Elevator brake fault detection system and method based on multiple sensors

Abstract

The embodiment of the invention provides an elevator brake fault detection system and method based on multiple sensors, and is applied to the technical field of fault detection. The system comprises a sensor module, a data processing module, a brake operation analysis module, an alarm module and a brake fatigue life analysis module which are connected in sequence, the sensor module is used for collecting elevator operation data; the data processing module is used for processing the elevator operation data and calculating to obtain elevator downlink operation parameters; the brake operation analysis module is used for analyzing and judging the operation state of the elevator brake according to the elevator descending operation parameters; the alarm module is used for giving an alarm for the brake with poor operation performance according to the analysis and judgment result; and the brake fatigue life analysis module is used for performing fatigue life analysis on the brake. In this way, the sensors can be comprehensively utilized, comprehensive detection of the elevator brake is achieved, potential faults are found in time, and safe operation of an elevator is guaranteed.

Description

Technical Field

[0001] The present application relates to the technical field of fault detection, and in particular to a multi-sensor based elevator brake fault detection system and method. Background Art

[0002] With the increasing number of high-rise buildings, the use of elevators is becoming more and more widespread. The performance of elevator brake components is directly related to the safe operation of elevators. Traditional detection methods often rely on manual regular inspections, which are not only inefficient and cause serious damage to elevators, but also prone to missed inspections and misjudgments.

[0003] With the increasing frequency of elevator use and the diversification of operating environments, in order to ensure the stability and safety of elevator operation, there is an urgent need for a more intelligent, efficient and accurate elevator brake component detection technology. Summary of the invention

[0004] The present application provides an elevator brake fault detection system and method based on multiple sensors, which solves the technical problems that existing manual inspections of elevator brake components lead to serious damage to the elevator, low efficiency, and impact on elevator safety and reliability.

[0005] According to a first aspect of the present application, there is provided an elevator brake fault detection system based on a multi-sensor, comprising a sensor module, a data processing module, a brake operation analysis module, an alarm module and a brake fatigue life analysis module connected in sequence;

[0006] The sensor module is used to collect elevator operation data and transmit it to the data processing module for processing;

[0007] The data processing module is used to process the elevator operation data and calculate the elevator down operation parameters;

[0008] The brake operation analysis module is used to analyze and judge the elevator brake operation state according to the elevator downward operation parameters calculated by the data processing module;

[0009] The alarm module is used to give an alarm prompt to the brake with poor operating performance according to the analysis and judgment result of the brake operation analysis module;

[0010] The brake fatigue life analysis module is used to perform fatigue life analysis on the brake with poor operating performance.

[0011] According to the above aspects and any possible implementation, there is further provided an implementation, wherein the sensor module includes a gravity sensor, a pressure sensor, and a speed sensor;

[0012] The gravity sensor is installed in the bottom frame of the elevator car and is used to measure the gravity on the elevator to obtain gravity data;

[0013] The pressure sensor is installed between the brake arm and brake shoe of the elevator brake and is used to measure the pressure value when the elevator is braked;

[0014] The speed sensor is installed on the elevator traction wheel and is used to measure the running speed and running time of the elevator.

[0015] According to the above aspects and any possible implementation, a further implementation is provided, wherein the elevator down operation parameter includes the elevator down total energy E t , braking force F and pressure and time value W.

[0016] According to a second aspect of the present application, a multi-sensor based elevator brake fault detection method is provided, comprising the following steps:

[0017] Collect and process elevator operation data to calculate the elevator down-running parameters;

[0018] Analyze and judge the elevator brake operation state according to the elevator downward operation parameters, obtain the brake with poor operation performance and issue an alarm prompt;

[0019] A fatigue life analysis is performed on the brake with poor operating performance, and the brake is repaired or replaced according to the analysis result.

