A space non-cooperative target safe obstacle avoidance rendezvous control method
By constructing a variety of potential functions and sliding mode controllers, the safety and control efficiency problems of the existing space non-cooperative target rendezvous control method are solved, the safe obstacle avoidance rendezvous of spacecraft is achieved, and the control accuracy and safety performance are improved.
Patent Information
- Application Number
- CN202310346310.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-04-03
- Publication Date
- 2025-10-10
- Estimated Expiration
- 2043-04-03
AI Technical Summary
Existing space non-cooperative target rendezvous control methods have poor safety and control efficiency when facing obstacles, and it is difficult to simultaneously ensure transient and steady-state performance. In addition, existing methods are difficult to reflect the dynamic information of the controlled system.
The target gravitational potential function, elliptical vine leaf surface safe rendezvous corridor potential function, obstacle repulsion potential function and speed safety corridor potential function are constructed, and the obstacle avoidance rendezvous control is designed in combination with the preset performance sliding mode surface. Obstacle avoidance and safe rendezvous with non-cooperative targets are achieved through artificial potential field and sliding mode controller.
The spacecraft speed is constrained by the speed safety corridor potential function to avoid collision and improve safety performance. The sliding mode controller is used to achieve precise obstacle avoidance and rendezvous, improving control accuracy and safety.
Smart Images
Figure CN116443275B_ABST
Abstract
Description
Technical Field
[0001] The embodiments of the present disclosure relate to the field of control technology, and in particular to a method for controlling safe obstacle avoidance and rendezvous of a non-cooperative space target. Background Art
[0002] Rendezvous and docking technology for non-cooperative space targets, which establishes a rigid connection between a spacecraft and a non-cooperative target in orbit, is a prerequisite and key to achieving space missions such as in-orbit maintenance and space debris removal. With the continuous development of the space industry and the increasing frequency of human space activities, the number of space targets is also increasing, which has, to a certain extent, led to a deterioration in the space environment. Some existing trajectory planning and control methods ignore the impact of obstacles in the rendezvous path, such as solar sails, in-orbit satellites, and spacecraft disintegration debris. If the service spacecraft collides with these obstacles, it may directly shorten the service life or even damage some components.
[0003] For non-cooperative target obstacle avoidance and rendezvous tasks, common sliding mode control methods, model predictive control methods, artificial potential field control methods, and optimization-based methods can achieve obstacle avoidance and safe rendezvous, but have the following defects: Most of the existing control methods are oriented towards either the transient or steady-state performance (overshoot, steady-state error, etc.) of the controlled system, and cannot guarantee both simultaneously; although the methods based on artificial potential functions have the characteristics of high efficiency and simple calculation, it is difficult to get rid of the limitations of their essentially kinematic scope and cannot reflect the dynamic information of the controlled system; the control accuracy of the optimization-based methods is relatively high, but due to the current satellite payload limitations, it is difficult to provide sufficient computing resources for the optimization process.
[0004] It can be seen that there is an urgent need for a space non-cooperative target safe obstacle avoidance rendezvous control method that can simplify the control process and improve rendezvous safety. Summary of the Invention
[0005] In view of this, an embodiment of the present disclosure provides a space non-cooperative target safe obstacle avoidance rendezvous control method, which at least partially solves the problems of poor safety and control efficiency in the prior art.
[0006] The present disclosure provides a method for controlling safe obstacle avoidance rendezvous of a non-cooperative space target, including:
[0007] Step 1: construct the dynamic model of the space non-cooperative target and the service spacecraft according to the motion parameters of the space non-cooperative target and the service spacecraft;
[0008] Step 2: construct an artificial potential field based on the target potential function, obstacle potential function, intersection potential function, and speed safety corridor potential function;
[0009] Step 3: Based on the dynamic models corresponding to the space non-cooperative target and the service spacecraft, as well as the constructed artificial potential field function and performance function, a preset performance sliding surface is designed to realize obstacle avoidance rendezvous control.
