Suspension inflatable antenna attitude control method based on cooperation of multiple mechanical arms

Abstract

The invention discloses a suspension inflatable antenna attitude control method based on cooperation of multiple mechanical arms, and relates to the technical field of inflatable antenna and robot cooperative control, and the method comprises the following steps: according to the related structure parameters of an inflatable antenna and a mechanical arm group, constructing and obtaining all related mechanical arm tail end coordinate systems and antenna coordinate systems; on the basis of the coordinate system of the tail end of each mechanical arm and the antenna coordinate system, whether the mechanical arm needs to relay to execute the task or not is judged according to the target posture needing to be adjusted by the inflatable antenna, so that the motion trail corresponding to the tail end of each mechanical arm is confirmed; and according to the motion trails and a kinematic equation of the mechanical arms, mechanical arm joint angle expressions corresponding to the motion trails are obtained, and therefore the tail ends of the mechanical arms are driven to operate according to the corresponding motion trails in sequence so as to adjust the posture of the current inflatable antenna. According to the control method, the dynamic response capability can be effectively improved, so that the inflatable antenna can track the target more accurately and reliably.

Description

Technical Field

[0001] The present disclosure generally relates to the technical field of inflatable antennas and robot collaborative control, and in particular to a method for controlling the posture of a suspended inflatable antenna based on multi-robot collaboration. Background Art

[0002] To meet the ever-increasing needs of radio astronomy, antennas have become larger and larger in diameter, with higher operating frequencies and more complex structures. These factors make it increasingly difficult to quickly deploy antenna systems. In this context, a suspended inflatable antenna with a base has gained rapid development due to its ability to quickly adjust azimuth and elevation, simple structure and easy deployment.

[0003] However, the existing suspended inflatable antenna system is driven by ropes, which introduces the problem of flexible deformation of the ropes during continuous rotation operations, resulting in increased hysteresis in the motion, which in turn reduces the overall control accuracy of the system.

[0004] Therefore, we propose a suspended inflatable antenna attitude control method based on multi-manipulator collaboration for the floating inflatable antenna system to improve its dynamic response capability, thereby ensuring that the inflatable antenna can track the target more accurately and reliably. Summary of the invention

[0005] In view of the above-mentioned defects or deficiencies in the prior art, it is desired to provide a method for controlling the posture of a suspended inflatable antenna based on the collaboration of multiple robotic arms.

[0006] The present application provides a method for controlling the attitude of a suspended inflatable antenna based on multi-mechanical arm collaboration, comprising: According to the relevant structural parameters of the inflatable antenna and the mechanical arm group, the associated mechanical arm end coordinate system and the antenna coordinate system are constructed; the mechanical arm group includes a plurality of mechanical arms arranged around the outside of the inflatable antenna, and the mechanical arms are used to perform the task of adjusting the posture of the inflatable antenna; Based on the coordinate system of each of the robot arms and the antenna coordinate system, according to the target posture that the inflatable antenna needs to adjust, it is determined whether the robot arm needs to relay the task, so as to confirm the motion trajectory corresponding to the end of each robot arm; According to the motion trajectory and the kinematic equation of the robotic arm, the corresponding robotic arm joint angle expression is obtained, so as to drive each robotic arm end to operate according to the corresponding motion trajectory in turn to adjust the current posture of the inflatable antenna.

[0007] According to the technical solution provided by the present application, based on the relevant structural parameters of the inflatable antenna and the robotic arm group, the associated coordinate systems of the end of each robotic arm and the antenna coordinate system are constructed, specifically including: A geodetic coordinate system is constructed with the geometric center of the base of the inflatable antenna contacting the ground surface as the origin; Taking the center of the inflatable antenna as the origin, constructing the antenna coordinate system, and calibrating the first conversion matrix between the earth coordinate system and the antenna coordinate system according to the relevant structural parameters of the inflatable antenna; Calibrate the second conversion matrix and the third conversion matrix between the robotic arm and the earth coordinate system and the antenna coordinate system through the position information of the connection point after each two adjacent ends of the robotic arm are connected, so as to confirm the robotic arm base coordinate system corresponding to each robotic arm; Based on the relevant structural parameters of the robot arm and the robot arm end, a fourth transformation matrix between each robot arm end and the corresponding robot arm base coordinate system is calculated to confirm the coordinate system with each robot arm end.

[0008] According to the technical solution provided by the present application, judging whether the robot arm needs to perform the task in relay, so as to confirm the motion trajectory corresponding to each robot arm, specifically includes: Among the multiple robotic arms, one is selected as a main robotic arm; The target posture is decomposed to obtain a corresponding trajectory matrix, and based on the trajectory matrix, relevant structural parameters of the inflatable antenna and the third conversion matrix, a target trajectory that the end of the main robotic arm needs to move when the main robotic arm adjusts the charging antenna to the target posture through a single operation is calculated; the target trajectory is a posture matrix composed of multiple posture information; According to the comparison between the target trajectory and the working range of the main robot arm, it is judged whether the robot arm needs to perform the task in relay, and a corresponding judgment result is generated; Based on the judgment result, the motion trajectory corresponding to each end of the robot arm is confirmed.

[0009] According to the technical solution provided by the present application, the judgment results include two situations: single operation of the robot arm and relay operation of the robot arm; Based on the judgment result, confirming the motion trajectory corresponding to each of the robot arm ends specifically includes: When the judgment result is that the robot arm is running once, the robot arm ends of the robot arms run synchronously with the target trajectory as the running trajectory; When the judgment result is that the robot arms are in relay operation, the target trajectory is decomposed into a plurality of motion trajectories corresponding to the ends of the robot arms within the working range.

