CN-116625618-B - Test device and method for quantifying uncertainty in assembly process of large flexible module

CN116625618BCN 116625618 BCN116625618 BCN 116625618BCN-116625618-B

Abstract

The invention discloses a test device and a method for quantifying uncertainty in an assembly process of a large flexible module. The device comprises a large flexible module, a free boundary suspension system, a non-contact motion capture system and a dismounting mechanical arm. The large flexible module is a test object to be tested. The free boundary suspension system provides a free movement boundary condition for the large flexible module and has the characteristics of adjustable static position and posture and dynamic free boundary. The non-contact motion capture system is used to measure the position and attitude response of the assembly process. The dismounting mechanical arm is used for assembling and disassembling a plurality of large flexible modules. The device provides a ground test scheme for researching the assembly and disassembly processes of the large flexible module in an in-orbit microgravity environment, and can repeat the assembly and disassembly processes for a plurality of times. The method can utilize the vibration response generated by the large flexible module in the assembly process to identify the dynamic characteristics of the structure, and further quantify the uncertainty of the dynamic parameters of the structure by using the data of repeated assembly and disassembly.

Inventors

WANG XING
ZHAO ZIHENG
JIANG GUOQI
LIN CHENGRONG
JIANG JIANPING
WU ZHIGANG

Assignees

中山大学·深圳
中山大学

Dates

Publication Date: 20260505
Application Date: 20230508

Claims (9)

