Multi-degree-of-freedom human arm vibration transmission characteristic test system and method

Abstract

The invention discloses a multi-degree-of-freedom human body arm vibration transmission characteristic test system and method, and relates to the technical field of human body vibration transmission characteristic test.The scheme includes that the system comprises a workbench, an adjusting mechanism is mounted on the upper surface of the workbench, and multi-degree-of-freedom excitation units are mounted at the two movable ends of the adjusting mechanism; according to the multi-degree-of-freedom vibration excitation device, the defects that in the prior art, scene coverage is incomplete, the degree of freedom is insufficient, and the data dimension is single are overcome, the actual operation working condition can be comprehensively restored, the working efficiency is improved, and the working efficiency is improved. And a more accurate test basis is provided for vibration machine structure optimization and vibration protection scheme design.

Description

Technical Field

[0001] This invention relates to the field of human body vibration transmission characteristic testing technology, specifically a multi-degree-of-freedom human arm vibration transmission characteristic testing system and method. Background Technology

[0002] With the development of industries such as machining, urban and rural construction, and agricultural machinery operations, the application of dual-handle vibratory implements (such as large cutting machines, tractors, and cranes) is becoming increasingly widespread. The multi-directional hand-transmitted vibrations they generate pose more complex hazards to the operator's arm system and physiological state. A search revealed that Chinese Patent Publication No. CN112022165A discloses a testing platform and method for the vibration transmission characteristics of the human arm system. The test includes an excitation unit, a testing unit, and a data acquisition and processing unit. The excitation unit includes a vibration table used to simulate vibration. The testing unit includes a handle clamp, a vibration handle assembly, a force sensor, and an acceleration sensor. The handle clamp is used to fix the vibration handle assembly to the vibration table. The vibration handle assembly is used to contact the human arm. The force sensor is used to sense force data, and the acceleration sensor is used to sense acceleration data. The data acquisition and processing unit is used to collect data from the force sensor and the acceleration sensor and perform further processing.

[0003] While the aforementioned technical solution, through this testing platform, can test and study the vibration characteristics of the human arm, and optimize the structure of the vibration equipment from the perspective of the human arm's working posture and applied force, thereby reducing the intensity and level of hand-transmitted vibration and minimizing the adverse effects of vibration on the human arm system, it has significant drawbacks: it only supports single-handle, single-degree-of-freedom vibration testing, failing to recreate the actual working conditions of coordinated two-handed operation; data acquisition is limited to mechanical and acceleration parameters, lacking physiological response assessment; and its structural flexibility is insufficient, resulting in poor versatility. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a testing system and method for the vibration transmission characteristics of a multi-degree-of-freedom human arm, solving the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a multi-degree-of-freedom human arm vibration transmission characteristic testing system, comprising a workbench, an adjustment mechanism mounted on the upper surface of the workbench, a multi-degree-of-freedom excitation unit mounted on each of the two movable ends of the adjustment mechanism, a test handle mounted on the multi-degree-of-freedom excitation unit, a multi-modal data acquisition and processing unit and a physiological sensing unit mounted on the upper surface of the workbench, and the adjustment mechanism, the multi-degree-of-freedom excitation unit, the test handle and the physiological sensing unit all connected to the multi-modal data acquisition and processing unit via wires; The multi-degree-of-freedom excitation unit includes a first mounting frame, an X-axis exciter rotatably connected inside the first mounting frame via a rotating shaft, a second mounting frame mounted on the movable end of the X-axis exciter, a Y-axis exciter mounted inside the second mounting frame, a third mounting frame mounted on the movable end of the Y-axis exciter, a Z-axis exciter mounted inside the third mounting frame, a mounting plate mounted on the movable end of the Z-axis exciter, and a test handle mounted on the mounting plate.

[0006] Preferably, the adjustment mechanism includes a base mounted on the upper surface of the workbench, a servo motor mounted on the base, a bidirectional lead screw mounted on the output shaft of the servo motor via a coupling, two slides symmetrically threaded on the outer surface of the bidirectional lead screw, and the corresponding multi-degree-of-freedom excitation unit mounted on the slides. The upper surface of the base is symmetrically provided with two slide rails that are slidably connected to the inside of the slides.

