Extraterrestrial celestial body sampling process simulation method based on satellite soil surface mechanical equivalent characteristics

Abstract

The invention discloses an extraterrestrial celestial body sampling process simulation method based on satellite soil surface mechanical equivalent characteristics. The method comprises the following steps: constructing a detector body rigid-flexible coupling dynamic model under any configuration of a solar wing; a sampling mechanical arm multi-body dynamic model is established, and a system dynamic model of the detector is formed; establishing a tail end pressure equivalent analytic function model of the sampler in contact with the star soil; and performing dynamics and control joint simulation in the small celestial body sampling process based on the tail end pressure equivalent analytic function model of the sampler in contact with the star soil. The invention discloses an extraterrestrial celestial body sampling process modeling simulation method based on star soil surface mechanical equivalent characteristics, and establishes a celestial body sampling process dynamics and control joint simulation model based on the star soil surface mechanical equivalent characteristics. Joint simulation analysis of detector dynamic motion, solar wing vibration, detector control and sampling mechanical arm driving is achieved, the method can be used for detector sampling process dynamic behavior prediction under different star soil characteristics, and the method has engineering practical value.

Description

Technical Field

[0001] This invention relates to a simulation method for sampling processes of extraterrestrial objects based on the equivalent mechanical properties of stellar soil surfaces, belonging to the field of spacecraft dynamics and control. Background Technology

[0002] Small bodies are relatively small celestial bodies that orbit the Sun. They may retain information about the original solar system. Conducting sampling and exploration of small bodies is of great significance for exploring scientific questions such as the origin of the solar system, planetary evolution, and the origin of life, and is currently a cutting-edge hot topic in space missions. For example... Figure 1 As shown, the sample return probe method is more challenging because the probe needs to complete complex steps such as contacting the surface of the small celestial body, obtaining samples, and sending them back to Earth.

[0003] Faced with the complex and unknown surface characteristics of small celestial bodies, the sampling of the probe is extremely difficult, involving multiple aspects such as the attitude and orbit control of the entire probe, the driving of the sampling mechanism, and the contact and collision between the sampler and the celestial body. In order to ensure the safety and reliability of the mission, it is necessary to carry out joint simulation analysis of the dynamics and control of the entire sampling process, predict the dynamic behavior of the probe during the sampling process, and provide support for the design and verification of the sampling mission scheme.

[0004] Researchers proposed a co-simulation framework based on a high-precision dynamic model, optimizing the detector sampling strategy through a combination of numerical simulation and experimental verification. Addressing the discontinuous medium characteristics of particles on the surface of small celestial bodies, they developed a simulation model coupling the discrete element method (DEM) with multibody dynamics to simulate the interaction between the sampler and loose particles. Furthermore, co-simulation of dynamics and control was also used to optimize the contact force control algorithm. However, the irregular shapes and multi-scale particle distributions of small celestial bodies place higher demands on the accuracy and computational efficiency of the simulation models. In recent years, the research focus of co-simulation of dynamics and control has gradually shifted to multiphysics coupling modeling and real-time optimization. For the microgravity behavior of particles on the surface of small celestial bodies, researchers combined the DEM with fluid dynamics to establish a multi-scale simulation model of particles, airflow, and sampler to analyze the motion patterns of particles under low gravity conditions. To improve simulation efficiency and ensure accuracy under limited computing resources, machine learning-based surrogate models have been introduced into dynamic simulations to accelerate the computation process in complex scenarios through data-driven methods. Furthermore, the "dynamic response modeling" method optimizes sampling strategies by simulating the motion of particles on the surface of small celestial bodies. A simulation framework incorporating data assimilation techniques has been proposed to correct dynamic model parameters in real time, addressing the uncertainties of unknown surface properties of small celestial bodies. However, these techniques remain primarily theoretical and require validation in practical engineering tasks to ensure the success of future small celestial body sampling missions. Summary of the Invention

[0005] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a simulation method for the sampling process of extraterrestrial objects based on the mechanical equivalent properties of the surface of stellar regolith, which provides important support for the dynamic simulation of the sampling process of detectors under different stellar regolith properties.

[0006] The technical solution of this invention is:

[0007] A simulation method for extraterrestrial object sampling processes based on the equivalent mechanical properties of stellar regolith surfaces includes:

[0008] (1) Construct a rigid-flexible coupling dynamic model of the detector body under arbitrary configuration of solar array;

[0009] (2) Based on step (1), establish a multibody dynamics model of the sampling robotic arm to form a system dynamics model of the detector;

[0010] (3) Based on step (2), establish an equivalent analytical function model of the end pressure of the sampler in contact with the star soil;

[0011] (4) Based on the equivalent analytical function model of the end pressure of the sampler in contact with the star soil, the dynamics and control of the small celestial body sampling process are jointly simulated.

