ELEVATOR SAFETY SYSTEM

Abstract

An elevator safety system includes an electronic safety controller running a software including a monitoring mode for monitoring the position of an elevator car within a hoistway. The system includes a position measurement device for measuring the elevator car position. There are limit position identification markers being installed in the hoistway for defining a starting point of a final movement zone in which the car is still allowed to run in a direction to the outermost ends of the hoistway. However, as soon as the end of the final limit zone is reached by the car, an emergency stop is triggered. The position data for the final limit zone are laid down in a memory of the safety controller as parametrized data for being able to adjust them if so needed. Therewith, it can be avoided that the hardware components in the shaft have to be replaced.

Claims

1. An elevator safety system, comprising: an electronic safety controller running software for monitoring the position of an elevator car within a hoistway; a position measurement device for measuring the elevator car position, the position measurement device being communicatively connected to the electronic safety controller; and at least one limit position identification marker installed at one end of the hoistway indicating a starting point for a final movement zone for the car in the direction to the hoistway's end, wherein the limit position identification marker comprises a scale for measuring an absolute position of an elevator car moving along the limit position identification marker, and wherein the installation position data of said limit position identification marker is stored in a memory of the safety controller as parametrized position data for being able to adjust said position data in the memory.

2. The elevator safety system of claim 1, wherein a length of the final movement zone is further defined in the memory by means of final end position data corresponding to absolute position data readable from the scale.

3. The elevator safety system according to claim 1, wherein the safety controller is configured to trigger an emergency stop when the car reaches the final end position of the final movement zone.

4. The elevator safety system according to claim 1, wherein there are two limit position identification markers at each end of the hoistway, each of the markers constituting a respective final limit zone.

5. The elevator safety system according to claim 1, wherein the limit position identification marker is the identification marker of a terminal landing.

6. The elevator safety system according to claim 1, wherein the safety system further comprises one or more final limit markers at one end of the hoistway, respectively, being installed consecutively to the limit position identification marker towards an outermost end of the hoistway, wherein the limit position identification marker in combination with the final limit marker(s) define the starting point of the final movement zone of the car.

7. The elevator safety system according to claim 1, further comprising identification markers installed in the hoistway, the positions of the identification markers being stored in the memory of the safety controller for calibrating the position data of the car as outputted by the position measurement device.

8. The elevator safety system according to claim 7, wherein the position data of the identification markers are stored as parametrized position data in the memory, respectively.

9. The elevator safety system according to claim 1, wherein means are comprised for adjusting the data in the memory to adapt said movement limit zone.

10. The elevator safety system according to claim 9, wherein the means for adjusting the position data includes include a manual user interface or an access link configured for adjusting said data.

11. The elevator safety system according to claim 1, wherein the position measurement device comprises a reader for reading said at least one limit position identification marker.

12. The elevator safety system according to claim 11, wherein the position measurement device comprises: an encoder indicating a movement of the elevator car, wherein the position of the car is calculated by mathematically integrating the movement data; and a signal strips identifier as identification markers configured to indicate linear door zone position data of the elevator car, wherein said reader is configured for reading said signal strips identifier, and wherein the electronic safety controller is configured to synchronize the position data as coming from the encoder with the data as issued by the signal strips identifier.

13. An elevator system, comprising the elevator safety system according to claim 1.

14. A method of running a controller of the elevator safety system according to claim 1, comprising the steps of: monitoring by means of the limit position identification marker whether the car has passed the starting point of the final movement zone; and if the safety controller detected that the car has passed the starting point of the final movement zone, allocating the final movement zone for a further movement in this direction while monitoring the position of the car within the final movement zone by means of absolute position data deprived by a scale comprised by said limit position identification marker and triggering an emergency stop in case the end of the final movement zone has been identified.

15. The method of running a controller of the elevator safety system according to claim 1, wherein the identification of arriving at the end of the final movement zone is realized by means of the linear position data of the car as being output by the position measurement device corresponding to absolute position data readable from a scale as comprised by the limit position identification marker.

16. The method according to claim 14, further comprising the step of if the safety controller detected that the car has arrived at the safety buffer before the end of the final movement zone, the safety controller is triggering an emergency stop and is requesting an adjustment of the end of the final moving zone data.

17. The method according to claim 16, further comprising the step of preventing an elevator nm until the end of the final movement zone has been adjusted.

18. The method according to claim 14, further comprising the steps of: recording of the position of the elevator car by means of the position measurement device and transferring the position data to an elevator controller and/or the elevator safety controller; and calibrating the positioning data as coming from the position measurement device by means of calibrating data from the identification markers within the hoistway and gaining therewith the linear position of the car;

19. The method according to claim 14, wherein before starting the method, the following steps are preceding: starting a setup-run before putting the elevator-system into operation the first time by moving a car slowly in the elevator shaft between extreme outermost positions of the car in the shaft; registering identification markers when the car passes the registration markers during movement in the hoistway, and storing the position data in the memory of the safety controller; and registering limit position identification markers defining the starting point for the final movement zone of the car, respectively, wherein at least the position data of said limit position identification markers or the data of said movement limit zone are laid down as parametrized data and in the memory of the safety controller.

