Elevator door state detection device and method

Abstract

The invention discloses an elevator door state detection device and method. The device comprises a permanent magnet, a linear Hall sensor and a processing unit. The permanent magnet is fixed to the edge of an elevator door. The linear Hall sensor is mounted at a corresponding position of a door frame, detects magnetic field intensity in real time and outputs an induced voltage signal; the processing unit obtains a door opening threshold value and a door closing threshold value through a dynamic self-learning mechanism, judges whether the elevator door is in a fully-closed state or a fully-opened state or a door opening state or a door closing state according to the comparison result of the real-time induced voltage and the threshold values, and transmits signals through the multi-mode output interface. According to the invention, full-state detection is realized through a single sensor, and the hardware cost is reduced by more than 50%; a dynamic threshold self-learning mechanism is adopted to adapt to door body structure difference, environment temperature excursion and sensor aging, and the detection precision is stable for a long time; after the device is adopted, a third-party maintenance enterprise can obtain the elevator door state without depending on a private protocol of an elevator manufacturer, and the maintenance difficulty and cost are reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of elevator safety, and in particular relates to an elevator door state detection device and method. Background Art

[0002] Elevator door status detection is crucial for safe elevator operation. However, current common elevator door status detection technologies have numerous drawbacks: proximity switches and photoelectric switches can only detect when the door is fully open or fully closed, failing to identify intermediate states during the door opening or closing process and being susceptible to interference from external factors such as stains. Encoder switches, while offering relatively comprehensive detection capabilities, are expensive and mechanically complex. Furthermore, several multi-sensor collaborative detection solutions have emerged.

[0003] Chinese Patent Publication No. CN212245798U discloses an elevator door status detection device that relies on dual Hall effect sensors for timing determination. This device lacks intermediate state recognition and fails to account for environmental changes and sensor aging. Chinese Patent Publication No. CN105460725A discloses an elevator door status monitor and fault diagnosis method. This device utilizes multiple sensors to determine the door status and implement fault alarms through logical combinations. However, the coordinated operation of multiple sensors increases both cost and failure rate. Chinese Patent Publication No. CN110713087A discloses an elevator door status detection method and device that utilizes a robot-mounted laser radar to scan and collect point cloud data to determine the door status. This method has high equipment cost, is significantly affected by environmental factors, and has limited application scenarios. Chinese Patent Publication No. CN109335907B uses a millimeter-wave radar installed on the elevator door leaf to detect the distance between the two door leaves to determine abnormal elevator door status. This reliance on millimeter-wave radar is costly and complex to install. The Chinese patent publication number CN101597001A discloses a detection device comprising two linear Hall sensors mounted on the car roof and a positioning plate composed of magnets mounted in the shaft, which is used to detect the upper and lower leveling positions of the elevator, rather than the open and closed status of the elevator door.

[0004] In summary, the elevator door state detection methods in the prior art generally have problems such as insufficient judgment of the intermediate state of the elevator door, high cost, complex installation and poor adaptability.

[0005] Therefore, a low-cost, high-precision elevator door status detection device and method that can adapt to environmental changes is urgently needed. Summary of the Invention

[0006] In order to solve the defects of the prior art, the present invention provides an elevator door status detection device and method.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0008] The present invention provides an elevator door status detection device, comprising a permanent magnet, a linear Hall sensor, and a processing unit. The permanent magnet is fixedly mounted on the edge of the elevator door, and the linear Hall sensor is mounted on the door frame at a position corresponding to the permanent magnet. When the elevator door is fully closed, the magnetic field intensity detected by the linear Hall sensor is at its maximum, and the output induced voltage also reaches its maximum value. As the elevator door opens or closes, the linear Hall sensor outputs a changing induced voltage and sends it to the processing unit. The processing unit includes a processor and an output interface. The processor utilizes a low-power microcontroller. After initialization, it cyclically executes threshold self-learning, dynamic adjustment of the self-learning cycle, and door status judgment logic, ultimately outputting the elevator door status to the outside through the output interface.

