Robot friction stir welding control system capable of carrying force position control system

Abstract

The invention discloses a robot friction stir welding control system capable of carrying a force position control system, and relates to the technical field of robot control systems, the robot friction stir welding control system comprises a six-degree-of-freedom robot, a pressure sensing mechanism, an electric spindle assembly and a gantry positioner; the six-degree-of-freedom robot comprises a base, a turntable motor combination, a turntable main body, a big arm motor combination, a big arm main body, a small arm motor combination, a small arm main body, a first connecting motor combination, a head, a second connecting motor combination, a converter body and a converter front end motor combination. According to the robot friction stir welding control system capable of carrying the force position control system, eight sets of motion shafts are configured, and an electric main shaft is integrated into the welding control system to form an integrated control framework. Meanwhile, the system is additionally provided with a pressure sensing mechanism which is used for monitoring axial pressure parameters in the friction stir welding process in real time. Based on the structural configuration, the system has the autonomous welding capacity of a spatial three-dimensional complex curve track.

Description

Technical Field

[0001] The invention relates to the technical field of robot control systems, and in particular to a robot friction stir welding control system capable of carrying a force position control system. Background Art

[0002] With the development of science and technology, traditional friction stir welding cannot meet the needs of three-dimensional curved surface welding due to equipment limitations. The combination of industrial robots and friction stir welding has greatly improved the automation level and welding production efficiency of friction stir welding. Therefore, robot friction stir welding is an important direction for the development of current friction stir welding technology and equipment. With the continuous improvement of robot load capacity, robot friction stir welding technology and equipment have gone out of the laboratory and are entering the stage of industrial application.

[0003] However, there are some problems in the application of industrial robots in stir friction welding. Due to its insufficient rigidity, the robot will vibrate and the mechanical arm will deform. During the welding pressure stage, the mechanical arm is flexibly deformed, and the stirring head cannot reach the expected depth position in the welding depth direction, resulting in processing position deviation and weld defects. In response to this phenomenon, there are two main control compensation methods, constant pressure control and constant position control. Analyzing these two methods from the stir friction welding process, the constant displacement control welding displacement changes quickly, the friction heat change is uncontrollable, and the quality of the weld formed is uneven. Constant pressure welding control is affected by the density of the welding material and is prone to welding position errors. Comprehensive analysis shows that welding under a single control mode does not have a good weld forming effect. Combining the characteristics of the two control methods, hybrid control welding will be a better choice.

[0004] Therefore, in order to solve the problems existing in the above-mentioned designs, the present invention provides a robot stir friction welding control system which can be equipped with a force position control system. Summary of the invention

[0005] The object of the present invention is to provide a robot stir friction welding control system that can be equipped with a force position control system to solve the problems raised in the above background technology.

[0006] To achieve the above-mentioned object, the present invention provides the following technical solutions: a robot stir friction welding control system capable of carrying a force position control system, comprising a six-degree-of-freedom robot, a pressure sensing mechanism, an electric spindle assembly and a gantry positioner;

[0007] The six-degree-of-freedom robot includes a base, a turntable motor assembly, a turntable body, a large arm motor assembly, a large arm body, a small arm motor assembly, a small arm body, a first connection motor assembly, a head, a second connection motor assembly, a converter body and a converter front-end motor assembly, the base is connected to the ground by bolts, and the base is connected to the turntable motor assembly by pins, the turntable motor assembly is connected to the turntable body by pins, and the turntable body is connected to the large arm motor assembly by pins, the large arm motor assembly is connected to the large arm body by pins, and the large arm body is connected to the small arm motor assembly by pins, the small arm motor assembly is connected to the small arm body by pins, and the small arm body is connected to the first connection motor assembly by pins, the first connection motor assembly is connected to the head by pins, and the head is connected to the second connection motor assembly by pins;

[0008] The pressure sensing mechanism comprises an upper connecting piece, a gasket, a force sensor and a lower connecting piece, wherein the upper connecting piece is connected to the front end motor assembly of the converter of the six-degree-of-freedom robot by a flange interface, and the upper connecting piece, the gasket, the force sensor and the lower connecting piece are connected by pins;