[0010] According to a specific implementation of the embodiment of the present disclosure, the expression of the dynamic model is:
[0011]
[0012] in,
[0013]
[0014] r = [x, y, z] T is the relative position vector, r c , r t are the relative position vectors of the service spacecraft and the non-cooperative target relative to the Earth's mass center, r c , r t are the corresponding scalars, u represents the control acceleration applied to the service spacecraft, μ=3.9860×10 14 m 3 ·s -2 represents the Earth's gravitational constant, are the true anomaly, instantaneous angular velocity and instantaneous angular acceleration of the non-cooperative target respectively, e represents the orbit eccentricity of the non-cooperative target, d is the additional interference, and ||d||≤D is satisfied, where D is a positive constant.
[0015] According to a specific implementation of an embodiment of the present disclosure, the artificial potential field function includes a target gravitational potential function, an elliptical vine and blade surface safe intersection corridor potential function, an obstacle repulsive potential function, and a speed safety corridor potential function.
[0016] According to a specific implementation of the embodiment of the present disclosure, step 2 specifically includes:
[0017] Step 2.1, construct the expression of the target gravitational potential function as
[0018]
[0019] Where Δx p =[e x , e y , e z ] T , Δx v =[e vx , e vy , e vz ] T Represent the position error vector and velocity error vector respectively, P p , Pv is a positive definite matrix representing the target gravitational gain;
[0020] Step 2.2, select the elliptical vine leaf surface as the intersection safety corridor, characterize it with Gaussian function, and introduce a quadratic term containing the position error vector, and the expression of the potential function of the elliptical vine leaf surface safety corridor is obtained as follows:
[0021]
[0022] Among them, P s is a positive definite matrix, ψ s represents the rendezvous safety corridor function;
[0023] Step 2.3, define the repulsive potential function of a single obstacle and extend it to the case of multiple obstacles, and obtain the expression of the obstacle repulsive potential function as follows:
[0024]
[0025] Among them, P o is a positive definite matrix, n represents the number of obstacles, ψ ro represents the repulsive potential function of a single obstacle;
[0026] Step 2.4, construct the potential function of the speed safety corridor as follows:
[0027]
[0028] Among them, λ 1v ,λ 2v >0, P v is a positive definite matrix, v=[v x , v y , v z ] T , k is a constant scaling factor.
[0029] According to a specific implementation of the embodiment of the present disclosure, step 3 specifically includes:
[0030] Step 3.1, obtain the feedback control quantity according to the artificial potential field function;
[0031] In step 3.2, the performance function is introduced, and the system error term is constrained by combining the preset performance method. The sliding surface is constructed based on the artificial potential field and the constrained error term, and the sliding mode controller is designed.
[0032] According to a specific implementation of the embodiment of the present disclosure, the expression of the sliding mode controller is:
[0033]
[0034] Among them, H and R are functions involved in the error conversion process, e v Represents the relative velocity error, ε1 and ε2 are both positive definite matrices, s represents the constructed sliding surface, Function representation: ε is a constant, represents the total potential field function.
[0035] The space non-cooperative target safe obstacle avoidance rendezvous control scheme in the disclosed embodiment includes: step 1, constructing a dynamic model of the space non-cooperative target and the service spacecraft based on the motion parameters of the space non-cooperative target and the service spacecraft; step 2, constructing an artificial potential field based on the target potential function, obstacle potential function, rendezvous and speed safety corridor potential function; step 3, designing a preset performance sliding surface to realize obstacle avoidance rendezvous control based on the dynamic model corresponding to the space non-cooperative target and the service spacecraft, as well as the constructed artificial potential field function and performance function.
[0036] The beneficial effects of the embodiments of the present disclosure are as follows: through the scheme of the present disclosure, the proposed speed safety corridor potential function can constrain the global speed of the service spacecraft, thereby avoiding loss of control and collision due to excessive speed, and further improving safety performance; combined with the preset performance method, the system error term is performance constrained, and the sliding mode controller constructed on this basis can achieve obstacle avoidance and safe rendezvous with non-cooperative targets. BRIEF DESCRIPTION OF THE DRAWINGS
[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.
