EP2516305B1 - Method and device for determining the movement and/or position of a lift cabin - Google Patents

Description

The invention relates to a method and a device for determining the movement and / or the position of an elevator car of an elevator installation, in particular for determining a possible faulty behavior of the elevator installation, as well as an elevator installation according to the preamble of the independent claims.

The movement and the position of an elevator car are detected in an elevator installation on the basis of sensor devices. It is typically provided that even a possible malfunction of the elevator system, such as an occurring overspeed of the elevator car, is detected in order to trigger the necessary security measures can.

A method and a device for measuring the speed and for detecting an overspeed in an elevator installation are in EP 0 712 804 A1 described. By means of this known device, the traveling speed of an elevator car guided in an elevator shaft and driven by a drive unit is monitored in order to stop it when an overspeed occurs.

For this purpose, a measuring strip is mounted on a wall of the elevator shaft and is scanned by a forked light barrier connected to the elevator car. The measuring bar has a measuring track with flags, with which the speed of the elevator car is measured. By comparing the measured speed with the predetermined maximum speed, the possible occurrence of an overspeed can be determined and signaled in the sequence. The length of the flags is in each case adapted to the maximum speed of the elevator car in the relevant shaft area, ie towards the upper and lower shaft end towards the flag segments are getting shorter. The duration of the scanning of the individual flags is therefore included an at least approximately constant limit, if the entire shaft area is traversed at the intended maximum speed. If the duration of the scan of a single flag is shorter than this limit, then there is an impermissible exceeding of the maximum speed.

The measuring strip also has a control track with window openings, each associated with a flag and arranged at the same height. If the measuring bar and the forked light barrier are installed correctly, the markings of the measuring track and the control track are scanned correctly. On the basis of the scanning of the window openings of the control track is thus checked whether the fork light barrier sufficiently deep into the measuring strip engages and the sequential interruption of the light barriers is ensured by the flags during the journey of the elevator car. By scanning the control track can also be determined whether individual flags are missing on the measuring bar, whereby the speed measurement would be distorted. The flags of the measuring track and the window openings of the control track are dimensioned and arranged such that always at least one light barrier is interrupted. If the photocells and the control track associated light barriers are not interrupted at the same time, therefore, there is an error that occurs, for example, when the fork light barrier has detached from the measuring bar.

In a preferred embodiment of this known device, the measuring strip in addition to the measuring track and the control track to a safety track, which serves the additional control of the elevator car in the upper and lower end of the hoistway.

Furthermore, the fork light barrier has a first and a second optical channel with independent light barriers whose signals are supplied to a first and a second measuring channel. If the measurement results of these two measurement channels deviate from each other, an error is detected that is due, for example, to a failure of a single optical component.

Despite these various security measures, errors can occur in this device under certain conditions that jeopardize the safe operation of the elevator system. For example, identical errors can occur in both channels of the forked light barrier. Furthermore, damage to the measuring strip or permanent effects of foreign bodies may occur. If the aforementioned defects occur at the fork light barrier or at the measuring strip, the markings of the measuring strip are no longer scanned correctly, which is why a correct measurement of the speed and thus also detection of an overspeed are no longer possible.

Under certain circumstances, the displayed states do not contain an immediately clear indication of the actual state of the elevator installation. For example, a condition may occur in which all photocells are interrupted by the measuring bar. This condition may occur for a long time when the elevator car is stopped at a corresponding position within the hoistway. However, the same condition may also occur when the elevator car is in motion and one of the above errors occurs. On the basis of the available information can therefore not be clearly determined whether the elevator car is held at a certain position or moves along the elevator shaft.

US 2005-269163 discloses a device according to the preamble of claim 10.

The present invention is therefore based on the object to provide a method and an apparatus for reliably determining the movement and / or the position of an elevator car of an elevator installation, by means of which the deficiencies described above are avoided. Furthermore, an elevator system provided with this device and operating according to this method is to be specified.

The method and the device, which are intended in particular to reliably detect a faulty behavior of the elevator installation, in particular an overspeed, should be able to be implemented with simple measures and lead to a significant improvement in the reliability of the monitoring of the elevator installation.

The method and the device, which serve for the reliable determination of the movement and / or the position of an elevator car of an elevator installation, have a first monitoring unit, from which first signals of a first sensor device are evaluated, information on the movement and / or the position of the elevator car to determine and detect any occurring misbehavior of the elevator system and to trigger appropriate safety measures, which relate for example to the dropping of safety switching elements and thereby the shutdown of the elevator.

According to the invention, a second sensor device which does not operate according to the principle of the first sensor device is provided by means of which changes in the state of motion of the elevator car are detected and corresponding second signals are output to a second monitoring unit which evaluates the second signals and detects changes in the state of motion of the elevator car, which is then checked whether motion signals determined by the first monitoring unit are coherent with the changes in the state of motion of the elevator car detected by the second monitoring unit. If there is no coherence, a first error signal is generated.

By checking the coherence of the measurement results of the independently operating first and second monitoring units a significantly higher reliability of the determination of the movement and / or the position of the elevator car and in particular a possible misconduct, in particular an impermissible overspeed of the elevator system is achieved. If the first monitoring unit determines, for example, the speed of the elevator car based on an optical first sensor device, then disturbances occurring there, as described above, are not relevant for an electro-mechanical second sensor device, based on which the second monitoring unit detects the occurrence of changes in the state of motion Elevator car detected. Conversely, disturbances that might possibly occur in the electromechanical second sensor device for the optical first sensor device are of little importance. The two monitoring units Therefore work according to different principles, or in different technical sub-areas, which is why a higher information gain is achieved when comparing the corresponding work results, as compared with additionally obtained measures in the same technical sub-area. So is the subject of the EP 0 712 804 A1 provided in a preferred embodiment, together with the measuring path and the control lane a security lane, the sampling provides additional information. On the other hand, the sampling of all three paths can be affected simultaneously by the same cause. For example, all three tracks can be covered by foreign bodies. Furthermore, all light sensors can be disturbed by extraneous light at the same time, or all light sensors can also be covered by foreign bodies. Furthermore, it is to be expected that if the measuring strip is damaged, all three tracks will be damaged, which is why the addition of an additional track, which is also optically scanned, does not give the desired improvement.

