Multi-degree-of-freedom impact excitation device for dynamic calibration of force sensor

Abstract

The invention relates to a multi-degree-of-freedom impact excitation device for dynamic calibration of a force sensor, which is suitable for a dynamic calibration experiment of the force sensor requiring multi-point and multi-direction impact excitation and comprises a movable base, an adjustable lifting platform, a multi-degree-of-freedom positioning oscillating bar system and an impact hammer. The movable base is adopted to realize large-range ground horizontal movement of the impact excitation device in a calibration environment so as to meet the requirements of large-range impact excitation dynamic calibration of excitation points at different positions on the force sensor; the adjustable lifting platform is used for realizing height adjustment of the position of the impact excitation point; the multi-degree-of-freedom positioning swing rod system has seven degrees of freedom and is used for achieving horizontal fine adjustment of the position of an impact excitation point, multi-degree-of-freedom adjustment of the impact excitation direction and graded control of the impact excitation amplitude. And the impact hammer is used for applying and measuring an impact excitation load. Therefore, the device provided by the invention can meet the requirements of multi-point, multi-direction adjustable and amplitude controllable impact excitation dynamic calibration on the force sensor.

Description

Technical Field

[0001] The present invention relates to the field of force sensor testing and is a multi-degree-of-freedom impact excitation device for dynamic calibration of force sensors, in particular an impact excitation device suitable for dynamic calibration experiments of force sensors requiring multi-point and multi-directional impact excitation, so as to realize dynamic calibration of force sensors by multi-directional or distributed impact excitation. Background Art

[0002] Impact excitation is a common excitation method for dynamic calibration of force sensors. For force sensors with complex fixture structures and high structural flexibility, or for multi-dimensional force sensors, multi-point, multi-directional, or distributed impact excitation is often required to improve dynamic calibration accuracy. This requires an impact excitation device that can flexibly adjust the impact excitation position and direction, and control the impact excitation amplitude to meet the dynamic calibration requirements of different force sensors.

[0003] Currently, the main ways to generate impact excitation are: 1. Use a handheld impact hammer to strike a designated striking point to generate impact excitation; 2. Lift a heavy object to a certain height and then release it, causing it to fall freely and hit a force sensor to generate impact excitation, such as Chinese patent CN221667513U (Hebei Xinda Steel Group Co., Ltd., a free-falling hammer impact test device, 2024-09-06), Chinese patent CN222812710U (Suzhou Abifu Testing Technology Co., Ltd., a drop hammer impact test device, 2025-04-29), and Chinese patent CN115112498B (China Aero Engine Shenyang Engine Research Institute, a cantilever drop hammer impact load test device and impact load Correction method, 2025-04-04), etc.; 3. Use movable and adjustable auxiliary devices to fix and constrain the impact hammer to achieve control of the impact point, impact direction, and impact amplitude, such as Chinese patent CN110243938B (High Speed ​​Aerodynamics Research Institute of China Aerodynamics Research and Development Center, a mobile hammer modal test device and system, 2022-02-01), Chinese patent CN117848874A (Yangzhou Yingmaike Measurement and Control Technology Co., Ltd., a pendulum hammer calibration device, 2024-04-09), and Chinese patent CN222299405U (Shandong Liangong Testing Equipment Co., Ltd., a pendulum impact testing machine, 2025-01-03), etc. The first approach cannot accurately control the striking point and striking direction and has poor repeatability, and is generally used in vibration modal testing situations or dynamic calibration situations where the impact excitation accuracy requirements are not high; the second approach can only achieve unidirectional striking in the vertical direction through the free fall motion of the heavy hammer, and is suitable for unidirectional impact excitation dynamic calibration of unidirectional force sensors; the third approach can achieve the adjustment of the impact excitation position and direction and the control of the impact amplitude by designing different auxiliary devices; however, the currently published technologies have few degrees of freedom in adjusting the impact excitation position and direction and lack flexibility, and often cannot meet the needs of multi-directional and distributed impact excitation for force sensors of complex tooling or dynamic calibration of multi-dimensional force sensors.

