A six-degree-of-freedom welding structural member performance testing device

Abstract

The present invention discloses a six-degree-of-freedom performance testing device for welded structural parts, which belongs to the technical field of performance testing devices. It solves the problem of mechanical performance evaluation of dissimilar metal welded structural parts under complex working conditions. By innovatively integrating the high-load characteristics of a hydraulic actuator with the three-degree-of-freedom spatial motion advantages of a Delta parallel mechanism, a multi-axis coupled loading system with a 10Hz dynamic bandwidth is successfully constructed. Experimental studies have shown that the platform can achieve multi-axis synchronous loading within a frequency range of 0.1 to 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 comparative analysis of finite element simulation and measured data, the structural integrity of the system under maximum load conditions is verified. The stress distribution of key load-bearing parts shows a maximum stress of 43MPa, and the end-stage posture accuracy of the motion platform is better than 20µm.

Description

Technical Field

[0001] The present 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 an important part of the overall structure and 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 structural component testing devices have a single testing method and very limited testing capabilities. For example, their testing 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 welded structural part performance testing device is designed. Summary of the Invention

[0006] The main purpose of the present 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:

[0008] A six-degree-of-freedom welded structural component performance testing device includes a force actuator having at least three sets of top ends, the three sets of top ends of the force actuator are respectively hinged to a first bidirectional rotation axis group, and are hinged to a connecting rod through the first bidirectional rotation axis group;

[0009] A second bidirectional rotating shaft group is hinged at the 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.

[0010] Preferably, the first bidirectional rotating shaft assembly includes a first shaft joint, a first connecting sleeve and a third shaft joint;

[0011] 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.

[0012] Preferably, the second bidirectional rotating shaft assembly includes a second shaft joint, a second connecting sleeve, and a fourth shaft joint;

[0013] 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 inside of the second connecting sleeve is hinged with the second shaft joint, and the middle of the second shaft joint is hinged with an arc rocker arm.

[0014] Preferably, the supporting base member comprises a base and a fixing device and a supporting shaft;

[0015] A fixing device is installed on the top of the base, and a supporting shaft is installed on the inner top of the fixing device. The supporting shaft is hinged to the arc-shaped rocker arm.

[0016] Preferably, the hydraulic system and the cylindrical connecting component;

[0017] 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.

[0018] Preferably, the method further includes a simulation force control model method:

[0019] Step 1: Parameterize the system, select a set of basic parameters to describe the model, and make assumptions about the corresponding values;

[0020] 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;

[0021] Step 3: Use the hydraulic system for analysis and build a hydraulic dynamics model using Simulink and Simscape Hydraulics toolbox;

[0022] Step 4: Perform rigid body dynamics analysis of the system, using Autodesk Inventor and Simulink software in conjunction with the Simscape Multibody toolbox to create a dynamic model of the entire system.

[0023] Step 5: Implement and simulate the force control model.

[0024] Preferably, the parameterization in step 1 specifically includes x-cylinder displacement;

[0025] - Length between the cylinder axis and the center of the rocker;

[0026] -Height between the cylinder joint and the center of the rocker;

[0027] -The distance between the arm joint at the joystick and the center of the joystick;

[0028] - the distance between the arm joint and its center at the actuator;

[0029] - Arm's length;

[0030] - one side of the triangle formed by the three towers;

[0031] - Joystick angle.

[0032] 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 formed between point 0-point 2-point 3 and x is :

[0033] ;

[0034] Where x represents the cylinder displacement, Indicates the length between the cylindrical axis and the center of the rocker, Indicates the height between the cylinder joint and the rocker center, Indicates the joystick angle.

[0035] The position of point 3 can be expressed as:

[0036] ;

[0037] 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.

[0038] Then write the same position of point 3 for other Towers. This operation is done in , the rotation transformation applied to these three angles is as follows:

[0039] ;

[0040] Among them, the rotation matrix Indicates winding Axis rotation transformation.

[0041] Finding a point location, point 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.

[0042] First, write a vector to describe the force transmitted by the joystick function, this force Perpendicular to the joystick. Expressed as:

[0043] ;

[0044] Among them, the table The angle between the hydraulic cylinder and the rocker is less than 1.5°, which can be ignored. The following is the force transmitted from the rocker arm to the arm:

[0045] ;

[0046] in, Express the rocker force, Represents the inner product operation.

[0047] The net force exerted by the cylinder on the actuator is expressed as: .

[0048] Preferably, the dynamic model is created using Simscape module, in which the dynamics and kinematics of the cylinder are used as input and output;

[0049] The model is designed based on the following main modules: Solid, world coordinate system, rigid body transformation, joints;

[0050] 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.

