Satellite holder suitable for extensible communication cabin and design method

Abstract

The invention discloses a satellite retainer suitable for an extensible communication cabin and a design method, and relates to the field of communication satellite final assembly, the satellite retainer comprises a south piece assembly, a north piece assembly, an upper trapezoidal beam assembly, a middle trapezoidal beam assembly, a lower trapezoidal beam assembly, a floor connecting piece, a horizontal plate connecting piece, a connecting device, a driving shaft system and a driven shaft system; an upper trapezoidal beam assembly, a middle trapezoidal beam assembly and a lower trapezoidal beam assembly are connected between the two opposite sides of the south piece assembly and the north piece assembly, a ground facing plate of the communication cabin is connected to the upper trapezoidal beam assembly through a ground facing plate connecting piece, and a horizontal plate of the communication cabin is connected to the lower trapezoidal beam assembly through a horizontal plate connecting piece; a connecting device is arranged on the inner side of the south piece assembly and connected with a communication cabin south plate of the communication cabin. A connecting device is arranged on the inner side of the north piece assembly and connected with the communication cabin north plate. And the general assembly precision of the communication cabin can be maintained.

Description

Technical Field

[0001] The present invention relates to maintaining the structural accuracy of a communication satellite in the final assembly stage of an aerospace product, and in particular to a satellite retaining frame adapted to an expandable communication cabin, belonging to the technical field of satellite structural subsystem precision assembly. Background Art

[0002] The appearance of the communication satellite is a rectangular box-shaped structure, which is mainly composed of a propulsion module and a communication module. According to the development process, the final assembly and integration work will be carried out after the structural assembly is completed. In the final assembly stage, the propulsion module and the communication module need to be disassembled, and the equipment installation of the two modules is carried out in parallel. The traditional Dongsi platform communication module is mainly composed of the floor, the south plate of the communication module, the north plate of the communication module, the south partition of the communication module, and the north partition of the communication module. The overall structure is "∏"-shaped, and the bottom of the structure is open. The overall rigidity is insufficient. If the module is directly divided, the communication module structure will be deformed or even damaged. Therefore, during the final assembly process, the communication module needs to be reinforced with a retaining tool (hereinafter referred to as the communication module retainer or retainer) to make it a closed rigid body.

[0003] The communication cabin retainer always maintains the structural accuracy of the communication cabin stably during the equipment assembly, parking, electrical measurement, hoisting, flipping and transportation of the communication cabin, and protects the south and north plates of the communication cabin and the components such as the OSR sheet on the outer surface during the above operations until the communication cabin is docked with the platform. The traditional communication cabin retainer is generally composed of a south plate assembly, a north plate assembly, an east side reinforcement beam assembly, a west side reinforcement beam assembly, connectors with the satellite body, and a flip shaft and a support shaft. The north and south plate assemblies are used to protect the north and south plates of the communication cabin, and the east and west side reinforcement beam assemblies are used to close the retainer as a whole. The flip shaft and the support shaft are engaged with the transmission shaft system of the flip frame vehicle (other supporting tooling), so that the communication cabin can achieve axial rotation during the assembly stage and adapt to various assembly conditions. The traditional Dongsi platform communication cabin is small in size, has no extension plates on the outer plates, and has a light full load weight. Therefore, the overall envelope size of the retainer is small, the design and development difficulty is low, and the deformation of the load-bearing components is small. However, as the demand for communication satellite payloads gradually increases, the Dongsi Extended and Dongsi EⅡ communication satellites have emerged. On the basis of the traditional configuration, an expansion cabin has been added, the overall height has increased by 25%, and the contour envelope of the expansion board of the floor and the north and south boards has become more complex. It has become the current mainstream platform (hereinafter referred to as the expandable communication cabin). The expandable communication cabin has put forward higher requirements in terms of external dimensions, heavy load eccentricity, full load mass, avoidance space, etc., and therefore puts forward higher challenges to the deformation load-bearing adaptability of the satellite cage. Summary of the invention

[0004] The technical problem solved by the present application is: to overcome the shortcomings of the prior art and provide a satellite retainer that is suitable for an expandable communication cabin, wherein the retainer body uses a standard aluminum alloy profile and is integrally formed using a riveting process. It has a certain degree of replacement adaptability with the satellite connection interface and is widely used in maintaining the assembly accuracy of an expandable communication cabin.

[0005] The technical solutions provided by this application are as follows:

[0006] A satellite retainer adapted for an expandable communication cabin comprises a south piece assembly, a north piece assembly, an upper ladder beam assembly, a middle ladder beam assembly, a lower ladder beam assembly, a floor connection piece, a horizontal plate connection piece, a connecting device, a driving shaft system and a driven shaft system; the south piece assembly and the north piece assembly are arranged relative to each other, the communication cabin is located between the south piece assembly and the north piece assembly, the upper ladder beam assembly, the middle ladder beam assembly and the lower ladder beam assembly are connected between the opposite sides of the south piece assembly and the north piece assembly, the floor of the communication cabin is connected to the upper ladder beam assembly through the floor connection piece, and the horizontal plate of the communication cabin is connected to the lower ladder beam assembly through the horizontal plate connection piece ; A connecting device is arranged on the inner side of the south piece component, and the connecting device is connected to the south plate of the communication cabin; a connecting device is arranged on the inner side of the north piece component, and the connecting device is connected to the north plate of the communication cabin; the connecting device includes a primary connecting member and a secondary connecting beam, the primary connecting member is connected to the inner side of the south piece component or the inner side of the north piece component, the length direction of the primary connecting member is parallel to the direction of the upper trapezoidal beam component pointing to the middle trapezoidal beam component, each primary connecting member is connected to multiple secondary connecting beams, and the other end of the secondary connecting beam is connected to the south plate of the communication cabin or the north plate of the communication cabin; the active shaft system is arranged in the south piece component, and the driven shaft system is arranged in the north piece component.