[0004] To this end, the present invention provides a multi-degree-of-freedom impact excitation device with adjustable impact excitation position and direction and controllable impact excitation amplitude, which solves the problems of low adjustment freedom and lack of flexibility in the impact excitation position, direction and amplitude in the prior art, and is suitable for multi-point and multi-directional impact excitation dynamic calibration experiments of force sensors. Summary of the Invention

[0005] The present invention solves the problem in the prior art that the impact excitation position and direction cannot be adjusted and the impact excitation amplitude cannot be controlled at the same time by providing a multi-degree-of-freedom impact excitation device for dynamic calibration of force sensors, so as to meet the needs of dynamic calibration of force sensors with multi-directional or distributed impact excitation.

[0006] The technical solution adopted by the present invention is: a multi-degree-of-freedom impact excitation device with adjustable impact excitation position and direction and controllable impact excitation amplitude is formed by adopting a movable base, an adjustable lifting platform, a multi-degree-of-freedom positioning rocker system and an impact hammer; firstly, a movable base with casters installed on the bottom is used as the bottom base of the device, so that it can be moved over a large range along the ground to cover different excitation positions of force sensors of various scales, providing basic positioning support for their dynamic calibration; secondly, an adjustable lifting platform is used to achieve height adjustment of the impact excitation position; thirdly, based on the solution of hammer swing impact, an XYR slide for controlling the fine adjustment of the horizontal orthogonal position and the horizontal swing angle adjustment, and a controllable impact hammer are used. The impact hammer is clamped by a four-joint, seven-degree-of-freedom positioning pendulum system consisting of an R slide for adjusting the radial roll angle of the swing axis, a telescopic pendulum arm for controlling the release height and swing radius of the impact hammer, and a transverse hinge for controlling the horizontal support orientation of the impact hammer. The impact excitation direction and position are assisted by tracking and adjusting the laser instrument installed in the pendulum system, thereby enabling the device of the present invention to apply accurate impact excitation with flexible and adjustable impact excitation position and direction. In addition, the initial swing angle limit hole and initial swing angle adjustment bolt of the impact hammer are set in the multi-degree-of-freedom positioning pendulum system to control the initial swing angle of the impact hammer's swing impact excitation, thereby achieving graded control of the impact excitation amplitude. Accordingly, the device of the present invention can provide impact excitation with adjustable impact position and direction and controllable amplitude for force sensors of various sizes, meeting their impact excitation requirements for multi-point, multi-directional dynamic calibration or distributed dynamic calibration.

[0007] The device of the present invention consists of a movable base 1, an adjustable lifting platform 2, a multi-degree-of-freedom positioning pendulum system 3, and an impact hammer 4. The movable base 1 is used to achieve large-scale horizontal movement on the ground in the calibration environment to meet the position requirements of the impact excitation dynamic calibration of different excitation points on the force sensor; the adjustable lifting platform 2 is installed on the movable base 1 to achieve height adjustment of the impact excitation point position; the multi-degree-of-freedom positioning pendulum system 3 is installed on the adjustable lifting platform 2 to achieve horizontal fine-tuning of the impact excitation point position, multi-degree-of-freedom adjustment of the impact excitation direction, and multi-speed control of the impact excitation amplitude; the impact hammer 4 is fixedly installed at the end of the multi-degree-of-freedom positioning pendulum system 3 and is used to apply and measure the impact excitation load. Accordingly, the device of the present invention can meet the requirements of multi-point, multi-directional adjustable and amplitude-controllable impact excitation dynamic calibration of the force sensor.

[0008] The movable base 1, the bottom foundation of the multi-degree-of-freedom impact excitation device of the present invention, comprises movable casters 1a, a support platform 1b, and a vertical bracket 1c. The movable casters 1a are mounted on the bottom of the support platform 1b and can be moved horizontally along the ground and locked. The vertical bracket 1c is mounted on the top of the support platform 1b and supports the other components of the device of the present invention.