[0051] Beneficial technical effects of the present invention:

[0052] The present invention provides a six-degree-of-freedom welded structural component performance testing device that solves the difficult problem of mechanical performance evaluation of dissimilar metal welded structural components under complex working conditions. By innovatively integrating the high-load characteristics of a hydraulic actuator with the three-degree-of-freedom spatial motion advantages of a Delta parallel mechanism, a multi-axis coupled loading system with a 10 Hz dynamic bandwidth was successfully constructed. Experimental studies have shown that the platform can achieve multi-axis synchronous loading within a frequency range of 0.1 to 10 Hz, and its dynamic force control accuracy reaches ±2%. Compared with the traditional PD control strategy, the improved sliding mode control algorithm reduces the tracking error by 42%. Through comparative analysis of finite element simulation and measured data, the structural integrity of the system under maximum load conditions is verified. The stress distribution of key load-bearing parts shows a maximum stress of 43 MPa, and the end-stage posture accuracy of the motion platform is better than 20 µm. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 This is a perspective structural diagram of the entire device according to a preferred embodiment of a six-degree-of-freedom welded structural component performance testing device of the present invention;

[0054] Figure 2 A first-perspective perspective structural diagram of the entire device (excluding the workbench and the force actuator after downward movement) of a preferred embodiment of a six-degree-of-freedom welded structural component performance testing device according to the present invention;

[0055] Figure 3 A second-view stereoscopic structural diagram of the entire device (excluding the workbench and the force actuator after downward movement) of a preferred embodiment of a six-degree-of-freedom welded structural component performance testing device according to the present invention;

[0056] Figure 4 This is a schematic diagram of the first-perspective three-dimensional 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 welded structural component performance testing device of the present invention;

[0057] Figure 5 A schematic diagram of the second perspective 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 welded structural component performance testing device of the present invention;

[0058] Figure 6 This is a schematic diagram of the three-dimensional structure of a fixing device according to a preferred embodiment of a six-degree-of-freedom welded structural component performance testing device of the present invention;

[0059] Figure 7 This 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 welded structural component performance testing device of the present invention;

[0060] Figure 8This is a schematic diagram of the stereoscopic structure from a second perspective of a force actuator according to a preferred embodiment of a six-degree-of-freedom welded structural component performance testing device of the present invention.

[0061] In the figure: 1-force actuator, 2-first axis joint, 3-connecting rod, 4-second axis joint, 5-arc rocker arm, 6-cylindrical connecting component, 7-hydraulic system, 8-fixing device, 9-base, 10-third axis joint, 11-fourth axis joint, 12-support shaft, 13-first connecting sleeve, 14-second connecting sleeve. DETAILED DESCRIPTION

[0062] 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 with reference to embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0063] like Figures 1-8 As shown, this embodiment provides a six-degree-of-freedom welded 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 that drives the arc rocker arm 5 and is hinged to the end of the arc rocker arm 5 is hinged on the inner side of the supporting base member.

[0064] 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 bidirectional rotating shaft group. The first bidirectional 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 to realize up, down, left and right rotation through the connecting rod 3. The connecting rod 3 is hinged to the second bidirectional rotating shaft group at one end away from the force actuator 1, so 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.

[0065] 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;

[0066] 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, which is hinged to the top of the force actuator 1 through the first shaft joint 2.

[0067] 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.

[0068] 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;

[0069] 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 shaft joint 4 is hinged on the inside of the second connecting sleeve 14, and an arc-shaped rocker arm 5 is hinged in the middle of the second shaft joint 4.

[0070] Local working principle: The movement of the arc-shaped rocker arm 5 drives the second shaft joint 4 to be pressed down or tilted, and the second connecting sleeve 14 is driven to move along with it through 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.

[0071] In this embodiment, the supporting base member includes a base 9, a fixing device 8 and a supporting shaft 12;

[0072] A fixing device 8 is installed on the top of the base 9 , and a support shaft 12 is installed on the inner top of the fixing device 8 . The support shaft 12 is hinged to the arc-shaped rocker arm 5 .

[0073] Partial working principle: Through the hinged 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, forming the movement mode of the seesaw.

[0074] In this embodiment, the hydraulic system 7 and the cylindrical connecting member 6;

[0075] The inner side of the fixing device 8 is hinged with a hydraulic system 7 , and the output end of the hydraulic system 7 is hinged to the end of the arc-shaped rocker arm 5 away from the second shaft joint 4 .

[0076] Partial 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.

[0077] Example 1: Further explanation: 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 bidirectional 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 bidirectional rotating shaft group is thick on both sides and slightly thin in the middle, and there are inserted protruding parts at both ends for connecting the connecting rod 3. The connecting rod 3 is symmetrically distributed in the device system, and there are circular holes of the same size at both ends. Its two ends are respectively connected to the force actuator 1 and the rocker arm 5 through the first bidirectional rotating shaft group and the second bidirectional rotating shaft group.

[0078] Further explanation: The rocker arm 5 is an irregularly shaped component with three circular holes on its surface and a groove at one end;

[0079] 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.

[0080] The fixing device 8 has a cylindrical connecting component 6 connecting the connecting hole on the fixing device 8 with the connecting hole on the rocker arm 5. Each group of fixing devices 8 is symmetrically distributed on both sides of the hydraulic system 7.

[0081] The six-degree-of-freedom welded part performance test device is controlled by three hydraulic systems 7 to control the movement of the force actuator 1 with six degrees of freedom. When the three hydraulic systems 7 exert forces on the corresponding rocker arms 5 and the angle between the forces and the force actuator 1 is °, the resultant force applied to the force actuator 1 is the largest.