[0007] The south piece assembly comprises a frame cross beam, a frame longitudinal beam, a connecting longitudinal beam, a short connecting cross beam and a short connecting longitudinal beam. Two frame cross beams and two frame longitudinal beams are arranged orthogonally and connected in sequence to form an outer frame of the south piece assembly. Two connecting longitudinal beams are connected between two frame cross beams. A plurality of short connecting cross beams are connected between two connecting longitudinal beams and between connecting longitudinal beams and adjacent frame longitudinal beams. A plurality of short connecting longitudinal beams are connected between short connecting cross beams between two connecting longitudinal beams and between short connecting cross beams and adjacent frame cross beams. The installation frame formed by the short connecting cross beams and the short connecting longitudinal beams is fixedly connected to a rotating shaft installation plate.

[0008] The structure of the north module is the same as that of the south module;

[0009] The shaft mounting plate of the north piece assembly is used to install the active shaft system, and the shaft mounting plate of the south piece assembly is used to install the driven shaft system.

[0010] The south piece assembly is connected to two connecting devices, and the primary connecting pieces of the two connecting devices are fixedly connected to the connecting longitudinal beam.

[0011] Teflon is arranged between the primary connecting piece and the connecting longitudinal beam, and the primary connecting piece and the connecting longitudinal beam are connected by bolts.

[0012] The south piece assembly is also provided with an oblique support beam, which includes a first oblique beam, a second oblique beam and a third oblique beam;

[0013] The short connecting beams between the two connecting longitudinal beams are a top short connecting beam, a middle short connecting beam and a lower short connecting beam; two short connecting longitudinal beams are connected between the middle short connecting beam and the lower short connecting beam;

[0014] One end of the first oblique beam is connected to the intersection of the frame cross beam and the connecting longitudinal beam, and the other end is connected to the middle of the top short connecting cross beam;

[0015] One end of the second oblique beam is connected to the intersection of the middle short connecting cross beam and a short connecting longitudinal beam, and the other end is connected to the intersection of the lower short connecting cross beam and the connecting longitudinal beam;

[0016] One end of the third oblique beam is connected to the intersection of the lower short connecting cross beam and the connecting longitudinal beam, and the other end is connected to the intersection of the frame longitudinal beam and a short connecting cross beam.

[0017] The active shaft system and the driven shaft system both include a rotating shaft, which is connected to a rotating shaft mounting plate. The rotating shaft and the rotating shaft mounting plate are connected by 8 evenly distributed screws, and two pins are arranged between the rotating shaft mounting plate and the rotating shaft of the north plate assembly, and the two pins are symmetrically distributed on opposite sides of the rotating shaft.

[0018] The advantages of the present invention compared with the prior art are:

[0019] (1) In the traditional cage installation process, the first-level connectors are first installed on the north and south plates of the communication cabin. Due to the large number of connectors, the flatness of the installation surface composed of the connectors is difficult to adjust on the satellite, and the relative position of the holes of each connector is also difficult to adjust. In this design, the second-level connectors and adjustment gaskets are added, and the relative accuracy of the first-level connectors is adjusted in the small assembly state on the ground. The parallelism and flatness of the installation surfaces on both sides are guaranteed through combined processing, which not only ensures the installation accuracy, but also greatly improves the work efficiency of installation and measurement and adjustment.

[0020] (2) If the satellite connection point interface changes, the north and south pieces of the cage cannot be reused, which is costly and inflexible. In this design, due to the addition of a secondary connector, only the secondary connection holes need to be re-produced or modified, and the connection holes with the north and south pieces remain unchanged, thus improving the adaptability of the cage and reducing the difficulty and cost of modification.

[0021] (3) The traditional process uses a support plate nut to provide a threaded connection at the installation point. For deep-cavity configurations with long pipe bodies, the operation is difficult. Special tools are required to install the support plate nut in place, and rivet connection holes are also required, which is a lot of work. In this design, the support plate nut is changed to a rivet nut, and the rivet nut is installed at the pre-prepared connection hole, and the operation can be completed using the pull riveting process.

[0022] (4) The traditional design process is: mechanical configuration design → mechanical simulation analysis → calculation of flipping torque. In the preliminary design of the flip axis position, the method of centering the height direction is generally adopted to determine it. The final design is completed through multiple rounds of iterations of the above three steps. Therefore, since the consideration of full load and extreme working conditions is not reflected in the preliminary design parameters, the calculation results often have large deviations, resulting in a large number of iterations and low design efficiency. In this design, the counterweight center of mass balancing method is introduced to introduce the influence of full load and extreme working conditions into the configuration size design process. The cross beam around the shaft mounting plate is designed as a whole, which can realize rapid adjustment of the center of mass and shorten the design reconstruction time.

