Elevator secondary leveling operation control method

Abstract

The invention discloses an elevator secondary leveling operation control method which comprises the following steps: S1, when an elevator is in a deceleration operation state, monitoring a speed instruction output by an elevator control system; s2, when the speed instruction is zero, the height difference between a car floor and a floor sill is obtained; s3, when the height difference is larger than a trigger threshold value, a door lock loop is short-circuited; s4, calculating a secondary leveling operation speed instruction according to the height difference; and S5, secondary leveling operation is executed. According to the method, the requirement for the control performance in the deceleration process is low, and the leveling precision is high.

Description

Technical Field

[0001] This invention relates to the field of elevator technology, and specifically to a method for controlling the secondary leveling operation of an elevator. Background Technology

[0002] Leveling accuracy of the elevator car is an important indicator of elevator operating performance and comfort. Fast, smooth, and accurate leveling performance can greatly improve the passenger's elevator experience. Conversely, if there is a large height difference between the car floor and the sill after the elevator stops, passengers are at risk of tripping when entering or exiting the car, and wheelchair users, forklift drivers, flatbed trucks, etc., may have difficulty entering or exiting the car due to the height difference.

[0003] On the other hand, as a vertical transportation tool, elevators cause passengers to experience noticeable weightlessness and g-force during acceleration and deceleration. This necessitates that the car's movement be as smooth as possible and that repeated speed changes be avoided to reduce passenger discomfort. Therefore, it is difficult to repeatedly accelerate and decelerate during the leveling and deceleration process, which poses a significant challenge to leveling control.

[0004] Achieving high-precision leveling of the elevator car during deceleration and leveling, without the possibility of repeated speed changes, places high demands on the control system. To improve leveling accuracy to a certain extent during deceleration, complex control strategies or algorithms are often required based on different elevator operating conditions. Summary of the Invention

[0005] The technical problem to be solved by this invention is to provide a universal control strategy that has low requirements for control performance during deceleration and at the same time has high leveling accuracy.

[0006] To solve the above-mentioned technical problems, the present invention provides an elevator secondary leveling operation control method, comprising: step S1, monitoring the speed command output by the elevator control system when the elevator is in a deceleration operation state; step S2, obtaining the height difference between the car floor and the floor sill when the speed command is zero; step S3, short-circuiting the door lock circuit when the height difference is greater than the trigger threshold; step S4, calculating the secondary leveling operation speed command based on the height difference; and step S5, executing the secondary leveling operation.

[0007] Preferably, an opening command is issued simultaneously when performing step S4.

[0008] Preferably, the unexpected car movement protection function remains effective during step S5.

[0009] Preferably, the trigger threshold is less than 5 mm.

[0010] Preferably, the formula for calculating the maximum operating speed in the secondary leveling operating speed command is as follows: ,in The maximum operating speed is given by f, the preset conversion factor is given by d, and the height difference is given by d in step S2.

[0011] Preferably, the secondary leveling operation speed command has a preset maximum operation speed limit value. When the maximum operation speed exceeds the maximum operation speed limit value, the maximum operation speed limit value is used as the maximum operation speed.

[0012] Preferably, the secondary leveling speed command is a trapezoidal speed command.

[0013] Preferably, the formula for calculating the deceleration point in the secondary leveling speed command is: ,in Let V be the deceleration point, V be the car speed at the moment deceleration begins, τ be the response lag parameter, and α be the deceleration.

[0014] Preferably, after the elevator completes its second leveling operation, the dead zone range for re-leveling is adjusted according to the changes in the load inside the car.

[0015] Preferably, after the elevator's second leveling operation is completed, the re-leveling dead zone range is first set as the first re-leveling dead zone range; within a preset time range, if the percentage change of the car load is less than the threshold Th1 for N consecutive times, the re-leveling dead zone range is adjusted to the second re-leveling dead zone range; within a preset time range, if the percentage change of the car load is greater than the threshold Th2 for M consecutive times, the re-leveling dead zone range is adjusted to the third re-leveling dead zone range; within a preset time range, if the percentage change of the car load is not changed, the re-leveling dead zone range is adjusted back to the first re-leveling dead zone range; where N is a positive integer greater than 2, and M is a positive integer; the third re-leveling dead zone range is larger than the first re-leveling dead zone range, and the first re-leveling dead zone range is larger than the second re-leveling dead zone range.

[0016] The present invention has the following technical effects: 1. High precision - The special low-speed secondary leveling operation is different from the general re-leveling operation. It is triggered only once during the deceleration leveling stage. There is no need to consider the problem of repeated re-leveling. Therefore, a very small trigger threshold can be set to reduce the leveling deviation through secondary leveling.

