Automatic Leveling System of an Elevator Car Top for Upper Maintenance Work

Abstract

The present invention relates to an automatic leveling system for the top section of an elevator car for upper maintenance work. The automatic leveling system according to the present invention includes: a memory storing elevator car height information (H_car), which is the physical height specification of the elevator car, and landing floor position information (P_floor) for each floor; a car top access switch disposed inside an emergency switch box provided in the operation control panel inside the elevator car to generate a signal to enter a leveling operation mode; a general operation input unit that receives administrator authentication and target floor information; and a load sensing unit that measures the passenger load inside the elevator car. When the disembarkation of a worker is confirmed through the load sensing unit, the control unit closes the door, calculates a leveling target position (P_target) by subtracting the elevator car height information (H_car) from the landing floor position information (P_floor) of the target floor, and controls the drive unit to move the elevator car to that position, thereby automatically and precisely aligning the top section of the elevator car with the landing floor.

Description

Technology Field

[0001] The present invention relates to the field of elevator control technology, and more specifically, to an automatic leveling system for an elevator car top that controls the level of the elevator car top to automatically and precisely match the level of the landing floor surface in order to ensure worker safety and increase work efficiency during elevator inspection operations. Background Technology

[0003] As elevators are a vital means of transporting passengers safely and quickly, regular inspection and maintenance are essential. These maintenance tasks are performed in a Maintenance Operation Mode, which departs from the Normal Operation Mode to prioritize worker safety, and the operating speed is limited to an extremely low level. Maintenance work can be broadly classified into lower maintenance, which involves inspecting the substructure, and upper maintenance, which involves inspecting the upper structure of the car.

[0005] In the case of lower maintenance work, the worker primarily performs the work in the maintenance space (pit) located at the very bottom of the elevator shaft. Since the car only needs to be lowered to the maintenance space and stopped at a position where sufficient space is secured above the worker, the lower maintenance operation method has relatively low technical difficulty or safety risk in setting the operating position.

[0007] However, problems arise during maintenance work on the top section (upper part) of the elevator car. Upper maintenance work is primarily carried out at the car top, and in most cases, workers board through the landing door to move to the car top.

[0009] Conventional upper maintenance operation methods utilized a manual adjustment process to align the top surface of the elevator car with the floor of the landing. Due to this reliance on manual operation, the accuracy of the leveling varied depending on the operator's skill level and field of view, frequently resulting in difficulties in achieving precise alignment.

[0011] In particular, when a misalignment occurred between the level of the elevator car's top section and the landing floor, there was a constant risk of falls or tipping over due to workers stumbling or falling while entering or exiting the car's top section. Additionally, the need for repetitive fine-tuning to achieve precise leveling resulted in reduced overall work efficiency.

[0013] In particular, when a misalignment occurred between the level of the elevator car's top section and the landing floor, there was a constant risk of falls or tipping over due to workers stumbling or falling while entering or exiting the car's top section. Additionally, the need for repetitive fine-tuning to achieve precise leveling resulted in reduced overall work efficiency. Prior art literature

[0015] Republic of Korea Patent Publication No. 2001-0107994 (December 7, 2001) The problem to be solved

[0016] The present invention was devised to solve the problems of the aforementioned prior art, and its main purpose is to enhance worker safety and work efficiency by providing an automatic leveling function that automatically and precisely aligns the level of the elevator car's top section with the level of the landing floor during upper maintenance operation of the elevator.

[0018] In addition, the present invention has another objective of preventing erroneous operation and security accidents by unauthorized persons by providing a separate input means for accessing the top section on the control panel inside the elevator car and ensuring that automatic leveling is performed only after undergoing a password authentication process through a floor selection button, etc.

[0020] In addition, another objective of the present invention is to prevent safety accidents that may occur when a worker forcibly opens the door of a moving car by visually indicating that leveling is in progress through a hall indicator on the landing while automatic leveling is being performed. means of solving the problem

[0022] An automatic leveling system for an elevator car top section for upper maintenance work according to the present invention for achieving the above objective comprises: a memory storing elevator car height information (H_car), which is the physical height specification of the elevator car, and landing floor surface location information (P_floor) for each floor; a car top access switch provided in the operation control panel inside the elevator car and disposed inside an emergency switch box that is normally kept in a locked state, which generates a signal to enter a leveling operation mode by operation by a worker; a general operation input unit that receives a password for administrator authentication and target floor information to perform leveling work when the signal to enter the leveling operation mode is received; and a load sensing unit that measures the passenger load inside the elevator car. The control unit comprises: when target floor information is input through the general operation input unit, determining whether a worker has disembarked through the load detection unit; and if the worker has disembarked, closing the landing door and the elevator car door, calculating the leveling target position (P_target = P_floor - H_car) by subtracting the elevator car height information (H_car) from the landing floor position information (P_floor) of the target floor stored in the memory, and controlling the drive unit so that the elevator car moves to the leveling target position (P_target).

[0024] Here, it is preferable that the control unit excludes the operation of moving the elevator car to the normal landing position (P_floor) of the target floor and then lowering it again, and controls the drive unit so that the elevator car sets the calculated leveling target position (P_target) as the final destination from the current position and drives directly without intermediate stopping.

[0026] Additionally, a leveling sensor is provided on the side of the elevator car, and a detected body interacting with the leveling sensor may be provided on a part of the side wall of each floor of the elevator shaft. In this case, when the elevator car is decelerating and moving adjacent to the leveling target position (P_target), the control unit finely corrects the stopping position by controlling the braking timing of the drive unit based on the signal in which the leveling sensor detects the detected body.

[0028] In addition, a display unit indicating the operating status of the elevator may be provided at the landing of each floor, and the control unit may, while the movement for automatic leveling is being performed, flash a specific character (L) indicating that leveling is in progress through the display unit of the target floor to warn of door opening from the outside, and when the leveling target position (P_target) is reached and leveling is completed, control the display unit to switch the screen to a completion indicator (O).

[0030] Finally, the control unit performs safety logic that, if the load value measured by the load detection unit exceeds a preset threshold (0 kg or empty weight), determines that an operator remains inside the elevator car, forcibly restricts the closing operation of the door and the movement of the elevator car, and outputs a warning signal. Effects of the invention

[0032] According to the present invention, unlike conventional methods that rely on manual operation by a worker, the control unit automatically and precisely aligns the top of the elevator car with the landing floor surface based on a calculated leveling target position (P_target), thereby fundamentally eliminating the risk of safety accidents such as tripping, falling, or falling that may occur when a maintenance worker enters or exits the elevator shaft.

[0034] In addition, the present invention significantly improves the operational reliability of the system by preventing accidents in which a worker is trapped inside the car or malfunctions caused by unauthorized operation by an unauthorized person, through the provision of an interlock function that starts operation after confirming the number of remaining personnel inside the car via a load detection unit, and a double security procedure through an emergency switch box and password authentication. Furthermore, by transmitting a visual warning signal to the landing indicator during the leveling operation, it blocks attempts by outsiders to forcibly open the door, thereby preventing safety accidents caused by third parties.