[0009] The adjustable lifting platform 2 is a lifting screw slide, which is fixedly mounted on the vertical bracket 1c of the movable base 1 and is used for adjusting and locking the height of the impact excitation point.

[0010] The multi-DOF positioning rocker system 3 is a four-joint, seven-DOF support system consisting of an adapter platform 3a, an XYR slide 3b, a large swing arm 3c, a transverse hinge 3d, an R slide 3e, a telescopic rocker 3f, a hammer fixture 3g, and a laser instrument 3h. It is fixedly mounted on the slider of the adjustable lifting platform 2 and is used to clamp the impact hammer 4 and flexibly adjust the impact excitation point position, impact excitation direction, and impact excitation amplitude. The XYR slide 3b, transverse hinge 3d, R slide 3e, and telescopic rocker 3f form four joints with a total of seven degrees of freedom, allowing the impact hammer 4 to have a wide range of working space for both the impact excitation point position and impact excitation direction.

[0011] The transfer platform 3 a is a fixed bracket used to fix the XYR slide 3 b on the adjustable lifting platform 2 so that the XYR slide 3 b can be adjusted up and down along with the slide of the adjustable lifting platform 2 .

[0012] The XYR slide 3b is a three-degree-of-freedom joint that includes position adjustment in two horizontal orthogonal directions and angle adjustment in the horizontal rotation direction. It has high-precision horizontal orthogonal X and Y displacement adjustment scales and angle adjustment scales, and has position and angle locking functions, which are used for fine-tuning the horizontal position of the impact excitation point and adjusting and locking the striking direction of the impact hammer 4.

[0013] The large swing arm 3 c is a support rod of fixed length, which is installed on the XYR slide 3 b and moves and rotates with the adjustment of the XYR slide 3 b, providing a large range of extension space for the impact hammer 4.

[0014] The fixed end of the transverse hinge 3d is installed at the end of the large swing arm 3c, and the movable end and the fixed end are connected by a shoulder screw, a bearing and a locking nut, which are used to adjust the horizontal rotation angle. The angle is locked by the locking nut to realize the control of the horizontal support orientation of the impact hammer 4.

[0015] The R slide 3e is installed at the movable end of the transverse hinge 3d, and is used to adjust the roll angle of the swing axis of the telescopic rocker 3f along its radial direction, thereby adjusting the inclination angle of the swing impact excitation of the impact hammer 4. It has a high-precision angle adjustment scale and a roll angle locking function.

[0016] The telescopic rocker 3f is a two-degree-of-freedom joint with one degree of freedom for swing angle adjustment and one degree of freedom for length extension. It consists of a fixed end, a shoulder screw, a preload nut, a bearing, a rocker tube, a telescopic rod, a locking screw, and an initial swing angle adjustment pin. The fixed end is mounted on the R slide 3e. The rocker tube and fixed end are connected via a shoulder screw, a bearing, and a preload nut, forming a single-degree-of-freedom swing joint. The telescopic rod is inserted into the rocker tube and is coaxial with it, allowing it to move along its axis within the tube, forming a single-degree-of-freedom telescopic joint for adjusting the rocker length. The telescopic length is locked using the locking screw. The preload nut ensures smooth, lateral play-free, single-degree-of-freedom swinging motion between the rocker barrel and the fixed end, thereby ensuring the accuracy of the single-degree-of-freedom swinging impact excitation direction. Initial swing angle limit holes are evenly spaced around the shoulder screw mounting hole on the fixed end. Initial swing angle adjustment bolts are inserted into these holes to control the initial swing angle of the impact hammer 4 in stages, thereby controlling the amplitude of the swinging impact excitation in stages. The telescopic joint formed by the rocker barrel and telescopic rod adjusts the swing radius of the impact hammer 4, thereby expanding the swing range and impact excitation amplitude adjustment range of the impact hammer 4. Consequently, the telescopic rocker 3f provides the impact hammer 4 with a swinging motion with adjustable release height and swing radius, adapting to the impact excitation requirements of different environmental interferences and impact amplitudes.

