CN104369877A - Method for designing pointing of antenna of deep space probe - Google Patents

Abstract

The invention provides a method for designing the antenna pointing of a deep space detector, the specific steps are: step 1, calculating the representation of the detector-earth center orientation vector on the mechanical coordinate system Step two, according to the Calculate the angle θ between the omnidirectional antenna azimuth vector and the detector-measurement and control station; step 3, when the angle θ is greater than the maximum allowable angle γ, make the detector rotate around the +x axis of the detector mechanical coordinate system, so that The gain of the omnidirectional antenna after rotation meets the requirements of uplink and downlink. This method rotates a certain angle around the sun orientation axis to ensure the continuity of the measurement and control process, reduce the operation of switching antennas on the ground, and reduce the complexity of ground operations.

Description

A Design Method of Antenna Pointing for Deep Space Detector

technical field

The invention relates to the technical field of deep space detection, in particular to a method for designing the antenna pointing of a deep space detector. the

Background technique

During the earth-moon transfer and the flight around the moon, the deep space probe usually adopts a fixed axis of the mechanical system (defined as +X axis below) to orient itself to the sun in the normal cruising mode and in the state of not imaging the moon, so as to ensure the solar wing method The line direction is parallel to the sunlight direction. In this case, if the installation orientation of the omnidirectional TT&C antenna can be parallel to the ±X-axis, whether the detector rotates around the X-axis will not affect the angle between the antenna axis and the detector-TTCS, so that the cruising flight of the detector will not be affected. There are no constraints required for poses. Under such conditions, the detector will adopt a slow-spin attitude, which can not only avoid the concave point of the antenna, but also improve the anti-interference ability by using the spin stability feature. the

However, for a detector with a complex configuration, there are many devices on the surface of the device, which limits the installation space. It is necessary to adopt a layout with a certain angle with the ±X axis of the detector to minimize the impact of the equipment around the antenna on the detector. the effect of its gain. Under this layout, if the detector adopts the spin mode, the angle between the antenna axis and the detector-measurement and control station may change periodically in the range of 0 to 180 degrees. If the ground measurement and control system performs an uplink command operation, the ground It is necessary to judge the antenna that is beneficial to the ground in real time, and switch the uplink frequency point frequently and periodically (usually the detector is equipped with two sets of omnidirectional antennas A and B in the entire space, and the omnidirectional antennas A and B are responsible for half of the space, with a point difference of 180 degrees. Omnidirectional antennas A and B have different point frequencies) to adapt to the above-mentioned angle change, thus increasing the work intensity and task complexity of the monitoring and operation of the ground measurement and control system. During this period of time, the uplink command cannot be sent, which reduces the emergency response capability. However, if the spin is not performed, it is also found according to the analysis that when the detector +X axis is oriented to the sun, and the Y and Z axes point to certain specific directions, the angle between the antenna axis and the detector-measurement and control station will always be at 90 degrees Oscillating near , at this time, the gain of the omnidirectional antenna on the upper and lower sides of the detector is the lowest, and there is still the problem of frequent switching point frequency. In order to ensure the antenna pointing, simply make the solar orientation axis of the detector deviate from the sun vector, because most of the solar wings are not driven by two axes, the pointing direction cannot be fully adapted, so that the normal line of the sun wing deviates from the direction of the sun vector, thus affecting the solar wing At the same time, because the sensor is fixedly installed on the detector and the field of view is limited, the pointing is usually aimed at a specific spatial range. If the orientation axis to the sun deviates from the sun vector, it may affect the normal capture and tracking of the sun sensor by the sun sensor. Or the star sensor is interfered by stray light such as sunlight and cannot work normally. the

Therefore, for the omnidirectional antenna, it is necessary to optimize the design of the Y and Z axis points (rotate a specific angle around the X axis) while the +X axis points to the sun to solve the above problems. the