[0009] The electric spindle assembly includes a heat sink, an electric spindle body, a water outlet channel, a water inlet channel, a tool handle and a stirring needle. The heat sink is connected to the electric spindle body by a pin, and the electric spindle body is connected to the tool handle by a pin, and the tool handle and the stirring needle are connected by a special fixture, which is convenient for subsequent replacement;

[0010] The gantry positioner includes a left flip axis, a right flip axis, a left workstation fixture, a right workstation fixture, a fixed seat, a left gantry, a right gantry and a workstation body. The left flip axis and the left gantry are connected internally by pins, and the left flip axis and the left workstation fixture are connected by bolts. The right flip axis and the right gantry are connected internally by pins, and the right flip axis and the right workstation fixture are connected by bolts. The left gantry, the right gantry and the fixed seat are all connected by bolts, and the fixed seat is connected to the ground by bolts.

[0011] Furthermore, the system consists of a total of eight axes, namely, a turntable motor assembly, a large arm motor assembly, a small arm motor assembly, a first connection motor assembly, a second connection motor assembly, a converter front end motor assembly, a left flip axis and a right flip axis, and the electric spindle assembly is integrated into the welding control system to realize an integrated system control solution. At the same time, the system also has a pressure sensing mechanism for monitoring the force of the welding system during stir friction welding. Based on the above functional foundation, the system can flexibly complete spatial complex curve trajectory welding.

[0012] Furthermore, the outer wall of the electric spindle body is connected with a water outlet channel and a water inlet channel, and the water outlet channel is located directly above the water inlet channel, forming an efficient water cooling circulation system, whose working principle is: cooling water is transported from the water outlet channel of the water cooler to the water inlet channel below the spindle, and after circulating inside the electric spindle body, it returns from the water outlet channel above the spindle to the water inlet channel of the water cooler, completing the cooling cycle.

[0013] Furthermore, the gantry positioner adopts an overall structural frame that combines a double-head frame type with a U-shaped double-seat head-tail double-turn type. This structural design has the following significant advantages: First, the double-head frame gantry positioner can effectively resist the mechanical stress generated during the processing process with its excellent rigidity characteristics, ensuring the operating stability of the system under heavy-load conditions. Secondly, the left gantry, the right gantry, the left flip axis, the right flip axis, and the workstation body are special structural designs of the U-shaped double-seat head-tail double-turn type, which makes the system accuracy and the table size independent of each other. This feature is particularly suitable for the precision processing requirements of large workpieces. In terms of the drive system, the left flip axis and the right flip axis adopt a coaxial symmetrical structure, and with the dual-motor symmetrical drive design, a precise force couple balance is achieved, which significantly improves the synchronization accuracy and dynamic response performance of the swing axis motion. This dual-motor symmetrical drive configuration not only enhances the system driving force, but also extends the service life of key components through the load balancing mechanism, and has redundant safety features. In particular, the organic combination of the cradle-type structural design and the eight-axis linkage system provides reliable protection for welding operations with complex spatial trajectories, and is especially suitable for the friction stir welding needs of three-dimensional curved surfaces. In addition, the synergy of the symmetrical mechanical structure and the dual-motor drive solution effectively suppresses the inertial load eccentricity during movement, thereby improving the vibration suppression capability and trajectory tracking accuracy of the processing process. This innovative structural design not only meets the process requirements of robot friction stir welding, but also provides reliable technical support for the precision processing of large and complex workpieces.

[0014] Furthermore, the measuring range of the force sensor exceeds 5000N, and the force sensor is a six-dimensional force sensor, whose central coordinate system is located at its geometric center.

[0015] Furthermore, the force sensor supports six-channel signal output, corresponding to the forces and moments in the X, Y, and Z directions, respectively. The maximum load for force acquisition in the X and Y directions is 15KN, the maximum load in the Z direction is 30KN, and the maximum range for moment acquisition in the three directions is 6KN·m.

[0016] Furthermore, the six-degree-of-freedom robot adopts an overall structural framework that combines modular joint design with lightweight materials. First, the modular joint design can quickly adapt to large-scale friction stir welding application scenarios with its high integration and flexible configuration characteristics, while simplifying the maintenance and upgrade process. Secondly, the use of lightweight materials in the six-degree-of-freedom robot significantly reduces the overall weight of the robot, which not only improves the movement speed and dynamic response performance, but also reduces energy consumption.

