Automatic flexible assembling device and method for circumferential ribs

Abstract

The invention relates to an automatic flexible assembling device and method for circumferential ribs. The automatic flexible assembling device for the circumferential ribs comprises an industrial robot and an end effector. The industrial robot is used for carrying the end effector to move to a specified operation area, so that the ribs are attached to the skin; the end effector is used for positioning and clamping the ribs and applying pressing force to the ribs to complete glue joint; the end executors comprise a long rib flexible assembly end executor and a short rib flexible assembly end executor; the long rib flexible assembly end effector comprises a main body frame and a plurality of first fixed type flexible positioning and pressing units. The short rib flexible assembly end effector comprises an inner static frame, an outer movable frame, a plurality of second fixed type flexible positioning and pressing units and a movable type flexible positioning and pressing unit. According to the device, automatic clamping, positioning and cementing assembly of solidified annular ribs of various types and various sizes can be achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aircraft part assembly, in particular to a circumferential rib automatic flexible assembly device and method. BACKGROUND

[0002] The material of aircraft parts gradually changes from metal to overall composite material, and the use of composite material parts can effectively reduce the weight of the structure and reduce resistance. The composite material complex rotary body structure with circumferential ribs has arc-shaped ribs, and the skin and the external ribs are formed by secondary gluing. The number of ribs is large, and the length difference is large. The glued ribs are manually loaded one by one, and the position of the rib is controlled by using a positioning card. The positioning card has many types and a large number, and the assembly efficiency is low and the degree of automation is low. The actual profile of the rib and the skin deviates from the theoretical profile, resulting in a gap between the rib and the skin. The existing positioning and installation of circumferential ribs are completed by manual holding, which has low automation degree and long assembly cycle, cannot realize simultaneous positioning of multiple glued ribs, and has uneven gap between the rib and the skin. The assembly precision and gluing quality are difficult to guarantee. SUMMARY

[0003] The present application provides a circumferential rib automatic flexible assembly device and method to solve the problems in the background art.

[0004] In a first aspect, the present application provides a circumferential rib automatic flexible assembly device, comprising an industrial robot and an end effector; the industrial robot is used to carry the end effector to move to a specified work area to make the rib adhere to the skin; the end effector is used for positioning, clamping of the rib, and applying pressure to the rib to complete gluing. The end effector comprises a long rib flexible assembly end effector and a short rib flexible assembly end effector; the long rib flexible assembly end effector comprises a main body frame and a plurality of first fixed flexible positioning and pressing units; the short rib flexible assembly end effector comprises an internal static frame, an external dynamic frame, a plurality of second fixed flexible positioning and pressing units, and a movable flexible positioning and pressing unit.

[0005] Further, a pneumatic quick clamping convex head is mounted on the end effector, and a clamping concave head is carried by the industrial robot; the positioning and clamping and loosening of the concave head on the convex head realize the switching of the two end effectors.

[0006] Further, a plurality of first fixed flexible positioning and pressing units are distributed on the main body frame according to the actual position of the rib, and are connected with the main body frame through guide columns and guide sleeves to realize movement along the radial direction of the rib. A plurality of the second fixed flexible positioning and pressing units are installed on the internal static frame for positioning and clamping one end of the short rib; one second fixed flexible positioning and pressing unit and a plurality of the mobile flexible positioning and pressing units are installed on the external dynamic frame for positioning and clamping the other end of the short rib.

[0007] Further, the first fixed flexible positioning and pressing unit comprises a pressing unit mounting support, a first servo pressing unit, a first positioning and clamping unit mounting base, a first pneumatic slide and a first positioning clamp plate. The pressing unit mounting support is welded on the main body frame. The first servo pressing unit comprises a servo motor, a lead screw, a guide shaft, a pressing head and a force sensor, which are installed on the pressing unit mounting support by screws, for positioning the lower edge of the rib and providing the pressing force required for gluing and feeding back measurement data. The first positioning clamp plate is installed on the first positioning and clamping unit mounting base by screws, for positioning the web of the rib. The first pneumatic slide is used to clamp and release the rib, which is installed on the first positioning and clamping unit mounting base by screws.

[0008] Further, the internal static frame is connected to the end of the industrial robot through a pneumatic quick clamping convex head, and the relative position with the industrial robot remains unchanged during the assembly of the short rib. Further, the short rib flexible assembly end effector further comprises a guide rail slide and a guide rail. The guide rail slide is installed on the outer side of the internal static frame, the guide rail is installed on the inner side of the external dynamic frame, and the guide rail slide cooperates with the guide rail to realize the movement of the external dynamic frame relative to the internal static frame along the circumference of the skin.