[0038] Figure 1 A flowchart of a space non-cooperative target safe obstacle avoidance rendezvous control method provided by an embodiment of the present disclosure;
[0039] Figure 2 A schematic diagram of a 2D elliptical vine leaf surface provided in an embodiment of the present disclosure;
[0040] Figure 3 A schematic diagram of a 3D elliptical vine leaf surface provided in an embodiment of the present disclosure;
[0041] Figure 4 Schematic diagram of obstacle avoidance and intersection trajectories under the control of three methods provided in the embodiments of the present disclosure;
[0042] Figure 5 A schematic diagram of the distances between the three trajectories and the first obstacle provided in an embodiment of the present disclosure;
[0043] Figure 6 A schematic diagram of the distances between the three trajectories and the second obstacle provided in an embodiment of the present disclosure;
[0044] Figure 7 Schematic diagram of relative position error changes under the control of three methods provided in the embodiments of the present disclosure;
[0045] Figure 8 A schematic diagram of relative speed error convergence under performance constraints provided by an embodiment of the present disclosure;
[0046] Figure 9 Schematic diagram of the acceleration control changes of the three methods provided in the embodiments of the present disclosure;
[0047] Figure 10 Schematic diagram of the convergence of the designed sliding surface provided in an embodiment of the present disclosure. DETAILED DESCRIPTION
[0048] The embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.
[0049] The following describes the embodiments of the present disclosure through specific examples, and those skilled in the art can easily understand other advantages and effects of the present disclosure from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all of the embodiments. The present disclosure can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present disclosure. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present disclosure.
[0050] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on this disclosure, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects described herein can be used to implement an apparatus and / or practice a method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this apparatus and / or practice this method.
[0051] It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present disclosure. The illustrations only show components related to the present disclosure and are not drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component can be changed at will, and the component layout type may also be more complicated.
[0052] Additionally, in the following description, specific details are provided to provide a thorough understanding of the examples. However, one skilled in the art will appreciate that the aspects described can be practiced without these specific details.
[0053] An embodiment of the present disclosure provides a space non-cooperative target safe obstacle avoidance rendezvous control method, which can be applied to the aircraft trajectory control process in aerospace scenarios.
[0054] See also Figure 1 , is a flow chart of a space non-cooperative target safe obstacle avoidance rendezvous control method provided by an embodiment of the present disclosure. Figure 1 As shown, the method mainly includes the following steps:
[0055] Step 1: construct the dynamic model of the space non-cooperative target and the service spacecraft according to the motion parameters of the space non-cooperative target and the service spacecraft;
[0056] Furthermore, the expression of the kinetic model is
[0057]
[0058] in,
[0059]
[0060] r = [x, y, z] T is the relative position vector, r c , r t are the relative position vectors of the service spacecraft and the non-cooperative target relative to the Earth's mass center, r c , r t are the corresponding scalars, u represents the control acceleration applied to the service spacecraft, μ=3.9860×10 14 m3·s -2 represents the Earth's gravitational constant, are the true anomaly, instantaneous angular velocity and instantaneous angular acceleration of the non-cooperative target respectively, e represents the orbit eccentricity of the non-cooperative target, d is the additional interference, and ||d||≤D is satisfied, where D is a positive constant.
[0061] In specific implementation, in the process of relative dynamics modeling for non-cooperative target rendezvous, the dynamics model for space non-cooperative targets and service spacecraft of the present invention is:
[0062]
[0063] in,
[0064]
[0065]
[0066] r = [x, y, z] T is the relative position vector, r c , r t are the relative position vectors of the service spacecraft and the non-cooperative target relative to the Earth's mass center, r c , r t are the corresponding scalars, u represents the control acceleration applied to the service spacecraft, μ=3.9860×10 14 m 3 ·s -2 represents the Earth's gravitational constant, are the true anomaly, instantaneous angular velocity and instantaneous angular acceleration of the non-cooperative target respectively, e represents the orbit eccentricity of the non-cooperative target, d is the additional interference, satisfying ||d||≤D, where D is a positive constant.
