EP1307395B2 - Monitoring device for an elevator - Google Patents

Abstract

A monitoring device for an elevator includes a plurality of switching devices connected in a series safety chain. Each switching device has an active unit generating a pattern and a passive unit that responds to the pattern within a defined spacing between the units.

Description

The invention relates to a monitoring device for an elevator, which comprises at least one non-contact operable switching device.

A Überuschungseinrichtung is eg off EP-A-0757011 already known.

In elevator systems, individual actions, for example a ride on a lift, are generally monitored by means of switching devices. Several of such switching devices must have a certain state in order to perform the intended action safely. In particular, in the case of an elevator installation it must be ensured that all doors remain closed and mechanically locked before the start of and during the journey of the elevator cage.

From the Scriptures EP 0 535 205 B1 is a monitoring device for a safety chain having a control device is known, which is provided with a non-contact triggerable sensor comprising a switching device. By approaching or removing a magnet, the switches or sensors are actuated.

A disadvantage of this solution is the fact that the switch or the sensor responds to each magnet, regardless of whether this magnet is the right and the particular of the selected switch or sensor magnet. It is sufficient to approximate a corresponding material to trigger a valid signal. As soon as the switch is within the working range of the magnet, it triggers a valid signal. A malfunction (incorrect triggering) of the switch or the sensor can hardly be excluded with reasonable effort. An erroneous trip can also be caused for example by artifacts and / or external interference, which is dangerous for the safe operation of the elevator system.

The invention has for its object to provide a monitoring device for an elevator of the type mentioned, which does not have the aforementioned disadvantages and allows safe and trouble-free monitoring. Furthermore, the monitoring device is insensitive to artifacts and external manipulations. By means of the monitoring device, the components to be monitored are uniquely identifiable.

This object is solved by the features of patent claims 1 and 9.

One advantage is the fact that a valid signal can only be triggered with an example worldwide only passive unit. The active unit can not generate a valid signal without having the right passive unit in range. Another advantage is that the monitoring is ensured with inexpensive producible elements.

The measures listed in the dependent claims advantageous developments and improvements of the claim 1 monitoring device are possible.

Another advantage is that several switching devices can be monitored for functionality and condition at the same time. The concatenation of several active units takes place in such a way that the answers of all passive units are linked in such a way that a mutual influence in the sense of a misinterpretation can be excluded.

Another advantage is the fact that a data exchange between active and passive unit can take place only by approaching the working as an antenna coils.

It is also advantageous that the passive unit does not need its own power supply or battery. This is achieved by having an energy store in which the energy transmitted by the active unit can be stored. This saves energy. Since the energy must be transmitted to generate the response, no spontaneous activity is possible.

• Fig. 1 eine Schalteinrichtung der Sicherheitskette im Ruhezustand, d.h. im unwirksamen Zustand,
• Fig. 2 die Schalteinrichtung aus Fig. 1 im Betriebszustand, d.h. im wirksamen Zustand,
• Fig. 3 eine Verkettung mehrerer Schalteinrichtungen,
• Fig. 4 eine passive Einheit gemäss einer Ausführungsform der Erfindung,
• Fig. 5 eine aktive Einheit gemäss einer Ausführungsform der Erfindung,
• Fig. 6 eine zentrale Kontrolleinheit gemäss einer Ausführungsform der Erfindung,
• Fig. 7 eine Sicherheitskette für die Türkontakte einer Aufzugsanlage.

Various embodiments of the invention are illustrated in the schematic drawings and explained in more detail in the following description. Show it:

• Fig. 1 a switching device of the safety chain at rest, ie in the inoperative state,
• Fig. 2 the switching device off Fig. 1 in the operating state, ie in the active state,
• Fig. 3 a chain of several switching devices,
• Fig. 4 a passive unit according to an embodiment of the invention,
• Fig. 5 an active unit according to an embodiment of the invention,
• Fig. 6 a central control unit according to an embodiment of the invention,
• Fig. 7 a safety chain for the door contacts of a lift installation.

