Sector scanning method, system and equipment for spherical surface of antenna

Abstract

The invention relates to the field of antenna test and calibration, discloses an antenna spherical sectorial scanning method, system and equipment, and aims to solve the problem that test and calibration of directional diagrams of special antennas such as a chip antenna controlled by a mechanical arm cannot be realized in the prior art. The method comprises the following steps: enabling a receiving antenna aperture position and a transmitting antenna aperture position to be coaxial and coplanar, measuring a distance between the positions as a scanning radius, and constructing a scanning ball by taking the transmitting antenna as a center; a plurality of initial positions where all joints of the mechanical arm do not interfere are determined, and the scanning range of the scanning ball is divided into a plurality of sectors; and each sector is traversed, and the mechanical arm is controlled to move in the sector and conduct spherical scanning based on the initial position of the mechanical arm. Self-interference of the mechanical arm is avoided in a sectorial scanning mode, the stability and reliability of spherical scanning are improved, and the technical problems that when the mechanical arm conducts antenna spherical scanning testing, the self-interference risk is high, the scanning posture is difficult to optimize, and the motion reliability is low are solved.

Description

Technical Field

[0001] This document relates to the field of antenna testing and calibration, and in particular to a method, system and equipment for antenna spherical sector scanning. Background Art

[0002] Antenna measurement technology first appeared in 1905. The first to appear was a simple far-field measurement. By the 1930s, antenna measurement technology developed rapidly, and the basic methods and problems of antenna far-field measurement were solved. In the 1950s, American scientist Kerns proposed the plane wave expansion method to measure the near field of the antenna, and then obtained the far-field radiation pattern of the antenna through a series of complex calculations. Since then, antenna measurement methods have received close attention from scientific researchers, and a large number of antenna measurement literature have emerged, and near-field methods and compression methods have been gradually studied. After the 1990s, due to the rapid development of computer and automation technology, the engineering technology of near-field measurement systems has been improved, and near-field measurement technology has also developed rapidly, and the accuracy and efficiency of near-field measurement have been greatly improved. At present, the main international antenna automatic test systems are mainly Orbit in Israel, NSI and MIT in the United States, and Satimo in France. In the 1990s, Orbit in Israel developed a large-scale antenna far-field test system. The entire test system can be managed and controlled by a computer to complete the corresponding tests, and it is easy to operate. In 2000, NSI, a US company, developed a highly automated and high-precision NSI2000 antenna test system. The test frequency range is (100MHz-40GHz). The system can not only perform far-field measurements on small-diameter antennas, but also automatically convert near-field amplitude and phase into far-field measurements on larger-diameter antennas. It also has multi-frequency measurement capabilities, high test efficiency, and is easy to use.

[0003] The antenna far-field pattern usually uses a fixed track, and the receiving antenna scans with the phase center of the transmitting antenna as the center of the circle. After scanning an arc, the transmitting antenna rotates a certain angle, and the receiving antenna repeats the arc scan. When the transmitting antenna rotates one circle, the entire far-field pattern of its upper half space can be obtained.

[0004] This test method is currently widely used in various waveguide and coaxial feed antennas. The overall test environment is placed in a darkroom and a scanning track needs to be arranged, but the structure is simple and easy to operate. However, for special antennas such as chip antennas, the antenna itself cannot rotate, so a mechanical arm is required to test and calibrate its radiation pattern.