[0012] Furthermore, step (1) constructs a rigid-flexible coupled dynamic model of the detector body under arbitrary configuration of the solar array. The specific steps are as follows:

[0013] (1.1) Divide the structural topology of the detector, treat the solar array and the central body of the detector as a whole, called the detector body, and establish its rigid-flexible coupling dynamic model.

[0014] (1.2) Establish the structural dynamics model of the drive mechanism SADA and the solar array, where the connection point between the drive mechanism SADA and the central body of the detector is denoted as point a, the connection point between the drive mechanism SADA and the solar array is denoted as point b, and the connection point between the solar array and the drive mechanism SADA is denoted as point c. Their kinematic relationships are as follows:

[0015]

[0016] Among them, E a E represents the amount of motion at point a. e U represents the vibration magnitude of point b relative to point a, U represents the vibration modal coordinates of the solar array, I represents the identity matrix, n represents the modal order, and E represents the vibration magnitude of point b relative to point a. c This represents the amount of motion at point c;

[0017] in, C a S is the attitude transformation matrix from the SADA coordinate system of the drive mechanism to the coordinate system of the solar array. aLet a be the position transformation matrix from point a to point b;

[0018] Dynamic model of the combined drive mechanism SADA and solar array:

[0019]

[0020] The dynamic model of the SADA and solar array combination is obtained:

[0021]

[0022] in, M a K a For the mass matrix and stiffness matrix of the drive mechanism SADA, M c K c The mass array and stiffness array of the flexible solar array;

[0023] (1.3) Construct the probe's body dynamics equations for the combination of the probe's central body, the drive mechanism SADA, and the solar array, and use the attitude transformation matrix C from the probe's central body coordinate system to the drive mechanism SADA coordinate system. b This yields the probe's body dynamics model under arbitrary solar array configurations. Let b be the reference point of the probe's central body, used to describe the pose motion of the central body, with the following kinematic relationship:

[0024] E a =C b ·S b ·E b (8)

[0025] Among them, E b Let C be the motion of point b on the central body of the detector. b S is the attitude transformation matrix from the detector's central body coordinate system to the SADA coordinate system. b Let be the position transformation matrix from point b at the center of the detector to point a on the SADA;

[0026] The detector's central body is described as a rigid body, and its dynamic equations are as follows:

[0027]

[0028] Among them, M b Let F be the mass matrix of the central body, and F be the force and torque acting on point O of the central body.

[0029] By solving equations (7), (8), and (9) simultaneously, we obtain the probe's body dynamics model, which includes the probe's central body, flexible joints, and solar array.

[0030]

[0031] in,

[0032] Further, in step (2), a multibody dynamics model of the sampling robotic arm is established to form the system dynamics model of the detector. The specific steps are as follows:

[0033] (2.1) Establish the system kinematic equations of the detector body and the sampling robotic arm, and describe them in a recursive form. The recursive relationship of the velocity terms between the k-th individual and the (k-1)-th individual is as follows:

[0034]

[0035] Among them, E k-1,1 E k-1,2 These are the coordinates of the interface point between the (k-1)th flexible body and the preceding and following bodies, F. k Let q be the elastic deformation of the joint between the (k-1)th flexible body and the kth flexible body. k Let β be the rotation angle of the k-th flexible body relative to the (k-1)-th flexible body. k S is the matrix for selecting the rotation axis. k-1 For the mounting array of the k-th flexible body relative to the (k-1)-th flexible body, C k-1 (q k ) represents the rotation transformation matrix of the k-th flexible body relative to the (k-1)-th flexible body;

[0036] (2.2) The kinematic equations of the system are rearranged to obtain the following form:

[0037]

[0038] Where, q 1～k =[q1,q2,...,q k ] T E 1～k-1,2 =[E 1,2 E 2,2 ,...,E k-1,2 ] T F 1～k-1,2 =[F 1,2 ,F 2,2 ,...,F k-1,2 ] T intermediate variables R k (q k ) = C k-1 (q k )S k-1 ;

[0039] (2.3) Using the second kind of Lagrange equation, the system dynamic equations are established as follows:

[0040]

[0041] In the formula, T is the driving torque of the robotic arm joint, F B The external forces and torques acting on the detector body are described in the body's reference frame; M is the system mass matrix, K is the system stiffness matrix; M(q) is the system mass, η T These are the body velocity, angular velocity, and vibration magnitude.

[0042] Furthermore, the specific steps for establishing the equivalent analytical function model of the end pressure of the sampler in contact with the star soil are as follows:

[0043] (3.1) Based on the data of the microgravity low-speed intrusion experiment, the particle dynamics model of the star soil used in the experiment was constructed based on the particle dynamics software. The process of the sampler intruding into the weathered layer was simulated according to the experimental process. The pressure and intrusion depth curves of the sampler when intruding into the weathered layer were obtained. The particle dynamics model adjustment parameters include particle size, porosity, friction coefficient and intrusion velocity.

