Autonomous navigation positioning method for lunar surface and earth-moon space

Abstract

The invention relates to an autonomous navigation positioning navigation method oriented to a lunar surface and earth-moon space. The method comprises the following steps: time synchronization of a lunar surface navigation base station and a lunar orbit satellite is carried out; the lunar orbit satellite and each lunar surface navigation base station send navigation signals of pseudo code spread spectrum of the station; the served object receives navigation signals from the lunar orbit satellite and each lunar surface navigation base station; performing data fusion processing; and calculating the time, position and speed of the receiver based on the multi-ball intersection measurement principle, calculating the deviation between the current position of the served object and a planned trajectory, and planning trajectory tracking. According to the method, the satellite and the base station are combined, the satellite is used for providing time service and determining the position of the lunar navigation base station, the base station broadcasts a navigation message, and then a receiver of a served object can realize high-precision positioning and navigation of the position of the receiver based on a multi-ball intersection principle.

Description

Technical Field

[0001] This invention relates to the field of lunar surface navigation, guidance and control technology, specifically to a high-precision navigation method for the lunar surface region based on a lunar orbit satellite and a lunar surface navigation base station. Background Technology

[0002] Currently, with the continuous development of aerospace technology, more and more countries are embarking on lunar exploration missions, placing higher demands on high-precision navigation in lunar areas. Existing navigation methods cannot meet the needs of practical engineering. High-precision regional navigation for lunar probes (rovers) or robots, and even lunar landers during the final landing phase, has become an important research direction. Traditional probe navigation methods mainly rely on ground command assistance, manual control, or autonomous navigation (optical navigation, inertial navigation, etc.). Ground command assistance or manual control requires the ground to calculate and send corresponding control commands for navigation. This navigation process is cumbersome, with many intermediate steps, time-consuming signal transmission, and poor real-time performance. Optical navigation mainly extracts the target center point or establishes a map database through its own optical navigation camera, and then selects the target point to achieve navigation. This navigation method requires first capturing images of the target area, resulting in poor real-time performance. Furthermore, as the resolution of navigation cameras increases, the quality of navigation cameras also increases significantly, increasing the requirements for the quality of the probe. Inertial navigation measures using inertial components, integrating the initial position and velocity to obtain the current position and velocity, and then achieving navigation. This navigation method gradually increases the error as the integration time increases, resulting in poor navigation accuracy. Therefore, current navigation methods for the lunar surface and Earth-Moon space suffer from low navigation accuracy (up to hundreds of meters), poor real-time performance, and weak anti-interference capabilities, exhibiting certain limitations. Furthermore, each probe must carry its own navigation equipment, significantly increasing development costs. Therefore, to achieve low-cost, high-real-time, and high-precision autonomous navigation on the lunar surface and in Earth-Moon space, it is necessary to research novel autonomous navigation and positioning methods based on navigation systems. This will reduce the development cost of navigation service objects and improve navigation and positioning accuracy and real-time performance. Summary of the Invention

[0003] The technical problem to be solved by this invention is how to achieve high-precision navigation on the lunar surface.

[0004] The present invention solves the above-mentioned technical problems through the following technical means:

[0005] An autonomous navigation and positioning method for the lunar surface and Earth-Moon space includes the following steps:

[0006] Step 1. Synchronize the lunar surface navigation base station with the lunar orbit satellites;

[0007] Step 2. Lunar orbit satellites and lunar surface navigation base stations transmit navigation signals spread using their local pseudocodes;

[0008] Step 3. The service recipient receives navigation signals from lunar orbit satellites and various lunar surface navigation base stations, and performs filtering processing;

[0009] Step 4. The service recipient performs fusion processing on the navigation data filtered in Step 3, including time synchronization, frequency synchronization, data quality judgment, and removal of poor quality data;

[0010] Step 5. The serviced object parses the navigation message after data fusion processing, calculates the receiver's time, position, and velocity based on the principle of multi-sphere rendezvous measurement, and calculates the deviation between the serviced object's current position and the planned trajectory by fusing data from lunar orbit satellites and lunar surface navigation base stations.

