A dual-arm space robot adhesion capture control method

Abstract

A double-arm space robot adhesion capture control method, characterized in that the double-arm space robot adhesion capture control method is used for a double-arm space robot system, the double-arm space robot system comprises a double-arm space robot platform (1), a first part of a space mechanical arm (2) and an end effector (4) thereof, a second part of a space mechanical arm (3) and an end effector (5) thereof, and the double-arm space robot adhesion capture control method comprises the following steps: step 1, proposing the concept of adhesion, designing a double-arm space robot adhesion capture mode; step 2, establishing a coordinate system, completing double-arm space robot dynamics modeling; step 3, designing an autonomous path planning algorithm in adhesion capture; step 4, completing controller design of adhesion capture by using a contact force control strategy; and step 5, closed-loop numerical simulation, verifying double-arm adhesion capture effectiveness.

Description

Technical Field

[0001] This invention belongs to the field of spacecraft on-orbit servicing and space debris removal technology, and relates to an adhesion and capture control method for a dual-arm space robot to capture moving targets. Background Technology

[0002] In recent years, space debris generated by launch failures, functional malfunctions, and even spacecraft disintegration has seriously affected the safety of the space environment. The amount of space debris in low Earth orbit far exceeds that of currently operational spacecraft, and it continues to increase over time. Space debris removal will become an urgent problem to be solved in the future aerospace field, and is key to reducing spacecraft operation and maintenance costs and improving the safety of the space environment.

[0003] The core of space debris removal is to use active spacecraft to capture space debris and transfer it to a graveyard orbit, thereby achieving the removal mission. Compared with conventional non-contact capture, using space robots to directly contact and capture debris targets offers advantages such as higher reliability, stronger safety, and greater controllability. To achieve target capture by space robots, many scholars both domestically and internationally have conducted extensive research, currently focusing primarily on single-armed space robots, with less research on dual-armed space robots. Compared to single-armed space robots, dual-armed space robots have greater payload capacity, higher operational flexibility, and stronger mission adaptability, making them more advantageous for space debris removal. However, existing research suffers from problems such as easy contact force saturation, susceptibility to damage at the robotic arm end effector, and the possibility of target escape. Therefore, utilizing dual-armed space robots as active spacecraft for debris removal remains a major research focus and a significant challenge.

[0004] In summary, to achieve the capture of moving debris by a dual-arm space robot, it is necessary to consider reducing the relative motion between the target and the robotic arm, ensuring it remains within the robotic arm's capture capability range, and avoiding damage due to excessive contact force at the end effector. Simultaneously, it is necessary to avoid pushing the target away from the dual-arm space robot, thus preventing relative trajectory control problems caused by the target escaping.

[0005] Based on the above, it is particularly important to design a new capture and control method that reduces the contact force at the end of the robotic arm, avoids contact force saturation, prevents damage to the end effector, and mitigates the risk of target escape. Summary of the Invention

[0006] The purpose of this invention is to provide a novel adhesion and capture control method for space debris removal tasks of dual-arm space robots. This method provides new ideas and methods for the design of ultra-compliant controllers for debris removal, effectively improving the compliant control performance of dual-arm space robots in capturing debris targets and avoiding the risks of contact force saturation, damage to the robotic arm, and target escape.

[0007] This invention provides a dual-arm space robot adhesion and capture control method. The dual-arm space robot system includes a dual-arm space robot platform (1), a first space robotic arm (2) and its end effector (4), and a second space robotic arm (3) and its end effector (5). The dual-arm space robot adhesion and capture control method includes the following steps:

[0008] Step 1: Propose the concept of adhesion and design an adhesion and capture method for a dual-arm space robot;

[0009] Step 2: Establish a coordinate system and complete the dynamic modeling of the dual-arm space robot;

[0010] Step 3: Design an autonomous path planning algorithm for adhesive capture;

[0011] Step 4: Design the controller for adhesive capture using a contact force control strategy;

[0012] Step 5: Closed-loop numerical simulation to verify the effectiveness of dual-arm adhesive capture.

[0013] Preferably, in step 1, the adhesion refers to the process of moving the end effector of the robotic arm along with the target for a period of time before performing the capture.

[0014] Preferably, in step 1, the dual-arm space robot adhesion and capture method includes: driving each joint of the robotic arm to maintain an adjustable small contact force between the end effector of each robotic arm and the target, thereby keeping the end effector near its corresponding target contact point.

[0015] Preferably, in step 2, the i-th (i = 1, 2) robotic arm in the dual-arm space robot has n... i There are (i = 1, 2) arms, which are connected by single-degree-of-freedom rotary joints;

[0016] Establish a coordinate system: The platform system of the dual-arm space robot is Σ. b Its origin is located at the center of mass of the space robot's platform; the target frame is Σ. t Its origin is located at the target's center of mass; the rod coordinate system Σ i,j The origin is located on the rotation axis of the j-th joint of the i-th robotic arm, and is fixed to the j-th arm link; the link reference coordinate system The origin is located on the rotation axis of the j-th joint of the i-th robotic arm, and the coordinate system is... With Σ i,j The z-axis is always aligned with the rotational joint axis Γ. i,j The direction is parallel; the end effector system Σ hiThe origin is located at the nth position of the i-th robotic arm. i The end of the root rod is used to describe the operational task; the capture point system The origin is located at the i-th capture point on the target. When the i-th robotic arm completes the capture, Σ hi With Σ hi* Coincident; Inertial coordinate system Σ I The origin is located at the center of the Earth, the z-axis points to the North Pole along the Earth's polar axis, the x-axis points to the vernal equinox, and the y-axis forms a right-handed coordinate system with the x and z axes;

[0017] Introducing the homogeneous transformation matrix A T B Its meaning is: the homogeneous transformation matrix of coordinate system B relative to coordinate system A, let... A r B and A R B Let B be the position vector matrix and the coordinate transformation matrix relative to coordinate system A, respectively. Then, the homogeneous transformation matrix between the two coordinate systems is... A T B It can be represented as: The forward kinematic equations of a dual-arm space robot, i.e., the end effector system Σ, can be solved using the homogeneous transformation matrix. hi Relative platform system Σ b The pose can be obtained using the homogeneous transformation matrix. in, b T hi For end effector system Σ hi Relative platform system Σ b The coordinate transformation matrix, b T i,1 For the rod coordinate system Σ i,1 Relative platform system Σ b The coordinate transformation matrix, i,(j-1) T i,j For the rod coordinate system Σ i,j Relative rod coordinate system Σ i,j-1 The coordinate transformation matrix, For end effector system Σ hi Relative rod coordinate system The coordinate transformation matrix;

[0018] The dynamic equations of the two-armed space robot can be derived using the Kane equations. Where M b With M m M represents the generalized mass array of the platform and the two robotic arms, respectively. bm V represents the coupling mass matrix of the platform and the two robotic arms. b For the platform's relative inertial frame Σ I The linear velocity and angular velocity are projected onto the platform system Σb middle; c represents the joint angular velocity of the two robotic arms. b With c m These represent the nonlinear generalized inertial forces corresponding to the platform and the two robotic arms, respectively; F b External forces affecting the platform system b The resulting spatial force is projected onto Σ b In the middle; τ represents the joint torque of the two robotic arms; J b With J m The Jacobian matrices for the platform and the robotic arm are respectively; F h The contact force / torque acting on the ends of the two robotic arms is projected onto the end effector system; similarly, the dynamic equation of the target to be captured is obtained as follows: Where M t A generalized mass matrix with the objective of V; t For the target relative inertial frame Σ I The linear velocity and angular velocity are projected onto the target system Σ. t c t Nonlinear generalized inertial force with the target in mind; The generalized Jacobian matrix with the objective as the target.