[0044] (3.2) Using the sampler terminal pressure as the influence variable of different stellar soil characteristics on the detector's dynamic behavior, and combining mathematical simulation and physical experimental results, the characteristics of the sampler terminal pressure variation curve with penetration depth are determined, and an equivalent analytical function model of the sampler terminal pressure is established:

[0045]

[0046] Where a is the amplitude of the first peak, b is the width of the first peak, c can adjust the sharpness of the peak, k is the approximate slope of the steady rise after the first peak, and P(x) represents the pressure at the end of the sampler.

[0047] (3.3) After the first peak, the pressure at the sampler's end also exhibits an oscillating component during its subsequent rise, which is described by the following function:

[0048]

[0049] Where R represents the random oscillation during the upward process, N is the number of random components, and A i It is the i-th random amplitude, f i It is the i-th random frequency, θ i is the i-th random phase, and x is the independent variable; by adjusting the parameters, the sampler end pressure curves of different characteristic star soils as a function of depth can be obtained;

[0050] Thus, the pressure function at the end of the sampler is obtained as: Y(x)=P(x)+R(x).

[0051] Furthermore, the data from the microgravity low-speed intrusion experiment include the intrusion depth at the sampler end and the force curve at the sampler end.

[0052] Furthermore, the specific steps for performing the joint simulation of the dynamics and control of the small celestial body sampling process are as follows:

[0053] (4.1) Design a dynamic simulation module based on the dynamic model of the detector system. The input of the dynamic simulation module is the control force and torque of the detector, the joint driving torque of the sampling robot arm, and the contact force at the end of the sampler. The output of the dynamic simulation module is the position, attitude, velocity, and angular velocity of the detector, the joint angle and angular velocity of the robot arm, and the position and attitude of the end of the sampler.

[0054] (4.2) The position and attitude control algorithm of the detector is encapsulated into a dynamic link library module. The input of the dynamic link library module is the position, attitude, velocity and angular velocity of the detector, and the output is the control force and torque. This dynamic link library module is denoted as the detector position and attitude control module.

[0055] The robotic arm control algorithm is encapsulated into a dynamic link library module. The input is the joint angle and angular velocity of the robotic arm, and the output is the joint control torque. This dynamic link library module is denoted as the sampling robotic arm control module.

[0056] The contact force at the sampler tip is calculated based on the equivalent analytical function model of the tip pressure and the sampler tip area. This calculation method is designed as a sampler contact force collision calculation module.

[0057] (4.3) A joint simulation model of the dynamics and control of the small celestial body sampling process was established based on Simulink. The dynamics simulation module, the detector position and attitude control module, the sampling robotic arm control module, and the sampler contact force collision calculation module form a closed-loop joint simulation. Each simulation step interacts with data to complete the single-step simulation calculation. By setting different sampler end pressure curve forms, the dynamics simulation of the detector sampling process under different celestial soil characteristics is realized.

[0058] Secondly, the present invention also proposes a processor for running a program, wherein the program executes the method during runtime.

[0059] Thirdly, the present invention also proposes a non-volatile storage medium comprising: a computer program product, wherein the method is executed when the computer program product is executed.

[0060] Fourthly, the present invention also proposes a computer program product, which includes a computer program that, when executed by a processor, implements the method described.

[0061] The beneficial effects of this invention compared to the prior art are:

[0062] (1) This invention discloses a modeling and simulation method for extraterrestrial body sampling process based on the equivalent mechanical properties of star soil surface. Combining the physical experiment of star soil intrusion of small celestial body particles with particle discrete element simulation analysis, it realizes the equivalent simulation of the mechanical properties of different star soil surfaces, laying the foundation for efficient simulation of the dynamics of small celestial body sampling process under different star soil properties.

[0063] (2) This invention discloses a modeling and simulation method for sampling process of extraterrestrial objects based on the mechanical equivalent properties of the surface of star soil. It provides a modeling method for rigid-flexible coupling dynamics of the detector body and multi-body dynamics of the robotic arm. It can provide a rapid modeling of the dynamics of the detector system under arbitrary configuration of the solar wing, and provides a model basis for dynamic simulation of the sampling process.

[0064] (3) This invention discloses a modeling and simulation method for extraterrestrial celestial body sampling process based on the mechanical equivalent properties of celestial soil surface. It establishes a joint simulation model of celestial body sampling process dynamics and control based on the mechanical equivalent properties of celestial soil surface, realizes joint simulation analysis of detector dynamic motion, solar wing vibration, detector control and sampling robotic arm drive, and can be used to predict the dynamic behavior of detector sampling process under different celestial soil characteristics, which has practical engineering value. Attached Figure Description

[0065] Figure 1 This is a schematic diagram of the detector's structural topology;

[0066] Figure 2 This is a schematic diagram of the pressure at the sampler tip as a function of penetration depth. Detailed Implementation

[0067] The specific embodiments of the present invention will now be described in further detail with reference to the accompanying drawings.

