阅读说明：本技术 一种船载卫星天线座和船载卫星天线跟踪系统 (Shipborne satellite antenna seat and shipborne satellite antenna tracking system ) 是由 项正山 胡蓉花 冯杰 叶祖昌 王捷玉 于 2020-12-31 设计创作，主要内容包括：本发明涉及一种船载卫星天线座和船载卫星天线跟踪系统,包括：方位轴、水平轴、俯仰轴以及伺服驱动机构、水平轴设置于方位轴上、俯仰轴设置于水平轴上,俯仰轴与水平轴垂直,伺服驱动机构用于分别驱动方位轴、水平轴以及俯仰轴分别绕各自的轴线转动。基于本发明的的船载卫星天线座和船载卫星天线跟踪系统,可实现载卫星天线对于轨道卫星的实时动态精确跟踪。(The invention relates to a ship-borne satellite antenna pedestal and a ship-borne satellite antenna tracking system, which comprise: the azimuth axis, the horizontal axis, the pitching axis and the servo driving mechanism are arranged on the azimuth axis, the pitching axis is arranged on the horizontal axis, the pitching axis is perpendicular to the horizontal axis, and the servo driving mechanism is used for respectively driving the azimuth axis, the horizontal axis and the pitching axis to rotate around respective axes. The shipborne satellite antenna seat and the shipborne satellite antenna tracking system based on the invention can realize real-time dynamic accurate tracking of the shipborne satellite antenna to the orbit satellite.)

1. The shipborne satellite antenna pedestal is characterized by comprising an azimuth axis (1), a horizontal axis (2), a pitching axis (3) and a servo driving mechanism, wherein the horizontal axis (2) is arranged on the azimuth axis (1), the pitching axis (3) is arranged on the horizontal axis (2), the pitching axis (3) is perpendicular to the horizontal axis, and the servo driving mechanism is used for respectively driving the azimuth axis (1), the horizontal axis (2) and the pitching axis (3) to rotate around respective axes.

2. The shipborne satellite antenna pedestal according to claim 1, wherein the servo driving mechanism comprises a first servo motor for driving the azimuth shaft (1) to rotate around the axis thereof, a second servo motor for driving the horizontal shaft (2) to rotate around the axis thereof, and a third servo motor for driving the pitch shaft (3) to rotate around the axis thereof, the lower end of the azimuth shaft (1) is fixed on the rotating shaft of the first servo motor, the second servo motor is fixed on the upper end of the azimuth shaft (1), one end of the horizontal shaft (2) is fixed on the rotating shaft of the second servo motor, the third servo motor is fixed on the other end of the horizontal shaft (2), and the pitch shaft (3) is fixed on the rotating shaft of the third servo motor.

3. An on-board satellite antenna tracking system, comprising:

an antenna mount according to claim 1 or 2, arranged on the hull, the azimuth axis (1) being arranged parallel to the hull normal;

an antenna (4), the antenna (4) being fixed to the tilt axis (3);

the acquisition module is used for acquiring a satellite motion track, a ship body position, a transverse rocking angle, a longitudinal rocking angle and a course angle of a ship body, and sending the satellite motion track, the ship body position, the transverse rocking angle, the longitudinal rocking angle and the course angle to the tracking calculation module;

the tracking calculation module is used for calculating an azimuth axis rotation angle, a horizontal axis rotation angle and a pitch axis rotation angle which are required by the antenna wave beam to be aligned with the target satellite at each moment in the ship navigation state according to the received satellite motion track, the ship position, the course angle, the roll angle and the pitch angle, and sending the azimuth axis rotation angle, the horizontal axis rotation angle and the pitch axis rotation angle to the control module;

and the control module is used for controlling the servo driving mechanism to drive the azimuth shaft, the horizontal shaft and the pitching shaft to rotate corresponding angles around respective axes according to the received azimuth shaft rotation angle, horizontal shaft rotation angle and pitching shaft rotation angle.

4. The shipborne satellite antenna tracking system of claim 3, wherein the tracking calculation module comprises:

a first calculating unit, configured to calculate, according to the received satellite motion trajectory and the initial position of the ship body, that the ship body is in the initial position state, and the antenna beam pointing at each time is aligned to the target satelliteThe antenna beam is directed at an azimuth angle alpha relative to the bow_jAnd the azimuth angle alpha is measured_jSent to a control module, the azimuth angle alpha_jAn azimuth axis rotation angle required for the antenna beam to be directed at a target satellite;

a second calculation unit, configured to calculate, according to the received satellite motion trajectory, the real-time position of the hull, and the heading angle, that the hull is in a driving state without pitching and rolling, an antenna beam pointing to the target satellite at each time, and an azimuth angle α pointed to with respect to the bow of the ship_iAnd the pitch angle beta of the antenna beam_i(ii) a For determining the azimuth angle alpha at each time_iAnd the azimuth angle alpha_jAnd said pitch angle β_iCalculating the angle theta required by the rotation of the horizontal axis of the antenna pedestal when the antenna beam points to the target satellite at each moment in the driving state without pitching and rolling_xiAngle theta required for rotation of pitch axis of antenna mount_yiAnd angle theta_xiAnd angle theta_yiSending the data to a fourth computing unit; the angle theta_xiIs the initial angle of the horizontal axis, the angle theta_yiIs the initial angle of the pitching axis;

a third calculating unit, which is used for receiving the rolling angle and the pitching angle of the ship body and the azimuth angle alpha pointed by the antenna wave beam relative to the ship head when the ship body is in the initial position state under the driving state of pitching and/or rolling_jAccording to the roll angle, pitch angle and azimuth angle alpha_jCalculating a rotation calibration angle of a horizontal axis and a rotation calibration angle of a pitch axis, which are required by the antenna beam to align with the target satellite at each moment in the driving state of the ship body pitching and/or pitching, so as to compensate the deviation of the antenna beam pointing direction caused by the ship body rolling and/or the ship body pitching, and sending the rotation calibration angle of the horizontal axis and the rotation calibration angle of the pitch axis to a fourth calculation unit;

the fourth calculation unit is used for summing the received initial angle of the horizontal shaft at each moment and the rotation calibration angle of the horizontal shaft to obtain the rotation angle of the horizontal shaft, which is required to be achieved by the actual rotation of the horizontal shaft in the ship body sailing state; and adding the received rotation calibration angle of the horizontal shaft and the received rotation calibration angle of the pitching shaft to obtain the rotation angle of the pitching shaft, which is required to be achieved by the actual rotation of the pitching shaft in the sailing state of the ship body, and sending the initial angle of the pitching shaft and the rotation calibration angle of the pitching shaft to a control module.