In FIG. 1 a switching device 1 of an electronic security chain is shown, wherein the switching device 1 has formed as an inquiry unit 2 active unit and designed as a response unit 3 passive unit. The response unit 3 may be, for example, a transponder, a tag, a smart card or a chip card. The interrogation unit 2 has a first coil 4 and the response unit 3 has a second coil 5. The query unit 2 and the response unit 3 are in a so-called resting state, that is, they are distanced from each other so far that no interaction so no electromagnetic coupling takes place between them. The interrogation unit 2 generates a pattern M which is transmitted to the response unit 3 and to which the response unit 3 does not respond.

In FIG. 2 is the same switching device 1 off FIG. 1 shown, but in this case is in a so-called operating state. The interrogation unit 2 and the response unit 3 are arranged so close to each other that an interaction takes place. So there is an electromagnetic coupling between the interrogation unit 2 and the response unit 3 instead. On the generated by the query unit 2 pattern M is given by the response unit 3, a complex response M '.

In one embodiment, the interrogation unit 2 may comprise a generator 6, a first modulator 7 and a first demodulator 8. The generator 6 may be, for example, an RF generator, an RF generator and so on. The response unit 3 may in turn comprise a second modulator 9 and a second demodulator 10. The response unit 3 may further comprise an energy store 11, which may be formed, for example, as a capacitor with a capacity. The response unit 3 therefore preferably has no own power supply or battery.

The essential operating principle of the system interrogation unit 2-response unit 3, in a preferred embodiment, described in more detail below:

The interrogation unit 2 is designed so that it is able to transmit information to the response unit 3 and / or to obtain information from the response unit 3. The first coil 4 and the second coil 5 are formed in this example as an antenna. The interrogation unit 2 transmits the energy to the response unit 3 via an electromagnetic field. Electromagnetic coupling is referred to as the energy transfer functions similarly as in a transformer where the energy from the primary winding is transferred by tight coupling to the secondary winding. The energy coupled in via the electromagnetic field temporarily stores the response unit 3 in the energy store 11. As soon as the response unit 3 has received sufficient energy, it becomes functional and responds in a very specific manner to the pattern M generated by the interrogation unit 2.

The pattern M and / or the answer M 'may be, for example, numbers represented by a bit pattern / bit sequence. The pattern M exciting the response unit 3 does not need to be very complex, since it serves primarily to transmit energy and to trigger a response M '. In one embodiment, the pattern M may be approximately an RF carrier and generated as a phase modulated RF signal. The pattern M is used by the response unit 3 only for power generation and synchronization of a response. In other words, the pattern M as an instruction to the response unit 3 can be understood to generate a corresponding response M '.

In this way a causal link between answer and inquiry is ensured.

The pattern M need not be constant and may be specified by the interrogation unit 2 or externally.

However, it would also be possible to exchange data according to classical modulation methods (amplitude modulation AM, frequency modulation FM, etc.) between the interrogation unit 2 and the response unit 3.

The response unit 3 changes the pattern M so as to ensure that this change is made by the corresponding response unit 3 itself and not by another element. This can be done, for example, by the response unit 3 responding to a request with the transmission of a one-to-one number. Thus, the response unit 3 is uniquely identified.

