Evaluation method for full-load braking performance of escalator

Abstract

The invention belongs to the technical field of escalators, and relates to an escalator full-load braking performance evaluation method, which comprises the following steps of: firstly, establishing an initial equivalent conversion relation between a no-load braking distance and a full-load braking distance based on braking test data of escalators of the same model under no-load and full-load working conditions; secondly, key assemblies participating in braking energy dissipation in the escalator are recognized, equivalent friction coefficients of the key assemblies under the no-load working condition and the full-load working condition are analyzed, a correction factor is generated based on the difference of the equivalent friction coefficients under the no-load working condition and the full-load working condition, and the initial equivalent conversion relation is corrected; and finally, the no-load braking distance of the target escalator in the current state is obtained, the full-load braking distance of the target escalator is predicted based on the corrected equivalent conversion relation, the service state information of the target escalator is brought into safety conformity evaluation of a prediction result, and the prediction precision and reliability of the full-load braking distance are effectively improved.

Description

Technical Field

[0001] This invention belongs to the field of escalator technology and relates to a method for evaluating the braking performance of escalators under full load. Background Technology

[0002] As an important vertical transportation tool in public places, the reliability of the braking performance of escalators is directly related to passenger safety. The quality of this performance under full load conditions is primarily reflected in whether the stopping distance meets safety standards. Therefore, accurately evaluating the braking distance of escalators under full load conditions is a crucial aspect of special equipment safety inspection.

[0003] Currently, existing technical solutions in this field are mainly divided into two categories: the first category is direct testing methods, such as the automatic motion capture method and device for escalators disclosed in Chinese Patent Publication No. CN108975119A. This method detects the motor's current value and the distance between the motor and a preset reference point in real time. It determines the braking start point by the continuous decrease in current and records a first distance value, and determines the stopping point by the distance change being less than a threshold and records a second distance value. The stopping distance is obtained by calculating the difference between the two values. This method can accurately test the stopping distance of an escalator under full load, and is simple and reliable to operate.

[0004] The second category is a relatively improved indirect testing method. For example, a method for measuring the stopping distance of an escalator published in Chinese Patent Publication No. CN112320550B collects parameters such as speed, power and average deceleration by sequentially performing no-load operation, no-load braking without braking, no-load braking with braking and a light-load braking test. These parameters are then substituted into the stopping distance conversion formula to calculate the full-load stopping distance, avoiding the use of a large number of weights and saving manpower and resources.

[0005] However, existing technologies, especially the calculation methods represented by the measurement method for stopping distance of escalators published in Chinese Patent Publication No. CN112320550B, still have the following limitations: 1. Existing technologies rely on fixed physical formulas to calculate the braking distance under full load. Their underlying logic implicitly assumes that the equivalent friction characteristics of the entire braking system of the escalator remain unchanged under no-load, light-load and full-load conditions. However, in reality, the friction behavior of key components such as brakes, step chains and guide rails will change nonlinearly with factors such as load pressure. Ignoring the differences in friction coefficients under different working conditions can easily lead to increased calculation errors, resulting in a fundamental limitation on the universality and accuracy of fixed physical formulas.

[0006] 2. Existing technologies only extrapolate based on instantaneous parameters from a single test, lacking consideration of the service status of different escalators, and cannot distinguish the differences in braking performance baselines between new and old equipment of the same model. The evaluation results lack individual adaptability and forward-looking warning capabilities, and may lead to the risk of missed or incorrect judgments.

[0007] 3. Existing technologies lack consistency criteria for no-load and full-load braking dynamic response based on synchronous comparative tests, as well as kinematic physical constraint tolerance criteria, resulting in a lack of physical basis for equivalent transformation relationships and weak reliability and interpretability. Summary of the Invention

[0008] In view of this, in order to solve the problems mentioned in the background technology, a method for evaluating the braking performance of escalators under full load is proposed.

[0009] The objective of this invention can be achieved through the following technical solution: This invention provides a method for evaluating the braking performance of escalators under full load, comprising: establishing an initial equivalent conversion relationship between the braking distance under no-load and full-load conditions based on braking test data of the same model of escalator under no-load and full-load conditions.