[0005] The control of multi-axis manipulators is relatively complex. Kinematic redundancy occurs when the number of degrees of freedom possessed by the manipulator is greater than the number of degrees of freedom required for a given task. In this case, the inverse dynamics problem has countless solutions, so a criterion is needed to select a solution. In most of the literature, the problem of how to use the redundant degrees of freedom for redundancy is solved. Many techniques solve the manipulation of the end effector of the manipulator with kinematic redundancy by solving the pseudo-inverse of the Jacobian matrix as the joint motion velocity. The pseudo-inverse of the Jacobian matrix is ​​used as the desired velocity of the end effector, and the optimality in the least squares sense is used as an optimal reconstruction of the Jacobian matrix during the calculation process to solve the inverse kinematics problem. However, even the instantaneous minimum joint velocity cannot completely avoid kinematic singularities. In addition, this method is not universal, that is, repeated end effector motion does not represent repeated joint motion. Klein et al. first discovered this phenomenon in the pseudo-inverse control of a three-joint manipulator in a plane. Baillieul improved the Jacobian matrix and proposed an extended Jacobian matrix, which is a square matrix and has an optimization function attached to it regarding some necessary information. The inverse of the extended Jacobian matrix is ​​solved and the inverse is used as the solution to the inverse kinematics. The algorithm based on calculating the extended Jacobian matrix has a major advantage over the pseudo-inverse technique due to its local loop. The disadvantage of this method is that although mechanical singularities can be avoided, the typical algorithmic singularities caused by the path constraints restrict the mechanical motion.

[0006] Therefore, it is necessary to provide a more reliable antenna spherical sector scanning method to achieve the test and calibration of the directional pattern of special antennas such as chip antennas controlled by a robotic arm. Summary of the invention

[0007] This manual provides a method for sector scanning of an antenna spherical surface, which solves the problem that interference may occur during the scanning process of the spherical surface due to the lack of automatic limit and path planning functions of some models of robotic arms. It effectively solves the vibration and instrument damage that may be caused by interference, while ensuring the continuity of the scanning process and the scanning accuracy, thereby realizing the test and calibration of the directional patterns of special antennas such as chip antennas controlled by robotic arms.

[0008] In a first aspect of the present invention, a spherical sector scanning method of an antenna is provided, which is applied to the test and calibration of a chip antenna controlled by a manipulator, wherein the chip antenna includes a transmitting antenna and a receiving antenna, and the scanning method includes:

[0009] Fix the transmitting antenna and the receiving antenna at the end of the robotic arm, and use the TCP point of the robotic arm as the antenna aperture position of the chip antenna;

[0010] Control the robotic arm to move the antenna aperture position to be coaxial and coplanar with the antenna aperture of the transmitting antenna, measure the distance between the transmitting antenna and the receiving antenna as the scanning radius, and construct a scanning sphere with the transmitting antenna as the center;

[0011] Position the reference coordinates and rotation axis of the robot arm to the center of the scanning sphere, and use the North Pole of the scanning sphere as the initial position of the robot arm;

[0012] According to the center of the scanning ball and the scanning radius, multiple initial positions where the joints of the robot arm do not interfere with each other are determined, and the scanning range of the scanning ball is divided into multiple sectors;

[0013] For any of the sectors, determine an initial position of the robotic arm corresponding to the sector, and control the robotic arm to move within the sector and perform spherical scanning based on the initial position;

[0014] Traverse each sector until the spherical scan of all sectors is completed.

[0015] Furthermore, the scanning range of the scanning ball includes: a horizontal angle range and a pitch angle range.

[0016] Furthermore, when the robot arm performs spherical scanning in the sector, a scanning method of gradually changing the pitch angle at a fixed horizontal angle is adopted.

[0017] Furthermore, after the robot arm completes scanning of a pitch angle range, it adjusts the horizontal angle and performs scanning of the next pitch angle range.

[0018] Furthermore, the initial position of the robotic arm is determined by verifying that no interference occurs between the joints of the robotic arm and with external devices when the robotic arm moves to the target position.

[0019] Furthermore, according to the center of the scanning ball and the scanning radius, multiple initial positions where the joints of the robot arm do not interfere with each other are determined, and the scanning range of the scanning ball is divided into multiple sectors, including:

[0020] Start scanning from the initial position of the robot arm. When the first interference occurs in each joint of the robot arm, record the corresponding meridian angle θ1 and return the robot arm to the initial position.

[0021] Repeatedly adjust the joint angles of the robotic arm to make the robotic arm pass through the first interference point. When the second interference occurs at each joint of the robotic arm, record the corresponding meridian angle θ2 and return the robotic arm to the initial position.

[0022] Repeat the joint angle adjustment and scanning of the robot arm, traverse the meridians of the scanning sphere, and obtain the meridian angles corresponding to multiple interference points;

[0023] The meridian angle θ1 from the initial meridian to the first interference point is recorded as sector 1, and the meridian angle θ1 from the first interference point to the meridian angle θ2 from the second interference point is recorded as sector 2, and the multiple sectors are obtained by traversing.

[0024] Furthermore, when interference occurs in the joints of the robot arm, the spherical scanning is suspended.

[0025] In a second aspect of the present invention, a spherical sector scanning system for an antenna is provided, which is used to control the movement of a mechanical arm and spherical data scanning corresponding to the above-mentioned spherical sector scanning method for an antenna, and the scanning system comprises:

[0026] The robot control module is configured as follows:

[0027] After the transmitting antenna is fixed, the receiving antenna is fixedly set at the end of the robotic arm, and the TCP point of the robotic arm is used as the antenna aperture position of the chip antenna, the robotic arm is controlled to move the antenna aperture position to be coaxial and coplanar with the antenna aperture of the transmitting antenna;

[0028] At the initial position of the robotic arm corresponding to each sector, the robotic arm is controlled to move within the sector based on the initial position;

[0029] The measuring module is configured to measure the distance between the transmitting antenna and the receiving antenna when the robot arm moves the antenna aperture position to be coaxial and coplanar with the antenna aperture of the transmitting antenna;

[0030] A scanning sphere construction module is configured to construct a scanning sphere with the distance between the transmitting antenna and the receiving antenna as a scanning radius and the transmitting antenna as a center;

[0031] The data scanning module is configured to perform spherical scanning when the robot arm is in each initial position and moves in each sector; when interference occurs in each joint of the robot arm, the spherical scanning is suspended.

[0032] According to a third aspect of the present invention, there is provided an electronic device, comprising:

[0033] at least one processor;

[0034] and a memory communicatively coupled to at least one of the processors;

[0035] The memory stores instructions that can be executed by the processor, and the instructions are used to be executed by the processor to implement the above-mentioned antenna spherical sector scanning method.

[0036] According to a fourth aspect of the present invention, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to be executed by the computer to implement the above-mentioned antenna spherical sector scanning method.

[0037] At least one of the above technical solutions adopted in the embodiments of this specification can achieve the following beneficial effects:

[0038] (1) The present invention divides the spherical scanning range into multiple sectors, and predetermines the optimal initial position of the robot arm for each sector, effectively avoiding interference between the robot arm's own joints during the scanning process. Since the scanning range of each sector is relatively small, the robot arm's posture changes less during the scanning process, significantly reducing the risk of interference during the movement process.

[0039] (2) The present invention divides the scanning range into sectors, so that the robot arm can adopt the optimal initial position and motion posture for different sectors, avoiding the problem that the robot arm needs to change its posture over a large range in the traditional overall scanning method. At the same time, through the reasonable planning of the scanning path of each sector, the continuity and stability of the scanning process are achieved, and the efficiency and accuracy of the antenna test are improved.

[0040] (3) The present invention adopts a coordinate system positioning method based on the scanning center, combined with the calibration of the North Pole position, to provide a stable and reliable spatial reference for spherical scanning. This method not only ensures the accuracy of the scanning trajectory, but also facilitates the post-processing and analysis of the scanning data, thereby improving the reliability and accuracy of the antenna test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0042] Figure 1 A schematic diagram of a flow chart of a method for scanning a spherical sector of an antenna provided in an embodiment of this specification;

[0043] Figure 2 A schematic diagram of sector scanning by a robotic arm provided in an embodiment of this specification. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solution and advantages of the present application clearer, the technical solution of the present application will be clearly and completely described below in combination with the specific embodiments of the present application and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0045] The technical solutions provided by various embodiments of the present application are described in detail below in conjunction with the accompanying drawings.

[0046] Glossary:

[0047] TCP point of the robot: The position of the robot and its movement are often related to the tool center contact point (TCP). Generally, this point is defined as a place on the tool, such as the center or end of the robot arm. Multiple tool center contact points can be defined, but only one can be used at a time. If a position is recorded, it is the position of the recorded tool center contact point and is also the point moving along a given path at a given rate. The fixed tool center contact point can be used when the robot arm is clamping an object and working on a fixed tool.

[0048] At present, there is little consideration on how to ensure that the end effector moves to the optimal state of the target and the coupling effect between the base and the robotic arm. The present invention is mainly aimed at the antenna spherical data scanning test system equipped with a 6-axis robotic arm. Taking the chip antenna calibration system for testing this method as an example, the robotic arm model is UR5. By programming to directly perform spherical point scanning, interference between the robotic arm and tooling and other parts at specific positions will occur. At this time, the entire spherical scanning work cannot be completed.

[0049] It is found in actual operation that the robotic arm tends to rotate to the smallest angle to move to the input position and posture. If the initial position is different, the movement trajectory and whether the final position point can be reached will be different. This is because when a multi-axis robotic arm is given the same three-dimensional coordinates and three-axis angle coordinates, the relative position of each arm has multiple numerical solutions. Therefore, for a specific scanning radius and range, it is only necessary to find the initial position of the robotic arm without interference within a certain specific angle range, and divide the sphere into sectors to complete the entire scanning work.

[0050] Figure 1 A schematic diagram of a flow chart of a spherical sector scanning method for an antenna provided in an embodiment of the present specification, the method is applied to the test and calibration of a chip antenna controlled by a robotic arm, the chip antenna comprising a transmitting antenna and a receiving antenna, see Figure 1 , the scanning method comprises the following steps:

[0051] Step S1, fix the transmitting antenna, fix the receiving antenna at the end of the mechanical arm, and use the TCP point of the mechanical arm as the antenna aperture position of the chip antenna.

[0052] Build a complete set of antenna spherical test system and fix the position of the robotic arm and the transmitting antenna.

[0053] Step S2, controlling the robot arm to move the antenna aperture position to be coaxial and coplanar with the antenna aperture of the transmitting antenna, measuring the distance between the transmitting antenna and the receiving antenna as the scanning radius, and constructing a scanning sphere with the transmitting antenna as the center.

[0054] Move the robot antenna aperture to be coaxial and coplanar with the transmitting antenna aperture. At this time, measure the distance between the two antennas and adjust it to the required measurement distance. This distance is the scanning radius for subsequent spherical scanning. The transmitting antenna, that is, the TCP point of the robot arm at the end of the robot arm, is the scanning center for subsequent spherical scanning. In this way, a scanning sphere can be constructed based on the scanning radius and scanning center.

[0055] Step S3, positioning the reference coordinates and the rotation axis of the robot arm to the center of the scanning sphere, and taking the North Pole position of the scanning sphere as the initial position of the robot arm.

[0056] Step S4 determines a plurality of initial positions where the joints of the robot arm do not interfere with each other according to the center of the scanning ball and the scanning radius, and divides the scanning range of the scanning ball into a plurality of sectors.

[0057] The scanning range of the scanning ball includes: horizontal angle range and pitch angle range.

[0058] When the robot arm performs spherical scanning within the sector, a scanning method of gradually changing the pitch angle at a fixed horizontal angle is adopted.

[0059] After the robot arm completes scanning in a pitch angle range, it adjusts the horizontal angle and scans in the next pitch angle range.

[0060] The initial position of the robotic arm is determined by verifying that no interference occurs between the joints of the robotic arm and with external devices when the robotic arm moves to the target position.

[0061] Reference Figure 2 , is a schematic diagram of sector scanning of a robot arm provided in an embodiment of the present specification, wherein multiple initial positions where the joints of the robot arm do not interfere with each other are determined according to the center of the scanning ball and the scanning radius, and the scanning range of the scanning ball is divided into multiple sectors, including:

[0062] Step S41, scanning is started from the initial position of the robot arm. When the first interference occurs in each joint of the robot arm, the corresponding meridian angle θ1 is recorded, and the robot arm is reset to the initial position.

[0063] Step S41, adjusting the joint angle of the robotic arm, and scanning again from the initial position of the robotic arm to see whether the robotic arm can pass through the first interference point;

[0064] Step S42, repeating step S41 until the robot arm passes through the first interference point, when the second interference occurs at each joint of the robot arm, recording the corresponding meridian angle θ2, and returning the robot arm to the initial position;

[0065] Step S43, adjusting the joint angle of the robotic arm, and scanning again from the initial position of the robotic arm to see whether the robotic arm can pass through the second interference point;

[0066] Step S44, repeating step S43 until the robot arm passes through the second interference point, when the third interference occurs at each joint of the robot arm, recording the corresponding meridian angle θ3, and returning the robot arm to the initial position;

[0067] Step S45, repeatedly adjusting the joint angles of the robot arm and scanning, traversing the meridians of the scanning sphere, and obtaining meridian angles corresponding to a plurality of interference points.

[0068] Step S46, record the meridian angle θ1 from the initial meridian to the first interference point as sector 1, record the meridian angle θ1 from the first interference point to the meridian angle θ2 from the second interference point as sector 2, and traverse to obtain the multiple sectors.

[0069] When interference occurs in the joints of the robot arm, the spherical scanning is suspended.

[0070] Step S5: for any of the sectors, determine the initial position of the robotic arm corresponding to the sector, and control the robotic arm to move within the sector and perform spherical scanning based on the initial position.

[0071] Step S6, traverse each sector and repeat step S5 until the spherical scanning of all sectors is completed.

[0072] The scanning method of the above-mentioned robot arm spherical surface corresponding to the chip antenna is divided into sectors. By stipulating the initial robot arm postures of different scanning sectors, possible interference between the arms of the robot arm during the scanning process is avoided. To a certain extent, it solves the motion interference problem caused by the robot arm without automatic limit and path planning functions when performing spherical scanning, and can make the spherical scanning work run continuously.

[0073] Another embodiment of the present specification provides an antenna spherical sector scanning system, which is used to control the mechanical arm movement and spherical data scanning corresponding to the above-mentioned antenna spherical sector scanning method. The scanning system includes:

[0074] The robot control module is configured as follows:

[0075] After the transmitting antenna is fixed, the receiving antenna is fixedly set at the end of the robotic arm, and the TCP point of the robotic arm is used as the antenna aperture position of the chip antenna, the robotic arm is controlled to move the antenna aperture position to be coaxial and coplanar with the antenna aperture of the transmitting antenna;

[0076] At the initial position of the robotic arm corresponding to each sector, the robotic arm is controlled to move within the sector based on the initial position;

[0077] The measuring module is configured to measure the distance between the transmitting antenna and the receiving antenna when the robot arm moves the antenna aperture position to be coaxial and coplanar with the antenna aperture of the transmitting antenna;

[0078] A scanning sphere construction module is configured to construct a scanning sphere with the distance between the transmitting antenna and the receiving antenna as a scanning radius and the transmitting antenna as a center;

[0079] The data scanning module is configured to perform spherical scanning when the robot arm is in each initial position and moves in each sector; when interference occurs in each joint of the robot arm, the spherical scanning is suspended.

[0080] The third embodiment of the present specification provides an electronic device, including:

[0081] at least one processor;

[0082] and a memory communicatively coupled to at least one of the processors;

[0083] The memory stores instructions that can be executed by the processor, and the instructions are used to be executed by the processor to implement the above-mentioned antenna spherical sector scanning method.

[0084] The fourth embodiment of the present specification provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to be executed by the computer to implement the above-mentioned antenna spherical sector scanning method.

[0085] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A method for scanning antenna spherical sectors, characterized in that: The chip antenna used for testing and calibration of a robot arm control includes a transmitting antenna and a receiving antenna. The scanning method includes: Fix the transmitting antenna, fix the receiving antenna at the end of the mechanical arm, and use the TCP point of the mechanical arm as the antenna aperture position of the chip antenna; Controlling the mechanical arm to move the antenna aperture position to be coaxial and coplanar with the antenna aperture of the transmitting antenna, measuring the distance between the transmitting antenna and the receiving antenna as a scanning radius, and constructing a scanning sphere with the transmitting antenna as the center; Positioning the reference coordinates and the rotation axis of the robotic arm to the center of the scanning sphere, and taking the North Pole of the scanning sphere as the initial position of the robotic arm; According to the center of the scanning ball and the scanning radius, a plurality of initial positions where the joints of the robot arm do not interfere with each other are determined, and the scanning range of the scanning ball is divided into a plurality of sectors; For any of the sectors, determine the initial position of the robotic arm corresponding to the sector, and control the robotic arm to move within the sector and perform spherical scanning based on the initial position; Traverse each sector until the spherical scan of all sectors is completed.

2. The antenna spherical sector scanning method according to claim 1, characterized in that: The scanning range of the scanning ball includes: a horizontal angle range and a pitch angle range.

3. The antenna spherical sector scanning method according to claim 2, characterized in that: When the mechanical arm performs spherical scanning in the sector, a scanning method of gradually changing the pitch angle at a fixed horizontal angle is adopted.

4. The antenna spherical sector scanning method according to claim 3, characterized in that: After the robot arm completes scanning in a pitch angle range, it adjusts the horizontal angle and scans in the next pitch angle range.

5. The antenna spherical sector scanning method according to claim 1, characterized in that: The initial position of the robotic arm is determined by verifying that no interference occurs between the joints of the robotic arm and with external equipment when the robotic arm moves to the target position.

6. The antenna spherical sector scanning method according to claim 5, characterized in that: According to the center of the scanning ball and the scanning radius, multiple initial positions where the joints of the robot arm do not interfere with each other are determined, and the scanning range of the scanning ball is divided into multiple sectors, including: Scanning is started from the initial position of the robot arm. When the first interference occurs at each joint of the robot arm, the corresponding meridian angle θ1 is recorded, and the robot arm is reset to the initial position; Repeatedly adjust the joint angles of the robotic arm so that the robotic arm passes through the first interference point. When the second interference occurs at each joint of the robotic arm, record the corresponding meridian angle θ2 and return the robotic arm to the initial position. Repeating the joint angle adjustment and scanning of the robot arm, traversing the meridians of the scanning sphere, and obtaining meridian angles corresponding to a plurality of interference points; The meridian angle θ1 from the initial meridian to the first interference point is recorded as sector 1, and the meridian angle θ1 from the first interference point to the meridian angle θ2 from the second interference point is recorded as sector 2, and the multiple sectors are obtained by traversing.

7. The antenna spherical sector scanning method according to claim 6, characterized in that: When interference occurs in the joints of the robot arm, the spherical scanning is suspended.

8. An antenna spherical sector scanning system, used to control the robot arm movement and spherical data scanning corresponding to the antenna spherical sector scanning method according to any one of claims 1 to 7, characterized in that: The scanning system includes: The robot control module is configured as follows: After the transmitting antenna is fixed, the receiving antenna is fixedly set at the end of the mechanical arm, and the TCP point of the mechanical arm is used as the antenna aperture position of the chip antenna, the mechanical arm is controlled to move the antenna aperture position to be coaxial and coplanar with the antenna aperture of the transmitting antenna; At the initial position of the robotic arm corresponding to each sector, the robotic arm is controlled to move within the sector based on the initial position; a measuring module, configured to measure the distance between the transmitting antenna and the receiving antenna when the mechanical arm moves the antenna aperture position to be coaxial and coplanar with the antenna aperture of the transmitting antenna; A scanning sphere construction module, configured to use the distance between the transmitting antenna and the receiving antenna as a scanning radius and to construct a scanning sphere with the transmitting antenna as a center; The data scanning module is configured to perform spherical scanning when the robot arm is in each initial position and moves in each sector; when interference occurs in each joint of the robot arm, the spherical scanning is suspended.

9. An electronic device, characterized in that: include: at least one processor; and a memory communicatively coupled to at least one of the processors; The memory stores instructions executable by the processor, and the instructions are used to be executed by the processor to implement the antenna spherical sector scanning method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to be executed by the computer to implement the antenna spherical sector scanning method according to any one of claims 1 to 7.

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