Cascaded gravitational siphon moon ladder model construction method and system

Abstract

The invention discloses a cascaded gravitational siphon moon ladder model construction method and system. The method comprises the following steps: defining a basic gravitational siphon moon ladder unit model; according to the basic gravitational siphon lunar ladder unit model, multi-body dynamics simplification and discrete node processing are carried out on continuous ropes; constructing a complete kinetic equation under a unified coordinate system, and performing cascade system expansion and modular integration; optimization and system-level performance matching of each component are implemented, and a cascade gravitational siphon lunar ladder model is constructed. The whole high ladder can be divided into a plurality of independent sections, independent operation and kinetic energy transmission are achieved, and the flexibility of a system is improved. The cascade gravitational siphon moon ladder model construction method and system can be widely applied to the technical field of spaceflight.

Description

Technical Field

[0001] This invention relates to the field of aerospace technology, and in particular to a method and system for constructing a cascaded gravitational siphon lunar ladder model. Background Technology

[0002] The Gravitational Siphon Lunar Elevator system, a novel and efficient inter-Earth-Moon transportation system, cleverly utilizes the dynamic characteristics of the Earth-Moon space environment. These include the Moon's tidally locked position to Earth, its relatively low orbital eccentricity, the relatively low gravitational acceleration in most areas of the Earth-Moon space (excluding the region closest to Earth), the high value of lunar minerals, the large demand for Earth-Moon transportation, and the large area of ​​Earth's oceans facilitating cargo transport. This comprehensive and ingenious utilization of various factors ensures the theoretical viability of the Gravitational Siphon Lunar Elevator. This system offers significant advantages over rocket transportation, combining the benefits of not consuming artificial energy sources like fuel, high transport speed, large cargo capacity, and ease of control.

[0003] However, due to the system's extreme length, the initial concept was still too advanced, and the system's reliability, operability, scalability, and maintainability, caused by its length, still differed from actual construction. The main problems include: 1) As an ultra-long system spanning over 300,000 kilometers, although it can theoretically operate smoothly as a whole, the damage or failure of any part will lead to the damage or failure of the entire system.

[0004] 2) Once the system reaches a steady-state operating condition, the speed is the same everywhere, which is determined by the design length and cannot be adjusted.

[0005] 3) The system is difficult to restart after shutdown, so a certain amount of initial cargo load needs to be loaded into each cargo box in the down direction.

[0006] 4) When the system is in steady state, it is difficult to adjust the load of each box each time. There are no cargo buffer or storage devices during transportation, so it is impossible to implement capacity adjustment.

[0007] 5) Apart from the lunar surface anchor point and the end fixed pulley, the system is in a state of overall motion throughout the entire journey, with no intermediate stations, making it impossible to deploy and expand functional facilities. Summary of the Invention

[0008] To address the aforementioned technical problems, the present invention aims to provide a method and system for constructing a cascaded gravitational siphon lunar ladder model, which can divide the entire ladder into multiple independent sections, enabling independent operation and kinetic energy transfer, thereby improving the system's flexibility.

[0009] The first technical solution adopted in this invention is: a method for constructing a cascaded gravitational siphon lunar ladder model, comprising the following steps: Define the basic gravitational siphon lunar ladder unit model; The basic gravitational siphon lunar ladder unit model simplifies the continuous rope through multibody dynamics and discretizes the nodes. Construct complete dynamic equations in a unified coordinate system, and carry out cascaded system expansion and modular integration; Implement component optimization and system-level performance matching to construct a cascaded gravitational siphon lunar ladder model.

[0010] Furthermore, the step of defining the basic gravitational siphon lunar ladder unit model specifically includes: Construct a closed-loop rope, with fixed pulleys (fixed to the near-Earth surface of the Moon) and movable pulleys (distributed on the near-Earth surface of the Earth) at both ends. The cargo boxes are fixed at equal intervals on the upper or lower sections of the closed-loop rope.

[0011] Furthermore, this step of simplifying multibody dynamics specifically includes: The continuous rope is divided into concentrated mass nodes, and adjacent nodes are connected by elastic straight bars. Feature node discrimination rules are introduced to determine the connection relationship between pulley and rope nodes.

[0012] Furthermore, the step of constructing the complete dynamic equations in a unified coordinate system specifically includes: Choose a rotating Earth-Moon coordinate system with its origin at the Earth-Moon system's center of mass. Obtain the position vectors of the Earth, Moon, rope nodes, and pulleys; Construct equations that include gravitational force, centrifugal force, Coriolis force, elastic force, and damping force.

