Method and device for measuring slippage of elevator traction medium

Abstract

The invention relates to a method and a device for measuring slippage of a traction medium of an elevator. The method comprises the following steps of: mounting speed measuring devices at a traction wheel and the traction medium; speed data of a traction wheel and speed data of a traction medium are collected when the elevator is started and stopped for one time respectively, data alignment processing is conducted on the collected speed data according to time, and speed curve graphs are generated respectively; and according to the speed curve graph, the running distance of the traction wheel and the running distance of the traction medium are calculated when the elevator is started and stopped for one time, and the difference value of the running distance of the traction wheel and the running distance of the traction medium is the relative slippage amount generated in the running process of the elevator. The method has the characteristics of simple and convenient measurement steps and less measurement data, can accurately measure the relative slippage of the traction medium to the traction wheel, and provides support for fault diagnosis analysis and wear life prediction of the elevator traction medium.

Description

Technical Field

[0001] The present invention relates to the technical field of elevator safety detection, and in particular to a method and device for measuring the slip amount of an elevator traction medium. Background Art

[0002] As the transmission medium of an elevator, the traction medium is connected to the car and the counterweight at both ends respectively. The car moves up and down by relying on the friction between the traction medium and the traction wheel. The slip between the traction medium and the traction wheel mainly occurs at the start and stop stages of the elevator. Due to the unbalanced forces at both ends of the traction medium, the traction medium may produce relative slip with respect to the traction wheel. The relative slip amount of the traction medium is one of the important parameters for evaluating the faults of the elevator traction system. Therefore, measuring the relative slip amount is of great significance for elevator safety.

[0003] Yu Ping (China Special Equipment Safety, 2020) used a method based on Euler-Eytelwain theory to calculate the slip distance. This method needs to consider factors such as acceleration, weights on both sides, and friction coefficient, and the calculation is relatively cumbersome;

[0004] Li Ke (Hoisting and Conveying Machinery, 2022) calculated the slip amount of the steel wire rope relative to the traction wheel by establishing a theoretical model; Xiong et al. (Sensors and Materials, 2024) calculated the relative slip amount according to the difference between the actual rotation speed and the theoretical rotation speed of the traction wheel by visually detecting the difference between the actual number of turns and the theoretical number of turns of the traction wheel. However, the accuracy error of the camera and the installation position of the camera will both cause errors in the accuracy of the number of turns and affect the result accuracy; The invention patent (application number: 201810474416.5) proposed a measurement system for the relative slip amount generated by the steel wire rope slipping on the traction wheel. The number of turns of the traction wheel measured by the encoder was converted into distance and the distance of the movement of the transport box measured by the laser sensor were transmitted to the computer for comparison to obtain the relative slip amount generated by the steel wire rope slipping on the traction wheel. The invention patent (application number: 201911389968.7) proposed a method for measuring the relative slip amount of an elevator steel wire rope, using the steel wire rope line marking method, and obtaining the relative slip amount through measurement and calculation. However, most of the existing measurements using line marking are for the slip amount of the elevator running back and forth once, and do not measure the slip amount of the elevator running once.

[0005] In summary, the existing slip distance calculation method based on the theoretical model needs to consider multiple parameters, and the calculation process is relatively complex; while the vision-based measurement method is easily affected by the accuracy of the camera and installation errors. Combining with the operating principle of the elevator traction system, that is, if there is no slip during the operation of the elevator, the linear speed of the traction wheel should be equal to the lifting speed of the elevator car; however, in actual operation, due to the occurrence of slip, the speed of the traction wheel will be higher than the car lifting speed. Therefore, the slip amount generated during one operation of the elevator can be obtained by integrating the speed difference between the traction wheel and the traction medium.

[0006] This case is proposed to solve or improve the shortcomings or deficiencies of the existing technology. Summary of the Invention

[0007] The present invention is implemented by adopting the following technical solutions:

[0008] For wire rope elevators

[0009] A speed measurement wheel device is respectively arranged on the traction wheel and the wire rope;

[0010] The encoder of the speed measurement wheel device selects the Heidenhain ERN1387 rotary encoder. The accuracy of this encoder system can reach 20 arcseconds, which can resolve very small angular changes. This encoder uses permanent magnet synchronous torque direct drive, has no transmission loss, and the waveform deviation of the output sine-cosine signal is less than 1%.