[0068] The basic idea of ​​this invention is as follows: First, a rigid-flexible coupled dynamic model of the detector body under arbitrary configuration of the solar array is constructed; further, a multi-body dynamic model of the sampling manipulator is established to form the system dynamic model of the detector; then, an equivalent analytical function model of the end pressure of the sampler in contact with the stellar soil is established; finally, a joint simulation model of the dynamics and control of the small celestial body sampling process is established, providing technical support for the dynamic simulation of the detector sampling process under different stellar soil characteristics.

[0069] This invention proposes a simulation method for extraterrestrial body sampling processes based on the equivalent mechanical properties of stellar regolith surfaces, comprising the following steps:

[0070] (1) Construct a rigid-flexible coupling dynamic model of the detector body under arbitrary configuration of solar array;

[0071] (1.1) Divide the structural topology of the detector, treat the solar array and the central body of the detector as a whole, called the detector body, and establish its rigid-flexible coupling dynamic model.

[0072] (1.2) Establish the structural dynamics model of the drive mechanism SADA and the solar array, where the connection point between the drive mechanism SADA and the central body of the detector is denoted as point a, the connection point between the drive mechanism SADA and the solar array is denoted as point b, and the connection point between the solar array and the drive mechanism SADA is denoted as point c. Their kinematic relationships are as follows:

[0073]

[0074] Among them, E a E represents the amount of motion at point a. e U represents the vibration magnitude of point b relative to point a, U represents the vibration modal coordinates of the solar array, I represents the identity matrix, n represents the modal order, and E represents the vibration magnitude of point b relative to point a. c This represents the amount of motion at point c;

[0075] in, C a S is the attitude transformation matrix from the SADA coordinate system of the drive mechanism to the coordinate system of the solar array. a Let a be the position transformation matrix from point a to point b;

[0076] Dynamic model of the combined drive mechanism SADA and solar array:

[0077]

[0078] The dynamic model of the SADA and solar array combination is obtained:

[0079]

[0080] in, M a K a For the mass matrix and stiffness matrix of the drive mechanism SADA, M c K c The mass array and stiffness array of the flexible solar array;

[0081] (1.3) Construct the probe's body dynamics equations for the combination of the probe's central body, the drive mechanism SADA, and the solar array, and use the attitude transformation matrix C from the probe's central body coordinate system to the drive mechanism SADA coordinate system. b This yields the probe's body dynamics model under arbitrary solar array configurations. Let b be the reference point of the probe's central body, used to describe the pose motion of the central body, with the following kinematic relationship:

[0082] E a =Cb ·S b ·E b (8)

[0083] Among them, E b Let C be the motion of point b on the central body of the detector. b S is the attitude transformation matrix from the detector's central body coordinate system to the SADA coordinate system. b Let be the position transformation matrix from point b at the center of the detector to point a on the SADA;

[0084] The detector's central body is described as a rigid body, and its dynamic equations are as follows:

[0085]

[0086] Among them, M b Let F be the mass matrix of the central body, and F be the force and torque acting on point O of the central body.

[0087] By solving equations (7), (8), and (9) simultaneously, we obtain the probe's body dynamics model, which includes the probe's central body, flexible joints, and solar array.

[0088]

[0089] in,

[0090] (2) Based on step (1), establish a multibody dynamics model of the sampling robotic arm to form a system dynamics model of the detector;

[0091] (2.1) Establish the system kinematic equations of the detector body and the sampling robotic arm, and describe them in a recursive form. The recursive relationship of the velocity terms between the k-th individual and the (k-1)-th individual is as follows:

[0092]

[0093] Among them, E k-1,1 E k-1,2 These are the coordinates of the interface point between the (k-1)th flexible body and the preceding and following bodies, F. k Let q be the elastic deformation of the joint between the (k-1)th flexible body and the kth flexible body. k Let β be the rotation angle of the k-th flexible body relative to the (k-1)-th flexible body. k S is the matrix for selecting the rotation axis. k-1 For the mounting array of the k-th flexible body relative to the (k-1)-th flexible body, C k-1 (q k ) represents the rotation transformation matrix of the k-th flexible body relative to the (k-1)-th flexible body;

[0094] (2.2) The kinematic equations of the system are rearranged to obtain the following form:

[0095]

[0096] Where, q 1～k =[q1,q2,...,q k ] T E 1～k-1,2 =[E 1,2 E 2,2 ,...,E k-1,2 ] T F 1～k-1,2 =[F 1,2 ,F 2,2 ,...,F k-1,2 ] T intermediate variables R k (q k ) = C k-1 (q k )S k-1 ;

[0097] (2.3) Using the second kind of Lagrange equation, the system dynamic equations are established as follows:

[0098]

[0099] In the formula, T is the driving torque of the robotic arm joint, F B The external forces and torques acting on the detector body are described in the body's reference frame; M is the system mass matrix, K is the system stiffness matrix; M(q) is the system mass, η T These are the body velocity, angular velocity, and vibration magnitude.

