An adaptive robot end effector for composite structure bonding and a method of applying adhesive

Abstract

The present application relates to the field of aviation manufacturing and robot automation, and particularly relates to a self-adaptive robot end effector for composite structure bonding and a gluing method, which comprises a propulsion mechanism, a gluing posture adjusting mechanism, a glue layer width adjusting mechanism, an adhesive quantitative extrusion mechanism, a gluing quality detection unit and a glue bucket temperature control unit, the propulsion mechanism is used to drive the end effector to move back and forth along the linear direction; the gluing posture adjusting mechanism is used to adjust the azimuth angle of the variable-width gluing nozzle relative to the gluing path; the glue layer width adjusting mechanism is used to dynamically adjust the glue line width during the gluing process; the adhesive quantitative extrusion mechanism is used to uniformly, continuously and quantitatively extrude the adhesive; the gluing quality detection unit is used to detect the width, continuity and thickness of the glue line in real time; and the glue bucket temperature control unit is used to preheat and constant-temperature control the adhesive. The present application greatly improves the production efficiency and quality consistency, and reduces the production cost and dependence on manual work.

Description

Technical Field

[0001] This invention relates to the fields of aerospace manufacturing and robotic automation technology, specifically to an adaptive robot end effector and adhesive application method for bonding composite material structures. Background Technology

[0002] Currently, drones widely adopt composite material structures, and their component assembly relies heavily on structural adhesive bonding technology. Compared with traditional mechanical connection methods such as riveting and bolting, adhesive bonding avoids drilling holes in composite materials, thus eliminating stress concentration problems caused by fiber cutting and effectively maintaining structural integrity. Simultaneously, the adhesive bonding surface is uniformly distributed, resulting in a more rational stress distribution, significantly improving the fatigue strength and durability of the structure, and facilitating lightweight design. Therefore, composite material adhesive bonding technology places extremely high demands on the uniformity, density, and thickness control of the adhesive layer. These factors directly determine the performance of the adhesive joint and ultimately affect the structural strength and operational safety of the drone.

[0003] However, current adhesive bonding operations for composite structures still primarily rely on manual application, making it difficult to consistently and efficiently leverage their inherent technological advantages. Manual operation has significant drawbacks: First, it's difficult to ensure consistency in adhesive strip width and thickness, especially when dealing with complex three-dimensional adhesive application with varying widths and curvatures, easily leading to quality issues such as adhesive breaks and bubbles, severely weakening the bond strength. Second, manual operation is inefficient and cannot meet the demands of large-scale, fast-paced modern production. Furthermore, volatile substances in structural adhesives pose a potential threat to the health of operators, necessitating improvements to the working environment.

[0004] To overcome the drawbacks of manual operation, automated glue application technology has emerged. Existing technology includes an end effector and glue application method for an automated glue application robot, which achieves automated operation through pre-programmed production paths, improving production efficiency. However, the end effector used in this system is a fixed-width nozzle, which cannot adjust the glue application width in real time during operation, thus it is only suitable for simple working conditions where the glue layer shape is constant. Existing technology includes an end effector and collaborative operation method for an automated glue application and scraping device with force control, which achieves automatic adjustment of the glue application amount and scraping thickness, meeting the production process requirements of automatic glue application followed by automatic scraping. However, this device lacks an adaptive mechanism for the glue layer width and does not integrate a visual feedback system. When dealing with complex three-dimensional variable-width glue layers, frequent production interruptions for manual intervention or program readjustment are still required.

[0005] However, existing automated adhesive application equipment often features end effectors with limited functionality. These end effectors may only offer simple adhesive scraping without adapting to width variations, or lack intelligent closed-loop control for real-time sensing and adjustment. This makes it difficult to meet the high-quality adhesive application requirements of complex spatial adhesive layers commonly found on composite material components in drones. This severely restricts the full realization of the advantages of adhesive bonding technology. Therefore, there is an urgent need to develop a robotic end effector that can automatically adapt to changes in adhesive layer geometry and is specifically designed to meet the requirements of high-performance structural adhesive bonding. This would overcome current technological and process bottlenecks and ensure that the inherent advantages of adhesive bonding assembly are perfectly realized in automated production.

