Method and controller for evaluating information about the current position of a cabin in an elevator shaft

Abstract

A method and controller (15) for evaluating information relating to the current position of a cabin (3) in a shaft (5) of an elevator (1) is proposed, the method comprising the steps of measuring a distance between a cabin reference position of the cabin (3) and a shaft reference position in the shaft (5) using a laser distance measuring device (33), obtaining laser quality data from the laser distance measuring device (33) representing the quality of a laser beam (35) detected by the laser distance measuring device (33) when measuring the distance, and evaluating information relating to the current position of the cabin (3) taking into account the measured distance and the laser quality data.

Description

[Technical Field]

[0001] The present invention relates to a method for evaluating information about the current position of a cabin in an elevator shaft, and also to a method for operating an elevator, and further to a controller configured to implement such a method, and to an elevator comprising such a controller. [Background technology]

[0002] In an elevator, the cabin typically displaces along a shaft to access various floors at different levels throughout a building. It is necessary to know the cabin's current location within the shaft in order to implement safety measures and / or to perform functions such as accurately displacing the cabin throughout the shaft and stopping the traveling cabin precisely at its intended level. Information regarding the cabin's current location may be used, for example, by an elevator controller, which controls the drive engine, braking mechanism, and / or other functions within the elevator.

[0003] There are various conventional methods and techniques for determining information about the current location of a cabin within a shaft. Typically, such methods and techniques must meet strict safety requirements in order to provide reliable position information.

[0004] EP 2516304 A1 discloses a floor position detection device for an elevator system. Hall sensors are used to detect magnetic markers located at different locations throughout the elevator shaft. While such an approach for determining cabin location based on local detection of one or more of a number of distributed magnetic markers can provide accurate and reliable position detection, it typically requires complex hardware. Therefore, manufacturing, installation, and / or maintenance of the position detection device can be laborious and expensive.

[0005] GB 2211046 A1 discloses an apparatus for monitoring the movement of a cabin within a shaft. A laser transmitter is positioned at one end of a shaft to transmit a laser beam along the length of the shaft. A reflector is attached to the cabin to reflect the laser beam back to a receiver positioned adjacent the transmitter. The receiver output is monitored to determine the position of the cabin within the shaft and the velocity of the cabin relative to the shaft. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] European Patent Application Publication No. 2516304 [Patent Document 2] GB Patent Application Publication No. 2211046 Summary of the Invention [Problem to be solved by the invention]

[0007] However, it has been found that such laser-based monitoring of the cabin's current position can be subject to various disturbances or errors, such that the reliability of such techniques may be insufficient for some safety-critical applications.

[0008] A method may be needed for evaluating information about the current position of a cabin in an elevator shaft, the method requiring relatively simple hardware and / or hardware that is easy to install and / or maintain while providing sufficient reliability of the determined position information. Additionally, a method may be needed for operating an elevator in which the cabin position is evaluated in the indicated manner. Furthermore, a controller for implementing such a method, and an elevator including such a controller, may be needed. [Means for solving the problem]

[0009] Such a need may be met by the subject matter of the independent claims. Advantageous embodiments are defined in the dependent claims and in the following description and drawings.

[0010] According to a first aspect of the invention, a method for evaluating information relating to the current position of a cabin in an elevator shaft is proposed, said method comprising at least the following steps, preferably in the order given: measuring a distance between a cabin reference position in the cabin and a shaft reference position in the shaft using a laser distance measuring device; acquiring laser quality data from the laser distance measuring device indicative of a quality of the laser beam detected by the laser distance measuring device when measuring the distance; - evaluating information about the current position of the cabin taking into account the measured distance and laser quality data; Equipped with.

[0011] According to a second aspect of the present invention, a method for operating an elevator is proposed, in which the function of the elevator is controlled based on information about the current position of the cabin in the elevator shaft, which information is evaluated by a method according to an embodiment of the first aspect of the present invention.

[0012] According to a third aspect of the present invention, a controller for determining information about a current position of a cabin in an elevator shaft is proposed, wherein the controller is configured to implement and / or control a method according to one embodiment of the first and second aspects of the present invention.