Due to the system-related decoupling of the first and second sensor device results in the inventive device a reduced susceptibility to simultaneously occurring disorders. If the first and second monitoring units are also electrically decoupled enough, the solution according to the invention results in a significantly increased safety gain with little effort. A mutual check of the first and second monitoring unit therefore makes it possible to immediately detect any faults and to protect the elevator system from danger.

In spite of the various functional principles, there is a direct relationship between the first measured variables determined on the one hand by the first sensor device and the first monitoring unit and the other measured variables determined by the second sensor device and the second monitoring unit, both of which relate to the movement of the elevator car both monitoring units allowed.

For a mutual check of the first and second monitoring unit, it is sufficient to monitor the coherent or coherent occurrence of mutually corresponding signals of both monitoring units. If the elevator car is being accelerated, optical first sensor device, which is guided along a stationary held measuring strip, and emitted from the electromechanical second sensor device to each other corresponding first or second signals, if both sensor devices are functional and thus coherent to each other. A check as to whether there are also second signals in the presence of first signals which signal a movement or a change in the movement of the elevator car and signal a corresponding change in the movement of the elevator cabin therefore makes it possible to verify that both monitoring units and the associated sensor devices are in proper operation , For the test various signals can be consulted which indicate connected states. Furthermore, it is also possible to calculate kinematic variables in both monitoring units and to compare them with each other.

It is not necessary that the respective signals of both monitoring units, which signal movements or changes in the movement of the elevator car, occur simultaneously. Due to different physical measurement principles and different measurement circuits, the mutually corresponding measurement signals typically occur with a mutual time shift, which can also vary within a certain range. In preferred embodiments, therefore, at least one time window is provided, within which the occurrence of two mutually corresponding signals or messages of both monitoring units is monitored. Typically, the time window is opened after a corresponding signal has been detected in one of the monitoring units.

In a preferred embodiment, the second sensor device comprises at least one electromechanical motion sensor, such as an acceleration sensor and / or a speed sensor. An acceleration sensor is a sensor normally provided with a test mass, with which the acceleration is measured by determining the inertial force acting on the test mass as acceleration or deceleration occurs. The gravitational acceleration acting on the test mass is preferably compensated electrically or electronically, so that the signals emitted by the acceleration sensor indicate the further accelerations acting on the acceleration sensor, which are typically due to the actions of the drive device and the brake device. Out Tietze-Schenk, semiconductor circuit technology, Springer-Verlag, Heidelberg 1999, 11th edition, page 1223 , an acceleration sensor is known in which the test mass acts on a diaphragm provided with strain gauges. Furthermore, a capacitively or inductively operating sensor can be used as an acceleration sensor, in which the test mass is suspended elastically and acts as part of a capacitor or is moved as a magnet within a coil. Furthermore, piezoelectric acceleration sensors are known. A speed sensor may, for example, have an impeller rolling in the elevator shaft, which is coupled to a measuring transducer. These electromechanical sensors therefore work on different principles than those from the EP 0 712 804 A1 known optical sensors which are preferably used in the first sensor device in the present invention. Alternatively or additionally, the second sensor device comprises a transducer connected to the drive and / or brake device, which detects causes that lead to a later change in the movement of the elevator car.

On the basis of the second sensor device signals are generated which relate to changes in the state of motion of the elevator car, which are compared within a correspondingly selected time window with corresponding signals of the first sensor device to determine whether the measurement results are coherent.

The choice of the size of the time window is preferably dependent on the intended speed of the elevator car, the signals to be compared and the measuring and evaluation methods used. If a movement change has already occurred and has been detected by the acceleration sensor, then the time window is selected to be correspondingly small. If, however, in the drive and / or braking device, a control command for commissioning of the system has been determined, the time window is selected correspondingly larger. When choosing the size of the time window, the applied measuring method is also taken into account. When using the forked light barrier described above, the time window is selected according to the distances of the markings of the measuring strip.

Preferably, the first sensor device is a light barrier device mounted on the elevator car, which has first optical elements which serve to form at least a first light barrier, with which at least the markings of a measuring path of a measuring strip, which is mounted stationary in the elevator shaft, are scanned while the elevator car is moving , From the first signals emitted by the first sensor device, the first activation signals are determined in the monitoring unit. When using light barriers, edge transitions or movement signals occur within the signal train, which indicate the closing or opening of the light barrier and thus the movement of the elevator car. The time interval of these motion signals is inversely proportional to the speed of the elevator car. If an acceleration of the elevator car from the idle state or from a drive with constant speed was determined by the second monitoring unit, the opening or interruption of the light barrier and thus a corresponding movement signal must be determined by the first monitoring unit within a correspondingly selected time window. By checking the arrival of the motion signal, therefore, the coherent operation of the two monitoring units can be verified.

In a further preferred refinement, the second signals emitted by the acceleration sensor and / or by the speed sensor and / or by the measuring transducer are evaluated in order to detect impermissible operating states, determining acceleration values lying above a limit value or speed values lying above a limit value or drive quantities lying outside of a tolerance range, wherein a second error signal is generated after determination of values which are above a limit value or outside the tolerance range. Malfunctions can be detected early on the basis of the second monitoring unit, possibly before an overspeed has occurred and has been detected by the first monitoring unit. In this case, not only the proper function of the first monitoring unit, but the behavior of the elevator system is independently monitored by the second monitoring unit.

