Traction machine band-type brake state monitoring method, device and equipment and storage medium

Abstract

The invention provides a traction machine band-type brake state monitoring method, device and equipment and a storage medium, and belongs to the technical field of elevators. The method comprises the steps that the encoder pulse number of an elevator traction machine is obtained; in response to an elevator starting operation instruction, if the encoder pulse number detected in a preset first time window exceeds a first set threshold value, it is determined that a band-type brake is in an opening effective state; and in response to an elevator running stopping instruction, if the encoder pulse number detected in a preset second time window is lower than a second set threshold value, it is determined that the band-type brake is in an effective closing state. On the basis of a physical microswitch, redundancy monitoring based on encoder pulses is added, a time window and a threshold value are set in the starting stage and the stopping stage respectively to judge the brake state, switch misoperation caused by small mechanical stroke and thermal expansion and cold contraction is reduced, and elevator sudden stop and people trapping faults are reduced.

Description

Technical Field

[0001] This invention belongs to the field of elevator technology, and in particular relates to a method, device, equipment and storage medium for monitoring the brake status of a traction machine. Background Technology

[0002] Elevator brake microswitches monitor the brake status through instantaneous mechanical action, ensuring safe elevator operation. Currently, elevator traction machines use brake microswitches to monitor the lowering and opening of the brake. When the elevator starts running, the brake opens, and the brake microswitch provides valid feedback. When the elevator reaches the destination floor, the traction machine begins to decelerate. After reaching zero speed, the brake lowers, the frequency converter stops outputting, and the brake microswitch provides invalid feedback.

[0003] In practical applications, the effectiveness of the brake microswitch is judged according to the above logic. If the effectiveness of the brake microswitch does not match the set logic, the fault is detected after a set time. In practical applications, the brake stroke is very small, generally only about 0.4mm. When the brake stroke is adjusted or the motor vibrates during elevator operation, the brake microswitch often malfunctions, causing the elevator to stop suddenly, affecting the normal operation of the elevator and leading to problems such as people being trapped. Summary of the Invention

[0004] In view of this, the present invention provides a method, apparatus, device and storage medium for monitoring the brake status of a traction machine, so as to improve the accuracy of monitoring the brake status of a traction machine.

[0005] A first aspect of the present invention provides a method for monitoring the brake status of a traction machine, comprising:

[0006] Obtain the encoder pulse count of the elevator traction machine;

[0007] In response to the elevator start-up command, if the number of encoder pulses detected within the preset first time window exceeds the first set threshold, it is determined that the brake is in an open and effective state.

[0008] In response to the elevator stop command, if the number of encoder pulses detected within the preset second time window is lower than the second set threshold, it is determined that the brake is in an effective closed state.

[0009] A second aspect of the present invention provides a monitoring device for the brake status of a traction machine, comprising:

[0010] The data acquisition module is used to acquire the encoder pulse count of the elevator traction machine;

[0011] The first response module is used to respond to the elevator start-up command. If the number of encoder pulses detected within the preset first time window exceeds the first set threshold, it determines that the brake is in an open and effective state.

[0012] The second response module is used to respond to the elevator stop command. If the number of encoder pulses detected within the preset second time window is lower than the second set threshold, it determines that the brake is in an effective closed state.

[0013] A third aspect of the present invention provides an electronic device including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements the method for monitoring the brake status of a traction machine as described in the first aspect above.

[0014] A fourth aspect of the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method for monitoring the brake status of a traction machine as described in the first aspect above.

[0015] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0016] This invention uses encoder pulse counts to determine the brake status, based on the fundamental principles of elevator operation: the brake must be open before the elevator starts so the traction machine can rotate; the brake must be closed when the elevator stops so the traction machine stops rotating. Therefore, there is a definite correspondence between the rotation state of the traction machine and the actual state of the brake, meaning the encoder pulses can characterize the rotation state of the traction machine, thus avoiding the impact on monitoring reliability caused by relying solely on microswitches.