[0013] According to a fourth aspect of the present invention, an elevator is proposed, comprising, inter alia, a cabin, a shaft, a laser distance measuring device for measuring a distance between a cabin reference position in the cabin and a shaft reference position in the shaft, and further comprising a controller according to an embodiment of the third aspect of the present invention.

[0014] The idea of ​​the embodiments underlying the present invention may be construed as being based, inter alia, on the following observations and realizations.

[0015] As already briefly mentioned above, technologies have been developed to detect the current position of the elevator cabin within the elevator shaft. To enable the determined position information to be used for safety-critical applications, such technologies must be reliable. For example, such technologies must comply with a high safety integrity level, such as SIL2 or SIL3. Therefore, conventional elevator cabin positioning technologies are generally complex and expensive.

[0016] Briefly summarized, the approach described herein aims to use a simple and relatively inexpensive technique for assessing or ultimately determining the current cabin position within an elevator shaft and significantly increase the reliability of such a technique. Specifically, a laser distance measuring device is applied to measure the distance between a fixed reference position within the elevator shaft and another reference position within the cabin. Because it is known that the results of such distance measurements can be subject to various influences and disturbances, potentially resulting in erroneous measurement results, it is proposed to additionally acquire laser quality data. Such laser quality data represents the quality of the laser beam detected by the laser distance measuring device while measuring the indicated distance. While such laser quality data does not contain sufficient information to measure the indicated distance in a sufficiently unambiguous manner, such quality data can provide additional information regarding the distance measurement process. Such additional information can then be taken into account when evaluating information regarding the cabin's current position based on the distance measured by the laser distance measuring device to increase the reliability of such measurements. Preferably, the laser quality data may be acquired using one or more data sources already accessible within the elevator system. For example, an optical sensor provided in a laser distance measuring device for detecting a reflected portion of an emitted laser beam may have as its primary purpose signals and data from which the distance to the reflecting object can be determined, and may provide as an additional source of information signals and data indicative of the laser quality of the reflected portion of the laser beam. Finally, by evaluating information about the current position of the elevator cabin based on both the distance measured by the laser distance measuring device and the acquired laser quality data, the resulting overall cabin position information may be provided with substantially greater reliability than if only the measurements of the laser distance measuring device were used without further consideration of the laser quality data.Therefore, in the techniques described herein, cabin position evaluation and determination may be performed with relatively simple and inexpensive hardware, and the reliability of the determination results may be increased, so that the provided cabin position information may be used even when safety and reliability requirements are increased. In particular, the proposed techniques generally require little or no additional hardware to increase the reliability of the measurement results of the laser distance measurement device, because hardware for providing appropriate laser quality data is generally accessible in elevator systems and / or their laser distance measurement devices.

[0017] In the following, possible embodiments of the approach proposed herein are described in more detail.

[0018] A laser distance measuring device applied to measure the distance between a cabin reference position and a shaft reference position may be a device that emits a laser beam toward an object, detects a portion of the laser beam reflected by the object, and measures the distance to the object based on analyzing the detected laser beam portion. For example, the laser distance measuring device may use time-of-flight (TOF) technology to measure the distance to the object. Here, the measured duration between emitting laser light and receiving the reflected portion of the laser light is used to calculate the distance to the reflecting object. Optionally, a phase shift in the oscillation phase between the emitted laser light and the received laser light may be used to determine the time-of-flight.

[0019] The laser distance measuring device may include a laser source for emitting a laser beam, a photodetector for detecting the reflected laser beam light, and a processing unit for analyzing the signal provided by the photodetector. The laser distance measuring device may be a conventional commercially available device with a relatively simple structure and / or high robustness. The laser source may emit any type of laser beam, such as a laser beam in the visible spectrum or an invisible laser beam, for example, in the infrared spectrum. The laser source may emit a continuous laser beam (cw laser) or a pulsed laser beam, for example, with a pulse length adapted for distance measuring purposes. The photodetector may be configured to detect a portion of the emitted laser beam when reflected by a distant object and provide a signal to the processing unit for analyzing such laser beam portion. The processing unit may then determine, for example, the time of flight to ultimately calculate the distance of the reflecting object.