In further preferred embodiments, the first and / or second sensor device and the first and / or second monitoring unit are at least partially formed redundant. The output signals of mutually corresponding redundant parts of these devices are compared with each other, wherein after occurrence of a difference, a third error signal is generated.

The first sensor device and at least a part of the second sensor device are preferably arranged in a common housing. In this way, a compact design of the sensor is possible. Preferably, at least the acceleration sensor is constructed as a micro-electro-mechanical system (MEMS) and, for example, cast into the housing of the two sensor devices. Corresponding micro-electro-mechanical sensor devices that can be easily integrated into the housing of the first sensor device, are for example in the WO2009117687A1 described.

Like the sensor system of the first sensor device, the sensor system of the second sensor device is preferably designed redundantly or multi-channel, so that a fault can be detected by comparing the signals of the different channels. Preferably, the single or redundant trained first and / or the second monitoring unit in the common Housing integrated the sensor devices. This results in a total of a compact and cost-effective design of the entire monitoring device, which can be realized for example in the form of a forked light barrier. In a preferred embodiment, two separate or interconnected such forked light barriers are used.

On the basis of the device according to the invention not only the overspeed of an elevator car can be reliably detected. It can also be determined whether a stop of the elevator car reported by the first monitoring unit actually exists. If an above-described error occurs in the first monitoring unit, the first sensor device or the measuring strip during the travel of the elevator car, it is possible that no movement signals will arrive from the first monitoring unit. This could be interpreted as the onset of hibernation of the elevator car, although it is still in progress. Again, the inventive review of the coherence of the measurement results of the first and second monitoring unit allows to recognize the error mentioned. If a standstill is reported by the first monitoring unit after the driving operation of the elevator car, it is checked whether a corresponding change in movement, in particular an acceleration opposite to the direction of movement of the elevator car, has also been detected by the second monitoring unit and thus there is coherence.

If a movement change is detected in one of the two monitoring units while the elevator car is moving, the size of the time window is preferably adjusted accordingly, within which a coherent confirmation of the change in movement is expected by the other monitoring unit. This not only determines whether the two monitoring units are in operation, but also whether they are working correctly.

The inventive method can therefore be advantageously used to check changes in the state of the elevator system and the state of monitoring devices and control devices.

The monitoring device or at least the monitoring units provided therein are preferably connected to the central control unit of the elevator installation and / or to a shaft information system which detects position data and / or movement information of the elevator car and transmits it to the control unit.

The exchange of information and signals between the sensor devices and the monitoring units as well as the control unit and the shaft information system can take place by means of wireless or wired transmission devices or a combination thereof.

Furthermore, the second monitoring unit can alternatively or additionally also process other information and signals, such as position signals and RFID signals, which reflect the status of the elevator installation. On the basis of more in-depth information, it is possible to further optimize the measurement results. For example, the tolerance ranges, e.g. the time window is reduced, if it was reported by the shaft information system that the elevator car is located in the lower or upper end of the elevator shaft.

Fig. 1

eine schematische Darstellung einer erfindungsgemässen Aufzugsanlage 1, welche eine Überwachungsvorrichtung 4 mit einer ersten und einer zweiten Überwachungseinheit 42, 43 aufweist, die mit Sensoreinrichtungen 2, 31, 32, 33 gekoppelt sind, anhand derer die Bewegungen einer in einem Aufzugsschacht 9 vertikal verfahrbaren Aufzugskabine 11 auf verschiedene Arten erfasst werden können;

Fig. 2

eine aus der EP 0 712 804 A1 bekannte Gabellichtschranke 2

Fig. 3

eine Messleiste 5 mit einer Messbahn 51 und einer Kontrollbahn 52, die mittels Lichtschranken LS_MB-A1, LS_MB-B1; LS_MB-A2, LS_MB-B2, LS_KB-A, LS_KB-B abgetastet werden, welche durch optische Elemente 21A, 22A; 23A, 24A; 21 B, 22B; 23B, 24B; 25A, 26A; 25B, 26B der Gabellichtschranke 2 von Figur 2 gebildet werden;

Fig. 4

die Lichtschranken LS_MB-A1, LS_MB-B1; LS_MB-A2, LS_MB-B2, LS_KB-A, LS_KB-B der Gabellichtschranke 2 von Figur 3, welche einerseits durch die Messleiste 5 und andererseits zumindest teilweise durch einen Fremdkörper 8 unterbrochen sind:

Fig. 5

ein Diagramm mit dem Verlauf der Signale S-51, S-52 der Gabellichtschranke 2 von Figur 3, welches zeigt, dass die entsprechenden Lichtschranken LS_MB-A1 und LS_KB-A, nach einem Zeitpunkt T2 verschlossen sind und daher entweder die Aufzugskabine 11 an einer bestimmten Position angehalten wurde oder ein Fehler aufgetreten ist;

Fig. 6

ein Diagramm, welches Signalverläufe die ersten Signale S-51, S-52 der Gabellichtschranke 2 von Fig. 3 und zweite Signale S-31, S-32 eines Beschleunigungssensors 31 und eines Geschwindigkeitssensors 32 sowie den Verlauf entsprechender Zählerstände Z1, Z2 zeigt, welche mit Grenzwerten verglichen werden, um die Kohärenz der Messergebnisse beider Überwachungseinheiten 42, 43 zu prüfen; und

Fig. 7

ein detailliertes Funktionsblockschaltbild der Überwachungsvorrichtung 4 von Figur 1.

