A pose calibration device and method for an aircraft engine automatic assembly equipment

Abstract

The present application relates to the technical field of aircraft assembly, and discloses a pose calibration device and method for an automatic aircraft engine assembly device, which comprises a first measuring calibration target ball on a pose adjustment platform, a visual recognition target on an aircraft body and a second measuring calibration target ball on the target, and the two target balls are each provided with a target ball positioning mechanism. The positioning mechanism comprises a positioning base and a positioning cover, the positioning cover is provided with a rotatable positioning block inside, the top of the positioning block is provided with a movable cover, an inner positioning frame and elastic sheets for clamping the target ball are arranged in the inner cavity, the center of the positioning base is provided with a positioning rod, and the spherical concave surface at the top of the positioning rod is concentric with the target ball; the positioning block is provided with a slidable sliding block outside, and a clamping mechanism on the sliding block penetrates through the sliding block, the positioning block and the inner positioning frame to clamp the target ball and adjust the angle and pose of the target ball. The present application improves the accuracy and reliability of calibration by combining SVD decomposition with the positions of the target ball on the target and the target ball on the pose adjustment platform for discrete point registration.

Description

Technical Field

[0001] This invention relates to the field of aircraft assembly posture calibration technology, and more specifically to a posture calibration device and method for automatic assembly equipment of aircraft engines. Background Technology

[0002] In the automated assembly of large aircraft power components, a vision-guided attitude adjustment platform is usually required to precisely adjust the attitude of the large aircraft power components. Therefore, the relative attitude of the vision system and the attitude adjustment platform needs to be given in the attitude calculation process.

[0003] Currently, there are two traditional solutions: one is to design a digital model to provide the theoretical pose, which has large and uncontrollable errors; the other is to use a "hand-eye calibration" method, where the "eye" is on the "hand," suitable for situations where the attitude adjustment platform has a wide six-degree-of-freedom range of motion. However, because there is limited space for parking the assembly platform during the assembly of large aircraft power components, the platform needs to be made relatively small. This results in a smaller six-degree-of-freedom range of motion for the assembly platform. In this case, using the "hand-eye calibration" method will lead to significant calibration errors and substantial deviations in automatic guidance. Summary of the Invention

[0004] To address the problems and shortcomings of existing technologies, this invention proposes a position calibration device and method for automatic assembly equipment of aircraft engines. By visually identifying the position of the target ball on the target and the target ball on the attitude adjustment platform, and combining SVD decomposition for discrete point registration, the accuracy and reliability of calibration are improved.

[0005] To achieve the above-mentioned objectives, the technical solution of the present invention is as follows:

[0006] This invention discloses an attitude calibration device for an automated assembly equipment for an aircraft engine. The attitude calibration device includes a first measurement calibration target ball mounted on an attitude adjustment platform, a visual recognition target fixed to the aircraft fuselage, and a second measurement calibration target ball mounted on the visual recognition target. Both the first and second measurement calibration target balls are externally provided with target ball positioning mechanisms for supporting and fixing the target balls.

[0007] The target ball positioning mechanism includes a positioning base, a positioning cover with openings at both the top and bottom, a rotatable positioning block inside the positioning cover, a movable cover fixedly connected to the top of the positioning block, an inner positioning frame fixedly connected inside the positioning block, and multiple elastic plates for clamping the target ball fixedly connected axially inside the inner positioning frame. The bottom of the positioning block is rotatably connected to the top of the positioning base, and a positioning rod is movably connected to the axis of the positioning base. The top of the positioning rod is a spherical concave arc surface. When the target ball is attached to the top of the positioning rod, the spherical concave arc surface at the top of the positioning rod is concentric with the target ball. The bottom of the positioning rod penetrates the positioning base and is a convex arc surface.

[0008] The outer surface of the positioning block is symmetrically connected with sliding blocks that can slide up and down along the surface of the positioning block. The sliding block is also provided with a clamping mechanism. One end of the clamping mechanism passes through the sliding block, the positioning block and the inner positioning frame, and extends into the cavity of the inner positioning frame to clamp the target ball. Under the action of the sliding block sliding up and down, it cooperates to adjust the angle and posture of the target ball.

[0009] Preferably, the outer surface of the sliding block is provided with a driving tooth block, which is meshed with a driving gear. The driving gear is mounted on a flexible shaft, which is fixed on the convex lug of the movable cover and extends circumferentially along the positioning block. Both ends of the flexible shaft are fixedly connected with driven gears, and both driven gears are meshed with main gears. One main gear is sleeved on the driving rod, and the top of the driving rod is fixedly connected with an adjusting block, which is rotatably connected to the movable cover. The other main gear is sleeved on the output shaft of the deflection motor.

[0010] Preferably, the surface of the elastic sheet is provided with a connecting film for adhering to the surface of the target ball.

[0011] Preferably, the gap between the elastic sheet and the inner positioning frame is filled with a support airbag, which has an inflation component.