[0010] The key components involved in the dissipation of braking energy in the escalator are identified, and the equivalent friction coefficients of the key components under no-load and full-load conditions are analyzed. Based on the difference in the equivalent friction coefficients under no-load and full-load conditions, a correction factor is generated to correct the initial equivalent transformation relationship, and the corrected equivalent transformation relationship is obtained.

[0011] Obtain the no-load braking distance of the target escalator in its current state, predict the full-load braking distance of the target escalator based on the corrected equivalent transformation relationship, and conduct a safety compliance evaluation based on the prediction results.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The present invention sets up a dual verification mechanism. Only when the physical constraint tolerance judgment is consistent with the dynamic response judgment can the initial equivalent conversion relationship between the unloaded braking distance and the fully loaded braking distance be established, ensuring that the dataset involved in the construction of the initial conversion relationship has authenticity and reliability, and improving the accuracy of the conversion relationship from the source.

[0013] (2) This invention identifies key components and inverts their equivalent friction coefficients under no-load and full-load conditions. Based on the difference in equivalent friction coefficients between the two conditions, a correction factor is generated to quantify and compensate for the nonlinear load effect of friction in the escalator braking system, thereby correcting the initial equivalent conversion relationship and effectively improving the prediction accuracy and reliability of the full-load braking distance.

[0014] (3) This invention incorporates the service status information of the target escalator into the safety compliance evaluation process of the full-load braking distance, realizing the individualization and dynamism of the safety evaluation standard, enabling forward warning of performance degradation, and effectively avoiding omissions or misjudgments. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a flowchart illustrating the implementation steps of the method of the present invention.

[0017] Figure 2 A schematic diagram illustrating the constraint logic for establishing the initial equivalent transformation relationship of this invention.

[0018] Figure 3 This is a schematic diagram of the equivalent friction coefficient inversion logic of the present invention. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Please see Figure 1 As shown, the present invention provides a method for evaluating the braking performance of an escalator under full load, comprising: S1. Based on braking test data of the same model of escalator under no-load and full-load conditions, establishing an initial equivalent conversion relationship between no-load braking distance and full-load braking distance.

[0021] Please see Figure 2 As shown, to establish a reliable initial equivalent transformation relationship, this invention first needs to obtain benchmark data through comparative experiments and double-verify the data quality to ensure the reliability of the physical basis for establishing subsequent relationships. The specific implementation process is as follows: synchronous comparative experiments are performed, and the first braking distance and first braking deceleration change sequences of the same model of escalator under laboratory conditions during unloaded emergency braking, and the second braking distance and second braking deceleration change sequences during fully loaded emergency braking are collected respectively.

[0022] Directly using raw experimental data to construct initial equivalent transformation relationships may be risky. Therefore, it is necessary to verify the validity of the data and the consistency of the braking system response. This process includes two layers of verification: physical constraint tolerance verification: based on classical kinematic principles, the braking distance and the average braking deceleration should satisfy... The basic relationship, among which Braking distance, The initial braking velocity, The average braking deceleration is used to calculate the first and second average braking decelerations under no-load and full-load conditions, respectively. It is then determined whether the deviation between the measured braking distance and the theoretical distance calculated from the average braking deceleration is within the preset physical constraint tolerance. For example, the deviation should not exceed ±5% of the measured braking distance. This verification is used to exclude invalid data due to gross measurement errors or severe data distortion.

[0023] Dynamic response consistency verification: The dynamic characteristics of the braking system should be load-invariant. By comparing the waveform, peak value, slope, and other trend characteristics of the first and second braking deceleration change sequences, it is determined whether the dynamic responses of no-load emergency braking and full-load emergency braking are consistent. Specifically, the two change sequences can first be aligned on the time axis, and then linear interpolation can be used to unify them to the same sampling frequency. Subsequently, the normalized cross-correlation coefficient of the two change sequences is calculated. When the normalized cross-correlation coefficient is greater than 0.85, the dynamic response is considered consistent, indicating that the dynamic characteristics of the braking system have not changed substantially under different loads, thus satisfying the premise of establishing a simple proportional relationship.

