JP2011144051A - System and method for measuring strength of tensile support - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a system and a method for monitoring the strength of a tensile support based on electric characteristics of the tensile support. <P>SOLUTION: This method and this system determine the probability strength of a tensile support of an elevator system by monitoring electric characteristics of the whole of a tensile support such as a total electric resistance of the tensile support, which changes with a change of the residual strength of the tensile support. One illustrative system manufactures an average deterioration map 100 by determining the relationship between deterioration in strength and various physical factors, for example, the deteriorating speed 102 relative to a given load, working environmental information 104 of the tensile support and estimated used data 106. Continuously, this average deterioration map 100 is used to manufacture one or more maps relating the deterioration in strength and the electric characteristic to each other. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to tensile support strength evaluation, and more particularly to a system and method for monitoring the strength of a tensile support based on the electrical properties of the tensile support.

  Tensile supports having metal cords such as coated steel belts and wire ropes are used to move the elevator car up and down in the elevator hoistway. Since the state of the tensile support is important for the safe operation of the elevator, it is necessary to determine the level of the residual strength of the tensile support and detect whether the level of the residual strength is below the minimum threshold.

  The strength of the tensile support can be reduced by normal operation of the elevator. The main cause of the deterioration of the strength of the tensile support is that the tensile support is periodically bent along the periphery of the pulley when the elevator moves up and down in the hoistway. Tensile support degradation is usually not uniform over the length of the tensile support, and areas with a high level of bending, i.e., significant cycles, degrade faster than areas with lower bending cycles.

  The electrical properties (such as electrical resistance and impedance) of some of the cords within the tensile support change as the cord cross-sectional area decreases. Therefore, it is theoretically possible to determine the residual strength of the support based on the electrical characteristics of the cord.

  However, as noted above, weak points on the tensile support usually depend on elevator usage (eg, speed, acceleration, jerk, etc.), elevator system layout, cord material, manufacturing variables, and other factors. Depending on the various distributions across the support, it is difficult to accurately determine when and where the tensile support has reached the minimum residual strength. Without a quantitative method to relate the electrical properties of the tensile support to the residual strength of the tensile support, electrical monitoring of the tensile support reveals that the tensile support is intact at best, or It is only broken.

  What is needed is a system and method that can quantitatively indicate the level of residual strength of a cord within a tensile support based on the electrical properties of the cord, and thus the electrical properties of the tensile support.

  The present invention is directed to a method and system that can determine strength degradation of a tensile support based on electrical properties such as electrical resistance. One exemplary system is the relationship between strength degradation and various physical factors, such as the rate of degradation for a given load, information on the tensile support operating environment, estimated usage data, or actual usage data. Etc. is obtained to obtain a map of average deterioration. This average degradation map is then one or more maps that relate strength degradation (ie, in the form of a percentage of residual strength) to electrical properties such as resistance that change with changes in the residual strength of the tensile support. Used to create. Based on these electrical property maps, electrical properties can be measured to determine when the tensile support has lost a given level of strength.

  In one embodiment, to create an electrical property map, the degradation rate of the tensile support, the relationship between electrical properties and strength degradation, variations in electrical equipment used to measure temperature and / or electrical properties are considered. The

FIG. 4 is a block diagram of a process for creating an average degradation map according to one embodiment of the present invention. FIG. 3 is a block diagram of a process for determining apparent resistance according to one embodiment of the present invention. FIG. 6 is a plot of the probability residual strength according to one embodiment of the present invention for a given increase in apparent resistance. FIG. 6 is a plot of estimated residual strength and actual usage according to another embodiment of the present invention. It is a block diagram which shows one Example of this invention.

  As described above, the strength of the tensile support depends on the cross-sectional area of the cord within the tensile support and the cord as the tensile support is bent or stretched around one or more pulleys during elevator operation. Related to the accumulation of destruction. Through experimental testing, we developed a strength loss model that relates the loss of tensile support strength to elevator operating factors such as tensile support load, pulley shape (eg, pulley diameter), and number of bending cycles. Obtainable. In other words, this model provides a relationship between the steady load and the strength degradation rate caused by the steady load.

  Since different sections of the tensile support have different rates of strength loss, it is desirable to create an average degradation map that predicts the magnitude of strength degradation in every section of the tensile support. In practice, it is almost impossible to directly identify the weakest part of the tensile support. However, because the weakened portion of the tensile support is distributed over the entire length of the tensile support in use, the resistance of the entire tensile support can accurately indicate the weakest section in the tensile support, which Defines the residual strength of the tensile support.

