Movable vibration exciter capable of automatically positioning

Abstract

The invention discloses a mobile vibration exciter capable of automatically positioning, and relates to the field of vibration testing. The motor drives the cam shaft to drive the knocking hammer to swing, the torsional spring is connected with the driven wheel shaft and the swing rod, the pre-torsion of the torsional spring is changed by adjusting the angle of the swing rod, accurate knocking and rapid resetting of the knocking hammer are achieved, and secondary knocking is avoided. A single-chip microcomputer controls rotation times and frequency of a motor through programming, and a two-axis servo system or a mechanical arm is combined with a visual identification technology to automatically generate a surface knocking grid of a measured object and drive a vibration exciter to move to a specified point according to a program; the NI data board card and the acceleration sensor collect vibration signals, the Labview test software analyzes a frequency response function, a phase curve and a damping value in real time, automatically extracts a peak value, generates a test report, and supports mistaken touch prevention alarm. The technical problems that an existing vibration exciter cannot automatically adjust the knocking force and cannot achieve full-modal measurement and automatic data processing are solved, and the testing efficiency and precision are remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of vibration testing technology, specifically relating to a mobile vibrator that can be automatically positioned. Background Technology

[0002] In the field of NVH (Noise, Vibration, and Harshness) testing, free modal measurement is fundamental to analyzing the vibration characteristics of components. This requires exciting the tested object to vibrate using an excitation source (such as a hammer) and then collecting data such as the frequency response function using a vibration analyzer. Traditional measurement methods rely on manually operating a hammer, which suffers from low efficiency, poor repeatability, and significant human error. While some automated vibration excitation equipment has emerged in recent years, its technology still exhibits the following significant drawbacks: 1. Structural and functional limitations of existing vibrators Fixed-point tapping and non-adjustable force: Most existing automatic tapping devices use servo motors for direct drive, which can achieve fixed-point tapping, but the tapping force cannot be adjusted through mechanical structure. The tapping force depends solely on the motor power, resulting in poor test consistency and an inability to adapt to the testing requirements of different materials.

[0003] Lack of automatic positioning and movement capabilities: Existing products require manual adjustment of the hammer position or rely on complex sensor positioning systems, and cannot automatically move the striking point according to the surface grid of the object being measured. During full modal measurement, it is necessary to repeatedly attach the accelerometer or manually move the hammer, which is time-consuming, labor-intensive, and prone to introducing human error.

[0004] 2. Non-automation and inefficiency of data processing Existing equipment requires manual data recording and analysis. The testing software has limited functionality, unable to display frequency response functions, phase curves, and damping values ​​in real time, and lacks the ability to automatically extract peak values ​​or generate test reports. Test results rely on manual interpretation, which is inefficient and prone to errors.

[0005] 3. Secondary tapping and stability issues Traditional vibrators suffer from inadequate reset mechanism design, leading to secondary impacts from the hammer due to inertia after the initial strike, resulting in data distortion. Some products attempt to address this issue through electromagnetic braking, but this approach is complex and costly.

[0006] Improvements and shortcomings of existing technologies Some manufacturers use a solution that combines servo motors with high-precision sensors to achieve tapping point positioning, but this requires a dedicated controller and complex algorithms, resulting in high costs and difficult maintenance.

[0007] While visual recognition technology has been proposed for automatic positioning, existing devices cannot seamlessly integrate vision systems with striking actuators (such as XY axis lead screws or robotic arms), resulting in insufficient positioning accuracy and response speed.

[0008] Existing vibrators have significant shortcomings in mechanical structure, automation level, and data processing capabilities, specifically: It is impossible to achieve flexible adjustment of striking force through a mechanical linkage structure; There is a lack of low-cost, high-precision automatic positioning and movement solutions; Data collection and analysis rely on manual operation, which makes it difficult to meet the needs of efficient and accurate full-modal testing.

[0009] Chinese invention patent with authorization announcement number "CN104155076B" provides a workbench-type automatic force hammer device and method. Compared with this invention, this invention adopts a cam-torsion spring mechanical linkage, which can mechanically adjust the preload of the torsion spring through the angle of the swing arm to achieve fully automatic grid positioning of the vision + servo system. In contrast, this patent uses synchronous belt drive, and the positioning relies on manual adjustment. Summary of the Invention

[0010] The technical problem to be solved by this invention is to overcome the shortcomings of the prior art and provide a mobile vibrator that can be automatically positioned. It uses a motor to drive a camshaft and a torsion spring reset mechanism, controls the striking force by adjusting the angle of the swing arm to avoid secondary striking, integrates a two-axis servo system or a robotic arm, and combines visual recognition technology to generate a striking grid to achieve fully automatic and precise positioning. A customized test system is developed based on LabVIEW software and NI data boards to collect and analyze data in real time and generate reports, reducing manual intervention.

