Elevator car monitoring system
By combining a TOF sensor and an in-car monitoring processor, the problem of elevator car monitoring systems being unable to accurately determine full load and prevent collisions has been solved. This enables accurate full load judgment and effective collision protection for elevators, improving transportation efficiency and safety.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHANGHAI MITSUBISHI ELEVATOR CO LTD
- Filing Date
- 2022-12-22
- Publication Date
- 2026-08-04
AI Technical Summary
Existing elevator car monitoring systems cannot accurately determine the full load status and cannot effectively prevent the car door from being hit by objects such as forklifts, leading to malfunctions and potential damage to the car door.
The system uses a TOF sensor to detect the height of objects inside the elevator car, and combines it with an in-car monitoring processor to perform environmental self-learning and occupancy detection. It then outputs a full load or impact signal, which is transmitted to the elevator control system through a signal interface to achieve accurate full load judgment and anti-collision protection.
It enables accurate judgment of elevator car full load and effective collision prevention, reduces the risk of malfunction and damage to car doors, and improves elevator transportation efficiency and safety.
Smart Images
Figure CN116002475B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of elevators, and more particularly to an elevator car monitoring system. Background Technology
[0002] Elevator car full load detection. Currently, the industry uses weight detection to determine the full load of the car. When the weight reaches a set threshold, the car issues an alarm and prohibits overloading. However, in the use of freight elevators, if the transported goods occupy a large area, even if the weight does not reach the full load limit, there is no extra usable space in the car. In this case, the traditional elevator car monitoring system cannot determine the full load.
[0003] In addition, when a forklift or handcart reverses in a freight elevator, the forklift's rear end may hit the car door, causing it to deform and potentially leading to malfunctions.
[0004] Current methods for detecting elevator car collisions include setting a stop line at the front of the car (e.g., using a light curtain). When an object crosses the stop line, the detection system alarms. However, this method has a drawback: even when not reversing, an object crossing the stop line can trigger an alarm. This detection system is prone to false alarms in forklift collision avoidance scenarios. Furthermore, simply issuing a warning without a corresponding response from the elevator system still carries the risk of impact / damage to the car door. Additionally, the presence of the stop line prevents effective use of the area in front of it within the car. Summary of the Invention
[0005] The technical problem to be solved by the present invention is how to accurately determine whether the car is fully loaded or has been impacted.
[0006] To solve the above-mentioned technical problems, the present invention provides an elevator car monitoring system, characterized in that it includes:
[0007] Sensors are used to detect the height of objects inside the car and output detection data;
[0008] The in-car monitoring processor is used to receive the detection data output by the sensor, compare it with preset data according to preset conditions, and output the corresponding signal.
[0009] The signal interface is used to receive signals from the in-car monitoring processor and transmit them to the elevator control system.
[0010] Preferably, the sensor is installed on the top of the elevator car and located on the center line of the elevator door opening range.
[0011] Preferably, the sensor is a TOF sensor, and the detection data is the coordinates and depth information of each pixel.
[0012] Preferably, the in-car monitoring processor includes an environment self-learning module, which is used to complete the initial state data setting and compare it with preset detection data to determine whether the elevator car monitoring system is abnormal.
[0013] Preferably, the initial state data is the initial detection area, the preset detection data is the preset detection area, and the environment self-learning module forms the initial detection area based on the data information provided by the sensor and the most consistent and numerous pixels within the error range. If the initial detection area is compared with the preset detection area and the shape is consistent, it is considered that the elevator car monitoring system has no abnormalities.
[0014] Preferably, the in-car monitoring processor includes an occupancy detection module. The occupancy detection module compares the occupancy pixels that meet preset requirements with the occupancy threshold in the real-time pixel information obtained by the sensor to determine whether the elevator car is fully loaded.
[0015] Preferably, the preset requirement is that the 3D depth information of each pixel satisfies <(detection depth H - occupied detection height h).
[0016] Preferably, the detection depth H is 2400 mm; the occupancy detection height h is 1000 mm; and the occupancy threshold is 95%.
[0017] Preferably, if the ratio exceeds the occupancy threshold, it is determined to be fully loaded, and the signal interface outputs a signal indicating full load.
[0018] Preferably, if the ratio does not exceed the occupancy threshold, it is determined to be non-full load, and the full load signal interface outputs a signal indicating non-full load.
