Load adaptive elevator counterweight dynamic adjustment system and method

Abstract

The application discloses a kind of elevator counterweight block dynamic adjustment system and method based on load adaptation, the system includes car load real-time detection module, counterweight demand calculation unit, counterweight block library, electromagnetic counterweight tray assembly, counterweight platform, control system and position detection device, the counterweight demand calculation unit is based on formula calculation and needs to be adjusted counterweight;The application is vertically moved between counterweight block library and counterweight platform by electromagnetic counterweight tray assembly and utilizes electromagnetic adsorption transfer standard counterweight block, realizes safe dynamic counterweight adjustment in combination with position detection device and anti-falling safety interlocking device, so that elevator can keep near balance on both sides of traction sheave under any load, greatly reduce energy consumption and prolong component life.

Description

Technical Field

[0001] This invention relates to the field of elevator technology, and in particular to a dynamic adjustment system and method for elevator counterweights based on load adaptation. Background Technology

[0002] Traditional elevator counterweight systems typically use fixed counterweights. This involves calculating and installing a fixed mass of counterweight based on the elevator's rated load capacity, the car's weight, and a preset balance coefficient (usually 0.4-0.5). This design assumes that load variations during elevator operation follow a statistical law, resulting in a compromise equilibrium point. A few elevator systems employ partially adjustable counterweight schemes. For example, they reserve installation positions for additional counterweights on the counterweight frame, allowing maintenance personnel to manually add or remove counterweights to adapt to seasonal or temporal changes in building usage. Additionally, technologies using hydraulic cylinders to move the counterweight or pump stations to adjust the liquid counterweight mass have emerged, attempting to achieve dynamic changes in counterweight mass.

[0003] First, with a fixed counterweight system, the significant mass difference between the counterweight side and the car side during light-load upward movement or heavy-load downward movement causes the traction motor to operate at high torque output for extended periods. This not only increases energy consumption but also accelerates wear on the wire ropes and traction sheaves. Even with manual counterweight adjustment, it's impossible to handle varying passenger flow throughout the day, such as heavy-load upward movement during the morning rush hour and heavy-load downward movement during the evening rush hour in office buildings. Second, existing hydraulic moving counterweight solutions are structurally complex, requiring the installation of hydraulic lines and cylinders within the shaft, posing a risk of leakage. Furthermore, the slow response speed of hydraulic systems makes it difficult to adjust the counterweight during short elevator stops. Liquid counterweight solutions face issues such as liquid sloshing, seal aging, and icing in extremely cold regions, making reliability difficult to guarantee.

[0004] Therefore, in response to the problems mentioned above, this invention proposes a dynamic adjustment system and method for elevator counterweights based on load adaptation. Summary of the Invention

[0005] To overcome the problems of existing elevator counterweight methods being unable to dynamically and accurately adjust according to real-time load and the leakage and safety risks of hydraulic or liquid solutions, this invention proposes a load-adaptive elevator counterweight dynamic adjustment system and method. This system automatically increases or decreases the number of standard counterweights on the counterweight device based on the real-time collected car load weight during the standby interval after each elevator stop, so that the elevator maintains an optimal operating state close to the preset balance coefficient under any load condition.

[0006] The technical solution of this invention is: a load-adaptive elevator counterweight dynamic adjustment system, comprising:

[0007] The car load real-time detection module is used to obtain the total load weight L of passengers and goods in the car in real time after each elevator stop and completes the door opening and closing operation;

[0008] The counterweight demand calculation unit communicates with the car load real-time detection module. This counterweight demand calculation unit stores the elevator car's self-weight P and calculates it based on the formula... Calculate the required amount of counterweight that needs to be adjusted. ,in This represents the current effective counterweight of the counterweight device;

[0009] The counterweight storage is located at one or more preset positions at the bottom or top of the elevator shaft, and is used to store several standard counterweights with the same unit weight (each weighs 5kg, with an allowable tolerance of ±0.1kg).

[0010] An electromagnetic counterweight tray assembly is slidably mounted on a counterweight frame and can move vertically under the drive of a control system. The electromagnetic counterweight tray assembly includes one or more electromagnetic adsorption units. When the electromagnetic adsorption unit is energized, it generates a controllable electromagnetic attraction force to establish or release a magnetic adsorption connection with a standard counterweight in the counterweight block library (the rated adsorption force of the electromagnetic adsorption unit on a single standard counterweight block is not less than 250N).

