Suspension inflatable antenna attitude control method based on multi-robot arm cooperation

Abstract

The application discloses a suspension inflatable antenna posture control method based on multi-robot arm cooperation, relates to the technical fields of inflatable antennas and robot cooperative control, and comprises the following steps: according to related structural parameters of an inflatable antenna and a robot arm group, a related terminal coordinate system of each robot arm and an antenna coordinate system are constructed; based on the terminal coordinate system of each robot arm and the antenna coordinate system, whether the robot arm needs to relay and execute a task is judged according to a target posture required by the inflatable antenna, so as to confirm a motion track corresponding to the terminal of each robot arm; according to the motion track and a kinematic equation of the robot arm, a corresponding joint angle expression of the robot arm is obtained, so that each robot arm terminal is driven to run according to the corresponding motion track in sequence, and the posture of the current inflatable antenna is adjusted. The control method can effectively improve the dynamic response capability, so that the inflatable antenna can more accurately and reliably track a target.

Description

TECHNICAL FIELD

[0001] The present disclosure generally relates to the technical field of inflatable antennas and robot collaborative control, and particularly relates to a floating inflatable antenna posture control method based on multi-robot arm collaboration. BACKGROUND

[0002] To meet the growing needs of radio astronomy, the aperture of the antenna is getting larger and larger, the working frequency is getting higher and higher, and the structure of the antenna is becoming more and more complex. These factors make it more and more difficult to quickly deploy the antenna system. In this case, a floating inflatable antenna with a bottom support has been rapidly developed because it can quickly adjust the azimuth and elevation, has a simple structure, and is easy to deploy.

[0003] However, the existing floating inflatable antenna system is driven by a rope, which introduces the problem of flexible deformation of the rope in continuous rotation operation, resulting in increased hysteresis of movement, and thus reducing the overall control accuracy of the system.

[0004] Therefore, we propose a floating inflatable antenna posture control method based on multi-robot arm collaboration for the floating inflatable antenna system to improve its dynamic response capability, so as to ensure that the inflatable antenna can more accurately and reliably track the target. SUMMARY

[0005] In view of the above-mentioned defects or deficiencies in the prior art, it is desirable to provide a floating inflatable antenna posture control method based on multi-robot arm collaboration.

[0006] The present application provides a floating inflatable antenna posture control method based on multi-robot arm collaboration, comprising:

[0007] According to the related structure parameters of the inflatable antenna and the robot arm group, the associated robot arm end coordinate system and the antenna coordinate system are constructed; the robot arm group includes a plurality of robot arms arranged around the outside of the inflatable antenna, and the robot arms are used to perform the task of adjusting the posture of the inflatable antenna;

[0008] Based on each robot arm end coordinate system and the antenna coordinate system, according to the target posture required for adjusting the inflatable antenna, it is judged whether the robot arm needs to relay the task to confirm the motion trajectory corresponding to each robot arm end;

[0009] According to the kinematic equation of the motion trajectory and the robot arm, the corresponding robot arm joint angle expression is obtained, so that each robot arm end is driven to run according to the corresponding motion trajectory in turn, so as to adjust the posture of the current inflatable antenna.

[0010] According to the technical scheme provided in the application, according to the related structural parameters of the inflatable antenna and the mechanical arm group, the related mechanical arm end coordinate systems and the antenna coordinate system are constructed, specifically including:

[0011] A geodetic coordinate system is constructed with the geometric center of the bottom support of the inflatable antenna contacting the ground surface as the origin;

[0012] The antenna coordinate system is constructed with the spherical center of the inflatable antenna as the origin, and the first conversion matrix between the geodetic coordinate system and the antenna coordinate system is calibrated according to the related structural parameters of the inflatable antenna;

[0013] The second conversion matrix and the third conversion matrix between the mechanical arm and the geodetic coordinate system and the antenna coordinate system are calibrated through the position information of each adjacent two connection points after the mechanical arm ends are connected, so as to confirm the corresponding mechanical arm base coordinate system of each mechanical arm;

[0014] Based on the related structural parameters of the mechanical arm and the mechanical arm end, the fourth conversion matrix between each mechanical arm end and the corresponding mechanical arm base coordinate system is calculated to confirm the mechanical arm end coordinate system.

[0015] According to the technical scheme provided in the application, it is judged whether the mechanical arm needs to relay to perform a task to confirm the corresponding motion trajectory of each mechanical arm, specifically including:

[0016] Among the plurality of mechanical arms, one is selected as the main mechanical arm;

[0017] The target posture is decomposed to obtain a corresponding trajectory matrix, and based on the trajectory matrix, the related structural parameters of the inflatable antenna and the third conversion matrix, the target trajectory required for the main mechanical arm to move when adjusting the inflatable antenna to the target posture through single operation is calculated; the target trajectory is a pose matrix composed of a plurality of pose information;

[0018] According to the comparison between the target trajectory and the working range of the main mechanical arm, it is judged whether the mechanical arm needs to relay to perform a task, and a corresponding judgment result is generated;

[0019] Based on the judgment result, the corresponding motion trajectory of each mechanical arm end is confirmed.

[0020] According to the technical scheme provided in the application, the judgment result includes two cases of mechanical arm single operation and mechanical arm relay operation;

[0021] Based on the judgment result, the corresponding motion trajectory of each mechanical arm end is confirmed, specifically including:

[0022] When the judgment result is that the robotic arm runs in a single operation, the end effector of each robotic arm runs synchronously along the target trajectory.

[0023] When the judgment result indicates that the robotic arm is in relay operation, the target trajectory is decomposed into multiple motion trajectories within the working range corresponding to the ends of each robotic arm.

[0024] According to the technical solution provided in this application, the robotic arm group includes: four robotic arms, and two robotic arms that are spaced apart belong to the same control group;

[0025] When the judgment result indicates that the robotic arm is in relay operation, the target trajectory is decomposed into multiple motion trajectories within the working range corresponding to the ends of each robotic arm, specifically including:

[0026] Based on the working range of each robotic arm and the target trajectory, the target trajectory is divided into multiple segments and the running trajectories corresponding to the robotic arms of different control groups;

[0027] The ends of the robotic arms of the two control groups run according to their respective running trajectories, cooperating with each other to adjust the current attitude of the inflatable antenna.