[0017] The hammer clamp 3g is fixedly installed at the end of the telescopic rod of the telescopic rocker 3f, and is used to clamp the impact hammer 4 and keep the hammer handle axis of the impact hammer 4 coaxial with the telescopic rod of the telescopic rocker 3f.

[0018] The laser instrument 3h is installed at the fixed end of the telescopic rocker 3f and is powered by a battery. It generates a laser line that coincides with the swing plane of the telescopic rod axis of the telescopic rocker 3f, which is used to assist in adjusting the position of the movable base 1, the height of the adjustable lifting platform 2, and the position and angle of each joint in the multi-degree-of-freedom positioning rocker system 3, so that the swing impact excitation direction and impact excitation point position of the impact hammer 4 clamped by the hammer clamp 3g are consistent with the desired impact excitation direction and impact excitation point position on the force sensor to be calibrated.

[0019] The impact hammer 4 consists of a hammer handle, a hammer head, a force sensor, and an impact head, and is used to apply impact excitation to the force sensor to be calibrated, and obtain the impact excitation amplitude through measurement by the force sensor.

[0020] The process of using the device of the present invention is as follows: first, move the movable base 1 so that the working space of the impact hammer 4 covers the specified excitation point and excitation direction on the force sensor to be calibrated; second, adjust the slide height of the adjustable lifting platform 2 so that the impact point position of the impact hammer 4 is close to the height of the specified excitation point; third, adjust the position and angle of each joint in the multi-degree-of-freedom positioning pendulum system 3 according to the light and shadow of the laser line emitted by the laser instrument 3h in the multi-degree-of-freedom positioning pendulum system 3 on the force sensor to be calibrated, so that the impact excitation point and the swing impact excitation direction of the impact hammer 4 are as close as possible to the specified impact excitation point and impact excitation direction; then, fine-tune the movable base 1 so that the working space of the impact hammer 4 covers the specified excitation point and excitation direction on the force sensor to be calibrated; Adjust the slide height of the lifting platform 2 and the joints in the multi-degree-of-freedom positioning rocker system 3 so that the impact excitation position and impact excitation direction of the impact hammer 4 coincide with the specified excitation point and impact excitation direction on the force sensor to be calibrated, and lock the position and angle of each joint; finally, adjust the initial swing angle limit hole into which the initial swing angle adjustment bolt on the telescopic rocker 3f in the multi-degree-of-freedom positioning rocker system 3 is inserted according to the requirement of the impact excitation amplitude, lift the impact hammer 4 clamped by the hammer clamp 3g to the initial swing angle adjustment bolt, and release the hammer, thereby realizing the impact excitation of the force sensor to be calibrated with a specified excitation point, excitation direction and controllable amplitude in grades.

[0021] The beneficial effects of the present invention are:

[0022] 1. The eight-degree-of-freedom adjustment capability provided by the movable base 1, the adjustable lifting platform 2, and the multi-degree-of-freedom positioning rocker system 3 makes the device of the present invention suitable for accurate multi-point and multi-directional impact excitation on the surface of the force sensor, and the impact excitation amplitude is adjustable. Therefore, it can be used for distributed dynamic calibration of force sensors with complex tooling or multi-point and multi-directional dynamic calibration of multi-dimensional force sensors.

[0023] Second, the large movement range of the movable base 1 makes the device of the present invention suitable for dynamic calibration of large-scale force sensors;

[0024] 3. The laser instrument and joint fine-tuning scale in the multi-degree-of-freedom positioning pendulum system 3 provide a basis for high-precision fine-tuning of the impact excitation point and impact excitation direction of the impact hammer 4, thereby ensuring the accuracy of the impact excitation. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of the device structure of a specific embodiment of the present invention;

[0026] Figure 2 Schematic diagram of the structure of a multi-degree-of-freedom positioning rocker system in a specific embodiment of the present invention;

[0027] Figure 3 Schematic diagram of the transverse hinge structure of the multi-degree-of-freedom positioning rocker system in a specific embodiment of the present invention;

