EP2723667A1

EP2723667A1 - Elevator system with zero-power sleep mode

Info

Publication number: EP2723667A1
Application number: EP11868312.7A
Authority: EP
Inventors: Arthur Hsu
Original assignee: Otis Elevator Co
Current assignee: Otis Elevator Co
Priority date: 2011-06-21
Filing date: 2011-06-21
Publication date: 2014-04-30
Also published as: BR112013028661A2; EP2723667A4; WO2012177240A1

Abstract

An elevator system that consumes zero power during a sleep mode during which the elevator system has an ability to receive new calls and an ability to detect hoistway intrusions

Description

ELEVATOR SYSTEM WITH ZERO-POWER SLEEP MODE

BACKGROUND OF THE INVENTION

[0001] The subject matter disclosed herein relates to an elevator system with a zero- power sleep mode.

[0002] Presently, elevator systems can operate in a reduced-power mode (often called 'standby mode') when an elevator is not anticipated to be imminently required for operation. In these cases, some elevator components are powered down and some other components continue to be powered.

[0003] For example, an approach to implement a low-power standby mode for an elevator system may be provided whereby virtually all components in the elevator system are powered off except for a "standby monitor" device that determines when the system should "wake up," sensors and interface devices that detect when elevator operation is required or requested, a communications system that passes signals from the sensors and interface devices to the standby monitor, and a safety chain that maintains a hoistway access detection function during standby.

[0004] While the items described above consume considerably less power than the elevator system as a whole when the elevator system is in full operational mode, the elevator system still consumes power during standby.

BRIEF DESCRIPTION OF THE INVENTION

[0005] According to one aspect of the invention, an elevator system that consumes zero power during a sleep mode during which the elevator system has an ability to receive new calls and an ability to detect hoistway intrusions.

[0006] According to another aspect of the invention, an elevator system having a communications system that consumes zero power during a sleep mode during which the elevator system has an ability to wake up upon reception of new calls and an ability to immediately detect hoistway intrusions upon waking up.

[0007] According to yet another aspect of the invention, an elevator system is provided and includes a switch disposed within or without an elevator car, a first relay coupled to the switch and a power source, the first relay being activated upon an actuation of the switch, a controller coupled to the first relay, which is woken up from a zero-power sleep mode to conduct controller operations by first relay activation and a second relay coupled to the controller and the power source, which is activated by the controller and configured to maintain a power supply.

[0008] These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWING

[0009] The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:

[0010] FIG. 1 is a schematic illustration of a circuit of a zero-power sleep mode of an elevator system;

[0011] FIG. 2 is a schematic illustration of a circuit of a zero-power sleep mode of an elevator system according to alternate embodiments;

[0012] FIG. 3 is a schematic illustration of a hoistway access detection system; and

[0013] FIG. 4 is a schematic illustration of the hoistway access detection system of FIG. 3 with the hoistway being accessed.

[0014] The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.

DETAILED DESCRIPTION OF THE INVENTION

[0015] An elevator system is provided with a zero-power sleep mode whereby the elevator system consumes zero power while maintaining certain required functions, such as an ability to receive new calls from within and without elevator cars and an ability to respond to a door open button and an ability to detect hoistway intrusions. The elevator system can therefore be operated with reduce power requirements and costs.

[0016] The elevator system has a zero-power sleep mode with a fast "wake up" time and a power-on startup. When the elevator system is completely powered off, the fast wake up time is assumed to be acceptably short between when a wake -up condition (e.g., pressing of hall call button) is detected and when the elevator system responds. For power-on startup, during the sleep mode, the elevator system is unpowered, but as soon as power is provided, the elevator system can automatically boot up.