In the following, the invention will be explained in more detail with reference to several embodiments in conjunction with the following figures.
Show it:

Fig. 1

a schematic representation of an inventive elevator system 1, which has a monitoring device 4 with a first and a second monitoring unit 42, 43, which are coupled to sensor devices 2, 31, 32, 33, based on which the movements of a lift shaft 9 vertically movable elevator car 11th can be detected in different ways;

Fig. 2

one from the EP 0 712 804 A1 known fork light barrier 2

Fig. 3

a measuring strip 5 with a measuring track 51 and a control track 52, which by means of light barriers LS _MB-A1 , LS _MB-B1 ; LS _MB-A2 , LS _MB-B2 , LS _KB-A , LS _KB-B , which are detected by optical elements 21A, 22A; 23A, 24A; 21B, 22B; 23B, 24B; 25A, 26A; 25B, 26B of the forked light barrier 2 of FIG. 2 be formed;

Fig. 4

the photocells LS _MB-A1 , LS _MB-B1 ; LS _MB-A2 , LS _MB-B2 , LS _KB-A , LS _KB-B the fork light barrier 2 of FIG. 3 which are interrupted on the one hand by the measuring strip 5 and on the other hand at least partially by a foreign body 8:

Fig. 5

a diagram with the course of the signals S-51, S-52 of the forked light barrier 2 of FIG. 3 showing that the respective light barriers LS _MB-A1 and LS _KB-A are closed after a time T2 and therefore either the elevator car 11 has been stopped at a certain position or an error has occurred;

Fig. 6

a diagram which waveforms the first signals S-51, S-52 of the forked light barrier 2 of Fig. 3 and second signals S-31, S-32 of an acceleration sensor 31 and a speed sensor 32 and the course of corresponding counter readings Z1, Z2 which are compared with limit values in order to check the coherence of the measurement results of both monitoring units 42, 43; and

Fig. 7

a detailed functional block diagram of the monitoring device 4 of FIG. 1 ,

Fig. 1 shows a schematic representation of an elevator system 1, which has a vertically movable in an elevator shaft 9 elevator car 11, which is connected via cables 12 and a traction sheave 13 with a drive unit 14. The elevator installation 1 is further provided with a device according to the invention, by means of which the speed and possible overspeeds of the elevator car 11 can be detected. The inventive device is constructed such that an error occurring therein can be reliably detected and the elevator system 1 can be secured accordingly. The device according to the invention comprises a monitoring device 4, in which two mutually independent monitoring units 42, 43 are provided, in which, in this preferred embodiment, a reference clock t _REF will be supplied from a shared time base 41.

The first monitoring unit 42 is provided with an in Fig. 2 Sensor device 2 shown connected in the embodiment shown in the EP 0 712 804 A1 known fork light barrier 2 corresponds. This fork light barrier 2 has two channels and comprises pairwise optical elements, namely transmitters 21A, 23A, 25A and receivers 22A, 24A, 26A for the first channel and transmitters 21B, 23B, 25B and receivers 22B, 24B, 26B for the second channel, based on their light barriers LS _MB-A1 , LS _MB-A2 , LS _KB-A , for the first channel and light barriers LS _MB-B1 ; LS _MB-B2 , LS _{KB-B are formed} for the second channel. The measurement signals generated on the basis of the light barriers of the two channels A and B are processed independently of one another and can be compared with one another in the first sensor device 2 or in the first monitoring unit by means of a comparator in order to detect malfunctions. For the following considerations, it is sufficient to consider the first and the third light barrier LS _MB-A1 , LS _{KB-A of} the first channel.

The fork light barrier 2 is arranged, for example, on the roof of the elevator car 11 in such a way that it embraces on one side a measuring strip 5 vertically aligned and stationarily mounted in the elevator shaft 9. During the travel of the elevator car 11, the fork light barrier 2 scans the markings 511, 512 of a measuring track 51 and a control track 52, which run parallel to one another along the measuring strip 5. The measuring track 51 has markings 511 in the form of exposed lugs, whose width decreases towards the end areas of the elevator shaft 9, in which a steadily decreasing maximum speed is prescribed. Due to the adaptation of the width of the markings 511 of the measuring track 51 to the maximum speed of the elevator car 11, the flanks of the markings 511 are always run through the first light barrier LS _{MB-A1 provided} at the same time intervals in a drive at maximum speed. In this case, also occur almost constant time intervals between the corresponding edges of the output from the forked light barrier 2 signals. These constant time intervals assume at maximum speed of the elevator car 11 to a minimum value, which is selected as a limit. If this minimum value or limit value is undershot, there is an overspeed. In this case, the first monitoring unit 42 emits an error signal F42 to a security module 44, which triggers, for example, the release of security switching elements in the sequence and stops the elevator car 11, as shown in FIG EP 0 712 804 A1 is described. On the basis of the second light barrier LS _MB-A2 , which also scans the measuring path 51, it is determined whether a mark 511 has passed or only been touched.

In the control track 52, window openings 521 are provided at the level of the markings for 111 of the measuring track, which are scanned by means of the third light barrier LS _{KB-A of} the fork light barrier 2. If the control track 52 is scanned correctly, it is ensured that the measuring strip 5 engages deep enough in the fork light barrier 2. If, however, the corresponding signals from the third light barrier LS _KB-A do not occur, then another error signal is output to the security module 44.

The scanning of the measuring track 51 and the control track 52 of the measuring strip 5 is in Fig. 3 shown. It can be seen that each mark 511 of the measuring track 51 is opposite to a window opening 521 of the control track 52. The width of the markings or flags 511 of the measuring path 51 is greater than the width of the window openings 521, which ensures that in normal operation always the first or third light barrier LS _MB-A1 , LS _{KB-A of} the fork light barrier 2 is interrupted. If the first and the third light barrier LS _MB-A1 , LS _KB-A are opened at the same time, an error is detected.

Like this in Fig. 4 is shown, a state is permissible in which both the first and the third light barrier LS _MB-A1 , LS _{KB-A of} the forked light barrier 2 are interrupted. This state, which can last for a longer time when the elevator car 11 stops at a certain position, is thus not interpreted as an error. Like this in Fig. 4 However, this state can actually be faulty and caused for example by a foreign body 8 become. Further, a defect of an optical element 21A, 23A, 25A, 22A, 24A, 26A, or a defect in the first monitoring unit 42 may cause the aforementioned condition. This state is therefore not clear, which is why corresponding dangers result.