[0010] According to the technical solution provided by the present application, the robotic arm group includes: four robotic arms, and two of the robotic arms spaced apart are in the same control group; When the judgment result is that the robot arm is in relay operation, the target trajectory is decomposed into multiple motion trajectories corresponding to the ends of each robot arm within the working range, specifically including: According to the working range of each of the robotic arms and the target trajectory, the target trajectory is evenly divided into a plurality of running trajectories corresponding to the robotic arms of different control groups; The mechanical arm ends of the mechanical arms of the two control groups respectively operate according to the corresponding operation trajectories and cooperate with each other to adjust the current posture of the inflatable antenna.

[0011] According to the technical solution provided by the present application, according to the motion trajectory and the kinematic equation of the robotic arm, the corresponding robotic arm joint angle expression is obtained, which specifically includes: According to the relevant structural parameters of the robotic arm, a fifth transformation matrix between the end of the robotic arm and the joint of the robotic arm is determined to obtain the kinematic equation of the robotic arm; Based on the operation trajectory corresponding to each of the robotic arms and the kinematic equation of the robotic arm, the joint expression of the robotic arm is obtained.

[0012] According to the technical solution provided by the present application, a posture sensor is provided inside the inflatable antenna. After adjusting the posture of the current inflatable antenna, the method further includes: According to the actual adjustment posture of the inflatable antenna presented by the posture sensor and the target posture, determining whether the inflatable antenna needs to be adjusted again; If so, the difference between the actual adjusted posture and the target posture is used as the new target posture, and the new target posture adjusted according to the inflatable antenna is repeatedly executed to determine whether the robotic arm needs to relay the task, so as to confirm the steps of the motion trajectory corresponding to the end of each robotic arm.

[0013] According to the technical solution provided in the present 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 the spherical outer surface of the inflatable antenna and is in a mutually attracted posture.

[0014] In summary, the present technical solution specifically discloses a method for controlling the attitude of a suspended inflatable antenna based on the collaboration of multiple robotic arms, including: constructing associated coordinate systems of the end of each robotic arm and the antenna coordinate system according to 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, and the robotic arms are used to perform the task of adjusting the attitude of the inflatable antenna; based on the coordinate systems of the end of each robotic arm and the antenna coordinate system, according to the target attitude that needs to be adjusted for the inflatable antenna, judging whether the robotic arm needs to relay the task, so as to confirm the motion trajectory corresponding to each robotic arm end; according to the motion trajectory and the kinematic equation of the robotic arm, obtaining the corresponding robotic arm joint angle expression, thereby driving each robotic arm end to operate in turn according to the corresponding motion trajectory, so as to adjust the attitude of the current inflatable antenna.

[0015] The existing suspended inflatable antenna system is driven by ropes, which introduces the problem of flexible deformation of the ropes during continuous rotation, resulting in increased hysteresis in the movement, which in turn reduces the overall control accuracy of the antenna system. This application constructs an associated robotic arm end coordinate system and antenna coordinate system to achieve precise adjustment of the posture of the inflatable antenna by controlling the robotic arm group; at the same time, a collaborative control strategy of mutual relay between robotic arms is proposed, which not only significantly improves the accuracy of the movement, but also satisfies the all-round control of the suspended inflatable antenna sphere, greatly improving its application flexibility and practical application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings: Figure 1 The figure is a flow chart of the attitude control method of a suspended inflatable antenna based on multi-robotic arm collaboration.

[0017] Figure 2 The figure is a schematic diagram of the unfolding process of step S1 in the method for controlling the attitude of a suspended inflatable antenna based on multi-robotic arm collaboration.

[0018] Figure 3 The figure is a schematic diagram of the unfolding process of step S2 in the method for controlling the attitude of a suspended inflatable antenna based on multi-robotic arm collaboration.

[0019] Figure 4 The figure is a schematic diagram of the unfolding process of step S3 in the posture control method of a suspended inflatable antenna based on multi-robotic arm collaboration.

[0020] Figure 5 Schematic diagram of the application system of the suspended inflatable antenna attitude control method based on multi-manipulator collaboration.

[0021] Figure 6This is a schematic diagram of the robot arm connection working conditions in the application system of the suspended inflatable antenna attitude control method based on multi-robot arm collaboration.

[0022] Figure 7 This is a schematic diagram of the first type of collaborative control in the attitude control method of a suspended inflatable antenna based on multi-robotic arm collaboration.

[0023] Figure 8 This is a schematic diagram of the second collaborative control method of the suspended inflatable antenna attitude control based on multi-robotic arm collaboration.

[0024] Numbers in the figure: 1. Inflatable antenna body; 2. Base; 3. Robotic arm; 4. Suction cup actuator; 5. Robotic arm base. DETAILED DESCRIPTION

[0025] The present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It is also necessary to explain that, for ease of description, only the parts related to the invention are shown in the accompanying drawings.

[0026] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0027] In order to make the technical solution of the embodiment of the present application clearer and easier to understand, the application background of the embodiment of the present application is introduced below.

[0028] To meet the ever-increasing needs of radio astronomy, antennas have become larger and larger in diameter, with higher operating frequencies and more complex structures. These factors make it increasingly difficult to quickly deploy antenna systems. In this context, a suspended inflatable antenna with a base has gained rapid development due to its ability to quickly adjust azimuth and elevation, simple structure and easy deployment.

[0029] At present, the main function of the suspended inflatable antenna is to provide efficient communication transmission in space. Compared with traditional antenna systems, the suspended inflatable antenna has a larger aperture and can achieve higher data transmission rates at lower weight, power consumption and complexity. In addition, due to its unique structure, the suspended inflatable antenna can also achieve dynamic adjustment in space to adapt to changing environments and communication needs.

[0030] However, the appearance of the suspended inflatable antenna is similar to a huge inflatable ball, which is usually made of flexible materials and can be inflated to become a large space structure. The shape of this antenna can be circular, elliptical or other regular geometric shapes, depending on the actual application requirements, so the existing suspended inflatable antenna system is generally driven by ropes, which introduces the problem of flexible deformation of the ropes in the continuous rotation operation, resulting in increased hysteresis of the movement, which in turn reduces the overall accuracy of the system.