5. The shipborne satellite antenna tracking system according to claim 3, characterized in that the rotation angle range of the pitching axis (3) is 0-95 degrees, when the rotation angle of the pitching axis (3) is 0, the antenna beam pointing direction is coincident with the horizontal axis (2) axis; the antenna beam is directed upwards and perpendicular to the axis of the horizontal axis (2) when the rotation angle range of the elevation axis (3) is 90 degrees.

6. The shipborne satellite antenna tracking system according to claim 3, further comprising a differential GPS and a tilt sensor, wherein the differential GPS is arranged on the ship body and is used for measuring the position and the course angle of the ship body in real time and sending the position and the course angle of the ship body to the acquisition module, and the tilt sensor is arranged on the ship body and is used for measuring the roll angle and the pitch angle of the ship body in real time and sending the roll angle and the pitch angle to the acquisition module.

Technical Field

The invention relates to the technical field of satellite tracking, in particular to a shipborne satellite antenna seat and a shipborne satellite antenna tracking system.

Background

In the shipborne satellite antenna tracking, the technical problem that the hemispherical airspace satellite continuous tracking is difficult to realize by the conventional double-shaft antenna pedestal design mode is solved, the common double-shaft antenna pedestal comprises a pitching-azimuth type antenna pedestal and an X-Y-axis type antenna pedestal, the pitching-azimuth type antenna pedestal has a top-crossing tracking blind area, the X-Y-axis type antenna pedestal can well solve the top-crossing problem, but the X-Y-axis type antenna pedestal has the problems of shaft counterweight and low elevation angle tracking difficulty, two tracking blind areas can appear along the X-axis direction when the elevation angle is low, and the blind areas are located on the horizon at infinite distance from two ends of the X-axis, so that the conventional double-shaft antenna pedestal is difficult to realize the hemispherical airspace satellite continuous tracking. The biggest difference between the shipborne satellite antenna and the ground fixed antenna is that a carrier for placing the antenna is a movable and swinging ship body, so that a stable antenna platform is needed to isolate the swinging of the ship body, the attitude stability of the antenna in motion is realized, the satellite is tracked and aligned in the moving process on the basis of the attitude stability, and the real-time dynamic accurate tracking of the orbit satellite is difficult to realize under the condition that a special shipborne stable platform is not available.

Disclosure of Invention

The technical problem solved by the invention is as follows: the ship-borne satellite antenna pedestal and the ship-borne satellite antenna tracking system can realize real-time dynamic accurate tracking of the orbit satellite.

The specific solution provided by the invention is as follows:

the invention provides a ship-borne satellite antenna pedestal, which comprises: the device comprises an azimuth shaft, a horizontal shaft, a pitching shaft and a servo driving mechanism, wherein the horizontal shaft is arranged on the azimuth shaft, the pitching shaft is arranged on the horizontal shaft, the pitching shaft is perpendicular to the horizontal shaft, and the servo driving mechanism is used for driving the azimuth shaft, the horizontal shaft and the pitching shaft to rotate around respective axes respectively.

According to the shipborne satellite antenna seat, the azimuth axis, the horizontal axis and the pitching axis can respectively rotate around the axes where the azimuth axis, the horizontal axis and the pitching axis are located, and the low elevation angle tracking difficulty and the over-top tracking blind area can be avoided, so that the continuous tracking of a hemispherical airspace satellite is realized, and the real-time dynamic accurate tracking of a shipborne satellite antenna on an orbit satellite is realized.

On the basis of the above scheme, the technical scheme of the invention can be further improved as follows:

further, servo drive mechanism is including being used for the drive the azimuth axis is around its rotatory first servo motor of axis, is used for the drive the horizontal axis is around its rotatory second servo motor of axis and be used for the drive the pitch axis is around its rotatory third servo motor of axis, azimuth axis lower extreme is fixed in first servo motor's the pivot, second servo motor is fixed in azimuth axis upper end, horizontal axis one end is fixed in second servo motor's the pivot, third servo motor is fixed in the other end of horizontal axis, the pitch axis is fixed in third servo motor's the pivot.

The rotation angles of the azimuth axis, the horizontal axis and the pitch axis are accurately controlled by using the servo motor as a drive.

The invention also provides a ship-borne satellite antenna tracking system, which comprises: the antenna pedestal is arranged on the ship body, and the azimuth axis is arranged in parallel to the normal of the ship body; an antenna fixed on the pitch axis; the acquisition module is used for acquiring a satellite motion track, a ship body position, a transverse rocking angle, a longitudinal rocking angle and a course angle of a ship body, and sending the satellite motion track, the ship body position, the transverse rocking angle, the longitudinal rocking angle and the course angle to the tracking calculation module; the tracking calculation module is used for calculating an azimuth axis rotation angle, a horizontal axis rotation angle and a pitch axis rotation angle which are required by the antenna wave beam to be aligned with the target satellite at each moment in the ship navigation state according to the received satellite motion track, the ship position, the course angle, the roll angle and the pitch angle, and sending the azimuth axis rotation angle, the horizontal axis rotation angle and the pitch axis rotation angle to the control module; and the control module is used for controlling the servo driving mechanism to drive the azimuth shaft, the horizontal shaft and the pitching shaft to rotate corresponding angles around respective axes according to the received azimuth shaft rotation angle, horizontal shaft rotation angle and pitching shaft rotation angle.