[0011] The traction wheel speed measurement device and the wire rope speed measurement wheel device are fixed on the same side of the elevator steel frame through magnetic bases, which is convenient for connecting the two encoders to the same controller through cables.

[0012] For steel belt elevators

[0013] In the steel belt elevator, a laser velocimeter is used to collect the speed curve graph of the traction wheel, and a speed measurement wheel device is arranged at the steel belt.

[0014] The laser velocimeter adopts the laser Doppler velocimeter which is widely used in industry. The measurement accuracy can reach ±0.1%, and the repeatability accuracy is better than 0.02%. It has the characteristics of high accuracy, high repeatability, wide measurement range and fast dynamic response, and can accurately measure the speed of the rotating traction wheel.

[0015] The encoder of the speed measurement wheel selects the Heidenhain ERN1387 rotary encoder. The accuracy of this encoder system can reach 20 arcseconds, which can resolve very small angular changes. This encoder uses permanent magnet synchronous torque direct drive, has no transmission loss, and the waveform deviation of the output sine-cosine signal is less than 1%.

[0016] The traction wheel laser speedometer of the steel belt elevator is fixedly connected to the elevator steel frame by bolts. The steel belt speed measuring wheel device is fixedly mounted on the same side of the elevator steel frame through a magnetic base. The laser speedometer and the speed measuring wheel encoder are connected to the same controller through cables.

[0017] Step 1: Collect the traction wheel speed data and the traction medium speed data of the elevator during one start-stop operation through the speed measuring device.

[0018] Step 2: Align the speed data collected by the sensor according to time and generate corresponding speed curves respectively.

[0019] Step 3: Calculate the slip amount of the traction medium relative to the traction wheel according to the speed curve.

[0020] Then according to the formula Calculate the running distance of the traction wheel during one start-stop operation of the elevator.

[0021] In the formula

[0022] f(v1) is the speed function of the traction wheel during the elevator acceleration stage from 0 to t1;

[0023] v m is the speed function of the traction wheel during the elevator constant speed stage from t1 to t2;

[0024] f(v2) is the speed function of the traction wheel during the elevator deceleration stage from t2 to t3.

[0025] Step 4: According to the formula Calculate the running distance of the traction medium during one start-stop operation of the elevator.

[0026] In the formula

[0027] f(v g1 ) is the speed function of the traction medium during the elevator acceleration stage from 0 to t1;

[0028] v m is the rated speed of the traction medium during the elevator constant speed stage from t1 to t2;

[0029] f(v g2 ) is the speed function of the traction medium during the elevator deceleration stage from t2 to t3.

[0030] Relative slip amount during one start-stop operation of the elevator

[0031] L = s y -s g

[0032] Calculate the total slip amount of the elevator during one operation according to the above formula. The positive or negative value of L represents that the slip direction of the traction medium is opposite to the rotation direction of the traction wheel.

[0033] The advantages and positive effects of the present invention are as follows:

[0034] 1. The present invention has the characteristics of simple measurement steps and few measurement data, and can provide support for the fault diagnosis and analysis of elevator traction media and the prediction of wear life.

[0035] 2. It can calculate the slip amount generated during one operation of the elevator, improve the measurement and monitoring accuracy and timeliness, and effectively improve the safety of equipment maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The present invention will be further described below in conjunction with the drawings and embodiments.

[0037] Figure 1 It is a schematic flow chart of the measurement method for the relative slip amount of the elevator traction medium in this embodiment.

[0038] Figure 2 It is a schematic installation diagram of the wire rope elevator speed measuring wheel device in this embodiment.

[0039] Figure 3 It is a schematic installation diagram of the steel belt elevator laser speedometer and speed measuring wheel device in this embodiment.

[0040] Figure 4 It is the speed curve diagram of the traction wheel in this embodiment.