[0020] According to the above aspects and any possible implementation, an implementation is further provided, wherein the process of collecting and processing elevator operation data and calculating the elevator down operation parameters is as follows:

[0021] Obtaining the downward gravity value of the elevator, the elevator descending height, the pressure on the elevator, the duration of the pressure, the elevator speed and the braking time according to the sensor module;

[0022] The kinetic energy and potential energy of the elevator when it is descending are calculated according to the downward gravity value of the elevator and the descending height of the elevator, and the total energy E of the elevator when it is descending is calculated. t ;

[0023] The braking force F of the elevator brake is calculated according to the elevator speed and the braking time;

[0024] The elevator pressure and time value W are calculated based on the pressure on the elevator and the duration of the pressure.

[0025] According to the above aspects and any possible implementation, an implementation is further provided, wherein the process of analyzing and judging the elevator brake operation state according to the elevator downward operation parameters, obtaining the brake with poor operation performance and issuing an alarm prompt is:

[0026] Collect the total energy E of the two groups t As well as the pressure and time value W data, the Pearson product moment calculation was used to obtain two sets of correlation coefficients r1 and r2;

[0027] The two sets of data are mixed and the correlation coefficient r3 is calculated using the Pearson product moment;

[0028] If the values ​​of r1 and r2 are closer to 1, it is judged that the elevator brake is operating stably;

[0029] If r3 is less than 1 and less than r1 and r2, it is determined that the elevator brake is operating poorly.

[0030] According to the above aspects and any possible implementation, an implementation is further provided, wherein the process of analyzing and judging the elevator brake operation state according to the elevator downward operation parameters, obtaining the brake with poor operation performance and issuing an alarm prompt may also be:

[0031] Collect two sets of braking force F and pressure and time value W data, and use Pearson product moment calculation to obtain two sets of correlation coefficients r1′ and r2′;

[0032] The two sets of data are mixed and the correlation coefficient r3′ is obtained by using Pearson product moment calculation;

[0033] If the values ​​of r1′ and r2′ are closer to 1, it is judged that the elevator brake is operating stably;

[0034] If r3′ is less than 1 and less than r1′ and r2′, it is determined that the elevator brake is operating poorly.

[0035] According to the above aspects and any possible implementation, an implementation is further provided, wherein the process of performing fatigue life analysis on the brake with poor operating performance and repairing or replacing the brake according to the analysis result is:

[0036] Collecting elevator performance parameters, and calculating elevator dynamic parameters based on the performance parameters;

[0037] Simulate and model the brake based on the thermal-structural coupling theory and draw the strain curve;

[0038] According to the elevator dynamics parameters and the strain curve, the thermal fatigue life of the brake is predicted using the Manson-Coffin formula to calculate the thermal fatigue life of the brake with poor operating performance;

[0039] The brake performance is evaluated based on the thermal fatigue life and the standard brake life of the brake, and the brake is repaired or replaced.

[0040] According to the above aspects and any possible implementation, an implementation is further provided, wherein the process of predicting the thermal fatigue life of the brake using the Manson-Coffin formula based on the elevator dynamics parameters and the strain curve to calculate the thermal fatigue life of the brake with poor operating performance is:

[0041] The total strain ε is calculated according to the elevator dynamic parameters:

[0042]

[0043] Among them, ε is the total strain, E is the elastic modulus of the material, and p′ is the equivalent pressure of the brake pad of the elevator brake;

[0044] Calculate the thermal fatigue life N of the brake wheel according to the total strain ε f :

[0045]

[0046] in, is the total strain amplitude, calculated from the total strain ε, is the elastic strain amplitude, is the plastic strain amplitude, N f is the number of stress cycles to failure, σ′ f is the fatigue strength coefficient, b is the fatigue strength index, c is the fatigue ductility index, ε r ′ is the fatigue ductility coefficient;

[0047] Based on the thermal fatigue life N f According to the linear fatigue cumulative damage theory, the thermal fatigue life N′ of the brake wheel during emergency braking is calculated as follows:

[0048]

[0049] Where N' is the thermal fatigue life of the brake wheel during emergency braking, N fi is the thermal fatigue life.