[0017] Specifically, in response to a start-up command, if the number of encoder pulses detected within a preset first time window exceeds a first set threshold, it indicates that the traction machine has started rotating normally, and the brake is thus determined to be open. In response to a stop-up command, if the number of encoder pulses detected within a preset second time window is lower than a second set threshold, it indicates that the traction machine has basically stopped, and the brake is thus determined to be closed. The setting of the time window and threshold effectively filters out the influence of pulse jitter or instantaneous interference on the judgment result, achieving reliable monitoring of the brake status without relying on physical contacts, reducing emergency stops and trapped personnel caused by switch malfunctions. Furthermore, this method does not increase hardware costs, being implemented only through software logic, and has good economic efficiency and applicability. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1This is a flowchart of a method for monitoring the brake status of a traction machine according to an embodiment of the present invention;

[0020] Figure 2 This is a flowchart of a method for determining the effective state of brake release provided in an embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram of a monitoring device for the brake status of a traction machine provided in an embodiment of the present invention;

[0022] Figure 4 This is a schematic diagram of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0023] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the present invention. However, those skilled in the art will recognize that the present application may be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted to avoid unnecessary detail that could obscure the description of the present application.

[0024] The technical solution of the present invention will be illustrated below through specific embodiments.

[0025] Reference Figure 1 This diagram illustrates a method for monitoring the brake status of a traction machine according to an embodiment of the present invention. This method can be executed by a device for monitoring the brake status of the traction machine. This device can be implemented in hardware and / or software and can be configured in an electronic device. Figure 1 As shown, the method may specifically include the following steps:

[0026] S101. Obtain the encoder pulse count of the elevator traction machine.

[0027] Traction machines are typically equipped with rotary encoders, which output pulse signals as the main shaft of the traction machine rotates, thus obtaining the encoder pulse count of the elevator traction machine.

[0028] During normal elevator operation, there is a definite correspondence between the rotation of the traction machine and the state of the brake: when the elevator is running, the brake must be in the open position for the traction machine to rotate normally; when the elevator stops, the brake must be in the closed position for the traction machine to stop rotating. Therefore, by monitoring the rotation status of the traction machine, the actual state of the brake can be indirectly determined.

[0029] The acquisition of encoder pulse counts is typically accomplished by a frequency converter or main controller. Specifically, the main controller acquires the pulse signal output by the encoder in real time through a high-speed counting channel. This pulse signal directly reflects the rotational state of the traction machine: when the traction machine is rotating, the pulse count continuously accumulates; when the traction machine is stationary, the pulse count remains unchanged.

[0030] It should be noted that the encoder pulse count in this invention is not an instantaneous frequency, but rather an accumulated value within a preset time window. This design is based on the following considerations: During the actual operation of the elevator, the encoder pulses may experience momentary jitter due to factors such as vibration and electromagnetic interference. If the instantaneous frequency is used as the basis for judgment, it is easy to make misjudgments. Therefore, this invention uses the accumulated value within a time window, which can filter out such momentary interference and improve the reliability of monitoring.

[0031] In practical implementation, the length of the time window can be set according to the sampling period of the control system and the response characteristics of the traction machine. For example, it can be set to 50 milliseconds, 100 milliseconds, or 200 milliseconds. If the time window is too short, it may not be able to effectively filter out interference; if the time window is too long, it may affect the real-time performance of the judgment. Therefore, the shortest possible time window should be selected while ensuring the filtering of interference.

[0032] S102. Upon receiving an elevator instruction, determine the type of elevator instruction.

[0033] Elevator commands include elevator start commands and elevator stop commands.

[0034] If the elevator command is an elevator start command, then execute S103; if the elevator command is an elevator stop command, then execute S104.

[0035] S103. In response to the elevator start-up command, if the number of encoder pulses detected within the preset first time window exceeds the first set threshold, determine that the brake is in an open and effective state.

[0036] During normal elevator operation, the brake must be released before the elevator starts. Only after the brake is released can the traction machine begin to rotate. If the brake fails to release, the traction machine will be stalled and unable to rotate normally. Therefore, whether the traction machine has started to rotate normally can be used as a basis for determining whether the brake has been released.

[0037] When the traction machine starts to rotate, the encoder pulse count accumulates rapidly within a unit of time; when the traction machine is stationary, the pulse count remains unchanged. Therefore, by monitoring the pulse accumulation value within a preset first time window, it can be determined whether the traction machine has started to rotate normally, and thus infer whether the brake has been released.

[0038] Considering that the brake requires a certain mechanical action time from receiving the release command to fully releasing, and this time is affected by factors such as the response speed of the brake electromagnet, the spring preload, and the brake shoe clearance, it is typically between tens of milliseconds and over a hundred milliseconds. Therefore, this embodiment sets a first time window to give the brake sufficient action time and avoid premature judgment before the brake is fully released. Secondly, the traction machine also requires a certain settling time to accelerate from a stationary state. Setting a first time window ensures that the pulse count is collected after the traction machine speed stabilizes, avoiding misjudgments caused by pulse fluctuations in the initial startup phase.