[0020] The laser distance measuring device is applied to measure the distance between a first position in a displaceable elevator cabin and a second position stationary in the elevator shaft. The first position, referred to herein as a cabin reference position, may correspond to any location or installation provided at a fixed position in the elevator cabin such that the cabin reference position unambiguously correlates with the position of the cabin in the elevator shaft. The second position, referred to herein as a shaft reference position, is a stationary position fixedly provided in the elevator shaft, for example, at the top or bottom of the elevator shaft. For example, the laser distance measuring device may be installed at the shaft reference position, and a laser beam reflector may be installed at the cabin reference position, or vice versa. Thus, by measuring the distance between the laser distance measuring device and the laser beam reflector, unambiguous information about the elevator cabin in the elevator shaft may be obtained.

[0021] However, it has been found that determining the cabin position solely based on the described measurements provided by the laser distance measuring device can be subject to various influences and disturbances. For example, over time and / or due to mechanical forces acting on the components, the laser distance measuring device and / or laser beam reflector may be displaced from their original cabin and shaft reference position and / or installation orientation, resulting in a less accurate indication of the current cabin position within the elevator shaft. Furthermore, the accumulation of dirt or grime on the laser distance measuring device and / or the laser beam reflector can reduce the detectability of the laser beam. In the worst case scenario, the direct line of sight between the laser distance measuring device and the laser beam reflector may be blocked, for example, by a foreign object within the elevator shaft, resulting in an erroneous measurement of the distance to the blocking object rather than the distance to the laser beam reflector. Similarly, the position and / or installation orientation of the laser distance measuring device and / or laser beam reflector may be changed excessively so that the laser distance measuring device no longer detects the laser beam portion reflected by the laser beam reflector, but may detect laser light reflected by other objects, and therefore measure the distance to such objects instead of the distance to the laser beam reflector.

[0022] In general, conventional techniques have not been able to reliably determine whether the distance measurement results of a laser distance measuring device are reliable. In particular, as long as the laser distance measuring device provides some signals, it has not been possible to determine whether these signals are due to detection of laser beam portions reflected by both the laser distance measuring device and the laser beam reflector, whether the laser distance measuring device and the laser beam reflector are accurately positioned, or whether such signals are due to disturbed or erroneous measurements.

[0023] To overcome these drawbacks, it has been proposed to obtain additional information that can improve the reliability of distance measurement results. In particular, the validity of the measured distance provided by the laser distance measurement device may be evaluated based on additional information about laser quality. As will be explained in more detail below, various types of laser quality data may be obtained and / or such laser quality data may be used in various ways when evaluating the distance measurement results to obtain the necessary information about the current position of the cabin in the shaft.

[0024] Here, it is important that the laser quality data relates to the quality of the laser beam portion detected by the laser distance measurement device so that the distance between the cabin reference position and the shaft reference position can be measured based on the detected laser beam portion. However, the laser quality data itself generally does not provide sufficient information to determine the indicated distance based on the laser quality data alone. Instead, upon detecting the reflected laser beam portion, in addition to the laser quality data, additional physical characteristics and corresponding data may be acquired to enable accurate and sufficiently unambiguous distance measurement results. For example, the acquired laser beam portion may be analyzed for its oscillation phase and / or its time of flight with respect to the laser beam portion originally emitted by the laser source of the laser distance measurement device. While information contained in such oscillation phase and / or time of flight may be used to accurately calculate the distance to the object from which the laser beam portion is reflected, the laser quality data additionally acquired during such measurement generally may change depending on such distance to the object. However, such change typically does not uniquely depend on the distance and therefore cannot be used to calculate such distance. In other words, while distance to an object may affect the laser quality data, there may be additional influences that may affect the laser quality data in the same or similar manner, and therefore, it may not be possible to determine based on the laser quality data alone whether the distance to an object has changed or whether a change in the laser quality data is the result of other influences. However, additionally acquired laser quality data may be useful, for example, for evaluating the vibration phase and / or time-of-flight data described above, for example, by analyzing the validity.

[0025] Therefore, by taking into account not only the distance measured by the laser distance measuring device but also the laser quality data, information about the current position of the cabin can be evaluated with significantly higher reliability. This may be particularly true since disturbances or errors in the distance measurement procedure can be recognized compared to the information contained in the laser quality data.

