An automatic detection and rescue method and system for elevator trapping

Abstract

The present application relates to the technical field of elevator trapped person detection, and provides an elevator trapped person automatic detection and rescue method and system, which comprises arranging displacement time and brake switching time into a time sequence event sequence, finding the nearest switching time for each displacement time, marking the displacement time as an abnormal displacement time only when the corresponding brake is closed, obtaining a trapped person candidate period by taking the intersection of the continuous abnormal displacement period and the passenger carrying period; in the period, confirming unidirectional displacement by the same direction in the direction sequence, confirming slow creep by the absolute value of acceleration being less than a preset acceleration threshold value within a preset time, and driving the car to stop and open the door after a trapped person confirmation signal is generated by the combination of the two. The present application realizes detection by using only existing sensors, without the need for adding new hardware, and fills the gap in the detection of creep and trapped person.

Description

Technical Field

[0001] This invention relates to the field of elevator entrapment detection technology, and more specifically, to an automatic elevator entrapment detection and rescue method and system. Background Technology

[0002] The content in this section only provides background information related to this invention and may not constitute prior art.

[0003] With the widespread use of high-rise buildings in cities, elevators have become an indispensable vertical transportation tool, and their operational safety is directly related to the safety of passengers. Elevator entrapment is a common emergency during elevator operation, referring to a situation where passengers are trapped in a stopped elevator car and unable to escape on their own. Current elevator entrapment detection mainly determines whether entrapment has occurred by detecting the status of the car door zone, changes in the car's position, and load signals inside the car. The commonly used solution is: when the elevator control system detects that the car is in a non-door zone position and the car door is closed, and at the same time the weighing sensor detects a load inside the car, it determines that a entrapment has occurred and triggers an alarm and rescue process.

[0004] However, existing solutions all assume that the elevator car must be completely stopped when entrapment occurs, presupposing that the car must be stationary. In actual operation, a long-overlooked danger exists: when the elevator brake, due to brake shoe wear, insufficient braking force, or counterweight imbalance, creeps while in the closed state, the car experiences continuous, minute unidirectional displacement even with the brake not released. In this case, the car has not stopped, but passengers are still trapped inside the car with the doors unable to open. Because the displacement and acceleration of creeping are very small, detection methods based on position or speed thresholds cannot reliably distinguish between normal operation and creeping. Existing entrapment detection systems, detecting changes in the car's position, mistakenly assume the elevator is in normal operation and fail to trigger an entrapment alarm, resulting in passengers being trapped for extended periods without timely rescue.

[0005] Furthermore, some solutions match and identify sensor signals by pre-setting trap feature templates. However, template matching relies on the pre-collection and storage of a large amount of historical trap data. For scenarios like creeping vehicles, which have a low probability of occurrence and limited industry research, there is often a lack of sufficient sample support, making it difficult to establish effective feature templates. Therefore, existing solutions have gaps in detecting people trapped by creeping vehicles when the brakes are closed, and there is an urgent need for a solution that can automatically identify such trapping situations and trigger rescue. Summary of the Invention

[0006] The purpose of this invention is to provide an automatic detection and rescue method and system for elevator entrapment, in order to improve the aforementioned problems. To achieve the above objective, the technical solution adopted by this invention is as follows: Firstly, this application provides an automatic detection and rescue method for people trapped in elevators, including: During elevator operation, the car position signal, weighing sensor signal, and brake status signal are collected. The car position signal is compared with adjacent signals at each time step, and the time when the car position changes is marked as the displacement time. The brake status signal is compared with adjacent signals at each time step, and the time when the brake status changes is marked as the switching time. The signal first collected after the elevator is powered on from the weighing sensor signal is used as the no-load reference signal. The displacement time and the switching time are arranged in chronological order to obtain the time sequence event sequence. In the sequence of time events, for each displacement moment, the nearest switching moment is searched backward. When the brake state corresponding to the nearest switching moment is closed, the displacement moment is marked as an abnormal displacement moment. The time period covered by consecutively occurring abnormal displacement moments is marked as a creeping period. Consecutive occurrence means that there is no corresponding switch moment with the brake released state between two adjacent abnormal displacement moments. During the creeping period, the weighing sensor signal is compared with the no-load reference signal every moment. The moments when the two are different are marked as the load moments, and the time period covered by consecutive load moments is marked as the manned period. The time intersection of the manned period and the creeping period is used to obtain the candidate manned period. During the candidate period for passenger entrapment, for each abnormal displacement moment, the abnormal displacement moment and the corresponding car position of the previous moment are read from the car position signal. The direction of increasing car position is marked as the upward direction, and the direction of decreasing car position is marked as the downward direction. The directions corresponding to all abnormal displacement moments during the candidate period are arranged in chronological order to obtain a direction sequence. Based on the change in car position corresponding to each abnormal displacement moment, the velocity change between adjacent abnormal displacement moments is calculated, and the acceleration is obtained based on the velocity change. When all directions in the direction sequence are the same, and the absolute value of the acceleration within a preset time is less than a preset acceleration threshold, a passenger entrapment confirmation signal is generated. In response to the entrapment confirmation signal, the car position at the start of the entrapment candidate time period is read, a car leveling and moving command is generated to move the car to the nearest door zone, and a door opening command is generated.

[0007] Furthermore, by arranging the displacement moments and switching moments in chronological order, a sequence of time-series events is obtained, which specifically includes: An event record is generated for each displacement moment and each switching moment. The event record includes the time when the event occurred and the event type identifier. Sort all event records in order of their occurrence time. When the displacement time and the switching time occur at the same time, arrange the event record of the switching time before the event record of the displacement time. Store the sorted event records in sequence to form a time-series event sequence.

[0008] Furthermore, for each displacement moment, the nearest switching moment is searched backwards. When the brake state corresponding to the nearest switching moment is closed, the displacement moment is marked as an abnormal displacement moment, specifically including: Extract the event record corresponding to each displacement moment from the time sequence event sequence in sequence. Starting from the event record, traverse the time sequence event sequence backward to find the event record corresponding to the first switching moment. Read the brake state corresponding to the switching moment. If the brake state is closed, it is determined that the brake has not been released and the car has moved. Mark the displacement moment as an abnormal displacement moment. If the brake state is released, mark the displacement moment as a normal displacement moment.

[0009] Furthermore, the time period covered by consecutive abnormal displacement moments is marked as the creeping period, specifically including: The scan begins from the starting position of the time-series event sequence. When the first abnormal displacement moment is encountered, that abnormal displacement moment is recorded as the start time of the creeping period. During the backward scan, if there is no switch moment between the brake release state and the previous abnormal displacement moment, the subsequent abnormal displacement moment is included in the same creeping period. When the switch moment of the brake release state is scanned, the last abnormal displacement moment before the switch moment is recorded as the end moment of the creeping period. The creeping period is composed of the start moment of the creeping period and the end moment of the creeping period.