[0023] (5) During the simulation process, the cage needs to create a satellite equivalent model to simulate the satellite stiffness, center of mass and mass. The traditional method establishes a simulation model according to the contour of the communication cabin, and then uses the method of adding density to adjust the center of mass and mass. This method has many iterations and often cannot achieve accurate simulation. In this design, a density allocation method based on nonlinear programming theory is proposed. It uses the contour size as a constraint and the minimum center of mass and mass deviation as the goal to solve the optimal density, which significantly improves the accuracy and efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Design process flow chart for the present invention;

[0025] Figure 2 Schematic diagram of the overall structure of the cage;

[0026] Figure 3 This is a schematic diagram of the north and south components;

[0027] Figure 4 Schematic diagram of the ladder beam assembly

[0028] Figure 5 is a schematic diagram of the connected components;

[0029] Figure 6 It is a schematic diagram of the connection parts of the floor and horizontal plate;

[0030] Figure 7 Schematic diagram of the shaft;

[0031] Figure 8 This is a schematic diagram of the connection between the retaining frame and the communication cabin;

[0032] Fig. 9 is a schematic diagram of the satellite coordinate system;

[0033] Fig.10 This is a schematic diagram of the structure of a primary connector.

[0034] Description of reference numerals: 11, south piece assembly; 12, north piece assembly; 13, upper trapezoidal beam assembly; 14, middle trapezoidal beam assembly; 15, lower trapezoidal beam assembly; 16, floor connecting piece; 17, horizontal plate connecting piece; 18, primary connecting piece; 19, secondary connecting beam;

[0035] 111. Driving shaft system; 112. Driven shaft system;

[0036] 21. Floor; 22. South plate of communication cabin; 23. North plate of communication cabin; 25. North partition of communication cabin; 26. Horizontal plate. DETAILED DESCRIPTION

[0037] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments disclosed in the present invention will be further described in detail below with reference to the accompanying drawings.

[0038] An embodiment of the present application discloses a satellite retaining frame adaptable to an expandable communication cabin, which is used to connect the communication cabin. The communication cabin includes a ground plane 21, a south plate 22, a north plate 23, a south partition, a north partition 25 and a horizontal plate 26. The south plate 22 and the north plate 23 are parallel and one end of each is connected to the ground plane 21. The horizontal plate 26 is arranged between the south plate 22 and the north plate 23. The south partition is arranged on the inner side of the south plate 22, and the north partition 25 is arranged on the inner side of the north plate 23.

[0039] like Figure 2 and Figure 8 As shown, the cage includes:

[0040] (1) The overall structure design of the cage, such as Figure 2 and Figure 3As shown, the cage consists of the following parts: south plate assembly 11, north plate assembly 12, upper trapezoidal beam assembly 13, middle trapezoidal beam assembly 14, lower trapezoidal beam assembly 15, floor connection piece 16, horizontal plate connection piece 17, primary connection piece 18, secondary connection beam 19, active shaft system (including gear) 111, driven shaft system 112, hanging point screws, rivets and screws between structures, etc. The cage is connected to the connection points of the south and north plates of the communication cabin through the primary connection piece using M5 screws; the secondary connection beam is installed on the outside of the primary connection piece, and the north and south plate assemblies are installed on the outside of the secondary connection beam, which is the main structure of the cage. Three sets of trapezoidal beam assemblies are installed in the east-west direction to form a closed whole. The cage is connected to the floor through the floor connection piece, and connected to the horizontal plate through the horizontal plate connection piece. The lateral connection points are connected using M5 screws. The components of the cage are connected using M8 hexagon socket screws. This error-proof design facilitates system operation and maintenance.

[0041] (2) The south and north components are installed on the ±Y sides of the satellite respectively. They have basically the same configuration and are generally symmetrical about the satellite reference plane XOZ (determined by whether the satellite profile is symmetrical). The main load-bearing beam is made of aluminum profiles with a cross-sectional size of 100×100mm, a wall thickness of 3.5mm, and a grade of LD31. Special corner connectors are used at the four corners to provide installation holes for the hanging point screws while achieving structural closure. The middle crossbeam and longitudinal beam are arranged orthogonally in a well or T shape. Polygonal reinforcement plates are set on the inner and outer surfaces of each intersection node, and reinforcement corner boxes are set in adjacent quadrants. The structural parts are connected by riveting to improve the overall connection strength. A shaft mounting plate is set in the central part for installing the active / driven shaft to realize the flipping condition of the cage and the satellite in the future. The shaft mounting plate is connected to the adjacent four beams by screws.