[0039] In practical applications, the length of the first time window can be set according to the acceleration performance of the traction machine and the braking action time. For example, it can be set to 200 milliseconds or 300 milliseconds. The specific value can be calibrated during factory commissioning or adjusted online according to the actual operating conditions.

[0040] The first set threshold is used to determine the lower limit of the number of pulses when the traction machine is running normally. The first set threshold is determined by the rated speed of the traction machine, because the rated speed of the traction machine determines the theoretical number of pulses per unit time. Since the traction machine has not yet reached its rated speed during the elevator startup and operation phase, the first set threshold should be less than this theoretical value.

[0041] In practical settings, the first threshold can be a percentage of the pulse count corresponding to the rated speed, such as 50% or 60%. It can also be calibrated based on the measured pulse curve during the traction machine's startup phase. For example, if the encoder outputs 1024 pulses per revolution and the traction machine's rated speed is 100 revolutions per minute, the theoretical pulse count per second is approximately 1707, and the first threshold is set to 850.

[0042] When the above conditions are met, the brake is determined to be in an active open state. This judgment result can be used in the following aspects:

[0043] First, it serves as a safety clearance signal for elevator operation. Only after the brake is confirmed to be open can the elevator accelerate normally. If a sufficient number of pulses are not detected within the preset first time window, the elevator system can determine that the brake has not been properly opened and take protective measures, such as outputting a stop operation command or issuing a fault alarm.

[0044] Secondly, it serves as a redundant monitoring signal, compared with the signal from the physical microswitch. When the judgment result from the physical microswitch differs from that of this solution, potential faults can be identified, improving the reliability of safety monitoring.

[0045] S104. In response to the elevator stop command, if the number of encoder pulses detected within the preset second time window is lower than the second set threshold, determine that the brake is in the closed effective state.

[0046] During the elevator's stopping process, once the traction machine decelerates to zero speed, the control system issues a brake closing command. The brake electromagnet is de-energized, and the brake shoes, under spring force, press against the brake disc, keeping the traction machine stationary. Similar to the starting phase's logic, the stopping phase's judgment is also based on the correspondence between the traction machine's rotation state and the brake's state: when the brake is fully closed, the traction machine should be stationary, and the encoder pulse count should approach zero. Therefore, by monitoring whether the accumulated pulse value within a preset second time window is lower than a certain low threshold (the second set threshold), it can be determined whether the traction machine has essentially stopped, and thus, whether the brake has closed.

[0047] Similar to the judgment logic in the startup phase, the judgment in the stopping phase is also based on the correspondence between the rotation state of the traction machine and the brake state: when the brake is fully closed, the traction machine should be in a stationary state, and the encoder pulse count should approach zero. Therefore, by monitoring whether the pulse accumulation value within the preset second time window is lower than a certain low threshold, it can be determined whether the traction machine has basically stopped, and thus infer whether the brake has been closed.

[0048] The traction machine requires a certain amount of time to decelerate to a complete stop. Although the control system can precisely control the deceleration process, at zero speed, the traction machine may still experience slight rotation due to inertia. Setting a time window ensures that the judgment is made only after the traction machine has completely stopped. Secondly, the brake also requires mechanical action time from receiving the closing command to fully engaging. Setting a second time window avoids judging the brake as closed before it is fully closed. In practical applications, the length of the second time window can be the same as the first time window, or it can be set separately according to the characteristics of the stopping process (different from the length of the first time window). For example, it can be set to 200 milliseconds.

[0049] The second threshold is used to determine the upper limit of the number of pulses at which the traction machine has essentially come to a stop. The setting of this threshold needs to consider the following factors:

[0050] Ideally, the encoder pulse count should be zero when the traction machine is completely stationary. However, in practical applications, due to encoder resolution limitations and signal transmission noise, the pulse count may fluctuate within a certain range. Therefore, the second set threshold should be set to a reasonably low value to allow for normal, minor fluctuations while effectively identifying abnormal rotation. This value should not be too small, otherwise it may lead to misjudgment due to normal fluctuations; nor should it be too large, otherwise it may be incorrectly judged as a stopped state before the traction machine has completely come to a stop.

[0051] In practical applications, the second set threshold can be set to 1% to 3% of the number of pulses corresponding to the rated speed. For example, if the number of pulses per second at the rated speed is 1707, then the second set threshold can be set to 17 to 51 pulses.

[0052] When the above conditions are met, the brake is determined to be in a closed and effective state. This judgment result can be used in the following aspects:

[0053] First, confirm that the elevator has stopped safely before allowing door opening and closing operations. If the pulse count fails to drop below the second set threshold within the preset time window, it indicates that the traction machine is still running and the brake may not have closed properly. The system should then prohibit door opening and issue a fault alarm.

