An adaptive micro-motion adjusting positioner based on force and displacement control and an implementation method thereof

Abstract

The application discloses a self-adaptive micro-motion adjustment positioner based on force and displacement control and an implementation method thereof, belongs to the technical field of aircraft part assembly, and is designed to directly monitor assembly stress of a process hole in an aircraft part assembly process, compare assembly stress measurement values with threshold values, and perform self-adaptive micro-motion adjustment on the position of the positioner, so that the assembly stress is released within an allowed positioning error range. The main working principle is that contact stress between a threaded pin and a process hole is collected, the collected contact stress is compared with a threshold value, the first micro-motion precision motion control mechanism and / or the second micro-motion precision motion control mechanism are moved in a micro-motion direction opposite to the stress direction according to a comparison result, and the displacement of the motion is monitored, so that the assembly stress is released within the allowed positioning error range.

Description

Technical Field

[0001] This invention belongs to the field of aircraft component assembly technology, specifically relating to an adaptive micro-motion adjustment positioner based on force and displacement control and its implementation method. Background Technology

[0002] Currently, fixed positioners are used in aircraft component assembly, lacking assembly stress measurement devices. This results in the inability to measure the contact stress between the process holes and locating pins during assembly. While some positioners are equipped with force sensors, due to space limitations and the size of existing force sensors, they are typically mounted at the rear of the positioner. This creates excessive mechanical connections and clearances between the sensor and the force point, often leading to inaccurate measurements. When assembly procedures or processes change, or when subjected to external interference, the contact stress between the locating pin and the process hole may exceed the material's yield strength, causing plastic deformation and affecting assembly quality. In severe cases, this can even lead to potential risks. The fixed positioners currently used in assembly neither reflect nor release the assembly stress during the process. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides an adaptive micro-motion adjustment positioner based on force and displacement control. This positioner enables direct measurement and stress release of contact stress for the assembly positioning of aircraft parts, while controlling the positioning error to remain within the allowable range, thereby improving assembly quality. Furthermore, it facilitates the collection of key data during the assembly process, providing data support for improving the assembly process.

[0004] The objective of this invention is achieved through the following technical solution:

[0005] An adaptive micro-motion adjustment positioner based on force and displacement control includes a base platform, a column assembly mounted on the base platform, a slide rail arm mounting plate mounted on the column assembly, a slide rail arm mounted on the slide rail arm mounting plate, an adaptive micro-motion adjustment component mounted at the front end of the slide rail arm, a positioner assembly mounted on the micro-motion adjustment component, and a process frame simulation component mounted on the positioner assembly.

[0006] Preferably, the adaptive micro-motion adjustment component includes a first micro-motion precision motion control mechanism and a second micro-motion precision motion control mechanism. The movement direction of the first micro-motion precision motion control mechanism is parallel to the surface of the base platform, and the movement direction of the second micro-motion precision motion control mechanism is perpendicular to the surface of the base platform.

[0007] Preferably, the first micro-motion precision motion control mechanism includes a mounting plate, which is mounted on the front end of the slide rail arm. The mounting plate is equipped with a first shaft seat, a first grating reader mounting plate, and a first motor mounting plate. A first fine-tooth lead screw shaft is mounted on the first shaft seat. The first fine-tooth lead screw shaft drives a first lead screw nut to move linearly via a first servo motor. The first servo motor is mounted on the first motor mounting plate. The first lead screw nut is mounted on an intermediate mounting plate. A guide rail is provided between the lower side of the intermediate mounting plate and the mounting plate. A grating ruler is mounted on the intermediate mounting plate, and a grating reader is mounted on the first grating reader mounting plate.

[0008] Preferably, the output end of the first servo motor is connected to the first synchronous pulley via a first synchronous belt, and the first synchronous pulley is mounted on the first fine-tooth lead screw shaft.

[0009] The second micro-motion precision control mechanism includes a second servo motor and a second fine-tooth lead screw shaft. The second servo motor is mounted on the middle mounting plate. The output end of the second servo motor and the second fine-tooth lead screw shaft are both equipped with second synchronous pulleys. The two second synchronous pulleys are connected by a second synchronous belt. The second fine-tooth lead screw shaft is mounted on a second shaft seat.

[0010] Preferably, both the first servo motor and the second servo motor are servo motors with brakes.