[0042] The south piece assembly 11 includes a frame crossbeam 111, a frame longitudinal beam 112, a connecting longitudinal beam 113, a short connecting crossbeam 114 and a short connecting longitudinal beam 115. Two frame crossbeams and two frame longitudinal beams are arranged orthogonally and connected in sequence to form the outer frame of the south piece assembly 11. Two connecting longitudinal beams are connected between two frame crossbeams. Multiple short connecting crossbeams are connected between two connecting longitudinal beams and between connecting longitudinal beams and adjacent frame longitudinal beams. Multiple short connecting longitudinal beams are connected between short connecting crossbeams between two connecting longitudinal beams and between short connecting crossbeams and adjacent frame crossbeams. The installation frame formed by the short connecting crossbeams and the short connecting longitudinal beams is fixedly connected to a rotating shaft installation plate.

[0043] (3) Figure 2 and Figure 4As shown, the ladder beam assembly (including the upper ladder beam assembly 13, the middle ladder beam assembly 14, and the lower ladder beam assembly 15) is installed on the ±X side of the satellite, wherein the upper ladder beam is located at the top (+Z direction) and the lower ladder beam is located at the bottom (-Z direction). The main structure of the ladder beam is made of aluminum profiles with a cross-sectional size of 90×50mm, a wall thickness of 3mm, and a grade of LD31. The connection between the ladder beam and the north and south piece assemblies is locally reinforced in the form of riveted M8 sleeves. Polygonal reinforcement plates are set on the inner and outer surfaces of the overlaps of each horizontal, vertical, and oblique beam, and reinforced corner boxes are set in adjacent quadrants. The structural parts are connected by riveting to improve the overall connection strength.

[0044] In this embodiment, the structure of an upper trapezoidal beam assembly 13 is provided, and the upper trapezoidal beam assembly 13 includes a first cross beam 141, a first longitudinal beam 142 and a first oblique beam 143. The two first cross beams are parallel to each other, and three parallel first longitudinal beams are connected between the two first cross beams. The first cross beam and the first longitudinal beam form two frame-shaped parts; the first oblique beam is arranged in the frame-shaped part and is arranged diagonally.

[0045] (4) Figure 5 As shown, the connection assembly consists of a secondary connection piece and a primary connection piece, which is used to connect the four columns of tooling holes on the +Y and -Y plates of the communication cabin. The secondary connection piece is made of LD31 aluminum profile with a cross-sectional size of 90×50mm and a wall thickness of 3mm. Two M8 nuts are riveted on the 90mm wide surface of the secondary connection cavity to connect with the primary connection; a 4mm thick connection plate is riveted on the other side, and the overall combined processing method is used to ensure the flatness of the connection surface. Two M8 nuts are riveted on one side of the secondary connection and the north and south pieces to provide connection points for the corresponding hole sleeves of the north and south piece components. The above method not only ensures the accuracy of the connection holes with the north and south pieces, but also enhances the maintainability of the connection assembly. The primary connection piece is milled from 2A12-H112, and 0.1mm Teflon is pasted at the connection between the primary connection piece and the north and south pieces to play a role in isolation and protection.

[0046] According to the specific connection position on the communication cabin, the secondary connection part and the primary connection part are connected to form an integral part to obtain a connection assembly. When connecting the satellite holder to the communication cabin, the connection assembly is first connected to the corresponding positions on the south plate and the north plate of the communication cabin, and then the south plate assembly and the north plate assembly are connected to the connection assembly. In the process of connecting the south plate assembly and the north plate assembly to the connection assembly, only the reference surface of the primary connection part needs to be adjusted.

[0047] (5) Figure 6 As shown, the floor connector and the horizontal plate connector are used to connect the retaining frame to the communication cabin floor and the ±X side connecting holes of the horizontal plate. They are box-type structures made of aluminum alloy, the material is 2A12H112, and are provided with reinforcing ribs to improve the overall rigidity.

[0048] (6) Figure 7 As shown, the shaft is installed on the shaft mounting plates of the south piece assembly and the north piece assembly, and docked with the flip frame, and is divided into two forms: the active end and the driven end. The active end (gear side) is installed on the -Y side, and the driven end (shaft) is installed on the +Y side. The shaft mounting plates on the north and south pieces of the shaft and the retaining frame are positioned with a Φ90mm shaft end and connected with 12.9-grade M16 screws. There are 8 screws on each of the north and south pieces, evenly distributed on a Φ125mm circle. In addition, in order to enhance the connection strength of the active end, two Φ12mm pins are set at the connection between the north piece adapter plate and the drive shaft, symmetrically distributed on a Φ125mm circle. A transmission gear is installed on the active end shaft, which cooperates with the shaft system on the flip frame to transmit torque and drive the retaining frame to flip, while a sleeve is installed at the corresponding position on the passive end shaft to form a rotating shaft system with the active end.

[0049] Example 1: Taking the design of a certain type of communication cabin holder as an example

[0050] Figure (1) shows the design process of the cage of the present invention, which is divided into 11 steps. Figure 1 As shown, they are:

[0051] (1) Define the satellite coordinate system: The communication cabin structure is defined by a local coordinate system. The origin of the coordinate system is located at the geometric center of the upper surface of the floor (X = 0, Y = 0, Z = 5100, in the mechanical coordinate system of the entire satellite). The +X, +Y, and +Z directions are the same as the coordinate system of the entire satellite. Fig. 9 As shown, +Z is perpendicular to the floor, and +Y is the direction from the north plate to the south plate of the communication cabin.