The shipborne satellite antenna tracking system can control the azimuth axis, the horizontal axis and the pitching axis of the antenna base to rotate by corresponding angles according to the motion condition of the ship body, thereby realizing the continuous tracking of the hemispherical airspace satellite and realizing the real-time dynamic accurate tracking of the shipborne satellite antenna on the orbit satellite.

Further, the tracking calculation module includes: a first calculating unit, configured to calculate, according to the received satellite motion trajectory and the initial position of the hull, that the hull is in the initial position state, at each time, the antenna beam pointing to the target satellite, and the azimuth angle α of the antenna beam pointing to the bow of the ship_jAnd the azimuth angle alpha is measured_jSent to a control module, the azimuth angle alpha_jAn azimuth axis rotation angle required for the antenna beam to be directed at a target satellite;

a second calculation unit, configured to calculate, according to the received satellite motion trajectory, the real-time position of the hull, and the heading angle, that the hull is in a driving state without pitching and rolling, an antenna beam pointing to the target satellite at each time, and an azimuth angle α pointed to with respect to the bow of the ship_iAnd the pitch angle beta of the antenna beam_i(ii) a For determining the azimuth angle alpha at each time_iAnd the azimuth angle alpha_jAnd said pitch angle β_iCalculating the angle theta required by the rotation of the horizontal axis of the antenna pedestal when the antenna beam points to the target satellite at each moment in the driving state without pitching and rolling_xiAngle theta required for rotation of pitch axis of antenna mount_yiAnd angle theta_xiAnd angle theta_yiSending the data to a fourth computing unit; the angle theta_xiIs the initial angle of the horizontal axis, the angle theta_yiIs the initial angle of the pitching axis;

a third calculating unit, which is used for receiving the rolling angle and the pitching angle of the ship body and the azimuth angle alpha pointed by the antenna wave beam relative to the ship head when the ship body is in the initial position state under the driving state of pitching and/or rolling_jAccording to the roll angle, pitch angle and azimuth angle alpha_jCalculating the driving state of the hull in pitching and/or rollingNext, the antenna beam is aligned to the rotation calibration angle of the horizontal axis and the rotation calibration angle of the pitch axis required by the target satellite at each moment so as to compensate for the deviation of the antenna beam pointing direction caused by the hull rolling and/or hull pitching, and the rotation calibration angle of the horizontal axis and the rotation calibration angle of the pitch axis are sent to the fourth computing unit;

the fourth calculation unit is used for summing the received initial angle of the horizontal shaft at each moment and the rotation calibration angle of the horizontal shaft to obtain the rotation angle of the horizontal shaft, which is required to be achieved by the actual rotation of the horizontal shaft in the ship body sailing state; and adding the received rotation calibration angle of the horizontal shaft and the received rotation calibration angle of the pitching shaft to obtain the rotation angle of the pitching shaft, which is required to be achieved by the actual rotation of the pitching shaft in the sailing state of the ship body, and sending the initial angle of the pitching shaft and the rotation calibration angle of the pitching shaft to a control module.

The ground fixed antenna can accurately track the satellite only by knowing the motion track of the satellite and the position of the ground fixed antenna; the difference between the shipborne satellite antenna and the ground fixed antenna is that the position and the course of a ship are always changed in the running process of the ship, and the pitching and the rolling in the running process of the ship body can be influenced. The azimuth axis rotation angle, the horizontal axis rotation angle, and the pitch axis rotation angle at each time are as follows:

(1) the azimuth axis rotation angle at each time is obtained by: calculating the azimuth angle alpha of the antenna beam pointing to the target satellite at each moment when the ship body is in the initial position state, wherein the antenna beam pointing to the ship head_jAnd the rotation angle is used as the azimuth axis rotation angle of the Z axis of the antenna pedestal at each moment.

(2) The horizontal axis rotation angle and pitch axis rotation angle acquisition process is as follows:

firstly, calculating the angle required to be reached by the rotation of a horizontal shaft, namely the initial angle theta of the horizontal shaft, wherein the antenna wave beam points to a target satellite at each moment when the ship body is in a driving state without pitching and rolling_xiThe angle to which the pitch axis is rotated, i.e. the pitch axis initial angle theta_yiSpecifically, by the following meansObtaining: according to the received satellite motion track, the real-time position and the course angle of the ship body, the ship body is calculated to be in a pitching and rolling-free running state, the antenna beam direction is aligned to the target satellite at each moment, and the azimuth angle alpha of the antenna beam direction relative to the ship bow direction is calculated_iAnd the pitch angle beta of the antenna beam_i(ii) a Then according to said azimuth angle alpha at each moment_iAnd the azimuth angle alpha_jAnd said pitch angle β_iAnd (4) calculating.

Secondly, when the ship body is in pitching and/or rolling, the initial angle theta of the horizontal shaft is rotated and rotated on the horizontal shaft_xiAnd the pitch axis rotates the pitch axis by the initial angle theta_yiThe angles of rotation of the horizontal axis and the pitch axis, that is, the angle of rotation calibration of the horizontal axis and the angle of rotation calibration of the pitch axis, are further adjusted to compensate for the deviation of the antenna beam pointing direction caused by the hull roll and/or hull pitch, and specifically, the angle of rotation calibration of the horizontal axis and the angle of rotation calibration of the pitch axis are obtained by: according to the roll angle and the pitch angle of the ship body and the azimuth angle alpha of the antenna beam pointing direction relative to the ship head pointing direction of the ship body in the initial position state_jAnd (4) calculating.

Finally, adding the initial angle of the horizontal shaft and the rotation calibration angle of the horizontal shaft to obtain the rotation angle of the horizontal shaft, which is required to be achieved by the actual rotation of the horizontal shaft in the ship body sailing state; and adding the initial angle of the pitch axis and the rotation calibration angle of the pitch axis to obtain the rotation angle of the pitch axis, which is required by the actual rotation of the pitch axis in the ship navigation state.

Further, the rotation angle range of the pitching axis is 0-95 degrees, and when the rotation angle of the pitching axis is 0, the beam direction of the antenna is coincided with the axis of the horizontal axis; the antenna beam is directed upward and perpendicular to the horizontal axis when the tilt axis is rotated through a range of 90 °.

