TWI465707B - Measurement system for diagnosing ball screw preload loss by vibration signal and voiceprint signal - Google Patents

Description

Measuring system and method for diagnosing ball lead screw pre-pressure imbalance using vibration signal and voiceprint signal

The invention relates to a measuring system for pre-pressure failure of a ball lead screw, in particular to a method for analyzing a voice signal and a vibration signal of a ball lead screw device by Hilbert-Huang Transform (HHT). , a measuring system for diagnosing a ball lead screw pre-pressure imbalance and a method thereof.

At present, the ball lead screw is an important component of the precision linear drive and positioning system. Its function is to use the lead screw to convert the rotary motion into linear motion to achieve linear transmission. Since the ball lead screw uses the ball as the power transmission medium between the screw and the nut, and the steel ball rolls instead of the conventional screw sliding mode, the mechanical efficiency and the high feed speed during the feed transmission can be greatly improved, and the precision positioning and Key mechanical components for high feed systems. Because of this, ball lead screws are often used in precision processing machines and semiconductor manufacturing equipment. In order to meet the high-precision machining route of high-precision cutting, the rotation speed and rigidity of the ball guide screw are constantly increased, resulting in high-friction torque of the ball lead screw due to high rotation speed and heavy pre-compression, and long-time reciprocating feed. Under the circumstance, the degree of internal ball wear is increased instantaneously, and then the thermal temperature rise and the thermal displacement are generated, so that the screw preloading failure image processing positioning accuracy is caused. Therefore, such as How to diagnose the pre-pressure failure of the ball lead screw has been a very important issue.

Since the pre-pressure of the ball lead screw affects the positioning accuracy, and the mechanical size of the ball lead screw cannot be directly measured, how to diagnose the pre-pressure failure of the ball lead screw early is a very important problem. However, the signal generated by the movement of the ball lead screw is an unsteady signal, and the measurement device of the prior art uses Fourier transform filtering, and the filtered result cannot be analyzed.

In 1998, Dr. Huang Wei proposed The Empirical Mode Decomposition and The Hilbert Spectrum for Nonlinear and Nonstationary Time Series Analysis, Proceedings of Royal Society of London Series A, Vol 454, pp. 903-9951998. The conversion method (Hilbert-Huang Transform, HHT) can effectively analyze the nonlinear and non-steady-state signals of rotating machinery fault vibration. Therefore, how to propose a measuring system for the pre-pressure failure of the ball lead screw can integrate the Hilbert yellow conversion method to more effectively detect the pre-pressure failure of the ball lead screw, which is the problem to be solved by the present invention.

In view of the above-mentioned problems of the prior art, one of the main purposes of the present invention is to provide a measurement system and method for diagnosing a pre-pressure imbalance of a ball lead screw using a vibration signal and a voiceprint signal to solve the measurement of the prior art. The system cannot accurately analyze the problem of pre-pressure failure of the ball lead screw.

According to the object of the present invention, a measuring system for diagnosing a pre-pressure imbalance of a ball lead screw by using a vibration signal is provided, which comprises: a signal capturing module, which is a vibration signal when the ball guiding screw device is operated; a signal pre-processing module Decomposition using empirical mode The (Empirical Mode Decomposition Method, EMD) converts the vibration signal into an intrinsic mode function diagram that can represent the pre-pressure characteristic signal of the ball lead screw under different vibration frequencies; the signal analysis module analyzes the intrinsic mode function diagram. And extracting the Intrinsic Mode Function (INF) of the ball lead screw pre-pressure characteristic signal at the preset vibration frequency; and the signal post-processing module by Multiscale Entropy (MSE) The intrinsic mode function is converted into a multi-scale entropy analysis graph, and the multi-scale entropy analysis graph represents the entropy change of the intrinsic mode function under different scales to measure the pre-pressure change of the ball lead screw. The signal pre-processing module converts the vibration signal captured at different time points into a plurality of intrinsic mode function diagrams, and the signal analysis module extracts the preset vibration from a plurality of intrinsic mode function maps. At the frequency, each intrinsic mode function of the ball lead screw pre-pressure characteristic signal appears, and then the signal post-processing module converts each intrinsic mode function into a multi-scale entropy analysis chart to measure the ball lead screw pre-pressure change.

