Lunar surface user positioning method and device and electronic equipment

Abstract

The invention provides a lunar surface user positioning method and device and electronic equipment. The positioning method comprises the steps that user equipment located on the lunar surface transmits an electromagnetic wave signal to a lunar satellite; receiving the electromagnetic wave signal reflected by the satellite, and recording the round-trip time t of the electromagnetic wave signal between the user equipment and the satellite; according to the round-trip time t, the distance d between the user equipment and the satellite is calculated, d = c.t / 2, and c is the light velocity; after the distances between the at least three satellites and the user equipment are obtained, the coordinates of the satellites are combined, and the user coordinates of the lunar surface are calculated through the three-ball rendezvous positioning principle. According to the method, accurate positioning of the user can be realized in the lunar environment, the required cost is low, the lunar satellite load configuration is simplified, and the future lunar exploration requirement can be met.

Description

Technical Field

[0001] The present invention mainly relates to the field of satellite positioning and navigation technology, and in particular to a positioning method, device and electronic equipment for users on the lunar surface. Background Art

[0002] The basic principle of satellite positioning is to receive signals transmitted by satellites, calculate the distance between the receiver and the satellite, and then determine the position of the receiver on the earth. Since the position of the satellite is precisely known, the position of the observation point can be solved by measuring the distance from the satellite to the receiver and using the distance formula in three-dimensional coordinates.

[0003] Lunar satellite positioning technology is one of the key technologies in lunar exploration activities. The development of lunar satellite positioning technology will provide important support for future lunar exploration activities, including real-time, high-precision navigation and positioning support for lunar surface activities, landing and takeoff, and enhance the feasibility and safety of long-term human lunar exploration. However, the GNSS system (Global Navigation Satellite System) is designed for near-Earth space users. For example, the service range of the BeiDou-3 navigation system that has been built is below 1,000 km in low-Earth orbit. For the moon, the geometric configuration of the Earth's navigation satellite constellation is degraded, and the space-time reference frame, space-time information measurement, determination and transmission methods are no longer applicable. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method, device and electronic equipment for positioning users on the lunar surface, which has low cost and simplifies the configuration of lunar satellite payloads.

[0005] To solve the above technical problems, in a first aspect, the present invention provides a positioning method for users on the lunar surface, comprising: a user device located on the lunar surface transmits an electromagnetic wave signal to a lunar satellite; receives the electromagnetic wave signal reflected by the satellite, and records the round-trip time t of the electromagnetic wave signal between the user device and the satellite; calculates the distance d between the user device and the satellite according to the round-trip time t, d=c·t / 2, where c is the speed of light; after obtaining the distances between at least three satellites and the user device, combines the coordinates of each of the satellites, and calculates the user coordinates on the lunar surface through the three-sphere intersection positioning principle.

[0006] Optionally, the satellite is a satellite in a constructed space segment, and the space segment consists of 4 NRHO orbit satellites and 24 ELFO orbit satellites.

[0007] Optionally, the electromagnetic wave signal is a laser signal.

[0008] Optionally, the user equipment is equipped with a high-precision clock and a laser ranging device, and the satellite is equipped with a laser corner reflector.

[0009] Optionally, calculating the user coordinates on the lunar surface by the three-sphere intersection positioning principle includes: if three satellites are used for positioning, calculating the user coordinates on the lunar surface by the following set of equations:

[0010]

[0011] Where (x1, y1) is the coordinate of the first satellite, (x2, y2) is the coordinate of the second satellite, (x3, y3) is the coordinate of the third satellite, (x, y, z) is the coordinate of the user on the lunar surface, and t1, t2, and t3 are the round-trip times recorded by the three satellites respectively.

[0012] Optionally, calculating the user coordinates on the lunar surface by the three-sphere intersection positioning principle includes: if four or more satellites are used for positioning, solving the coordinates (x, y, z) of the user on the lunar surface by a numerical method, satisfying:

[0013]

[0014] Where n represents n satellites, n≥4, (x i ,y i ,z i ) is the coordinate of the i-th satellite, d i is the distance between the i-th satellite and the user equipment.