[0012] Preferably, the positioning block is externally fixedly connected to an external gear ring, which is meshed with an adjusting gear, which is sleeved on the output shaft of the rotary motor.

[0013] Preferably, the positioning block is externally fixedly connected to an external gear ring, which is meshed with an adjusting gear, which is sleeved on the output shaft of the rotary motor.

[0014] Preferably, the clamping mechanism includes a positioning air rod fixedly connected to the sliding block. An adsorption head is movably connected inside the positioning air rod. A pressure spring is provided between the adsorption head and the positioning air rod. The positioning air rod has an installation cavity, a narrow oral cavity, a connecting cavity, and an air inlet cavity inside. A connecting pipe is provided outside the air inlet cavity. An air pump is provided outside the connecting pipe. The pressure spring is located inside the installation cavity. A connecting air hole is provided between the installation cavity and the connecting cavity. An air valve block is provided outside the installation cavity. The installation cavity is connected to the outside through the air valve block.

[0015] Preferably, a measuring rod is fixedly connected to the outside of the adsorption head, and the measuring rod is slidably connected inside the narrow oral cavity. The adsorption head connects the connecting cavity and the air inlet cavity through the measuring rod. Annular magnetic strips are uniformly arranged on the outside of the measuring rod, and a probe is arranged on the outside of the narrow oral cavity. The probe is used to measure the sliding distance of the measuring rod inside the narrow oral cavity.

[0016] Preferably, the upper surface of the positioning base is provided with an arc groove, and the positioning rod is installed at the center of the arc groove.

[0017] Based on the same inventive concept, another aspect of the present invention discloses a pose calibration method for an automatic assembly equipment for an aircraft engine. The pose calibration method is based on the pose of the aforementioned automatic assembly equipment for an aircraft engine and includes the following steps:

[0018] S1. Use a laser tracker to measure the position of the second measurement calibration target ball on the visual recognition target in the laser tracker coordinate system;

[0019] S2. Based on the position of the target ball in the laser tracker coordinate system according to the second measurement calibration, discrete point registration is performed through SVD decomposition, and the pose relationship between the visual recognition target coordinate system and the laser tracker coordinate system is calculated.

[0020] S3. Use a laser tracker to measure the position of the first measurement calibration target ball on the attitude adjustment platform in the laser tracker coordinate system;

[0021] S4. Based on the position of the target ball in the coordinate system of the laser tracker according to the first measurement calibration, discrete point registration is performed by SVD decomposition, and the pose relationship between the attitude adjustment platform and the coordinate system of the laser tracker is calculated.

[0022] S5. Use a vision system recognition algorithm to determine the positional relationship between the visual recognition target and the vision system on the posture adjustment platform;

[0023] S6. Based on the positional relationship between the visual recognition target and the attitude adjustment platform, the pose relationship between the visual system and the attitude adjustment platform is calculated through the transfer relationship, thereby realizing the measurement and calibration of the visual system.

[0024] Preferably, in step S6, the method for calculating the pose relationship between the vision system and the pose adjustment platform through the transfer relationship is as follows:

[0025] ;

[0026] in, The pose relationship between the vision system and the pose adjustment platform. To visually identify the pose relationship between the target coordinate system and the laser tracker coordinate system. This represents the pose relationship between the attitude adjustment platform and the laser tracker coordinate system.

[0027] The beneficial effects of this invention are:

[0028] 1. The pose calibration of this invention does not require the pose adjustment platform to move during the calibration process. It only requires target measurement through a laser tracker and a vision system, which greatly reduces the error introduced during the calibration process. It is especially suitable for situations where the pose adjustment platform has a small six-degree-of-freedom motion range. By measuring the position of the target ball on the visual recognition target and the target ball on the pose adjustment platform through the laser tracker, and performing discrete point registration by combining SVD decomposition, the pose relationship between the visual recognition coordinate system and the laser tracker coordinate system, as well as the pose relationship between the pose adjustment platform and the laser tracker coordinate system, can be accurately calculated. Furthermore, the pose relationship between the visual recognition target and the visual system is obtained by recognizing and calculating through the vision system, thereby accurately calculating the pose relationship between the vision system and the pose adjustment platform, improving the accuracy and reliability of the calibration.

[0029] 2. The pose calibration device of the present invention, through the use of the measuring rod and the probe, causes a deviation in the offset distance of the two adsorption heads, resulting in a deviation in the offset distance of the measuring rod in the narrow oral cavity. The probe detects the deviation in the distance of the measuring rod, thus facilitating the adjustment of the air pressure inside the mounting cavity. When the air pressure inside one mounting cavity increases and the air pressure inside the other mounting cavity decreases, the adsorption head shifts to the positioning rod on the lower pressure side under the action of the pressure spring, thereby achieving the effect of fine-tuning the target ball and ensuring the accuracy of the target ball positioning.