[0006] Therefore, there is a need to provide an adaptive robot end effector and adhesive application method for bonding composite material structures to solve the above problems. Summary of the Invention

[0007] To address the technical challenge of existing adhesive application equipment being unable to adaptively apply three-dimensional adhesive layers with varying widths and curvatures during continuous operation, and to achieve online detection and closed-loop control of adhesive layer thickness, this invention provides an adaptive robotic end effector and adhesive application method for bonding composite material structures, thereby solving the existing problems.

[0008] The first aspect of this invention provides an adaptive robot end effector for adhesive bonding of composite material structures, employing the following technical solution, including: A propulsion mechanism is used to drive the end effector to move back and forth in a straight line. The glue application posture adjustment mechanism is used to adjust the azimuth angle of the variable width glue application nozzle relative to the glue application path; The adhesive layer width adjustment mechanism is used to dynamically adjust the adhesive line width during the adhesive application process; An adhesive metering extrusion mechanism is used to uniformly, continuously, and quantitatively extrude adhesives. The adhesive coating quality inspection unit is used to detect the width, continuity, and thickness of the adhesive lines in real time. And a glue bucket temperature control unit, used for preheating and temperature control of the adhesive.

[0009] A further technical solution of the present invention is that the propulsion mechanism includes: one end of a linear cylinder is fixed on the mounting base of the end effector, the other end of the linear cylinder is connected to the main mounting plate, a linear guide rail is provided on the main mounting plate, and the sliding pair of the linear guide rail is fixedly connected to the side of the end effector.

[0010] A further technical solution of the present invention is that the adhesive layer width adjustment mechanism includes: a servo motor and a variable width dispensing nozzle. The output shaft of the servo motor drives the variable width mechanism inside the variable width dispensing nozzle through gear transmission to adjust the adhesive line width.

[0011] A further technical solution of the present invention is that the adhesive application posture adjustment mechanism includes: a first servo motor, which drives the variable width adhesive application nozzle to rotate around its own axis through a gear transmission pair.

[0012] A further technical solution of the present invention is that the adhesive quantitative extrusion mechanism includes: a rotary cylinder, a second servo motor, a ball screw, and a pusher rod. The second servo motor drives the ball screw to convert the rotational motion into linear motion, and pushes the pusher rod to realize the quantitative extrusion of the adhesive. The rotary cylinder controls the opening and closing of the adhesive dispensing.

[0013] A further technical solution of the present invention is that the adhesive coating quality detection unit includes: an industrial camera, used to scan the adhesive layer during or after the adhesive coating process to measure the thickness of the adhesive layer, wherein the industrial camera is a 3D line scan camera.

[0014] A further technical solution of the present invention is that the glue bucket temperature control unit includes: a glue bucket, a constant temperature heating element and a temperature sensor. The glue bucket has two independent semi-circular cavities inside, each cavity is used to contain one component of the finished structural adhesive. The constant temperature heating element is installed on the outer wall of the glue bucket. The temperature sensor is used to monitor the temperature of the adhesive. The robot controller controls the switching of the constant temperature heating element according to the temperature of the adhesive to achieve preheating and constant temperature control of the adhesive.

[0015] The second aspect of the present invention provides a method for applying adhesive to an adaptive robot end effector for bonding composite material structures. This method uses the end effector provided in the first aspect of the present invention for adhesive application, and the adhesive application steps are as follows: Offline programming and path planning: Based on the 3D model of the workpiece and the requirements of the adhesive bonding process, the robot's motion trajectory, adhesive layer width variation curve, adhesive extrusion rate and visual inspection points are planned, an executable program is generated and simulation verification is performed. On-site coordinate system calibration: On-site calibration of the coordinate system of the variable width dispensing nozzle, the zero point of the variable width mechanism, the linear guide travel and the visual inspection coordinate system to compensate for installation errors and environmental deformation; Adhesive preheating: The two-component adhesive is simultaneously heated to the set temperature and kept at that temperature for the set time to achieve the working viscosity; Workpiece positioning and variable width dispensing nozzle bonding: The robot positions the end effector above the workpiece and drives the position of the variable width dispensing nozzle to bond with the workpiece surface via a linear cylinder; Glue application posture adjustment: The angle of the variable width glue application nozzle is adjusted by the glue application posture adjustment mechanism, and the position of the industrial camera is adjusted so that the variable width glue application nozzle is perpendicular to the surface to be glued. Width preset and dynamic adjustment: The initial glue line width of the variable width dispensing nozzle is preset according to the path planning, and the glue line width is dynamically adjusted in real time according to the width change curve during the glue application process; Synchronous extrusion and trajectory tracking: The robot moves along the planned path, the rotary cylinder opens the glue dispensing switch, and at the same time the adhesive metering extrusion mechanism extrudes the adhesive synchronously at a flow rate that matches the robot's movement speed; Online quality inspection and closed-loop compensation: During or after the glue application process, the width, continuity and thickness of the glue layer are detected in real time by a vision inspection unit, and the process parameters are dynamically adjusted for compensation based on the inspection results; Anomaly Handling and Quality Recording: When a serious defect is detected, the operation is paused and an alarm is triggered. The defect location information is recorded, and the coating can be returned for recoating. The entire process quality data is saved.