[0067] Assuming that the orbit of the non-cooperative target is a circular orbit or a near-circular orbit, then e=0, and substituting it into
[0068]
[0069] Furthermore, there
[0070]
[0071] Step 2: construct an artificial potential field based on the target potential function, obstacle potential function, intersection potential function, and speed safety corridor potential function;
[0072] Furthermore, the artificial potential field function includes a target gravitational potential function, an elliptical vine and leaf surface safe intersection corridor potential function, an obstacle repulsive potential function, and a speed safety corridor potential function.
[0073] Furthermore, the step 2 specifically includes:
[0074] Step 2.1, construct the expression of the target gravitational potential function as
[0075]
[0076] Where Δx p =[ex , e y , e z ] T , Δx v =[e vx , e vy , e vz ] T Represent the position error vector and velocity error vector respectively, P p , P v is a positive definite matrix representing the target gravitational gain;
[0077] Step 2.2, select the elliptical vine leaf surface as the intersection safety corridor, characterize it with Gaussian function, and introduce a quadratic term containing the position error vector, and the expression of the potential function of the elliptical vine leaf surface safety corridor is obtained as follows:
[0078]
[0079] Among them, P s is a positive definite matrix, ψ s represents the rendezvous safety corridor function;
[0080] Step 2.3, define the repulsive potential function of a single obstacle and extend it to the case of multiple obstacles, and obtain the expression of the obstacle repulsive potential function as follows:
[0081]
[0082] Among them, P o is a positive definite matrix, m represents the number of obstacles, ψ ro represents the repulsive potential function of a single obstacle;
[0083] Step 2.4, construct the potential function of the speed safety corridor as follows:
[0084]
[0085] Among them, λ 1v ,λ 2v >0, P v is a positive definite matrix, v=[v x , v y , v z ] T , k is a constant scaling factor.
[0086] In specific implementation, the artificial potential field in the present invention is mainly composed of four parts, namely the target attraction potential function, the elliptical vine leaf surface safe intersection corridor potential function, the obstacle repulsion potential function, and the speed safety corridor potential function. The following will introduce each part:
[0087] Target gravitational potential function
[0088]
[0089] Where Δx p =[e x , e y , e z ] T , Δx v =[e vx , e vy , e vz ] T Represent the position error vector and velocity error vector respectively, P p , P v is a positive definite matrix representing the target gravitational gain.
[0090] Potential function of the safety corridor on the leaf surface of an elliptical vine
[0091] The elliptical vine leaf surface is selected as the intersection safety corridor. Its 2D and 3D comparison with the traditional conical safety corridor is shown as follows: Figure 2 and Figure 3 As shown. The function expression of the elliptical vine leaf surface is:
[0092]
[0093] Among them, γ and a represent the safety angle and safety distance respectively.
[0094] The rendezvous safety corridor represented by Gaussian function is defined as:
[0095]
[0096] Among them, λ 1s ,λ 2s >0.
[0097] In order to ensure that the repulsive force of the rendezvous safety corridor is strictly zero when the relative position error vector converges to the expected value, a quadratic term containing the position error vector is introduced:
[0098]
[0099] Among them, P s is a positive definite matrix.
[0100] Obstacle repulsion potential function
[0101] The repulsive potential function of a single obstacle is defined as:
[0102]
[0103] Among them, λ 1o ,λ 2oApproximately represents the length and width of the Gaussian potential function, r op , r oi Represent the relative position vectors of the non-cooperative target and the obstacle, and the coordinate vector of the obstacle mass center, and r op =r t -r oi .
[0104] Extension to multiple obstacles:
[0105]
[0106] Among them, P o is a positive definite matrix, and n represents the number of obstacles.
[0107] Speed safety corridor potential function
[0108] The speed safety corridor is represented by a function:
[0109]
[0110] Where v = [v x , v y , v z ] T , k is a constant scaling factor.