[0024] The experimental data are considered valid and applicable for constructing the initial equivalent transformation relationship only if both the physical constraint tolerance verification and the dynamic response consistency verification are passed.

[0025] Subsequently, a correlation analysis was conducted on the first braking distance and the second braking distance, and the mass ratio was defined as the ratio of the total load mass of the escalator under full load condition to the total load mass under empty load condition. This is based on the fundamental physical principle of the balance between inertial force and friction during the braking process.

[0026] The mass ratio conversion factor is obtained by dividing the ratio of the second braking distance to the first braking distance by the mass ratio.

[0027] However, in order to improve the universality and robustness of the initial equivalent conversion relationship, it is necessary to use multiple sets of data to calibrate the mass ratio conversion factor: select multiple sets of effective no-load and full-load braking distance data of the same model but different machines, or the same machine under different test cycles, calculate the mass ratio conversion factor corresponding to each set, and statistically analyze the standard deviation of multiple sets of mass ratio conversion factors.

[0028] If the standard deviation is less than or equal to the preset fluctuation threshold, which can be set according to engineering experience, for example 0.05, it indicates that the data consistency is good. The multiple quality ratio conversion factors are sorted directly according to the numerical order, and the median of the sequence is selected as the conversion factor marked by the initial equivalent conversion relationship to resist the influence of possible slight outliers.

[0029] Conversely, if the standard deviation is greater than the preset fluctuation threshold, it indicates that the data dispersion is large and there may be outlier tests. In this case, box plots or the three-standard-deviation principle should be used to identify and remove outliers that significantly deviate from the cluster. Then, the arithmetic mean of the quality ratio conversion factor should be recalculated using the remaining valid data as the final conversion factor for the initial equivalent conversion relationship. This establishes the initial equivalent conversion relationship with the quality ratio as the conversion factor.

[0030] If the verification fails, the braking test for the corresponding state must be re-executed until valid data that meets the dual verification requirements is obtained, thus forming a closed loop for data quality control.

[0031] This invention establishes a dual verification mechanism, ensuring that the initial equivalent conversion relationship between the no-load braking distance and the full-load braking distance is established only when the physical constraint tolerance judgment is consistent with the dynamic response judgment. This ensures that the dataset involved in the initial conversion relationship construction is authentic and reliable, thereby improving the accuracy of the conversion relationship from the source.

[0032] The initial equivalent transformation relationship is based solely on the mass ratio and fails to reflect the nonlinear changes in the internal frictional characteristics of the braking system with load. To improve prediction accuracy, it is necessary to delve deeper into the braking system, quantify the load-sensitivity characteristics of key components, and correct the initial equivalent transformation relationship accordingly.

[0033] Based on this, S2. Identify the key components involved in the dissipation of braking energy in the escalator, analyze the equivalent friction coefficients of the key components under no-load and full-load conditions, and generate a correction factor based on the difference in equivalent friction coefficients under no-load and full-load conditions to correct the initial equivalent conversion relationship and obtain the corrected equivalent conversion relationship.

[0034] Since the braking process of an escalator is essentially a process in which kinetic energy is converted into heat energy and dissipated through friction between various components of the braking system, the key components involved in the braking energy dissipation in the overall structure of the escalator can be obtained first. These key components include at least the brake, the step chain, and the guide rail.

[0035] Based on the principle of energy conservation, the total kinetic energy consumed during braking is equal to the sum of the frictional dissipation energy of each key component. The total kinetic energy consumed during the braking process can be decomposed into the frictional dissipation energy term borne by each key component. Using the equivalent friction coefficient corresponding to each key component as the parameter to be solved, a total frictional torque equation containing the frictional dissipation energy term of all key components is established.

[0036] Taking the aforementioned set of key components, including the brake, ladder chain, and guide rail, as an example, the corresponding equation for the total frictional torque is as follows: .

[0037] in For total load mass, It is the acceleration due to gravity. These are the equivalent friction coefficients for the brake, ladder chain, and guide rail, respectively. These are constant dimensionless structural parameters reflecting the force relationship between the brake and the step chain. They are standard technical parameters provided by escalator manufacturers and can convert the total load weight into equivalent normal force acting on the brake and step chain. The angle of inclination of the escalator. The term represents the component of the total load weight perpendicular to the guide rail.