[0050] According to the above aspects and any possible implementation, an implementation is further provided, wherein the process of evaluating the brake performance according to the thermal fatigue life of the brake with poor operating performance and the standard braking life of the brake and repairing or replacing the brake is as follows:

[0051] Obtaining a standard brake life of the brake and setting a proportional value to obtain a brake performance evaluation index value, and comparing the thermal fatigue life of the brake with poor operating performance with the evaluation index value;

[0052] If the thermal fatigue life of the brake with poor operating performance is greater than or equal to the evaluation index value, it is determined that the brake is operating normally and repairs are performed;

[0053] If the thermal fatigue life of the brake with poor operating performance is less than the evaluation index value, the brake is judged to be operating abnormally and has no repair value, and is replaced.

[0054] The present invention discloses the following technical effects:

[0055] The present invention realizes comprehensive, real-time and accurate detection of elevator brakes by utilizing pressure sensors, gravity sensors and speed sensors, timely discovers potential faults and ensures safe operation of the elevator. At the same time, the present invention combines thermal-structural coupling theory to simulate and model the brakes, draws strain curves, and uses the Manson-Coffin formula to predict the thermal fatigue life of the brakes, thereby realizing life prediction for faulty brakes, timely replacement of low-life brakes, and repair of long-life brakes, which can better reduce costs and improve the safety of elevator operation.

[0056] It should be understood that the contents described in the Summary of the Invention are not intended to limit the key or important features of the embodiments of the present application, nor are they intended to limit the scope of the present application. Other features of the present application will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] The above and other features, advantages and aspects of the embodiments of the present application will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. The accompanying drawings are used to better understand the present solution and do not constitute a limitation of the present application. In the accompanying drawings, the same or similar reference numerals represent the same or similar elements, among which:

[0058] Figure 1 A schematic structural diagram of an elevator brake fault detection system based on multiple sensors according to an embodiment of the present application is shown;

[0059] Figure 2 A schematic flow chart of a method for detecting elevator brake faults based on multiple sensors according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0060] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0061] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0062] Please refer to Figure 1 As shown, this embodiment provides an elevator brake fault detection system based on multiple sensors, including a sensor module 1, a data processing module 2, a brake operation analysis module 3, an alarm module 4 and a brake fatigue life analysis module 5 connected in sequence;

[0063] The sensor module 1 is used to collect elevator operation data and transmit it to the data processing module 2 for processing; the data processing module 2 is used to process the elevator operation data and calculate the elevator downward operation parameters; the brake operation analysis module 3 is used to analyze and judge the elevator brake operation status according to the elevator downward operation parameters calculated by the data processing module 2; the alarm module 4 is used to alarm the brake with poor operating performance according to the analysis and judgment results of the brake operation analysis module 3; the brake fatigue life analysis module 5 is used to perform fatigue life analysis on the brake with poor operating performance.

[0064] This embodiment, through the comprehensive use of pressure sensors, gravity sensors, and speed sensors, realizes comprehensive, real-time, and accurate detection of elevator brakes, timely discovers potential faults, and ensures the safe operation of the elevator.

[0065] In a further embodiment, specifically, the sensor module 1 is connected to the data processing module 2, and the elevator operation data is collected and transmitted to the data processing module 2 for processing; the sensor module 1 specifically includes a gravity sensor 11, a pressure sensor 12, and a speed sensor 13;

[0066] Among them, the gravity sensor 11 is installed in the bottom frame of the elevator car to measure the gravity of the elevator. When installing the gravity sensor, it should be ensured that the sensor can evenly bear the weight of the car;

[0067] The pressure sensor 12 is installed between the brake arm and the brake shoe of the elevator brake and is used to measure the pressure value when the elevator is braked;

[0068] The speed sensor 13 is installed on the elevator traction wheel and is used to measure the running speed and running time of the elevator.

[0069] The data processing module 2 receives and processes the measurement data of the sensor module 1, and calculates the total energy, braking force and pressure value when the elevator is descending.