20. The method according to claim 14, further comprising the step of adjusting the end of the final movement zone data by means of an interface that is configured to adjust the end of the final movement zone data.

21. A computer program embodied on a non-transitory computer readable medium and comprising program code adapted to cause the method according to claim 14 to be executed on a data-processing unit of the elevator safety system.

Description

[0044] The aforementioned summary of the invention will be better understood by the aid of the following description referenced to the drawing FIG. 1 in which description it is about the final limit area in the bottom part of the hoistway. The same structure is however to be found at the upper part of the shaft in a mirrored configuration.

[0045] FIG. 1 presents an elevator, which comprises an elevator car 3, which is adapted to be movable in an elevator hoistway 4 along a trajectory “x”. The elevator also comprises an electric drive 7, for driving the elevator car 3. The elevator car 3 is moved with elevator ropes 22 passing via the traction sheave of the hoisting machine. A frequency converter is controlled with the movement profile calculated by an elevator control unit 9 in such a way that the elevator car 3 transfers passengers according to the movement profile from one stopping floor 12 to another in the manner required by the elevator calls given by the passengers.

[0046] A positioning device of the safety system for determining the location of the elevator car 3 is fitted to the elevator. This can be accomplished in that the running speed of the elevator car is obtained by measuring the speed of rotation of the traction sheave of the hoisting machine. Alternatively or additionally, the position measurement device comprises an encoder being mounted to a rope pulley 21 of the elevator car. When the pulley 21 rotates, the encoder signal indicates a movement of the elevator car, by means of which a travelled distance of the car can be calculated. This position calculation for the car is correlated with at least one reference position, such as by means of a door zone magnet at positions of numbers 1A, 1B, of the middle floors and/or at number 1C of the terminal floor. Reference numeral 20 indicates a controller of the safety system of the elevator.

[0047] While the elevator control unit needs information about the location of the elevator car for calculating the movement profile, the elevator safety system, on the other hand, requires that the elevator car 3 remains in the area defined by the extreme limits of permitted movement in the elevator hoistway. These types of extreme limits of permitted movement is the bottom end limit position identification marker 1C; optionally in combination with the final limit marker 1E acting then also as a limit position identification marker. Starting from the limit position identification marker 1C there is a further allowable distance the car may move further on defined as final movement zone. The distance and or the position of it is held adaptable since the position data of the limit position identification marker 1C for the final movement zone is laid down in the memory as a parametrized position data that can be amended. In case the final limit marker is an additional one being in combination with the limit position identification marker 1C of the outermost floor, the final limit marker 1E can be also stored in the memory with parametrized position data for being able to adjust it. At least one of such final limit markers comprises a scale by means of which absolute position data of the car can be gained during its presence within the final movement zone.

[0048] There are also top end limits of the elevator hoistway—although not shown in the FIGURE.

[0049] Independently from them, there can be additionally or alternatively different extreme limits set, too, e.g. for the normal operation mode of the elevator and/or for the servicing mode of the elevator when running it in the maintenance mode.

[0050] The positioning device of FIG. 1 comprises permanently-magnetized position identifiers being the markers 1A, 1B, 1C, 1D, 1E, which are disposed in the elevator hoistway 4 by the side of the trajectory of the elevator car 3. The position identifiers 1A, 1B, 1C, 1D and 1E are read with a reader device 2 installed on the elevator car 3 below the car-floor. The reader device 2 detects a position identifier marker 1A, 1B, 1C, 1D, 1E, when the reader device 2 is situated in the immediate proximity of one of them. The position data is transferred from the reader device 2 to the elevator control unit and to the electronic safety controller 20 along trailing cables which include a safety bus 11. The reader device 2 can also be situated elsewhere in connection with the elevator car 3, e.g. on the roof of the elevator car. Said reader also reads the scale as comprised by one of the final markers that are responsible for indicating the starting point for the final movement zone.

[0051] Position identifiers indicate the linear position “s” of the elevator car 3, i.e. the linear and stepless varying position data of the elevator car 3 in the measuring range of the position identifier. Exact linear position feedback data “s” is needed e.g. when stopping the elevator car at a stopping floor 12, to make sure that the floor of the elevator car 3 is flush with the floor level 12 in such a way that a step detrimental to passage is not formed between the floor level 12 and the floor of the elevator car 3. Both the position identifier and also the linear position data are coded into the magnetic field of a position identifier. Alternatively or additionally, position identifier may comprise additional identification means, such as RFID tag. Consequently, inter alia, stopping floor identifiers as well as the extreme limit markers required for elevator safety are provided with identifications.

[0052] At least the following position identifiers are possible: [0053] bottom end limit identifier of elevator car trajectory [0054] top end limit identifier of elevator car trajectory [0055] stopping floor identifier [0056] top floor identifier [0057] bottom floor identifier [0058] servicing space identifier [0059] identifier of reference point between stopping floors.