[0009] Preferably, the parameter initialization includes:

[0010] Set the initial value of the door opening threshold to the upper limit of the variable type, and the initial value of the door closing threshold to 0;

[0011] Set the initial value of the self-learning cycle to 2 times the total duration of a single complete door opening and closing action of the elevator, and set the upper limit of the self-learning cycle to 5 times the total duration of a single complete door opening and closing action of the elevator;

[0012] Set the execution cycle to 100 milliseconds based on the real-time detection requirements;

[0013] Reset the learning completion flag;

[0014] Set the limit door state to fully closed;

[0015] Calculate the preset coefficient K1 according to the following formula:

[0016]

[0017] Among them, W1 represents the maximum movement distance of the door leaf when opening and closing the door, and W2 represents the distance between the permanent magnet and the sensor when the elevator door is fully closed;

[0018] The preset coefficient K2 is set to twice the preset coefficient K1.

[0019] Preferably, the increase ratio of the dynamic adjustment of the self-learning cycle is 10%.

[0020] Preferably, the total duration of a single complete door opening and closing action of the elevator includes the standard time for opening the elevator door, the standard time for passengers to enter and exit the elevator car, and the standard time for closing the elevator door.

[0021] Preferably, the logic for determining the door status includes:

[0022] When the self-learning completion flag is valid:

[0023] If the current induced voltage is equal to the door closing threshold, the limit door state and the current door state are set to the door fully closed state;

[0024] If the current induced voltage is equal to the door opening threshold, the limit door state and the current door state are set to the door fully open state;

[0025] If the current induced voltage is between the two thresholds, the current door state is set to the door-opening state or the door-closing state in combination with the extreme door state.

[0026] The present invention also provides an elevator door state detection method, comprising the following steps:

[0027] The induced voltage corresponding to the magnetic field strength is obtained in real time through the linear Hall sensor;

[0028] Dynamic self-learning of the closing and opening thresholds of the induction voltage;

[0029] Based on threshold comparison and state logic, determine the state of the elevator door, including fully closed, fully open, opening or closing;

[0030] The determined door status signal is output to an external device.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The invention uses a single sensor to replace a combination of multiple devices to realize the monitoring of multiple states of elevator doors, effectively reducing hardware costs by more than 50%; through the dynamic adjustment mechanism of the threshold, it can adapt to factors such as environmental changes, component aging and installation differences, ensuring long-term stability of detection accuracy; the output interface is compatible with multiple communication protocols, and third-party maintenance companies do not need to rely on the elevator manufacturer's private protocol to obtain the elevator door status, reducing the difficulty and cost of maintenance; it can monitor the intermediate state of the elevator door in real time, promptly discover potential safety hazards, and enhance safety warning capabilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic diagram of the installation structure of the elevator door status detection device of the present invention;

[0034] In the figure: 1, permanent magnet; 2, linear Hall sensor; 3, processing unit; 31, processor; 32, output interface;

[0035] Figure 2 This is a schematic diagram of magnetic field induction according to the present invention;

[0036] Figure 3 This is a flowchart of the processor of the present invention;

[0037] Figure 4 This is a flow chart of the self-learning of the door opening / closing threshold value of the present invention;

[0038] Figure 5 This is a logic flow chart of the door status judgment of the present invention. DETAILED DESCRIPTION

[0039] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0040] Example 1

[0041] This embodiment provides an elevator door state detection device, including a permanent magnet 1 , a linear Hall sensor 2 , and a processing unit 3 .

[0042] To achieve long-distance detection, permanent magnet 1 uses an N52 brand neodymium iron boron magnet, which has a high magnetic energy product. Its ring shape takes advantage of its uniform magnetic field distribution and slow decay with distance. Its dimensions are 20 mm in diameter and 20 mm in thickness to ensure a certain magnetic field strength. Linear Hall effect sensor 2 uses a 12-bit A / D sampling device to ensure high detection accuracy. Processor 31 uses the STM32F303, and output interface 32 utilizes RS-485 communication.