Fig. 5 shows a diagram with signals S-51, S-52 of the forked light barrier 2, from which it can be seen that the respective light barriers LS _MB-A1 and LS _KB-A , are closed at the times T1 and T2. At time T1, both light barriers LS _MB-A1 and LS _{KB-A are} closed by the measuring strip 5 and are subsequently opened again, so that two flank signals S-51 F and S-52F can each be detected in the first monitoring unit 42. After the time T2, the light barriers LS _MB-A1 and LS _KB-A remain permanently closed, so that either the elevator car at the in Fig. 4 position has been stopped or a safety-relevant error has occurred.

To overcome this problem, the monitoring device 4 has a second monitoring unit 43, which is connected to a second sensor device 31, 32, 33, detected by means of the changes of the state of motion of the elevator car 11 and corresponding second signals S-31; S-32; S-33 are delivered to the second monitoring unit 43.

In the present embodiment, the second sensor device 31, 32, 33 comprises an acceleration sensor 31 and a speed sensor 32, which are connected to the elevator car 11. The acceleration sensor 31 may operate according to one of the principles described above. The speed sensor 32 has a transmitter, which is coupled to an impeller 321, which is guided along the shaft wall, for example in a rail. Of both electromechanical motion sensors 31, 32, signals S-31; S-32 delivered, which signal the changes of the state of motion of the elevator car 11. Furthermore, the second sensor device comprises a transducer 33 connected to the drive device 14 and preferably also to the brake device, from which signals are monitored which indicate the initiation of movement changes of the elevator car 11. Of the second monitoring unit 43, the signals S-31; S-32; S-33 of the second sensor device 31, 32, 33 therefore evaluated in order to determine whether or not expected changes in the state of motion of the elevator car 11 have occurred.

After detection of a change in the state of motion of the elevator car, possibly only during acceleration from the idle state or, if necessary, during acceleration or deceleration from a constant speed drive, it is checked whether the movement signals S-51 determined by the first monitoring unit 42 F and the detected by the second monitoring unit 43 changes in the state of motion of the elevator car 11 are coherent to each other, wherein in the absence of coherence, an error signal is generated. The verification of the coherence of the measurement results determined by the two monitoring units 42, 43 may be limited to checking a single signal S-51F or may involve the comparison of further determined kinematic information.

After the detection of an acceleration or deceleration of the elevator car 11 in the second monitoring unit 43, this status change is also to be registered by the first monitoring unit 42 if it is functional. The measurement results of the two monitoring units 42, 43 are therefore coherent during trouble-free operation and are checked one-sidedly or mutually in order to determine any occurring error. In the exemplary embodiment shown, the movement signals S-51F ascertained by the first monitoring unit 42 are transmitted to the second monitoring unit 43, where they are checked for coherence.

Conversely, the validity of the measurement results of the second monitoring unit 43 can also be checked by the first monitoring unit 42. After the detection and measurement of edge signals S-51 F, it is checked whether the changes in the movement state determined by the second monitoring unit 43 are coherent thereto. For this purpose, the measurement results S-43 of the second monitoring unit 43 are transmitted to the first monitoring unit 42 and evaluated there accordingly.

The examination of the monitoring units 42, 43 can therefore be one-sided or mutually. As a result of the preferably performed mutual checking, errors that may occur in the first or second sensor device 2, 31, 32, 33 or in the first or second monitoring unit 42, 43 are detected and signaled immediately. In a preferred embodiment, the mutual checking of the two monitoring units 42, 43 takes place in a separate module 45 (see FIG Fig. 7 ).

In Fig. 1 It is further shown that the monitoring device 4 is preferably connected to the control unit 6 and / or to a shaft information system 7. On the basis of the control unit 6 the monitoring device 4 current operating data, such as changed maximum values for accelerations and speeds can be transmitted. Data of the shaft information system 7 can be used to individually take into account the respective position of the elevator car 11 in the evaluation of the first or second signals S51, S-31, S-32, S-33.

Fig. 6 shows the course of the signals from Fig. 5 after time T2. For a first consideration, it is assumed that the elevator car 11 was stopped at time T2 and accelerated again at time T3. Between the times T2 and T3, therefore, no movement signals S-51 F, S-52F occur in the signal paths S-51, S-52. Even after the time instant, a motion signal S-51 F, S-52F does not occur directly, since the first and third light barriers LS _MB-A1 , LS _{KB-A are} normally removed from the edges of the markings 511, 521 of the measuring strip 5, like this in Fig. 4 is shown.

At time T4, it is determined based on the signal S-31 output by the acceleration sensor 31 that a movement change or an acceleration of the elevator car 11 has occurred. At this point in time T4, a time window W is opened and it is checked whether a movement signal S-51 F arrives from the first monitoring unit 42 within this time window W, indicating that the first light barrier LS _{MB-A1 has been} opened or closed.

For this purpose, a counter acted upon by the reference clock t _REF (counter 433 in FIG Fig. 7 ) started. The current count is compared in the sequence in each case with a limit G1, which may not be exceeded and would be reached at the time T8, if no motion signal S-51 F arrives. If, however, the limit value is reached at time T8, the first error signal F1 is output to the fuse module 44, as shown in FIG Fig. 7 is shown.

In Fig. 6 is shown that within the course of the signal S-51, however, already before reaching the time T8, namely at the time T7, a movement signal S-51 F or the opening or closing of the first light barrier LS _MB-A1 and thus the proper function of the first Sensor device 2 and the first monitoring unit 42 has been detected. In this embodiment, after the detection of the motion signal S-51F, the counter is reset and restarted to monitor the occurrence of the next edge change and the next motion signal S-51F, respectively. With the resetting of the counter, a new time window W is simultaneously opened, within which the arrival of the next movement signal S-51 F is monitored. The monitoring is terminated in this preferred embodiment only when the stoppage of the elevator car 11 has been detected.