[0019] Preferably, step 3 includes:

[0020] Step 31: Calculate the kinematic relationship of the dual-arm space robot to obtain the relative pose information between the end effector of each robotic arm and the target capture point;

[0021] Step 32: Using the relative pose information between the end effector of the robotic arm and the target capture point, the visual servoing method can be used to complete the trajectory planning of the robotic arm in the workspace, laying the foundation for the subsequent design of the adhesive capture controller.

[0022] Preferably, step 31 includes:

[0023] Let the target system Σ t The end effector system relative to the i-th robotic arm hi The position and attitude are respectively hi p t and hi R t Assuming that the center of the camera in each robotic arm coincides with the origin of its end effector system, then we can obtain... hi p t =( I R hi ) T ( I p t - I p hi ), hi R t=( I R hi ) TI R t ,in I p t and I R t Σ t Relative inertial frame Σ I The position vector and coordinate transformation matrix, I p hi and I R hi Σ hi Relative Σ I The position vector matrix and coordinate transformation matrix; according to the definition of the homogeneous transformation matrix, the target system Σ can be obtained. t Relative end effector system Σ hi homogeneous transformation matrix hi T t for: On the other hand, since the pose of the capture point on the target is fixed, the capture point system Σ hi* Relative target frame Σ t homogeneous transformation matrix t T hi* It is a constant matrix; therefore, the i-th end effector system of the robotic arm is Σ. hi Its corresponding capture point system Σ hi* The homogeneous transformation matrix between them is: hi T hi* = hi T tt T hi* .

[0024] Preferably, step 32 includes:

[0025] Define the grasping pose error of the i-th robotic arm end effector. for in hi p hi* and hi θ hi* These represent the position and attitude angle of the target capture point relative to the end effector of the robotic arm; based on the kinematic relationship of the robotic arm, combined with... hi p hi* and hi θ hi* From the rate of change, the time derivative of the expected capture pose error of the end effector in the workspace can be obtained as: in hi R b For platform system Σ b Relative Σ hi The coordinate transformation matrix; E3 is a 3×3 identity matrix; 0 3×3It is a 3×3 zero matrix; Let be the Jacobian matrix of the i-th robotic arm; Let T be the joint angular velocity of the i-th robotic arm; hi θ hi* Let be the rotation direction matrix of the axis of rotation; the superscript "×" is the symbol for finding the antisymmetric matrix of the cross product; let the Jacobian matrix be... The desired trajectory of the end effector in the workspace can then be converted into the desired trajectory of each robot joint angle in the joint space. The joint angular velocity command in the joint space is: In the formula, the superscript "+" indicates the symbol for finding the pseudo-inverse of the matrix. Let be the positive definite symmetric matrix to be selected.

[0026] Preferably, step 4 includes:

[0027] Define the desired positions and angular velocities of the two robotic arm end effectors relative to the platform as follows: and The control law for the force control loop can then be designed as follows: In the formula, and The desired contact force and torque at the end effector of the robotic arm are described in the context of the end effector system, f. h and τ h The measured values ​​of contact force and torque are described under the end effector system; and The desired velocity and angular velocity of the robotic arm end effector under force control are described in the end effector system; K is the control gain matrix, and the subscript t indicates translation and o indicates rotation;

[0028] When the contact force is less than the desired value, the above control law will cause the end of the robotic arm to move in the contact direction, thereby increasing the contact force and gradually making it equal to the desired value;

[0029] The motion controller for the robotic arm used with the force controller can be designed as follows: In the formula, b P h and b ω h K represents the actual position and angular velocity of the end effectors of the two robotic arms relative to the platform. Dp K Pp K Do and K Po All are control gain matrices; The attitude error is defined by the following formula: In the formula, b x h , b y h and bz h The coordinate transformation matrix of the end effector system of the two robotic arms relative to the platform system. b R h The amount; and The desired coordinate transformation matrix of the end effector system of the two robotic arms relative to the platform system. The components, specifically the relationship is: [ b x h b y h b z h ]= b R h ,

[0030] The acceleration and angular acceleration of the end effector relative to the platform are obtained by redundancy decomposition of the acceleration stages to obtain the joint angular acceleration. for: In the formula, J m Let be the geometric Jacobian matrix of the robotic arm.

[0031] Based on the dynamic equations of the dual-arm space robot system derived in step 2, when considering the contact force and contact torque at the end of the robotic arm, the dynamic model of the robotic arm with a fixed base can be written as: The control torque command for the robotic arm joints can be obtained using the inverse dynamics control method of the robotic arm: In the formula,

[0032] Preferably, step 5 includes: based on the system kinematics and dynamics model established in step 2, using the autonomous trajectory planning algorithm and adhesion capture controller designed in steps 3 and 4, simulating a space debris removal task in aerospace engineering applications, and completing a closed-loop numerical simulation of the process of a dual-arm space robot capturing a six-degree-of-freedom single rigid body target; by analyzing the closed-loop simulation results, if the capture position and attitude errors of the two robotic arms can converge to near zero, it proves that the designed adhesion capture control is effective.

[0033] The beneficial effects of this invention include:

[0034] 1. The capture method of the present invention cleverly applies the ball-stopping technology of ball-receiving force to the capture control of the robotic arm, and designs an adhesion process before formal capture, so that the end effector moves with the target in a small range, avoiding direct capture that would cause the target to escape.

[0035] 2. The capture method of the present invention combines adhesion with an improved adaptive impedance control method, which effectively improves the compliant control performance of the dual-arm space robot in capturing debris targets and avoids contact force saturation and damage to the end of the robotic arm.

