CN117185078A - Elevator multi-parameter measurement method based on MEMS triaxial acceleration sensor - Google Patents

Abstract

An elevator multi-parameter measurement method based on a MEMS three-axis acceleration sensor, which relates to the technical field of multi-parameter comprehensive detection of elevators or escalators. In the elevator multi-parameter measurement method based on MEMS three-axis acceleration sensor, the vertical elevator braking performance parameters, three-axis vibration comfort of the car, running speed, running acceleration, start-stop acceleration and deceleration, etc. are measured through the MEMS three-axis acceleration sensor. Comprehensive detection and analysis of parameters such as car levelness, guide rail installation plumbness, and abnormal vibration frequency of mechanical components can effectively improve measurement accuracy and real-time on-site calculations; use MEMS three-axis acceleration sensors to brake escalators or moving walkways Comprehensive detection and analysis of performance parameters, carrier device vibration comfort, handrail vibration comfort, running speed, escalator inclination angle, abnormal vibration frequency of main mechanical components and other parameters can effectively improve measurement accuracy and real-time on-site calculations.

Description

Elevator multi-parameter measurement method based on MEMS three-axis acceleration sensor

Technical field

The present invention relates to the technical field of multi-parameter comprehensive detection of elevators or escalators, and in particular to a multi-parameter measurement method for elevators based on a MEMS three-axis acceleration sensor.

Background technique

As a type of vertical transportation vehicle, elevators play an important role in people's production and life. At the same time, as a type of electromechanical special equipment, their safety performance has also received widespread attention.

According to different structures, elevators can be divided into vertical elevators, inclined elevators, escalators and moving walkways. All types of elevators require various testing methods, testing tools and testing instruments during installation, maintenance, inspection, spot checks, accident investigation and other aspects.

A large number of various sensors are used in testing instruments to measure the physical parameters of elevator mechanical components and electrical components on site. Acceleration sensors have been widely used in the field of elevator detection. Combining different acceleration data analysis methods can achieve the measurement of different elevator parameters. For example: based on the up and down fluctuation characteristics of acceleration data around the average value, elevator vibration comfort can be analyzed; numerical integration calculation of acceleration can measure elevator speed, running distance and other parameters; acceleration signal frequency domain analysis can obtain the main vibration frequency composition, so as to Conduct fault tracing of failed components; by analyzing the projection components of gravity acceleration on the three data axes of the sensor, the tilt angle data can be obtained.

Existing elevator detection instruments based on three-axis acceleration sensors usually use traditional analog output acceleration sensors. The whole machine is large in size, has a single function, and is not highly integrated. It is difficult to meet the multi-parameter detection requirements of the elevator on-site. For example: the EVA625 comprehensive elevator performance tester that is widely used in the industry is large in size and has many application modes in elevators or escalators. However, the test results cannot be obtained immediately on site. It is necessary to copy the data files with a USB flash drive and then perform manual analysis on the computer; and , EVA625 detector data files are closed to users, making it inconvenient for customized data analysis and secondary drawing.

Contents of the invention

The purpose of the present invention is to provide a multi-parameter measurement method for elevators based on a MEMS three-axis acceleration sensor, which can be comprehensively used in elevator or escalator motion parameter measurement, vibration comfort assessment, braking parameter measurement, mechanical component failure analysis, tilt In detection situations such as angle measurement, the application performance of MEMS acceleration sensors can be fully utilized.

In order to achieve the above objects, the present invention adopts the following technical solutions:

An elevator multi-parameter measurement method based on MEMS three-axis acceleration sensor, including the following steps:

Three-axis acceleration sensor is used to measure various parameters of vertical elevators:

There are three tapered legs at the bottom of the module of the measuring device. When measuring vibration comfort, place the measuring device on the car floor and make the X-axis or Y-axis perpendicular to the elevator door. The operator holds the data terminal and stands inside the car. Operate the elevator from the bottom to the top or from the top to the bottom, record the three-axis vibration acceleration signal during the operation of the elevator, and the data terminal analyzes the data to obtain vibration characteristic parameters to quantitatively evaluate the vibration ride quality of the car;

During the braking performance test, the module of the measuring device is placed on the car floor. During the data collection process, people leave the elevator car. The test ends after the braking is completed and the floor is leveled. The data terminal automatically performs data analysis;

When testing the vibration of the ferromagnetic components of the elevator host, there is no need to use legs. The magnets inside the measuring device are directly attached to the metal surface of the component to be tested, and the vibration conditions are tested; or, by installing a circular ring at the bottom of the module of the measuring device The magnetic holder allows the sensor to be adsorbed on the surface of the object to be measured;

Three-axis acceleration sensors are used to measure various parameters of escalators or moving walkways:

Place the measuring device on the step, adjust the position of the legs so that the three legs are stuck into the grooves on the surface of the step at the same time. The operator stands on the step near the step where the module of the measuring device is located, and presses the switch button to realize communication with the data terminal. Communication, after the test starts, operate the escalator and test the vibration conditions of the steps during operation to achieve the upward vibration comfort test or downward vibration comfort test of the escalator steps, or test the average braking deceleration and braking distance of the escalator parameters;

In the same way, when testing the vibration comfort of the moving walkway pedal, place the measuring device at the inclined section and the horizontal section;

When testing the vibration of the escalator or moving walkway handrails, the operator stands on the escalator steps or moving walkway pedals, holds the vibration measuring device, and removes the three legs at the bottom of the module so that the X direction of the measuring device points to the elevator movement. direction, operate the escalator or moving walkway, and test the vibration of the handrail during operation;

During the test, the vibration conditions of the two handrails in both upward and downward directions were measured, and the running speed of the handrails in a short period of time was measured.

Among them, when analyzing the vibration comfort of straight elevators, affected by the unevenness of the car floor and assembly errors of the module circuit board, the module horizontal inclination angle must be compensated and the DC component of gravity acceleration must be deducted before the vibration comfort is calculated to obtain the orthogonal three-dimensional Shaft vibration acceleration data sequence;

According to the projection components of the gravity acceleration on the three data axes when the module is stationary, the angles between the X-axis, Y-axis, and Z-axis and the horizontal plane are calculated. The calculation principle is:

In the formula: α is the angle rad between the X axis of the module and the horizontal plane, β is the angle rad between the Y axis of the module and the horizontal plane, γ is the angle rad between the Z axis of the module and the horizontal plane, _a ^The _projected component m/s ² _on the ² .

Specifically, when calculating, a _x , a _y and a _z take the average acceleration within 1 s of the module in the stationary state; the original acceleration is corrected according to the projection relationship of the gravity acceleration on the three measurement axes to ensure that the acceleration data participates in subsequent analysis It is the data in absolute horizontal and vertical directions, and the correction method is:

A _x =a _x -A _z sinα, A _y =a _y -A _z sinβ;

In the formula: A _z is the corrected Z-axis acceleration m/s ² , A _x is the corrected X-axis acceleration m/s ² , A _y is the corrected Y-axis acceleration m/s ² .

Furthermore, affected by the physiological structure of the human body, different vibration frequencies will lead to differences in passengers' perception of vibration amplitude. In order to make the vibration test results more consistent with the human body's comfort experience when riding an elevator, frequency weighting of vibration acceleration is required;

Frequency weighting includes four filtering processes: high-pass and low-pass second-order Butterworth filtering, a-v transform filtering, and high-pass filtering. The three-axis acceleration time domain curve after frequency weighting is obtained; and the peak-to-peak vibration of the three axes is obtained through curve analysis. Sequence, sort the vibration peaks, solve for the maximum vibration peaks and A95 vibration peaks, and quantitatively evaluate the vibration comfort.

Among them, when analyzing the vibration comfort of the escalator, the total frequency weighting function is the product of four filter functions: high-pass and low-pass second-order Butterworth filter, a-v transform filter, and high-order filter; the digital filter Z transform transfer of each filtering process The function is:

Among them, H(z) is the Z transform output value, a is the digital filter numerator vector: a=[1,a2,a3], b is the digital filter denominator vector: b=[b ₁ , b ₂ , b ₃ ] , the Z vector is: Z=[1, z ^-1 , z ^-2 ] ^T .

Specifically, different vibration sensing parts, vibration directions and human body postures use different frequency weighting methods, corresponding to different filter parameters;

The horizontal whole-body vibration of standing posture adopts frequency weighting W _d , the vertical whole-body vibration of standing posture adopts frequency weighting W _k , and the hand-transmitted vibration adopts frequency weighting W _h . Different filtering processes use different filter vectors a under different frequency weighting methods. and b, the recursive calculation formula when performing digital filtering on the mth acceleration data is:

y(m)＝b ₁ x(m)+b ₂ x(m-1)+b ₃ x(m-2)-a ₂ y(m-1)-a ₃ y(m-2);

In the formula, x is the data sequence before filtering, y is the data sequence after filtering, and m is the number of the filtered data in the sequence.

Furthermore, for the step vibration, it is necessary to calculate the RMS value of the data after three-axis frequency weighting; for the handrail vibration, it is necessary to calculate the RMS value of the handrail's downward X _h direction frequency-weighted data, and the time constant is 1s. The calculation formula for the Nth RMS data is:

In the formula, n is the number of acceleration data within the 1s time constant, and a is the acceleration value after frequency weighting;

For step vibration, the three-axis RMS vector sum is used to evaluate the overall vibration energy:

In the formula, a _xyz is the vibration vector sum, a _x is the X-axis vibration RMS value, a _y is the Y-axis vibration RMS value, and a _z is the Z-axis vibration RMS value.