For the landing mission on the far side of the moon, since the lander cannot achieve direct communication with the ground, it is necessary to use a probe around the moon or at the Lagrangian point (L2 point) of the earth and the moon (that is, a relay satellite) to realize data transmission. The efficiency of data transmission through the relay satellite, especially the real-time monitoring of the key mission stage, needs to realize real-time forwarding, and the relay satellite must use two sets of directional antennas for the ground and the moon. Due to the narrow beam of the directional antenna, considering the orbit changes of the earth and the moon, it is generally necessary to use a two-axis rotating tracking mechanism to achieve continuous long-term pointing to the earth and the moon, but the use of a rotating mechanism will increase weight and power consumption, and pointing control Calculations are complex and so on. the

Therefore, a relatively simple pointing control method must be designed for directional antennas to ensure that the moon and the ground point at the same time for a long time, and meet the pointing constraints required for solar wing power supply. the

Contents of the invention

In view of this, the purpose of the present invention is to overcome the deficiencies in the prior art and provide a method for designing the antenna pointing of a deep space probe, which can make the whole Rotate the antenna at a certain angle around the sun-aligning axis to achieve measurement and control. Only one set of antennas is used for most of the uplink and downlink, ensuring the continuity of the measurement and control process, reducing the operation of switching antennas on the ground and reducing the complexity of ground operations. At the same time, the antenna is in a position with a large gain Interval, improve the link channel margin. the

Technical solution of the present invention is as follows:

A kind of design method of antenna pointing of deep space probe, described antenna comprises omnidirectional antenna, and the concrete steps of described omnidirectional antenna pointing to ground are:

The mechanical coordinate system (X, Y, Z) of the detector is defined as: the +X axis is a fixed axis for orientation to the sun, and the +Y axis and +Z axis are determined according to the principle of the right-handed coordinate system;

Step 1. Calculate the representation of the detector-earth center azimuth vector on the mechanical coordinate system ${\stackrel{\&Right\; Arrow;}{V}}_{2m}=[{\stackrel{\&Right\; Arrow;}{V}}_{2\mathrm{mx}},{\stackrel{\&Right\; Arrow;}{V}}_{2\mathrm{my}},{\stackrel{\&Right\; Arrow;}{V}}_{2\mathrm{mz}}];$

Step two, according to the Calculate the angle θ between the omnidirectional antenna azimuth vector and the detector-measurement and control station;

$\mathrm{\θ}=\arccos \left(\frac{{\stackrel{\&Right\; Arrow;}{V}}_1\&Center\; Dot;{\stackrel{\&Right\; Arrow;}{V}}_{2m}}{\left|{\stackrel{\&Right\; Arrow;}{V}}_1\right|\left|{\stackrel{\&Right\; Arrow;}{V}}_{2m}\right|}\right)$ in, ${\stackrel{\&Right\; Arrow;}{V}}_1=\left[\begin{array}{ccc}{V}_{1x}& V_{1\mathrm{the\; y}}& V_{1z}\end{array}\right]$ is the azimuth vector of the omnidirectional antenna on the detector in the mechanical coordinate system of the detector;

Step 3: When the included angle θ is greater than the maximum allowable angle γ, rotate the detector around the +x axis of the detector mechanical coordinate system, so that the gain of the omnidirectional antenna meets the requirements of the uplink and downlink after rotation. the

Further, the omnidirectional antenna of the present invention includes an omnidirectional antenna A and an omnidirectional antenna B, and the rotation around the +x axis in the step 3 is:

Calculate with the azimuth vector of the omnidirectional antenna A:

(1) Calculate the angle β ₁ between V _1y and the machine coordinate system + Y axis, and calculate the angle β ₂ between V _2my and the machine coordinate system + Y axis;

(2) When V _1x ·V _2mx ≥ 0, use the omnidirectional antenna A after rotating the detector around the mechanical coordinate system + X axis by β angle;

When V _1x ·V _2mx <0, judge whether the included angle θ between the azimuth vector of the omnidirectional antenna A and the detector-measurement and control station satisfies θ≤90°, and if so, make the detector circle around + After the X axis is rotated, use the omnidirectional antenna A, otherwise, use the omnidirectional antenna B after rotating the detector around the +X axis according to the β angle calculated above.