[0028] Figure 4 Schematic diagram of the telescopic swing arm structure of the multi-degree-of-freedom positioning swing arm system in a specific embodiment of the present invention;

[0029] Figure 5 Schematic diagram of a dynamic calibration experiment of a force sensor subjected to impact excitation in a specific embodiment of the present invention. DETAILED DESCRIPTION

[0030] The present invention will be further described below with reference to the accompanying drawings:

[0031] The design concept of the present invention is: to meet the dynamic calibration experiment requirements of multi-point, multi-directional impact excitation of force sensors with controllable impact excitation amplitude, based on the impact excitation application method of swinging and knocking of the hammer, a multi-degree-of-freedom impact excitation device is designed that integrates a mobile base, a lifting slide, an azimuth fine-tuning slide, a telescopic rocker arm, etc., to achieve large-scale coverage of the impact hammer working space and flexible regulation of the impact excitation position, direction and amplitude. Specifically, a movable base is used as the bottom base of the multi-degree-of-freedom impact excitation device of the present invention, so that the impact hammer can move in any horizontal direction along the ground, thereby providing full-space coverage capability; an adjustable lifting platform is installed on the movable base to control the height of the impact hammer and its impact excitation point, meeting the impact excitation requirements of different height positions on the force sensor; further, an XYR slide, a lateral hinge, an R slide, a telescopic rocker, and a laser instrument for assisting in tracking and adjusting the impact excitation position and direction are used to form a multi-degree-of-freedom positioning rocker system, which is installed on the slide of the adjustable lifting platform, and an impact hammer for generating and measuring impact excitation is clamped at its end, thereby meeting the requirements of fine-tuning the impact excitation position, omnidirectional adjustment of the impact excitation direction, and graded controllable impact excitation amplitude. Accordingly, the multi-degree-of-freedom impact excitation device of the present invention can meet the dynamic calibration requirements of multi-point, multi-directional, and amplitude-controllable impact excitation of force sensors in situations where the tooling structure is complex and large-scale, further ensuring the dynamic calibration accuracy of the force sensor under complex working conditions.

[0032] Figure 1 The figure shows a schematic diagram of the structure of a device according to a specific embodiment of the present invention, comprising a movable base 1, an adjustable lifting platform 2, a multi-degree-of-freedom positioning pendulum system 3, and an impact hammer 4. The adjustable lifting platform 2 is mounted on the movable base 1; the multi-degree-of-freedom positioning pendulum system 3 is mounted on the adjustable lifting platform 2; and the impact hammer 4 is fixedly mounted at the end of the multi-degree-of-freedom positioning pendulum system 3.

[0033] The movable base 1, the bottom foundation of the multi-degree-of-freedom impact excitation device of the present invention, comprises movable casters 1a, a support platform 1b, and a vertical bracket 1c. The movable casters 1a are mounted on the bottom of the support platform 1b and can be moved horizontally along the ground and locked. The vertical bracket 1c is mounted on the top of the support platform 1b and supports the other components of the device of the present invention.

[0034] The adjustable lifting platform 2 is a lifting screw slide, which is mainly composed of a base plate, a linear guide rail, a slider, a screw, an adjusting wheel, and a lock. It is fixedly mounted on the vertical bracket 1c of the movable base 1 and is used for height adjustment and locking of the impact excitation point. A commercial lifting screw slide can also be directly used.

[0035] Figure 2 The figure is a schematic structural diagram of the multi-DOF positioning rocker system 3. The multi-DOF positioning rocker system 3 is a four-joint, seven-DOF support system consisting of an adapter 3a, an XYR slide 3b, a large swing arm 3c, a transverse hinge 3d, an R slide 3e, a telescopic rocker 3f, a hammer fixture 3g, and a laser instrument 3h. It is fixedly mounted on the slider of the adjustable lifting platform 2 and is used to clamp the impact hammer 4 and flexibly adjust the impact excitation point position, impact excitation direction, and impact excitation amplitude. The XYR slide 3b, transverse hinge 3d, R slide 3e, and telescopic rocker 3f form four joints with a total of seven degrees of freedom, allowing the impact excitation point position and impact excitation direction of the clamped impact hammer 4 to have a wide range of working space.