1. A large flexible module assembly test device comprises a large flexible module, a free boundary suspension system, a non-contact motion capture system and a disassembly and assembly mechanical arm; The large flexible module is a test object to be tested and is suspended on the free boundary suspension system; the free boundary suspension system is fixed on the ground and is used for providing a boundary condition of free movement for the large flexible module; The non-contact motion capture system is fixed at a position suitable for observing the large flexible module and is used for measuring the position and gesture response of the large flexible module in the assembly process; the dismounting mechanical arm can move freely and is used for assembling and disassembling a plurality of large flexible modules; the number of the large flexible modules is N, wherein the value of N is equal to or greater than 2, the side parts of the large flexible modules are provided with quick-mounting connectors which are in butt joint with other large flexible modules, and the quick-mounting connectors can realize modularized assembly or disassembly among the large flexible modules; the dismounting mechanical arm assembles N large flexible modules through the quick-mounting connector; the non-contact motion capture system measures time domain response data of vibration generated by assembly and butt joint of the structure, and identifies modal parameters of the assembled structure by using a working modal analysis method; the uncertainty of the kinetic parameters brought about by the assembly process is quantified by the measured data.
2. The large flexible module assembly test device according to claim 1, wherein the free boundary suspension system comprises a support truss, a guide rail, a pulley assembly, a self-locking winder and a soft elastic rope; The guide rail is arranged on the support truss, and a proper installation mode is selected for the guide rail according to the assembly mode of the large flexible module; The pulley assembly is arranged on the guide rail and can slide freely along the guide rail, and a rod structure with the self-locking wire winder at two ends is hung below the pulley assembly through a steel wire rope; The soft elastic ropes are connected with the self-locking winder in series, and the large flexible module is suspended by using two soft elastic ropes through two sides of the top of the large flexible module; the self-locking winder mainly comprises a ratchet wheel and a steel wire rope; the wire rope is wound on the ratchet wheel and used for adjusting the length of the wire rope in the self-locking winder; One end of the steel wire rope is connected with the soft elastic rope in series by using a wire locking device.
3. The large flexible module assembly test device according to claim 2, wherein the static position posture of the free boundary suspension system is adjusted by adjusting the length of a steel wire rope in a self-locking winder through a rotating ratchet wheel, the dynamic free boundary of the free boundary suspension system is realized through a guide rail, a pulley assembly capable of freely sliding along the guide rail and a soft elastic rope with ultra-low rigidity in the vertical direction, the dynamic free boundary is that the modal frequency of rigid motion of the large flexible module caused by the soft elastic rope suspension is not more than 1/5 of the flexible vibration fundamental frequency of the large flexible module, and the non-contact motion capturing system measures the three-dimensional coordinates of a reflective marking point adhered on the large flexible module through an infrared lens.
4. A test method for quantifying uncertainty in a large flexible module assembly process using a large flexible module assembly test apparatus according to claim 3, comprising the steps of: S1, hanging the N large flexible modules on the free boundary hanging system through soft elastic ropes; s2, adjusting the N large flexible modules to a horizontal posture through the self-locking winder, and adjusting the N large flexible modules to the same vertical height; S3, assembling the N large flexible modules through the quick connector by utilizing the dismounting mechanical arm; s4, measuring time domain response data of vibration generated by assembling and butting of the structure by using the non-contact motion capture system, and identifying modal parameters of the assembled structure by using a working modal analysis method; s5, the dismounting mechanical arm is used for dismounting the assembled N large flexible modules through the quick connector; s6, repeating the steps S3 to S5 for M times, wherein the value of M is equal to or greater than 3; s7, quantifying uncertainty of dynamic parameters brought by the assembly process through measured data.
5. The method for quantifying the uncertainty of said assembly process of said flexible module according to claim 4, wherein said method is applicable to coplanar assembly, non-coplanar assembly; The types of rails in the free-boundary suspension system include at least cross rails when co-planar assembly is performed; the types of rails in the free-boundary suspension system include at least transverse rails and longitudinal rails when non-coplanar assembly is performed.
6. The method for testing the uncertainty of the assembly process of the large flexible module according to claim 4, wherein the specific steps of the step S2 are as follows: s2-1, rotating a ratchet wheel of the self-locking winder, adjusting the length of a steel wire rope, and adjusting N large flexible modules to a horizontal posture; s2-2, rotating a ratchet wheel of the self-locking winder, adjusting the length of the steel wire rope, and adjusting N large flexible modules to the same vertical height.
7. The method for testing the uncertainty of the assembly process of the large flexible module according to claim 4, wherein the specific steps of the step S3 are as follows: S3-1, capturing, namely moving the dismounting mechanical arm to a proper position before the large flexible module is assembled into the test device, utilizing the non-contact type motion capture system to carry out position measurement on two large flexible modules to be assembled to obtain the relative distance between the two large flexible modules to be assembled under a space rectangular coordinate system and the position coordinates of the grippers of the two large flexible modules under the working coordinate system of the dismounting mechanical arm; s3-2, sensing, namely measuring and calculating the position and the posture of two large flexible modules to be assembled relative to the dismounting mechanical arm under the working coordinate system of the dismounting mechanical arm, and acquiring the angle data of each joint of the dismounting mechanical arm; S3-3, planning tracks according to the data measured in the step S3-2 and expected tracks of two large flexible modules to be assembled in the assembling process, so as to obtain tracks required for disassembling and assembling all joints of the mechanical arm in the assembling process, wherein the expected tracks of the two large flexible modules to be assembled are required to be the minimum in the out-of-plane direction displacement in the assembling process, so that the stability of the assembling process is ensured; S3-4, performing assembly, namely inputting the track obtained by planning in the S3-3 into a disassembly and assembly mechanical arm, starting an assembly process under the condition that the posture of the whole system is stable and no obvious external disturbance exists, and gradually approaching two large flexible modules to be assembled until the two large flexible modules are butted; s3-5, repeating the steps S3-1 to S3-4 until the assembly of the N large flexible modules is completed.
8. The method for testing the uncertainty of the assembly process of the large flexible module according to claim 4, wherein the specific steps of the step S5 are as follows: S5-1, capturing, namely moving the dismounting mechanical arm to a proper position before assembling the large flexible modules into the test device, and utilizing a non-contact motion capture system to measure the positions of the grippers of the two large flexible modules to be dismounted to obtain the position coordinates of the grippers under the working coordinate system of the dismounting mechanical arm; s5-2, sensing, namely measuring and calculating the position and the posture of two large flexible modules to be disassembled relative to the disassembly and assembly mechanical arm under the working coordinate system of the disassembly and assembly mechanical arm, and acquiring the angle data of each joint of the disassembly and assembly mechanical arm; S5-3, detaching the two large flexible modules through a quick-fit joint between the two large flexible modules to be detached according to the data measured in the S5-2; S5-4, repeating the steps S5-1 to S5-3 until the disassembly of the N large flexible modules is completed.
9. The method for testing the uncertainty of the assembly process of the large flexible module according to claim 4, wherein the specific step of the step S7 is that uncertainty of the front n-order modal frequency and the modal damping ratio of the structure after the assembly of the large flexible module is calculated through repeating the measured data of M times, so that uncertainty of the front n-order modal frequency and the modal damping ratio brought by the assembly process is quantified, and the value of n is equal to or larger than 3.