[0052] (2) Determine the maximum envelope size of the ±X and ±Y sides of the cage: According to technical requirements, the ±Y direction size should meet the following requirements: ① The distance between the inner surface of the north and south pieces and the outer surface of the north and south plates of the communication cabin is ≥60mm; ② The size of the traveling wave tube radiant head to be avoided in the Y direction is ≥135mm on one side. Assuming that the distance between the outer surfaces of the north and south plates is 2100mm, the above two points preliminarily determine that the ±Y side size of the cage is ≥2100+2*135+2*100=2570mm (the thickness of the main beam of the north and south pieces). According to technical requirements, the ±X direction size is ≤3450mm. In order to ensure the effectiveness of the north and south pieces in protecting the north and south plates, the ±X direction size of the north and south pieces should be as large as possible, preliminarily set at 3440mm.

[0053] (3) Determine the size of the primary connector: One side of the primary connector is connected to the communication cabin and provides an M5 mounting countersunk hole. The other side is connected to the secondary connecting beam and requires two through holes. The specific size needs to be adjusted according to the hole position of the structural plate (specific design is carried out according to the specific size of each satellite). Fig.10 Shown is a schematic diagram of the structure of a primary connector.

[0054] (4) After connecting the primary connection with the embedded threaded parts of the communication cabin, assemble the secondary connection beam of suitable length with the primary connection parts, construct the hole position of the support plate nut on the secondary connection beam through the position of the primary connection through hole, and assemble several groups of connection plates on the side where the secondary connection beam is installed with the north and south pieces. In the actual assembly process, firstly, the primary connection is spread out on the assembly platform, and after assembling and riveting to form the primary and secondary connection beams, as shown in the figure. Figure 5 As shown, one side of the connecting piece is subjected to combined processing to ensure that the parallelism of the upper and lower surfaces meets the requirements.

[0055] (5) Design the preliminary models of the north and south pieces and the trapezoidal beam assembly: First, according to the ±X±Y side envelope dimensions determined in step (2), determine the outline dimensions of the south piece and the north piece. The four corners use corner fittings (universal parts), and the rest of the main body is assembled using 100×100×3.5 aluminum square tubes, with no outer fillet and an inner fillet of R5. According to the influence of full load conditions and extreme conditions on the overturning moment, calculate the position of the shaft mounting plate in the X and Z directions, arrange the horizontal and longitudinal beams in a tic-tac-toe pattern around the shaft mounting plate, and arrange two longitudinal beams at the position connected to the first and second level connecting beams to form the main body of the north and south pieces, as shown in Figure 1. Figure 3 As shown. After assembling the south and north components with the secondary connecting beam, the upper, middle and lower trapezoidal beam components in the ±X direction are designed under this envelope. The main part is assembled with 90×50×3 aluminum square tubes, without external fillets and with internal fillets of R5. The width dimension of a single set of beams is equal to the ±Y dimension of the north and south components, and is connected to them through riveted M8 connecting sleeves. The height dimension design fully considers the following factors: ① the weight of a single component, ② the avoidance structure and working space dimensions between components, and ③ the upper trapezoidal beam and the middle trapezoidal beam are connected to the satellite body through the floor connector and the horizontal plate connector respectively, so the height dimension of the connector needs to be reserved, as shown in Figure 4 shown.

[0056] (6) After completing the preliminary design, assemble the above parts / components with the communication cabin, check the interference, and add inclined beams to the north and south components for reinforcement design based on the stress conditions. Determine the reinforcement form and quantity based on the weight margin.

[0057] (7) Connect the floor connection pieces and horizontal plate connection pieces to the trapezoidal beams and the lateral embedded pieces of the floor and horizontal plates to form a closed configuration, such as Figure 2 By changing the single-sided oblong hole design of the floor plate connector and the horizontal plate connector to a double-sided vertical oblong hole design (i.e., a horizontal oblong hole on one side of the vacant space and a vertical oblong hole on the other side), deviations in two orthogonal directions can be accommodated.

[0058] (8) According to the satellite structural plate contour design calculation, the equivalent model is used to assign the distributed load density to the structural plate using nonlinear programming theory (not limited to Excel, MATLAB and other software built-in toolboxes) to simulate the satellite's total loaded mass and center of mass position. The elastic modulus of the aluminum alloy material is 71GPa, and the elastic modulus of the equivalent structural plate material is set to 50GPa, which is slightly smaller than the product on the premise of being close to the actual performance of the product, to ensure that the equivalent model is not treated as a rigid body, thereby distorting the result.

