Six-degree-of-freedom welding structural member performance testing device

Abstract

The invention discloses a six-degree-of-freedom welded structural member performance testing device, belongs to the technical field of performance testing devices, solves the problem of mechanical property evaluation of a dissimilar metal welded structural member under complex working conditions, and provides a high-load performance testing device for a dissimilar metal welded structural member by innovatively integrating the high-load characteristic of a hydraulic actuating mechanism and the three-degree-of-freedom spatial motion advantage of a Delta parallel mechanism. The multi-axis coupling loading system with the 10Hz dynamic bandwidth is successfully constructed, experimental research shows that the platform can achieve multi-axis synchronous loading within the frequency range of 0.1-10 Hz, the dynamic force control precision of the platform reaches + / -2%, compared with a traditional PD control strategy, the tracking error is reduced by 42% through an improved sliding mode control algorithm, and through finite element simulation and actually-measured data contrastive analysis, the dynamic force control precision of the platform is greatly improved. The structural integrity of the system under the maximum load working condition is verified, the stress distribution of a key bearing part shows that the maximum stress is 43 MPa, and the pose precision of the tail end of a motion platform is superior to 20 m.

Description

Technical Field

[0001] The invention relates to a performance testing device, in particular to a performance testing device for a six-degree-of-freedom welded structural component, and belongs to the technical field of performance testing devices. Background Art

[0002] In many important fields such as aerospace, transportation, household appliances, and construction engineering, welded structural parts are important components of the overall structure and they play an important role in the operation of the overall system mechanism.

[0003] Because the parameter performance of welded structural parts will directly affect the stability and safety of the entire system structure, before applying welded structural parts to important systems such as space shuttles, ships, and new energy vehicles, their performance must be comprehensively tested.

[0004] However, ordinary welding structure testing devices have a single test method and very limited test capabilities. For example, their test accuracy is not high, and their own unreasonable design structure leads to their lack of flexibility in actual work.

[0005] It is difficult to complete the testing tasks of different welded structural parts in a variety of environments. In order to be able to test more types of welded structural parts, more universal testing equipment must be developed so that the testing tasks of welded structural parts can be completed under different circumstances to solve the above problems. For this purpose, a six-degree-of-freedom welding structural part performance testing device is designed. Summary of the invention

[0006] The main purpose of the invention is to provide a six-degree-of-freedom welding structural part performance testing device.

[0007] The purpose of the present invention can be achieved by adopting the following technical solutions: A six-degree-of-freedom welding structural part performance testing device comprises a force actuator, the force actuator has at least three sets of top ends, the three sets of top ends of the force actuator are respectively hinged to a first bidirectional rotating shaft set, and are hinged to a connecting rod through the first bidirectional rotating shaft set; A second bidirectional rotating shaft group is hinged at one end of the connecting rod away from the force actuator, and the second bidirectional rotating shaft group is hinged on the arc rocker arm. The middle part of the arc rocker arm is hinged on the supporting base member, and a hydraulic group that drives the arc rocker arm and is hinged to the end of the arc rocker arm is hinged on the inner side of the supporting base member.

[0008] Preferably, the first bidirectional rotating shaft group includes a first shaft joint, a first connecting sleeve and a third shaft joint; The end of the connecting rod is hinged with a third shaft joint, a first connecting sleeve is installed at the end of the third shaft joint away from the connecting rod, and a first shaft joint is hinged on the inner side of the first connecting sleeve, which is hinged to the top of the force actuator through the first shaft joint.

[0009] Preferably, the second bidirectional rotating shaft assembly includes a second shaft joint, a second connecting sleeve, and a fourth shaft joint; The end of the connecting rod away from the third shaft joint is hinged with the fourth shaft joint, the end of the fourth shaft joint away from the connecting rod is installed on the outside of the second connecting sleeve, the second shaft joint is hinged inside the second connecting sleeve, and an arc rocker arm is hinged in the middle of the second shaft joint.

[0010] Preferably, the supporting base member comprises a base and a fixing device and a supporting shaft; A fixing device is installed on the top of the base, and a supporting rotating shaft is installed on the inner top of the fixing device. The supporting rotating shaft is hinged with the arc-shaped rocker arm.

[0011] Preferably, the hydraulic system and the cylindrical connecting component; A hydraulic system is hinged on the inner side of the fixing device, and an output end of the hydraulic system is hinged to an end of the arc-shaped rocker arm away from the second shaft joint.