Description

Test device and method for quantifying uncertainty in assembly process of large flexible module Technical Field The invention relates to the field of environmental simulation test technology and test method of aerospace assembly structures, in particular to a test device and method for quantifying uncertainty in an assembly process of a large flexible module. Background The large aerospace structure can be constructed through modularized design, multiple rocket launches and on-orbit assembly. But different from a general aerospace structure, the large-sized assembled aerospace structure has the characteristics of light weight and large size, so that the large-sized assembled aerospace structure has the characteristics of low frequency and dense frequency, and is easily influenced by gravity environment in the ground test process. In addition, the contact compression state of the joints between the modules is difficult to be guaranteed to be completely consistent in the assembly process, and the overall structure after assembly has certain uncertainty of dynamic parameters. These uncertainties present fundamental challenges to existing model-based kinetic test theory and methods. For ground simulation test devices for on-orbit assembly of large flexible aerospace modules, no description or report of similar technology is found at present. The test method for the uncertainty quantification of the dynamic parameters brought by the assembly process has not collected similar data at home and abroad. Disclosure of Invention The invention discloses a test device and a method for quantifying uncertainty in the assembly process of a large flexible module, and aims to solve the problems that a ground simulation test device for on-orbit assembly dynamics of a large flexible module for spaceflight is lack and a method for quantifying uncertainty in the dynamic parameter is lack in the background art. The test device comprises a large flexible module, a free boundary suspension system, a non-contact motion capture system and a dismounting mechanical arm. The large flexible module is a test object to be tested, has the characteristics of large geometric dimension and low natural frequency, and is provided with a quick-mounting connector which is in butt joint with other large flexible modules. The free boundary suspension system provides a boundary condition of free movement for the large flexible module and has the characteristics of adjustable static position and posture and dynamic free boundary. The non-contact motion capture system is used for measuring the position and gesture response of the large flexible module in the assembly process. The dismounting mechanical arm is used for assembling and disassembling a plurality of large flexible modules. The test method mainly uses the dismounting mechanical arm to assemble and disassemble the module for a plurality of times, adopts a working mode analysis method to analyze a plurality of groups of response data measured by the non-contact motion capture system during the period, and quantifies the uncertainty of dynamic parameters brought by the assembly process. The device provides a ground test scheme for researching the assembly and disassembly processes of the large flexible module in an in-orbit microgravity environment, and can repeat the assembly and disassembly processes for a plurality of times. The method can utilize the vibration response generated by the large flexible module in the assembly process to identify the dynamic characteristics of the structure, and further quantify the uncertainty of the dynamic parameters of the structure from the data of multiple assembly and disassembly tests. The invention provides theoretical and technical support for quantitatively characterizing the assembly dynamics of large flexible modules. In order to achieve the above purpose, the technical scheme of the invention is as follows: The invention provides a large flexible module assembly test device, which comprises a large flexible module (a first large flexible module, a second large flexible module, an N large flexible module), a free boundary suspension system, a non-contact motion capture system and a disassembly and assembly mechanical arm; The large flexible module is a test object to be tested and is hung on the free boundary suspension system, and has the characteristics of large geometric dimension and low natural frequency; the free boundary suspension system is fixed on the ground and is used for providing boundary conditions of free movement for the large flexible module, and has the characteristics of adjustable static position and posture and dynamic free boundary; The non-contact motion capture system is fixed at a position suitable for observing the large flexible module and is used for measuring the position and gesture response of the large flexible module in the assembly process; the dismounting mechanical arm can move freely and is used for assembling