According to the object of the present invention, a method for measuring the pre-pressure imbalance of the ball lead screw by using the vibration signal is further provided, which comprises the steps of: taking the vibration signal of the ball lead screw device running at different time points through the signal capturing module. The signal pre-processing module converts the vibration signals captured at different time points into a plurality of intrinsic mode function diagrams; the signal analysis module is extracted from the plurality of intrinsic mode function maps at a preset vibration frequency, Each intrinsic mode function of the ball lead screw pre-pressure characteristic signal appears; and each intrinsic mode function is converted into a multi-scale entropy analysis chart by the signal post-processing module to measure the ball lead screw pre-pressure change.

The intrinsic mode function represents the instantaneous amplitude and instantaneous frequency of the vibration signal.

Among them, the signal analysis module converts the intrinsic mode function map into a marginal map ( Marginal Spectrum), the marginal map can indicate the frequency position of the ball lead screw pre-pressure characteristic signal to find the internal 禀 mode function of the ball lead screw pre-pressure characteristic signal at the preset vibration frequency.

Among them, the signal acquisition module is an acceleration gauge.

According to the object of the present invention, a measuring system for diagnosing a pre-pressure imbalance of a ball lead screw by using a voiceprint signal is provided, which comprises: a signal capturing module, which is a voice signal generated when the ball guiding screw device is operated; The module is stored under different pre-stress conditions, and the voiceprint data of the voiceprint signal generated when the ball screw device is operated; the signal processing module converts the voiceprint signal into different representations by using the empirical mode decomposition method. Under the voiceprint frequency, the internal curve mode function diagram of the ball lead screw pre-pressure characteristic signal, and extracting the internal 禀 mode function of the ball lead screw pre-pressure characteristic signal at the preset voiceprint frequency; and the signal analysis module The short-time Fourier Transform (STFT) is used to convert the intrinsic mode function into a time-frequency diagram, and the time-frequency diagram is analyzed to generate a Marginal Time and a Marginal Frequency Domain (Marginal). Frequency), and compared with the voiceprint data, to measure the pre-pressure change of the ball lead screw.

According to the purpose of the present invention, a method for measuring the pre-pressure imbalance of the ball lead screw by using the voiceprint signal is further provided, which comprises the following steps: using the signal capture module to capture the voiceprint signal generated when the ball lead screw device is operated; The voiceprint data generated by the ball guide screw device is stored under different pre-stress conditions by the storage module; the signal processing module uses the empirical mode decomposition method to convert the voiceprint signal into the intrinsic mode function. And extracting the internal 禀 mode function of the ball lead screw pre-pressure characteristic signal at the preset voiceprint frequency; converting the 禀 mode function into the time-frequency diagram, the marginal time-domain diagram and the marginal frequency through the signal analysis module Domain map and voiceprint data Alignment to measure the pre-pressure change of the ball lead screw.

The intrinsic mode function represents the instantaneous amplitude and instantaneous frequency of the voiceprint signal.

The signal acquisition module is a microphone.

In accordance with the present invention, a measurement system and method for diagnosing a ball lead screw pre-pressure imbalance using a Hilbert yellow conversion method according to the present invention may have one or more of the following advantages:

(1) The proposed method of the present invention can effectively analyze the nonlinear and non-steady-state signals of the rotating mechanical fault vibration, and thus can accurately measure whether the ball lead screw pre-pressure is invalid.

(2) The invention can effectively judge whether the ball lead screw pre-pressure is invalid by the Hibbert yellow conversion method and the multi-scale entropy analysis method, and the method can effectively detect whether the ball lead screw pre-pressure is invalid without stopping the inspection. To improve the life of the ball lead screw.