[0036] Furthermore, the present invention eliminates unnecessary back-and-forth movement of moving the elevator car to a normal landing position and then lowering it again, and applies an optimized driving algorithm that moves directly from the current position to a leveling target position. This not only increases work efficiency by shortening maintenance preparation time but also contributes to saving energy and extending the expected lifespan of the elevator by reducing motor driving time and mechanical fatigue. Brief explanation of the drawing

[0038] FIG. 1 is a control block diagram showing the overall configuration of an automatic leveling system for an elevator car top section for upper maintenance work of an elevator according to one embodiment of the present invention. FIG. 2 is an exemplary diagram showing the detailed configuration of an input unit according to the present invention, showing the arrangement of a general operation input unit and a cartop access switch inside an emergency switch box. FIG. 3 is a flowchart showing the overall execution process of an automatic leveling method for a elevator car top section according to an embodiment of the present invention in chronological order. FIG. 4 is a conceptual diagram for explaining the movement control principle (Offset Targeting) and direct path of the elevator car during automatic leveling according to the present invention. FIG. 5 is an example diagram showing the safety notification status (in progress / completed) output through the hall indicator during automatic leveling according to the present invention. FIG. 6 is an enlarged cross-sectional view illustrating the principle of correcting mechanical errors and implementing precise imaging through the interaction between a leveling sensor and a body to be detected according to the present invention. FIG. 7 is a flowchart showing an automatic leveling movement control process according to the first embodiment of the present invention, showing a method of descending after passing through a normal landing position using an encoder. FIG. 8 is a flowchart showing an automatic leveling movement control process according to a second embodiment of the present invention, showing a method of descending and stopping through leveling sensor feedback after passing through a normal landing position. FIG. 9 is a flowchart illustrating an automatic leveling movement control process according to a third embodiment of the present invention, showing a method of moving directly to a calculated leveling target position and then performing fine correction with a sensor. Specific details for implementing the invention

[0039] The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms.

[0041] The embodiments described herein are provided to ensure that the disclosure of the invention is complete and to fully inform those skilled in the art of the scope of the invention. The invention is defined only by the scope of the claims. Accordingly, in some embodiments, well-known components, well-known operations, and well-known techniques are not specifically described to avoid the invention being interpreted ambiguously.

[0043] Throughout the specification, the same reference numerals refer to the same components. Furthermore, the terms used (mentioned) in this specification are for describing the embodiments and are not intended to limit the invention. In this specification, the singular form includes the plural form unless specifically stated otherwise in the text. Additionally, components and operations referred to as "comprising (or comprising)" do not exclude the presence or addition of one or more other components and operations.

[0045] Unless otherwise defined, all terms used in this specification (including technical and scientific terms) may be used in a meaning commonly understood by those skilled in the art to which the present invention pertains. Additionally, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively unless otherwise defined.

[0047] Embodiments of the present invention will be described below with reference to the attached drawings. FIG. 1 is a block diagram showing the overall configuration of an automatic leveling system for the elevator car top section for upper maintenance work of an elevator.

[0049] FIG. 1 is a block diagram showing the overall configuration of an automatic leveling system for an elevator car top section for upper maintenance work of an elevator according to the present invention.

[0051] As illustrated in FIG. 1, the automatic leveling system according to the present invention is configured around a control unit (110) for comprehensively controlling the overall operation and safety logic of the elevator. In addition, the system is configured to include a memory (120) for storing specification information and operation data of the elevator car, an input unit (130) for receiving operation mode switching and control commands from an operator, a position detection unit (140) for measuring the vertical position of the elevator car in real time, a sensor unit (150) for detecting the physical state and landing precision inside and outside the elevator car, a driving unit (160) for driving the elevator car up and down according to the command of the control unit (110), a door control unit (170) for controlling the opening and closing of the elevator car door and the landing door, and a display unit (180) for visually informing external users of the current operation status of the elevator.

[0053] Below, the functions and specific operating principles of each component shown in FIG. 1 will be explained in detail.

[0055] The control unit (110) is a central processing unit (CPU, MCU, etc.) that acts as the brain of the automatic leveling system according to the present invention, and collects and analyzes various signals transmitted from the input unit (130), the position detection unit (140), and the sensor unit (150), and controls the driving unit (160) and the door control unit (170), etc. according to a preset algorithm. Specifically, when the control unit (110) receives a signal to enter 'Top Access Mode' through the input unit (130), it stops the normal driving mode for general passenger transport and switches to the car-top leveling driving mode. In this process, the control unit (110) activates an authentication module to perform a password verification procedure to block unauthorized access by unauthorized persons, and grants leveling control authority only to workers whose authentication is complete. In addition, when performing automatic leveling, the control unit (110) does not simply move the elevator car to a specific floor, but loads the elevator car height information (H_car) stored in the memory (120) and performs calculation processing. That is, it calculates the 'leveling target position (P_target)' in real time by subtracting the elevator car height (H_car) from the landing floor level (P_floor) of the target floor designated by the operator, and issues speed and position commands to the drive unit (160) so that the elevator car moves directly to the leveling target position without unnecessary detours. In addition, the control unit (110) performs core logic for preventing safety accidents. Before issuing a drive command, it checks the load inside the elevator car through the sensor unit (150) to determine whether the operator has disembarked, and if a load is detected, it forcibly blocks the drive. In addition, during movement, it controls the display unit (180) to send a warning signal to outsiders, thereby ensuring the safety integrity of the overall system.

[0057] The memory (120) is a storage medium in which various data and programs necessary for the control unit (110) to perform automatic leveling are stored. The memory (120) stores 'normal landing position information (P_floor),' which is the absolute position value (or pulse value) of the landing floor surface for each floor of a building where an elevator is installed, in a table format. In particular, in the present invention, the memory (120) necessarily stores 'lift car height information (H_car),' which is the physical height specification of the elevator car. This height information refers to the vertical distance value from the floor surface of the lift car to the top surface of the lift car, and is used as an offset value when the control unit (110) calculates the leveling target position. In addition, the memory (120) stores an administrator password for entering the upper top access mode, past failure history and leveling operation log data, and zero point correction data of the sensor unit (150), and is implemented as a non-volatile memory such as Flash Memory or EEPROM so that the stored data is not lost even if the power supply is cut off.

[0059] The input unit (130) is an interface device that receives commands necessary for the operation of the elevator from a worker or passenger. The input unit (130) of the present invention can be broadly divided into a 'general operation input unit' used by general passengers to register a destination floor or to open and close doors, and an 'emergency operation input unit (or emergency switch box)' that only maintenance workers can access to issue special commands. The general operation input unit includes floor selection buttons, door open / close buttons, emergency call buttons, etc., exposed on the Car Operating Panel (COP) inside the elevator car. In the present invention, these general operation buttons can be utilized by temporarily switching their function to a numeric keypad for entering a password during the authentication stage. The emergency operation input unit is provided at the bottom of the Car Operating Panel or at a separate location, and is normally closed by a cover equipped with a locking device, but is configured so that a worker can open it using a dedicated key. Inside this emergency operation input unit, the 'Car Top Access Switch,' which is the core function of the present invention, is provided. As the operator turns this switch ON, an upper top access mode activation signal is transmitted to the control unit (110).