[0017] Thus, the elevator system includes a wake-up activation device whereby it is assumed that, in every wake-up scenario (e.g., pressing of hall call button, pressing of door open button, etc.), the sensor or switch detecting the wake-up condition is capable of closing an electric circuit (directly or indirectly) that powers up the controller and elevator system, retaining the detected condition (e.g., which hall call button is pressed) until a controller is ready to process the detected condition, and clearing the detected condition after the controller has processed the condition. The elevator system further includes a zero-power detection device whereby any condition that the elevator system must detect during the sleep mode can be detected by a sensor or switch that consumes zero power (e.g., a mechanical switch).

[0018] In the zero-power sleep mode, the elevator system has the ability to detect, when the elevator system is powered down, any condition when the elevator system should wake up using devices that consume no power. In current elevator systems with standby modes, communications networks between hall call buttons and the "standby monitor" controller board that monitors if a hall call button is pressed must remain powered so that the controller can receive the hall call. In the zero-power approach of the present disclosure, however, there are no active communications during sleep mode. Instead, each switch (e.g., hall call button, door open button) that should wake up the elevator system consumes no power, as is the case of a passive, mechanical switch. However, as soon as a button is depressed, a circuit that either directly powers the controller, or, more practically, powers a relay that when powered itself closes a circuit to thereby power the controller and the elevator system. The switch also "latches" either mechanically or electromechanically to ensure the system is powered up (rather than requiring the user to hold the button until the system is completely powered up). The switch device holds the state indicating the particular switch was depressed (as opposed to any other switch) such that, when the controller is powered up (perhaps a few seconds later), it can determine which switch was depressed and then react accordingly. The switch may also be re-settable by the controller.

[0019] With reference to FIG. 1, an example of a circuit 10 that implements the zero- power sleep mode is illustrated. The circuit 10 uses mechanical latching switches 11. The circuit 10 consists of n switches 11, each of which is a type of switch that, when pressed, causes the elevator system to wake up. For example, a 6-stop elevator typically has 5 up hall call buttons and 5 down hall call buttons and at least one additional button inside the car. In this case, the value of n would be 11. The circuit 10 also has a first device or "wakeup relay" 12 coupled to a power source and the switches 11 and a second device or "sustain relay" 13 as well as an elevator controller 14, which is unpowered when the elevator controller 14 is in sleep mode and powered when the elevator controller 14 is operational. Each of the switches 11 may be a latching, double-pole, single-throw (DPST) switch that is normally open (NO) meaning that, when the switch 11 is pressed, the first input (e.g., Xi) is connected to the first output (e.g., A and the second input (e.g., Yi) is connected to the second output (e.g., Bi), but, when the switch 11 is reset, both connections are open. Each switch 11 is also a latching switch with a remote reset (e.g., Ri) meaning that once the switch 11 is pressed, both poles remain closed until the input Ri is "pulled" to high (meaning that the line connected to Ri is set to the high voltage). Both the wakeup relay 12 and the sustain relay 13 may be single-pole power devices or relays that are normally open (NO).

[0020] In sleep mode, all connections to the supply of high voltage (indicated by the plus sign in FIG. 1) are initially open and thus no current flows in the circuit 10 and the system consumes no power. However, as soon as any of the switches 11 are pressed, the wakeup relay 12 is activated. For instance, if a first one of the switches 11 is pressed, Yi, which is high, will be connected to Bi and W₂ will be set to the high voltage causing the wakeup relay 12 to "pull" output Wi to high. This provides power to the elevator controller 14, which causes the elevator to "wake up".

