Low-resistance torque routing design method and system for satellite mechanism active cables

Abstract

This invention provides a low-resistance torque design method and system for the movement cable of a satellite mechanism. The method determines the starting point, ending point, and branching point of the cable's spatial movement section based on the movement range of the mechanism. A fixed-point distribution circle is defined in a plane perpendicular to the movement axis of the mechanism, with its center located at either the branching point or the movement axis. The cable is branched into N branches from the branching point, and each branch is guided to one of the N evenly distributed fixed points on the fixed-point distribution circle. The path of each branch is designed as a spatial arc, and all branches together form a hollow three-dimensional lantern-shaped structure. The total resistance torque exerted by the cable on the mechanism during movement is calculated. By adjusting the arc radius of the branches, the method ensures that the cable meets the requirements of non-interference and total resistance torque throughout its entire movement range. This invention effectively reduces the resistance torque of the mechanism's moving cable, extends cable lifespan, and improves the mechanism's operational stability and pointing accuracy.

Description

Technical Field

[0001] This invention relates to the field of satellite mechanical design, and more specifically, to a method and system for designing the low-resistance torque routing of a satellite mechanism's movable cable. Background Technology

[0002] Satellite motion mechanisms (such as solar panel drive mechanisms and antenna pointing mechanisms) are key components for satellite platforms to achieve attitude control, energy harvesting, and payload pointing. The cables of these motion mechanisms (referred to as "motion cables") need to continuously and reliably transmit power and signals during the mechanism's movement. However, the motion cables themselves generate significant resistance torque during repeated bending and twisting. This resistance torque directly acts on the drive mechanism, leading to decreased motion accuracy, increased servo control energy consumption, and accelerated mechanical fatigue of the cables due to stress concentration, threatening the long-term reliable operation of the entire satellite in orbit.

[0003] Traditional cable routing design primarily serves static layouts, with the primary goals of avoiding interference, optimizing path length, and facilitating installation. For movable cables, the conventional approach is to reserve "slack sections" or adopt simple S-shaped or loop routing. These methods heavily rely on the designer's experience and mainly avoid interference through passive adaptation rather than active optimization, often leading to problems such as low design efficiency, high resistance torque, and short lifespan. This has become a bottleneck restricting the performance of high-precision, long-life movable mechanisms.

[0004] Although existing technologies have proposed various cable design methods, none of them are specifically optimized to reduce the resistance torque of moving cables, and thus have obvious limitations.

[0005] 1) The patent document "A Design Method for the Route of a Space Motion Cable" (CN107766667B) proposes to use a "spiral winding" method to solve the problems of cable wear and fatigue. Its core is to avoid physical interference through geometric constraint envelope. This application proposes a "bundled lantern-shaped" structure, which raises the design goal from "avoiding interference" to "performance optimization". Through multi-branch symmetrical layout and coordinated deformation, it actively reduces and offsets the resistance torque, solving the problem of mechanism motion accuracy that the former failed to address.

[0006] 2) The patent document "An Autonomous Optimization Design Method for Spacecraft Cable Networks" (CN113722816B) focuses on the automated and intelligent cabling of the entire satellite cable network, aiming to improve design efficiency by creating common paths and finding the shortest path through intelligent algorithms. This application, however, focuses on the dynamic performance of cables in the specific scenario of moving mechanisms, providing a dedicated cable shape design scheme that can directly optimize drag torque, which is fundamentally different from the former in terms of application objectives and core technologies.

[0007] 3) "A Shortest Path Planning Method for Satellite Cables Based on Directed Graph Optimization Technology" (CN105279574B) This patent document abstracts cable path planning into a graph theory problem, pursuing the "shortest path" for static cabling. However, this application focuses on the mechanical behavior of cables during dynamic movement. The "lantern-shaped" path is not the shortest, but rather the one with the optimal mechanical performance. It introduces a resistance torque calculation model that was not covered in the previous document.

[0008] 4) "A Satellite Matrix Cable Network Design Method" (CN107317395B) focuses on the electrical connection relationship, resource allocation, and coiled cable topology of the matrix signal to achieve cable weight reduction. This application, on the other hand, takes a completely mechanical motion and mechanics perspective and innovatively proposes a three-dimensional spatial form of the cable that can reduce resistance torque. The two belong to two different design dimensions: electrical connection and mechanical structure.