[0061] The position detection unit (140) detects the current vertical position of the elevator car moving within the elevator shaft in real time and provides it to the control unit (110). The position detection unit (140) may be configured to include a rotary encoder, which is generally installed on the motor shaft or governor of the drive unit (160). The position detection unit (140) counts pulse signals generated according to the movement of the elevator car to precisely calculate the distance traveled, speed, and current position of the elevator car. The control unit (110) controls the deceleration time and the stopping time so that the elevator car can accurately reach the target point by comparing (feedback control) the current position value received from the position detection unit (140), the data loaded from the memory (120), and the calculated leveling target position (P_target) in real time. According to an embodiment, the position detection unit (140) may further include a plate sensor installed at each floor to recognize the absolute position of the elevator shaft or a barcode / QR code-based absolute position recognition system.

[0063] The sensor unit (150) performs the role of detecting the physical state of the elevator car and fine position information for precise landing, in addition to the macroscopic position information provided by the position detection unit (140). In the present invention, the sensor unit (150) mainly includes a 'load detection unit' and a 'leveling sensor'. The load detection unit (Load Weighing Device) is installed at the bottom of the elevator car or at the rope connection part to measure the passenger load inside the elevator car. While this is typically used to prevent overload, in the present invention, it is utilized as a safety sensor to determine whether a worker remains inside the elevator car before automatic leveling starts. The control unit (110) allows the leveling operation only when the value of the load detection unit is '0kg' or within a set tolerance range (e.g., less than 5kg). The leveling sensor is composed of an optical sensor, a magnetic sensor, or a laser distance measuring device installed on the top or side of the elevator car. When the elevator car reaches a target position based on calculations by the control unit (110), the leveling sensor detects a detection target (reflector, magnet, etc.) installed on the elevator shaft wall or the lower part of the landing threshold and generates a precise position signal. This signal is used to finally correct position errors on the encoder that may occur due to slip or elongation of the wire rope.

[0065] The drive unit (160) is a power generating device that moves the elevator car up and down within the elevator shaft according to a control signal from the control unit (110). The drive unit (160) mainly includes a traction machine and an inverter system that controls it. In the present invention, the drive unit (160) controls the rotational speed and torque of the motor according to a speed profile transmitted from the control unit (110). In particular, in the upper top access mode, the elevator car is controlled to travel at an inspection speed (e.g., 0.3 m / s to 0.6 m / s) that is significantly lower than the normal rated speed for the safety of the operator. Additionally, the drive unit (160) drives the motor to travel along an optimal path toward a leveling target position (P_target) calculated from the current position without the inefficient operation of raising the elevator car to the floor level of the target target floor and then lowering it again in accordance with the direct movement command of the control unit (110), and firmly fixes the elevator car by engaging the electromagnetic brake when the target position is reached.

[0067] The door control unit (170) controls the opening and closing operation of the car door installed in the elevator car and the landing door installed at each floor landing. Typically, when the elevator car door driving device (Door Operator) drives the car door, the landing door is linked through a mechanical coupling device (Coupler / Vane) to open and close together. In the present invention, the door control unit (170) transmits a signal to the control unit (110) confirming that the elevator car door and the landing door are completely closed and the door locking device (Interlock) is engaged before the automatic leveling process begins. This is to prevent shearing or falling accidents that may occur when the elevator car moves in an open state. Additionally, the door control unit (170) is controlled to ignore any door opening command input during the leveling operation and maintain a closed state.

[0069] The display unit (180) includes a hall indicator installed on the landing wall or the top of the door of each floor and a position indicator inside the elevator car. Normally, the display unit (180) displays the floor number where the elevator car is currently located and the direction of travel (arrow). The display unit (180) according to the present invention functions as a safety device that transmits a warning message to an external user during automatic leveling under the control of the control unit (110). When the control unit (110) starts automatic leveling, the display unit (180) of the corresponding target floor displays a specific character, such as the letter 'L' meaning 'Leveling' or 'Under Inspection,' in a blinking form instead of displaying the floor number. This allows waiting passengers or external workers to intuitively recognize that the elevator car is moving to an abnormal position (top leveling position), thereby suppressing attempts to forcibly open the door using an emergency key. When leveling is complete, the display unit (180) displays characters such as 'O', 'OK', or 'Completed' to indicate that the worker can safely open the door and enter.

[0071] FIG. 2 is an example diagram specifically illustrating the configuration of an input unit (130) that receives a user's command in an automatic leveling system for an elevator car top part for upper maintenance work of an elevator according to the present invention.

[0073] Referring to FIG. 2, the input unit (130) of the present invention is installed in the Car Operating Panel (COP) inside the elevator car and is broadly divided into a 'general operation input unit (131)' for the general purpose of passenger boarding and an 'emergency operation input unit (132)' which can be accessed by only authorized managers, such as maintenance workers, to perform special functions. These two input units may be physically separated or functionally separated within a single panel.

[0075] First, the general operation input section (131) is positioned in an exposed manner on the top or middle of the control panel so that passengers can easily identify and operate it visually. This includes a number of floor selection buttons (buttons 1 to 10 in the drawing), door open / close buttons, and an emergency call button. In the normal 'normal operation mode', this general operation input section (131) performs the usual functions of registering the destination floor that the passenger wishes to move to or opening and closing the door when boarding or alighting.

[0077] However, when entering the 'Levelling Operation Mode' according to the present invention, the control unit (110) changes the function mapping of the general operation input unit (131) to utilize it as an input interface for security authentication. Specifically, when an operator generates a signal to enter the Levelling Operation Mode by operating the car-top access switch (1321) described later, the control unit (110) converts the floor selection buttons of the general operation input unit (131) into a numeric keypad for password input. For example, if the administrator password is '1-2-3-4', the operator performs the authentication process by sequentially pressing the 1st floor, 2nd floor, 3rd floor, and 4th floor buttons. At this time, the control unit (110) changes the color of the LED lamp inside the button or changes the flashing pattern to visually provide feedback to the operator that the corresponding buttons are currently operating for password input rather than for floor registration.

[0079] In addition, after password authentication is completed, the general operation input unit (131) switches its function back to a means of selecting a 'target floor' to perform leveling operations. When the operator presses the 5th floor button, the control unit (110) recognizes the 5th floor as the target floor and loads the normal implantation location information (P_floor) of the 5th floor from the memory (120) to calculate the leveling target location (P_target). As such, the present invention has the effect of simplifying the hardware configuration and reducing costs by utilizing the existing button for multiple purposes without adding a separate password input device.