[0016] A further technical solution of the present invention is to use a 3D line scan camera to directly measure the height of the adhesive layer.

[0017] The beneficial effects of this invention are: This invention addresses the process requirements of uniform adhesive layer thickness and continuous variable-width forming in composite material bonding. It tackles the thickness fluctuations, abrupt width changes, and adhesive breakage defects inherent in manual adhesive application. It employs a constant-temperature adhesive supply, a variable-width nozzle driven by a servo motor and servo motor, and online height measurement technology using a 3D line scan camera. This achieves consistent adhesive layer thickness, stepless width adjustment, and real-time defect compensation, significantly improving bonding quality consistency. It not only enables adaptive adhesive layer width but also ensures the stable and controllable final adhesive layer thickness—a key quality indicator—making it specifically designed for high-requirement aerospace structural bonding. It realizes the automation and intelligent transformation of UAV composite component bonding assembly from planning and execution to inspection, significantly improving production efficiency and quality consistency while reducing production costs and reliance on manual labor. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a three-dimensional structural schematic diagram of an adaptive robot end effector for bonding composite material structures according to the present invention.

[0020] Figure 2 This is a three-sided structural diagram of the end effector of the present invention. Figure 3 This is a three-view view of the adhesive layer width adjustment mechanism of the present invention.

[0021] Figure 4 This is a cross-sectional view of the adhesive layer width adjustment mechanism of the present invention.

[0022] Figure 5 This is a cross-sectional view of the glue bucket temperature control unit of the present invention.

[0023] In the diagram: 1. Mounting base; 2. Glue bucket; 3. Linear cylinder; 4. Variable width dispensing nozzle; 5. First servo motor; 6. Ball screw; 7. Linear guide rail; 8. Rotary cylinder; 9. Servo motor; 10. Industrial camera; 11. Camera bracket; 12. Thermostatic heating element; 13. Temperature sensor; 14. Main mounting plate; 15. Drive gear; 16. Driven gear; 17. Glue pusher rod; 18. Cable drag chain; 19. Second servo motor; 20. Adapter; 21. Glue delivery hose; 22. Transmission gear. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] This invention provides an embodiment of an adaptive robot end effector for adhesive bonding of composite material structures. In this embodiment, the end effector is an electromechanical integrated device that combines mechanical drive, adhesive dosage control, and visual inspection. Figure 1 and Figure 2 As shown, the end effector includes: a propulsion mechanism, an adhesive application posture adjustment mechanism, an adhesive layer width adjustment mechanism, an adhesive metering extrusion mechanism, an adhesive application quality detection unit, and a glue tank temperature control unit. The propulsion mechanism drives the end effector to move back and forth in a straight line; the adhesive application posture adjustment mechanism adjusts the azimuth angle of the variable-width adhesive nozzle relative to the adhesive application path; the adhesive layer width adjustment mechanism dynamically adjusts the adhesive line width during the adhesive application process; the adhesive metering extrusion mechanism extrudes the adhesive uniformly, continuously, and quantitatively; the adhesive application quality detection unit detects the width, continuity, and thickness of the adhesive line in real time; and the glue tank temperature control unit preheats and maintains a constant temperature for the adhesive.

