EP1637493B1 - Elevator system with a device for determining the position of an elevator cabin and method to operate the elevator system - Google Patents

Description

The invention relates to an elevator installation with a cabin and a device for determining a cabin position, and to a method for operating such an elevator installation as defined in the patent claims.

It is known to determine the car position of an elevator installation in order to derive from this information control signals which are further used by the elevator control. This is how the German utility model teaches DE9210996U1 a device for determining the car position with magnetic tape and magnetic head for reading the magnetic tape. The magnetic tape has a magnetic coding and extends along the entire travel distance of the cabin. The magnetic head attached to the cab reads the coding without contact. From the read codes, a car position is determined.

A further development of this device is in the patent W003011733A1 which also forms the closest prior art for the present invention. According to the teaching of this patent specification, the coding of the magnetic tape consists of a multiplicity of code marks arranged in a row. The code marks are magnetized as either South Pole or North Pole. Several consecutive code marks form a codeword. The code words in turn are in a row as a code mark pattern with arranged binary pseudo-random coding. Each codeword thus represents an absolute cabin position.

For scanning the magnetic fields of the code marks, the device of the patent specification WO03011733A1 a sensor device with multiple sensors, which allows simultaneous scanning of multiple code marks. The sensors convert the different polarity of the magnetic fields into a corresponding binary information. For south poles, they output a bit value "0" and for north poles a bit value "1". This binary information is evaluated by an evaluation unit of the device and processed in an understandable for the elevator control absolute position information and used by the elevator control as control signals. Upon detecting the magnetic field of the code marks, the resolution of the absolute cabin position is equal to the length of a code mark, ie 4 mm.

The patent WO03011733A1 further teaches the use of small, 3 mm long sensors, which are arranged in two rows on adjacent tracks, so come to lie on the length of a code mark two mutually offset in the travel direction by half a pole pitch (λ / 2) sensors. With this arrangement of the sensors it is achieved that when the sensors of one row detect a position in the region between two code marks (poles), the sensors of the other row are in the optimum reading range over a respective code mark. At each read-out clock, it is ensured that the number of position-detection sensors whose sensors are positioned above the code marks in the mentioned optimum reading range at the time of the read-out clock is always evaluated.

A disadvantage of the device of the patent WO03011733A1 Firstly, the sensors must be guided with great accuracy of +/- 1 mm transversely to the direction of travel centered above the code marks, so that the sensors always move within the allowable lateral deviation from the track of the code marks, by the lateral limits of readability the magnetic fields of the code marks is given. It should be noted that the strength of the magnetic fields - also referred to below as signal strength - decreases in the direction of the lateral edges of the code marks.

Another disadvantage of this device is that the strength of the magnetic field in the normal direction above the code marks decreases rapidly and the sensors must therefore be positioned at a small distance of 3 mm above the code marks. For sufficiently high security and sufficient reliability of the elevator installation, the sensor device above the code mark pattern must be carried out consuming. This is expensive. Especially at high cabin speeds of 10m / sec, the associated expense is very large.

The present invention has for its object to provide an elevator system with a car and a device for determining the car position and a method for operating such an elevator system, which accurately scanning a code mark pattern by a sensor device with little effort - especially with little effort for the leadership the sensor device against the code marks - allows without affecting the safety and reliability of the position detection.

This object is achieved by the invention according to the definition of the claims. The elevator system has at least one car and at least one device for determining a car position. The device has a code mark pattern and a sensor device. The code mark pattern is mounted along the travel distance of the car and consists of a plurality of code marks arranged in a single track. The sensor device is mounted on the cabin and scans the code marks with sensors without contact. The sensor device contains at least two sensor groups each having a number of sensors, wherein the sensor groups scan the code marks independently of each other redundantly. By "redundantly scanning" is meant that in the normal operating state and in any permissible position of the car, at least the sensors of one of the sensor groups provide the complete information corresponding to the current position of the car to the evaluation unit.

The advantage of the invention is the significantly increased safety and reliability that the sensor device supplies the correct information about the current position of the car to the evaluation unit and thus to the elevator control in the normal operating state and in every permissible position of the car.

According to a particularly preferred embodiment of the invention, the sensor groups have a suitable distance U to each other transversely to the track direction. This ensures that, given the signal strength of the code marks, the greatest possible lateral displacements between the sensor device and the track of the code marks as well as the greatest possible distances between the code marks and the Sensors are allowed, since the sensor groups independently detect the magnetic fields of the code marks, always at least one of the two sensor groups is in a favorable range of Kodemarken signal strength, even if the sensor device is relatively offset transversely to the direction of travel relative to the track of the code marks. In addition, the width of the code marks measured transversely to the direction of travel can thereby be kept relatively low, which brings considerable advantages in terms of the limited installation space of the code mark pattern as well as its production method and production costs.