[0031] The existing inflatable antenna driving system mainly uses a rope structure to achieve the rotation and pitch angle adjustment of the sphere. Although this design is simple, due to the flexible characteristics of the rope, it may introduce more risks to the system when the inflatable antenna is in continuous motion. Specifically, when the inflatable antenna is in motion, if the rope is in a tight state, it will increase the tension of the rope on the inflatable balloon and the drive motor, and in severe cases may cause the inflatable balloon to deform; if the rope is in a loose state, the drive motor will have a significant lag in pulling the inflatable antenna, significantly reducing the positioning accuracy of the antenna.

[0032] In view of this, an embodiment of the present application proposes a suspended inflatable antenna attitude control method based on multi-manipulator collaboration for a floating inflatable antenna system to improve its dynamic response capability, thereby ensuring that the inflatable antenna can track the target more accurately and reliably.

[0033] Specifically, please refer to Figure 1 and Figure 5 The embodiment shown in the figure provides a flow chart of a method for controlling the posture of a suspended inflatable antenna based on multi-mechanical arm collaboration and an application system chart, the method comprising: S1. According to the relevant structural parameters of the inflatable antenna and the robotic arm group, the associated coordinate systems of the end of each robotic arm and the antenna coordinate system are constructed; the robotic arm group includes a plurality of robotic arms arranged around the outside of the inflatable antenna, and the robotic arms are used to perform the task of adjusting the posture of the inflatable antenna; First, due to the unique spherical shape of the inflatable antenna, its dynamic posture adjustment is mainly performed by multiple mechanical arms 3 arranged around it. Figure 5 Schematic working condition; in order to enable the robotic arm group to accurately adjust the posture of the inflatable antenna, it is necessary to calibrate multiple associated coordinate systems in advance to achieve accurate conversion of the target posture that the inflatable antenna itself needs to adjust to the required running trajectory of the robotic arm end. The coordinate system here includes at least: the robotic arm end coordinate system and the antenna coordinate system; in addition, it also needs to include: the associated geodetic coordinate system and the robotic arm base coordinate system.

[0034] 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 robot arm 3 can be imported into MatlabThe calibration task of the associated coordinate system is performed in.

[0035] It should be explained that in order to facilitate the subsequent explanation of the relationship and conversion between the coordinate systems, the coordinate systems are defined as follows: The geodetic coordinate system is denoted as {W} , the antenna coordinate system is recorded as {A}、 The robot base coordinate system is recorded as {B} , the end coordinate system of the robot arm is recorded as {T cq } , where the robot base coordinate system corresponding to each robot 3 can be recorded as {B 1 }、 {B 2 }、{B 3 } and {B 4 }， The above coordinate system definition form is not specifically limited and can be adjusted according to actual conditions. The geodetic coordinate system is recorded as {W} , the antenna coordinate system is recorded as {A}、 The robot base coordinate system is recorded as {B} Corresponding to Figure 5 The labels W, A and B in it.

[0036] like Figure 2 As shown, in a preferred embodiment, step S1 is further expanded to include the following: S11. Construct a geodetic coordinate system with the geometric center of the base of the inflatable antenna touching the ground surface as the origin; First, based on the size 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 contacting the ground surface as the origin. {W} .

[0037] S12, constructing an antenna coordinate system with the center of the inflatable antenna as the origin, and calibrating a first conversion matrix between the earth coordinate system and the antenna coordinate system according to relevant structural parameters of the inflatable antenna; The inflatable antenna includes an inflatable antenna body 1. Based on the structure of the inflatable antenna body 1, through the relevant parameters of the inflatable antenna (for example, shape, antenna reflection surface, etc.), the antenna coordinate system is constructed with the center of gravity of the sphere of the inflatable antenna or the geometric center of the sphere of the inflatable antenna as the origin. {A} ; At the same time, 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 calibrated. {W} and antenna coordinate system {A} The first transformation matrix between .

[0038] For example, the distance between the geometric center of the base 2 contacting the ground surface and the center of gravity of the sphere is 400 mm. The first transformation matrix TWA The structure example is as follows formula (1): (1) Combination Figure 6 S13, calibrate the robot 3 and the earth coordinate system through the position information of the connection point F after each two adjacent robot ends are connected {W} and antenna coordinate system {A} A second conversion matrix and a third conversion matrix are used to determine the robot base coordinate system corresponding to each robot 3; Through the "two-two handshake" calibration method between adjacent robotic arms 3, each robotic arm 3 is calibrated with the earth coordinate system {W} and antenna coordinate system {A} Specifically, this method constructs a handshake-like posture by moving the ends of two adjacent and collaborative robotic arms from the origin to the same point in the collaborative space, forms the above-mentioned connection point F, and records the robot joint angle at this time. {B 1 } The forward kinematics of the robot arm (substituting the joint angle into the robot arm model) obtains the spatial coordinates of the connection point F, and finally obtains the robot base coordinates of the other robot arm through the coordinates of the connection point F and the kinematics of the other robot arm {B 2 } , and so on, completing the calibration of all robot arms 3.

[0039] Because the connection point F is in the geodetic coordinate system {W} The position information, that is, the coordinate value, is unique, so the coordinates of the connection point F in the two robot base coordinate systems can be obtained by comparing it with the earth coordinate system. {W}、 Antenna coordinate system {A} The conversion relationship between them is converted to each other. With the help of this series of transformation relationships, the calibration equation is constructed to solve the transformation relationship between the two robot arm base coordinate systems, thereby completing the base coordinate system calibration problem of multiple collaborative robot arms 3.

