A spatial positioning method and system for a truss sliding on-track assembly robot

Abstract

The present invention relates to a spatial positioning method and system for a truss sliding type on-orbit assembly robot, including: Step S1: The spacecraft central positioning base station O sends out a first positioning request message; Step S2: The spacecraft remote positioning base station P returns a first response message; Step S3: The spacecraft central positioning base station O calculates and obtains a first relative distance D according to the first positioning request message and the first response message OP and transmits it to the on-orbit assembly robot R; Step S4: The on-orbit assembly robot R sends out a second positioning request message; Step S5: The spacecraft central positioning base station O returns a second response message, and the spacecraft remote positioning base station P returns a third response message; Step S6: The on-orbit assembly robot R calculates and obtains the spatial position R(X, Y, Z) according to the second response message, the third response message and the first relative distance D OP The present invention can improve the accuracy of spatial positioning.

Description

Technical Field

[0001] The present invention mainly relates to the technical field of space positioning of spacecraft, and specifically relates to a space positioning method and system for a truss sliding on-orbit assembly robot. Background Art

[0002] After being launched into orbit, spacecraft and its components (such as an on-orbit assembly robot used to assemble extended antennas) need to be positioned in space to ensure the normal operation of the spacecraft and its components.

[0003] Prior art 1 (publication number: CN113276106A) discloses a spatial positioning method and a spatial positioning system for a climbing robot, which proposes a spatial positioning method for a climbing robot, mainly using a visual method to match a real-time image with pre-stored model information, or using video monitoring, QR code marking, etc. for positioning, but there are several problems with the visual positioning method on a space truss: for example, the lighting conditions in space are poor, there are no light times and strong exposure conditions, which have a great impact on the visual positioning method; the spacecraft is in the process of on-orbit assembly, and the spacecraft model cannot be pre-stored at this time, making it difficult to perform real-time matching and positioning; the robot is on the truss and it is difficult to take a full picture of the spacecraft. Since the on-orbit assembled spacecraft may be symmetrical, it is difficult to distinguish its own spatial position by relying on local images.

[0004] Prior art 2 (publication number: CN112566028A) discloses an indoor robot positioning method based on UWB, which relies on time synchronization and clock offset calculation between base stations. However, in the process of performing time synchronization and clock offset calculation through ultra-wideband signals, due to the influence of time asynchrony and frequency asynchrony between base stations, the time synchronization and clock frequency shift calculation accuracy is poor, and a complex filtering algorithm is required for solution.

[0005] Prior art 3 (publication number: CN116600384A) discloses a multi-base station positioning method, device, storage medium and system, which utilizes multiple base stations in space to collect signals for spatial positioning when the coordinates of each base station are known. However, on a spacecraft assembled on-orbit in space, even if multiple base stations are deployed, the base stations cannot determine their own positions due to the lack of GPS positioning signals on the high-orbit track. At the same time, the relative positions between the base stations change with the changes in the on-orbit assembly of the spacecraft. Therefore, it is not suitable for the spatial positioning of robots on spacecraft assembled on-orbit in space.

[0006] Prior art 4 (publication number: CN117589195A) discloses a method for correcting the two-dimensional positioning error of UWB dual base stations, which proposes a method for positioning using ultra-wideband signals of two base stations, and realizes positioning solution by relative distance measurement based on flight time. However, it is limited to the fact that the two base stations can only perform two-dimensional positioning, and its error correction relies on the preliminary measurement of fixed reference points. After the error correction model is formed, high-precision positioning can be achieved. It is difficult to find a fixed reference point with a clear spatial position in the on-orbit assembly of a spacecraft in space, and the relative positions of each base station continue to change with the on-orbit assembly of the spacecraft, making it difficult to establish an error correction model to improve positioning accuracy.

[0007] In the existing space positioning solutions, there is a problem of low space positioning accuracy when there is no assistance from the GPS satellite system in high orbit. Summary of the invention

[0008] The technical problem to be solved by the present application is to provide a spatial positioning method and system for a truss sliding on-track assembly robot, which can improve the accuracy of spatial positioning.

[0009] The technical solution adopted by the present application to solve the above technical problems is a spatial positioning method for a truss sliding on-orbit assembly robot, wherein the on-orbit assembly robot R is used to move along the truss, and a spacecraft central positioning base station O and a spacecraft remote positioning base station P with the same time-frequency reference are respectively arranged at both ends of the truss. The spatial positioning method comprises: step S1: the spacecraft central positioning base station O sends a first positioning request message; step S2: in response to the first positioning request message, the spacecraft remote positioning base station P returns a first response message; step S3: in response to the first response message, the spacecraft central positioning base station O calculates a first relative distance D according to the first positioning request message and the first response message. OP , transmit the first relative distance D OP to the on-orbit assembly robot R; step S4: the on-orbit assembly robot R sends a second positioning request message; step S5: in response to the second positioning request message, the spacecraft center positioning base station O returns a second response message, and the spacecraft remote positioning base station P returns a third response message; step S6: in response to the second response message and the third response message, the on-orbit assembly robot R responds to the second response message, the third response message and the first relative distance D OP The spatial position R (X, Y, Z) is obtained by solution, where the Z axis represents the direction in which the center of the truss extends outward, and the X axis, Y axis, and Z axis are perpendicular to each other.