1, 6‧‧‧ Ball lead screw pre-pressure measuring system

11, 61‧‧‧ Signal capture module

111‧‧‧Vibration signal

12, 62‧‧‧ signal pre-processing module

121, 621‧‧‧Experience mode decomposition

122, 622‧‧‧Intrinsic mode function diagram

13, 63‧‧‧ Signal Analysis Module

131, 623‧‧‧Intrinsic mode function

14‧‧‧ Signal Post Processing Module

141‧‧‧Multi-scale entropy analysis

142‧‧‧Multi-scale entropy analysis

611‧‧‧ voiceprint signal

64‧‧‧Storage module

641‧‧‧ voiceprint data

631‧‧‧Short-term Fourier transform

632‧‧‧Time-frequency diagram

633‧‧‧Marginal time domain map

634‧‧‧Marginal frequency domain map

S51~S54, S81~S84‧‧‧ Step procedure

Figure 1 is a block diagram of the measurement system for diagnosing the pre-pressure imbalance of the ball lead screw using the vibration signal of the present invention.

2A and 2B are diagrams showing the internal enthalpy function of the first embodiment of the measurement system for diagnosing the pre-pressure imbalance of the ball guide screw using the vibration signal.

Fig. 3 is a marginal view of the first embodiment of the measuring system for diagnosing the pre-pressure imbalance of the ball lead screw using the vibration signal of the present invention.

Figure 4 is a multi-scale entropy analysis diagram of the first embodiment of the measurement system for diagnosing the pre-pressure imbalance of the ball guide screw using the vibration signal.

Fig. 5 is a flow chart showing the method for measuring the pre-pressure imbalance of the ball lead screw using the vibration signal of the present invention.

Figure 6 is a diagram of the use of the voiceprint signal to diagnose the pre-pressure imbalance of the ball lead screw of the present invention. A block diagram of the measurement system.

7A, 7B, and 7C are time-frequency diagrams, marginal time-domain diagrams, and marginal frequency-domain diagrams of the first embodiment of the measurement system for vibrating the ball lead screw pre-pressure imbalance using the voiceprint signal.

Figure 8 is a flow chart of the measurement system for diagnosing the pre-pressure imbalance of the ball guide screw using the voiceprint signal of the present invention.

The invention adopts the Empirical Mode Decomposition (EMD) published by Dr. Huang Wei of the National Aeronautics and Space Administration (NASA) in 1998, and uses the time scale of the data itself as energy to decompose the original signal into From the high frequency to the low frequency, the Intrinsic Mode Function (IMF), and the intrinsic mode function as the base of the expansion, the physical characteristics of the original signal can be fully represented by using these substrates. The integrity of the decomposition, avoiding the high orthogonality of the distortion, and the locality of the signal that changes instantaneously, and the adaptability of the nonlinear signal analysis, and then the instantaneous amplitude of the intrinsic mode function is converted by Hibbert. With the frequency, the signal and characteristics that enable the signal to change instantaneously are called Hilbert Huang Transform (HHT).

In addition, the present invention further employs Multiscale Entropy (MSE). Since the entropy and complexity of a system imply the motion regularity of the whole system, the physical meaning of entropy and complexity is directly related to the nature of the system's single variable. When calculating entropy and complexity, it is generally associated with the symbol time series analysis method developed by symbol dynamics theory in recent years. Symbolic time series analysis is essentially an analysis method combining chaotic time series analysis and information theory. Its essence is the sequence value first. Symbolization, post-symbol coding, encoding to calculate entropy or complexity and other characteristics.

Hereinafter, an embodiment of a measurement system and a method for diagnosing a ball lead screw pre-pressure imbalance using a vibration signal and a voiceprint signal according to the present invention will be described with reference to the related drawings. For ease of understanding, the same is true in the following embodiments. Components are denoted by the same reference numerals.

Please refer to FIG. 1 , which is a block diagram of the measurement system for diagnosing the pre-pressure imbalance of the ball lead screw by using the vibration signal. As shown in the figure, the ball lead screw pre-pressure measuring system 1 includes a signal capturing module 11, a signal pre-processing module 12, a signal analysis module 13, and a signal post-processing module 14.