[0081] Meanwhile, the emergency operation input section (132) is positioned at the bottom of the general operation input section (131) or at the very bottom of the control panel where passengers' eyes do not easily reach. Since it contains important operation switches directly related to the safety of the elevator, it is normally closed by an opaque locking cover to prevent erroneous operation by unauthorized persons, such as passengers or children. This cover is equipped with a keyhole, and a physical security device is provided so that only an administrator possessing a dedicated key can open the cover and access the internal control section.

[0083] Referring to the enlarged view on the right side of FIG. 2, various switches necessary for maintenance, such as a manual up / down button (UP / DOWN), a light switch, a fan switch, and a stop switch, are arranged inside the emergency operation input section (132). Among these, the core component of the present invention is the car top access switch (1321). The car top access switch (1321) is a switch that acts as a trigger to activate the automatic leveling system according to the present invention. Although a toggle switch is exemplified in the drawing, various forms such as a rotary switch or a push button may be applied.

[0085] When an operator opens the locking cover and operates this car-top access switch (1321) to the 'ON' position, an electrical signal is immediately transmitted to the control unit (110). The control unit (110) recognizes this signal as a top-priority interrupt, cancels all calls from general passengers currently in progress or waiting, and forcibly switches the elevator's operating state from 'normal operation mode' to 'leveling operation mode'. In conventional technology, even if the maintenance mode switch is turned on, the operator must manually move the car, but the present invention is distinguished in that this car-top access switch (1321) functions as the starting point of the automatic leveling process. That is, as soon as this switch is turned ON, the system does not simply enter a manual operation standby state, but is prepared to perform a series of automated sequences, starting a password authentication procedure and subsequently leading to load detection and automatic position control.

[0087] Additionally, a separate LED indicator or text label indicating the status (ON / OFF) of the switch is attached around the car-top access switch (1321) to help the operator clearly recognize whether the system has entered leveling operation mode. If the operation is completed and the switch is returned to 'OFF', the control unit (110) returns the system to normal operation mode and allows general passengers to board.

[0089] FIG. 3 is a flowchart specifically illustrating the chronological execution process of an automatic leveling method for the upper part of an elevator car for upper maintenance work according to an embodiment of the present invention. The control method according to the present invention is performed primarily by the control unit (110) of FIG. 1 described above, and is implemented through organic signal exchange with a memory (120), an input unit (130), a position detection unit (140), a sensor unit (150), a driving unit (160), a door control unit (170), and a display unit (180).

[0091] Below, the control process for each step will be described in detail with reference to FIG. 3.

[0093] First, the process begins with an elevator maintenance worker boarding the elevator car to inspect or repair the car top. The worker opens the locking cover of the emergency operation input located at the bottom of the control panel inside the elevator car using a dedicated key and operates the car top access switch (1321) provided inside to the 'ON' state. When the control unit (110) receives an activation signal for the car top access switch from the input unit (130), it immediately stops the general passenger transport service currently being performed and switches the elevator's operation mode from normal operation mode to 'Levelling Operation Mode' (S310). At this stage, the control unit (110) blocks the landing call button input for all floors to ignore attempts by external passengers to board.

[0095] When the leveling operation mode is entered, the control unit (110) performs an authentication step (S320) to prevent system misoperation and security accidents by unauthorized persons. The control unit (110) switches the general operation input unit (131) of the operation control panel from a floor registration function to a password input function. At this time, so that the operator can intuitively recognize that the current state is an authentication waiting state, the control unit (110) may change the LED color of the floor button (e.g., switch from white to red) or broadcast a voice guidance message saying "Please enter the administrator password" through the speaker inside the elevator car. The operator enters a pre-set password by combining the buttons of the general operation input unit.

[0097] When the password input is completed by the operator, the control unit (110) compares the entered password data with the administrator authentication information stored in memory (120) to determine whether they match (S330). If the entered password does not match the stored information (N), the control unit (110) outputs a warning voice or visual notification saying "The password is incorrect" and returns the process to the password input waiting stage (S320) (S335). This prevents the subsequent leveling operation from being executed even if a general passenger or non-expert who does not know the password operates the switch out of curiosity.

[0099] On the other hand, when password authentication is successfully completed (Y), the control unit (110) grants leveling control authority to the operator and receives 'target floor' information to perform leveling work from the operator (S340). When the operator presses a specific floor button (e.g., 3rd floor) on the general operation input unit, the control unit (110) sets the floor as the target point for this leveling operation and loads the normal implantation location information (P_floor) of the floor from the memory (120).

[0101] Once the target floor setting is complete, a disembarkation guidance and safety inspection sequence is performed to ensure the safety of the worker prior to full-scale mechanical operation. The control unit (110) broadcasts a message via an announcement saying, "Automatic leveling is starting. Please disembark from the elevator car immediately," and maintains a waiting state for a certain period of time (e.g., 10 to 20 seconds) to allow the worker to disembark safely (S350).

[0103] After the waiting time has elapsed, the control unit (110) receives real-time load data inside the elevator car from the load weighing device of the sensor unit (150) and precisely determines whether the inside of the elevator car is empty (0kg) (S360). At this time, the standard for '0kg' may include a pre-set empty weight (e.g., less than 5kg) considering the error range of the sensor. If a significant load is detected by the load weighing device (N), the control unit (110) considers that a worker is still inside the elevator car or that cargo remains. Since there is a risk of entrapment accidents, etc., if the elevator car moves to a leveling target position (a position lower than the landing floor) while a worker is on board, the control unit (110) prohibits door closing and driving operations, and loops back to the disembarking guidance step (S350) to continuously induce disembarking or generate a warning sound.

[0105] When it is confirmed that the inside of the elevator car is completely empty as a result of the load detection (Y), the control unit (110) issues a command to the door control unit (170) to completely close the elevator car door and the landing door and engage the door interlock. At the same time, the control unit (110) controls the display unit (180) to flash the letter 'L', which means 'Leveling', on the landing hall indicator of the target floor (S370). This visual warning serves to warn other workers or managers waiting outside the landing not to attempt to forcibly open the door after realizing that the elevator car is moving.

[0107] When the safety state of the door is secured, the control unit (110) controls the drive unit (160) to perform automatic leveling movement (S380). At this stage, the control unit (110) does not simply move to the 'normal landing position (P_floor)' of the target floor. The control unit (110) reads the height information (H_car) of the elevator car stored in the memory (120) and performs a calculation to subtract the height (H_car) of the elevator car from the normal landing position (P_floor) of the target floor, thereby calculating the 'leveling target position (P_target = P_floor - H_car)', which is the final destination to be moved to. Then, the control unit (110) receives feedback on the encoder signal of the position detection unit (140) and controls the elevator car to move directly from the current position toward the calculated leveling target position (P_target). In other words, it moves the elevator car quickly and efficiently to the point where the top aligns with the landing sill via a single direct path, without the unnecessary round-trip movement of raising the car to the floor and lowering it again.