[0007] Preferably, the test handle includes a vertically arranged U-shaped frame, with a connecting plate installed between the two ends of the U-shaped frame. Force sensors are installed on the outer surfaces of both ends of the connecting plate. A connecting handle is installed between two force sensors located on one side. A groove is formed on the inner wall of the connecting handle. A first three-axis accelerometer is installed on one side of the inner wall of the U-shaped frame, and a second three-axis accelerometer is installed inside the groove. A gripping part is provided on the outer side of the connecting handle, and a locking mechanism is provided between the gripping part and the connecting handle.

[0008] Preferably, the connecting handle includes an arc-shaped plate, with connecting strips installed at both ends of the arc-shaped plate. The connecting strips are connected to corresponding mechanical sensors by screws, and the groove is formed at the center of the inner wall of the arc-shaped plate. The gripping part includes a gripping plate, the inner wall of which contacts the outer wall of the arc-shaped plate, and an anti-slip sleeve is adhered to the outside of the gripping plate.

[0009] Preferably, the snap-fit ​​mechanism includes mounting grooves at both ends of the arc-shaped plate, with a J-type buckle slidably connected inside the mounting groove, a snap groove on the inner wall of the gripping plate that mates with the J-type buckle, a reset spring inside the mounting groove for resetting the J-type buckle, a limiting plate on the inner wall of the gripping plate, and a limiting groove on the outer surface of the arc-shaped plate that mates with the limiting plate.

[0010] Preferably, the multimodal data acquisition and processing unit includes a power amplifier, a vibration feedback controller, a data acquisition and processing module, and a display screen, which are sequentially mounted on the workbench, with the controller installed at the bottom of the display screen.

[0011] Preferably, the physiological sensing unit includes a placement box mounted on a workbench, and an electromyography sensor, a heart rate sensor, and a skin conductance sensor are placed inside the placement box in sequence.

[0012] A method for testing the vibration transmission characteristics of a multi-degree-of-freedom human arm includes the following steps: S1. System calibration and parameter configuration: calibrate the position of each mechanism and each sensor within the system. S2. Tester preparation: The tester should wear light clothing, short-sleeved clothing, and remove metal jewelry such as watches, rings, and bracelets to avoid interfering with the sensor signal acquisition. The tester should sit in a chair. Staff assisted the test subjects in installing the physiological sensing unit: attaching the electromyography sensor to the designated location, applying medical conductive gel and ensuring that the electrode pads adhered to the skin without air bubbles; wearing the heart rate sensor on the wrist and adjusting the tightness of the wristband; attaching the electrodermal response sensor to the thenar eminence of the palm and securing the wires with medical tape. The tester holds two test handles with each hand and observes the grip strength and pushing force values ​​in real time on the display screen. By adjusting the force exerted by the arms, the grip strength and pushing force are stabilized at the preset target value. After maintaining this stable value for 30 seconds without fluctuation, the tester signals the staff to start the test.

[0013] S3. Multi-dimensional data acquisition: Staff activate two multi-degree-of-freedom excitation units, which output three-dimensional vibration according to preset scenario parameters; the vibration feedback controller monitors the vibration output parameters in real time to ensure that the deviation from the preset value is ≤5%; The data acquisition and processing module starts synchronously, acquiring grip force and thrust signals from the mechanical sensor, X, Y, and Z axis acceleration signals from the first and second triaxial accelerometers, and electromyography, heart rate, and skin conductivity signals from the physiological sensing unit in real time; during the acquisition process, the display screen shows the change curves of various data in real time in different areas; When the vibration duration reaches the preset 40 seconds, the multi-degree-of-freedom excitation unit automatically stops vibrating; the data acquisition and processing module continues to acquire data for 5 seconds and then stops to ensure data integrity. S4. Data Processing and Analysis: The data acquisition and processing module processes the acquired raw data and performs feature analysis on the processed data: calculates the vibration transmission characteristics and mechanical impedance related indicators at different frequencies; analyzes the changing patterns of electromyography signals, heart rate signals, and skin conductivity signals, and assesses the degree of muscle fatigue and physiological load level. The built-in CNN model integrates and analyzes mechanical, vibration, and physiological data to output a quantitative assessment of vibration hazards. S5. Test Result Output and Comparison: The display screen synchronously displays the three-dimensional vibration transmission characteristic surface diagram, mechanical impedance frequency curve, muscle fatigue change curve, physiological load level radar chart, and comprehensive evaluation report. S6. Different sizes of grips, the distance between the two test handles, and the vibration scene parameters or arm posture can be replaced. Repeat steps S1-S5 to conduct multiple sets of comparative tests and obtain vibration transmission characteristic data under different conditions.