[0010] In one embodiment of the present application, the first positioning request message includes a first sending time timestamp O1, and the first response message includes a first receiving time timestamp P1; in step S3, the spacecraft center positioning base station O calculates the first relative distance D according to the first positioning request message and the first response message.OP The steps include: using the following formula to calculate the first relative distance D OP :

[0011] D OP =[(P1–O1)+(O2–P2)] / 2*c

[0012] Among them, the first relative distance D OP represents the relative distance between the spacecraft central positioning base station O and the spacecraft remote positioning base station P; P2 represents the timestamp when the spacecraft remote positioning base station P returns the first response message to the spacecraft central positioning base station O; O2 represents the timestamp when the spacecraft central positioning base station O receives the first response message; c represents the speed of light.

[0013] In one embodiment of the present application, the second response message includes a second receiving time timestamp O1, and the third response message includes a third receiving time timestamp P1; in step S6, the on-track assembly robot R receives the second response message, the third response message and the first relative distance D OP The steps of solving to obtain the spatial position R (X, Y, Z) include: step S6a: constructing a first equation according to the second receiving time stamp O1 and the third receiving time stamp P1; step S6b: constructing a first equation according to the first relative distance D OP Construct the first position triangle area S1, the first position triangle area S1 is the area on the space plane formed by the on-orbit assembly robot R, the spacecraft center positioning base station O, and the spacecraft remote positioning base station P; step S6c: according to the first relative distance D OP Construct the second position triangle area S2; Step S6d: Solve the first position triangle area S1, the second position triangle area S2, and the first equation to obtain the second relative distance D PR , the second relative distance D PR is the relative distance between the spacecraft remote positioning base station P and the on-orbit assembly robot R; Step S6e: Calculate the Z-axis coordinate of the spatial position R (X, Y, Z) according to the triangle relationship on the spatial plane, and calculate the Z-axis coordinate of the on-orbit assembly robot R according to the distance D of the on-orbit assembly robot R relative to the center point of the truss t The X-axis coordinate of the spatial position R (X, Y, Z) is obtained by solving the problem.

[0014] In one embodiment of the present application, in step S6a, the following formula is used to construct the first equation:

[0015] (P1–O1)*c=D PR –D OR

[0016] Among them, D PR Indicates the second relative distance; D ORrepresents the relative distance between the spacecraft center positioning base station O and the on-orbit assembly robot R.

[0017] In one embodiment of the present application, in step S6b, the first position triangle area S1 is constructed using the following formula:

[0018]

[0019] Here, sqrt[·] represents the square root function.

[0020] In one embodiment of the present application, in step S6c, the second position triangle area S2 is constructed using the following formula:

[0021]

[0022] Wherein, d represents the distance between the parallel line of the truss where the on-orbit assembly robot R is located and the line formed by the spacecraft center positioning base station O and the spacecraft remote positioning base station P.

[0023] In one embodiment of the present application, in step S6d, the second relative distance D is obtained by solving the first position triangle area S1, the second position triangle area S2, and the first equation simultaneously. PR The steps include: setting the area of ​​the first triangle S1 equal to the area of ​​the second triangle S2, thereby deriving the relationship D PR +D OR :

[0024] D PR +D OR =sqrt(4*D OP ^2 *d ^2 / [D OP –(D PR –D OR )]*[D OP +(D PR –D OR )]+

[0025] D OP ^2 );

[0026] Solve the first equation and relation D simultaneously PR +D OR Get the second relative distance D PR :

[0027]

[0028] In one embodiment of the present application, in step S6e, the Z-axis coordinate D of the spatial position R (X, Y, Z) is calculated according to the triangle relationship on the spatial plane using the following formula: O’R :

[0029] D P’R =sqrt(D PR ^2 –d ^2 )

[0030] D O’R =D OR -D P’R

[0031] In step S6e, the following formula is used according to the distance D between the on-track assembly robot R and the center point of the truss: t Solve to get the X-axis coordinate r of the spatial position R (X, Y, Z):

[0032] r=D t +D jia / sqrt(2)

[0033] Among them, D jia Indicates the single side length of the truss outer contour.

[0034] In order to solve the above-mentioned technical problems, the present application also proposes a spatial positioning system for a truss sliding on-orbit assembly robot, comprising: a truss; a spacecraft central positioning base station O, which is arranged at one end of the truss; a spacecraft remote positioning base station P, which is arranged at the other end of the truss, and the spacecraft remote positioning base station P and the spacecraft central positioning base station O have the same time-frequency reference; an on-orbit assembly robot R, which is provided with a robot positioning antenna, and the on-orbit assembly robot R is used to move along the truss; a memory, which is used to store instructions that can be executed by a processor; and a processor, which is used to execute instructions to implement the above-mentioned spatial positioning method for the truss sliding on-orbit assembly robot.