The antenna pedestal can realize the tracking of any satellite track in a nearly hemispherical area under the condition of pitching and/or rolling; and the antenna pedestal has reduced limitation on the size of the antenna, can be used for mounting a large-caliber antenna, and has wide application range.

The system comprises a ship body, a differential GPS and an inclination angle sensor, wherein the differential GPS is arranged on the ship body and used for measuring the position and the course angle of the ship body in real time and sending the position and the course angle of the ship body to the acquisition module, and the inclination angle sensor is arranged on the ship body and used for measuring the roll angle and the pitch angle of the ship body in real time and sending the roll angle and the pitch angle to the acquisition module.

Therefore, the position and the course angle of the ship body are obtained through the differential GPS, and the roll angle and the pitch angle of the ship body are measured by the inclination angle sensor. The transverse rocking angle and the longitudinal rocking angle respectively range from minus 90 degrees to plus 90 degrees, and the signs represent the inclination directions of the transverse rocking angle and the longitudinal rocking angle.

According to the shipborne satellite antenna tracking system disclosed by the invention, under the condition that a ship body swings, the satellite tracking equipment (antenna) can still aim narrow beams at a high-speed mobile satellite of any orbit in real time, so that the satellite-borne equipment can intercept signals transmitted by the satellite tracking equipment in real time.

Drawings

Fig. 1 is a schematic right-view structural diagram of an antenna mount according to an embodiment of the present invention.

Fig. 2 is a schematic rear view structure according to an embodiment of the present invention.

Fig. 3 is a schematic structural diagram of a shipborne satellite antenna tracking system according to the present invention.

Fig. 4 shows the rotation angle of each axis in the satellite tracking process.

Fig. 5 shows the direction and pitch values of the antenna beam pointing during satellite tracking.

In fig. 1-5, the names of the components represented by the various reference numbers are as follows:

an azimuth axis 1;

a horizontal axis 2;

a pitch axis 3;

an antenna 4.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

The invention is described with reference to specific embodiments in conjunction with figures 1-5.

As shown in fig. 1-2, the shipborne satellite antenna pedestal based on the invention comprises: the azimuth axis 1, the horizontal axis 2, the pitching axis 3 and the servo driving mechanism, wherein the horizontal axis 2 is arranged on the azimuth axis 1, the pitching axis 3 is arranged on the horizontal axis 2, the pitching axis 3 is perpendicular to the horizontal axis, and the servo driving mechanism is used for respectively driving the azimuth axis 1, the horizontal axis 2 and the pitching axis 3 to rotate around respective axes. According to the shipborne satellite antenna seat, the azimuth axis, the horizontal axis and the pitching axis can respectively rotate around the axes where the azimuth axis, the horizontal axis and the pitching axis are located, and the low elevation angle tracking difficulty and the over-top tracking blind area can be avoided, so that the continuous tracking of a hemispherical airspace satellite is realized, and the real-time dynamic accurate tracking of a shipborne satellite antenna on an orbit satellite is realized.

Based on the shipborne satellite antenna pedestal, the servo driving mechanism comprises a first servo motor for driving the azimuth axis 1 to rotate around the axis of the azimuth axis 1, a second servo motor for driving the horizontal axis 2 to rotate around the axis of the horizontal axis, and a third servo motor for driving the pitching shaft 3 to rotate around the axis of the pitching shaft, the lower end of the azimuth axis 1 is fixed on a rotating shaft of the first servo motor, the second servo motor is fixed on the upper end of the azimuth axis 1, one end of the horizontal axis 2 is fixed on a rotating shaft of the second servo motor, the third servo motor is fixed on the other end of the horizontal axis 2, and the pitching shaft 3 is fixed on a rotating shaft of the third servo motor. The rotation angles of the azimuth axis, the horizontal axis and the pitch axis are accurately controlled by using the servo motor as a drive.

As shown in fig. 3, the ship-borne satellite antenna tracking system according to the present invention includes: the antenna pedestal is arranged on the ship body, and the azimuth axis 1 is arranged parallel to the normal of the ship body; an antenna 4, wherein the antenna 4 is fixed on the pitching shaft 3; the acquisition module is used for acquiring a satellite motion track, a ship body position, a transverse rocking angle, a longitudinal rocking angle and a course angle of a ship body, and sending the satellite motion track, the ship body position, the transverse rocking angle, the longitudinal rocking angle and the course angle to the tracking calculation module; the tracking calculation module is used for calculating an azimuth axis rotation angle, a horizontal axis rotation angle and a pitch axis rotation angle which are required by the antenna wave beam to be aligned with the target satellite at each moment in the ship navigation state according to the received satellite motion track, the ship position, the course angle, the roll angle and the pitch angle, and sending the azimuth axis rotation angle, the horizontal axis rotation angle and the pitch axis rotation angle to the control module; and the control module is used for controlling the servo driving mechanism to drive the azimuth shaft, the horizontal shaft and the pitching shaft to rotate corresponding angles around respective axes according to the received azimuth shaft rotation angle, horizontal shaft rotation angle and pitching shaft rotation angle. The azimuth axis, the horizontal axis and the pitch axis of the antenna pedestal can be controlled to rotate by corresponding angles according to the motion condition of the ship body, so that the continuous tracking of the hemispherical airspace satellite is realized, and the real-time dynamic accurate tracking of the shipborne satellite antenna on the orbit satellite is realized.