[0026] For example, in one specific embodiment, the propulsion mechanism includes a linear cylinder 3 and a linear guide rail 7. One end of the linear cylinder 3 is fixed to the mounting base 1 of the end effector, and the other end of the linear cylinder 3 is connected to the main mounting plate 14. The main mounting plate 14 is provided with the linear guide rail 7. The sliding pair of the linear guide rail 7 is fixedly connected to the side of the end effector. The linear cylinder 3 drives the piston rod to extend and retract, thereby driving the end effector to move back and forth along the direction of the linear guide rail. In this embodiment, the length of the linear guide rail 7 is 150mm, and the repeatability of the sliding pair (slider) is ≤0.01mm. When the linear cylinder 3 receives an extension signal, it drives the entire end effector to move forward along the direction of the linear guide rail 7, so that the variable-width dispensing nozzle 4 contacts the workpiece surface; when retracted, it disengages from the workpiece, facilitating the robot to move to the next station. The cables and air pipes of each electrical unit are integrated into a cable drag chain 18. The cable drag chain 18 is fixed on the main mounting plate 14. When the end effector moves with the robot and the linear cylinder 3 drives the extension and retraction, it plays a role in regulating, protecting and guiding the air pipe of the cable drag chain 18.

[0027] For example, in one specific embodiment, the adhesive layer width adjustment mechanism includes: a servo motor 9, a variable width applicator nozzle 4, and an adapter. The output shaft of the servo motor 9 drives the variable width mechanism inside the variable width applicator nozzle through gear transmission to adjust the adhesive line width. The variable width mechanism is a gear transmission pair composed of a driving gear 15 and a driven gear 16. That is, in this embodiment, the output torque of the servo motor 9 is 2.5 N·m. The output shaft of the servo motor 9 drives the variable width applicator nozzle 4 to rotate through a gear pair composed of a driving gear 15 and a driven gear 16, thereby changing the angle between the variable width applicator nozzle 4 and the adhesive surface, thus achieving continuous adjustment of the adhesive width. The typical applicable range of the outlet width of the variable width applicator nozzle 4 is 3 mm to 20 mm. The rotation of the output shaft of the servo motor 9 achieves continuous adjustment of the outlet width of the variable width applicator nozzle 4 during a single application, dynamically adapting to the variable width adhesive layer requirements of complex contours.

[0028] For example, in one specific embodiment, such as Figure 3 and Figure 4 As shown, the adhesive application posture adjustment mechanism includes: a first servo motor 5 and a transmission gear 22. The first servo motor 5 drives the variable width adhesive application nozzle to rotate around its own axis through the transmission gear 22. Specifically, in this embodiment, the first servo motor 5 has a built-in reducer with a reduction ratio of 10:1. The first servo motor 5 drives the variable width adhesive application nozzle 4 and the industrial camera 10 to rotate as a whole around the axis through the transmission gear 22, with an angle adjustment range of ±30°. This is used to ensure the relative position between the variable width adhesive application nozzle 4, the industrial camera 10, and the adhesive application surface of the workpiece, and to compensate for workpiece clamping errors and path curvature changes.

[0029] For example, in one specific embodiment, the adhesive metering extrusion mechanism includes: a rotary cylinder 8, a second servo motor 19, a ball screw 6 (lead 3mm), and a pusher rod 16. The second servo motor 19 drives the ball screw 6 to convert rotational motion into linear motion, pushing the pusher rod 16 to achieve metered extrusion of the adhesive. The rotary cylinder 8 controls the dispensing and shut-off of the adhesive. Specifically, in this embodiment, the second servo motor adopts closed-loop control, with a rated speed of 3000 r / min, and is connected to the ball screw 6 via a coupling. The pusher rod 16 has a diameter of 20mm and a chrome-plated surface. The extrusion flow rate of the pusher rod 16 is linearly related to the rotational speed of the second servo motor 19, with a flow control accuracy of ±0.5%. The rotary cylinder 8 (SMC CRB2 series) is installed between the actuator mounting base 1 and the main mounting plate 14, with a rotation angle of ±90°. The rotary cylinder 8 drives the glue delivery tube 21 to rotate. The glue delivery tube 21 is connected to the valve core at the outlet of the glue bucket, thereby controlling the rotation of the valve core at the outlet of the glue bucket. This enables precise opening and rapid cutting of the glue flow channel, completing the glue gun's dispensing and shut-off actions. At the same time, the glue delivery tube has a hollow structure with a diameter of 10 mm inside, which is connected to the adapter 20 to realize the delivery of adhesive from the glue bucket 2 to the variable width dispensing nozzle 4.

