CN105947238B - Anti-interference attitude control method for Mars lander with uncertain rotational inertia - Google Patents

Abstract

The invention relates to an anti-interference attitude control method for a Mars lander with uncertain rotational inertia. The anti-interference attitude control method comprises the steps that firstly, an attitude kinematics and dynamics model of the Mars lander with the uncertain rotational inertia is established; secondly, aiming at the influence brought by the uncertain rotational inertia of the Mars lander, a self-adaptive controller is designed to estimate the uncertain rotational inertia; thirdly, the interference influence of gust on the Mars lander is estimated through a nonlinear interference observer, and then the gust estimated value is fed back to a control system to be subjected to feedforward offset; and finally, the nonlinear interference observer, the self-adaptive controller and a sliding mode controller for ensuring the system attitude precision are composited, so that the anti-interference attitude control method for the Mars lander with the uncertain rotational inertia is constructed. The anti-interference attitude control method for the Mars lander with the uncertain rotational inertia has the characteristics of being high in anti-interference performance and adaptability, and compared with a traditional Mars lander attitude control method, the practical engineering value is higher.

Description

A kind of anti-interference attitude control method of the uncertain Mars landing device of rotary inertia

Technical field

The present invention relates to a kind of anti-interference attitude control method of the uncertain Mars landing device of rotary inertia, in fitful wind Under the influence of Mars landing device there are problems that the uncertain gesture stability of rotary inertia, using based on Nonlinear Disturbance Observer with from The thinking that sliding formwork control combines is adapted to, the anti-interference of Mars landing device is improve compared with traditional control method and is adapted to Ability, improves engineering application value.

Background technology

For exploration of the universe origin, seek sign of life and understanding objective world, it is that the mankind are insistent to explore outer space Dream.With the continuous maturation of space technology, the gradually accumulation of experience, the step of the external deep space probing of the mankind is stepped from the moon To Mars.Similar with moon exploration, lander understands the most direct means of celestial body as the mankind, mars exploration is served to Close important effect.And can Mars landing device accurately reach the destination according to the needs of tasks of science, directly affect and detect The success or failure of task.High-precision landing requires that the gesture stability then to lander in flight course is put forward higher requirement. The attitude control method of early stage mainly adopts linearization method of controlling, by carrying out approximate linearization to system model, and then adopts With sides such as the frequency response method in classical cybernetics, root-locus technique, POLE PLACEMENT USING, the linear quadratic regulations in linear control theory Method is processed.Because attitude control system belongs to nonlinear control system, so it is controlled rule only with inearized model Design be difficult to ensure that control effect.Later stage, many scholars were incorporated into Control of Nonlinear Systems method in gesture stability, obtained Preferable effect is simultaneously widely applied.But traditional attitude control method mainly considers the essence of attitude control system Degree, have ignored uncertain, fitful wind of rotary inertia that Mars landing device can face in flight course etc. from the inside and outside portion pair of system The interference effect that lander attitude control system is brought, leads to not ensure the gesture stability essence of lander under multi-source interference effect Degree.The multi-source interference effect that Mars landing device attitude control system is subject to is proposed greatly to traditional attitude control method Challenge.

The content of the invention

The present invention technology solve problem be：For the deficiency of existing Mars landing device attitude control method, there is provided a kind of The anti-interference attitude control method of the uncertain Mars landing device of rotary inertia with common-path interference, strong adaptability.

The present invention technical solution be：A kind of anti-interference gesture stability side of the uncertain Mars landing device of rotary inertia Method, it is characterised in that comprise the following steps：First, build containing the uncertain Mars landing device attitude kinematics of rotary inertia with Kinetic model；Secondly, the rotary inertia for Mars landing device does not know the impact for bringing, and design adaptive controller is to turning Dynamic inertia is uncertain to be estimated；Again, the interference that fitful wind brings to Mars landing device is estimated using Nonlinear Disturbance Observer Affect, and then fitful wind estimate is fed back to carry out in control system feedforward cancellation；Finally, by Nonlinear Disturbance Observer, from The sliding mode controller of adaptive controller and guarantee posture precision is combined, the uncertain Mars landing of construction rotary inertia The anti-interference attitude control method of device；Comprise the following steps that：

The first step, builds the attitude kinematics and kinetic model of the uncertain Mars landing device of rotary inertia

Build as follows with kinetic model containing the uncertain Mars landing device attitude kinematics of rotary inertia：