[0014] This invention provides a system and method for testing the vibration transmission characteristics of a multi-degree-of-freedom human arm. It has the following beneficial effects: This multi-degree-of-freedom human arm vibration transmission characteristic testing system and method offers more comprehensive scenario coverage: Adopting a "dual-handle + three-dimensional multi-degree-of-freedom excitation" design, it breaks through the limitations of traditional single-handle, single-degree-of-freedom testing. It can accurately reproduce the unidirectional or composite vibration conditions of single / dual-handle vibrating machines, highly matching real-world scenarios such as machining and agricultural machinery operations, objectively reflecting the arm vibration transmission state, and avoiding test deviations caused by scenario simplification.

[0015] Richer Data Dimensions: A multi-dimensional acquisition system encompassing mechanics, vibration, and physiology is constructed. In addition to acquiring core parameters such as grip strength and vibration acceleration, it also captures physiological signals such as electromyography, heart rate, and skin conductivity. This not only analyzes the vibration transmission patterns but also quantifies muscle fatigue and physiological load, filling the gaps in traditional physiological assessment testing and providing more comprehensive data support for protective design.

[0016] More flexible structural design: The modular, detachable handle allows for quick replacement of grips of different sizes, and the adjustment mechanism can flexibly adapt to the handle spacing and the tester's arm span. The lightweight, low-interference physiological sensing unit is easy to install and does not affect operation. Multi-scenario testing can be completed without replacing the entire device, greatly improving system versatility and operational efficiency.

[0017] Deeper analytical capabilities: Multimodal data fusion algorithms enable in-depth data mining, quantifying vibration hazard levels and providing precise support for the optimization of vibration equipment structures and the formulation of occupational health standards. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the adjustment mechanism of the present invention; Figure 3 This is a schematic diagram of the structure of the multi-degree-of-freedom excitation unit of the present invention; Figure 4 This is a schematic diagram of the structure of the test handle of the present invention; Figure 5 This is a schematic diagram of the structure of the U-shaped frame, connecting plate, mechanical sensor, and first triaxial accelerometer of the present invention; Figure 6 This is a schematic diagram of the connecting handle and gripping part of the present invention; Figure 7This is a schematic diagram of the internal structure of the connecting handle and the gripping part of the present invention; Figure 8 This is a schematic diagram of the internal structure of the connecting handle of the present invention; Figure 9 This is a schematic diagram of the internal structure of the gripping part of the present invention.

[0019] In the diagram: 1. Worktable; 2. Adjustment mechanism; 21. Base; 22. Servo motor; 23. Bidirectional lead screw; 24. Slide block; 25. Slide rail; 3. Multi-degree-of-freedom excitation unit; 31. First mounting bracket; 32. X-axis exciter; 33. Second mounting bracket; 34. Y-axis exciter; 35. Third mounting bracket; 36. Z-axis exciter; 37. Mounting plate; 4. Test handle; 41. U-shaped frame; 42. Connecting plate; 43. Mechanical sensor; 44. Connecting handle; 441. Arc-shaped plate; 442. 45. Connecting bar; 46. Groove; 47. First triaxial accelerometer; 48. Second triaxial accelerometer; 49. Grip part; 40. Grip plate; 41. Anti-slip sleeve; 42. Snap-fit ​​mechanism; 43. J-type buckle; 44. Slot; 45. Return spring; 46. Limiting plate; 47. Limiting groove; 58. Multimodal data acquisition and processing unit; 59. Power amplifier; 50. Vibration feedback controller; 51. Data acquisition and processing module; 52. Display screen; 6. Physiological sensing unit. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] Example: like Figure 1 As shown, a multi-degree-of-freedom human arm vibration transmission characteristic testing system includes a workbench 1, an adjustment mechanism 2 installed on the upper surface of the workbench 1, a multi-degree-of-freedom excitation unit 3 installed on each of the two movable ends of the adjustment mechanism 2, a test handle 4 installed on the multi-degree-of-freedom excitation unit 3, a multi-modal data acquisition and processing unit 5 and a physiological sensing unit 6 installed on the upper surface of the workbench 1, and the adjustment mechanism 2, the multi-degree-of-freedom excitation unit 3, the test handle 4 and the physiological sensing unit 6 are all connected to the multi-modal data acquisition and processing unit 5 through wires; like Figures 1 to 3As shown, the multi-degree-of-freedom excitation unit 3 includes a first mounting frame 31. An X-axis exciter 32 is rotatably connected inside the first mounting frame 31 via a rotating shaft. A second mounting frame 33 is mounted on the movable end of the X-axis exciter 32. A Y-axis exciter 34 is mounted inside the second mounting frame 33. A third mounting frame 35 is mounted on the movable end of the Y-axis exciter 34. A Z-axis exciter 36 is mounted inside the third mounting frame 35. A mounting plate 37 is mounted on the movable end of the Z-axis exciter 36. A test handle 4 is mounted on the mounting plate 37.