[0109] When the elevator car reaches the vicinity of the leveling target position (P_target) and enters the deceleration section, the control unit (110) switches the subject of position control from the encoder-based position detection unit (140) to the sensor unit (150) based on an optical or magnetic leveling sensor, or utilizes both in parallel. When the leveling sensor installed on the side of the elevator car detects a target object (such as a reflector) on the elevator shaft wall and generates an On-Level Signal, the control unit (110) immediately controls the motor torque of the drive unit (160) upon receiving this signal to precisely land the elevator car and applies a mechanical brake to brake it (S390). Through this, a perfect leveling state is achieved with minimized error between the top surface of the elevator car and the floor surface of the elevator landing, regardless of changes in the elongation of the wire rope or the load.

[0111] When the automatic leveling operation is completed and the elevator car has stopped safely, the control unit (110) switches the status of the display unit (180) from an 'L' flashing indicator to an 'O (OK)' or 'Complete' indicator to notify an external worker that the leveling has been successfully completed. Subsequently, the system switches to a standby state while maintaining the door lock until a worker manually opens the door by inserting an emergency key into the key hole of the landing door (S395), thereby terminating the series of control processes for automatic leveling. After confirming the completion signal from the display unit, the worker can safely open the door, enter the top of the elevator car, and perform maintenance work.

[0113] FIG. 4 is a conceptual diagram illustrating the movement control principle (Offset Targeting) applied when the automatic leveling system according to the present invention controls the elevator car to move it to a target point, and the actual driving path of the elevator car accordingly.

[0115] With reference to FIG. 4, the position calculation logic and driving control process performed by the control unit (110) of the present invention will be described in detail.

[0117] Generally, in the 'normal operation mode' where the elevator transports passengers, the goal of the control system is to align the floor of the elevator car with the sill of the corresponding floor. The '① normal landing position (P_floor)' depicted in the upper right corner of Fig. 4 refers to this point. If upper maintenance work is performed using a conventional method to which the present invention is not applied, the worker must go through the cumbersome process of first moving the elevator car to this normal landing position (P_floor) and then manually lowering it by the height of the elevator car. This method not only causes unnecessary power consumption but also causes a decrease in work efficiency by inducing repetitive fine adjustments (Inching) to align the lowering position.

[0119] However, when the control unit (110) according to the present invention enters the 'leveling operation mode', it does not set the above-mentioned normal landing position (P_floor) as the final destination. As soon as a movement command is input, the control unit (110) calls two core data stored in memory (120). The first is the 'normal landing position information (P_floor)', which is the absolute position value of the landing floor of the target floor (e.g., 3rd floor), and the second is the 'elevator car height information (H_car)', which is the unique physical specification of the elevator car. Here, the elevator car height information (H_car) refers to the vertical distance from the floor of the elevator car to the top surface of the elevator car where the worker will actually step, i.e., the offset value.

[0121] The control unit (110) uses these two data to calculate the 'leveling target position (P_target)' that the actual elevator car must reach in real time, as shown in the formula below.

[0123] P_target = P_floor - H_car

[0125] That is, the control unit (110) subtracts the height of the elevator car itself (H_car) from the height of the floor surface (P_floor) of the target floor, and sets a virtual coordinate (P_target) as a new driving target point where the top part (Car Top) can be perfectly level with the floor surface (Sill) of the elevator car when it stops. The '② Leveling target position (P_target)' indicated by the center dotted box in FIG. 4 is the target point newly defined by the present invention.

[0127] After going through this calculation process, the control unit (110) controls the drive unit (160) to start the movement of the elevator car. At this time, it should be noted that the '③ Direct Path' shown in the lower right corner of FIG. 4 is a point of interest.

[0129] As shown in the drawing, the elevator car (solid line box) currently located on the 2nd floor (starting point) travels directly toward the calculated leveling target position (②) without passing through the normal landing position (①) on the 3rd floor. Since the control unit (110) generates a velocity profile targeting P_target from the starting point, the elevator car does not perform an unnecessary over-travel and return operation of rising to the 3rd floor floor level and then coming back down.

[0131] Instead, the elevator car automatically enters a deceleration pattern when it approaches the leveling target position (P_target) during ascent, and comes to a smooth stop the moment it accurately reaches the top leveling position. In FIG. 4, the top surface of the elevator car (center dotted box) that has reached the leveling position is precisely aligned with the line of the 3rd floor landing surface (Sill), which visually demonstrates the final result of this control.

[0133] This 'offset calculation-based direct movement control' method provides the following technical effects.

[0135] First, it maximizes energy efficiency. It reduces the potential energy consumed in unnecessarily lifting the elevator car to a higher position (P_floor) and prevents braking heat loss from the motor when lowering it.

[0137] Second, it reduces working time and increases convenience. Since it immediately reaches the position optimized for the task (top leveling position) with just a single movement command, the operator can open the door and safely enter without any separate position adjustments.

[0139] Third, it reduces mechanical wear. Since unnecessary lifting and lowering reversing movements are eliminated, it lowers the mechanical fatigue of the drive system, such as wire ropes, sheaves, and brake linings, thereby contributing to extending the elevator's lifespan.

[0141] Consequently, the control logic illustrated in FIG. 4 demonstrates that the present invention is not merely a simple position moving device, but an intelligent leveling system designed to simultaneously consider the safety of the worker and the efficiency of the system. During this process, the control unit (110) continuously monitors the encoder feedback signal of the position detection unit (140) to correct the error with the calculated path in real time, and at the final landing point, secondarily checks the signal of the sensor unit (150) to ensure perfect precision.

[0143] FIG. 5 is an example diagram showing the operating state of a display unit (180) for visually informing a worker or general user outside the platform of the current operating state while the automatic leveling system according to the present invention is in operation.

[0145] Referring to FIG. 5, the system of the present invention prevents safety accidents by intuitively conveying the internal situation through a Hall Indicator located at the top of the landing door when performing the leveling operation mode.

[0147] Figure 5 (A) shows the driving state in which the control unit (110) is moving the elevator car to the leveling target position (P_target). At this time, the control unit (110) displays the letter 'L', which means 'Levelling', instead of the current floor number on the target floor display unit (180). Preferably, this 'L' character is blinked at regular intervals to increase visibility, thereby allowing a worker waiting outside to recognize that the elevator car is moving. This serves as a warning function to prevent accidents such as falling or being trapped that may occur when a worker forcibly opens the landing door using an emergency key while the elevator car is moving to an abnormal position for top leveling.

[0149] Figure 5 (B) shows the completed state where the elevator car has accurately reached the leveling target position (P_target) and stopped. When the precise landing is confirmed through the sensor unit (150) and the brake is engaged, the control unit (110) switches the screen of the display unit (180) to the 'O' (or 'OK') character. This is a signal indicating that safe entry is possible because the top surface of the elevator car and the floor surface (Sill) of the landing are level. After confirming this completion indicator, the operator can manually open the door by inserting an emergency key into the key hole provided at the top right of the landing door, and safely move to the top of the car to begin maintenance work.