[0030] For example, in one specific embodiment, the adhesive coating quality detection unit includes an industrial camera 10, used to scan the adhesive layer during or after the adhesive coating process to measure the adhesive layer thickness. Specifically, in this embodiment, the industrial camera 10 is a Basler ace 3D line scan camera with a resolution of 2048×1088. The industrial camera 10 is mounted 50mm behind the variable width dispensing nozzle 4 via a camera bracket 11 and screwed onto the actuator mounting base 1. It is at a 45° angle to the dispensing direction, has a field of view of 80mm×60mm, and an acquisition frequency of 200Hz. It can realize real-time measurement of adhesive layer thickness (0.1mm~3mm) with a measurement accuracy of ±0.02mm.

[0031] like Figure 5As shown, the glue bucket temperature control unit includes: exemplarily, in one specific embodiment, a glue bucket 2, a constant temperature heating element 12, and a temperature sensor 13. The constant temperature heating element 12 is installed on the outer wall of the glue bucket, and the temperature sensor 13 is used to monitor the adhesive temperature. The robot controller controls the switching of the constant temperature heating element 12 according to the adhesive temperature to achieve preheating and constant temperature control of the adhesive. The glue bucket 2 adopts an integrated dual-cavity structure, which is divided into two independent semi-circular cavities. The two semi-circular cavities are used to hold the finished structural adhesives of components A and B, respectively. The glue bucket 2 is made of aluminum alloy and has a cylindrical shape. The internal diameter of one cavity is 40 mm, and the height is adapted to the standard two-component commercial glue bucket size, so it can be directly loaded into pre-packaged glue buckets. A set of annular constant temperature heating elements 12 is evenly covered on the inner wall of the glue bucket to synchronously and evenly heat the two semi-circular cavities. A PT100 temperature sensor 13 is installed in the middle of the inner wall of the glue bucket to directly monitor the temperature of the glue bucket 2 to indirectly reflect the adhesive temperature. The temperature control system uses a PID algorithm, with a temperature control range of 20℃~60℃ and a temperature fluctuation of ≤±1℃.

[0032] This embodiment provides a glue application method using the above-described end effector, with the specific steps as follows: Step 1: Offline Programming and Path Planning Import the 3D model of the workpiece (such as the wing frame of a drone) into the offline programming module of Delmia software, and define the adhesive layer path according to the bonding process requirements. The adhesive layer width varies along the path, for example, 20mm at the root and 8mm at the tip. Set the robot movement speed to 200mm / s, and match the extrusion rate to the speed. Set a detection point every 50mm along the path, generate an executable program for the robot, and perform collision detection and reachability verification.

[0033] Step 2: On-site coordinate system calibration: Mounting plate 14 onto the flange of the ABB IRB 6700 robot and calibrate the system using a laser tracker (Leica AT960): (1) Variable width dispensing nozzle coordinate system calibration: attach a target ball to the tip of the variable width dispensing nozzle and measure its coordinates in the robot base coordinate system; (2) Zero-point calibration of variable width mechanism: Drive the servo motor to the mechanical zero point and record the encoder value; (3) Camera coordinate system calibration: Using a standard grid calibration board, calculate the transformation matrix between the camera and robot coordinate systems; (4) Guide rail stroke calibration: Measure the position deviation of the variable width glue nozzle when the cylinder is fully extended / retracted.

[0034] After calibration, the alignment error of each coordinate system is ≤0.1mm.

[0035] Step 3: Adhesive preheating and viscosity stabilization: Start the glue tank temperature control unit and set the target temperature to 45℃. The constant temperature heating element 12 starts working, and the temperature sensor 13 monitors the glue temperature in real time. When the glue temperature reaches the set temperature, maintain the temperature for 15 minutes. The second servo motor 19 slowly pushes the glue pusher rod 16 at a speed of 5r / min to squeeze out 5ml of adhesive to remove air bubbles and cold glue.

[0036] Step 4: Workpiece positioning and fitting of the variable width dispensing nozzle: The robot, carrying the end effector, moves to a position above the workpiece and pauses 10mm above the surface. Linear cylinder 3 extends, pushing the variable-width applicator nozzle 4 to contact the workpiece surface at a speed of 5mm / s. The contact force is controlled at 5N ± 0.5N via a cylinder pressure regulating valve. The contact is maintained for 2 seconds to stabilize.