[0026] For example, if analysis of the laser quality data indicates that the measured distance appears to be valid and therefore reliable, the information regarding the current position of the cabin can be marked as reliable. In other words, the information regarding the current position of the cabin can consist not only of actual position data indicating the position of the cabin in the elevator shaft measured by the laser distance measuring device, but also of reliability data indicating the reliability of such position data. For example, the reliability data can indicate that the distance measured by the laser distance measuring device is valid within a tight tolerance, valid within an acceptable tolerance, not valid within the acceptable tolerance but only slightly outside the tolerance range, or not valid at all. Therefore, other components of the elevator, such as, for example, an elevator controller, that subsequently use these position data in the cabin position information can determine whether these data meet reliability requirements based on the additionally provided reliability data.

[0027] According to one embodiment, the laser quality data may represent the intensity of the laser beam detected by the laser distance measurement device when measuring the distance between the cabin reference position and the shaft reference position.

[0028] In other words, the laser quality data can be correlated with physical characteristics detected using a sensor provided in the laser distance measuring device and detected simultaneously with the measurement of the indicated distance. These physical characteristics are then correlated with the intensity of the laser beam portion detected in the laser distance measuring device, based on which the indicated distance can be determined accurately and with sufficient clarity. Such intensity can be correlated, for example, with the illumination power of the laser beam portion incident on the surface of the optical sensor of the laser distance measuring device.

[0029] Generally, the intensity of the laser beam detected by the laser distance measuring device when measuring the above-mentioned distances varies substantially depending on the measured distance. In this case, the greater the distance between the cabin reference position and the shaft reference position, the smaller the intensity of the detected laser beam typically becomes. Generally, the intensity of the detected laser beam may vary linearly or nonlinearly with the indicated distance. Therefore, by taking into account the measured intensity of the laser beam detected by the laser distance measuring device, distances determined based on other physical properties of such detected laser beam, such as its oscillation phase and / or its time-of-flight data, may be checked for their validity.

[0030] For example, if the measured distance appears to be currently decreasing, i.e., the cabin appears to be approaching the shaft reference position, but the simultaneously acquired laser quality data shows that the intensity of the laser beam is simultaneously decreasing, instead of increasing as would be expected in such a situation, this can be interpreted as indicating a certain discrepancy between the actual distance measurements of the laser distance measuring device and the behavior of its laser quality data. Therefore, the reliability of the distance measurement results provided by the laser distance measuring device can be considered to be suboptimal or even unacceptably reduced.

[0031] However, in addition to the dependence on the distance between the shaft reference position and the cabin reference position mentioned above, the intensity of the laser beam detected by the laser distance measuring device may depend on further effects and influences.

[0032] For example, such intensity may be substantially affected by any misalignment between, for example, a laser source of a laser distance measuring device that emits a laser beam and a laser beam reflector that reflects a portion of this laser beam. For example, in the event of such a misalignment, the emitted laser beam may no longer be focused on the laser beam reflector, and / or the portion of the laser beam reflected by the laser beam reflector may no longer be directed toward the photodetector provided in the laser distance measuring device. Therefore, as a result of such a misalignment, the intensity of the detected laser beam may be substantially smaller than in the case of sufficient alignment. Therefore, detecting a decrease in the intensity of the laser beam may be considered as an indication of the described misalignment and, therefore, may indicate that the information about the current position of the cabin derived from the distance measurement may be less reliable.

[0033] According to one embodiment, if the laser quality data indicates that the quality of the detected laser beam is below a predetermined lower limit, the information about the current position of the cabin is considered to be insufficiently reliable.

[0034] In other words, the quality of the detected laser beam portion used by the laser distance measuring device may be continuously or repeatedly monitored, and the acquired laser quality data may be analyzed. Such analysis may check whether the monitored quality of the detected laser beam portion is below a predetermined limit. Such limit may be set before starting operation of the elevator or its laser distance measuring device. The limit may be set, for example, based on previous experiments, research, simulations, calculations, etc. In particular, the limit may be set such that any laser quality data indicating that the detected laser quality is below such limit may be interpreted as indicating some malfunction, damage, misalignment, or other defect that occurred in determining the current position of the cabin in the shaft using the laser distance measuring device.