[0040] Specifically, since the robot arm 3 is fixedly arranged on the periphery of the inflatable antenna, the robot arm base 5 is relative to the earth coordinate system. {W} The position is unique. If the robot base coordinate system is constructed with the center of the robot base 5 as the origin, it is assumed that the geometric center of one of the robot base 5 centers and the antenna base 2 contacting the ground surface is in the geodetic coordinate system. {W} of X-axis The direction distance is 730mm, then the geodetic coordinate system {W} With the robot base coordinate system {B 1 } The second transformation matrix between T WB1The structure example is as follows formula (2): (2) Furthermore, the antenna coordinate system {A} With the robot base coordinate system {B 1 } The conversion relationship between the two coordinate systems can be obtained through the following process, which is equivalent to converting the robot base coordinate system {B} Antenna coordinate system {A} Indicates; among them, The rotation matrix can be expressed as the robot base coordinate system {B} Coordinate system around antenna {A} of X, Y, Z The product of the conversion relationship of the axis rotation, the specific structure example is as follows formula (3): (3) The translation vector It can be expressed as the following formula (4): (4) Finally, the third transformation matrix T AB It can be expressed as the following formula (5): (5) in, c and s express cos and sin ; Represent the robot base coordinate system {B} To the antenna coordinate system {A} The spatial transformation along the antenna coordinate system {A} of X, Y, Z Angle of rotation of the axis; translation vector The elements in represent the robot base coordinate system {B} The origin of the antenna coordinate system {A} The spatial coordinates under the antenna coordinate system {A} is the base coordinate system, the robot base coordinate system {B} The position vector of the origin.

[0041] Combination Figure 6 , S14, based on the relevant structural parameters of the robot arm 3 and the robot arm end, calculate the coordinate system of each robot arm end and the corresponding robot arm base {B} The fourth transformation matrix between the two to confirm the coordinate system of each robot end {T cq } .

[0042] Due to the aforementioned calibration method of "two-to-two handshake" of the robot arms 3, the two robot arms 3 have the same connection point F in space, and the connection point F is in the geodetic coordinate system. {W} The position of is unique, and it is also the same point of the two manipulators in space, and it is also the surface geometric center point of the suction cup actuator 4 at the end of the manipulator. Therefore, according to the manipulator base coordinate system, the specific parameters of the manipulator end actuator, and the position coordinates of the connection point F on the manipulator flange (the manipulator end coordinate system is established based on the manipulator flange as the origin), the fourth transformation matrix between the manipulator base coordinate system and the manipulator end coordinate system is obtained. T Tcp1B1 .

[0043] Specifically, the same as the above conversion principle, the position coordinates of the connection point F on the robot arm flange (the robot arm end coordinate system is established based on the robot arm flange) can be obtained through the shape and size of the suction cup actuator 4 at the end of the robot arm, and then the position coordinates of the connection point F in the robot arm base coordinate system can be used to obtain the conversion relationship between the robot arm base coordinates and the robot arm end, thereby confirming the fourth conversion matrix T Tcp1B1 , and the calibration of the entire system is completed accordingly.

[0044] After completing the calibration according to the above steps, the conversion relationship between any coordinate systems can be determined. For example, if two adjacent robotic arms are defined as robotic arm 1 and robotic arm 2, the conversion 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 converted using the following formula (6): (6) Among them, T Tcp1B1 , T Tcp2B2 Represented as the coordinate system of each robot end and each robot base {B} The conversion relationship between Tcp1Tcq2 It is represented as the transformation matrix between the suction cup actuator at the end of robot arm 1 and the suction cup actuator at the end of robot arm 2; T B1B2 It is represented as the transformation matrix between the robot base coordinates of robot arm 1 and the robot base coordinates of robot arm 2; T Tcp1B1 and T B2Tcp2 They respectively represent the transformation matrices of the robot base coordinates and the robot end coordinates of robot 1 and the robot base coordinates and the robot end coordinates of robot 2.

[0045] Finally, according to the above transformation process, the conversion relationship torque between each robot end and each robot base coordinate can be calculated. T Tcp1B1 , TTcp2B2 , T Tcp3B3 , T Tcp4B4 , and determine the coordinate system of each robot end T cq1 , T cq2 , T cq3 , T cq4 , based on this, the coordinate systems of the entire system can be converted into each other.

[0046] S2, based on the coordinate system of each robot end {T cq } and antenna coordinate system {A} , according to the target posture that the inflatable antenna needs to adjust, determine whether the robot arm 3 needs to relay the task to confirm the motion trajectory corresponding to the end of each robot arm; At the end coordinate system of the robot arm {T cq } and antenna coordinate system {A} After the calibration is completed, the position information of the required movement of the end of the robotic arm corresponding to the posture adjustment information of the inflatable antenna can be obtained through the conversion relationship according to the target posture that the inflatable antenna needs to adjust, 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 operation trajectory for each robotic arm 3, it is also necessary to determine whether multiple robotic arms 3 are required to relay and cooperate. In other words, it is necessary to determine whether the motion needs to be decomposed to complete the task of adjusting the inflatable antenna to the target posture.

[0047] Specifically, the target posture can be set by inputting the rotation and pitch angles of the inflatable antenna, and then the program calculates the required running trajectory of the end of the robotic arm corresponding to the rotation and pitch angles of the inflatable antenna through the corresponding conversion relationship, and then determines whether the robotic arm 3 needs to cooperate in performing the task.

[0048] like Figure 3 As shown, in a preferred embodiment, the step S2 of determining whether the robot arm 3 needs to relay the task to confirm the motion trajectory corresponding to each robot arm 3 further includes: S21, selecting one of the multiple robotic arms 3 as a main robotic arm; Among the multiple robot arms 3, one is selected as the main robot arm, and the others are cooperative robot arms, which serve as the basic judgment condition for whether relay cooperation between the robot arms 3 is required in the subsequent process.