[0037] Step 5: Adjusting the adhesive application posture: The first servo motor 5 starts, and the first servo motor 5 drives the gear to rotate the variable width dispensing nozzle 4 to a normal angle of 0° with the workpiece surface (vertical state), with an angle control accuracy of ≤0.2°.

[0038] Step Six: Width Parameter Preset and Dynamic Adjustment: Servo motor 9 drives the variable width mechanism inside the variable width dispensing nozzle 4 to the corresponding position according to the width requirement at the starting point of the path (e.g., 12mm). During the dispensing process, the robot controller reads the width setting value on the path in real time and sends angle commands to the servo motor via the CAN bus. The width change gradient is limited to within 1mm / 50mm to avoid abrupt changes.

[0039] Step 7: Synchronous Extrusion and Trajectory Tracking The robot begins to move along the path, while the second servo motor 19 drives the ball screw 6 at a preset speed (e.g., 120 r / min). Extrusion flow rate The formula for calculating (ml / min) is: ,in, The thickness coefficient of the adhesive layer (obtained from experimental data, taken as 0.15) is used. The robot speed is (mm / s). The width of the adhesive layer is shown in mm. The extrusion system and robot movement are synchronized in real time, with a synchronization error of ≤50ms.

[0040] Step 8: Online quality inspection and closed-loop compensation: Industrial camera 10 continuously acquires images of the adhesive layer during the coating process. A 3D line scan camera performs high-speed scanning of the adhesive lines during or after coating, directly measuring the adhesive layer height. The image processing system analyzes the adhesive width, continuity, and thickness. If defects are detected, their location is recorded and an alarm is triggered. The system can automatically adjust subsequent process parameters for compensation and optimization. The image processing algorithm performs the following detections: 1. Width detection: Extract the edge of the adhesive line, calculate the actual width, and compare it with the digital model of the surface to be coated; 2. Continuity Inspection: Detects defects such as glue breakage and air bubbles through morphological operations; 3. Thickness measurement: The thickness is calculated by using the deformation of the laser line on the adhesive layer and the triangular geometric relationship.

[0041] When a width deviation > 0.3 mm or a thickness deviation > 0.05 mm is detected, the system will automatically adjust: Width deviation is controlled by adjusting the angle of the glue applicator nozzle via servo motor 9; thickness deviation is controlled by adjusting the speed of the second servo motor 19.

[0042] Step Nine: Exception Handling and Quality Records When a serious defect is detected (such as a glue break length > 3mm), the robot pauses its movement and issues an audible and visual alarm. After operator confirmation, the system records the defect location, and the robot returns to the point of defect recoating. All detection data (width, thickness, defect location) is automatically saved to the database, generating a glue coating quality report.

[0043] Through the above embodiments, the end effector and adhesive application method of the present invention achieve high-precision and adaptive adhesive application of variable-width adhesive layers in composite material structures. The adhesive layer width consistency reaches ±0.3mm, and the thickness consistency reaches ±0.05mm, which significantly improves production efficiency and bonding quality, and meets the high standard requirements of aerospace manufacturing for bonding quality.

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An adaptive robot end effector for adhesive bonding of composite material structures, characterized in that, include: A propulsion mechanism is used to drive the end effector to move back and forth in a straight line. The glue application posture adjustment mechanism is used to adjust the azimuth angle of the variable width glue application nozzle relative to the glue application path; The adhesive layer width adjustment mechanism is used to dynamically adjust the adhesive line width during the adhesive application process; An adhesive metering extrusion mechanism is used to uniformly, continuously, and quantitatively extrude adhesives. The adhesive coating quality inspection unit is used to detect the width, continuity, and thickness of the adhesive lines in real time. And a glue bucket temperature control unit, used for preheating and temperature control of the adhesive.

2. The adaptive robot end effector for bonding composite material structures according to claim 1, characterized in that, The propulsion mechanism includes a linear cylinder and a linear guide rail. One end of the linear cylinder is fixed to the mounting base of the end effector, and the other end of the linear cylinder is connected to the main mounting plate. The main mounting plate is provided with a linear guide rail, and the sliding pair of the linear guide rail is fixedly connected to the side of the end effector.