[0028] According to the technical solution provided in this application, based on the motion trajectory and the kinematic equation of the robotic arm, the corresponding expression for the joint angle of the robotic arm is obtained, specifically including:

[0029] Based on the relevant structural parameters of the robotic arm, the fifth transformation matrix between the end effector of the robotic arm and the joint of the robotic arm is determined, so as to obtain the kinematic equation of the robotic arm;

[0030] Based on the running trajectory of each robotic arm and the kinematic equation of the robotic arm, the joint expression of the robotic arm is obtained.

[0031] According to the technical solution provided in this application, the inflatable antenna is equipped with an attitude sensor. After adjusting the current attitude of the inflatable antenna, the method further includes:

[0032] Based on the actual adjusted posture of the inflatable antenna and the target posture presented by the posture sensor, it is determined whether the inflatable antenna needs to be adjusted again.

[0033] If so, the difference between the actual adjusted posture and the target posture is taken as the new target posture, and the new target posture that needs to be adjusted according to the inflatable antenna is repeatedly executed to determine whether the robotic arm needs to take over the task, so as to confirm the motion trajectory corresponding to the end of each robotic arm.

[0034] According to the technical solution provided in this application, the end of the robotic arm is a suction cup actuator; when the suction cup actuator drives the inflatable antenna to move, it is tangent to and mutually attracted to the spherical outer surface of the inflatable antenna.

[0035] In summary, this technical solution specifically discloses a method for attitude control of a suspended inflatable antenna based on multi-robotic arm collaboration, comprising: constructing an associated coordinate system of each robotic arm end-effector and an antenna coordinate system based on the relevant structural parameters of the inflatable antenna and the robotic arm group; the robotic arm group includes multiple robotic arms arranged around the outside of the inflatable antenna, which are used to perform the task of adjusting the attitude of the inflatable antenna; based on the coordinate system of each robotic arm end-effector and the antenna coordinate system, determining whether the robotic arms need to relay the task according to the target attitude to be adjusted of the inflatable antenna, so as to confirm the motion trajectory corresponding to each robotic arm end-effector; and obtaining the expression of the corresponding robotic arm joint angle according to the motion trajectory and the kinematic equation of the robotic arm, thereby driving each robotic arm end-effector to run sequentially according to the corresponding motion trajectory to adjust the attitude of the current inflatable antenna.

[0036] Existing suspended inflatable antenna systems are driven by ropes, which introduces the problem of rope flexibility and deformation during continuous rotation, leading to increased motion lag and reduced overall control accuracy. This application addresses this by constructing an associated coordinate system between the robotic arm end effector and the antenna coordinate system, enabling precise adjustment of the inflatable antenna's attitude through the control of the robotic arm assembly. Furthermore, it proposes a collaborative control strategy involving relaying between the robotic arms, significantly improving motion accuracy and allowing for omnidirectional control of the suspended inflatable antenna sphere, greatly enhancing its application flexibility and practical value. Attached Figure Description

[0037] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0038] Figure 1 This is a flowchart illustrating the attitude control method for a suspended inflatable antenna based on multi-robotic arm collaboration.

[0039] Figure 2 This is a schematic diagram of the unfolding process of step S1 in the attitude control method for a suspended inflatable antenna based on multi-robotic arm collaboration.

[0040] Figure 3 This is a schematic diagram illustrating the unfolding process of step S2 in the attitude control method for a suspended inflatable antenna based on multi-robotic arm collaboration.

[0041] Figure 4 This is a schematic diagram illustrating the unfolding process of step S3 in the attitude control method for a suspended inflatable antenna based on multi-robotic arm collaboration.

[0042] Figure 5 This is a schematic diagram of the application system in the attitude control method of a suspended inflatable antenna based on multi-robotic arm collaboration.

[0043] Figure 6 This is a schematic diagram of the robotic arm connection conditions in an application system of a multi-robotic arm collaborative attitude control method for a suspended inflatable antenna.

[0044] Figure 7 This is a schematic diagram of the first type of cooperative control in the attitude control method of a suspended inflatable antenna based on multi-manipulator cooperation.

[0045] Figure 8 This is a schematic diagram of the second type of cooperative control in the attitude control method of a suspended inflatable antenna based on multi-manipulator cooperation.

[0046] The following are labeled in the diagram: 1. Inflatable antenna body; 2. Base; 3. Robotic arm; 4. Suction cup actuator; 5. Robotic arm base. Detailed Implementation

[0047] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0048] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0049] To make the technical solutions of the embodiments of this application clearer and easier to understand, the application background of the embodiments of this application is introduced below.

[0050] To meet the ever-evolving demands of radio astronomy, antenna apertures are becoming increasingly larger, operating frequencies are rising, and antenna structures are becoming more complex. These factors make rapid deployment of antenna systems increasingly difficult. In this context, a suspended inflatable antenna with a base has rapidly gained popularity due to its ability to quickly adjust azimuth and elevation, its simple structure, and its ease of deployment.

[0051] Currently, the primary function of levitated inflatable antennas is to provide high-efficiency communication transmission in space. Compared to traditional antenna systems, levitated inflatable antennas have a larger aperture, enabling higher data transmission rates with lower weight, power consumption, and complexity. Furthermore, due to their unique structure, levitated inflatable antennas can be dynamically adjusted in space to adapt to constantly changing environments and communication needs.

[0052] However, the appearance of a levitating inflatable antenna resembles a giant inflatable ball, typically made of flexible materials, which can be inflated to form a large spatial structure. The shape of this antenna can be circular, elliptical, or other regular geometric shapes, depending on the specific application requirements. Therefore, existing levitating inflatable antenna systems are generally driven by ropes. This introduces the problem of rope flexibility and deformation during continuous rotation, leading to increased motion lag and consequently reducing the overall accuracy of the system.