[0012] Preferably, a simulation force control model method is also included: Step 1: Parameterize the system, select a set of basic parameters to describe the model, and make assumptions about the corresponding values; Step 2: Perform kinematic and inverse kinematic analysis on the system and construct a set of equations to describe the kinematic relationship between input and output; Step 3: Use the hydraulic system for analysis and build a hydraulic dynamics model using Simulink and Simscape Hydraulics toolbox; Step 4: Perform rigid body dynamics analysis of the system, which uses Autodesk Inventor and Simulink software in conjunction with the Simscape Multibody toolbox to create a dynamic model of the entire system. Step 5: Implement and simulate the force control model.

[0013] Preferably, the parameterization in step 1 specifically includes x-cylinder displacement; - Length between the cylinder axis and the center of the rocker; - height between the cylinder joint and the center of the rocker; - the distance between the arm joint at the joystick and the center of the joystick; - the distance between the arm joint and its center at the actuator; - Arm's length; - one side of the triangle formed by the three towers; - Stick angle.

[0014] Preferably, in step 2, a kinematic analysis is performed, including selecting generalized coordinates and transferring the entire system to the center by a distance of , to eliminate the space occupied by the force actuator (1), the angle between point 0-point 2-point 3 and x is : ; Where x represents the cylinder displacement, Indicates the length between the cylinder axis and the center of the rocker, Indicates the height between the cylinder joint and the center of the rocker. Indicates the joystick angle.

[0015] The position of point 3 can be expressed as: ; in, Indicates the position of the joint, Indicates the distance between the arm joint at the rocker and the center of the rocker. Represents the angle between point 0-point 2-point 3 and x.

[0016] Then write the same position of point 3 for other Towers. This operation is done in , the rotation transformation applied at these three angles is as follows: ; Among them, the rotation matrix Indicates winding Axis rotation transformation.

[0017] Finding Points location, point The position at the center of the actuator is the intersection of the three spheres, and the sphere equation is: ,in are the coordinates of the actuator, are the coordinates of the center of the sphere. is the radius of the sphere.

[0018] First, write a vector to describe the force transmitted by the joystick function, this force Perpendicular to the joystick. Expressed as: ; Among them, the table The angle between the hydraulic cylinder and the rocker arm is less than 1.5°, which can be ignored. The force transmitted from the rocker arm to the arm is then expressed: ;

[0019] in, Express the rocker force, Represents the inner product operation.

[0020] The net force exerted by the cylinder on the actuator is expressed as: .

[0021] Preferably, the dynamic model is created using Simscape module, in which the dynamics and kinematics of the cylinder are used as input and output; The model is designed based on the following main modules: Solid, world coordinate system, rigid body transformation, joints; The Solid module represents each rigid part of the system and contains all relevant properties. This module is directly connected to the reference frame module and creates local coordinates.

[0022] Beneficial technical effects of the present invention: A six-degree-of-freedom welding structural part performance testing device provided by the present invention solves the problem of mechanical performance evaluation of dissimilar metal welding structural parts under complex working conditions. By innovatively integrating the high-load characteristics of the hydraulic actuator and the three-degree-of-freedom spatial motion advantage of the Delta parallel mechanism, a multi-axis coupled loading system with a dynamic bandwidth of 10 Hz is successfully constructed. Experimental studies show that the platform can achieve multi-axis synchronous loading in the frequency range of 0.1~10 Hz, and its dynamic force control accuracy reaches ±2%. Compared with the traditional PD control strategy, the improved sliding mode control algorithm is used to reduce the tracking error by 42%. Through finite element simulation and comparative analysis of measured data, the structural integrity of the system under the maximum load condition is verified, the stress distribution of key load-bearing parts shows that the maximum stress is 43MPa, and the end posture accuracy of the motion platform is better than 20µm. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a three-dimensional structural diagram of the whole device of a preferred embodiment of a six-degree-of-freedom welding structural component performance testing device according to the present invention; Figure 2 It is a first-view stereoscopic structural diagram of the entire device (except for the workbench and the force actuator moving downward) according to a preferred embodiment of a six-degree-of-freedom welding structural component performance testing device of the present invention; Figure 3 A second-view stereoscopic structural diagram of the entire device (except for the workbench and the force actuator moving downward) according to a preferred embodiment of a six-degree-of-freedom welding structural component performance testing device of the present invention; Figure 4It is a schematic diagram of the first-view stereoscopic structure of a hydraulic system, an arc-shaped rocker arm, and a connecting rod assembly according to a preferred embodiment of a six-degree-of-freedom welding structural component performance testing device of the present invention; Figure 5 A schematic diagram of the second perspective stereoscopic structure of a hydraulic system, an arc-shaped rocker arm, and a connecting rod assembly according to a preferred embodiment of a six-degree-of-freedom welding structural component performance testing device of the present invention; Figure 6 It is a schematic diagram of the three-dimensional structure of a fixing device according to a preferred embodiment of a six-degree-of-freedom welding structural component performance testing device of the present invention; Figure 7 It is a schematic diagram of the three-dimensional structure of a force actuator from a first perspective according to a preferred embodiment of a six-degree-of-freedom welding structural component performance testing device of the present invention; Figure 8 It is a schematic diagram of the stereoscopic structure from a second viewing angle of a force actuator according to a preferred embodiment of a six-degree-of-freedom welding structural component performance testing device of the present invention.