[0017] Furthermore, the turntable motor combination, upper arm motor combination, lower arm motor combination, first connection motor combination, second connection motor combination, and converter front end motor combination all use high-precision servo motors in conjunction with harmonic reducers, achieving precise position control and torque output, and ensuring the positioning accuracy and repeatability of the end effector.

[0018] Furthermore, the pressure sensing mechanism is placed between the six-degree-of-freedom robot and the electric spindle assembly, and the pressure sensing mechanism is equipped with an adaptive control algorithm, so that it can accurately sense and adjust the contact force with the workpiece.

[0019] The present invention provides a robot stir friction welding control system that can be equipped with a force position control system, which has the following beneficial effects:

[0020] 1. The present invention is equipped with eight sets of motion axes, and the electric spindle is integrated into the welding control system to form an integrated control architecture. At the same time, the system is equipped with a pressure sensing mechanism for real-time monitoring of the axial pressure parameters during the friction stir welding process. Based on the above structural configuration, the system has the ability to autonomously weld complex three-dimensional curve trajectories in space, and achieves high-precision welding operations through the fusion control of multi-axis coordinated motion and force feedback.

[0021] 2. The present invention constructs a closed-loop water-cooling circulation system by integrating independently designed water inlet and outlet channels inside the electric spindle. In specific implementation, cooling water is introduced from the outlet channel of the water cooler through the water inlet channel at the bottom of the spindle, circulates through the inside of the spindle, and returns to the water cooler through the top outlet channel, forming a continuous heat exchange path. This design quickly conducts and accurately regulates the temperature of the electric spindle through circulating cooling water, stably controls the working temperature of the spindle in the optimal range, effectively solves the overheating problem in long-term welding operations, and avoids the risk of equipment performance degradation and failure. On this basis, the stable temperature environment ensures the uniformity of welding heat input, significantly improves the consistency of weld quality and process reliability. The system also has outstanding energy-saving and environmental protection characteristics: the closed-loop circulation design of cooling water realizes efficient use of water resources, and the supporting heat recovery device (supported by a water cooler) can convert waste heat into usable energy, which has the dual benefits of reducing energy consumption and reducing carbon emissions. This innovation not only breaks through the thermal management bottleneck of traditional welding equipment, but also achieves process optimization by extending equipment life and improving welding quality, and provides an implementable technical solution for green manufacturing through a resource recycling mechanism.

[0022] 3. The present invention is provided with an overall structural frame of a gantry positioner that combines a double-head frame type with a U-shaped double-seat head-tail double-turn type (cradle type). This design has excellent rigidity characteristics, can effectively resist mechanical stress during processing, and ensure the operating stability of the system under heavy load conditions. The flip axis adopts a coaxial symmetrical structure, combined with a dual-motor symmetrical drive design, to achieve precise force couple balance, significantly improving the synchronization accuracy and dynamic response performance of the swing axis motion. In addition, the organic combination of the cradle-type structural design and the eight-axis linkage system provides reliable guarantees for welding operations with complex spatial trajectories, and is particularly suitable for the stir friction welding requirements of three-dimensional curved surfaces. The device not only enhances the driving force of the system, but also extends the service life of key components through a load balancing mechanism. At the same time, it has redundant safety features, meets the process requirements of robot stir friction welding, and provides reliable technical support for the precision machining of large and complex workpieces.

[0023] 4. The present invention has a high-precision force and position detection function. The overall system adopts a modular design, and its force and position detection function is realized by a six-dimensional force sensor, that is, the operator only needs to start the system, and the sensor can collect the force and torque signals in the welding process in real time. It is easy to operate, responds quickly, and is highly practical. In addition, due to the strain gauge design inside the sensor and the high-precision signal processing circuit, the force and position detection is more accurate and reliable. The device adopts a six-channel signal output, which can simultaneously measure the force and torque in the X, Y, and Z directions. The maximum load reaches 15KN and 30KN respectively, meeting the high load requirements of the stir friction welding process. The system has a compact structure and is easy to install. It can effectively avoid vibration interference during the welding process and ensure the stability and accuracy of force signal acquisition. At the same time, the system has low manufacturing and maintenance costs, is easy to maintain, and is suitable for large-scale promotion and application.