[0111] The potential function form is expressed as:
[0112]
[0113] Among them, λ 1v ,λ 2v >0, P v is a positive definite matrix.
[0114] In summary, the system potential function is defined as:
[0115]
[0116] Step 3: Based on the dynamic models corresponding to the space non-cooperative target and the service spacecraft, as well as the constructed artificial potential field function and performance function, a preset performance sliding surface is designed to realize obstacle avoidance rendezvous control.
[0117] Based on the above embodiment, step 3 specifically includes:
[0118] Step 3.1, obtain the feedback control quantity according to the artificial potential field function;
[0119] In step 3.2, the performance function is introduced, and the system error term is constrained by combining the preset performance method. The sliding surface is constructed based on the artificial potential field and the constrained error term, and the sliding mode controller is designed.
[0120] Furthermore, the expression of the sliding mode controller is
[0121]
[0122] Among them, H and R are functions involved in the error conversion process, e v Represents the relative velocity error, ε1 and ε2 are both positive definite matrices, s represents the constructed sliding surface, Function representation: ε is a constant, represents the total potential field function.
[0123] In specific implementation, the design process of the sliding mode controller can be as follows:
[0124] 1) Artificial potential function control combined with speed safety corridor
[0125] Based on the artificial potential field function in step 2, a feedback control quantity can be obtained:
[0126]
[0127] Where P is a positive definite matrix, r f represents the desired position vector.
[0128] 2) Preset performance sliding mode controller
[0129] Introducing performance functions:
[0130]
[0131] Where v = [v1, v2, v3] T , The initial value is v0, the convergence time and the final value are
[0132] Take e v =Δx v =[e v1 , e v2 , e v3 ] T , impose the constraint:
[0133] -Lv i (t)<e vi <v i (t), i=1, 2, 3. (17)
[0134] Among them, L>0.
[0135] For deformation:
[0136]
[0137] make Take the unconstrained transfer function:
[0138]
[0139] in,
[0140]
[0141] Define state variable q = [q1, q2, q3] T , and there are
[0142]
[0143] Furthermore, there
[0144]
[0145] in,
[0146]
[0147] Combined with the potential function, the sliding surface is designed for the state variable q
[0148]
[0149] Where ε is a constant,
[0150]
[0151] Select the sliding mode reaching law as:
[0152]
[0153] Among them, ε1 and ε2 are both positive definite matrices,
[0154] To sum up, build the controller:
[0155]
[0156] After the sliding mode controller is obtained, the sliding mode controller can be used to control the spacecraft.
[0157] The space non-cooperative target safe obstacle avoidance and rendezvous control method provided in this embodiment can constrain the global speed of the service spacecraft through the speed safety corridor potential function, thereby avoiding loss of control and collision due to excessive speed, and further improving safety performance; combined with the preset performance method, the system error term is subjected to performance constraints, and the sliding mode controller constructed on this basis can achieve obstacle avoidance and safe rendezvous with non-cooperative targets.
[0158] The following is a specific example to further illustrate this solution. For safe obstacle avoidance rendezvous with a non-cooperative target, the specific simulation parameters are as follows:
[0159] The initial position of the service spacecraft is r0 = [100, 500, -100] T / m, the initial speed is The expected relative position and relative velocity are r f =[0, 5, 0] T / m, The simulation time is 4000s.
[0160] Obstacle parameter settings are shown in Table 1:
[0161]
[0162] Table 1
[0163] External interference is defined as:
[0164]
[0165] The control parameters are shown in Table 2:
[0166]
[0167]
[0168] Table 2
[0169] like Figure 4 As shown, Figure 4 The simulation trajectories of three methods (artificial potential function method APF without Velocity Safety Corridor, improved artificial potential function method APF and preset performance sliding mode control method PPC-SMCAPF of the present invention) are demonstrated. Compared with the first two methods, the trajectory of the proposed method is smoother. Figure 5 and Figure 6 It reflects the distance between the trajectory and the two obstacles under the three methods. Figure 7 and Figure 8 The relative distance error convergence and relative speed error convergence under the three control methods are demonstrated respectively. From the performance envelope and convergence status of the third method, it can be seen that its error convergence accuracy is significantly higher than that of the other two methods. Figure 9 It reflects the acceleration changes under the control of three methods. Figure 10 The convergence of the sliding surface in the preset performance sliding mode control method is demonstrated.