[0024] In the figure: 1-force actuator, 2-first shaft joint, 3-connecting rod, 4-second shaft joint, 5-arc rocker arm, 6-cylindrical connecting component, 7-hydraulic system, 8-fixing device, 9-base, 10-third shaft joint, 11-fourth shaft joint, 12-support shaft, 13-first connecting sleeve, 14-second connecting sleeve. DETAILED DESCRIPTION

[0025] In order to make the technical solution of the present invention more clear and specific to those skilled in the art, the present invention is further described in detail below in conjunction with embodiments and drawings, but the implementation manner of the present invention is not limited thereto.

[0026] like Figure 1-Figure 8 As shown, this embodiment provides a six-degree-of-freedom welding structural performance testing device, the force actuator 1 has at least three groups of top ends, the three groups of top ends are respectively hinged to a first two-way rotating shaft group, and the connecting rod 3 is hinged through the first two-way rotating shaft group, and the second two-way rotating shaft group is hinged at the end of the connecting rod 3 away from the force actuator 1, the second two-way rotating shaft group is hinged to the arc rocker arm 5, the middle part of the arc rocker arm 5 is hinged to the supporting base member, and a hydraulic group for driving the arc rocker arm 5 and hinged to the end of the arc rocker arm 5 is hinged on the inner side of the supporting base member.

[0027] Overall working principle: The force actuator 1 is a centrally symmetrical component and is similar to a triangle shape, with three tops and a gap between two adjacent tops. ° distribution, each top end has a threaded hole of the same size, which is used to connect the connecting rod 3 through the first two-way rotating shaft group. The first two-way rotating shaft group can realize rotation within the plane, that is, up, down, left and right rotation. Therefore, the force actuator 1 can be adjusted through the connecting rod 3 to realize up, down, left and right rotation. The connecting rod 3 is hinged to the second two-way rotating shaft group at one end away from the force actuator 1. Therefore, the arc rocker arm 5 can adjust the connecting rod 3 and can also realize rotation within the plane, that is, up, down, left and right rotation. The hydraulic group hinged at the end of the arc rocker arm 5 is driven by the hydraulic group to realize axial rotation, and the arc rocker arm 5 hinged on the supporting base member can also realize axial rotation, so the six-degree-of-freedom adjustment effect can be achieved.

[0028] In this embodiment, the first bidirectional rotating shaft assembly includes a first shaft joint 2, a first connecting sleeve 13 and a third shaft joint 10; A third shaft joint 10 is hinged at the end of the connecting rod 3, a first connecting sleeve 13 is installed at the end of the third shaft joint 10 away from the connecting rod 3, and a first shaft joint 2 is hinged on the inner side of the first connecting sleeve 13, and is hinged to the top end of the force actuator 1 through the first shaft joint 2.

[0029] Local working principle: The first connecting sleeve 13 and the first shaft joint 2 are driven to follow the movement through the movement adjustment of the connecting rod 3, and the third shaft joint 10 and the connecting rod 3 rotate with each other to form a degree of freedom, and the first shaft joint 2 and the first connecting sleeve 13 rotate with each other to form a degree of freedom. Because the first shaft joint 2 can rotate relative to the first connecting sleeve 13, the force actuator 1 can also be flexibly adjusted by the first shaft joint 2 and the connecting rod 3.