[0059] (9) According to the technical requirements, the following working conditions of the cage are analyzed: ① +Z direction vertically upward (the cage is in a vertical parking state on the tilting rack), ② ±X direction vertically upward (the cage is in a horizontal parking state on the tilting rack), ③ vertical lifting, ④ horizontal lifting, ⑤ horizontal transportation. The simulation process is as follows: ① define the material, and assign material properties to the cage and simulated satellite according to the material parameters determined in step (8); ② perform finite element analysis on the model. The software used in this example is ANSYS workbench18.2. The structure is meshed, the mesh type is AUTO, and the mesh size is 20 mm; ③ apply an acceleration environment. When parking and lifting on the trolley, a downward acceleration of 1.3 g (overload acceleration) is applied. During transportation, the satellite is in a horizontal state. After shock absorption (up and down vibration), the acceleration is 0.6 g, which is 1.6 g after superposition with the gravity deceleration. After considering 1.3 times the overload, it is 2.08 g. The acceleration in the horizontal direction (vehicle travel direction) is 1 g, which is 1.3 g after considering 1.3 times the overload. Therefore, an acceleration vector superimposed in two directions is applied. ④ Apply constraints. When parking on the flip frame, the constraint part is the curved surface on the shaft mounting plate that matches the shaft. When lifting, the constraint part is the curved surface set of the lifting point mounting hole. When transporting, the constraint part is the curved surface of the longitudinal beam on the ±X side of the north and south piece components. ⑤ Simulation results. Through finite element analysis, two observation results of maximum deformation and maximum stress are applied to each working condition. The maximum deformation in each direction is required to be ≤1mm, and the maximum stress should meet the 3 times safety factor. The yield limit of aluminum alloy is 170MPa, so the maximum stress should be ≤56.7MPa. If the requirements are not met, local reinforcement is required according to the weak links. Common reinforcement methods include adding inclined beam supports, adding fixed corner box parts, etc., and then recalculating and iterating until the requirements are met. Due to the increase in the connection size between the structure body and the cage, the stiffness has decreased. Therefore, the 50mm grid size is changed to 20mm during the simulation process to express the deformation details more clearly.

[0060] (10) Calculate the system rollover torque: The rollover torque of the satellite and cage system needs to be calibrated. It is known that the driving torque of the rollover frame vehicle is ≥2600N.m, the system alarms, and ≥3000N.m, the system shuts down. Therefore, the rollover torque of the satellite and cage system should be ≤2600N.m. The verification process is as follows: ① For the empty cabin state (after the delivery of the structure, the load has not yet been installed), the mass and center of mass of the cage can be read from the cage model. The designer has given the mass and center of mass of the empty cabin, and the communication cabin coordinate system is translated to the center height of the rollover axis to establish a new rollover coordinate system C1. The direction of the coordinate axis remains unchanged, and a virtual counterweight mass is introduced to adjust the rollover torque, which is generally located at the top or bottom of the cage. Update the coordinate values ​​of the cage and the satellite in the C1 coordinate system, and calculate the center of mass according to the formula R x =m1*r1+m2*r2+m3*r3, m1 represents the mass of the cage, r1 represents the coordinate value of the cage on the X-axis, m2 represents the mass of the satellite cabin, r2 represents the coordinate value of the satellite cabin state on the X-axis, m3 represents the mass of the virtual counterweight, r3 represents the coordinate value of the virtual counterweight on the X-axis, R x is the comprehensive centroid coordinate of the satellite and cage system on the X axis. Similarly, R z is the combined centroid coordinate of the satellite and cage system on the Z axis. Since the system rotates around the Y axis, there is no need to calculate R y The system eccentric moment M = m*g*L, where m represents the system mass, i.e. the total mass of the satellite + holder, g is the gravitational acceleration, and L is the lever arm. L = (|R x |) 2 +|R z |) 2 ) 0.5 , if M<2600*90% (capacity coefficient), the system can flip. If the flipping condition is not met, the torque correction is performed by adjusting the value of m3. According to the above steps, the full cabin state (all loads are assembled) and the limit state (loads are concentrated in a certain direction) are checked respectively. If the requirements are not met, there are mainly the following measures: ① By analyzing the direction of the torque, analyzing the counterweight installation point, and applying the counterweight to compensate for the center of mass, this method generally has a comprehensive counterweight mass of ≤120kg, otherwise it is difficult to implement. ② By reselecting the flip axis position to balance the center of mass, each shaft mounting plate has 5 mounting holes in the upper, lower, left, right and middle positions, and the distance between the centers of two adjacent mounting holes is 175mm, so it can compensate for larger torques. Recheck the flipping torque according to the previous steps. ③ Iteratively modify the model, adjust the position of the shaft mounting plate, and adapt to the center of mass.

[0061] (11) Complete the design of the whole model: After the mechanical analysis in step (9) and the overturning moment check in step (10) meet the requirements, the structural model is refined, including the reinforcement plate, reinforcement corner box, hole sleeve and other details. According to GB / T3098.1-2010 "Mechanical properties of fasteners bolts, screws and studs", the yield strength of M12 steel screws with a performance grade of 12.9 is 1080MPa. According to the third strength theory, the allowable shear stress of the screw is = 216MPa. The minor diameter d of the screw is 10.1mm. Substituting d into the following formula, the allowable stress F value of the screw can be obtained:

[0062]

[0063] Under the corresponding allowable stress, the torque that the 8 M12 screws can withstand is:

[0064] T max =8×16.665×103×(140 / 2)×10-3=9332N.m>M max =2600N.m(all working conditions

[0065] The maximum eccentric moment overload is 1.3 times), and 8 M12 screws can meet the requirements. To ensure the shear strength of the screws, two shear pins are added to the active end for reinforcement. The following tests should be proposed for the cage, including but not limited to:

[0066] 1) Docking test with the communication cabin: ① Test procedure, make a communication cabin simulation, the appearance interface size is consistent with the real communication cabin; install the communication cabin holder and check the interface size; assemble the communication cabin simulation to the holder, and counterweight the total mass of the communication cabin simulation to 1750±50kg; install the support shaft and the flip shaft to the connection holes of the south and north pieces of the holder respectively (a total of five groups, all need to be verified), and pay attention to ensure the insulation between the holder and the frame during operation; install counterweights of different weights at the lower end of the south and north pieces. ② Test result evaluation, requiring the holder to dock with the communication cabin conveniently and reliably, and the docking size on the holder can ensure a 2mm adjustment margin; the rotating shaft can accurately match the five holes on the south and north pieces, the rotating shaft installation operation is convenient, and there is no obvious gap between the shaft systems; the installation operation of the counterweight is convenient and reliable.

[0067] 2) Cage accuracy retention test: ① Test procedure, assemble the communication cabin simulation part to the cage, add counterweight to the communication cabin simulation part, so that the total mass of the communication cabin simulation part is 1750±50kg; raise the bottom of the simulation part, and suspend the cage; install the dial indicator at the four corners of the bottom of the simulation part, and the head of the dial indicator contacts the corresponding positions of the four corners of the bottom of the cage. Note that the deformation of each corner in the X, Y, and Z directions should be measured; lift the cage with the simulation part, level the bottom of the cage, suspend the simulation part, and evenly fall on the cage. Observe the deformation shown by the dial indicator. ② Test result evaluation, the deformation of the cage should be within the allowable range of the test requirements.

[0068] 3) No-load and full-load hoisting, rotation, and lifting test: ① Test procedure, the trolley flip system is raised to the highest position; the cage is hoisted on the trolley; verify whether the cage is flexible and reliable when flipping (electrically or manually); whether it can be reliably positioned after flipping; verify whether the lifting is flexible and reliable; verify whether it can reliably self-lock after lifting; verify whether the emergency stop is timely and effective; interfere with unilateral movement, and verify whether the other side stops running in time after a unilateral failure. ② Test result evaluation, the cage flipping, flipping, and lifting are flexible and reliable.

[0069] Thus, a satellite holder design suitable for expandable communication cabin has been completed.

[0070] The contents not described in detail in this application specification belong to the common knowledge of those skilled in the art.

[0071] The present application is described in detail above in conjunction with specific implementation methods and exemplary examples, but these descriptions cannot be understood as limiting the present application. Those skilled in the art understand that, without departing from the spirit and scope of the present application, a variety of equivalent replacements, modifications or improvements can be made to the technical solution of the present application and its implementation methods, all of which fall within the scope of the present application. The scope of protection of the present application shall be subject to the attached claims.

Claims

1. A satellite holder adapted to an expandable communication cabin, characterized in that: It comprises a south plate assembly (11), a north plate assembly (12), an upper ladder beam assembly (13), a middle ladder beam assembly (14), a lower ladder beam assembly (15), a connecting piece (16) of a counter plate (21), a connecting piece (17) of a horizontal plate (26), a connecting device, a driving shaft system (111) and a driven shaft system (112); The south piece component (11) and the north piece component (12) are arranged opposite to each other, the communication cabin is located between the south piece component (11) and the north piece component (12), the upper ladder beam component (13), the middle ladder beam component (14) and the lower ladder beam component (15) are connected between the south piece component (11) and the north piece component (12) on opposite sides, the floor (21) of the communication cabin is connected to the upper ladder beam component (13) via the floor (21) connecting piece (16), and the horizontal plate (26) of the communication cabin is connected to the lower ladder beam component (15) via the horizontal plate (26) connecting piece (17); A connecting device is provided on the inner side of the south piece component (11), and the connecting device is connected to the south plate (22) of the communication cabin; a connecting device is provided on the inner side of the north piece component (12), and the connecting device is connected to the north plate (23) of the communication cabin; The connection device comprises a primary connection member (18) and a secondary connection beam (19), wherein the primary connection member (18) is connected to the inner side of the south plate assembly (11) or the inner side of the north plate assembly (12), the length direction of the primary connection member (18) is parallel to the upper ladder beam assembly (13) and points to the direction of the middle ladder beam assembly (14), each primary connection member (18) is connected to a plurality of secondary connection beams (19), and the other end of the secondary connection beam (19) is connected to the south plate (22) or the north plate (23) of the communication cabin; The driving shaft system (111) is arranged on the south piece assembly (11), and the driven shaft system (112) is arranged on the north piece assembly (12).