Advantageously, the distance between the two sensor groups is selected such that at least the sensors of one of the two sensor groups provide the complete information about the current position of the car, provided that measured transversely to the track of the code marks deviation of the current position of the sensor device from its relative to the track of Code mark centered position does not exceed a value of 25%, preferably 30% of the width of the code marks.

Advantageously, the distance between the two sensor groups is selected such that each of the two sensor groups can scan the complete codeword corresponding to the current position of the car, ie can provide complete information about the current car position, provided the deviation measured transversely to the track of the code marks the position of the sensor device from its optimum position relative to the track of the code marks a value of, for example, 10%, preferably 15%, does not exceed the width of the code marks.

According to an expedient embodiment of the invention, the sensors (85, 85 ') associated with each sensor group (87, 88) are arranged in two sensor tracks (87.1, 87.1', 88.1, 88.1 ') running parallel to the track of the code marks (83). This embodiment has the advantage that even sensors can be used whose housing dimensions do not allow an arrangement on a single track.

According to a particularly preferred embodiment of the invention, the respective sensor group associated sensors are each arranged in a single, parallel to the track of the code marks sensor track. Using a single track for the code marks and a single track for the sensors of each sensor group, efficient and lossless scanning of the code marks occurs in a region where they have high signal strength. Here, it is considered that a given signal strength of the code marks on the one hand decreases towards the edges of the code marks, and on the other hand decreases with increasing distance from the surface of the code marks. The high signal strengths of the code marks scanned in this way efficiently and without losses, in combination with the use of two complete sensor groups spaced apart from one another perpendicular to the track direction, lead to the greatest possible confidence interval, ie to a large range of the possible position of the sensors with respect to the code marks the sensors can safely and reliably scan the code marks with sufficiently strong sensor signals. Thus, it is possible to design the confidence range specifically, ie to optimize the interdependent permissible ranges of the distance between the code marks and the sensors, as well as the lateral displacement of the sensor device relative to the track of the code marks. With the proposed Measures the cost of the management of the sensor device compared to the Kodemarkenmuster is reduced, without affecting the safety and reliability of the position detection of the cabin and thus the elevator system.

Expediently, the evaluation unit processing the signals of the sensors is designed such that when the two sensor groups provide different information due to a deviation of the position of the sensor device from its optimum position with respect to the track of the code marks, the different information is combined to one information representing the effective one current position of the car (1) represents.

Advantageously, the evaluation unit is designed such that it compares the signals received from the two sensor groups and stores or displays information if the received signals deviate from each other over a defined period of time or during a defined number of trips of the car.

Favorable maximum permissible distances between the code marks and the sensors of the sensor device are achieved in that the code marks have a brand length λ> 5 mm.

Advantageously, the sensors are guided above the code marks so that a maximum distance between the sensors and the code marks of 100% of the width of the code marks is not exceeded.

Fig. 1

schematisch eine Aufzuganlage mit einer Kabine und einer Einrichtung zur Ermittlung der Kabinenposition,

Fig. 2

schematisch den Aufbau eines Teils einer Einrichtung zur Ermittlung der Kabinenposition mit Sensorvorrichtung und Kodemarkenmuster aus dem Stand der Technik der Patentschrift WO03011733A1 ,

Fig. 3

schematisch einen Querschnitt durch die Einrichtung zur Ermittlung der Kabinenposition mit Sensorvorrichtung und Kodemarkenmuster gemäss WO03011733A1 ,

Fig. 4

schematisch eine Seitenansicht der Einrichtung zur Ermittlung der Kabinenposition mit Sensorvorrichtung und Kodemarkenmuster gemäss WO03011733A1 ,

Fig. 5

schematisch den Aufbau eines Teils einer Einrichtung zur Ermittlung der Kabinenposition mit Sensorvorrichtung und Kodemarkenmuster gemäss einer ersten Ausführungsform der Erfindung,

Fig. 6

schematisch eine Seitenansicht der Einrichtung zur Ermittlung der Kabinenposition mit Sensorvorrichtung und Kodemarkenmuster gemäss der in Fig. 5 dargestellten ersten Ausführungsform der Erfindung,

Fig. 7A

schematisch einen Querschnitt durch die Einrichtung zur Ermittlung der Kabinenposition mit Sensorvor- richtung und Kodemarkenmuster gemäss der in Fig. 5 dargestellten ersten Ausführungsform der Erfindung, mit zwei doppelspurig ausgeführten, zentrisch über der Spur der Kodemarken angeordneten Sensorgruppen,