[0100] (3) Based on step (2), establish an equivalent analytical function model of the end pressure of the sampler in contact with the star soil;

[0101] (3.1) Based on the data from the microgravity low-speed intrusion experiment, a particle dynamics model of the star soil used in the experiment was constructed using particle dynamics software. The process of the sampler intruding into the weathered layer was simulated according to the experimental process. The pressure and intrusion depth curves of the sampler when intruding into the weathered layer were obtained. The particle dynamics model adjustment parameters include particle size, porosity, friction coefficient, and intrusion velocity. The microgravity low-speed intrusion experiment data includes the intrusion depth at the end of the sampler and the force curve at the end of the sampler.

[0102] (3.2) Using the sampler terminal pressure as the influence variable of different stellar soil characteristics on the detector's dynamic behavior, and combining mathematical simulation and physical experimental results, the characteristics of the sampler terminal pressure variation curve with penetration depth are determined, and an equivalent analytical function model of the sampler terminal pressure is established:

[0103]

[0104] Where a is the amplitude of the first peak, b is the width of the first peak, c can adjust the sharpness of the peak, k is the approximate slope of the steady rise after the first peak, and P(x) represents the pressure at the end of the sampler.

[0105] (3.3) After the first peak, the pressure at the sampler's end also exhibits an oscillating component during its subsequent rise, which is described by the following function:

[0106]

[0107] Where R represents the random oscillation during the upward process, N is the number of random components, and A i It is the i-th random amplitude, f i It is the i-th random frequency, θ i is the i-th random phase, and x is the independent variable; by adjusting the parameters, the sampler end pressure curves of different characteristic star soils as a function of depth can be obtained;

[0108] Thus, the pressure function at the end of the sampler is obtained as: Y(x)=P(x)+R(x).

[0109] (4) Based on the equivalent analytical function model of the end pressure of the sampler in contact with the star soil, the dynamics and control of the small celestial body sampling process are jointly simulated.

[0110] (4.1) Design a dynamic simulation module based on the dynamic model of the detector system. The input of the dynamic simulation module is the control force and torque of the detector, the joint driving torque of the sampling robot arm, and the contact force at the end of the sampler. The output of the dynamic simulation module is the position, attitude, velocity, and angular velocity of the detector, the joint angle and angular velocity of the robot arm, and the position and attitude of the end of the sampler.

[0111] (4.2) The position and attitude control algorithm of the detector is encapsulated into a dynamic link library module. The input of the dynamic link library module is the position, attitude, velocity and angular velocity of the detector, and the output is the control force and torque. This dynamic link library module is denoted as the detector position and attitude control module.

[0112] The robotic arm control algorithm is encapsulated into a dynamic link library module. The input is the joint angle and angular velocity of the robotic arm, and the output is the joint control torque. This dynamic link library module is denoted as the sampling robotic arm control module.

[0113] The contact force at the sampler tip is calculated based on the equivalent analytical function model of the tip pressure and the sampler tip area. This calculation method is designed as a sampler contact force collision calculation module.

[0114] (4.3) A joint simulation model of the dynamics and control of the small celestial body sampling process was established based on Simulink. The dynamics simulation module, the detector position and attitude control module, the sampling robotic arm control module, and the sampler contact force collision calculation module form a closed-loop joint simulation. Each simulation step interacts with data to complete the single-step simulation calculation. By setting different sampler end pressure curve forms, the dynamics simulation of the detector sampling process under different celestial soil characteristics is realized.

[0115] Example:

[0116] This embodiment presents a simulation method for extraterrestrial object sampling processes based on the equivalent mechanical properties of stellar regolith surfaces, including:

[0117] (1) First, the structural topology of the detector is divided, such as Figure 1 As shown, since the solar array usually maintains a fixed configuration rather than rotates rapidly during the sampling process, the solar array and the central body of the detector can be regarded as a whole, called the detector body, and a rigid-flexible coupling dynamic model can be established for it.

[0118] (2) In order to obtain the detector's body dynamics model under a certain angle configuration of the solar array, a structural dynamics model of the drive mechanism SADA and the solar array is established. The connection point between SADA and the detector's central body is denoted as point a, the connection point between SADA and the solar array is denoted as point b, and the connection point between the solar array and SADA is denoted as point c. Their kinematic relationships are as follows:

[0119]

[0120] Among them, E a E represents the amount of exercise a undergoes. e E represents the amount of vibration of point b relative to point a. c Let c represent the motion quantity at point c, U represent the vibration modal coordinates of the solar array, I represent the identity matrix, and n represent the modal order. C a S is the attitude transformation matrix from the SADA coordinate system to the solar array coordinate system. a Let be the position transformation matrix from point a to point b.

[0121] Combine the dynamic model of SADA and the solar array:

[0122]

[0123] The dynamic model of the SADA and solar array combination is obtained:

[0124]

[0125] in, M a K a For the mass matrix and stiffness matrix of the drive mechanism SADA, M c K c The mass array and stiffness array of the flexible solar array.