[0170] The units involved in the embodiments described in this disclosure may be implemented by software or hardware.
[0171] It should be understood that various parts of the present disclosure can be implemented in hardware, software, firmware, or a combination thereof.
[0172] The above description is merely a specific embodiment of the present disclosure, but the scope of protection of the present disclosure is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this disclosure should be included in the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure should be based on the scope of protection of the claims.
Claims
1. A space non-cooperative target safe obstacle avoidance rendezvous control method, characterized in that: include: Step 1: construct the dynamic model of the space non-cooperative target and the service spacecraft according to the motion parameters of the space non-cooperative target and the service spacecraft; Step 2: construct an artificial potential field based on the target potential function, obstacle potential function, intersection potential function, and speed safety corridor potential function; The step 2 specifically includes: Step 2.1, construct the expression of the target gravitational potential function as Where Δx p =[e x , e y , e z ] T , Δx v =[e vx , e vy , e vz ] T Represent the position error vector and velocity error vector respectively, P p ,P v is a positive definite matrix representing the target gravitational gain; Step 2.2, select the elliptical vine leaf surface as the intersection safety corridor, characterize it with Gaussian function, and introduce a quadratic term containing the position error vector, and the expression of the potential function of the elliptical vine leaf surface safety corridor is obtained as follows: Among them, P s is a positive definite matrix, ψ s represents the rendezvous safety corridor function; Step 2.3, define the repulsive potential function of a single obstacle and extend it to the case of multiple obstacles, and obtain the expression of the obstacle repulsive potential function as follows: Among them, P o is a positive definite matrix, n represents the number of obstacles, ψ ro represents the repulsive potential function of a single obstacle; Step 2.4, construct the potential function of the speed safety corridor as follows: Among them, λ 1v ,λ 2v >0, P v is a positive definite matrix, v=[v x , v y , v z ] T , k is a constant proportional factor; Step 3: Based on the dynamic models corresponding to the space non-cooperative target and the service spacecraft, as well as the constructed artificial potential field function and performance function, a preset performance sliding surface is designed to realize obstacle avoidance rendezvous control.
2. The method according to claim 1, characterized in that , the expression of the kinetic model is in, r = [x, y, z] T is the relative position vector, r c , r t are the relative position vectors of the service spacecraft and the non-cooperative target relative to the Earth's mass center, r c , r t are the corresponding scalars, u represents the control acceleration applied to the service spacecraft, μ=3.9860×10 14 m 3 ·s -2 represents the Earth's gravitational constant, θ, are the true anomaly, instantaneous angular velocity and instantaneous angular acceleration of the non-cooperative target respectively, e represents the orbit eccentricity of the non-cooperative target, d is the additional interference, and ||d||≤D is satisfied, where D is a positive constant.
3. The method according to claim 2, characterized in that ,The artificial potential field function includes the target gravitational potential function, the elliptical vine and leaf surface safe intersection corridor potential function, the obstacle repulsive potential function and the speed safety corridor potential function.
4. The method according to claim 3, characterized in that , the step 3 specifically includes: Step 3.1, obtain the feedback control quantity according to the artificial potential field function; In step 3.2, the performance function is introduced, and the system error term is constrained by combining the preset performance method. The sliding surface is constructed based on the artificial potential field and the constrained error term, and the sliding mode controller is designed.
5. The method according to claim 4, characterized in that , the expression of the sliding mode controller is Among them, H and R are functions involved in the error conversion process, e v Represents the relative velocity error, ε1 and ε2 are both positive definite matrices, s represents the constructed sliding surface, Function representation: ε is a constant, represents the total potential field function.