[0035] In view of the situation where there is no GPS satellite system in high orbit, this application proposes a single-request response space positioning method using ultra-wideband microwave signals in combination with the truss characteristics of the spacecraft. Based on the advantages of the synchronization of the time and frequency reference of the same spacecraft, this application performs positioning through dual base stations at both ends of the truss. The spatial position solution method of this application is simple, and the positioning accuracy is high, which can reach the millimeter level. It can also be positioned throughout the entire cycle from the initial to the final stage of the on-orbit assembly of the spacecraft, and the engineering implementation feasibility is strong. The on-orbit assembly robot of this application can perform three-dimensional position solution based on two dual base stations with a common time and frequency reference, and achieve millimeter-level positioning accuracy. This application does not rely on the time synchronization and frequency synchronization of the on-orbit assembly robot and the spacecraft, so there is no system error caused by time asynchrony and clock offset, which further ensures the high accuracy of space positioning. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below with reference to the accompanying drawings, wherein:

[0037] Figure 1 is an exemplary flow chart of a spatial positioning method of a truss sliding on-track assembly robot according to an embodiment of the present application;

[0038] Figure 2 It is a schematic diagram of the arrangement of a spacecraft central positioning base station and a spacecraft remote positioning base station in one embodiment of the present application;

[0039] Figure 3 is a schematic diagram of a spatial positioning system of a truss sliding on-track assembly robot according to an embodiment of the present application;

[0040] Figure 4 It is a schematic diagram of a planar layout in which a robot positioning antenna of an on-track assembly robot is perpendicular to a truss in one embodiment of the present application;

[0041] Figure 5 is a schematic diagram of an on-track assembly robot and a truss in one embodiment of the present application;

[0042] Figure 6 It is a schematic diagram of converting the spatial positioning system layout of the truss sliding on-rail assembly robot into a two-dimensional plane in one embodiment of the present application;

[0043] Figure 7 It is a schematic diagram of a plane formed by an on-orbit assembly robot, a spacecraft central positioning base station, and a spacecraft remote positioning base station in one embodiment of the present application;

[0044] Figure 8 is a schematic diagram of the location of the robot positioning antenna and the outer contour of the truss in one embodiment of the present application;

[0045] Fig. 9 is a schematic diagram of a communication process between a spacecraft central positioning base station and a spacecraft remote positioning base station in an embodiment of the present application;

[0046] Fig.10 It is a schematic diagram of the communication process between the on-orbit assembly robot and the spacecraft central positioning base station and the spacecraft remote positioning base station in one embodiment of the present application;

[0047] Fig.11 is a schematic diagram of a spatial position coordinate system in an embodiment of the present application;

[0048] Fig.12 It is a system block diagram of a spatial positioning system of a truss sliding on-track assembly robot according to an embodiment of the present application. DETAILED DESCRIPTION

[0049] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below with reference to the accompanying drawings.

[0050] In the following description, many specific details are set forth to facilitate a full understanding of the present application, but the present application may also be implemented in other ways different from those described herein, and therefore the present application is not limited to the specific embodiments disclosed below.

[0051] 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.

[0052] 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.

[0053] The present application proposes a spatial positioning method for a truss-sliding on-orbit assembly robot, which can be applied to application scenarios in which high-orbit GPS satellite systems are not available for assisted positioning. The spatial positioning method for a truss-sliding on-orbit assembly robot of the present application can be run in the satellite computer of a spacecraft, and can also be run on the ground side. When the spatial positioning method for a truss-sliding on-orbit assembly robot is run on the ground side, the data on the ground side interacts with the spacecraft data through a wireless network. The present application does not limit the operating environment of the spatial positioning method for a truss-sliding on-orbit assembly robot.

[0054] To facilitate understanding of the technical solution of the present application, the on-orbit composition of the spacecraft and the spatial positioning system of the truss sliding on-orbit assembly robot of the present application are first introduced here, and the spatial positioning method of the truss sliding on-orbit assembly robot will be introduced later.

[0055] Figure 2 is a schematic diagram of the arrangement of a spacecraft central positioning base station and a spacecraft remote positioning base station in an embodiment of the present application, with reference to Figure 2 As shown, in this embodiment, four positioning base stations are arranged on the on-orbit assembled spacecraft, one spacecraft center positioning base station O is connected to three spacecraft remote positioning base stations P through a truss 200, and the positioning base station antenna is deployed on the top of the spacecraft platform.