[0021] Because each of the switches 11 is a latching switch, once it is depressed, its circuits remain closed even if the user has released the button. Also, any of the switches can act as a new call receiver that will activate the wakeup relay 12. As the elevator wakes up, the elevator controller 14 provides a high voltage to Ci hence pulling the sustain relay 13 to high. This signal effectively sustains power to the elevator system when the elevator system is to remain awake regardless of the position of any of the switches 11. The elevator controller 14 can then check each of the states of the output signals Ai thru A„ to determine which switch 11 was pressed and, if a switch i is pressed, its output signal would be set to high (since the connection between Xj and Aj is closed). The connection between output signal Aj to the controller is not shown, but typically that would use the conventional communication system between the buttons and the controller, which need not be powered when the elevator system is in the sleep mode. Once the elevator controller 14 has checked that a switch 11 was depressed, the elevator controller 14 can control an appropriate elevator car to respond and could then send the reset signal to the switch 11. Circuitry for resetting is not shown but the mechanism is typically as simple as sending a high signal to R,. Note that this circuit can receive more than one switch signals during the wakeup duration and the elevator system can poll each switch and reset those that are pressed.

[0022] An alternative circuit can be devised without the use of latching switches, where each latching DPST switch is replaced by a switch and relays. Shown in FIG. 2 is a combination of a single-pole, single-throw (SPST) switch 20 that is normally open (NO), a double-pole single-throw (DPST) "set" relay 21 that is normally open (NO) and a single-pole single-throw (SPST) relay 22 that is normally closed (NC). Each instance of this circuit can replace an instance of a switch 11 in FIG. 1 with the same outputs Ai and Bi and same input Ri.

[0023] FIG. 2 shows the switch and relay positions in sleep mode with all connections to high voltage open so the devices consume no power. When the switch 20 is depressed, 2Si becomes high and the "set relay" 21 is activated, which sets Bi to high and Ai to high. As discussed in the description of FIG. 1, setting Bi to high powers up the elevator controller 14 and setting Ai to high provides the signal when the elevator controller 14 is ready to determine which switch 20 was pressed. In this case, setting Ai to high also has the side- effect of keeping the set relay 21 activated by maintaining 2Si at high even if the switch 20 is no longer pressed. This may be required since the switch 20 here is not a latching switch and hence the set relay 21 actually self-latches. However, once the controller has read in the Ai signal and there is no longer a need to keep the set relay activated since the elevator is powered up, if the controller sets the reset signal Ri to high, the reset relay 22, which is normally closed, will now open and the set relay 21 lifts back to the open position.

[0024] The elevator controller 14 can put itself and the rest of the elevator system into sleep mode when demand for the elevator is anticipated to be such that the elevator is not needed in the immediate future. With reference back to FIG. 1, when the elevator controller 14 has determined that it is ready to "go to sleep", the last step of the sleep transition could be to de-energize the signal C_l5 hence high voltage is removed from Si and the system will shut down.

[0025] Current low-power standby mode schemes maintain the safety chain for the purpose of detecting if the hoistway is accessed (e.g., someone opens a hoistway door and enters the hoistway) during standby mode. This is an important condition because the elevator, once it has powered up, should be prevented from running if a hoistway access was detected during the time when the elevator was in sleep mode.

[0026] In one embodiment of the zero-power sleep mode scheme, the elevator system does not immediately react when the hoistway access condition occurs. Instead, the scheme relies on devices that passively change from a clear state to a detection state when a hoistway access occurs. It is only when the elevator is woken up that all such devices are checked and, if any such device indicates a hoistway detection, the elevator controller 14 will not allow the car to run and may optionally signal for a mechanic. [0027] In general, any hoistway door opening must be detected during sleep mode with no power and the embodiment illustrated in FIGS. 3 and 4 assumes that, before the elevator system transitions to sleep mode, all hoistway doors are closed. With reference to FIG. 3, a possible hoistway access detection device installed in every hoistway door can passively detect if a hoistway door is open. As shown, a magnet 30 is attached within one of the doors 31 and is indicated by "N". Another magnet 32 is installed in the other door 33 and is indicated by "S". The second magnet 32 is attached to a moveable arm 34 that swivels around fulcrum F. The arm 34 is unbalanced such that the only thing holding the arm 34 in the upright position is the attraction between magnets 30 and 32. However, if one or both of the doors 31, 33 were to open, as shown in FIG. 4, the imbalance on the arm 34 would cause it to swivel about the fulcrum F. Once in the swiveled position, the arm 34 will not move back up even if the doors 31, 33 are closed. Hence, once the doors 31, 33 are open, the arm 34 moves to the 'set' position (the swiveled position) until it is reset.

