WO2007039750A2

WO2007039750A2 - Elevator floor levelling sensor system

Info

Publication number: WO2007039750A2
Application number: PCT/GB2006/003714
Authority: WO
Inventors: Stephen Peter Hutchinson; Eamonn Reid
Original assignee: DEWHURST PLC
Current assignee: DEWHURST PLC
Priority date: 2005-10-05
Filing date: 2006-10-05
Publication date: 2007-04-12
Anticipated expiration: 2008-04-05
Also published as: GB0520206D0; WO2007039750A3

Abstract

A sensor system (1) for an elevator assembly determines the alignment between the floor level of an elevator car (2) and the floor level (3) of a building when the car has come to a stop. The elevator assembly comprises an elevator shaft (4), means (6) for moving the elevator car in the shaft, a plurality of openings in the shaft corresponding to floors of the building and a control system (20) to cause the car to stop at a particular floor. The system (20) comprises sensor means (10, 13, 14) to detect the position of the elevator car (2), processing means (15) to calculate the alignment between the floor level of the elevator car (2) and the floor level (3 ) of the building when the elevator car stops at a floor, and storage means (19) for storing the data at least when it is determined that the alignment between the floor of the car and the floor level is outside predetermined tolerances.

Description

SENSOR SYSTEM

This invention relates to a sensor system and in particular to a sensor system for lifts or elevators to monitor the alignment of an elevator car with respect to the floor level.

As can be appreciated, an elevator is primarily for transporting people to different floors in a multi-storey building. Thus, it will be understood that the term "floor" means any storey in the building at which the elevator is adapted to stop to allow people to enter or alight and does not specifically relate to the floor in the context of the physical support surface for that storey. However, the term "floor level" shall be understood to mean the level of the building's physical support surface at a particular storey in the building. The "floor level of the car" refers to the level of the threshold of the elevator car. It is important that when an elevator car stops , the floor level of the car is aligned with the floor level on to which the car opens. If the floor level of the car is too high or too low with respect to the floor level, there is a risk that a person stepping from or to the elevator car could trip thereby possibly causing injury. The risk of injury to the passengers using an elevator must be kept to a minimum.

The liability for such injuries may rest with the elevator manufacturer or installation company or maintenance company. A further problem is the filing of false or dubious personal injury claims against elevator manufacturers or installation or maintenance companies. It is difficult to prove or disprove that the elevator stopped at the correct level when the injury allegedly occurred, even if the elevator is later tested and determined to be working correctly. Elevators have been provided with various types of signalling systems to ensure that the elevator car stops at the correct position with respect to the floor level. Further, systems are employed that prevent the elevator door from opening unless the car is within a door opening zone. These systems attempt to ensure that the elevator operates accurately and reliably. However, the accuracy of these systems in practice is not known.

According to the present invention, we provide a sensor system for an elevator assembly for determining the alignment between the floor level of an elevator car and the floor level of a building when the car has come to a stop, the elevator assembly comprising an elevator shaft, means for moving the elevator car in the shaft, a plurality of openings in the shaft corresponding to floors of the building and a control system to cause the car to stop at a particular floor, the system comprising sensor means to detect the position of the elevator car in the elevator shaft, processing means to calculate, from the data supplied by the sensor means, the alignment between the floor level of the elevator car and the floor level of the building when the elevator car stops at a floor, and storage means for storing the data at least when it is determined that the alignment between the floor of the car and the floor level is outside predetermined tolerances.

The sensor system of the invention can therefore be fitted to existing elevator assemblies or integrated with the control system of a new elevator assembly. The sensor system allows the elevator assembly and its associated control system to be monitored to check it is bringing the car to a halt in alignment with a floor level. This is advantageous as the sensor system can accurately monitor where the elevator car stops and record this measurement data with any additional information that is required, such as the floor number and the time and date. The status of the elevator doors may also be recorded so it can be determined whether they were open or closed when the data was recorded. Clearly, there can be no tripping hazard if the doors are closed. This information can then be recorded in the storage means and recalled when required.

