Method for analysis and measurement system for measuring an elevator shaft of an elevator system

Abstract

An analysis method and a measurement system for surveying an elevator shaft of an elevator system wherein the elevator shaft is surveyed by a measurement system having a camera system and an inertial measurement unit having acceleration and angular rate sensors, i.e. designed as an optically inertial measurement system. On the basis of the measured data, a digital model of the elevator shaft is created. Further information on the position of the measurement system in a main extension direction of the elevator shaft, in addition to the information from the acceleration and angular rate sensors of the inertial measurement unit, is recorded and evaluated to create the digital model. In this way, a particularly accurate digital model of the elevator shaft is created.

Claims

1. A method for analyzing an elevator shaft of an elevator system, the elevator shaft extending in a main extension direction, including surveying the elevator shaft with a measurement system having a camera system and creating a digital model of the elevator shaft on the basis of data determined during the survey, the method comprising the steps of: estimating a position of the measurement system in the elevator shaft using an inertial measurement unit of the measurement system having acceleration and angular-rate sensors; and recording and analyzing information representing the estimated position from the acceleration and angular rate sensors and further information on a position of the measurement system in the main extension direction to create the digital model of the elevator shaft.

2. The method according to claim 1 wherein the camera system of the measurement system includes at least three stereo cameras which, during the survey of the elevator shaft, are arranged transversely to the main extension direction to ensure an all-round view of the elevator shaft by the cameras.

3. The method according to claim 2 wherein the measurement system is coupled to a position determination unit that determines a position of the measurement system in the main extension direction, and providing the determined position as the further information on the position of the measurement system in the main extension direction.

4. The method according to claim 3 wherein the position determination unit determines the further information on the position of the measurement system in the main extension direction using an elongate positional information carrier oriented in the main extension direction, and the cameras and the positional information carrier are arranged relative to one another such that the positional information carrier is not recorded by any of the cameras.

5. The method according to claim 1 including arranging at least one reference element in the elevator shaft before performing the survey with the measurement system, and during the survey recording information on the at least one reference element with the measurement system as the further information on the position of the measurement system in the main extension direction.

6. The method according to claim 5 wherein the at least one reference element is arranged at a known position in the main extension direction in the elevator shaft and analyzing the known position to create the digital model of the elevator shaft.

7. The method according to claim 5 arranging another reference element in the elevator shaft at a known distance from the at least one reference element in the main extension direction and analyzing the known distance to create the digital model of the elevator shaft.

8. The method according to claim 1 including arranging an elongate orientation element extending in the main extension direction in the elevator shaft before performing the survey with the measurement system and during the survey using the elongate orientation element to verify the further information on the position of the measurement system.

9. The method according to claim 1 including after the digital model of the elevator shaft is created, comparing the digital model with a target model of the elevator shaft and generating a check of whether the elevator shaft meets specifications.

10. The method according to claim 1 including after the digital model of the elevator shaft is created, checking whether a planned design of the elevator system can be implemented in the surveyed elevator shaft.

11. The method according to claim 10 including wherein if the planned design of the elevator system cannot be implemented in the surveyed elevator shaft, making adjustments to at least one of the elevator shaft and the planned design of the elevator system.

12. A measurement system for surveying an elevator shaft of an elevator system, the elevator shaft extending in a main extension direction, including a camera system, comprising: an inertial measurement unit having acceleration and angular rate sensors for estimating a position of the measurement system in the elevator shaft; and an evaluation unit for recording and evaluating information representing the estimated position from the acceleration and angular rate sensors and further information on a position of the measurement system in the main extension direction to create a digital model of the elevator shaft.

13. The measurement system according to claim 12 including: at least three stereo cameras which, during the survey of the elevator shaft, are arranged transversely to the main extension direction to ensure an all-round view of the elevator shaft in relation to the main extension direction by the cameras; and a position determination unit having a reading unit for reading out information of a positional information carrier in the elevator shaft, the reading unit determining a position of the measurement system in the main extension direction as the further information.

14. The measurement system according to claim 13 wherein the reading unit and the cameras are arranged relative to one another such that the reading unit is not recorded by any of the cameras.

Description

DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a side view of a measurement system during the survey of an elevator shaft,

(2) FIG. 2 shows a second embodiment of a measurement system according to the invention for surveying an elevator shaft, and

(3) FIG. 3 shows a third embodiment of a measurement system according to the invention for surveying an elevator shaft.