[0036] 3. To verify the adhesion effect, the capture method of the present invention provides the adhesion threshold condition for starting the adhesion process, and verifies its effectiveness through multiple sets of comparative numerical simulations. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the embodiments will be briefly described below. Referring to the accompanying drawings will provide a clearer understanding of the features and advantages of the present invention. The drawings are illustrative and should not be construed as limiting the present invention in any way. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort. Wherein:

[0038] Figure 1 This is a flowchart of the method of the present invention;

[0039] Figure 2 This is a schematic diagram of a dual-arm space robot capturing a target;

[0040] Figure 3 It is the technique of stopping the shuttlecock in badminton.

[0041] Figure 4 It is a dual-arm space robot adhesive capture method

[0042] Figure 5 This is a diagram of a coordinate system.

[0043] Figure 6 This is a block diagram of contact force control in adhesive capture.

[0044] Figure 7 It is the movement state of the arms adhering to and capturing the target.

[0045] Figure 8 The first robotic arm's grasping posture error

[0046] Figure 9 It is the grasping posture error of the second robotic arm.

[0047] Figure 10 It is the contact force and contact torque acting on the end effector of the first robotic arm.

[0048] Figure 11 It is the contact force and contact torque acting on the end effector of the second robotic arm.

[0049] Figure 12 The first robotic arm's joint angles and joint angular velocities

[0050] Figure 13 The joint angles and joint angular velocities of the second robotic arm

[0051] Figure 14 Comparison of the grasping error of the first robotic arm with and without adhesion

[0052] Figure 15 Comparison of the grasping error of the second robotic arm with and without adhesion

[0053] Explanation of reference numerals in the attached figures:

[0054] 1- Dual-arm space robot platform; 2- First robotic arm; 3- Second robotic arm; 4- End effector of the first robotic arm; 5- End effector of the second robotic arm; 6- First capture point; 7- Second capture point; 8- Target. Detailed Implementation

[0055] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0056] The technical solution of this invention is: a dual-arm spatial robot adhesive capture control method. Inspired by the technical principles of ball-stopping techniques in badminton, the concept of adhesion is proposed, a novel dual-arm spatial robot adhesive capture control method is designed, and the controller design for adhesive capture is completed. The method is applicable to any dual-arm spatial robot capture system, which includes a dual-arm spatial robot platform, two spatial robotic arms and their end effectors. The spatial robotic arms are used for transmission, and the end effectors are used for capturing the target 8. To achieve the above objective, the method of this invention includes the following steps: Step 1: Proposing the concept of adhesion and designing a dual-arm spatial robot adhesive capture method; Step 2: Establishing a coordinate system and completing the dynamic modeling of the dual-arm spatial robot; Step 3: Designing an autonomous path planning algorithm for adhesive capture; Step 4: Completing the controller design for adhesive capture using a contact force control strategy; Step 5: Verifying the effectiveness of the dual-arm spatial robot adhesive capture through closed-loop numerical simulation.

[0057] The concept of adhesion in step one is inspired by badminton's ball-stopping technique. The key to ball-stopping is to receive the ball and slow its impact; specifically, when a ball comes towards you, the racket needs to move alongside the ball for a short distance before slowly contacting the ball with the racket face, thus stopping the ball steadily on the racket face. During this stopping process, the racket and ball need to maintain consistent movement to avoid directly contacting the ball and sending it flying. This invention defines this process of the racket moving alongside the ball for a short distance as adhesion.

[0058] In step two, both the dual-armed space robot and the target debris are treated as rigid bodies, and a volume coordinate system, a joint reference system, and a capture system are established. Based on the established coordinate system, the concepts of homogeneous transformation matrix and spatial velocity are introduced to derive the open-chain kinematic equations of the dual-armed space robot. Simultaneously, the Kane equations are used to establish the dynamic equations of the dual-armed space robot and the target, laying the foundation for trajectory planning and control in subsequent robot adhesion and capture operations.

[0059] In step three, it is assumed that the camera coordinate system in each robotic arm coincides with the end effector system of the robotic arm. Then, the relative pose information between the end effector of the robotic arm and the target capture point is given from a kinematic perspective. Then, the desired motion trajectory in the workspace of each robotic arm is planned in real time online using a position-based visual servoing method, thus completing the autonomous path planning for the dual-arm space robot to capture moving targets.

[0060] In step four, under the adhesive effect, each robotic arm's end effector maintains a small contact force with the target, ensuring it remains close to the target. This means the end effector moves slightly with the target, thus avoiding excessive contact force and preventing contact force saturation during capture. Furthermore, considering the uncertainties of the capture environment, adhesion is combined with improved adaptive impedance control to achieve adhesive capture operations for the dual-arm space robot, preventing accidental damage.

[0061] In step five, a dual-arm space robot is used to capture the moving target, realizing the entire process from trajectory planning, approach, adhesion to capture. The effectiveness of the dual-arm adhesion capture method is verified by comparative numerical simulation.

[0062] The specific solution of the present invention is described below. A dual-arm spatial robot adhesion and capture control method, inspired by the technical principles of ball-stopping techniques in badminton, proposes the concept of adhesion, designs a novel dual-arm spatial robot adhesion and capture control method, and completes the controller design for adhesion and capture. The method is applicable to any dual-arm spatial robot capture system, which includes a dual-arm spatial robot platform (1), two spatial robotic arms, and their end effectors. The adhesion and capture control method includes the following steps:

[0063] Step 1: Propose the concept of adhesion and design an adhesion and capture method for a dual-arm space robot.

[0064] The key to stopping a shuttlecock in badminton is to use a gentle, reactive approach. When a shuttlecock arrives at high speed with spin, if the racket travels a short distance with the shuttlecock before slowly contacting it with the racket face, the shuttlecock will stop smoothly on the racket face. Inspired by this, the process of a robotic arm's end effector accompanying the target for a period of time before grasping it is defined as adhesion. The adhesive grasping method of a dual-arm space robot can be designed by using a controller to maintain a small, autonomously adjustable contact force between the end effector of each robotic arm and the target, ensuring that the end effector remains near its corresponding contact point with the target. Under the effect of adhesion, the relative motion between the end effector of each robotic arm and the target is small. Therefore, the maximum contact force and contact torque generated when the end effector grasps the target are also relatively small, effectively avoiding contact force saturation and damage to the end effector.

[0065] Step 2: Establish a coordinate system and complete the dynamic modeling of the dual-arm space robot.

[0066] Suppose that the i-th (i = 1, 2) robotic arm in a dual-arm space robot has n... i There are (i = 1, 2) arms, connected by single-degree-of-freedom rotary joints. The established coordinate system is shown below: The platform system of the dual-arm space robot is Σ. b Its origin is located at the center of mass of the space robot's platform; the target frame is Σ. t Its origin is located at the target's center of mass; the rod coordinate system Σ i,j The origin is located on the rotation axis of the j-th joint of the i-th robotic arm, and is fixed to the j-th arm link; the link reference coordinate system The origin is located on the rotation axis of the j-th joint of the i-th robotic arm, and the coordinate system is... With Σ i,j The z-axis is always aligned with the rotational joint axis Γ. i,j The direction is parallel; the end effector system Σ hi The origin is located at the nth position of the i-th robotic arm. i The end of the root rod is used to describe the operational task; the capture point system The origin is located at the i-th capture point on the target. When the i-th robotic arm completes the capture, Σ hi With Σ hi* Coincident; Inertial coordinate system Σ I The origin is located at the center of the Earth, the z-axis points to the North Pole along the Earth's polar axis, the x-axis points to the vernal equinox, and the y-axis forms a right-handed coordinate system with the x and z axes.