[0038] The left side of the equation represents the total kinetic energy possessed by the escalator at the moment of braking initiation.

[0039] The right-hand side of the equation represents the total work consumed by friction of all key components during braking, which can be decomposed into the brake friction dissipation energy term. Cascade chain friction dissipation energy term and the energy dissipation due to friction of the guide rail .

[0040] It should be noted that this decomposition does not refer to the independent and sequential energy consumption of each key component, but rather describes the parallel and superimposed relationship of their work done simultaneously within the same braking process and braking distance. In actual braking, all key components generate friction simultaneously, collectively causing the escalator to decelerate. This equation assumes that the frictional force of each key component is constant or has a constant average effect throughout the braking process, and that the braking distance is the same. Therefore, the total work is the sum of the work done by the frictional forces of each key component. Furthermore, since the frictional force of each key component is proportional to the total load mass, the right-hand side of the equation can be factored out to present a compact form.

[0041] The entire equation is based on the principle of energy conservation. The frictional energy consumption of each key component during braking is physically equivalent and lumped by introducing equivalent friction coefficients and structural parameters, thereby transforming the complex multibody friction problem into a solvable mathematical equation.

[0042] Please see Figure 3 As shown, the first braking distance and the total unloaded load mass, and the second braking distance and the total fully loaded load mass are substituted into the total friction torque equation, respectively, to obtain the equivalent friction coefficients of each key component under unloaded and fully loaded conditions. The specific process is as follows: Based on the overall deviation between the predicted braking distance calculated from the total friction torque equation using the current equivalent friction coefficient and the measured braking distance under the corresponding conditions, a target error function is constructed. The form of the target error function can refer to the root mean square error function. The smaller the function value, the more the current equivalent friction coefficient matches the measured data.

[0043] To improve inversion efficiency and avoid getting trapped in local optima, reasonable initial guess values ​​need to be set for each equivalent friction coefficient. Based on the structural layout of the escalator, all mechanical contact interfaces that participate in kinetic energy dissipation during braking are identified, and each key component is mapped to one or more mechanical contact interfaces.

[0044] By consulting mechanical design manuals, the typical friction coefficient range of the materials involved in each mechanical contact interface is obtained. The median value of this range is taken as the reference friction coefficient of the corresponding mechanical contact interface. When a key component corresponds to only one mechanical contact interface, the reference friction coefficient of the mapped mechanical contact interface is directly used as the initial guess value of the equivalent friction coefficient of the key component.

[0045] When a critical component corresponds to multiple mechanical contact interfaces, the multiple mechanical contact interfaces are equivalent to a single aggregate interface. The reference friction coefficients are weighted and averaged based on the equivalent action radius of each mechanical contact interface, and the final weighted average value is used as the initial guess value of the equivalent friction coefficient of the critical component.

[0046] Starting from the initial guess value, for both no-load and full-load conditions, the equivalent friction coefficient of each key component is iteratively updated to bring the value of the target error function to within the preset tolerance range.

[0047] It should be noted that the iterative update method can be gradient descent, quasi-Newton method, etc., which is determined by the actual application, and this invention does not impose any special restrictions.

[0048] During the iteration process, multiple sets of candidate equivalent friction coefficients that make the target error function converge are recorded, and the set of equivalent friction coefficients that minimizes the global target error function is selected as the final inversion result output.

[0049] The ratio of the equivalent friction coefficient of each key component under full load and no-load conditions is taken as the friction change rate.

[0050] However, the influence of each key component in the braking energy transmission path varies. It is necessary to determine the topological order of each key component in the energy transmission path from the drive system to the actuator. The topological structure is usually brake-drive transmission component-step chain-guide rail. The key components are assigned weights according to this topological order, following the principle that the earlier the component is in the topological order, the greater the weight. This principle is based on the premise that the entire braking system of the escalator is regarded as a series energy dissipation chain. The key component located at the front of the topological order has changes in its friction characteristics that not only affect its own energy consumption, but also cascade and affect the energy state available to all subsequent components. Therefore, its weight should be greater.

