CN104635740B - A kind of deep space probe autonomous attitude maneuver control method - Google Patents

Abstract

A kind of deep space probe autonomous attitude maneuver control method disclosed by the invention, is related to autonomous attitude maneuver control method, belongs to technical field of spacecraft attitude control.The present invention is using ORRT algorithm as paths planning method, stochastical sampling is carried out to the Uniformly distributed node of configuration space, then carry out weighing preferentially extensions path, with greedy extended mode in safe space incremental expansion, detector attitude maneuver Dynamic Constraints model is set up respectively under detector body coordinate system, Practical Project restricted model and detector geometrical constraint model, it is met the path node of constraint and the control moment generating node, and then generate detector attitude maneuver path and required control moment, according to generate detector attitude maneuver path and required control moment realize detector motor-driven to targeted attitude.The present invention, under the conditions of meeting the various Complex Constraints that detector faces, shortens the path planning time, improves detector from the motor-driven efficiency to targeted attitude of reference attitude.

Description

A kind of deep space probe autonomous attitude maneuver control method

Technical field

The present invention relates to a kind of autonomous attitude maneuver control method, belong to technical field of spacecraft attitude control.

Background technology

Detector needs during in orbit to complete the switching between different attitudes sensings by substantial amounts of attitude maneuver Work；Simultaneously as the multiformity of detector task, the attitude maneuver process of some detectors has certain space and points to Constraint.Secondly, the control input of detector also suffers restraints.This constraint is mainly caused by two factors：One is carried out The moment amplitude that mechanism provides is limited；Two is after actuator occurs partial destruction.3rd, due to some angular velocity sensors Range limited it is desirable to the angular velocity of detector preferably must be held in the range of certain, which forms angular speed constraint.In the face of with Upper all multiple constraints, attitude control technology has to obtain being correspondingly improved the growth requirement that could meet space mission.

For this problem, Mengali G, Quarta A A is in " Spacecraft Control with Potential-energy function method is utilized to solve in a Constrained Fast Reorientation and Accurate Pointing " literary composition This problem, this method calculates simply, less to resource requirement on detector, but the method is difficult to process bounded control input Problem.

Cheng Xiaojun, Cui Hutao, Cui Pingyuan, Xu Rui is in " Large angular autonomous attitude maneuver of deep spacecraft using pseudospectral method” Solve this problem using pseudo- spectrometry in one literary composition, preferably consider overall performance, but because pseudo- spectrometry is by non-uniform section Point sliding-model control kinetics recursion, is difficult in view of the path constraint between node, is easily caused hop violation several What constrains.

Content of the invention

The technical problem to be solved in the present invention is that shortening is selected under the conditions of meeting the various Complex Constraints that detector faces The time in optimum programming path, improve detector from the motor-driven efficiency to targeted attitude of reference attitude.One kind disclosed by the invention Deep space probe autonomous attitude maneuver control method, under the conditions of meeting the various Complex Constraints that detector faces, can be quick Make detector from reference attitude motor-driven to targeted attitude.Described various Complex Constraints include Dynamic Constraints, Practical Project Constraint, geometrical constraint.

The present invention is achieved through the following technical solutions：

A kind of deep space probe autonomous attitude maneuver control method disclosed by the invention, with ORRT (Optimized Rapidly Exploring Random Tree) algorithm, as paths planning method, enters to the Uniformly distributed node of configuration space Row stochastical sampling, then carries out weighing preferentially extensions path, with greedy extended mode in safe space incremental expansion, detect Detector attitude maneuver Dynamic Constraints model, Practical Project restricted model and detector is set up respectively several under device body coordinate system What restricted model, is met the path node of constraint and the control moment generating node, and then generates detector attitude maneuver Path and required control moment, realize detector according to generation detector attitude maneuver path and required control moment Motor-driven to targeted attitude.The present invention not only allows for the physical constraint facing in engineering, and fully meets detector and face Dynamic Constraints and geometrical constraint, shorten the time in optimum programming path selected, improve detector from reference attitude motor-driven to The efficiency of targeted attitude.

A kind of deep space probe autonomous attitude maneuver control method disclosed by the invention, specific implementation step is：

Step one：According to the ephemeris moment in attitude maneuver moment at that time, determine related bright table under inertial system for the celestial body Show r_I, it is then determined that inertia is tied to the pose transformation matrix C under detector body coordinate system_BI, therefore can represent bright sky Position vector v under detector body system for the body_B；

According to detector itself mounting characteristics, determine position vector r under detector body system for the sensor_B.