DETAILED DESCRIPTION

(4) According to FIG. 1, an optically inertial measurement system 10 is suspended on a shaft ceiling 13 of a shaft head 14 of a mainly square elevator shaft 15 by means of a support means in the form of a rope 11 and by means of a displacement device in the form of a winch 12. The elevator shaft 15 extends in a vertically oriented main extension direction 16 and has a total of four shaft walls, although the side view in FIG. 1 only shows one rear shaft wall 17 and one front shaft wall 18. The front shaft wall 18 comprises a total of three door openings 19a, 19b, 19c, which are arranged one above the other in the main extension direction 16. At a later point in time, shaft doors allowing the elevator shaft 15 to be closed and an elevator car to be accessed will be installed in the shaft openings 19a, 19b, 19c. Opposite the shaft head 14, the elevator shaft 15 has a shaft pit 20, which is closed by a shaft floor 21.

(5) The measurement system 10 comprises a camera system in the form of a digital stereo camera 22 having a first camera 22a and a second camera 22b. The stereo camera 22 is arranged on a mainly square main body 23 of the measurement system 10 in such a way that it is oriented vertically downward toward the shaft floor 20 when in the suspended state shown. The stereo camera 22 is designed such as to be able to record portions of all four shaft walls when in the shown state. The stereo camera 22 is connected by signals to an evaluation unit 24 of the measurement system 10, which receives and evaluates the images recorded by the stereo camera 22. The evaluation unit 24 searches the images for distinctive points, for example corners or protrusions in any of the shaft walls. As soon as it has identified a distinctive point in the two images of the cameras 22a, 22b, using the known distance between the two cameras 22a, 22b and the different locations of the distinctive point in the two images, said unit can use triangulation to determine the location of the distinctive point in relation to the camera 22a, 22b and thus in relation to the measurement system 10.

(6) Between the two cameras 22a, 22b, an inertial measurement unit 25 is arranged on the main body 23 of the measurement system 10. The inertial measurement unit 25 comprises three acceleration sensors (not shown) arranged perpendicularly to one another and three angular rate sensors (not shown) arranged perpendicularly to one another, by means of which the accelerations in the x, y and z-directions and the angular accelerations about the x, y and z axes can be determined. From the measured accelerations, the inertial measurement unit 25 can estimate its position based on a starting position, and thus also that of the measurement system 10, and can transmit these to the evaluation unit 24 of the measurement system 10. It is also possible for the inertial measurement unit 25 to only transmit the measured accelerations to the evaluation unit 24 and for the evaluation unit 24 to estimate the position of the measurement system 10 therefrom.

(7) To determine the position of the measurement system 10 in the main extension direction 16 in the elevator shaft 15 more accurately, the measurement system 10 is coupled to a position determination unit 26. The position determination unit 26 has a positional information carrier, which is oriented in the main extension direction 16 and is in the form of a code strip 27 stretched between the shaft floor 21 and shaft ceiling 13. The code strip 27 comprises invisible magnetic code marks, which represent information on the position in the main extension direction 16. The position determination unit 26 further comprises a reading unit 28 that is arranged on the side of the main body 23 of the measurement system 10 and through which the code strip 27 is guided. The code strip 27 thus counteracts rotation of the measurement system 10 about an axis in the main extension direction 16 and displacement of the measurement system 10 transversely to the main extension direction 16, and thus acts as a guide for the measurement system 10. The reading unit 28 reads out information in the form of the magnetic code marks of the code strip 27 and can thus very accurately determine the position of the reading unit 28 and thus of the measurement system 10 in the main extension direction 16. The information read out from the code strip 27 can thus be considered further information on the position of the measurement system 10 in the main extension direction 16 in addition to the information from the acceleration and angular rate sensors of the inertial measurement unit 25.

(8) The position of the measurement system 10 in the main extension direction 16 determined by means of the position determination unit 26 is considered the correct position of the measurement system 10 and thus replaces the position of the measurement unit 10 in the main extension direction estimated by means of the inertial measurement unit 25. However, it is also possible for an average of the two aforementioned positions to be taken as the correct position.

(9) From the position of the measurement system 10 determined as described above, and the location of a distinctive point relative to the measurement system 10, as determined by means of triangulation, the evaluation unit 24 determines the absolute position of the distinctive point. The evaluation unit 24 thus determines the positions of a plurality of distinctive points and in this way creates a digital model of the elevator shaft 15, which model initially consists of a plurality of individual points, i.e. what is known as a point cloud. At a later point in time when the data are processed further (a process not usually carried out by the evaluation unit 24), lines and areas can be derived from the point cloud. To survey the entire elevator shaft 15, the measurement system 10 is displaced downward in the elevator shaft 15 by the winch 12.