[0126] (3) Construct the probe's body dynamics equations combining the probe's central body, SADA, and solar arrays, and use the attitude transformation matrix C from the probe's central body coordinate system to the SADA coordinate system. b This allows us to obtain the probe's body dynamics model under any configuration of the solar array. Let b be the reference point of the probe's central body, used to describe its pose motion, and the following kinematic relationship exists:

[0127] E a =C b ·S b ·E b (8)

[0128] Among them, E b Let C be the motion of point b on the central body of the detector. b S is the attitude transformation matrix from the detector's central body coordinate system to the SADA coordinate system. b Let be the position transformation matrix from point b at the center of the detector to point a on the SADA.

[0129] The detector's central body is described as a rigid body, and its dynamic equations are as follows:

[0130]

[0131] Among them, M b Let F be the mass matrix of the central body, and F be the force and torque acting on point O of the central body. Here, F is a vector, which includes a total of 6 quantities, namely 3 forces and 3 torques.

[0132] By combining equations (7), (8), and (9), we can obtain the probe's body dynamics model, which includes the probe's central body, flexible joints, and solar array.

[0133]

[0134] in,

[0135] (4) Establish the system kinematic equations of the detector body and the sampling robotic arm, and describe them in a recursive form. The recursive relationship of the velocity terms between the kth individual and the (k-1)th individual is as follows:

[0136]

[0137] Among them, E k-1,1 E k-1,2 These are the coordinates of the interface point between the (k-1)th flexible body and the preceding and following bodies, and so on; F k Let q be the elastic deformation of the joint between the (k-1)th flexible body and the kth flexible body. k Let β be the rotation angle of the k-th flexible body relative to the (k-1)-th flexible body. k S is the matrix for selecting the rotation axis. k-1 For the mounting array of the k-th flexible body relative to the (k-1)-th flexible body, C k-1 (q k ) is the rotation transformation matrix of the k-th flexible body relative to the (k-1)-th flexible body.

[0138] (5) Further simplification of the system's kinematic equations yields the following form:

[0139]

[0140] Where, q 1～k =[q1,q2,...,q k ] T E 1～k-1,2 =[E 1,2 E 2,2 ,...,E k-1,2 ] T F 1～k-1,2 =[F 1,2 ,F 2,2 ,...,F k-1,2 ] T ,

[0141] R k (q k ) = C k-1 (q k )S k-1 .

[0142] (6) Using the second kind of Lagrange equations, the system dynamics equations are established as follows:

[0143]

[0144] In the formula, T is the driving torque of the robotic arm joint, F B The external forces and torques acting on the detector body are described in the body's reference frame; M is the system mass matrix, K is the system stiffness matrix; M(q) is the system mass, η T These are the body velocity, angular velocity, and vibration magnitude.

[0145] (7) Based on the data of the microgravity low-speed intrusion experiment, the particle dynamics model of the star soil used in the experiment was constructed based on the particle dynamics software. The process of the sampler intruding into the weathered layer was simulated according to the experimental process. The pressure and intrusion depth curves of the sampler when intruding into the weathered layer were obtained. The particle model adjustment parameters include particle size, porosity, friction coefficient and intrusion velocity.

[0146] (8) Using the sampler terminal pressure as the influence variable of different stellar soil characteristics on the detector's dynamic behavior, and combining mathematical simulation and physical experimental results, the characteristics of the sampler terminal pressure variation curve with penetration depth were determined, and an equivalent analytical function model of the sampler terminal pressure was established:

[0147]

[0148] Where a is the amplitude of the first peak, b is the width of the first peak, c can adjust the sharpness of the peak, k is the approximate slope of the steady rise after the first peak, and P(x) represents the pressure at the end of the sampler.

[0149] (9) After the first peak, the pressure at the sampler terminal exhibits an oscillating component during its subsequent rise. Fourier transform analysis of this oscillating component fails to yield a definite pattern. To describe this oscillation process, the following function is used:

[0150]

[0151] Where R represents the random oscillation during the upward process, N is the number of random components, and A i It is the i-th random amplitude, f i It is the i-th random frequency, θ i It is the i-th random phase, and x is the independent variable; by adjusting the parameters, the sampler end pressure curves of different characteristics of star soil as a function of depth can be obtained, such as... Figure 2 As shown.

[0152] Thus, the pressure function at the end of the sampler is obtained as: Y(x)=P(x)+R(x).

[0153] (10) Design a dynamic simulation module based on the dynamic model of the detector system. The module inputs are the control force and torque of the detector, the joint driving torque of the sampling robot arm, and the contact force at the end of the sampler. The module outputs are the position, attitude, velocity, and angular velocity of the detector, the joint angle and angular velocity of the robot arm, and the position and attitude of the end of the sampler.

[0154] (11) The position and attitude control algorithm of the detector is encapsulated into a dynamic link library module. The input of the dynamic link library module is the position, attitude, velocity and angular velocity of the detector, and the output is the control force and torque. This dynamic link library module is denoted as the detector position and attitude control module.