[0053] Existing inflatable antenna drive systems primarily employ a rope structure to adjust the sphere's rotation and pitch angle. While this design is simple, the flexibility of the rope can introduce more risks to the system during continuous antenna movement. Specifically, if the rope is taut during antenna movement, it increases the tension on the inflatable balloon and drive motor, potentially causing deformation of the balloon in severe cases. Conversely, if the rope is slack, the drive motor's traction on the antenna exhibits significant lag, substantially reducing the antenna's positioning accuracy.

[0054] In view of this, this application proposes a method for attitude control of a floating inflatable antenna system based on multi-robotic arm collaboration, in order to improve its dynamic response capability and thus ensure that the inflatable antenna can track the target more accurately and reliably.

[0055] For details, please refer to Figure 1 and Figure 5 The flowchart and application system diagram shown in this embodiment illustrate a method for attitude control of a suspended inflatable antenna based on multi-robotic arm collaboration. The method includes:

[0056] S1. Based on the relevant structural parameters of the inflatable antenna and the robotic arm assembly, construct the associated coordinate system of each robotic arm end and the antenna coordinate system; the robotic arm assembly includes multiple robotic arms arranged around the outside of the inflatable antenna, and the robotic arms are used to perform the task of adjusting the attitude of the inflatable antenna.

[0057] First, due to the unique spherical shape of the inflatable antenna, its dynamic attitude adjustment is mainly performed by multiple robotic arms 3 set around its periphery, as detailed in [reference needed]. Figure 5 The schematic diagram shows the working conditions. In order for the robotic arm assembly to accurately adjust the attitude of the inflatable antenna, multiple associated coordinate systems need to be calibrated in advance to achieve accurate conversion between the target attitude that the inflatable antenna needs to be adjusted to and the running trajectory required by the end of the robotic arm. The coordinate systems here include at least the end coordinate system of the robotic arm and the antenna coordinate system. In addition, the associated geodetic coordinate system and the base coordinate system of the robotic arm also need to be included.

[0058] In the actual design process, the size parameters of the inflatable antenna, the size parameters of the base 2, and the relevant parameters of the robotic arm 3 can be imported into the system. Matlab The task of calibrating the associated coordinate system is carried out.

[0059] It should be explained that, for the sake of facilitating subsequent explanations of the relationships and transformations between different coordinate systems, the coordinate systems are defined as follows: The geodetic coordinate system is denoted as... {W} The antenna coordinate system is denoted as {A}、 The base coordinate system of the robotic arm is denoted as {B} The coordinate system of the robotic arm's end effector is denoted as... {T cq } The base coordinate systems of each robotic arm 3 can be denoted as follows: {B 1 }、 {B 2 }、{B 3 } and {B 4 }， The above coordinate system definition is not specifically limited and can be adjusted according to actual conditions. The geodetic coordinate system is denoted as follows: {W} The antenna coordinate system is denoted as {A}、 The base coordinate system of the robotic arm is denoted as {B} Corresponding to Figure 5 The labels W, A, and B in the text.

[0060] like Figure 2 As shown, in a preferred embodiment, step S1 further includes the following:

[0061] S11. Construct a geodetic coordinate system with the geometric center of the inflatable antenna base in contact with the ground surface as the origin;

[0062] First, based on the dimensions and other structural parameters of the base 2 of the inflatable antenna, a geodetic coordinate system is constructed with the geometric center of the base 2 in contact with the ground surface as the origin. {W} .

[0063] S12. Construct an antenna coordinate system with the center of the inflatable antenna as the origin, and calibrate the first transformation matrix between the geodetic coordinate system and the antenna coordinate system based on the relevant structural parameters of the inflatable antenna.

[0064] The inflatable antenna includes an inflatable antenna body 1. Based on the structure of the inflatable antenna body 1, and using the relevant parameters of the inflatable antenna (e.g., shape, antenna reflector, etc.), an antenna coordinate system is constructed with the center of gravity of the inflatable antenna sphere or the geometric center of the inflatable antenna sphere as the origin. {A} ;

[0065] Simultaneously, based on the distance between the base 2 of the inflatable antenna and the center of gravity of the sphere, the geodetic coordinate system is then calibrated. {W}and antenna coordinate system {A} The first transformation matrix between them.

[0066] Taking a distance of 400mm between the geometric center of the base 2 contacting the ground surface and the center of gravity of the sphere as an example, the first transformation matrix... T WA The structural example is shown in formula (1):

[0067] (1)

[0068] Combination Figure 6 S13. Using the position information of the connection point F after the ends of each two adjacent robotic arms are connected, calibrate the relationship between robotic arm 3 and the geodetic coordinate system. {W} and antenna coordinate system {A} The second and third transformation matrices are used to confirm the robot arm base coordinate system corresponding to each robot arm 3;

[0069] The calibration method of "pair handshake" between adjacent robotic arms 3 is used to calibrate the relationship between each robotic arm 3 and the geodetic coordinate system. {W} and antenna coordinate system {A} The transformation matrix between them; specifically, this method constructs a handshake-like posture by moving the ends of two adjacent and cooperative robotic arms from the origin to the same point in the cooperative space, forming the aforementioned connection point F, and recording the robot joint angles at this time, which can be achieved through a known robotic arm base coordinate system. {B 1 } The spatial coordinates of the connection point F are obtained by substituting the joint angles into the robot arm model using the forward kinematics of the robot arm. Finally, the base coordinates of the other robot arm are obtained by using the coordinates of the connection point F and the kinematics of the other robot arm. {B 2 } And so on, to complete the calibration of all robotic arms 3.

[0070] Because the connection point F is in the geodetic coordinate system {W} The location information, i.e., the coordinate values, is unique. Therefore, the coordinates of the connection point F in the two robot arm base coordinate systems can be correlated with the geodetic coordinate system. {W}、 Antenna coordinate system {A} The transformation relationships between the two base coordinate systems can be converted into each other. By constructing calibration equations using these transformation relationships, the transformation relationships between the base coordinate systems of the two robotic arms can be solved, thereby completing the base coordinate system calibration problem of multiple collaborative robotic arms 3.