[0022] Through the above technical solutions, the X-axis vibrator 32, Y-axis vibrator 34 and Z-axis vibrator 36 can perform three-dimensional multi-degree-of-freedom vibration simulation, accurately simulate the multi-directional vibration scenarios of vibrating tools in actual operation, break through the limitations of single-degree-of-freedom testing, and meet the complex working conditions of dual-handle tools.

[0023] like Figure 1 and Figure 2 As shown, the adjustment mechanism 2 includes a base 21 mounted on the upper surface of the workbench 1. A servo motor 22 is mounted on the base 21. The output shaft of the servo motor 22 is mounted with a bidirectional lead screw 23 via a coupling. Two slide blocks 24 are symmetrically threaded on the outer surface of the bidirectional lead screw 23. The corresponding multi-degree-of-freedom excitation unit 3 is mounted on the slide block 24. Two slide rails 25 are symmetrically provided on the upper surface of the base 21 and are slidably connected to the inside of the slide block 24.

[0024] Through the above technical solution, the servo motor 22 drives the bidirectional lead screw 23 to rotate, causing the two symmetrical slide blocks 24 to move in the same or opposite directions along the slide rail 25, so that the multi-degree-of-freedom excitation unit 3 moves synchronously with the slide blocks 24. The distance between the two test handles 4 can be flexibly adjusted to adapt to the arm span of different testers or the handle distance of different types of vibration machines, thus improving the versatility of the system.

[0025] like Figures 1 to 9 As shown, the test handle 4 includes a vertically arranged U-shaped frame 41, a connecting plate 42 installed between the two ends of the U-shaped frame 41, a force sensor 43 installed on the outer surface of both ends of the connecting plate 42, a connecting handle 44 installed between the two force sensors 43 on one side, a groove 45 opened on the inner wall of the connecting handle 44, a first triaxial acceleration sensor 46 installed on one side of the inner wall of the U-shaped frame 41, a second triaxial acceleration sensor 47 installed inside the groove 45, a gripping part 48 provided on the outer side of the connecting handle 44, and a locking mechanism 49 provided between the gripping part 48 and the connecting handle 44.

[0026] Through the above technical solution, when the tester holds the grip part 48, the force sensor 43 collects grip and thrust signals, while the first triaxial accelerometer 46 and the second triaxial accelerometer 47 collect vibration acceleration signals at different locations. The locking mechanism 49 enables the grip part 48 to be detachable. Simultaneous acquisition of mechanical and vibration parameters, and support for replacing the grip part 48 to adapt to different tool grip configurations, enriches the testing scenarios. Furthermore, such as Figure 6 As shown, the connecting handle 44 includes an arc-shaped plate 441, with connecting strips 442 installed at both ends of the arc-shaped plate 441. The connecting strips 442 are connected to the corresponding mechanical sensors 43 by screws, and the groove 45 is opened at the center of the inner wall of the arc-shaped plate 441.

[0027] The arc plate 441 is fixed to the mechanical sensor 43 by screws through the connecting strips 442 at both ends. The inner wall groove 45 provides installation space for the second triaxial acceleration sensor 47, ensuring the stability of the sensor position and guaranteeing the accuracy of data acquisition.

[0028] The grip portion 48 includes a grip plate 481, the inner wall of which contacts the outer wall of the arc plate 441, and an anti-slip sleeve 482 is adhered to the outside of the grip plate 481.

[0029] The inner wall of the grip plate 481 is fitted to the outer wall of the arc plate 441. The outer anti-slip sleeve 482 increases the friction between the hand and the grip part 48, improves grip comfort, prevents the tester from slipping when holding the grip, reduces the interference of grip instability on the data, and improves the operating experience during the test.