[0070] Specifically, the total energy includes the kinetic energy and potential energy of the elevator when it is descending. The elevator load is obtained by receiving the gravity value measured by the gravity sensor 11, and the elevator speed is obtained by the speed sensor 13, and the kinetic energy E of the elevator when it is descending is calculated. k :

[0071]

[0072] Among them, m is the load of the elevator car, and v is the speed of the elevator;

[0073] Its potential energy E p It can be calculated by the following formula:

[0074] E p =mgh (2)

[0075] Wherein, g is the acceleration due to gravity, and h is the height to which the elevator descends, obtained by the speed sensor 13;

[0076] The braking force F is calculated by mass m and acceleration a, where acceleration a is calculated according to the following formula:

[0077]

[0078] Among them, v is the speed at the beginning of braking, which is obtained by the speed sensor 13, and t is the braking time, which is obtained by the speed sensor 13.

[0079] The pressure and time value W (the pressure change value during the entire braking process multiplied by the change time period) collected by the pressure sensor 12 is calculated by the following formula:

[0080] W=p1t1+p2t2+p3t3+…+p n t n (4)

[0081] Among them, p i It is the pressure on the elevator, obtained through the pressure sensor 12. Each time the pressure changes, it is accumulated until the braking ends.

[0082] The brake performance analysis module 3 is connected to the data analysis module 2 and is used to analyze and judge the elevator brake performance according to the calculation results of the data analysis module 2.

[0083] Specifically, first calculate the total energy E of the elevator each time it stopst The pressure sensor is subjected to pressure and time value W, and the specific E t =E k +E p .

[0084] Collect two groups of E and W data, each group has 100 times, where the first group is the current 100 recent braking data n1, and the second group is the braking data 100 days ago n2, x1 is E t , y1 is W;

[0085] The correlation coefficient is calculated using the Pearson product moment formula:

[0086]

[0087] Where n1, n2 are the number of data points.

[0088] Calculate the first set of 100 data points using the formula to get r1;

[0089] Calculate the second set of 100 points of data using the formula to get r2;

[0090] After the calculation is completed, the two sets of data are mixed into 200 points and sorted in positive order of x to obtain n3, and the value r3 is calculated by formula (7);

[0091]

[0092] The correlation coefficient r ranges from -1 to 1. When r = 1, it indicates a completely positive correlation. As x1 increases, y1 also increases, and they show a strict linear relationship. The closer r is to 1, the stronger the correlation is, and the closer it is to 0, the weaker the correlation is.

[0093] Specifically, in this embodiment, the closer the values ​​of r1 and r2 are to 1, the greater the total energy E t The stronger the correlation between the pressure sensor 12 and the time value W, the more stable the elevator brake is.

[0094] When r3 is smaller than 1, and significantly smaller than r1 and r2, the braking power of the brake is decreasing and the performance is getting worse, and an alarm signal is issued.

[0095] Secondly, the braking force F of the elevator stop brake and the collected data of the pressure and time value W received by the pressure sensor are analyzed each time.

[0096] Collect two groups of F and W data, each group has 100 times, of which the first group is the current 100 braking data, and the second group is the braking data 100 days ago, x2 is F, y2 is W;

[0097] The correlation coefficient is calculated using the same Pearson product moment method as above, and three sets of correlation coefficients r1′, r2′, and r3′ are calculated. The value range of the correlation coefficient r is between -1 and 1:

[0098] When the values ​​of r1′ and r2′ are closer to 1, the correlation between the braking force F and the pressure and time value W received by the pressure sensor 12 is stronger, indicating that the brake is operating stably.

[0099] When r3′ is significantly smaller than r1′ and r2′, it indicates that the performance of the brake has deteriorated and an alarm signal is issued.

[0100] The alarm signal sent by the brake performance analysis module 3 is transmitted to the alarm module 4, which then sends out an alarm message. The brake fatigue analysis module 5 performs fatigue analysis and calculates the fatigue life of the abnormal performance brake.

[0101] Specifically, after performing the elevator braking performance analysis, the fatigue damage of the elevator brake with deteriorated performance is calculated to determine the braking performance of the elevator brake and the degree of maintenance required.