[0067] Introducing the homogeneous transformation matrix A T B Its meaning is: the homogeneous transformation matrix of coordinate system B relative to coordinate system A, let... A r B and AR B Let B be the position vector matrix and the coordinate transformation matrix relative to coordinate system A, respectively. Then, the homogeneous transformation matrix between the two coordinate systems is... A T B It can be represented as: The forward kinematic equations of a dual-arm space robot, i.e., the end effector system Σ, can be solved using the homogeneous transformation matrix. hi Relative platform system Σ b The pose can be obtained using the homogeneous transformation matrix. in, b T hi For end effector system Σ hi Relative platform system Σ b The coordinate transformation matrix, b T i,1 For the rod coordinate system Σ i,1 Relative platform system Σ b The coordinate transformation matrix, i,(j-1) T i,j For the rod coordinate system Σ i,j Relative rod coordinate system Σ i,j-1 The coordinate transformation matrix, For end effector system Σ hi Relative rod coordinate system The coordinate transformation matrix.

[0068] The dynamic equations of the two-armed space robot can be derived using the Kane equations. Where M b With M m M represents the generalized mass array of the platform and the two robotic arms, respectively. bm V represents the coupling mass matrix of the platform and the two robotic arms. b For the platform's relative inertial frame Σ I The linear velocity and angular velocity are projected onto the platform system Σ b middle; c represents the joint angular velocity of the two robotic arms. b With c m These represent the nonlinear generalized inertial forces corresponding to the platform and the two robotic arms, respectively; F b External forces affecting the platform system b The resulting spatial force is projected onto Σ b In the middle; τ represents the joint torque of the two robotic arms; J b With J m The Jacobian matrices for the platform and the robotic arm are respectively; F h Let be the contact force / torque acting on the ends of the two robotic arms, projected onto the end effector system. Similarly, the dynamic equations of the target to be captured can be obtained as follows: Where M t A generalized mass matrix with the objective of V;t For the target relative inertial frame Σ I The linear velocity and angular velocity are projected onto the target system Σ. t c t Nonlinear generalized inertial force with the target in mind; The generalized Jacobian matrix with the objective as the target.

[0069] Step 3: Design an autonomous path planning algorithm for adhesive capture.

[0070] Because the dual-arm space robot and the target are moving in real time, the capture point system... In the platform system b The target's position and orientation are constantly changing. At this time, it is necessary to use a hand-eye camera to capture the target's capture point in real time, and then use a sensor to measure the relative pose information between the target and the camera.

[0071] First, by calculating the kinematic relationships of the dual-arm space robot, the relative pose information between the end effector of each arm and the target grasping point is obtained. Let the target frame be Σ. t The end effector system relative to the i-th robotic arm hi The position and attitude are respectively hi p t and hi R t Assuming that the center of the camera in each robotic arm coincides with the origin of its end effector system, then we can obtain... hi p t =( I R hi ) T ( I p t - I p hi ), hi R t =( I R hi ) TI R t ,in I p t and I R t Σ t Relative inertial frame Σ I The position vector and coordinate transformation matrix, I p hi and I R hi Σ hi Relative Σ I The position vector matrix and coordinate transformation matrix. According to the definition of a homogeneous transformation matrix, the target system Σ can be obtained. t Relative end effector system Σ hi homogeneous transformation matrixhi T t for: On the other hand, since the pose of the capture point on the target is fixed, the capture point system Σ hi* Relative target frame Σ t homogeneous transformation matrix t T hi* It is a constant matrix. Therefore, the i-th end effector of the robotic arm is Σ. hi Its corresponding capture point system Σ hi* The homogeneous transformation matrix between them is: hi T hi* = hi T tt T hi* .

[0072] Then, using the relative pose information between the robotic arm's end effector and the target grasping point, a visual servoing method can be selected to complete the trajectory planning of the robotic arm in the workspace, laying the foundation for the subsequent design of the adhesive grasping controller. The grasping pose error of the i-th robotic arm end effector is defined. for in hi p hi* and hi θ hi* These represent the position and attitude angle of the target capture point relative to the end effector of the robotic arm. Based on the kinematics of the robotic arm, combined with... hi p hi* and hi θ hi* From the rate of change, the time derivative of the expected capture pose error of the end effector in the workspace can be obtained as: in hi R b For platform system Σ b Relative Σ hi The coordinate transformation matrix; E3 is a 3×3 identity matrix; 0 3×3 It is a 3×3 zero matrix; Let be the Jacobian matrix of the i-th robotic arm; Let T be the joint angular velocity of the i-th robotic arm; hi θ hi* Let be the rotation direction matrix of the axis of rotation; the superscript "×" is the symbol for calculating the antisymmetric matrix of the cross product. Let the Jacobian matrix be... The desired trajectory of the end effector in the workspace can then be converted into the desired trajectory of each robot joint angle in the joint space. The joint angular velocity command in the joint space is: In the formula, the superscript "+" indicates the symbol for finding the pseudo-inverse of the matrix. Let be the positive definite symmetric matrix to be selected.

[0073] Step 4: Design the controller for adhesive capture using a contact force control strategy.

[0074] During the target capture process of a dual-arm space robot, the end effectors of both robotic arms come into contact with the capture points on the target, generating complex collision contact forces. Due to measurement and control errors, the contact force between the end effector and the target can be quite large, potentially leading to damage to the end effector or capture failure. To reduce the impact of physical contact between the end effector and the target on the capture phase, this invention incorporates an adhesion capture process in the early stages of capture. During adhesion, a relatively small contact force is maintained between the end effector and the target, ensuring the robotic arm end remains close to the target contact point. Under adhesion, the relative motion between the end effector and the target is minimal, resulting in relatively small maximum contact force and contact torque at the capture moment, preventing contact force saturation and end effector damage.

[0075] Define the desired positions and angular velocities of the two robotic arm end effectors relative to the platform as follows: and The control law for the force control loop can then be designed as follows: In the formula, and The desired contact force and torque at the end effector of the robotic arm are described in the context of the end effector system, f. h and τ h The measured values ​​of contact force and torque are described under the end effector system; and The desired velocity and angular velocity of the robotic arm's end effector under force control are described in the end effector system; K is the control gain matrix, with the subscript t indicating translation and o indicating rotation. When the contact force is less than the desired value, the above control law will cause the robotic arm's end effector to move in the contact direction, thereby increasing the contact force and gradually making it equal to the desired value.