[0024] 5. The present invention has high-precision and flexible motion functions. The overall structure adopts a modular joint design combined with lightweight materials. Its modular design can quickly adapt to large-scale stir friction welding scenarios with its high integration and flexible configuration characteristics. At the same time, it simplifies the maintenance and upgrade process, is easy to use, easy to operate, and has strong practicality. In addition, due to the use of lightweight materials, the overall weight of the robot is significantly reduced, which not only improves the movement speed and dynamic response performance, but also reduces energy consumption. The device adopts a high-precision servo motor with a harmonic reducer to achieve precise position control and torque output, ensuring the positioning accuracy and repeatability of the end effector. In particular, the six-degree-of-freedom design gives the robot the ability to move flexibly in any posture in three-dimensional space, enabling it to complete tasks with complex trajectories. In addition, the built-in pressure sensing mechanism of the robot can be equipped with an adaptive control algorithm, which enables it to accurately sense and adjust the contact force with the workpiece, thereby improving the safety and stability of the operation. The innovative structural design of the device not only meets the diversified needs in the field of industrial automation, but also provides reliable technical support for high-end applications such as precision assembly and flexible manufacturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the overall structure of a robot stir friction welding control system that can be equipped with a force position control system according to the present invention;

[0026] Figure 2 It is a schematic structural diagram of a six-degree-of-freedom robot of a robot stir friction welding control system that can be equipped with a force position control system according to the present invention;

[0027] Figure 3 This is a schematic diagram of the structure of a pressure sensing mechanism of a robot stir friction welding control system that can be equipped with a force position control system according to the present invention;

[0028] Figure 4It is a schematic structural diagram of an electric spindle assembly of a robot stir friction welding control system that can be equipped with a force position control system according to the present invention;

[0029] Figure 5 It is a schematic structural diagram of a gantry positioner of a robot stir friction welding control system that can be equipped with a force position control system according to the present invention;

[0030] Figure 6 It is a schematic diagram of a split perspective of a six-degree-of-freedom robot of a robot stir friction welding control system that can be equipped with a force position control system according to the present invention;

[0031] Figure 7 It is a schematic diagram of a split perspective second of a six-degree-of-freedom robot of a robot stir friction welding control system that can be equipped with a force position control system according to the present invention;

[0032] Figure 8 It is a schematic diagram of a split perspective of a gantry positioner of a robot stir friction welding control system that can be equipped with a force position control system according to the present invention;

[0033] Fig. 9 This is a schematic diagram of the second split perspective of the gantry positioner of a robot stir friction welding control system that can be equipped with a force position control system of the present invention.

[0034] In the figure: 1. 6-DOF robot; 101. base; 102. turntable motor assembly; 103. turntable body; 104. upper arm motor assembly; 105. upper arm body; 106. lower arm motor assembly; 107. lower arm body; 108. first connection motor assembly; 109. head; 1010. second connection motor assembly; 1011. converter body; 1012. converter front end motor assembly; 2. pressure sensing mechanism; 201. upper connection piece; 202. Gasket; 203, force sensor; 204, lower connecting piece; 3, electric spindle assembly; 301, heat dissipation chamber; 302, electric spindle body; 303, water outlet channel; 304, water inlet channel; 305, tool handle; 306, stirring needle; 4, gantry positioner; 401, left flip axis; 402, right flip axis; 403, left station fixture; 404, right station fixture; 405, fixed seat; 406, left gantry; 407, right gantry; 408, station body. DETAILED DESCRIPTION

[0035] The following embodiments of the present invention are described in further detail in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0036] like Figure 1-Figure 9As shown, a robot stir friction welding control system capable of carrying a force position control system comprises a six-degree-of-freedom robot 1, a pressure sensing mechanism 2, an electric spindle assembly 3 and a gantry positioner 4;