Among them, when analyzing the acceleration, deceleration, speed, and displacement of the start and stop of a straight elevator or escalator, before analyzing the elevator motion characteristics, first perform a second-order Butterworth low-pass filter on the sensor Z-axis raw acceleration data, and the filter cutoff frequency is 10Hz;

Acceleration and deceleration reflect the amount of pressure exerted by the human body on the car floor. Quantifying the maximum acceleration and maximum deceleration can be used to judge whether the operation control settings corresponding to the elevator and ride quality results are reasonable; the maximum acceleration is the maximum value of the acceleration signal when the elevator starts. The maximum Deceleration is the maximum absolute value of the deceleration signal during the elevator braking process; A95 acceleration value is statistically calculated within the range of 5% to 95% of the maximum speed during acceleration, and 95% of the acceleration data within this range are less than this value; A95 The deceleration value is statistically calculated within the range of 95% to 5% of the maximum speed during the deceleration process. The absolute value of 95% of the deceleration data within this range is less than this value;

The maximum speed is the maximum absolute value of the speed within the entire elevator operation cycle; the limit range of the V95 speed in statistical calculation is from 1s after the time point corresponding to 95% of the maximum speed V _max1 in the acceleration phase to the maximum speed V _max2 in the deceleration phase 95% corresponds to the first 1s of the time point where the data is located, and 95% of the speed values within the calculation limit are less than the V95 speed.

Specifically, the complex 1/3 Simpson numerical integration method is used to integrate the Z-axis acceleration after Butterworth filtering to calculate the velocity sequence. The numerical integral velocity calculation formula at time t is:

In the formula, v(t) is the velocity at time t, unit m/s, h is the time step of the acceleration data sequence, a(0) is the acceleration at the initial time, unit m/s ² , a(t) is the acceleration at time t The unit is m/s ² , n is the number of data in the integration interval;

The complex 1/3 Simpson method is used to numerically integrate the speed data, and the elevator running displacement sequence is calculated. Information such as the lifting height can be obtained. The numerical integral displacement calculation formula at time t is:

Furthermore, when analyzing the braking parameters of a straight ladder or escalator, in order to reflect the actual running acceleration of the steps on the Z-axis, the gravity acceleration offset needs to be subtracted. When calculating, the Z-axis acceleration within 3 seconds after braking is completed and before data collection is stopped is taken. The average value of the data is the gravity acceleration offset;

According to the numerical integration method, the speed and displacement data sequences in the horizontal and vertical directions are obtained, and the X-axis and Z-axis acceleration, speed, and displacement curves of the braking process are drawn respectively, and the characteristic values of the curves are comprehensively analyzed to control the horizontal and vertical directions of the escalator. Calculate the dynamic parameters; the actual running direction of the escalator steps during the braking process is inclined downward, the sum of the speed vectors in the X direction and the Z direction is the actual running speed of the steps, and the sum of the displacement vectors is the step displacement; comprehensive analysis of the step speed vector and curve and displacement The vector sum curve can solve for the average braking deceleration and total braking distance.

Compared with the existing technology, the elevator multi-parameter measurement method based on MEMS three-axis acceleration sensor according to the present invention has the following advantages:

In the elevator multi-parameter measurement method based on the MEMS three-axis acceleration sensor provided by the present invention, the vertical elevator braking performance parameters, three-axis vibration comfort of the car, running speed, running acceleration, start and stop acceleration and subtraction are measured through the MEMS three-axis acceleration sensor. Comprehensive detection and analysis of parameters such as speed, car level, guide rail installation plumbness, and abnormal vibration frequency of mechanical components can effectively improve measurement accuracy and real-time on-site calculations; the MEMS three-axis acceleration sensor is used to detect escalators or moving walkways. Comprehensive detection and analysis of braking performance parameters, carrier device vibration comfort, handrail vibration comfort, running speed, escalator inclination angle, abnormal vibration frequency of major mechanical components and other parameters can effectively improve measurement accuracy and real-time on-site calculations.