The shipborne satellite antenna tracking system based on the embodiment of the invention comprises a tracking calculation module and a tracking calculation module, wherein the tracking calculation module comprises: a first calculating unit, configured to calculate, according to the received satellite motion trajectory and the initial position of the hull, that the hull is in the initial position state, at each time, the antenna beam pointing to the target satellite, and the azimuth angle α of the antenna beam pointing to the bow of the ship_jAnd the azimuth angle alpha is measured_jSent to a control module, the azimuth angle alpha_jAn azimuth axis rotation angle required for the antenna beam to be directed at a target satellite; a second calculation unit, configured to calculate, according to the received satellite motion trajectory, the real-time position of the hull, and the heading angle, that the hull is in a driving state without pitching and rolling, an antenna beam pointing to the target satellite at each time, and an azimuth angle α pointed to with respect to the bow of the ship_iAnd the pitch angle beta of the antenna beam_i(ii) a For determining the azimuth angle alpha at each time_iAnd the azimuth angle alpha_jAnd said pitch angle β_iCalculating the angle theta required by the rotation of the horizontal axis of the antenna pedestal when the antenna beam points to the target satellite at each moment in the driving state without pitching and rolling_xiAngle theta required for rotation of pitch axis of antenna mount_yiAnd angle theta_xiAnd angle theta_yiSending the data to a fourth computing unit; the angle theta_xiIs the initial angle of the horizontal axis, the angle theta_yiIs the initial angle of the pitching axis; a third calculating unit, which is used for receiving the rolling angle and the pitching angle of the ship body and the azimuth angle alpha pointed by the antenna wave beam relative to the ship head when the ship body is in the initial position state under the driving state of pitching and/or rolling_jAccording to the roll angle, pitch angle and azimuth angle alpha_jCalculating a rotation calibration angle of a horizontal axis and a rotation calibration angle of a pitch axis, which are required by the antenna beam to align with the target satellite at each moment in the driving state of the ship body pitching and/or pitching, so as to compensate the deviation of the antenna beam pointing direction caused by the ship body rolling and/or the ship body pitching, and sending the rotation calibration angle of the horizontal axis and the rotation calibration angle of the pitch axis to a fourth calculation unit; the fourth calculation unit is used for summing the received initial angle of the horizontal shaft at each moment and the rotation calibration angle of the horizontal shaft to obtain the rotation angle of the horizontal shaft, which is required to be achieved by the actual rotation of the horizontal shaft in the ship body sailing state; and adding the received rotation calibration angle of the horizontal shaft and the received rotation calibration angle of the pitching shaft to obtain the rotation angle of the pitching shaft, which is required to be achieved by the actual rotation of the pitching shaft in the sailing state of the ship body, and sending the initial angle of the pitching shaft and the rotation calibration angle of the pitching shaft to a control module.

The ground fixed antenna can accurately track the satellite only by knowing the motion track of the satellite and the position of the ground fixed antenna; the difference between the shipborne satellite antenna and the ground fixed antenna is that the position and the course of a ship are always changed in the running process of the ship, and the pitching and the rolling in the running process of the ship body can be influenced. The azimuth axis rotation angle, the horizontal axis rotation angle, and the pitch axis rotation angle at each time are as follows:

(1) the azimuth axis rotation angle at each time is obtained by: calculating the azimuth angle alpha of the antenna beam pointing to the target satellite at each moment when the ship body is in the initial position state, wherein the antenna beam pointing to the ship head_jAnd the rotation angle is used as the azimuth axis rotation angle of the Z axis of the antenna pedestal at each moment.

(2) The horizontal axis rotation angle and pitch axis rotation angle acquisition process is as follows:

firstly, calculating the angle required to be reached by the rotation of a horizontal shaft, namely the initial angle theta of the horizontal shaft, wherein the antenna wave beam points to a target satellite at each moment when the ship body is in a driving state without pitching and rolling_xiThe angle to which the pitch axis is rotated, i.e. the pitch axis initial angle theta_yiSpecifically, the method comprises the following steps: according to the received satellite motion track, the real-time position and the course angle of the ship body, the ship body is calculated to be in a pitching and rolling-free running state, the antenna beam direction is aligned to the target satellite at each moment, and the azimuth angle alpha of the antenna beam direction relative to the ship bow direction is calculated_iAnd the pitch angle beta of the antenna beam_i(ii) a Then according to said azimuth angle alpha at each moment_iAnd the azimuth angle alpha_jAnd said pitch angle β_iAnd (4) calculating.

Secondly, when the ship body is in pitching and/or rolling, the initial angle theta of the horizontal shaft is rotated and rotated on the horizontal shaft_xiAnd the pitch axis rotates the pitch axis by the initial angle theta_yiThe angles of rotation of the horizontal axis and the pitch axis, that is, the angle of rotation calibration of the horizontal axis and the angle of rotation calibration of the pitch axis, are further adjusted to compensate for the deviation of the antenna beam pointing direction caused by the hull roll and/or hull pitch, and specifically, the angle of rotation calibration of the horizontal axis and the angle of rotation calibration of the pitch axis are obtained by: according to the roll angle and the pitch angle of the ship body and the azimuth angle alpha of the antenna beam pointing direction relative to the ship head pointing direction of the ship body in the initial position state_jAnd (4) calculating.

Finally, adding the initial angle of the horizontal shaft and the rotation calibration angle of the horizontal shaft to obtain the rotation angle of the horizontal shaft, which is required to be achieved by the actual rotation of the horizontal shaft in the ship body sailing state; and adding the initial angle of the pitch axis and the rotation calibration angle of the pitch axis to obtain the rotation angle of the pitch axis, which is required by the actual rotation of the pitch axis in the ship navigation state.

According to the shipborne satellite antenna tracking system disclosed by the embodiment of the invention, the range of the rotation angle of the pitching shaft 3 is 0-95 degrees, and when the rotation angle of the pitching shaft 3 is 0, the beam direction of the antenna is coincided with the axis of the horizontal shaft 2; when the rotation angle range of the elevation axis 3 is 90 °, the antenna beam is directed upward and perpendicular to the axis of the horizontal axis 2.

The antenna pedestal can realize the tracking of any satellite track in a nearly hemispherical area under the condition of pitching and/or rolling; and the antenna pedestal has reduced limitation on the size of the antenna, can be used for mounting a large-caliber antenna, and has wide application range.