[0009] 5) "A Cable Network Loop-Eliminating Design Method" (CN115146423B) addresses the loop problem in the layout of complex static cable networks. Its core design goal is to eliminate loop paths through algorithms or rules to ensure the rationality and installability of the cable network layout. This method focuses on the topology and static geometric arrangement of the cable network. In contrast, this application addresses the dynamic mechanical performance of the following cables in moving mechanisms, proposing a "bundled lantern-shaped" structure. Its design goal is not to change the network topology, but to optimize the resistance torque during cable movement by creating a pre-defined, axisymmetric mechanical configuration. The two address fundamentally different technical problems and employ different technical methods.

[0010] In summary, existing technologies primarily focus on the static layout of cables, path length optimization, interference avoidance, and electrical connection relationships, lacking specialized research and optimization methods for the resistance torque characteristics of moving cables in motion. Therefore, there is an urgent need for an innovative cable routing design method that, through careful design of the spatial geometry of moving cables, fundamentally optimizes the stress and deformation of the cables, achieving a significant reduction in resistance torque and a comprehensive improvement in motion reliability. Summary of the Invention

[0011] To address the shortcomings of existing technologies, the purpose of this invention is to provide a low-resistance torque routing design method and system for satellite mechanism active cables.

[0012] A low-resistance torque routing design method for a satellite mechanism movable cable provided by the present invention includes:

[0013] Step S1: Determine the starting point, ending point, and branching point of the cable spatial movement part based on the range of motion of the moving mechanism; Step S2: Define a fixed point distribution circle in a plane perpendicular to the motion axis of the moving mechanism, wherein the center of the fixed point distribution circle is located at the split point or the center of the motion axis; Step S3: Divide the cable into N branches from the splitting point, where N ≥ 2, and guide each branch to N fixed points evenly distributed on the circumference of the fixed point distribution circle; Step S4: Design the path of each branch as a spatial arc, and all branches together form a hollow three-dimensional lantern-shaped structure; Step S5: Based on the three-dimensional lantern-shaped structure, calculate the total resistance torque of the cable acting on the moving mechanism during the movement; Step S6: Check whether the cable meets the requirements of non-interference and total resistance torque throughout its entire range of motion. If not, adjust the radius of the arc of the branch and reconstruct the three-dimensional lantern-shaped structure until the requirements are met.

[0014] Furthermore, the radius R of the circle where the fixed points are distributed... c From formula R c = k1× L max Determined, where L max k1 represents the maximum displacement of the cable connection point when the moving mechanism is in motion, and is an empirical coefficient between 0.4 and 0.6.

[0015] Furthermore, the radius R of the arc of each branch b Greater than or equal to the minimum allowable bending radius R of the cable min .

[0016] Furthermore, the total drag torque M total for: M total = Σ [ (M bend_i + M torsion_i ) × cos(θ i ) ] Among them, M bend_i and M torsion_i The bending and torsional resistance moments of the i-th branch are θ and θ, respectively. i This is the angle between the resistance direction of this branch and the direction of the mechanism's motion.

[0017] Furthermore, the minimum permissible bending radius R of the cable min for: R min = k2 × k3 × d Where d is the outer diameter of the cable, k2 is the cable type coefficient, and k3 is the motion period coefficient.

[0018] A low-resistance torque routing design system for a satellite mechanism's movable cable, provided by the present invention, comprises: Module M1: Determines the starting point, ending point, and branching point of the cable's spatial movement section based on the range of motion of the moving mechanism; Module M2: Define a fixed-point distribution circle in a plane perpendicular to the motion axis of the moving mechanism, wherein the center of the fixed-point distribution circle is located at the split point or the center of the motion axis; Module M3: Divides the cable from the split point into N branches, where N≥2, and guides each branch to N fixed points evenly distributed on the circumference of the fixed point distribution circle; Module M4: The path of each branch is designed as a spatial arc, and all branches together form a hollow three-dimensional lantern-shaped structure; Module M5: Based on the aforementioned three-dimensional lantern-shaped structure, calculate the total resistance torque of the cable acting on the moving mechanism during its movement; Module M6: Verify whether the cable meets the requirements of non-interference and total resistance torque throughout its entire range of motion. If not, adjust the radius of the arc of the branch and reconstruct the three-dimensional lantern-shaped structure until the requirements are met.

[0019] Furthermore, the radius R of the circle where the fixed points are distributed... c From formula R c = k1× L max Determined, where L max k1 represents the maximum displacement of the cable connection point when the moving mechanism is in motion, and is an empirical coefficient between 0.4 and 0.6.

[0020] Furthermore, the radius R of the arc of each branch b Greater than or equal to the minimum allowable bending radius R of the cable min .

[0021] Furthermore, the total drag torque M total for: M total = Σ [ (M bend_i + M torsion_i ) × cos(θ i ) ] Among them, M bend_i and M torsion_i The bending and torsional resistance moments of the i-th branch are θ and θ, respectively. i This is the angle between the resistance direction of this branch and the direction of the mechanism's motion.