[0056] Figure 3is a schematic diagram of a spatial positioning system of a truss sliding on-track assembly robot according to an embodiment of the present application, with reference to Figure 3 As shown, the spatial positioning system of the truss sliding on-rail assembly robot of this embodiment includes: a truss 200; a spacecraft center positioning base station O, which is arranged at one end of the truss 200; a spacecraft remote positioning base station P, which is arranged at the other end of the truss 200, and the spacecraft remote positioning base station P and the spacecraft center positioning base station O have the same time-frequency reference; an on-rail assembly robot R, which is provided with a robot positioning antenna (not shown), and the on-rail assembly robot R is used to move along the truss 200; a memory (not shown) for storing instructions executable by a processor; a processor (not shown) for executing instructions to implement the spatial positioning method of the truss sliding on-rail assembly robot as described later. Exemplarily, the on-rail assembly robot R can slide along the upper surface of the truss 200.

[0057] Figure 4 1 is a schematic diagram of a plane layout in which a robot positioning antenna of an on-track assembly robot is perpendicular to a truss in one embodiment of the present application. Figure 5 It is a schematic diagram of an on-track assembly robot and a truss in one embodiment of the present application. Figure 4 The vertical plane between the robot positioning antenna and the truss 200 is roughly shown by a diamond. Figure 5 As shown, the robot positioning antenna is located at the bottom of the on-orbit assembly robot R. Figure 5 The truss outer profile is shown in FIG. , and the truss outer profile is rectangular.

[0058] Figure 6 is a schematic diagram of converting the spatial positioning system layout of the truss sliding on-rail assembly robot into a two-dimensional plane in one embodiment of the present application, Figure 7 Schematic diagram of a plane formed by an on-orbit assembly robot, a spacecraft center positioning base station, and a spacecraft remote positioning base station in one embodiment of the present application. Figure 6 and Figure 7 As shown, illustratively, the present application converts the spatial positioning system layout of the truss sliding on-rail assembly robot into a two-dimensional plane to facilitate the formula description below. Figure 6 In the figure, point O represents the deployment position of the base station for the center positioning of the spacecraft, and points N, P, and Q represent the deployment positions of the base stations for the remote positioning of the spacecraft. In the space positioning method introduced later in this application, points O and P are used as examples. Figure 7 In the equation, d represents the distance between the parallel line of the truss where the on-orbit assembly robot R is located and the line formed by the spacecraft center positioning base station O and the spacecraft remote positioning base station P.

[0059] Figure 8 is a schematic diagram of the location of the robot positioning antenna and the outer contour of the truss in one embodiment of the present application. For example, Figure 8The length of one side of the truss outer profile of the middle truss 200 is D jia , D t It represents the distance between the on-track assembly robot R and the center point of the truss.

[0060] The spatial positioning method of the truss sliding on-track assembly robot of the present application will be introduced below.

[0061] Figure 1 is an exemplary flow chart of a spatial positioning method of a truss sliding on-track assembly robot according to an embodiment of the present application, with reference to Figure 1 As shown, the spatial positioning method of the truss sliding on-track assembly robot of this embodiment includes the following steps:

[0062] Step S1: The spacecraft center positioning base station O sends a first positioning request message.

[0063] Step S2: In response to the first positioning request message, the spacecraft remote positioning base station P returns a first response message.

[0064] Step S3: In response to the first response message, the spacecraft center positioning base station O calculates the first relative distance D according to the first positioning request message and the first response message. OP , transmit the first relative distance D OP To the on-orbit assembly robot R.

[0065] Step S4: The on-track assembly robot R sends a second positioning request message.

[0066] Step S5: In response to the second positioning request message, the spacecraft central positioning base station O returns a second response message, and the spacecraft remote positioning base station P returns a third response message.

[0067] Step S6: In response to the second response message and the third response message, the on-track assembly robot R generates an on-track assembly robot according to the second response message, the third response message and the first relative distance D OP The spatial position R (X, Y, Z) is obtained by solution, where the Z axis represents the direction in which the center of the truss extends outward, and the X axis, Y axis, and Z axis are perpendicular to each other.

[0068] The above steps S1 to S6 are described in detail below:

[0069] Exemplarily, steps S1 to S3 described below are equivalent to the process of the spacecraft central positioning base station O and the spacecraft remote positioning base station P performing relative distance calculation, and the relative distance communication is transmitted to the on-orbit assembly robot R. Steps S4 to S6 are equivalent to the process of the on-orbit assembly robot R calculating its own spatial position based on the central positioning base station and the remote positioning base station on the truss where it is located. The base stations share a common time-frequency reference, and the time-frequency between the on-orbit assembly robot R and the base stations is not unified. In steps S4 to S6, the on-orbit assembly robot R sends a positioning request message, and the positioning base station returns a corresponding response message after receiving the request message. The on-orbit assembly robot R can select the base station of the truss where it is located according to the base station number, and calculate the position through the timestamp.

[0070] Fig. 9 Schematic diagram of the communication process between the spacecraft central positioning base station and the spacecraft remote positioning base station in one embodiment of the present application. Fig. 9 This is to help understand steps S1 to S3 described below. Fig. 9 The request message includes the base station's own number and a timestamp of the sending time; the response message includes the base station's own number and a timestamp of the receiving time. O1, O2, P1, and P2 are all times. A single request message or response message is a pulse signal of 0.2ns to 1ns, and ns represents nanoseconds.