Description of the drawings

Figure 1 is a schematic structural diagram of the first measurement state of the elevator multi-parameter measurement method based on a MEMS three-axis acceleration sensor provided by an embodiment of the present invention;

Figure 2 is a schematic structural diagram of the second measurement state of the elevator multi-parameter measurement method based on MEMS three-axis acceleration sensors provided by the embodiment of the present invention;

Figure 3 is a schematic structural diagram of the third measurement state of the elevator multi-parameter measurement method based on MEMS three-axis acceleration sensors provided by the embodiment of the present invention;

Figure 4 is a schematic structural diagram of the fourth measurement state of the elevator multi-parameter measurement method based on MEMS three-axis acceleration sensors provided by the embodiment of the present invention;

Figure 5 is a schematic structural diagram of the fifth measurement state of the elevator multi-parameter measurement method based on a MEMS three-axis acceleration sensor provided by an embodiment of the present invention.

Detailed ways

For ease of understanding, the elevator multi-parameter measurement method based on the MEMS three-axis acceleration sensor provided by the embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

An embodiment of the present invention provides a multi-parameter measurement method for an elevator based on a MEMS three-axis acceleration sensor, as shown in Figures 1-5, including the following steps:

Three-axis acceleration sensor is used to measure various parameters of vertical elevators:

There are three tapered legs at the bottom of the module of the measuring device. When measuring vibration comfort, place the measuring device on the car floor and make the X-axis or Y-axis perpendicular to the elevator door. The operator holds the data terminal and stands inside the car. Operate the elevator from the bottom to the top or from the top to the bottom, record the three-axis vibration acceleration signal during the operation of the elevator, and the data terminal analyzes the data to obtain vibration characteristic parameters to quantitatively evaluate the vibration ride quality of the car;

During the braking performance test, the module of the measuring device is placed on the car floor. During the data collection process, people leave the elevator car. The test ends after the braking is completed and the floor is leveled. The data terminal automatically performs data analysis;

When testing the vibration of the ferromagnetic components of the elevator host, there is no need to use legs. The magnets inside the measuring device are directly attached to the metal surface of the component to be tested, and the vibration conditions are tested; or, by installing a circular ring at the bottom of the module of the measuring device The magnetic holder allows the sensor to be adsorbed on the surface of the object to be measured;

Three-axis acceleration sensors are used to measure various parameters of escalators or moving walkways:

Place the measuring device on the step, adjust the position of the legs so that the three legs are stuck into the grooves on the surface of the step at the same time. The operator stands on the step near the step where the module of the measuring device is located, and presses the switch button to realize communication with the data terminal. Communication, after the test starts, operate the escalator and test the vibration conditions of the steps during operation to achieve the upward vibration comfort test or downward vibration comfort test of the escalator steps, or test the average braking deceleration and braking distance of the escalator parameters;

In the same way, when testing the vibration comfort of the moving walkway pedal, place the measuring device at the inclined section and the horizontal section;

When testing the vibration of the escalator or moving walkway handrails, the operator stands on the escalator steps or moving walkway pedals, holds the vibration measuring device, and removes the three legs at the bottom of the module so that the X direction of the measuring device points to the elevator movement. direction, operate the escalator or moving walkway, and test the vibration of the handrail during operation;

During the test, the vibration conditions of the two handrails in both upward and downward directions were measured, and the running speed of the handrails in a short period of time was measured.

Compared with the existing technology, the elevator multi-parameter measurement method based on the MEMS three-axis acceleration sensor described in the embodiment of the present invention has the following advantages:

In the elevator multi-parameter measurement method based on the MEMS three-axis acceleration sensor provided by the embodiment of the present invention, the vertical elevator braking performance parameters, three-axis vibration comfort of the car, running speed, running acceleration, start and stop are measured through the MEMS three-axis acceleration sensor. Comprehensive detection and analysis of parameters such as acceleration and deceleration, car levelness, guide rail installation plumb bob, and abnormal vibration frequency of mechanical components can effectively improve measurement accuracy and real-time on-site calculations; use MEMS three-axis acceleration sensors to measure escalators or automatic Comprehensive detection and analysis of pavement braking performance parameters, carrier device vibration comfort, handrail vibration comfort, running speed, escalator inclination angle, abnormal vibration frequency of main mechanical components and other parameters can effectively improve measurement accuracy and on-site calculation real-time performance .

Among them, when analyzing the vibration comfort of straight elevators, affected by the unevenness of the car floor and assembly errors of the module circuit board, the module horizontal inclination angle must be compensated and the DC component of gravity acceleration must be deducted before the vibration comfort is calculated to obtain the orthogonal three-dimensional Shaft vibration acceleration data sequence;

According to the projection components of the gravity acceleration on the three data axes when the module is stationary, the angles between the X-axis, Y-axis, and Z-axis and the horizontal plane are calculated. The calculation principle is:

In the formula: α is the angle rad between the X axis of the module and the horizontal plane, β is the angle rad between the Y axis of the module and the horizontal plane, γ is the angle rad between the Z axis of the module and the horizontal plane, _a ^The _projected component m/s ² _on the ² .