[0054] Secondly, it serves as a basis for monitoring braking performance. If there is an abnormal change in the time interval between the issuance of the stop command and the pulse count falling below the threshold, it may indicate a decline in the performance of the brake spring or wear of the brake shoes, and an early warning can be issued.

[0055] It should be noted that the judgment results of S103 and S104 can be used in multiple stages such as operation permission, fault alarm, and status monitoring, forming a complete closed loop from data collection to result application.

[0056] The method in this embodiment serves as a redundant monitoring means for the physical brake microswitch, and is used together with the physical microswitch for safety monitoring of the brake status.

[0057] The traction machine brake status monitoring method provided by this invention indirectly monitors the brake status by acquiring encoder pulse counts and setting judgment logic during elevator start-up and stop phases. Specifically, in response to a start-up command, if the number of encoder pulses detected within a preset first time window exceeds a first set threshold, it indicates that the traction machine has started operating normally, and the brake is thus determined to be open. In response to a stop-up command, if the number of encoder pulses detected within a preset second time window is lower than a second set threshold, it indicates that the traction machine has basically stopped, and the brake is thus determined to be closed. The setting of time windows and thresholds effectively filters out the influence of pulse jitter or instantaneous interference on the judgment results, achieving reliable monitoring of the brake status without relying on physical contacts, and reducing emergency stops and passenger entrapment caused by switch malfunctions.

[0058] In an optional embodiment, the first set threshold and / or the second set threshold are dynamically set based on at least one parameter among the elevator's rated speed, load weight, and real-time speed curve.

[0059] The first set threshold is used to determine whether the brake has opened during the start-up phase. Its setting is based on at least one parameter from the elevator's rated speed, load weight, and real-time speed curve. The rated speed determines the theoretical number of pulses per unit time during normal operation of the traction machine and can serve as a benchmark reference value. Load weight affects acceleration performance during the start-up phase; under heavy load, the traction machine accelerates more slowly, resulting in fewer pulses within the same time window. Using a fixed threshold might lead to the traction machine failing to reach the threshold under heavy load, resulting in a misjudgment that the brake has not opened. Therefore, the first set threshold needs to be compensated and corrected based on the load weight. The real-time speed curve reflects the speed change pattern during elevator start-up. By dynamically adjusting the threshold according to the speed curve, it is possible to more accurately determine whether the traction machine has reached the expected start-up state.

[0060] The second threshold is used to determine whether the brake is closed during the stopping phase, and its setting can also be based on at least one of the parameters mentioned above. During the stopping phase, the rated speed can be used to determine the lower limit of the number of pulses corresponding to the basic stable stopping state; the load weight has a relatively small impact on the stopping process, but it can still be used as a reference in some scenarios; the real-time speed curve can be used to determine whether the deceleration process is normal.

[0061] When the elevator starts, the motor accelerates after the brake is released, inevitably resulting in a high pulse count. When it stops, the motor decelerates to near zero speed before the brake is closed, inevitably reducing the pulse count to a low level. Therefore, the first set threshold is greater than the second set threshold.

[0062] In practical implementation, dynamic setting can be accomplished through table lookup, formula calculation, or adaptive algorithms. For example, the optimal threshold under different load conditions is calibrated through testing at the factory to form a mapping table; during operation, the corresponding threshold is obtained by looking up the table based on the current load weight. Another example is that the threshold can be dynamically adjusted based on the slope of the real-time speed curve to ensure that the judgment conditions match the current operating state in real time.

[0063] By adopting a dynamic threshold setting method, this method can be adapted to elevators with different rated speeds, different load conditions, and different speed control strategies, avoiding misjudgments caused by fixed thresholds and improving the reliability and adaptability of brake status monitoring.

[0064] In an optional embodiment, such as Figure 2 The flowchart shown illustrates a method for determining the effective open state of a brake, which further includes determining that the brake is in the effective open state:

[0065] S201. Obtain the trend of motor current change.

[0066] S202. If the motor current drops from the stall current to the normal starting current range, and the number of encoder pulses detected within the preset first time window exceeds the first set threshold, then the holding brake is determined to be in the open effective state.

[0067] In this embodiment, based on the detection that the number of encoder pulses exceeds a first preset threshold within the first time window, the current change trend of the motor is further acquired. If the motor current drops from the stall current to the normal starting current range, it is finally determined that the brake is in an effective open state.