2. A satellite holder adapted to an expandable communication cabin according to claim 1, characterized in that: The south piece assembly (11) comprises a frame crossbeam (111), a frame longitudinal beam (112), a connecting longitudinal beam (113), a short connecting crossbeam (114) and a short connecting longitudinal beam (115); two frame crossbeams and two frame longitudinal beams are arranged orthogonally and connected in sequence to form an outer frame of the south piece assembly (11); two connecting longitudinal beams are connected between two frame crossbeams; a plurality of short connecting crossbeams are connected between two connecting longitudinal beams and between a connecting longitudinal beam and an adjacent frame longitudinal beam; a plurality of short connecting longitudinal beams are connected between short connecting crossbeams between two connecting longitudinal beams and between a short connecting crossbeam and an adjacent frame crossbeam; and a mounting frame formed by the short connecting crossbeams and the short connecting longitudinal beams is fixedly connected to a rotating shaft mounting plate; The structure of the north piece assembly (12) is the same as that of the south piece assembly (11); The rotating shaft mounting plate of the north piece assembly (12) is used for mounting the driving shaft system (111), and the rotating shaft mounting plate of the south piece assembly (11) is used for mounting the driven shaft system (112).

3. A satellite holder adapted to an expandable communication cabin according to claim 2, characterized in that: The south piece assembly (11) is connected to two connecting devices, and the primary connecting members (18) of the two connecting devices are fixedly connected to the connecting longitudinal beam.

4. A satellite holder adapted to an expandable communication cabin according to claim 3, characterized in that: Teflon is provided between the primary connecting piece (18) and the connecting longitudinal beam, and the primary connecting piece (18) and the connecting longitudinal beam are connected by bolts.

5. The satellite holder adapted to the expandable communication cabin according to claim 3, characterized in that: The south piece assembly (11) is also provided with an inclined support beam, which includes a first inclined beam, a second inclined beam and a third inclined beam; The short connecting beams between the two connecting longitudinal beams are a top short connecting beam, a middle short connecting beam and a lower short connecting beam; two short connecting longitudinal beams are connected between the middle short connecting beam and the lower short connecting beam; One end of the first oblique beam is connected to the intersection of the frame cross beam and the connecting longitudinal beam, and the other end is connected to the middle of the top short connecting cross beam; One end of the second oblique beam is connected to the intersection of the middle short connecting cross beam and a short connecting longitudinal beam, and the other end is connected to the intersection of the lower short connecting cross beam and the connecting longitudinal beam; One end of the third oblique beam is connected to the intersection of the lower short connecting cross beam and the connecting longitudinal beam, and the other end is connected to the intersection of the frame longitudinal beam and a short connecting cross beam.

6. A satellite holder adapted to an expandable communication cabin according to claim 2, characterized in that: The active shaft system (111) and the driven shaft system (112) both include a rotating shaft, which is connected to a rotating shaft mounting plate. The rotating shaft and the rotating shaft mounting plate are connected via 8 evenly distributed screws, and two pins are arranged between the rotating shaft mounting plate of the north plate assembly (12) and the rotating shaft, and the two pins are symmetrically distributed on opposite sides of the rotating shaft.

7. The design method of a satellite holder adapted to an expandable communication cabin according to any one of claims 1 to 6, characterized in that: include: S1: Define the satellite coordinate system. The origin of the coordinate system is located at the geometric center of the upper surface of the communication cabin. The +X, +Y, and +Z directions are the same as the entire satellite coordinate system. S2: Determine the maximum envelope size of the ±X and ±Y sides of the cage according to the communication cabin structure; S3: Determine the connection position of the primary connector and the communication cabin according to the south plate and the north plate of the communication cabin, thereby determining the size of the primary connector. S4: After the primary connection piece is connected to the communication cabin, the secondary connection beam is assembled with the primary connection piece, and the connection hole position on the secondary connection beam is constructed according to the position of the primary connection through hole; S5: Determine the outline dimensions of the south piece assembly and the north piece assembly according to the maximum envelope dimensions of the ±X and ±Y sides of the retainer; determine the position of the shaft mounting plate, and determine the positions of the corresponding short connecting cross beams and short connecting longitudinal beams according to the position of the shaft mounting plate; then assemble the south piece assembly and the north piece assembly with the secondary connecting beam, and then determine the upper trapezoidal beam assembly, the middle trapezoidal beam assembly and the lower trapezoidal beam assembly; S6: Assemble the primary connectors, secondary connecting beams, south piece components and north piece components obtained from S1-S5 with the communication cabin, check the interference, add oblique support beams to the south piece components and north piece components according to the stress conditions, and determine the oblique support beams and the number of oblique support beams according to the weight margin; S7: Connect the floor connection piece to the floor and the upper ladder beam assembly of the communication cabin, and connect the horizontal plate connection piece to the horizontal plate and the middle ladder beam assembly of the communication cabin; S8: According to the equivalent model for satellite structure plate contour design calculation, the cage is given a distributed load density using nonlinear programming theory; S9: Connect the cage to the overturning frame car through the driving shaft system and the driven shaft system, and perform simulation analysis on the cage under different working conditions. If the maximum deformation and maximum stress do not meet the requirements, reinforce them and repeat the iteration until the maximum deformation and maximum stress meet the requirements. S10: Check the rollover moment. If the rollover moment does not meet the requirements, the center of mass compensation is performed by applying a counterweight according to the counterweight installation point, or the axis position is reselected and the model is iteratively modified until the rollover moment meets the requirements.

8. The design method according to claim 7, characterized in that: In S5, determining the position of the rotating shaft mounting plate includes: calculating the position of the rotating shaft mounting plate in the X and Z directions according to the influence of the full load condition and the extreme condition on the overturning moment.

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