[0151] FIG. 6 is an enlarged cross-sectional view showing the configuration and operating principle of a sensor unit used by an automatic leveling system according to the present invention to correct computational errors or mechanical minute errors of a position detection unit (encoder) and to precisely stop the elevator car at a leveling target position.

[0153] Referring to FIG. 6, a ‘sensing body’ consisting of a magnet, a reflector, a light-absorbing plate, etc. is installed on the elevator shaft wall (or the lower part of the landing threshold), which is a fixed structure of the elevator shaft, and a ‘leveling sensor’ consisting of a light sensor or a proximity sensor is provided on the side wall (or upper part) of the elevator car that moves vertically in response to this.

[0155] In this case, the installation height of the detected object and the leveling sensor is of great significance. They are precisely positioned so that they can face each other directly and exchange signals when the surface of the elevator car's top reaches the precise 'leveling target position (P_target),' which is level with the landing sill.

[0157] The control unit (110) moves the elevator car to the vicinity of the leveling target position (P_target) through calculations using the encoder value, and then monitors the signal of the leveling sensor during the final landing stage. At the moment the elevator car moves and the leveling sensor matches the position of the object to be detected, the sensor generates a detection signal and transmits it to the control unit (110).

[0159] As soon as the detection signal is received, the control unit (110) issues a stop command to the drive unit (160) and applies the brake. This sensor-based feedback control method physically corrects minute positional errors that may occur due to changes in wire rope tension or fluctuations in load, thereby ensuring a perfectly level state that allows a worker to safely enter the elevator car top section without any steps.

[0161] FIG. 7 is a flowchart illustrating a specific control process of the automatic leveling movement execution step (S380) according to the first embodiment of the present invention. The first embodiment corresponds to a 'cost-effective' implementation method that aims to achieve the purpose of the present invention solely through software algorithm improvements by fully utilizing only the functions of the existing drive unit (160) and position detection unit (140, encoder) without installing a separate additional leveling sensor or hardware device in the elevator system.

[0163] Hereinafter, the movement control process of the elevator car according to the first embodiment will be described in detail step by step with reference to FIG. 7.

[0165] 1. Initial migration phase: Migration to normal implantation site (S710)

[0166] First, when the door closing and safety check are completed in step S370 of FIG. 3, the control unit (110) begins full-scale leveling movement. In the first embodiment, the control unit (110) does not move immediately to the leveling target position, but rather sets the 'normal landing position (P_floor)' of the target floor as the primary destination. The control unit (110) issues a movement command to the drive unit (160) to move the elevator car to the target floor (S710). At this time, the driving pattern is controlled similarly to the pattern used for general passenger transport, but considering that the current system is in 'leveling driving mode,' it is desirable that the acceleration and driving speed be limited to a low speed lower than the normal rated speed (e.g., 50% or less of the rated speed or inspection driving speed) for the safety of the operator. The purpose of this step is to secure an accurate 'Reference Point' for the descent movement described later by positioning the elevator car at the reference coordinate most accurately recognized by the elevator system, namely the normal landing position for each floor (P_floor).

[0168] 2. Reference point securing phase: Normal implantation position stop (S720)

[0169] When the elevator car reaches the target floor and reaches the normal landing position (P_floor) where the floor of the elevator car and the floor of the landing (Sill) coincide, the control unit (110) controls the drive unit (160) to temporarily stop the elevator car (S720). This stopping state may be accompanied by the application of a physical brake, or it may be an electrical stopping state in which zero speed torque is applied to the motor through inverter control to maintain the position. Importantly, at this point, the system's position data is synchronized so that the current position coordinates of the elevator car match the absolute position value (P_floor) of the corresponding floor. This is a preparatory process to eliminate accumulated errors that may occur due to long-term operation and to maximize the precision of the next step, fine descent control.

[0171] 3. Calculation Step: Calculation of Downward Shift Target Value (S730)

[0172] While the elevator car is stopped at a reference point (or just before stopping), the control unit (110) retrieves the elevator car height information (H_car), which is the specification data of the elevator car stored in the memory (120). Then, it calculates how much it must descend from the current position (P_floor) to enable top-leveling (S730). In the case of the first embodiment, since the elevator car has already reached the normal landing position (P_floor), the distance to be moved that the control unit (110) needs to calculate is simply the height value of the elevator car, 'H_car' itself, without the need for complex absolute coordinate calculations. That is, the control unit (110) generates a relative position control command to "move down by H_car from the current position." This relative position control method has the advantage of increasing system stability by having a low computational load and a simple control logic.

[0174] 4. Execution Phase: Encoder-based precision descent drive (S740)

[0175] When the operation is completed, the control unit (110) controls the drive unit (160) to lower the elevator car (S740). At this time, the lowering speed is controlled at a very slow micro-drive speed (Creep Speed, e.g., around 0.1 m / s). In this process, the position detection unit (140), that is, the rotary encoder, plays a key role in position control. The control unit (110) counts the pulse signals generated by the encoder in real time as the motor rotates. For example, assuming that the elevator car moves 10 mm per motor rotation and the encoder outputs 1,000 pulses, if the elevator car height (H_car) is 3,000 mm, the control unit (110) continues the lowering operation until a total of 300,000 pulses are counted. This method is also called 'Pulse Control' and is a technology that can control the travel distance with considerable precision using only the amount of rotation of the motor without a separate external sensor. The control unit (110) applies a deceleration pattern just before reaching the target number of pulses, thereby precisely controlling the motor torque so that the elevator car does not overshoot the target position due to inertia.

[0177] 5. Completion Phase: Braking and Process Return (S750)

[0178] When the accumulated pulse value of the encoder reaches the set lowering target value (number of pulses corresponding to H_car), the control unit (110) determines that the top surface of the elevator car is aligned with the level of the landing floor surface, immediately sends a stop signal to the drive unit (160), and engages the mechanical brake (S750). When the brake is engaged and the elevator car is mechanically fixed, the automatic leveling movement process according to the first embodiment is terminated, and the system returns to step S390 (or S395 completion indicator step) of FIG. 3 to perform subsequent actions.

[0180] The first embodiment described above offers excellent economic efficiency and versatility in that the functions of the present invention can be implemented solely through a firmware update without modifying the hardware of the existing elevator. In particular, since most recently installed elevators are equipped with high-precision encoders as standard, this method alone can secure a leveling precision (within an error range of ±10mm) sufficient for workers to safely enter low-rise buildings or small elevators where minute slip of the wire rope does not occur.

[0182] FIG. 8 is a flowchart illustrating a specific control process of the automatic leveling movement execution step (S380) according to the second embodiment of the present invention. While the first embodiment described above had a strong 'open-loop control' nature relying on pulse counting of an encoder, the second embodiment illustrated in FIG. 8 applies a 'closed-loop feedback control' method that checks the position in real time and brakes by utilizing a leveling sensor that detects physical position information. This configuration is designed to ensure perfect landing precision by hardware-correcting minute elongation of the wire rope or slip of the drive wheel that may occur in high-rise buildings or aging elevators.