[0036] The transfer platform 3 a is a fixed bracket used to fix the XYR slide 3 b on the adjustable lifting platform 2 so that the XYR slide 3 b can be adjusted up and down along with the slide of the adjustable lifting platform 2 .

[0037] The XYR slide 3b is a three-degree-of-freedom joint that includes position adjustment in two horizontal orthogonal directions and angle adjustment in the horizontal rotation direction. It has high-precision horizontal orthogonal X and Y displacement adjustment scales and angle adjustment scales, and has position and angle locking functions, which are used for fine-tuning the horizontal position of the impact excitation point and adjusting and locking the striking direction of the impact hammer 4.

[0038] The large swing arm 3 c is a support rod of fixed length, which is installed on the XYR slide 3 b and moves and rotates with the adjustment of the XYR slide 3 b, providing a large range of extension space for the impact hammer 4.

[0039] Figure 3 The figure shows the structure of the transverse hinge 3d. The transverse hinge 3d is a single-degree-of-freedom joint that adjusts the horizontal rotation angle. Its fixed end is mounted on the end of the large swing arm 3c, and the movable end is connected to the fixed end via a shoulder screw, a bearing, and a lock nut. This is used to adjust the horizontal rotation angle. The lock nut locks the angle, controlling the horizontal support position of the impact hammer 4.

[0040] The R slide 3e is a single-degree-of-freedom joint for adjusting the roll angle. It is installed at the movable end of the transverse hinge 3d and is used to adjust the roll angle of the swing axis of the telescopic rocker 3f along its radial direction, thereby adjusting the inclination angle of the swing impact excitation of the impact hammer 4. It has a high-precision angle adjustment scale and a roll angle locking function.

[0041] Figure 4 The diagram below is a schematic diagram of the telescopic rocker arm 3f described in a specific embodiment of the present invention. The telescopic rocker arm 3f is a two-degree-of-freedom joint, comprising one degree of freedom for swing angle adjustment and one degree of freedom for length extension. It consists of a fixed end, a shoulder screw, a preload nut, a bearing, a rocker arm barrel, a telescopic rod, a locking screw, and an initial swing angle adjustment pin. The fixed end is mounted on the R slide 3e; the rocker arm barrel and fixed end are connected via a shoulder screw, a bearing, and a preload nut, forming a single-degree-of-freedom swing joint. The telescopic rod is inserted into the rocker arm barrel and is coaxial with it, allowing it to move along its axis within the barrel, forming a single-degree-of-freedom telescopic joint for adjusting the rocker arm's length. The telescopic length is locked using a locking screw. The preload nut ensures smooth, lateral play-free, single-degree-of-freedom swinging motion between the rocker barrel and the fixed end, thereby ensuring the accuracy of the single-degree-of-freedom swinging impact excitation direction. Initial swing angle limit holes are evenly spaced around the shoulder screw mounting hole on the fixed end. Initial swing angle adjustment bolts are inserted into these holes to control the initial swing angle of the impact hammer 4 in stages, thereby controlling the amplitude of the swinging impact excitation in stages. The telescopic joint formed by the rocker barrel and telescopic rod adjusts the swing radius of the impact hammer 4, thereby expanding the swing range and impact excitation amplitude adjustment range of the impact hammer 4. Consequently, the telescopic rocker 3f provides the impact hammer 4 with a swinging motion with adjustable release height and swing radius, adapting to the impact excitation requirements of different environmental interferences and impact amplitudes.

[0042] The hammer clamp 3g is fixedly installed at the end of the telescopic rod of the telescopic rocker 3f, and is used to clamp the impact hammer 4 and keep the hammer handle axis of the impact hammer 4 coaxial with the telescopic rod of the telescopic rocker 3f.