[0013] Furthermore, the cascaded system extends this step, specifically by including: The hierarchical design proceeds from the first lunar stage to the Earth stage, with each stage independently forming a closed loop around the traction wheel. An integrated station, including a traction sheave set, is set up at the interstage connection point. The kinetic energy is transferred and the direction is controlled through a clutch-transmission-reversing-speed change device.

[0014] Furthermore, the step of optimizing each component specifically includes: Different grades of cables use different cross-sectional dimensions; The cargo containers are evenly distributed across the various levels of the ladder, with adjustable spacing; The power system is matched with a first-stage active drive, and subsequent stages rely on the gravitational siphon effect for operation. The traction wheel is used for speed regulation and energy recovery.

[0015] Furthermore, the structure of the cascaded gravitational siphon lunar ladder model also includes: Each stage operates independently, and energy transfer between stages is achieved through integrated stations; The segmented design allows for localized maintenance without affecting overall operation and supports modular expansion.

[0016] Furthermore, the cascaded gravitational siphon lunar ladder model includes a segmented series gravitational siphon lunar ladder and a series-parallel combined gravitational siphon lunar ladder.

[0017] The second technical solution adopted in this invention is: a cascaded gravitational siphon lunar ladder model construction system, comprising: The first module is used to define the basic gravitational siphon lunar ladder unit model; The second module is used for the basic gravitational siphon lunar ladder unit model, which simplifies the multibody dynamics of the continuous rope and handles the discrete nodes. The third module is used to construct complete dynamic equations in a unified coordinate system and to extend and modularize cascaded systems. The fourth module is used to optimize each component and match system-level performance, and to build a cascaded gravitational siphon lunar ladder model.

[0018] The beneficial effects of the method and system of this invention are as follows: This invention simplifies multibody dynamics and processes discrete nodes based on a fundamental gravitational siphon lunar ladder unit model, and constructs the dynamic equations for each node to obtain a single-segment model of the lunar ladder. The single-segment model is then cascaded and modularly integrated to obtain a preliminary cascaded gravitational siphon lunar ladder model. Different segments can independently set optimal operating speeds according to their spatial environment characteristics, thus optimizing overall transportation efficiency. Furthermore, the preliminary cascaded gravitational siphon lunar ladder model undergoes component optimization and dynamic matching to construct a cascaded gravitational siphon lunar ladder model. The cascaded design allows for more efficient use of material strength, enabling the setting of different specifications of ladder materials in different sections. Additionally, the cascaded design discretizes the continuous system, allowing for independent and precise dynamic control and damping suppression of each segment. This divides the entire ladder into multiple independent segments, achieving independent operation and kinetic energy transfer, and improving the system's flexibility. Attached Figure Description

[0019] Figure 1 This is a flowchart of the steps in constructing a cascaded gravitational siphon lunar ladder model according to the present invention; Figure 2 This is a structural block diagram of a cascaded gravitational siphon lunar ladder model construction system according to the present invention; Figure 3 This is a schematic diagram of a three-stage series gravitational siphon lunar ladder provided in a specific embodiment of the present invention; Figure 4 This is a schematic diagram of a four-stage series gravitational siphon lunar ladder provided in a specific embodiment of the present invention; Figure 5 This is a schematic diagram of a series-parallel combined gravitational siphon lunar ladder provided in a specific embodiment of the present invention; Figure 6 This is a schematic diagram of the Hall three-dimensional structure of the cascaded gravitational siphon lunar ladder system provided in a specific embodiment of the present invention; Figure 7 This is a schematic diagram of the EER structure of the cascaded gravitational siphon lunar elevator system provided in a specific embodiment of the present invention; Figure 8 This is a schematic diagram of a combined gear train design of multiple small traction sheaves provided in a specific embodiment of the present invention; Figure 9 This is a schematic diagram of a typical dual-threaded task overall planning provided in a specific embodiment of the present invention. Detailed Implementation

[0020] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. The step numbers in the following embodiments are only for ease of explanation and do not limit the order of the steps. The execution order of each step in the embodiments can be adapted according to the understanding of those skilled in the art.