[0011] Preferably, the positioner assembly includes a handle nut, a threaded pin, an optical fiber sensor, and a threaded pin sleeve. The threaded pin has four mounting slots circumferentially, which extend along the length direction. The optical fiber sensor is fixed in the mounting slot. The front end of the threaded pin is connected to the handle nut and together with the threaded pin, it positions the component process frame. The rear end of the threaded pin is connected to the threaded pin sleeve, which is used to connect the entire positioner assembly to the adaptive micro-motion adjustment assembly.

[0012] Preferably, the base platform has an array of equally spaced holes.

[0013] Preferably, the column assembly adopts a hollow design.

[0014] Preferably, the positioner assembly and the micro-adjustment assembly are connected by a flange.

[0015] Preferably, the threaded pin on the positioner assembly is installed with a clearance fit tolerance to the hole in the process frame to position the process frame.

[0016] An implementation method for an adaptive micro-motion adjustment positioner based on force and displacement control is disclosed. During product assembly, the first and second servo motors in the first and second micro-motion precision motion control mechanisms remain enabled and braked. Four fiber optic sensors collect the assembly stress of the threaded pins. The collected stress data is transmitted to the host computer, where the direction and magnitude of the force are calculated and compared with a set threshold. If the stress value exceeds the set value, the software sends a motion control command to the PLC. The PLC outputs several pulses according to the command, and the first and / or second micro-motion precision motion control mechanisms move in the opposite direction of the force by the displacement corresponding to the number of pulses. Simultaneously, a grating ruler and a grating reader are used to monitor the displacement in real time. Each movement displacement does not exceed 1 / 10 of the assembly tolerance. During the movement, the assembly stress is collected in real time. If the assembly stress decreases, the command continues to be issued to fine-tune in the same direction. If the stress value increases, the movement stops. The above motion control is repeated multiple times until the collected assembly stress is lower than the threshold, at which point the movement stops, the motor brakes, and the system self-locks.

[0017] The beneficial effects of this technical solution are as follows:

[0018] I. The present invention provides an adaptive micro-motion adjustment positioner based on force and displacement control, which can directly and accurately measure the assembly stress between the positioner and aircraft components, reflect the influence of the assembly process on the stress of product assembly, and at the same time, can make micro-motion adjustments to the assembly positioning position. After adjustment, the positioner can perform motion self-locking, reduce assembly stress and improve assembly quality within the range of fit tolerance.

[0019] II. The present invention provides an adaptive micro-motion adjustment positioner based on force and displacement control. A fiber optic sensor with a diameter of only 0.2 mm is directly placed at the force-bearing position of the threaded pin of the positioner to directly measure the assembly contact stress. At the same time, the original fixed positioner is redesigned into a mechanism capable of two-axis high-precision micro-motion (i.e., a first micro-motion precision motion control mechanism and a second micro-motion precision motion control mechanism). By measuring the force value, the first micro-motion precision motion control mechanism and / or the second micro-motion precision motion control mechanism are controlled to move within the allowable fit tolerance range, thereby releasing excessive assembly stress. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the installation of the adaptive locator and the column.

[0021] Figure 2 This is a schematic diagram of an adaptive adjustment micro-motion mechanism.

[0022] Figure 3 This is a schematic diagram of the fiber optic force positioner.

[0023] Figure 4 It is an adaptive micro-motion adjustment implementation process based on force and displacement control.

[0024] Figure 5 Schematic diagram of motion control connection.

[0025] In the diagram: 1. Base platform; 2. Column assembly; 3. Slide rail arm mounting plate; 4. Slide rail arm; 5. Micro-adjustment assembly; 6. Process frame simulation component; 7. Positioner assembly; 8. Mounting plate; 9. First shaft seat; 10. First synchronous belt pulley; 11. First fine-tooth lead screw shaft; 12. First synchronous belt; 13. First motor mounting plate; 14. First servo motor; 15. Second grating reader mounting plate; 16. Intermediate mounting plate; 17. Second servo motor; 18. Second synchronous belt; 19. Second synchronous belt pulley; 20. Second fine-tooth lead screw shaft; 21. Second shaft seat; 22. Positioner mounting plate; 23. Grating reader; 24. Grating ruler; 25. First grating reader mounting plate; 26. Guide rail; 27. Lead screw nut; 28. Handle nut; 29. ​​Threaded pin; 30. Fiber optic sensor; 31. Threaded pin sleeve. Detailed Implementation

[0026] The present invention will be further described in detail below with reference to embodiments, but the implementation of the present invention is not limited thereto.