[0011] Step 6. Calculate the required control quantity based on the position deviation;

[0012] Step 7. Allocate control quantities according to the current status of the actuator; the actuator executes the corresponding control action until the planned trajectory is tracked.

[0013] Furthermore, the calculation method for time synchronization between the lunar surface navigation base station and the lunar orbit satellite in step 1 is as follows: the lunar surface navigation base station receives the navigation signal from the lunar orbit satellite and calculates the transmission time of the lunar orbit satellite. By calculating the spatial delay between the lunar orbit satellite and the lunar surface navigation base station, the accurate time of the local clock within the lunar orbit satellite time system is obtained, thereby achieving time synchronization.

[0014] Furthermore, the navigation signal in step 2 includes navigation message, pseudo-random code and carrier signal.

[0015] Furthermore, the locations of the lunar orbit satellite and the lunar surface navigation base station are both known.

[0016] Furthermore, the lunar navigation base station includes a master base station and a slave base station, wherein the slave base station receives navigation signals from the master base station.

[0017] The advantages of this invention are:

[0018] This invention utilizes a combination of satellites and base stations. Satellites provide timing and determine the location of lunar navigation base stations, which then broadcast navigation messages. The receiver of the served object, based on the principle of multi-sphere rendezvous, can achieve high-precision positioning and navigation. Compared to existing optical and inertial navigation, the navigation and positioning accuracy can be improved from the hundreds of meters to the meters, significantly enhancing the navigation and positioning accuracy of the served object. According to the navigation implementation process of this invention, high-precision positioning and navigation of the probe can be achieved, ensuring the probe can safely and successfully complete its exploration mission. Attached Figure Description

[0019] Figure 1This is a navigation method of the navigation system in an embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the navigation system in an embodiment of the present invention;

[0021] Figure 3 This is a structural block diagram of the navigation system in an embodiment of the present invention. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] This embodiment discloses a process for implementing regional navigation on the lunar surface and in the Earth-Moon space. The specific process is as follows:

[0024] like Figure 1 As shown, the regional navigation implementation process for the lunar surface and Earth-Moon space of this invention includes the following steps:

[0025] Step 1: Synchronize the time between the lunar surface main base station and the lunar orbit satellite;

[0026] Step 2: Synchronize the time between the lunar base station and the main base station;

[0027] Step 3: Lunar orbit satellites and lunar surface navigation base stations transmit navigation signals (including navigation messages, pseudo-random codes, and carrier signals) spread by their local pseudocodes;

[0028] Step 4: The antenna of the receiver being served receives navigation signals from lunar orbit satellites and various lunar surface navigation base stations;

[0029] Step 5: The filter of the service object filters the navigation messages from lunar orbit satellites and various lunar navigation base stations to filter out noise signals caused by electromagnetic interference, multipath effects, etc., thereby improving the signal-to-noise ratio; filter out harmonic components to reduce the impact of harmonic distortion on the signal; limit bandwidth to reduce noise input and improve signal quality, thereby reducing the impact of various frequency interferences on the system, and thus improving the receiver's anti-interference capability and positioning accuracy.

[0030] Step Six: The navigation receiver of the served object performs fusion processing on the navigation data filtered in Step Five, including data time synchronization, frequency synchronization, data quality judgment and removal of poor quality data, etc., to improve the system's coverage, availability and positioning accuracy.

[0031] Step 7: The navigation chip of the serviced object parses the navigation message after data fusion processing, calculates the receiver's time, position and velocity based on the principle of multi-sphere rendezvous measurement, and fuses data from lunar orbit satellites and lunar surface navigation base stations;

[0032] Step 8: Calculate the deviation between the current location of the serviced object and the planned trajectory;

[0033] Step 9: Calculate the required control quantity based on the position deviation;

[0034] Step 10: Allocate control quantities based on the current status of the actuator;

[0035] Step 11: The computer generates the corresponding control commands and sends them to the corresponding control actuators;

[0036] Step 12: The actuator performs the corresponding control action to eliminate or reduce position deviation;

[0037] Step 13: Repeat steps 1 to 12 until the planned trajectory is tracked.

[0038] Step 1: Before starting time synchronization, the positions of the lunar orbit satellites and lunar surface navigation base stations in the navigation system are known.