The stoppage of the elevator car 11 can in turn be determined in various known ways. If no movement signals S-51 F arrive from the first monitoring unit 42, the idle state of the elevator car 11 is thereby indicated. Preferably, the coherence of the measurement results of the first and second monitoring unit 42, 43 is also checked in this case. In this case, it is checked whether the second monitoring unit 43 has detected a corresponding change in movement or an acceleration opposite to the direction of movement of the elevator car, which can lead to a standstill of the elevator car 11. If the measurement results of both monitoring units 42, 43, however, are not coherent, an error signal is emitted again.

Like this in Fig. 6 is illustrated, the coherence of various signals, events and information within individual time windows can be compared. At time T5, for example, based on the signals S-32 of the speed sensor 32, a speed change is detected. After the detection of the speed change, a second counter is started and its count Z2 compared with a limit. This second counter is reset on the occurrence of a falling edge S-52F of the signals S-52.

Next is in the diagram of Fig. 6 a limit value G2 is shown by which a maximum speed of the elevator car 11 is determined. If the counter (see counter 423 in Fig. 7 ) does not reach this limit value G2 before it is reset, the time interval between the movement signals S-51 F is too low, which is why the traveling speed of the elevator car 11 is above the maximum speed.

Preferably, in the evaluation of the signals S-31; S-32; S-33 of the second sensor device 31, 32, 33 additionally checked whether inadmissible operating states of the elevator installation 1 and in particular the elevator car 11 are present. If it is determined that the measured acceleration values or speed values are outside a tolerance range above a limit value or drive variables, an error signal F43 is generated and transmitted to the fuse module 44. In this embodiment of the monitoring device 4 according to the invention, malfunctions, in particular overspeeds, can therefore be detected and signaled not only by the first monitoring unit 42 but also by the second monitoring unit 43.

In Fig. 6 is illustrated by the curves of the output from the acceleration sensor 31 and the speed sensor 32 signals S-31, S-32 that various fault events E1, E2, E3 can occur, which are safety-relevant, and should be signaled as an error. The course of the output from the acceleration sensor 31 signal S-31 shows that too high Accelerations may occur (event E1) or that an acceleration may take too long (event E2), which is why the occurrence of an overspeed is expected. In addition, the course of the output from the speed _sensor 32 signal S-32 is shown, from which the exceeding of the limit value G _VMAX the maximum speed can be read directly.

Fig. 7 shows a detailed functional block diagram of the monitoring device 4 of Fig. 1 with the first monitoring unit 42, the signals S-51, S-52 are supplied from the first sensor device 2, and the second monitoring unit 43, the signals S-31, S-32, S-33 from the acceleration sensor 31, the speed sensor 32 and be supplied from the transducer 33. The two monitoring units 42, 43, to which clock signals t _REF are supplied from a shared time base 41, evaluate the supplied signals S-51, S-52; S-31, S-32, S-33 and the signals S-51F, S-43, exchanged between the two monitoring units 42, 43, and transmit corresponding error signals or error messages F1, ..., F5 after the detection of faults the security module 44, which transmits corresponding control signals C to the drive device 14 and corresponding information to the control unit 6.

The first signals S-51, S-52 output by the first sensor device 2 are supplied in the first monitoring unit 42 to an edge detector 421, which transmits motion signals or edge signals S-51F, S-52F to an evaluation unit 422. The time intervals of the occurrence of the movement signals S-51F, S-52F are checked by the evaluation unit 422 using a counter 423 to determine whether these time intervals are not below a limit value (see limit value G2 in FIG Fig. 6 ), which is selected according to the maximum permissible speed. The evaluation unit 422 transmits further determined events, movement information or only individual movement signals S-51 F to the second monitoring unit 43.

The second signals S-31, S-32, S-33 emitted by the acceleration sensor 31, the speed sensor 32 and the measuring transducer 33 are fed in the second monitoring unit 43 to a detector unit 431, which transmits relevant movement changes and state changes to an evaluation unit 432. The evaluation unit 433 checks whether the detected movement changes and state changes lie within the specified limit values and tolerance ranges. Furthermore, the evaluation unit 433 checks whether the detected movement changes and state changes are coherent with the events, movement information or movement signals S-51 F reported by the first monitoring unit 42. Since the events, information and signals determined in the first and second monitoring units 42, 43 typically do not occur simultaneously, a counter 433 is provided by which a time window W is determined, within which it is checked whether the mutually corresponding events, information and signals occur and the first and second monitoring unit 42, 43 work coherently.

In Fig. 6 It is further shown that the movement changes and state changes determined by the second monitoring unit 43 are communicated to the first monitoring unit 42 by means of a message S-43, which in turn checks whether the communicated movement changes and state changes are coherent with the own measured values. In this way, a malfunction that has occurred in the second sensor device 31, 32, 33 or in the second monitoring unit 43 can also be determined.

The check for coherence of the measurement results of the two monitoring units 42, 43 is carried out in a preferred embodiment in a separate test module 45. This results in a simplified modular design that can be expanded as desired. By checking the coherence of the reported measurement results, further data can be taken into account by the test module 45, which data are reported, for example, by at least one further monitoring unit or the control unit 6.

With knowledge of the present invention, the elevator expert can arbitrarily change the set shapes and arrangements. In particular, any sensor devices can be used, by means of which kinematic variables can be detected. The solution according to the invention is arbitrarily scalable and can also additionally take into account further information, for example information of the shaft information system, and thus be adapted to the respective requirements of the user. In the examples, the use of acceleration sensor 31, speed sensor 32, and transducer 33 is shown as second signals S-31, S-32, S-33. Of course, the elevator expert can use these different sensors in combination but also individually.