[0051] To this end, this invention provides a specific example of assigning weights to key components, defining a weight decay mechanism based on topological position, setting the weight value of the first key component in the topological order to 1, then the key component in the topological order is located at the [missing value]. The weight values ​​of each key component can be respectively as follows: , As a preset attenuation factor, It can be simulated or experimentally calibrated according to the energy transfer efficiency of different escalator models. The value is usually between 0.7 and 0.9, and it is used to control the attenuation rate of energy or weight along the transmission path.

[0052] The friction change rate of each key component is weighted and multiplied, and the result of the weighted multiplication is squared to obtain the correction factor, which is the total number of key components.

[0053] The correction factor Conversion factor with quality ratio By coupling, a corrected equivalent transformation relation is generated, which can be expressed as the following formula: .

[0054] in, The braking distance and total load weight under full load conditions. The braking distance and total load weight are under no-load conditions.

[0055] It should be noted that this formula is a mathematical expression of the equivalent transformation relationship derived step by step and finally established in steps S1 and S2 above. The meaning, acquisition process and function of each parameter in the formula have been explained in the preceding content. The purpose of presenting it here is to clearly show the final structure of the equivalent transformation relationship after correction, so as to facilitate understanding and application. The specific derivation details and physical principles will not be repeated.

[0056] This invention identifies key components and inverts their equivalent friction coefficients under no-load and full-load conditions. Based on the difference in equivalent friction coefficients between the two conditions, a correction factor is generated to quantify and compensate for the nonlinear load effect of friction in the escalator braking system, thereby correcting the initial equivalent conversion relationship and effectively improving the prediction accuracy and reliability of the full-load braking distance.

[0057] To ensure the reliability of the corrected equivalent transformation relationship and its applicability to the target equipment in engineering applications, and to avoid prediction biases that may result from directly extrapolating the equivalent transformation relationship established based on specific samples to similar equipment, this invention introduces a verification step for the applicability of the corrected mapping relationship before performing an unloaded braking test on the target escalator to predict its full-load braking performance: First, at least one reference escalator with the same model, manufacturing batch, and service life as the target escalator is selected as a verification sample.

[0058] Secondly, no-load and full-load braking tests were performed on the reference escalator to obtain its measured braking distance under no-load and full-load conditions.

[0059] Then, the unloaded measured braking distance of the reference escalator is input into the formula presented by the above-corrected equivalent transformation relationship to calculate its full-load predicted braking distance and compare it with the actual full-load measured braking distance of the reference escalator to evaluate whether the prediction error is within the preset engineering accuracy acceptance range, such as ±10% which is acceptable in engineering. This threshold example is set based on the industry consensus on the general accuracy of indirect prediction methods.

[0060] If the prediction error meets the accuracy requirements, the corrected mapping relationship is deemed applicable to the same type of escalator and can be used for predicting the full-load braking distance of the target escalator. Otherwise, data from multiple reference escalators needs to be collected again to optimize the mapping relationship.

[0061] Based on the fact that the prediction error meets the accuracy requirements, S3. Obtain the no-load braking distance of the target escalator in the current state, predict the full-load braking distance of the target escalator based on the corrected equivalent transformation relationship, and conduct a safety compliance evaluation based on the prediction results.

[0062] The specific process of the safety compliance evaluation is as follows: collect service status information of the target escalator from its maintenance file, including the cumulative operating cycle, the number of brake actions, and the most recent maintenance record.

[0063] Based on the service status information, determine whether the current service status of the target escalator meets at least one of the following key braking performance degradation characteristics: I. The cumulative operating cycle exceeds the critical braking aging cycle specified for the target escalator.

[0064] II. The number of braking cycles exceeds the design durability cycle of the escalator's embedded brake.

[0065] III. The most recent maintenance record is more than a reasonable maintenance interval has passed since then, and no critical braking components were replaced during that period.

[0066] It should be noted that the critical period for brake aging is set based on the overhaul cycle recommended by the escalator manufacturer, the number of design durability cycles is the mechanical life cycle specified in the brake product manual, and the reasonable maintenance interval is determined based on the maintenance cycle recommended in the technical maintenance manual provided by the equipment manufacturer, combined with industry-recognized maintenance procedures.