The signal capture module 11 can capture the vibration signal generated when the ball guide screw device is in operation. The signal capture module 11 can be an acceleration gauge. The signal pre-processing module 12 can convert the vibration signal 111 into an intrinsic mode function which can represent one of the ball pilot screw pre-pressure characteristic signals under different vibration frequencies by using the empirical mode decomposition method 121 in the Hilbert transform method. In FIG. 122, the intrinsic mode function can represent the instantaneous amplitude and instantaneous frequency of the vibration signal 111. The signal analysis module 13 can analyze the intrinsic mode function map 122 and convert it into a marginal spectrum (Marginal Spectrum), and the margin map can indicate the frequency position of the ball lead screw pre-stress characteristic signal to find the preset vibration. At the frequency, the intrinsic mode function 131 of the ball lead screw pre-pressure characteristic signal appears.

It is worth mentioning that since the intrinsic mode function diagram 122 includes a plurality of intrinsic mode functions 131, the characteristic signals displayed by the respective intrinsic mode functions 131 have different meanings. Therefore, only the characteristic signal appearing at a specific frequency is the signal related to the ball lead screw. Therefore, the signal analysis module 13 needs to extract the internal 禀 mode of the ball lead screw pre-pressure characteristic signal at the preset vibration frequency from the intrinsic mode function diagram 122. Function 131 is used as the basis for subsequent analysis.

The signal post-processing module 14 converts the intrinsic mode function 131 into a multi-scale entropy analysis graph 142 by multi-scale entropy 141 (MSE), and the multi-scale entropy analysis graph 142 represents under different scales. The entropy value of the intrinsic mode function 131 is varied to measure the pre-pressure change of the ball lead screw.

Therefore, the signal pre-processing module 12 is used to convert the vibration signal 111 captured at different time points into a plurality of intrinsic mode function maps 122, and the ball lead screw pre-pressure characteristic signal appears from the preset vibration frequency. Each of the intrinsic mode functions 131. The signal post-processing module 14 then converts each of the intrinsic mode functions 131 into a multi-scale entropy analysis map 142. As the pre-pressure of the ball lead screw changes, a change in the entropy value is produced in the multi-scale entropy analysis map 142. Therefore, by analyzing the change of the entropy value of each curve in the multi-scale entropy analysis graph 142, the change of the pre-pressure of the ball lead screw can be measured.

Further, with the method of the present invention, even when the ball lead screw device is operated, it is possible to determine whether or not the pre-pressure is invalid, so that it is not necessary to stop the inspection, which is more convenient in practical use.

Please refer to FIGS. 2A and 2B, which are diagrams showing the internal enthalpy function of the first embodiment of the measuring system for diagnosing the pre-pressure imbalance of the ball lead screw using the vibration signal. The signal pre-processing module can convert the vibration signal captured at different time points into an intrinsic mode function graph by using the empirical mode decomposition method in the Hilbert transform method, and the characteristic signal of the intrinsic mode function graph display has Different meanings. For example, it is known through prior training that the characteristic signal associated with the ball lead screw pre-pressure will fall near the frequency of 320 Hz. The signal pre-processing module converts the intrinsic mode function map into a Marginal Frequency, as shown in Figure 3. It can be clearly seen from Figure 3 that Group 3 The characteristic signal of the marginal map of the intrinsic mode function (IMF3) appears near the frequency of 320 Hz. Therefore, it can be concluded that the third group internal helium mode function is related to the ball lead screw pre-pressure.

Please refer to FIG. 4, which is a multi-scale entropy analysis diagram of a first embodiment of a measurement system for diagnosing a ball screw lead pre-pressure imbalance using a vibration signal. The signal post-processing module converts the intrinsic mode function related to the ball lead screw pre-pressure into a multi-scale entropy analysis graph at various time points by multi-scale entropy analysis. It can be clearly seen from Fig. 4 that the entropy value of the ball lead screw is relatively increased (Entropy 0~1.2). After 35 minutes, due to the temperature rise balance, the overall complexity is relatively stable at high scale.

Please refer to FIG. 5, which is a flow chart of a method for measuring the pre-pressure imbalance of the ball lead screw using the vibration signal according to the present invention.

