Actuator, assembly system and method for assembling array antenna T / R components

Abstract

The present invention relates to an actuator, an assembly system and a method for assembling T / R components of an array antenna. The actuator uses machine vision recognition to guide a mechanical arm to grab the T / R component and locate the assembly position. The actuator is controlled by a system controller to tighten the screws for fixing. The whole process is completed automatically, which greatly improves the assembly efficiency and reduces the influence of human factors on the assembly quality. When the actuator is executed, the method of feeding screws on both sides at the same time is adopted, which is convenient for controlling the posture of the T / R component during assembly, and avoids the problem that the axial pre-tightening force on both sides of the T / R component generated by the unilateral feeding screws is difficult to control. At the same time, the tightening process uses force / displacement coupling control, which improves the control accuracy of the axial pre-tightening force of the screw compared to the traditional single torque control method, and takes into account the vibration prevention and long fatigue life of the threaded assembly. The present invention is suitable for intelligent assembly in the manufacturing process of array radars.

Description

Technical Field

[0001] The present invention belongs to the technical field of radar manufacturing, and in particular relates to an end effector, an assembly system and a method for assembling T / R components of an array antenna. Background Art

[0002] High-precision integrated array antennas are key components of early warning detection systems. Array antennas are generally composed of tens of thousands of units, namely T / R components. The accurate assembly of a large number of T / R components is related to the performance of the array antenna. However, according to the inventors’ understanding, there is currently no automated equipment on the market for array antenna assembly, and assembly is still mainly done manually, with problems such as poor assembly quality, long cycle, and low efficiency. At the same time, automated assembly solutions in other fields are generally not applicable or cannot meet the assembly requirements of T / R components. For example, Chinese patent CN107538208A proposes a screw-tightening robot using machine vision, which uses a hand-eye camera to correct the screw coordinates in real time. However, the process of tightening the screw uses an open-loop control tightening method, and the control accuracy of the screw axial preload cannot meet the assembly requirements of the T / R component. Summary of the invention

[0003] In order to meet the automation and high-precision requirements of array antenna assembly, the present invention proposes an end effector, an assembly system and a method for assembling T / R components of an array antenna.

[0004] The technical solution adopted by the present invention is:

[0005] An end effector for assembling the array antenna T / R assembly, comprising an upper substrate, a vacuum chuck, an industrial camera, a lens, a ring light source, two first support plates, two stroke readable cylinders, two pneumatic chucks and two DC motors;

[0006] The upper base plate is arranged horizontally, and a rear side plate is vertically fixed to the left and right sides of the rear side of the upper base plate, and a vertical linear guide is fixed to the inner side of each rear side plate; the first support plate is L-shaped, and the long sections of the two first support plates are respectively fixedly connected to the sliders of the two linear guides;

[0007] A torque sensor is fixed on the upper end surface of the short section of each of the two first support plates, a second support plate is vertically fixed on the inner side of the long section of each of the two first support plates above the corresponding torque sensor, a planetary reducer is fixed on the upper end surface of each second support plate, and the output shaft of the planetary reducer is inserted downward into the corresponding torque sensor; the output shaft of the torque sensor passes downward through the short section of the corresponding first support plate, and is connected to an electric screwdriver through a bellows coupling; the output shafts of the two DC motors are inserted downward into the corresponding planetary reducers, and a magnetoelectric encoder is installed at the tail of each DC motor;

[0008] A partition plate is vertically fixed in the middle of the lower end surface of the upper base plate to separate the two DC motors and the two linear guide rails; the two stroke readable cylinders are respectively fixed to the left and right positions of the front side of the lower end surface of the upper base plate, and the output shafts of the two stroke readable cylinders are respectively fixedly connected to the short end of each of the two first support plates;

[0009] A suction cup bracket plate is fixed at the bottom of the partition plate, and the vacuum suction cup is fixed below the suction cup bracket plate; a serpentine plate is fixed at the bottom of each of the two rear side plates, and the ends of the two serpentine plates are bent and extended to the left and right sides of the vacuum suction cup, and the two pneumatic chucks are respectively fixed at the bottom of the ends of the two serpentine plates, and the pneumatic chucks are coaxial with the corresponding electric screwdriver heads;

[0010] The industrial camera is fixed on the outside of an angular fixing plate, a groove-shaped fixing plate is fixed on the upper end surface of the annular light source, the angular fixing plate and the groove-shaped fixing plate are fixed to the bottom of the partition plate together by bolts, and the industrial camera is located above the annular light source; the lens is threadedly connected to the industrial camera.