[0019] Preferably, the in-car monitoring processor includes a moving object impact detection module. The moving object impact detection module compares the moving pixels that meet the preset requirements with the moving anti-collision threshold in the real-time pixel information obtained by the sensor to determine whether the elevator car has been collided with.
[0020] Preferably, the preset requirement is that the 3D depth information of each pixel satisfies <(detection depth H - motion detection height h2).
[0021] Preferably, the moving collision avoidance threshold is: 2 * minimum detection diameter 2 / collision avoidance detection diameter 2.
[0022] Preferably, if the ratio is less than the moving anti-collision threshold, it is determined to be a non-collision mode, and the anti-collision detection interface outputs a non-collision mode signal.
[0023] Preferably, if the ratio is greater than the moving collision avoidance threshold and the detected object is determined to be stationary, the system still enters the non-collision mode.
[0024] Preferably, if the ratio is greater than the moving collision avoidance threshold C, and the detected object is determined to be non-stationary, its moving direction and angle are retained based on the information changes of the sensor within the sampling frequency, and then the elevator car is determined to be collided with based on the moving direction and angle.
[0025] Preferably, if the movement angle is within the initially defined collision angle and the movement direction is consistent with the initially defined collision direction, then it is determined to be a collision mode.
[0026] Preferably, the signal interface includes: a positive power supply interface, a negative power supply interface, a full-load signal interface, or an anti-collision detection interface.
[0027] Preferably, the full load signal interface outputs a signal indicating whether the system is fully loaded or not.
[0028] Preferably, the elevator system reads the signal from the full load signal interface after the elevator door closes and before it starts running. If it is a non-full load signal, the elevator runs normally according to the set program; if it is a full load signal, the elevator system enters full load mode—it no longer responds to external calls at different floors until it reaches the destination floor, at which point the people / goods leave the car, and the full load signal interface outputs a non-full load signal.
[0029] Preferably, the anti-collision detection interface outputs a collision mode or a non-collision mode signal.
[0030] Preferably, when the elevator car is level with the floor and before the elevator door system drives the door system to close, the elevator system reads the signal from the anti-collision detection interface; if it is a collision mode signal, the elevator does not close the door until the collision source disappears and the anti-collision detection interface outputs a non-collision mode signal.
[0031] Preferably, when the elevator car is level with the floor and the elevator door system motor is in the closing process, the elevator system continuously reads the signal from the anti-collision detection interface. If it is a collision mode signal, the elevator door system motor reverses to open the door; until the collision source disappears, the anti-collision detection interface outputs a non-collision mode signal, and the elevator system restarts the door system motor to close the door.
[0032] Preferably, the elevator car monitoring system further includes a voice generator for issuing voice alarms.
[0033] Preferably, the number of sensors is two.
[0034] To improve transportation efficiency, the elevator car monitoring system of this invention sends a full-load signal to the elevator main control module when it determines that the car is at full utilization. At this time, the elevator will no longer respond to external calls until the people / goods in the car reach the designated floor, at which point the elevator car monitoring system issues a non-full-load signal. Attached Figure Description
[0035] Figure 1This is a schematic diagram of the structure of Embodiment 1 of the present invention.
[0036] Figure 2 This is a functional module diagram of Embodiment 1 of the present invention.
[0037] Figure 3 This is a schematic diagram of the environment self-learning module in Embodiment 1 of the present invention.
[0038] Figure 4 This is a schematic diagram of the occupancy detection module according to Embodiment 1 of the present invention.
[0039] Figure 5 This is the definition of the collision angle and collision direction of a moving object in Embodiment 1 of the present invention.
[0040] Figure 6 This is a schematic diagram of a moving object impact detection module according to Embodiment 1 of the present invention.
[0041] Figure 7 This is a schematic diagram of the structure of Embodiment 4 of the present invention. Detailed Implementation
[0042] Example 1
[0043] like Figures 1-6 As shown, the elevator car monitoring system includes a TOF sensor, an in-car monitoring processor, and a signal interface with the car top station (elevator control system).
[0044] The TOF sensor is installed on the roof of the car, located on the center line of the door opening range. It is used to detect the height of objects inside the car.
[0045] The in-car monitoring processor has three modules: 1. Environmental self-learning module; 2. Car occupancy detection module; 3. Moving object collision detection module.