[0068] If the encoder pulse count exceeds the first set threshold, it indicates that the traction machine has started to rotate; however, the rotation signal alone is not enough to completely rule out certain extreme situations. For example, if the traction sheave slips, the motor may rotate but the car may not move. In this case, the brake may have been released but the elevator may be malfunctioning. Alternatively, the encoder signal may be affected by momentary interference, causing the pulse count to be artificially high. The situation is different after adding motor current judgment.

[0069] The stall current is a large current value generated when the motor rotor is stuck and cannot rotate, typically several times the rated current. When the brake is closed, the traction machine cannot rotate, and the motor current is in a stall state. After the brake is released, the rotor gains free rotation space, the load resistance disappears, and the motor current quickly drops to the normal starting current range. Therefore, the current dropping from the stall value to the normal starting range directly reflects the state that the brake has been released and the load resistance has disappeared.

[0070] In practical implementation, the normal starting current range can be pre-calibrated based on the traction machine's rated current, load conditions, and measured data. For example, it can be set to 80% to 120% of the rated current as the normal starting current range, or different range values ​​can be set according to different operating conditions such as no-load and full-load. The identification of stall current can be achieved by detecting the peak current at the moment of startup. When the current exceeds a set multiple of the rated current (such as 5 times), it is determined to be in a stall state.

[0071] Through the above dual verification mechanism, this embodiment retains the advantages of encoder pulse judgment while adding a verification method based on motor current, which further improves the reliability of brake open state judgment and effectively avoids misjudgment caused by factors such as slippage, signal interference or mechanical jamming.

[0072] In an optional embodiment, it further includes:

[0073] During each brake release, monitor the response time taken for the motor current to drop from the stall current to the preset normal starting current range; based on the trend of the response time change, determine the degree of aging of the brake spring or the degree of wear of the brake shoe.

[0074] From receiving the release command to fully releasing the brake, a series of mechanical actions are required, including electromagnet engagement, overcoming spring preload, and brake shoe separation from the brake disc. The time required for this process directly reflects the condition of the brake mechanical system. When the brake spring ages, its elasticity decreases, and the electromagnet needs more time to overcome the spring force to complete the action, resulting in a longer response time. When the brake shoes wear, the gap between the brake shoes and the brake disc increases, and the brake stroke lengthens, also leading to an increased response time. Therefore, the trend of response time can serve as a quantitative indicator of the degradation of the brake mechanical condition. In general, an increased response time indicates a more severe aging of the brake spring or wear of the brake shoes.

[0075] In practice, the moment the current drops from the stall current to the normal starting current range precisely corresponds to the moment the brake is physically released. This is because before the brake is released, the motor is in a stalled state, and the current remains at a high level; at the instant the brake is released, the load resistance disappears, and the motor current drops rapidly. By capturing the inflection point of the current drop, the exact time when the brake completes its mechanical action can be determined. The duration from the issuance of the brake release command to this point in time is the response time.

[0076] Specifically, the response time of each brake release process is recorded and stored to form a historical data sequence. By analyzing the trend of this sequence, the degree of degradation of the brake's mechanical condition can be determined. For example, if the response time shows a continuous increasing trend in multiple operations, it indicates that the brake spring is gradually aging or the brake shoe is gradually wearing down; if the rate of increase in response time accelerates, it may indicate that a failure is imminent and maintenance needs to be arranged.

[0077] In practical applications, various trend analysis methods can be employed. For example, an early warning threshold can be set, and a maintenance warning can be issued when the moving average of the response time exceeds a set percentage (such as 120%) of the calibrated value. Alternatively, a baseline model of the response time can be established, and algorithms such as linear regression can be used to predict future trends, thereby achieving predictive maintenance.

[0078] Through the above methods, this embodiment not only achieves real-time monitoring of the brake status, but also has the ability to track and predict the mechanical aging and wear of the brake over a long period of time, thus avoiding sudden brake failure.

[0079] In an optional embodiment, it further includes:

[0080] During each brake release process, monitor the time interval from the issuance of the elevator start-up command to the first time the encoder pulse count exceeds the first set threshold; determine the aging degree of the brake spring or the wear degree of the brake shoe based on the changing trend of the time interval.

[0081] After the brake release command is issued, the elevator system needs to sequentially complete a series of processes, including electromagnet engagement, brake shoe release, traction machine start-up, and encoder pulse accumulation until a threshold is exceeded. The time interval from command issuance to the first pulse exceeding the threshold reflects the overall response speed of the entire start-up chain. When the brake spring ages, the electromagnet needs more time to overcome the spring force, resulting in delayed brake shoe release and consequently delaying the start-up of the traction machine. When the brake shoes wear, the brake travel lengthens, also causing a response delay. Therefore, the trend of this time interval can indirectly reflect the degree of degradation of the brake's mechanical condition. In general, an increased time interval indicates a more severe aging of the brake spring or wear of the brake shoes.