  FIG. 1 illustrates one method for creating an average degradation map 100. In this example, the map 100 is created based on an elevator system strength loss model 102, elevator configuration 104, and estimated elevator traffic 106 under consideration. Each of these components is described in detail below.

  To obtain the strength loss model 102, the rate of deterioration of the tensile support at a given steady load is determined experimentally. In one embodiment, bending cycles are repeatedly applied to a plurality of tensile support samples until the support sample breaks. This can be done using known fatigue test machines. The information thus obtained makes it possible to determine the statistical distribution of the number of bending cycles required for a given tensile support to break at a known steady load.

  Also, the residual strength of the tensile support is determined by the elevator configuration 104, such as the number of pulleys in the elevator system, the route selection of the tensile support around the pulley, the distance between the pulleys, and the form of the pulley. Further, when the average deterioration map is created, the estimated elevator transportation amount 106 such as the use frequency and the average passenger weight is taken into consideration. Detailed usage conditions such as the number of elevator movements between specific floors directly affect the magnitude and location of degradation of the tensile support. By taking into account the estimated elevator travel 106 and the elevator configuration 104, the number of times the pulley touches a particular section of the tensile support and the resulting tension is tracked and known. This tracking is performed by the pulley contact and load tracking algorithm 108. From this information, the wear state of a given section of the tensile support can be predicted, and thus the remaining strength of the entire tensile support can be predicted.

  The average degradation map 100 for a given elevator configuration 104 monitors the estimated elevator traffic data 106, degradation rate data 102, and the impact of the load in the region where the pulley contacts the tensile support under different loads and transport conditions. Statistical analysis can be performed by changing the data 108 to be changed. The resulting average degradation map 100 provides a statistical distribution of the strength degradation of a particular elevator system for a given steady load. In other words, the average degradation map 100 shows the range of bending cycles in which the tensile support is expected to break in some types of elevator systems.

  In order to detect the residual strength of the tensile support based on electrical properties such as electrical resistance, it is necessary to relate the information of the average degradation map 100 and the electrical properties of the tensile support, preferably in the form of an electrical property map. is there. The block diagram of FIG. 2 illustrates a process 200 according to one embodiment of the present invention, which determines the relationship between electrical resistance and residual strength.

  In order to create an electrical resistance map in this example, the degradation map 100 is first considered along with a degradation rate variation 202 that reflects the degradation rate uncertainty reflected by the map 100. The average degradation map 100 provides a range of possible values, but the range reflected in the map 100 can also vary. This is taken into account by the degradation rate variation 202 in determining the resistance map. The magnitude of the variation may be determined experimentally.

  Evaluating the degradation map 100 taking into account the degradation rate variation 202 provides a range of tensile support usage patterns and wear rates, as well as a minimum tensile support and / or maximum braking strength loss ( A range of LBS (Loss in breaking strength) 204 is given, which reflects the maximum amount the tensile support can degrade. More specifically, by taking the degradation rate variation 202 into account and detecting the point where the strength of the tensile support in the degradation map is minimized, then using this point as the maximum LBS value 204, the maximum LBS can be determined. The maximum LBS 204 indicates the point at which the tensile support breaks when subjected to extreme loads.

  This maximum LBS value 204 is related to the apparent resistance value 205. This will be described in more detail later. From the above relationship, when the apparent resistance value 205 reaches a value corresponding to the maximum LBS 204, the driver is warned that the state of the tensile support is weak.

  Note that associating the relationship between resistance and LBS for multiple tensile supports only provides a range of possible resistance values to the maximum LBS value. To obtain the relationship between the resistance value and the strength characteristics other than LBS, additional analysis is required, which will be described below.

  As described above, the loss of the tensile support cord cross-sectional area and the accumulation of cord breakage can affect the electrical properties of the tension support, such as increased resistance. In the embodiment shown in FIG. 2, the relationship between electrical resistance R and LBS is formed experimentally and analytically to provide an R vs. LBS map 206. Because the relationship between electrical resistance R and LBS can vary randomly from tension to support due to uncontrollable factors such as manufacturing variables and different material properties, process 200 can account for these irregular variations. Simulate in the variation map 208 and add this to the R vs LBS map 206.

  The modified degradation maps 100, 202 and the modified R vs LBS maps 206, 208 are combined to provide an electrical resistance map 210. The electrical resistance map 210 reflects the resistance value for a given section of the tensile support. As shown, the corresponding map points in the modified degradation maps 100, 102 and the modified R vs LBS maps 206, 208 are multiplied to obtain a resistance map 210. The total resistance of the tensile support at a given time can be calculated by summing 212 the resistance of each section of the tensile support.