[0009] Further, the short rib flexible assembly end effector further comprises a sliding positioning sheet and a positioning block. The sliding positioning sheet is welded on the external dynamic frame, and the positioning block is welded on the internal static frame. The pin hole on the sliding positioning sheet is aligned with the pin hole on the positioning block, and the relative position of the two frames is fixed by inserting a positioning pin and locking with a screw.

[0010] Further, the short rib flexible assembly end effector further comprises a guide column mounting frame and a reinforcing corner piece. A plurality of the mobile flexible positioning and pressing units are installed in the guide column mounting frame through guide column guide sleeves, the guide column mounting frame is fixed on the external dynamic frame by screws, and the reinforcing corner piece is used to reinforce the guide column mounting frame.

[0011] Further, the structure of the second fixed flexible positioning and pressing unit is consistent with that of the first fixed flexible positioning and pressing unit. The mobile flexible positioning and pressing unit comprises a guide column, a sliding positioning plate, a sliding base, a second servo pressing unit, a second positioning clamping plate, a second pneumatic sliding table, and a second positioning clamping unit mounting base. The guide column is connected with the guide column mounting frame in an interference fit, and the sliding base is internally provided with a guide sleeve for sliding along the guide column and being positioned and locked through the pin hole and the threaded hole on the sliding positioning plate. The second positioning clamping unit mounting base is mounted on the sliding base through the guide column guide sleeve, and the second positioning clamping plate and the second pneumatic sliding table are mounted on the second positioning clamping unit mounting base through screws for positioning and clamping of the short rib web surface.

[0012] In a second aspect, the application provides an automatic flexible assembly method for ring-shaped ribs, which is realized by using the automatic flexible assembly device for ring-shaped ribs as described above. The automatic flexible assembly method for ring-shaped ribs comprises the following steps. According to the length of the rib, the industrial robot is switched to the corresponding end effector; The industrial robot drives the end effector to move to the rib upper shelf operation area, so that the pose of the end effector is convenient for the operator to position the rib; Adjust each flexible positioning and pressing unit to the preset state, and open each pneumatic sliding table to a width at which the rib can be smoothly placed; Place multiple ribs in the same group on the designated position on the end effector for positioning, and after the operator issues an instruction, simultaneously clamp the rib web of each pneumatic sliding table on the end effector, so that the rib does not slide relative to the pneumatic sliding table; Uniformly glue each rib, and the gluing range covers the entire area of the contact surface between the rib and the skin; The end effector carries the rib to quickly move to the vicinity of the skin assembly area according to the pre-defined trajectory of offline programming, and the rib does not contact the skin during the movement; The end effector clamps the rib to slowly move according to the pre-set motion trajectory, and the pose and motion trajectory of the end effector are monitored and compensated in real time based on the laser tracker during the movement. When the reading of the force sensor on the servo pressing unit is displayed, the end effector stops moving, and at this time, the rib slightly contacts the skin; The industrial robot remains in a stationary state, the servo motor of the servo pressing unit is switched to force control mode, the theoretical close contact force is set as the expected force of the motor, each servo pressing unit is extended forward according to the expected force, and when the actual contact force detected by the force sensor on each servo pressing unit is equal to the expected force, the servo pressing unit moves, and the rib is pressed on the skin surface to complete the pressing task; Each pneumatic slide table is opened simultaneously, and the opening width meets the requirement that the end effector does not interfere when leaving the rib; Repeat the above steps until all the rib installation is completed.

[0013] The above technical solutions of the present application have the following advantages: The automatic flexible assembly device and method for ring-shaped ribs provided by the present application are used to perform automatic positioning and gluing processes of multiple ribs in the same group, and include an industrial robot, an end effector, the end effector including a long-rib flexible assembly end effector and a short-rib flexible assembly end effector, the ribs are divided into a long-rib group and a short-rib group according to the length of the ring-shaped ribs and the assembly area, and the assembly tasks of ribs in different groups are performed by the long-rib flexible assembly end effector and the short-rib flexible assembly end effector respectively, so as to reduce the positioning and clamping and trajectory planning difficulty, improve the assembly efficiency, and the high-flexibility robot end effector designed according to the shape characteristics and assembly process of the ring-shaped ribs can effectively realize flexible positioning and clamping and automatic gluing and assembly of different types and sizes of ring-shaped ribs. BRIEF DESCRIPTION OF DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the specific embodiments or prior art of the present application, the drawings needed in the description of the specific embodiments or prior art will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0015] Figure 1 The structure schematic diagram of the automatic flexible assembly device for ring-shaped ribs provided by the present application is shown in the figure. Figure 2 The structure schematic diagram of the long-rib flexible assembly end effector provided by the present application is shown in the figure. Figure 3 The structure schematic diagram of the short-rib flexible assembly end effector provided by the present application is shown in the figure. Figure 4 The installation schematic diagram of the first fixed flexible positioning and pressing unit provided by the present application is shown in the figure. Figure 5 The composition schematic diagram of the first fixed flexible positioning and pressing unit provided by the present application is shown in the figure. Figure 6 The composition schematic diagram of the short-rib flexible assembly end effector provided by the present application is shown in the figure. Figure 7 The composition schematic diagram of the mobile flexible positioning and pressing unit provided by the present application is shown in the figure. Figure 8 The process flow diagram of the automatic flexible assembly process for ring-shaped ribs provided by the present application is shown in the figure.