Wherein, J represents rotary inertia of the Mars landing device in body coordinate system, such as Σ₄It is shown.ω_e=[ω_ex,ω_ey, ω_ez]^TRepresent the axis angular rate tracking error of Mars landing device three, σ_e=[σ_ex,σ_ey,σ_ez]^TRepresent axle amendment sieve of Mars landing device three Delhi lattice parameter (Modified Rodrigues Parameter, MRP) tracking error.ω_d=[ω_x,ω_y,ω_z]^TRepresent fire The axle of star lander three expects angular speed.U=[u_x,u_y,u_z]^TRepresent the axle control input of Mars landing device three.D=[d_x,d_y,d_z]^TTable Show three axle gust disturbance torque suffered by Mars landing device.

Second step, constructs adaptive controller

Do not know for the rotary inertia in Mars landing device attitude kinematics and kinetic model, construct Self Adaptive Control Device is estimated rotary inertia.

Linear operator L (χ) is defined first, and concrete form is as follows：

Then have：

Σ₇:J χ=L (χ) θ

Wherein θ=[J₁₁ J₁₂ J₁₃ J₂₂ J₂₃ J₃₃]^T∈R⁶To need the parameter vector of identification.

The estimate of rotary inertia J isAnd uncertain being converted into for estimating rotary inertia is estimated into that θ's is uncertain, estimate It is worth and is

Design adaptive control laws are as follows：

Wherein, k is the scalar more than 0,

Wherein, W is auxiliary variable, F=G (σ_e)^-1, s is sliding-mode surface.

3rd step, designs Nonlinear Disturbance Observer

For the ease of the design of Nonlinear Disturbance Observer, by system Σ₁、Σ₂It is converted into type such as Σ₁₁Nonlinear system Model：

x∈R⁶It is state vector, u ∈ R⁶It is control input, d ∈ R³It is disturbance torque.Wherein,

H (x (t))=x (t).

Assume interference model such as Σ₁₂：

ξ∈R^6×6, d ∈ R³, disturb d to be continuously applied in system Σ₁₁On.

Design interference observer Σ₁₃：

Wherein, z ∈ R^6×6It is the state variable of observer, p (x) ∈ R^6×6It is the nonlinear function of design.Nonlinear perturbations Observer gain is Σ₁₄Formula：

4th step, by the sliding mode controller of Nonlinear Disturbance Observer, adaptive controller and guarantee posture precision It is combined, the anti-interference attitude control method of the uncertain Mars landing device of construction rotary inertia

Design first ensures that the sliding mode controller of attitude accuracy is as follows：

Σ₁₅:u₂=-G^T(σ_e)k_ssgn(s)-G^T(σ_e)gs

Wherein, k_sIt is three-dimensional diagonal positively definite matrix with g.

Secondly construction composite controller form is as follows：

Present invention advantage compared with prior art is：The uncertain Mars landing device of rotary inertia of the present invention is anti-dry Disturb attitude control method and employ anti-interference attitude control method, control method includes Self Adaptive Control, sliding formwork control and front Three parts of feedback compensation interference effect：Feedforward compensation interference effect part is made up of Nonlinear Disturbance Observer, for compensating ring The interference effect that border fitful wind brings to lander system；It is not true that Self Adaptive Control part is used for On-line Estimation lander rotary inertia It is fixed；Sliding formwork control part ensures the attitude accuracy of Mars landing device attitude control system；Relative to existing Mars landing device appearance State control method, the anti-interference attitude control method of present invention design has in terms of antijamming capability and adaptability and greatly changes It is kind.

Description of the drawings

Fig. 1 is a kind of design cycle of the anti-interference attitude control method of the uncertain Mars landing device of rotary inertia of the invention Figure；

Specific embodiment

As shown in figure 1, the present invention implement step it is following (below by taking Mars landing device attitude control system as an example for Bright method is implemented)：

1st, build containing the uncertain Mars landing device attitude kinematics of rotary inertia and kinetic model

Build as follows with kinetic model containing the uncertain Mars landing device attitude kinematics of rotary inertia：