[0021] First, it should be noted that this invention addresses all the potential operational problems of existing gravitational siphon lunar elevators, and, considering the dynamic characteristics of siphon elevators (such as greater length, speed, and opening), proposes a more rational and controllable inter-Earth-Moon transportation system—the cascaded gravitational siphon lunar elevator. This design divides the entire elevator into multiple independent sections, combined in series or a series-parallel configuration. Each stage or section is surrounded by a pair of traction wheels forming a closed loop, achieving independent operation and kinetic energy transfer. This segmented design not only improves the system's flexibility but also enhances its stability and maintainability.

[0022] Reference Figure 1 This invention provides a method for constructing a cascaded gravitational siphon lunar ladder model, the method comprising the following steps: S100, Define the basic gravitational siphon lunar ladder unit model; Specifically, the basic gravitational siphon lunar ladder unit model includes a closed-loop rope encircling the Earth and the Moon. One end of the closed-loop rope is a fixed pulley, which is fixedly distributed on the near-Earth surface of the Moon, and the other end of the closed-loop rope is a movable pulley, which is distributed on the near-Earth surface of the Earth. The cargo boxes are fixed at equal intervals on the upward (pointing to the Moon) or downward (pointing to the Earth) section of the closed-loop rope.

[0023] In this embodiment, the construction process begins with defining a basic gravitational siphon lunar ladder unit model. The core structure of this model includes a "closed-loop rope" encircling the Earth and the Moon. Two key pulleys are passed around the ends of the rope: one is considered a "fixed pulley," fixedly located on the near-Earth surface of the Moon (i.e., the large traction wheel of the lunar base station); the other is considered a "moving pulley," located on the near-Earth surface of the Earth (or the terminal station). Cargo containers are evenly spaced and fixed to the ascending (pointing towards the Moon) or descending (pointing towards the Earth) sections of the closed-loop rope. This model utilizes the difference in gravitational fields between the Earth and the Moon, as well as the centrifugal force generated by the system's rotation around the Earth-Moon center of mass, allowing the rope and cargo containers to automatically operate under the net force under specific conditions, thereby reducing or eliminating the need for traditional propellant—this is the physical basis of the "gravitational siphon effect."

[0024] S200, the basic gravitational siphon lunar ladder unit model, simplifies the multibody dynamics of the continuous rope and handles discrete nodes.

[0025] Furthermore, the basic gravitational siphon lunar ladder unit model is simplified using multibody dynamics. The continuous closed-loop rope is divided into several small segments at equal intervals. Each segment of the closed-loop rope is regarded as a node, and the fixed pulley and the movable pulley are regarded as special nodes, thus constructing the multibody system dynamics of the lunar ladder.

[0026] In this embodiment, directly performing dynamic analysis on a continuous rope hundreds of thousands of kilometers long is extremely difficult; therefore, a "bead-point simplification" (or multibody dynamics simplification) method is required. This step divides the continuous closed-loop rope into several small segments at equal intervals, each segment being simplified into a "node" with concentrated mass. Adjacent nodes are connected by an "elastic straight rod" model to simulate the tension and deformation of the rope. Fixed and movable pulleys in the model are also considered as special nodes. In this way, a complex continuum problem is transformed into a multibody system dynamics problem consisting of a finite number of mass points and elastic connections, laying the foundation for numerical solutions. The introduction of characteristic node discrimination rules is to accurately determine the connection relationship between pulleys and rope nodes, ensuring the correctness of the constraint relationships in the dynamic equations.

[0027] S300: Construct complete dynamic equations under a unified coordinate system, and carry out cascade system expansion and modular integration.

[0028] Furthermore, the center of mass of the Earth-Moon system is obtained as the origin to construct an Earth-Moon rotating coordinate system. Based on the Earth-Moon rotating coordinate system, the position vectors of the Earth, the Moon, each rope node and special node are determined, and the dynamic equation of each node is constructed. The dynamic equation of each node is transformed into a system of pure ordinary differential equations, and continuous time history simulation is performed by numerical integration method to obtain a single-day staircase model.

