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CN-121618214-B - Satellite-borne antenna pointing mechanism and control method thereof

CN121618214BCN 121618214 BCN121618214 BCN 121618214BCN-121618214-B

Abstract

The invention discloses a satellite-borne antenna pointing mechanism and a control method thereof, belongs to the technical field of spacecraft attitude control, and solves the problems of high cost and low control precision of the antenna pointing mechanism in the prior art; the dual-axis antenna device comprises an antenna dual-axis pointing mechanism, wherein the bottom of the antenna dual-axis pointing mechanism is fixed on an antenna support, an antenna reflecting surface is arranged at the top of the antenna dual-axis pointing mechanism, a locking and releasing device is connected with the antenna support and the antenna dual-axis pointing mechanism, the locking and releasing device releases the connection effect on the antenna support and the antenna dual-axis pointing mechanism after a satellite enters an orbit, and the antenna dual-axis pointing mechanism comprises a pitching data transmission mechanism and a horizontal data transmission mechanism. According to the invention, the pointing precision of the satellite-borne antenna pointing mechanism is improved from the magnitude of 1.8 degrees of open loop of the stepping motor to < +/-0.1 degrees through 'output end full closed loop' measurement and 'silence calibration', the working time is in an 'open loop holding' mode, the power consumption is far lower than that of a servo system which continuously runs in a closed loop, and the satellite-borne antenna pointing mechanism is particularly suitable for small microsatellites with higher power consumption requirements.

Inventors

  • NIE KAIFENG
  • LIU JIANMING
  • Shan Lingdi
  • WANG JIAN
  • Liu shihang
  • ZHANG CONG

Assignees

  • 陕西索飞电子科技有限公司

Dates

Publication Date
20260512
Application Date
20260203

Claims (9)