[0071] Specifically, since the robotic arm 3 is fixedly mounted on the periphery of the inflatable antenna, the robotic arm base 5 is relative to the geodetic coordinate system. {W}The position is unique. If we construct a base coordinate system for the robotic arm with the center of the robotic arm base 5 as the origin, and assume that the geometric center of the center of one of the robotic arm base 5 and the antenna base 2 in contact with the ground surface is in the geodetic coordinate system... {W} of X axis If the directional distance is 730mm, then the geodetic coordinate system... {W} With the robot arm's base coordinate system {B 1 } The second transformation matrix between T WB1 The structural example is shown in formula (2):

[0072] (2)

[0073] Furthermore, the antenna coordinate system {A} With the robot arm's base coordinate system {B 1 } The transformation relationship between the two coordinate systems can be obtained through the following process, which is equivalent to transforming the robot arm's base coordinate system. {B} Using the antenna coordinate system {A} Indicates; among which, The rotation matrix can be represented as the robot arm's base coordinate system. {B} Around the antenna coordinate system {A} of X, Y, Z The product of the transformation relationship of axis rotation is shown in the following formula (3):

[0074] (3)

[0075] Then the translation vector It can be expressed as the following formula (4):

[0076] (4)

[0077] Finally, the third transformation matrix T AB It can be expressed as the following formula (5):

[0078] (5)

[0079] in, c and s express cos and sin ; Representing the base coordinate system of the robotic arm {B} To the antenna coordinate system {A} Spatial transformation along the antenna coordinate system {A} of X, Y, Z Angle of rotation of axis; translation vector The elements in the table represent the base coordinate system of the robotic arm. {B}The origin is in the antenna coordinate system {A} The spatial coordinates below, i.e., the antenna coordinate system {A} The robot arm's base coordinate system is based on the coordinate system. {B} The position vector of the origin.

[0080] Combination Figure 6 S14. Based on the relevant structural parameters of robotic arm 3 and its end effector, calculate the coordinate system of each robotic arm end effector relative to its corresponding base coordinate system. {B} The fourth transformation matrix is ​​used to confirm the coordinate systems of each robotic arm end effector. {T cq } .

[0081] Because of the aforementioned calibration method using the "two-way handshake" of robotic arms 3, the two robotic arms 3 have the same connection point F in space, and this connection point F is in the geodetic coordinate system. {W} The location is unique, and it is also the same point in space for both robotic arms, as well as the geometric center point of the suction cup actuator 4 at the end of the robotic arm. Therefore, based on the base coordinate system of the robotic arm, the specific parameters of the end effector, and the position coordinates of the connection point F on the robotic arm flange (the end effector coordinate system is established with the robotic arm flange as the origin), the fourth transformation matrix between the base coordinate system and the end effector coordinate system is obtained. T Tcp1B1 .

[0082] Specifically, similar to the aforementioned conversion principle, the position coordinates of the connection point F on the robotic arm flange (the robotic arm end coordinate system is established based on the robotic arm flange) can be obtained by using the shape and size of the suction cup actuator 4 at the end of the robotic arm. Then, by using the position coordinates of the connection point F in the robotic arm base coordinate system, the conversion relationship between the robotic arm base coordinates and the robotic arm end can be obtained, thereby confirming the fourth conversion matrix. T Tcp1B1 This is used to complete the calibration of the entire system.

[0083] After completing the calibration according to the above steps, the transformation relationship between any coordinate system can be determined. For example, if two adjacent robotic arms are defined as robotic arm 1 and robotic arm 2 respectively, then the transformation between the suction cup actuator at the end of robotic arm 1 and the suction cup actuator at the end of robotic arm 2 can be performed by the following formula (6):

[0084] (6)

[0085] Among them, T Tcp1B1 T Tcp2B2 Represented as the coordinate system of each robotic arm end effector and its respective robotic arm base coordinate system. {B} The conversion relationship between them, T Tcp1Tcq2T represents the transformation matrix between the suction cup actuator at the end of robotic arm 1 and the suction cup actuator at the end of robotic arm 2; B1B2 It is represented as the transformation matrix between the base coordinates of robot arm 1 and the base coordinates of robot arm 2; T Tcp1B1 and T B2Tcp2 These represent the transformation matrices between the base coordinates of robotic arm 1 and its end-effector coordinates, and between the base coordinates of robotic arm 2 and its end-effector coordinates, respectively.

[0086] Finally, based on the above transformation process, the torque transformation relationship between the end effector of each robotic arm and its respective base coordinate can be calculated. T Tcp1B1 , T Tcp2B2 , T Tcp3B3 , T Tcp4B4 And determine the coordinate system of each robotic arm end effector. T cq1 , T cq2 , T cq3 , T cq4 Therefore, the coordinate systems of the entire system can be transformed into each other.

[0087] S2, Based on the coordinate system of each robotic arm end effector {T cq } and antenna coordinate system {A} According to the target posture that the inflatable antenna needs to be adjusted, determine whether the robotic arm 3 needs to take over the task, so as to confirm the motion trajectory corresponding to the end of each robotic arm.

[0088] coordinate system at the end of the robotic arm {T cq } and antenna coordinate system {A} After calibration, the position information of the robotic arm end that needs to move corresponding to the attitude adjustment information of the inflatable antenna can be obtained by conversion relationship according to the target attitude adjustment required by the inflatable antenna, and then the corresponding motion trajectory can be obtained. Considering that the motion range of a single robotic arm 3 is limited, in order to achieve all-round control of the inflatable antenna sphere, before generating the specific running trajectory for each robotic arm 3, it is also necessary to determine whether multiple robotic arms 3 need to work together in relay. In other words, it is necessary to determine whether the motion needs to be decomposed in order to complete the task of adjusting the inflatable antenna to the target attitude.

[0089] Specifically, the target attitude can be set by inputting the required rotation and pitch angles of the inflatable antenna, and then the program calculates the required running trajectory of the robotic arm end effector corresponding to the required rotation and pitch angles of the inflatable antenna through the corresponding conversion relationship, and then determines whether the robotic arm 3 needs to perform the task collaboratively.

[0090] like Figure 3 As shown, in a preferred embodiment, step S2, determining whether the robotic arm 3 needs to relay the task to confirm the motion trajectory corresponding to each robotic arm 3, further includes:

[0091] S21. Select one of the multiple robotic arms 3 as the master robotic arm;

[0092] Among multiple robotic arms 3, one is selected as the master robotic arm and the others as cooperative robotic arms, which serves as the basis for determining whether relay cooperation between robotic arms 3 is required in the subsequent process.