As shown in fig. 3, the shipborne satellite antenna tracking system based on the embodiment of the present invention further includes a differential GPS and an inclination sensor, the differential GPS is disposed on the ship body and is configured to determine a position and a heading angle of the ship body in real time and send the position and the heading angle of the ship body to the obtaining module, and the inclination sensor is disposed on the ship body and is configured to determine a roll angle and a pitch angle of the ship body in real time and send the roll angle and the pitch angle to the obtaining module. The position and the course angle of the ship body are obtained through a differential GPS, and the roll angle and the pitch angle of the ship body are measured by an inclination angle sensor. The transverse rocking angle and the longitudinal rocking angle respectively range from minus 90 degrees to plus 90 degrees, and the signs represent the inclination directions of the transverse rocking angle and the longitudinal rocking angle.

The process of carrying out satellite tracking by the shipborne satellite antenna tracking system based on one embodiment of the invention comprises the following steps:

the method comprises the following steps: resetting and calibrating the antenna pedestal to ensure that the antenna pedestal device is in a resetting state (namely a tracking starting point state, at the moment, an antenna beam points to a satellite, an azimuth axis (hereinafter, an antenna pedestal Z axis) is arranged in parallel with the normal line of the ship body, a horizontal axis (hereinafter, an antenna pedestal X axis) is parallel with a ship body pitching axis, a pitching axis (hereinafter, an antenna pedestal Y axis) is parallel with a ship body swaying axis, the antenna pedestal Z axis can rotate around the axis where the antenna pedestal Z axis is positioned at 0-360 degrees, the pointed azimuth angle of the ship head in the resetting state is defined as the 0-degree azimuth angle of the antenna pedestal Z axis, and the pointed azimuth direction of the ship head is defined as the 0-degree direction of the antenna pedestal.

Step two: calculating the azimuth angle alpha of the antenna beam pointing to the target satellite at each moment when the ship body is in the initial position state, wherein the antenna beam pointing to the ship head_jAnd the azimuth angle alpha is measured_jAnd sending the data to a control module, wherein the specific process comprises the following steps:

and (2-1) calculating the angular speed of the Z-axis rotation of the antenna pedestal.

Calculating to obtain the track starting point parameter (alpha) of the antenna base tracking satellite under the state that the ship body is at the initial position (namely under the static state) according to the satellite motion track and the initial position of the ship body₀,β₀,t₀) The tracking endpoint parameter is (alpha)_N,β_N,t_N) Arbitrarily tracking time t_iThe satellite trajectory point parameter is (alpha)_i，β_i，t_i) In the satellite tracking process, for the convenience of calculation and control, the Z axis of the antenna pedestal is set to rotate at a constant speed, that is, the angular velocity of the Z axis of the antenna pedestal is a fixed value, the angular velocity of the Z axis of the antenna pedestal can be obtained according to the parameter information of the azimuth angle of the satellite tracking starting point and the azimuth angle of the satellite tracking end point, and the angular velocity of the Z axis of the antenna pedestal is shown in formula (1):

t_N＝t₀+N·Δt，N＝0,1,2…i

(2-2) calculating the azimuth angle of the actual direction of the antenna beam relative to the direction of 0 degree of the Z axis of the antenna pedestal at each moment according to the rotating angular speed of the Z axis of the antenna pedestal;

in the real-time satellite trajectory tracking process of the antenna pedestal, the Z axis of the antenna pedestal always follows the angular velocity delta alpha_vIf the antenna base rotates at a constant speed, after the time i · Δ t, the rotating azimuth angle of the Z axis of the antenna base is the actual rotating azimuth angle of the antenna beam, and the calculation of the actual pointing azimuth angle of the antenna beam at the time is shown in formula (2):

in the formulae (1) and (2), Delta alpha_vAngular velocity, a, of Z-axis rotation of the antenna mount₀Tracking the azimuth angle alpha of the beam pointing of the antenna of the starting point relative to the Z axis of the antenna pedestal by 0 DEG under the state that the ship body is at the initial position_jTo track time t_iThe antenna beam is actually directed at an azimuth angle, a, of 0 deg. with respect to the Z-axis of the antenna mount_NFor tracking the azimuth angle, t, of the end-point antenna beam pointing at 0 deg. with respect to the Z-axis of the antenna mount₀Satellite tracking start time, t_NFor tracking the end point time, Δ t is the time step of the rotation angle of the Z axis of the antenna pedestal, where N is 0,1,2 … i; i is 0,1,2 …; delta alpha_vThe angular speed of the rotation of the Z axis of the antenna pedestal is theta more than or equal to 0 DEG_ziLess than or equal to 360 degrees, and in the calculation process, if the angle value of more than 360 degrees appears, 360 degrees need to be subtracted, and if the angle value of less than 0 degrees needs to be added, 360 degrees need to be added.

Step three: calculating the angle theta required to be reached when the ship body is in a driving state without pitching and rolling, the antenna beam points to the target satellite, and the horizontal axis of the antenna pedestal rotates at each moment_xiAngle theta required to be reached by rotation of pitching axis of antenna base at each moment_yiSaid angle θ_xiIs the initial angle of the horizontal axis, the angle theta_yiIs the pitch axis initial angle.

Because the Z axis of the antenna mount is set to change at a constant speed, at any time, the actual azimuth angle pointed by the antenna beam after the Z axis of the antenna mount rotates inevitably deviates from the azimuth angle pointed by the antenna beam aligned with the satellite (the antenna beam points to the satellite), and the deviation of the azimuth angle pointed by the antenna beam can be compensated by rotating the X axis and the Y axis, and the specific calculation process is as follows:

(3-1) acquiring the motion trail of the satellite and the real-time position of the ship body under the driving state without pitching and rolling, and calculating to obtain the starting point parameter (alpha) of the satellite track tracked by the antenna base at each time_a0,β_e0,t₀) The terminal parameter of the tracked satellite track is (alpha)_aN,β_eN,t_N) Arbitrarily tracking time t_iThe satellite trajectory point parameter is (alpha)_ai，β_ai，t_i)。

(3-2) calculating an azimuth angle that the antenna beam points to the satellite should satisfy:

(3-3) calculating a pitch angle that the antenna beam points to the satellite should satisfy:

β_i＝β_ai(4)

in the above formula, A is the tracking time t_iThe bow points at an azimuth angle relative to the north positive angle; alpha is alpha_aiTo track time t_iThe antenna beam points to the azimuth angle of the satellite relative to the north angle; alpha is alpha_iTo track time t_iThe antenna beam points at the azimuth of the satellite relative to the bow of the vessel; beta is a_iThe antenna beam is pointed at the elevation angle of the satellite for the i · Δ t time.