[0030] Furthermore, such as Figures 7 to 9 As shown, the snap-fit ​​mechanism 49 includes mounting grooves at both ends of the arc-shaped plate 441. A J-type buckle 491 is slidably connected inside the mounting groove. The inner wall of the gripping plate 481 is provided with a snap groove 492 that cooperates with the J-type buckle 491. The mounting groove is provided with a reset spring 493 for resetting the J-type buckle 491. The inner wall of the gripping plate 481 is provided with a limiting plate 494. The outer surface of the arc-shaped plate 441 is provided with a limiting groove 495 that cooperates with the limiting plate 494.

[0031] With the above technical solution, during installation, the limiting plate 494 of the grip plate 481 is embedded into the limiting groove 495 of the arc-shaped plate 441 for positioning, and the J-type buckle 491 is locked into the slot 492 under the action of the return spring 493 for fixation; during disassembly, pressing the J-type buckle 491 compresses the return spring 493, disengaging it from the slot 492 to remove the grip part 48. This allows for quick assembly and disassembly of the grip part 48, simplifies the replacement process for grip parts 48 of different specifications, and improves testing efficiency.

[0032] like Figure 1As shown, the multimodal data acquisition and processing unit 5 includes a power amplifier 51, a vibration feedback controller 52, a data acquisition and processing module 53, and a display screen 54, which are sequentially installed on the workbench 1. The controller is installed at the bottom of the display screen 54.

[0033] Power amplifier 51 amplifies the vibration control signal, vibration feedback controller 52 monitors and corrects vibration output parameters, data acquisition and processing module 53 receives and processes various sensor signals, and display screen 54 displays data and results in real time. This achieves precise control of vibration signals, centralized processing of multi-dimensional data, and visualized monitoring of the testing process, ensuring test accuracy and data reliability.

[0034] The physiological sensing unit 6 includes a placement box installed on the workbench 1, and an electromyography sensor, a heart rate sensor and a skin conductance sensor are placed inside the placement box in sequence.

[0035] Electromyography (EMG), heart rate, and skin conductance sensors are placed in contact with designated areas of the test subject's body to collect corresponding physiological signals and transmit them to the data acquisition and processing module 53. This obtains data on the impact of vibration on human muscles, heart rate, and skin conductance, filling the gap in traditional testing that only focuses on mechanical and vibration parameters, and enriching the testing dimensions.

[0036] A method for testing the vibration transmission characteristics of a multi-degree-of-freedom human arm includes the following steps: S1. System calibration and parameter configuration: calibrate the position of each mechanism and each sensor within the system. S2. Tester preparation: The tester should wear light clothing, short-sleeved clothing, and remove metal jewelry such as watches, rings, and bracelets to avoid interfering with the sensor signal acquisition. The tester should sit in a chair. Staff assisted the test subject in installing physiological sensing unit 6: attaching the electromyography sensor to the designated location, applying medical conductive gel and ensuring that the electrode pads adhered to the skin without air bubbles; wearing the heart rate sensor on the wrist and adjusting the tightness of the wristband; attaching the skin conduction sensor to the thenar eminence of the palm and securing the wires with medical tape. The tester holds two test handles 4 with both hands and observes the grip strength and pushing force values ​​in real time through the display screen 54. By adjusting the force exerted by the arm, the grip strength and pushing force are stabilized at the preset target value. After maintaining this for 30 seconds without fluctuation, the tester signals the staff to start the test.