Also, the first and / or the second sensor device 2, 31, 32, 33 and / or the first and the second monitoring unit 42, 43 can optionally be integrated in a unit, for example in a common housing or in a common measuring body, so that a single functional unit is formed.

In Fig. 2 it is shown that the forked light barrier 2 not only optical elements 21A, 22A; 23A, 24A; 21B, 22B; 23B, 24B; 25A, 26A; 25B, 26B for the realization of the light barriers LS _MB-A1 , LS _MB-B1 ; LS _MB-A2 , LS _MB-B2 , LS _KB-A , LS _KB-B , but also an acceleration sensor 31A for a first channel and an acceleration sensor 31B for a preferably provided second channel, the total in the body 28 of the forked light barrier 2 are integrated. Furthermore, the first and / or the second monitoring unit 42, 43 can be integrated into the body 28 of the forked light barrier 2.

Since the acceleration sensor 31 encloses all elements required for measuring the acceleration, in particular the test mass, in a housing, its use in combination with an arbitrarily designed first sensor device 2, in particular a fork light barrier, is particularly advantageous. The installation of the acceleration sensor 31 in the fork light barrier 2 requires little additional space. Preferably, the acceleration sensor becomes 31, poured into the body 28 of the first sensor device 2 and thereby optimally protected. The combination of the first and the second sensor device 2, 31 provides a complete sensor unit which can monitor itself and which does not require any further information to be fed in from outside for this purpose.

Even with the use of an acceleration sensor 31, a significant increase in the reliability of the device is achieved. The speed sensor 32 and the transducer 33 may additionally be used if a further increase in the reliability of the measurement results is desired. Furthermore, the speed sensor 32 and / or the transducer 33 can also be used as an alternative to the acceleration sensor 31. As mentioned, the first and / or the second sensor device 2, 31, 32, 33 can be constructed as single-channel or multi-channel.

Fig. 7 therefore shows only an embodiment in which only the possibility of using a plurality of sensors 31, 32, 33 for the second sensor device is shown. In practical application, at least one of the aforementioned sensors 31, 32, or 33 is present in each case.

In a further preferred embodiment, at least the second monitoring unit 43 has a filter stage, by means of which disturbances are eliminated which could lead to false alarms. By means of the filter stage, e.g. is integrated in the detector unit 431, in particular, signals are suppressed, e.g. due to irrelevant vibrations.

Claims (15)

1. Method of determining a movement and/or a position of a lift cage (11) of a lift installation (1),

   - with a first monitoring unit (42), by which first signals (S-51; S-52) of a first sensor device (2) are evaluated in order to ascertain data with respect to the movement and/or position of the lift cage (11) and to detect possibly occurring faulty behaviour of the lift installation (1) and trigger appropriate safety measures,

   - with a second sensor device (31, 32, 33), which operates otherwise than in accordance with the principle of the first sensor device (2) and by means of which a change in the movement state of the lift cage (11) is detected and corresponding second signals (S-31; S-32; S-33) are delivered to a second monitoring unit (43), which evaluates the second signals (S-31; S-32; S-33) and detects a change which occurs in the movement state of the lift cage (11),

   comprising the steps:

   - ascertaining a time instant (T4) of a change in the movement state of the lift cage (11) in the first or second monitoring unit (42; 43),

   - monitoring the occurrence of at least one of the first movement signal or function signal (S-51F, S-52F), which is generated by the second or first monitoring unit (43; 42), within at least one time window (W) adjoining the time instant (T4), and