[0049] It should be explained that in the embodiment of the present application, the number of robotic arms 3 selected is four, and the type of each robotic arm 3 is the same model of six-axis robotic arm. Accordingly, the working range of each robotic arm is also the same, but the specific number of robotic arms can be adjusted according to actual conditions and is not specifically limited here.

[0050] S22, decomposing the target posture to obtain a corresponding trajectory matrix, and calculating 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 through a single operation based on the trajectory matrix, relevant structural parameters of the inflatable antenna, and the third conversion matrix; the target trajectory is a posture matrix composed of multiple posture information; Specifically, it is necessary to obtain the target attitude that the inflatable antenna needs to adjust, and the target attitude is, for example: a rotation angle of 30 degrees and a pitch angle of 0 degrees; wherein, regarding the definition of the rotation and pitch angles, the rotation angle refers to the inflatable antenna sphere in the geodetic coordinate system. {W} Down along its Z The angle of axis rotation; the pitch angle refers to the inflatable antenna sphere in the geodetic coordinates. {W} Around it X The angle of axis rotation.

[0051] When judging whether the robot arm 3 needs to relay the task, the target trajectory that the end of the robot arm needs to move when each robot arm adjusts the inflatable antenna to the target posture can be calculated based on the working range of the main robot arm if only relying on a single operation of the robot arm; specifically, the calculation process of the target trajectory is based on the following principle: since the end of the robot arm is a suction cup actuator 4, the suction cup actuator needs to always maintain a tangent to the outside of the inflatable antenna sphere and a relatively attracted and fixed posture accompanied by the synchronous movement of the inflatable antenna. In other words, it can be imagined that the suction cup actuator 4 at the end of the robot arm is fixed on the outside of the inflatable antenna sphere, and a series of position information of the suction cup actuator can be obtained by driving the inflatable antenna sphere to rotate, and the conversion relationship of each coordinate system can be used to reversely calculate the target trajectory of the suction cup actuator 4 when it is necessary to drive the inflatable antenna to adjust the current posture according to the preset rotation and pitch angles.

[0052] Specifically, here we take the target posture as a rotation angle of 30 degrees and a pitch angle of 0 degrees as an example: first, the rotation angle and the 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; Substituting the obtained trajectory matrix and the spherical radius of the inflatable antenna into the above formula (5) together, a series of posture transformation matrices containing posture information are obtained. In the posture matrix, the 1st to 3rd rows of the 4th column represent the trajectory points corresponding to the target posture, and the 1st to 3rd rows of the 1st to 3rd columns represent the posture information that the end of the robot arm needs to maintain during the corresponding movement, which is the target trajectory. Path0 ; Among them, the target trajectory Path0 is a pose matrix composed of multiple pose information, and its structure example is as follows formula (7): (7) in, T Bn,i Represented as a pose matrix in the trajectory of the robot, - It represents a series of posture matrices, which constitute the target path Path0 (pose matrix vector).

[0053] S23, judging whether the robot arm 3 needs to perform the task in relay according to the comparison between the target trajectory and the working range D of the main robot arm, and generating a corresponding judgment result; After obtaining the target trajectory, it can be compared with the working range D of the main robot arm to determine whether the robot arm can complete the posture adjustment of the inflatable antenna through a single movement, and then determine whether the robot arm 3 needs to relay to perform the task, thereby generating a corresponding judgment result; the definition of "relay" here can be understood from the difference in the number of movements, that is, whether the robot arm can adjust the inflatable antenna to the target posture through a single operation trajectory. If it cannot be completed, the robot arm needs to decompose the operation to obtain multiple operation trajectories. At this time, the multiple coordinated operations of the robot arm are the robot arm relaying the task.

[0054] It should be explained that since the inflatable antenna is spherical, the calibration of the working range D of the main robot arm can be achieved by discretizing the robot arm joints within the limit range and then limiting them in combination with the robot arm 3's own parameters (for example, the lengths of each link of the robot arm, link offsets, link angles, joint angle limits, etc.). By using the Monte Carlo method and establishing a kinematic model, the set of overlapping parts of the position of the end of the robot arm in space and the surface of the inflatable antenna sphere is obtained, and the working range D of the robot arm 3 is finally obtained, that is, the working range D is the maximum curved surface where the maximum moving range of the robot arm overlaps with the surface of the inflatable antenna sphere.

[0055] In addition, the specific judgment process can be to compare the position vector in the obtained target trajectory with the working range. If the position vector is not in the working range, it means that several robot arms 3 need to relay and cooperate.

[0056] S24. Based on the judgment result, confirm the motion trajectory corresponding to the end of each robot arm.

[0057] After determining whether the main robotic arm can complete a posture adjustment in a single operation, the corresponding motion trajectory of each robotic arm end will be planned according to the corresponding judgment result. For example, if the robotic arm can complete the posture adjustment in a single operation, then the ends of each robotic arm can be directly controlled to move synchronously according to the calculated target trajectory as the corresponding motion trajectory, driving the inflatable antenna to rotate and pitch; if the robotic arm cannot complete the target posture adjustment in a single operation, then it is necessary to calculate the motion trajectory corresponding to the ends of each robotic arm based on the decomposed motion during relay cooperation.

[0058] Specifically, in a preferred embodiment, the above judgment results include two situations: single operation of the robot arm and relay operation of the robot arm; then step S24, based on the judgment result, confirming the motion trajectory corresponding to the end of each robot arm, specifically includes: Step 1: When the judgment result is that the robot arm is running once, the robot end of each robot arm runs synchronously with the target trajectory as the running trajectory; Combined with the above content, at this time, the target trajectory is within the working range of the robot arm, and the robot arm can adjust the inflatable antenna to the target posture in a single operation. Then, each end of the robot arm can directly perform synchronous movement according to the calculated target trajectory as the corresponding motion 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 robot arm, and then transferred to the remaining collaborative robot arms through the conversion relationship between each robot arm, realizing the synchronous movement of multiple robot arms.