[0041] Figure 5 It is the speed curve diagram of the traction medium in this embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0042] The present invention will now be further described in detail in conjunction with the drawings. These drawings are all simplified schematic diagrams, only illustrating the basic structure of the present invention in a schematic manner, so they only show the components related to the present invention.

[0043] The following will further elaborate on the embodiments of the present invention in conjunction with the drawings:

[0044] If there are terms related to directional indication or positional relationship in the embodiments of the present application (such as up, down, left, right, front, back, inside, outside, top, bottom, center, vertical, horizontal, longitudinal, transverse, length, width, counterclockwise, clockwise, axial, radial, circumferential, etc.), such terms are only used to explain the relative positional relationship and movement conditions between components in a certain specific posture (as shown in the drawings); if this specific posture changes, then the directional indication or positional relationship will also change accordingly. In addition, the terms "first", "second", etc. involved in the embodiments of the present application are only for the purpose of convenient description and cannot be understood as indicating or implying relative importance.

[0045] As Figures 1-5As shown, a method and device for measuring the slip amount of an elevator traction medium according to the present invention include the following detection instruments and steps as follows:

[0046] See Figure 1 , this embodiment provides a method for measuring the relative slip amount of an elevator traction medium, including the following equipment and steps:

[0047] For a wire rope elevator, as Figure 2 shown, a speed measuring wheel device is provided on each of the traction wheel and the wire rope;

[0048] The encoder of the speed measuring wheel device is selected as the Heidenhain ERN1387 rotary encoder. The accuracy of this encoder system can reach 20 arcseconds, and it can distinguish very small angular changes. This encoder uses permanent magnet synchronous torque direct drive without transmission loss, and the waveform deviation of the output sine-cosine signal is less than 1%.

[0049] The traction wheel speed measuring device and the wire rope speed measuring wheel device are fixed on the same side of the elevator steel frame through magnetic bases, facilitating the connection of the two encoders to the same controller through cables.

[0050] For a steel belt elevator, as Figure 3 shown, in the steel belt elevator, a laser speedometer is used to collect the speed curve of the traction wheel, and a speed measuring wheel device is set at the steel belt.

[0051] The laser speedometer adopts the laser Doppler speedometer widely used in industry. The measurement accuracy can reach ±0.1%, and the repeatability accuracy is better than 0.02%. It has the characteristics of high accuracy, high repeatability, wide measurement range and fast dynamic response, and can accurately measure the speed of the rotating traction wheel.

[0052] The encoder of the speed measuring wheel is selected as the Heidenhain ERN1387 rotary encoder. The accuracy of this encoder system can reach 20 arcseconds, and it can distinguish very small angular changes. This encoder uses permanent magnet synchronous torque direct drive without transmission loss, and the waveform deviation of the output sine-cosine signal is less than 1%.

[0053] The traction wheel laser speedometer of the steel belt elevator is fixed on the elevator steel frame by bolt connection, the steel belt speed measuring wheel device is fixed on the same side of the elevator steel frame through a magnetic base, and the laser speedometer and the speed measuring wheel encoder are connected to the same controller through a cable.

[0054] Collect the speed data of the traction wheel and the traction medium during one start-stop operation of the elevator through the speed measuring device.

[0055] Align the speed data collected by the sensor according to time and generate corresponding speed curves respectively.

[0056] Calculate the slip amount of the traction medium relative to the traction wheel according to the speed curve.

[0057] 1. As shown in the traction wheel speed curve graph, according to the formula Figure 4 , the running distance of the traction wheel during one start-stop operation of the elevator is calculated.

[0058] In the formula

[0059] f(v1) is the speed function of the traction wheel during the elevator acceleration stage from 0 to t1;

[0060] v m is the speed function of the traction wheel during the elevator constant-speed stage from t1 to t2;

[0061] f(v2) is the speed function of the traction wheel during the elevator deceleration stage from t2 to t3.

[0062] 2. As shown in the traction medium speed curve graph, according to the formula Figure 5 , the running distance of the traction medium during one start-stop operation of the elevator is calculated.