[0010] Furthermore, during the creeping period, the load cell signal is compared with the no-load reference signal time by time, and the time when the two are different is marked as the load time, specifically including: Several load cell signals are continuously collected when the elevator is unloaded. The maximum fluctuation amplitude of the collected signals is recorded and used as the load judgment threshold. At each collection moment covered during the creep period, the load cell signal corresponding to that moment is read and the difference between the load cell signal and the unloaded reference signal is calculated. When the difference exceeds the load judgment threshold, it is determined that there is a person load in the car and the moment is marked as the load moment. When the difference does not exceed the load judgment threshold, the moment is marked as the unloaded moment.

[0011] Furthermore, after generating the entrapment confirmation signal, it also includes: Within a preset time period, the acceleration at each moment is compared with the average acceleration at all moments within the preset time period. When the acceleration at a moment is greater than the average, that moment is marked as a positive deviation moment. When the acceleration at a moment is less than the average, that moment is marked as a negative deviation moment. The system counts the number of times positive and negative deviations alternate within a preset time period. When the number of alternations exceeds the set number, it is determined that the brake shoe and brake wheel are in an intermittent contact state that is sometimes sticky and sometimes sliding. When the number of alternations does not exceed the set number, it is determined that the brake shoe and brake wheel are in a stable sliding state with continuous contact but insufficient friction. The determination result is output along with the trapped person confirmation signal for subsequent leveling rescue strategy selection.

[0012] Furthermore, after generating the car leveling and moving command to move the car to the nearest door zone, it also includes: Read the judgment result. When the result is intermittent contact, suspend the execution of the car leveling movement command. First, generate multiple release and resetting commands for the brake. Control the brake to repeatedly perform release and close actions. Try to restore braking force by removing the oxide layer on the contact surface through the friction between the brake shoe and the brake wheel. After the multiple release and resetting commands for the brake are completed, re-check the brake status. If the brake has restored normal braking force, continue the leveling movement at the normal rescue speed. If the brake has not yet been restored, continue the leveling movement at a safe speed. When the result is a stable sliding state, it is determined that the brake shoe friction surface has been worn as a whole, and the braking force cannot be restored by releasing and resetting the brake. The leveling movement is then performed directly at a safe speed.

[0013] Secondly, this application also provides an automatic detection and rescue system for people trapped in elevators, including: The signal acquisition module is used to acquire car position signals, weighing sensor signals, and brake status signals during elevator operation. The event timing module is used to compare adjacent car position signals moment by moment and mark the moment when the car position changes as the displacement moment; compare adjacent brake status signals moment by moment and mark the moment when the brake status changes as the switching moment; use the signal first collected after the elevator is powered on from the weighing sensor signal as the no-load reference signal; and arrange the displacement moment and the switching moment in chronological order to obtain the timing event sequence. The creep detection module is used to find the nearest switching time for each displacement time in the time sequence of events. When the brake state corresponding to the nearest switching time is closed, the displacement time is marked as an abnormal displacement time. The time period covered by consecutive abnormal displacement times is marked as a creep period. Consecutive occurrence means that there is no corresponding switch time with the brake released state between two adjacent abnormal displacement times. The manned discrimination module is used to compare the weighing sensor signal with the no-load reference signal hour by hour during the creeping period. The time when the two are different is marked as the load time, and the time period covered by consecutive load times is marked as the manned period. The intersection of the manned period and the creeping period is used to obtain the candidate period for trapping people. The passenger entrapment confirmation module is used to read the abnormal displacement moment and the corresponding car position of the previous moment from the car position signal for each abnormal displacement moment within the passenger entrapment candidate period. The direction of increasing car position is marked as the upward direction, and the direction of decreasing car position is marked as the downward direction. The directions corresponding to all abnormal displacement moments within the passenger entrapment candidate period are arranged in chronological order to obtain a direction sequence. Based on the change in car position corresponding to each abnormal displacement moment, the velocity change between adjacent abnormal displacement moments is calculated, and the acceleration is obtained based on the velocity change. When all directions in the direction sequence are the same, and the absolute value of the acceleration within a preset time is less than a preset acceleration threshold, a passenger entrapment confirmation signal is generated. The automatic rescue module is used to respond to the entrapment confirmation signal, read the car position at the start time of the entrapment candidate period, generate a car leveling movement command to move the car to the nearest door area, and generate a door opening command.

[0014] Thirdly, this application also provides an electronic device, including: Memory, used to store computer programs; A processor is used to implement the method steps as described in the first aspect when executing a computer program.

[0015] Fourthly, this application also provides a readable storage medium on which a computer program is stored, which, when executed by a processor, implements the method steps of the first aspect.

[0016] The beneficial effects of this invention are as follows: This invention integrates displacement moments and brake switching moments into the same temporal event sequence. For each displacement moment, it searches backward for the nearest switching moment, marking it as an abnormal displacement moment only when the brake is closed, thus excluding normal operating displacements from a causal perspective. The time period covered by consecutive abnormal displacement moments is marked as a creeping period, and the intersection of this period with the passenger-carrying period obtained by comparing it with the weighing signal yields a candidate entrapment period, ensuring that displacement occurs while someone is in the car and the brake is continuously closed. Within the candidate entrapment period, the displacement is confirmed to be driven unidirectionally by a constant gravity difference by ensuring all directions in the direction sequence are the same, and the absolute value of the acceleration within a preset time is less than a preset acceleration threshold, confirming that the car is in continuous slow creeping rather than normal acceleration / deceleration. Both are combined to generate an entrapment confirmation signal. Subsequently, the car position at the start of the candidate entrapment period is read, and a leveling movement command is generated to move the car to the nearest door zone and open the door. Utilizing existing elevator car position, weighing, and brake status sensors, no new hardware is required, filling the gap in creeping and entrapment detection and preventing passengers from being trapped for extended periods without rescue due to the system mistakenly believing the elevator is in normal operating condition. Attached Figure Description

[0017] Figure 1 A flowchart of an automatic detection and rescue method for people trapped in elevators provided by the present invention; Figure 2 This is a schematic diagram of an automatic detection and rescue system for people trapped in an elevator, provided by the present invention. Figure 3 This is a schematic diagram of an electronic device provided by the present invention.

[0018] In the diagram: 201, signal acquisition module; 202, event timing module; 203, creep detection module; 204, passenger-carrying identification module; 205, trapped passenger confirmation module; 206, automatic rescue module; 301, processor; 302, memory. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0020] like Figure 1 As shown in the figure, an automatic detection and rescue method for people trapped in elevators according to an embodiment of the present invention includes: S101 collects car position signals, weighing sensor signals, and brake status signals during elevator operation.

[0021] Specifically, the elevator operation process covers the entire time from power-on start-up, normal passenger-carrying operation, arrival at the station and stoppage until power failure. The reason for continuously collecting signals during elevator operation is that entrapment faults often occur at the moment of transition between operation and stoppage. Only by continuously acquiring the underlying state data throughout the entire process can we provide a complete basis for subsequent time-by-time comparison and event sequence reconstruction, and avoid missing abnormal displacements due to sampling gaps.