[0011] The counterweight platform is fixedly installed on the counterweight frame. The standard counterweight blocks attracted by the electromagnetic counterweight tray assembly are transferred to the counterweight platform for locking or releasing.

[0012] The control system is electrically connected to the car load real-time detection module, the counterweight demand calculation unit, and the electromagnetic counterweight tray assembly, respectively. This control system calculates the counterweight demand output by the counterweight demand calculation unit. The system calculates the number N of standard counterweights that need to be added or removed, and issues a control command to drive the electromagnetic counterweight tray assembly to move to the counterweight storage position to pick up the corresponding number of standard counterweights through electromagnetic adsorption, or releases the standard counterweights already adsorbed on the electromagnetic counterweight tray assembly into the counterweight storage, thereby realizing the adjustment of the total amount of counterweight.

[0013] The position detection device is electrically connected to the control system and is used to monitor the vertical position of the electromagnetic counterweight tray assembly in real time and compare it with the preset counterweight block library position and counterweight platform position (detection accuracy is ±0.5mm). The control system only allows the electromagnetic adsorption unit to perform adsorption or release operations when the electromagnetic counterweight tray assembly accurately reaches the counterweight block library position or counterweight platform position.

[0014] A fall arrestor safety interlock device, connected to the control system, prevents the elevator from starting when the electromagnetic counterweight pallet assembly is in an unlocked state. This device is a relay contact connected in series in the elevator safety circuit. When the electromagnetic counterweight pallet assembly is in an unlocked state (i.e., during movement, or with counterweights attached to the pallet but not yet on the platform), the relay is de-energized, its normally open contact opens, directly cutting off the elevator main controller's operating permission signal. The elevator's traction machine and brake are de-energized, ensuring the elevator cannot start until the counterweight adjustment is complete. Only when the pallet assembly returns to the standby position and all counterweights are reliably locked in the platform or storage position will the relay engage, restoring the safety circuit.

[0015] Furthermore, the control system performs the following counterweight adjustment method:

[0016] S1, after each elevator stop and completes the door opening and closing operation, the car load real-time detection module collects the total load weight data in the current car and sends it to the counterweight demand calculation unit.

[0017] S2, the counterweight requirement calculation unit calculates according to the formula... Calculate the required amount of counterweight adjustment. Where K is a preset constant ranging from 0.4 to 0.5;

[0018] S3, the control system adjusts the counterweight requirement. Determine the number N of standard counterweights that need to be added or removed. ,in This refers to the mass of a single standard counterweight. It is a rounding function;

[0019] S4, when N>0 and >0 indicates that when additional counterweight is needed, the control system drives the electromagnetic counterweight tray assembly to move to the counterweight block storage position. The electromagnetic adsorption unit is energized to adsorb N standard counterweight blocks. Then, the electromagnetic counterweight tray assembly moves to the counterweight platform position and places the standard counterweight blocks one by one into the counterweight block slots, which are then locked by the locking mechanism.

[0020] S5, when N>0 and <0 indicates that when the counterweight needs to be reduced, the control system drives the electromagnetic counterweight tray assembly to move to the counterweight platform position, releases the lock of the corresponding counterweight block slot, the electromagnetic adsorption unit is energized to adsorb N standard counterweight blocks, and then the electromagnetic counterweight tray assembly moves to the counterweight block storage position and releases the standard counterweight blocks to the corresponding storage position.

[0021] S6. After the counterweight adjustment is completed, the control system updates and stores the adjusted total counterweight data and allows the elevator to enter the next operating cycle.

[0022] The total time for the control system to complete a single weight adjustment does not exceed 6 seconds.

[0023] Preferably, the electromagnetic counterweight tray assembly includes a tray base, a vertical guide mechanism, a vertical drive motor, and several electromagnetic adsorption units mounted on the tray base; the counterweight storage compartment has several standard counterweight storage positions arranged in an array, and each storage position has a positioning mark at its bottom that cooperates with the position detection sensor on the electromagnetic counterweight tray assembly; the counterweight platform is located inside the counterweight frame, and includes one or more counterweight slots for receiving and locking standard counterweights, and each counterweight slot has a locking mechanism at its bottom, which is connected to the control system and automatically locks after the electromagnetic counterweight tray assembly places the standard counterweight into the slot.

[0024] Preferably, the real-time load detection module for the car is a pressure sensor array installed at the bottom of the car or a tension sensor on the car suspension rope; the control system is the elevator main controller or an independently set counterweight management controller, and the counterweight management controller communicates with the elevator main controller via a CAN bus with a communication rate of 250kbps to 500kbps.