Wherein, J represents rotary inertia of the Mars landing device in body coordinate system, such as Σ₄Shown, value isIt is unknown parameter when controller is designed.ω_e=[ω_ex,ω_ey,ω_ez]^TRepresent that Mars The axis angular rate tracking error of land device three, σ_e=[σ_ex,σ_ey,σ_ez]^TRepresent the axle modified discrete chirp-Fourier transform of Mars landing device three (Modified Rodrigues Parameter, MRP) tracking error.ω_d=[ω_x,ω_y,ω_z]^TRepresent Mars landing device three Axle expects angular speed, and wherein initial attitude MRP values and initial angular velocity is respectively σ₀=[- 0.169, -0.014,0.526]^TWith ω₀=[0,0,0]^T, expect attitude MRP value and expect that angular speed is respectively σ_d=[0.131 0.186 0.226]^TWithU=[u_x,u_y,u_z]^TRepresent the axle control input of Mars landing device three.D=[d_x, d_y,d_z]^TThree axle gust disturbance torques suffered by Mars landing device are represented, and assumes that disturbance torque is

2nd, adaptive controller is constructed

Do not know for the rotary inertia in Mars landing device attitude kinematics and kinetic model, construct Self Adaptive Control Device is estimated rotary inertia.

Linear operator L (χ) is defined first, and concrete form is as follows：

Then have：

Σ₇:J χ=L (χ) θ

Wherein θ=[J₁₁ J₁₂ J₁₃ J₂₂ J₂₃ J₃₃]^T∈R⁶To need the parameter vector of identification.

The estimate of rotary inertia J isAnd uncertain being converted into for estimating rotary inertia is estimated into that θ's is uncertain, estimate It is worth and is

Design adaptive control laws are as follows：

Wherein, k is the scalar more than 0,

Wherein, W is auxiliary variable, F=G (σ_e)^-1, s is sliding-mode surface.

3rd, Nonlinear Disturbance Observer is designed

For the ease of the design of Nonlinear Disturbance Observer, by system Σ₁、Σ₂It is converted into type such as Σ₁₁Nonlinear system Model：

x∈R⁶It is state vector, u ∈ R⁶It is control input, d ∈ R³It is disturbance torque.Wherein,

H (x (t))=x (t).

Assume interference model such as Σ₁₂：

ξ∈R^6×6, d ∈ R³, disturb d to be continuously applied in system Σ₁₁On.

Design interference observer Σ₁₃：

Wherein, z ∈ R^6×6It is the state variable of observer, p (x) ∈ R^6×6It is the nonlinear function of design.Nonlinear perturbations Observer gain is Σ₁₄Formula：

4th, the sliding mode controller of Nonlinear Disturbance Observer, adaptive controller and guarantee posture precision is carried out multiple Close, the anti-interference attitude control method of the uncertain Mars landing device of construction rotary inertia

Design first ensures that the sliding mode controller of attitude accuracy is as follows：

Σ₁₅:u₂=-G^T(σ_e)k_ssgn(s)-G^T(σ_e)gs

Wherein, k_sIt is three-dimensional diagonal positively definite matrix with g.

Secondly construction composite controller form is as follows：

The characteristics of present invention has common-path interference and strong adaptability, relative to traditional Mars landing device gesture stability side Method engineering practical value is higher.

The content not being described in detail in description of the invention belongs to prior art known to professional and technical personnel in the field.

Claims (4)

1. the anti-interference attitude control method of the uncertain Mars landing device of a kind of rotary inertia, it is characterised in that including following step Suddenly：

The first step, builds containing the uncertain Mars landing device attitude kinematics of rotary inertia and kinetic model；

Second step, for the rotary inertia in Mars landing device attitude kinematics and kinetic model the interference shadow for bringing is not known Ring, design adaptive controller is uncertain to rotary inertia to be estimated, obtains rotary inertia estimate；

3rd step, according to the rotary inertia estimate that second step adaptive controller is estimated, is estimated using Nonlinear Disturbance Observer Meter fitful wind interference effect that Mars landing device is brought, and then fitful wind estimate is fed back in attitude control system feedovered Offset；

4th step, finally by the 3rd step Nonlinear Disturbance Observer, second step adaptive controller and guarantee attitude control system The sliding mode controller of attitude accuracy is combined, the anti-interference gesture stability side of the uncertain Mars landing device of construction rotary inertia Method；

The first step, builds the attitude kinematics containing the uncertain Mars landing device of rotary inertia and realizes with kinetic model It is as follows：

Build as follows with kinetic model containing the uncertain Mars landing device attitude kinematics of rotary inertia：

Σ₁:

Σ₂:

Σ₃:

Σ₄:

Σ₅:

Wherein, J represents rotary inertia of the Mars landing device in body coordinate system, ω_e=[ω_ex,ω_ey,ω_ez]^TRepresent Mars The axis angular rate tracking error of lander three, σ_e=[σ_ex,σ_ey,σ_ez]^TRepresent the axle modified discrete chirp-Fourier transform of Mars landing device three (Modified Rodrigues Parameter, MRP) tracking error；ω_d=[ω_x,ω_y,ω_z]^TRepresent Mars landing device three Axle expects angular speed, u=[u_x,u_y,u_z]^TRepresent the axle control input of Mars landing device three, d=[d_x,d_y,d_z]^TRepresent Mars landing Three axle gust disturbance torque suffered by device.