[0022] The car position signal is output by a position detection device installed at the traction machine shaft end or inside the hoistway, reflecting the real-time height position of the car in the hoistway. Its principle is to convert the rotation angle of the traction sheave or the absolute displacement of the car into a readable numerical value. The load cell signal is output by a weighing device located at the bottom of the car or at the rope assembly, reflecting the current weight carried inside the car. Its principle is to use elastic body deformation or pressure-sensitive elements to convert the load magnitude into an electrical signal. This helps distinguish whether there are people inside the car, thus differentiating between simple empty car slippage and actual entrapment, reducing false alarm rates. The brake status signal is output by the brake's auxiliary contacts or status detection circuit, reflecting whether the brake is currently in a closed or released state. Its principle is to convert the mechanical action of the brake shoes into a switching quantity or status code. This allows subsequent steps to determine whether the brake is in the proper released state when car movement occurs, and is a key criterion for distinguishing between normal operating displacement and abnormal displacement due to brake failure. The three signals are collected synchronously with a unified time base to ensure that the car position, load weight and brake status at each moment correspond one-to-one, providing a data foundation of the same source and frequency for arranging the displacement time and switching time into a time sequence of events.

[0023] S102, perform adjacent comparisons on the car position signal at each time step, and mark the time when the car position changes as the displacement time step; perform adjacent comparisons on the brake status signal at each time step, and mark the time when the brake status changes as the switching time step; take the signal first collected after the elevator is powered on from the weighing sensor signal as the no-load reference signal; arrange the displacement time step and the switching time step in chronological order to obtain the time sequence event sequence.

[0024] Specifically, this step is a key step in transforming the continuously acquired state signals at the bottom layer into a set of discrete events that can be used for subsequent logical judgment. Its core lies in extracting state change nodes from the continuous signal stream by comparing adjacent nodes at each time step, and aligning events from different sources with a unified time sequence, thereby providing structured input for subsequent abnormal displacement identification and creep period determination.

[0025] First, the car position signal is compared moment-by-moment, and the moment when the car position changes is marked as the displacement moment. This moment-by-moment comparison refers to comparing the current car position value with the previous car position value according to the sampling time sequence determined by the unified time base in S101. When the difference between the two is not zero, it indicates that the car has undergone actual displacement within that sampling interval, and therefore the current moment is marked as the displacement moment. The expression for the change in car position is:

[0026] In the formula, For the first The change in car position at each sampling time; For the first The car position signal value at each sampling time; For the first -1 sampling time value of the car position signal. If If ≠0, then the first Each sampling time is marked as a displacement time.

[0027] The principle is that the car position signal itself is an analog quantity or discrete sampled value that changes continuously with time. Directly processing all moments would introduce a large amount of static redundant data. However, by comparing adjacent moments and extracting only the moments when the position changes, it is possible to accurately pinpoint every time point when the car starts to move or continues to move. The effect is that it transforms the judgment of "whether the car is moving" from a vague interval description into a precise time marker, so that each subsequent displacement can be independently traced and attributed.

[0028] Similarly, the brake state signal is compared moment-by-moment, and the moment when the brake state changes is marked as the switching moment. The brake state signal is a switch quantity or a finite state code. The adjacent comparison determines whether the brake state at the current moment is consistent with the previous moment. When the brake changes from closed to open or from open to closed, the current moment is the switching moment. The expression for the change in brake state is as follows:

[0029] In the formula, For the first The change in brake state at each sampling time; For the first The brake status signal value at each sampling time; For the first -1 sampling time of the brake state signal value. If If ≠0, then the first Each sampling time is marked as a switching time.

[0030] The principle is that, under normal circumstances, the brake state only changes a limited number of times during elevator startup and parking. By extracting the switching moments, the time boundary of the brake action can be precisely determined. Its effect is to provide a clear time anchor point for subsequent determination of "what state the brake is in when displacement occurs," avoiding the obscuring of the instantaneous action due to continuous reading of steady-state values.

[0031] Secondly, the signal first collected from the weighing sensor after the elevator is powered on is used as the no-load reference signal. At the moment the elevator is powered on, the car is not yet carrying passengers. At this time, the signal output by the weighing sensor reflects the baseline value formed by the weight of the car itself and the zero drift of the sensor. This initial collected value is fixed as the no-load reference signal. The principle is to use the natural no-load conditions at the moment of power-on to establish a load comparison benchmark. The effect is that a reference baseline consistent with the current operating environment can be obtained without performing an additional no-load calibration process, providing a comparable reference object for determining whether there are people in the car in S104.

[0032] Finally, the displacement and switching moments are arranged chronologically to obtain a time-series event sequence. This involves: generating an event record for each displacement and switching moment, with each record containing the event occurrence time and event type identifier; sorting all event records in chronological order, prioritizing those occurring at the same time as the switching moment; and storing the sorted event records sequentially to form the time-series event sequence. Its expression is as follows:

[0033]

[0034]

[0035] like ,but and .

[0036] In the formula, It is a sequence of time-series events; For the first in the sequence One event record; For the first The moment when the event occurs; For the first The type identifier of each event, take or ; The total number of event records; For the event log number; Indicates the displacement time type; This indicates the type of switching time. When the displacement time and the switching time occur at the same time, the event record of the switching time is arranged before that of the displacement time.

[0037] This process generates event records for each displacement and switching moment, essentially adding a structured label to each state change node. The event type identifier distinguishes whether the record belongs to a displacement moment or a switching moment. The principle is to unify the change points in heterogeneous signals into the same data structure, enabling mixed sorting and traversal within the same sequence. After sorting by occurrence time, events from different sources are restored to the true timeline, allowing causal relationships like "whether the brake releases first or the car moves first" to be directly determined through simple forward and backward traversal. When a displacement moment and a switching moment occur simultaneously, the switching moment is prioritized. This rule is based on the principle that brake state switching is a prerequisite for car displacement. Even if both appear to occur simultaneously under sampling precision, logically, the brake state should be confirmed first before assessing whether the displacement under that state is abnormal. This ensures that when "searching forward for the most recent switching moment," the brake state at the same moment can be correctly associated with the displacement moment, avoiding incorrect state attribution due to reversed sorting.

[0038] For example, suppose the elevator brake switches from closed to open at time t1, the car position begins to change at time t2, the brake switches from open to closed at time t3, and the car position still changes at time t4. Then, S102 generates four event records and sorts them by time as t1 (switching), t2 (displacement), t3 (switching), and t4 (displacement). The displacement time t4 searches backward to find the nearest switching time, which is t3 and corresponds to the closed state, so it is identified as an abnormal displacement in subsequent steps. If t2 and t1 happen to coincide in a certain sampling, the switching record is ranked first according to the rules to ensure that the displacement time t2 can be correctly associated with the open state of t1.