Further, the method of the present invention is executed when the probe is in the earth-moon transfer phase and the phase around the moon. the

Further, the specific process of step one of the present invention is:

(a) Calculate the three-axis position of the detector in the geocentric J2000 inertial coordinate system based on the currently received detector telemetry data $\stackrel{\&Right\; Arrow;}{R}={\left[\begin{array}{ccc}{R}_x& R_{\mathrm{the\; y}}& R_z\end{array}\right]}^T,$ Then the expression of the detector-geocentric unit vector in the geocentric J2000 inertial coordinate system is ${\stackrel{\&Right\; Arrow;}{V}}_2=\left[\begin{array}{ccc}{V}_{2x}& V_{2\mathrm{the\; y}}& V_{2z}\end{array}\right];$

${\stackrel{<span\; class="notranslate">\; \&Right\; Arrow;</span>}{\mathrm{<span\; class="notranslate">\; V</span>}}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; -</span>\frac{\stackrel{<span\; class="notranslate">\; \&Right\; Arrow;</span>}{\mathrm{<span\; class="notranslate">\; R</span>}}}{<span\; class="notranslate">\; |</span>\stackrel{<span\; class="notranslate">\; \&Right\; Arrow;</span>}{\mathrm{<span\; class="notranslate">\; R</span>}}<span\; class="notranslate">\; |</span>}$

(b) Calculate the matrix C _mb C _bi for converting the earth-centered J2000 inertial coordinate system to the detector mechanical coordinate system;

(c) Calculate according to the matrix C _mb C _bi The orientation vector in the detector mechanical coordinate system is ${\stackrel{\&Right\; Arrow;}{V}}_{2m}=C_{\mathrm{mb}}{C}_{\mathrm{bi}}{\stackrel{\&Right\; Arrow;}{V}}_2.$

Further, when the present invention executes the method, the detector is in the phase around the moon, and the calculation in step 1 Using the ephemeris to calculate the azimuth vector of the lunar center-earth center line vector in the earth center J2000 inertial coordinate system to replace.

Further, the antenna of the present invention also includes a directional antenna, and the design of the directional antenna pointing to the ground and pointing to the moon is:

The coordinate system (x, y, z) is defined as: the +x axis points to the installation surface of the directional antenna to the moon, the +z axis points to the installation surface of the directional antenna to the ground, and the +y axis, the +x axis, and the +z axis are formed according to the right-hand rule Cartesian coordinate system;

The directional antenna of the detector to the ground is fixed on the detector body, and the antenna to the ground is pointing to the center of the earth in the moon's white track; the directional antenna of the detector to the moon is installed with a dual-axis drive mechanism. When the connection line of the landing point is not within the ±90-degree range enveloped by the moon-pointing directional antenna, the probe rotates 180 degrees around its body + z-axis. , to cancel the corresponding attitude adjustment. the

Beneficial effect

The method of the present invention can use only one group of antennas for most of the time for measurement and control uplink and downlink by rotating a certain angle around the orientation axis of the sun without affecting the power supply of the solar wing and the use of sensors, so as to ensure the continuity of the measurement and control process and reduce the ground Switch the operation of using the antenna to reduce the complexity of ground operations, and at the same time, the antenna is in a region with a large gain to improve the link channel margin. the

Detailed ways

The present invention will be described in detail below in conjunction with specific examples. the

Pre-defined coordinate system: The detector control coordinate system is defined as the inertial spindle coordinate system. the

Earth-centered J2000 inertial coordinate system: the origin of the coordinates is at the center of mass of the earth, the reference plane is the J2000.0 flat equatorial plane, the Z axis points north to the north pole of the flat equatorial plane, the X axis points to the J2000.0 flat vernal equinox, and the Y axis is composed of X and Z axes Right-angle right-handed system. the

Mechanical coordinate system of the detector: +X axis is the orientation axis towards the sun, +Y axis points to a specific structural feature of the detector, and is perpendicular to the +X axis, +Z, +X axis and +Y axis form a right-handed coordinate system. the