[0039] In this embodiment, the planned trajectory tracking technology is the same as the ground trajectory planning technology, and will not be described in detail here.

[0040] The navigation system involved in this invention has the advantages of high navigation and positioning accuracy, strong economy and practicality, strong anti-interference ability and good scalability. According to the navigation implementation process of this invention, high-precision positioning and navigation of the detector can be achieved, ensuring that the detector can safely and smoothly complete the detection task.

[0041] As a carrier for implementing the above method, this embodiment also provides an autonomous navigation and positioning system for the lunar surface and Earth-Moon space, such as... Figure 2 As shown, it includes a lunar surface navigation base station and a lunar orbit satellite. The positions of the lunar surface navigation base station and the lunar orbit satellite are known and synchronized in time. The lunar orbit satellite, the location of the lunar surface navigation base station, and the served object are connected in communication. The lunar orbit satellite and the lunar surface navigation base station broadcast navigation messages, which are received by the served object. Based on the principle of multi-sphere intersection, the location and navigation of the served object are realized.

[0042] A typical system structure in this embodiment can be: two lunar orbit satellites and four lunar surface base stations. The two lunar orbit satellites provide navigation signals and also serve as the system's time reference, synchronizing the time of the lunar surface navigation base stations. Each lunar surface base station provides navigation signals and also serves as a differential reference, differentiating and broadcasting corrections for pseudorange, phase, etc., of the satellites. It receives signals from the two lunar satellites and calculates the satellite transmission times. By calculating the spatial delay between the satellites and the lunar surface navigation base stations, it obtains the precise time of its local clock within the satellite time system, achieving time synchronization. Additionally, the lunar surface slave base stations also need to receive navigation signals from the master lunar surface navigation base station (designated by the system or distributed in a master-slave manner). In the event of satellite signal interruption, they achieve time synchronization with other lunar surface navigation base stations to ensure that the navigation accuracy of the service target is not affected. The receivers of the navigation system service target receive navigation messages from the two satellites and base stations. Based on the multi-sphere intersection measurement principle, the receiver's time, position, and velocity can be calculated, thereby achieving high-precision navigation within the coverage area of ​​the lunar surface and low-altitude lunar surface base stations. An example of a typical system composition is shown below. Figure 3 As shown.

[0043] In this system, the number of lunar surface base stations is not a hard requirement. Theoretically, four lunar surface navigation base stations can achieve high-precision positioning and time synchronization based on the principle of multi-sphere intersection. This article only takes four lunar surface navigation base stations as an example for detailed introduction. The number of lunar surface navigation base stations can be selected according to actual application needs and appropriately increased to expand the service area.

[0044] In this system, the format of navigation messages broadcast by satellites and lunar navigation base stations in the navigation system can refer to the navigation message formats of Earth navigation satellites such as Beidou, GPS, and Galileo, but is not limited to them, and can also be customized according to requirements;

[0045] In this system, the selection of radio frequencies for lunar orbit satellites and lunar surface navigation base stations is highly flexible. Since there is no radio noise interference from other systems and there are no adverse factors such as atmospheric refraction on the lunar surface, appropriate frequencies can be selected according to requirements. The only consideration is that they do not conflict with the measurement, control, communication, and data transmission frequencies of the objects served by the navigation system.

[0046] In this system, in addition to broadcasting navigation messages as navigation satellites, the satellites in the navigation system can also serve as communication relay satellites to provide communication relay services to the served objects. At the same time, they can carry remote sensing payloads to provide remote sensing data of the lunar surface to the ground.

[0047] This embodiment can achieve the following advantages:

[0048] 1. High precision: By combining satellites and base stations, satellites provide timing and determine the location of lunar navigation base stations. The base stations broadcast navigation messages, and the receivers of the served objects can achieve high-precision positioning and navigation based on the principle of multi-sphere rendezvous. Compared with existing optical navigation and inertial navigation, the navigation and positioning accuracy can be improved from hundreds of meters to meters, which significantly improves the navigation and positioning accuracy of the served objects.