[0076] The motion controller for the robotic arm used with the force controller can be designed as follows: In the formula, b P h and b ω h K represents the actual position and angular velocity of the end effectors of the two robotic arms relative to the platform. Dp K Pp K Do and K Po All are control gain matrices; The attitude error is defined by the following formula: In the formula, b x h , b y h and b zh The coordinate transformation matrix of the end effector system of the two robotic arms relative to the platform system. b R h The amount; and The desired coordinate transformation matrix of the end effector system of the two robotic arms relative to the platform system. The components, specifically the relationship is: [ b x h b y h b z h ]= b R h ,

[0077] The acceleration and angular acceleration of the end effector relative to the platform can be obtained by redundancy decomposition of the acceleration stages to obtain the joint angular acceleration. for: In the formula, J m Let be the geometric Jacobian matrix of the robotic arm.

[0078] Based on the dynamic equations of the dual-arm space robot system derived in the second step, when considering the contact force and contact torque at the end of the robotic arm, the dynamic model of the robotic arm with a fixed base can be written as: The control torque command for the robotic arm joints can be obtained using the inverse dynamics control method of the robotic arm: In the formula,

[0079] Step 5: Verify the effectiveness of the dual-arm space robot's adhesive capture mechanism through closed-loop numerical simulation. Based on the system kinematics and dynamics model established in Step 2, utilize the autonomous trajectory planning algorithm and adhesive capture controller designed in Steps 3 and 4 to simulate a space debris removal mission in aerospace engineering applications. Complete the closed-loop numerical simulation of the dual-arm space robot capturing a six-degree-of-freedom single rigid body target. Analysis of the closed-loop simulation results shows that if the capture position and attitude errors of both robotic arms converge to near zero, the designed adhesive capture control is effective.

[0080] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other. Many specific details are set forth in the following description to provide a thorough understanding of the present invention; however, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0081] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0082] The flowchart of the method of the present invention is as follows: Figure 1 As shown, specifically, the adhesive capture control method includes the following steps:

[0083] Step 1: Propose the concept of adhesion and design an adhesion and capture method for a dual-arm space robot.

[0084] A schematic diagram of the dual-arm space robot capturing the target in this invention is shown below. Figure 2 As shown, the dual-arm space robot consists of a spacecraft platform and two space robotic arms. Each robotic arm is equipped with an end effector at its end, enabling it to capture a target. The target to be captured can be considered as a single rigid body with six degrees of freedom, and there are two capture points on the target.

[0085] The adhesion concept proposed in this invention originates from the ball-stopping technique in badminton, and its key technique is to absorb the force of the incoming ball, such as... Figure 3 As shown. When a badminton shuttlecock flies towards you at high speed with spin, directly contacting the shuttlecock with the racket can cause it to bounce away. However, if the racket first moves with the shuttlecock a short distance before slowly contacting it with the racket face, i.e., using a buffering motion, the shuttlecock can be brought to a stable stop on the racket face. Inspired by this, this invention defines the process of the robotic arm's end effector moving with the target for a period of time before grasping it as adhesion. Figure 4 As shown, the adhesive grasping method of the dual-arm space robot designed in this invention maintains a small contact force between the end effector of each robotic arm and the target through controller design, ensuring that the end effector of each robotic arm remains close to the contact point with the target. Under the effect of adhesion, the relative motion between the end effector of each robotic arm and the target is small. Therefore, the maximum contact force and contact torque generated when the end effector performs grasping are also relatively small, effectively avoiding contact force saturation and preventing damage to the end effector.

[0086] Step 2: Establish a coordinate system and complete the dynamic modeling of the dual-arm space robot.

[0087] Suppose that the i-th (i = 1, 2) robotic arm in a dual-arm space robot has n... i There are (i = 1, 2) arms, connected by single-degree-of-freedom rotary joints. The coordinate system established in this invention is as follows: Figure 5 As shown, the platform system of the dual-arm space robot is Σ. b Its origin is located at the center of mass of the space robot's platform; the target frame is Σ. t Its origin is located at the target's center of mass; the rod coordinate system Σ i,jThe origin is located on the rotation axis of the j-th joint of the i-th robotic arm, and is fixed to the j-th arm link; the link reference coordinate system The origin is located on the rotation axis of the j-th joint of the i-th robotic arm, and the coordinate system is... With Σ i,j The z-axis is always aligned with the rotational joint axis Γ. i,j The direction is parallel; the end effector system Σ hi The origin is located at the nth position of the i-th robotic arm. i The end of the root rod is used to describe the operational task; the capture point system The origin is located at the i-th capture point on the target. When the i-th robotic arm completes the capture, Σ hi With Σ hi* Coincident; Inertial coordinate system Σ I The origin is located at the center of the Earth, the z-axis points to the North Pole along the Earth's polar axis, the x-axis points to the vernal equinox, and the y-axis forms a right-handed coordinate system with the x and z axes.

[0088] Introducing the homogeneous transformation matrix A T B Its meaning is: the homogeneous transformation matrix of coordinate system B relative to coordinate system A, let... A r B and A R B Let B be the position vector matrix and the coordinate transformation matrix relative to coordinate system A, respectively. Then, the homogeneous transformation matrix between the two coordinate systems is... A T B It can be represented as: The forward kinematic equations of a dual-arm space robot, i.e., the end effector system Σ, can be solved using the homogeneous transformation matrix. hi Relative platform system Σ b The pose can be obtained using the homogeneous transformation matrix. in, b T hi For end effector system Σ hi Relative platform system Σ b The coordinate transformation matrix, b T i,1 For the rod coordinate system Σ i,1 Relative platform system Σ b The coordinate transformation matrix, i,(j-1) T i,j For the rod coordinate system Σ i,j Relative rod coordinate system Σ i,j-1 The coordinate transformation matrix, For end effector system Σ hi Relative rod coordinate system The coordinate transformation matrix.

[0089] The dynamic equations of the two-armed space robot can be derived using the Kane equations. Where M b With M m M represents the generalized mass array of the platform and the two robotic arms, respectively. bm V represents the coupling mass matrix of the platform and the two robotic arms. b For the platform's relative inertial frame Σ I The linear velocity and angular velocity are projected onto the platform system Σ b middle; c represents the joint angular velocity of the two robotic arms. b With c m These represent the nonlinear generalized inertial forces corresponding to the platform and the two robotic arms, respectively; F b External forces affecting the platform system b The resulting spatial force is projected onto Σ b In the middle; τ represents the joint torque of the two robotic arms; J b With J m The Jacobian matrices for the platform and the robotic arm are respectively; F h Let be the contact force / torque acting on the ends of the two robotic arms, projected onto the end effector system. Similarly, the dynamic equations of the target to be captured can be obtained as follows: Where M t A generalized mass matrix with the objective of V; t For the target relative inertial frame Σ I The linear velocity and angular velocity are projected onto the target system Σ. t c t Nonlinear generalized inertial force with the target in mind; The generalized Jacobian matrix with the objective as the target.