[0016] Reference signs: 1 - industrial robot; 2 - end effector; 21 - long rib flexible assembly end effector; 22 - short rib flexible assembly end effector; 211 - pneumatic quick clamping boss; 212 - main body frame; 213 - first fixed flexible positioning and pressing unit; 2131 - pressing unit mounting support; 2132 - first servo pressing unit; 2133 - first positioning and clamping unit mounting base; 2134 - first pneumatic slide table; 2135 - first positioning clamping plate; 221 - pneumatic quick clamping boss; 222 - inner static frame; 223 - outer dynamic frame; 224 - guide rail slider; 225 - guide rail; 226 - sliding positioning piece; 227 - positioning block; 228 - second fixed flexible positioning and pressing unit; 229 - movable flexible positioning and pressing unit; 2210 - guide column mounting frame; 2211 - reinforcing corner piece; 2291 - guide column; 2292 - sliding positioning plate; 2293 - sliding base; 2294 - second servo pressing unit; 2295 - second positioning clamping plate; 2296 - second pneumatic slide table; 2297 - second positioning and clamping unit mounting base. DETAILED DESCRIPTION

[0017] In the following description, for the purposes of explanation and not limitation, specific details are set forth, such as particular system configurations, techniques, etc. in order to provide a thorough understanding of the embodiments described. However, it will be apparent to one skilled in the art that the application can be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the application with unnecessary detail.

[0018] It should be understood that the term "comprising" when used in this specification and the appended claims, indicates the presence of the described features, integers, steps, operations, elements, and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0019] In addition, the terms "first", "second", "third", etc. are used herein only to describe different features, and do not imply or suggest relative importance.

[0020] Reference to "one embodiment" or "some embodiments" or "one implementation" or "some implementations" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The appearances of the phrase "in one embodiment" or "in some embodiments" in various places in the specification are not necessarily all referring to the same embodiment, although it can. The terms "including," "comprising," "having" and variations thereof are meant to encompass the items listed thereafter and equivalents thereof as well as additional items. The terms "plurality" and "a plurality" encompass both "two or more" and "three or more."

[0021] The traditional assembly method of the hoop rib includes the processes of gluing, positioning, gluing, heating and pressurizing curing, etc., wherein the first three steps are completed by manual holding of the rib, one rib is assembled at a time, and the operation process is complicated and inefficient.

[0022] Therefore, it is urgent to develop an automatic flexible assembly system for hoop ribs, which integrates force-position hybrid control technology, robot trajectory planning and simulation technology, online pose accuracy detection and compensation technology, etc., to realize automatic clamping positioning and gluing assembly of various types and sizes of cured hoop ribs, so as to solve the problems of heavy manual work and easy errors, and improve the assembly quality and efficiency.

[0023] The specific embodiments of the present application are described in further detail below in conjunction with the accompanying drawings and embodiments. The following embodiments are used to illustrate the present application, but are not used to limit the scope of the present application.

[0024] The embodiment of the present application provides an automatic flexible assembly device for hoop ribs, which comprises an industrial robot and an end effector; the industrial robot is used to carry the end effector to move to a specified work area, so that the rib is attached to the skin; the end effector is used for positioning, clamping of the rib, and applying pressure to the rib to complete gluing; the end effector comprises a long rib flexible assembly end effector and a short rib flexible assembly end effector; the long rib flexible assembly end effector comprises a main body frame and a plurality of first fixed flexible positioning and pressing units; the short rib flexible assembly end effector comprises an internal static frame, an external dynamic frame, a plurality of second fixed flexible positioning and pressing units and a movable flexible positioning and pressing unit.

[0025] In some embodiments, a pneumatic quick clamping convex head is mounted on the end effector, and a clamping concave head is carried by the industrial robot; the positioning, clamping and loosening of the convex head by the concave head realize the switching of the two end effectors.

[0026] In some embodiments, a plurality of the first fixed flexible positioning and pressing units are distributed on the main frame according to the actual positions of the ribs, connected with the main frame through guide columns and guide sleeves, and move along the radial direction of the ribs; a plurality of the second fixed flexible positioning and pressing units are installed on the internal static frame for positioning and clamping one end of the short ribs; one second fixed flexible positioning and pressing unit and a plurality of the mobile flexible positioning and pressing units are installed on the external dynamic frame for positioning and clamping the other end of the short ribs.