Earth-moon transfer phase and phase around the moon:

The ground calculates the rotation angle and direction of the detector around the +X axis according to the attitude telemetry data transmitted by the detector, and then sends the calculation result back to the detector. The detector controls the antenna by adjusting the attitude of the detector according to the returned result. The rotation of the detector-antenna vector minimizes the angle between the detector-earth and the detector-earth, optimizes the antenna gain range used, and increases the channel margin of the measurement and control link. At the same time, under the condition that the detector + X axis is oriented to the sun, since the sun vector changes slowly along the ecliptic, the angle between the antenna axis and the detector-the center of the earth changes little in a short period of time, so it can be periodically Compute and return operations. the

A kind of deep space probe antenna pointing design method, described antenna comprises omnidirectional antenna, and the concrete steps of described omnidirectional antenna pointing to ground are:

Step 1. Calculate the representation of the detector-earth center azimuth vector on the mechanical coordinate system ${\stackrel{\&Right\; Arrow;}{V}}_{2m}=[{\stackrel{\&Right\; Arrow;}{V}}_{2\mathrm{mx}},{\stackrel{\&Right\; Arrow;}{V}}_{2\mathrm{my}},{\stackrel{\&Right\; Arrow;}{V}}_{2\mathrm{mz}}];$

Step two, according to the Calculate the angle θ between the omnidirectional antenna azimuth vector and the detector-measurement and control station;

$\mathrm{<span\; class="notranslate">\; \&theta;</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; arccos</span>}<span\; class="notranslate">\; (</span>\frac{{\stackrel{<span\; class="notranslate">\; \&Right\; Arrow;</span>}{\mathrm{<span\; class="notranslate">\; V</span>}}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>{\stackrel{<span\; class="notranslate">\; \&Right\; Arrow;</span>}{\mathrm{<span\; class="notranslate">\; V</span>}}}_{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; m</span>}}}{<span\; class="notranslate">\; |</span>{\stackrel{<span\; class="notranslate">\; \&Right\; Arrow;</span>}{\mathrm{<span\; class="notranslate">\; V</span>}}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; |</span>{\stackrel{<span\; class="notranslate">\; \&Right\; Arrow;</span>}{\mathrm{<span\; class="notranslate">\; V</span>}}}_{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; |</span>}<span\; class="notranslate">\; )</span>$

That is, the angle between the omnidirectional antenna azimuth vector and the detector-earth center azimuth vector is obtained, where, ${\stackrel{\&Right\; Arrow;}{V}}_1=\left[\begin{array}{ccc}{V}_{1x}& V_{1\mathrm{the\; y}}& V_{1z}\end{array}\right]$ is the azimuth vector of the omnidirectional antenna on the detector in the mechanical coordinate system of the detector;

Step 3. When the included angle θ is greater than the maximum allowable angle γ, rotate the detector around the +x axis, so that the gain of the omnidirectional antenna after rotation meets the requirements of the uplink and downlink, that is, the uplink and downlink can realize omnidirectional on a certain surface The normal and continuous acquisition and tracking of the corresponding frequency point of the antenna has a gain greater than that of the other omnidirectional antenna. the

According to the omnidirectional antenna pattern, when the angle between the antenna axis and the detector-measurement and control station is within γ degrees, the corresponding antenna gain margin is relatively large, which can meet the uplink and downlink requirements. Therefore, whether to adjust the threshold of the rotation angle around the X-axis is based on the following principles. The ground calculates the θ angle in real time based on the telemetry and orbit determination data (combined with the periodic calculation of the telemetry and orbit determination data update cycle). The present invention compares the angle θ between the calculated omnidirectional antenna and the detector-measurement and control station with the maximum allowable angle γ, if θ≤γ, it shows that the gain margin of the omnidirectional antenna pattern is relatively large at this time, and it can also To meet the requirements of the uplink and downlink, do not rotate the omnidirectional antenna at this time. If θ>γ, it means that the gain margin of the omnidirectional antenna in use at this time cannot meet the requirements of the uplink and downlink. Rotate the omnidirectional antenna at this time, The gain thereof meets the requirements, thereby improving the reliability of the communication between the detector and the outside. the