[0017] 2. High Efficiency – The special low-speed secondary leveling operation is performed during the door opening phase, and leveling is completed before the door is fully open. There is no additional delay in leveling time when the door is closing, and the passenger efficiency is the same as the traditional leveling operation logic, without any reduction.

[0018] 3. Seamless – During the door opening process, a special low-speed secondary leveling operation is performed. The speed and acceleration / deceleration of the operation itself are very small, and passengers are often moving to prepare to exit the escalator at this time. The combination of these two factors results in a virtually seamless experience for passengers, with no discomfort.

[0019] 4. Low control performance requirements - This invention reduces the control accuracy requirements of the control system to a certain extent. Even if there is a large deviation when the first leveling operation stops, as long as the deviation value is within the allowable door opening range of the UCMP device, the special low-speed secondary leveling operation will take effect.

[0020] 5. Easy to implement – ​​The special low-speed secondary leveling operation is executed only after the speed command for normal operation has ended, and it is not coupled with normal operation, so it does not affect the normal operation logic. The operating distance and speed of the special low-speed secondary leveling operation are very small, and factors such as car load, shaft friction, and wire rope slippage have little impact on this operation. Therefore, high-precision leveling results can be easily achieved through the special low-speed secondary leveling operation. Attached Figure Description

[0021] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments: Figure 1 This is a schematic diagram of the elevator secondary leveling operation control method steps in Example 1. Detailed Implementation

[0022] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can fully understand other advantages and technical effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through different specific embodiments, and the details in this specification can also be applied based on different viewpoints, with various modifications or changes made without departing from the overall design concept of the invention. It should be noted that, unless otherwise specified, the following embodiments and features can be combined with each other. The following exemplary embodiments of the present invention can be implemented in many different forms and should not be construed as being limited to the specific embodiments set forth herein. It should be understood that these embodiments are provided to make the disclosure of the present invention thorough and complete, and to fully convey the technical solutions of these exemplary embodiments to those skilled in the art. Example 1

[0023] like Figure 1 As shown, this embodiment provides a method for controlling the secondary leveling operation of an elevator, including: step S1, monitoring the speed command output by the elevator control system when the elevator is in a deceleration state; step S2, obtaining the height difference between the car floor and the floor sill when the speed command is zero; step S3, short-circuiting the door lock circuit when the height difference is greater than a trigger threshold; step S4, calculating the secondary leveling operation speed command based on the height difference; and step S5, executing the secondary leveling operation.

[0024] In this embodiment, the trigger threshold Th_trig can be much smaller than the leveling target area range. For example, if the trigger threshold Th_trig is less than 5mm, it can be set to Th_trig=2mm. In contrast, the leveling target area range is generally >10mm, and it only needs to be not less than the minimum moving distance that the drive system can respond normally. Therefore, it is possible to ensure that leveling accuracy is improved through special low-speed secondary leveling operation. In addition, after the secondary leveling operation is completed, it means that the elevator's current leveling operation is over. Subsequent load changes causing car movement will only trigger normal re-leveling operation, and will not trigger special low-speed secondary leveling operation again before the next normal start, thus avoiding repeated leveling behavior.

[0025] In existing technologies, the leveling target area refers to a threshold value for the height difference between the car floor and the floor sill. If the height difference is within this threshold value, the elevator control system considers that the elevator leveling accuracy meets the control requirements and does not move the car further.

[0026] The secondary leveling operation is performed only after the speed command output by the elevator control system is zero. It has no requirements regarding the control circuit or brake status, nor the actual feedback speed of the car at that moment. Therefore, after the elevator's normal deceleration operation, even if the elevator has not completely stopped and the brake is still in an unbraked state, when the height difference exceeds the trigger threshold, the door lock circuit is immediately short-circuited, initiating the secondary leveling operation and outputting a new speed command.

[0027] During secondary leveling operation, the Unexpected Car Movement Protection (UCMP) function remains active. During special low-speed secondary leveling operation, the door is in the open phase. Therefore, before performing this operation, the door lock circuit needs to be short-circuited. The UCMP device ensures safety during this phase, preventing shearing hazards. Since both the door lock short-circuit circuit and the UCMP protection device are required functions for elevators with door-opening re-leveling capabilities, this embodiment does not incur additional physical device costs for elevators with re-leveling functionality.