[0025] Preferably, when performing counterweight adjustment, the control system further obtains the number of standard counterweight blocks currently available in the counterweight block library. If the number of available counterweight blocks in the counterweight block library is insufficient to meet the need to increase the counterweight, the control system generates a counterweight shortage alarm signal; if the number of standard counterweight blocks on the counterweight platform is insufficient to meet the need to reduce the counterweight, the control system generates a counterweight redundancy shortage alarm signal.

[0026] Furthermore, the counterweight adjustment method is executed when the elevator is in a non-operating state, which refers to the standby period after the elevator control system issues a ready signal, the traction machine brake is in a braking state, and the car door is completely closed; if an elevator operation command is received during the counterweight adjustment process, the control system completes the locking or releasing operation of the current counterweight block with the highest priority and issues a safety confirmation signal before responding to the operation command.

[0027] The beneficial effects of this invention are:

[0028] 1. This invention uses a closed-loop calculation formula through a car load real-time detection module and a counterweight demand calculation unit to achieve dynamic adjustment of the total counterweight to a fully balanced state according to the current load L. This solves the problem that the traditional fixed counterweight method cannot adapt to real-time load changes, causing the traction machine to deviate from the balance point for a long time. Compared with the existing hydraulic or liquid counterweight schemes, it does not require changes to the main structure of the elevator and there is no risk of leakage.

[0029] 2. This invention uses an electromagnetic counterweight tray assembly in conjunction with a locking mechanism and position detection device on the counterweight platform to accurately pick up, transfer and lock the standard counterweight block within the elevator stop interval. The single adjustment time does not exceed 8 seconds and the positioning accuracy reaches ±0.5mm. At the same time, the safety interlocking mechanism ensures zero risk of the counterweight block falling.

[0030] 3. The present invention designs the counterweight platform to accommodate multiple standard counterweight blocks, and stores multiple spare counterweight blocks in the counterweight block library. It can achieve full compensation under the working condition of load fluctuation range ±50kg, with an energy saving rate of more than 25%, while reducing the unbalanced wear of traction sheave and wire rope, and extending the service life of key elevator components. Attached Figure Description

[0031] Figure 1 The diagram shown is a schematic representation of the overall system framework of the present invention.

[0032] Figure 2 The diagram shown is a schematic flowchart of the dynamic adjustment method for the counterweight block according to the present invention. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] This invention provides an embodiment:

[0035] Please see Figure 1 This invention is applied to conventional traction passenger elevators or freight elevators. The elevator shaft contains standard components such as a car, counterweight, traction machine, wire ropes, and guide rails. The specific details of this invention are as follows:

[0036] The real-time load detection module for the elevator car is installed between the bottom of the car and the lower beam. It employs a rectangular array of sixteen high-precision resistance strain gauge pressure sensors, each with a rated range of 0-2000 kg and an overall accuracy of ±0.5%FS. The output signals from all sensors are multiplexed and connected to a 24-bit analog-to-digital converter (ADC). A digital signal processor (DSP) calculates the total load weight L within the car. This module triggers data acquisition once each time the elevator doors open or close and the car comes to a standstill. The acquisition period is 200 ms, and the median value is taken after five consecutive acquisitions to eliminate the instantaneous impact error caused by passenger movement.

[0037] The counterweight demand calculation unit is installed as an independent embedded module in the elevator control cabinet, communicating with the car load real-time detection module via an RS485 interface. Its internal memory pre-programs the elevator car's self-weight P and the current effective counterweight of the counterweight device. It is also stored in this unit, and the control system updates this value after each counterweight adjustment. After receiving the load weight data L in real time, this unit immediately executes the following formula:

[0038] ;

[0039] This formula is used to achieve complete dynamic balance on both sides of the traction sheave. The ideal total mass on the counterweight side should be equal to the total mass on the car side (car weight P plus current load L), while the current actual total mass on the counterweight side is... Therefore, the required increase or decrease in counterweight mass is: .when When the value is positive, it indicates that the current counterweight is insufficient and more counterweights need to be added; when... When the value is negative, it indicates that the current counterweight is excessive and the counterweight blocks need to be reduced; when... A value of zero indicates that the system is in a perfectly balanced state and requires no adjustment. Each time this computational unit completes a calculation, it will... The results are sent to the control system via the CAN bus.