[0027] Example 1

[0028] like Figure 1 As shown, an adaptive micro-motion adjustment positioner based on force and displacement control includes a base platform 1, a column assembly 2 mounted on the base platform 1, a slide rail arm mounting plate 3 mounted on the column assembly 2, a slide rail arm 4 mounted on the slide rail arm mounting plate 3, an adaptive micro-motion adjustment component 5 mounted at the front end of the slide rail arm 4, a positioner assembly 7 mounted on the micro-motion adjustment component 5, and a process frame simulation component 6 mounted on the positioner assembly 7.

[0029] Example 2

[0030] The difference between this embodiment and Embodiment 1 is that, as Figure 2 and Figure 3 As shown, the adaptive micro-motion adjustment component 5 includes a first micro-motion precision motion control mechanism and a second micro-motion precision motion control mechanism. The movement direction of the first micro-motion precision motion control mechanism is parallel to the surface of the base platform 1, and the movement direction of the second micro-motion precision motion control mechanism is perpendicular to the surface of the base platform 1. These two orthogonal micro-motion precision motion control mechanisms can both output micron-level step increments and achieve motion self-locking.

[0031] The first micro-motion precision motion control mechanism includes a mounting plate 8, which is installed at the front end of the slide rail arm 4. A first shaft seat 9, a first grating reader mounting plate 25, and a first motor mounting plate 13 are mounted on the mounting plate 8. A first fine-tooth lead screw shaft 11 is mounted on the first shaft seat 9. The first fine-tooth lead screw shaft 11 drives a first lead screw nut 27 to move linearly through a first servo motor 14. The first servo motor 14 is mounted on the first motor mounting plate 13. The first lead screw nut 27 is mounted on an intermediate mounting plate 16. A guide rail 26 is provided between the lower side of the intermediate mounting plate 16 and the mounting plate 8. A grating ruler 24 is provided on the intermediate mounting plate 16. A grating reader 23 is provided on the first grating reader mounting plate 25.

[0032] The output end of the first servo motor 14 is connected to the first synchronous pulley 10 via the first synchronous belt 12, and the first synchronous pulley 10 is mounted on the first fine-tooth lead screw shaft 11.

[0033] The second micro-motion precision control mechanism includes a second servo motor 17 and a second fine-tooth lead screw shaft 20. The second servo motor 17 is mounted on the intermediate mounting plate 16. The output end of the second servo motor 17 and the second fine-tooth lead screw shaft 20 are both provided with second synchronous pulleys 19. The two second synchronous pulleys 19 are connected by a second synchronous belt 18. The second fine-tooth lead screw shaft 20 is mounted on a second shaft seat 21.

[0034] The first servo motor 14 and the second servo motor 17 are both servo motors with brakes.

[0035] The positioner assembly 7 includes a handle nut 28, a threaded pin 29, an optical fiber sensor 30, and a threaded pin sleeve 31. The threaded pin 29 has four circumferentially oriented mounting slots that extend along its length. The optical fiber sensor 30 is fixed within one of these mounting slots. The front end of the threaded pin 29 connects to the handle nut 28, working together with the threaded pin 29 to position the component's process frame. The rear end of the threaded pin 29 connects to the threaded pin sleeve 31, which connects the entire positioner assembly 7 to the adaptive micro-motion adjustment assembly 5. The optical fiber sensor 30 uses bare optical fiber with an outer diameter of only 0.2 mm. The mounting slot size is 0.5 × 0.3 mm, and the slotted design has almost no impact on the bending strength of the threaded pin.

[0036] Four micro-grooves are made on the threaded pin 29, with the grooves passing through the locator along the length. The circumferential spacing of the grooves is 90 degrees. The size of the grooves is controlled within a range that does not significantly affect the bending strength of the pin. Four fiber optic sensors 30 are installed in the grooves. There is no mechanical connection between the fiber optic sensors 30 and the object being measured, and the contact stress at the assembly position is measured directly.

[0037] The base platform 1 has equidistant array holes.

[0038] The column assembly 2 is hollow.