[0035] Thus, upon acquiring laser quality data indicating that the laser quality has fallen below a predetermined lower limit, it may be assumed that the distance measurement results provided by the laser distance measuring device are currently subject to insufficient reliability. Therefore, such distance measurement results may be marked or discarded accordingly. For example, upon detecting that the acquired laser quality data indicates laser quality below a predetermined limit, the laser distance measuring device may issue data indicating information about the insufficient reliability together with the data representing the distance measurement results. Thus, for example, an elevator controller that normally uses these distance measurement results may take such information about the insufficient reliability into account.

[0036] For example, if the laser quality data represents the intensity of the laser beam detected by a laser distance measuring device, laser quality data indicating that such intensity is below a predetermined lower limit intensity may be interpreted as indicating that the reliability of distance measurement results obtained simultaneously with the laser distance measuring device is insufficient.

[0037] In such a scenario, the lower intensity limit may be set so that even when the elevator cabin is at the maximum distance from the shaft reference position, i.e., when there is a maximum distance between the laser distance measuring device and the laser beam reflector, the laser beam intensity detected by the optical sensor of the laser distance measuring device exceeds such lower intensity limit, as long as the laser distance measuring device and the laser beam reflector are accurately aligned with each other. Thus, if the laser beam intensity is detected to be below such a predetermined limit, this may indicate, for example, that there is a substantial misalignment between the laser distance measuring device and the laser beam reflector.

[0038] Alternatively, if the laser beam intensity is detected to be below a predetermined limit, this may indicate, for example, an excessive amount of dirt or dust on components provided in the laser distance measuring device and / or the laser beam reflector. The accumulation of dirt or dust can substantially reduce the intensity of the emitted laser beam and / or the intensity of the reflected portion of such laser beam. Thus, the intensity of the laser beam portion that ultimately reaches the photodetector in the laser distance measuring device may be so low that distance measurements may be unreliable.

[0039] According to one embodiment, if the laser quality data indicates that the quality of the detected laser beam suddenly drops by more than a predetermined difference limit, the information about the current position of the cabin is considered to be insufficiently reliable.

[0040] In other words, if a sudden significant degradation in the quality of the laser beam portion received by the optical sensor of the laser distance measuring device is detected, i.e., degraded beyond an acceptable amount, this may be the result of some malfunction, damage, misalignment, or other defect that occurred in determining the current position of the cabin in the shaft using the laser distance measuring device. Therefore, the laser quality data showing such a sudden degradation may be an indicator of such malfunction, damage, misalignment, etc., and the corresponding laser distance measurement provided by the laser distance measuring device may be marked or discarded accordingly.

[0041] For example, a sudden decrease in the laser beam intensity of a detected laser beam portion may be the result of a sudden misalignment between the laser beam source and the laser beam reflector in the laser distance measuring device. Such a misalignment may result in the emitted laser beam no longer being reflected by the laser beam reflector but instead being reflected by another surface in the elevator system. Alternatively, such a misalignment may result in the emitted laser beam being reflected by the laser beam reflector in another direction instead of being reflected toward the optical sensor in the laser distance measuring device. Such a sudden misalignment may occur, for example, during maintenance work, i.e., when a technician hits the laser beam reflector and unintentionally deforms and changes its orientation.

[0042] Similar to what has been described above for the previous embodiment, for example, an elevator controller that normally uses distance measurements may take into account markers that serve as information about insufficient reliability.

[0043] According to one embodiment, there are situations during elevator operation where the laser distance measurement device is temporarily shut down, and in such situations, the method described herein is performed to measure distances and obtain laser quality data after restarting the laser distance measurement device after such a prior temporary shutdown.

[0044] It has been found that it can be advantageous to actively temporarily shut down the laser distance measuring device under certain conditions. This can, for example, reduce the energy consumption caused by the laser distance measuring device. Furthermore, it has been observed that the laser distance measuring device can be subject to unintentional temporary shutdown, for example, in the event of a power supply interruption, a power outage, or similar events. As a further alternative, the entire elevator system may be temporarily stopped or shut down, for example, due to the detection of a safety-critical malfunction or to perform maintenance work. The shutdown of the laser distance measuring device may last for a few seconds (e.g., more than 10 seconds), a few minutes (e.g., more than 10 minutes), a few hours (e.g., more than 1 hour), or a few days (e.g., more than 1 day).