(10) When reworking the digital model of the elevator shaft 15, said model is compared with a target model of the elevator shaft 15. It is thus checked whether the actual elevator shaft 15 meets the specifications. If there are excessively large discrepancies, reworking is required and/or the elevator shaft 15 may be denied approval. A check is also carried out as to whether a planned construction of the elevator system can be implemented in the surveyed elevator shaft 15. It is thus checked whether the individual components of the elevator system, such as the elevator car, counterbalance and guide rails, can be installed as planned. If this is not the case, adjustments are made to the elevator shaft 15 and/or to the design of the elevator system. For example, the shaft walls of the elevator shaft 15 may be altered, the size of the elevator car and/or the counterbalance adjusted, other retainers for guide rails provided, or planned positions of said retainers changed.

(11) Instead of or in addition to using the position determination unit 26, additional information and tools can be used to survey the elevator shaft 15. Tools of this kind are also shown in FIG. 1. In the region of each shaft opening 19a, 19b, 19c, one reference element in the form of a marking 29a, 29b, 29c is arranged on a shaft wall. The markings 29a, 29b, 29c are in particular designed as what are known as meter levels, which are spaced apart by one meter from the eventual floor covering. In relation to each marking 29a, 29b, 29c, the absolute height above sea level or the relative height above the shaft floor 21 is known. As a result, the positions of the markings 29a, 29b, 29c in the main extension direction 16 within the elevator shaft 15 are known. The evaluation unit 24 can determine the location of a marking 29a, 29b, 29c with respect to the measurement system 10 as described above, and can deduce the actual position of the measurement system 10 in the main extension direction 16 on the basis of the known position of the marking 29a, 29b, 29c in the main extension direction and the aforementioned location. This actual position of the measurement system 10 thus determined is then used for surveying the elevator shaft 15. The position of one of more of the markings 29a, 29b, 29c can thus be considered further information on the position of the measurement system 10 in the main extension direction 16 in addition to the information from the acceleration and angular rate sensors of the inertial measurement unit 25.

(12) Additionally or in addition to the markings 29a, 29b, 29c, an elongate orientation element in the form of a rope 30 can be stretched between the shaft floor 21 and the shaft ceiling 13. The rope 30 extends in particular in the main extension direction 16, i.e. in the vertical direction in this case. Said rope comprises reference elements in the form of distance markings 31 at a defined distance of e.g. one meter. The evaluation unit 24 can determine the positions of the distance markings 31 in the main extension direction 16 as described above, and can thus calculate the distance between each one. By comparing the calculated distances with the known actual distances, the evaluation unit 24 can verify and, where necessary, correct the used position of the measurement system 10 in the main extension direction 16. The distance between the distance markings 31 established by the evaluation unit 24 can thus be considered further information on the position of the measurement system 10 in the main extension direction 16 in addition to the information from the acceleration and angular rate sensors of the inertial measurement unit 25.

(13) The rope 30 can also be used to verify the position of the measurement system 10 transversely to the main extension direction 16. The established position of the optically inertial measurement system can be verified as mentioned above either during the survey or later when creating the digital model of the elevator shaft.

(14) FIG. 2 is a plan view (not to scale) of an alternative measurement system 110 to the measurement system 10 from FIG. 1 in an elevator shaft 15. Generally, the measurement system 110 has the same functionality as the measurement system 10 from FIG. 1, and so an elevator shaft is generally measured in the same manner. For these reasons, only the differences between the measurement systems will be discussed.

(15) The measurement system 110 has a main body 123 having a cross section in the shape of an equilateral triangle. While the elevator shaft 15 is being measured, the measurement system 110 is oriented such that said cross section is transverse to, i.e. perpendicular to the main extension direction of the elevator shaft 15. In FIG. 2, the main extension direction of the elevator shaft 15 is oriented perpendicularly to the plane of the drawing.

(16) On each side of the aforementioned equilateral triangle, a stereo camera 122a, 122b, 122c is arranged such as to face transversely to the main extension direction. The stereo cameras 122a, 122b, 122c are thus facing shaft walls 17, 18, 32, 33 of the elevator shaft 15. It is also possible for the stereo cameras to be arranged in a slightly tilted manner relative to the main extension direction, in particular toward the shaft pit.