Specifically, when calculating, a _x , a _y and a _z take the average acceleration within 1 s of the module in the stationary state; the original acceleration is corrected according to the projection relationship of the gravity acceleration on the three measurement axes to ensure that the acceleration data participates in subsequent analysis It is the data in absolute horizontal and vertical directions, and the correction method is:

A _x =a _x -A _z sinα, A _y =a _y -A _z sinβ;

In the formula: A _z is the corrected Z-axis acceleration m/s ² , A _x is the corrected X-axis acceleration m/s ² , A _y is the corrected Y-axis acceleration m/s ² .

Furthermore, affected by the physiological structure of the human body, different vibration frequencies will lead to differences in passengers' perception of vibration amplitude. In order to make the vibration test results more consistent with the human body's comfort experience when riding an elevator, frequency weighting of vibration acceleration is required;

Frequency weighting includes four filtering processes: high-pass and low-pass second-order Butterworth filtering, a-v transform filtering, and high-pass filtering. The three-axis acceleration time domain curve after frequency weighting is obtained; and the peak-to-peak vibration of the three axes is obtained through curve analysis. Sequence, sort the vibration peaks, solve for the maximum vibration peaks and A95 vibration peaks, and quantitatively evaluate the vibration comfort.

Among them, when analyzing the vibration comfort of the escalator, the total frequency weighting function is the product of four filter functions: high-pass and low-pass second-order Butterworth filter, a-v transform filter, and high-order filter; the digital filter Z transform transfer of each filtering process The function is:

Among them, H(z) is the Z transform output value, a is the digital filter numerator vector: a＝[1,a ₂ ,a ₃ ], b is the digital filter denominator vector: b＝[b ₁ ,b ₂ ,b ₃ ], Z vector is: Z = [1, z ^-1 , z ^-2 ] ^T .

Specifically, different vibration sensing parts, vibration directions and human body postures use different frequency weighting methods, corresponding to different filter parameters;

The horizontal whole-body vibration of standing posture adopts frequency weighting W _d , the vertical whole-body vibration of standing posture adopts frequency weighting W _k , and the hand-transmitted vibration adopts frequency weighting W _h . Different filtering processes use different filter vectors a under different frequency weighting methods. and b, the recursive calculation formula when performing digital filtering on the mth acceleration data is:

y(m)＝b ₁ x(m)+b ₂ x(m-1)+b ₃ x(m-2)-a ₂ y(m-1)-a ₃ y(m-2);

In the formula, x is the data sequence before filtering, y is the data sequence after filtering, and m is the number of the filtered data in the sequence.

Furthermore, for the step vibration, it is necessary to calculate the RMS value of the data after three-axis frequency weighting; for the handrail vibration, it is necessary to calculate the RMS value of the handrail's downward X _h direction frequency-weighted data, and the time constant is 1s. The calculation formula for the Nth RMS data is:

In the formula, n is the number of acceleration data within the 1s time constant, and a is the acceleration value after frequency weighting;

For step vibration, the three-axis RMS vector sum is used to evaluate the overall vibration energy:

In the formula, a _xyz is the vibration vector sum, a _x is the X-axis vibration RMS value, a _y is the Y-axis vibration RMS value, and a _z is the Z-axis vibration RMS value.

Among them, when analyzing the acceleration, deceleration, speed, and displacement of the start and stop of a straight elevator or escalator, before analyzing the elevator motion characteristics, first perform a second-order Butterworth low-pass filter on the sensor Z-axis raw acceleration data, and the filter cutoff frequency is 10Hz;

Acceleration and deceleration reflect the amount of pressure exerted by the human body on the car floor. Quantifying the maximum acceleration and maximum deceleration can be used to judge whether the operation control settings corresponding to the elevator and ride quality results are reasonable; the maximum acceleration is the maximum value of the acceleration signal when the elevator starts. The maximum Deceleration is the maximum absolute value of the deceleration signal during the elevator braking process; A95 acceleration value is statistically calculated within the range of 5% to 95% of the maximum speed during acceleration, and 95% of the acceleration data within this range are less than this value; A95 The deceleration value is statistically calculated within the range of 95% to 5% of the maximum speed during the deceleration process. The absolute value of 95% of the deceleration data within this range is less than this value;

The maximum speed is the maximum absolute value of the speed within the entire elevator operation cycle; the limit range of the V95 speed in statistical calculation is from 1s after the time point corresponding to 95% of the maximum speed V _max1 in the acceleration phase to the maximum speed V _max2 in the deceleration phase 95% corresponds to the first 1s of the time point where the data is located, and 95% of the speed values within the calculation limit are less than the V95 speed.