[0155] The robotic arm control algorithm is encapsulated into a dynamic link library module. The input is the joint angle and angular velocity of the robotic arm, and the output is the joint control torque. This dynamic link library module is denoted as the sampling robotic arm control module.

[0156] The contact force at the sampler end is calculated based on the equivalent analytical function model of the end pressure and the sampler end area. This calculation method is designed as a sampler contact force collision calculation module.

[0157] (12) A joint simulation model of the dynamics and control of the small celestial body sampling process was established based on Simulink. The dynamics simulation module, the detector position and attitude control module, the sampling robotic arm control module, and the sampler contact force collision calculation module form a closed-loop joint simulation. Each simulation step interacts with data to complete the single-step simulation calculation. By setting different sampler end pressure curve forms, the dynamics simulation of the detector sampling process under different celestial soil characteristics is realized.

[0158] The parts of this invention not described in detail are common knowledge to those skilled in the art.

Claims

1. A simulation method for extraterrestrial body sampling process based on the equivalent mechanical properties of stellar soil surface, characterized in that... ,include: (1) Construct a rigid-flexible coupling dynamic model of the detector body under arbitrary configuration of solar array; (2) Based on step (1), establish a multibody dynamics model of the sampling robotic arm to form a system dynamics model of the detector; (3) Based on step (2), establish an equivalent analytical function model of the end pressure of the sampler in contact with the star soil; (4) Based on the equivalent analytical function model of the end pressure of the sampler in contact with the star soil, the dynamics and control of the small celestial body sampling process are jointly simulated.

2. The simulation method for extraterrestrial body sampling process based on the mechanical equivalent properties of stellar soil surface according to claim 1, characterized in that: Step (1) Construct a rigid-flexible coupled dynamic model of the detector body under arbitrary configuration of the solar array. The specific steps are as follows: (1.1) Divide the structural topology of the detector, treat the solar array and the central body of the detector as a whole, called the detector body, and establish its rigid-flexible coupling dynamic model. (1.2) Establish the structural dynamics model of the drive mechanism SADA and the solar array, where the connection point between the drive mechanism SADA and the central body of the detector is denoted as point a, the connection point between the drive mechanism SADA and the solar array is denoted as point b, and the connection point between the solar array and the drive mechanism SADA is denoted as point c. Their kinematic relationships are as follows: Among them, E a E represents the amount of motion at point a. e U represents the vibration magnitude of point b relative to point a, U represents the vibration modal coordinates of the solar array, I represents the identity matrix, n represents the modal order, and E represents the vibration magnitude of point b relative to point a. c This represents the amount of motion at point c; in, C a S is the attitude transformation matrix from the SADA coordinate system of the drive mechanism to the coordinate system of the solar array. a Let a be the position transformation matrix from point a to point b; Dynamic model of the combined drive mechanism SADA and solar array: The dynamic model of the SADA and solar array combination is obtained: in, M a K a For the mass matrix and stiffness matrix of the drive mechanism SADA, M c K c The mass array and stiffness array of the flexible solar array; (1.3) Construct the probe's body dynamics equations for the combination of the probe's central body, the drive mechanism SADA, and the solar array, and use the attitude transformation matrix C from the probe's central body coordinate system to the drive mechanism SADA coordinate system. b This yields the probe's body dynamics model under arbitrary solar array configurations. Let b be the reference point of the probe's central body, used to describe the pose motion of the central body, with the following kinematic relationship: E a =C b ·S b ·E b (8) Among them, E b Let C be the motion of point b on the central body of the detector. b S is the attitude transformation matrix from the detector's central body coordinate system to the SADA coordinate system. b Let be the position transformation matrix from point b at the center of the detector to point a on the SADA; The detector's central body is described as a rigid body, and its dynamic equations are as follows: Among them, M b Let F be the mass matrix of the central body, and F be the force and torque acting on point O of the central body. By solving equations (7), (8), and (9) simultaneously, we obtain the probe's body dynamics model, which includes the probe's central body, flexible joints, and solar array. in, 3. The simulation method for extraterrestrial body sampling process based on the mechanical equivalent properties of stellar soil surface according to claim 1, characterized in that: Step (2) Establish the multibody dynamics model of the sampling robotic arm to form the system dynamics model of the detector. The specific steps are as follows: (2.1) Establish the system kinematic equations of the detector body and the sampling robotic arm, and describe them in a recursive form. The recursive relationship of the velocity terms between the k-th individual and the (k-1)-th individual is as follows: Among them, E k-1,1 E k-1,2 These are the coordinates of the interface point between the (k-1)th flexible body and the preceding and following bodies, F. k Let q be the elastic deformation of the joint between the (k-1)th flexible body and the kth flexible body. k Let β be the rotation angle of the k-th flexible body relative to the (k-1)-th flexible body. k S is the matrix for selecting the rotation axis. k-1 For the mounting array of the k-th flexible body relative to the (k-1)-th flexible body, C k-1 (q k ) represents the rotation transformation matrix of the k-th flexible body relative to the (k-1)-th flexible body; (2.2) The kinematic equations of the system are rearranged to obtain the following form: Where, q 1～k =[q1,q2,...,q k ] T E 1～k-1,2 =[E 1,2 E 2,2 ,...,E k-1,2 ] T F 1～k-1,2 =[F 1,2 ,F 2,2 ,...,F k-1,2 ] T intermediate variables R k (q k ) = C k-1 (q k )S k-1 ; (2.3) Using the second kind of Lagrange equation, the system dynamic equations are established as follows: In the formula, T is the driving torque of the robotic arm joint, F B The external forces and torques acting on the detector body are described in the body's reference frame; M is the system mass matrix, K is the system stiffness matrix; M(q) is the system mass, η T These are the body velocity, angular velocity, and vibration magnitude.