[0043] The laser instrument 3h is installed at the fixed end of the telescopic rocker 3f and is powered by a battery. It generates a laser line that coincides with the swing plane of the telescopic rod axis of the telescopic rocker 3f, which is used to assist in adjusting the position of the movable base 1, the height of the adjustable lifting platform 2, and the position and angle of each joint in the multi-degree-of-freedom positioning rocker system 3, so that the swing impact excitation direction and impact excitation point position of the impact hammer 4 clamped by the hammer clamp 3g are consistent with the desired impact excitation direction and impact excitation point position on the force sensor to be calibrated.

[0044] The impact hammer 4 consists of a hammer handle, a hammer head, a force sensor, and an impact head, and is used to apply impact excitation to the force sensor to be calibrated, and obtain the impact excitation amplitude through measurement by the force sensor. A commercial handheld high-precision impact hammer can also be directly used.

[0045] Figure 5 FIG2 is a schematic diagram of a dynamic calibration test of a force sensor subjected to impact excitation in a specific embodiment of the present invention. The force sensor is fixed on the calibration platform. According to the specified excitation point and excitation direction on the force sensor, first, the movable base 1 is moved so that the working space of the impact hammer 4 can cover the specified excitation point position and excitation direction of the force sensor; secondly, the slide height of the adjustable lifting platform 2 is adjusted according to the height of the excitation point, and the joint positions and angles in the multi-degree-of-freedom positioning pendulum system 3 are adjusted according to the laser instrument 3h in the multi-degree-of-freedom positioning pendulum system 3, and the joint degrees of freedom other than the swing degree of freedom in the telescopic pendulum 3f are locked, so that the impact excitation point and impact direction of the impact hammer 4 coincide with the specified excitation point and impact excitation direction on the force sensor to be calibrated; finally, according to the requirement of the impact excitation amplitude, the initial swing angle limit hole into which the initial swing angle adjustment bolt on the telescopic pendulum 3f in the multi-degree-of-freedom positioning pendulum system 3 is inserted is adjusted, the impact hammer 4 clamped by the hammer clamp 3g is lifted to the initial swing angle adjustment bolt, and the impact hammer 4 is released. The force sensor to be calibrated is subjected to a controllable impact excitation with a specified excitation point, excitation direction and amplitude, and the dynamic calibration of the impact excitation is completed.

[0046] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A multi-degree-of-freedom impact excitation device for dynamic calibration of force sensors, suitable for dynamic calibration experiments requiring multi-point, multi-directional impact excitation of force sensors, comprising a movable base, an adjustable lifting platform, a multi-degree-of-freedom positioning pendulum system, and an impact hammer, characterized by: The movable base is the bottom base of the multi-degree-of-freedom impact excitation device of the present invention, and includes movable casters, a support platform, and a vertical bracket; the movable casters are installed at the bottom of the support platform, can move horizontally along the ground, and can be locked; the vertical bracket is installed on the table top of the support platform and is used to support other components of the device of the present invention; The adjustable lifting platform is a lifting screw slide, which is mainly composed of a base plate, a linear guide rail, a slider, a screw, an adjustment wheel, and a locker. It is fixedly mounted on the vertical bracket of the movable base and is used for height adjustment and locking of the impact excitation point; The multi-degree-of-freedom positioning rocker system is a four-joint, seven-degree-of-freedom support system, fixedly mounted on the slider of the adjustable lifting platform, and is used to clamp the impact hammer and flexibly adjust the impact excitation point position, impact excitation direction, and impact excitation amplitude, so that the impact excitation point position and impact excitation direction of the clamped impact hammer have a wide range of working space; The impact hammer consists of a hammer handle, a hammer head, a force sensor, and an impact head, and is used to apply impact excitation to the force sensor to be calibrated, and the impact excitation amplitude is measured by the force sensor in the impact hammer.