(17) Recording ranges of the stereo cameras 122a, 122b, 122c are designed such that each point of the elevator shaft 15, which is in more or less the same position in the main extension direction as the measurement system 110, can be recorded by a stereo camera 122a, 122b, 122c. An all-round view in relation to the main extension direction is thus ensured by the three stereo cameras 122a, 122b, 122c. The recording ranges of the three stereo cameras 122a, 122b, 122c overlap, although this is not strictly necessary. To illustrate this, FIG. 2 shows a boundary 134b of the recording range of the stereo camera 122b in the direction of stereo camera 122c, and a boundary 134c of the recording range of the stereo camera 122c in the direction of stereo camera 122b. As can be seen in FIG. 2, the boundaries 134b and 134c intersect while still within the elevator shaft 15, thus producing an overlap region between the recording ranges of the two stereo cameras 122b, 122c. Accordingly, overlap regions are produced between all the stereo cameras 122a, 122b, 122c.

(18) The measurement system 110 additionally comprises a reading unit 128 for a code strip 27 of a position determination unit. In this case, the code strip 27 is guided through the reading unit 128, which is arranged behind the three stereo cameras 122a, 122b, 122c such that the reading unit 128 and the code strip 27 cannot be recorded by any of the three stereo cameras 122a, 122b, 122c. The reading unit 128 and the code strip 27 are thus not positioned within any of the recording ranges of the three stereo cameras 122a, 122b, 122c.

(19) The measurement system 110 further comprises an evaluation unit 124 and an inertial measurement unit 125, which are also arranged such that they cannot be recorded by any of the three stereo cameras 122a, 122b, 122c.

(20) FIG. 3 is a plan view (not to scale) of an alternative measurement system 210 to both the measurement system 10 from FIG. 1 and the measurement system 110 from FIG. 2 in an elevator shaft 15. The measurement system 210 has predominantly the same design as the measurement system 110 from FIG. 2, and so only the differences between the measurement systems will be discussed.

(21) The measurement system 210 has a main body 223 having a cross section in the shape of a square. While the elevator shaft 15 is being surveyed, the measurement system 210 is oriented such that said cross section is transverse to, i.e. perpendicular to the main extension direction of the elevator shaft 15.

(22) On each side of the aforementioned square, a stereo camera 222a, 222b, 222c, 222d is arranged such as to face transversely to the main extension direction. The stereo cameras 222a, 222b, 222c, 222d are thus directly facing shaft walls 17, 18, 32, 33 of the elevator shaft 15. It is also possible for the stereo cameras to be arranged in a slightly tilted manner relative to the main extension direction, in particular toward the shaft pit.

(23) Recording ranges of the stereo cameras 222a, 222b, 222c, 222d are designed such that each point of the elevator shaft 15, which is in more or less the same position in the main extension direction as the measurement system 210, can be recorded by a stereo camera 222a, 222b, 222c, 222d. An all-round view in relation to the main extension direction is thus ensured by the four stereo cameras 222a, 222b, 222c, 222d. The recording ranges of the four stereo cameras 222a, 222b, 222c, 222d overlap, although this is not strictly necessary. To illustrate this, FIG. 3 shows a boundary 234c of the recording range of the stereo camera 222c in the direction of stereo camera 222d, and a boundary 234d of the recording range of the stereo camera 222d in the direction of stereo camera 222c. As can be seen in FIG. 3, the boundaries 234c and 234d intersect while still within the elevator shaft 15, thus producing an overlap region between the recording ranges of the two stereo cameras 222c, 222d. Accordingly, overlap regions are produced between all the stereo cameras 222a, 222b, 222c, 222d.

(24) The measurement system 210 additionally comprises a reading unit 228 for a code strip 27, an evaluation unit 224, and an inertial measurement unit 225. The reading unit 228, the code strip 27, the evaluation unit 224, and the inertial measurement unit 225 are arranged such that they cannot be recorded by any of the four stereo cameras 222a, 222b, 222c, 222d.

(25) Lastly, it should be noted that terms such as having, comprising and the like do not preclude other elements or steps, and terms such as a or one do not preclude a plurality. Furthermore, it should be noted that features or steps that have been described with reference to one of the above embodiments may also be used in combination with other features or steps of other embodiments described above.

(26) In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiment. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.