  1. 1. A satellite-borne antenna pointing mechanism is characterized by comprising an antenna reflecting surface (1), an antenna double-axis pointing mechanism (2), an antenna support (3) and a locking release device (4), wherein the bottom of the antenna double-axis pointing mechanism (2) is fixed on the antenna support (3), the antenna reflecting surface (1) is arranged at the top of the antenna double-axis pointing mechanism (2), the lower end of the locking release device (4) is connected with the antenna support (3), and the upper end of the locking release device (4) is connected with the antenna double-axis pointing mechanism (2); The antenna double-axis pointing mechanism (2) comprises a pitching support (25), wherein the bottom of the pitching support (25) is fixed on the antenna support (3), a pitching data transmission mechanism (26) is installed on the pitching support (25), a horizontal support (23) is connected to the pitching data transmission mechanism (26), a horizontal data transmission mechanism (24) is arranged inside the horizontal support (23), a reflecting surface support frame (21) is connected to the horizontal data transmission mechanism (24), the antenna reflecting surface (1) is installed on the reflecting surface support frame (21), and an optical prism (29) is also installed on the pitching support frame (25); The horizontal data transmission mechanism (24) has the same structure as the pitch data transmission mechanism (26); The horizontal data transmission mechanism (24) and the pitching data transmission mechanism (26) both comprise a shell (246), the end part of the shell (246) is connected with an outer flange of a stepping motor (241), an output shaft of the stepping motor (241) is fixedly connected with a harmonic speed reducer wave generator (242) through a screw, a harmonic speed reducer flexible wheel (244) is sleeved on the harmonic speed reducer wave generator (242), the harmonic speed reducer flexible wheel (244) deforms under the extrusion action of the harmonic speed reducer wave generator (242), the outer part of the deformed harmonic speed reducer flexible wheel (244) is meshed with the inner part of a harmonic speed reducer rigid wheel (243), and the harmonic speed reducer rigid wheel (243) is fixed inside the shell (246); The harmonic speed reducer flexible gear (244) is fixedly connected with the end part of a rotary transformer rotor (2410) through a screw at the end far away from the harmonic speed reducer wave generator (242), a rotary transformer stator (247) is movably connected outside the rotary transformer rotor (2410), the rotary transformer stator (247) is fixed inside the shell (246), a rotary transformer position feedback line (2412) is led out of a copper wire winding of the rotary transformer stator (247), the rotary transformer position feedback line (2412) penetrates out of the side surface of the shell (246), a carrier signal line (249) is led out of a copper wire winding of the rotary transformer rotor (2410), and the carrier signal line (249) penetrates out of the inside of the rotary transformer rotor (2410); the shell (246) of the horizontal data transmission mechanism (24) is arranged on the horizontal bracket (23) through a flange plate, and a rotary transformer rotor (2410) of the horizontal data transmission mechanism (24) is in transmission connection with the reflecting surface supporting frame (21) through a flat key; The shell (246) of the pitching data transmission mechanism (26) is mounted on the pitching support (25) through a flange plate, a rotary transformer rotor (2410) of the pitching data transmission mechanism (26) penetrates through the horizontal support (23) and then is sleeved on the inner ring of the bearing C (28), and the outer ring of the bearing C (28) is fixed on the pitching support (25).
  2. 2. The satellite-borne antenna pointing mechanism of claim 1, wherein the rotary transformer rotor (2410) is movably connected with the housing (246) through a bearing A (245) and a bearing B (248), one end of the housing (246) far away from the stepping motor (241) is connected with a harmonic blocking cover (2411) through a screw, and the harmonic blocking cover (2411) is fixedly pressed against the bearing B (248) and the rotary transformer stator (247).
  3. 3. The satellite-borne antenna pointing mechanism according to claim 1, wherein the material of the rigid gear (243) of the harmonic speed reducer is 40CrMnMo, and the surface nitriding treatment is carried out, the material of the flexible gear (244) of the harmonic speed reducer is 30CrMnSiA, and isothermal deformation heat treatment is adopted; the tooth surfaces of the harmonic speed reducer flexible wheel (244) and the harmonic speed reducer rigid wheel (243) are coated with molybdenum disulfide-resin-based solid lubrication dry films.
  4. 4. The satellite-borne antenna pointing mechanism according to claim 1, wherein the locking and releasing device (4) comprises a bolt housing (46), a base (48) is connected to the bottom of the bolt housing (46), the bottom of the base (48) is mounted on the top of the antenna support (3) through a screw, a sensor (47) is mounted on the top of the base (48), a fixing support (42) with an L-shaped structure is arranged on the top of the bolt housing (46), one end of the fixing support (42) is connected with the bolt housing (46) through a grooving bolt (44), the other end of the fixing support (42) is mounted on the reflecting surface supporting frame (21), and a recovery cap (41) is mounted on the top of the fixing support (42) through a bolt; The expansion coil (45) is sleeved on the grooving bolt (44), the bottom of the expansion coil (45) is abutted to a flange at the bottom of the grooving bolt (44), the top of the grooving bolt (44) is connected with a locking nut (43) in a threaded mode, a cutting groove is formed in the grooving bolt (44) and located between the fixing support (42) and the bolt shell (46), the grooving bolt (44) is stretched after the expansion coil (45) is electrified and heated to expand, and the grooving bolt (44) is broken at the cutting groove.
  5. 5. The satellite-borne antenna pointing mechanism according to claim 1, wherein positioning pins A (22) are inserted into positioning pin holes of the horizontal support (23) and the reflecting surface support frame (21), and positioning pins B (27) are inserted into positioning pin holes of the horizontal support (23) and the pitching support frame (25).
  6. 6. A control method based on the satellite-borne antenna pointing mechanism according to any one of claims 1 to 5, characterized by comprising the following steps: the method comprises the following steps that S1, a satellite system sends out an unlocking signal after a satellite enters an orbit, an expansion coil (45) is electrified and then is heated to expand and stretch out a grooving bolt (44), unlocking release is completed, constraint between an antenna double-axis pointing mechanism (2) and an antenna support (3) is eliminated, a fracture part of the grooving bolt (44) touches a sensor (47), and a release signal is sent out; S2, enabling a satellite to reach a working area, enabling a satellite system to send an antenna power-on signal, and preparing to scan a target; S3, the satellite system reads the absolute position theta Absolute value (Absolute) of the output shaft of the current stepping motor (241) fed back by the rotary transformer position feedback line (2412); Step S4, the satellite system determines a deviation absolute value |delta theta| according to the current absolute position theta Absolute value (Absolute) and a command target position theta Target object preset in the satellite system: |Δθ|=θ Target object -θ Absolute value (Absolute) And comparing the absolute deviation value |delta theta| with a preset tolerance threshold epsilon; s5, silence calibration is carried out according to the comparison result; When |delta theta| > epsilon, the satellite system controls the antenna double-axis pointing mechanism (2) to operate and calibrate until |delta theta| is less than epsilon; When the absolute delta theta is less than or equal to epsilon, namely the absolute delta theta is less than or equal to epsilon when the satellite-borne antenna pointing mechanism is powered on, the satellite system records micro-step coordinates theta Recording of a stepping motor (241) corresponding to the current moment, and cuts off a power supply of the stepping motor (241), and the stepping motor (241) keeps the current position by means of magnetism of the stepping motor (241) to realize outage self-locking; And S6, periodically monitoring the satellite-borne antenna pointing mechanism by the satellite system and performing out-of-step fault tolerance.
  7. 7. The method of claim 6, wherein the tolerance threshold ε is set to 0.03 ° according to the accuracy requirement and the noise level in step S4.
  8. 8. The method for controlling a satellite-borne antenna pointing mechanism according to claim 6, wherein in the step S5, the step of calibrating operation of the satellite system control antenna biaxial pointing mechanism (2) comprises: the satellite system converts the absolute value of deviation |delta theta| into the total number of micro steps required to be passed by the stepping motor (241), plans an S-shaped speed curve and carries out smooth limitation on acceleration and deceleration; The micro-step driving, wherein the satellite system sends pulse signals with corresponding quantity and frequency to the stepping motor (241) according to the planned S-shaped speed curve, and drives the stepping motor (241) to operate in a mode of 1/256 micro-step; And in the driving process, continuously acquiring the absolute position theta Absolute value (Absolute) of the output shaft of the current stepping motor (241) fed back by the rotary transformer position feedback line (2412) by the satellite system, and stopping pulse output until the absolute position theta Target object -θ Absolute value (Absolute) is less than epsilon, and judging that the calibration is finished.
  9. 9. The method for controlling a satellite-borne antenna pointing mechanism according to claim 8, wherein the step S6 comprises the steps of: the method comprises the steps of reading feedback, namely starting a timing interrupt with a period of T under the condition of open loop maintenance of a satellite system, and continuously reading the absolute position theta Absolute value (Absolute) of the output shaft of a current stepping motor (241) fed back by a rotary transformer position feedback line (2412) in each period of T by the satellite system; Step out judgment, namely calculating the deviation between the absolute position theta Absolute value (Absolute) and the micro-step coordinate theta Recording in the step S5, if the absolute value of the deviation is smaller than or equal to a tolerance threshold epsilon, continuously maintaining an open loop state of the satellite system, and if the absolute value of the deviation is larger than the tolerance threshold epsilon, judging that a step out event occurs, repeatedly executing the step S5 by the satellite system, starting a silence calibration operation, and driving the antenna back to a correct target position; Logging, namely recording the occurrence time and the deviation of the out-of-step event into a nonvolatile memory for downstream telemetry and ground analysis.