[0040] The counterweight storage unit is located in the empty space next to the buffer at the bottom of the elevator shaft. It has three independent storage shelves, with ten standard counterweight storage positions evenly arranged horizontally on each shelf, totaling thirty storage positions. Each storage position consists of a rubber shock-absorbing pad at the bottom and a limiting block at the rear. A permanent magnet is embedded in the center of the bottom of each storage position to assist in positioning and prevent the counterweight from shifting during elevator vibrations. The standard counterweights are made of cast iron, are rectangular in shape, and each weighs 5 kg. The mass tolerance of all counterweights is controlled within ±0.1 kg, ensuring interchangeability among multiple counterweights. A circular adsorption groove is machined at the center of the upper surface of each counterweight. This groove matches the shape of the pole piece of the electromagnetic adsorption unit, maximizing the magnetic contact area.

[0041] The electromagnetic counterweight tray assembly is installed on one side of the counterweight frame and consists of a linear guide pair, a tray base, a vertical drive motor, and four electromagnetic adsorption units. The guide rail portion of the linear guide pair is fixed to the side column of the counterweight frame, and the slider is fixedly connected to the tray base. The vertical drive motor is a permanent magnet synchronous servo motor with a built-in encoder, which converts the rotational motion into the vertical linear motion of the tray base through a ball screw. The electromagnetic adsorption units use energized electromagnets. Each electromagnetic adsorption unit consists of a ring excitation coil, an iron core, a magnetic shielding ring, and pole shoes. The rated voltage is DC24V, and the rated current is 1.2A. When the adsorption surfaces are well adhered, the static adsorption force generated by a single unit is not less than 250N (approximately 25.5kgf). The four electromagnetic adsorption units are arranged in a 2×2 array and can be independently controlled to switch on and off. Therefore, they can simultaneously adsorb multiple counterweights or selectively adsorb some counterweights. A laser displacement sensor is also installed under the tray base as part of the position detection device. It has a range of 2000mm, an accuracy of ±0.5mm, and a sampling frequency of 100Hz.

[0042] The counterweight platform is fixed to the internal crossbeams of the counterweight frame. Five counterweight slots are vertically oriented on the platform surface, each precisely matching the dimensions of a standard counterweight. An electric locking mechanism is located at the bottom of each slot. Once the counterweight is fully seated, the control system outputs a locking signal, and the electric locking mechanism engages with the locking hole on the side of the counterweight, securing it in place. Each slot also contains a microswitch to detect whether the counterweight is in position. The counterweight platform can accommodate up to ten standard counterweights simultaneously, meaning a maximum adjustable counterweight weight of 50 kg. For elevators with larger rated load capacities, the number of slots can be increased to fifteen, with each counterweight still weighing 5 kg, resulting in a total adjustment range of 75 kg, sufficient to cover the balance compensation needs under most operating conditions.

[0043] The control system communicates with the elevator main controller via a CAN bus at a communication rate of 500kbps. The control system receives the output from the counterweight demand calculation unit. Then, first, amplitude limiting is performed: if

[0044] If the value is greater than the smaller of the total available mass in the current counterweight block library and the remaining capacity of the counterweight platform, then limit it to that smaller value; if If the value is negative and its absolute value is greater than the total mass of the existing counterweights on the current platform, then the limit is set to the negative of the total mass of the current platform. Then, the number of standard counterweights that need to be adjusted is calculated. ,in This refers to the mass of a single standard counterweight. Rounding to the nearest integer. (For example, after limiting the frame rate.) =+12kg, then N=round(12 / 5)=2 pieces, the actual increase or decrease is 10kg, and the rounding error is 2kg; if =+13kg, then N=3 pieces, the actual increase or decrease is 15kg, the error is +2kg. This error is acceptable in engineering, and can be corrected again during subsequent docking. The control system maintains two variables: the number of available counterweights in the storage (initial value is 30) and the current number of counterweights on the platform (initial value is 0 or based on a preset initial value). When adding counterweights, it first checks whether the number of available counterweights in the storage is ≥N. If it is insufficient, an alarm is triggered and the adjustment is abandoned. When reducing counterweights, it checks whether the current number on the platform is ≥N. If it is insufficient, an alarm is triggered.