[0082] 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 the active mechanism and the force actuator 1 serves as the 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.

[0083] Example 2: In a control system, system parameterization is first performed, that is, a set of basic parameters are selected to describe the model and assumptions are made on the corresponding values.

[0084] Next, we performed kinematic and inverse kinematic analysis on the system, using geometric relationships to construct a set of equations describing the kinematic relationship between input and output. Next, we analyzed the hydraulic system, building a hydraulic dynamics model using Simulink and the Simscape Hydraulics toolbox.

[0085] 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.

[0086] Finally, force control models such as proportional-derivative and sliding mode control are implemented and simulated.

[0087] 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; - Joystick angle.

[0088] 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.

[0089] The angle between point 0-point 2-point 3 and x is :

[0090] ;

[0091] Where x represents the cylinder displacement, Indicates the length between the cylindrical axis and the center of the rocker, Indicates the height between the cylinder joint and the rocker center, Indicates the joystick angle.

[0092] The position of point 3 can be described as:

[0093] ;

[0094] 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.

[0095] Then write the same position of point 3 for other Towers. This operation is done in Apply rotation transformation on these three angles. The details are as follows:

[0096]

[0097] Among them, the rotation matrix Indicates winding Axis rotation transformation.

[0098] Then find the point location, point 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.

[0099] First, write a vector to describe the force transmitted by the joystick function, this force Perpendicular to the joystick. Expressed as:

[0100]

[0101] Among them, the table The angle between the hydraulic cylinder and the rocker is less than 1.5°, which can be ignored. The following is the force transmitted from the rocker arm to the arm:

[0102] ;

[0103] in, Express the rocker force, Represents the inner product operation.

[0104] The net force exerted by the cylinder on the actuator is expressed as: .

[0105] 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 location of the servo valve control signal, output 1-the ground reference connected to the multi-body model, and 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 volumes A and B: 128.2mL, and initial pressures A and B: 0Pa.

[0106] Building the dynamics model: This dynamics model was created using Simscape modules to describe the test bench's kinematic behavior. The dynamics and kinematics of the cylinders served as inputs and outputs. The model was designed based on several main modules: Solid, World Coordinate System, Rigid Body Transformation, and 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.

[0107] The above is only a further embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes based on the technical solutions and concepts of the present invention within the scope disclosed by the present invention, which fall within the scope of protection of the present invention.

Claims

1. A six-degree-of-freedom welded structural component performance testing device, characterized by: The force actuator (1) comprises a force actuator (1), the force actuator (1) having at least three sets of top ends, the three sets of top ends of the force actuator (1) being respectively hinged to a first bidirectional rotating shaft set, and being hinged to a connecting rod (3) via the first bidirectional rotating shaft set; A second bidirectional rotating shaft group is hinged at one end of the connecting rod (3) away from the force actuator (1), the second bidirectional rotating shaft group is hinged on the arc-shaped rocker arm (5), the middle part of the arc-shaped rocker arm (5) is hinged on the supporting base member, and a hydraulic group for driving the arc-shaped rocker arm (5) and hinged to the end of the arc-shaped rocker arm (5) is hinged on the inner side of the supporting base member; The first bidirectional rotating shaft assembly comprises a first shaft joint (2), a first connecting sleeve (13) and a third shaft joint (10); The end of the connecting rod (3) is hingedly connected to a third shaft joint (10), 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 hingedly connected to the inner side of the first connecting sleeve (13), and is hingedly connected to the top end of the force actuator (1) through the first shaft joint (2); 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); the inside of the second connecting sleeve (14) is hingedly connected to a second shaft joint (4); and an arc-shaped rocker arm (5) is hingedly connected to the middle of the second shaft joint (4); 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 support shaft (12) is installed on the inner top of the fixing device (8), and the support shaft (12) is hinged to the arc-shaped rocker arm (5); 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).

2. A six-degree-of-freedom welded structural component performance testing device according to claim 1, 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, using 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.

3. The six-degree-of-freedom welded structural component performance testing device according to claim 2, characterized in that: 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; - Joystick angle.

4. The six-degree-of-freedom welded structural component performance testing device according to claim 3, characterized in that: In step 2, kinematic analysis is performed, which involves selecting generalized coordinates and moving the entire system toward the center. The distance of the transfer is , to eliminate the space occupied by the force actuator (1), and The angle formed between : ； in, Indicates cylinder displacement, Indicates the length between the cylindrical axis and the center of the rocker, Indicates the height between the cylinder joint and the rocker center, 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. express and The angle formed between Write the same location of point 3 for other Towers. This operation is done in , the rotation transformation applied to these three angles is as follows: ； Among them, the rotation matrix Indicates winding Rotational transformations about axes; Finding a point location, point The position of the actuator center 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 is less than 1.5°, which can be ignored. The following is the force transmitted from the rocker arm to the arm: ； in, Express the rocker force, represents the inner product operation; The net force exerted by the cylinder on the actuator is expressed as: .

5. The six-degree-of-freedom welded structural component performance testing device according to claim 4, characterized in that: The dynamic model was created using Simscape module. In this dynamic model, 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 can create local coordinates.

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