[0027] In some embodiments, the first fixed flexible positioning and pressing unit comprises a pressing unit mounting support, a first servo pressing unit, a first positioning and clamping unit mounting base, a first pneumatic sliding table, and a first positioning clamping plate; the pressing unit mounting support is welded on the main frame; the first servo pressing unit comprises a servo motor, a lead screw, a guide shaft, a pressing head, and a force sensor, which are installed on the pressing unit mounting support through screws, and are used to position the lower edge of the rib and provide the pressing force required for gluing and feedback measurement data; the first positioning clamping plate is installed on the first positioning and clamping unit mounting base through screws, and is used to position the web surface of the rib; the first pneumatic sliding table is used to clamp and release the rib, and is installed on the first positioning and clamping unit mounting base through screws.

[0028] In some embodiments, the internal static frame is connected with the end of the industrial robot through a pneumatic quick clamping convex head, and the relative position with the industrial robot remains unchanged during the assembly of the short rib. In some embodiments, the short rib flexible assembly end effector further comprises a guide rail slider and a guide rail; the guide rail slider is installed on the outer side of the internal static frame, the guide rail is installed on the inner side of the external dynamic frame, and the guide rail slider cooperates with the guide rail to realize the movement of the external dynamic frame relative to the internal static frame along the circumference of the skin.

[0029] In some embodiments, the short rib flexible assembly end effector further comprises a sliding positioning sheet and a positioning block; the sliding positioning sheet is welded on the external dynamic frame, and the positioning block is welded on the internal static frame; the pin holes on the sliding positioning sheet are aligned with the pin holes on the positioning block, and the relative position of the two frames is fixed by inserting a positioning pin and locking with a screw.

[0030] In some embodiments, the short rib flexible assembly end effector further comprises a guide column mounting frame and a reinforcing corner piece; a plurality of the mobile flexible positioning and pressing units are installed in the guide column mounting frame through guide column guide sleeves, the guide column mounting frame is fixed on the external dynamic frame through screws, and the reinforcing corner piece is used to reinforce the guide column mounting frame.

[0031] In some embodiments, the structure of the second fixed flexible positioning and pressing unit is consistent with the first fixed flexible positioning and pressing unit; the mobile flexible positioning and pressing unit comprises a guide column, a sliding positioning plate, a sliding base, a second servo pressing unit, a second positioning clamping plate, a second pneumatic slide and a second positioning clamping unit mounting base; the guide column is connected with the guide column mounting frame by interference, the sliding base is internally provided with a guide sleeve for sliding along the guide column and is positioned and locked through the pin hole and the threaded hole on the sliding positioning plate; the second positioning clamping unit mounting base is mounted on the sliding base through the guide column guide sleeve, and the second positioning clamping plate and the second pneumatic slide are mounted on the second positioning clamping unit mounting base through screws for positioning and clamping of the short rib web surface.

[0032] The annular rib automatic flexible assembly system relates to an automatic positioning and gluing process of multiple ribs in the same group, which is composed of an industrial robot, an end effector and general electrical, pneumatic elements, etc. The industrial robot adopts a six-degree-of-freedom serial robot, has high flexibility, a large workspace and good repeatability, and is used for realizing large-range movement of the end effector at different work positions.

[0033] The size, shape and mounting position of the annular rib on the skin have great differences, and it is difficult to meet the positioning and clamping requirements of all kinds of ribs by using the same effector. According to the length and assembly area of the annular rib, the rib is divided into a long rib group and a short rib group, and different groups of rib assembly tasks are performed by a long rib flexible assembly end effector and a short rib flexible assembly end effector respectively, so as to reduce the positioning and clamping and trajectory planning difficulty and improve the assembly efficiency. The main frame of the effector is provided with a pneumatic quick clamping convex head, the robot body end carries a clamping concave head, the quick positioning and clamping and loosening of the concave head on the convex head realize the quick switching of the two end effectors. In order to improve the assembly efficiency and shorten the product development cycle, the end effector is designed to simultaneously meet the positioning and installation of 5 ribs in the same group.