The omnidirectional antenna of the present invention comprises an omnidirectional antenna A and an omnidirectional antenna B, and the rotation around the x axis in the step 3 is:

Calculated with the azimuth vector of the omnidirectional antenna A,

(1) Calculate the angle β ₁ between V _1y and the machine coordinate system + Y axis, and calculate the angle β ₂ between V _2my and the machine coordinate system + Y axis; then

$\begin{array}{cc}{\mathrm{<span\; class="notranslate">\; \&beta;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; arccos</span>}<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}\mathrm{<span\; class="notranslate">\; the\; y</span>}}}{\sqrt{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}\mathrm{<span\; class="notranslate">\; the\; y</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}\mathrm{<span\; class="notranslate">\; z</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}<span\; class="notranslate">\; )</span>& {\mathrm{<span\; class="notranslate">\; \&beta;</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; arccos</span>}<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; my</span>}}}{\sqrt{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; my</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; mz</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}<span\; class="notranslate">\; )</span>\end{array}$

(2) When V _1x ·V _2mx ≥ 0, use the omnidirectional antenna A after rotating the detector around the mechanical coordinate system + X axis by an angle of β;

When V _1x ·V _2mx <0, the method is the same as the above table, but it is necessary to judge the included angle to determine which group of omnidirectional antennas to use, that is, to judge the included angle θ between the azimuth vector of the omnidirectional antenna A and the detector-measurement and control station Whether it is satisfied that θ≤90° is true, if it is true, the detector is rotated according to the β calculated above and the omnidirectional antenna A is used, otherwise the detector is rotated according to the β calculated above and the omnidirectional antenna B is used.

Usually, after the installation of the antenna in the mechanical system of the detector is determined, the positive and negative values of V _1x , V _1y , V _1z and β ₁ are determined, and the above calculation method can be further simplified. After adopting the above method, the continuous measurement and control process can be guaranteed, and a group of antennas are used most of the time, which reduces the complexity of ground operations.

Fill in the rotation angle into the data block, and inject it into the computer on the detector through the ground, and the computer on the device uses this value as the deviation of the rotation angle around the X axis, and uses the control algorithm to drive the actuator (thruster or momentum wheel) to perform closed loop control so that the deviation gradually decreases to zero. the

If the detector has the ability of autonomous navigation, the computer on the device will automatically calculate the rotation angle and direction of the detector around the +X axis according to the above method and execute it autonomously. Different from the calculation on the ground, the description of the detector-measurement and control station unit vector in the geocentric J2000 inertial coordinate system Compute automatically on the router. From the day 2 after the detector's arrow was separated, It can be approximated as the description of the detector-earth vector in the earth-centered J2000 inertial coordinate system to simplify the calculation.

Usually, the detector is equipped with two sets of omnidirectional antennas (omnidirectional antenna A and omnidirectional antenna B, the pointing difference between A and B is 180 degrees), each of which is responsible for the measurement and control tasks in the hemispheric space. In the present invention, when there are at least two pairs of omnidirectional antennas on the detector, the omnidirectional antennas in the above steps 2 and 3 are A or B omnidirectional antennas. the

The present invention calculates the representation of the detector-earth center azimuth vector on the mechanical coordinate system The specific process is:

(1) Obtain the attitude quaternion Q ₀ of the detector control coordinate system relative to the earth-centered J2000 inertial coordinate system at T ₀ according to the attitude telemetry data of the detector.

(2) The attitude conversion matrix for converting the detector control coordinate system to the mechanical coordinate system is C _mb .