[0082] Compared to the aforementioned monitoring schemes based on current response time, this embodiment uses encoder pulses as the judgment criterion, which has the advantages of simple implementation and no need for additional sensors. The encoder pulse signal already exists in the elevator control system, and monitoring can be completed directly using this signal without increasing hardware costs.

[0083] In practice, the elevator system records the time interval during each brake opening process, forming a historical data sequence. By analyzing the trend of this sequence, the degradation of the brake's mechanical condition can be determined. For example, if the time interval shows a continuous increasing trend over multiple runs, it indicates that the brake spring is gradually aging or the brake shoes are gradually wearing out; if the rate of increase accelerates, it may indicate that a failure is imminent and maintenance needs to be arranged.

[0084] In practical applications, various trend analysis methods can be employed. For example, an early warning threshold can be set: when the moving average of the time interval exceeds a set percentage (such as 120%) of the calibrated value, a maintenance warning is issued. Alternatively, a benchmark model of the time interval can be established, and algorithms such as linear regression can be used to predict future trends, thus achieving predictive maintenance.

[0085] Through the above method, this embodiment utilizes existing encoder pulse signals to achieve long-term tracking and fault prediction of mechanical aging and wear of the brake, thus avoiding sudden brake failure.

[0086] In an optional embodiment, it further includes:

[0087] During the elevator's constant speed operation phase, monitor the amplitude of the motor's current fluctuation.

[0088] If the detected current fluctuation exceeds the preset threshold, and the fluctuation of the encoder pulse count detected within multiple consecutive third time windows relative to the theoretical pulse count corresponding to the rated speed does not exceed the preset percentage, then it is determined that there is a drag brake fault where the holding brake is not fully opened.

[0089] When the brake is fully released, the traction machine is in a free-rotating state. The motor current mainly reflects the change in load torque and should remain relatively stable during the constant-speed operation phase. The encoder pulse count reflects the actual speed of the traction machine and should also remain stable during the constant-speed operation phase. If the brake is not fully released, abnormal friction exists between the brake shoes and the brake disc, generating additional resistance torque. This resistance torque is usually uneven and changes periodically with the rotation of the brake disc, causing abnormal fluctuations in the motor current. At the same time, due to the action of speed closed-loop control, the control system will adjust the torque output to maintain the set speed. Therefore, the actual speed of the traction machine (i.e., the encoder pulse count) may still remain relatively stable. Therefore, when abnormal fluctuations occur in the current while the speed remains stable, it can be determined that a brake failure exists.

[0090] In practical implementation, the monitoring of current fluctuation amplitude can be achieved using a sliding window method. During the constant speed operation phase, the motor current value is continuously collected, and the difference between the maximum and minimum current values ​​within the window, or the standard deviation of the current, is calculated as a quantitative indicator of the fluctuation amplitude. When this fluctuation amplitude exceeds a preset threshold, it indicates that there is abnormal fluctuation in the current.

[0091] The stability of the encoder pulse count is also continuously monitored using a third time window. The length of the third time window can be set according to the sampling period of the control system and the rotational speed of the traction machine, for example, it can be set to 100 milliseconds or 200 milliseconds. Within each third time window, the system detects the actual value of the encoder pulse count and compares it with the theoretical pulse count corresponding to the rated speed to calculate the fluctuation amplitude. When the fluctuation amplitude of the pulse count does not exceed a preset percentage (e.g., ±5%) within multiple consecutive third time windows, it indicates that the traction machine speed remains stable.

[0092] Here, "consecutive multiple" refers to a preset number of time windows. This preset number can be set according to the system's anti-interference requirements, such as 3 or 5, but usually no less than 2. By requiring that multiple consecutive time windows meet the conditions, misjudgments caused by single instantaneous fluctuations can be effectively avoided. For example, a brief fluctuation in grid voltage or a momentary change in load may cause a brief fluctuation in current, but if the speed also fluctuates at the same time, it should not be judged as a tripping fault; only when the current fluctuates abnormally continuously while the speed remains stable does it indicate the existence of continuous abnormal resistance, i.e., a tripping fault.