[0102] Specifically, first, this embodiment uses dynamic analysis to analyze the emergency braking process of the elevator brake to obtain dynamic analysis parameters of the elevator braking pressure, brake equivalent moment of inertia, and braking time;

[0103] The obtained kinetic analysis is specifically shown as follows:

[0104]

[0105] Among them, p' is the equivalent pressure of the brake pad of the elevator brake, T is the rated torque, f is the friction coefficient, r4 is the inner ring radius of the brake pad, d is the width of the brake pad, R1 is the outer ring radius of the brake wheel, and W is the pressure and time value.

[0106] Then the moment of inertia of the elevator braking system is calculated, specifically:

[0107]

[0108] Where I is the equivalent moment of inertia of the braking system, m1 is the weight of the brake wheel, and m is the weight of the car. is the balance coefficient, and i is the elevator traction ratio.

[0109] Finally, the braking time t is calculated as:

[0110]

[0111] Among them, ω0 is the rated speed and a is the acceleration.

[0112] After calculating the dynamic analysis parameters, the thermal-structural coupling theory is used to simulate the brake model and draw the strain curve.

[0113] Specifically, this embodiment uses transient finite element analysis to establish a three-dimensional temperature field model of the brake, specifically:

[0114]

[0115] Among them, r z , θ, z are the temperature field coordinates in the three-dimensional x, y, and z directions of space, λ is the thermal conductivity, ρ is the density, c is the specific heat capacity, T′ is the temperature, and t is the braking time.

[0116] When t=0, the distribution state of the temperature field is:

[0117] T′(r,θ,z,0)=T0 (12)

[0119] The brake wheel and friction area of ​​the elevator brake generate heat energy which is dissipated into the air through heat conduction and heat convection in the axial, radial and axial planes. Therefore, the thermal convection boundary conditions between the area and the surrounding environment are:

[0120] (13)

[0122] Where q is the free interface temperature, T0 is the ambient temperature, N is the unit external normal vector of the interface, and h c is the convection exchange coefficient.

[0123] The strain field curve of the brake is obtained according to the above model, and the thermal fatigue life of the brake is predicted using the Manson-Coffin formula.

[0124] Specifically, in the case of emergency braking, the thermal fatigue life of the brake wheel is calculated by the following formula:

[0125]

[0126] in, is the total strain amplitude, calculated from the total strain ε, is the elastic strain amplitude, is the plastic strain amplitude, N f is the number of stress cycles to failure, σ′ f is the fatigue strength coefficient, b is the fatigue strength index, c is the fatigue ductility index, ε r ′ is the fatigue ductility coefficient.

[0127] The total strain is then calculated as:

[0128]

[0129] Among them, ε is the total strain, E is the elastic modulus of the material, and p′ is the equivalent pressure of the brake pad of the elevator brake.

[0130] In the embodiment of the present invention, the total strain ε refers to the total strain accumulated over a period of time under emergency braking conditions, and the total strain amplitude refers to the maximum range or amplitude of strain change, that is, the range of strain change from the minimum value to the maximum value (i.e., amplitude). To calculate it, it is necessary to know how the strain changes over time (or during the loading process). Specifically, a complete record of the change of strain over time (or other related variables) can be obtained through experimental measurement or numerical simulation. Determine the strain range: Find the minimum value of the strain (ε) during the entire recording period. min ) and the maximum value (ε max ).

[0131] Alternatively, the total strain amplitude can be calculated by using the following formula: max -ε min .

[0132] Furthermore, the strain is calculated by equation (15) and the thermal fatigue life of the brake wheel is obtained by equation (14), that is, N f .

[0133] According to the linear fatigue cumulative damage theory, it is calculated that:

[0134]

[0135] Based on the calculated thermal fatigue life of the brake wheel, the thermal fatigue life N′ of the brake wheel during emergency braking is calculated.

[0136] Calculate the thermal fatigue life of brakes with poor stability and evaluate brake performance based on the brake's standard braking life.

[0137] like Figure 2 As shown, this embodiment also provides an elevator brake fault detection method based on multiple sensors, comprising the following steps:

[0138] S101, collecting and processing elevator operation data, and calculating and obtaining elevator downward operation parameters;

[0139] S102, analyzing and judging the elevator brake operation state according to the elevator downward operation parameters, obtaining the brake with poor operation performance and giving an alarm prompt;

[0140] S103. Perform fatigue life analysis on brakes with poor operating performance, and repair or replace the brakes based on the analysis results.