[0030] In this embodiment, the second bidirectional rotating shaft assembly includes a second shaft joint 4, a second connecting sleeve 14, and a fourth shaft joint 11; The end of the connecting rod 3 away from the third shaft joint 10 is hinged to the fourth shaft joint 11, and the end of the fourth shaft joint 11 away from the connecting rod 3 is installed on the outside of the second connecting sleeve 14. The second connecting sleeve 14 is hinged to the inside of the second shaft joint 4, and an arc rocker arm 5 is hinged in the middle of the second shaft joint 4.

[0031] Local working principle: the movement of the arc-shaped rocker arm 5 drives the second shaft joint 4 to be pressed down or lifted, and the second connecting sleeve 14 is driven to move along with the second shaft joint 4. The connecting rod 3 is hinged to the fourth shaft joint 11. Therefore, when the first shaft joint 2 moves left and right, it will drive the connecting rod 3 and the fourth shaft joint 11 to rotate in an articulated manner, thus forming two degrees of automation.

[0032] In this embodiment, the supporting base member includes a base 9, a fixing device 8 and a supporting shaft 12; A fixing device 8 is installed on the top of the base 9 , and a supporting shaft 12 is installed on the inner top of the fixing device 8 . The supporting shaft 12 is hinged to the arc-shaped rocker arm 5 .

[0033] Partial working principle: Through the hinge connection between the arc-shaped rocker arm 5 and the supporting shaft 12, the arc-shaped rocker arm 5 can rotate around the supporting shaft 12, thus forming the movement mode of the seesaw.

[0034] In this embodiment, the hydraulic system 7 and the cylindrical connecting member 6; A hydraulic system 7 is hinged to the inner side of the fixing device 8 , and an output end of the hydraulic system 7 is hinged to an end of the arc-shaped rocker arm 5 away from the second shaft joint 4 .

[0035] Local working principle: By starting the hydraulic system 7 to adjust the arc-shaped rocker arm 5 to rotate around the supporting shaft 12, the connecting rod 3 is driven to move.

[0036] Embodiment 1: Further explanation: The force actuator 1 is a centrally symmetrical component and is similar to a triangle shape, with three top ends and a gap between two adjacent top ends. ° distribution, each top end has a threaded hole of the same size, which is used to connect the connecting rod 3 through the first two-way rotating shaft group. There is a triangular groove in the middle just above the force actuator 1, and the protruding part just below is used to install the sensor. The first two-way rotating shaft group is thick on both sides and slightly thin in the middle, and there are inserted and extended parts at both ends for connecting the connecting rod 3. The connecting rod 3 is symmetrically distributed in the device system, and circular holes of the same size are distributed at both ends. Its two ends are respectively connected to the force actuator 1 and the rocker arm 5 through the first two-way rotating shaft group and the second two-way rotating shaft group.

[0037] Further explanation: The rocker arm 5 is an irregularly shaped component with three circular holes on its surface and a groove at one end; The hydraulic system 7 includes a hydraulic unit 300L, 37KW, 60L / min, 280bar, a double-acting cylinder 250bar, 64KN, and a reversing valve 350bar. The output end of the hydraulic system 7 is connected to the rocker arm 5, and the lower end is connected to the base 9.

[0038] The fixing device 8 has a cylindrical connecting component 6 connecting the connecting holes on the fixing device 8 and the connecting holes on the rocker arm 5 . Each group of fixing devices 8 is symmetrically distributed on both sides of the hydraulic system 7 .

[0039] The six-degree-of-freedom welded part performance test device is composed of three hydraulic systems 7 that jointly control the movement of the force actuator 1 with six degrees of freedom. When the angle between the force applied by the three hydraulic systems 7 to the corresponding rocker arm 5 and the force actuator 1 is °, the resultant force applied to the force actuator 1 is the largest.

[0040] Further explanation: The hydraulic system 7 provides power for the entire test bench system. The power provided by the hydraulic system is transmitted to the connecting rod 3 through the rocker arm 5. The connecting rod 3 serves as an active mechanism and the force actuator 1 serves as a driven mechanism. The combined external force of the three hydraulic systems 7, the rocker arm 5 and the connecting rod 3 drives the force actuator 1 to move in all directions.

[0041] Embodiment 2: In a control system, the system is first parameterized, that is, a set of basic parameters are selected to describe the model, and assumptions are made on the corresponding values.

[0042] Next, the system is subjected to kinematic and inverse kinematic analysis, which uses geometric relationships to construct a set of equations to describe the kinematic relationship between input and output. Next, the hydraulic system is analyzed, which uses Simulink and Simscape Hydraulics toolboxes to build a hydraulic dynamics model.