[0059] Step 2: When the judgment result is that the robot arms are in relay operation, the target trajectory is decomposed into multiple motion trajectories corresponding to the ends of each robot arm within the working range.

[0060] Combined with the above content, this is the case where the main robotic arm cannot adjust the inflatable antenna to the target posture through a single operation. The next step is to decompose the target trajectory to obtain the motion trajectory corresponding to the end of each robotic arm, and it is necessary to ensure that the multiple segments of the decomposed running trajectory are within the working range of the robotic arm.

[0061] Specifically, in a preferred embodiment, the robot arm group includes: four robot arms 3, and the two robot arms 3 set at an interval are the same control group; for the convenience of subsequent explanation, the two groups of robot arms 3 under the same control are respectively recorded as M Group of robotic arms and N Group of robotic arms.

[0062] In the above step 2, when the judgment result is that the robot arm 3 is in relay operation, the target trajectory is decomposed into multiple motion trajectories corresponding to the ends of each robot arm within the working range, specifically including: Step J1, according to the working range of each of the robotic arms and the target trajectory, dividing the target trajectory into a plurality of running trajectories corresponding to the robotic arms of different control groups; Specifically, it is assumed that based on the working range and target trajectory of the robot arm 3 Path0 The comparison found that the target trajectory Path0 The running trajectory after being divided into two sections is within the working range of the robot 3, so the target trajectory can be Path0 , decomposed to get the trajectory Path01 and Path02 .

[0063] It should be explained that each control group includes two robotic arms and the target trajectory Path0 The main robot is used as the basis for planning, so it is necessary to combine the drive strategy and the conversion relationship between each robot arm, and then convert the trajectory Path01 and Path02 They are respectively converted to the corresponding robot arms 3 to form corresponding running trajectories, which will not be described in detail here.

[0064] Step J2: The robot arms 3 of the two control groups respectively move according to corresponding moving trajectories and cooperate with each other to adjust the posture of the current inflatable antenna.

[0065] Specifically, the target trajectory is still Path0 An example is given below showing the situation where the trajectory after being divided into two sections is within the working range of the robot arm 3 .

[0066] See also Figure 7 , control strategy 1: (1) If the original target trajectory Path0 Divided into two parts; set M The running trajectory of the robot arm Path01 The pose matrix is ​​expressed as [ p 1... p 10 ],and N The running trajectory of the robot arm Path02 The pose matrix is ​​expressed as [ q 1... q 10 ]; (2) First N The robot arm disconnects from the inflatable antenna sphere; M Group the robotic arms according to [ p 1... p 10] to carry out their respective motion trajectories, M After the robotic arm is assembled, disconnect the inflatable antenna balloon; (3) M When the robot arm is disconnected, N The robot arm re-adsorbs the inflatable antenna sphere and follows [ q 1... q 10 ] to carry out their respective running trajectory movements. At this time, M Group the robotic arms according to [ p 10 ... p 1] perform their respective reset motion trajectories and then return to the initial position.

[0067] See also Figure 8 , control strategy 2: (1) The original target trajectory is also Path0 It is divided into two sections, one of which is the running track. Path01 The pose matrix is ​​also [ p 1... p 10 ], another running track Path02 The pose matrix is ​​also [ q 1... q 10 ]; (2) First, M Group and N The group of robotic arms work together according to [ p 1... p 10 ] to carry out their respective motion trajectories. After the operation is completed, M The robotic arm disconnects from the inflatable antenna balloon and follows the [ p 10 ... p 1] to carry out their respective motion trajectories. At this time, N The group of mechanical arms remain stationary, thereby maintaining the stability of the inflatable antenna; (3) Wait M After the group robot arm reset movement is completed, disconnect N The connection between the robot arm and the inflatable antenna is handed over to M Group the robotic arms according to [ q 1... q 10 ] perform their own trajectory movements, and at the same time N Group the robotic arms according to [ p 10 ... p 1] perform their respective reset motion trajectories and then return to the initial position.

[0068] Based on the contents of the two control schemes, it can be seen that the scheme for controlling the relay cooperation between the robotic arms 3 to adjust the posture of the inflatable antenna is not unique, and the relay cooperation method is also related to the set number of robotic arms 3, so the specific relay drive and control method is not limited in the embodiment of the present application.

[0069] S3, according to the motion trajectory and the kinematic equation of the robot arm 3, the corresponding robot arm joint angle expression is obtained, so as to drive each robot arm end to run according to the corresponding motion trajectory in turn to adjust the posture of the current inflatable antenna; Combining the above content, it can be seen that the target trajectory and the corresponding running trajectory of each robot end are presented in the form of a posture matrix. The robot end can drive the inflatable antenna to accurately adjust its posture according to the corresponding trajectory; at the same time, since the action execution of the robot end is also inseparable from the accurate driving of the robot joint, the corresponding robot joint angle expression can be obtained through the motion trajectory and the kinematic equation of the robot 3, thereby achieving precise operation.

[0070] like Figure 4 As shown, in a preferred embodiment, the corresponding robot arm joint angle expression is obtained according to the motion trajectory and the kinematic equation of the robot arm 3 in step S3, and the specific expansion includes: S31, according to the relevant structural parameters of the robot arm 3, confirm the fifth conversion matrix between the end of the robot arm and the joint of the robot arm to obtain the kinematic equation of the robot arm 3; Taking the UR10 collaborative robot arm as an example, it is known that the internal joints of this type of robot arm have the following conversion relationship: i -1 joint coordinate system { O i -1}Convert to i The joint coordinate system { O i} can be obtained by the fifth transformation matrix T i To achieve this, the fifth transformation matrix T i That is the homogeneous transformation matrix of the fourth transformation, and its structure is shown in the following formula (8): (8) in, ; Rot(z, ) Represented as a coordinate system { O i -1} around the joint coordinate system { O i Z-axis rotation in Spend; Trans(0,0,d i ) Represented as { O i -1} in the joint coordinate system { O i Z-axis displacement in d i Unit distance; Trans(a i ,0,0) Represented as { O i -1} in the joint coordinate system { O i X-axis displacement in a i Unit distance; Rot(x, ) Represented as a coordinate system { O i -1} around the joint coordinate system { O i X-axis rotation in Spend.