2. A multi-degree-of-freedom impact excitation device for dynamic calibration of a force sensor according to claim 1, characterized in that: The multi-degree-of-freedom positioning rocker system consists of an adapter table, an XYR slide, a large rocker arm, a transverse hinge, an R slide, a telescopic rocker arm, a hammer fixture, and a laser instrument; wherein the XYR slide, the transverse hinge, the R slide, and the telescopic rocker arm constitute four joints, with a total of seven degrees of freedom; The transfer table is a fixed bracket used to fix the XYR slide on the adjustable lifting platform so that it can be adjusted up and down with the slide of the adjustable lifting platform; The XYR slide is a three-degree-of-freedom joint that includes two horizontal orthogonal position adjustments and one horizontal rotation angle adjustment. It has high-precision horizontal orthogonal X and Y displacement adjustment scales and an angle adjustment scale, and has position and angle locking functions for fine-tuning the horizontal position of the impact excitation point and adjusting and locking the striking direction of the impact hammer. The large swing arm is a fixed-length support rod installed on the XYR slide, which moves and rotates with the adjustment of the XYR slide, providing a wide range of extension space for the impact hammer; The transverse hinge is a single-degree-of-freedom joint for adjusting the horizontal rotation angle. Its fixed end is installed at the end of the large swing arm. The movable end and the fixed end are connected by a shoulder screw, a bearing and a locking nut. It is used to adjust the horizontal rotation angle. The locking nut locks the angle to achieve control of the horizontal support position of the impact hammer. The R slide is a single-degree-of-freedom joint for adjusting the roll angle. It is installed at the movable end of the transverse hinge and is used to adjust the roll angle of the swing axis of the telescopic swing arm along its radial direction, thereby adjusting the inclination angle of the swing impact excitation of the impact hammer. It has a high-precision angle adjustment scale and a roll angle locking function. The telescopic rocker arm is a two-degree-of-freedom joint including one degree of freedom for swing angle adjustment and one degree of freedom for length extension and retraction, and is composed of a fixed end, a shoulder screw, a pre-tightening nut, a bearing, a rocker arm tube, a telescopic rod, a locking screw, and an initial swing angle adjustment bolt; its fixed end is mounted on the R slide; the rocker arm tube and the fixed end are connected by a shoulder screw, a bearing and a pre-tightening nut to form a single-degree-of-freedom swing joint; the telescopic rod is inserted into the rocker arm tube and is coaxial with it, and can move in the rocker arm tube along its axial direction to form a single-degree-of-freedom telescopic joint for adjusting the length of the rocker arm, and the telescopic length is locked by the locking screw; wherein the pre-tightening nut is used to ensure that the single-degree-of-freedom swinging motion between the rocker arm tube and the fixed end is smooth and has no lateral movement. The clearance moves, thereby ensuring the accuracy of the single-degree-of-freedom swing impact excitation direction; initial swing angle limiting holes are evenly distributed along the circumferential direction of the shoulder screw mounting hole on the fixed end, and initial swing angle adjustment bolts are inserted into the limiting holes to control the initial swing angle of the impact hammer in stages, thereby controlling the amplitude of the swing impact excitation in stages; the telescopic joint composed of the pendulum tube and the telescopic rod is used to adjust the swing radius of the swing impact of the impact hammer, thereby expanding the swing space adjustment range of the impact hammer and the adjustment range of the impact excitation amplitude; accordingly, the telescopic pendulum rod provides the impact hammer with a swing motion with adjustable release height and swing radius, thereby meeting the impact excitation requirements of different environmental interferences and different impact amplitudes; The hammer clamp is fixedly mounted on the end of the telescopic rod of the telescopic swing arm, and is used to clamp the impact hammer and keep the hammer handle axis of the impact hammer coaxial with the telescopic rod of the telescopic swing arm; The laser instrument is installed at the fixed end of the telescopic rocker arm and is powered by a battery. It generates a laser line that coincides with the swing plane of the telescopic rod axis of the telescopic rocker arm, which is used to assist in adjusting the position of the movable base, the height of the adjustable lifting platform, and the position and angle of each joint in the multi-degree-of-freedom positioning rocker arm system, so that the swing impact excitation direction and impact excitation point position of the impact hammer clamped by the hammer clamp are consistent with the expected impact excitation direction and impact excitation point position on the force sensor to be calibrated.

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