[0015] Optionally, the method further includes: using Kalman filtering technology to correct the calculated coordinate position of the user on the lunar surface.

[0016] In a second aspect, the present invention provides a positioning device for users on the lunar surface, comprising: a signal transmitting module, used to enable a user device located on the lunar surface to transmit an electromagnetic wave signal to a lunar satellite; a signal receiving module, used to receive the electromagnetic wave signal reflected back by the satellite, and record the round-trip time t of the electromagnetic wave signal between the user device and the satellite; a first calculation module, used to calculate the distance d between the user device and the satellite based on the round-trip time t, d=c·t / 2, where c is the speed of light; a second calculation module, used to calculate the user coordinates on the lunar surface by the three-sphere intersection positioning principle after obtaining the distances between at least three satellites and the user device, combined with the coordinates of each of the satellites.

[0017] In a third aspect, the present invention provides an electronic device comprising: a processor and a memory, wherein the memory stores programs or instructions that can be run on the processor, and when the programs or instructions are executed by the processor, the steps of the method for positioning users on the lunar surface as described in the first aspect are implemented.

[0018] In a fourth aspect, the present invention provides a readable storage medium storing a program or instruction, which, when executed by a processor, implements the steps of the method for positioning a user on the lunar surface as described in the first aspect.

[0019] Compared with the prior art, the present invention has the following advantages: first, the user equipment located on the lunar surface transmits an electromagnetic wave signal to the lunar satellite, then receives the electromagnetic wave signal reflected by the satellite, and records the round-trip time t of the electromagnetic wave signal between the user equipment and the satellite, and calculates the distance d between the user equipment and the satellite based on the round-trip time t, d=c·t / 2, where c is the speed of light, and finally, after obtaining the distances between at least three satellites and the user equipment, the coordinates of each satellite are combined and the user coordinates on the lunar surface are calculated by the three-sphere intersection positioning principle, thereby achieving precise positioning in the lunar environment, with low cost and simplified lunar satellite payload configuration. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are included to provide a further understanding of the present application. They are included and constitute a part of the present application. The accompanying drawings illustrate embodiments of the present application and together with the present specification serve to explain the principles of the present application. In the accompanying drawings:

[0021] Figure 1 is a flow chart of a method for locating a user on the lunar surface according to an embodiment of the present invention;

[0022] Figure 2 is a schematic diagram of the structure of a positioning device for a user on the lunar surface according to an embodiment of the present invention;

[0023] Figure 3 FIG. 4 is a schematic diagram of an electronic device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for the description of the embodiments. Obviously, the drawings described below are only some examples or embodiments of the present application. For ordinary technicians in this field, the present application can also be applied to other similar scenarios based on these drawings without creative work. Unless it is obvious from the language environment or otherwise explained, the same reference numerals in the figures represent the same structure or operation.

[0025] As shown in this application and claims, unless the context clearly indicates an exception, the words "a", "an", "an" and / or "the" do not refer to the singular and may also include the plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0026] In addition, it should be noted that the use of words such as "first" and "second" to define components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above words have no special meaning and cannot be understood as limiting the scope of protection of this application. In addition, although the terms used in this application are selected from well-known and commonly used terms, some terms mentioned in the specification of this application may be selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant parts of the description of this article. In addition, it is required to understand this application not only by the actual terms used, but also by the meaning implied by each term.

[0027] Flowcharts are used in the present application to illustrate the operations performed by the system according to the embodiments of the present application. It should be understood that the preceding or following operations are not necessarily performed accurately in order. On the contrary, various steps may be processed in reverse order or simultaneously. At the same time, other operations may be added to these processes, or one or more operations may be removed from these processes.