Preferably the sensor means comprises a laser and detector means to measure the distance between the laser transmitter and a reflector. The reflector is preferably mounted on the elevator car and the laser is mounted at the top of an elevator shaft. The sensor means may comprise an encoder or alternatively inductive sensors. The sensor means may alternatively comprise a wire system.

Preferably the sensor system includes warning means that warns passengers in the elevator that there is a hazard when the sensor means determines that the elevator car is not sufficiently accurately aligned with the floor. The warning means may comprise audible warning means or visual warning means or both. The audible warning means may include a speaker and recorded message that announces a warning. The visual warning means may comprise an illuminated sign. Preferably the warning means is located inside the elevator car. Warning means may also be provided on each floor of the building adjacent the elevator doors. The warning means is operated when the car has stopped and the doors are to be opened.

Preferably the sensor system includes visual recording means to capture an image or images of the elevator car when the sensor means determines that the elevator car is not sufficiently accurately aligned with the floor. The visual recording means is operated when the car has stopped and the doors are to be opened. The storage means may be integrated with the processing means and may comprise memory associated with the processing means. The storage means may comprise a computer connected to the processing means. Thus, the measurement data from the sensor system may be stored on-site in the same building as the elevator. However, it is likely that there will be few or no people in the building familiar with the elevator systems and therefore the computer means could be tampered with or accidentally turned off. Preferably the storage means is remote from the sensor system and a communication means is used to transfer the measurement data from the processing means to the storage means. Thus, the storage means may be located off-site. As the measurement data is stored remotely, and possibly by a separate company, it is more secure against accidental deletion or corruption.

The communication means may therefore comprise the Internet or an Intranet. The processing means may also be connected to a network that communicates with the database means via the Internet. Alternatively, the measurement data from the processing means is transferred to the database means when a "health check" is performed. A "health check" is when the sensor system connects to and automatically communicates with a remote computer by establishing a connection through a telephone line. The information sent to the remote computer is used to check the telephone line and sensor system for anomalies. This is advantageous as the same communication means can be used to perform the health check and send the measurement data from the processing means.

Preferably the storage means comprises database means for storing the measurement data from the processing means. This is advantageous as the data can be easily stored and then recalled with any additional information that is required, such as the floor number, elevator door status and the time and date. Further, the database means may record a reference that uniquely identifies the particular elevator the data is from. Preferably, all the data calculated by the processing means is stored.

Preferably, at least the sensor means communicates with the processing means via Ethernet based communication means. Alternatively, they may communicate via PSTN, GSM, CAN, RS232, RS422, RS485, Bluetooth, WiFi or USB. Preferably the warning means and visual recording means also communicate via Ethernet based communication means or any of the alternatives mentioned above.

There now follows by way of example only a detailed description of the present invention with reference to the accompanying drawings in which

Figure 1 shows a diagrammatic view of an elevator in the elevator shaft wherein the sensor system uses a laser;

Figure 2 shows a second embodiment of the invention in which an alternative sensor means is used;

Figure 3 shows a third embodiment of the invention in which an alternative sensor means is used; and

Figure 4 shows a fourth embodiment of the invention in which an alternative sensor means is used;

The present invention is a sensor system 1 that is adapted to determine the alignment between the floor of the elevator car 2 and the floor 3 of the building. It will be appreciated that the Figures show an example of an elevator having four floors, although only one floor is represented in the Figures. It will also be appreciated that the present invention may be used in elevators having any number of floors. The sensor system 1 is a monitoring device and is adapted to operate in conjunction with a standard elevator assembly 8. Standard elevators already possess means to locate door positions so that the elevator comes to a stop at the appropriate position. However, these systems are not necessarily absolutely accurate and thus the sensor system of the invention is adapted to obtain and record data about where elevator car 2 actually stops in practice.