[0045] It has been found that, particularly during such outages, elevator systems, and in particular their laser distance measuring devices, may be susceptible to changes and modifications that may result in the determination of current cabin position information being erroneous or at least not sufficiently reliable. For example, during a temporary outage, components of the laser distance measuring device or the laser beam reflector may be slightly displaced in their position relative to the intended cabin and shaft reference positions, respectively. As another example, such components may be damaged, or the laser beam reflector may even be unintentionally destroyed, for example, during maintenance work.

[0046] While such changes and modifications in the laser distance measuring device may be detectable during normal operation of the device, for example, due to a sudden change in the signal provided by such a device, the changes and modifications may remain undetected during a temporary device shutdown. Therefore, for example, to enable evaluation or analysis of the validity of such measured distances, it is proposed to specifically measure the distance between the cabin reference position and the shaft reference position using the laser distance measuring device as soon as possible after the laser distance measuring device is restarted, and then also acquire laser quality data in a timely manner. For example, such distance measurement, laser quality data acquisition, and / or validity analysis procedures may be performed when or just before normal operation of the elevator and its laser distance measuring device is resumed. By way of example, such procedures may be performed within less than one minute, preferably less than ten seconds, after restarting the laser distance measuring device.

[0047] In a further particular embodiment, the laser distance measuring device is temporarily deactivated when the cabin comes to a stop in the shaft and is reactivated when the cabin begins to displace in the shaft.

[0048] For example, the laser distance measuring device may be deactivated while the cabin is stationary on any floor. In such a situation, the cabin generally cannot move significantly within the shaft, and therefore the current position of the cabin may be assumed to be stationary so that repeated measurements of this current position are not necessary, thereby saving associated energy consumption. When the cabin begins to move again within the shaft, the laser distance measuring device may be activated so that the current position of the traveling cabin can be measured continuously or repeatedly. Upon such activation, a distance indicative of the current cabin position is measured, evaluated using laser quality data, and, in some cases, its veracity is analyzed. This may be performed simultaneously with the start of cabin movement or, preferably, immediately before such movement begins. Under certain circumstances, such as to meet certain safety requirements, such distance measurement, evaluation, and / or veracity analysis may also be performed immediately after the start of displacement, for example, within a sufficiently short period before the cabin speed exceeds a predetermined allowable limit.

[0049] The applicant filed another patent application simultaneously with, i.e., on the same day as, the present application. The other patent application is entitled "Method and controller for determining information about a current location of a cabin in a shaft of an elevator." The determination method described in the above application includes the steps of measuring a distance between a cabin reference position of the cabin and a shaft reference position of the shaft using a laser distance measuring device, analyzing the reliability of the measured distance in consideration of reliability information that correlates with the current location of the cabin independently of the distance measurement, and finally determining information about the current location of the cabin based on the measured distance and the analyzed reliability. Embodiments and details of the determination method described in the other patent application may be applicable to or adapted to the method for evaluating information about the current cabin location described herein. Therefore, the entire contents of the other patent application are incorporated herein by reference.

[0050] In an embodiment of the elevator operation method according to the second aspect of the present invention, various functions of the elevator may be controlled based on information about the current position of the cabin in the elevator shaft, as evaluated in the method proposed herein. For example, the displacement of the elevator cabin in the elevator shaft and / or the stopping of the elevator cabin at an intended location, such as a landing, may be controlled based on information about the current cabin position. This information may then be provided to and used by an elevator controller, which, for example, controls the functions of the elevator drive engine.

[0051] An embodiment of the controller according to the third aspect of the present invention may include, for example, one or more interfaces through which the controller can receive signals or data provided by the laser distance measuring device. Furthermore, the controller may also include one or more interfaces through which the controller can receive signals or data from other devices, such as door sensors, acceleration sensors, encoder sensors, and brake sensors. Thus, signals received via such interfaces may be used to obtain laser quality data and / or other data useful for evaluating and / or determining information about the elevator cabin's current location. Furthermore, the controller may include a processing unit for processing both signals or data from the laser distance measuring device and signals or data received from other devices to derive laser quality data, for example, to analyze the authenticity of the measured distances and determine information about the cabin's current location based on the measured distances and the analyzed authenticity. Furthermore, the controller may include additional components, such as a memory, for storing distance information and / or laser quality data, as described above.