[0039] S103, in the time sequence of events, for each displacement moment, look up the nearest switching moment. When the brake state corresponding to the nearest switching moment is closed, mark the displacement moment as an abnormal displacement moment. Mark the time period covered by consecutively occurring abnormal displacement moments as a creeping period. Consecutive occurrence means that there is no corresponding switch moment with the brake released state between two adjacent abnormal displacement moments.

[0040] Specifically, this step is the core step in transforming discrete event records in a time-series event sequence into physically meaningful anomaly determination results. Its principle lies in utilizing the inherent causal constraint relationship between brake state and car displacement; that is, under normal circumstances, the car will only move after the brake is released. By tracing back the most recent brake state switch before each displacement moment, it can be determined whether the displacement occurred within the legal time period when the brake should be released. Its effect is to distinguish simple position changes into normal operating displacement and abnormal displacement under brake failure, providing a time-by-time determination basis for the subsequent definition of creep periods.

[0041] For each displacement moment, the nearest switching moment is searched backwards. When the brake state corresponding to the nearest switching moment is closed, the displacement moment is marked as an abnormal displacement moment. Specifically, this involves: first, sequentially retrieving the event record corresponding to each displacement moment from the time-series event sequence; then, starting from this event record, traversing backwards through the time-series event sequence to find the event record corresponding to the first switching moment. This forward traversal means searching sequentially from the event record corresponding to the current displacement moment towards earlier times, according to the order of the event records in the time-series event sequence, until the first event record with the event type identified as a switching moment is encountered. The principle is that the time-series event sequence has already mixed and sorted the displacement moments and switching moments according to a unified time base. Therefore, the first switching moment found through forward traversal is the closest brake action before the displacement moment occurred, and the brake state corresponding to this action is the actual state of the brake at the moment the displacement occurred. The effect is that it eliminates the need for complex correlation calculations on all historical signals; state attribution can be determined simply through a unidirectional linear traversal, making the logic concise and traceable. Then, the brake status corresponding to the switching moment is read. If the brake status is closed, it is determined that the brake has not been released and the car has moved, and this displacement moment is marked as an abnormal displacement moment; if the brake status is released, this displacement moment is marked as a normal displacement moment. The principle is that when the brake is closed, it means that the brake shoes are gripping the brake wheel, the traction machine main shaft should be locked, and the car should not physically move. If the car position still changes at this time, it indicates that the braking force is insufficient to keep the car stationary, and there is a risk of brake failure or brake shoe slippage. Conversely, when the brake is released, the movement of the car is a normal operating behavior and no intervention is required. Its effect is that by using binary state determination, each displacement moment is clearly classified as abnormal or normal, avoiding missed or misjudged judgments caused by fuzzy intervals, and at the same time providing a point-by-point marking basis for the aggregation of subsequent continuous abnormal periods.

[0042] The process involves marking the time period covered by consecutive abnormal displacement moments as the creeping period. Specifically, this includes: First, scanning begins from the start of the time sequence of events. When the first abnormal displacement moment is encountered, it is recorded as the start of the creeping period. The principle is that creeping manifests as a continuous abnormal displacement process over time. Therefore, using the first abnormal displacement moment as the starting point of this process accurately pinpoints the instant when brake failure begins, providing a clear lower bound for subsequent load detection and entrapment confirmation. Second, during the subsequent scan, if there is no brake release state transition between subsequent abnormal displacement moments and the previous abnormal displacement moment, the subsequent abnormal displacement moments are included in the same creeping period. The principle is that as long as the brake does not undergo a release state transition, the braking circuit remains in a closed brake command state. All displacements occurring during this period belong to the continuous creeping process within the same brake failure process and should not be split into multiple independent time periods. This ensures the temporal continuity and integrity of the creeping period, preventing the same fault from being fragmented due to sampling intervals or momentary stillness. Finally, when the switch to the brake release state is detected, the last abnormal displacement moment before this switch is recorded as the end time of the creep period. The creep period consists of the start and end times of the creep period. The principle is that the switch to the brake release state marks the system entering the normal operation command phase, and the previous braking failure process ends at this point. Therefore, using the last abnormal displacement moment before this switch as the end boundary of the creep period can accurately define the time range of the fault. The effect is that each creep period corresponds to a complete braking failure event, with clear time boundaries, which facilitates subsequent load comparison and kinematic analysis within that period.

[0043] For example, suppose the sequence of events records the following events in sequence: at time t1, the brake switches from closed to open; at time t2, the car position begins to change; at time t3, the brake switches from open to closed; at time t4, the car position changes again; at time t5, the car position changes again; and at time t6, the brake switches from closed to open. Searching backwards from t2, the most recent switching time is t1, which corresponds to the open state, so t2 is marked as a normal displacement time. Searching backwards from t4, the most recent switching time is t3, which corresponds to the closed state, so t4 is marked as an abnormal displacement time. Searching backwards from t5, the most recent switching time is also t3, which corresponds to the closed state, so t5 is also marked as an abnormal displacement time. Since there is no switch between the brake release state and t4 and t5, and they are consecutive abnormal displacement moments, the creep period starts at t4. When scanning backward to t6, the switch between the brake release state and t6, the last abnormal displacement moment before it is recorded as the end of the creep period at t5. Finally, the creep period consisting of t4 to t5 is obtained. This period is the time range for load comparison and trap candidate determination in the subsequent steps.

[0044] S104. During the creeping period, the weighing sensor signal and the no-load reference signal are compared hour by hour. The time when the two are different is marked as the load time. The time period covered by the consecutive load times is marked as the manned period. The time intersection of the manned period and the creeping period is taken to obtain the candidate time period for trapping people.

[0045] Specifically, this step follows the creeping period defined in S103. Its purpose is to further filter out empty car slippage scenarios from abnormal displacements under brake failure through load comparison, thereby accurately pinpointing the time period where people might actually be trapped. The comparison is limited to the creeping period because the creeping period itself corresponds to abnormal displacements when the brake is closed. If there are also people loaded inside the car at this time, it constitutes a necessary condition for a entrapment failure. If load detection is only performed outside the creeping period, the passenger-carrying state during normal operation would be mistakenly included in the judgment range, resulting in an unreasonable expansion of the candidate entrapment time period.

[0046] The principle behind comparing the weighing sensor signal with the no-load reference signal moment by moment is to use the no-load reference signal established in S102 as a baseline and examine whether the current load weight deviates from the no-load baseline moment by moment. When the two are different, it indicates that there is a difference between the current load weight of the car and the no-load baseline at the moment of power-on, thus inferring that there may be a person load in the car. Its effect is to transform the judgment of "whether there is a person in the car" into a numerical comparison that can be performed moment by moment, so that the load status at each collection moment can be independently marked, thereby providing point-by-point basis for the continuous aggregation of subsequent passenger-carrying periods.