[0030] 3. The target ball positioning mechanism of the present invention forms a triple positioning system through concentric support of the positioning rod, flexible wrapping of the elastic sheet, and auxiliary fixation of the support airbag. The spherical arc surface at the bottom of the positioning rod is concentric with the target ball, ensuring the accuracy of the initial positioning reference of the target ball; the elastic sheet is attached to the surface of the target ball through the connecting film to avoid damage to the target ball by rigid clamping; after the support airbag is inflated, it can adaptively fill the gap between the target ball and the elastic sheet, further enhancing the fixation stability of the target ball.

[0031] 4. The target ball positioning mechanism of the present invention supports both manual and automatic bidirectional adjustment. Manual adjustment is achieved by rotating the adjustment block to drive the sliding block and the clamping mechanism to slide, thereby achieving fine adjustment of the target ball's attitude. Automatic adjustment is achieved by deflection motor driving gear transmission, and the adjustment trajectory is concentric with the center of the target ball to ensure adjustment accuracy. At the same time, the target ball offset is monitored in real time by the measuring rod (with annular magnetic strip) and the probe head. When the target ball is tilted, the air pressure difference in the positioning air rod can be adjusted to drive the adsorption head to fine adjust the target ball's attitude, ensuring that the target ball is always at the optimal measurement angle of the laser tracker and avoiding measurement errors caused by target ball attitude deviation.

[0032] 5. The positioning rod of the present invention has a raised arc-shaped surface, which can ensure that the surface of the test piece and the target ball base are in point contact, avoiding false contact when the test surface with large curvature is in contact during measurement.

[0033] 6. In this invention, the gap between the elastic sheet and the inner positioning frame is filled with annular arc-shaped air bladders. The air bladders serve to assist in supporting the target ball at the center position and also prevent the elastic sheet from being squeezed and deformed. Attached Figure Description

[0034] The foregoing and hereinafter detailed description of the invention becomes clearer when read in conjunction with the following drawings, in which:

[0035] Figure 1 This is a schematic diagram of the posture adjustment platform of the present invention;

[0036] Figure 2 This is a schematic diagram of the visual recognition target of the present invention;

[0037] Figure 3 This is a schematic diagram of the target ball and target ball positioning mechanism of the present invention;

[0038] Figure 4 This is a first-view schematic diagram of the target ball positioning mechanism of the present invention;

[0039] Figure 5 This is a schematic diagram of the target ball positioning mechanism of the present invention from a second perspective.

[0040] Figure 6 This is a schematic diagram of the first cross-sectional view of the target ball positioning mechanism of the present invention;

[0041] Figure 7 This is a schematic diagram of the second cross-sectional view of the target ball positioning mechanism of the present invention;

[0042] Figure 8 This is a schematic diagram of the discrete states of the target ball positioning mechanism of the present invention;

[0043] Figure 9 This is a schematic diagram showing the connection between the positioning block, movable cover, and inner positioning frame of the present invention;

[0044] Figure 10 This is a schematic diagram showing the connection between the sliding block and the clamping mechanism of the present invention;

[0045] Figure 11 This is a schematic diagram of the clamping mechanism of the present invention.

[0046] In the picture:

[0047] 1. First measurement and calibration target ball; 2. Attitude adjustment platform remote controller; 3. Visual recognition target; 4. Second measurement and calibration target ball; 5. Attitude adjustment platform local control unit; 6. Positioning base; 7. Positioning cover; 71. Positioning block; 72. Movable cover; 73. Adjusting block; 74. Inner positioning frame; 75. Elastic sheet; 76. Connecting membrane; 77. Support airbag; 8. Positioning rod; 9. Clamping mechanism; 91. Positioning air rod; 92. Adsorption head; 93. Pressure spring; 94. Measuring rod; 95. Probe head; 96. Air valve block; 97. Connecting pipe; 98. Air pump; 10. Sliding block; 11. Drive gear block; 12. Drive gear; 13. Flexible shaft; 14. Driven gear; 15. Main gear; 16. Drive rod; 161. Deflection motor; 17. External gear ring; 18. Adjusting gear; 100. Attitude adjustment platform; 200. Vision system; 300. Bracket. Detailed Implementation

[0048] To enable those skilled in the art to better understand the technical solutions of this invention, specific embodiments will be used to further illustrate the technical solutions for achieving the objectives of this invention. It should be noted that the technical solutions claimed by this invention include, but are not limited to, the following embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort should fall within the scope of protection of this invention.