[0028] This scheme illustrates a possible embodiment whereby a door opening can be detected with zero power. Once the elevator is woken up, it checks the position of the arm 34 in each hoistway door. If all of the arms 34 are up, then the conclusion is that there has been no hoistway access during the duration of the sleep mode. However, if any of the arms 34 are down, the elevator controller should not allow the car to run until a mechanic arrives onsite, checks the hoistway and clears the condition by restoring the position of the arm 34.

[0029] Note that during regular elevator operation, the hoistway doors will open hence the arm 34 will be prone to turn down normally. There are several possible responses to this. One is that during regular operation, the elevator system relies only on the standard safety chain and that the arm 34 positions are ignored; only when the elevator is preparing to transition to sleep mode are the arms 34 moved to the upright position (e.g., by an electromagnet for each arm). A second response is that after doors 31, 33 are closed at the end of a door cycle, the arm 34 is moved back upright. A third response is that the arms 34 are maintained in an upright position when the elevator is in regular operation (e.g., by an electromagnet).

[0030] While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.

Claims

CLAIMS:

1. An elevator system that consumes zero power during a sleep mode during which the elevator system has an ability to receive new calls and an ability to detect hoistway intrusions.

2. The elevator system according to claim 1, wherein the elevator system receives the new calls from within and without elevator cars.

3. The elevator system according to claim 1, wherein the hoistway intrusions are passively detectable.

4. The elevator system according to claim 1, further comprising a new call receiver to receive the new calls.

5. An elevator system having a communications system that consumes zero power during a sleep mode during which the elevator system has an ability to wake up upon reception of new calls and an ability to immediately detect hoistway intrusions upon waking up.

6. The elevator system according to claim 5, wherein the elevator system receives the new calls from within and without elevator cars.

7. The elevator system according to claim 5, wherein the hoistway intrusions are passively detectable.

8. The elevator system according to claim 5, further comprising a new call receiver to receive the new calls and to cause the elevator system to wake up.

9. An elevator system, comprising:

a switch disposed within or without an elevator car;

a first device coupled to the switch and a power source, the first device being activated upon an actuation of the switch;

a controller coupled to the first device, which is woken up from a zero-power sleep mode to conduct controller operations by first device activation; and

a second device coupled to the controller and the power source, which is activated by the controller and configured to maintain a power supply.

10. The elevator system according to claim 9, wherein the switch comprises a hall call button.

11. The elevator system according to claim 9, wherein the switch comprises a latching, double-pole, single-throw (DPST) switch that is normally open (NO).

12. The elevator system according to claim 9, wherein the switch comprises a remote reset configured to receive a reset signal from the controller.

13. The elevator system according to claim 9, wherein the switch comprises:

a single -pole, single-throw (SPST) switch that is normally open (NO);

a double-pole single-throw (DPST) device that is normally open (NO); and a single -pole single-throw (SPST) device that is normally closed (NC).

14. The elevator system according to claim 9, wherein the first device comprises a wake up relay and the second device comprises a sustain relay.

15. The elevator system according to claim 9, wherein the first and second devices each comprise a single-pole power device that is normally open (NO).

16. The elevator system according to claim 9, wherein the switch is plural in number and an actuation of any one of the plural switches activates the first device to wake up the controller.

17. The elevator system according to claim 16, wherein the controller operations comprise:

the controller determining which of the plural switches was actuated;

the controller controlling an elevator to respond; and

the controller issuing a reset signal to the actuated switch.

18. The elevator system according to claim 9, wherein the controller operations comprise the controller determining whether hoistway access has occurred.

19. The elevator system according to claim 9, further comprising a hoistway access detection device.