}\right]\right)$

Wherein, I is three axle moment of inertia matrix；ω₀It is orbit angular velocity；RepresentCorresponding attitude matrix；

Step S3.4, carry out angle momentum coupling compensation at steady state：

T_c=T_c-ω×(H-H_z0)

Wherein, ω is the inertia angular speed that gyro to measure obtains；H is the angular momentum of current executing agency；H_z0It is that system is steady The three shaft angle momentum biasing during state.

The present invention devises the linearity error sliding-mode surface being made up of quaternary number deviation and attitude angular velocity deviation it is ensured that system Normally can move along sliding-mode surface, take the processing method for sign function for the boundary layer functions, can effectively reduce and be System tremble shake, improve the service life of unit and the dynamo-electric stationarity that system is good, also to the coupling torque in mobile process with Angular momentum is compensated, and improves control accuracy.

Brief description

Fig. 1 is a kind of flow process of sliding moding structure composite control method based on angular acceleration feedforward that the present invention provides Figure.

Specific embodiment

Illustrate presently preferred embodiments of the present invention below according to Fig. 1.

As shown in figure 1, the present invention provides a kind of sliding moding structure composite control method based on angular acceleration feedforward, comprise Following steps：

Step S1, calculating linearity error sliding-mode surface function；

Step S2, calculating boundary layer thickness；

Step S3, the control moment based on angular acceleration feedforward for the calculating；

Step S4, calculate the control instruction of corresponding executing agency according to control moment.

In described step S1, the step calculating linearity error sliding-mode surface function comprises：

Step S1.1, calculating sliding-mode surface coefficient；

$K_i=\frac{k_{bi}{\mathrm{\&omega;}}_{f\_\min }}{2\&times;1.5538{\mathrm{\&zeta;}}_i},i=x,y,z$

Wherein, k_biIt is the isolation multiple of system bandwidth and flexible appendage fundamental frequency, can be taken as 0.05-0.5, by ground remote control Parameter can be changed；ω_{f_min}It is flexible appendage fundamental frequency；ζ_iIt is system damping coefficient, can be taken as 0.1-2, by ground remote control parameter Can change；

Step S1.2, calculating sliding-mode surface function；

The form of three direction design sliding-mode surfaces is as follows：

S_i=K_iq_e+Ω_e, i=x, y, z

Wherein, q_e=q_v-q_vdIt is quaternary number vector error, q_vIt is the celestial body quaternary number obtaining when pre-testVector portion Point, q_vdIt is the attitude maneuver quaternary number Q of planning_dVector section；It is attitude angular velocity error,It is current survey The celestial body attitude angular velocity measuring, ω_dIt is the attitude maneuver angular speed of planning.

In described step S2, the step calculating boundary layer thickness comprises：

${\mathrm{\&epsiv;}}_i=\frac{T_{res\_i}}{4{\mathrm{\&zeta;}}_i^2{I}_{ii}{K}_i},i=x,y,z$

Wherein, T_{res_i}It is the moment that system is reserved, the ability according to actual executing agency sets；ζ_iIt is system damping system Number；I_iiIt is the principal moments in three directions of system；K_iIt is sliding-mode surface coefficient.

In described step S3, the step calculating the control moment based on angular acceleration feedforward comprises：

Step S3.1, calculating control moment：

${T_{ci}}^{\&prime;}=\left\{\begin{array}{cc}{T}_{res\_i}& S_i>{\mathrm{\&epsiv;}}_i\\ T_{res\_i}\frac{S_i}{{\mathrm{\&epsiv;}}_i}& \left|S_i\right|<{\mathrm{\&epsiv;}}_i\\ -T_{res\_i}& S_i<-{\mathrm{\&epsiv;}}_i\end{array}\right.,i=x,y,z$

Angular acceleration feedforward is added in step S3.2, control moment：

T_ci'=T_ci'-I_iα_di, i=x, y, z

Wherein, α_diIt is the attitude maneuver angular acceleration instruction of planning；

Step S3.3, carry out torque compensation：

$T_c={T_c}^{\&prime;}-I\left({\widehat{\mathrm{\&omega;}}}_r\&times;R\left({\hat{q}}_{ao}\right)\left[\begin{array}{c}0\\ -{\mathrm{\&omega;}}_0\\ 0\end{array}\right]\right)$

Wherein, I is three axle moment of inertia matrix；ω₀It is orbit angular velocity；RepresentCorresponding attitude matrix；

Step S3.4, carry out angle momentum coupling compensation at steady state：

T_c=T_c-ω×(H-H_z0)

Wherein, ω is the inertia angular speed that gyro to measure obtains；H is the angular momentum of current executing agency；H_z0It is that system is steady The three shaft angle momentum biasing during state.