[0028] The speed command setting rules for secondary leveling operations are as follows: Maximum operating speed calculation: The maximum operating speed V_max is set to be proportional to the distance (i.e., height difference) between the car and the target leveling point before operation. Therefore, the longer the secondary leveling distance, the higher the operating speed, thereby improving efficiency. (This can be set...) In the formula, V_max is the maximum operating speed in m / s; d is the distance between the car and the target leveling point before the start of the secondary leveling operation, i.e., the height difference obtained in step S2, in meters; a is the conversion operator, which can be determined experimentally. In this example, a=2 is used. Since the special low-speed secondary leveling operation is performed only after the elevator has reached its normal level, the actual distance d is relatively small. Taking d=10mm as an example, V_max is only 0.02m / s. The target leveling point refers to the car position value obtained by the control system when the car floor and the floor sill are aligned.

[0029] Maximum operating speed limit: A maximum operating speed limit value V_thmax is preset, and V_max ≤ V_thmax. When the maximum operating speed exceeds the maximum operating speed limit value, the maximum operating speed limit value is used as the maximum operating speed. This avoids calculating an excessively high operating speed when the normal leveling deviation is large, which would result in an overly obvious secondary leveling sensation inside the car and reduce comfort.

[0030] Acceleration / Deceleration Strategy: Due to the extremely low operating speed and considering the smoothing effect of the drive system's hysteresis characteristics, a simple trapezoidal speed command can achieve good running comfort and greatly simplify the design of the speed command. Because of the low operating speed, a small acceleration value can also be selected; in this example, α = 0.1 m / ss is used.

[0031] Selection of deceleration point: During the secondary leveling operation, after the car reaches the deceleration point, it begins to decelerate uniformly until it reaches 0, at which point the secondary leveling operation is completed. Therefore, the selection of the car's deceleration point affects the accuracy of the secondary leveling. The closer the distance between the deceleration point and the leveling target point matches the actual deceleration distance, the higher the leveling accuracy. Because uniform deceleration is used, the total distance traveled by the car during the deceleration process depends only on the speed at the beginning of deceleration. According to the uniform speed change formula, we know... In the formula, S' is the ideal uniform deceleration travel distance, V is the car speed at the start of deceleration, and α is the deceleration. Due to the response lag in the elevator control and drive system, the actual deceleration travel distance is corrected to... In the formula, τ represents the response lag, which can be selected experimentally; in this example, τ is assumed to be 100 ms. Therefore, when the car reaches the target leveling point S, it begins to decelerate, achieving high-precision secondary leveling. Using the parameter values ​​selected in this example: assuming the speed before deceleration is V = 0.02 m / s, then the deceleration point S for this operation is 4 mm. Example 2

[0032] After the elevator has leveled a floor, re-leveling technology is a feature found in many elevators to improve user comfort: When a large number of people and goods enter and exit the car, the car will move up and down due to the expansion and contraction of the steel cables. This can cause a significant drop between the car floor and the floor sill. At this time, re-leveling technology can drive the main unit again to make the car move slightly, reducing the drop.

[0033] Traditional elevators use photoelectric switches and other switch combination logic to achieve leveling. However, these leveling sensors cannot accurately detect the car's position when the switch signal remains unchanged, making further control of the car's movement impossible. They also inherently have a dead zone range where the car will not re-level. Even when using continuous position sensing systems such as magnetic scales, a certain dead zone range must be designed to avoid repeatedly activating the main unit. When the drop between the car floor and the floor sill falls within this dead zone range, the car will no longer attempt to level itself.

[0034] In existing technologies, the releveling dead zone range refers to a threshold value for the height difference between the car floor and the floor sill. Within this threshold value, the elevator control system will not trigger releveling operation.

[0035] Whether it's a discrete leveling sensor or a continuous position sensor, the aforementioned dead zone range is often fixed, lacking flexibility. However, an excessively large dead zone range makes re-leveling difficult to trigger, causing the car to fail to move even with a significant floor difference, reducing the riding experience and functional value. Conversely, an excessively small dead zone range may lead to repeated activation of the main unit due to car swaying, reducing device lifespan. Control tracking deviations may also cause repeated re-leveling, similarly reducing the riding experience.

[0036] This embodiment, based on Embodiment 1, adjusts the re-leveling dead zone range according to changes in the load inside the elevator car after the elevator's second leveling operation. The adjustment logic is as follows: After the elevator completes its second leveling operation, the dead zone range of the second leveling operation is first set as the dead zone range of the second leveling operation. Within a preset time range, if the percentage change in car load is less than threshold Th1 for N consecutive times (e.g., N=3) after low-pass filtering, the re-leveling dead zone range is adjusted to the second re-leveling dead zone range; within a preset time range, if the percentage change in car load is greater than threshold Th2 for M consecutive times (e.g., M=1) after low-pass filtering, the re-leveling dead zone range is adjusted to the third re-leveling dead zone range; within a preset time range, if the percentage change in car load is not changed, the re-leveling dead zone range is adjusted to the first re-leveling dead zone range. The third releveling dead zone is larger than the first releveling dead zone, and the first releveling dead zone is larger than the second releveling dead zone.