[0071] In step S1, the spacecraft center positioning base station O sends a first positioning request message. Exemplarily, the first positioning request message includes a first sending time timestamp O1.

[0072] In step S2, in response to the first positioning request message, the spacecraft remote positioning base station P returns a first response message. Exemplarily, the first response message includes a first receiving time timestamp P1.

[0073] In step S3, in response to the first response message, the spacecraft center positioning base station O calculates the first relative distance D according to the first positioning request message and the first response message. OP , transmit the first relative distance D OP To the on-orbit assembly robot R. Exemplarily, step S3 is equivalent to the spacecraft central positioning base station O performing position calculation according to the timestamp and transmitting the relative distance to the on-orbit assembly robot R through communication.

[0074] In some embodiments, in step S3, the spacecraft center positioning base station O calculates the first relative distance D according to the first positioning request message and the first response message. OP The steps include: using the following formula (1) to calculate the first relative distance D OP :

[0075] D OP= [(P1 – O1) + (O2 – P2)] / 2 * c (1)

[0076] Among them, the first relative distance D OP represents the relative distance between the spacecraft central positioning base station O and the spacecraft remote positioning base station P; P2 represents the timestamp when the spacecraft remote positioning base station P returns the first response message to the spacecraft central positioning base station O; O2 represents the timestamp when the spacecraft central positioning base station O receives the first response message; c represents the speed of light.

[0077] Fig.10 Schematic diagram of the communication process between the on-orbit assembly robot and the spacecraft central positioning base station and the spacecraft remote positioning base station in one embodiment of the present application. Fig.10 This is to help understand steps S4 to S6 described later. Fig.10 The request message includes the on-track assembly robot R's own number and the timestamp of the sending time; the response message includes the base station's own number and the timestamp of the receiving time, and O1, O2, R1, R2, R3, P1, and P2 are all times.

[0078] In step S4, the on-track assembly robot R sends a second positioning request message.

[0079] In step S5, in response to the second positioning request message, the spacecraft central positioning base station O returns a second response message, and the spacecraft remote positioning base station P returns a third response message. Exemplarily, the second response message includes a second receiving time timestamp O1, and the third response message includes a third receiving time timestamp P1.

[0080] In step S6, in response to the second response message and the third response message, the on-track assembly robot R generates a signal according to the second response message, the third response message and the first relative distance D. OP The spatial position R (X, Y, Z) is obtained by solution, where the Z axis represents the direction in which the center of the truss extends outward, and the X axis, Y axis, and Z axis are perpendicular to each other.

[0081] Fig.11 is a schematic diagram of a spatial position coordinate system in an embodiment of the present application. For example, Fig.11 The cylindrical coordinate system XYZ is shown in .

[0082] In some embodiments, in step S6, the on-track assembly robot R generates a signal based on the second response message, the third response message and the first relative distance D OP The steps to solve the spatial position R (X, Y, Z) include:

[0083] Step S6a: construct a first equation according to the second receiving time stamp O1 and the third receiving time stamp P1;

[0084] Step S6b: According to the first relative distance D OP Construct a first position triangle area S1, where the first position triangle area S1 is a triangle area OPR on a space plane formed by the on-orbit assembly robot R, the spacecraft center positioning base station O, and the spacecraft remote positioning base station P;

[0085] Step S6c: According to the first relative distance D OP Construct the second position triangle area S2, that is, the triangle area OPR;

[0086] Step S6d: Solve the first relative distance D by combining the area of ​​the triangle at the first position S1, the area of ​​the triangle at the second position S2, and the first equation. PR , the second relative distance D PR is the relative distance between the spacecraft remote positioning base station P and the on-orbit assembly robot R;

[0087] Step S6e: Calculate the Z-axis coordinate of the spatial position R (X, Y, Z) according to the triangle relationship on the spatial plane, and calculate the Z-axis coordinate of the spatial position R (X, Y, Z) according to the distance D between the on-track assembly robot R and the center point of the truss t The X-axis coordinate of the spatial position R (X, Y, Z) is obtained by solving the problem.

[0088] In some embodiments, in step S6a, the following formula (2) is used to construct the first equation:

[0089] (P1 – O1) * c = D PR – D OR (2)

[0090] Among them, D PR Indicates the second relative distance; D OR represents the relative distance between the spacecraft center positioning base station O and the on-orbit assembly robot R. Exemplarily, the present application considers that the spacecraft center positioning base station O and the spacecraft remote positioning base station P share a common time-frequency reference, thereby constructing the above formula (2).

[0091] In some embodiments, in step S6b, the first position triangle area S1 is constructed using the following formula (3):

[0092]

[0093] Wherein, sqrt[·] represents a square root function. For example, referring to Figure 7 As shown, the above formula (3) is used to construct the area of ​​triangle OPR.