[0093] It should be noted that in this embodiment, four robotic arms 3 are selected, and each robotic arm 3 is a six-axis robotic arm of the same type. Correspondingly, the working range of each robotic arm is also the same. However, the specific number of robotic arms can be adjusted according to the actual situation, and no special limitation is made here.

[0094] S22. Decompose the target posture to obtain the corresponding trajectory matrix. Based on the trajectory matrix, the relevant structural parameters of the inflatable antenna and the third transformation matrix, calculate the target trajectory that the end of the main robotic arm needs to move when the robotic arm adjusts the charging antenna to the target posture in a single operation. The target trajectory is a pose matrix composed of multiple pose information.

[0095] Specifically, it is necessary to obtain the target attitude that the inflatable antenna needs to be adjusted, for example: a rotation angle of 30 degrees and a pitch angle of 0 degrees. Here, regarding the definition of rotation and pitch angles, the rotation angle refers to the angle of the inflatable antenna sphere in the geodetic coordinate system. {W} lower edge Z The angle of rotation of the axis; the pitch angle refers to the angle of the inflatable antenna sphere in the geodetic coordinate system. {W} Circling it X The angle of rotation of the axis.

[0096] When determining whether robotic arm 3 needs to relay the task, the target trajectory that the end effector of the robotic arm needs to move when each robotic arm adjusts the inflatable antenna to the target posture can be calculated first, based on the working range of the main robotic arm. Specifically, the calculation process of the target trajectory is based on the following principle: Since the end effector of the robotic arm is a suction cup actuator 4, the suction cup actuator needs to maintain a tangent and relatively fixed posture with the outside of the inflatable antenna sphere at all times, moving synchronously with the inflatable antenna. In other words, it can be imagined that the suction cup actuator 4 at the end effector of the robotic arm is fixed to the outside of the inflatable antenna sphere. By driving the inflatable antenna sphere to rotate, a series of position and posture information of the suction cup actuator can be obtained. Then, the target trajectory of the suction cup actuator 4 when it needs to drive the inflatable antenna to adjust the current posture according to the preset rotation and pitch angle can be calculated in reverse using the transformation relationship of each coordinate system.

[0097] Specifically, let's take the target attitude as a rotation angle of 30 degrees and a pitch angle of 0 degrees as an example: First, the rotation angle and pitch angle need to be divided into multiple parts (for example, 100 parts, and the more parts, the more accurate the trajectory) to form a trajectory matrix.

[0098] Substituting the obtained trajectory matrix and the sphere radius of the inflatable antenna into the above formula (5) yields a series of pose transformation matrices containing attitude information. In this pose matrix, the first to third rows of the fourth column represent the trajectory points corresponding to the target attitude, while the first to third rows of the first to third columns represent the attitude information that the end effector of the robotic arm needs to maintain during the corresponding motion, which is the target trajectory. Path0 Among them, the target trajectory Path0 The pose matrix is ​​composed of multiple pose information, and its structure is illustrated in the following formula (7):

[0099] (7)

[0100] in, T Bn,i This is represented as a pose matrix in the trajectory of the robotic arm. - This represents a series of attitude matrices that constitute the target path. Path0 (Attitude matrix vector).

[0101] S23. Based on the comparison between the target trajectory and the working range D of the main robotic arm, determine whether robotic arm 3 needs to take over the task and generate the corresponding judgment result.

[0102] After obtaining the target trajectory, it can be compared with the working range D of the main robotic arm to determine whether the robotic arm can complete the attitude adjustment of the inflatable antenna in a single movement. This also determines whether robotic arm 3 needs to take over the task, thus generating the corresponding judgment result. Here, the definition of "taking over" can be understood from the difference in the number of movements, that is, whether the robotic arm can adjust the inflatable antenna to the target attitude in a single movement trajectory. If it cannot be completed, the robotic arm needs to decompose the movement into multiple movement trajectories. At this time, the multiple coordinated movements of the robotic arm are the robotic arm taking over the task.

[0103] It should be explained that, since the inflatable antenna is spherical, the working range D of the main robotic arm can be calibrated by discretizing the joints of the robotic arm within the limit range and combining the own parameters of the robotic arm 3 (e.g., the length of each link of the robotic arm, link offset, link rotation angle, joint rotation angle limit, etc.). By using the Monte Carlo method and establishing a kinematic model, the set of parts of the position of the end of the robotic arm in space that coincide with the surface of the inflatable antenna sphere is obtained, and finally the working range D of the robotic arm 3 is obtained. That is, the working range D is the maximum curved surface that coincides with the maximum range of movement of the robotic arm and the surface of the inflatable antenna sphere.

[0104] Furthermore, the specific judgment process can be achieved by comparing the position vector in the obtained target trajectory with the working range. If the position vector is not within the working range, it means that several robotic arms 3 need to work together in relay.

[0105] S24. Based on the judgment results, confirm the motion trajectory corresponding to the end effector of each robotic arm.

[0106] After determining whether the main robotic arm can complete a single attitude adjustment, the motion trajectory of each robotic arm end effector is planned based on the judgment result. For example, if the robotic arm can complete the attitude adjustment in a single operation, then each robotic arm end effector can be directly controlled to move synchronously according to the calculated target trajectory, driving the inflatable antenna to rotate and pitch. If the robotic arm cannot complete the target attitude adjustment in a single operation, then it is necessary to calculate the motion trajectory of each robotic arm end effector based on the decomposed motion when they work together in relay.

[0107] Specifically, in a preferred embodiment, the above judgment result includes two cases: single operation of the robotic arm and relay operation of the robotic arm; then step S24, based on the judgment result, confirms the motion trajectory corresponding to the end effector of each robotic arm, specifically includes:

[0108] Step 1: When the judgment result is that the robotic arm runs for a single time, the end effector of each robotic arm runs synchronously along the target trajectory.