[0028] Figure 1 is a flow chart of a method for locating a user on the lunar surface according to an embodiment of the present invention, with reference to Figure 1 As shown, method 100 includes: S110, a user device located on the lunar surface transmits an electromagnetic wave signal to a lunar satellite; S120, receiving the electromagnetic wave signal reflected by the satellite, and recording the round-trip time t of the electromagnetic wave signal between the user device and the satellite; S130, calculating the distance d between the user device and the satellite according to the round-trip time t, d=c·t / 2, where c is the speed of light; S140, after obtaining the distances between at least three satellites and the user device, combining the coordinates of each of the satellites, and calculating the user coordinates on the lunar surface through the three-sphere intersection positioning principle.

[0029] In this embodiment, the lunar satellites have known ephemeris, that is, their precise orbital data. The user equipment located on the lunar surface acts as a transmitter, sending electromagnetic wave signals, such as radio signals / laser signals, to the satellites in orbit. By adopting radio / laser ranging and velocity measurement technology, the distance and speed information between the satellite carrying precise orbital data and the lunar surface equipment are analyzed, thereby calculating the user's accurate position on the lunar surface. It can be seen that although this embodiment applies the three-ball intersection positioning principle, based on the particularity of user positioning on the lunar surface, the method of this embodiment arranges the signal transmitting device in the user equipment on the lunar surface. On the one hand, this is because there are fewer users (or equipment) on the lunar surface at present, and on the other hand, it can reduce the lunar satellite configuration, reduce the satellite load, and improve the payload utilization of the lunar satellite.

[0030] In one example, the satellites are satellites in a constructed space segment, which consists of 4 NRHO orbit satellites and 24 ELFO orbit satellites. Through the above lunar satellite configuration, 100% 4-fold coverage of the entire lunar surface is achieved. Each satellite carries precise ephemeris data, that is, their precise position in orbit (x i ,y i ,z i ) is known.

[0031] NRHO orbit is a Near Rectilinear Halo Orbit, a subset of halo orbits in the Earth-Moon system, characterized by being close to the Moon and exhibiting nearly stable behavior. NRHO orbit combines the advantages of a low lunar orbit (surface visit) and a far retrograde orbit (fuel efficiency). NRHO orbit also provides scientists with the opportunity to conduct radiation experiments in a deep space environment, which helps to gain a deeper understanding of the potential impact of space weather on personnel and instruments.

[0032] The ELFO orbit is an elliptical lunar frozen orbit with an almost constant eccentricity and an almost constant periodic direction. The motion of satellites in this orbit is relatively stable, requiring less thrust to maintain the orbital position. In a frozen orbit, the average motion speed of the satellite matches the rotation speed of the celestial body, and the satellite maintains a relatively fixed position relative to the surface of the celestial body. The ELFO orbit is being considered for the construction of a lunar navigation constellation to ensure real-time high-precision positioning of lunar missions.

[0033] In one example, the electromagnetic wave signal is a laser signal. The laser beam is concentrated, and its power density falling on the receiving terminal is high, so the receiver can be made smaller and lighter. The laser beam is very narrow and less likely to be intercepted.

[0034] In one example, a high-precision clock and a laser ranging device are configured on the user device, and a laser corner reflector is configured on the satellite. With the above configuration, the user device on the lunar surface emits a laser beam pointing to the laser corner reflector in the space segment. After the laser hits the corner reflector on the satellite, it is accurately reflected back to the user device. After that, the user device receives the reflected laser and records the total round-trip time t of the laser.

[0035] In one example, the user coordinates on the lunar surface can be calculated by the three-sphere intersection positioning principle. If three satellites are used for positioning, the user coordinates on the lunar surface can be calculated by the following set of equations:

[0036]

[0037] Where (x1, y1) is the coordinate of the first satellite, (x2, y2) is the coordinate of the second satellite, (x3, y3) is the coordinate of the third satellite, (x, y, z) is the coordinate of the user on the lunar surface, and t1, t2, and t3 are the round-trip times recorded by the three satellites respectively.

[0038] In one example, the user coordinates on the lunar surface calculated by the three-sphere intersection positioning principle can be, if four or more satellites are used for positioning, then the numerical method is used to solve, satisfying:

[0039]

[0040] For example, the least square method is used to find the best coordinate position (i.e., the optimal solution) by minimizing the square difference of the distance. In the above formula, n represents n satellites, n≥4, (x, y, z) is the coordinate of the user on the lunar surface, (x i ,y i ,z i ) is the coordinate of the ith satellite.