[0043] Then, a rigid body dynamics analysis of the system is performed, which uses Autodesk Inventor and Simulink software in conjunction with the Simscape Multibody toolbox to create a dynamic model of the entire system.

[0044] Finally, force control models such as proportional derivative and sliding mode control are implemented and simulated.

[0045] The parameterization specifically includes: - Length between the cylinder axis and the center of the rocker; - height between the cylinder joint and the center of the rocker; - the distance between the arm joint at the joystick and the center of the joystick; - the distance between the arm joint and its center at the actuator; - Arm's length; - one side of the triangle formed by the three towers; - Stick angle.

[0046] The kinematic analysis includes selecting generalized coordinates and shifting the entire system toward the center by a distance d to eliminate the space occupied by the actuator.

[0047] The angle between point 0-point 2-point 3 and x is : ; Where x represents the cylinder displacement, Indicates the length between the cylinder axis and the center of the rocker, Indicates the height between the cylinder joint and the center of the rocker. Indicates the joystick angle.

[0048] The position of point 3 can be described as: ;

[0049] in, Indicates the position of the joint, Indicates the distance between the arm joint at the rocker and the center of the rocker. Represents the angle between point 0-point 2-point 3 and x.

[0050] Then write the same position of point 3 for other Towers. This operation is done in The rotation transformation is applied to these three angles. The details are as follows:

[0051] Among them, the rotation matrix Indicates winding Axis rotation transformation.

[0052] Then find the point location, point The position at the center of the actuator is the intersection of the three spheres, and the sphere equation is: ,in are the coordinates of the actuator, are the coordinates of the center of the sphere. is the radius of the sphere.

[0053] First, write a vector to describe the force transmitted by the joystick function, this force Perpendicular to the joystick. Expressed as:

[0054] Among them, the table The angle between the hydraulic cylinder and the rocker arm is less than 1.5°, which can be ignored. The force transmitted from the rocker arm to the arm is then expressed: ; in, Express the rocker force, Represents the inner product operation.

[0055] The net force exerted by the cylinder on the actuator is expressed as: .

[0056] Construct a hydraulic model, which assumes that the pump is ideal and increases the constant pressure output. Any properties of the pump must be entered in the model. The model has three external connections, one input and two outputs. The input is: signal-the connection position of the servo valve control signal, output 1-the ground reference connected to the multi-body model, output 2-the force signal emitted by the cylinder. The hydraulic oil block parameters used in this model are ISO VG 22, and the parameters of the double-acting cylinder are: piston A area: 2563.54mm, piston B area: 2563.54mm, fixed volume A and B: 128.2mL, initial pressure A and B: 0pa.

[0057] Building a dynamic model: This dynamic model was created using the Simscape module to describe the motion behavior of this test bench. In this dynamic model, the dynamics and kinematics of the cylinder are used as input and output. The model is designed based on the following main modules: Solid, world coordinate system, rigid body transformation, joints, where the Solid module represents each rigid part of the system and contains all relevant properties. This module is directly connected to the reference system module and creates local coordinates.

[0058] The above description is only a further embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and concepts of the present invention within the scope disclosed by the present invention, which belong to the protection scope of the present invention.

Claims

1. A six-degree-of-freedom welding structural part performance testing device, characterized in that: The force actuator (1) comprises at least three groups of top ends, the three groups of top ends of the force actuator (1) are respectively hinged to a first bidirectional rotating shaft group, and are hinged to a connecting rod (3) via the first bidirectional rotating shaft group; A second bidirectional rotating shaft group is hingedly connected to one end of the connecting rod (3) away from the force actuator (1), the second bidirectional rotating shaft group is hingedly connected to the arc-shaped rocker arm (5), the middle part of the arc-shaped rocker arm (5) is hingedly connected to the supporting base member, and a hydraulic group that drives the arc-shaped rocker arm (5) and is hingedly connected to the end of the arc-shaped rocker arm (5) is hingedly connected to the inner side of the supporting base member.

2. A six-degree-of-freedom welding structural component performance testing device according to claim 1, characterized in that: The first bidirectional rotating shaft assembly comprises a first shaft joint (2), a first connecting sleeve (13) and a third shaft joint (10); A third shaft joint (10) is hingedly connected to the end of the connecting rod (3); a first connecting sleeve (13) is installed at the end of the third shaft joint (10) away from the connecting rod (3); a first shaft joint (2) is hingedly connected to the inner side of the first connecting sleeve (13); and the first shaft joint (2) is hingedly connected to the top end of the force actuator (1) via the first shaft joint (2).