[0046] The signal interfaces with the car top station (elevator control system) include: a positive power interface, a negative power interface, a full load signal interface, and an anti-collision detection interface.
[0047] When the elevator car is free of debris and the car door is closed, the elevator car monitoring system is connected to the elevator control system. Upon power-up, it automatically enters the environment self-learning module. The environment self-learning module completes the initial state setting and fault detection of the elevator car monitoring system. In this embodiment, the full-load detection area is preset to a "convex" shape; the anti-collision detection area is a semicircle with a diameter of 500mm centered on the door opening center (e.g., ...). Figure 1 (As shown). The preset full-load detection area can be the entire car floor area or a portion of the car floor area.
[0048] The environment self-learning module uses the coordinates and depth information of each pixel provided by the TOF sensor to form an initial full-load detection area by selecting the pixels with the most consistent depth information within the error range. If the shape matches the preset full-load detection area, the elevator car monitoring system is considered to be functioning normally; otherwise, an abnormal signal is output (in this embodiment, a low-level signal is output through the anti-collision detection interface).
[0049] After setting the full-load detection area, the detection depth H of this elevator car is 2400mm. Then, based on the initial anti-collision detection area, the pixels of the anti-collision detection area are divided from the full-load detection area.
[0050] After the initial settings are completed, the monitoring device enters the occupancy detection module and the moving object collision detection module.
[0051] The occupancy detection module operates as follows: Real-time 3D information of pixels is obtained through a TOF sensor. A pixel is considered occupied if its 3D depth information is less than (detection depth H - occupancy detection height h). The area of the occupied pixel / the area of the full-load detection area is compared with a set occupancy threshold (in this embodiment, detection depth H is 2400mm; occupancy detection height h is 1000mm; and the occupancy threshold is 95%). If the ratio exceeds the occupancy threshold, it is determined to be full-load, and the full-load signal interface outputs a signal indicating full load (defined as a high-level signal in this embodiment). If the ratio does not exceed the occupancy threshold, it is determined to be non-full-load, and the full-load signal interface outputs a signal indicating non-full load (defined as a low-level signal in this embodiment).
[0052] The operation process of the moving object collision detection module is as follows: Considering the forklift reversing operation, the moving object is defined as having a detection height of not less than 1300mm and a detection diameter of not less than 100mm. Real-time 3D information of pixels is obtained through a TOF sensor. The 3D depth information of each pixel satisfies <(detection depth H - moving detection height h2) for a moving detection point (in this embodiment, the detection depth H is 2400mm; the moving detection height h2 is 1300mm). The area of the pixel meeting the requirements / the area of the pixels in the anti-collision detection area is compared with the moving anti-collision threshold C for judgment (C = 2 * minimum detection diameter 2 / anti-collision detection diameter 2, in this embodiment C = 8%). If the ratio is less than the moving anti-collision threshold C, it is determined to be in non-collision mode, and the anti-collision detection interface outputs a non-collision mode signal (a high-level signal in this embodiment). If the ratio is greater than the moving anti-collision threshold C, it may be in collision mode, requiring further judgment on whether the detected object is moving. If it is determined to be stationary, it still enters non-collision mode.
[0053] If the state is determined to be non-stationary, its direction of movement and angle are preserved based on the changes in 3D information of the TOF sensor within the sampling frequency.
[0054] If the movement angle is within the initially defined collision angle and the movement direction is consistent with the initially defined collision direction, it is determined to be in collision mode. Otherwise, it remains in non-collision mode. In collision mode, the anti-collision detection interface outputs a collision mode signal (in this embodiment, the collision mode signal is a low-level signal).
[0055] In this embodiment, the elevator system reads the signals from the full load signal interface and the anti-collision detection interface under specific conditions.