(3) Usually the detector is equipped with two sets of omnidirectional antennas (omnidirectional antenna A and omnidirectional antenna B, the pointing difference between A and B is 180 degrees), each of which is responsible for the measurement and control tasks in the hemispheric space. The omnidirectional antenna A is used for illustration below:

Suppose the angle between the azimuth vector of the omnidirectional antenna A and the three axes of the mechanical coordinate system O _m -X _m Y _m Z _m is (α, β, γ), then the expression of the azimuth vector of the omnidirectional antenna A in the mechanical coordinate system of the detector is for ${\stackrel{\&Right\; Arrow;}{V}}_1=\left[\begin{array}{ccc}{V}_{1x}& V_{1\mathrm{the\; y}}& V_{1z}\end{array}\right]=\left[\begin{array}{ccc}\cos \mathrm{\&alpha;}& \cos \mathrm{\&beta;}& \cos \mathrm{\&gamma;}\end{array}\right].$

(4) Obtain the three-axis position of the detector in the geocentric J2000 inertial coordinate system at T ₀ according to the orbit determination results of the ground measurement and control system $\stackrel{\&Right\; Arrow;}{R}={\left[\begin{array}{ccc}{R}_x& R_{\mathrm{the\; y}}& R_z\end{array}\right]}^T,$ Then the expression of the detector-geocentric unit vector in the geocentric J2000 inertial coordinate system is

${\stackrel{<span\; class="notranslate">\; \&Right\; Arrow;</span>}{\mathrm{<span\; class="notranslate">\; V</span>}}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; -</span>\frac{\stackrel{<span\; class="notranslate">\; \&Right\; Arrow;</span>}{\mathrm{<span\; class="notranslate">\; R</span>}}}{<span\; class="notranslate">\; |</span>\stackrel{<span\; class="notranslate">\; \&Right\; Arrow;</span>}{\mathrm{<span\; class="notranslate">\; R</span>}}<span\; class="notranslate">\; |</span>}$

in, ${\stackrel{\&Right\; Arrow;}{V}}_2=\left[\begin{array}{ccc}{V}_{2x}& V_{2\mathrm{the\; y}}& V_{2z}\end{array}\right].$

(5) Transform the attitude quaternion Q ₀ in (1) into an attitude transformation matrix C _bi (transformed from the earth-centered J2000 inertial coordinate system to the control coordinate system), then the earth-centered J2000 inertial coordinate system is converted to the mechanical coordinates of the detector The transformation matrix of the system is C _mb C _bi ;

(6) The orientation vector in the detector mechanical coordinate system is

Phases of the Moon:

After the probe circles the moon, the calculation method is the same as that of the earth-moon transfer phase. Since the direction of the line vector between the moon center and the center of the earth is basically the same as that of the unit vector of the detector-measurement and control station, the azimuth vector of the line vector between the center of the moon and the center of the earth in the J2000 inertial coordinate system of the center of the earth can also be calculated according to the ephemeris replace to simplify the calculation.

The antenna of the present invention also includes a directional antenna, and the design of the directional antenna to the ground and to the moon is as follows: the coordinate system (x, y, z) is defined as: the +x axis points to the installation surface of the directional antenna to the moon, and +z The axis points to the installation surface of the ground-oriented antenna, and the +y axis, the +x axis, and the +z axis form a rectangular coordinate system according to the right-hand rule;

(1) For the lunar orbit probe (relay satellite), design the pointing control method as follows:

The detector's ground-pointing directional antenna adopts the installation method fixed on the detector body. The ground-pointing antenna points to the center of the earth on the moon's white track. Under the condition that the probe is not blocked by the moon, the probe rotates around the mechanical coordinate system +y axis The rotation can realize the continuous ground pointing of the ground directional antenna, and the rotation period is 1 month. The probe uses a dual-axis drive mechanism for the moon-pointing directional antenna. Affected by the moon's rotation within a month, the menstrual longitude of the landing area relative to the orbital plane changes periodically. When the line connecting the relay satellite and the landing point of the lander is not within the range of ±90 degrees of the directional antenna pointing, the relay satellite needs to rotate 180 degrees around its body + z axis, and the adjustment cycle can occur up to four times within a month , when the lander on the far side of the moon is dormant on a moon night and there is no need for forwarding to the ground, the corresponding attitude adjustment can be canceled. the