Specifically, A is a course angle which can be obtained by a differential GPS; alpha is alpha_aiThe azimuth angle of the antenna beam pointing satellite relative to the north-positive angle can be obtained by calculating the satellite motion track and the real-time position of the ship body, and the satellite motion track and the real-time position of the ship body can be respectively obtained by a satellite operation control center and a differential GPS.

And (3-4) calculating an initial angle of a horizontal axis and an initial angle of a pitch axis.

Because the Z axis of the antenna pedestal always rotates at a constant speed, which does not meet the actual requirement of actual tracking of the satellite, the actual pointing azimuth angle of the antenna beam after the Z axis of the antenna pedestal rotates at the ith · Δ t (i is 0,1,2 …) and the azimuth angle of the antenna beam pointing to the satellite must deviate, in order to realize accurate tracking of the antenna beam to the satellite, that is, to realize that the antenna beam is aligned to the target satellite, the deviation of the pointing azimuth angle of the antenna beam is compensated, the required rotating angle of the X axis of the antenna pedestal is:

in order to realize accurate tracking of the antenna beam to the satellite and compensate the azimuth deviation pointed by the antenna beam, the required rotating angle of the Y axis of the antenna pedestal is as follows:

θ_yi＝90°-arcsin(cosΔa_icosβ_i) (6)

Δα_i＝α_j-α_i (7)

θ_xiin the driving state without pitching and rolling, at the ith-delta t moment, in order to compensate the azimuth angle deviation of the antenna beam pointing direction, the angle of the X axis which should be rotated is the initial angle of the horizontal axis; theta_yiIn the driving state without pitching and rolling, at the ith-delta t moment, in order to compensate the azimuth angle deviation of the antenna beam pointing direction, the angle which the Y axis should rotate is the initial angle of the pitching axis; delta alpha_iThe azimuth deviation, beta, of the actual antenna beam pointing direction from the azimuth angle that the satellite should meet for the i · Δ t time_iThe antenna wave beam points to the pitch angle of the satellite at the ith-delta t moment; alpha is alpha_iTo track time t_iThe antenna beam points at the azimuth of the satellite relative to the bow of the vessel; alpha is alpha_jTo track time t_iThe antenna beam is actually pointing at an azimuth angle of 0 deg. with respect to the Z-axis of the antenna mount.

Assuming a certain moment, theoretically, the antenna beam pointing to the satellite should satisfy an azimuth angle of 19.5 ° and a pitch angle β_i20 deg. but the Z-axis of the antenna mount has only rotated at a constant speed to an azimuth angle of 17.6 deg., from which it can be derived, deltaa_iAzimuth angle, pitch angle and Δ a are adjusted to 1.9 °_iSubstituting equation (5) and equation (6) for 1.9 yields θ_yi≈20.086，θ_xi≈5.205。

Therefore, when the ship body is in a driving state without pitching and rolling, the specific tracking process is as follows:

tracking the starting point moment, and respectively rotating an antenna pedestal Z axis, an antenna pedestal X axis and an antenna pedestal Z axis to enable an antenna beam to be aligned with a satellite, wherein the antenna beam corresponds to an azimuth angle and a pitch angle; tracking time t at any time without pitching and rolling of the hull_iOnly the following are required: azimuth angle rate of change of antenna pedestal Z axis all the timeIs delta alpha_vThe angle of the X-axis rotation satisfies theta_xiThe angle of rotation of the X-axis satisfies theta_yiThe accurate tracking and the over-top tracking of the satellite can be realized, as shown in fig. 4 and 5, which are the rotation angle of each axis in the satellite tracking process and the direction value and the pitch value of the antenna beam pointing in the satellite tracking process in a specific satellite over-top tracking process respectively.

Step four: and calculating the rotation calibration angle of the horizontal axis and the rotation calibration angle of the pitching axis required by the antenna beam to be aligned with the target satellite at each moment under the driving state that the ship body is in the pitching and/or pitching so as to compensate the deviation of the antenna beam pointing direction caused by the ship body rolling and/or the ship body pitching.

In the presence of roll and pitch of the hull: the hull shaking generates a pitching angle and a rolling angle, so that the antenna beam pointing direction and the offset of the normal direction of the hull are brought, the offset can be calibrated and compensated through rotating the X axis and the Y axis, and the specific calibration compensation angles (namely the rotation calibration angle of the horizontal axis and the rotation calibration angle of the pitching axis) are calculated as follows:

(4-1) calculating the normal direction change of the ship body caused by rolling and pitching according to the rolling angle and the pitching angle, wherein the normal direction of the ship body after the change isWherein alpha is_iIs the normal line of the ship bodyAzimuth angle, beta, directed at 0 deg. with respect to the Z axis of the antenna mount_i' isThe pitch angle of (d).

Specifically, a space coordinate system 1 (X) is established by taking the antenna pedestal device as a center when the ship body does not roll or pitch₁、Y₁、Z₁) Wherein the coordinate system X₁Axis is parallel to the straight line of the ship (or ship) and coordinate system Y₁The axis is parallel to the head and tail lines of the ship (or warship), and the coordinate system Z₁Axle (i.e. hull normal)) Points to the opposite direction of the geocentric,perpendicular to the straight transverse line and the head-tail line of the ship (or warship), and the direction is parallel to the Z axis of the antenna pedestal. Normal to ship body caused by rolling and pitchingA change in orientation, andthe directional change is consistent with the Z-axis directional change of the antenna pedestal. Without pitch and roll, assume hull normalThe azimuth angle which points at 0 degrees relative to the Z axis of the antenna pedestal is 0, and when the ship rolls and pitches, the normal line of the ship body is normalThe pointing direction changes, the beam pointing is off the satellite, and at this time,has an azimuth angle of alpha_i', pitch angle is beta_i′。