Specifically, the complex 1/3 Simpson numerical integration method is used to integrate the Z-axis acceleration after Butterworth filtering to calculate the velocity sequence. The numerical integral velocity calculation formula at time t is:

In the formula, v(t) is the velocity at time t, unit m/s, h is the time step of the acceleration data sequence, a(0) is the acceleration at the initial time, unit m/s ² , a(t) is the acceleration at time t The unit is m/s ² , n is the number of data in the integration interval;

The complex 1/3 Simpson method is used to numerically integrate the speed data, and the elevator running displacement sequence is calculated. Information such as the lifting height can be obtained. The numerical integral displacement calculation formula at time t is:

Furthermore, when analyzing the braking parameters of a straight ladder or escalator, in order to reflect the actual running acceleration of the steps on the Z-axis, the gravity acceleration offset needs to be subtracted. When calculating, the Z-axis acceleration within 3 seconds after braking is completed and before data collection is stopped is taken. The average value of the data is the gravity acceleration offset;

According to the numerical integration method, the speed and displacement data sequences in the horizontal and vertical directions are obtained, and the X-axis and Z-axis acceleration, speed, and displacement curves of the braking process are drawn respectively, and the characteristic values of the curves are comprehensively analyzed to control the horizontal and vertical directions of the escalator. Calculate the dynamic parameters; the actual running direction of the escalator steps during the braking process is inclined downward, the sum of the speed vectors in the X direction and the Z direction is the actual running speed of the steps, and the sum of the displacement vectors is the step displacement; comprehensive analysis of the step speed vector and curve and displacement The vector sum curve can solve for the average braking deceleration and total braking distance.

Furthermore, when analyzing the spectrum of abnormal vibrations of elevators or escalators, the frequency spectrum can be obtained by performing Fast Fourier Transform (FFT) on the vibration data; by analyzing the FFT data sequence and sorting the amplitudes, the maximum vibration energy can be obtained The corresponding frequency is generally the vibration frequency of the motor; if there is an abnormal vibration frequency, an abnormal peak will appear in the frequency spectrum, and the corresponding frequency is the abnormal vibration frequency; by analyzing the size and running speed of each moving part of the elevator or escalator, it can be reversed The natural frequency of each component is calculated, and the mechanical component that generates abnormal vibration can be analyzed by comparing the abnormal frequency with the natural frequency.

Furthermore, when analyzing the installation verticality of the escalator car or the inclination angle of the escalator, when the module is in a static state, the acceleration projection components of the gravity acceleration (about 9.8m/s ² ) on the three acceleration data axes are obtained. The vector sum of the projection components is the vertical downward gravity acceleration; according to the vector decomposition model, the angle between the three data axes of XYZ and the horizontal plane can be calculated, that is, the horizontal tilt angle; when the module is placed horizontally, the Z-axis tilt angle is 90 degrees. The inclination angle of the XY axis is 0 degrees, and parameters such as the inclination angle of the escalator and the verticality of the installation of the straight elevator car can be measured.

To sum up, the elevator multi-parameter measurement method based on the MEMS three-axis acceleration sensor provided by the embodiment of the present invention mainly has the following advantages:

1. Using MEMS acceleration sensors, a single module can be used to test the multi-parameter compatibility of multiple components such as elevator cars, escalator steps, escalator handrails, and hosts;

2. Comprehensive use of vibration frequency weighting, digital filtering, numerical integration, curve fitting, fast Fourier transform, mathematical statistics and other algorithms to analyze the vibration comfort parameters and operating parameters of the straight elevator or escalator, such as speed, start and stop acceleration and subtraction Speed, lifting height, braking time, braking distance, braking deceleration, abnormal vibration frequency, tilt angle, etc.;

3. Relying on the powerful data processing capabilities of the handheld smart terminal, the test results can be obtained immediately through text, curves, etc. at the elevator or escalator site, and original table data such as electronic test reports and drawing curves can be exported on-site without the need to test again. Import the data into a computer for analysis.

The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention. should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims (10)