[0049] This invention first discloses a position calibration device for an automated assembly equipment for aircraft engines. The position calibration device is mainly used for position calibration of automated assembly equipment for large power components such as aircraft engines. The automated assembly equipment includes an attitude adjustment platform 100, which lifts the product to be installed and drives the product to perform attitude adjustment movements. Figure 1 and 2 As shown, the attitude calibration device includes a first measurement calibration target ball 1 mounted on the attitude adjustment platform 100, a visual recognition target 3 fixed on the aircraft fuselage, and a second measurement calibration target ball 4 mounted on the visual recognition target 3; both the first measurement calibration target ball 1 and the second measurement calibration target ball 4 are provided with target ball positioning mechanisms for supporting and fixing the target balls; the first measurement calibration target ball 1 is provided on both sides of the front end of the attitude adjustment platform 100 and on the bracket 300 of the attitude adjustment platform 100, and two second measurement calibration target balls 4 are provided on both sides of the front end of the visual recognition target 3; wherein,

[0050] The posture adjustment platform has a posture adjustment platform local control unit 5 that controls the movement of the posture adjustment platform 100 and a posture adjustment platform remote controller 2 that is communicatively connected to the posture adjustment platform local control unit 5 to realize remote control of the movement of the posture adjustment platform 100.

[0051] The visual recognition target 3 is the calibration plate used for pose calibration, which is installed and fixed on the aircraft fuselage. It interacts with... Figure 1 The vision system 200 on the attitude adjustment platform works in conjunction with the aircraft to establish a detection coordinate system, which is used to determine the positional relationship between the attitude adjustment platform 100 of the assembly equipment and the aircraft. The vision system 200 is generally a binocular vision camera.

[0052] like Figures 3-10 As shown, the target ball positioning mechanism includes a positioning base 6 and a positioning cover 7. The positioning base 6 has a base plate. During installation, the entire target ball positioning mechanism is fixedly connected to the attitude adjustment platform 100 or the visual recognition target 3 through the base plate of the positioning base 6. The positioning base 6 is a cylinder with external threads on its outer circumferential surface. The inner wall of the positioning cover 7 has internal threads. The positioning cover 7 is fitted onto the positioning base 6 and threadedly connected to the positioning base 6. The positioning cover 7 is a cylindrical body with open top and bottom ends.

[0053] The positioning cover 7 has a rotatable positioning block 71 in its internal cavity. The top of the positioning block 71 is fixedly connected to a movable cover 72. The bottom of the positioning block 71 is rotatably connected to the upper surface of the positioning base 6. The positioning block 71 can rotate horizontally around the center of the positioning base 6 in the internal cavity of the positioning cover 7 relative to the positioning base 6.

[0054] An inner positioning frame 74 is fixedly connected inside the positioning block 71. The cavity formed by the inner positioning frame 74 is used to accommodate the target ball. An elastic sheet 75 for clamping the target ball is fixedly connected inside the inner positioning frame 74. The surface of the elastic sheet 75 is usually covered with a connecting film 76. The connecting film 76 is attached to the outside of the target ball. The connecting film 76 is a protective film that isolates the elastic sheet 75 and the target ball, thus protecting the target ball.

[0055] The positioning base 6 is movably connected to a positioning rod 8 for supporting a target ball. The top of the positioning rod 8 is designed as a spherical concave arc surface that fits the outer surface of the target ball. When the target ball is fitted and supported on the top of the positioning rod 8, the concave arc surface at the top of the positioning rod 8 is concentric with the target ball. The bottom of the positioning rod 8 penetrates the positioning base 6 and the base plate of the positioning base 6, and the bottom of the positioning rod 8 is set as a convex arc surface (that is, the positioning base 6 and the base plate are provided with openings for the bottom of the positioning rod 8 to pass through).

[0056] The outer surface of the positioning block 71 is symmetrically connected to a sliding block 10, which can slide up and down along the arc-shaped surface of the positioning block 71. A clamping mechanism 9 is provided on the sliding block 10. One end of the clamping mechanism 9 passes through the sliding block 10, the positioning block 71, the inner positioning frame 74, and through the gap between two adjacent elastic plates 75, extending into the spherical space formed by the elastic plates 75 to clamp the target ball. Under the up-and-down sliding action of the sliding block 10, it cooperates to adjust the angle and posture of the target ball within the cavity. Specifically, during the up-and-down sliding process of the sliding block 10, it drives the clamping mechanism 9 connected to it to move together, pushing the target ball to rotate within the cavity. During rotation, under the clamping action of the elastic plates 75 and the support of the positioning rod 8, the target ball will not shift or deviate, but will rotate around its own center point to adjust, ensuring the accuracy of the center point position, thereby achieving the effect of adjusting the angle and posture of the target ball. Furthermore, since the clamping mechanism 9 moves up and down along with the sliding block 10, both the positioning block 71 and the inner positioning frame 74 are provided with waist-shaped holes for the clamping mechanism 9 to move up and down.

[0057] In the embodiment described in this invention, for the installation of the elastic sheet 75, the upper end is fixedly welded to the inner wall of the inner positioning frame 74, and the lower end is a movable end that curves upward toward the inner positioning frame 74 to form a hook. The elastic sheet 75 is strip-shaped and evenly arranged along the circumference of the inner positioning frame 74. A plurality of elastic sheets 75 evenly arranged along the circumference together form a spherical space that fits the outer spherical surface of the target ball. The target ball is located in the spherical space and is clamped and fixed by the elastic sheet 75.