The solar wing of the relay star is installed on the ±Y axis of the mechanical coordinate system of the probe, and can realize rotation around the ±Y axis. Considering that the angle between the ecliptic plane, the moon, and the white plane is small (about 5 degrees), the solar wing rotates around the Y axis at about 1° The angular velocity of /day rotates at a constant speed to achieve orientation to the sun, and the rotation period is 1 year. the

The present invention supports the landing task on the back of the moon (i.e., the relay satellite), and can also meet the conditions of the solar wing power supply on the attitude and pointing constraints, and only use a group of two-axis drive mechanisms to realize the directional antenna to the earth and the moon and to the earth. The synchronization points to the requirements. the

(2) For the detector (relay star) located at the L2 point of the earth and the moon, design the pointing control method as follows:

The detector's ground-pointing directional antenna adopts the installation method fixed on the detector body, and the ground-pointing antenna points to the center of the earth on the moon's white track; under the condition that the probe is not blocked by the moon, the probe rotates around the mechanical coordinate system +y axis The rotation can realize the continuous ground pointing of the ground directional antenna, and the rotation period is 1 month. The probe's moon-pointing antenna adopts a dual-axis drive mechanism. When the line connecting the relay star and the landing point of the lander is not within the range of ±90 degrees of the pointing point of the moon-pointing directional antenna, the relay star rotates 180 degrees around its body + z axis. If the lander on the far side of the moon is dormant on a moon night and there is no need for forwarding to the ground, the corresponding attitude adjustment will be cancelled. the

The control method of the L2 point solar wing is the same as that of the orbit around the moon. The directional antenna adopts the above-mentioned adjustment form, which can enable smooth communication between the directional antenna for the moon and the lander on the far side of the moon. the

To sum up, the above are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention. the

Claims (6)