[0011] Furthermore, the upper part of the rear side plate is bent and fixed to the upper base plate by screws; the linear guide is fixed to the rear side plate by bolts; the slider is fixed to the long section of the first support plate by screws; the magnetoelectric encoder is fixed to the tail of the DC motor by screws; the second support plate is fixed to the long section of the first support plate by screws; the torque sensor is fixed to the short section of the first support plate by screws; the stroke-readable cylinder is fixed to the upper base plate by bolts; the end of the output shaft of the stroke-readable cylinder is provided with a thread, which is fixed to the end of the short section of the first support plate by a nut; the upper end of the suction cup bracket plate is fixed to the bottom of the partition plate by screws, and the vacuum suction cup is fixed to the suction cup bracket plate by double nuts; the serpentine plate is fixed to the rear side plate by bolts, and the pneumatic chuck is fixed to the end of the serpentine plate by nuts; the industrial camera is fixed to the angle fixing plate by screws, and the annular light source is fixed to the groove fixing plate by screws.

[0012] An assembly system for assembling array antenna T / R components, comprising a base, a mechanical arm, a vacuum generating system, a system controller and the above-mentioned end effector; the mechanical arm is mounted on the base, and the upper base plate is connected to the end flange of the mechanical arm;

[0013] The vacuum generating system comprises an air source, a supply valve, a destroying valve, a throttle valve and a vacuum generator, wherein the supply valve is respectively connected to the air supply port of the vacuum generator and the air source; the destroying valve is respectively connected to the air inlet of the throttle valve and the air source, and the air outlet of the throttle valve is connected to the vacuum suction cup; the vacuum port of the vacuum generator is connected to the vacuum suction cup; and the system controller is used to control the robotic arm, the vacuum generating system and the end effector to realize the assembly of the T / R component in the array back plate.

[0014] The assembly method for assembling the array antenna T / R assembly includes the following steps:

[0015] Step a, camera calibration, real-time image acquisition and identification of T / R components through contour detection and template matching methods;

[0016] Step b: the system controller controls the robot arm to make the vacuum suction cup grab the T / R component in the T / R component storage and move it above the array back plate;

[0017] Step c, image acquisition and detection of threaded hole positions. Based on the detection results, the system controller controls the robot arm to move to the target position, aligns the T / R assembly with the electrical connector in the array backplane and inserts it. After insertion, the vacuum suction cup is separated from the T / R assembly.

[0018] Step d, the two stroke readable cylinders move downward at the same time, and the two DC motors work to drive the electric screwdriver bit to rotate. The electric screwdriver bit screws the screw into the assembly hole of the T / R component. During the tightening process, the stroke readable cylinder and the torque sensor respectively record the axial feed signal and torque signal fed back during the tightening process to control the axial preload of the thread to meet the assembly requirements.

[0019] Furthermore, in step d, the difference in axial feed amount at both ends is controlled to be less than 0.01 mm by a two-stroke readable cylinder.

[0020] Further, in step d, when the torque sensor detects a torque surge, the system controller controls the DC motor to further tighten until the torques T1 and T2 on both sides reach range C:

[0021] C={(T1,T2)|T min1 ≤T1≤T max1 , T min2 ≤T2≤T max2}, where T min1 and T max1 are the minimum tightening torque and maximum tightening torque for the screw on one side to meet fatigue performance, T min2 and T max2 They are the minimum tightening torque and maximum tightening torque for the other side screw to meet fatigue performance; the torque unit is N·m.