[0109] Based on the above, this situation occurs when the target trajectory is within the robotic arm's workstation range, meaning the robotic arm can adjust the inflatable antenna to the target posture in a single operation. Therefore, each robotic arm end effector can directly perform synchronized movement according to the calculated target trajectory to adjust the inflatable antenna to the target posture. In the specific driving process, the target trajectory can be directly... Path0 The value is assigned to the main robotic arm, and then transferred to the other cooperating robotic arms through the conversion relationship between each robotic arm, so as to realize the synchronous movement of multiple robotic arms.

[0110] Step 2: When the judgment result is that the robotic arm is in relay operation, the target trajectory is decomposed into multiple motion trajectories corresponding to the ends of each robotic arm within the working range.

[0111] Based on the above, this is a case where the main robotic arm cannot adjust the inflatable antenna to the target posture in a single operation. The next step is to decompose the target trajectory to obtain the motion trajectory corresponding to each end of the robotic arm, and it is necessary to ensure that the multiple segments of the decomposed trajectory are all within the working range of the robotic arm.

[0112] Specifically, in a preferred embodiment, the robotic arm group includes four robotic arms 3, with two robotic arms 3 spaced apart belonging to the same control group; for ease of subsequent explanation, the two groups of robotic arms 3 under the same control are referred to as... M Assemble robotic arms and N Assemble a robotic arm.

[0113] Step two above, when the judgment result is that the robotic arm 3 is in relay operation, decompose the target trajectory into multiple motion trajectories within the working range corresponding to the ends of each robotic arm, specifically including:

[0114] Step J1: Based on the working range of each robotic arm and the target trajectory, divide the target trajectory into multiple segments and the running trajectories corresponding to the robotic arms of different control groups;

[0115] Specifically, assuming that the working range of robotic arm 3 is related to the target trajectory... Path0 The comparison revealed that the target trajectory Path0 The trajectory after being divided into two segments falls within the working range of robotic arm 3, so it can be based on the target trajectory. Path0 Decomposition yields the trajectory Path01 and Path02 .

[0116] It should be explained that, since each control group includes two robotic arms, and the target trajectory... Path0 It is designed based on the main robotic arm, so it is necessary to combine the drive strategy and the transformation relationship between each robotic arm to further refine the trajectory.Path01 and Path02 The corresponding movements are then transferred to the corresponding robotic arm 3 to form the corresponding running trajectories, which will not be elaborated further here.

[0117] In step J2, the ends of the robotic arms 3 of the two control groups move according to their corresponding running trajectories and cooperate with each other to adjust the current attitude of the inflatable antenna.

[0118] Specifically, the target trajectory will still be as described above. Path0 An example is given of the trajectory after being divided into two segments within the working range of robotic arm 3.

[0119] See Figure 7 Control Strategy 1:

[0120] (1) If the original target trajectory is... Path0 Divided into two parts; setting and M The corresponding running trajectory of the robotic arm Path01 The pose matrix is ​​represented as [ p 1... p 10 ],and N The corresponding running trajectory of the robotic arm Path02 The pose matrix is ​​represented as [ q 1... q 10 ];

[0121] (2) First N The robotic arm disconnected from the inflatable antenna sphere; by M The robotic arm is assembled according to [ p 1... p 10 Each will move along its own trajectory. M After the robotic arm is assembled, disconnect it from the inflatable antenna balloon.

[0122] (3) In M When the robotic arm disconnects, by N The robotic arm re-attaches the inflatable antenna sphere and follows [ q 1... q 10 They each move along their own trajectories. M The robotic arm is assembled according to [ p 10 ... p 1] Perform their respective reset trajectories and return to their initial positions.

[0123] See Figure 8 Control Strategy Two:

[0124] (1) Similarly, the original target trajectory is... Path0Divided into two segments, one of which is the trajectory Path01 The pose matrix is ​​also [ p 1... p 10 Another running trajectory Path02 The pose matrix is ​​also [ q 1... q 10 ];

[0125] (2) First, by M Groups and N The robotic arms work together according to [ p 1... p 10 Each element will perform its own motion trajectory. Once the operation is complete, M The robotic arm disconnected from the inflatable antenna balloon and followed […]. p 10 ... p 1] Each of them will move along its own trajectory. At this time, N The robotic arm remains stationary, thus stabilizing the inflatable antenna;

[0126] (3) Waiting M After the robotic arm completes its reset motion, disconnect. N The connection between the robotic arm and the inflatable antenna is handed over to... M The robotic arm is assembled according to [ q 1... q 10 They each perform their own trajectory movements, while N The robotic arm is assembled according to [ p 10 ... p 1] Perform their respective reset trajectories and return to their initial positions.

[0127] Based on the content of the two control schemes, it can be seen that there is no single way to control the relay cooperation between the robotic arms 3 to adjust the attitude of the inflatable antenna, and the relay cooperation method is also related to the number of robotic arms 3. Therefore, the specific relay drive and control method is not limited in this application embodiment.

[0128] S3. Based on the motion trajectory and the kinematic equation of the robotic arm 3, obtain the corresponding expression for the joint angle of the robotic arm, thereby driving the end of each robotic arm to run sequentially according to the corresponding motion trajectory to adjust the attitude of the current inflatable antenna.

[0129] Based on the above, it can be seen that both the target trajectory and the corresponding running trajectory of each robotic arm end are presented in the form of a pose matrix. The robotic arm end can drive the inflatable antenna to make accurate attitude adjustments according to the corresponding trajectory. At the same time, since the execution of the robotic arm end action is also inseparable from the accurate driving of the robotic arm joints, the corresponding robotic arm joint angle expression can be obtained by using the motion trajectory and the kinematic equation of robotic arm 3, thereby achieving precise operation.

[0130] like Figure 4 As shown, in a preferred embodiment, step S3, based on the motion trajectory and the kinematic equations of the robotic arm 3, yields the corresponding expressions for the joint angles of the robotic arm, which further includes:

[0131] S31. Based on the relevant structural parameters of the robotic arm 3, confirm the fifth transformation matrix between the end effector and the joint of the robotic arm to obtain the kinematic equation of the robotic arm 3.