  The apparent resistance of the tensile support may change due to temperature changes and variations in the electronic equipment of the elevator system. In general, the effects of temperature-dependent variation 214 and electronic device variation 216 can be determined experimentally and / or analytically. For example, the effect of temperature changes on the resistance of the tensile support can be measured, either experimentally or experimentally, and variations between electronic devices can be determined experimentally by testing. The process 200 incorporates the effect of temperature variations 214 and electronic device variations 216 on resistance values to create a resistance map that reflects the possible values of the apparent resistance 205. Alternatively, if the temperature across the tensile support is known or simulated, the temperature variation may be applied to each value in the resistance map 210 before summing 212 is performed. .

  Accordingly, the analysis shown in FIGS. 1 and 2 provides a distribution of estimated values for the minimum residual strength of the tensile support and a distribution of apparent resistance corresponding to the strength estimates. These distributions are statistically analyzed to provide a probability estimate of the residual strength of the tensile support for the selected electrical resistance.

  FIG. 3 is a graph showing the relationship that can occur between the apparent total tensile support resistance and the stochastic estimate of the residual strength of the tensile support. As shown, the greater the percentage increase in apparent resistance (shown as “DR” in FIG. 3), the lower the residual strength of the tensile support. The distribution shown in FIG. 3 shows the percentage of a tensile support having a given percentage of residual strength for a given percentage increase in apparent resistance. From this graph, it is easy to estimate the magnitude of the residual strength of the tensile support based on the amount of increase in resistance.

  In other embodiments, the average degradation map 100 used to calculate the apparent resistance and determine the intensity probability map is based on actual elevator usage data rather than simulated or recorded data. Yes. In order to obtain this embodiment, the estimated elevator traffic 106 in FIG. 1 may be replaced with actual elevator usage data.

  The actual elevator usage data may be fed intermittently to the pulley contact and load tracking algorithm 108 and thus as new data regarding elevator usage is obtained, the average degradation map 100, and thus the apparent resistance value 205 and the corresponding resistance. The map is updated intermittently. In addition to the elevator usage factors used to estimate tensile support degradation, this example considers how the elevator was actually used, passenger load, and any section of the tensile support. Taking into account the number of bending cycles and the degree of severity. Because the strength probability estimates are based on actual elevator usage, the range of residual strength level estimates obtained in this example is compared to the first example, which encompasses a wide range of potential elevator uses. Narrow.

  FIG. 4 compares the estimated residual strength value of the tensile support based on the estimated use of the elevator and the estimated residual strength value of the tensile support based on the actual use of the elevator. The actual elevator usage data provides an electrical resistance value that increases the residual strength estimate of the tensile support of a given elevator system, which allows the particular elevator system to be monitored in the elevator system safety monitoring system. It is possible to set an action threshold related to.

  FIG. 5 is a representative block diagram of a system for estimating tensile support strength as described above. In general, the system 300 preferably includes at least one electrical property measurement device that monitors a tensile support, such as an ohmmeter 302, and a temperature measurement device 303 that monitors the environment of the tensile support. The system 300 also includes a processor 304 that creates the aforementioned map from the measured electrical and temperature characteristics and determines the residual strength of the tensile support. The particular components used in system 300 can be selected by those skilled in the art.

  By measuring the strength of the tensile support based on electrical properties such as electrical resistance, the present invention monitors the residual strength level of the tensile support, detects the minimum residual strength level, and if desired Encourage action based on the residual intensity level. While the above-described embodiments are directed to tensile supports such as coated steel belts used in elevator applications, the present invention can be applied to any structure having electrical properties that vary based on the strength of the tensile support. It may be used to monitor body strength. Furthermore, although the above-described embodiments are directed to resistance that correlates with residual strength, other electrical characteristics may be monitored and used. The present invention may be implemented in a known manner using desired parts. One skilled in the art will understand the equipment necessary to obtain electrical property data, obtain simulation data, and create a program that can implement the present invention in, for example, a processor.

  Obviously, various alternatives to the described embodiments of the invention may be used to implement the invention. The appended claims are intended to define the scope of the invention and to encompass the methods and apparatus within the scope of the claims.