[0022] The beneficial effects of the present invention are:

[0023] The present invention uses machine vision recognition to guide the mechanical arm (robot) to grab the T / R assembly and locate the assembly position. The system controller controls the end effector to tighten the screws for fixing. The whole process is completed automatically, which greatly improves the assembly efficiency and reduces the influence of human factors on the assembly quality. During the end execution, the method of feeding the screws on both sides at the same time is adopted, which is convenient for controlling the posture of the T / R assembly during assembly, and avoids the problem that the axial preload force on both sides of the T / R assembly generated by the unilateral feeding screws is difficult to control. At the same time, the tightening process uses force / displacement coupling control, which improves the control accuracy of the axial preload force of the screw compared to the traditional single torque control method, and takes into account the vibration prevention and long fatigue life of the threaded assembly. The present invention is suitable for intelligent assembly in the manufacturing process of array radars. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a structural schematic diagram of the end effector;

[0025] Figure 2 for Figure 1 Side view of

[0026] Figure 3 It is a structural diagram of the assembly system;

[0027] Figure 4 It is a structural schematic diagram of the vacuum generating system;

[0028] Figure 5 is a torque diagram;

[0029] Figure markings: 1-upper base plate, 2-rear side plate, 3-linear guide, 4-slider, 5-first support plate, 6-stroke readable cylinder, 7-suction cup bracket plate, 8-vacuum suction cup, 9-snake plate, 10-pneumatic chuck, 11-electric screwdriver head, 12-bellows coupling, 13-torque sensor, 14-second support plate, 15-planetary reducer, 16-DC motor, 17-magnetoelectric encoder, 18-partition plate, 19-angle fixing plate, 20-groove fixing plate, 21-industrial camera, 22-lens, 23-ring light source, 24-base, 25-robot arm, 26-T / R assembly, 27-array back plate. DETAILED DESCRIPTION

[0030] The end effector, assembly system and method for assembling the array antenna T / R assembly of the present invention are further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0031] like Figure 1 and Figure 2As shown, the end effector for assembling the array antenna T / R component includes an upper substrate 1, a vacuum suction cup 8, an industrial camera 21, a lens 22, a ring light source 23, two first support plates 5, two stroke readable cylinders 6, two pneumatic chucks 10 and two DC motors 16.

[0032] The upper base plate 1 is arranged horizontally, and a rear side plate 2 is vertically fixed to the left and right sides of the rear side of the upper base plate 1, and a vertical linear guide 3 is fixed to the inner side of each rear side plate 2. The first support plate 5 is L-shaped, and the long sections of the two first support plates 5 are fixedly connected to the sliders 4 of the two linear guides 3 respectively.

[0033] A torque sensor 13 is fixed to the upper end surface of the short section of each of the two first support plates 5, and a second support plate 14 is fixed vertically on the inner side of the long section of each of the two first support plates 5 above the corresponding torque sensor 13. A planetary reducer 15 is fixed to the upper end surface of each second support plate 14, and the output shaft of the planetary reducer 15 is inserted downward into the corresponding torque sensor 13. The output shaft of the torque sensor 13 passes downward through the short section of the corresponding first support plate 5 and is connected to the electric screwdriver 11 through the bellows coupling 12. The output shafts of the two DC motors 16 are inserted downward into the corresponding planetary reducer 15, and a magnetoelectric encoder 17 is installed at the tail of each DC motor 16.

[0034] A partition plate 18 is vertically fixed at the middle position of the lower end surface of the upper base plate 1 to separate the two DC motors 16 and the two linear guide rails 3. The two stroke readable cylinders 6 are respectively fixed at the left and right positions of the front side of the lower end surface of the upper base plate 1, and the output shafts of the two stroke readable cylinders 6 are respectively fixedly connected to the short ends of the two first support plates 5. The output shaft (cylinder rod) of the stroke readable cylinder 6 pushes the first support plate 5 and the slider 4 to move up and down along the linear guide rail 3.

[0035] A suction cup support plate 7 is fixed at the bottom of the partition plate 18, and a vacuum suction cup 8 is fixed below the suction cup support plate 7. A serpentine plate 9 is fixed at the bottom of each of the two rear side plates 2, and the ends of the two serpentine plates 9 are bent and extended to the left and right sides of the vacuum suction cup 8. Two pneumatic chucks 10 are respectively fixed at the bottom of the ends of the two serpentine plates 9, and the pneumatic chucks 10 are coaxial with the corresponding electric screwdriver head 11.