[0060] The identifier marker 1C of the terminal landing indicates also the beginning of the extreme final movement zone for the final permitted movement of the elevator car in the pit of the elevator hoistway. The length of the final movement zone during normal operation of the elevator is set differently, namely nearer to the bottom end of the elevator hoistway as compared to the maintenance driving mode, for example. The identifier marker of the top end limit is not presented in FIG. 1, but it is disposed nearer to the top end of the elevator hoistway compared to the top floor identifier marker in a corresponding manner as it is with reference to the bottom end limit identifier marker. It also comprises a scale as it is true for the final limit marker of the pit. Further, there may be end limit-values of the final movement zone for the servicing mode in the elevator hoistway 4 final movement zone, so that sufficient safety space and working space for a serviceman remains in the proximity of the ends outside the trajectory of the elevator car 3. In this aspect there may be an additional servicing space identification marker but being also not presented in FIG. 1.

[0061] The identifier marker 1D of a reference point between stopping floors 12 may be used to increase positioning accuracy between stopping floors. It may also be used e.g. as a mark of the deceleration point of the elevator car to indicate the point at which the elevator car must start to decelerate when stopping at a floor. The identifier marker 1D can also mark a point that allows a serviceman access from the floor level of a stopping floor 12 to the roof of the elevator car via the hoistway door (i.e. a point where the roof of the car and the floor level are at the same height). Deceleration point markers may be used especially in those embodiments where there is no acceleration sensor or speed sensor or no encoder transferring data for the linear position of the car.

[0062] The stopping floor identifier markers 1A, 1B are disposed in such a way that the floor of the elevator car 3 is flush with the floor level 12 when the reader device 2 and the stopping floor identifier marker 1A, 1B are situated facing each other, respectively.

[0063] So, the safety system receives continuously the position data of the car via the safety bus 11. In case the elevator car 3 passes the identifier marker 1C there is triggered a monitoring check mode in the safety system 9 for the final movement zone such that the car is still allowed to move a specific distance after which passing an emergency stop is triggered, meaning that the safety system then sends an alarm signal to stop the car. This is realized by interrupting the current to the drive 7 and/or by opening the brakes. This ensures that the car does not hit the buffer (not shown in the Fig.). However, in case the buffer is actually hit without triggering the emergency, it is clear that there must be a correction of the positioning data allocated to marker(s) 1C, 1E since this situation actually should not happen. In other words, the positioning data pretended a position of the car that showed a remaining distance to the buffer although not having been present. Alternatively, the limit zone data are amended in the memory of the safety controller, i.e. the length of the final movement zone and/or the end position of the final movement zone. In some alternative embodiments, the marker 1E is replaced with a mechanical safety switch, providing additional safety in combination with the safety controller-memorized final limit.

[0064] In case the data for at least the final movement zone as laid down in the memory of the safety system zo have to be adjusted, the same can be realized by a person 10 on a mobile 13 running an app that enables him to login on the safety controller for amending the parametrization of the positioning data. Alternatively, the allowed distance following the recognition of the final limit marker is amended. By means of this, the physical position of the identifiers, especially the limit markers, in the hoistway can remain unchanged. The adjustment can be also accomplished by a manual user interface—as for example a tablet—or an access link or like a remote link being configured for adjusting the at least one final limit position.

[0065] With regard to the first steps before commissioning the elevator, the following procedures may be useful as a convenient embodiment: [0066] Starting a setup-run before putting the elevator-system into operation the first time by moving the car slowly in the elevator shaft 4 between its extreme outermost shaft-positions; [0067] Recording the position of the car 3 by means of a position-measurement-sensor and transferring the position data to the elevator safety controller 20; [0068] Registering the identification markers 1A, 1B, 1D in the memory of the safety controller zo when the car 3 passes them by during its slow movement in the shaft 4, and storing these position data as calibrating data in a memory of the safety controller; [0069] Registering limit position identification markers 1C installed at the terminal landing and defining therewith a starting point for a further allowed movement limit zone of the car, respectively, wherein at least the data of the allowed final movement zone are parametrized and stored in the memory of the safety controller as parametrized position data; [0070] If in a test run an emergency is triggered by the safety controller before the car hits the buffer at one end of the shaft, the normal operation mode can start since the functioning is right, [0071] If, however, in a test run the buffer at one end of the shaft has been hit before triggering an emergency stop by the safety controller, the parametrized data as laid down in the memory of the safety controller have to be adjusted.

[0072] To this end, the parametrization of the position data for the final limit zone can be adjusted by means of an interface configured to adjust them.

[0073] Finally, the inventive method steps of the normal run in the normal operation mode can be started as monitoring by means of the limit position identification marker(s) 1C; 1E whether the car 3 has passed the starting point of the final movement zone. If the safety controller detected that the car has passed the starting point of the final movement zone, then the final movement zone is allocated for a further movement in this direction. As soon as the end of the final movement zone is identified an emergency stop is triggered then. Otherwise, the movement of the car turns in the other direction and the normal operation mode is continued.