Step 2：Set up detector attitude maneuver Dynamic Constraints model, set up the Practical Project constraint facing in engineering Model.Set up the geometrical constraint model that detector faces.Specifically point three steps：

The first step：Set up detector attitude maneuver Dynamic Constraints model.

Attitude kinematics and kinetics equation are expressed as follows：

J ω=T- ω × J ω (2)

Wherein, q=[q₀,q₁,q₂,q₃]^T, meet normalization constraint | | q | |₂=1, | | | |₂Represent 2- norm.ω= [ω₁,ω₂,ω₃]^TIt is the expression under body series for the angular velocity of spacecraft relative inertness system, and

J=diag (J₁,J₂,J₃) represent the inertial matrix that spacecraft opposing body is, u=[T₁,T₂,T₃]^TFor controling power Component under body series for the square.

Second step：Set up the Practical Project restricted model facing in engineering.Described Practical Project constraint includes controling power Square bounded and angular velocity bounded.

Because, in Practical Project, control moment bounded is expressed as：

|T_i|≤γ_Ti(4)

During attitude maneuver, because measuring cell has measurement range or the normal work for some instruments, Need by angular velocity amplitude limit within the specific limits, angular velocity bounded is expressed as：

|ω_i|≤γ_ωi(5)

3rd step：Set up geometrical constraint model.

Wherein, r_BRepresent direction vector under body series for the sensing element, v_BFor direction under body coordinate for the high light celestial body Vector in order to avoid spacecraft is in mobile process, high light celestial body light enter in the visual field of optical sensing element it is necessary to Ensure that the angle between the visual lines vector of such Sensitive Apparatuses and high light celestial body direction vector cannot be below threshold θ.

(6) formula is converted into quaternary number representation

v_B=C_BIr_I=r_I-2q ^T qr_I+2q q ^Tr_I+2q₀([r_I×]q) (7)

Wherein, r_IRepresent component to the direction vector of high light celestial body under inertial system for the detector, C_BIRepresent spacecraft Attitude cosine matrix.

Wherein,q=[q₁,q₂,q₃]^TFor quaternary number vector section.[r_I×] it is multiplication cross matrix, concrete form is

Following form is identical.(6) are expressed as overall compact form, obtain the quadratic constraints form in (9) formula.

q^TAq≤0 (9)

Wherein,

Step 3：The various Complex Constraints proposing in conjunction with above-mentioned steps two, draw autonomous attitude using ORRT planning algorithm Maneuver autopilot method.Described various Complex Constraints include Dynamic Constraints, Practical Project constraint, geometrical constraint.

ORRT is the greedy expansion process in consistent attitude sample space, including random targets node sample, neighbouring section Point calculates and new node extension.Initialized first, then generated planning space, have to before this choose effectively Metric function：

Whereinq _eThe arrow portion of deviation, ω between for two attitude quaternions_eFor the deviation between two angular velocity.

Then generate M random node in planning space, then screening is optimized according to evaluation function f (q, w), looks for Go out nearest node to be extended.

Wherein, a and b is weighting matrix.

It is extended after optimization nearest node, now it is also contemplated that kinetic part.

State equation (1) and (2) are carried out single order Euler linearisation,

Q (k+1)=q (k)+△ T (0.5Q (k) ω (k+1))

(13)

J ω (k+1)=J ω (k)+△ T (u (k+1)-ω (k) × J ω (k))

And then it is expressed as overall compact linear restriction expression formula

FX=E (14)

Wherein,

X=[u (k+1)^T,ω(k+1)^T,q(k+1)^T]^T(15)

Thus it is calculated new node after extension, then carry out judging whether to meet the constraint of step 2, if discontented Foot, re-starts search, if meet to judge whether to reach targeted attitude, if reaching targeted attitude, the return that stops search is whole again Individual result, if do not reach targeted attitude to proceed to search for.Search can be met path node and the life of constraint after terminating Become the control moment of node.Meet the constraint refers to meet the various complexity such as Dynamic Constraints, Practical Project constraint, geometrical constraint about Bundle.

Step 4：Using the attitude maneuver method designed, realize from reference attitude motor-driven to targeted attitude.Providing spy Under the conditions of surveying reference attitude and the targeted attitude of device, cook up the path node of meet the constraint by above-mentioned steps one, two, three Control moment with generating node, can generate detector attitude maneuver path and required control moment, visit according to generating Survey device attitude maneuver path and required control moment realize detector motor-driven to targeted attitude.