[0045] Furthermore, the following describes a complete working cycle of the system using specific numerical values. Assume elevator parameters: car weight P = 800 kg, initial counterweight platform has 0 counterweight blocks, counterweight storage is full with 30 blocks (total 150 kg), and the counterweight device, in addition to the adjustable counterweight blocks added by this invention, also has a fixed base counterweight (usually P + kQ, where Q is the elevator's rated load capacity, taken as 1000 kg, and k is the balance coefficient, taken as 0.45). To ensure compatibility with actual elevator structures, the counterweight platform of this invention is added on top of the original fixed counterweight blocks. Therefore, the original fixed counterweight is 1250 kg (corresponding to P + 0.45Q = 1250), and the additional adjustable counterweight blocks added to the platform of this invention range from 0-50 kg. = 1250+ ,in This represents the total mass of the adjustable weights currently available on the platform. Initially... =0, =1250kg.

[0046] Example 1:

[0047] Please see Figure 2 When the elevator stops at the first floor and the car doors are fully closed, the control system determines that the elevator is in a non-operational state (brake engaged, door lock circuit closed). The car load real-time detection module collects the current load L=0kg (no load). The data is sent to the counterweight demand calculation unit. The unit calculates... =(800+0)-1250=-450kg. This value is negative and has a large absolute value, indicating that the current weight is far from excessive and needs to be reduced by 450kg. However, the adjustable range of this system is only 0-50kg, therefore the control system... Bandwidth limiting: Currently, the platform already has... =0kg, the maximum reduction is 0kg, therefore after limiting the amplitude =0kg. The control system determines that no adjustment is needed and allows the elevator to run directly.

[0048] Example 2:

[0049] Assuming the elevator runs multiple times, initially... The load remains at 1250kg. At a certain moment, the car load L = 500kg (half load). Calculate. =(800+500)-1250=50kg. This value is within the system's adjustment capability. The control system found 30 available counterweights in the storage, and 10 remaining slots on the platform. The maximum weight that can be added is N=10, corresponding to an additional 50kg. Therefore, the operation of adding 10 counterweights is executed: the electromagnetic counterweight tray assembly moves to the counterweight storage location, the electromagnetic adsorption unit is energized to adsorb 10 standard counterweights, and then moves to the counterweight platform location, placing the counterweights one by one into the slots and locking them with the locking mechanism. After completion, Updated to 1250 + 50 = 1300 kg. =50kg. At this time, the imbalance changes from the original (1250-1300)=-50kg (the car is heavier) to (1300-1300)=0kg, and the output torque of the traction machine is reduced by 100% accordingly, resulting in significant energy saving.

[0050] During a subsequent stop, the elevator car load L increased to 300 kg. At this point... Still 1300kg (10 pieces remain on the platform). Calculation =(800+300)-1300=-125kg, the limit is the maximum reduction that can be achieved on the current platform -50kg (i.e., 10 weights). The control system executes the counterweight reduction operation: the electromagnetic tray moves to the counterweight platform, releases the locks on the 10 slots, the electromagnetic adsorption unit is energized to adsorb 10 counterweight blocks, and then moves them to the counterweight block storage for release. After completion... Restored to 1250kg =0kg. At this point, the imbalance changes from (1300-1100)=200kg (overweight) to (1250-1100)=150kg, an improvement of approximately 25%. It is evident that each adjustment continuously reduces... Approaching in the direction of P+L.

[0051] The adjustments include (taking the addition of N=5 weights as an example):

[0052] The control system requests to enter maintenance mode from the elevator main controller via the CAN bus. After the main controller confirms that the traction machine brake is engaged, the door lock circuit is disconnected, and there are no running commands, it returns a signal to allow adjustment. This process takes approximately 50ms.

[0053] The control system drives the electromagnetic counterweight pallet assembly to move downwards from its initial position to the counterweight block storage position. The moving speed is set to 200 mm / s, the stroke is 1200 mm, and the time is 6 seconds. During the movement, the laser displacement sensor continuously detects the distance to the reference plate at the bottom of the shaft. When the detected distance is equal to the preset storage position distance and the fluctuation is less than ±0.5 mm, the control system determines that the position is in place, stops the drive motor, and applies a holding torque.

[0054] The control system reads the occupancy status sensor (photoelectric sensor) of the designated storage position in the counterweight block library to confirm that all 5 counterweight blocks to be picked up are present and not covered by foreign objects. If a block is missing from a position, an adjacent position is automatically selected.

[0055] The control system outputs a control signal to simultaneously energize the four coils of the electromagnetic adsorption unit, causing the excitation current to rise linearly from 0 to 1.2A in approximately 50ms. After the electromagnetic attraction is generated, the tray base is slightly raised by about 0.5mm (achieved through motor fine-tuning) to confirm that the counterweight has been reliably adsorbed. Simultaneously, the pressure sensor on the tray detects the attraction force; if the total attraction force is greater than 200N (the sum of the four units), the adsorption is considered successful.