[0058] Furthermore, a support airbag 77 is provided in the gap between the elastic sheet 75 and the inner positioning frame 74, and an inflation component is provided on the outside of the support airbag 77. The support airbag 77 is an annular arc-shaped airbag, a non-solid structure, used to fill the gap space between the elastic sheet 75 and the inner positioning frame 74, not only serving to assist in supporting the target ball at the center position, but also preventing the elastic sheet 75 from being squeezed and deformed. The airbag and the hook formed by the upturned tail end of the elastic sheet 75 are in movable contact with the elastic sheet 75, and the whole is installed on the elastic sheet 75 in a free state.

[0059] During installation, the spherical convex arc surface at the bottom of the positioning rod 8 abuts against the test piece or test point, and the spherical concave arc surface at the top of the positioning rod 8 is concentric with the target ball, thereby ensuring the accuracy of the target ball positioning.

[0060] During installation, the target ball is snapped between multiple elastic plates 75 and comes into contact with the connecting film 76 on the surface of the elastic plates 75. Then, the positioning cover 7 is threaded onto the outside of the positioning base 6, thus completing the support and installation of the target ball. The target ball is fixed to the outside by the elastic plates 75 and the supporting airbag 77, thereby avoiding damage to the target ball and ensuring safety during the fixation process.

[0061] Finally, the target ball is fixed by the threaded connection of the positioning cover 7, which ensures that the overall process of fixing the target ball is simple, easy to operate, and facilitates the efficiency of target ball maintenance or replacement. The positioning rod 8 supports the positioning target ball, effectively ensuring the accuracy of target ball positioning.

[0062] In the embodiment described in this invention, the position of the positioning base 6 on the attitude adjustment platform 100 and the visual recognition target 3 is determined during manufacturing. Furthermore, the upper surface of the positioning base 6 is provided with an arc groove, and the positioning rod 8 is installed at the center of the arc groove.

[0063] like Figures 4-6 As shown, an external gear ring 17 is fixedly connected to the outside of the positioning block 71. The external gear ring 17 is meshed with an adjusting gear 18, which is sleeved on the output shaft of the rotary motor. The rotary motor is installed inside the positioning base 6. Driven by the adjusting gear 18, the external gear ring 17 drives the positioning block 71 to rotate horizontally as a whole. The target ball clamped and fixed inside the positioning block 71 will also rotate accordingly, thereby achieving the effect of adjusting the target ball.

[0064] In the embodiment described in this invention, the sliding block 10 adjusts the angle and posture of the target ball installed in the positioning block 71 through the clamping mechanism 9. Therefore, through the cooperation of the sliding blocks 10 on both sides and the clamping mechanism 9, the stability and accuracy of fixing the target ball can be further ensured, thereby ensuring the accuracy of posture adjustment during assembly. Figures 5-9 As shown, the outer surface of the sliding block 10 is provided with a driving tooth block 11, which is meshed with a driving gear 12. The driving gear 12 is fixedly mounted on a flexible shaft 13, which is fixed on the convex lug of the movable cover 72 and extends circumferentially along the positioning block 71. Both ends of the flexible shaft 13 are fixedly connected with driven gears 14, and both ends of the driven gears 14 are meshed with corresponding main gears 15. One of the main gears 15 is sleeved on the driving rod 16, and the top of the driving rod 16 is fixedly connected with an adjusting block 73, which is rotatably connected to the movable cover 72. The other main gear 15 is sleeved on the output shaft of the deflection motor 161, which is fixedly mounted on the movable cover 73.

[0065] During the adjustment process, the main gear 15 drives the driven gear 14 to rotate, and the driven gear 14 drives the drive gear 12 to rotate through the flexible shaft 13. The drive gear 12 drives the sliding block 10 to slide up and down on the outer circumferential surface of the positioning block 71 through the drive tooth block 11. The sliding block 10 drives the clamping mechanism 9 connected to it to move up and down together. Finally, the clamping mechanism 9 drives the target ball to deflect (the target ball rotates around its own center to adjust), thereby achieving the effect of adjusting the angle and attitude of the target ball. This effectively facilitates the target ball to receive and reflect the measurement laser emitted by the laser tracker, improves the position accuracy of the attitude adjustment platform 100, and ensures the attitude adjustment accuracy.

[0066] During the adjustment process, the main gear 15 is rotated, which drives the sliding block 10 to slide up and down. The sliding trajectory of the sliding block 10 is concentric with the target ball, thus effectively ensuring the accuracy of the target ball deflection adjustment and the convenience of the target ball adjustment.