[0090] Step 3: Design an autonomous path planning algorithm for adhesive capture.

[0091] Because the dual-armed space robot and the target are moving in real time, the capture point system Σ hi* In the platform system b The target's position and orientation are constantly changing. At this time, it is necessary to use a hand-eye camera to capture the target's capture point in real time, and then use a sensor to measure the relative pose information between the target and the camera.

[0092] First, by calculating the kinematic relationships of the dual-arm space robot, the relative pose information between the end effector of each arm and the target grasping point is obtained. Let the target frame be Σ. t The end effector system relative to the i-th robotic arm hi The position and attitude are respectively hi p t and hi R tAssuming that the center of the camera in each robotic arm coincides with the origin of its end effector system, then we can obtain... hi p t =( I R hi ) T ( I p t - I p hi ), hi R t =( I R hi ) TI R t ,in I p t and I R t Σ t Relative inertial frame Σ I The position vector and coordinate transformation matrix, I p hi and I R hi Σ hi Relative Σ I The position vector matrix and coordinate transformation matrix. According to the definition of a homogeneous transformation matrix, the target system Σ can be obtained. t Relative end effector system Σ hi homogeneous transformation matrix hi T t for: On the other hand, since the pose of the capture point on the target is fixed, the capture point system Σ hi* Relative target frame Σ t homogeneous transformation matrix t T hi* It is a constant matrix. Therefore, the i-th end effector of the robotic arm is Σ. hi Its corresponding capture point system Σ hi* The homogeneous transformation matrix between them is: hi T hi* = hi T tt T hi* .

[0093] Then, using the relative pose information between the robotic arm's end effector and the target grasping point, a visual servoing method can be selected to complete the trajectory planning of the robotic arm in the workspace, laying the foundation for the subsequent design of the adhesive grasping controller. The grasping pose error of the i-th robotic arm end effector is defined. for in hi p hi* and hi θ hi*These represent the position and attitude angle of the target capture point relative to the end effector of the robotic arm. Based on the kinematics of the robotic arm, combined with... hi p hi* and hi θ hi* From the rate of change, the time derivative of the expected capture pose error of the end effector in the workspace can be obtained as: in hi R b For platform system Σ b Relative Σ hi The coordinate transformation matrix; E3 is a 3×3 identity matrix; 0 3×3 It is a 3×3 zero matrix; Let be the Jacobian matrix of the i-th robotic arm; Let T be the joint angular velocity of the i-th robotic arm; hi θ hi* Let be the rotation direction matrix of the axis of rotation; the superscript "×" is the symbol for calculating the antisymmetric matrix of the cross product. Let the Jacobian matrix be... The desired trajectory of the end effector in the workspace can then be converted into the desired trajectory of each robot joint angle in the joint space. The joint angular velocity command in the joint space is: In the formula, the superscript "+" indicates the symbol for finding the pseudo-inverse of the matrix. Let be the positive definite symmetric matrix to be selected.

[0094] Step 4: Design the controller for adhesive capture using a contact force control strategy.

[0095] During the target capture process of a dual-arm space robot, the end effectors of both robotic arms come into contact with the capture points on the target, generating complex collision contact forces. Due to measurement and control errors, the contact force between the end effector and the target can be quite large, potentially leading to damage to the end effector or capture failure. To reduce the impact of physical contact between the end effector and the target on the capture phase, this invention adds an adhesion capture process in the early stages of capture. During adhesion, a relatively small contact force is maintained between the end effector and the target, ensuring that the end of the robotic arm remains close to the target contact point. Under adhesion, the relative motion between the end effector and the target is small, resulting in relatively small maximum contact force and contact torque at the capture moment, preventing contact force saturation and end effector damage. A controller for the adhesion capture process is designed using a contact force control method, and the control block diagram is shown below. Figure 6 As shown.

[0096] Define the desired positions and angular velocities of the two robotic arm end effectors relative to the platform as follows: and The control law for the force control loop can then be designed as follows: In the formula, and The desired contact force and torque at the end effector of the robotic arm are described in the context of the end effector system, f. h and τ h The measured values ​​of contact force and torque are described under the end effector system; and The desired velocity and angular velocity of the robotic arm's end effector under force control are described in the end effector system; K is the control gain matrix, with the subscript t indicating translation and o indicating rotation. When the contact force is less than the desired value, the above control law will cause the robotic arm's end effector to move in the contact direction, thereby increasing the contact force and gradually making it equal to the desired value.

[0097] The motion controller for the robotic arm used with the force controller can be designed as follows: In the formula, b P h and b ω h K represents the actual position and angular velocity of the end effectors of the two robotic arms relative to the platform. Dp K Pp K Do and K Po All are control gain matrices; The attitude error is defined by the following formula: In the formula, b x h , b y h and b z h The coordinate transformation matrix of the end effector system of the two robotic arms relative to the platform system. b R h The amount; and The desired coordinate transformation matrix of the end effector system of the two robotic arms relative to the platform system. The components, specifically the relationship is: [ b x h b y h b z h ]= b R h ,

[0098] The acceleration and angular acceleration of the end effector relative to the platform can be obtained by redundancy decomposition of the acceleration stages to obtain the joint angular acceleration. for: In the formula, J m Let be the geometric Jacobian matrix of the robotic arm.

[0099] Based on the dynamic equations of the dual-arm space robot system derived in step 2, when considering the contact force and contact torque at the end of the robotic arm, the dynamic model of the robotic arm with a fixed base can be written as: The control torque command for the robotic arm joints can be obtained using the inverse dynamics control method of the robotic arm: In the formula,

[0100] Step 5: Verify the effectiveness of the dual-arm space robot's adhesive capture through closed-loop numerical simulation.

[0101] Based on the system kinematics and dynamics model established in step 2, and utilizing the autonomous trajectory planning algorithm and adhesion capture controller designed in steps 3 and 4, a space debris removal mission in aerospace engineering applications is simulated. Closed-loop numerical simulation is performed on the process of a dual-arm space robot capturing a six-degree-of-freedom single rigid body target. Analysis of the closed-loop simulation results shows that if the capture position and attitude errors of both robotic arms converge to near zero, the designed adhesion capture control is effective.

[0102] To facilitate understanding of the above technical solutions of the present invention, the following detailed description of the above technical solutions of the present invention is provided through specific embodiments.

[0103] Example

[0104] Taking a free-floating dual-arm space robot system and a six-degree-of-freedom motion target as the research object, the method of the present invention is analyzed to verify the effectiveness of the method.