[0011] This invention provides a mobile vibrator capable of automatic positioning, characterized in that it comprises: An electric motor is used to drive the camshaft to rotate. A cam is provided on the camshaft, and the cam is connected to the driven wheel. The driven wheel is mounted on the driven wheel shaft. The driven wheel shaft drives the striking hammer to swing by rotating at a small angle. The striking hammer is fixed on the driven wheel shaft by a set screw. A torsion spring is installed on the driven wheel axle. One end of the spring is fixed to the driven wheel axle, and the other end is connected to an adjustable rocker arm. The preload of the torsion spring is changed by adjusting the angle of the rocker arm, thereby controlling the swing acceleration and striking force of the hammer. The housing has mounting rods for securing the vibrator to the slide or robotic arm; The camshaft and torsion spring work together. The rotation of the cam drives the hammer to swing, and the preload of the torsion spring enables the push rod to quickly reset, preventing secondary impact.

[0012] As a further technical solution of the present invention, it also includes: A microcontroller is connected to the motor and controls the motor's start / stop, speed, and number of strikes through programming. A two-axis servo system controls the XY axis linear screws or robotic arms to drive the vibrator to move and position automatically according to a preset grid.

[0013] Furthermore, it also includes a visual recognition module that acquires images of the object under test through a camera and generates a tapping grid, and the servo system drives the vibrator to move precisely according to the grid points.

[0014] Furthermore, it also includes LabVIEW testing software, which communicates with the microcontroller and the servo system to set the striking parameters, monitor the striking quality in real time, and synchronously process the vibration signals collected by the accelerometer. When an overload of the striking force, positional deviation, or no striking occurs is detected, the LabVIEW testing software automatically triggers an alarm and controls the servo system to readjust its position, forming a closed-loop data control.

[0015] Furthermore, a Hall effect sensor is provided on the top of the camshaft to detect the rotation cycle of the cam and count the number of taps.

[0016] Furthermore, it also includes: an NI data board, which connects to the LabVIEW testing software to perform Fourier transform on the vibration signal collected by the accelerometer, generate a frequency response function, phase curve and damping value, and output a test report.

[0017] The advantages of this invention are that, through the deep integration of mechanical structure innovation, automated control and intelligent data analysis, it solves the technical bottlenecks of existing vibrators in terms of impact force adjustment, positioning accuracy and data processing efficiency, significantly improves the accuracy, efficiency and repeatability of NVH testing, and provides an efficient and low-cost solution for vibration analysis in the automotive, aerospace and other fields. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the mechanical structure of the vibrator of the present invention; Figure 2 This is an electrical schematic diagram of the control device of the present invention. Detailed Implementation

[0019] Please see Figure 1 and Figure 2 This embodiment provides a mobile vibrator with automatic positioning according to the present invention, characterized in that it includes: The motor (1) is used to drive the camshaft (2) to rotate; A cam is provided on the camshaft (2), and the cam is connected to the driven wheel (3) for transmission. The driven wheel (3) is mounted on the driven wheel shaft (5). The driven wheel shaft (5) drives the striking hammer (7) to swing by rotating at a small angle. The striking hammer (7) is fixed on the driven wheel shaft (5) by a set screw. The torsion spring (4) is installed on the driven wheel shaft (5). One end of the spring is fixed to the driven wheel shaft (5), and the other end is connected to the adjustable angle swing rod (8). The preload of the torsion spring is changed by adjusting the angle of the swing rod (8) to control the swing acceleration and striking force of the hammer (7). The housing has mounting rods for securing the vibrator to the slide or robotic arm; The camshaft (2) and the torsion spring (4) work together to drive the hammer (7) to swing through the rotation of the cam, and the preload of the torsion spring (4) enables the push rod to quickly reset, preventing secondary impact.

[0020] This exciter also includes: A microcontroller is connected to the motor and controls the motor's start / stop, speed, and number of strikes through programming. A two-axis servo system controls the XY axis linear screws or robotic arms to drive the vibrator to move and position automatically according to a preset grid.

[0021] The visual recognition module acquires images of the object under test through a camera and generates a tapping grid. The servo system drives the vibrator to move precisely according to the grid points.

[0022] The LabVIEW testing software communicates with the microcontroller and the servo system to set the striking parameters, monitor the striking quality in real time, and synchronously process the vibration signals collected by the accelerometer. When an overload of the striking force, positional deviation, or no striking occurs is detected, the LabVIEW testing software automatically triggers an alarm and controls the servo system to readjust its position, forming a closed-loop data control.

[0023] A Hall effect sensor (9) is provided on the top of the camshaft (2) for detecting the rotation cycle of the cam and counting the number of taps.

[0024] The NI data board is connected to the LabVIEW testing software to perform Fourier transform on the vibration signal collected by the accelerometer, generate the frequency response function, phase curve and damping value, and output a test report.