[0184] Hereinafter, the movement control process of the elevator car according to the second embodiment will be described in detail step by step with reference to FIG. 8.

[0186] 1. Initial movement and reference point securing phase (S810 ~ S820)

[0187] The initial entry process of the second embodiment proceeds similarly to the first embodiment. After step S370 of FIG. 3, the control unit (110) controls the drive unit (160) to move the elevator car to the 'normal landing position (P_floor)' of the target floor, rather than immediately lowering the elevator car (S810). The elevator car ascends or descends according to a set driving profile to reach the target floor, and stops at the normal landing position (P_floor) where the bottom surface of the elevator car coincides with the landing floor (Sill) (S820). This process is a step that clarifies the starting point of the subsequent sensor-based descent operation by positioning the elevator car at physically determined coordinates (the door section of the corresponding floor) and forms initial conditions for the sensor to search for the object to be detected. At this time, the control unit (110) makes the speed of the elevator car completely '0' and then proceeds to the next step.

[0189] 2. Sensor Activation and Search Descent Step (S830)

[0190] When the elevator car stops at the normal landing position, the control unit (110) supplies power to the 'leveling sensor' included in the sensor unit (150) to switch to an enabled state. This leveling sensor is installed on the side or top of the elevator car and is configured to detect a target object (reflector, magnet, etc.) installed on the elevator shaft wall. When the sensor is enabled, the control unit (110) controls the drive unit (160) to start lowering the elevator car (S830). At this time, the lowering speed is controlled to a very slow creep speed, similar to the first embodiment. However, while the goal of the first embodiment was to move a 'calculated distance (number of pulses),' the lowering operation of the second embodiment has the nature of a 'Searching Mode' that moves 'until the sensor detects a signal.' Therefore, rather than setting a separate limit on the distance of movement, the control unit (110) continues the lowering while treating sensor signal monitoring as a top priority process.

[0192] 3. Real-time location monitoring and signal identification step (S840)

[0193] As the elevator car descends at a low speed, the leveling sensor attached to the side of the elevator car also descends and scans the elevator shaft wall. The control unit (110) monitors whether a detection signal is received from the leveling sensor during the descent at a high-speed cycle of several microseconds (μs) (S840). At this time, the position of the object to be detected installed on the elevator shaft wall is precisely adjusted in advance to correspond to a 'leveling target position' where the top surface of the elevator car exactly matches the floor surface of the elevator landing. If a detection signal is not received from the leveling sensor (N), the control unit (110) determines that the elevator car has not yet reached the target position and continues the descent drive. During this process, the control unit (110) may run a safety logic in the background to monitor whether the travel distance exceeds the allowable error range (e.g., 110%) of the elevator car height (H_car) via an encoder in preparation for a potential sensor failure.

[0195] 4. Precision landing and braking stage (S850)

[0196] When the elevator car descends and the leveling sensor enters the area of ​​the object to be detected, and a valid detection signal (Rising Edge) is received from the sensor (Y), the control unit (110) determines that the elevator car has reached the correct 'leveling target position'. Immediately upon detection of the signal, the control unit (110) applies a stopping torque to the inverter of the drive unit (160) and immediately engages the electromagnetic brake to rapidly stop the elevator car in place (S850). In the second embodiment, by finely adjusting the position of the object to be detected by considering the reaction speed of the sensor and the mechanical response speed of the brake, ultra-precision landing with an error range of ±1 to 2 mm can be achieved without slippage due to inertia.

[0198] This second embodiment has the advantage of being robust against changes in the mechanical state of the elevator because it performs feedback control using hardware sensors. For example, even if a discrepancy occurs between the position on the encoder and the actual physical position due to the wire rope stretching slightly from loading heavy parts or changes in the friction of the guide rail caused by temperature fluctuations, the second embodiment guarantees consistent leveling quality because it ultimately stops at the position visually confirmed by the sensor. Therefore, the second embodiment can be considered the most suitable embodiment for application in high-rise buildings and large cargo elevator systems where the frequency of top-level operations is high or precise safety is required.

[0200] FIG. 9 is a flowchart illustrating a specific control process of an automatic leveling movement execution step (S380) according to a third embodiment of the present invention. While the preceding first and second embodiments adopted an 'indirect movement method' in which the elevator car is first moved to a normal landing position (P_floor) and then lowered again, the third embodiment illustrated in FIG. 9 adopts a 'direct path method' in which a target position is calculated in advance before movement and the elevator travels directly to that point. This is a core algorithm of the present invention designed to maximize energy efficiency by shortening the unnecessary travel distance of the elevator and to drastically reduce work preparation time.

[0202] Hereinafter, the movement control process of the elevator car according to the third embodiment will be described in detail step by step with reference to FIG. 9.

[0204] 1. Preliminary operation step: Offset calculation and target setting (S910)

[0205] The most significant feature of the third embodiment is that a position calculation process is performed within the control unit (110) before operating the drive unit (160). When the leveling operation preparation is completed at step S370 of FIG. 3, the control unit (110) accesses the memory (120) without immediately issuing a movement command. The control unit (110) retrieves the 'normal landing position (P_floor)' of the target floor and the 'elevator height information (H_car)', which is the unique specification of the elevator car, and then calculates the 'leveling target position (P_target)', which is the final destination that the actual elevator car must reach, according to the following formula (S910).

[0207] P_target = P_floor - H_car

[0209] For example, if the normal landing position (P_floor) of the third floor is 9,000 mm relative to the floor surface and the height of the elevator car (H_car) is 2,500 mm, the control unit (110) sets the 6,500 mm point as the new 'leveling target position (P_target)'. Since this step is processed in milliseconds (ms) within the CPU without physical movement, almost no delay occurs.

[0211] 2. Driving Phase: Direct movement to leveling target position (S920)

[0212] When the target coordinates are determined, the control unit (110) issues a movement command to the drive unit (160). At this time, the control unit (110) creates a speed profile by setting the destination of the elevator car to a calculated 6,500 mm (leveling target position) instead of 9,000 mm (normal position) (S920). Accordingly, the elevator car starts from its current position (e.g., 2nd floor) and travels in a straight line toward the leveling target position (P_target) without passing through the normal position on the 3rd floor. This is called "direct driving." Unlike the prior art or previous embodiments which went through a four-step sequence of "rising -> stopping -> descending -> stopping," the third embodiment is completed with only a two-step sequence of "rising -> stopping," thereby not only drastically shortening the operating time but also reducing the frequency of motor start / stop, thereby minimizing power consumption and mechanical wear.