[0056] For example, after the elevator doors close but before starting operation, the elevator system reads the signal from the full-load signal interface. If it is a non-full-load signal (low level), the elevator operates normally according to the set program. If it is a full-load signal (high level), the elevator system enters full-load mode—it no longer responds to external calls at different floors until it reaches the destination floor, at which point the passenger / freight vehicle leaves the car, and the full-load signal interface outputs a non-full-load signal (low level). When the car is leveled and before the elevator door system drives the door system to close, the elevator system reads the signal from the anti-collision detection interface. If it is a collision mode signal (low level), the elevator does not close the doors until the collision source disappears, and the anti-collision detection interface outputs a non-collision mode signal (high level). When the car is leveled and the elevator door system motor is in the closing process, the elevator system also continuously reads the signal from the anti-collision detection interface. If it is a collision mode signal (low level), the elevator door system motor reverses, opening the doors; until the collision source disappears, the anti-collision detection interface outputs a non-collision mode signal (high level), and the elevator system restarts the door system motor to close the doors.
[0057] To notify passengers of the elevator car's status and reduce unnecessary voice warnings, a voice generator is installed in the elevator system. When the elevator system reads the signals from the full load signal interface and the anti-collision detection interface, the voice generator will simultaneously issue a voice alarm if a full load or collision occurs.
[0058] Example 2
[0059] Compared to Example 1, in this example, both the full-load signal interface and the anti-collision detection interface use protocol signals to enable the elevator car monitoring system to feed back the detection results to the elevator system. The full-load signal interface uses three data fields to distinguish between full-load signals, non-full-load signals, and abnormal signals; the anti-collision detection signal interface uses four data fields to distinguish between non-collision mode signals, collision mode-fast door opening signals, collision mode-normal door opening signals, and abnormal signals. Among them, the collision mode-fast door opening signals and collision mode-normal door opening signals are distinguished based on the movement speed of the detected object. When the speed of the detected object exceeds a set threshold, the collision mode-fast door opening signal is output.
[0060] When the elevator car is level with the floor and the elevator door system motor is in the closing process, the elevator system continuously reads the signal from the anti-collision detection interface. If it is a collision mode - normal door opening signal, the elevator door system motor reverses to open the door at a normal speed; if it is a collision mode - fast door opening signal, the elevator door system motor reverses to open the door at a speed higher than normal. This embodiment further refines the elevator system's processing modes based on embodiment 1, minimizing the risk of collisions with the car door.
[0061] Example 3
[0062] Compared to Example 1, the elevator car monitoring system also includes a voice generator. The signal interface between the elevator car monitoring system and the car top station (elevator control system) also includes an input interface.
[0063] When the input interface receives a detection request from the elevator system, the elevator monitoring device enters the environment self-learning module, the car occupancy detection module, and the moving object impact detection module respectively. Within 200ms, it outputs signals to the full load signal interface and the anti-collision detection interface. When a full load or impact occurs, the voice generator simultaneously issues a voice alarm. After receiving the signals output from the full load signal interface and the anti-collision detection interface, the elevator system enters various operating modes.
[0064] Example 4
[0065] like Figure 7 As shown, compared to Embodiment 1, this embodiment uses two TOF sensors, each with its own full-load detection area and collision detection area. In this embodiment, the full-load detection area is preset to be a "U"-shaped full load, covering the area near the front wall of the car; the collision detection area is square. The moving object collision detection module's moving collision avoidance threshold C = minimum area of the collision detection object / area of the collision detection area.
[0066] Two TOF sensors detect collisions in collision detection area 1 and collision detection area 2 respectively. As long as a collision mode is detected in either area, the collision detection interface outputs a collision mode signal, and the elevator system takes corresponding measures.
[0067] This embodiment can handle scenarios with relatively large door openings, avoiding loss of detection accuracy under the condition of the same TOF sensor pixels.
[0068] The present invention has been described in detail above through specific embodiments and examples, but these are not intended to limit the invention. Many modifications and improvements can be made by those skilled in the art without departing from the principles of the invention, and these should also be considered within the scope of protection of the present invention.