[0141] Specifically, the standard braking life of the brake is obtained and a proportional value is set to obtain a brake performance evaluation index value, and the thermal fatigue life of the brake with poor operating performance is compared with the evaluation index value; in this embodiment, the standard braking life of the brake is the fatigue life of the brake before use. Since fatigue life analysis of the brake with poor braking performance is required in this embodiment, the value of half of the standard braking life of the brake is uniformly set as the brake performance evaluation index value in this embodiment, and the thermal fatigue life is compared and judged by this value;

[0142] If the thermal fatigue life of the brake with poor operating performance is greater than or equal to the evaluation index value, the brake is judged to be operating normally and repairs are performed;

[0143] If the thermal fatigue life of a brake with poor operating performance is less than the evaluation index value, the brake is judged to be operating abnormally, has no repair value, and is replaced.

[0144] It should be noted that, for the aforementioned method embodiments, for the sake of simplicity, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the described order of actions, because according to the present application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all optional embodiments, and the actions and modules involved are not necessarily required by the present application.

[0145] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps recorded in this application can be executed in parallel, sequentially or in different orders, as long as the expected results of the technical solution disclosed in this application can be achieved, and this document is not limited here.

[0146] The above specific implementations do not constitute a limitation on the protection scope of this application. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principles of this application should be included in the protection scope of this application.

Claims

1. An elevator brake fault detection system based on multiple sensors, characterized in that: It comprises a sensor module (1), a data processing module (2), a brake operation analysis module (3), an alarm module (4) and a brake fatigue life analysis module (5) which are connected in sequence; The sensor module (1) is used to collect elevator operation data and transmit it to the data processing module (2) for processing; The data processing module (2) is used to process the elevator operation data and calculate the elevator down-running parameters; The brake operation analysis module (3) is used to analyze and judge the elevator brake operation state according to the elevator downward operation parameters calculated by the data processing module (2); The alarm module (4) is used to issue an alarm prompt to a brake with poor operating performance according to the analysis and judgment result of the brake operation analysis module (3); The brake fatigue life analysis module (5) is used to perform fatigue life analysis on the brake with poor operating performance.

2. The multi-sensor based elevator brake fault detection system according to claim 1, characterized in that: The sensor module (1) comprises a gravity sensor (11), a pressure sensor (12), and a speed sensor (13); The gravity sensor (11) is installed in the bottom frame of the elevator car and is used to measure the gravity exerted on the elevator to obtain gravity data; The pressure sensor (12) is installed between the brake arm and the brake shoe of the elevator brake and is used to measure the pressure value when the elevator is braked; The speed sensor (13) is installed on the elevator traction wheel and is used to measure the running speed and running time of the elevator.

3. The multi-sensor based elevator brake fault detection system according to claim 2, characterized in that: The elevator down operation parameters include the total energy E of the elevator down t , braking force F and pressure and time value W.

4. A method for detecting a fault of an elevator brake based on a multi-sensor, implemented by using the system for detecting a fault of an elevator brake based on a multi-sensor as claimed in claim 3, characterized in that: The following steps are involved: Collect and process elevator operation data to calculate the elevator down-running parameters; Analyze and judge the elevator brake operation state according to the elevator downward operation parameters, obtain the brake with poor operation performance and issue an alarm prompt; A fatigue life analysis is performed on the brake with poor operating performance, and the brake is repaired or replaced according to the analysis result.

5. The elevator brake fault detection method based on multiple sensors according to claim 4 is characterized in that: The process of collecting and processing the elevator operation data and calculating the elevator down-running parameters is as follows: Obtaining the downward gravity value of the elevator, the descending height of the elevator, the pressure on the elevator, the duration of the pressure, the speed of the elevator and the braking time according to the sensor module (1); The kinetic energy and potential energy of the elevator when it is descending are calculated according to the downward gravity value of the elevator and the descending height of the elevator, and the total energy E of the elevator when it is descending is calculated. t ; The braking force F of the elevator brake is calculated according to the elevator speed and the braking time; The elevator pressure and time value W are calculated based on the pressure on the elevator and the duration of the pressure.