[0041] In one example, the method 100 further includes correcting the calculated coordinate position of the user on the lunar surface using a Kalman filter technique.

[0042] The practical application of the method 100 of this embodiment may be affected by factors such as the reflection characteristics of the lunar surface, the time accuracy of the device, satellite orbit errors, etc. Therefore, filtering technology can be used to optimize and correct the coordinate position, thereby reducing errors and improving the reliability of positioning results.

[0043] Kalman Filter can estimate the state of a dynamic system in the presence of noise and uncertainty. The core idea is to use the linear system state equation to optimally estimate the system state through the input and output observation data of the system. The working principle of Kalman filter is based on two key steps: prediction and update. In the prediction stage, the filter uses the estimate of the previous state to predict the current state. In the update stage, the filter uses the observation of the current state to optimize the predicted value, thereby obtaining a more accurate new estimate.

[0044] In the lunar environment, the Kalman filter uses the pseudorange and pseudorange change rate provided by the lunar navigation satellite as observation values, and combines the receiver's dynamic model of integrating microwave direction finding, optical measurement, inertial navigation, and chip atomic clock information to predict the state, and dynamically adjusts the error covariance matrix according to the deviation between the observed value and the predicted value. Through the recursive prediction and update process, the Kalman filter effectively suppresses the impact of noise on positioning accuracy, overcomes the lack of lunar surface geographic information and weak infrastructure, and can improve positioning accuracy in the complex lunar environment.

[0045] When applying the method of this embodiment, the positioning system is arranged in a user segment and a space segment. The user segment equipment is deployed on the lunar surface and has the ability to send signals to the space segment satellites. The space segment includes at least three micro-satellites carrying precise ephemeris data, which are deployed on a specific orbit of the moon to achieve full coverage of the lunar surface. The user equipment on the lunar surface transmits signals of a specific frequency to the satellites in orbit. These space segment satellites have known precise orbital data. Through ranging and speed measurement technology such as radio, combined with the precise orbital data of the satellite and the ranging information of the lunar surface transmitter, the user's position on the lunar surface can be accurately calculated.

[0046] Compared with the traditional satellite navigation system, the method of this embodiment reduces the complexity requirements for satellites. Space segment satellites are mainly used as fixed reference points with known positions, and there is no need to broadcast conventional navigation signals. The user end can complete the positioning solution of the user segment by performing a single distance measurement with the space segment. The method of this embodiment has a wide range of applications and can be used for the positioning and navigation of lunar rover navigation, mining operations, scientific research, and other lunar surface activities.

[0047] Another embodiment of the present invention provides a positioning device for a user on the lunar surface, referring to Figure 2 As shown, the device 200 includes: a signal transmitting module 201, which is used to enable a user device located on the lunar surface to transmit an electromagnetic wave signal to a lunar satellite; a signal receiving module 202, which is used to receive the electromagnetic wave signal reflected by the satellite and record the round-trip time t of the electromagnetic wave signal between the user device and the satellite; a first calculation module 203, which is used to calculate the distance d between the user device and the satellite according to the round-trip time t, d=c·t / 2, where c is the speed of light; a second calculation module 204, which is used to calculate the user coordinates on the lunar surface by the three-sphere intersection positioning principle after obtaining the distances between at least three satellites and the user device, combined with the coordinates of each of the satellites.

[0048] In one example, the satellite is a satellite in a constructed space segment, and the space segment consists of 4 NRHO orbit satellites and 24 ELFO orbit satellites.

[0049] In one example, the electromagnetic wave signal is a laser signal.

[0050] In one example, a high-precision clock and a laser ranging device are configured on the user equipment, and a laser corner reflector is configured on the satellite.