[0067] Furthermore, the present invention provides both manual and automatic adjustment for the deflection of the target ball; wherein,

[0068] Manual adjustment is achieved by driving the adjustment block 73 to rotate, which in turn drives the main gear 15 to rotate via the drive rod 16.

[0069] Automatic adjustment: During the adjustment process, the deflection motor 161 is driven to rotate, and the deflection motor 161 drives the main gear 15 to rotate, thereby completing the automatic adjustment.

[0070] like Figure 11 As shown, the clamping mechanism includes a positioning air rod 91 fixedly connected to the sliding block 10. An adsorption head 92 is movably connected inside the positioning air rod 91. A pressure spring 93 is provided between the adsorption head 92 and the positioning air rod 91. The positioning air rod 91 has an installation cavity, a narrow oral cavity, a connecting cavity, and an air inlet cavity inside. A connecting pipe 97 is provided outside the air inlet cavity. An air pump 98 is provided outside the connecting pipe 97. The pressure spring 93 is located inside the installation cavity. A connecting air hole is provided between the installation cavity and the connecting cavity. An air valve block 96 is provided outside the installation cavity. The installation cavity is connected to the outside through the air valve block 96.

[0071] In this invention, the air valve block 96 is similar to a pressure valve. The pressure spring 93 holds the ball in place. When the internal negative pressure exceeds the threshold, the ball is attracted and opens downward, allowing external gas to enter the inner cavity. When the positive pressure inside the cavity exceeds or equals the external air pressure, the pressure spring 93 pushes the ball up with its elastic force, sealing the air outlet and ultimately achieving internal and external pressure balance.

[0072] During the fixation process, the adsorption head 92 is attached to the surface of the target ball, and the air pump 98 generates negative pressure inside the positioning air rod 91 through the connecting pipe 97. The positioning air rod 91 generates negative pressure adsorption force at the end of the adsorption head 92 through the measuring rod 94.

[0073] By using the adsorption head 92 to adsorb and fix the target ball, the stability of the adsorption and fixation of the target ball can be guaranteed, while avoiding damage to the target ball caused by pressure clamping, thus ensuring the fixation effect of the target ball.

[0074] The adsorption head 92 is fixedly connected to a measuring rod 94, which is slidably connected inside the narrow oral cavity. The adsorption head 92 connects the connecting cavity and the air inlet cavity through the measuring rod 94. Annular magnetic strips are evenly arranged on the outside of the measuring rod 94. A probe head 95 is arranged on the outside of the narrow oral cavity. The probe head 95 is used to measure the sliding distance of the measuring rod 94 inside the narrow oral cavity.

[0075] It should be noted that when the adsorption head 92 adsorbs the target ball, the connecting cavity simultaneously generates negative pressure inside the mounting cavity through the connecting air hole. The pressure values ​​inside the mounting cavity and the adsorption head are the same. When the negative pressure inside the mounting cavity reaches the set threshold of the air valve block 96, the air valve block 96 opens, thereby effectively ensuring the stability of the adsorption force of the adsorption head 92 on the target ball. At the same time, the negative pressure inside the mounting cavity generates a pulling force on the adsorption head 92, thereby generating a pulling force on the target ball by the adsorption head 92. The pulling forces of the adsorption heads 92 on both sides of the target ball are balanced, thereby further ensuring the accuracy of the target ball's position.

[0076] Furthermore, when the target ball tilts, the offset distance of the two adsorption heads 92 deviates, causing the offset distance of the measuring rod 94 in the narrow oral cavity to deviate. The probe head 95 detects the deviation in the distance of the measuring rod 94, thus facilitating the adjustment of the air pressure inside the mounting cavity. When the air pressure inside one mounting cavity increases and the air pressure inside the other mounting cavity decreases, the adsorption head 92, under the action of the pressure spring 93, shifts to the positioning rod 91 on the lower pressure side, thereby achieving the effect of fine-tuning the target ball and ensuring the accuracy of the target ball positioning.

[0077] Based on the same inventive concept, this invention also discloses a pose calibration method for an automated aircraft engine assembly equipment. The pose calibration method is implemented using the aforementioned pose calibration device for the automated aircraft engine assembly equipment, as detailed below:

[0078] (1) Before starting the measurement, the direction of each target ball is adjusted by the clamping mechanism 9 and the positioning block 71 to ensure that the second measurement calibration target ball 4 on the visual recognition target 3 and the first measurement calibration target ball 1 on the attitude adjustment platform 100 are simultaneously aligned with the laser tracker (that is, to ensure that the laser tracker can simultaneously measure the first measurement calibration target ball 1 and the second measurement calibration target ball 4). Then, the laser tracker is used to measure the position of the second measurement calibration target ball 4 on the visual recognition target 3 in the coordinate system of the laser tracker (that is, the coordinate values ​​in the X, Y and Z directions), and the position of the first measurement calibration target ball 1 on the attitude adjustment platform 100 in the coordinate system of the laser tracker.