Beneficial effect：

1st, the present invention carries out stochastical sampling using ORRT algorithm to the Uniformly distributed node of configuration space, so that search is spread all over Whole configuration space, with greedy extended mode in safe space incremental expansion, improve global search speed, using evaluating letter Number balance preferentially extensions path, improves the searching efficiency of secure path node, shortens the path planning time.

2nd, the attitude maneuver path that the present invention cooks up not only allows for the physical constraint facing in engineering, and fully full Dynamic Constraints and geometrical constraint that foot detector faces, it is to avoid detector sensing element during attitude maneuver is strong The infringement of light celestial body, it is ensured that actuator executes moment without departing from the maximum that it is born, improves in detector attitude maneuver Stability.

Brief description

Geometrical constraint schematic diagram suffered by Fig. 1 detector attitude maneuver；

Fig. 2 is a kind of path planning process figure of present invention deep space probe autonomous attitude maneuver control method；

Detector attitude maneuver path examples figure under Fig. 3 celestial coordinate system；

The control moment instance graph of Fig. 4 plane-generating.

Specific embodiment

In order to better illustrate objects and advantages of the present invention, with example, content of the invention is done further below in conjunction with the accompanying drawings Explanation.

Embodiment 1：

Disclosed in this example, a kind of deep space probe autonomous attitude maneuver control method, implements step as follows:

Step one：According to the ephemeris moment in attitude maneuver moment at that time, determine that sunny vector under inertial system is r_I= [1 0 0]^T, it is then determined that the pose transformation matrix that inertia is tied under detector body coordinate system isThe position vector v under the sunny system in detector body therefore can be represented_B= C_BIr；

According to detector itself mounting characteristics, determine position vector under detector body system for the sensor.In order to test Card algorithm validity, if value has 8 sensors, their parameter such as following table：

Step 2：Quantitatively represent the problem of actuator boundedness.

Due in Practical Project, control moment bounded, there is constraint in its kinetics：

|T_i|≤1Nm

During attitude maneuver, because measuring cell has measurement range or the normal work for some instruments, Need by angular velocity amplitude limit within the specific limits,

|ω_i|≤0.05rad/s

By the quadratic constraints form in (9) formula：q^TAq≤0, can obtain A₁,A₂,A₃,A₄,A₅,A₆,A₇,A₈Eight geometry Constraint.

Step 3：The various Complex Constraints proposing in conjunction with above step two, draw autonomous attitude using ORRT planning algorithm Maneuver autopilot method.

Initialized first, then generated planning space, in planning space, then generated 10 random nodes, then Screening is optimized according to evaluation function f (q, w), finds out nearest node and be extended.

Wherein,

It is extended after optimization nearest node, now it is also contemplated that kinetic part.

State equation (1) and (2) are carried out single order Euler linearisation,

Q (k+1)=q (k)+△ T (0.5Q (k) ω (k+1))

J ω (k+1)=J ω (k)+△ T (u (k+1)-ω (k) × J ω (k))

And then it is expressed as overall compact linear restriction expression formula

FX=E

Wherein,

X=[u (k+1)^T,ω(k+1)^T,q(k+1)^T]^T

Thus it is calculated new node after extension, then carry out judging whether to meet the constraint of step 2, if discontented Foot, re-starts search, if meet to judge whether to reach targeted attitude, if reaching targeted attitude, the return that stops search is whole again Individual result, if do not reach targeted attitude to proceed to search for.Search can be met the path node of constraint after terminatingqAnd life Become the control moment u of node.Meet the constraint refers to meet the various complexity such as Dynamic Constraints, Practical Project constraint, geometrical constraint about Bundle.Detail flowchart is as shown in Figure 2.

Step 4：Using the attitude maneuver method designed, realize from reference attitude motor-driven to targeted attitude.Provide detection The reference attitude of deviceq(0)=[- 0.4746-0.4746 0.4746 0.5695]^TAnd targeted attitudeq(t)=[1 00 0]^T, Cook up the path node of meet the constraint by above-mentioned steps one, two, threeqWith generate node control moment u, path node Represent under celestial coordinate system and obtain detector attitude maneuver path as shown in figure 3, required control moment is as shown in Figure 4.

The scope of the present invention is not only limited to embodiment, and embodiment is used for explaining the present invention, all with the present invention identical Change under the conditions of principle and design or modification are all within protection domain disclosed by the invention.