[0047] The time when the two are different is marked as the load time. The difference here is not an absolute difference in exponential value, but a significant difference confirmed after threshold judgment. The principle is that the weighing sensor signal itself has noise fluctuations. If equality is used directly as the criterion, the small fluctuations in the no-load state will be misjudged as loads. Therefore, a load judgment threshold needs to be introduced to distinguish between real personnel loads and sensor fluctuations. Its effect is to suppress false alarms from the source and ensure that the load time corresponds only to the collection time when there is actually personnel load.

[0048] The time period covered by consecutive load moments is marked as a passenger-carrying period. The principle behind this is that the presence of a person in the elevator car is usually a continuous time process, rather than an isolated single moment. By aggregating consecutive load moments into a period, the complete time interval from a person entering the elevator car to leaving the car can be accurately depicted. The effect is that it transforms discrete load moments into passenger-carrying periods with clear start and end boundaries, facilitating subsequent time intersection calculations with creeping periods.

[0049] The intersection of the passenger-carrying period and the creeping period yields candidate periods for passenger entrapment. The principle is that the establishment of a passenger entrapment fault requires the simultaneous fulfillment of two conditions: first, the car undergoes abnormal displacement while the brake is closed, i.e., it is in the creeping period; second, there are personnel loads inside the car, i.e., it is in the passenger-carrying period. The interval where the two conditions overlap in time is the period when passenger entrapment is truly possible. The effect is that by performing time intersection calculations based on the dual conditions, the candidate range is further compressed, eliminating the case of empty car sliding with only abnormal displacement but no one in the car, as well as the non-fault case where there are people in the car but the displacement is normal operation. This allows the subsequent kinematic analysis of S105 to focus only on candidate periods for passenger entrapment with high confidence.

[0050] During the creeping period, the load cell signal is compared with the no-load reference signal moment by moment, and the moment when the two are different is marked as the load moment, specifically including: First, load cell signals are continuously collected several times under no-load conditions in the elevator, and the maximum fluctuation amplitude of the collected signals is recorded. This maximum fluctuation amplitude is used as the load determination threshold. The principle is that the load cell does not output a constant value under no-load conditions, but rather exhibits random fluctuations within a certain range due to factors such as temperature drift, mechanical vibration, and electromagnetic interference. By continuously collecting several signals under no-load conditions and recording the maximum fluctuation amplitude, the inherent noise limit of the sensor in the current operating environment can be quantified through actual measurement. Using this maximum fluctuation amplitude as the load determination threshold means that only when the signal deviates from the no-load reference signal by more than the inherent noise limit is the deviation considered to be caused by actual personnel load rather than sensor fluctuations. The effect is that the threshold is derived from actual field measurements rather than empirical settings, allowing it to adapt to the sensor characteristics and installation environment of different elevators, avoiding misjudgments of no-load conditions due to an excessively low threshold or missed judgments of light load conditions due to an excessively high threshold.

[0051] Secondly, at each acquisition moment covered during the creeping period, the corresponding weighing sensor signal is read, and the difference between this signal and the no-load reference signal is calculated. The principle is to use the no-load reference signal as the zero point, and through difference calculation, convert the current weighing signal into an offset relative to the no-load baseline. The magnitude of this offset directly reflects the weight of the additional load inside the car. The effect is to convert the absolute weighing value into a relative difference, eliminating the influence of the car's own weight and sensor zero drift, thus providing a unified reference benchmark for subsequent threshold comparisons.

[0052] Then, when the difference exceeds the load judgment threshold, it is determined that there is personnel load in the car, and this moment is marked as a load moment; when the difference does not exceed the load judgment threshold, this moment is marked as an empty moment. The principle is to use the load judgment threshold as a boundary to perform binary judgment on the difference. Exceeding the threshold indicates that the current load deviation has exceeded the sensor's inherent fluctuation range and can only be explained by personnel in the car or other additional loads, thus it is determined that there is personnel load and marked as a load moment. Conversely, not exceeding the threshold indicates that the current load deviation is still within the sensor's inherent fluctuation range, and it is impossible to distinguish between noise and real load, so it is conservatively marked as an empty moment. Its effect is to achieve moment-by-moment binary output of the load status through explicit threshold comparison, providing deterministic input for continuous aggregation of passenger-carrying periods, while using a conservative strategy to classify ambiguity intervals into empty periods, further reducing the risk of false alarms.

[0053] S105, within the candidate period for passenger entrapment, for each abnormal displacement moment, read the abnormal displacement moment and the corresponding car position of the previous moment from the car position signal, mark the direction of increasing car position as the upward direction, and mark the direction of decreasing car position as the downward direction; arrange the directions corresponding to all abnormal displacement moments within the candidate period for passenger entrapment in chronological order to obtain a direction sequence; calculate the velocity change between adjacent abnormal displacement moments based on the change in car position corresponding to each abnormal displacement moment, and obtain the acceleration based on the velocity change; when all directions in the direction sequence are the same, and the absolute value of the acceleration within a preset time is less than the preset acceleration threshold, generate a passenger entrapment confirmation signal.

[0054] Specifically, this step is limited to the candidate period for entrapment because S104 has previously ruled out two non-fault scenarios—empty car slippage and normal passenger transport—by the intersection of the creeping period and the passenger-carrying period. The displacements within this period all occur under the condition that the brake is closed and there are personnel loads in the car. Only by performing kinematic analysis on these conditions can entrapment be confirmed. The effect is to focus computational resources on high-confidence candidate intervals and avoid indiscriminate processing of data across all time periods.

[0055] The principle behind reading abnormal displacement moments and their corresponding car positions from the car position signal is that the car position signal is sampled hourly using a unified time base. The position difference between two adjacent sampling moments directly reflects the actual direction and amount of movement of the car within that sampling interval. Motion state can be inverted from position data without the need for an additional speed sensor. Its effect is that direction determination is completed using the already acquired underlying signals without increasing hardware costs. The direction in which the car position increases is marked as the upward direction, and the direction in which the car position decreases is marked as the downward direction. The principle is that the car position signal is output from the position detection device at the traction machine shaft end or in the hoistway. The value increases as the car rises and decreases as the car descends. Binarization of the value increases or decreases converts continuous position changes into discrete direction identifiers. Its effect is to provide a unified symbolic input for the consistency judgment of subsequent direction sequences.

[0056] The expression for the change in car position is:

[0057] In the formula, For the first The change in car position at each abnormal displacement moment; For the first At each abnormal displacement moment; This represents the car position signal value at that moment; The car position signal value at the previous sampling time; The sampling period; This is the time number of the abnormal displacement.

[0058] The directions corresponding to all abnormal displacement moments within the candidate period for passenger entrapment are arranged chronologically to obtain a direction sequence. The principle is that the candidate period for passenger entrapment may contain multiple consecutive abnormal displacement moments, each moment corresponding to an upward or downward direction indicator. Arranging them chronologically can reconstruct the evolution of the car's motion direction throughout the entire candidate period. Organizing the direction determination moment by moment into a sequence structure that can be examined as a whole makes it easier to determine whether the car is always creeping in a single direction.