[0067] If at least two of the following conditions are met, the braking performance of the target escalator is determined to be severely degraded.

[0068] If only one of the performance criteria is met, the braking performance is judged to be moderately diminished.

[0069] If any one of the performance criteria is not met, the braking performance is determined to be either no degradation or slight degradation.

[0070] Based on the graded assessment results of the braking performance degradation of the target escalator, the maximum allowable value of the full-load braking distance specified in the safety standard of the target escalator is adaptively adjusted. Specifically, the preset safety factor mapping relationship is queried. If the braking performance is severely degraded, the adjustment factor is the preset minimum safety factor.

[0071] If the attenuation is moderate, the adjustment coefficient is determined by linear interpolation within a preset adjustment coefficient range based on the magnitude of the over-limit parameter in the corresponding key attenuation performance. Taking the cumulative operating cycle exceeding the critical braking aging period of the target escalator as an example, the number of days of overdue operation is taken as the over-limit parameter, and the ratio of it to the critical braking aging period of the target escalator is taken as the over-limit magnitude. The adjustment coefficient obtained after linear interpolation is obtained by subtracting the product of the over-limit magnitude and the range of the adjustment coefficient range from the preset maximum safety factor.

[0072] The other two key attenuation indicators correspond to the following over-limit parameters: the number of braking cycles exceeding the design durability cycle and the number of days exceeding the reasonable maintenance cycle. The specific process of determining the adjustment coefficient by linear interpolation is the same as the specific logic of the above example of the cumulative operating cycle exceeding the critical cycle of braking aging of the target escalator, and will not be elaborated here.

[0073] If there is no attenuation or slight attenuation, the adjustment factor is the preset maximum safety factor.

[0074] The basis for the above-mentioned grading assessment of braking performance degradation and corresponding adaptive adjustments is that: escalators simultaneously meeting at least two key degradation characteristics indicate that the deterioration of their braking system has multi-dimensional and systemic features. For example, the coexistence of overdue operation and excessive braking actions means that components are simultaneously experiencing material fatigue and excessive mechanical wear; overdue maintenance coupled with any other manifestation indicates that performance degradation continues to accumulate without intervention. The superposition of multiple factors significantly increases the risk of systemic failure, therefore, the most stringent safety limit tightening strategy must be adopted.

[0075] The escalator only meets the single-item degradation performance standard, indicating the existence of a clear and isolated risk factor. Although this factor will cause negative performance changes, the state of the rest of the system is still acceptable, and the overall degradation is in a controllable and gradual stage. Therefore, appropriate adjustments to the safety limits are needed based on the specific degree to which this risk factor exceeds the limits.

[0076] The escalator did not meet any critical attenuation performance criteria, indicating that its operating time, number of actuations, and maintenance records are all within design or specification benchmarks. The braking system has no significant abnormal risks, and its performance baseline is stable or only exhibits slight natural aging. Therefore, it can be directly evaluated using standard safety margins without the need for preventative limit tightening.

[0077] As an example, the preset minimum safety factor is 0.7, the maximum safety factor is 1.0, and the adjustment factor range is [0.7, 1.0]. This setting is based on maintaining a standard safety margin under no-attenuation or mild-attenuation conditions. Under severe-attenuation conditions, based on the industry's conservative estimate of performance degradation under extreme wear conditions of critical components, the safety margin is further tightened by 30%. Those skilled in the art can adjust this principle based on specific safety specifications.

[0078] The dynamic safety limit is obtained by multiplying the adjustment coefficient by the original maximum allowable braking distance under full load.

[0079] If the predicted full-load braking distance is less than or equal to the dynamic safety limit, it is determined that the target escalator meets the dynamic safety standard under its current service condition; otherwise, a maintenance warning or a command to prohibit full-load operation is issued.

[0080] This invention incorporates the service status information of the target escalator into the safety compliance evaluation process of the full-load braking distance, realizing the individualization and dynamism of the safety evaluation standard, enabling forward warning of performance degradation, and effectively avoiding missed or misjudgments.