6. The elevator brake fault detection method based on multiple sensors according to claim 5 is characterized in that: The process of analyzing and judging the elevator brake operation state according to the elevator downward operation parameters, obtaining the brake with poor operation performance and giving an alarm prompt is as follows: Collect the total energy E of the two groups t As well as the pressure and time value W data, the Pearson product moment calculation was used to obtain two sets of correlation coefficients r1 and r2; The two sets of data are mixed and the correlation coefficient r3 is calculated using the Pearson product moment; If the values ​​of r1 and r2 are closer to 1, it is judged that the elevator brake is operating stably; If r3 is less than 1 and less than r1 and r2, it is determined that the elevator brake is operating poorly.

7. The elevator brake fault detection method based on multiple sensors according to claim 5 is characterized in that: The process of analyzing and judging the elevator brake operation state according to the elevator downward operation parameters, obtaining the brake with poor operation performance and giving an alarm prompt may also be: Collect two sets of braking force F and pressure and time value W data, and use Pearson product moment calculation to obtain two sets of correlation coefficients r1′ and r2′; The two sets of data are mixed and the correlation coefficient r3′ is obtained by using Pearson product moment calculation; If the values ​​of r1′ and r2′ are closer to 1, it is judged that the elevator brake is operating stably; If r3′ is less than 1 and less than r1′ and r2′, it is determined that the elevator brake is operating poorly.

8. The multi-sensor based elevator brake fault detection method according to claim 4, characterized in that: The process of performing fatigue life analysis on the brake with poor running performance and repairing or replacing the brake according to the analysis result is as follows: Collecting elevator performance parameters, and calculating elevator dynamic parameters based on the performance parameters; Simulate and model the brake based on the thermal-structural coupling theory and draw the strain curve; According to the elevator dynamics parameters and the strain curve, the thermal fatigue life of the brake is predicted using the Manson-Coffin formula to calculate the thermal fatigue life of the brake with poor operating performance; The brake performance is evaluated based on the thermal fatigue life and the standard brake life of the brake, and the brake is repaired or replaced.

9. The elevator brake fault detection method based on multiple sensors according to claim 8, characterized in that: The process of predicting the thermal fatigue life of the brake using the Manson-Coffin formula according to the elevator dynamics parameters and the strain curve and calculating the thermal fatigue life of the brake with poor operating performance is as follows: The total strain ε is calculated according to the elevator dynamic parameters: Among them, ε is the total strain, E is the elastic modulus of the material, and p′ is the equivalent pressure of the brake pad of the elevator brake; Calculate the thermal fatigue life N of the brake wheel according to the total strain ε f : in, is the total strain amplitude, calculated from the total strain ε, is the elastic strain amplitude, is the plastic strain amplitude, N f is the number of stress cycles to failure, σ′ f is the fatigue strength coefficient, b is the fatigue strength index, c is the fatigue ductility index, ε r ′ is the fatigue ductility coefficient; Based on the thermal fatigue life N f According to the linear fatigue cumulative damage theory, the thermal fatigue life N′ of the brake wheel during emergency braking is calculated as follows: Where N' is the thermal fatigue life of the brake wheel during emergency braking. is the thermal fatigue life.

10. The elevator brake fault detection method based on multiple sensors according to claim 9, characterized in that: The process of evaluating the brake performance according to the thermal fatigue life of the brake with poor running performance and the standard braking life of the brake and repairing or replacing the brake is as follows: Obtaining a standard brake life of the brake and setting a proportional value to obtain a brake performance evaluation index value, and comparing the thermal fatigue life of the brake with poor operating performance with the evaluation index value; If the thermal fatigue life of the brake with poor operating performance is greater than or equal to the evaluation index value, it is determined that the brake is operating normally and repairs are performed; If the thermal fatigue life of the brake with poor operating performance is less than the evaluation index value, the brake is judged to be operating abnormally and has no repair value, and is replaced.

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