[0079] (2) Based on the position of the second measurement calibration target ball 4 in the laser tracker coordinate system, discrete point registration is performed by SVD decomposition, and the pose relationship between the visual recognition target coordinate system and the laser tracker coordinate system is calculated.

[0080] (3) Based on the position of the first measurement calibration target ball 1 in the coordinate system of the laser tracker, discrete point registration is performed by SVD decomposition, and the pose relationship between the attitude adjustment platform 100 and the coordinate system of the laser tracker is calculated.

[0081] (4) Use a vision system recognition algorithm to determine the positional relationship between the visual recognition target 3 and the vision system 200 on the posture adjustment platform 100;

[0082] (5) Based on the positional relationship between the visual recognition target 3 and the pose adjustment platform 100, the pose relationship between the visual system 200 and the pose adjustment platform 100 is calculated through the transfer relationship, thereby realizing the measurement calibration of the visual system 200; wherein, the method of calculating the pose relationship between the visual system and the pose adjustment platform through the transfer relationship is as follows:

[0083] ;

[0084] In the above formula, The pose relationship between the vision system and the pose adjustment platform. To visually identify the pose relationship between the target coordinate system and the laser tracker coordinate system. This represents the pose relationship between the attitude adjustment platform and the laser tracker coordinate system.

[0085] In this invention, the SVD decomposition is used to minimize the error between the measured point and the theoretical point.

[0086] In this invention, the visual system recognition algorithm mainly includes steps such as image acquisition, image processing (noise reduction, grayscale conversion, geometric transformation, etc.), feature extraction, segmentation and detection, which are existing technologies and will not be described in detail here.

[0087] The calibration method of this invention eliminates the need for attitude adjustment platform movement during calibration. Target measurement is performed solely through a laser tracker and vision system 200, significantly reducing errors introduced during calibration. This method is particularly suitable for situations where the attitude adjustment platform has a small six-degree-of-freedom range of motion. By measuring the positions of the target ball on the visual recognition target 3 and the target ball on the attitude adjustment platform 100 using the laser tracker, and combining this with SVD decomposition for discrete point registration, the pose relationship between the visual recognition target coordinate system and the laser tracker coordinate system, as well as the pose relationship between the attitude adjustment platform 100 and the laser tracker coordinate system, can be accurately calculated. Furthermore, the pose relationship between the visual recognition target and the vision system 200 is determined through vision system recognition and calculation, thereby accurately calculating the pose relationship between the vision system 200 and the attitude adjustment platform 100.

[0088] 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. A position calibration device for an automated aircraft engine assembly system, characterized in that, The pose calibration device includes a first measurement calibration target ball (1) set on the attitude adjustment platform (100), a visual recognition target (3) fixed on the aircraft body, and a second measurement calibration target ball (4) installed on the visual recognition target (3); both the first measurement calibration target ball (1) and the second measurement calibration target ball (4) are provided with target ball positioning mechanisms for supporting and fixing the target ball; wherein, The target ball positioning mechanism includes a positioning base (6), a positioning cover (7) with openings at both the top and bottom of the positioning base (6), a rotatable positioning block (71) inside the positioning cover (7), a movable cover (72) fixedly connected to the top of the positioning block (71), an inner positioning frame (74) fixedly connected inside the positioning block (71), and multiple elastic plates (75) for clamping the target ball fixedly connected axially inside the inner positioning frame (74). The bottom of the positioning block (71) is rotatably connected to the top of the positioning base (6), and a positioning rod (8) is movably connected to the axis of the positioning base (6). The top of the positioning rod (8) is set as a spherical concave arc surface. When the target ball is attached to the top of the positioning rod (8), the spherical concave arc surface at the top of the positioning rod (8) is concentric with the target ball. The bottom of the positioning rod (8) penetrates the positioning base (6) and is set as a convex arc surface. The outer surface of the positioning block (71) is symmetrically connected with a sliding block (10) that can slide up and down along the surface of the positioning block (71). The sliding block (10) is also provided with a clamping mechanism (9). One end of the clamping mechanism (9) passes through the sliding block (10), the positioning block (71), the inner positioning frame (74), and through the gap between two adjacent elastic plates (75). It extends into the spherical space formed by the elastic plates (75) to clamp the target ball. Under the sliding action of the sliding block (10), it adjusts the angle and posture of the target ball. The positioning block (71) and the inner positioning frame (74) are both provided with waist-shaped holes for the clamping mechanism (9) to move up and down.

2. The attitude calibration device for an automatic assembly equipment for an aircraft engine according to claim 1, characterized in that, The outer surface of the sliding block (10) is provided with a drive tooth block (11), which is meshed with a drive gear (12). The drive gear (12) is mounted on a flexible shaft (13). The flexible shaft (13) is fixed on the convex lug of the movable cover (72) and extends along the circumference of the positioning block (71). Both ends of the flexible shaft (13) are fixedly connected with driven gears (14). Both ends of the driven gears (14) are meshed with main gears (15). One of the main gears (15) is sleeved on the drive rod (16). The top of the drive rod (16) is fixedly connected with an adjusting block (73). The adjusting block (73) is rotatably connected to the movable cover (72). The other main gear (15) is sleeved on the output shaft of the deflection motor (161).