FIG. 3 shows a concatenation of several switching devices 1, which are serially linked to a central control unit 12. The central control unit 12 sends a command r (x) and an instruction a (w) in data word format via a serial channel 13 to all query units 2 of the safety chain S. From this an electromagnetic signal is generated and as a pattern M, for example, with the function M (R, x) can be represented, the response units 3 transmitted. The pattern M excites the respective response units 3 if they are in range / within the range of the interrogation units 2. Each response unit 3 has a characteristic function fi (x), where i represents the number of participants, that is, in this example, the response units 3 are denoted by the characteristic functions f0 (x), f1 (x) and f2 (x). The response units 3 process the pattern M with the respective characteristic functions fi (x). The respective responses M 'formed as electromagnetic information, which can be represented by the function M' (A, fi (x)), for example, are converted into data word information and additively linked along the serial channel 13. The result a (w + fi (x)) is returned to the central control unit 12. This checks the result for validity and thus decides on the state of the safety chain S, ie on the state of the individual switching devices 1. Of course, the central control unit 12 must be functional and reliable, which can be ensured for example by a redundant decision branch, not shown in a known manner , The answers M 'of the response units 3 can be additively linked, ensuring that the responses of all the switching devices 1 are independent of one another. In this example, this is achieved by the characteristic functions f0 (x), f1 (x) and f2 (x).

The communication with the central control unit 12 and the data transfer to the same takes place via a bus 13.

The characteristic function fi (x) of the response unit 3 is stored, for example, in a table. This means that the determination of the function value is attributed to reading out a memory addressed by the function argument. The structure of the table can be done in a one-time initialization cycle. The table contents are chosen to be different across all response units. For example, the linear function fi (x) = ui + vi * x can be used, ensuring that the image areas are each disjoint. If subsets of response units 3 are also to be identified in a circle, the requirements must be correspondingly stricter. In general, all additive subsets must be disjoint.

A preferred embodiment results from an arrangement as in the following FIGS. 4, 5 and 6 is set forth.

In FIG. 4 The response unit 3 has an address / data memory 14, an intermediate data memory 15, a local control unit 16, a modulation / demodulation unit 17 and an antenna 18, which may be formed as a coil , For example, the pattern M may be represented by the function M (R, x), where R represents a request and x represents an address. If a pattern M (R, x) is received by the antenna 18 and subsequently demodulated by the modulation / demodulation unit 17, this is communicated as a request R to a local control unit 16. This then causes the reading of the cell with the address x from the address / data memory. The read-out value is interpreted as the result fi (x), modulated together with the identifier A and emitted via the antenna 18 as a response M ', which can thus be represented as a function M' (A, fi (x)).

The configuration of the address / data memory so that the contents at the addresses x correspond to the values f (x) can also be effected via analogous mechanisms with corresponding commands or else separately, for example by means of a laser and a permanent change in the semiconductor structure.

The linking of the answers M 'of several response units is carried out by serial addition of the individual results along a bus 13. By means of this, the queries of the response units 3 can be triggered using appropriate commands.

In FIG. 5 are the essential components of a query unit 2 shown. The interrogation unit 2 has a further antenna 19, a further modulation / demodulation unit 20, a further local control unit 21, a further intermediate data memory 22, an adder 23, and a bus coupling 24, which is positioned along the serial bus 13.

A query command r (x), which is propagated along the bus, triggers the generation of a pattern M (R, x) in each interrogation unit. Subsequently, the further intermediate data memory 22 is set to the value 0. All response units 3 which are in sufficient proximity of the further antenna 19 then respond with the answer M '(A, f (x)). This is demodulated and stored in the further intermediate data memory 22 as a result. If thereupon an instruction a (w) with argument w passes through the bus 13, the sum w + f (x) is generated in the serial adder 23 and passed on via the bus coupling 24 as a (w + f (x)).

To evaluate the result, the result determined by the summation over all tags is compared with that determined by the interrogation unit, and if the safety circuit matches, it is evaluated as closed.

In FIG. 6 the essential components of the central control unit 12 are shown. The central control unit has a control unit 25, a random number generator 26, a memory 27, a computer 28, a comparator 29 and a coupling 30, which ensures the serial connection to the interrogation units 2.