[0037] The six-degree-of-freedom robot 1 is composed of a base 101, a turntable motor assembly 102, a turntable body 103, an arm motor assembly 104, an arm body 105, an arm motor assembly 106, an arm body 107, a first connection motor assembly 108, a head 109, a second connection motor assembly 1010, a converter body 1011 and a converter front end motor assembly 1012. First, the twelve modules can be produced and transported separately, and when transported to a designated location, they are connected and fixed with a flange interface through pins. The turntable motor assembly 102 forms a slewing pair with the base 101 through the pin, driving the turntable body 103 to complete the first degree of freedom of the base 360° rotation; the upper arm motor assembly 104 is hinged with the turntable body 103 through the pin, driving the upper arm body 105 to achieve the second degree of freedom of pitch motion; the small arm motor assembly 106 is connected to the end of the upper arm body 105 with a pin, and controls the small arm body 107 to complete the third and fourth degrees of freedom of the extension and deflection compound action; the first connection motor assembly 108 drives the head 109 to rotate around the small arm axis through the pin for the fifth degree of freedom; the second connection motor assembly 1010 is connected to the converter body 1011 by a pin, realizing the sixth degree of freedom of the end effector swinging around the axis; the converter front end motor assembly 1012 can be quickly installed through the flange interface. Thus, a six-degree-of-freedom robot 1 of a robot stir friction welding control system that can be equipped with a force position control system is assembled.

[0038] In this embodiment, the six-degree-of-freedom robot 1 adopts an overall structural framework combining modular joint design and lightweight materials. First, the modular joint design can quickly adapt to large-scale stir friction welding application scenarios with its high integration and flexible configuration characteristics, while simplifying the maintenance and upgrade process. Secondly, the use of lightweight materials in the six-degree-of-freedom robot 1 significantly reduces the overall weight of the robot, not only improving the movement speed and dynamic response performance, but also reducing energy consumption. In terms of the drive system, each motor combination turntable motor combination 102, big arm motor combination 104, small arm motor combination 106, first connection motor combination 108, second connection motor combination 1010, converter front end motor combination 1012 uses a high-precision servo motor with a harmonic reducer to achieve precise position control and torque output, ensuring the positioning accuracy and repeatability of the end effector. In particular, the six-degree-of-freedom design gives the robot the ability to move flexibly in any posture in three-dimensional space, enabling it to complete complex trajectory tasks. In addition, the robot's built-in pressure sensing mechanism 2 can be equipped with an adaptive control algorithm, which enables it to accurately sense and adjust the contact force with the workpiece, thereby improving the safety and stability of the operation. This innovative structural design not only meets the diverse needs of the industrial automation field, but also provides reliable technical support for high-end applications such as precision assembly and flexible manufacturing.

[0039] The pressure sensing mechanism 2 is composed of an upper connecting piece 201, a gasket 202, a force sensor 203 and a lower connecting piece 204. Similar to the six-degree-of-freedom robot 1, these four modules can be produced and transported separately. When transported to the designated location, they are connected and fixed with pins through flange interfaces. The upper connecting piece 201 realizes rapid modular installation with the converter front-end motor assembly 1012 of the six-degree-of-freedom robot 1 through a flange interface, and an array of pin positioning holes is processed on its bottom; the titanium alloy gasket 202 and the high-precision force sensor 203 stacked in sequence in the middle are positioned in series through hardened steel pins to form a sandwich-type sensing unit; the end of the lower connecting piece 204 is reserved with an M6 threaded interface, which is compatible with the installation of end tools such as grippers / suction cups. The mechanism realizes multi-dimensional force decoupling through four groups of axially symmetrically distributed pin groups, each component containing 3 stepped positioning pins, and can detect the forces of the three axes of X, Y, and Z and the torques of the three axes of MX, MY, and MZ in real time. After the measurement data is fed back to the control system, the closed-loop control of the end contact force is realized. Thus, the pressure sensing mechanism 2 of the robot stir friction welding control system which can be equipped with a force position control system is assembled.