[0022] Furthermore, the minimum permissible bending radius R of the cable min for: R min = k2 × k3 × d Where d is the outer diameter of the cable, k2 is the cable type coefficient, and k3 is the motion period coefficient.

[0023] Compared with the prior art, the present invention has the following beneficial effects: 1) Fundamentally reduces resistance torque and improves the motion accuracy of the mechanism. The "branched lantern-shaped" routing method proposed in this invention reconstructs the force path of the cable. Through the design of symmetrical branches, it greatly reduces the resistance torque of the moving cable, thereby improving the pointing accuracy and motion stability of the mechanism.

[0024] 2) Optimize stress distribution and extend cable life. Traditional U-shaped or ring-shaped routing is prone to stress concentration at local bends, leading to fatigue. This invention splits a single bundle into multiple branches with reasonable arc radii, reducing the peak stress concentration and improving the reliability of long-term stable operation in the rail.

[0025] 3) It has good engineering applicability and scalability. Unlike conventional experience-based design, the design principles and methods proposed in this invention are clear and explicit, and can be further developed based on 3D simulation software to realize the fast-tracking design of mobile cables; the bundled topology concept can flexibly adapt to different numbers of branches and spatial constraints, providing solutions for cable routing design in various satellite layout scenarios. Attached Figure Description

[0026] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Appendix Figure 1 This is a flowchart illustrating a low-resistance torque routing design method for a satellite mechanism active cable according to an embodiment of the present invention; Appendix Figure 2 This is a schematic diagram of the bundled lantern-shaped routing of the movable cable of the two-axis rotating mechanism in an embodiment of the present invention.

[0027] Appendix Figure 3 This is a schematic diagram showing the typical dimensions of the bundled lantern-shaped routing of the movable cable in the two-axis rotating mechanism of this invention.

[0028] Appendix Figure 4 This is a schematic diagram of a two-axis rotating mechanism movable cable bundle type fixed cable bracket in an embodiment of the present invention. Detailed Implementation

[0029] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0030] like Figure 1 As shown, a low-resistance torque routing design method for a satellite mechanism's movable cable includes: Step S1: Determine the starting point, ending point, and branching point of the cable space movement part based on the range of motion of the moving mechanism.

[0031] Step S2: Define a fixed-point distribution circle in a plane perpendicular to the motion axis of the movable mechanism. The center of the fixed-point distribution circle is located at the branch point or the center of the motion axis. The radius R of the fixed-point distribution circle is... c for: R c = k1× L max Where L max k1 represents the maximum displacement of the cable connection point when the moving mechanism is in motion, and is an empirical coefficient between 0.4 and 0.6.

[0032] Step S3: Divide the cable into N branches from the splitting point, where N ≥ 2, and guide each branch to N fixed points evenly distributed on the circumference of the fixed point distribution circle.

[0033] Step S4: Design the path of each branch as a spatial arc, with all branches together forming a hollow three-dimensional lantern-shaped structure. The radius R of the arc of each branch is... b Greater than or equal to the minimum allowable bending radius R of the cable min Minimum allowable bending radius R of cable min for: R min = k2 × k3 × d Where d is the outer diameter of the cable, k2 is the cable type coefficient, and k3 is the motion period coefficient.

[0034] Step S5: Based on the parameters of the three-dimensional lantern-shaped structure, calculate the total resistance torque acting on the moving mechanism by the cable during its movement. Total resistance torque M total for: M total = Σ [ (M bend_i + M torsion_i ) × cos(θ i ) ] Among them, M bend_i and M torsion_i The bending and torsional resistance moments of the i-th branch are θ and θ, respectively. i This is the angle between the resistance direction of this branch and the direction of the mechanism's motion.

[0035] Step S6: Establish the corresponding lantern-shaped cable routing model in the 3D design software, and verify whether the cable meets the requirements of non-interference and total resistance torque within the entire range of motion through motion simulation. If it does not meet the requirements, adjust the arc radius of the branches and reconstruct the 3D lantern-shaped structure until the requirements are met.

[0036] The process of adjusting the arc radius of the branch is as follows: First, determine the reason why the current requirements are not met. If the simulation results show that the total resistance torque exceeds the design allowable value, then appropriately increase the arc radius R of the branch. b To reduce the resistive torque component contributed by cable bending and torsional stiffness; if interference occurs between cable branches or between branches and surrounding structures, the radius R of the arc should be appropriately reduced. b (But not less than the minimum allowable bending radius Rmin of the cable) to tighten the spatial envelope of the lantern-shaped structure; if both excessive resistance torque and interference problems exist simultaneously, the radius of the arc should be adjusted first to the minimum feasible radius to avoid interference, and then the radius of the arc should be gradually increased until the resistance torque meets the requirements. After each adjustment, modeling and motion simulation should be performed again, and the minimum resistance torque R corresponding to satisfy all constraints should be determined through iterative optimization. b value.