[0029] In this embodiment, after discretizing the model, dynamic analysis needs to be performed in a unified reference frame. Typically, the "Earth-Moon rotating coordinate system" is chosen as the reference frame. The origin of this coordinate system is set at the center of mass of the Earth-Moon system, which naturally describes the influence of the relative motion between the Earth and the Moon. Based on this coordinate system, the position vectors of the Earth, Moon, each rope node, and pulleys can be obtained. Subsequently, the dynamic equations for each node are constructed, comprehensively considering the various forces acting on it, including but not limited to the "gravitational force" of the Earth and Moon, the "centrifugal force" and "Coriolis force" generated by the system's rotation, the "elastic force" and "damping force" of the connecting rods between nodes. For pulley nodes, "friction" also needs to be considered. All these forces together constitute the right-hand side of the dynamic equations, while the left-hand side is the product of mass and acceleration. By introducing a characteristic node discrimination rule, the differential-algebraic equations describing the system constraints can be transformed into a system of pure ordinary differential equations, thereby enabling continuous time-history simulation using numerical integration methods to analyze the system's stability and dynamic response.

[0030] S200. By cascading and modularly integrating the single-segment lunar ladder model, a preliminary cascaded gravitational siphon lunar ladder model is obtained. Specifically, the single-stage lunar ladder model is cascaded and expanded, with the lunar surface as the first stage and subsequent stages numbered sequentially towards Earth. Each stage represents an independent closed-loop system formed around a pair of traction wheels. Based on the lunar base station and the end of the closed-loop rope, modular integration is performed, and large traction wheels are set up. The connection points of each stage of the ladder and the Earth-Moon Lagrange point are obtained, and a comprehensive station is set up. The comprehensive station adopts a wheel system of small traction wheels, thus constructing a preliminary cascaded gravitational siphon lunar ladder model.

[0031] In this embodiment, a single-segment ladder model was constructed. The innovation of the cascading design lies in expanding this single segment into a network system composed of multiple levels and layers of ladders. The construction process includes: 1) Classification and Layering: Starting with the first level on the lunar surface, subsequent levels are numbered sequentially towards Earth. Each level is an independent, closed-loop system formed around a pair of traction wheels. In certain sections, a parallel layered design can be used to increase transport capacity or flexibility.

[0032] 2) Integrated Station Design: "Integrated stations" are set up at the connection points of each level of the elevator system. The most important device within each station is the traction sheave assembly coupled to the preceding and following levels of the elevator. These traction sheaves typically employ a gear train system of small wheels rather than a single large wheel to reduce rotational inertia, facilitate control, and balance the overall momentum of the station. The gear trains achieve kinetic energy transfer, recovery, and directional control through a "clutch-transmission-reversing-speed change" mechanism. Kinetic energy can be directly transferred mechanically or converted into electrical energy through an electrification system and stored in advanced energy storage devices at the station, then distributed as needed. This greatly enhances the system's operational flexibility and energy utilization efficiency.

[0033] 3) Key Site Functional Positioning: The lunar base station (stage 1 drive end) requires high-strength anchoring and a large traction wheel, responsible for cargo loading and initial propulsion. The terminal station (the end closest to Earth) is responsible for launching cargo to Earth in a controlled manner, typically using small rockets and parachutes for precise landing (or splashdown) in a designated area, and then recovered by a salvage vessel. Deploying large, integrated stations near Earth-Moon Lagrange points (such as L1) can leverage the dynamic characteristics of these points to enhance system stability.

[0034] S400, implement component optimization and system-level performance matching, and construct a cascaded gravitational siphon lunar ladder model.

[0035] Specifically, the preliminary cascaded gravitational siphon lunar ladder model was optimized by refining the closed-loop rope step by step along the direction from the moon to the earth, with the cargo boxes evenly distributed on the closed-loop rope. The large traction wheel of the lunar base station was used as the driving wheel, and the large traction wheel at the earth end was used as the driven wheel. The driving wheel operated through active drive, and the driven wheel operated automatically through the gravitational siphon effect, thus completing the power matching and constructing the cascaded gravitational siphon lunar ladder model.

[0036] In this embodiment, the final improvement of the cascaded model lies in the targeted optimization design of each component to achieve system-level performance improvement, specifically including: 1) Ladder Cable System: A key advantage of the cascaded design is that it allows for the use of different cross-sectional dimensions for cables at different levels. For example, thicker, stronger cables can be used in sections with drastic changes in gravitational gradients or high stress (such as near point L1), while thinner cables can be used in sections with lower stress (such as near the Earth's edge). This design results in a more uniform stress distribution within the cables, more efficient material utilization, a significant reduction in the overall system mass, and lower costs.