[0034] The end effector mainly consists of a main frame and a plurality of flexible positioning and pressing units. A single long rib is positioned and installed by three flexible positioning and pressing units, which are uniformly distributed along the circumference of the rib. The size difference between the long ribs in different installation areas is small, so the relative positions of the three flexible positioning and pressing units along the circumference of the rib are fixed. The outer shape of the circumferential rib is not a standard circular arc, and different flexible units have different positioning and clamping positions of the rib along the radial direction. A guide column and a guide sleeve are installed between the flexible positioning and pressing unit and the main frame, so that the flexible unit can move along the skin radial direction relative to the main frame to adapt to the change of the radial positioning and clamping position of different ribs. The fixed flexible positioning and pressing unit is divided into a positioning and clamping unit and a servo pressing unit. The positioning and clamping unit mainly consists of an installation base, a positioning clamping plate and a pneumatic sliding table, which is used for positioning and clamping the rib web; the servo pressing unit mainly consists of a servo motor, a lead screw, a guide shaft, a pressing head and a force sensor, which is used for positioning the lower edge of the rib and applying pressing force after the rib is attached to the skin surface and feeding back the pressing force value.

[0035] The short rib is positioned and installed by two flexible positioning and pressing units. The size difference between the short ribs in the circumferential and axial installation areas is large, so the fixed flexible positioning and pressing unit cannot meet the positioning and clamping of all short ribs. Therefore, the flexibility of the flexible unit along the circumference of the rib needs to be increased to adapt to the change of the positioning and clamping position of different size short ribs. The main frame of the flexible assembly end effector of the short rib is divided into an internal static frame and an external dynamic frame, and the outer shape is a circular arc to match the part shape. The internal static frame is connected to the robot end through a quick clamping protrusion, and the external dynamic frame is connected to the internal static frame through a guide rail sliding block mechanism, which can slide along the circular arc circumference relative to the internal static frame.

[0036] The internal static frame contains five fixed flexible positioning and pressing units, which have the same structure as the flexible unit of the long rib end effector, and are used for positioning and clamping one end of the short rib; the external dynamic frame contains one fixed flexible positioning and pressing unit and four movable flexible positioning and pressing units, which are used for positioning and clamping the other end of the short rib. The movable flexible unit adds a degree of freedom along the tangent direction of the circular arc on the basis of the fixed flexible unit to cope with the change of the positioning and clamping position of different groups and different lengths of short ribs. When assembling different groups of short ribs, the position of the movable flexible positioning and pressing unit relative to the external dynamic frame and the position of the external dynamic frame relative to the internal static frame are manually adjusted by manual adjustment, and are positioned and locked by positioning pins, positioning sheets and screws.

[0037] The following will be described by specific examples.

[0038] Embodiment The circumferential rib flexible automatic assembly system in this embodiment is as shown in Figure 1As shown, it includes an industrial robot 1 and an end effector 2. The industrial robot 1 is used to carry the end effector 2 to move quickly to the designated work area, and to slowly match the rib and the skin during bonding. The end effector 2 is used for positioning, clamping of the rib, and applying pressure to complete the bonding after the rib is matched with the skin.

[0039] To meet the assembly needs of different types of ribs, the end effector is divided into long rib flexible assembly end effector 21 and short rib flexible assembly end effector 22, as shown in Figure 2 and Figure 3 The two actuators are respectively provided with pneumatic quick clamping convex heads 211 and 221, which cooperate with the quick clamping concave heads on the end of the robot to realize quick switching of different end effectors.

[0040] As shown in Figure 4 and Figure 5 The long rib flexible assembly end effector is composed of a pneumatic quick clamping convex head 211, a main frame 212 and a first fixed flexible positioning and pressing unit 213. The main frame 212 is designed in one piece, which has high strength and rigidity. The 15 first fixed flexible positioning and pressing units 213 are distributed on the main frame 212 according to the actual position of the rib, and are connected with the main frame 212 through guide column and guide sleeve, which can realize movement along the radial direction of the rib. The flexible unit is divided into 5 groups, each group has 3 flexible units to realize positioning and clamping of a single long rib, and the 5 groups of fixed flexible positioning and pressing units can realize bonding and assembly of 5 ribs in the same group at the same time.

[0041] The first fixed flexible positioning and pressing unit 213 is composed of a pressing unit mounting support 2131, a first servo pressing unit 2132, a first positioning and clamping unit mounting base 2133, a first pneumatic slide 2134 and a first positioning card 2135. The pressing unit mounting support 2131 is welded on the main frame 212, the first servo pressing unit 2132 is composed of a servo motor, a lead screw, a guide shaft, a pressing head and a force sensor, which is installed on the pressing unit mounting support 2131 through screws, and is used to realize positioning of the lower edge of the rib and provide pressing force required for bonding and feedback measurement data. The first positioning card 2135 is installed on the first positioning and clamping unit mounting base 2133 through screws, which is used to position the web surface of the rib. The first pneumatic slide 2134 is used to realize clamping and loosening of the rib, which is also installed on the first positioning and clamping unit mounting base 2133 through screws.