[0056] The control system drives the electromagnetic counterweight tray assembly to move upwards with five counterweight blocks to the counterweight platform position. The moving speed remains at 200mm / s, the stroke is 1200mm, and the time is 6 seconds. The arrival detection is also based on a laser displacement sensor, with an arrival accuracy of ±0.5mm.

[0057] The electromagnetic counterweight tray assembly aligns the counterweight with an empty slot on the platform and slowly lowers it until the counterweight falls into the slot. Each time a counterweight is placed, a microswitch at the bottom of the slot is triggered. Upon receiving the positioning signal, the control system immediately activates the electromagnet of the slot's locking mechanism, engaging the counterweight in its locking hole. A locking confirmation signal is then sent back from the locking position switch. This process is repeated until all five counterweights are locked.

[0058] The control system cuts off the power to the electromagnetic adsorption unit, the excitation current drops to 0, and the magnetic force disappears. The tray assembly rises slightly by 1mm to confirm that all counterweights have detached. The counterweight addition is now complete. The control system updates M_current to 1275kg, reduces the number of available counterweights in the storage by 5, and increases the number of counterweights on the platform by 5.

[0059] The control system sends a "counterweight adjustment complete, safety lock confirmed" signal to the elevator main controller, which then allows the elevator to start running. The total time for a single adjustment (excluding waiting time during movement) is approximately 6.5 seconds.

[0060] The process of reducing the weight is similar, only in the opposite direction.

[0061] To verify the effectiveness of this invention, the following comparative experiment was designed. The experiment was conducted on a passenger elevator with a rated load capacity of 1000 kg and a rated speed of 1.75 m / s, which was installed in a 5-story experimental building. All experimental data were recorded using a high-precision power analyzer, laser rangefinder, accelerometer, and data acquisition device.

[0062] Experiment 1:

[0063] This experiment compares the energy consumption of the dynamic counterweight system of this invention with that of the traditional fixed counterweight system under different load fluctuations in an elevator's single operation. The fixed counterweight uses a constant P + 0.45Q = 1250 kg. The dynamic counterweight system of this invention initially has M_current = 1250 kg, with a counterweight adjustment range of ±50 kg (±10 pieces). After each stop, the system calculates M_target = (P + L) - M_current and performs a limit adjustment.

[0064] This experiment simulated 200 operations per day (100 upward and 100 downward), with the load L fluctuating randomly between 0 and 800 kg, but the fluctuation ranges were set to ±50 kg (small amplitude), ±150 kg (medium amplitude), and ±300 kg (large amplitude), respectively. Two modes, fixed counterweight and dynamic counterweight, were run under each fluctuation range. The total power consumption at the traction machine input (unit: kWh) was recorded, and the energy saving rate was calculated. The results are shown in Table 1.

[0065] As shown in Table 1, when the load fluctuation is small (±50kg), the ±50kg adjustment range of this invention can cover all fluctuations, allowing the traction machine to frequently operate in a near-balanced state, achieving an energy saving rate of 26.5%. When the fluctuation increases to ±150kg, the adjustment range can only cover 1 / 3 of the fluctuation, and the energy saving rate drops to 12.3%. When the fluctuation reaches ±300kg, the adjustment range is severely insufficient, with an energy saving rate of only 4.7%. This indicates that this invention is best suited for scenarios with relatively stable loads but minor fluctuations, such as office buildings or residential buildings where the number of passengers does not change significantly within the same time period.

[0066] Experiment 2:

[0067] This experiment was conducted to verify the positioning accuracy and electromagnetic adsorption success rate of the electromagnetic counterweight pallet assembly under different vertical movement distances.

[0068] In this experiment, the system of this invention was installed inside an elevator shaft, with the counterweight storage located at the bottom of the shaft (1200mm vertically from the counterweight platform). A cyclical operation of "picking up one counterweight from the counterweight platform and transferring it to the counterweight storage" was performed 1000 times consecutively. During each operation, the positioning error of the electromagnetic counterweight tray assembly when it reached the target position (the absolute value of the difference between the laser displacement sensor reading and the preset position), the adsorption success rate of the electromagnetic adsorption unit after it was powered on (determined by the pressure sensor on the tray detecting whether the adsorption force is ≥200N), and the total time from issuing the movement command to completing the locking and releasing were recorded. The results are shown in Table 2.