[0040] In this embodiment, the force sensor 203 in the pressure sensing mechanism 2 bears a large dynamic load because the electric spindle assembly 3 in the welding system has a large load and vibrates significantly during operation. The force sensor 203 in this system has a range of more than 5000N, which not only meets the requirement of "the load capacity of the stir friction welding robot exceeds 5000N" in the previous investigation, but also can be well restored to the initial state after the robot welding is completed, avoiding elastic damage. In addition, the force sensor 203 is a six-dimensional force sensor, whose central coordinate system is located at its geometric center, and can simultaneously measure three forces and three moments of the neutral coordinate system. When the inner and outer rings of the sensor are subjected to relative forces, the force measuring piece will strain in proportion to the magnitude of the external force, and convert the strain force into an electrical signal output. The sensor supports six-channel signal output, corresponding to the forces and moments in the X, Y, and Z directions respectively. Among them, the maximum load of the force acquisition in the X and Y directions is 15KN, the maximum load in the Z direction is 30KN, and the maximum range of the moment acquisition in the three directions is 6KN·m. The load ranges of these forces meet the actual process requirements and ensure the stable operation of the force signal acquisition system.

[0041] The electric spindle assembly 3 is composed of an integral casting shell, a water outlet channel 303, a water inlet channel 304, an inner cavity partition, a spiral guide groove, a 45° oblique water return port and other parts. Similarly, these six parts can be produced and transported separately. When transported to the designated location, they are connected to each other through the connecting devices fixed in the parts by flange connection. The water inlet channel 304 and the water outlet channel 303 are connected by connecting devices respectively; the inner cavity partition is located between the water inlet channel 304 and the water outlet channel 303, and is connected by a connecting device. The contact surfaces of the spiral guide groove and the integral casting shell, the water inlet channel 304, the water outlet channel 303, the inner cavity partition, and the 45° oblique water return port are all connected by flanges to ensure the strength of the connection. Thus, an electric spindle assembly 3 of a robot stir friction welding control system that can carry a force position control system is assembled. After the electric spindle assembly 3 is assembled, the assembler uses an external pushing device to push the electric spindle assembly 3 along the inclined track on the auxiliary assembly device for assembly. When the raised fixed position is determined, the assembler will dismantle the bottom connecting device and replace the auxiliary assembly device with the flat plate.

[0042] In the present embodiment, the outer wall of the electric spindle body 302 is connected with a water outlet channel 303 and a water inlet channel 304, and the water outlet channel 303 is located directly above the water inlet channel 304, forming an efficient water cooling circulation system, whose working principle is as follows: cooling water is transported from the water outlet channel 303 of the water cooler to the water inlet channel 304 below the spindle, and after circulating inside the electric spindle body 302, it returns from the water outlet channel 303 above the spindle to the water inlet channel of the water cooler, completing the cooling cycle; this system design effectively solves the problem of excessive internal temperature of the electric spindle during long-term welding operations, and accurately controls the internal temperature of the spindle within the optimal working range through water cooling circulation. The water cooling system has multiple technical advantages: first, the circulating cooling water quickly conducts and removes the heat generated inside the electric spindle, fundamentally avoiding the risk of equipment performance degradation or failure due to overheating; second, stable temperature control ensures the uniformity of heat input during welding, thereby significantly improving the consistency and reliability of welding quality; finally, the cooling water is circulated in the water chiller system, which not only saves water resources, but also can achieve energy reuse through the heat recovery device if the water chiller supports it, fully reflecting the environmental and economic benefits of the system. This innovative design not only ensures the stable operation of the equipment, but also provides technical support for green manufacturing.

[0043] The gantry positioner 4 is composed of a left flip axis 401, a right flip axis 402, a left station fixture 403, a right station fixture 404, a fixed seat 405, a left gantry 406, a right gantry 407 and a station body 408. Similarly, these eight parts can be produced and transported separately. After being transported to a designated location, they are connected to each other by connecting devices fixed in the parts through high-strength bolts. The left gantry 406 and the right gantry 407 are connected to the fixed seat 405 by connecting devices respectively; the station body 408 is located between the left station fixture 403 and the right station fixture 404, and is connected by connecting devices. The left flip axis 401 and the right flip axis 402 are respectively connected with the fixed seat 405, the right gantry 407, the left station fixture 403, the right station fixture 404, and the station body 408 contact surface by high-strength bolts to ensure the strength of the connection, thereby a gantry positioner 4 of a robot stir friction welding control system that can carry a force position control system is assembled. After the gantry positioner 4 is assembled, the assembler uses an external pushing device to push the gantry positioner 4 along the inclined track on the auxiliary assembly device for assembly. When it is estimated to be in the raised fixed position, the assembler disassembles the bottom connecting device and replaces the auxiliary assembly device with a flat plate.