4. The simulation method for extraterrestrial body sampling process based on the mechanical equivalent properties of stellar soil surface according to claim 1, characterized in that: The specific steps for establishing the equivalent analytical function model of the end pressure of the sampler in contact with the star soil are as follows: (3.1) Based on the data of the microgravity low-speed intrusion experiment, the particle dynamics model of the star soil used in the experiment was constructed based on the particle dynamics software. The process of the sampler intruding into the weathered layer was simulated according to the experimental process. The pressure and intrusion depth curves of the sampler when intruding into the weathered layer were obtained. The particle dynamics model adjustment parameters include particle size, porosity, friction coefficient and intrusion velocity. (3.2) Using the sampler terminal pressure as the influence variable of different stellar soil characteristics on the detector's dynamic behavior, and combining mathematical simulation and physical experimental results, the characteristics of the sampler terminal pressure variation curve with penetration depth are determined, and an equivalent analytical function model of the sampler terminal pressure is established: Where a is the amplitude of the first peak, b is the width of the first peak, c can adjust the sharpness of the peak, k is the approximate slope of the steady rise after the first peak, and P(x) represents the pressure at the end of the sampler. (3.3) After the first peak, the pressure at the sampler's end also exhibits an oscillating component during its subsequent rise, which is described by the following function: Where R represents the random oscillation during the upward process, N is the number of random components, and A i It is the i-th random amplitude, f i It is the i-th random frequency, θ i is the i-th random phase, and x is the independent variable; by adjusting the parameters, the sampler end pressure curves of different characteristic star soils as a function of depth can be obtained; Thus, the pressure function at the end of the sampler is obtained as: Y(x)=P(x)+R(x).

5. The simulation method for extraterrestrial body sampling process based on the mechanical equivalent properties of stellar soil surface according to claim 4, characterized in that: The data from the microgravity low-speed intrusion experiment include the intrusion depth at the sampler tip and the force curve at the sampler tip.

6. The method for modeling extraterrestrial body sampling processes based on the mechanical equivalent properties of stellar soil surfaces according to claim 1, characterized in that: The specific steps for performing the joint simulation of dynamics and control of the small celestial body sampling process are as follows: (4.1) Design a dynamic simulation module based on the dynamic model of the detector system. The input of the dynamic simulation module is the control force and torque of the detector, the joint driving torque of the sampling robot arm, and the contact force at the end of the sampler. The output of the dynamic simulation module is the position, attitude, velocity, and angular velocity of the detector, the joint angle and angular velocity of the robot arm, and the position and attitude of the end of the sampler. (4.2) The position and attitude control algorithm of the detector is encapsulated into a dynamic link library module. The input of the dynamic link library module is the position, attitude, velocity and angular velocity of the detector, and the output is the control force and torque. This dynamic link library module is denoted as the detector position and attitude control module. The robotic arm control algorithm is encapsulated into a dynamic link library module. The input is the joint angle and angular velocity of the robotic arm, and the output is the joint control torque. This dynamic link library module is denoted as the sampling robotic arm control module. The contact force at the sampler tip is calculated based on the equivalent analytical function model of the tip pressure and the sampler tip area. This calculation method is designed as a sampler contact force collision calculation module. (4.3) A joint simulation model of the dynamics and control of the small celestial body sampling process was established based on Simulink. The dynamics simulation module, the detector position and attitude control module, the sampling robotic arm control module, and the sampler contact force collision calculation module form a closed-loop joint simulation. Each simulation step interacts with data to complete the single-step simulation calculation. By setting different sampler end pressure curve forms, the dynamics simulation of the detector sampling process under different celestial soil characteristics is realized.

7. A processor, characterized in that, The processor is used to run a program, wherein the program executes the method according to any one of claims 1 to 6 when it runs.

8. A non-volatile storage medium, characterized in that, include: A computer program product that, when executed, performs the method described in any one of claims 1 to 6.

9. A computer program product, characterized in that, The computer program product includes a computer program that, when executed by a processor, implements the steps of the method according to any one of claims 1 to 6.

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