[0071] Therefore, the forward kinematics equation of the UR10 robot arm can be obtained as follows (9): (9) in, The conversion relationship between the joint coordinate system at the end of the robot arm and the base coordinate system of the robot arm is represented by ; since the robot arm used in the embodiment of the present application is a six-axis robot arm, the - Represents the conversion relationship between each two adjacent joints. For example, It represents the conversion relationship between the second joint and the third joint.

[0072] S32. Based on the running trajectories corresponding to the robotic arms 3 and the kinematic equations of the robotic arms 3, obtain the joint expressions of the robotic arms.

[0073] Specifically, since it is necessary to calculate the joint angles of the robot arm through a given running trajectory, it is necessary to substitute the corresponding running trajectory (the target trajectory or the trajectory decomposed based on the target trajectory) into the right side of formula (9), and the expressions of the joint angles of the robot arm 3 can be obtained according to the correspondence between the left and right elements of the matrix; accordingly, based on the above process, the expressions of the joint angles of the robot arm 3 can be obtained, and the robot arm 3 can be driven to complete the movement of adjusting the posture of the inflatable antenna.

[0074] In addition, in order to further improve the accuracy of the posture adjustment of the inflatable antenna, in a preferred embodiment, a posture sensor is provided inside the inflatable antenna. After adjusting the posture of the current inflatable antenna, the method further includes: Step K1, judging whether the inflatable antenna needs to be adjusted again according to the actual adjustment posture and the target posture of the inflatable antenna presented by the posture sensor; In practical applications, the type of the attitude sensor is, for example, a gyroscope attitude sensor, and the attitude sensor is used to determine the actual rotation and pitch angles of the inflatable antenna.

[0075] Specifically, based on the information fed back in real time by the attitude sensor, by comparing the actual spherical motion trajectory of the simulated inflatable antenna, it is determined whether the inflatable antenna moves according to the prescribed trajectory. If a large pointing error occurs, dynamic adjustment is required to ensure the motion accuracy of the inflatable antenna.

[0076] In addition, a kinematic model of the entire antenna system can be established to monitor whether the inflatable antenna needs to be adjusted again. Specifically, the angle of movement of the inflatable antenna is calculated through the angle information of the robotic arm joint, and the actual movement angle of the inflatable antenna is compared with the simulated antenna movement angle 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 the attitude adjustment of the inflatable antenna is not limited to one, so it is not specifically limited in the present application.

[0077] Step K2: If yes, the difference between the actual adjusted posture and the target posture is used as the new target posture, and the new target posture adjusted according to the inflatable antenna is repeatedly executed to determine whether the robot arm 3 needs to relay the task, so as to confirm the motion trajectory corresponding to the end of each robot arm.

[0078] When it is found that the robot arm 3 has a large pointing error when adjusting 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 difference between the two. The error posture is used as the new target posture, and the above steps S2 and S3 are repeated until the inflatable antenna is adjusted to the target posture initially input.

[0079] It should be explained that the difference between the actual adjusted attitude and the target attitude can also be obtained through an attitude sensor or a constructed antenna system kinematic model, which will not be elaborated here.

[0080] Based on the above description, the present application proposes a method for controlling the attitude of a suspended inflatable antenna based on multi-manipulator collaboration, the method comprising: constructing an associated and mutually convertible geodetic coordinate system, an antenna coordinate system, a base coordinate system of each manipulator, and a manipulator end coordinate system according to the relevant structural parameters of the inflatable antenna, the inflatable antenna base 2, and each manipulator 3 in the manipulator group, thereby assisting each manipulator 3 in performing the task of adjusting the attitude of the inflatable antenna; through the conversion relationship between the coordinate system of each manipulator end and the antenna coordinate system, the target trajectory of the main manipulator when controlling the inflatable antenna for attitude adjustment in a single time can be obtained according to the target attitude that needs to be adjusted for the input inflatable antenna (for example, the rotation and pitch angles required for the inflatable antenna), and then judging whether the manipulator 3 needs to relay the task, and finally confirming the motion trajectory corresponding to the end of each manipulator; after obtaining the corresponding motion trajectory, the corresponding manipulator arm joint angle expression can be further obtained according to the motion trajectory and the kinematic equation of the manipulator 3, thereby driving each manipulator 3 to operate in turn according to the corresponding motion trajectory to adjust the attitude of the current inflatable antenna.

[0081] It can be seen that the embodiment of the present application first takes a different approach to design an inflatable antenna attitude solution that is collaboratively controlled by multiple robotic arms. By constructing an associated robotic arm end coordinate system and antenna coordinate system, the attitude of the inflatable antenna is accurately adjusted by controlling the robotic arm group. In addition, considering the limited range of motion of a single robotic arm, a collaborative control strategy of mutual relay between robotic arms is further proposed. After determining whether the robotic arm needs to relay to perform the task, the motion trajectory corresponding to the end of each robotic arm is confirmed, and finally the corresponding robotic arm joint angle expression is obtained to achieve omnidirectional motion of the inflatable antenna sphere. This control method not only significantly improves the accuracy of motion through collaborative relay control between robotic arms, realizes omnidirectional control of the suspended inflatable antenna sphere, but also enables the antenna system to be quickly deployed, 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 when the inflatable antenna is inflated, it is necessary to obtain the difference between the actual adjustment attitude and the target attitude, and make dynamic adjustments in a timely manner to ensure the control accuracy of the inflatable antenna attitude adjustment.