[0105] The platform of the dual-arm space robot system is a cube with a side length of 2m, a mass of 3000kg, and a rotational inertia of 2000kg·m for each of its three axes. 2 Without considering center of mass deviation, both robotic arms are equipped with 7 arms, each of which can be considered as a cylindrical, homogeneous, solid rod.

[0106] In step two, the two robotic arms have the same structure and mass parameters, as shown in Table 1. The two robotic arms are mounted on the +z plane of the platform, along the Σ... b Symmetric along the x-axis, its root installation positions are [-1 0.85 1]. T m and [-1 -0.85 1] T m. The geometric and mass characteristics of the target star are consistent with the platform of the dual-arm space robot system. The two capture points on the target are located at Σ. t The position in the middle is set to [0 0.6 -1]. T m and [0 -0.6 -1] T m.

[0107] Table 1 Structural and mass characteristic parameters of each robotic arm

[0108]

[0109] In step three, the control gain matrix to be determined can be selected as follows:

[0110] In step four, the desired contact force and contact torque at the robotic arm's end effector are selected as 5 N and 0 Nm, respectively. The threshold values ​​for the adhesion and grasping phases are defined as σ... i (i=1,2) and η i (i = 1, 2). When the grasping pose error of the i-th robotic arm's end effector is... satisfy At that time, the system autonomously switches to the adhesion stage; when satisfy At this point, the system ends the adhesion phase and begins the capture process. The initial system state during the capture phase is the final system state value from the adhesion phase. The adhesion threshold and the capture threshold are selected as σ... i =[0.1 0.1 0.1 5 5 5] T (i=1,2) and η i =[0.03 0.03 0.03 1 1 1] T (i = 1, 2).

[0111] The motion process of a dual-arm space robot adhering to and capturing a moving target was obtained through closed-loop numerical simulation in Matlab, such as... Figure 7 As shown in the figure, the dual-arm space robot system was close to the target capture point at t=8.4s and began adhesion. Adhesion ended at t=17s, and capture began. Both robotic arms successfully captured the target at both capture points, and the target did not escape. The position and attitude errors of the two robotic arms during capture are shown in the figure. Figure 8 and Figure 9 As shown, the grasping posture error of both robotic arms converges to near zero within 20 seconds, verifying that both robotic arms can successfully capture the target. The contact force and contact torque at the ends of the two robotic arms are respectively as follows: Figure 10 and Figure 11 As shown, during the adhesion phase, the end effector experiences relatively small contact forces and torques. At this time, the distance between the end effector and the target contact point is close, and the relative motion is small. Therefore, the maximum contact force and contact torque at the moment of grasping are relatively small, avoiding the risk of contact force saturation and damage to the robotic arm's end effector. The joint angles and joint angular velocities of the two robotic arms are as follows: Figure 12 and Figure 13As shown, both are within reasonable ranges, and no unusual problems with the robotic arms were observed. To verify the impact of the adhesion process on the target capture of the dual-arm space robot, a set of simulation experiments in which adhesion was not considered in the capture control were selected as a control group. The comparison results of the capture position and attitude errors of the two robotic arms are shown below. Figure 14 and Figure 15 As shown in the figure, considering adhesion can significantly reduce the grasping error of the robotic arm, thus verifying the superiority of the designed adhesive grasping control.

[0112] In summary, the adhesive capture control method for a dual-arm space robot of this invention utilizes an adhesive contact force control strategy before the two robotic arms formally capture a moving target. This strategy maintains a relatively small contact force between the end effector and the target, ensuring the end effector remains close to the target contact point. Capture is then initiated when the relative motion between the robotic arm and the target is minimal. This method avoids the risk of target escape and effectively improves the compliant control performance of the dual-arm space robot in capturing debris targets, preventing contact force saturation and damage to the end effector. It has significant theoretical research value and engineering application value for my country's space debris removal missions, reducing the threat of debris impacts to spacecraft in orbit and improving the safety of the space environment.

[0113] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A method for adhesive grasping control of a dual-arm space robot, characterized in that, The dual-arm space robot adhesion and capture control method is used in a dual-arm space robot system, which includes a dual-arm space robot platform (1), a first space manipulator (2) and its end effector (4), a second space manipulator (3) and its end effector (5). The dual-arm space robot adhesion and capture control method includes the following steps: Step 1: Design an adhesive capture method for a dual-arm space robot; the adhesive refers to the process of moving the end effector of the robotic arm with the target for a period of time before capturing it. Step 2: Establish a coordinate system and complete the dynamic modeling of the dual-arm space robot; Step 3, designing an autonomous path planning algorithm for adhesive capture; Step 3 includes: Step 31: Calculate the kinematic relationship of the dual-arm space robot to obtain the relative pose information between the end effector of each robotic arm and the target capture point; Step 32: Using the relative pose information between the end effector of the robotic arm and the target capture point, a visual servoing method is selected to complete the trajectory planning of the robotic arm in the workspace. Step 4: Design the controller for adhesive capture using a contact force control strategy; Step 4 includes: Define the desired positions and angular velocities of the two robotic arm end effectors relative to the platform as follows: and The control law design for the force control loop is as follows: In the formula, and The desired contact force and torque at the end effector of the robotic arm are described in the context of the end effector system, f. h and τ h The measured values ​​of contact force and torque are described under the end effector system; and The desired velocity and angular velocity of the robotic arm end effector under force control are described in the end effector system; K is the control gain matrix, and the subscript t indicates translation and o indicates rotation; When the contact force is less than the desired value, the above control law will cause the end of the robotic arm to move in the contact direction, thereby increasing the contact force and gradually making it equal to the desired value; The motion controller for the robotic arm used in the force controller is designed as follows: In the formula, b P h and b ω h The actual position and angular velocity of the end effectors of the two robotic arms relative to the platform; K Do and K Po All are control gain matrices; The attitude error is defined by the following formula: In the formula, b x h , b y h and b z h The coordinate transformation matrix of the end effector system of the two robotic arms relative to the platform system. b R h The amount; and The desired coordinate transformation matrix of the end effector system of the two robotic arms relative to the platform system. The components, specifically the relationship is: The acceleration and angular acceleration of the end effector relative to the platform are obtained by redundancy decomposition of the acceleration stages to obtain the joint angular acceleration. for: In the formula, J m Let be the geometric Jacobian matrix of the robotic arm. Based on the dynamic equations of the dual-arm space robot system derived in step 2, when considering the contact force and contact torque at the end of the robotic arm, the dynamic model of the robotic arm with a fixed base can be written as follows: The joint control torque command of the robotic arm is obtained by using the inverse dynamics control method of the robotic arm: In the formula, Step 5: Closed-loop numerical simulation to verify the effectiveness of dual-arm adhesive capture.