[0037] 2) Cargo container layout: Within each level of the ladder, cargo containers should be evenly distributed to maintain the mass balance on both sides of the system at that level and ensure the stable operation of the gravitational pull effect. However, different cargo container spacing and operating speeds can be set between different levels according to transportation needs, which reflects the flexibility of the cascade system.

[0038] 3) Power Matching: The first-stage ladder, needing to overcome lunar gravity to lift cargo out of the lunar gravity trap, typically requires active propulsion (with the traction wheel acting as the driving wheel). Subsequent stages, however, if the overall net force points towards Earth, can operate automatically primarily through gravitational pull, with the traction wheel mostly acting as a driven wheel or used for speed regulation and energy recovery. This differentiated power configuration further optimizes the system's energy consumption.

[0039] In this embodiment, there are several possible approaches to improving the gravitational siphon lunar ladder configuration. It could be a segmented, series-connected type, such as... Figure 3 as well as Figure 4 As shown, it can also be a nested parallel type, such as... Figure 5 As shown. The latter utilizes the phenomenon that the opening of the siphon ladder varies with different design lengths. The number of segments can also be varied.

[0040] More specifically, in Figure 3 , Figure 4 as well as Figure 5 In this system, the combined force of several cascaded lunar ladders is a pull towards Earth, which helps stabilize the structure. Each ladder segment forms a closed loop around a pair of traction wheels, called a level. The ladder levels are numbered sequentially from the lunar end to the Earth end; in parallel configurations, they are layered, with the level whose lower traction wheel is located higher (i.e., on the inside) having the earlier number. For example, in... Figure 3 as well as Figure 4 The purple part in the image is called Level 2, Layer 1.

[0041] The operation of each level and layer is independent, and they can transfer kinetic energy to each other through the "clutch-transmission-reversing-speed change" device arranged at the integrated station, driving each other to operate according to the task plan and needs. Of course, a more flexible option is to use an electrification system to convert the kinetic energy of operation into electrical energy, which enters the advanced energy storage device at the integrated station and then supplies the required mechanisms as needed.

[0042] The section closest to the moon is the first stage. If the end of the first stage is more than 120,000 kilometers from Earth, the net force acting on it will be directed towards the moon, making it impossible to continuously load cargo from the lunar surface for automated operation using gravitational siphon. An active force is required. This active force can be provided by the lunar anchoring wheels using a traction method, or by the drive wheels at the end station, or by a combination of both ends. Subsequent stages, if the net force acting on them is directed towards Earth, can operate automatically using the siphon effect. By rationally arranging these stages, tiers of siphonic ladders, and integrated stations, a cascaded gravitational siphon lunar ladder system is formed.

[0043] Finally, the following description is provided in conjunction with the accompanying drawings of this embodiment: like Figure 6 as well as Figure 7 As shown, the design, construction, management, operation, and mission execution of the cascaded gravitational siphon lunar elevator are all complex systems engineering projects. The system is analyzed using Hall's three-dimensional structure theory as follows.

[0044] Figure 7 The document describes the relationships between some important system structural entities and devices, as well as the functions and attributes of each entity. A descriptive analysis of some of these important entities is provided below.

[0045] 1) Lunar Base Station. The lunar base station needs to withstand tensile forces, therefore requiring a high-strength pull-out anchoring system. The most important component of the base station is a large traction sheave, potentially hundreds of meters in diameter. This traction sheave operates without slippage against the first-stage ladder, only experiencing static friction. This traction sheave can be either the driving or driven sheave. The sheave system is equipped with clutches, brakes, and other devices. When the traction sheave acts as the driving sheave, it requires electric power. A nuclear power plant is the optimal choice for providing a stable power supply.

[0046] It's important to note that nuclear power was chosen primarily for its stability. The lunar environment makes it impossible to install thermal, wind, or hydroelectric power plants, while solar power plants require large-scale energy storage to provide a stable supply. This doesn't mean that a high-power nuclear power plant is necessary to drive the first stage of operation; in fact, the power output of a solar power plant is sufficient. Because the traction system is similar to an elevator in a building, the unloaded upward and downward sides are balanced by weights. The traction sheave only needs to provide the driving force to overcome the lunar gravity to carry the cargo load. Only large-scale, continuous mining operations require high drive power.

[0047] The base station needs to be equipped with a smooth loading and unloading system, similar to a cable car station. The operating speed of the first-level elevator may reach hundreds of meters per second, requiring a sophisticated and reliable sliding buffer loading and unloading area.