Figure 1 shows an elevator car 2 for movement within an elevator shaft 4. The elevator is of the typical known traction type and therefore suspended in the elevator shaft by a steel cable 5. The car 2 is raised and lowered by a motor 6 mounted at the top of the elevator shaft 4. The cable 5 has counterweights 7 attached to its other end thereby balancing the load and making it easier for the motor 6 to lift and lower the car 2 at an appropriate speed. The present invention is, however, equally applicable to other known elevator designs, such as hydraulically-operated elevators for example.

The elevator shaft 4 shown in the Figures has four openings, one to each of four floors. It is important that the floor of the elevator car 2 is aligned with the floor level 3 of the floor on to which it opens, to prevent a tripping hazard to the passengers. The operation of the elevator assembly 8 is controlled by an elevator control system 20. The control system 20 is of standard type and controls the motor 6 to raise and lower the elevator 2 in response to users calling the elevator to a particular floor and travelling to their destination floor. The elevator assembly 8 includes a door position sensor 22 mounted to the elevator car 2. The door position sensor 22 is an inductive position sensor that is separate from the sensor system 1 of the invention. Although an inductive position sensor is shown it will be appreciated that any other suitable type of sensor may be used. The door position sensor 22 detects a signal emitted from a door zone target 23 that is located at an appropriate position in the vicinity of the door of each floor level. The signals detected by the door position sensor 22 are passed to the control means 20 via a connection 24. The elevator control means 20 uses this information to stop the elevator car 2 at the correct floor.

Figure 1 shows the sensor system 1 having sensor means in the form of a laser 10 mounted at the top 11 of the elevator shaft 4 and pointed in a downward direction toward the car 2. A laser beam 12, generated by the laser transmitter, is incident upon a reflector 13 and is reflected back to a detector 14, integral with the laser 10. The position of the laser 10 and detector 14, the location of the reflector 13 on the car 2 with respect to the floor of the car and the level of each floor 3 in the building are known. Thus, the sensor means can be used to determine precisely the alignment between the floor of the car 2 and the floor of the building 3 when the elevator has stopped. The sensor system also includes a door status sensor 34 in the elevator car 2, to sense whether or not the doors are open. There can only be a tripping hazard when the car is at rest and the doors are open.

The data from the sensor means 10 and the door status sensor 34 is received by a processing means 15, which forms part of a control means 16. The control means 16 receives power to operate from an uninterruptible power supply 17. The processing means 15 calculates, from the data supplied by the sensor means 10 and sensor 34, the alignment or misalignment between the elevator car 2 and the floor level 3 of the building when the elevator car stops at the floor and the doors are open. The processing means 15 sends this data via communication means 18 to a storage means in the form of a database means 19. The database means 19 securely stores the data with any references required to identify the particular elevator the data was acquired from. The database means 19 is located off-site from the building containing the elevator, but could be on-site, for example in a security office of a large building or complex. The processing means 15 may send the data to the database means 19 as it is acquired. In this embodiment, the processing means 15 includes storage means 21 in the form of memory to store the acquired data which is uploaded to the database means 19 at regular intervals or when the storage means 21 reaches capacity or when the sensor system 1 detects a tripping hazard. Preferably data is transferred to a database means 19 when a "health check" is performed. A "health check" is when the sensor system 1 connects to and automatically communicates with a remote computer (not shown) by establishing a connection through a telephone line. The information sent to the remote computer is used to check the telephone line and the sensor system 1 for anomalies. This is advantageous as the same communication channel can be used to perform the health check and send the alignment data.

The sensor system 1 shown in Figure 1 also includes a warning means 30 and a visual recording means 31, which are connected to the processing means 15 by communication channels 32, 33. The communication channels 32, 33 may be Ethernet, PSTN, GSM, CAN, RS232, RS422,

RS485, Bluetooth, WiFi or USB based depending upon the elevator assembly 8 and other factors. The warning means 30 comprises an audio/visual warning device comprising a visual warning means such as an illuminated sign and an audible warning means comprising a speaker.