[0132] Taking the UR10 collaborative robotic arm as an example, it is known that the following transformation relationship exists between the joints inside this type of robotic arm: From the first... i -1 joint coordinate system { O i -1} Convert to the first i Joint coordinate system { O i It can be achieved through the fifth transformation matrix. T i The fifth transformation matrix is ​​used to achieve this. T i This is the homogeneous transformation matrix of the fourth transformation, and its structure is shown in the following formula (8):

[0133] (8)

[0134] in, ; Rot(z, ) Represented as a coordinate system { O i -1 The coordinates in} are about the joint coordinate system { O i Z-axis rotation in} Spend; Trans(0,0,d i ) Represented as { O i -1 The coordinates in} are along the joint coordinate system { O i Z-axis displacement in} d i Unit distance; Trans(a i,0,0) Represented as { O i -1 The coordinates in} are along the joint coordinate system { O i X-axis displacement in} a i Unit distance; Rot(x, ) Represented as a coordinate system { O i -1 The coordinates in} are about the joint coordinate system { O i X-axis rotation in} Spend.

[0135] Therefore, the forward kinematic equation of the UR10 robotic arm can be obtained as follows (9):

[0136] (9)

[0137] in, This is represented by the transformation relationship between the joint coordinate system at the end of the robotic arm and the base coordinate system of the robotic arm; since the robotic arm used in this embodiment is a six-axis robotic arm, this... - These represent the transformation relationship between each pair of adjacent joints, in order to... For example, This represents the conversion relationship between the second and third joints.

[0138] S32. Based on the running trajectory of each robotic arm 3 and the kinematic equation of the robotic arm 3, the joint expression of the robotic arm is obtained.

[0139] Specifically, since it is necessary to calculate the joint angles of the robotic arm based on the given running trajectory, it is necessary to substitute the corresponding running trajectory (target trajectory or trajectory obtained by decomposing the target trajectory) into the right side of formula (9). Then, according to the method that the left and right elements of the matrix are equal, the expression of the joint angles of the robotic arm 3 can be obtained. Accordingly, based on the above process, the expression of the joint angles of each robotic arm 3 can be obtained, which can drive the robotic arm 3 to complete the movement of adjusting the attitude of the inflatable antenna.

[0140] Furthermore, to further improve the accuracy of attitude adjustment of the inflatable antenna, in a preferred embodiment, an attitude sensor is provided inside the inflatable antenna. After adjusting the current attitude of the inflatable antenna, the method further includes:

[0141] Step K1: Based on the actual adjusted attitude and target attitude of the inflatable antenna as presented by the attitude sensor, determine whether the inflatable antenna needs to be adjusted again.

[0142] In practical applications, the type of attitude sensor is, for example, a gyroscope attitude sensor, which is used to determine the actual rotation and pitch angles of the inflatable antenna.

[0143] Specifically, based on the real-time feedback information from the attitude sensor, the system compares the simulated inflatable antenna with the actual sphere's trajectory to determine whether the inflatable antenna is moving along the prescribed path. If a large pointing error occurs, dynamic adjustments are required to ensure the inflatable antenna's motion accuracy.

[0144] In addition, the kinematic model of the entire antenna system can be established to monitor whether the inflatable antenna needs to be re-adjusted. Specifically, the angle of movement of the inflatable antenna can be calculated by using the joint angle information of the robotic arm. The actual angle of movement of the inflatable antenna is compared with the simulated angle of movement of the antenna to obtain the error of the antenna movement. If a large pointing error occurs, dynamic adjustment is required. In summary, the means of monitoring the effect of inflatable antenna attitude adjustment are not limited to one, so no special limitation is made in this application.

[0145] Step K2: If yes, then take the difference between the actual adjusted posture and the target posture as the new target posture, and repeat the new target posture adjustment according to the inflatable antenna, and determine whether the robotic arm 3 needs to take over the task to confirm the motion trajectory corresponding to the end of each robotic arm.

[0146] If a large pointing error is found when the robotic arm 3 adjusts the inflatable antenna, it is necessary to obtain the difference between the actual adjustment posture and the target posture, that is, the error posture of the two. This error posture is used as the new target posture, and the aforementioned steps S2 and S3 are repeated until the inflatable antenna is adjusted to the initial input target posture.

[0147] It should be noted that the difference between the actual adjusted attitude and the target attitude can also be obtained through the attitude sensor or the constructed kinematic model of the antenna system, which will not be elaborated here.

[0148] Based on the above description, this application proposes a method for attitude control of a suspended inflatable antenna based on multi-manipulator collaboration. This method includes: constructing an associated and mutually convertible geodetic coordinate system, antenna coordinate system, base coordinate system of each manipulator, and end-effector coordinate system based on the relevant structural parameters of the inflatable antenna, the inflatable antenna base 2, and each manipulator 3 within the manipulator group; thereby assisting each manipulator 3 in performing the task of adjusting the attitude of the inflatable antenna; through the transformation relationship between the end-effector coordinate system and the antenna coordinate system, the target trajectory of the main manipulator during a single attitude adjustment of the inflatable antenna can be obtained according to the input target attitude to be adjusted (e.g., the required rotation and pitch angles of the inflatable antenna), thereby determining whether the manipulator 3 needs to relay the task, and finally confirming the motion trajectory corresponding to the end-effector of each manipulator; after obtaining the corresponding motion trajectory, the expression for the corresponding manipulator joint angle can be obtained further based on the motion trajectory and the kinematic equations of the manipulator 3, thereby driving each manipulator 3 to run sequentially according to the corresponding motion trajectory to adjust the attitude of the current inflatable antenna.

[0149] As can be seen, this application firstly proposes a novel approach to design an inflatable antenna attitude control solution using multiple robotic arms. By constructing an associated coordinate system between the robotic arm end effectors and the antenna coordinate system, the attitude of the inflatable antenna can be precisely adjusted by controlling the robotic arm group. Furthermore, considering the limited range of motion of a single robotic arm, a collaborative control strategy of relay between robotic arms is proposed. After determining whether the robotic arms need to relay the task, the motion trajectory corresponding to the end effectors of each robotic arm is confirmed, and finally, the corresponding joint angle expression of the robotic arms is obtained to achieve omnidirectional movement of the inflatable antenna sphere. This control method, through collaborative relay control between robotic arms, not only significantly improves the accuracy of the movement and achieves omnidirectional control of the suspended inflatable antenna sphere, but also enables the antenna system to be deployed quickly, greatly improving its application flexibility. Finally, an auxiliary means for monitoring the attitude adjustment effect of the inflatable antenna is also proposed. When a large pointing error occurs during the inflating of the antenna, it is necessary to obtain the difference between the actual adjusted attitude and the target attitude and make timely dynamic adjustments to ensure the control accuracy of the inflatable antenna attitude adjustment.