[0052] An embodiment of an elevator according to a fourth aspect of the present invention includes an elevator cabin that is displaceable throughout the elevator shaft. The elevator further includes a laser distance measuring device and a controller as described herein. The laser distance measuring device may be mounted in the elevator cabin, and the laser beam reflector may be fixedly installed in the elevator shaft, or vice versa. The controller may control one or more functions of the elevator and may communicate with other components of the elevator, such as its drive engine.

[0053] It should be noted that possible features and advantages of embodiments of the present invention are described herein in part with respect to methods for evaluating and / or determining current cabin position information, in part with respect to methods for operating an elevator using such information, in part with respect to a controller configured to implement such methods, and in part with respect to an elevator comprising such a controller. Those skilled in the art will recognize that features may be suitably transferred from one embodiment to another, and that features may be modified, adapted, combined, and / or interchanged, to arrive at further embodiments of the present invention.

[0054] Advantageous embodiments of the present invention will now be described with reference to the accompanying drawings, in which: However, neither the drawings nor the description should be construed as limiting the present invention. [Brief explanation of the drawings]

[0055] [Figure 1] 1 shows an elevator equipped with a controller for implementing a method for evaluating information relating to the current position of a cabin in a shaft according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0056] The figures are only schematic and are not to scale. Like numbers refer to like or similar features.

[0057] FIG. 1 shows an elevator 1 in which a cabin 3 can be vertically displaced along a shaft 5. The cabin 3 and a counterweight 7 are suspended by a suspension traction means 9. The suspension traction means 9 extends along the circumferential surface of a drive disk 13 of a drive engine 11. The operation of the drive engine 11 is controlled by a controller 15. For example, the controller 15 may control the drive engine 11 so that the cabin 3 can be stopped at one of a plurality of landings 17 so that a cabin door 19 provided on the cabin 3 is positioned opposite a landing door 21 provided on the landing 17.

[0058] The elevator 1 described here is provided with a laser distance measuring device 33, which is to be used in evaluating and determining information about the current position of the cabin 3 in the shaft 5.

[0059] In the illustrated example, the laser distance measuring device 33 is fixed to the side of the cabin 3 and emits a laser beam 35 downward, which is directed towards a laser beam reflector 37 installed at or near the bottom of the shaft 5.

[0060] In order to determine information about the current position of the cabin 3 in the shaft 5, the distance between a cabin reference position of the cabin 3 and a shaft reference position of the shaft 5 is measured using a laser distance measuring device 33. Furthermore, laser quality data is obtained from the laser distance measuring device 33, which laser quality data represents the quality of a portion of the laser beam 35 as it is reflected by a laser beam reflector 37 and then detected by a photodetector provided in the laser distance measuring device 33 when measuring said distance. Taking both the measured distance and the laser quality data into consideration, information about the current position of the cabin 3 in the shaft 5 may be evaluated.

[0061] In such a procedure, the laser quality data may represent the intensity of the laser beam 35 as detected by the laser distance measurement device 33. Alternatively, the laser quality data may relate to other physical properties of the laser beam 35 as reflected by an object, such as the laser beam reflector 37, and then detected by the laser distance measurement device 33. Such physical properties may relate, for example, to the laser beam width, the length of the laser beam pulse, the spectrum of the laser beam, etc. More generally, such physical properties may relate to properties of the laser beam 35 that may be affected by any malfunctions, disturbances, degradation, misalignments, and / or other defects that occur during elevator operation, which tend to result in unreliable distance measurements.

[0062] Specifically, this is laser quality data that may represent the quality of the laser beam 35 when detected by the laser distance measuring device 33 after being reflected by the laser beam reflector 37. For example, the detected light intensity may vary depending on the current position of the cabin 3 and, correspondingly, the distance the laser beam 35 must travel from the laser distance measuring device 33 to the laser beam reflector 37 and back. Furthermore, the detected laser light intensity will in most cases decrease significantly, for example, when the laser beam 35 becomes misaligned and is no longer focused on the laser beam reflector 37, or when it no longer reaches the photodetector in the laser distance measuring device 33 when reflected by the laser beam reflector 37. Therefore, such a decrease in light intensity may indicate a loss of validity or reliability of the measurements provided by the laser distance measuring device 33.