In step S51, the vibration signal of the ball lead screw device operation at different time points is captured by the signal acquisition module.

In step S52, the signal pre-processing module is used to convert the vibration signals captured at different time points into a plurality of intrinsic mode function maps.

In step S53, the signal analysis module extracts, from the plurality of intrinsic mode function maps, the respective intrinsic mode functions of the ball lead screw pre-pressure characteristic signal at the preset vibration frequency.

In step S54, the signal processing module converts each intrinsic mode function into a multi-scale entropy analysis map to measure the ball lead screw pre-pressure change.

Please refer to FIG. 6 for the use of the voiceprint signal to diagnose the ball lead screw preloading of the present invention. A block diagram of the measurement system for force imbalance. As shown, the ball lead screw pre-pressure measuring system 6 includes a signal capturing module 61, a storage module 64, a signal analysis module 63, and a signal processing module 62.

The signal capture module 61 can capture the voiceprint signal 611 generated when the ball guide screw device is in operation. The signal capture module 61 can be a microphone. The storage module 64 can store the voiceprint data 641 of the voiceprint signal generated when the ball lead screw device operates under different pre-stress conditions. Therefore, the voiceprint data under different pre-stress conditions (such as 2% in light pre-pressing, 4% in pre-pressing, and 6% in pre-loading) can be stored in the storage module 64 for comparison by prior training. measuring.

The signal processing module can use the empirical mode decomposition method 621 in the Hilbert transform method to convert the voiceprint signal 611 into an internal 禀 mode function diagram that can represent the pre-pressure characteristic signal of the ball lead screw under different voiceprint frequencies. 622, and select the intrinsic mode function 623 of the ball lead screw pre-pressure characteristic signal at the preset voiceprint frequency.

The signal analysis module 63 converts the intrinsic mode function 623 into a time-frequency map 632 by using a Short-Time Fourier Transform (STFT), and generates a marginal time domain map 633 according to the time domain map 632 ( Marginal Time and Marginal Frequency 634 are compared with the voiceprint data 641. The above-mentioned method can effectively measure the pre-pressure change of the ball lead screw.

Please refer to FIGS. 7A, 7B and 7C for the time-frequency diagram, the marginal time domain diagram and the marginal frequency domain diagram of the first embodiment of the measurement system for diagnosing the ball screw lead pre-pressure imbalance using the voiceprint signal. The present invention utilizes the empirical mode decomposition method in the Hilbert transform method to convert the intrinsic mode function containing the screw characteristic signal by short-time Fourier transform Converted to a time-frequency diagram, and a red cross indicator in the time-frequency diagram decomposes the signal into a Marginal Time and a Marginal Frequency.

As shown in the figure, under different pre-pressures (light preload 2%, medium preload 4%, heavy preload 6%), the overall sound pressure trend shows the sound pressure excited by the ball lead screw at start and stop. Larger. The ball lead screw also has sound pressure near the round trip point of the stroke, but the sound pressure generated by the energy and the start and stop is much smaller, because the ball lead screw needs to overcome the friction when starting and stopping. When the ball lead screw is at the round-trip point of the stroke, the ball turns from the clockwise to the counterclock, and it is necessary to overcome the frictional force during the reverse rotation. However, for the comparison of sound pressure, the sound pressure caused by the ball lead screw at the start and stop is more severe.

It can be clearly seen from Fig. 7A that the ball lead screw of 2% pre-pressure has a large backlash, and the signal characteristic exhibited by the friction is long and evacuated. Conversely, the 4% and 6% pre-pressure screw friction in Figures 7B and 7C exhibits shorter and tighter signal characteristics. In Figure 7C, the internal ball of the ball screw with over 6% preloading is tighter than the other screws. It can be found that the friction of the ball screw with 6% preloading at start and stop is not as high as that of other screws. Instead, the maximum value is presented from the beginning until the energy begins to rise and fall after overcoming the friction. As shown in the figure, the red dotted arrow is the friction signal for starting and stopping, and the red circle dotted line is the friction force when the ball is reversed. Therefore, the present invention can determine the screw of different pre-pressure by the sound pressure data of the ball lead screw of different motor speeds and different pre-pressures.