[0042] The short rib flexible assembly end effector is as shown in Figure 6 and Figure 7As shown, it is mainly composed of pneumatic quick clamping convex head 221, internal static frame 222, external dynamic frame 223, guide rail slider 224, guide rail 225, sliding positioning piece 226, positioning block 227, second fixed flexible positioning and pressing unit 228, movable flexible positioning and pressing unit 229, guide column mounting frame 2210 and reinforcing corner piece 2211. The internal static frame 222 is connected with the robot end through the pneumatic quick clamping convex head 221, and the relative position with the robot remains unchanged during the assembly process of the short bar. The guide rail slider 224 is installed on the outer side of the internal static frame 222, the guide rail 225 is installed on the inner side of the external dynamic frame 223, the guide rail slider 224 cooperates with the guide rail 225, realizes the movement of the external dynamic frame 223 relative to the internal static frame 222 along the circumference of the skin, and thus expands the clamping range of the flexible positioning and pressing unit.

[0043] The sliding positioning piece 226 is welded on the external dynamic frame 223, and the positioning block 227 is welded on the internal static frame 222. When performing assembly work of different groups of short bars, the external dynamic frame 223 is slid to align the pin holes on the sliding positioning piece 226 with the pin holes on the positioning block 227, a positioning pin is inserted and locked with a screw to fix the relative position of the two frames. Each short bar is clamped and positioned by two flexible units, and the flexible assembly end effector of the short bar contains 10 flexible units, which can simultaneously realize the gluing assembly of 5 short bars in the same group. The second fixed flexible positioning and pressing unit 228 has the same structure as the first fixed flexible positioning and pressing unit 213, wherein 5 second fixed flexible units 228 are installed on the internal static frame 222 for positioning and clamping of one end of the short bar; one second fixed flexible unit 228 and four movable flexible positioning and pressing units 229 are installed on the external dynamic frame 223 for positioning and clamping of the other end of the short bar. The same group of 5 short bars distributed along the skin axis may have a large difference in length, and only changing the relative position of the external dynamic frame 223 cannot meet the positioning and installation requirements of the short bars in the same group, so an additional degree of freedom is needed on the external dynamic frame 223.

[0044] 4 mobile flexible positioning and pressing units 229 are installed in the guide pillar mounting frame 2210 through guide pillar guide sleeves, can be manually adjusted to move along the circular tangent direction, and realize positioning and clamping of different end positions of 5 short ribbons in the same group. The guide pillar mounting frame 2210 is fixed on the outer moving frame 223 through screws, and the reinforcing angle piece 2211 is used for reinforcing the guide pillar mounting frame 2210. The mobile flexible positioning and pressing unit 229 is composed of a guide pillar 2291, a sliding positioning plate 2292, a sliding base 2293, a second servo pressing unit 2294, a second positioning clamping plate 2295, a second pneumatic sliding table 2296 and a second positioning clamping unit mounting base 2297. The guide pillar 2291 is connected with the guide pillar mounting frame 2210 in an interference fit, the sliding base 2293 is internally provided with a guide sleeve, and is manually adjusted to slide along the guide pillar 2291, and is positioned and locked through the pin holes and threaded holes on the sliding positioning plate 2292. The second positioning clamping unit mounting base 2297 is installed on the sliding base 2293 through a guide pillar guide sleeve, the second positioning clamping plate 2295 and the second pneumatic sliding table 2296 are installed on the second positioning clamping unit mounting base 2297 through screws, and are used for positioning and clamping of the short ribbon web surface. The second servo pressing unit 2294 is consistent with the first servo pressing unit 2132 in structure and function.

[0045] The embodiment also provides a ring-shaped rib automatic flexible assembly method, which is realized by the ring-shaped rib automatic flexible assembly device. Figure 8 As shown in the figure, the ring-shaped rib automatic flexible assembly method comprises the following steps: (1) According to the length of the rib, the industrial robot system 1 is switched to the corresponding end effector 21 or 22; (2) The industrial robot 1 drives the rib flexible assembly end effector 21 or 22 to move to the rib manual feeding operation area, so that the pose of the end effector 21 or 22 is convenient for the operator to position the rib; the robot 1 stops moving; (3) Adjust each flexible positioning and pressing unit 213 or 228 and 229 to a preset state; (4) Each pneumatic sliding table 2134 or 2296 is opened to a width at which the rib can be smoothly placed; (5) Manually place 5 ribs in the same group on the designated position of the end effector 21 or 22 for positioning; (6) After the operator issues an instruction, each pneumatic sliding table 2134 or 2296 on the end effector simultaneously clamps the rib web, so that the rib does not slide relative to the pneumatic sliding table 2134 or 2296; (7) Each rib is manually coated with glue, the glue should be evenly coated, and the coating range covers the entire area of the contact surface between the rib and the skin; (8) The robot end effector 21 or 22 carries the rib to the vicinity of the skin assembly area along the pre-defined trajectory offline programmed, and the rib does not contact the skin during the movement; then, the end effector 21 or 22 clamps the rib and moves slowly along the preset motion trajectory, the pose and motion trajectory of the end effector 21 or 22 are monitored and compensated in real time based on the laser tracker during the movement, and the end effector 21 or 22 stops moving when the force sensor on the servo compression unit 2132 or 2294 displays the reading, at which time the rib slightly contacts the skin.