[0063] For example, information about the current position of the cabin obtained based on distance measurements provided by the laser distance measuring device 33 may be supplemented by a specific marker. Such a marker may indicate the reliability of such cabin position information. In particular, for example, if the laser quality data indicates that the quality of the detected laser beam 35 is below a predetermined lower limit and / or if the laser quality data indicates that the quality of the detected laser beam 35 suddenly drops beyond a predetermined difference limit, the cabin position information may be considered to be insufficiently reliable.

[0064] In particular, the presented procedure may be performed after the laser distance measuring device 33 has been temporarily deactivated, for example, while the cabin 3 is stopped at one of the landings 17. Thus, upon restarting the operation of the laser distance measuring device 33, the distance between the laser distance measuring device 33 and the laser beam reflector 37 may be measured, and the measurement results may be checked for their validity, for example, in order to significantly increase the reliability of the information provided thereby about the current position of the cabin 3. Such information may therefore be used for safety-critical functions, such as, for example, controlling the operation of the drive engine 11 for displacing the cabin 3 throughout the shaft 5.

[0065] In general, signals or data may be transmitted between the various sensors and information sources on one side and the controller 15 on the other side, for example using a wireless signal transmitting device 41. Alternatively, hard wiring may be established. In particular, the laser distance measuring device 33 may output various signals or data, including, for example, information regarding the oscillation phase, time of flight, and / or quality of the detected laser beam 35. These signals and data may be transmitted from the laser distance measuring device 33 to the controller 15. The signals or data may then be processed in the processing unit 43. Furthermore, the signals or data may be stored in the memory 45 before or after their processing.

[0066] Finally, it should be noted that the word "comprising" does not exclude other elements or steps, and "a" or "an" do not exclude a plurality. Also, elements described in association with different embodiments may be combined. It should also be noted that the reference signs in the claims should not be construed as limiting the scope of the claims.

Claims

1. A method for evaluating information about the current position of a cabin (3) in a shaft (5) of an elevator (1), comprising: measuring the distance between a cabin reference position in the cabin (3) and a shaft reference position in the shaft (5) using a laser distance measuring device (33); obtaining laser quality data from the laser distance measuring device (33) representative of a quality of the laser beam (35) detected by the laser distance measuring device (33) when measuring the distance; - evaluating information relating to the current position of the cabin (3) taking into account the measured distance and laser quality data; A method for providing the above.

2. The laser quality data represents the intensity of the laser beam (35) detected by the laser distance measuring device (33) when measuring the distance. The method of claim 1.

3. - if the laser quality data indicates that the quality of the detected laser beam (35) is below a predefined lower limit, the information about the current position of the cabin is considered to be insufficiently reliable; The method according to claim 1 or 2.

4. if the laser quality data indicates that the quality of the detected laser beam (35) suddenly drops by more than a predetermined difference limit, the information about the current position of the cabin is considered to be insufficiently reliable. The method according to any one of claims 1 to 3.

5. The laser distance measuring device (33) is temporarily stopped, The distance is measured and laser quality data is obtained after restarting the laser distance measuring device (33). The method according to any one of claims 1 to 4.

6. When the cabin (3) is stopped in the shaft (5), the laser distance measuring device (33) is temporarily stopped, When the cabin (3) starts to move in the shaft (5), the laser distance measuring device (33) is reactivated. The method according to claim 5.

7. A method for operating an elevator, comprising: A method, in which the functioning of an elevator (1) is controlled based on information about the current position of a cabin (3) in a shaft (5) of the elevator (5), evaluated with the method according to any one of claims 1 to 6.

8. A controller (15) for determining information about a current position of a cabin (3) in a shaft (5) of an elevator (1), the controller (15) being configured for at least one of implementing and controlling the method according to any one of claims 1 to 7.

9. An elevator (1), Cabin (3), A shaft (5); a laser distance measuring device (33) for measuring the distance between a cabin reference position of the cabin (3) and a shaft reference position of the shaft (5); A controller (15) according to claim 8; An elevator (1) comprising:

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