[0037] The results of this invention have been successfully verified and implemented in specific models. This method abstracts and extracts design ideas, further expanding the application scope.

[0038] The following uses the movable cable of the two-axis rotating camera load on a certain type of satellite as a specific embodiment. Taking the bundled lantern-shaped routing design of this movable cable as an example, the routing design process is described as follows: Step S1: Determine the range of motion of the moving mechanism and the starting point, ending point, and branching point of the cable space moving part.

[0039] like Figure 2 As shown, the two-axis rotating camera can rotate around the pitch and azimuth axes respectively. A movable cable extends from the bottom of the azimuth axis into the satellite cabin. During camera rotation, the cable extending from the bottom moves accordingly. Using the center of the bottom of the azimuth axis as the origin of the coordinate system, the starting point, ending point, and branching point coordinates of the moving portion of the cable are determined. The coordinate values ​​are shown below. Figure 3 .

[0040] Step S2: Define a fixed-point distribution circle in a plane perpendicular to the motion axis, with the center of the circle located at the split point or the center of the motion axis.

[0041] The radius R of the circle where the fixed points are distributed c From formula R c = k1×L max =0.5×80=40mm. Based on the endpoint and R c Cable supports can be designed, such as Figure 4 As shown.

[0042] Step S3: Divide the cable into 4 branches from the split point, and guide each branch to 4 fixed points evenly distributed on the distribution circumference.

[0043] Step S4: Design the path of each branch as a spatial arc, and all branches together form a hollow three-dimensional lantern-shaped structure.

[0044] The minimum permissible bending radius R of the branch cable is determined based on empirical formulas. min From the empirical formula, R can be obtained. min =k2× k3× d = 10 × 1.2 × 5 = 60mm; Based on experience, the radius R of the arc of each branch b Not less than the minimum allowable bending radius R of the cable min Let's tentatively set it to R. b =100mm.

[0045] Step S5: Based on the lantern-shaped structure parameters, calculate the total resistance torque of the cable acting on the mechanism during the motion.

[0046] By creating a 3D model of the cable and performing envelope and resistance torque simulation analysis in cable rotation simulation software, curves showing the changes in the cable's maximum envelope and resistance torque as a function of the camera's rotation angle can be obtained.

[0047] Step S6: Check whether there is interference within the entire range of motion of the moving cable and whether the resistance torque meets the requirements. If not, change R. b If the value is not met, repeat steps S4 and S5 until the design requirements are met.

[0048] This invention also provides a low-resistance torque routing design system for a satellite mechanism's movable cable. This system can be implemented by executing the steps of the low-resistance torque routing design method for the satellite mechanism's movable cable. That is, those skilled in the art can understand the low-resistance torque routing design method for the satellite mechanism's movable cable as a preferred embodiment of the low-resistance torque routing design system. The system includes: Module M1: Determines the starting point, ending point, and branching point of the cable's spatial moving part based on the range of motion of the moving mechanism. Module M2: Define a fixed-point distribution circle in a plane perpendicular to the motion axis of the moving mechanism, wherein the center of the fixed-point distribution circle is located at the branch point or the center of the motion axis. Module M3: Divides the cable from the split point into N branches, where N≥2, and guides each branch to N fixed points evenly distributed on the circumference of the fixed point distribution circle. Module M4: The path of each branch is designed as a spatial arc, and all branches together form a hollow three-dimensional lantern-shaped structure. Module M5: Based on the aforementioned three-dimensional lantern-shaped structure, calculate the total resistance torque exerted by the cable on the moving mechanism during its motion. Module M6: Verify whether the cable meets the requirements of non-interference and total resistance torque throughout its entire range of motion. If not, adjust the radius of the arc of the branch and reconstruct the three-dimensional lantern-shaped structure until the requirements are met.

[0049] Those skilled in the art will understand that, besides implementing the system and its various devices, modules, and units provided by this invention in the form of purely computer-readable program code, the same functions can be achieved entirely through logical programming of the method steps, making the system and its various devices, modules, and units of this invention function in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers. Therefore, the system and its various devices, modules, and units provided by this invention can be considered as a hardware component, and the devices, modules, and units included therein for implementing various functions can also be considered as structures within the hardware component; alternatively, the devices, modules, and units for implementing various functions can be considered as both software modules implementing the method and structures within the hardware component.