[0069] As shown in Table 2, the positioning errors are all better than the system's required accuracy of ±0.5mm. While the positioning error slightly increases with the number of counterweights due to the increased pallet inertia caused by the increased total mass, it still meets the requirements. The total time is basically in line with the design target of 6 seconds for a single adjustment. When 10 counterweights need to be transferred, the longest time is 8.6 seconds, slightly exceeding the target, but this is still acceptable considering that the elevator stop interval is usually 8-12 seconds.

[0070] Experiment 3:

[0071] This experiment was conducted to measure the vibration acceleration and noise level inside the elevator car during the counterweight adjustment process and during normal elevator operation after adjustment, in order to assess whether it had a negative impact on ride comfort.

[0072] In this experiment, a triaxial accelerometer (range ±2g, accuracy 0.001g) and a sound level meter (A-weighted, slow setting) were installed in the center of the car floor. Measurements were taken under the following three conditions:

[0073] State 1: The elevator is moving upwards without any load and no counterweight adjustment has been made (baseline).

[0074] State 2: The elevator is half-loaded and moving upwards, while simultaneously performing an adjustment operation to add 2 counterweights (the elevator remains stationary during the adjustment process).

[0075] Status 3: After the elevator completes the counterweight adjustment, it runs downwards fully loaded.

[0076] As shown in Table 3, during the adjustment process, the noise level slightly increased to 52.3 dB(A) due to the operation of the electromagnetic adsorption unit and the motor, but it is still lower than the requirement of ≤55 dB(A) for elevator operating noise specified in the national standard GB / T 10058. The operating vibration after adjustment is basically the same as the baseline state, indicating that the counterweight block will not introduce additional vibration after being reliably locked. Therefore, the system of the present invention does not affect passenger comfort at all.

[0077] As described above, this invention can be used in office buildings where a large number of passengers travel upwards during the morning rush hour (heavy load upward travel) and downwards during the evening rush hour (heavy load downward travel). The system can quickly adjust the counterweight after each stop, ensuring that the traction machine always operates in a near-balanced state, achieving an overall energy saving rate of 15-25%. It can also be used in hospital elevators with stretchers or wheelchairs, where load changes drastically and high leveling accuracy is required. The dynamic counterweight can reduce the unbalanced torque on both sides of the traction sheave, improving leveling accuracy.

[0078] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments that can be applied to other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A load-adaptive dynamic adjustment system for elevator counterweights, characterized in that, include: The car load real-time detection module is used to obtain the total load weight L of passengers and goods in the car in real time after each elevator stop and completes the door opening and closing operation; The counterweight demand calculation unit communicates with the car load real-time detection module. This counterweight demand calculation unit stores the elevator car's self-weight P and calculates it based on the formula... Calculate the required amount of counterweight that needs to be adjusted. ,in This represents the total effective counterweight of the current counterweight device; A counterweight storage unit is located at one or more preset positions at the bottom or top of the elevator shaft to store several standard counterweights with the same unit weight. An electromagnetic counterweight tray assembly is slidably mounted on a counterweight frame and can move vertically under the drive of a control system. The electromagnetic counterweight tray assembly includes one or more electromagnetic adsorption units. When the electromagnetic adsorption unit is energized, it generates a controllable electromagnetic attraction force to establish or release a magnetic adsorption connection with a standard counterweight in the counterweight library. The counterweight platform is fixedly installed on the counterweight frame. The standard counterweight blocks attracted by the electromagnetic counterweight tray assembly are transferred to the counterweight platform for locking or releasing. The control system is electrically connected to the car load real-time detection module, the counterweight demand calculation unit, and the electromagnetic counterweight tray assembly, respectively. This control system calculates the counterweight demand output by the counterweight demand calculation unit. The system calculates the number N of standard counterweights that need to be added or removed, and issues a control command to drive the electromagnetic counterweight tray assembly to move to the counterweight storage position to pick up the corresponding number of standard counterweights through electromagnetic adsorption, or releases the standard counterweights already adsorbed on the electromagnetic counterweight tray assembly into the counterweight storage, thereby realizing the adjustment of the total amount of counterweight. The position detection device is electrically connected to the control system and is used to monitor the vertical position of the electromagnetic counterweight tray assembly in real time and compare it with the preset counterweight block storage position and counterweight platform position. The control system only allows the electromagnetic adsorption unit to perform adsorption or release operations when the electromagnetic counterweight tray assembly accurately reaches the counterweight block storage position or counterweight platform position.