[0037] Threshold Th1 is the threshold for determining that the load is light, and the unit is the percentage of the rated load, such as 10%. If the percentage of the car load changes less than threshold Th1 for N consecutive times (such as N=3), it is determined that the car is experiencing continuous changes in light load, such as continuous entry and exit of people.

[0038] Threshold Th2 is the threshold for determining that the load is overloaded, such as 30%. If the percentage of load on the car changes more than threshold Th2 for M consecutive times (e.g., M=1), it is determined that the car has experienced overload changes such as cargo entering or leaving.

[0039] This embodiment uses the change in car load to perform a simple classification and judgment of the type of load entering and exiting, thereby selecting an appropriate re-leveling operation logic and accuracy range. This avoids the computational burden on the control system or the cost of additional sensors caused by frequently collecting car position information when directly assessing car sway. It effectively balances the need to improve re-leveling accuracy and avoid frequent re-leveling without overly complicating the re-leveling operation logic.

[0040] The elevator discussed in this embodiment can acquire relatively continuous positional information near the leveling target point. This embodiment can be applied to elevators employing absolute position sensing systems, magnetic strip leveling sensors, or continuous photoelectric switch leveling sensors. These elevators can further acquire precise values ​​(X mm) of leveling deviation or distance increment information (e.g., near, medium, far) within the allowable range of leveling movements.

[0041] The present invention has been described in detail above through specific embodiments and examples, but these are not intended to limit the invention. Many modifications and improvements can be made by those skilled in the art without departing from the principles of the invention, and these should also be considered within the scope of protection of the present invention.

Claims

1. A method for controlling the secondary leveling operation of an elevator, characterized in that, include: Step S1: When the elevator is in a deceleration state, monitor the speed command output by the elevator control system. Step S2: When the speed command is zero, obtain the height difference between the car floor and the floor sill. Step S3: When the height difference is greater than the trigger threshold, short-circuit the door lock circuit; Step S4: Calculate the secondary leveling speed command based on the height difference; Step S5: Perform a second leveling operation.

2. The elevator secondary leveling operation control method according to claim 1, characterized in that, While executing step S4, an opening command is simultaneously issued.

3. The elevator secondary leveling operation control method according to claim 1, characterized in that, When performing step S5, the unexpected car movement protection function remains active.

4. The elevator secondary leveling operation control method according to claim 1, characterized in that, The trigger threshold is less than 5 mm.

5. The elevator secondary leveling operation control method according to claim 1, characterized in that, The formula for calculating the maximum operating speed in the secondary leveling operation speed command is as follows: ,in The maximum operating speed is given by f, the preset conversion factor is given by d, and the height difference is given by d in step S2.

6. The elevator secondary leveling operation control method according to claim 5, characterized in that, The secondary leveling operation speed command has a preset maximum operating speed limit value. When the maximum operating speed exceeds the maximum operating speed limit value, the maximum operating speed limit value is used as the maximum operating speed.

7. The elevator secondary leveling operation control method according to claim 1, characterized in that, The secondary leveling speed command is a trapezoidal speed command.

8. The elevator secondary leveling operation control method according to claim 7, characterized in that, The formula for calculating the deceleration point in the secondary leveling speed command is as follows: ,in Let V be the deceleration point, V be the car speed at the moment deceleration begins, τ be the response lag parameter, and α be the deceleration.

9. The elevator secondary leveling operation control method according to claim 1, characterized in that, After the elevator completes its second leveling operation, the dead zone range for re-leveling is adjusted according to changes in the load inside the car.

10. The elevator secondary leveling operation control method according to claim 9, characterized in that, After the elevator completes its second leveling operation, the dead zone range of the second leveling operation is first set as the dead zone range of the second leveling operation. Within a preset time range, if the percentage of car load changes less than the threshold Th1 for N consecutive times, the re-leveling dead zone range is adjusted to the second re-leveling dead zone range; within a preset time range, if the percentage of car load changes greater than the threshold Th2 for M consecutive times, the re-leveling dead zone range is adjusted to the third re-leveling dead zone range; within a preset time range, if the percentage of car load does not change, the re-leveling dead zone range is adjusted to the first re-leveling dead zone range; where N is a positive integer greater than 2, and M is a positive integer; The third releveling dead zone is larger than the first releveling dead zone, and the first releveling dead zone is larger than the second releveling dead zone.

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