Please refer to FIG. 8 , which is a flow chart of the measuring system for diagnosing the pre-pressure imbalance of the ball lead screw by using the voiceprint signal.

In step 81, the signal capture module is used to capture the voiceprint signal generated when the ball lead screw device is in operation.

In step 82, the voiceprint data of the voiceprint signal generated when the ball lead screw device is operated is stored by the storage module under different pre-stress conditions.

In step 83, the signal processing module converts the voiceprint signal into the intrinsic mode function map by using the empirical mode decomposition method, and extracts the internal mode of the ball lead screw pre-stress characteristic signal at the preset voiceprint frequency. function.

In step 84, the signal analysis module converts the intrinsic mode function into a time-frequency map, a marginal time domain map, and a marginal frequency domain map, and compares with the voiceprint data to measure the ball lead screw pre-pressure change.

In summary, the measurement system and method for diagnosing the pre-pressure imbalance of the ball lead screw by using the vibration signal and the voiceprint signal can effectively analyze the nonlinear and non-steady-state signals of the vibration vibration of the rotating machine, so that the measurement can be accurately measured. Whether the ball lead screw pre-pressure is invalid. The invention can effectively detect whether the ball lead screw pre-pressure is invalid without stopping the inspection, so as to improve the life of the ball lead screw. It can be seen that the present invention has achieved the desired effect under the prior art, and is not familiar with the skill of the artist, and has been in compliance with the patent application requirements.

The above is intended to be illustrative only and not limiting. Any equivalent modifications or alterations to the spirit and scope of the invention are intended to be included in the scope of the appended claims.

1‧‧‧Bead lead screw pre-pressure measuring system

11‧‧‧Signal capture module

111‧‧‧Vibration signal

12‧‧‧ Signal Pre-Processing Module

121‧‧‧Experience mode decomposition

122‧‧‧Intrinsic mode function diagram

13‧‧‧Signal Analysis Module

131‧‧‧Intrinsic mode function

14‧‧‧ Signal Post Processing Module

141‧‧‧Multi-scale entropy analysis

142‧‧‧Multi-scale entropy analysis

Claims (14)