The means 30 is mounted in the elevator car and additional devices 30' may be located on each floor (one device is shown outside the car in

Figure 1) . The audio/visual warning device 30 is activated when the processing means 15 of the sensor system 1 determines that the alignment between the car 2 and the floor level 3 is outside predetermined tolerances. Thus, passengers can be warned to take care when stepping into or out of the elevator car 2.

The video recording means 31 comprises a camera mounted in the elevator car 2. The camera may be a still camera, video camera or of webcam type. The camera 31 may capture images constantly and send them to the processing means 15 for recording. In the embodiment of Figure 1 , the camera 31 is activated when the processing means 15 of the sensor system 1 determines that the alignment between the car 2 and the floor level 3 is outside predetermined tolerances. The images captured by the video 31 are included with the data collected by the sensor means 10 and are sent by the processing means 15 for storage at the database means 19. The video images can then be used as evidence if a passenger claims that they have been injured by tripping and falling while stepping into or from the elevator car 2.

In a modification (not shown) the laser 10 and detector 14 and the reflector 13 may be in a different location. Thus, the laser 10 may be mounted at the bottom of the elevator shaft 4, and point up to a reflector 13 mounted to the bottom of the car 2. Alternatively the laser 10 may be mounted on the car 2, either on top and pointing up to a reflector 13 at the top of the shaft 4, or on the bottom and pointing down to a reflector 13 at the bottom of the shaft.

The sensor system 1 and elevator assembly 8 shown in Figure 2 are substantially identical to the embodiment shown in Figure 1. However, the sensor means comprises an encoder means 35 instead of a laser 10 and detector 14. The encoder means 35 is connected by means (not shown) to the motor 6 and from the movement of the motor 6 is able to calculate the position of the elevator car 2. This positional information is used by the processing means 15 to calculate the alignment between the elevator car 2 and the floor level 3 of the building when the elevator car stops at the floor. Although in this embodiment the encoder uses the relative movement of the motor to determine the position of the elevator car, it will be appreciated that the relative movement of the motor's gearbox (not shown) , the car itself, the counterweights 7, a governor (not shown) or a shaft tape could alternatively be used. Further, any suitable type of encoder may be used such as an encoder of incremental, absolute, resolver or quadrature type. If the encoder means 35 is of relative type it may be adapted to calibrate itself using datum points where the position of the elevator car 2 in the shaft 4 is known.

The embodiment of Figure 3 is also substantially identical to the embodiment shown in Figure 1. However, the sensor means is an inductive sensor 37. The inductive sensor is integral with the door location sensor 22 and is adapted to measure accurately where the elevator car 2 stops. The remainder of the sensor system operates as in the previous two embodiments.

Figure 4 also shows an alternative sensor means in the form of a wire system 38. The wire system 38 is of known type and includes wire 40 and means 39 on the elevator car 2. The wire system 38 uses high frequency modulation to calculate the position of the elevator car in the shaft, which is passed to the processing means 15 by an Ethernet connection 43, or any other appropriate communication channels such as PSTN, GSM, CAN, RS232, RS427, RS485, Bluetooth, WiFi or USB.

The Figures show the sensor system 1 separate from the elevator assembly 8, so that the sensor system can be fitted to any existing elevator assembly following its installation. In a modification, not shown, the sensor system 1 may be integrated into the control system of a new elevator assembly. In that case the control means 16 of the sensor system would be integrated into the elevator control system 20.