[0048] 2) Ladder Cables. In a cascaded ladder system, each level of the cable has a uniform cross-section, but the cross-sectional thickness can vary between levels. This is one of the key advantages of a cascaded design. The two levels adjacent to point L1 require thicker cables; the closer to Earth, the thinner the cables are recommended. This ensures that stress remains approximately constant along the cable axis, effectively utilizing the material for load-bearing capacity. Due to the astronomical length of the cables and the proposed design principles, the overall mass of the cables should be significantly greater than that of the cargo container.

[0049] 3) Cargo Boxes (Elevator Cars). The cargo boxes should be evenly distributed in each step of the elevator to ensure the gravitational pull is effective and to ensure counterweight balance on both sides of each step when there is no cargo. However, the spacing between them can vary between different steps, which reflects the flexibility advantage of cascaded systems.

[0050] 4) Integrated Station. The integrated station is located between adjacent levels and floors. The most important component is at least two large traction sheaves, which are coupled to the cables of the upper and lower levels, respectively. Each traction sheave also functions as both a driving and driven sheave, switching between power recovery and output states through a clutch-transmission system.

[0051] Traction wheels within the same integrated station can drive each other, achieving angular momentum exchange. Due to the Coriolis force, all stages and layers must rotate in the same direction (from a top-down perspective of the moon's clockwise revolution, the cable must rotate counterclockwise) to ensure that the ascending and descending lines do not collide. Momentum exchange between all traction wheels of the same stage requires a reversing device.

[0052] Integrated stations must also be equipped with certain warehousing capabilities to cope with different operational plans between different levels and to handle redundant deliveries from the previous level within a certain period. Integrated stations can also be expanded with various necessary operational equipment.

[0053] An obviously advantageous layout is to place a large-scale integrated station near point L1, concentrating most of the functions in this station to fully utilize the combined balance characteristics of point L1.

[0054] 5) Terminal Station. The terminal station does not have a lower-level ladder. The station has traction wheels that couple with the upper-level ladder. It has storage functions to receive and temporarily store cargo arriving from the upper-level ladder. The most important function of the terminal station is as a transit point for transportation between Earth and the ladder. Its method of delivering cargo to Earth is primarily by dropping cargo, releasing it at the appropriate time, with the appropriate initial velocity and direction. If necessary, small rockets are equipped in the cargo to control its landing (sea) trajectory, ensuring the cargo lands in a predetermined area on the ground (sea).

[0055] 6) Salvage Ship. The most valuable cargo on the moon is minerals. A single cargo hold of minerals has a considerable weight, while the landing rockets and parachutes have limited capacity, and the land surface cannot withstand the landing process of such a large mass of cargo. Splash-in into the ocean is recommended. The cargo can be equipped with buoyancy devices, and then a salvage ship can be used to retrieve it.

[0056] Further elaborating on the design of the traction sheaves at intermediate stations, it is unsuitable to use a single giant sheave. Such a sheave is excessively large in size, weight, and moment of inertia, placing a significant mechanical burden on the system and increasing the difficulty of starting, braking, and speed changes. Furthermore, since the ropes within the stations are primarily in contact with the traction sheaves, lacking any suspended portion, it is difficult to operate the car and cargo, further complicating energy recovery and transfer. Therefore, it is recommended to use a combination of smaller sheaves, such as... Figure 8 As shown, this type of wheel has a smaller individual wheel and a smaller moment of inertia, and the different wheels rotate in opposite directions, which can balance the overall moment of inertia of the integrated station and avoid or reduce the overall precession and nutation of the station caused by the high-speed rotation of the large-inertia traction wheel.

[0057] Finally, based on the typical mission planning of the above model, the primary design mission of the cascaded lunar elevator is to transport lunar minerals on a large scale, while also serving as a means of transporting general cargo and personnel up and down.

[0058] Assuming the system, after optimized design and proper operation, possesses stable operation, flexible start-up and shutdown capabilities, and sufficient tiered warehousing capacity and safety margin, it means the system is ready to effectively execute various target tasks. This section will use a three-stage series siphon ladder system as an example for task planning. The example parameters of this ladder are as follows.

[0059] The planning of specific tasks needs to take into account transportation time requirements, the transportation status of goods at all levels and layers during transportation, and the instantaneous configuration and dynamics of the system. A typical dual-threaded task represented by a time-series swimlane BPMN diagram is as follows.