Description

Satellite-borne antenna pointing mechanism and control method thereof Technical Field The invention relates to the technical field of spacecraft attitude control, in particular to a satellite-borne antenna pointing mechanism and a control method thereof. Background With the rapid development of the small microsatellite technology, the small microsatellite technology has increasingly stringent requirements on the pointing precision, reliability and cost control of the satellite-borne communication antenna. In the prior art, a satellite-borne antenna pointing mechanism mainly adopts two paths. The first is a technical scheme adopting a brushless direct current servo motor. The technical scheme adopts a configuration of a brushless direct current motor (BLDC), a high-precision encoder and a complex servo driver, and has the following problems that the cost is high, the space navigation level BLDC, the high-resolution encoder and the multi-loop servo driver are high, and the scheme is contrary to the trend of low cost and mass development of small microsatellites. The system is complex, the current loop, the speed loop and the position loop are required to be controlled stably, the algorithm is complex, the ground debugging and on-orbit verification period is long, and the difficulty is high. The power consumption is higher, even in the position maintaining stage, the motor still needs to be continuously electrified to provide torque, and the power consumption of the whole machine is larger. The second is to adopt an open loop stepping motor technical scheme. In order to reduce the cost, the technical scheme generally adopts an open loop control mode of a stepping motor and a speed reducer, and the scheme has the advantages of simple control, low cost and self-locking after power failure, but inherent defects limit on-orbit application of the scheme, such as step-out risk, easy step-out under the condition of complex load disturbance (such as mechanism friction change and thermal resistance moment fluctuation) in a space environment, positioning accumulated errors are caused, and the system cannot sense and recover. The absolute position is lost, the absolute pointing angle of the antenna cannot be memorized after the system is powered off, and mechanical zero searching operation with long time consumption and high risk must be executed after the system is powered on again, so that the satellite emergency response capability is affected. The low-speed vibration and the torque pulsation of the traditional full-step/half-step driving mode are obvious at low speed, so that micro-vibration can be caused, and the stability and the communication quality of a platform are affected. Therefore, there is an urgent need in the art for a satellite-borne antenna pointing solution that can achieve low cost, high accuracy, high reliability and easy control. Disclosure of Invention Aiming at the defects in the prior art, the invention provides a satellite-borne antenna pointing mechanism and a control method thereof, and solves the problems of high cost and low control precision of the antenna pointing mechanism in the prior art. In order to achieve the above object, the present invention adopts the following technical scheme: The satellite-borne antenna pointing mechanism comprises an antenna reflecting surface, an antenna double-axis pointing mechanism, an antenna support and a locking and releasing device, wherein the bottom of the antenna double-axis pointing mechanism is fixed on the antenna support, the antenna reflecting surface is arranged at the top of the antenna double-axis pointing mechanism, the lower end of the locking and releasing device is connected with the antenna support, the upper end of the locking and releasing device is connected with the antenna double-axis pointing mechanism, the antenna double-axis pointing mechanism comprises a pitching support, the bottom of the pitching support is fixed on the antenna support, a pitching data transmission mechanism is arranged on the pitching support, a horizontal support is connected with the pitching data transmission mechanism, a horizontal data transmission mechanism is arranged inside the horizontal support, the antenna reflecting surface is arranged on the reflecting surface support, and an optical prism is further arranged on the pitching support. In this scheme, horizontal data transmission mechanism is used for adjusting the horizontal rotation angle of reflector support frame, and every single move data transmission mechanism is used for adjusting the holistic every single move rotation angle that horizontal support, horizontal data transmission mechanism and reflector support frame constitute. The locking and releasing device is connected with the antenna support and the antenna double-shaft pointing mechanism, so that movement between the antenna support and the antenna double-shaft pointing mechanism in the satellite transmitting process is avoided, a