3. A six-degree-of-freedom welding structural component performance testing device according to claim 2, characterized in that: The second bidirectional rotating shaft assembly comprises a second shaft joint (4), a second connecting sleeve (14), and a fourth shaft joint (11); One end of the connecting rod (3) away from the third shaft joint (10) is hingedly connected to a fourth shaft joint (11); one end of the fourth shaft joint (11) away from the connecting rod (3) is mounted on the outside of a second connecting sleeve (14); a second shaft joint (4) is hingedly connected to the inside of the second connecting sleeve (14); and an arc-shaped rocker arm (5) is hingedly connected to the middle of the second shaft joint (4).

4. A six-degree-of-freedom welding structural component performance testing device according to claim 3, characterized in that: The supporting base member comprises a base (9), a fixing device (8) and a supporting rotating shaft (12); A fixing device (8) is installed on the top of the base (9), and a supporting shaft (12) is installed on the inner top of the fixing device (8), and the supporting shaft (12) is hinged to the arc-shaped rocker arm (5).

5. A six-degree-of-freedom welding structural component performance testing device according to claim 4, characterized in that: A hydraulic system (7) and a cylindrical connecting component (6); A hydraulic system (7) is hingedly connected to the inner side of the fixing device (8), and an output end of the hydraulic system (7) is hingedly connected to an end of the arc-shaped rocker arm (5) away from the second shaft joint (4).

6. A six-degree-of-freedom welding structural component performance testing device according to claim 5, characterized in that: Also included are methods for simulating force control models: Step 1: Parameterize the system, select a set of basic parameters to describe the model, and make assumptions about the corresponding values; Step 2: Perform kinematic and inverse kinematic analysis on the system and construct a set of equations to describe the kinematic relationship between input and output; Step 3: Use the hydraulic system (7) for analysis and build a hydraulic dynamics model using Simulink and Simscape Hydraulics toolbox; Step 4: Perform rigid body dynamics analysis of the system, which uses Autodesk Inventor and Simulink software in conjunction with the Simscape Multibody toolbox to create a dynamic model of the entire system. Step 5: Implement and simulate the force control model.

7. A six-degree-of-freedom welding structural component performance testing device according to claim 6, characterized in that: In step 1, the parameters are specifically x-cylinder displacement; - Length between the cylinder axis and the center of the rocker; - height between the cylinder joint and the center of the rocker; - the distance between the arm joint at the joystick and the center of the joystick; - the distance between the arm joint and its center at the actuator; - Arm's length; - one side of the triangle formed by the three towers; - Stick angle.

8. A six-degree-of-freedom welding structural component performance testing device according to claim 7, characterized in that: In step 2, kinematic analysis is performed, which involves selecting generalized coordinates and moving the entire system toward the center by a distance of , to eliminate the space occupied by the force actuator (1), the angle between point 0-point 2-point 3 and x is : ； Where x represents the cylinder displacement, Indicates the length between the cylinder axis and the center of the rocker, Indicates the height between the cylinder joint and the center of the rocker. Indicates the joystick angle; The position of point 3 is expressed as: ； in, Indicates the position of the joint, Indicates the distance between the arm joint at the rocker and the center of the rocker. It represents the angle between point 0-point 2-point 3 and x; Write the same position of point 3 for the other Towers. This operation is done in , the rotation transformation applied at these three angles is as follows: ； Among them, the rotation matrix Indicates winding Rotational transformation of axes; Finding Points location, point The position at the center of the actuator is the intersection of the three spheres, and the sphere equation is: ,in are the coordinates of the actuator, are the coordinates of the center of the sphere, is the radius of the sphere; First, write a vector to describe the force transmitted by the joystick function, this force Perpendicular to the joystick, expressed as: ； Among them, the table The angle between the hydraulic cylinder and the rocker arm is less than 1.5°, which can be ignored. The force transmitted from the rocker arm to the arm is then expressed: ； in, Express the rocker force, represents the inner product operation; The net force exerted by the cylinder on the actuator is expressed as: .

9. A six-degree-of-freedom welding structural component performance testing device according to claim 8, characterized in that: The dynamic model was created using Simscape module, in which the dynamics and kinematics of the cylinder were used as input and output; The model is designed based on the following main modules: Solid, world coordinate system, rigid body transformation, joints; The Solid module represents each rigid part of the system and contains all relevant properties. This module is directly connected to the reference frame module and creates local coordinates.

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