[0059] Based on the change in car position corresponding to each abnormal displacement moment, the velocity change between adjacent abnormal displacement moments is calculated, and the acceleration is obtained from the velocity change. The principle is that dividing the change in car position by the time interval between adjacent abnormal displacement moments yields the average velocity within that time period. The difference between two adjacent average velocities, divided by the corresponding time interval, gives the acceleration. By using second-order difference analysis of the position signals, kinematic features reflecting changes in braking force can be extracted from the displacement data. Therefore, without the need for additional acceleration sensors, the acceleration or deceleration trend during car creep can be deduced from existing position signals, providing a quantitative basis for subsequent brake contact state determination.

[0060] The formula for calculating acceleration is as follows:

[0061]

[0062]

[0063] In the formula, For the first The car speed values ​​corresponding to each abnormal displacement moment; For the first The change in car position at each abnormal displacement moment; The sampling period; This represents the velocity change between two adjacent abnormal displacement moments. For the first +1 velocity value at abnormal displacement time; This represents the average acceleration between two adjacent abnormal displacement moments. For the first At each abnormal displacement moment; For the first +1 abnormal displacement time; This is the time number of the abnormal displacement.

[0064] A passenger entrapment confirmation signal is generated when all directions in the direction sequence are the same, and the absolute value of acceleration within a preset time is less than a preset acceleration threshold. The principle is that genuine passenger entrapment creep typically manifests as the car slowly sliding down a single direction due to gravitational imbalance while the brakes are closed. If alternating directions occur in the direction sequence, it indicates that the car is experiencing reciprocating vibrations, possibly due to maintenance, adjustments, or external interference, rather than continuous creep. Simultaneously, the absolute value of acceleration consistently being less than the preset acceleration threshold indicates that the car is in a near-uniform, slow sliding state, ruling out non-faulty movements such as sudden stops or normal starts and stops. Both conditions must be met simultaneously to confirm a passenger entrapment fault. The dual constraints of directional consistency and acceleration stability further compress the false alarm space, ensuring high reliability of the passenger entrapment confirmation signal.

[0065] For example, assuming the candidate time period for passenger entrapment is from t4 to t9, which includes six abnormal displacement moments: t4, t5, t6, t7, t8, and t9, after reading the car position at each moment and the previous moment, the calculated position change is positive. Therefore, the direction sequence is [upward, upward, upward, upward, upward, upward], with all directions being the same. Further, based on the position change, the velocity at each adjacent moment is calculated, and the acceleration is derived. It is found that the absolute value of the acceleration at each moment within the preset time is less than the preset acceleration threshold of 0.05 m / s². 2 The two conditions are met, thus generating a confirmation signal that the person is trapped.

[0066] Furthermore, after generating the entrapment confirmation signal, within a preset time period, the acceleration at each moment is compared with the average acceleration at all moments within that preset time period. When the acceleration at a moment is greater than the average, that moment is marked as a positive deviation moment; when the acceleration at a moment is less than the average, that moment is marked as a negative deviation moment. The principle is that the direction of acceleration fluctuation around the average value can reflect the trend of instantaneous changes in braking force. A positive deviation indicates that the instantaneous acceleration is higher than the average level, i.e., slippage is aggravated; a negative deviation indicates that the instantaneous acceleration is lower than the average level, i.e., slippage is suppressed. By comparing with the average value rather than with zero, the DC bias caused by the overall gravitational imbalance can be eliminated. Converting absolute acceleration into a relative deviation ensures that subsequent alternating statistics are not affected by the overall sliding acceleration baseline.

[0067] The average value of the acceleration over all time moments is:

[0068] In the formula, This is the average value of all accelerations within a preset time window; The number of acceleration values ​​within a preset time window; For the first One acceleration value; This is the sequence number of the acceleration value.

[0069] Then, the number of times positive and negative deviations alternate within a preset time period is counted. When the number of alternations exceeds a set number, it is determined that the brake shoe and brake wheel are in an intermittent contact state, sometimes sticking and sometimes sliding. When the number of alternations does not exceed a set number, it is determined that the brake shoe and brake wheel are in a stable sliding state with continuous contact but insufficient friction. The principle is that if there is an oxide layer or local unevenness on the contact surface between the brake shoe and brake wheel, a stick-slip phenomenon will occur during the sliding process, with the corresponding acceleration frequently alternating around the average value. If the friction surface of the brake shoe is uniformly worn, the friction is continuously insufficient, the car slides at an approximately uniform speed, and the acceleration deviation direction alternates less. The effect is to distinguish between two different physical causes of braking failure by the time-domain characteristics of acceleration fluctuations, providing a basis for subsequent rescue strategy selection.

[0070] The formula for calculating the number of alternating occurrences is as follows:

[0071] In the formula, This represents the number of times positive and negative deviation moments alternate. For the first The direction of acceleration deviation is indicated; For the first +1 acceleration deviation direction indicator; The number of acceleration values ​​within a preset time window; This is the sequence number of the acceleration value; This is an indicator function that takes the value 1 if the condition within the parentheses is true, and 0 otherwise.

[0072] The judgment result is output along with the trapped person confirmation signal for subsequent leveling rescue strategy selection. In the intermittent contact state, braking force can be restored by repeatedly releasing and closing the brake to grind the oxide layer, while in the stable slip state, this method is ineffective. These two states correspond to different rescue procedures. This allows the leveling rescue action of S106 to adaptively select the optimal strategy based on the actual brake failure mode.

[0073] S106, in response to the entrapment confirmation signal, reads the car position at the start time of the entrapment candidate period, generates a car leveling movement command to move the car to the nearest door zone, and generates a door opening command.

[0074] Specifically, this step is the key link in the entire detection and rescue process from fault confirmation to actual rescue execution. The principle is that the trapped person confirmation signal has been confirmed with high confidence that there are people in the car and they are in a slow crawling state under brake failure through the time intersection of the aforementioned creeping period and the passenger-carrying period, as well as the dual constraints of directional consistency and acceleration stability. At this time, the primary goal of the rescue is to safely move the car to the door area where the door can be opened in order to release the trapped people.

[0075] The principle of reading the car position at the start of the candidate period for trapped passengers is that the start time corresponds to the instant when the brake failure just occurred. At this time, the car position is closest to the normal stopping position before the failure. Using this as a reference, the distance and direction to the nearest door area can be calculated. This can avoid the inaccuracy of the leveling target calculation due to the car position shifting during the creeping process, and provide an accurate initial position anchor point for leveling movement, ensuring the shortest rescue path and the least time consumption.

[0076] The generation of a car leveling and movement command moves the car to the nearest door zone. This works by using a door zone detection device on each floor of the elevator shaft. By comparing the difference between the current car position and the door zone positions on each floor, the device selects the door zone with the smallest absolute value as the target leveling position. This allows the car to reach the safe door opening position with the shortest travel distance, reducing waiting time for trapped passengers and lowering the risk of secondary malfunctions during long-distance movement. The generation of the door opening command is the release action executed after the car has accurately reached the door zone.