[0082] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with (but not limited to) technical features with similar functions disclosed in the present application.

Claims

1. A method for controlling the attitude of a suspended inflatable antenna based on multi-manipulator collaboration, characterized in that: include: According to the relevant structural parameters of the inflatable antenna and the mechanical arm group, the associated mechanical arm end coordinate system and the antenna coordinate system are constructed; the mechanical arm group includes a plurality of mechanical arms arranged around the outside of the inflatable antenna, and the mechanical arms are used to perform the task of adjusting the posture of the inflatable antenna; Based on the coordinate system of each of the robot arms and the antenna coordinate system, according to the target posture that the inflatable antenna needs to adjust, it is determined whether the robot arm needs to relay the task, so as to confirm the motion trajectory corresponding to the end of each robot arm; According to the motion trajectory and the kinematic equation of the robotic arm, the corresponding robotic arm joint angle expression is obtained, so as to drive each robotic arm end to operate according to the corresponding motion trajectory in turn to adjust the current posture of the inflatable antenna.

2. The method for controlling the attitude of a suspended inflatable antenna based on multi-mechanical arm collaboration according to claim 1 is characterized in that: According to the relevant structural parameters of the inflatable antenna and the robotic arm group, the associated coordinate systems of the robotic arm ends and the antenna coordinate system are constructed, including: A geodetic coordinate system is constructed with the geometric center of the base of the inflatable antenna contacting the ground surface as the origin; Taking the center of the inflatable antenna as the origin, constructing the antenna coordinate system, and calibrating the first conversion matrix between the earth coordinate system and the antenna coordinate system according to the relevant structural parameters of the inflatable antenna; Calibrate the second conversion matrix and the third conversion matrix between the robotic arm and the earth coordinate system and the antenna coordinate system through the position information of the connection point after each two adjacent ends of the robotic arm are connected, so as to confirm the robotic arm base coordinate system corresponding to each robotic arm; Based on the relevant structural parameters of the robot arm and the robot arm end, a fourth transformation matrix between each robot arm end and the corresponding robot arm base coordinate system is calculated to confirm the coordinate system with each robot arm end.

3. The method for controlling the attitude of a suspended inflatable antenna based on multi-mechanical arm collaboration according to claim 2 is characterized in that: Determining whether the robot arms need to relay tasks to confirm the motion trajectories corresponding to the robot arms specifically includes: Among the multiple robotic arms, one is selected as a main robotic arm; The target posture is decomposed to obtain a corresponding trajectory matrix, and based on the trajectory matrix, relevant structural parameters of the inflatable antenna and the third conversion matrix, a target trajectory that the end of the main robotic arm needs to move when the main robotic arm adjusts the charging antenna to the target posture through a single operation is calculated; the target trajectory is a posture matrix composed of multiple posture information; According to the comparison between the target trajectory and the working range of the main robot arm, it is judged whether the robot arm needs to perform the task in relay, and a corresponding judgment result is generated; Based on the judgment result, the motion trajectory corresponding to each end of the robot arm is confirmed.

4. The method for controlling the posture of a suspended inflatable antenna based on multi-mechanical arm collaboration according to claim 3 is characterized in that: The judgment results include two situations: single operation of the robot arm and relay operation of the robot arm; Based on the judgment result, confirming the motion trajectory corresponding to each of the robot arm ends specifically includes: When the judgment result is that the robot arm is running once, the robot arm ends of the robot arms run synchronously with the target trajectory as the running trajectory; When the judgment result is that the robot arms are in relay operation, the target trajectory is decomposed into a plurality of motion trajectories corresponding to the ends of the robot arms within the working range.

5. The method for controlling the posture of a suspended inflatable antenna based on multi-manipulator collaboration according to claim 4 is characterized in that: The robotic arm group includes: four robotic arms, and two of the robotic arms spaced apart are in the same control group; When the judgment result is that the robot arm is in relay operation, the target trajectory is decomposed into multiple motion trajectories corresponding to the ends of each robot arm within the working range, specifically including: According to the working range of each of the robotic arms and the target trajectory, the target trajectory is evenly divided into a plurality of running trajectories corresponding to the robotic arms of different control groups; The mechanical arm ends of the mechanical arms of the two control groups respectively operate according to the corresponding operation trajectories, and cooperate with each other to adjust the current posture of the inflatable antenna.

6. The method for controlling the attitude of a suspended inflatable antenna based on multi-manipulator collaboration according to claim 1 is characterized in that: According to the motion trajectory and the kinematic equation of the robotic arm, the corresponding robotic arm joint angle expression is obtained, which specifically includes: According to the relevant structural parameters of the robotic arm, a fifth transformation matrix between the end of the robotic arm and the joint of the robotic arm is determined to obtain the kinematic equation of the robotic arm; Based on the operation trajectory corresponding to each of the robotic arms and the kinematic equation of the robotic arm, the joint expression of the robotic arm is obtained.

7. The method for controlling the attitude of a suspended inflatable antenna based on multi-mechanical arm collaboration according to claim 1 is characterized in that: The inflatable antenna is provided with a posture sensor inside. After adjusting the posture of the current inflatable antenna, the method further includes: According to the actual adjustment posture of the inflatable antenna presented by the posture sensor and the target posture, determining whether the inflatable antenna needs to be adjusted again; If so, the difference between the actual adjusted posture and the target posture is used as the new target posture, and the new target posture adjusted according to the inflatable antenna is repeatedly executed to determine whether the robotic arm needs to relay the task, so as to confirm the steps of the motion trajectory corresponding to the end of each robotic arm.

8. The method for controlling the attitude of a suspended inflatable antenna based on multi-mechanical arm collaboration according to claim 1 is characterized in that: The end of the mechanical arm is a suction cup actuator; when the suction cup actuator drives the inflatable antenna to move, it is tangent to the spherical outer surface of the inflatable antenna and is in a mutually attracted posture.

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