[0039] The positioner assembly 7 and the micro-adjustment assembly 5 are connected by a flange.

[0040] The threaded pin 29 on the locator assembly 7 is installed with a clearance fit tolerance with the hole in the process frame to position the process frame.

[0041] like Figure 4 and Figure 5 As shown, an implementation method for an adaptive micro-motion adjustment positioner based on force and displacement control is described. During product assembly, the first servo motor 14 and the second servo motor 17 in the first and second micro-motion precision motion control mechanisms are kept enabled and braked. Four fiber optic sensors 30 collect the assembly stress of the threaded pin. After the collected stress data is transmitted to the host computer, the direction and magnitude of the force are calculated. The calculation result is compared with a set threshold. When the stress value exceeds the set value, the software sends a motion control command to the PLC. The PLC outputs a single command according to the command. A number of pulses drive the first micro-motion precision motion control mechanism and / or the second micro-motion precision motion control mechanism to move in the opposite direction of the force by the displacement corresponding to the number of pulses. At the same time, the displacement is monitored in real time using a grating ruler 24 and a grating reader 23. The displacement of each movement does not exceed 1 / 10 of the assembly tolerance. During the movement, the assembly stress is collected in real time. If the assembly stress decreases, the command is issued to continue fine-tuning in the same direction. If the stress value increases, the movement stops. The above motion control is repeated multiple times until the collected assembly stress is lower than the threshold, at which point the movement stops, the motor brakes, and the system self-locks.

[0042] After the fiber optic sensor 30 collects the assembly stress, it calculates the magnitude and direction of the collected value and compares it with a preset threshold. If the threshold is exceeded, the controller outputs a pulse to drive the first micro-motion precision motion control mechanism and the second micro-motion precision motion control mechanism to feed, so that the positioner moves in the opposite direction of the force. At the same time, the grating ruler 24 and the grating reader 23 (the grating ruler 24 and the grating reader 23 form a grating displacement sensor) collect the displacement feedback and control the displacement to not exceed the positioning error range.

[0043] The calculation of the direction and magnitude of the force is existing technology and will not be described in detail here; the software that issues motion control commands to the PLC is existing technology and will not be described in detail here.

[0044] The beneficial effects of this technical solution are as follows:

[0045] I. The present invention provides an adaptive micro-motion adjustment positioner based on force and displacement control, which can directly and accurately measure the assembly stress between the positioner and aircraft components, reflect the influence of the assembly process on the stress of product assembly, and at the same time, can make micro-motion adjustments to the assembly positioning position. After adjustment, the positioner can perform motion self-locking, reduce assembly stress and improve assembly quality within the range of fit tolerance.

[0046] II. The present invention provides an adaptive micro-motion adjustment positioner based on force and displacement control. A fiber optic sensor 30 with a diameter of only 0.2 mm is directly arranged at the force-bearing position of the threaded pin 29 of the positioner to directly measure the assembly contact stress. At the same time, the original fixed positioner is redesigned into a mechanism capable of two-axis high-precision micro-motion (i.e., a first micro-motion precision motion control mechanism and a second micro-motion precision motion control mechanism). By measuring the force value, the first micro-motion precision motion control mechanism and / or the second micro-motion precision motion control mechanism are controlled to move within the allowable fit tolerance range, releasing excessive assembly stress.

[0047] III. An implementation method for an adaptive micro-motion adjustment positioner based on force and displacement control, designed for use in the assembly process of aircraft parts, to directly monitor the assembly stress of process holes, and simultaneously compare the measured assembly stress value with a threshold to adaptively micro-adjust the position of the positioner, releasing the assembly stress within the allowable positioning error range. Its main working principle is to collect the contact stress between the threaded pin 29 and the process hole, compare the collected contact stress with a threshold, and based on the comparison result, a first micro-motion precision motion control mechanism and / or a second micro-motion precision motion control mechanism move slightly in the opposite direction of the applied force, monitoring the displacement and releasing the assembly stress within the allowable positioning error range.