[0060] like Figure 9As shown, the main task is the ore transport. 1000 tons of cargo, transported in 500 containers at 2-ton per container, is temporarily stored at the L1 point integrated station. This journey provides the main power for the first-stage space ladder. The L1 integrated station sorts the cargo, a process that takes about 10 days. Approximately 500 tons of high-grade ore continue to be transported down to Earth, while approximately 500 tons of low-grade ore are temporarily stored at the integrated station for future use, utilizing lunar gravity to power the first-stage space ladder. High-grade ore descends to Earth on the second-stage space ladder at 5-ton per container, with the pace controlled to ensure that the inventory at the transfer station does not exceed 100 tons. The transfer station then arranges the unloading based on the readiness level of the final station. The third-stage space ladder has a container size of approximately 2 tons. The final station calculates the unloading trajectory based on the phase of Earth's rotation, arranges the appropriate unloading angle, and unloads the ore at the appropriate time. The secondary line task involves the cargo handlers at the terminal station returning to the L1 main station. They take the third-level elevator upwards in a gondola, arrive at the transfer station, attend a meeting there, and rest for approximately 24 hours. Afterwards, they take the second-level elevator upwards back to the L1 main station. Due to its large size and complete facilities, the L1 main station can be used for cargo handlers to rotate shifts and rest.

[0061] In the daily operation of the elevator, the recommended model is to implement a regular schedule. The operating times for each segment should be planned in advance and made public. Reserve transport capacity and storage capacity should be prepared in a planned manner, and resources such as ore should be secured. If any warehouse is understaffed, pre-fabricated equivalent minerals (cargo) can be loaded to maintain the system's dynamic parameters. In summary, the embodiments of the present invention have the following advantages over the prior art: 1) Significantly Reduced Material Requirements: The most direct benefit is that it breaks the absolute dependence on "miracle materials." A single celestial ladder requires a continuous cable strong enough to withstand the enormous span between the Earth and the Moon. Currently, only carbon nanotubes are theoretically capable of this, but their large-scale fabrication remains a global challenge. The cascaded design can make fuller use of material strength, allowing for the use of different specifications of ladder materials in different sections. This makes it possible to utilize existing ultra-strong fiber materials, greatly accelerating the engineering process.

[0062] 2) More precise dynamic control: The gravitational siphon elevator is a complex multibody dynamic system. Even a small disturbance in a single elevator structure can be amplified along the hundreds of thousands of kilometers of cable, producing unpredictable vibrations. The cascaded design discretizes the continuous system, allowing for independent and precise dynamic control and damping suppression of each segment.

[0063] 3) Enhanced operational flexibility: Different segments can independently set optimal operating speeds ("opening") based on their space environment characteristics (such as Earth's gravitational region, microgravity region, and lunar gravitational region). For example, a lower speed can be used in segments near the lunar surface to ensure docking accuracy, while high-speed cruising can be used in the middle space segment. This "site-specific" strategy optimizes overall transportation efficiency, which is difficult to achieve with a single space elevator.

[0064] 4) Modular construction reduces initial costs and risks: The entire system can be constructed in phases. For example, the "Lunar-Lagrange point" segment, with relatively lower technical requirements, can be built first to support lunar scientific research and resource development, generating benefits quickly, before gradually extending towards Earth. This model significantly reduces the initial investment threshold and risks.

[0065] 5) Fundamentally Improved Maintainability: This is one of the most prominent advantages of cascaded design. If a single sky elevator experienced cable wear at an altitude of 200,000 kilometers, maintenance would be a nightmare. However, in a cascaded system, any segment requiring maintenance or upgrades can be suspended independently without affecting the normal operation of other segments. Transfer hubs can serve as maintenance bases, storing spare parts and housing robots or personnel. This transforms the sky elevator from a fragile structure "difficult to touch once built" into a maintainable, upgradeable, and sustainable modern infrastructure.

[0066] 6) Improved economic efficiency: Due to more controllable construction and maintenance costs, as well as increased reliability and frequency of transportation, the final transportation cost per kilogram of supplies is expected to be far lower than that of traditional rockets (it is estimated that the cost of transporting supplies by the space elevator can be as low as 4% of that of traditional rockets), and even lower than the estimated cost of a single space elevator.