[0037] S3. Multi-dimensional data acquisition: The staff starts two multi-degree-of-freedom excitation units 3, which output three-dimensional vibration according to the preset scene parameters; the vibration feedback controller 52 monitors the vibration output parameters in real time to ensure that the deviation from the preset value is ≤5%; The data acquisition and processing module 53 starts synchronously, acquiring in real time the grip force and pushing force signals from the force sensor 43, the X, Y, and Z axis acceleration signals from the first triaxial accelerometer 46 and the second triaxial accelerometer 47, and the electromyography signal, heart rate signal, and skin conductivity signal from the physiological sensing unit 6; during the acquisition process, the display screen 54 displays the change curves of various data in real time in different areas; When the vibration duration reaches the preset 40s, the multi-degree-of-freedom excitation unit 3 automatically stops vibrating; the data acquisition and processing module 53 continues to acquire data for 5s and then stops to ensure data integrity. S4. Data Processing and Analysis: The data acquisition and processing module 53 processes the acquired raw data and performs feature analysis on the processed data: calculates the vibration transmission characteristics and mechanical impedance related indicators at different frequencies; analyzes the changing patterns of electromyographic signals, heart rate signals, and skin conductivity signals, and assesses the degree of muscle fatigue and physiological load level. The built-in CNN model integrates and analyzes mechanical, vibration, and physiological data to output a quantitative assessment of vibration hazards. S5. Test Result Output and Comparison: The display screen 54 synchronously displays the three-dimensional vibration transmission characteristic surface diagram, mechanical impedance frequency curve, muscle fatigue change curve, physiological load level radar chart, and comprehensive evaluation report. S6. Replace the grip part 48 with different specifications, adjust the distance between the two test handles 4, adjust the vibration scene parameters or arm posture, repeat steps S1-S5, conduct multiple sets of comparative tests, and obtain vibration transmission characteristic data under different conditions.

[0038] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0039] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A multi-degree-of-freedom human arm vibration transmission characteristic testing system, characterized in that: The system includes a workbench (1), an adjustment mechanism (2) is installed on the upper surface of the workbench (1), a multi-degree-of-freedom excitation unit (3) is installed on both movable ends of the adjustment mechanism (2), a test handle (4) is installed on the multi-degree-of-freedom excitation unit (3), a multi-modal data acquisition and processing unit (5) and a physiological sensing unit (6) are installed on the upper surface of the workbench (1), and the adjustment mechanism (2), the multi-degree-of-freedom excitation unit (3), the test handle (4) and the physiological sensing unit (6) are all connected to the multi-modal data acquisition and processing unit (5) through wires; The multi-degree-of-freedom excitation unit (3) includes a first mounting frame (31), an X-axis exciter (32) is rotatably connected inside the first mounting frame (31) via a rotating shaft, a second mounting frame (33) is mounted on the movable end of the X-axis exciter (32), a Y-axis exciter (34) is mounted inside the second mounting frame (33), a third mounting frame (35) is mounted on the movable end of the Y-axis exciter (34), a Z-axis exciter (36) is mounted inside the third mounting frame (35), a mounting plate (37) is mounted on the movable end of the Z-axis exciter (36), and the test handle (4) is mounted on the mounting plate (37).

2. The multi-degree-of-freedom human arm vibration transmission characteristic testing system according to claim 1, characterized in that: The adjustment mechanism (2) includes a base (21) mounted on the upper surface of the workbench (1). A servo motor (22) is mounted on the base (21). A bidirectional lead screw (23) is mounted on the output shaft of the servo motor (22) via a coupling. Two slide blocks (24) are symmetrically threaded on the outer surface of the bidirectional lead screw (23). The corresponding multi-degree-of-freedom excitation unit (3) is mounted on the slide block (24). Two slide rails (25) that are symmetrically slidably connected to the inside of the slide block (24) are provided on the upper surface of the base (21).

3. The multi-degree-of-freedom human arm vibration transmission characteristic testing system according to claim 1, characterized in that: The test handle (4) includes a vertically arranged U-shaped frame (41), a connecting plate (42) is installed between the two ends of the U-shaped frame (41), a force sensor (43) is installed on the outer surface of both ends of the connecting plate (42), a connecting handle (44) is installed between the two force sensors (43) on one side, a groove (45) is provided on the inner wall of the connecting handle (44), a first triaxial acceleration sensor (46) is installed on one side of the inner wall of the U-shaped frame (41), a second triaxial acceleration sensor (47) is installed inside the groove (45), a gripping part (48) is provided on the outer side of the connecting handle (44), and a snap-fit ​​mechanism (49) is provided between the gripping part (48) and the connecting handle (44).

4. The multi-degree-of-freedom human arm vibration transmission characteristic testing system according to claim 3, characterized in that: The connecting handle (44) includes an arc plate (441), and connecting strips (442) are installed at both ends of the arc plate (441). The connecting strips (442) are connected to the corresponding mechanical sensors (43) by screws. The groove (45) is opened at the center of the inner wall of the arc plate (441). The gripping part (48) includes a gripping plate (481), the inner wall of the gripping plate (481) is in contact with the outer wall of the arc plate (441), and an anti-slip sleeve (482) is bonded to the outside of the gripping plate (481).