1. a design method for deep space detector antenna pointing, said antenna comprises omnidirectional antenna, it is characterized in that, the specific steps of said omnidirectional antenna pointing to the ground are: Step 1. Calculate the representation of the detector-earth center azimuth vector on the mechanical coordinate system ${\stackrel{\&Right\; Arrow;}{V}}_{2m}=\left[\begin{array}{ccc}{\stackrel{\&Right\; Arrow;}{V}}_{2m},& {\stackrel{\&Right\; Arrow;}{V}}_{2\mathrm{my}},& {\stackrel{\&Right\; Arrow;}{V}}_{2\mathrm{mz}}\end{array}\right];$ Step two, according to the Calculate the angle θ between the omnidirectional antenna azimuth vector and the detector-measurement and control station; $\mathrm{<span\; class="notranslate">\; \&theta;</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; arccos</span>}<span\; class="notranslate">\; (</span>\frac{{\stackrel{<span\; class="notranslate">\; \&Right\; Arrow;</span>}{\mathrm{<span\; class="notranslate">\; V</span>}}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>{\stackrel{<span\; class="notranslate">\; \&Right\; Arrow;</span>}{\mathrm{<span\; class="notranslate">\; V</span>}}}_{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; m</span>}}}{<span\; class="notranslate">\; |</span>{\stackrel{<span\; class="notranslate">\; \&Right\; Arrow;</span>}{\mathrm{<span\; class="notranslate">\; V</span>}}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; |</span>{\stackrel{<span\; class="notranslate">\; \&Right\; Arrow;</span>}{\mathrm{<span\; class="notranslate">\; V</span>}}}_{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; |</span>}<span\; class="notranslate">\; )</span>$ in, ${\stackrel{\&Right\; Arrow;}{V}}_1=\left[\begin{array}{ccc}{V}_{1x}& V_{1\mathrm{the\; y}}& V_{1z}\end{array}\right]$ is the azimuth vector of the omnidirectional antenna on the detector in the mechanical coordinate system of the detector; Step 3: When the included angle θ is greater than the maximum allowable angle γ, rotate the detector around the +x axis of the detector mechanical coordinate system, so that the gain of the omnidirectional antenna meets the requirements of the uplink and downlink after rotation. 2. according to the design method of the described deep space probe antenna pointing of claim 1, it is characterized in that, described omnidirectional antenna comprises omnidirectional antenna A and omnidirectional antenna B, and in described step 3, rotate around +x axis as: Calculate the azimuth vector with the omnidirectional antenna A as, (1) Calculate the angle β ₁ between V _1y and the machine coordinate system + Y axis, and calculate the angle β ₂ between V _2my and the machine coordinate system + Y axis; (2) When V _1x ·V _2mx ≥ 0, use the omnidirectional antenna A after rotating the detector around the mechanical coordinate system + X axis by an angle of β; When V _1x ·V _2mx <0, judge whether the included angle θ between the azimuth vector of the omnidirectional antenna A and the detector-measurement and control station satisfies θ≤90°, and if so, make the detector circle around + After the X axis is rotated, use the omnidirectional antenna A, otherwise, use the omnidirectional antenna B after rotating the detector around the +X axis according to the β angle calculated above. 3. The design method for the antenna pointing of the deep space probe according to claim 2, characterized in that, the design method is executed when the probe is in the Earth-Moon transfer phase and the Moon-circle phase. 4. according to the design method of the described deep space probe antenna pointing of claim 1 or 3, it is characterized in that, the concrete process of described step 1 is: (a) Calculate the three-axis position of the detector in the geocentric J2000 inertial coordinate system based on the currently received detector telemetry data $\stackrel{\&Right\; Arrow;}{R}={\left[\begin{array}{ccc}{R}_x& R_{\mathrm{the\; y}}& R_z\end{array}\right]}^T,$ Then the expression of the detector-geocentric unit vector in the geocentric J2000 inertial coordinate system is ${\stackrel{\&Right\; Arrow;}{V}}_2=\left[\begin{array}{ccc}{V}_{2x}& V_{2\mathrm{the\; y}}& V_{2z}\end{array}\right];$ ${\stackrel{<span\; class="notranslate">\; \&Right\; Arrow;</span>}{\mathrm{<span\; class="notranslate">\; V</span>}}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; -</span>\frac{\stackrel{<span\; class="notranslate">\; \&Right\; Arrow;</span>}{\mathrm{<span\; class="notranslate">\; R</span>}}}{<span\; class="notranslate">\; |</span>\stackrel{<span\; class="notranslate">\; \&Right\; Arrow;</span>}{\mathrm{<span\; class="notranslate">\; R</span>}}<span\; class="notranslate">\; |</span>}$ (b) Calculate the matrix C _mb C _bi for converting the earth-centered J2000 inertial coordinate system to the detector mechanical coordinate system; (c) Calculate according to the matrix C _mb C _bi The orientation vector in the detector mechanical coordinate system is ${\stackrel{\&Right\; Arrow;}{V}}_{2m}=C_{\mathrm{mb}}{C}_{\mathrm{bi}}{\stackrel{\&Right\; Arrow;}{V}}_2.$ 5. according to the design method of the described deep space probe antenna pointing of claim 1 or 2, it is characterized in that, when the probe is in the phase around the moon, the calculation of the first step Using the ephemeris to calculate the azimuth vector of the lunar center-earth center line vector in the earth center J2000 inertial coordinate system to replace. 6. according to the design method of the described deep space probe antenna pointing of claim 1 or 2, it is characterized in that, described antenna also comprises directional antenna, and the design of described directional antenna pointing to the ground and pointing to the moon is: The coordinate system (x, y, z) is defined as: the +x axis points to the installation surface of the directional antenna to the moon, the +z axis points to the installation surface of the directional antenna to the ground, and the +y axis, the +x axis, and the +z axis are formed according to the right-hand rule Cartesian coordinate system; The directional antenna of the detector to the ground is fixed on the detector body, and the antenna to the ground is pointing to the center of the earth in the moon's white track; the directional antenna of the detector to the moon is installed with a dual-axis drive mechanism. When the connection line of the landing point is not within the ±90-degree range enveloped by the moon-pointing directional antenna, the probe rotates 180 degrees around its body + z-axis. , to cancel the corresponding attitude adjustment.