[0050] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A method for designing the low-resistance torque routing of a satellite mechanism's movable cable, characterized in that, include: Step S1: Determine the starting point, ending point, and branching point of the cable spatial movement part based on the range of motion of the moving mechanism; Step S2: Define a fixed point distribution circle in a plane perpendicular to the motion axis of the moving mechanism, wherein the center of the fixed point distribution circle is located at the split point or the center of the motion axis; Step S3: Divide the cable into N branches from the splitting point, where N≥2, and guide each branch to N fixed points evenly distributed on the circumference of the fixed point distribution circle; Step S4: Design the path of each branch as a spatial arc, and all branches together form a hollow three-dimensional lantern-shaped structure; Step S5: Based on the three-dimensional lantern-shaped structure, calculate the total resistance torque of the cable acting on the moving mechanism during the movement; Step S6: Check whether the cable meets the requirements of non-interference and total resistance torque throughout its entire range of motion. If not, adjust the radius of the arc of the branch and reconstruct the three-dimensional lantern-shaped structure until the requirements are met.

2. The low-resistance torque routing design method for the satellite mechanism movable cable according to claim 1, characterized in that, The radius R of the circumference on which the fixing points are distributed c is determined by the formula R c = k1 x L max where L max is the maximum displacement of the cable connection point during movement of the active mechanism and k1 is an empirical coefficient between 0.4 and 0.

6.

3. The low-resistance torque routing design method for the satellite mechanism movable cable according to claim 1, characterized in that, The radius R of the circular arc of each branch b greater than or equal to the minimum permissible bending radius R of the cable min .

4. The low-resistance torque routing design method for the satellite mechanism movable cable according to claim 1, characterized in that, The total resistance moment M total is: M total = Σ [ (M bend_i + M torsion_i ) × cos(θ i ) ] where M bend_i and M torsion_i are the bending and torsional moments of the i-th branch, respectively, and θ i is the angle between the direction of the resistance of the branch and the direction of the motion of the mechanism.

5. The low-resistance torque routing design method for the satellite mechanism movable cable according to claim 3, characterized in that, Minimum allowable bending radius R of cable min for: R min = k2× k3× d Where d is the outer diameter of the cable, k2 is the cable type coefficient, and k3 is the motion period coefficient.

6. A low-resistance torque routing design system for a satellite mechanism's movable cable, characterized in that, include: Module M1: Determines the starting point, ending point, and branching point of the cable's spatial movement section based on the range of motion of the moving mechanism; Module M2: Define a fixed-point distribution circle in a plane perpendicular to the motion axis of the moving mechanism, wherein the center of the fixed-point distribution circle is located at the split point or the center of the motion axis; Module M3: Divides the cable from the split point into N branches, where N≥2, and guides each branch to N fixed points evenly distributed on the circumference of the fixed point distribution circle; Module M4: The path of each branch is designed as a spatial arc, and all branches together form a hollow three-dimensional lantern-shaped structure; Module M5: Based on the aforementioned three-dimensional lantern-shaped structure, calculate the total resistance torque of the cable acting on the moving mechanism during its movement; Module M6: Verify whether the cable meets the requirements of non-interference and total resistance torque throughout its entire range of motion. If not, adjust the radius of the arc of the branch and reconstruct the three-dimensional lantern-shaped structure until the requirements are met.

7. The low-resistance torque routing design system for satellite mechanism movable cables according to claim 6, characterized in that, The radius R of the circle where the fixed points are distributed c From formula R c = k1× L max Determined, where L max k1 represents the maximum displacement of the cable connection point when the moving mechanism is in motion, and is an empirical coefficient between 0.4 and 0.

6.

8. The low-resistance torque routing design system for satellite mechanism movable cables according to claim 6, characterized in that, The radius R of the arc of each branch b Greater than or equal to the minimum allowable bending radius R of the cable min .

9. The low-resistance torque routing design system for satellite mechanism movable cables according to claim 6, characterized in that, The total resistance torque M total for: M total = Σ [ (M bend_i + M torsion_i ) × cos(θ i ) ] Among them, M bend_i and M torsion_i The bending and torsional resistance moments of the i-th branch are θ and θ, respectively. i This is the angle between the resistance direction of this branch and the direction of the mechanism's motion.

10. The low-resistance torque routing design system for the satellite mechanism movable cable according to claim 8, characterized in that, Minimum allowable bending radius R of cable min for: R min = k2× k3× d Where d is the outer diameter of the cable, k2 is the cable type coefficient, and k3 is the motion period coefficient.

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