[0094] In some embodiments, in step S6c, the second position triangle area S2 is constructed using the following formula (4):

[0095]

[0096] Among them, reference Figure 7 As shown, d represents the distance between the parallel line of the truss where the on-orbit assembly robot R is located and the line formed by the spacecraft center positioning base station O and the spacecraft remote positioning base station P. Exemplarily, after the installation position of the spacecraft truss is determined, d is a known quantity. According to the above formula (1), the area of ​​the triangle OPR shown in the above formula (4) can be obtained.

[0097] In some embodiments, in step S6d, the second relative distance D is obtained by solving the first position triangle area S1, the second position triangle area S2, and the first equation simultaneously. PR The steps include:

[0098] Step S6d1: Let the area of ​​the triangle at the first position S1 be equal to the area of ​​the triangle at the second position S2, that is, let formula (3) and formula (4) be equal, thereby deriving the relationship D shown in the following formula (5): PR +D OR :D PR +D OR =sqrt(4*D OP ^2 *d ^2 / [D OP –(D PR –D OR )]*[D OP +(D PR –D OR )]+D OP ^2 )(5);

[0099] Step S6d2: Solve the first equation of formula (2) and the relational equation D of formula (5) simultaneously PR +D OR The second relative distance D shown in the following formula (6) is obtained: PR :

[0100]

[0101] refer to Figure 7 As shown, in some embodiments, in step S6e, the Z-axis coordinate D of the spatial position R (X, Y, Z) is calculated according to the triangle relationship on the spatial plane using the following formulas (7) and (8): O’R :

[0102] D P’R = sqrt(D PR ^2 – d ^2) (7)

[0103] D O’R = D OR -D P’R (8)

[0104] refer to Figure 8 As shown, in step S6e, the following formula (9) is used according to the distance D between the on-track assembly robot R and the center point of the truss t Solve to get the X-axis coordinate r of the spatial position R (X, Y, Z):

[0105] r = D t + D jia / sqrt(2) (9)

[0106] Among them, D jia Indicates the single side length of the truss outer contour.

[0107] refer to Fig.11 As shown, for example, in a cylindrical coordinate system with O as the origin, the extension direction of the truss center as the Z axis, and the top of the truss as the X axis, the spatial position of the on-track assembly robot R is: R(r,0,D O’R ). Through the space positioning method of the present application, the time-frequency synchronization reference accuracy of multiple positioning base stations of the spacecraft is within 10e-11, and the on-orbit assembly robot R can be precisely positioned at the millimeter level.

[0108] The innovations of this application mainly include the following five aspects:

[0109] (1) The time frequency of the on-orbit assembly robot is inconsistent with that of the spacecraft. To avoid the influence of this error, a positioning base station under the same time frequency reference is used to perform single request response distance solution, which can achieve millimeter-level positioning accuracy.

[0110] (2) Usually, four base stations are required for spatial positioning. During the on-track assembly process, the truss is not completed. The present application does not rely on multiple base stations when assembling a single truss. Only two positioning base station units at both ends of the truss are required for positioning.

[0111] (3) Considering the characteristics of the truss-type spacecraft being fixed and the on-orbit assembly robot moving along the truss, the on-orbit assembly robot can perform three-dimensional position calculation through the dual base stations with a common time-frequency reference.

[0112] (4) Since the on-orbit assembly robot positioning adopts ultra-wideband microwave signals, compared with laser ranging, it has the advantages of no obstruction, no need for alignment, low power consumption, and simple hardware implementation.

[0113] (5) This application does not rely on the time synchronization and frequency synchronization of the on-orbit assembly robot and the spacecraft. There is no system error caused by time asynchrony and clock offset. The positioning accuracy is high and it is feasible for engineering implementation.

[0114] Fig.12 1 is a system block diagram of a spatial positioning system of a truss sliding on-track assembly robot according to an embodiment of the present application. Fig.12 As shown, the spatial positioning system 1200 of the truss sliding on-track assembly robot may include an internal communication bus 1201, a processor 1202, a read-only memory (ROM) 1203, a random access memory (RAM) 1204, and a communication port 1205. The spatial positioning system 1200 of the truss sliding on-track assembly robot may also include a hard disk 1206. The internal communication bus 1201 can realize data communication between the components of the spatial positioning system 1200 of the truss sliding on-track assembly robot. The processor 1202 can make judgments and issue prompts. In some embodiments, the processor 1202 can be composed of one or more processors. The communication port 1205 can realize data communication between the spatial positioning system 1200 of the truss sliding on-track assembly robot and the outside. In some embodiments, the spatial positioning system 1200 of the truss sliding on-track assembly robot can send and receive information and data from the network through the communication port 1205. The spatial positioning system 1200 of the truss sliding on-track assembly robot may also include different forms of program storage units and data storage units, such as a hard disk 1206, a read-only memory (ROM) 1203 and a random access memory (RAM) 1204, which can store various data files used for computer processing and / or communication, and possible program instructions executed by the processor 1202. The processor executes these instructions to implement the main part of the method. The results processed by the processor are transmitted to the user device through the communication port and displayed on the user interface.