[0046] (9) The robot 1 remains in a stationary state, the servo motor of the servo compression unit 2132 or 2294 is switched to force control mode, and the theoretical close contact force is set as the desired force of the motor, each servo compression unit 2132 or 2294 extends forward according to the desired force, and when the actual contact force detected by the force sensor on each servo compression unit 2132 or 2294 is equal to the desired force, the guide pillar servo compression unit 2132 or 2294 moves, and the rib is compressed on the skin surface.

[0047] (10) Each pneumatic slide 2134 or 2296 is opened at the same time, and the opening width meets the requirement that the end effector 21 or 22 does not interfere when it leaves the rib; (11) Repeat steps (1) to (10) until all rib installations are completed.

[0048] The automatic flexible assembly device and method for the annular rib provided by the embodiments of the present application solve the following problems: (1) The existing rib automatic positioning and clamping assembly technology and equipment are mostly suitable for straight line stringers, and cannot cope with the more complex arc type annular rib in the assembly process, and the current annular rib gluing assembly still adopts manual positioning and installation, the high flexibility robot end effector designed according to the shape characteristics and assembly process of the annular rib can effectively realize the flexible positioning, clamping and automatic gluing assembly of different types of annular ribs; (2) When using manual assembly, only one rib can be assembled at a time, the worker's task is heavy, and the assembly cycle is long, the end effector in the present application has multiple stations, and can simultaneously realize the positioning, clamping and gluing assembly of multiple ribs, reduces the number of manual assembly and clamping and the number of robot movements, and greatly improves the assembly efficiency; (3) The end effector adopts modular design, has high flexibility and part interchangeability, can effectively cope with the gluing needs of annular ribs of different lengths and shapes and different assembly areas, and is convenient to maintain; (4) The present application uses force-position hybrid control technology, online detection and compensation technology, etc., and can realize automatic high-precision positioning and high-quality gluing of the annular rib.

[0049] Due to the above characteristics, the automatic flexible assembly device and method for the annular rib can realize automatic positioning of the rib, reduce the intervention of manual work, have high automation, can position multiple ribs at a time, has high assembly efficiency, and can realize high-precision positioning of the rib.

[0050] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above functional units and modules is exemplified, and in actual application, the above functions can be completed by different functional units and modules according to needs, that is, the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above. Each functional unit or module in the embodiment can be integrated in one processing unit, or each unit can exist physically independently, or two or more units can be integrated in one unit. In addition, the specific names of each functional unit or module are only for easy distinction, and do not limit the protection scope of the application.

[0051] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can still be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. An automated flexible assembly device for annular ribbing, characterized in that, The application relates to a flexible assembly end effector for a long string and a short string. The end effector comprises a long string flexible assembly end effector and a short string flexible assembly end effector. The long string flexible assembly end effector comprises a main body frame and a plurality of first fixed flexible positioning and pressing units; the short string flexible assembly end effector comprises an internal static frame, an external dynamic frame, a plurality of second fixed flexible positioning and pressing units and a movable flexible positioning and pressing unit.

2. The automated flexible assembly of hoop fillets apparatus of claim 1, wherein, The end effector is provided with a pneumatic quick clamping convex head, and the industrial robot is provided with a clamping concave head; the positioning, clamping and loosening of the convex head by the concave head realize the switching of the two end effectors.

3. The automated flexible assembly of hoop fillets apparatus of claim 1, wherein, The first fixed flexible positioning and pressing units are distributed on the main body frame according to the actual position of the string, are connected with the main body frame through guide columns and guide sleeves and realize the movement along the radial direction of the string. The second fixed flexible positioning and pressing units are installed on the internal static frame and are used for the positioning and clamping of one end of the short string; one second fixed flexible positioning and pressing unit and a plurality of movable flexible positioning and pressing units are installed on the external dynamic frame and are used for the positioning and clamping of the other end of the short string.