   - generating a first fault signal (F1) if the first movement signal (S-51), which indicates coherent mode of operation of the corresponding monitoring unit (42; 43), does not arise within the time window (W).
2. Method according to claim 1, wherein the second sensor device (31, 32, 33) comprises at least one electromechanical movement sensor such as an acceleration sensor (31) and/or a speed sensor (32) and/or a measurement value pick-up (33) connected with the drive and/or brake device (14), by means of which changes in the movement state of the lift cage (11), such as changes in acceleration and changes in speed or corresponding causes in the drive and/or brake device (14), are detected.
3. Method according to claim 2, wherein the first signals (S-51; S-52) delivered by the first sensor device (2) are evaluated in order to determine the speed, in a given case a possible excess speed, of the lift cage (11); and/or the second signals (S-31; S-32; S-33) delivered by the acceleration sensor (31) and/or by the speed sensor (32) and/or by the measurement value pick-up (33) are evaluated in order to ascertain impermissible operating states, such as acceleration values lying above a limit value or speed values lying above a limit value or drive variables lying outside a tolerance range, wherein after ascertaining values lying above a limit value or outside the tolerance range a second fault signal (F2) is generated.
4. Method according to any one of claims 1 to 3, wherein the second monitoring unit (43) comprises a detector unit (431), to which the second signals (S-31; S-32; S-33) of the sensor device (31, 32, 33) are fed and which detects a change in the movement state of the lift cage (11) and signals an associated evaluating unit (432), which after receipt of a corresponding third signal (4311) activates a counter unit (433) and within the time window (W) measured by the counter unit (433) monitors receipt of the expected first movement or function signal (S-51) from the first monitoring unit (42) and if the expected first movement signal (S-51) is absent generates the first fault signal (F1) and supplies it to a safety module (44).
5. Method according to any one of claims 1 to 4, wherein monitoring of the coherence of the measurement results of the first and second monitoring units (42, 43) is concluded only with detection of standstill of the lift cage (11), which is verified in the second monitoring unit (43) with consideration of the detection of corresponding changes in movement, particularly an acceleration directed oppositely to the direction of movement of the lift cage (11); and/or in the case of detection of changes in movement in one of the monitoring units (42; 43) of the size of the time window (W) within which a coherent confirmation of the change of movement is expected from the other monitoring unit (43; 42) is appropriately adapted.
6. Method according to any one of claims 1 to 5, wherein the first sensor device (2) is a light barrier device (2) which is mounted on the lift cage (11) and preferably of multichannel construction and which comprises first optical elements (21A, 22A, 23A, 24A; 21 B, 22B; 23B, 24B) serving for formation of at least one light barrier (LS_MB-A1, LS_MB-B1, LS_MB-A2, LS_MB-B2), by way of which at least markings (511) of a measurement path (51) of a measurement strip (5) mounted in stationary position are scanned and corresponding first signals (S-51) are formed, from which the first movement signals (S-51F) are ascertained in the first monitoring unit (42).
7. Method according to claim 6, wherein the light barrier device (2) comprises two optical elements (25A, 26A; 25B, 26B) serving for formation of at least one second light barrier (LS_KB-A, LS_KB-B), by way of which at least markings (512) of a control path (52) of the measurement strip (5) are scanned and further first signals (S-52) are formed, from which second movement signals (S-52F) are formed in the first monitoring unit (42).
8. Method according to claim 6 or 7, wherein the first monitoring unit (42) comprises a flank detector (421), which ascertains, by way of the first and/or second part of the first signals (S-51, S-52) delivered by the barrier device (2), changes in status of the light barriers (LS_MB-A1, LS_MB-B1; LS_MB-A2, LS_MB-B2; LS_KB-A, LS_KB-B) which occur and supplies the corresponding first and second movement signals (S-51, S-52) on the one hand to the second monitoring unit (43) and on the other hand to an associated evaluating unit (421), which after receipt of a first movement signal (S-51) caused by the measurement path (51) activates a counter unit (423) and checks whether up to receipt of the succeeding first movement signal (S-51) a defined counter state is exceeded and which in the case of falling below the intended counter state generates a fourth fault signal (F4) and supplies it to the safety module (44) and in the absence of second movement signals (S-52) caused by the control path (52) generates a fifth fault signal (F5) and supplies it to the safety module (44).
9. Method according to any one of claims 6 to 8, wherein the length of the at least one time window (W) in the case of use of at least one light barrier (LS_MB-A1, LS_MB-B1, LS_MB-A2, LS_MB-B2) in the first monitoring unit (42) is selected in dependence on a spacing between the markings (511, 521) of the measurement path (51), the control path (52) and/or a safety path.
10. Device for determining a movement and/or position of a lift cage (11) of a lift installation (1), according to any one of claims 1 to 9,

    - with a first monitoring unit (42), by which first signals (S-51; S-52) of a first sensor device (2) can be evaluated in order to ascertain data with respect to the movement and/or position of the lift cage (11) and to detect possibly occurring faulty behaviour of the lift installation (1) and trigger appropriate safety measures,

    - with a second sensor device (31, 32, 33), which operates otherwise than in accordance with the principle of the first sensor device (2) and which serves for detection of changes in the movement state of the lift cage (11) and for the delivery of corresponding second signals (S-31; S-32; S-33) to a second monitoring unit (43), by means of which the second signals (S-31; S-32; S-33) can be evaluated and

    - with a module (45) which checks whether the movement signals (S-51F) ascertained by the first monitoring unit (42) and the changes, which are detected by the second monitoring unit (43), in the state of movement of the lift cage (11) are coherent with one another and which in the absence of coherence a first fault signal (F1) can be generated,

    characterised in that the coherence of the movement signals (S-51F, S-52F) ascertained in the first monitoring unit (42) and the changes, which are detected in the second monitoring unit (43), in the movement state of the lift cage (11) can be checked in the model (45) by way of a counter (433) by which a time window (W) is determinable.
11. Device according to claim 10, characterised in that the first sensor device (2) is a light barrier device (2), which is mounted in the lift cage (11) and preferably of multichannel construction and which comprises first optical elements (21A, 22A, 23A, 24A, 21 B, 22B, 23B, 24B) serving for formation of at least one first light barrier (LS_MB-A1, LS_MB-B1, LS_MB-A2, LS_MB-B2), by way of which at least markings (511) of a measurement path (51) of a measurement strip (5) mounted in stationary position can be scanned, and that the light barrier device (2) comprises second optical elements (25A, 26A; 25B, 26B) serving for formation of at least one second light barrier (LS_KB-A, LS_KB-B), by way of which at least markings (512) of a control path (52) of the measurement strip (5) can be scanned.
12. Device according to claim 10 or 11, characterised in that the second sensor device (31, 32, 33) comprises at least one electromechanical movement sensor such as an acceleration sensor (31) and/or a speed sensor (32) and/or a measurement value pick-up (33) connected with the drive and/or brake device (14), by means of which changes in the movement state of the lift cage (11), such as changes in acceleration and changes in speed or corresponding causes in the drive and/or brake device (14), are detectable.
13. Device according to any one of claims 10 to 12, characterised in that

    a) the first sensor device (2) and at least a part of the second sensor device (31, 32, 33) are arranged within a common housing (28) and/or

    b) the first sensor device (2) and the first monitoring unit (42) are arranged within a common housing (28) and/or the second sensor device (31, 32, 33) and the second monitoring unit (43) are arranged within a common housing (28) and/or

    c) the first and second monitoring units (42, 43) of simple or redundant construction are arranged within a common housing (4) and/or

    d) the module (45) is constructed as a separate component or as a component integrated in the first or second monitoring unit (42, 43) or in the common housing (4).
14. Device according to any one of claims 10 to 13, characterised in that the first and/or the second monitoring unit (42; 43) is or are connected with a central control unit (6) of the lift installation (1) and/or a shaft information system (7), which shaft information system (7) detects position data and/or items of movement information of the lift cage (11) and transmits them to the control unit (6).
15. Lift installation (1) with a device according to any one of claims 10 to 14.

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