[0115] The above-mentioned spatial positioning method of the truss sliding on-rail assembly robot can be implemented as a computer program, saved in the hard disk 1206, and can be loaded into the processor 1202 for execution to implement the spatial positioning method of the truss sliding on-rail assembly robot of the present application.

[0116] The present application also includes a computer-readable medium storing a computer program code, which, when executed by a processor, implements the spatial positioning method of the truss sliding on-track assembly robot described above.

[0117] When the spatial positioning method of the truss sliding on-track assembly robot is implemented as a computer program, it can also be stored in a computer-readable storage medium as a product. For example, a computer-readable storage medium may include, but is not limited to, a magnetic storage device (e.g., a hard disk, a floppy disk, a magnetic strip), an optical disk (e.g., a compact disk (CD), a digital versatile disk (DVD)), a smart card, and a flash memory device (e.g., an electrically erasable programmable read-only memory (EPROM), a card, a stick, a key drive). In addition, the various storage media described herein can represent one or more devices and / or other machine-readable media for storing information. The term "machine-readable medium" may include, but is not limited to, wireless channels and various other media (and / or storage media) that can store, contain and / or carry code and / or instructions and / or data.

[0118] It should be understood that the embodiments described above are only illustrative. The embodiments described herein may be implemented in hardware, software, firmware, middleware, microcode, or any combination thereof. For hardware implementation, the processor may be implemented in one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, and / or other electronic units designed to perform the functions described herein, or a combination thereof.

[0119] Some aspects of the present application may be performed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The above hardware or software may be referred to as "data blocks", "modules", "engines", "units", "components" or "systems". The processor may be one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DAPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, or combinations thereof. In addition, various aspects of the present application may be expressed as computer products located in one or more computer-readable media, which include computer-readable program codes. For example, computer-readable media may include, but are not limited to, magnetic storage devices (e.g., hard disks, floppy disks, tapes ...), optical disks (e.g., compact disks CDs, digital versatile disks DVDs ...), smart cards, and flash memory devices (e.g., cards, sticks, key drives ...).

[0120] A computer-readable medium may include a propagated data signal containing computer program code, such as in baseband or as part of a carrier wave. The propagated signal may have a variety of manifestations, including electromagnetic, optical, etc., or a suitable combination. A computer-readable medium may be any computer-readable medium other than a computer-readable storage medium, which may be connected to an instruction execution system, device or apparatus to communicate, propagate or transmit a program for use. The program code on the computer-readable medium may be propagated via any suitable medium, including radio, cable, fiber optic cable, radio frequency signal, or similar medium, or any combination of the above mediums.

[0121] The basic concepts have been described above. Obviously, for those skilled in the art, the above application disclosure is only an example and does not constitute a limitation of the present application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements and amendments to the present application. Such modifications, improvements and amendments are suggested in the present application, so such modifications, improvements and amendments still belong to the spirit and scope of the exemplary embodiments of the present application.

[0122] At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0123] In some embodiments, numbers describing the number of components and attributes are used. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise specified, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may change according to the required features of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of the present application are approximate values, in specific embodiments, the setting of such numerical values ​​is as accurate as possible within the feasible range.

Claims

1. A spatial positioning method for a truss sliding on-track assembly robot, characterized in that: The on-orbit assembly robot R is used to move along the truss. The two ends of the truss are respectively provided with a spacecraft center positioning base station O and a spacecraft remote positioning base station P having the same time-frequency reference. The space positioning method includes: Step S1: The spacecraft center positioning base station O sends a first positioning request message; Step S2: In response to the first positioning request message, the spacecraft remote positioning base station P returns a first response message; Step S3: In response to the first response message, the spacecraft center positioning base station O calculates a first relative distance D according to the first positioning request message and the first response message. OP , transmit the first relative distance D OP To the on-orbit assembly robot R; Step S4: the on-track assembly robot R sends a second positioning request message; Step S5: In response to the second positioning request message, the spacecraft central positioning base station O returns a second response message, and the spacecraft remote positioning base station P returns a third response message; Step S6: In response to the second response message and the third response message, the on-track assembly robot R generates an on-track assembly robot according to the second response message, the third response message and the first relative distance D OP The spatial position R (X, Y, Z) is obtained by solving the problem, wherein the Z axis represents the direction in which the center of the truss extends outward, and the X axis, Y axis, and Z axis are perpendicular to each other; the second response message includes a second receiving time timestamp O1, and the third response message includes a third receiving time timestamp P1; in the step S6, the on-track assembly robot R generates an on-track assembly robot according to the second response message, the third response message, and the first relative distance D OP The steps to solve the spatial position R (X, Y, Z) include: Step S6a: constructing a first equation according to the second receiving time stamp O1 and the third receiving time stamp P1; Step S6b: According to the first relative distance D OP Construct a first position triangle area S1, where the first position triangle area S1 is an area on a spatial plane jointly formed by the on-orbit assembly robot R, the spacecraft center positioning base station O, and the spacecraft remote positioning base station P; Step S6c: According to the first relative distance D OP Construct the second position triangle area S2; Step S6d: Solve the first relative distance D by combining the first position triangle area S1, the second position triangle area S2, and the first equation. PR , the second relative distance D PR is the relative distance between the spacecraft remote positioning base station P and the on-orbit assembly robot R; Step S6e: Calculate the Z-axis coordinate of the spatial position R (X, Y, Z) according to the triangle relationship on the spatial plane, and calculate the Z-axis coordinate of the spatial position R (X, Y, Z) according to the distance D between the on-track assembly robot R and the center point of the truss. t The X-axis coordinate of the spatial position R (X, Y, Z) is obtained by solving the problem.