[0044] In this embodiment, the gantry positioner 4 adopts an overall structural frame that combines a double-head frame type with a U-shaped double-seat head-tail double-turn cradle type. This structural design has the following significant advantages: First, the double-head frame gantry positioner 4 can effectively resist the mechanical stress generated during the processing process with its excellent rigidity characteristics, ensuring the operating stability of the system under heavy-load conditions. Secondly, the left gantry 406, the right gantry 407, the left flip axis 401, the right flip axis 402, and the station body 408 are special structural designs of the U-shaped double-seat head-tail double-turn type, so that the system accuracy and the table size are independent of each other. This feature is particularly suitable for the precision processing requirements of large workpieces. In terms of the drive system, the left flip axis 401 and the right flip axis 402 adopt a coaxial symmetrical structure, and cooperate with the dual-motor symmetrical drive design to achieve accurate force couple balance, significantly improving the synchronization accuracy and dynamic response performance of the swing axis motion. This dual-motor symmetrical drive configuration not only enhances the system driving force, but also extends the service life of key components through the load balancing mechanism, and has redundant safety characteristics. In particular, the organic combination of the cradle-type structural design, the head-tail double rotation type and the eight-axis linkage system provides reliable guarantee for welding operations with complex spatial trajectories, and is especially suitable for the friction stir welding needs of three-dimensional curved surfaces. In addition, the synergy of the symmetrical mechanical structure and the dual-motor drive solution effectively suppresses the inertial load eccentricity during movement, thereby improving the vibration suppression capability and trajectory tracking accuracy of the processing process. This innovative structural design not only meets the process requirements of robot friction stir welding, but also provides reliable technical support for the precision processing of large and complex workpieces.

[0045] In this embodiment, the system consists of a total of eight axes, namely, a turntable motor assembly 102, a large arm motor assembly 104, a small arm motor assembly 106, a first connection motor assembly 108, a second connection motor assembly 1010, a converter front end motor assembly 1012, a left flip axis 401 and a right flip axis 402, and the electric spindle assembly 3 is integrated into the welding control system to realize an integrated system control solution. At the same time, the system also has a pressure sensing mechanism 2 for monitoring the force of the welding system during stir friction welding. Based on the above functional foundation, the system can flexibly complete spatial complex curve trajectory welding.

[0046] The embodiments of the present invention are given for the purpose of illustration and description, and are not intended to be exhaustive or to limit the invention to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present invention and to enable those of ordinary skill in the art to understand the present invention and thereby design various embodiments with various modifications suitable for specific uses.

Claims

1. A robot stir friction welding control system capable of being equipped with a force position control system, comprising a six-degree-of-freedom robot (1), a pressure sensing mechanism (2), an electric spindle assembly (3) and a gantry positioner (4), characterized in that: The six-degree-of-freedom robot (1) comprises a base (101), a turntable motor assembly (102), a turntable body (103), a large arm motor assembly (104), a large arm body (105), a small arm motor assembly (106), a small arm body (107), a first connection motor assembly (108), a head (109), a second connection motor assembly (1010), a converter body (1011) and a converter front end motor assembly (1012); the pressure sensing mechanism (2) comprises an upper connection member (201), a gasket (202) , a force sensor (203) and a lower connecting piece (204), the electric spindle assembly (3) includes a heat dissipation chamber (301), an electric spindle body (302), a water outlet channel (303), a water inlet channel (304), a tool handle (305) and a stirring needle (306), and the gantry positioner (4) includes a left flip axis (401), a right flip axis (402), a left workstation fixture (403), a right workstation fixture (404), a fixing seat (405), a left gantry (406), a right gantry (407) and a workstation body (408).