[0036] The industrial camera 21 is fixed on the outside of an angle fixing plate 19, a groove fixing plate 20 is fixed on the upper end surface of the annular light source 23, the angle fixing plate 19 and the groove fixing plate 20 are fixed to the bottom of the partition plate 18 by bolts, and the industrial camera 21 is located above the annular light source 23. The lens 22 is threadedly connected to the industrial camera 21.

[0037] In this embodiment, the upper part of the rear side plate 2 is bent and fixed to the upper base plate 1 by screws. The linear guide 3 is fixed to the rear side plate 2 by bolts. The slider 4 is fixed to the long section of the first support plate 5 by screws. The magnetoelectric encoder 17 is fixed to the tail of the DC motor 16 by screws. The second support plate 14 is fixed to the long section of the first support plate 5 by screws. The torque sensor 13 is fixed to the short section of the first support plate 5 by screws. The stroke-readable cylinder 6 is fixed to the upper base plate 1 by bolts. The end of the output shaft of the stroke-readable cylinder 6 is provided with a thread, which is fixed to the end of the short section of the first support plate 5 by a nut. The upper end of the suction cup bracket plate 7 is fixed to the bottom of the partition plate 18 by screws, and the vacuum suction cup 8 is fixed to the suction cup bracket plate 7 by a double nut. The serpentine plate 9 is fixed to the rear side plate 2 by bolts, and the pneumatic chuck 10 is fixed to the end of the serpentine plate 9 by nuts. The industrial camera 21 is fixed to the angle fixing plate 19 by screws, and the annular light source 23 is fixed to the groove fixing plate 20 by screws.

[0038] like Figure 3 and Figure 4 As shown, the assembly system for assembling the array antenna T / R assembly includes a base 24, a mechanical arm 25, a vacuum generating system, a system controller and the above-mentioned end effector. The mechanical arm 25 is installed on the base 24, and the upper substrate 1 is connected to the end flange of the mechanical arm 25.

[0039] The vacuum generating system includes an air source, a supply valve, a destroying valve, a throttle valve and a vacuum generator. The supply valve is connected to the air supply port and the air source of the vacuum generator respectively. The destroying valve is connected to the air inlet and the air source of the throttle valve respectively, and the air outlet of the throttle valve is connected to the vacuum suction cup 8. The vacuum port of the vacuum generator is connected to the vacuum suction cup 8. The system controller is used to control the robot arm 25, the vacuum generating system and the end effector to realize the assembly of the T / R assembly 26 in the array back plate 27.

[0040] The assembly method for assembling the array antenna T / R assembly includes the following steps:

[0041] Step a, camera calibration (monocular vision system calibration, which is a prior art that can achieve multi-point position measurement of the end effector in the world coordinate system, robotic arm motion control, and acquisition of camera images and robotic arm status), real-time image acquisition and identification of the T / R component 26 through contour detection and template matching methods.

[0042] Step b, the system controller controls the robot arm 25 to make the vacuum suction cup 8 grab the T / R component 26 in the T / R component storage library (open the supply valve, close the destruction valve, so that the contact part of the vacuum suction cup 8 and the T / R component 26 generates negative pressure to achieve the grabbing of the T / R component 26), and move it to the top of the array back plate 27.

[0043] Step c, take a photo with the industrial camera 21 and detect the position of the threaded hole (specifically the center position of the threaded hole). According to the detection result, the system controller controls the robot arm 25 to move to the target position, aligns the T / R assembly 26 with the electrical connector in the array back plate 27 and inserts it. After insertion, the vacuum suction cup 8 is disengaged from the T / R assembly 26 (close the supply valve, open the destruction valve, so that the vacuum suction cup 8 is disengaged from the TR assembly).

[0044] Step d, the two stroke readable cylinders 6 move downward at the same time, and the two DC motors 16 work to drive the electric screwdriver bit 11 to rotate. The electric screwdriver bit 11 screws the screw into the assembly hole of the T / R component 26. During the tightening process, the stroke readable cylinder 6 and the torque sensor 13 respectively record the axial feed signal and torque signal fed back during the tightening process to control the axial preload force of the thread to meet the assembly requirements (the screw first passes through the rubber tube and is blown into the pneumatic chuck 10 by the air pump. During the downward movement of the stroke readable cylinder 6, the electric screwdriver bit 11 will drive the screw to push open the clamping claw at the front end of the pneumatic chuck 10 and screw the screw into the assembly hole of the T / R component 26).