To determine the state of the safety circuit, a random argument x is generated by the random number generator 26 and output to the interrogation units 2 as a command r (x). The random argument x will then correspond to an address of the address / data memory 14 of the response unit 3. At the same time, by means of the information regarding the functions fi stored in the memory 27, the "desired value" f.sub.10 (x) +... + F.sub.N (x) is calculated. In doing so, all those response units T0... TN which are necessary to achieve a certain security state are taken into account. After a well-determined period of time, the query of the results by means of the statement a (0). The result f0 (x) +... + FN (x) thus determined is compared in the comparator 29 with the desired value and, according to the result, either the "closed circuit" or "open circuit" directive is output. An assessment of the safety status can be cyclical or on request.

Other functions f (x) can also be used. Ideally, f is chosen so that a simple criterion can be used to test the result. Ideally, the determination of f (x) is very difficult, while the examination of the equality relation w = f (x) is very simple. Such functions are well known by the term "one-way function" or "trap door function" in the field of cryptography. The function does not necessarily have to deliver scalar results.

For communication a variety of known bus system can be used. Since the security is ensured at a higher hierarchical level, the requirements for the bus system itself are very low.

The concatenation of the interrogation stations can also be accomplished by other functions than the addition.

The safety requirements for the components are low. Security comes first and foremost through the handling of information. It only needs to be ensured that the comparator operates safely and whose input signals originate from independent sources (calculation / bus).

With regard to the safety chain S according to FIG FIG. 3 in which three switching devices 1 connected in series are monitored, a query command r (x), which is propagated along the bus 13 by means of the interrogation units 2, is output by the central control unit 12. The query command r (x) serves to generate a response in the response units 3 for each request unit 2, as it were, as a drive command. The response units 3 in the series have the characteristic functions f0 (x), f1 (x) and f2 (x). At certain time intervals or continuously, the central control unit also sends the instruction a (w) on the bus 13, which is interpreted as a read-out command by the interrogation units 2, to read the answers M 'and forward them. In the example shown FIG. 3 the central control unit 12 sends the instruction a (w0) to the first polling unit 2 seen in the row, w0 = 0 being set at the beginning. After receiving the answer M ', the first interrogation unit 2 sends to the second interrogation unit 2 the instruction a (w1), where w1 = a (w0 + f0 (x)). This procedure is repeated in a similar manner along the bus 13 with the second and third switching means 1 in the series. After the third switching means 1, the central control unit is returned the signal a (w3) as a result, w3 = f0 (x) + f1 (x) + f2 (x).

In FIG. 7 is the concatenation according to FIG. 3 shown as a safety chain for the door contacts of a lift system. On three floors 31 of a building elevator doors 32 are provided, which are formed in this example as shaft doors 32. Each landing door 32 has a first door 32 'and a second door 32 "movable relative to each other for opening and closing the door FIG. 4 represented by the arrows P. The first door 32 'has the interrogation unit 2 and the second door 32 "includes the answering unit 3. The interrogation unit 2 and the answering unit 3 are arranged on the respective door 32', 32" so as to be so close when the landing door 32 is closed The interrogation units 2 and the response units 3 are preferably located on those parts of the respective door wings that overlap when the door is closed. The interrogation units 2 and the answering units 3 are preferably arranged on the corresponding door wings 32 ', 32 "such that they do not interact within the meaning of the invention until the door wings 32', 32" are already mechanically or electromechanically locked. The interrogation units 2 of each landing door 32 are connected in series via a bus line 13 and to a control unit 12. The query of the interrogation units 2, the answer of the answering units 3 as well as the data transmission to the control unit 12 functions exactly as in FIG. 3 is shown. With the aid of this safety chain S operating in the manner according to the invention, the door contacts of the shaft doors can be safely monitored and uniquely identified. Wrong trips are avoided. The control unit 12 continuously monitors the state of the door contacts and is connected to a central elevator control, not shown, in a conventional manner.

The same principle can also be applied to the car door of the elevator.

The monitoring device according to the invention can be used at all points of a lift to be secured, and the switching devices can replace all safety switches of a lift.

The active and / or the passive unit can also be provided with switching contacts or with semiconductor switches, for example, put the energy storage or the antenna out of operation. This could be applied, for example, to existing mechanical contacts.