[0081] The above content is merely an example and illustration of the concept of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the concept of the invention or exceed the scope defined by the present invention, and all such modifications and additions should fall within the protection scope of the present invention.

Claims

1. A method for evaluating the full-load braking performance of an escalator, characterized by, The method comprises: establishing an initial equivalent conversion relationship between the empty load braking distance and the full load braking distance based on the braking test data of the escalator under the empty load and full load conditions; identifying key components participating in braking energy dissipation in the escalator, analyzing the equivalent friction coefficients of the key components under the empty load and full load conditions respectively, and generating a correction factor based on the difference between the equivalent friction coefficients under the empty load and full load conditions to correct the initial equivalent conversion relationship, thereby obtaining a corrected equivalent conversion relationship; obtaining the empty load braking distance of the target escalator under the current state, predicting the full load braking distance of the target escalator based on the corrected equivalent conversion relationship, and performing safety compliance evaluation on the prediction result.

2. The method for evaluating the full load braking performance of an escalator according to claim 1, wherein The method for establishing the initial equivalent conversion relationship between the empty load braking distance and the full load braking distance comprises: performing a synchronous comparison test to respectively collect a first braking distance and a first braking deceleration change sequence when the escalator is under an empty load emergency braking, and a second braking distance and a second braking deceleration change sequence when the escalator is under a full load emergency braking in a laboratory environment; calculating a first braking average deceleration and a second braking average deceleration, and verifying whether the numerical relationship between the first braking distance and the first braking average deceleration and the second braking distance and the second braking average deceleration conforms to the physical constraint tolerance based on the kinematic relationship; verifying whether the dynamic response of the empty load emergency braking and the full load emergency braking is consistent through the trend feature comparison of the first braking deceleration change sequence and the second braking deceleration change sequence; when and only when the physical constraint tolerance verification conforms and the dynamic response verification is consistent, the first braking distance and the second braking distance are associated and analyzed to establish the initial equivalent conversion relationship with the mass ratio as the conversion factor; otherwise, the braking test under the corresponding state needs to be re-performed until the requirements are met.

3. The method for evaluating the full load braking performance of an escalator according to claim 2, characterized by, The method for establishing the initial equivalent conversion relationship with the mass ratio as the conversion factor comprises: defining the mass ratio as the ratio of the total load mass of the escalator under the full load condition to the total load mass under the empty load condition; dividing the ratio of the second braking distance to the first braking distance by the mass ratio to obtain the mass ratio conversion factor; selecting multiple sets of empty load and full load braking distance data of the same type escalator or the same escalator under different test periods, respectively calculating the mass ratio conversion factor of each set, and statistically calculating the standard deviation of the multiple mass ratio conversion factors; if the standard deviation is less than or equal to a preset fluctuation threshold, the multiple mass ratio conversion factors are sorted in numerical size order, and the median of the sequence is selected as the conversion factor calibrated by the initial equivalent conversion relationship; otherwise, if the standard deviation is greater than the preset fluctuation threshold, the sequence outliers are identified and removed, and the arithmetic mean of the mass ratio conversion factor is recalculated using the remaining valid data as the conversion factor calibrated by the initial equivalent conversion relationship.

4. The method for evaluating the full load braking performance of an escalator according to claim 1, wherein The method for analyzing the equivalent friction coefficients of the key components under the empty load and full load conditions comprises: obtaining a key component set participating in braking energy dissipation in the escalator structure, wherein the key components at least include a brake, a step chain, and a guide rail; Based on the principle of energy conservation, the total kinetic energy consumed in the whole braking process is decomposed into the friction dissipation energy of each key component; The equivalent friction coefficient of each key component is taken as the parameter to be solved, and the total friction torque equation containing the friction dissipation energy of all key components is established; The first braking distance and the total load mass under no load and the second braking distance and the total load mass under full load are substituted into the total friction torque equation respectively, and the equivalent friction coefficient of each key component under no load and full load is obtained by inversion.