3. The attitude calibration device for an automatic assembly equipment for an aircraft engine according to claim 1, characterized in that, The surface of the elastic sheet (75) is provided with a connecting film (76) for adhering to the surface of the target ball.

4. The attitude calibration device for an automatic assembly equipment for an aircraft engine according to claim 1, characterized in that, The gap between the elastic sheet (75) and the inner positioning frame (74) is filled with a support airbag (77), which has an inflation component.

5. The attitude calibration device for an automatic assembly equipment for an aircraft engine according to claim 1, characterized in that, The positioning block (71) is externally fixedly connected to an external gear ring (17), which is meshed with an adjusting gear (18). The adjusting gear (18) is sleeved on the output shaft of the rotary motor.

6. The attitude calibration device for an automatic assembly equipment for an aircraft engine according to claim 1, characterized in that, The clamping mechanism (9) includes a positioning air rod (91) fixedly connected to the sliding block (10). An adsorption head (92) is movably connected inside the positioning air rod (91). A pressure spring (93) is provided between the adsorption head (92) and the positioning air rod (91). The positioning air rod (91) has an installation cavity, a narrow oral cavity, a connecting cavity and an air inlet cavity inside. A connecting pipe (97) is provided outside the air inlet cavity. An air pump (98) is provided outside the connecting pipe (97). The pressure spring (93) is located inside the installation cavity. A connecting air hole is provided between the installation cavity and the connecting cavity. An air valve block (96) is provided outside the installation cavity. The installation cavity is connected to the outside through the air valve block (96).

7. The attitude calibration device for an automatic assembly equipment for an aircraft engine according to claim 6, characterized in that, The adsorption head (92) is fixedly connected to a measuring rod (94), which is slidably connected inside the narrow oral cavity. The adsorption head (92) is connected to the connecting cavity and the air inlet cavity through the measuring rod (94). Annular magnetic strips are uniformly arranged on the outside of the measuring rod (94). A probe head (95) is arranged on the outside of the narrow oral cavity. The probe head (95) is used to measure the sliding distance of the measuring rod (94) inside the narrow oral cavity.

8. The attitude calibration device for an automatic assembly equipment for an aircraft engine according to claim 1, characterized in that, The upper surface of the positioning base (6) is provided with an arc groove, and the positioning rod (8) is installed at the center of the arc groove.

9. The attitude calibration device for an automatic assembly equipment for an aircraft engine according to claim 1, characterized in that, Two second measurement calibration target balls (4) are provided on both sides of the front end of the visual recognition target (3).

10. The attitude calibration device for an automatic assembly equipment for an aircraft engine according to claim 1, characterized in that, The first measurement calibration target ball (1) is provided on both sides of the front end of the attitude adjustment platform (100) and on the two brackets (300).

11. A method for attitude calibration of an automatic aircraft engine assembly equipment, wherein the method is implemented based on an attitude calibration device for an automatic aircraft engine assembly equipment as described in any one of claims 1-10, characterized in that, Includes the following steps: S1. Use a laser tracker to measure the position of the second measurement calibration target ball (4) on the visual recognition target (3) in the laser tracker coordinate system; S2. Based on the position of the second measurement calibration target ball (4) in the laser tracker coordinate system, perform discrete point registration through SVD decomposition, and calculate the pose relationship between the visual recognition target coordinate system and the laser tracker coordinate system; S3. Use a laser tracker to measure the position of the first measurement calibration target ball (1) on the attitude adjustment platform (100) in the laser tracker coordinate system; S4. Based on the position of the first measurement calibration target ball (1) in the coordinate system of the laser tracker, the discrete point registration is performed by SVD decomposition, and the pose relationship between the attitude adjustment platform (100) and the coordinate system of the laser tracker is calculated. S5. Using a vision system recognition algorithm, determine the positional relationship between the visual recognition target (3) and the vision system (200) on the posture adjustment platform (100); S6. Based on the positional relationship between the visual recognition target (3) and the posture adjustment platform (100), the pose relationship between the visual system (200) and the posture adjustment platform (100) is calculated through the transfer relationship, thereby realizing the measurement and calibration of the visual system (200).

12. The position calibration method for an automatic assembly equipment for an aircraft engine according to claim 11, characterized in that, In step S6, the pose relationship between the vision system (200) and the pose adjustment platform (100) is calculated by means of the transfer relationship: ； in, The pose relationship between the vision system and the pose adjustment platform. To visually identify the pose relationship between the target coordinate system and the laser tracker coordinate system. This represents the pose relationship between the attitude adjustment platform and the laser tracker coordinate system.

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