[0077] Furthermore, after generating the car leveling and moving command to move the car to the nearest door zone, the process also includes reading the judgment result. When the result indicates an intermittent contact state, the execution of the car leveling and moving command is paused, and a multiple brake release and resetting command is generated first. The brake is controlled to repeatedly perform release and closing actions, attempting to restore braking force by removing the oxide layer on the contact surface through friction between the brake shoe and the brake wheel. The principle is that the intermittent contact state corresponds to an alternating stick-slip phenomenon caused by an oxide layer or local unevenness between the brake shoe and the brake wheel. At this time, the braking force is not completely lost but is in an unstable state. By repeatedly releasing and closing the brake, the brake shoe and the brake wheel generate relative friction and grinding, which can physically remove the oxide layer and burrs on the contact surface. The effect is to attempt to restore braking force in a low-cost mechanical self-repairing way, avoiding the safety hazards caused by directly moving the car in a failed state. After multiple brake release and reset commands are executed, the brake status is re-checked. If the brake has recovered normal braking force, leveling movement continues at the normal rescue speed. If the brake has not recovered, leveling movement continues at a safe speed. The principle is that the effect of brake release and reset is uncertain, and the recovery result must be verified by actual braking force testing. When normal braking force is restored, leveling can be completed efficiently at the normal rescue speed. When it has not recovered, the speed needs to be reduced to ensure that the car remains in a controllable, slow movement under insufficient braking force. The effect is to adaptively adjust the rescue speed according to the actual recovery result, balancing rescue efficiency and safety. When the result is a stable sliding state, it is determined that the brake shoe friction surface is worn as a whole, and brake release and reset cannot restore braking force. Leveling movement is directly performed at a safe speed. The principle is that the friction material in a stable sliding state has been uniformly worn to the point of continuous insufficient friction. Repeated brake release and reset cannot restore the friction coefficient through grinding, and may even aggravate wear. Therefore, the reset step is skipped and low-speed leveling is directly entered; this avoids ineffective operations that delay the rescue opportunity and completes the release of personnel at a conservative but reliable safe speed.

[0078] like Figure 2 As shown, based on the same inventive concept, this embodiment provides an automatic detection and rescue system for people trapped in elevators, including: The signal acquisition module 201 is used to acquire car position signals, weighing sensor signals and brake status signals during elevator operation; The event timing module 202 is used to perform adjacent comparisons of the car position signal moment by moment, and mark the moment when the car position changes as the displacement moment; to perform adjacent comparisons of the brake status signal moment by moment, and mark the moment when the brake status changes as the switching moment; to use the signal first collected after the elevator is powered on from the weighing sensor signal as the no-load reference signal; and to arrange the displacement moment and the switching moment in chronological order to obtain the timing event sequence. The creep detection module 203 is used to search for the nearest switching time for each displacement time in the time sequence of events. When the brake state corresponding to the nearest switching time is closed, the displacement time is marked as an abnormal displacement time. The time period covered by consecutively occurring abnormal displacement times is marked as a creep period. Consecutive occurrence means that there is no switching time when the brake is in the released state between two adjacent abnormal displacement times. The manned discrimination module 204 is used to compare the weighing sensor signal with the no-load reference signal hour by hour during the creeping period, mark the time when the two are different as the load time, mark the time period covered by the consecutive load times as the manned period; and take the time intersection of the manned period and the creeping period to obtain the candidate period for trapped people. The passenger entrapment confirmation module 205 is used to read the abnormal displacement moment and the corresponding car position of the previous moment from the car position signal for each abnormal displacement moment during the passenger entrapment candidate period. The direction of increasing car position is marked as the upward direction, and the direction of decreasing car position is marked as the downward direction. The directions corresponding to all abnormal displacement moments during the passenger entrapment candidate period are arranged in chronological order to obtain a direction sequence. Based on the change in car position corresponding to each abnormal displacement moment, the velocity change between adjacent abnormal displacement moments is calculated, and the acceleration is obtained based on the velocity change. When all directions in the direction sequence are the same, and the absolute value of the acceleration within a preset time is less than a preset acceleration threshold, a passenger entrapment confirmation signal is generated. The automatic rescue module 206 is used to respond to the entrapment confirmation signal, read the car position at the start time of the entrapment candidate period, generate a car leveling movement command to move the car to the nearest door area, and generate a door opening command.

[0079] like Figure 3 As shown, based on the same inventive concept, this embodiment provides an electronic device, including: Memory 302 is used to store computer programs; Processor 301 is used to implement the method steps as described in the first aspect when executing a computer program.

[0080] Based on the same inventive concept, this embodiment provides a readable storage medium on which a computer program is stored, and when the computer program is executed by a processor, it implements the method steps as described in the first aspect.

[0081] It should be noted that the specific methods by which each module performs operations in the system described in the above embodiments have been described in detail in the embodiments related to the method, and will not be elaborated here.

[0082] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An automatic detection and rescue method for people trapped in elevators, characterized in that, include: During elevator operation, the car position signal, weighing sensor signal, and brake status signal are collected. The car position signal is compared with adjacent signals at each time step, and the time when the car position changes is marked as the displacement time; the brake status signal is compared with adjacent signals at each time step, and the time when the brake status changes is marked as the switching time; the signal first collected after the elevator is powered on from the weighing sensor signal is used as the no-load reference signal. Arrange the displacement time and the switching time in chronological order to obtain a time sequence event sequence; In the time sequence of events, for each displacement moment, the nearest switching moment is searched backward. When the brake state corresponding to the nearest switching moment is closed, the displacement moment is marked as an abnormal displacement moment. The time period covered by consecutive abnormal displacement moments is marked as the creep period. The consecutive occurrence means that there is no corresponding brake release state switching moment between two adjacent abnormal displacement moments. During the creeping period, the weighing sensor signal is compared with the no-load reference signal moment by moment. The moments when the two are different are marked as the load moments, and the time period covered by consecutive load moments is marked as the manned period. The intersection of the manned time period and the creeping time period is used to obtain the candidate time period for trapping people. Within the candidate period for passenger entrapment, for each abnormal displacement moment, the abnormal displacement moment and the corresponding car position of the previous moment are read from the car position signal. The direction in which the car position increases is marked as the upward direction, and the direction in which the car position decreases is marked as the downward direction. The directions corresponding to all abnormal displacement moments within the candidate period for passenger entrapment are arranged in chronological order to obtain a direction sequence. Based on the change in car position corresponding to each abnormal displacement moment, the velocity change between adjacent abnormal displacement moments is calculated, and the acceleration is obtained based on the velocity change. When all directions in the direction sequence are the same, and the absolute value of the acceleration is less than a preset acceleration threshold within a preset time, a tethered person confirmation signal is generated. In response to the entrapment confirmation signal, the car position at the start time of the entrapment candidate period is read, a car leveling movement command is generated to move the car to the nearest door area, and a door opening command is generated.