[0051] In one example, the user coordinates on the lunar surface can be calculated by the three-sphere intersection positioning principle. If three satellites are used for positioning, the user coordinates on the lunar surface can be calculated by the following set of equations:

[0052]

[0053] Where (x1, y1) is the coordinate of the first satellite, (x2, y2) is the coordinate of the second satellite, (x3, y3) is the coordinate of the third satellite, (x, y, z) is the coordinate of the user on the lunar surface, and t1, t2, and t3 are the round-trip times recorded by the three satellites respectively.

[0054] In one example, the user coordinates on the lunar surface calculated by the three-sphere intersection positioning principle can be: if four or more satellites are used for positioning, the coordinates (x, y, z) of the user on the lunar surface are solved by numerical methods to satisfy:

[0055]

[0056] Where n represents n satellites, n≥4, (x i ,y i ,z i ) is the coordinate of the i-th satellite, d i is the distance between the i-th satellite and the user equipment.

[0057] In one example, the apparatus 200 further includes a correction module for correcting the calculated coordinate position of the user on the lunar surface using a Kalman filter technique.

[0058] The details of other operations performed by each module in this embodiment can be referred to the aforementioned embodiments and will not be elaborated here.

[0059] In the positioning device for users on the lunar surface of the present embodiment, first, the user equipment located on the lunar surface transmits an electromagnetic wave signal to the lunar satellite, then receives the electromagnetic wave signal reflected by the satellite, and records the round-trip time t of the electromagnetic wave signal between the user equipment and the satellite. Then, based on the round-trip time t, the distance d between the user equipment and the satellite is calculated, where d=c·t / 2, where c is the speed of light. Finally, after obtaining the distances between at least three satellites and the user equipment, the coordinates of the user on the lunar surface are calculated by the three-sphere intersection positioning principle in combination with the coordinates of each satellite, thereby achieving precise positioning in the lunar environment, with low cost and simplified lunar satellite payload configuration.

[0060] A positioning device for a user on the lunar surface in the embodiment of the present application may be a device, or a component, integrated circuit, or chip in a terminal. A positioning device for a user on the lunar surface in the embodiment of the present application may be a device with an operating system. The operating system may be an Android operating system, an iOS operating system, or other possible operating systems, which are not specifically limited in the embodiment of the present application.

[0061] The present application also provides an electronic device, comprising: a memory for storing programs or instructions executable by a processor; and a processor for executing the above-mentioned programs or instructions to implement the various processes of the above-mentioned lunar surface user positioning method embodiment, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0062] Figure 3 300 is a schematic diagram of an electronic device according to an embodiment of the present invention. The electronic device 300 may include an internal communication bus 301, a processor (Processor) 302, a read-only memory (ROM) 303, a random access memory (RAM) 304, and a communication port 305. When applied to a personal computer, the electronic device 300 may also include a hard disk 306. The internal communication bus 301 can realize data communication between components of the electronic device 300. The processor 302 can make judgments and issue prompts. In some embodiments, the processor 302 can be composed of one or more processors. The communication port 305 can realize data communication between the electronic device 300 and the outside. In some embodiments, the electronic device 300 can send and receive information and data from the network through the communication port 305. The electronic device 300 may also include different forms of program storage units and data storage units, such as a hard disk 306, a read-only memory (ROM) 303 and a random access memory (RAM) 304, which can store various data files used for computer processing and / or communication, and possible programs or instructions executed by the processor 302. The processing result of the processor 302 is transmitted to the user equipment through the communication port 305 and displayed on the user interface.

[0063] The above-mentioned method for locating a user on the lunar surface may be implemented as a computer program, stored in the hard disk 306 , and recorded in the processor 302 for execution, so as to implement any method for locating a user on the lunar surface in the present application.

[0064] The embodiment of the present application also provides a readable storage medium, on which a program or instruction is stored. When the program or instruction is executed by a processor, each process of the above-mentioned lunar surface user positioning method embodiment is implemented, and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0065] Similarly, it should be noted that in order to simplify the description of the disclosure of this application and thus help understand one or more embodiments of the invention, in the above description of the embodiments of this application, multiple features are sometimes combined into one embodiment, figure or description thereof. However, this disclosure method does not mean that the features required by the object of this application are more than the features mentioned in the claims. In fact, the features of the embodiments are less than all the features of the single embodiment disclosed above.