1. An elevator multi-parameter measurement method based on a MEMS three-axis acceleration sensor, which is characterized by including the following steps: Three-axis acceleration sensor is used to measure various parameters of vertical elevators: There are three tapered legs at the bottom of the module of the measuring device. When measuring vibration comfort, place the measuring device on the car floor and make the X-axis or Y-axis perpendicular to the elevator door. The operator holds the data terminal and stands inside the car. Operate the elevator from the bottom to the top or from the top to the bottom, record the three-axis vibration acceleration signal during the operation of the elevator, and the data terminal analyzes the data to obtain vibration characteristic parameters to quantitatively evaluate the vibration ride quality of the car; During the braking performance test, the module of the measuring device is placed on the car floor. During the data collection process, people leave the elevator car. The test ends after the braking is completed and the floor is leveled. The data terminal automatically performs data analysis; When testing the vibration of the ferromagnetic components of the elevator host, there is no need to use legs. The magnets inside the measuring device are directly attached to the metal surface of the component to be tested, and the vibration conditions are tested; or, by installing a circular ring at the bottom of the module of the measuring device The magnetic holder allows the sensor to be adsorbed on the surface of the object to be measured; Three-axis acceleration sensors are used to measure various parameters of escalators or moving walkways: Place the measuring device on the step, adjust the position of the legs so that the three legs are stuck into the grooves on the surface of the step at the same time. The operator stands on the step near the step where the module of the measuring device is located, and presses the switch button to realize communication with the data terminal. Communication, after the test starts, operate the escalator and test the vibration conditions of the steps during operation to achieve the upward vibration comfort test or downward vibration comfort test of the escalator steps, or test the average braking deceleration and braking distance of the escalator parameters; In the same way, when testing the vibration comfort of the moving walkway pedal, place the measuring device at the inclined section and the horizontal section; When testing the vibration of the escalator or moving walkway handrails, the operator stands on the escalator steps or moving walkway pedals, holds the vibration measuring device, and removes the three legs at the bottom of the module so that the X direction of the measuring device points to the elevator movement. direction, operate the escalator or moving walkway, and test the vibration of the handrail during operation; During the test, the vibration conditions of the two handrails in both upward and downward directions were measured, and the running speed of the handrails in a short period of time was measured. 2. The elevator multi-parameter measurement method based on MEMS three-axis acceleration sensor according to claim 1, characterized in that when analyzing the vibration comfort of the straight elevator, the vibration is affected by the unevenness of the car floor and the assembly error of the module circuit board. Before comfort calculation, the module horizontal inclination angle must be compensated and the DC component of gravity acceleration must be deducted to obtain an orthogonal three-axis vibration acceleration data sequence; According to the projection components of the gravity acceleration on the three data axes when the module is stationary, the angles between the X-axis, Y-axis, and Z-axis and the horizontal plane are calculated. The calculation principle is: In the formula: α is the angle rad between the X axis of the module and the horizontal plane, β is the angle rad between the Y axis of the module and the horizontal plane, γ is the angle rad between the Z axis of the module and the horizontal plane, _a ^The _projected component m/s ² _on the ² . 3. The elevator multi-parameter measurement method based on MEMS three-axis acceleration sensor according to claim 2, characterized in that, when calculating, _ax , _ay and _az take the average acceleration within 1s in the stationary state of the module; according to gravity The projection relationship of acceleration on the three measurement axes corrects the original acceleration to ensure that the acceleration data involved in subsequent analysis is absolute horizontal and vertical data. The correction method is: A _x =a _x -A _z sinα, A _y =a _y -A _z sinβ; In the formula: A _z is the corrected Z-axis acceleration m/s ² , A _x is the corrected X-axis acceleration m/s ² , A _y is the corrected Y-axis acceleration m/s ² . 4. The elevator multi-parameter measurement method based on MEMS three-axis acceleration sensor according to claim 3, characterized in that, affected by the physiological structure of the human body, different vibration frequencies will lead to differences in passengers’ perception of vibration amplitude. In order to make the vibration test The result is more in line with the human body's comfort experience when riding an elevator, and the vibration acceleration needs to be frequency weighted; Frequency weighting includes four filtering processes: high-pass and low-pass second-order Butterworth filtering, a-v transform filtering, and high-pass filtering. The three-axis acceleration time domain curve after frequency weighting is obtained; and the peak-to-peak vibration of the three axes is obtained through curve analysis. Sequence, sort the vibration peaks, solve for the maximum vibration peaks and A95 vibration peaks, and quantitatively evaluate the vibration comfort. 5. The multi-parameter measurement method for elevators based on MEMS three-axis acceleration sensors according to claim 1, characterized in that when analyzing escalator vibration comfort, the total frequency weighting function is high-pass and low-pass second-order Butterworth filtering, The product of the four filter functions of a-v transform filtering and high-order filtering; the Z transform transfer function of the digital filter in each filtering process is: Among them, H(z) is the Z transform output value, a is the digital filter numerator vector: a=[1, a ₂ , a ₃ ], b is the digital filter denominator vector: b=[b ₁ , b ₂ , b ₃ ], Z vector is: Z = [1, z ^-1 , z ^-2 ] ^T . 