Claims

1. A sensor system (1) for an elevator assembly (8) for determining the alignment between the floor level of an elevator car (2) and the floor level (3) of a building when the car has come to a stop, the elevator assembly comprising an elevator shaft (4) , means (6) for moving the elevator car in the shaft, a plurality of openings in the shaft corresponding to floors of the building and a control system (20) to cause the car to stop at a particular floor, the system comprising sensor means (10, 13, 14) to detect the position of the elevator car (2) in the elevator shaft (4) , processing means (15) to calculate, from the data supplied by the sensor means, the alignment between the floor level of the elevator car (2) and the floor level of the building when the elevator car stops at a floor, and storage means (19) for storing the data at least when it is determined that the alignment between the floor of the car and the floor level is outside predetermined tolerances.

2. A sensor system according to claim 1, in which the status of the elevator doors is recorded so it can be determined whether they were open or closed when the data was recorded.

3. A sensor system according to claim 1 or claim 2, in which the sensor means comprises a laser (10) and detector means (14) to measure the distance between the laser transmitter and a reflector (13) .

4. A sensor system according to claim 3, in which the reflector (13) is mounted on the elevator car (2) and the laser (10) is mounted at the top of the elevator shaft (4) .

5. A sensor system according to claim 1 or claim 2, in which the sensor means comprises an encoder (35) .

6. A sensor system according to claim 1 or claim 2, in which the sensor means comprises inductive sensors (37) .

7. A sensor system according to claim 1 or claim 2, in which the sensor means comprises a wire system (38) .

8. A sensor system according to any preceding claim, in which the sensor system (1) includes warning means (30) that warns passengers in the elevator that there is a hazard when the sensor means determines that the elevator car is not sufficiently accurately aligned with the floor.

9. A sensor system according to claim 8, in which the warning means (30) comprises audible warning means or visual warning means or both.

10. A sensor system according to claim 9, in which the audible warning means includes a speaker and recorded message that announces a warning.

11. A sensor system according to claim 9, in which the visual warning means comprises an illuminated sign.

12. A sensor system according to any of claims 8 to 11 , in which the warning means (30) is located inside the elevator car (2).

13. A sensor system according to any of claims 8 to 12, in which the warning means (30) is provided on each floor of the building adjacent the elevator doors.

14, A sensor system according to any of claims 8 to 13, in which the warning means (30) is operated when the car (2) has stopped and the doors are to be opened.

15. A sensor system according to any preceding claim, in which the sensor system includes visual recording means (31) to capture an image or images of the elevator car (2) when the sensor means determines that the elevator car is not sufficiently accurately aligned with the floor.

16. A sensor system according to claim 15, in which the visual recording means (31) is operated when the car has stopped and the doors are to be opened.

17. A sensor system according to any preceding claim, in which the storage means (19) is integrated with the processing means (15) .

18. A sensor system according to claim 17, in which the storage means comprises memory (21) associated with the processing means (15) .

19. A sensor system according to any preceding claim, in which the storage means comprises a computer connected to the processing means.

20. A sensor system according to any preceding claim, in which the measurement data from the sensor system is stored on-site in the same building as the elevator.

21. A sensor system according to any of claims 1 to 19, in which the storage means (19) is remote from the sensor system and a communication means is used to transfer the measurement data from the processing means to the storage means.

22. A sensor system according to claim 21, in which the communication means comprises the Internet.

23. A sensor system according to claim 21 , in which the communication means comprises an Intranet.

24. A sensor system according to any preceding claim, in which the processing means (15) is connected to a network that communicates with the database means (19) via the Internet.

25. A sensor system according to any preceding claim, in which the measurement data from the processing means is transferred to the database means when a "health check" is performed.

26. A sensor system according to any preceding claim, in which the storage means comprises database means (19) for storing the measurement data from the processing means.

27. A sensor system according to claim 26, in which the database means records a reference that uniquely identifies the particular elevator the data is from.

28. A sensor system according to claim 26, in which all the data calculated by the processing means is stored in the database means.

29. A sensor system according to any preceding claim, in which at least the sensor means (10, 13, 14) communicates with the processing means (15) via Ethernet based communication means (18) .

30. A sensor system according to any of claims 15 to 29, in which the warning means (30) and visual recording means (31) communicate via Ethernet based communication means.