[0093] In practical applications, preset thresholds and preset percentages can be calibrated based on the rated parameters of the traction machine and the on-site operating conditions. For example, the current fluctuation threshold can be set to 10% to 20% of the rated current, and the pulse fluctuation percentage can be set to 3% to 5%. Specific values ​​can be determined during factory commissioning or adaptively obtained during operation.

[0094] Through the above method, this embodiment utilizes existing motor current and encoder pulse signals to achieve real-time monitoring of brake malfunctions. This monitoring method does not increase additional hardware costs, can promptly detect brake malfunctions, and prevent abnormal wear of the brake shoes.

[0095] In an optional embodiment, it further includes:

[0096] Monitor the motor current after the elevator stops running and the frequency converter stops outputting.

[0097] If a persistent residual current is detected and the encoder pulse count is not zero, it is determined that the brake has a fault of not closing properly.

[0098] Residual current refers to the weak current that still exists in the motor windings after the frequency converter stops outputting. When the brake is fully closed, the traction machine should be stationary with zero motor current. If the brake is not fully closed, the car may slip under gravity, causing the traction machine to rotate and inducing current in the motor windings. By monitoring this residual current and combining it with encoder pulses, it is possible to determine whether there is a fault in the brake's closure.

[0099] In practice, residual current can be monitored as follows: After the inverter stops outputting, the current value of the motor windings is continuously collected by a current sensor. Under normal circumstances, the current should quickly decay to zero or close to zero. If the detected current value is continuously higher than a certain low threshold (e.g., 1% to 3% of the rated current) and the duration exceeds a preset time (e.g., 500 milliseconds or 1 second), then residual current is determined to exist.

[0100] The encoder pulse count is monitored simultaneously with the residual current. If the encoder pulse count is not zero, it indicates that the traction machine is rotating. Combined with the presence of the residual current, it can be confirmed that the traction machine's instantaneous pulses are not caused by accidental factors such as external impacts, but rather by continuous slippage due to improper brake closure.

[0101] It should be noted that this embodiment employs a method where both residual current and encoder pulse count are simultaneously satisfied, which effectively avoids false alarms. For example, if only residual current is detected but the encoder pulse count is zero, it may be due to current sensor zero drift or electromagnetic interference, and does not necessarily indicate a brake malfunction. Similarly, if only the encoder pulse count is detected as non-zero but there is no residual current, it may be due to external vibration or encoder signal noise, and again, it does not necessarily indicate a brake malfunction. When both conditions are met simultaneously, it is more reliable to determine that the brake is not properly closed.

[0102] In this embodiment, the residual current after the inverter stops outputting and the encoder pulse signal are used to accurately monitor the fault of the brake not closing properly, thus providing additional protection for the safe stopping of the elevator.

[0103] It should be noted that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0104] Reference Figure 3 The diagram illustrates a monitoring device for the brake status of a traction machine according to an embodiment of the present invention, which may specifically include the following modules:

[0105] The data acquisition module 301 is used to acquire the encoder pulse count of the elevator traction machine;

[0106] The first response module 302 is used to respond to the elevator start-up command. If the number of encoder pulses detected within the preset first time window exceeds the first set threshold, it determines that the brake is in an open and effective state.

[0107] The second response module 303 is used to respond to the elevator stop command. If the number of encoder pulses detected within the preset second time window is lower than the second set threshold, it determines that the brake is in the closed effective state.

[0108] The present invention provides a monitoring device for the brake status of a traction machine. By applying the monitoring device for the brake status of a traction machine, the various steps in the aforementioned embodiments of the monitoring method for the brake status of a traction machine can be realized, and the corresponding technical effects are achieved. These will not be elaborated further here.

[0109] It should be noted that the module division in the various traction machine brake status monitoring devices provided in the above embodiments is illustrative and only represents a logical functional division. In actual implementation, other division methods may also be used. Furthermore, the functional modules in the various embodiments of this invention can be integrated into a single processor, exist as separate physical entities, or be integrated into a single module. The integrated modules described above can be implemented in hardware or as software functional modules.

[0110] If the integrated module is implemented as a software functional module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the technical solution of the embodiments of the present invention can be embodied in the form of a computer program product, which is stored in a computer storage medium and includes several instructions to cause an electronic device or processor to execute all or part of the steps of the methods in the various embodiments of the present invention. The aforementioned computer storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0111] Furthermore, the traction machine brake status monitoring device and the traction machine brake status monitoring method provided in the above embodiments belong to the same concept, and their specific implementation process can be found in the method embodiments, which will not be repeated here.