[0025] LabVIEW testing software. Firstly, it serves as the input for motor execution, allowing you to set the parameters required for the experiment, such as the number of hammer strikes and parameters for determining whether a strike has occurred. Secondly, as output, it primarily processes and analyzes the collected data, including but not limited to displaying the frequency response function, phase curve, and damping value of the strikes; automatically retrieving PEAK values ​​and averages; preventing accidental touches; and outputting test reports. It is flexible and customizable.

[0026] The sound processor can perform Fourier transforms on the input from the excitation source and the input from the accelerometer to process the signal and obtain the relevant frequency response function, phase and damping.

[0027] An accelerometer is used to acquire relevant acceleration vibration signals.

[0028] The automatic hammer device is an actuator that controls the rotation of the motor (1) according to the output command of the automatic hammer control device. The motor (1) drives the camshaft (2) to rotate. The rotation of the camshaft can drive the driven wheel (3) to rotate. When the driven wheel shaft (5) rotates, the hammer (7) mounted on the driven wheel shaft swings. One end of the torsion spring (4) is connected to the driven wheel shaft, and the other end is connected to the swing arm. The function of the torsion spring (4) is to make the top rod quickly reset. The swing arm is adjustable. When the swing arm angle is large, the force of the torsion spring increases, thereby controlling the swing acceleration of the hammer (7) and adjusting the hammer force (7).

[0029] This vibrator uses a cam and an angled push rod to swing the hammer, and adjusts the hammer's striking force via a torsion spring, effectively preventing secondary impacts. The entire structure is compact, low-cost, consistent, and easily replicable. This vibrator uses a microcontroller and programming to set the number of strikes and the frequency of strikes on the drive motor, which is simple and convenient and meets the testing requirements. The vibrator controls the back-and-forth movement of two vertical XY axis linear screws through a two-axis servo system. It achieves origin positioning through programming and accurately moves and strikes according to the relevant grid striking points, satisfying the striking measurement of the parts in all modes.

[0030] This vibrator can monitor the impact quality of the hammer in real time through a programmed setting. It will automatically alarm and readjust if the impact position is off, the impact force is overloaded, or no impact occurs.

[0031] This vibrator, through its self-developed LabVIEW testing software, can control the testing process, perform customized data analysis and processing, including but not limited to automatically and synchronously displaying the frequency response function, damping and phase, automatically extracting PEAK value and mean value, preventing accidental touches, and generating corresponding test reports.

[0032] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the specific embodiments described above. The specific embodiments and descriptions in the specification are merely for further illustrating the principles of the invention. Various changes and modifications can be made to the present invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the claims and their equivalents.

Claims

1. A mobile vibrator capable of automatic positioning, characterized in that, include: An electric motor is used to drive the camshaft to rotate. A cam is provided on the camshaft, and the cam is connected to the driven wheel. The driven wheel is mounted on the driven wheel shaft. The driven wheel shaft drives the striking hammer to swing by rotating at a small angle. The striking hammer is fixed on the driven wheel shaft by a set screw. A torsion spring is installed on the driven wheel axle. One end of the spring is fixed to the driven wheel axle, and the other end is connected to an adjustable rocker arm. The preload of the torsion spring is changed by adjusting the angle of the rocker arm, thereby controlling the swing acceleration and striking force of the hammer. The housing has mounting rods for securing the vibrator to the slide or robotic arm.

2. The mobile vibrator with automatic positioning according to claim 1, characterized in that, Also includes: A microcontroller is connected to the motor and controls the motor's start / stop, speed, and number of strikes through programming. A two-axis servo system controls the XY axis linear screws or robotic arms to drive the vibrator to move and position automatically according to preset grid points.

3. The mobile vibrator with automatic positioning according to claim 2, characterized in that, Also includes: The visual recognition module acquires images of the object under test through a camera and generates a tapping grid. The servo system drives the vibrator to move precisely according to the grid points.

4. The automatically positioning mobile vibrator according to claim 2, characterized in that, Also includes: The LabVIEW testing software communicates with the microcontroller and the servo system to set the striking parameters, monitor the striking quality in real time, and synchronously process the vibration signals collected by the accelerometer. When an overload of the striking force, positional deviation, or no striking occurs is detected, the LabVIEW testing software automatically triggers an alarm and controls the servo system to readjust its position, forming a closed-loop data control.

5. The automatically positioning mobile vibrator according to claim 1, characterized in that, A Hall effect sensor is provided on the top of the camshaft to detect the rotation cycle of the cam and count the number of taps.

6. A mobile vibrator capable of automatic positioning according to claim 4, characterized in that, Also includes: The NI data board is connected to the LabVIEW testing software to perform Fourier transform on the vibration signal collected by the accelerometer, generate the frequency response function, phase curve and damping value, and output a test report.

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