2. The spatial positioning method according to claim 1, characterized in that: The first positioning request message includes a first sending time timestamp O1, and the first response message includes a first receiving time timestamp P1; in the step S3, the spacecraft center positioning base station O calculates the first relative distance D according to the first positioning request message and the first response message. OP The steps include: using the following formula to calculate the first relative distance D OP : D OP =[(P1–O1)+(O2–P2)] / 2*c Wherein, the first relative distance D OP represents the relative distance between the spacecraft central positioning base station O and the spacecraft remote positioning base station P; P2 represents the timestamp when the spacecraft remote positioning base station P returns the first response message to the spacecraft central positioning base station O; O2 represents the timestamp when the spacecraft central positioning base station O receives the first response message; c represents the speed of light.

3. The spatial positioning method according to claim 1, characterized in that: In step S6a, the first equation is constructed using the following formula: (P1–O1)*c=D PR -D OR Among them, D PR represents the second relative distance; D OR Represents the relative distance between the spacecraft center positioning base station O and the on-orbit assembly robot R.

4. The spatial positioning method according to claim 3, characterized in that: In step S6b, the following formula is used to construct the first position triangle area S1: Here, sqrt[·] represents the square root function.

5. The spatial positioning method according to claim 4, characterized in that: In step S6c, the second position triangle area S2 is constructed using the following formula: Wherein, d represents the distance between the parallel line of the truss where the on-orbit assembly robot R is located and the line formed by the spacecraft center positioning base station O and the spacecraft remote positioning base station P.

6. The spatial positioning method according to claim 5, characterized in that: In the step S6d, the second relative distance D is obtained by solving the first position triangle area S1, the second position triangle area S2, and the first equation simultaneously. PR The steps include: Let the area of ​​the first triangle S1 be equal to the area of ​​the second triangle S2, and then we can derive the relationship D PR +D OR : D PR +D OR =sqrt(4*D OP ^2 *d ^2 / [D OP –(D PR –D OR )]*[D OP +(D PR –D OR )]+D OP ^2 ); Solve the first equation and the relation D simultaneously PR +D OR The second relative distance D is obtained PR :

7. The spatial positioning method according to claim 6, characterized in that: In step S6e, the Z-axis coordinate D of the spatial position R (X, Y, Z) is calculated according to the triangle relationship on the spatial plane using the following formula: O’R : <h2 style=";text-align:left;direction:ltr">D<h2 style=";text-align:left;direction:ltr"> P’R <h2 style=";text-align:left;direction:ltr"> =sqrt(D<h2 style=";text-align:left;direction:ltr"> PR <h2 style=";text-align:left;direction:ltr"> ^2 <h2 style=";text-align:left;direction:ltr"> -d<h2 style=";text-align:left;direction:ltr"> ^2 <h2 style=";text-align:left;direction:ltr"> ) D O’R =D OR -D P’R In step S6e, the following formula is used according to the distance D between the on-track assembly robot R and the center point of the truss: t The X-axis coordinate r of the spatial position R (X, Y, Z) is obtained by solving: <h2 style=";text-align:left;direction:ltr">r=D<h2 style=";text-align:left;direction:ltr"> t <h2 style=";text-align:left;direction:ltr"> +D<h2 style=";text-align:left;direction:ltr"> jia <h2 style=";text-align:left;direction:ltr"> / sqrt(2) Among them, D jia Indicates the single side length of the outer contour of the truss.

8. A spatial positioning system for a truss sliding on-track assembly robot, characterized in that: include: truss; A spacecraft center positioning base station O is arranged at one end of the truss; A spacecraft remote positioning base station P is arranged at the other end of the truss, and the spacecraft remote positioning base station P and the spacecraft central positioning base station O have the same time and frequency reference; An on-track assembly robot R is provided with a robot positioning antenna, and the on-track assembly robot R is used to move along the truss; a memory for storing instructions executable by a processor; A processor, configured to execute the instructions to implement the spatial positioning method as described in any one of claims 1 to 7.

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