6. The elevator multi-parameter measurement method based on MEMS three-axis acceleration sensor according to claim 5, characterized in that different vibration sensing parts, vibration directions and human body postures adopt different frequency weighting methods, corresponding to different filters. parameter; The horizontal whole-body vibration of standing posture adopts frequency weighting W _d , the vertical whole-body vibration of standing posture adopts frequency weighting W _k , and the hand-transmitted vibration adopts frequency weighting W _h . Different filtering processes use different filter vectors a under different frequency weighting methods. and b, the recursive calculation formula when performing digital filtering on the mth acceleration data is: y(m)＝b ₁ x(m)+b ₂ x(m-1)+b ₃ x(m-2)-a ₂ y(m-1)-a ₃ y(m-2); In the formula, x is the data sequence before filtering, y is the data sequence after filtering, and m is the number of the filtered data in the sequence. 7. The elevator multi-parameter measurement method based on MEMS three-axis acceleration sensor according to claim 6, characterized in that, for the step vibration, the RMS value of the three-axis frequency weighted data needs to be calculated respectively; for the handrail vibration, It is necessary to calculate the RMS value of the frequency-weighted data in the X _h direction of the handrail downstream. The time constant is 1s. The calculation formula for the Nth RMS data is: In the formula, n is the number of acceleration data within the 1s time constant, and a is the acceleration value after frequency weighting; For step vibration, the three-axis RMS vector sum is used to evaluate the overall vibration energy: In the formula, a _xyz is the vibration vector sum, a _x is the X-axis vibration RMS value, a _y is the Y-axis vibration RMS value, and a _z is the Z-axis vibration RMS value. 8. The multi-parameter measurement method of an elevator based on a MEMS three-axis acceleration sensor according to claim 1, characterized in that when analyzing the start-stop acceleration, deceleration, speed, and displacement of a straight elevator or escalator, before analyzing the elevator motion characteristics, First, perform second-order Butterworth low-pass filtering on the original acceleration data of the sensor Z-axis, and the filtering cutoff frequency is 10Hz; Acceleration and deceleration reflect the amount of pressure exerted by the human body on the car floor. Quantifying the maximum acceleration and maximum deceleration can be used to judge whether the operation control settings corresponding to the elevator and ride quality results are reasonable; the maximum acceleration is the maximum value of the acceleration signal when the elevator starts. The maximum Deceleration is the maximum absolute value of the deceleration signal during the elevator braking process; A95 acceleration value is statistically calculated within the range of 5% to 95% of the maximum speed during acceleration, and 95% of the acceleration data within this range are less than this value; A95 The deceleration value is statistically calculated within the range of 95% to 5% of the maximum speed during the deceleration process. The absolute value of 95% of the deceleration data within this range is less than this value; The maximum speed is the maximum absolute value of the speed within the entire elevator operation cycle; the limit range of the V95 speed in statistical calculation is from 1s after the time point corresponding to 95% of the maximum speed V _max1 in the acceleration phase to the maximum speed V _max2 in the deceleration phase 95% corresponds to the first 1s of the time point where the data is located, and 95% of the speed values within the calculation limit are less than the V95 speed. 9. The elevator multi-parameter measurement method based on MEMS three-axis acceleration sensor according to claim 8, characterized in that the Z-axis acceleration after Butterworth filtering is integrated using the complex 1/3 Simpson numerical integration method to calculate the speed. Sequence, the numerical integral speed calculation formula at time t is: In the formula, v(t) is the velocity at time t, unit m/s, h is the time step of the acceleration data sequence, a(0) is the acceleration at the initial time, unit m/s ² , a(t) is the acceleration at time t The unit is m/s ² , n is the number of data in the integration interval; The complex 1/3 Simpson method is used to numerically integrate the speed data, and the elevator running displacement sequence is calculated. Information such as the lifting height can be obtained. The numerical integral displacement calculation formula at time t is: 10. The elevator multi-parameter measurement method based on MEMS three-axis acceleration sensor according to claim 9, characterized in that when analyzing the braking parameters of a straight ladder or escalator, in order to reflect the actual running acceleration of the steps in the Z-axis, gravity needs to be subtracted. Acceleration offset, when calculating, take the average value of the Z-axis acceleration data within 3 seconds after braking and before stopping data collection as the gravity acceleration offset; According to the numerical integration method, the speed and displacement data sequences in the horizontal and vertical directions are obtained, and the X-axis and Z-axis acceleration, speed, and displacement curves of the braking process are drawn respectively, and the characteristic values of the curves are comprehensively analyzed to control the horizontal and vertical directions of the escalator. Calculate the dynamic parameters; the actual running direction of the escalator steps during the braking process is inclined downward, the sum of the speed vectors in the X direction and the Z direction is the actual running speed of the steps, and the sum of the displacement vectors is the step displacement; comprehensive analysis of the step speed vector and curve and displacement The vector sum curve can solve for the average braking deceleration and total braking distance.