[0066] Although the present application has been described with reference to the current specific embodiments, ordinary technicians in this technical field should recognize that the above embodiments are only used to illustrate the present application, and various equivalent changes or substitutions may be made without departing from the spirit of the present application. Therefore, as long as the changes and modifications to the above embodiments are within the essential spirit of the present application, they will fall within the scope of the claims of the present application.

Claims

1. A method for positioning a user on the lunar surface, characterized in that: include: User equipment located on the lunar surface transmits electromagnetic wave signals to the lunar satellite; receiving an electromagnetic wave signal reflected by the satellite, and recording a round trip time t of the electromagnetic wave signal between the user equipment and the satellite; According to the round trip time t, calculate the distance d between the user equipment and the satellite, d=c·t / 2, where c is the speed of light; After obtaining the distances between at least three satellites and the user equipment, the user coordinates on the lunar surface are calculated by combining the coordinates of each of the satellites using the three-sphere intersection positioning principle.

2. The method for locating a user on the lunar surface as claimed in claim 1, characterized in that: The satellite is a satellite in a constructed space segment, and the space segment consists of 4 NRHO orbit satellites and 24 ELFO orbit satellites.

3. The method for locating a user on the lunar surface as claimed in claim 1, characterized in that: The electromagnetic wave signal is a laser signal.

4. The method for locating a user on the lunar surface as claimed in claim 3, characterized in that: The user equipment is equipped with a high-precision clock and a laser ranging device, and the satellite is equipped with a laser corner reflector.

5. The method for locating a user on the lunar surface as claimed in claim 1, characterized in that: The user coordinates on the lunar surface calculated by the three-sphere intersection positioning principle include: If three satellites are used for positioning, the user coordinates on the lunar surface are calculated using the following set of equations: Where (x1, y1) is the coordinate of the first satellite, (x2, y2) is the coordinate of the second satellite, (x3, y3) is the coordinate of the third satellite, (x, y, z) is the coordinate of the user on the lunar surface, and t1, t2, and t3 are the round-trip times recorded by the three satellites respectively.

6. The method for locating a user on the lunar surface as claimed in claim 1, characterized in that: The user coordinates on the lunar surface calculated by the three-sphere intersection positioning principle include: If four or more satellites are used for positioning, the coordinates (x, y, z) of the user on the lunar surface are solved by numerical methods to satisfy: Where n represents n satellites, n≥4, (x i ,y i ,z i ) is the coordinate of the i-th satellite, d i is the distance between the i-th satellite and the user equipment.

7. The method for locating a user on the lunar surface as claimed in claim 1, characterized in that: Also includes: The Kalman filter technique is used to correct the calculated coordinate position of the user on the lunar surface.

8. A positioning device for users on the lunar surface, characterized in that: include: A signal transmission module is used to enable user equipment on the lunar surface to transmit electromagnetic wave signals to the lunar satellite; A signal receiving module, used to receive the electromagnetic wave signal reflected by the satellite, and record the round-trip time t of the electromagnetic wave signal between the user equipment and the satellite; A first calculation module is used to calculate the distance d between the user equipment and the satellite according to the round-trip time t, where d=c·t / 2, where c is the speed of light; The second calculation module is used to calculate the user coordinates on the lunar surface by the three-sphere intersection positioning principle after obtaining the distances between at least three satellites and the user equipment, combining the coordinates of each of the satellites.

9. An electronic device, characterized in that: include: A processor and a memory, wherein the memory stores a program or instruction that can be run on the processor, and when the program or instruction is executed by the processor, the steps of the method for positioning a user on the lunar surface as described in any one of claims 1 to 7 are implemented.

10. A readable storage medium, characterized in that: The readable storage medium stores a program or instruction, and when the program or instruction is executed by the processor, the steps of the method for positioning a user on the lunar surface as described in any one of claims 1 to 7 are implemented.

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