[0048] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. An adaptive micro-motion adjustment positioner based on force and displacement control, characterized in that: Includes a base platform (1), on which a column assembly (2) is installed, on which a slide rail arm mounting plate (3) is installed, on which a slide rail arm (4) is provided, on which an adaptive micro-motion adjustment assembly (5) is installed at the front end of the slide rail arm (4), on which a positioner assembly (7) is installed, and on which a process frame simulation component (6) is installed; The adaptive micro-motion adjustment component (5) includes a first micro-motion precision motion control mechanism and a second micro-motion precision motion control mechanism. The movement direction of the first micro-motion precision motion control mechanism is parallel to the surface of the base platform (1), and the movement direction of the second micro-motion precision motion control mechanism is perpendicular to the surface of the base platform (1). The first micro-motion precision motion control mechanism includes a mounting plate (8), which is mounted on the front end of the slide rail arm (4). The mounting plate (8) is equipped with a first shaft seat (9), a first grating reader mounting plate (25), and a first motor mounting plate (13). The first shaft seat (9) is equipped with a first fine-tooth lead screw shaft (11). The first fine-tooth lead screw shaft (11) drives the first lead screw nut (27) to move linearly through a first servo motor (14). The first servo motor (14) is mounted on the first motor mounting plate (13). The first lead screw nut (27) is mounted on an intermediate mounting plate (16). A guide rail (26) is provided between the lower side of the intermediate mounting plate (16) and the mounting plate (8). A grating ruler (24) is provided on the intermediate mounting plate (16). A grating reader (23) is provided on the first grating reader mounting plate (25). The second micro-motion precision control mechanism includes a second servo motor (17) and a second fine-tooth lead screw shaft (20). The second servo motor (17) is mounted on the intermediate mounting plate (16). The output end of the second servo motor (17) and the second fine-tooth lead screw shaft (20) are both equipped with second synchronous pulleys (19). The two second synchronous pulleys (19) are connected by a second synchronous belt (18). The second fine-tooth lead screw shaft (20) is mounted on a second shaft seat (21). The positioner assembly (7) includes a handle nut (28), a threaded pin (29), an optical fiber sensor (30), and a threaded pin sleeve (31). The threaded pin (29) has four mounting slots circumferentially, which extend along the length direction. The optical fiber sensor (30) is fixed in the mounting slot. The front end of the threaded pin (29) is connected to the handle nut (28) and together with the threaded pin (29), it positions the component process frame. The rear end of the threaded pin (29) is connected to the threaded pin sleeve (31). The threaded pin sleeve (31) is used to connect the entire positioner assembly (7) to the adaptive micro-motion adjustment assembly (5).

2. The adaptive micro-motion adjustment positioner based on force and displacement control according to claim 1, characterized in that: The output end of the first servo motor (14) is connected to the first synchronous pulley (10) via the first synchronous belt (12), and the first synchronous pulley (10) is mounted on the first fine-tooth lead screw shaft (11).

3. The adaptive micro-motion adjustment positioner based on force and displacement control according to claim 2, characterized in that: Both the first servo motor (14) and the second servo motor (17) are servo motors with brakes.

4. The adaptive micro-motion adjustment positioner based on force and displacement control according to claim 3, characterized in that: The base platform (1) has equidistant array holes.

5. The adaptive micro-motion adjustment positioner based on force and displacement control according to claim 4, characterized in that: The column assembly (2) adopts a hollow design.

6. A method for implementing an adaptive micro-motion adjustment positioner based on force and displacement control according to any one of claims 1-5, characterized in that: During product assembly, the first servo motor (14) and the second servo motor (17) in the first and second micro-motion precision motion control mechanisms are kept enabled and braked. Four fiber optic sensors (30) collect the assembly stress of the threaded pin (29). After the collected stress data is transmitted to the host computer, the direction and magnitude of the force are calculated. The calculation result is compared with the set threshold. When the stress value exceeds the set value, the software sends a motion control command to the PLC. The PLC outputs several pulses according to the command. The first and / or second micro-motion precision motion control mechanisms move in the opposite direction of the force by the displacement corresponding to the number of pulses. At the same time, the grating ruler (24) and grating reader (23) are used to monitor the displacement in real time. Each movement displacement does not exceed 1 / 10 of the assembly tolerance. During the movement, the assembly stress is collected in real time. If the assembly stress decreases, the command is sent to fine-tune in the same direction. If the stress value increases, the movement stops. The above motion control is repeated multiple times until the collected assembly stress is lower than the threshold. Then the movement stops, the motor brakes, and the system self-locks.

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