When the roll angle is less than theta from minus 90 degrees_RiTheta is not more than 0 degree and the longitudinal rocking angle is not less than 0 degree_PiLess than 90 degrees to the normal of the ship bodyPointed azimuth angle alpha_i' is located in the first quadrant, i.e. the azimuth angle alpha_iThe range of' is 0 to 90 DEG, alpha_iThe calculation of' is shown in equation (8):

when crossingThe rocking angle is more than theta from minus 90 degrees_RiLess than 90 degrees, pitch angle-90 degrees and theta_PiNot more than 0 degree and normal line of ship bodyPointed azimuth angle alpha_i' is located in the second and third quadrants, i.e. the azimuth angle alpha_iThe range of' is 90 to 270 DEG, alpha_iThe calculation of' is shown in equation (9):

when the transverse rocking angle is not less than 0 degree_RiTheta is less than 90 degrees and the longitudinal rocking angle is less than or equal to 0 degree_PiLess than 90 degrees to the normal of the ship bodyPointed azimuth angle alpha_i' in the fourth quadrant (azimuth angle range 270-360 DEG), alpha_iThe calculation of' is shown in equation (10):

the transverse rocking angle is more than theta from minus 90 degrees_RiLess than 90 degrees, pitch angle-90 degrees and theta_PiLess than 90 degrees to the normal of the ship bodyThe range of the corresponding pitch angle is 0 to 90 degrees and beta_iThe calculation of' is as in equation (11):

β_i′＝arcsin(cos(θ_Ri)×cos(θ_Pi)) (11)

in the above formula, α_i' for pitch and roll conditions, the hull normalDirected at an azimuth angle of 0 deg. relative to the Z-axis of the antenna mount, i.e. the Z-axis of the antenna mount is directed at an azimuth angle of 0 deg. relative to the Z-axis of the antenna mount, beta_i' isAngle of pitch, theta_RiIs the ship roll angle, theta_PiIs the ship pitch angle;

(4-2) normalizing the ship bodyDirection inversion is obtained

Normal of ship bodyThe direction reversal is to counteract the directional direction angle and pitch angle change of antenna wave beam caused by rolling and pitching at the moment, the rotation of X-axis and Y-axis is required to achieve the directional change of the wave beam, A_iThe calculation of' is shown in equation (12):

β_i"＝β_i'

in the above formula, α_i' for pitch and roll conditions, the hull normalDirected at an azimuth angle, A, of 0 DEG with respect to the Z-axis of the antenna mount_i' isAzimuth angle, beta, directed at 0 deg. with respect to the Z axis of the antenna mount_i' isAngle of pitch, beta_i' isThe pitch angle of (d).

(4-3) computation trackingUnder the condition of the time-lapse,pointing at an azimuth angle relative to the time of day antenna mount Z-axis pointing.

In the process of satellite tracking, the directions of an X axis and a Y axis in the antenna pedestal and the direction of a ship head change along with the rotation of a Z axis of the antenna pedestal, and the directions are pointed at the ith delta t momentAzimuth angle C pointing relative to Z axis of antenna pedestal_iThe calculation is shown in equation (13):

θ_zi＝a_j

in the above formula, θ_ziFor tracking the time i.Deltat, the Z axis of the antenna mount points at an azimuth angle of 0 DEG relative to the Z axis of the antenna mount, A_i' in order to track the time of day,pointing at an azimuth angle of 0 deg. with respect to the Z-axis of the antenna mount, Ci' being the tracking moment,pointing to an azimuth angle relative to the Z-axis pointing direction of the antenna pedestal at the moment; alpha is alpha_jTo track time t_iThe antenna beam is actually pointing at an azimuth angle of 0 deg. with respect to the Z-axis of the antenna mount.

(4-4) according toAn azimuth angle pointing to the Z-axis of the antenna mount at that moment andand (4) calculating a rotation calibration angle of a horizontal shaft of the antenna pedestal and a rotation calibration angle of a pitch shaft according to the pointed pitch angle.

In order to compensate the tracking error caused by the rolling and pitching of the ship body, the rotation of the X axis of the antenna pedestal and the Y axis of the antenna pedestal is calibrated by an angle theta_xi' and theta_yiThe calculation of' is shown in equation (14) and equation (15):

θ_yi′＝90°-arcsin(cosC_i'cosβ_i”) (15)

in the above formula, C_i' in order to track the time of day,azimuth angle, beta, directed relative to the Z-axis of the antenna mount at that moment_i' isAngle of pitch, theta_xi' is a horizontal axis rotation calibration angle, θ_yi' is the pitch axis rotation calibration angle.

And (4-4) calculating the rotation angle of the horizontal axis, the rotation angle of the pitch axis and the rotation angle of the azimuth axis of the antenna pedestal at each moment when the antenna beam points to the satellite.

At each moment, the antenna beam tracks the satellite, and the angular trajectories of the rotation of the X axis of the antenna pedestal, the Y axis of the antenna pedestal and the Z axis of the antenna pedestal, namely the rotation angles of the horizontal axis, the pitch axis and the azimuth axis corresponding to each moment are shown in formulas (16) to (18):

θ_Xi＝θ_xi+θ_xi′ (16)

θ_Yi＝θ_yi+θ_yi′ (17)

in the above formula, C_i' is the i.at time of tracking,azimuth angle theta pointing to the Z-axis of the antenna mount at that moment_xi' rotation of the horizontal axis by a calibrated angle; theta_yi' is the pitch axis rotation calibration angle; theta_xiIs the initial angle of the horizontal axis; theta_yiIs the initial angle of the pitching axis; theta_XiIs the angle of rotation of the horizontal axis, theta_YiAngle of rotation of pitch axis, θ_ZiIs the azimuth axis rotation angle; delta alpha_vThe angular velocity of the rotation of the azimuth axis of the antenna pedestal.

In particular, said theta_xi、θ_Yi、θ_Xi、θ_Yi、θ_Zi、Δα_vAll have directionality, positive values represent clockwise rotation and negative values represent counterclockwise rotation.

Although embodiments of the present invention have been described in detail above, those of ordinary skill in the art will understand that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.