2. The adhesive grasping control method for a dual-arm space robot according to claim 1, characterized in that, In step 1, the dual-arm space robot adhesion and capture method includes: by driving each joint of the robotic arm, the end effector of each robotic arm maintains a small contact force that is autonomously adjusted with the target, thereby keeping the end effector near its corresponding target contact point.

3. The adhesive grasping control method for a dual-arm space robot according to claim 1, characterized in that, In step 2, let the i-th (i = 1, 2) robotic arm in the dual-arm space robot have n... i There are (i = 1, 2) arms, which are connected by single-degree-of-freedom rotary joints; Establish a coordinate system: The platform system of the dual-arm space robot is Σ. b Its origin is located at the center of mass of the space robot's platform; the target frame is ∑ t Its origin is located at the target's center of mass; the rod coordinate system ∑ i,j The origin is located on the rotation axis of the j-th joint of the i-th robotic arm, and is fixed to the j-th arm link; the link reference coordinate system The origin is located on the rotation axis of the j-th joint of the i-th robotic arm, and the coordinate system is... With ∑ i,j The z-axis is always aligned with the rotational joint axis Γ. i,j The direction is parallel; the end effector system ∑ hi The origin is located at the nth position of the i-th robotic arm. i The end of the root rod is used to describe the operational task; the capture point system The origin is located at the i-th capture point on the target. When the i-th robotic arm completes the capture, ∑ hi With Σ hi* Coincident; Inertial coordinate system Σ I The origin is located at the center of the Earth, the z-axis points to the North Pole along the Earth's polar axis, the x-axis points to the vernal equinox, and the y-axis forms a right-handed coordinate system with the x and z axes; Introducing the homogeneous transformation matrix A T B Its meaning is: the homogeneous transformation matrix of coordinate system B relative to coordinate system A, let... A r B and A R B Let B be the position vector matrix and the coordinate transformation matrix relative to coordinate system A, respectively. Then, the homogeneous transformation matrix between the two coordinate systems is... A T B Represented as: In the formula 0 1×3 =[0 0 0]; Solve the forward kinematics equations of the dual-arm space robot using the homogeneous transformation matrix, i.e., the end effector system ∑ hi Relative platform system ∑ b The pose is obtained by solving the homogeneous transformation matrix. in, b T hi For end effector system Σ hi Relative platform system Σ b The coordinate transformation matrix, b T i,1 For the rod coordinate system ∑ i,1 Relative platform system ∑ b The coordinate transformation matrix, i,(j-1) T i,j For the rod coordinate system ∑ i,j Relative rod coordinate system ∑ i,j-1 The coordinate transformation matrix, For the end effector system ∑ hi Relative rod coordinate system The coordinate transformation matrix; The dynamic equations of the two-armed space robot are derived using the Kane equations. Where M b With M m M represents the generalized mass array of the platform and the two robotic arms, respectively. bm Let V be the coupling mass matrix of the platform and the two robotic arms, with the superscript "T" indicating the matrix transpose; b For the platform's relative inertial frame ∑ I The linear velocity and angular velocity are projected onto the platform system ∑ b middle; c represents the joint angular velocity of the two robotic arms. b With c m These represent the nonlinear generalized inertial forces corresponding to the platform and the two robotic arms, respectively; F b External forces affecting the platform system b The resulting spatial force is projected onto Σ b In the middle; τ represents the joint torque of the two robotic arms; J b With J m The Jacobian matrices for the platform and the robotic arm are respectively; F h The contact force / torque acting on the ends of the two robotic arms is projected onto the end effector system; similarly, the dynamic equation of the target to be captured is obtained as follows: Where M t A generalized mass matrix with the objective of V; t For the target relative inertial frame ∑ I The linear velocity and angular velocity, projected onto the target system ∑ t c t Nonlinear generalized inertial force with the target in mind; The generalized Jacobian matrix with the objective as the target.

4. The adhesive grasping control method for a dual-arm space robot according to claim 3, characterized in that, Step 31 includes: Let the target system ∑ t The end effector system relative to the i-th robotic arm ∑ hi The position and attitude are respectively hi p t and hi R t Assuming the center of the camera in each robotic arm coincides with the origin of its end effector system, we obtain... hi p t =( I R hi ) T ( I p t - I p hi ), hi R t =( I R hi ) TI R t ,in I p t and I R t ∑ t Relative inertial frame ∑ I The position vector and coordinate transformation matrix, I p hi and I R hi ∑ hi Relative ∑ I The position vector matrix and coordinate transformation matrix; according to the definition of the homogeneous transformation matrix, the target system ∑ t Relative end effector system ∑ hi homogeneous transformation matrix hi T t for: On the other hand, since the pose of the capture point on the target is fixed, the capture point system ∑ hi* Relative target system ∑ t homogeneous transformation matrix t T hi* It is a constant matrix; therefore, the system of the i-th end effector of the robotic arm is ∑ hi Its corresponding capture point system ∑ hi* The homogeneous transformation matrix between them is: hi T hi* = hi T tt T hi* .

5. The adhesive grasping control method for a dual-arm space robot according to claim 4, characterized in that, Step 32 includes: Define the grasping pose error of the i-th robotic arm end effector. for in hi p hi* and hi θ hi* These represent the position and attitude angle of the target capture point relative to the end effector of the robotic arm; based on the kinematic relationship of the robotic arm, combined with... hi p hi* and hi θ hi* The rate of change of is used to obtain the time derivative of the expected capture pose error of the end effector in the workspace: in hi R b For platform system ∑ b Relative ∑ hi The coordinate transformation matrix; E3 is a 3×3 identity matrix; 0 3×3 It is a 3×3 zero matrix; Let be the Jacobian matrix of the i-th robotic arm; Let T be the joint angular velocity of the i-th robotic arm; hi θ hi* Let be the rotation direction matrix of the axis of rotation; the superscript "×" is the symbol for finding the antisymmetric matrix of the cross product; let the Jacobian matrix be... The desired trajectory of the end effector in the workspace is then converted into the desired trajectory of each robot joint angle in the joint space. The joint angular velocity command in the joint space is: In the formula, the superscript "+" indicates the symbol for finding the pseudo-inverse of the matrix. Let be the positive definite symmetric matrix to be selected.

6. The adhesive grasping control method for a dual-arm space robot according to claim 5, characterized in that, Step 5 includes: based on the system kinematics and dynamics model established in step 2, using the autonomous trajectory planning algorithm and adhesion capture controller designed in steps 3 and 4, simulating a space debris removal task in aerospace engineering applications, and completing a closed-loop numerical simulation of the process of a dual-arm space robot capturing a six-degree-of-freedom single rigid body target; by analyzing the closed-loop simulation results, if the capture position and attitude errors of the two robotic arms can converge to near zero, it proves that the designed adhesion capture control is effective.

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