[0045] The difference in axial feed at both ends is controlled by the two-stroke readable cylinder 6 to be less than 0.01 mm. When the torque sensor 13 detects a surge in torque (i.e. the screw is about to be tightened), the system controller controls the DC motor 16 to further tighten until the torques T1 and T2 on both sides reach the range C: C = {(T1, T2)|T min1 ≤T1≤T max1 , T min2 ≤T2≤ Tmax2}, where T min1 and T max1 are the minimum tightening torque and maximum tightening torque for the screw on one side to meet fatigue performance, T min2 and T max2 The minimum tightening torque and maximum tightening torque for the other side screw to meet fatigue performance are shown in Figure 5 The unit of torque is N·m.

[0046] In this embodiment, in step b, the positions of the pneumatic chuck 10 and the threaded hole are measured by image vision, and the movement of the mechanical arm 25 is controlled by the precision compensation method to ensure the matching accuracy between the chuck outlet and the threaded hole. Specifically, it includes: obtaining the coordinate P of the threaded hole, searching the cubic grid where the point P is located in the robot base coordinate system, inputting the theoretical coordinates of the eight vertices of the point P in the cubic grid into the BP neural network, predicting the actual coordinates of the eight vertices, and calculating the errors of the point P in three directions by the interpolation method, thereby reversely correcting the theoretical coordinates to obtain accurate coordinates, and the system controller controls the mechanical arm 25 to move to the corresponding position to complete the matching of the chuck outlet and the threaded hole.

[0047] In the present invention, after the installation of one T / R assembly 26 is completed, the stroke readable cylinder 6 is reset and the DC motor 16 stops rotating. Then the installation of the next T / R assembly 26 is carried out.

[0048] The above are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should be regarded as the protection scope of the present invention.