Claims (1)

1. a kind of deep space probe autonomous attitude maneuver control method it is characterised in that：With ORRT (Optimized Rapidly Exploring Random Tree) algorithm, as paths planning method, adopted at random to the Uniformly distributed node of configuration space Sample, then carries out weighing preferentially extensions path, with greedy extended mode in safe space incremental expansion, detector body sit Detector attitude maneuver Dynamic Constraints model, Practical Project restricted model and detector geometrical constraint mould is set up respectively under mark system Type, is met the path node of constraint and the control moment generating node, and then generates detector attitude maneuver path and institute The control moment needing, according to generate detector attitude maneuver path and required control moment realize detector motor-driven to mesh Mark attitude；

Implement step as follows,

Step one：According to the ephemeris moment in attitude maneuver moment at that time, determine expression r under inertial system for the related high light celestial body_I, It is then determined that inertia is tied to the pose transformation matrix C under detector body coordinate system_BI, therefore can represent high light celestial body at this Direction vector v under body coordinate_B；

According to detector itself mounting characteristics, determine direction vector r under body coordinate system for the sensing element_B；

Step 2：Set up detector attitude maneuver Dynamic Constraints model, set up the Practical Project restricted model facing in engineering； Set up the geometrical constraint model that detector faces；Specifically point three steps：

The first step：Set up detector attitude maneuver Dynamic Constraints model；

Attitude kinematics and kinetics equation are expressed as follows：

$\stackrel{\·}{q}=\frac{1}{2}Q\mathrm{\ω}=\frac{1}{2}\mathrm{\Ω}\mathrm{\ω}---\left(1\right)$

J ω=T- ω × J ω (2) Wherein, q=[q₀,q₁,q₂,q₃]^T, meet normalization constraint | | q | |₂=1, | | | |₂Represent 2- norm；ω=[ω₁, ω₂,ω₃]^TIt is the expression under body series for the angular velocity of spacecraft relative inertness system, and

$Q=\left[\begin{array}{ccc}-q_1& -q_2& -q_3\\ q_0& -q_3& q_2\\ q_3& q_0& -q_1\\ -q_2& q_1& q_0\end{array}\right],\mathrm{\Ω}=\left[\begin{array}{cccc}0& -{\mathrm{\ω}}_1& -{\mathrm{\ω}}_2& -{\mathrm{\ω}}_3\\ {\mathrm{\ω}}_1& 0& {\mathrm{\ω}}_3& -{\mathrm{\ω}}_2\\ {\mathrm{\ω}}_2& -{\mathrm{\ω}}_3& 0& {\mathrm{\ω}}_1\\ {\mathrm{\ω}}_3& {\mathrm{\ω}}_2& -{\mathrm{\ω}}_1& 0\end{array}\right]---\left(3\right)$

J=diag (J₁,J₂,J₃) represent the inertial matrix that spacecraft opposing body is, u=[T₁,T₂,T₃]^TFor control moment at this Component under system；

Second step：Set up the Practical Project restricted model facing in engineering；Described Practical Project constraint includes control moment to be had Bound constrained and angular velocity bounded；

Because, in Practical Project, control moment bounded is expressed as：

|T_i|≤γ_Ti(4)

During attitude maneuver, because measuring cell has measurement range or the normal work for some instruments, need By angular velocity amplitude limit within the specific limits, angular velocity bounded is expressed as：

|ω_i|≤γ_ωi(5)

3rd step：Set up geometrical constraint model；

$r_B^T{v}_B\≤cos\mathrm{\θ}---\left(6\right)$

Wherein, r_BRepresent direction vector under body series for the sensing element, v_BFor direction arrow under body coordinate for the high light celestial body Amount；In order to avoid spacecraft is in mobile process, high light celestial body light enters in the visual field of optical sensing element it is necessary to protect The angle demonstrate,proved between the visual lines vector of such Sensitive Apparatuses and high light celestial body direction vector cannot be below threshold θ；

(6) formula is converted into quaternary number representation

v_B=C_BIr_I=r_I-2q ^T qr_I+2qq ^Tr_I+2q₀([r_I×]q) (7)

Wherein, r_IRepresent component to the direction vector of high light celestial body under inertial system for the detector, C_BIRepresent the attitude of spacecraft Transition matrix；

Wherein,q=[q₁,q₂,q₃]^TFor quaternary number vector section；[r_I×] it is multiplication cross matrix, concrete form is