Claims
1. An elevator car monitoring system, characterized in that, include: Sensors are used to detect the height of objects inside the car and output detection data; The in-car monitoring processor is used to receive the detection data output by the sensor, compare it with preset data according to preset conditions, and output the corresponding signal. A signal interface is used to receive signals from the in-car monitoring processor and transmit them to the elevator control system. The sensor is a TOF sensor, and the detection data consists of the coordinates and depth information of each pixel. The in-car monitoring processor includes a moving object impact detection module. The moving object impact detection module compares the area of pixels that meet preset requirements in the real-time pixel information obtained by the sensor with the area of pixels in the anti-collision detection area and the moving anti-collision threshold to determine whether the elevator car has been collided with. The preset requirement is that the 3D depth information of each pixel satisfies < (detection depth H - motion detection height h2); The mobile collision avoidance threshold is: 2 * minimum detection diameter² / collision avoidance detection diameter²; If the ratio is less than the moving anti-collision threshold, it is determined to be in non-collision mode, and the anti-collision detection interface outputs a non-collision mode signal. If the ratio is greater than the moving collision avoidance threshold and the detected object is determined to be stationary, it will still enter the non-collision mode; If the ratio is greater than the moving collision avoidance threshold and the detected object is determined to be non-stationary, the moving direction and angle are retained based on the information changes of the sensor within the sampling frequency, and then the elevator car is determined to be collided based on the moving direction and angle. If the movement angle is within the initially defined collision angle and the movement direction is consistent with the initially defined collision direction, then it is determined to be a collision mode; The signal interface includes: a positive power interface, a negative power interface, a full-load signal interface, or an anti-collision detection interface; The anti-collision detection interface outputs a signal indicating either collision mode or non-collision mode. When the elevator car is level with the floor and before the elevator door system drives the door system to close, the elevator system reads the signal from the anti-collision detection interface; if it is a collision mode signal, the elevator will not close the door until the collision source disappears. The anti-collision detection interface outputs a non-collision mode signal. When the elevator car is level with the landing and the elevator door system motor is in the closing process, the elevator system continuously reads the signal from the anti-collision detection interface. If it is a collision mode signal, the elevator door system motor reverses to open the door. Until the collision source disappears, the anti-collision detection interface outputs a non-collision mode signal, and the elevator system restarts the door system motor to close the door.
2. The elevator car monitoring system as described in claim 1, characterized in that, The sensor is installed on the top of the elevator car and is located on the center line of the elevator door opening range.
3. The elevator car monitoring system as described in claim 1, characterized in that, The in-car monitoring processor includes an environment self-learning module, which is used to complete the initial state data setting and compare it with preset detection data to determine whether the elevator car monitoring system is abnormal.
4. The elevator car monitoring system as described in claim 3, characterized in that, The initial state data is the initial detection area, and the preset detection data is the preset detection area. The environment self-learning module forms the initial detection area based on the data information provided by the sensor and the most consistent and numerous pixels within the error range. If the shape is consistent with the preset detection area, it is considered that the elevator car monitoring system has no abnormalities.
5. The elevator car monitoring system as described in claim 1, characterized in that, The in-car monitoring processor includes an occupancy detection module. The occupancy detection module compares the area of occupied pixels that meet preset requirements with the area of pixels in the full-load detection area obtained from the real-time pixel information obtained by the sensor, and the occupancy threshold to determine whether the elevator car is fully loaded.
6. The elevator car monitoring system as described in claim 5, characterized in that, The preset requirement is that the 3D depth information of each pixel satisfies < (detection depth H - occupied detection height h).
7. The elevator car monitoring system as described in claim 6, characterized in that, The detection depth H is 2400mm; the occupancy detection height h is 1000mm; and the occupancy threshold is 95%.
8. The elevator car monitoring system as described in claim 5, characterized in that, If the ratio exceeds the occupancy threshold, it is determined to be fully loaded, and the signal interface outputs a signal indicating full load.
9. The elevator car monitoring system as described in claim 5, characterized in that, If the ratio does not exceed the occupancy threshold, it is determined to be not fully loaded, and the full load signal interface outputs a signal indicating that it is not fully loaded.
10. The elevator car monitoring system as described in claim 1, characterized in that, The full load signal interface outputs a signal indicating whether the system is fully loaded or not.
11. The elevator car monitoring system as described in claim 1, characterized in that, After the elevator doors close and before the elevator starts running, the elevator system reads the signal from the full load signal interface. If it is a non-full load signal, the elevator runs normally according to the set program; if it is a full load signal, the elevator system enters full load mode—it no longer responds to external calls at different floors until it reaches the destination floor, at which point the passenger / freight personnel leave the car, and the full load signal interface outputs a non-full load signal.
12. The elevator car monitoring system as described in claim 1, characterized in that, The elevator car monitoring system also includes a voice generator for issuing voice alarms.
13. The elevator car monitoring system as described in claim 1, characterized in that, The number of sensors is two.