Claims (24)

A method for modeling the state of an elevator tension support,
Determining the rate of deterioration of the tensile support for a selected load;
Modeling the configuration of at least one selected elevator system;
Estimating the transportation pattern of the elevator,
Determining pulley contact and load information using the determined degradation rate, the modeled configuration, and the estimated transport pattern;
Determining the average degradation of the tensile support from the determined pulley contact and load information;
A method for modeling the state of an elevator tension support comprising:   The method of claim 1, comprising determining a plurality of average degradation values by changing at least one of the modeled configuration and the estimated elevator transport pattern.   Determination to determine the relationship between the electrical properties of the tensile support and the selected state of the tensile support and to determine the apparent electrical property value corresponding to the selected state of the tensile support The method of claim 1 including using the determined relationship and the determined average degradation.   The steps of claim 3 are repeatedly performed to determine a plurality of said apparent electrical property values and said plurality of apparent electrical properties to determine a relationship between the corresponding measured electrical property and the state of the tensile support. 4. The method of claim 3, comprising using characteristic values.   The method of claim 4, wherein the electrical property is resistance.   Subsequently measuring the resistance of the tensile support and using the determined relationship between the resistance and the selected state of the tensile support to determine the current state of the tensile support. 5. The method according to 5. Creating a first map from the determined average degradation;
Creating a second map that relates electrical characteristics to the selected degree of strength degradation;
Combining the first and second maps to create a third map relating the electrical properties and the residual strength of the tensile support;
The method of claim 1 comprising:   The method of claim 7, wherein creating the first map includes incorporating at least one tensile support actuation factor and the strength loss model.   9. The method of claim 8, wherein the at least one tensile support operating factor is selected from the group consisting of elevator system configuration, estimated elevator traffic, actual elevator usage, and pulley contact.   The operating factor of the at least one tensile support is the actual elevator usage, and the step of creating the first map repeats the relating step based on the updated actual elevator usage. 10. The method of claim 9, further comprising: The combining step comprises:
Creating an intermediate map associating the electrical properties with the residual strength of one segment of the tensile support, wherein the tensile support comprises an intermediate map comprising a plurality of segments; ,
Summing the residual strengths of the plurality of segments to create the third map;
The method of claim 7 comprising:   8. The method of claim 7, comprising incorporating a degradation rate variation factor into the first map.   8. The method of claim 7, comprising incorporating an electrical property variation factor into the second map.   8. The method of claim 7, including incorporating at least one of a temperature-related variation factor and an electronic device variation factor to create the third map.   The method of claim 7, wherein the electrical property is resistance. A system for determining the state of an elevator tension support,
An apparatus for measuring electrical properties of at least one portion of the tensile support;
A controller that determines the current state of the tensile support by associating the measured property with a predetermined data set indicating a relationship between a corresponding apparent property value and the state of the tensile support;
A system for determining the state of an elevator tension support. The control device is
Determining the rate of deterioration of the tensile support for a selected load;
Modeling the configuration of at least one selected elevator system;
Estimate elevator transportation patterns,
Determine pulley contact and load information using the determined degradation rate, modeled configuration, and estimated transport pattern,
17. The system of claim 16, wherein the average degradation of the tensile support is determined from the determined pulley contact and load information.   The controller is determined to determine a relationship between an electrical property and a selected state of the tensile support and to determine an apparent electrical property value corresponding to the selected state of the tensile support. 18. The system of claim 17, wherein said relationship and determined average degradation are used.   The controller determines the plurality of apparent electrical property values and uses the plurality of apparent electrical property values to determine a relationship between the corresponding measured electrical property and the state of the tensile support. 19. A system according to claim 18 characterized in that   The system of claim 16, wherein the electrical property is resistance. A control device useful for determining the state of an elevator tension support,
Creating a program to determine the rate of degradation of the tensile support for a selected load;
Modeling the configuration of at least one selected elevator system;
Estimating the transportation pattern of the elevator,
Determining pulley contact and load information using the determined degradation rate, the modeled configuration, and the estimated transport pattern;
Determining the average degradation of the tensile support from the determined pulley contact and load information;
A control device useful for determining the state of an elevator tension support including:   The control device according to claim 21, further comprising: creating a program to determine a plurality of average deterioration values by changing at least one of the modeled configuration or the estimated elevator transportation pattern.   The determined relationship and determined to determine a relationship between an electrical property and a selected state of the tensile support and to determine an apparent electrical property value corresponding to the selected state of the tensile support. 23. The control device of claim 21, comprising creating a program to use the average degradation.   Determining a plurality of the apparent electrical property values and creating a program to use the apparent electrical property values to determine a relationship between the corresponding measured electrical property and the state of the tensile support. 24. The control device according to claim 23.

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