5. The multi-degree-of-freedom human arm vibration transmission characteristic testing system according to claim 4, characterized in that: The latching mechanism (49) includes mounting grooves at both ends of the arc plate (441), with a J-type buckle (491) slidably connected inside the mounting groove. The inner wall of the gripping plate (481) has a slot (492) that mates with the J-type buckle (491). The mounting groove has a reset spring (493) for resetting the J-type buckle (491). The inner wall of the gripping plate (481) has a limiting plate (494), and the outer surface of the arc plate (441) has a limiting groove (495) that mates with the limiting plate (494).

6. The multi-degree-of-freedom human arm vibration transmission characteristic testing system according to claim 1, characterized in that: The multimodal data acquisition and processing unit (5) includes a power amplifier (51), a vibration feedback controller (52), a data acquisition and processing module (53), and a display screen (54) installed sequentially on the workbench (1). The controller is installed at the bottom of the display screen (54).

7. The multi-degree-of-freedom human arm vibration transmission characteristic testing system according to claim 1, characterized in that: The physiological sensing unit (6) includes a placement box installed on the workbench (1), and an electromyography sensor, a heart rate sensor and a skin conductance sensor are placed inside the placement box in sequence.

8. A method for testing the vibration transmission characteristics of a multi-degree-of-freedom human arm, based on the system described in any one of claims 1-7, characterized in that: Includes the following steps: S1. System calibration and parameter configuration: calibrate the position of each mechanism and each sensor within the system. S2. Tester preparation: The tester should wear light clothing, short-sleeved clothing, and remove metal jewelry such as watches, rings, and bracelets to avoid interfering with the sensor signal acquisition. The tester should sit in a chair. Staff assisted the test subject in installing the physiological sensing unit (6): pasted the electromyography sensor at the designated location, applied medical conductive gel and ensured that the electrode pads adhered to the skin without air bubbles; wore the heart rate sensor on the wrist and adjusted the tightness of the wristband; pasted the skin electrical response sensor on the thenar eminence of the palm and fixed the wire with medical tape. The tester holds two test handles (4) with both hands and observes the grip and push force values ​​in real time through the display screen (54). By adjusting the force exerted by the arm, the grip and push force are stabilized at the preset target value. After maintaining no fluctuation for 30 seconds, the tester signals the staff to start the test. S3, Multi-dimensional data acquisition: The staff starts two multi-degree-of-freedom excitation units (3), and the two multi-degree-of-freedom excitation units (3) output three-dimensional vibration according to the preset scene parameters; the vibration feedback controller (52) monitors the vibration output parameters in real time to ensure that the deviation from the preset value is ≤5%; The data acquisition and processing module (53) is started synchronously, and the grip force and pushing force signals of the mechanical sensor (43), the X, Y and Z axis acceleration signals of the first triaxial accelerometer (46) and the second triaxial accelerometer (47), and the electromyographic signal, heart rate signal and skin conductivity signal of the physiological sensing unit (6) are collected in real time. During the acquisition process, the display screen (54) displays the change curves of various data in real time in different areas. When the vibration duration reaches the preset 40s, the multi-degree-of-freedom excitation unit (3) automatically stops vibrating; the data acquisition and processing module (53) continues to acquire data for 5s and then stops to ensure data integrity; S4. Data processing and analysis: The data acquisition and processing module (53) processes the acquired raw data and performs feature analysis on the processed data: calculates the vibration transmission characteristics and mechanical impedance related indicators at different frequencies; analyzes the changing patterns of electromyography signals, heart rate signals, and skin conductivity signals, and assesses the degree of muscle fatigue and physiological load level. The built-in CNN model integrates and analyzes mechanical, vibration, and physiological data to output a quantitative assessment of vibration hazards. S5. Test result output and comparison: The display screen (54) synchronously displays the three-dimensional vibration transmission characteristic surface diagram, mechanical impedance frequency curve, muscle fatigue change curve, physiological load level radar chart and comprehensive evaluation report. S6. Replace the grip (48) of different specifications, the distance between the two test handles (4), adjust the vibration scene parameters or arm posture, repeat steps S1-S5, conduct multiple sets of comparative tests, and obtain vibration transmission characteristic data under different conditions.

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