3. The adaptive robot end effector for bonding composite material structures according to claim 1, characterized in that, The adhesive layer width adjustment mechanism includes a servo motor and a variable width dispensing nozzle. The servo motor output shaft drives the variable width mechanism inside the variable width dispensing nozzle through a gear transmission pair to adjust the adhesive line width.

4. An adaptive robot end effector for bonding composite material structures according to claim 3, characterized in that, The adhesive application posture adjustment mechanism includes: a first servo motor, which drives the variable width adhesive application nozzle to rotate around its own axis through a gear transmission pair.

5. An adaptive robot end effector for bonding composite material structures according to claim 1, characterized in that, The adhesive metering extrusion mechanism includes a rotary cylinder, a second servo motor, a ball screw, and a glue-pushing guide rod. The second servo motor drives the ball screw to convert the rotary motion into linear motion, which pushes the glue-pushing guide rod to realize the metered extrusion of the adhesive. The rotary cylinder controls the opening and closing of the glue dispensing.

6. An adaptive robot end effector for adhesive bonding of composite material structures according to claim 1, characterized in that, The adhesive coating quality inspection unit includes an industrial camera used to scan the adhesive layer during or after the adhesive coating process to measure the adhesive layer thickness.

7. An adaptive robot end effector for adhesive bonding of composite material structures according to claim 6, characterized in that, The industrial camera is a 3D line scan camera.

8. An adaptive robot end effector for adhesive bonding of composite material structures according to claim 1, characterized in that, The glue bucket temperature control unit includes: a glue bucket, a constant temperature heating element, and a temperature sensor. The glue bucket has two independent semi-circular cavities inside, each of which is used to contain one component of the finished structural adhesive. The constant temperature heating element is installed on the outer wall of the glue bucket, and the temperature sensor is used to monitor the temperature of the adhesive. The robot controller controls the switching of the constant temperature heating element according to the adhesive temperature to achieve preheating and constant temperature control of the adhesive.

9. A method for applying adhesive to an adaptive robot end effector for bonding composite material structures, characterized in that, The end effector according to any one of claims 1 to 8 is used for adhesive application, and the adhesive application steps are as follows: Offline programming and path planning: Based on the 3D model of the workpiece and the requirements of the adhesive bonding process, the robot's motion trajectory, adhesive layer width variation curve, adhesive extrusion rate and visual inspection points are planned, an executable program is generated and simulation verification is performed. On-site coordinate system calibration: On-site calibration of the coordinate system of the variable width dispensing nozzle, the zero point of the variable width mechanism, the linear guide travel and the visual inspection coordinate system to compensate for installation errors and environmental deformation; Adhesive preheating: The two-component adhesive is simultaneously heated to the set temperature and kept at that temperature for the set time to achieve the working viscosity; Workpiece positioning and variable width dispensing nozzle bonding: The robot positions the end effector above the workpiece and drives the position of the variable width dispensing nozzle to bond with the workpiece surface via a linear cylinder; Glue application posture adjustment: The angle of the variable width glue application nozzle is adjusted by the glue application posture adjustment mechanism, and the position of the industrial camera is adjusted so that the variable width glue application nozzle is perpendicular to the surface to be glued. Width preset and dynamic adjustment: The initial glue line width of the variable width dispensing nozzle is preset according to the path planning, and the glue line width is dynamically adjusted in real time according to the width change curve during the glue application process; Synchronous extrusion and trajectory tracking: The robot moves along the planned path, the rotary cylinder opens the glue dispensing switch, and at the same time the adhesive metering extrusion mechanism extrudes the adhesive synchronously at a flow rate that matches the robot's movement speed; Online quality inspection and closed-loop compensation: During or after the glue application process, the width, continuity and thickness of the glue layer are detected in real time by a vision inspection unit, and the process parameters are dynamically adjusted for compensation based on the inspection results; Anomaly Handling and Quality Recording: When a serious defect is detected, the operation is paused and an alarm is triggered. The defect location information is recorded, and repainting is supported. The entire process quality data is saved.

10. The adhesive application method for an adaptive robot end effector used for bonding composite material structures according to claim 9, characterized in that, A 3D line scan camera is used to directly measure the adhesive layer height.

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