[0112] Reference Figure 4 The diagram illustrates an electronic device according to an embodiment of the present invention. Figure 4 As shown, the electronic device in this embodiment of the invention includes: a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps in the above-described embodiment of the traction machine brake state monitoring method. Alternatively, when the processor executes the computer program, it implements the functions of each module in the above-described embodiment of the traction machine brake state monitoring device.

[0113] For example, the computer program may be divided into one or more modules, which are stored in the memory and executed by the processor to complete this application. The one or more modules may be a series of computer program instruction segments capable of performing a specific function, which can be used to describe the execution process of the computer program in the electronic device.

[0114] The electronic device may be a desktop computer, a cloud server, or other computing device. The electronic device may include, but is not limited to, a processor and memory. Those skilled in the art will understand that... Figure 4 This is merely one example of an electronic device and does not constitute a limitation on the electronic device. It may include more or fewer components than illustrated, or combine certain components, or different components. For example, the electronic device may also include input / output devices, network access devices, buses, etc.

[0115] The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor.

[0116] The memory can be an internal storage unit of the electronic device, such as a hard drive or RAM. Alternatively, it can be an external storage device, such as a plug-in hard drive, Smart Media Card (SMC), Secure Digital (SD) card, Flash Card, etc. Furthermore, the memory can include both internal and external storage units. The memory is used to store the computer program and other programs and data required by the electronic device. The memory can also be used to temporarily store data that has been output or will be output.

[0117] This invention also discloses an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the method for monitoring the traction machine brake status as described in the foregoing embodiments.

[0118] This invention also discloses a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method for monitoring the traction machine brake status as described in the foregoing embodiments.

[0119] This invention also discloses a computer program product that, when run on a computer, causes the computer to execute the traction machine brake status monitoring method described in the foregoing embodiments.

[0120] The embodiments described above are only used to illustrate the technical solutions of this application, and are not intended to limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A method for monitoring the brake status of a traction machine, characterized in that, include: Obtain the encoder pulse count of the elevator traction machine; In response to the elevator start-up command, if the number of encoder pulses detected within the preset first time window exceeds the first set threshold, it is determined that the brake is in an open and effective state. In response to the elevator stop command, if the number of encoder pulses detected within the preset second time window is lower than the second set threshold, it is determined that the brake is in an effective closed state.

2. The method according to claim 1, characterized in that, The first set threshold and / or the second set threshold are dynamically set based on at least one parameter among the elevator's rated speed, load weight, and real-time speed curve.

3. The method according to claim 1, characterized in that, The determination that the brake is in the active open state also includes: Obtain the trend of current change in the motor; If the motor current drops from the stall current to the normal starting current range, and the number of encoder pulses detected within the preset first time window exceeds the first set threshold, then the brake is determined to be in an open effective state.

4. The method according to claim 3, characterized in that, Also includes: During each brake release, monitor the response time taken for the motor current to drop from the stall current to the preset normal starting current range; Based on the changing trend of the response time, determine the degree of aging of the brake spring or the degree of wear of the brake shoe.

5. The method according to claim 1, characterized in that, Also includes: During each brake release process, the time interval from the issuance of the elevator start-up command to the first time the encoder pulse count exceeds the first set threshold is monitored; Based on the changing trend of the time interval, determine the degree of aging of the brake spring or the degree of wear of the brake shoe.

6. The method according to any one of claims 1-5, characterized in that, Also includes: During the elevator's constant speed operation phase, monitor the amplitude of the motor's current fluctuation. If the detected current fluctuation exceeds a preset threshold, and the fluctuation of the encoder pulse count detected within multiple consecutive third time windows relative to the theoretical pulse count corresponding to the rated speed does not exceed a preset percentage, then it is determined that there is a drag brake fault where the holding brake is not fully opened.

7. The method according to any one of claims 1-5, characterized in that, Also includes: Monitor the motor current after the elevator stops running and the frequency converter stops outputting. If a persistent residual current is detected and the encoder pulse count is not zero, it is determined that the brake has a fault of not closing properly.

8. A monitoring device for the brake status of a traction machine, characterized in that, include: The data acquisition module is used to acquire the encoder pulse count of the elevator traction machine; The first response module is used to respond to the elevator start-up command. If the number of encoder pulses detected within the preset first time window exceeds the first set threshold, it determines that the brake is in an open and effective state. The second response module is used to respond to the elevator stop command. If the number of encoder pulses detected within the preset second time window is lower than the second set threshold, it determines that the brake is in an effective closed state.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method for monitoring the traction machine brake status as described in any one of claims 1-7.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the method for monitoring the brake status of the traction machine as described in any one of claims 1-7.

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