[0067] Reference Figure 2 A cascaded gravitational siphon lunar ladder model construction system, comprising: Module 201 is used to define the basic gravitational siphon lunar ladder unit model; The second module 202 is used for the basic gravitational siphon lunar ladder unit model, which simplifies the multibody dynamics and discretizes the nodes of the continuous rope. The third module 203 is used to construct complete dynamic equations in a unified coordinate system and to carry out cascade system expansion and modular integration. Module 4, 204, is used to implement component optimization and system-level performance matching to construct a cascaded gravitational siphon lunar ladder model.

[0068] The content of the above method embodiments is applicable to this system embodiment. The specific functions implemented in this system embodiment are the same as those in the above method embodiments, and the beneficial effects achieved are also the same as those achieved in the above method embodiments.

[0069] The above is a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A method for constructing a cascaded gravitational siphon lunar ladder model, characterized in that, Includes the following steps: Define the basic gravitational siphon lunar ladder unit model; The basic gravitational siphon lunar ladder unit model simplifies the continuous rope through multibody dynamics and discretizes the nodes. Construct complete dynamic equations in a unified coordinate system, and carry out cascaded system expansion and modular integration; Implement component optimization and system-level performance matching to construct a cascaded gravitational siphon lunar ladder model.

2. The method for constructing a cascaded gravitational siphon lunar ladder model according to claim 1, characterized in that, The step of defining the basic gravitational siphon lunar ladder unit model specifically includes: Construct a closed-loop rope, with fixed pulleys (fixed to the near-Earth surface of the Moon) and movable pulleys (distributed on the near-Earth surface of the Earth) at both ends. The cargo boxes are fixed at equal intervals on the upper or lower sections of the closed-loop rope.

3. The method for constructing a cascaded gravitational siphon lunar ladder model according to claim 2, characterized in that, The process of simplifying multibody dynamics specifically includes: The continuous rope is divided into concentrated mass nodes, and adjacent nodes are connected by elastic straight bars. Feature node discrimination rules are introduced to determine the connection relationship between pulley and rope nodes.

4. The method for constructing a cascaded gravitational siphon lunar ladder model according to claim 3, characterized in that, The step of constructing the complete dynamic equations in a unified coordinate system specifically includes: Choose a rotating Earth-Moon coordinate system with its origin at the Earth-Moon system's center of mass. Obtain the position vectors of the Earth, Moon, rope nodes, and pulleys; Construct equations that include gravitational force, centrifugal force, Coriolis force, elastic force, and damping force.

5. The method for constructing a cascaded gravitational siphon lunar ladder model according to claim 4, characterized in that, The cascading system expansion step specifically includes: The hierarchical design proceeds from the first lunar stage to the Earth stage, with each stage independently forming a closed loop around the traction wheel. An integrated station, including a traction sheave set, is set up at the interstage connection point. The kinetic energy is transferred and the direction is controlled through a clutch-transmission-reversing-speed change device.

6. The method for constructing a cascaded gravitational siphon lunar ladder model according to claim 5, characterized in that, The step of optimizing each component specifically includes: Different grades of cables use different cross-sectional dimensions; The cargo containers are evenly distributed across the various levels of the ladder, with adjustable spacing; The power system is matched with a first-stage active drive, and subsequent stages rely on the gravitational siphon effect for operation. The traction wheel is used for speed regulation and energy recovery.

7. The method for constructing a cascaded gravitational siphon lunar ladder model according to claim 6, characterized in that, The structure of the cascaded gravitational siphon lunar ladder model also includes: Each stage operates independently, and energy transfer between stages is achieved through integrated stations; The segmented design allows for localized maintenance without affecting overall operation and supports modular expansion.

8. The method for constructing a cascaded gravitational siphon lunar ladder model according to claim 7, characterized in that, The cascaded gravitational siphon lunar ladder model includes a segmented series gravitational siphon lunar ladder and a series-parallel combined gravitational siphon lunar ladder.

9. A cascaded gravitational siphon lunar ladder model construction system, characterized in that, Includes the following modules: The first module is used to define the basic gravitational siphon lunar ladder unit model; The second module is used for the basic gravitational siphon lunar ladder unit model, which simplifies the multibody dynamics of the continuous rope and handles the discrete nodes. The third module is used to construct complete dynamic equations in a unified coordinate system and to extend and modularize cascaded systems. The fourth module is used to optimize each component and match system-level performance, and to build a cascaded gravitational siphon lunar ladder model.

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