2. The automatic detection and rescue method for people trapped in an elevator according to claim 1, characterized in that, The step of arranging the displacement time and the switching time in chronological order to obtain a time-series event sequence specifically includes: An event record is generated for each displacement moment and each switching moment, and the event record includes the event occurrence time and the event type identifier; All event records are sorted in chronological order according to the time of occurrence. When the displacement time and the switching time occur at the same time, the event record of the switching time is arranged before the event record of the displacement time. The sorted event records are stored sequentially to form the time-series event sequence.

3. The automatic detection and rescue method for people trapped in an elevator according to claim 1, characterized in that, The process of searching forward for the nearest switching time for each displacement moment, and marking the displacement moment as an abnormal displacement moment when the brake state corresponding to the nearest switching time is closed, specifically includes: The event record corresponding to each displacement moment is sequentially extracted from the time sequence of events. Starting from the event record, the time sequence of events is traversed backward to find the event record corresponding to the first switching moment. The brake state corresponding to the switching moment is read. If the brake state is closed, it is determined that the brake has not been released and the car has moved. The displacement moment is marked as the abnormal displacement moment. If the brake state is released, the displacement moment is marked as the normal displacement moment.

4. The automatic detection and rescue method for people trapped in an elevator according to claim 3, characterized in that, The step of marking the time period covered by consecutive abnormal displacement moments as the creeping period specifically includes: The scan begins from the starting position of the time-series event sequence. When the first abnormal displacement moment is detected, this abnormal displacement moment is recorded as the start time of the creeping period. During the backward scan, if there is no switch moment between the brake release state and the previous abnormal displacement moment, the subsequent abnormal displacement moment is included in the same creeping period. When the switch moment of the brake release state is scanned, the last abnormal displacement moment before the switch moment is recorded as the end moment of the creeping period. The creeping period is composed of the start moment of the creeping period and the end moment of the creeping period.

5. The automatic detection and rescue method for people trapped in an elevator according to claim 1, characterized in that, During the creeping period, the weighing sensor signal is compared with the no-load reference signal hour by hour, and the times when the two are different are marked as the loading times, specifically including: Several weighing sensor signals are continuously collected when the elevator is unloaded. The maximum fluctuation amplitude of the collected signals is recorded and used as the load determination threshold. At each collection moment covered by the creeping period, the weighing sensor signal corresponding to that moment is read, and the difference between the weighing sensor signal and the unloaded reference signal is calculated. When the difference exceeds the load determination threshold, it is determined that there is a person load in the car, and the moment is marked as the load moment. When the difference does not exceed the load determination threshold, the moment is marked as the unloaded moment.

6. The automatic detection and rescue method for people trapped in an elevator according to claim 1, characterized in that, After generating the trapped person confirmation signal, the process also includes: Within the preset time period, the acceleration at each moment is compared with the average acceleration at all moments within the preset time period. When the acceleration at a moment is greater than the average, the moment is marked as a positive deviation moment. When the acceleration at a moment is less than the average, the moment is marked as a negative deviation moment. The number of times positive and negative deviation moments alternate within the preset time period is counted; when the number of alternations exceeds the set number, it is determined that the brake shoe and brake wheel are in an intermittent contact state that is sometimes sticky and sometimes sliding; when the number of alternations does not exceed the set number, it is determined that the brake shoe and brake wheel are in a stable sliding state with continuous contact but insufficient friction; the result of the determination is output along with the trapped person confirmation signal for subsequent leveling rescue strategy selection.

7. The automatic detection and rescue method for people trapped in an elevator according to claim 6, characterized in that, After the generated car leveling and movement command moves the car to the nearest door zone, it also includes: The result of the determination is read. When the result is an intermittent contact state, the execution of the car leveling movement command is paused. First, a multiple release and resetting command for the brake is generated. The brake is controlled to repeatedly perform release and closing actions. The friction between the brake shoe and the brake wheel removes the oxide layer on the contact surface in an attempt to restore braking force. After the multiple release and resetting command for the brake is completed, the brake status is re-checked. If the brake has restored normal braking force, the leveling movement continues at the normal rescue speed. If the brake has not yet restored, the leveling movement continues at a safe speed. When the result is a stable sliding state, it is determined that the brake shoe friction surface has been worn as a whole, and the braking force cannot be restored by releasing and resetting the brake. The leveling movement is then performed directly at a safe speed.

8. An automatic elevator entrapment detection and rescue system, based on the automatic elevator entrapment detection and rescue method described in claim 1, characterized in that, include: The signal acquisition module is used to acquire car position signals, weighing sensor signals, and brake status signals during elevator operation. The event timing module is used to perform adjacent comparisons on the car position signal at each time step, and mark the time when the car position changes as the displacement time. The brake status signal is compared sequentially at each time step, and the time when the brake status changes is marked as the switching time; the signal first collected after the elevator is powered on from the weighing sensor signal is used as the no-load reference signal. Arrange the displacement time and the switching time in chronological order to obtain a time sequence event sequence; The creep detection module is used to search for the nearest switching time for each displacement time in the time sequence of events. When the brake state corresponding to the nearest switching time is closed, the displacement time is marked as an abnormal displacement time. The time period covered by consecutive abnormal displacement moments is marked as the creep period. The consecutive occurrence means that there is no corresponding brake release state switching moment between two adjacent abnormal displacement moments. The manned discrimination module is used to compare the weighing sensor signal with the no-load reference signal hour by hour during the creeping period, mark the time when the two are different as the load time, and mark the time period covered by consecutive load times as the manned period. The intersection of the manned time period and the creeping time period is used to obtain the candidate time period for trapping people. The passenger entrapment confirmation module is used to, within the passenger entrapment candidate period, for each abnormal displacement moment, read the abnormal displacement moment and the corresponding car position of the previous moment from the car position signal, mark the direction of increasing car position as the upward direction, and mark the direction of decreasing car position as the downward direction; arrange the directions corresponding to all abnormal displacement moments within the passenger entrapment candidate period in chronological order to obtain a direction sequence; calculate the velocity change between adjacent abnormal displacement moments based on the change in car position corresponding to each abnormal displacement moment, and obtain the acceleration based on the velocity change; When all directions in the direction sequence are the same, and the absolute value of the acceleration is less than a preset acceleration threshold within a preset time, a tethered person confirmation signal is generated. The automatic rescue module is used to respond to the entrapment confirmation signal, read the car position at the start time of the entrapment candidate time period, generate a car leveling movement command to move the car to the nearest door area, and generate a door opening command.

9. An electronic device, characterized in that, include: Memory, used to store computer programs; A processor is configured to execute the computer program to implement the automatic detection and rescue method for elevator entrapment as described in any one of claims 1 to 7.

10. A readable storage medium, characterized in that: The readable storage medium stores a computer program, which, when executed by a processor, implements an automatic detection and rescue method for elevator entrapment as described in any one of claims 1 to 7.

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