[0049] 2. Economic Efficiency and Practicality: Compared to traditional probe navigation methods (optical or inertial navigation), this invention employs a combination of satellites and base stations. The base stations can be integrated into a single chip (the entire base station consists of a chip, power supply and distribution unit, management unit, and antenna—a miniaturized system achievable with existing technology). During construction, the system can be directly transported by a carrier or probe to a higher elevation within the selected service area, reducing the development cost of the navigation system. The navigation system can be reused for extended periods and can simultaneously serve a large number of lunar probes (rovers) or robots. Navigation can be achieved simply by carrying a universal navigation receiver with the same communication system, significantly reducing the development cost of the navigation system for the target objects and demonstrating high economic efficiency and practicality. Furthermore, compared to building a new lunar navigation constellation, this application provides navigation services through a system composed of satellites and lunar surface navigation base stations. The navigation service utilizes both satellites and lunar surface navigation base stations to provide navigation signals, rather than solely relying on a satellite constellation. This reduces the need for a large number of satellites, requiring only two, significantly lowering the overall cost. Furthermore, compared to directly utilizing existing Earth-orbiting GNSS constellations (which serve ground-based objects and have limited navigation signals reaching the moon, resulting in smaller beam angles and poor continuity, necessitating the addition of high-gain two-dimensional directional tracking antennas to ensure signal gain and stability), this invention offers a more mature solution. It eliminates the need for bulky and expensive two-dimensional directional tracking antennas to increase gain. The short transmission distance of the navigation signal further reduces the requirements for antenna gain and power consumption, further lowering the carrying capacity requirements of the served objects and effectively reducing their development costs.

[0050] 3. Scalability: The navigation system of this invention can be expanded and optimized according to the needs of the exploration mission, exhibiting high scalability and adaptability, such as adding lunar surface navigation base stations to expand the service area. Furthermore, the navigation system of this invention also possesses a certain degree of adaptability, making it suitable for exploration and resource development missions on other planets and celestial bodies.

[0051] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An autonomous navigation and positioning method for the lunar surface and Earth-Moon space, characterized in that, Includes the following steps: Step 1. Synchronize the lunar surface navigation base station with the lunar orbit satellites; Step 2. Lunar orbit satellites and lunar surface navigation base stations transmit navigation signals spread using their local pseudocodes; Step 3. The service recipient receives navigation signals from lunar orbit satellites and various lunar surface navigation base stations, and performs filtering processing; Step 4. The service recipient performs fusion processing on the navigation data filtered in Step 3, including time synchronization, frequency synchronization, data quality judgment, and removal of poor quality data; Step 5. The service recipient parses the navigation message after data fusion processing, calculates the receiver's time, position, and velocity based on the principle of multi-sphere rendezvous measurement, and fuses data from lunar orbit satellites and lunar surface navigation base stations; Calculate the deviation between the current location of the serviced object and the planned trajectory; Step 6. Calculate the required control quantity based on the position deviation; Step 7. Allocate control quantities according to the current status of the actuator; the actuator executes the corresponding control action until the planned trajectory is tracked.

2. The autonomous navigation and positioning method for the lunar surface and Earth-Moon space according to claim 1, characterized in that, The calculation method for synchronizing the time between the lunar surface navigation base station and the lunar orbit satellite in step 1 is as follows: The lunar surface navigation base station receives the navigation signal from the lunar orbit satellite and calculates the transmission time of the lunar orbit satellite. By calculating the spatial delay between the lunar orbit satellite and the lunar surface navigation base station, the accurate time of the local clock within the lunar orbit satellite's time system is obtained, thus achieving time synchronization.

3. The autonomous navigation and positioning method for the lunar surface and Earth-Moon space according to claim 1 or 2, characterized in that, The navigation signals in step 2 include navigation messages, pseudo-random codes, and carrier signals.

4. The autonomous navigation and positioning method for the lunar surface and Earth-Moon space according to claim 1 or 2, characterized in that, Step 1: Before starting time synchronization, the positions of the lunar orbit satellite and the lunar surface navigation base station are known.

5. A method for autonomous navigation and positioning on the lunar surface and in Earth-Moon space according to claim 1 or 2, characterized in that, The lunar navigation base station includes a master base station and slave base stations, wherein the slave base station receives navigation signals from the master base station.

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