Claims

1. An assembly method for assembling an array antenna T / R assembly, using an assembly system for assembling an array antenna T / R assembly, the assembly system comprising a base (24), a mechanical arm (25), a vacuum generating system, a system controller and an actuator; the mechanical arm (25) is mounted on the base (24); The vacuum generating system comprises an air source, a supply valve, a destroying valve, a throttle valve and a vacuum generator, wherein the supply valve is respectively connected to the air supply port of the vacuum generator and the air source; the destroying valve is respectively connected to the air inlet of the throttle valve and the air source, and the air outlet of the throttle valve is connected to a vacuum suction cup (8); the vacuum port of the vacuum generator is connected to the vacuum suction cup (8); the system controller is used to control the mechanical arm (25), the vacuum generating system and the actuator to realize the assembly of the T / R component (26) in the array back plate (27); The actuator comprises an upper substrate (1), a vacuum suction cup (8), an industrial camera (21), a lens (22), an annular light source (23), two first support plates (5), two stroke readable cylinders (6), two pneumatic chucks (10) and two DC motors (16); The upper base plate (1) is arranged horizontally, and a rear side plate (2) is vertically fixed to the left and right sides of the rear of the upper base plate (1), and a vertical linear guide rail (3) is fixed on the inner side of each rear side plate (2); the first support plate (5) is L-shaped, and the long sections of the two first support plates (5) are respectively fixedly connected to the sliders (4) of the two linear guide rails (3); the upper base plate (1) is connected to the end flange of the mechanical arm (25); A torque sensor (13) is fixed to the upper end surface of the short section of each of the two first support plates (5); a second support plate (14) is vertically fixed to the inner side of the long section of each of the two first support plates (5) and located above the corresponding torque sensor (13); a planetary reducer (15) is fixed to the upper end surface of each second support plate (14); the output shaft of the planetary reducer (15) is inserted downward into the corresponding torque sensor (13); the output shaft of the torque sensor (13) passes downward through the short section of the corresponding first support plate (5) and is connected to the electric screwdriver (11) through a bellows coupling (12); the output shafts of the two DC motors (16) are inserted downward into the corresponding planetary reducer (15), and a magnetoelectric encoder (17) is installed at the tail of each DC motor (16); A partition plate (18) is vertically fixed at the middle position of the lower end surface of the upper base plate (1) to separate the two DC motors (16) and the two linear guide rails (3); the two stroke readable cylinders (6) are respectively fixed at the left and right positions on the front side of the lower end surface of the upper base plate (1), and the output shafts of the two stroke readable cylinders (6) are respectively fixedly connected to the short ends of the two first support plates (5); A suction cup support plate (7) is fixed at the bottom of the partition plate (18), and a vacuum suction cup (8) is fixed below the suction cup support plate (7); a serpentine plate (9) is fixed at the bottom of each of the two rear side plates (2), and the ends of the two serpentine plates (9) are bent and extended to the left and right sides of the vacuum suction cup (8), and the two pneumatic chucks (10) are respectively fixed at the bottom of the ends of the two serpentine plates (9), and the pneumatic chucks (10) are coaxial with the corresponding electric screwdriver head (11); The industrial camera (21) is fixed on the outside of an angled fixing plate (19); a grooved fixing plate (20) is fixed on the upper end surface of the annular light source (23); the angled fixing plate (19) and the grooved fixing plate (20) are fixed to the bottom of the partition plate (18) together by bolts; the industrial camera (21) is located above the annular light source (23); the lens (22) is threadedly connected to the industrial camera (21); The upper part of the rear side plate (2) is bent and fixed to the upper base plate (1) by screws; the linear guide rail (3) is fixed to the rear side plate (2) by bolts; the slider (4) is fixed to the long section of the first support plate (5) by screws; the magnetoelectric encoder (17) is fixed to the tail of the DC motor (16) by screws; the second support plate (14) is fixed to the long section of the first support plate (5) by screws; the torque sensor (13) is fixed to the short section of the first support plate (5) by screws; the stroke readable cylinder (6) is fixed to the upper base plate (1) by bolts; the stroke readable cylinder The end of the output shaft of (6) is provided with a thread and is fixed to the end of the short section of the first support plate (5) by a nut; the upper end of the suction cup bracket plate (7) is fixed to the bottom of the partition plate (18) by a screw, and the vacuum suction cup (8) is fixed to the suction cup bracket plate (7) by a double nut; the serpentine plate (9) is fixed to the rear side plate (2) by a bolt, and the pneumatic chuck (10) is fixed to the end of the serpentine plate (9) by a nut; the industrial camera (21) is fixed to the angle fixing plate (19) by a screw, and the annular light source (23) is fixed to the groove fixing plate (20) by a screw; It is characterized in that The assembly method comprises the following steps: Step a, camera calibration, real-time image acquisition and identification of T / R components (26) through contour detection and template matching methods; Step b, the system controller controls the robot arm (25) to make the vacuum suction cup (8) grab the T / R component (26) in the T / R component storage and move it to the top of the array back plate (27); Step c, image acquisition and detection of threaded hole positions. Based on the detection results, the system controller controls the robot arm (25) to move to the target position, aligns the T / R assembly (26) with the electrical connector in the array back plate (27) and inserts it. After the insertion, the vacuum suction cup (8) is separated from the T / R assembly (26); Step d, the two-stroke readable cylinder (6) moves downward, and at the same time, the two DC motors (16) work to drive the electric screwdriver bit (11) to rotate, and the electric screwdriver bit (11) screws the screw into the assembly hole of the T / R component (26). During the tightening process, the stroke readable cylinder (6) and the torque sensor (13) respectively record the axial feed amount signal and torque signal fed back during the tightening process to control the axial preload force of the thread to meet the assembly requirements; the difference in axial feed amount at both ends is controlled to be less than 0.01 mm by the two-stroke readable cylinder (6); In step d, when the torque sensor (13) detects a torque surge, the system controller controls the DC motor (16) to further tighten until the torques T1 and T2 on both sides reach a range C: C = {(T1, T2) | T min1 ≤T1≤T max1 , T min2 ≤T2≤T max2 }, where T min1 and T max1 are the minimum tightening torque and maximum tightening torque for the screw on one side to meet fatigue performance, T min2 and T max2 They are the minimum tightening torque and maximum tightening torque for the other side screw to meet fatigue performance; the torque unit is N·m.

Images