[0043] like Figure 1 As shown, permanent magnet 1 is secured to the top of the door using a snap-fit ​​mechanism. Since circular magnets have no distinct poles, their installation direction is unrestricted. Linear Hall sensor 2 is installed at the lower edge of the door frame, corresponding to the position of the permanent magnet. When the door is fully closed, the distance between linear Hall sensor 2 and the permanent magnet is W2. When the door is fully open, the door leaf moves a distance W1, and the distance between linear Hall sensor 2 and the permanent magnet is W1 + W2. Processing unit 3 is installed in the control box on the elevator car roof.

[0044] The linear Hall sensor 2 converts the sensed permanent magnet 1 into an induced voltage and sends it to the processor 31; the processor 31 determines the door status after processing and sends it to the output interface 32; the output interface 32 outputs the door status through I / O, serial communication or wireless transmission.

[0045] like Figure 2 As shown, the magnetic field generated by the permanent magnet 1 passes through the linear Hall sensor 2, which generates an induced voltage.

[0046] like Figure 3 As shown, the specific working process of the processor is as follows:

[0047] S1: Initialization:

[0048] Assuming the storage variable type is a 32-bit word, set the initial value of the door opening threshold to the upper limit of the variable type 0xFFFFFFFF, and the initial value of the door closing threshold to 0;

[0049] Set the initial value of the self-learning cycle to twice the total duration of a single complete door opening and closing action of the elevator (7s*2=14s), and set the upper limit of the self-learning cycle to five times the total duration of a single complete door opening and closing action of the elevator (7s*5=35s);

[0050] Set the execution cycle to 100 milliseconds based on the real-time detection requirements;

[0051] Reset the learning completion flag;

[0052] Set the limit door state to fully closed;

[0053] The preset coefficient K1 is calculated according to the formula. Assuming that the maximum movement distance W1 of the door leaf when opening and closing the door is 600mm, and the distance W2 between the permanent magnet and the sensor when the elevator door is fully closed is 10mm, the preset coefficient

[0054] The preset coefficient K2 is set to twice the preset coefficient K1 (1860.5*2=3721).

[0055] Set the limit door state to fully closed and go to S2.

[0056] S2: The processor reads the current sensed voltage value in each execution cycle and enters S3.

[0057] S3: Open / Close threshold self-learning:

[0058] like Figure 4 As shown, the processor continuously records the sensed voltage values ​​100 times (10 seconds ÷ 100 milliseconds = 100). Assuming the maximum value extracted is 4.9V and the minimum value is 0.002V, since (4.9V / 0.001V) > 1860.5, the threshold update condition is met. Therefore, the closing threshold is updated to 4.9V and the opening threshold is updated to 0.002V, and the learning completion flag is set. If the maximum value detected in a self-learning cycle subsequently decreases due to sensor aging, for example, to 4.7V, the system will automatically update the closing threshold to 4.7V to ensure detection accuracy. The process then proceeds to S4.

[0059] Each time the elevator door undergoes a complete opening and closing cycle, the closing and opening thresholds are automatically adjusted, effectively eliminating detection errors caused by environmental changes, sensor aging, and other factors. Furthermore, in the event of anomalies such as improper threshold updates, such as when the elevator door is blocked or there is no opening or closing motion, the opening / closing thresholds will not be updated because the maximum and minimum values ​​extracted over multiple consecutive self-learning cycles do not meet the conditions (maximum value is greater than K multiplied by the minimum value).

[0060] S4: Dynamic adjustment of self-learning cycle:

[0061] If the maximum value recorded in a certain period is 4.0V and the minimum value is 0.04V, and the current self-learning period is 14s, since (4.0V / 0.04V)<3721, the self-learning period is increased by 10% (14s*1.1=15.4s), which does not exceed its upper limit (35s).

[0062] In this embodiment, even if the door opening and closing resistance increases and the time is prolonged due to aging components, or if the time for passengers to enter and exit the elevator car is prolonged due to high passenger volume, by increasing the self-learning cycle, the device can still accurately obtain the induced voltage when the door is fully open and fully closed. In addition, to prevent the threshold from being learned in a timely manner due to an excessively long self-learning cycle, an upper limit is set for the self-learning cycle.