LIST OF REFERENCE NUMBERS

1

switching device

2

interrogation unit

3

response unit

4

First coil

5

Second coil

6

generator

7

First modulator

8th

First demodulator

9

Second modulator

10

Second demodulator

11

energy storage

12

Central control unit

13

Serial channel / bus

14

Address / data storage

15

Intermediate data store

16

Local control unit

17

Modulation / demodulation

18

antenna

19

Another antenna

20

Further modulation / demodulation unit

21

Another local control unit

22

Another intermediate data store

23

adder

24

bus connection

25

control unit

26

random generator

27

Storage

28

computer

29

comparator

30

coupling

31

Floor of a building

32

elevator door

32 '

First door

32 "

Second door leaf

M

template

M '

answer

P

Closing direction of the shaft door

S

safety chain

Claims (8)

1. Monitoring device for a lift, which comprises at least one contactlessly actuable switching device (1), which comprises an active unit (2) and a passive unit (3), wherein the active unit (2) and the passive unit (3) are so constructed that the passive unit (3) is excited exclusively by a pattern (M) generated by the active unit (2), wherein the passive unit (3) is excited by the pattern (M) from the active unit (2) from a defined spacing between the active and passive units (2, 3) and generates an answer (M'), wherein the answer (M') is transmissable as identification signal to a central checking unit (12) by way of a bus (13), characterised in that several switching devices (1) are provided which are serially connected together into a safety chain (S) by way of the bus (13) to the central checking unit (12) and that the pattern (M) and the answer (M') are numbers which can be represented by a bit pattern / bit sequence, wherein each passive unit (3) has a characteristic function fi(x) and the pattern (M) with the respective characteristic function fi(x) is processed so that the passive unit (3) is uniquely identifiable and wherein the respective answers (M'), which have the form of electromagnetic data, are converted into data-word data and interlinked along the bus (13) by means of a function and the result is reported back to the central checking unit (12).
2. Monitoring device according to one claim 1, characterised in that the active unit (2) comprises a first coil (4) and the passive unit (3) comprises a second coil (5).
3. Monitoring device according to one of the preceding claims, characterised in that the passive unit (3) comprises an energy store (11) which stores energy.
4. Monitoring device according to any one of the preceding claims, characterised in that the lift comprises at least one lift door (32), which comprises a first door panel (32') and a second door panel (32"), wherein the active unit (2) is arranged at the first door panel (32') and the passive unit (3) is arranged at the second door panel (32").
5. Monitoring device according to claim 4, characterised in that the lift door (32) is a shaft door or a cage door.
6. Monitoring device according to any one of the preceding claims, characterised in that the active unit (2) is constructed as a transceiver and the passive unit (3) as a transponder.
7. Method of monitoring a lift with at least one contactlessly actuable switching device (1), which comprises an active unit (2) and a passive unit (3), wherein the passive unit (3) is excited exclusively by a pattern (M) generated by the active unit (2), wherein the passive unit (3) is excited by the pattern (M) from the active unit (2) from a defined spacing between the active and passive units (2, 3) and generates an answer (M'), wherein the answer (M') is transmissable as identification signal to a central checking unit (12) by way of a bus (13), characterised in that several switching devices (1) are serially connected together into a safety chain (S) by way of the bus (13) to the central checking unit (12) and that as pattern (M) and the answer (M') numbers are used which can be represented by a bit pattern / bit sequence, wherein each passive unit (3) uses a characteristic function fi(x) and the pattern (M) with the respective characteristic function fi(x) is processed so that the passive unit (3) is uniquely identifiable and wherein the respective answers (M'), which have the form of electromagnetic data, are converted into data-word data and interlinked along the bus (13) by means of a function and the result is reported back to the central checking unit (12).
8. Method according to claim 7, characterised in that no answer (M') is generated by the passive unit (3) if the defined spacing is exceeded.

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