2. the anti-interference attitude control method of the uncertain Mars landing device of a kind of rotary inertia according to claim 1, its It is characterised by：The second step, the construction of adaptive controller is as follows：

Linear operator L (χ) is defined first, and concrete form is as follows：

Σ₆:

Then have：

Σ₇:J χ=L (χ) θ

Wherein θ=[J₁₁ J₁₂ J₁₃ J₂₂ J₂₃ J₃₃]^T∈R⁶To need the rotary inertia parameter vector of identification, χ=[χ₁ χ₂ χ₃ ]^T∈R³It is auxiliary variable, R represents real number field；

The estimate of rotary inertia J isAnd uncertain being converted into for estimating rotary inertia is estimated into that θ's is uncertain, estimate is

Design adaptive control laws are as follows：

Σ₈:

Wherein, k is the scalar more than 0,

Σ₉:

Σ₁₀:

Wherein, W is auxiliary variable, F=G (σ_e)^-1, s is sliding-mode surface.

3. the anti-interference attitude control method of the uncertain Mars landing device of a kind of rotary inertia according to claim 1, its It is characterised by：3rd step, the design of Nonlinear Disturbance Observer is as follows：

For the ease of the design of Nonlinear Disturbance Observer, by system Σ₁、Σ₂It is converted into type Σ₁₁Nonlinear system model：

Σ₁₁:

x∈R⁶It is state vector, u ∈ R⁶It is control input, d ∈ R³It is disturbance torque, wherein,

$f\left(x\right(t\left)\right)=\left[\begin{array}{c}{J}^{-1}(-\[{({\mathrm{\ω}}_e+R({\mathrm{\σ}}_e\left){\mathrm{\ω}}_d\right)}^{\×}\]J({\mathrm{\ω}}_e+R\left({\mathrm{\σ}}_e\right){\mathrm{\ω}}_d)+J(\[{{\mathrm{\ω}}_e}^{\×}\]R({\mathrm{\σ}}_e){\mathrm{\ω}}_d-R\left({\mathrm{\σ}}_e\right){\stackrel{\·}{\mathrm{\ω}}}_d))\\ G\left({\mathrm{\σ}}_e\right){\mathrm{\ω}}_e\end{array}\right],$

$R\left({\mathrm{\σ}}_e\right)=\frac{\[(1-6{{\mathrm{\σ}}_e}^2+{{\mathrm{\σ}}_e}^4)I_3+8{\mathrm{\σ}}_e{{\mathrm{\σ}}_e}^T-4(1-{{\mathrm{\σ}}_e}^2)\[{{\mathrm{\σ}}_e}^{\×}\]\]}{{(1+{{\mathrm{\σ}}_e}^2)}^2},g_1\left(x\right(t\left)\right)=g_2\left(x\right(t\left)\right)=\left[\begin{array}{c}{J}^{-1}\\ 0\end{array}\right],$

H (x (t))=x (t)；

Σ₁:

Σ₂:

Assume interference model Σ₁₂：

Σ₁₂:

ξ∈R^6×6, d ∈ R³, disturb d to be continuously applied in system Σ₁₁On；

Design interference observer Σ₁₃：

Σ₁₃:

Wherein, z ∈ R^6×6It is the state variable of observer, p (x) ∈ R^6×6It is the nonlinear function of design, Nonlinear perturbations are observed Device gain is Σ₁₃Formula：

Σ₁₄:

4. the anti-interference attitude control method of the uncertain Mars landing device of a kind of rotary inertia according to claim 1, its It is characterised by：4th step, the anti-interference attitude control method of the uncertain Mars landing device of construction rotary inertia is as follows：

Design first ensures that the sliding mode controller of attitude accuracy is as follows：

Σ₁₅:u₂=-G^T(σ_e)k_s sgn(s)-G^T(σ_e)gs

Wherein, k_sIt is three-dimensional diagonal positively definite matrix with g；S is sliding-mode surface；

Secondly construction composite controller form is as follows：

Σ₁₆: