Method for testing autonomous pointing precision of directional antenna of planet vehicle

Abstract

A planet vehicle directional antenna autonomous pointing precision test method belongs to the technical field of spaceflight measurement, and comprises the following steps: designing a relay communication test track according to an on-orbit relay track; a laser emitting device is installed at a directional antenna beam opening of the planet vehicle, and the laser outward irradiation direction of the laser emitting device coincides with the directional antenna beam center; designing a target plate according to a test site range; directional antenna errors are calibrated, and error influences are eliminated; the laser emitting device is kept in an open state, the planet vehicle is lifted, the planet vehicle moves according to the relay communication test track and swings according to a preset working condition, the rotation angle of the antenna and the position of a light spot on the target plate in the test process are recorded, and the pointing precision under different postures and different speeds is obtained; and completing the pointing precision test of the planet vehicle dynamic directional antenna. Through the design of the special relay communication test track and the design of the target plate, the problems that the motion range of a target point is large, and accurate measurement is difficult are solved.

Description

Technical Field

[0001] The invention relates to an autonomous pointing accuracy testing method for a directional antenna of a planetary rover, and belongs to the technical field of aerospace measurement. Background Art

[0002] Generally speaking, the pointing accuracy measurement of directional antennas is divided into two categories: static measurement and dynamic measurement, which respectively represent the directional antenna pointing to a static target and pointing to a dynamic target. The accuracy test difficulty of the body being stationary and pointing to a static target and the body being stationary and pointing to a dynamic target is relatively low. Due to the large orbit radius and small attitude change of the spacecraft, the directional antenna on board the spacecraft can also be tested for pointing accuracy in the form of the body being stationary and pointing to a static / dynamic target.

[0003] The current rovers in orbit also use the form of stationary body and antenna tracking to achieve data transmission. The measurement and control communication efficiency is low, and it is impossible to complete "communication in motion", and it is difficult to effectively exert the potential of mobile detection. However, with the development of spacecraft technology, especially the development of rovers in orbit, "communication in motion" has become an urgent need for space robots in orbit. During the "communication in motion" process, the tracking target is the transit link such as pointing to the ground / relay satellite / lander. The displacement of the rover is small compared to the radius of the relay orbit and can be ignored; but the rover body is in the process of moving, and the attitude (heading angle, pitch angle and roll angle) changes rapidly. Therefore, high-precision measurement of the pointing accuracy of the directional antenna under the moving state of the rover (mainly attitude change) has become an urgent need.

[0004] At present, there is no method for measuring the pointing accuracy of directional antennas when the rover is moving in the prior art. Therefore, summarizing the above situation, the current directional antenna pointing accuracy test has the problems of large test range, high resource consumption and great difficulty in quantitative evaluation when the rover is moving (mainly attitude changes). Summary of the invention

[0005] The technical problem solved by the present invention is: to overcome the deficiencies of the prior art, to provide a method for testing the autonomous pointing accuracy of a rover's directional antenna, and to solve the problem of accurately measuring the pointing accuracy during the rover's movement.

[0006] The technical solution of the present invention is: a method for testing the autonomous pointing accuracy of a rover directional antenna, comprising:

[0007] Design a relay communication test track based on the on-orbit relay track;

[0008] A laser emitting device is installed at the beam port of the directional antenna of the rover, and the external irradiation direction of the laser coincides with the center of the directional antenna beam. During the movement of the rover, the laser emitting device is reliably connected without shaking, slipping or bumping.

[0009] Design the target plate according to the scope of the test site;

[0010] Calibrate directional antenna errors to eliminate the impact of errors in directional antenna installation accuracy and laser launch device installation accuracy;

[0011] The laser emitting device remains turned on, the rover is lifted, and the rover is moved along the relay communication test track and swung according to preset working conditions. The antenna rotation angle and the position of the light spot on the target board are recorded during the test to obtain the pointing accuracy at different postures and speeds, thus completing the pointing accuracy test of the rover's dynamic directional antenna.

[0012] Furthermore, the semi-major axis of the relay communication test orbit is not less than 10,000 km, the eccentricity does not exceed 0.8, the orbital position of the relay communication satellite is the apogee of the relay communication test orbit, and the azimuth angle changes by no less than 1° in 30 minutes; the inclination of the relay communication test orbit and the right ascension of the ascending node are the apogee of the relay communication test orbit, and the altitude angle of the relay orbit during the test time meets the on-orbit usage status; when the perigee argument of the relay communication test orbit is the apogee of the relay communication test orbit, it is 90°±5° in the test site coordinate system, which is used for vertical target sticking to the wall.

[0013] Furthermore, the laser emitting device is adapted to the lighting environment of the test site, and the effective irradiation distance is greater than 30m; at an irradiation distance of 30m, the diameter of the laser point spot is no more than 1 cm; and the continuous working time of the laser emitting device is no less than 1 hour.

[0014] Furthermore, designing the target plate according to the range of the test site includes: considering the horizontal distance and the vertical distance at the same time, taking the rover test position and the target object pointing as a reference, taking the beam angle as a constraint, and setting the gear positions in a uniform and discrete form.

[0015] Furthermore, the target plate is provided with a shading, and a grid with a certain accuracy is used as the shading background; the target plate is installed vertically.

[0016] Furthermore, the calibrating directional antenna error includes:

[0017] Park the rover at a specified location and height, which will be used as a reference value for subsequent dynamic measurements;

[0018] Measure the position and attitude of the rover, using the three-dimensional coordinates of the target plate center P0; use the relationship between the two to solve the motion angle θ0 of the directional antenna mechanism;

[0019] Move the directional antenna to an angle of θ0, turn on the laser emitting device, and measure the three-dimensional coordinates P1 of the laser spot position on the target plate;

[0020] The offset distance P1-P0 of the laser spot caused by the system error is calculated, and the offset is converted into the zero position of the directional antenna movement for compensation, so that the center of the laser spot is located at the center of the target plate in the initial state.

[0021] Furthermore, the planetary rover is swung at a constant speed according to a preset working condition.

[0022] Furthermore, the preset working conditions include:

[0023] The rover pitches and rotates from low speed to high speed, and the rotation range covers the on-orbit use range;

[0024] The planetary rover yaws and rotates from low speed to high speed, with a rotation range of 360°;

[0025] The rover tilts and rotates from low speed to high speed, and the rotation range covers the on-orbit use range;

[0026] The planetary rover has three-axis compound rotation, from low speed to high speed, and its rotation range covers the on-orbit usage range.

[0027] Furthermore, the suspension height of the planetary rover is the same as the calibration test height.

[0028] Furthermore, the method for recording the rotation angle of the antenna during the test is to use a camera with a frame rate exceeding 10 Hz for shooting and recording.

[0029] The advantages of the present invention compared with the prior art are:

[0030] The problem of large target point movement range and difficulty in accurate measurement was solved through the design of dedicated relay communication test track and target plate. The problem of measuring and eliminating initial system errors was solved through static precision measurement of the rover. The problem of large site requirements, high resource consumption and difficult quantitative evaluation for conventional mobile tests was solved through lifting the rover's center of mass and swinging it at a constant speed, ensuring that autonomous pointing accuracy tests of directional antennas can be carried out with high precision when the rover is in a moving state. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0032] Figure 1 a and b are schematic diagrams of the original relay track and the dedicated relay communication test track design of the present invention, respectively;

[0033] Figure 2This is a schematic diagram of the target plate design of the present invention;

[0034] Figure 3 The figure is a top view of the test site layout of the present invention. DETAILED DESCRIPTION

[0035] In order to better understand the above technical scheme, the technical scheme of the present invention is described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical scheme of the present invention, rather than limitations on the technical scheme of the present invention. In the absence of conflict, the embodiments of the present invention and the technical features in the embodiments can be combined with each other.

[0036] The following is a further detailed description of a method for testing the autonomous pointing accuracy of a rover directional antenna provided by an embodiment of the present invention in conjunction with the accompanying drawings of the specification. The specific implementation method may include: designing a dedicated relay communication test track so that the azimuth angle of the track changes very little during the test time and the altitude angle meets the on-orbit use requirements, so as to facilitate the determination of the pointing direction of the directional antenna; installing a laser pen at the beam port of the directional antenna and designing a dedicated target plate in the form of "scale + circle area" to facilitate visual confirmation of whether it is in the tracking range and confirmation of whether the accuracy meets the requirements through quantitative analysis; through static precision measurement of the rover, the system error calibration and elimination in the initial state are completed; through the method of lifting the center of mass of the rover and swinging at a constant speed (pitch, yaw and roll three axes), the mobile state of the rover (including obstacle crossing, pit crossing, climbing, etc.) is set, and the quantitative measurement of the pointing accuracy is completed in the form of recording the target plate with a high-speed camera.

[0037] The solution provided in the embodiment of the present invention specifically includes:

[0038] Products required for the test: Planetary rover (including directional antenna and its autonomous pointing control system)

[0039] Ground equipment required for the test: low-gravity suspension (with the ability to suspend and rotate the rover at a constant speed), laser launch device, test target board, camera (frame rate needs to be more than 10Hz)

[0040] Others required for testing: Relay communication test track

[0041] (1) Dedicated relay communication test track

[0042] like Figure 1 a, b, in the ground test state, it is necessary to simulate the on-orbit relay track as much as possible. The design of the dedicated relay communication test track should be designed according to the following characteristics:

[0043] a) The orbit has a long semi-major axis and a large eccentricity. Near the apogee of the communication arc, the azimuth angle needs to change by at least 1° every 30 minutes. Therefore, the target point changes very little during the test time.

[0044] b) The designed orbit inclination and ascending node right ascension should be selected at the apogee of the communication arc. During the test period, the relay orbit altitude angle should be consistent with the on-orbit use status;

[0045] c) The designed orbit perigee angle and the communication arc apogee angle need to be close to 90° in the test site coordinate system, and the target should be basically vertically attached to the wall to facilitate target setting.

[0046] Taking the autonomous pointing accuracy test of the lunar rover directional antenna as an example, the dedicated relay communication test track is as follows: Figure 1 shown.

[0047] (2) Laser emission device installed at the directional antenna beam port

[0048] For the convenience of ground testing, the directional antenna beam needs to be presented in a visual form, so the beam port needs to be laser modified. The laser irradiation direction needs to coincide with the beam center, and during the movement of the directional antenna, the laser emitting device must be connected reliably without shaking, slipping or bumping.

[0049] The laser emitting device should adapt to the lighting environment of the test site, and the effective irradiation distance should be greater than 30m; at an irradiation distance of 30m, the diameter of the laser point spot should not be greater than 1cm to facilitate high-precision measurement; the continuous working time of the laser emitting device should be no less than 1 hour.

[0050] (3) Design of special test target board

[0051] like Figure 2 The design of the target plate needs to be combined with the scope of the test site, with the test position of the rover and the target direction as the benchmark (both the horizontal distance and the vertical distance need to be considered), and the beam angle as the constraint. The gear position is set in a uniform and discrete form to facilitate preliminary visual judgment during the test. Taking the beam angle of 5° as an example, the boundaries can be drawn according to the outward deflection of the beam center by 1°, 2°, 3°, 4°, and 5°, respectively, to facilitate preliminary visual judgment during the test.

[0052] At the same time, the target plate needs to be textured and a grid with a certain accuracy is used as the texture background to facilitate the subsequent detailed data analysis to clarify the pointing accuracy. The dedicated test target plate is installed vertically and can be fixed on the wall. After installation, the target plate needs to be kept flat.

[0053] Taking the autonomous pointing accuracy test of the lunar rover directional antenna as an example, the dedicated test target board is as follows: Figure 2 shown.

[0054] (4) Error calibration of the rover static directional antenna system

[0055] After the ground equipment and the required track are prepared, due to the influence of system errors such as the installation accuracy of the directional antenna and the installation accuracy of the laser launch device, it is necessary to first complete the calibration of the directional antenna system error.

[0056] The location of the products and equipment required for calibration is as follows: Figure 3 shown.

[0057] The rover is parked at a specified position and height by a parking support frame, etc. The height should be consistent with the subsequent dynamic measurement.

[0058] The position and attitude of the rover are precisely measured by the theodolite, and the three-dimensional coordinates of the center P0 of the target plate are precisely measured by the theodolite. The relationship between the two is used to solve the motion angle θ0 of the directional antenna mechanism.

[0059] Move the directional antenna to an angle of θ0, turn on the laser emitting device, and use a theodolite to accurately measure the three-dimensional coordinates P1 of the laser spot position on the target plate.

[0060] The offset distance of the laser spot caused by the system error is P1-P0. This offset can be converted into the zero position of the directional antenna movement for compensation, so that the center of the laser spot is located at the center of the target plate in the initial state.

[0061] (5) Test of the pointing accuracy of the rover's dynamic directional antenna

[0062] After completing the system error calibration, the dynamic directional antenna pointing accuracy test of the rover is carried out. The test status is as shown in the attached figure. Figure 3 As shown, the laser emitting device remains turned on, and a camera is used to record the position of the light spot during the test.

[0063] The planetary rover is hoisted by low gravity suspension. The suspension height is the same as the calibration test height. The planetary rover is swung at a constant speed according to the following working conditions:

[0064] a) Pitch rotation of the vehicle (rotation from low speed to high speed, the rotation range covers the on-orbit use range);

[0065] b) The vehicle yaws and rotates (rotates from low speed to high speed, with a rotation range of 360°);

[0066] c) The vehicle rolls and rotates (rotates from low speed to high speed, and the rotation range covers the on-track use range);

[0067] d) Three-axis compound rotation (rotation from low speed to high speed, the rotation range covers the on-orbit use range).