4. The automated flexible assembly of hoop fillets apparatus of claim 1, wherein, The first fixed flexible positioning and pressing unit comprises a pressing unit mounting support, a first servo pressing unit, a first positioning and clamping unit mounting base, a first pneumatic sliding table and a first positioning clamping plate. The pressing unit mounting support is welded on the main body frame. The first servo pressing unit comprises a servo motor, a lead screw, a guide shaft, a pressing head and a force sensor, is installed on the pressing unit mounting support through screws and is used for realizing the positioning of the lower edge of the string and providing the pressing force required by the gluing and feeding back the measured data. The first positioning clamping plate is installed on the first positioning and clamping unit mounting base through screws and is used for positioning the web surface of the string. The first pneumatic sliding table is used for realizing the clamping and loosening of the string, is installed on the first positioning and clamping unit mounting base through screws.

5. The automated flexible assembly of hoop fillets apparatus of claim 1, wherein, The internal static frame is connected with the end of the industrial robot through the pneumatic quick clamping convex head and keeps the relative position unchanged with the industrial robot during the assembly of the short string.

6. The automatic flexible assembly device for hoop ribs according to claim 1, characterized in that: The short string flexible assembly end effector further comprises a guide rail sliding block and a guide rail. The guide rail sliding block is installed on the outer side of the internal static frame, the guide rail is installed on the inner side of the external dynamic frame, the guide rail sliding block cooperates with the guide rail and realizes the movement of the external dynamic frame relative to the internal static frame along the circumferential direction of the skin.

7. The automated flexible assembly of hoop fillets apparatus of claim 1, wherein, The short string flexible assembly end effector further comprises a sliding positioning sheet and a positioning block. The sliding positioning sheet is welded on the external dynamic frame, the positioning block is welded on the internal static frame, the pin holes on the sliding positioning sheet are aligned with the pin holes on the positioning block, a positioning pin is inserted and locked through screws so as to fix the relative position of the two frames.

8. The automated flexible assembly of hoop fillets apparatus of claim 1, wherein, The short rib flexible assembly end effector further comprises a guide pillar mounting frame and a reinforcing corner piece; A plurality of the mobile flexible positioning and pressing units are mounted in the guide pillar mounting frame through guide pillar guide sleeves, the guide pillar mounting frame is fixed on the outer movable frame through screws, and the reinforcing corner piece is used for reinforcing the guide pillar mounting frame.

9. The automated flexible assembly of hoop fillets apparatus of claim 8, wherein, The structure of the second fixed flexible positioning and pressing unit is consistent with that of the first fixed flexible positioning and pressing unit; The mobile flexible positioning and pressing unit comprises a guide pillar, a sliding positioning plate, a sliding base, a second servo pressing unit, a second positioning clamping plate, a second pneumatic sliding table and a second positioning clamping unit mounting base; The guide pillar is connected with the guide pillar mounting frame in an interference fit, the sliding base is internally provided with a guide sleeve for sliding along the guide pillar, and is positioned and locked through pin holes and threaded holes on the sliding positioning plate; The second positioning clamping unit mounting base is mounted on the sliding base through a guide pillar guide sleeve, and the second positioning clamping plate and the second pneumatic sliding table are mounted on the second positioning clamping unit mounting base through screws, for positioning and clamping of the short rib web surface.

10. An automated flexible assembly method for hoop ribs, characterized in that, The annular rib automatic flexible assembly device of any one of claims 1 to 9 is realized; The annular rib automatic flexible assembly method comprises: According to the length of the rib, the industrial robot is switched to the corresponding end effector; The industrial robot drives the end effector to move to the rib upper shelf operation area, so that the pose of the end effector is convenient for the operator to position the rib; Adjust each flexible positioning and pressing unit to a preset state, and open each pneumatic sliding table to a width at which the rib can be smoothly placed; Place multiple ribs in the same group on the designated position of the end effector for positioning, and after the operator issues an instruction, simultaneously clamp the rib web of each pneumatic sliding table on the end effector, so that the rib does not slide relative to the pneumatic sliding table; Uniformly glue each rib, and the gluing range covers the entire area of the contact surface between the rib and the skin; The end effector carries the rib to move quickly to the vicinity of the skin assembly area according to the pre-defined trajectory of offline programming, and the rib does not contact the skin during the movement; The end effector clamps the rib and moves slowly according to the pre-defined movement trajectory, the pose and movement trajectory of the end effector are monitored and compensated in real time based on the laser tracker during the movement, and the end effector stops moving when the force sensor on the servo pressing unit displays the reading, at which time the rib slightly contacts the skin; The industrial robot remains in a stationary state, the servo motor of the servo pressing unit is switched to force control mode, the theoretical close contact force is set as the expected force of the motor, each servo pressing unit extends forward according to the expected force, and when the actual contact force detected by the force sensor on each servo pressing unit is equal to the expected force, the servo pressing unit moves, and the rib is pressed on the skin surface to complete the pressing task; Simultaneously open each pneumatic sliding table, and the opening width meets the requirement that the end effector does not interfere with the rib when leaving the rib; Repeat the above steps until all rib installations are completed.

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