2. The elevator counterweight dynamic adjustment system based on load adaptation according to claim 1, characterized in that: The electromagnetic counterweight tray assembly includes a tray base, a vertical guide mechanism, a vertical drive motor, and several electromagnetic adsorption units mounted on the tray base. The adsorption surface of each electromagnetic adsorption unit corresponds to and is attached to the adsorption surface of the standard counterweight block.

3. The elevator counterweight dynamic adjustment system based on load adaptation according to claim 2, characterized in that: The counterweight storage unit has several standard counterweight storage positions arranged in an array. Each storage position has a positioning mark at the bottom that works in conjunction with the position detection sensor on the electromagnetic counterweight tray assembly.

4. The elevator counterweight dynamic adjustment system based on load adaptation according to claim 1, characterized in that: The counterweight platform is located inside the counterweight frame and includes one or more counterweight slots for receiving and locking standard counterweight blocks. Each counterweight slot has a locking mechanism at its bottom, which is connected to the control system and locks the standard counterweight block after the electromagnetic counterweight tray assembly places it into the slot.

5. The elevator counterweight dynamic adjustment system based on load adaptation according to claim 1, characterized in that: The real-time load detection module for the car is a pressure sensor array installed at the bottom of the car or a tension sensor on the car suspension rope.

6. The elevator counterweight dynamic adjustment system based on load adaptation according to claim 1, characterized in that: The control system is either the elevator main controller or a separately set counterweight management controller, which communicates with the elevator main controller via a CAN bus.

7. The elevator counterweight dynamic adjustment system based on load adaptation according to claim 1, characterized in that: The system also includes a fall protection safety interlock device, which is connected to the control system. When the electromagnetic counterweight pallet assembly is in an unlocked state, the elevator is prohibited from starting.

8. A load-adaptive dynamic adjustment method for elevator counterweights, employing the load-adaptive dynamic adjustment system for elevator counterweights as described in any one of claims 1-7, characterized in that... Includes the following steps: S1, after each elevator stop and completes the door opening and closing operation, the car load real-time detection module collects the total load weight data in the current car and sends it to the counterweight demand calculation unit. S2, the counterweight requirement calculation unit calculates according to the formula... Calculate the required amount of counterweight adjustment. Where K is a preset constant ranging from 0.4 to 0.5; S3, the control system adjusts the counterweight requirement. Determine the number N of standard counterweights that need to be added or removed. ,in This refers to the mass of a single standard counterweight. It is a rounding function; S4, when N>0 and >0 indicates that when additional counterweight is needed, the control system drives the electromagnetic counterweight tray assembly to move to the counterweight block storage position. The electromagnetic adsorption unit is energized to adsorb N standard counterweight blocks. Then, the electromagnetic counterweight tray assembly moves to the counterweight platform position and places the standard counterweight blocks one by one into the counterweight block slots, which are then locked by the locking mechanism. S5, when N>0 and <0 indicates that when the counterweight needs to be reduced, the control system drives the electromagnetic counterweight tray assembly to move to the counterweight platform position, releases the lock of the corresponding counterweight block slot, the electromagnetic adsorption unit is energized to adsorb N standard counterweight blocks, and then the electromagnetic counterweight tray assembly moves to the counterweight block storage position and releases the standard counterweight blocks to the corresponding storage position. S6. After the counterweight adjustment is completed, the control system updates and stores the adjusted total counterweight data and allows the elevator to enter the next operating cycle.

9. The method for dynamic adjustment of elevator counterweight based on load adaptation according to claim 8, characterized in that: In step S3, the control system further obtains the number of standard counterweights currently available in the counterweight block library. If the number of available counterweights in the counterweight block library is insufficient to meet the need to increase the counterweight, the control system generates a counterweight shortage alarm signal. If the number of standard counterweights on the counterweight platform is insufficient to meet the need to reduce the counterweight, the control system generates a counterweight redundancy shortage alarm signal.

10. The method for dynamic adjustment of elevator counterweight based on load adaptation according to claim 8, characterized in that: Steps S1 to S6 are executed when the elevator is in a non-operating state, which refers to the standby period after the elevator control system sends a ready signal, the traction mechanism brake is in a braking state, and the car door is completely closed. If an elevator operation command is received during the counterweight adjustment process, the control system will complete the locking or releasing operation of the current counterweight block with the highest priority and issue a safety confirmation signal before responding to the operation command.

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