[0063] In the formula

[0064] f(v g1 ) is the speed function of the traction medium during the elevator acceleration stage from 0 to t1;

[0065] v m is the rated speed of the traction medium during the elevator constant-speed stage from t1 to t2;

[0066] f(v g2 ) is the speed function of the traction medium during the elevator deceleration stage from t2 to t3.

[0067] The relative slip amount during one start-stop operation of the elevator

[0068] L = s y - s g

[0069] The total slip amount during one operation of the elevator is calculated according to the above formula. The positive or negative value of L represents that the slip direction of the traction medium is opposite to the rotation direction of the traction wheel.

[0070] It should be emphasized that the embodiments described in the present invention are illustrative rather than restrictive. Therefore, the present invention is not limited to the embodiments described in the specific embodiments. Any other embodiments obtained by those skilled in the art according to the technical solutions of the present invention also fall within the scope of protection of the present invention.

Claims

1. An elevator traction medium slip measurement device, characterized in that: For a steel - belt elevator, a laser velocimeter is used to collect the speed curve graph of the traction sheave. A speed - measuring wheel device is set at the steel - belt position. The speed - measuring wheel device is fixed on the same side of the elevator steel frame. The laser velocimeter and the speed - measuring wheel encoder are connected to the same controller through a cable. The speed - measuring device collects the traction sheave speed data and the traction medium speed data when the elevator starts and stops and runs once. For a wire - rope elevator, a speed - measuring wheel device is respectively set on the traction sheave and the wire rope. The speed - measuring wheel devices set on the traction sheave and the wire rope are fixed on the same side of the elevator steel frame. The two encoders supporting them are connected to the same controller through a cable.

2. The elevator traction medium slip amount measuring device according to claim 1, characterized in that: For a wire - rope elevator, the encoder of the speed - measuring wheel device selects the Heidenhain ERN1387 rotary encoder.

3. A device for measuring the slip amount of an elevator traction medium according to claim 1, characterized in that: For a steel - belt elevator, the laser velocimeter adopts a laser Doppler velocimeter, and the speed - measuring wheel encoder selects the Heidenhain ERN1387 rotary encoder.

4. The elevator traction medium slip amount measuring device according to claim 1, wherein: The two speed - measuring wheel devices configured on the wire - rope elevator are fixed on the same side of the elevator steel frame through magnetic bases.

5. The elevator traction medium slip amount measuring device according to claim 1, characterized in that: The laser velocimeter configured in the steel - belt elevator is fixed on the elevator steel frame by bolt connection, and the steel - belt speed - measuring wheel device is fixed on the same side of the elevator steel frame through a magnetic base.

6. The measuring method using the elevator traction medium slip - amount measuring device according to any one of claims 1 - 5 includes the following steps: Step 1: Collect the traction sheave speed data and the traction medium speed data when the elevator starts and stops and runs once through the speed - measuring device, align the speed data collected by the sensor according to time, and respectively generate corresponding speed curve graphs. Step 2: Calculate the slip of the traction medium relative to the traction sheave according to the speed curve diagram. According to the formula Calculate the running distance of the traction sheave when the elevator starts and stops once. Where: f(v1) is the speed function of the traction sheave in the elevator acceleration stage from 0 to t1; v m is the speed function of the traction sheave during the constant-speed stage of the elevator from t1 to t2; f(v2) is the speed function of the traction sheave in the elevator deceleration stage from t2 to t3; Step 3: According to the formula calculate the running distance of the traction medium when the elevator starts and stops once. Where: f(v g1 ) is the speed function of the traction medium during the elevator acceleration phase from 0 to t1; v m is the rated speed of the traction medium during the constant-speed stage of the elevator from t1 to t2; f(v g2 ) is the speed function of the traction medium during the elevator deceleration stage from t2 to t3; Step 4: Obtain the relative slip amount when the elevator starts and stops and runs once L = s y -s g Calculate the total slip amount of the elevator running once according to the above formula. The positive and negative of L represent that the slip direction of the traction medium is opposite to the rotation direction of the traction sheave.

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