[0063] S5: Current door status judgment (such as Figure 5 shown):

[0064] If the current sensed voltage value is 4.9V, which is equal to the door closing threshold, the door is determined to be fully closed;

[0065] If the current sensed voltage value is 0.002V, which is equal to the door opening threshold, the door is determined to be fully open;

[0066] If the current sensed voltage value is 1.8V and the limit door state is fully closed, it is determined that the door is opening;

[0067] If the current sensed voltage value is 1.8V and the limit door state is fully open, it is determined to be closing;

[0068] Go to S6.

[0069] S6: The processor outputs the current door status through the RS-485 communication interface, then returns to S2 and executes the above operations in a loop.

[0070] This embodiment successfully solves the cost and adaptability problems of elevator door status detection by combining a single sensor with an intelligent algorithm, and has significant market competitiveness and industrialization potential.

[0071] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. An elevator door status detection device, characterized in that: include: A permanent magnet (1) is fixed to the top edge of the elevator door; A linear Hall sensor (2) is installed at the door frame at a position corresponding to the permanent magnet, and is used to detect the magnetic field strength in real time and output an induced voltage signal; A processing unit (3), comprising a processor (31) and an output interface (32); The processor (31) adopts a low-power microcontroller and periodically performs the following tasks after completing parameter initialization: Threshold self-learning: Continuously record the induced voltage value during the self-learning cycle, extract the maximum and minimum values, and when the ratio of the maximum to the minimum value exceeds the preset coefficient K1, the maximum value is set as the closing threshold, the minimum value is set as the opening threshold, and the learning completion flag is set; Dynamic adjustment of self-learning cycle: After each self-learning cycle, if the ratio of the maximum value to the minimum value recorded in the cycle is less than the preset coefficient K2, the self-learning cycle will be increased according to a certain ratio, but not exceeding its upper limit; Door status judgment: After self-learning is completed, based on the comparison result of the real-time induction voltage and the threshold value, combined with the previous limit door state, it is determined whether the elevator door is fully closed, fully open, opening or closing; The output interface (32) outputs the current door status signal via I / O, serial communication or wireless transmission.

2. An elevator door state detection device according to claim 1, characterized in that: The parameter initialization includes: Set the initial value of the door opening threshold to the upper limit of the variable type, and the initial value of the door closing threshold to 0; Set the initial value of the self-learning cycle to 2 times the total duration of a single complete door opening and closing action of the elevator, and set the upper limit of the self-learning cycle to 5 times the total duration of a single complete door opening and closing action of the elevator; Set the execution cycle to 100 milliseconds based on the real-time detection requirements; Reset the learning completion flag; Set the limit door state to fully closed; Calculate the preset coefficient K1 according to the following formula: Among them, W1 represents the maximum movement distance of the door leaf when opening and closing the door, and W2 represents the distance between the permanent magnet and the sensor when the elevator door is fully closed; The preset coefficient K2 is set to twice the preset coefficient K1.

3. The elevator door state detection device according to claim 1, characterized in that: The increase ratio of the dynamic adjustment of the self-learning cycle is 10%.

4. An elevator door state detection device according to claim 2, characterized in that: The total duration of a single complete door opening and closing action of the elevator includes the standard time for opening the elevator door, the standard time for passengers to enter and exit the elevator car, and the standard time for closing the elevator door.

5. The elevator door state detection device according to claim 1, characterized in that: The logic of the door status judgment includes: When the self-learning completion flag is valid: If the current induced voltage is equal to the door closing threshold, the limit door state and the current door state are set to the door fully closed state; If the current induced voltage is equal to the door opening threshold, the limit door state and the current door state are set to the door fully open state; If the current induced voltage is between the two thresholds, the current door state is set to the door-opening state or the door-closing state in combination with the extreme door state.

6. A method for detecting the state of an elevator door, characterized in that: The following steps are involved: The induced voltage corresponding to the magnetic field strength is obtained in real time through the linear Hall sensor; Dynamic self-learning of the closing and opening thresholds of the induction voltage; Determine the elevator door status based on threshold comparison and state logic; Output door status signal to external devices.

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