The control instruction of corresponding executing agency in described step S4, is calculated according to control moment；

In one embodiment, as executing agency, then calculate the rotary speed instruction of flywheel, be sent to winged as with flywheel Wheel；

In another embodiment, then calculate controling power as with single-gimbal control moment gyros as executing agency The rotary speed instruction of square gyro outside framework, is sent to control-moment gyro.

The present invention devises the linearity error sliding-mode surface being made up of quaternary number deviation and attitude angular velocity deviation it is ensured that system Normally can move along sliding-mode surface, take the processing method for sign function for the boundary layer functions, can effectively reduce and be System tremble shake, improve the service life of unit and the dynamo-electric stationarity that system is good, also to the coupling torque in mobile process with Angular momentum is compensated, and improves control accuracy.

Although present disclosure has been made to be discussed in detail by above preferred embodiment, but it should be appreciated that above-mentioned Description is not considered as limitation of the present invention.After those skilled in the art have read the above, for the present invention's Multiple modifications and substitutions all will be apparent from.Therefore, protection scope of the present invention should be limited to the appended claims.

Claims (4)

1. a kind of sliding moding structure composite control method based on angular acceleration feedforward is it is characterised in that comprise the steps of：

Step S1, calculating linearity error sliding-mode surface function；

Step S2, calculating boundary layer thickness；

Step S3, the control moment based on angular acceleration feedforward for the calculating；

Step S4, calculate the control instruction of corresponding executing agency according to control moment.

2. the sliding moding structure composite control method based on angular acceleration feedforward as claimed in claim 1 is it is characterised in that institute In step S1 stated, the step calculating linearity error sliding-mode surface function comprises：

Step S1.1, calculating sliding-mode surface coefficient；

$K_i=\frac{k_{bi}{\mathrm{\&omega;}}_{f\_min}}{2\&times;1.5538{\mathrm{\&zeta;}}_i},i=x,y,z$

Wherein, k_biIt is the isolation multiple of system bandwidth and flexible appendage fundamental frequency；ω_{f_min}It is flexible appendage fundamental frequency；ζ_iIt is system resistance Buddhist nun's coefficient；

Step S1.2, calculating sliding-mode surface function；

The form of three direction design sliding-mode surfaces is as follows：

S_i=K_iq_e+Ω_e, i=x, y, z

Wherein, q_e=q_v-q_vdIt is quaternary number vector error, q_vIt is the celestial body quaternary number obtaining when pre-testVector section, q_vdIt is the attitude maneuver quaternary number Q of planning_dVector section；It is attitude angular velocity error,It is current survey The celestial body attitude angular velocity measuring, ω_dIt is the attitude maneuver angular speed of planning.

3. the sliding moding structure composite control method based on angular acceleration feedforward as claimed in claim 2 is it is characterised in that institute In step S2 stated, the step calculating boundary layer thickness comprises：

${\mathrm{\&epsiv;}}_i=\frac{T_{res\_i}}{4{\mathrm{\&zeta;}}_i^2{I}_{ii}{K}_i},i=x,y,z$

Wherein, T_{res_i}It is the moment that system is reserved；ζ_iIt is system damping coefficient；I_iiIt is the principal moments in three directions of system；K_iIt is Sliding-mode surface coefficient.

4. the sliding moding structure composite control method based on angular acceleration feedforward as claimed in claim 3 is it is characterised in that institute In step S3 stated, the step calculating the control moment based on angular acceleration feedforward comprises：

Step S3.1, calculating control moment：

${T_{ci}}^{\&prime;}=\left\{\begin{array}{cc}{T}_{res\_i}& S_i>{\mathrm{\&epsiv;}}_i\\ T_{res\_i}\frac{S_i}{{\mathrm{\&epsiv;}}_i}& \left|S_i\right|<{\mathrm{\&epsiv;}}_i\\ -T_{res\_i}& S_i<-{\mathrm{\&epsiv;}}_i\end{array}\right.,i=x,y,x$

Angular acceleration feedforward is added in step S3.2, control moment：

T_ci'=T_ci′-I_iα_di, i=x, y, z

Wherein, α_diIt is the attitude maneuver angular acceleration instruction of planning；

Step S3.3, carry out torque compensation：

$T_c={T_c}^{\&prime;}-I({\widehat{\mathrm{\&omega;}}}_r\&times;R({\hat{q}}_{ao}\left)\left[\begin{array}{c}0\\ -{\mathrm{\&omega;}}_0\\ 0\end{array}\right]\right)$

Wherein, I is three axle moment of inertia matrix；ω₀It is orbit angular velocity；RepresentCorresponding attitude matrix；

Step S3.4, carry out angle momentum coupling compensation at steady state：

T_c=T_c-ω×(H-H_z0)

Wherein, ω is the inertia angular speed that gyro to measure obtains；H is the angular momentum of current executing agency；H_z0When being systematic steady state Three shaft angle momentum of biasing.