[0150] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A method for attitude control of a suspended inflatable antenna based on multi-robotic arm collaboration, characterized in that, include: Based on the relevant structural parameters of the inflatable antenna and the robotic arm assembly, the associated coordinate systems of each robotic arm end and the antenna coordinate system are constructed; the robotic arm assembly includes multiple robotic arms arranged around the outside of the inflatable antenna, and the robotic arms are used to perform the task of adjusting the attitude of the inflatable antenna; Based on the coordinate system of each robotic arm end and the coordinate system of the antenna, according to the target posture that the inflatable antenna needs to be adjusted, it is determined whether the robotic arm needs to take over the task, so as to confirm the motion trajectory corresponding to each robotic arm end. Based on the motion trajectory and the kinematic equation of the robotic arm, the corresponding expression for the joint angle of the robotic arm is obtained, thereby driving the end effector of each robotic arm to run sequentially according to the corresponding motion trajectory to adjust the current attitude of the inflatable antenna; Based on the relevant structural parameters of the inflatable antenna and the robotic arm assembly, the associated coordinate systems of each robotic arm end effector and the antenna coordinate system are constructed, specifically including: A geodetic coordinate system is constructed with the geometric center of the inflatable antenna base in contact with the ground surface as the origin; With the center of the inflatable antenna as the origin, the antenna coordinate system is constructed, and the first transformation matrix between the geodetic coordinate system and the antenna coordinate system is calibrated according to the relevant structural parameters of the inflatable antenna. By using the position information of the connection point after the ends of each two adjacent robotic arms are connected, the second transformation matrix and the third transformation matrix between the robotic arm and the earth coordinate system and the antenna coordinate system are calibrated to confirm the robotic arm base coordinate system corresponding to each robotic arm; Based on the relevant structural parameters of the robotic arm and the robotic arm end effector, a fourth transformation matrix between each robotic arm end effector and the corresponding robotic arm base coordinate system is calculated to confirm the coordinate system of each robotic arm end effector. Determining whether the robotic arm needs to relay the task, in order to confirm the motion trajectory corresponding to each robotic arm, specifically includes: Among the plurality of robotic arms, one is selected as the master robotic arm; The target posture is decomposed to obtain the corresponding trajectory matrix. Based on the trajectory matrix, the relevant structural parameters of the inflatable antenna, and the third transformation matrix, the target trajectory that the end effector of the main robotic arm needs to move when the main robotic arm adjusts the inflatable antenna to the target posture in a single operation is calculated. The target trajectory is a pose matrix composed of multiple pose information. Based on the comparison between the target trajectory and the working range of the main robotic arm, it is determined whether the robotic arm needs to take over the task and a corresponding judgment result is generated. Based on the judgment result, the motion trajectory corresponding to the end effector of each robotic arm is confirmed.

2. The attitude control method for a suspended inflatable antenna based on multi-robotic arm cooperation according to claim 1, characterized in that, The judgment results include two cases: single operation of the robotic arm and relay operation of the robotic arm. Based on the judgment result, the motion trajectory corresponding to the end effector of each robotic arm is confirmed, specifically including: When the judgment result is that the robotic arm runs in a single operation, the end effector of each robotic arm runs synchronously along the target trajectory. When the judgment result indicates that the robotic arm is in relay operation, the target trajectory is decomposed into multiple motion trajectories within the working range corresponding to the ends of each robotic arm.

3. The attitude control method for a suspended inflatable antenna based on multi-robotic arm cooperation according to claim 2, characterized in that, The robotic arm group includes four robotic arms, and two robotic arms that are spaced apart belong to the same control group; When the judgment result indicates that the robotic arm is in relay operation, the target trajectory is decomposed into multiple motion trajectories within the working range corresponding to the ends of each robotic arm, specifically including: Based on the working range of each robotic arm and the target trajectory, the target trajectory is divided into multiple segments and the running trajectories corresponding to the robotic arms of different control groups; The ends of the robotic arms of the two control groups run according to their respective running trajectories, cooperating with each other to adjust the current attitude of the inflatable antenna.

4. The attitude control method for a suspended inflatable antenna based on multi-robotic arm cooperation according to claim 1, characterized in that, Based on the motion trajectory and the kinematic equations of the robotic arm, the corresponding expressions for the joint angles of the robotic arm are obtained, specifically including: Based on the relevant structural parameters of the robotic arm, the fifth transformation matrix between the end effector of the robotic arm and the joint of the robotic arm is determined, so as to obtain the kinematic equation of the robotic arm; Based on the running trajectory of each robotic arm and the kinematic equation of the robotic arm, the joint expression of the robotic arm is obtained.

5. The attitude control method for a suspended inflatable antenna based on multi-robotic arm cooperation according to claim 1, characterized in that, The inflatable antenna has an internal attitude sensor. After adjusting the current attitude of the inflatable antenna, the method further includes: Based on the actual adjusted posture of the inflatable antenna and the target posture presented by the posture sensor, it is determined whether the inflatable antenna needs to be adjusted again. If so, the difference between the actual adjusted posture and the target posture is taken as the new target posture, and the new target posture that needs to be adjusted according to the inflatable antenna is repeatedly executed to determine whether the robotic arm needs to take over the task, so as to confirm the motion trajectory corresponding to the end of each robotic arm.

6. The attitude control method for a suspended inflatable antenna based on multi-robotic arm cooperation according to claim 1, characterized in that, The end of the robotic arm is a suction cup actuator; when the suction cup actuator moves the inflatable antenna, it is tangent to and attracted to the spherical outer surface of the inflatable antenna.

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