$\[r_I\×\]=\left[\begin{array}{ccc}0& -r_{I3}& r_{I2}\\ r_{I3}& 0& -r_{I1}\\ -r_{I2}& r_{I1}& 0\end{array}\right]---\left(8\right)$

Following form is identical；(6) are expressed as overall compact form, obtain the quadratic constraints form in (9) formula；

q^TAq≤0 (9)

Wherein,

$A=\left[\begin{array}{cc}{r}_B^T{r}_I-cos\mathrm{\θ}& -r_B^T\[r_I\×\]\\ -r_B^T\[r_I\×\]& 2r_I{r}_B^T-(r_B^T{r}_I+cos\mathrm{\θ})I_3\end{array}\right]---\left(10\right)$

Step 3：The various Complex Constraints proposing in conjunction with above-mentioned steps two, draw autonomous attitude maneuver using ORRT planning algorithm Control method；

ORRT is the greedy expansion process in consistent attitude sample space, including random targets node sample, adjacent node meter Calculate and new node extension；Initialized first, then generated planning space, have to before this choose effective tolerance Function：

$\mathrm{\ρ}={\underset{\‾}{q}}_e^T{\underset{\‾}{q}}_e+{\mathrm{\ω}}_e^T{\mathrm{\ω}}_e---\left(11\right)$

Whereinq _eThe arrow portion of deviation, ω between for two attitude quaternions_eFor the deviation between two angular velocity；

Then generate M random node in planning space, then screening is optimized according to evaluation function f (q, w), finds out Near node is extended；

$f(q,w)={\underset{\‾}{q}}_e^{T}a{\underset{\‾}{q}}_e+{\mathrm{\ω}}_e^T{\mathrm{b\ω}}_e---\left(12\right)$

Wherein, a and b is weighting matrix；

It is extended after optimization nearest node, now it is also contemplated that kinetic part；

State equation (1) and (2) are carried out single order Euler linearisation,

$\begin{array}{c}q(k+1)+q\left(k\right)+\mathrm{\Δ}T\left(0.5Q\right(k\left)\mathrm{\ω}\right(k+1\left)\right)\\ J\mathrm{\ω}(k+1)=J\mathrm{\ω}\left(k\right)+\mathrm{\Δ}T\left(u\right(k+1)-\mathrm{\ω}(k)\×J\mathrm{\ω}(k\left)\right)\end{array}---\left(13\right)$

And then it is expressed as overall compact linear restriction expression formula

FX=E (14)

Wherein,

X=[u (k+1)^T,ω(k+1)^T,q(k+1)^T]^T(15)

$F=\left[\begin{array}{ccc}-{\mathrm{\ΔTI}}_{3\×3}& J& 0_{3\×4}\\ 0_{4\×3}& -0.5\mathrm{\Δ}TQ\left(k\right)& I_{4\×4}\end{array}\right]---\left(16\right)$

$E=\left[\begin{array}{c}J\mathrm{\ω}\left(k\right)-\mathrm{\Δ}T\[\mathrm{\ω}\left(k\right)\×\]J\mathrm{\ω}\left(k\right)\\ q\left(k\right)\end{array}\right]---\left(17\right)$

$Q\left(k\right)=\left[\begin{array}{ccc}-q_1\left(k\right)& -q_2\left(k\right)& -q_3\left(k\right)\\ q_0\left(k\right)& -q_3\left(k\right)& q_2\left(k\right)\\ q_3\left(k\right)& q_0\left(k\right)& -q_1\left(k\right)\\ -q_2\left(k\right)& q_1\left(k\right)& q_0\left(k\right)\end{array}\right]---\left(18\right)$

Thus it is calculated new node after extension, then carry out judging whether to meet the constraint of step 2, if being unsatisfactory for, weight Newly scan for, if meet to judge whether to reach targeted attitude, if reaching targeted attitude, the return that stops search is whole to tie again Really, proceed to search for if not reaching targeted attitude；Search can be met the path node of constraint and generate section after terminating The control moment of point；Meet the constraint refers to meet the various Complex Constraints such as Dynamic Constraints, Practical Project constraint, geometrical constraint；

Step 4：Using the attitude maneuver method designed, realize from reference attitude motor-driven to targeted attitude；Providing detector Reference attitude and targeted attitude under the conditions of, cook up path node and the generation of meet the constraint by above-mentioned steps one, two, three The control moment of node, can generate detector attitude maneuver path and required control moment, according to generation detector appearance The motor-driven path of state and required control moment realize detector motor-driven to targeted attitude.