[0214] 3. Approach and Deceleration Phase: Entering Creep Speed ​​(S930)

[0215] When the elevator car reaches the vicinity of the leveling target position (P_target) (e.g., a point 100mm to 200mm ahead of the target) based on feedback from the position detection unit (encoder), the control unit (110) rapidly reduces the driving speed and switches to a fine driving speed (Creep Speed) (S930). This step is intended to eliminate inertia caused by high-speed driving and to create a stable entry environment for precise detection by the leveling sensor described later. At this time, the control unit (110) recognizes that it has almost reached the target point based on the encoder position, but since the possibility of mechanical error due to changes in wire rope tension or load cannot be ruled out, it does not stop immediately but switches to a sensor verification mode.

[0217] 4. Precision calibration step: Sensor signal monitoring and fine movement (S840)

[0218] In a deceleration state, the control unit (110) prioritizes monitoring the leveling sensor signal of the sensor unit (150) (S840). (Note: S840 in the drawing means that it performs the same function as the sensor detection step of FIG. 8.) Even if the elevator car has mechanically reached P_target, the leveling sensor may not yet have detected the object to be detected due to a minute error (N). In this case, the control unit (110) moves the elevator car slightly (Inching) at ultra-low speed until the sensor signal is received, even if it slightly exceeds the target position on the encoder. This is a logic to ensure final safety by trusting the actual physical sensor alignment state more than the mathematically calculated position.

[0220] 5. Completion Phase: Precision Imaging and Braking (S950)

[0221] When the elevator car moves and a valid detection signal (Rising Edge) is received from the leveling sensor (Y), the control unit (110) confirms that the point is physically in a perfectly horizontal state and immediately controls the drive unit (160) to completely stop the elevator car and simultaneously apply the mechanical brake (S950). As a result, the top surface of the elevator car aligns with the floor surface of the landing without error, and the control unit (110) returns to step S390 of FIG. 3 and switches to a state of completion indication and door unlocking waiting.

[0223] This third embodiment can be described as the most advanced form of leveling control method that organically combines the speed of 'computational control' using a position detection unit with the accuracy of 'sensor control' using a leveling sensor. Specifically, this embodiment ensures speed by fundamentally eliminating unnecessary over-travel paths, thereby drastically shortening work preparation time. At the same time, it provides excellent efficiency by reducing the actual driving time of the motor, thereby promoting energy savings and extending the lifespan of the driving equipment. Furthermore, it guarantees perfect landing precision by applying a dual control method in which the system moves quickly to an approximate target position using an encoder, and then precisely fine-corrects the stopping position using a leveling sensor at the final stage. Accordingly, when applying the system of the present invention to actual field operations, it is most desirable to adopt and operate the algorithm of the third embodiment, which possesses all the aforementioned technical advantages, as the default value of the system.

[0225] Although preferred embodiments of the present invention have been described in detail above, this is merely an example to aid in understanding the invention, and the present invention is not limited to the above embodiments. Those skilled in the art to which the present invention pertains can make various modifications, variations, and applications without departing from the technical spirit or scope of the present invention, and it is obvious that such modified embodiments are also included within the scope of protection of the present invention. Accordingly, the scope of protection of the present invention is determined by the appended claims, and all technical ideas within the scope equivalent to the claims should be interpreted as being included within the scope of rights of the present invention. Explanation of the symbols

[0227] 110: Control unit 120: Memory 130: Input section 140: Position detection unit 150: Sensor section 160: Drive unit 170: Door Control 180: Display section

Claims

Claim 1 An automatic leveling system for the elevator car top section for upper maintenance work of an elevator comprises: a memory storing elevator car height information (H_car), which is the physical height specification of the elevator car, and landing floor surface location information (P_floor) for each floor; a car top access switch provided in the operation control panel inside the elevator car and disposed inside an emergency switch box that is normally kept in a locked state, which generates a signal to enter a leveling operation mode upon operation by a worker; a general operation input unit that receives a password for administrator authentication and target floor information to perform leveling work upon receiving the signal to enter the leveling operation mode; and a load sensing unit that measures the passenger load inside the elevator car in real time. A control unit that, when target floor information is input through the general operation input unit, determines whether a worker has disembarked through the load detection unit, and if the worker's disembarkation is confirmed, closes the landing door and the elevator car door, calculates a leveling target position (P_target = P_floor - H_car) by subtracting the elevator car height information (H_car) from the landing floor position information (P_floor) of the target floor stored in the memory, and controls the drive unit so that the elevator car moves to the leveling target position (P_target);The control unit is configured to calculate the height of the top of the elevator car based on the reference stop position information after the elevator car reaches a reference stop position corresponding to the target floor, and to recalculate the leveling target position (P_target) based on the difference from the landing floor position information (P_floor); the leveling target position (P_target) is set so that the top of the elevator car, rather than the floor of the elevator car, is aligned with the landing floor; the control unit is configured to control the drive unit to move directly to the leveling target position (P_target) without passing through the reference stop position again when controlling movement to the leveling target position (P_target); the control unit closes the landing door and the elevator car door and initiates a leveling operation only when it is confirmed that the load value received in real time from the load detection unit is less than or equal to a preset reference value; and if the load value received in real time from the load detection unit exceeds the preset reference value, it is determined that an operator remains inside the elevator car, and the landing door and An automatic leveling system for an elevator car top, characterized by restricting the closing operation of the elevator car door and the movement of the elevator car, outputting a warning signal, and, if the load value received in real time from the load detection unit while the leveling operation is performed exceeds the preset reference value, stopping the operation of the elevator car to restrict the movement of the elevator car and outputting a warning signal. Claim 2 An automatic leveling system for an elevator car top according to claim 1, wherein the control unit excludes the operation of moving the elevator car to the normal landing position (P_floor) of the target floor and then lowering it again, and controls the drive unit so that the elevator car sets the calculated leveling target position (P_target) as the final destination from the current position and drives directly without intermediate stopping, wherein the direct driving may be performed at a position before or after reaching the reference stopping position, and the control unit is configured to set a deceleration section according to the relative position with respect to the leveling target position (P_target) and perform low-speed control. Claim 3 An automatic leveling system for the top of an elevator car according to claim 2, wherein a leveling sensor is provided on the side or top of the elevator car, and a detection body interacting with the leveling sensor is provided on the side wall or structure of each floor landing of the elevator shaft, and the control unit is configured to finely correct the stopping position by controlling the braking timing of the drive unit based on a signal in which the leveling sensor detects the detection body when the elevator car is decelerating in proximity to the leveling target position (P_target), and to perform precise stopping control by comparing the error between the sensor signal and the leveling target position. Claim 4 An automatic leveling system for an elevator car top according to claim 1, wherein a display unit indicating the operating status of the elevator is provided at the landing of each floor, and the control unit restricts attempts to open the door from the outside by flashing a specific character (L) indicating that leveling is in progress through the display unit of the target floor while movement for automatic leveling is performed, and when the leveling target position (P_target) is reached and leveling is completed, the control unit switches the screen of the display unit to a completion indicator (O) and simultaneously indicates that the door is in a state where it can be opened. Claim 5 delete

Images