5. The method for evaluating the full load braking performance of an escalator according to claim 4, wherein The equivalent friction coefficient inversion process of each key component under no load and full load includes: An overall deviation between the braking distance prediction value calculated from the total friction torque equation based on the current equivalent friction coefficient and the measured braking distance under the corresponding working condition is constructed to form a target error function; According to the structure layout of the escalator, all mechanical contact interfaces participating in kinetic energy dissipation in the braking process are identified, and each key component is mapped to one or more mechanical contact interfaces; According to the typical friction coefficient range of the materials involved in the mechanical contact interface, an initial guess value is set for the equivalent friction coefficient of each key component; Taking the initial guess value as the starting point, the value of the equivalent friction coefficient of each key component is updated iteratively for no load and full load conditions respectively, so that the target error function converges within a predetermined tolerance range; During the iteration process, a plurality of candidate equivalent friction coefficients that make the target error function converge are recorded, and the equivalent friction coefficient with the minimum target error function is selected as the final inversion result output.

6. The method for evaluating the full load braking performance of an escalator according to claim 5, wherein The initial guess value for the equivalent friction coefficient of each key component includes: The median value of the typical friction coefficient range of the materials involved in the mechanical contact interface is taken as the reference friction coefficient of the mechanical contact interface; If a key component corresponds to only one mechanical contact interface, the reference friction coefficient of the mapped mechanical contact interface is taken as the initial guess value; If it corresponds to multiple mechanical contact interfaces, it is equivalent to an aggregated interface, and its initial guess value is the weighted average of the reference friction coefficients of the interfaces involved based on the specified action radius.

7. The method for evaluating the full load braking performance of an escalator according to claim 3, wherein The correction of the initial equivalent conversion relationship includes: The ratio of the equivalent friction coefficients of each key component under full load and no load is taken as the friction change rate; According to the energy transfer direction, the topological order of each key component in the energy transfer path is determined, and the weight of each key component is assigned according to the topological order; The friction change rate of each key component is weighted and multiplied, and the weighted multiplication result is subjected to square root operation to obtain a correction factor; The correction factor is coupled with the mass ratio conversion factor to generate the corrected equivalent conversion relationship.

8. The method for evaluating the full load braking performance of an escalator according to claim 1, wherein The safety compliance evaluation includes: Collecting the service state information of the target escalator, including the cumulative running period, the number of brake actions, and the latest maintenance record; According to the service state information, the braking performance degradation of the target escalator is evaluated, and the maximum allowable value of the full load braking distance specified in the safety standard of the target escalator is adaptively adjusted to generate a dynamic safety limit value; If the predicted full-load braking distance is less than or equal to the dynamic safety limit, it is determined that the full-load braking distance of the target escalator under the current service state meets the dynamic safety standard, otherwise a maintenance warning or an instruction to prohibit full-load operation is issued.

9. The method for evaluating the full load braking performance of an escalator according to claim 8, wherein The braking performance attenuation degree of the target escalator is graded and evaluated, including: It is determined whether the current service state of the target escalator meets at least one of the following key braking performance attenuation performances: I. The cumulative running period exceeds the braking aging specified critical period of the target escalator; II. The number of brake braking times exceeds the design durability number of the embedded brake of the target escalator; III. The time interval between the last maintenance record and the current time has exceeded the reasonable maintenance interval, and the key brake components have not been replaced during the interval; If at least two performances are met, it is determined that the braking performance of the target escalator is severely attenuated; If only one performance is met, it is determined that the braking performance is moderately attenuated; If none of the performances is met, it is determined that the braking performance is not attenuated or is slightly attenuated.

10. The method for evaluating the full load braking performance of an escalator according to claim 9, wherein The adaptive adjustment process includes: According to the braking performance attenuation degree grade, the corresponding adjustment coefficient is obtained by querying the preset safety coefficient mapping relationship; Wherein, the safety coefficient mapping relationship at least specifies: If the braking performance is severely attenuated, the adjustment coefficient is the preset lowest safety coefficient; If it is moderately attenuated, the adjustment coefficient is determined by linear interpolation in the preset adjustment coefficient interval according to the amplitude of the over-limit parameter in the corresponding key attenuation performance; If it is not attenuated or slightly attenuated, the adjustment coefficient is the preset highest safety coefficient; The adjustment coefficient is multiplied by the original maximum allowable value of the full-load braking distance to obtain the dynamic safety limit.

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