2. A robot stir friction welding control system capable of carrying a force position control system according to claim 1, characterized in that: The base (101) is connected to the ground by bolts, and the base (101) and the turntable motor assembly (102) are connected by pins, the turntable motor assembly (102) and the turntable body (103) are connected by pins, and the turntable body (103) and the upper arm motor assembly (104) are connected by pins, the upper arm motor assembly (104) and the upper arm body (105) are connected by pins, and the upper arm body (105) and the lower arm motor assembly (106) are connected by pins, the lower arm motor assembly (106) and the lower arm body (107) are connected by pins, and the lower arm body (107) and the first connection motor assembly (108) are connected by pins, the first connection motor assembly (108) and the head (109) are connected by pins, and the head (109) and the second connection motor assembly (1010) are connected by pins; The turntable motor assembly (102), the upper arm motor assembly (104), the lower arm motor assembly (106), the first connection motor assembly (108), the second connection motor assembly (1010), and the converter front end motor assembly (1012) all use high-precision servo motors in conjunction with harmonic reducers.

3. A robot stir friction welding control system capable of carrying a force position control system according to claim 1, characterized in that: The upper connecting member (201) is connected to the converter front end motor assembly (1012) via a flange interface, and the upper connecting member (201), the gasket (202), the force sensor (203) and the lower connecting member (204) are connected via pins.

4. The robot stir friction welding control system capable of carrying a force position control system according to claim 1, characterized in that: The heat dissipation bin (301) and the electric spindle body (302) are connected by pins, the electric spindle body (302) and the tool handle (305) are connected by pins, and the tool handle (305) and the stirring needle (306) are connected by a fixture.

5. The robot stir friction welding control system capable of carrying a force position control system according to claim 1, characterized in that: The left flip shaft (401) and the left gantry (406) are connected internally by pins, and the left flip shaft (401) and the left workstation fixture (403) are connected by bolts, the right flip shaft (402) and the right gantry (407) are connected internally by pins, and the right flip shaft (402) and the right workstation fixture (404) are connected by bolts, the left gantry (406), the right gantry (407) and the fixed seat (405) are all connected by bolts, and the fixed seat (405) and the ground are connected by bolts.

6. The robot stir friction welding control system capable of carrying a force position control system according to claim 1, characterized in that: The system comprises a total of eight axes, namely a turntable motor assembly (102), a large arm motor assembly (104), a small arm motor assembly (106), a first connection motor assembly (108), a second connection motor assembly (1010), a converter front end motor assembly (1012), a left flip axis (401) and a right flip axis (402), and the electric spindle assembly (3) is integrated into a welding control system to realize an integrated system control solution.

7. The robot stir friction welding control system capable of carrying a force position control system according to claim 1, characterized in that: The outer wall of the electric spindle body (302) is connected through a water outlet channel (303) and a water inlet channel (304), and the water outlet channel (303) is located directly above the water inlet channel (304), forming an efficient water cooling circulation system.

8. The robot stir friction welding control system capable of carrying a force position control system according to claim 1, characterized in that: The gantry positioner (4) adopts an overall structural frame that combines a double-head frame type with a U-shaped double-seat head-tail double-turn type (cradle type), and the left flip axis (401) and the right flip axis (402) adopt a coaxial symmetrical structure, coordinated with a dual-motor symmetrical drive design.

9. The robot stir friction welding control system capable of carrying a force position control system according to claim 1, characterized in that: The force sensor (203) has a measuring range exceeding 5000N, and the force sensor (203) is a six-dimensional force sensor, whose central coordinate system is located at its geometric center. The force sensor (203) supports six-channel signal output, corresponding to forces and moments in the X, Y, and Z directions, respectively, wherein the maximum loads for force acquisition in the X and Y directions are 15KN, the maximum load in the Z direction is 30KN, and the maximum ranges for moment acquisition in the three directions are all 6KN·m.

10. The robot stir friction welding control system capable of carrying a force position control system according to claim 1, characterized in that: The pressure sensing mechanism (2) is placed between the six-degree-of-freedom robot (1) and the electric spindle assembly (3), and the pressure sensing mechanism (2) is equipped with an adaptive control algorithm for sensing and adjusting the contact force with the workpiece.

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