[0068] The antenna rotation angle and light spot movement of the above working conditions are stored to obtain the pointing accuracy under different postures and speeds.

[0069] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

[0070] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A method for testing the autonomous pointing accuracy of a rover directional antenna, characterized in that: include: Design a relay communication test track based on the on-orbit relay track; A laser emitting device is fixedly installed at the beam port of the directional antenna of the rover, and the outward irradiation direction of the laser coincides with the center of the directional antenna beam; Design the target plate according to the scope of the test site; Calibrate directional antenna errors to eliminate the impact of errors in directional antenna installation accuracy and laser launch device installation accuracy; The laser emitting device remains turned on, the rover is lifted, and the rover is moved along the relay communication test track and swung according to preset working conditions. The antenna rotation angle and the position of the light spot on the target board are recorded during the test to obtain the pointing accuracy at different postures and speeds, thus completing the pointing accuracy test of the rover's dynamic directional antenna.

2. The method for testing the autonomous pointing accuracy of a rover directional antenna according to claim 1, characterized in that: The semi-major axis of the relay communication test orbit is not less than 10,000 km and the eccentricity does not exceed 0.

8. The orbital position of the relay communication satellite is the apogee of the relay communication test orbit, and the azimuth angle changes by no less than 1° in 30 minutes. The inclination of the relay communication test orbit and the right ascension of the ascending node are the apogee of the relay communication test orbit, and the altitude angle of the relay orbit during the test time meets the on-orbit usage status. When the perigee argument of the relay communication test orbit is the apogee of the relay communication test orbit, it is 90°±5° in the test site coordinate system, which is used for vertical target sticking to the wall.

3. The method for testing the autonomous pointing accuracy of a rover directional antenna according to claim 1, characterized in that: The laser emitting device is adapted to the lighting environment of the test site, and the effective irradiation distance is greater than 30m; at an irradiation distance of 30m, the diameter of the laser point spot is no more than 1 cm; the continuous working time of the laser emitting device is no less than 1 hour.

4. The method for testing the autonomous pointing accuracy of a rover directional antenna according to claim 1, characterized in that: The design of the target plate according to the range of the test site includes: considering the horizontal distance and the vertical distance at the same time, taking the rover test position and the target object pointing as a reference, taking the beam angle as a constraint, and setting the gear positions in a uniform and discrete form.

5. The method for testing the autonomous pointing accuracy of a rover directional antenna according to claim 4, characterized in that: The target plate is provided with a shading pattern, and a grid with a certain accuracy is used as the shading pattern background; the target plate is installed vertically.

6. The method for testing the autonomous pointing accuracy of a rover directional antenna according to claim 1, characterized in that: The calibrated directional antenna error includes: Park the rover at a specified location and height, which will be used as a reference value for subsequent dynamic measurements; Measure the position and attitude of the rover, using the three-dimensional coordinates of the target plate center P0; use the relationship between the two to solve the motion angle θ0 of the directional antenna mechanism; Move the directional antenna to an angle of θ0, turn on the laser emitting device, and measure the three-dimensional coordinates P1 of the laser spot position on the target plate; The offset distance P1-P0 of the laser spot caused by the system error is calculated, and the offset is converted into the zero position of the directional antenna movement for compensation, so that the center of the laser spot is located at the center of the target plate in the initial state.

7. The method for testing the autonomous pointing accuracy of a rover directional antenna according to claim 1, characterized in that: The planetary rover is swung at a constant speed according to the preset working conditions.

8. The method for testing the autonomous pointing accuracy of a rover directional antenna according to claim 1, characterized in that: The preset working conditions include: The rover pitches and rotates from low speed to high speed, and the rotation range covers the on-orbit use range; The planetary rover yaws and rotates from low speed to high speed, with a rotation range of 360°; The rover tilts and rotates from low speed to high speed, and the rotation range covers the on-orbit use range; The planetary rover has three-axis compound rotation, from low speed to high speed, and its rotation range covers the on-orbit usage range.

9. The method for testing the autonomous pointing accuracy of a rover directional antenna according to claim 1, characterized in that: The suspension height of the planetary rover is the same as the calibration test height.

10. The method for testing the autonomous pointing accuracy of a rover directional antenna according to claim 1, characterized in that: The method for recording the rotation angle of the antenna during the test is to use a camera with a frame rate exceeding 10 Hz to shoot and record.

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