The utility model relates to a measuring system for diagnosing a pre-pressure imbalance of a ball lead screw by using a vibration signal, comprising: a signal capturing module, which is a vibration signal when the ball guiding screw device is operated; a pre-processing module of the signal is used for experience. The Modem Decomposition Method (EMD) converts the vibration signal into a 禀 mode function diagram which can represent one of the ball pilot screw pre-pressure characteristic signals under different vibration frequencies; a signal analysis module is an analysis The intrinsic mode function diagram, and extracting from a preset vibration frequency, an intrinsic mode function (INF) of one of the ball lead screw pre-pressure characteristic signals; and a signal post-processing module, Multiscale Entropy (MSE) converts the intrinsic mode function into a multi-scale entropy analysis graph, which represents the entropy change of the intrinsic mode function under different scales. Measuring the pre-pressure change of the ball lead screw; wherein the signal pre-processing module converts the vibration signal captured at different time points into the complex number a mode function diagram of the inner 禀 mode, and the signal analysis module extracts the internal 禀 mode function of the ball lead screw pre-pressure characteristic signal from a plurality of 禀 mode function diagrams at a preset vibration frequency, and then The signal processing module converts each of the intrinsic mode functions into the multi-scale entropy analysis map to measure the ball lead screw pre-pressure change. Use the vibration signal to diagnose the ball lead screw preload according to the scope of claim 1 A force imbalance measurement system, wherein the intrinsic mode function represents an instantaneous amplitude and an instantaneous frequency of the vibration signal. The measuring system for diagnosing the ball screw pre-pressure imbalance using the vibration signal according to the second aspect of the patent application, wherein the signal analysis module converts the intrinsic mode function map into a Marginal Spectrum, The marginal map can indicate the frequency position at which the ball lead screw pre-pressure characteristic signal appears to find the intrinsic mode function at which the ball lead screw pre-pressure characteristic signal appears at the preset vibration frequency. The measuring system for diagnosing the ball screw pre-pressure imbalance using the vibration signal according to the first aspect of the patent application, wherein the signal capturing module is an acceleration gauge. A measuring method for diagnosing a pre-pressure imbalance of a ball lead screw by using a vibration signal, comprising the steps of: taking a vibration signal of a ball guiding screw device at different time points through a signal capturing module; using a signal pre-processing The module converts the vibration signals captured at different time points into a plurality of intrinsic mode function diagrams; and a signal analysis module extracts the ball from a plurality of intrinsic mode function diagrams at a preset vibration frequency. Each intrinsic mode function of the lead screw pre-stress characteristic signal; and converting each of the intrinsic mode functions into a multi-scale entropy analysis map through a signal post-processing module to measure the pre-pressure change of the ball lead screw. A method for measuring a pre-pressure imbalance of a ball lead screw using a vibration signal as described in claim 5, wherein the intrinsic mode function represents an instantaneous amplitude and an instantaneous frequency of the vibration signal. A method for measuring a pre-pressure imbalance of a ball lead screw using a vibration signal as described in claim 6 of the patent application scope, wherein the signal analysis module converts the internal helium mode function In place of the marginal map, the marginal map can indicate the frequency position at which the ball lead screw pre-pressure characteristic signal appears to find the intrinsic mode function of the ball lead screw pre-pressure characteristic signal at the preset vibration frequency. The method for measuring the pre-pressure imbalance of the ball lead screw by using the vibration signal as described in claim 5, wherein the signal acquisition module is an acceleration gauge. A measuring system for diagnosing a pre-pressure imbalance of a ball lead screw by using a voiceprint signal comprises: a signal capturing module for generating a voiceprint signal when the ball guiding screw device is operated; and a storage module for storing Under different pre-stress conditions, one of the voiceprint signals generated by the ball screw device during operation; a signal processing module converts the voiceprint signal into one by using an empirical mode decomposition method. Below the voiceprint frequency, one of the in-line mode function diagrams of the ball lead screw pre-pressure characteristic signal, and extracting from a preset voiceprint frequency, an intrinsic mode function of one of the ball lead screw pre-pressure characteristic signals; The signal analysis module converts the intrinsic mode function into a time-frequency map by using Short-Time Fourier Transform (STFT), and analyzes the time-frequency map to generate a Marginal Time map. And the marginal frequency domain map (Marginal Frequency), and compared with the voiceprint data to measure the ball lead screw pre-pressure change. A measuring system for diagnosing a ball lead screw pre-pressure imbalance using a voiceprint signal according to claim 9 wherein the intrinsic mode function represents an instantaneous amplitude and an instantaneous frequency of the voiceprint signal. The measuring system for diagnosing the pre-pressure imbalance of the ball lead screw by using the voiceprint signal according to claim 9 of the patent application, wherein the signal capturing module is a microphone. A method for measuring a pre-pressure imbalance of a ball lead screw by using a voiceprint signal comprises the steps of: using a signal capture module to capture a voice signal generated during operation of the ball guide screw device; Stored under different pre-stress conditions, one of the voiceprint data generated by the ball guide screw device during operation; the signal processing module uses an empirical mode decomposition method to convert the voiceprint signal into an internal mode function And extracting from a preset voiceprint frequency, an intrinsic mode function of one of the ball lead screw pre-stress characteristic signals; and converting the intrinsic mode function into a time-frequency diagram and a side by a signal analysis module The time domain map and the inter-frequency frequency domain map are compared with the voiceprint data to measure the pre-pressure change of the ball lead screw. A method for measuring a pre-pressure imbalance of a ball lead screw using a voiceprint signal as described in claim 12, wherein the intrinsic mode function represents an instantaneous amplitude and an instantaneous frequency of the voiceprint signal. The method for measuring a pre-pressure imbalance of a ball lead screw using a voiceprint signal as described in claim 12, wherein the signal acquisition module is a microphone.