Fig. 7B

schematisch einen Querschnitt durch die Einrichtung zur Ermittlung der Kabinenposition mit Sensorvorrichtung und Kodemarkenmuster gemäss der in Fig. 5 dargestellten ersten Ausführungsform der Erfindung, mit zwei versetzt über der Spur der Kodemarken angeordneten Sensorgruppen,

Fig. 8

schematisch den Aufbau eines Teils einer Einrichtung zur Ermittlung der Kabinenposition mit Sensorvorrichtung und Kodemarkenmuster gemäss einer zweiten Ausführungsform der Erfindung,

Fig. 9

schematisch eine Seitenansicht der Einrichtung zur Ermittlung der Kabinenposition mit Sensorvorrichtung und Kodemarkenmuster gemäss der in Fig. 8 dargestellten zweiten Ausführungsform der Erfindung, und

Fig. 10A

schematisch einen Querschnitt durch die Einrichtung zur Ermittlung der Kabinenposition mit Sensorvorrichtung und Kodemarkenmuster gemäss der in Fig. 8 dargestellten zweiten Ausführungsform der Erfindung, mit zwei einspurig ausgeführten, zentrisch über der Spur der Kodemarken angeordneten Sensorgruppen,

Fig. 10B

schematisch einen Querschnitt durch die Einrichtung zur Ermittlung der Kabinenposition mit Sensorvorrichtung und Kodemarkenmuster gemäss der in Fig. 8 dargestellten zweiten Ausführungsform der Erfindung, mit zwei einspurig ausgeführten, versetzt über der Spur der Kodemarken angeordneten Sensorgruppen,

Hereinafter, the invention with reference to embodiments according to the Fig. 1 to 10B explained in detail. It shows:

Fig. 1

schematically an elevator installation with a cabin and a device for determining the cabin position,

Fig. 2

schematically the construction of a part of a device for determining the car position with sensor device and Kodemarkenmuster from the prior art of the patent specification WO03011733A1 .

Fig. 3

schematically a cross section through the device for determining the car position with sensor device and code mark pattern according to WO03011733A1 .

Fig. 4

schematically a side view of the device for determining the car position with sensor device and code mark pattern according to WO03011733A1 .

Fig. 5

1 shows schematically the construction of a part of a device for determining the car position with sensor device and code mark pattern according to a first embodiment of the invention,

Fig. 6

schematically a side view of the device for determining the car position with sensor device and code mark pattern according to the in Fig. 5 illustrated first embodiment of the invention,

Fig. 7A

1 schematically shows a cross section through the device for determining the car position with sensor direction and code mark patterns in accordance with Fig. 5 illustrated first embodiment of the invention, with two double-track running, arranged centrally above the track of the code marks sensor groups,

Fig. 7B

schematically a cross section through the device for determining the car position with sensor device and code mark pattern according to the in Fig. 5 illustrated first embodiment of the invention, with two offset over the track of the code marks arranged sensor groups,

Fig. 8

1 shows schematically the construction of a part of a device for determining the car position with sensor device and code mark pattern according to a second embodiment of the invention,

Fig. 9

schematically a side view of the device for determining the car position with sensor device and code mark pattern according to the in Fig. 8 illustrated second embodiment of the invention, and

Fig. 10A

schematically a cross section through the device for determining the car position with sensor device and code mark pattern according to the in Fig. 8 illustrated second embodiment of the invention, with two single-track running, arranged centrally above the track of the code marks sensor groups,

Fig. 10B

schematically a cross section through the device for determining the car position with sensor device and code mark pattern according to the in FIG. 8th illustrated second embodiment of the invention, with two single-lane, offset over the track of the code marks arranged sensor groups,

Fig. 1 schematically shows an inventive elevator system 10. A car 1 and a counterweight 2 are suspended on at least one support cable 3 in a shaft 4 in a building 40. The support cable 4 passes over a guide roller 5 and is driven by a drive 6.2 via a drive pulley 6.1. Deflection pulley 5, traction sheave 6.1 and drive 6.2 can be arranged in a separate machine room 4 ', but they can also be located directly in the shaft 4. By turning left or right of the traction sheave 6, the cabin 1 is moved along a trajectory in or against a travel direction y and serves floors 40.1 to 40.7 of the building 40th

A device 8 for determining the car position has a code mark pattern 80 with code marks, a sensor device 81 and an evaluation unit 82. The code mark pattern 80 has a numerical coding of absolute positions of the car 1 in the pit 4 with respect to a reference point. The code mark pattern 80 is fixedly mounted in the shaft 4 along the entire travel distance of the car 1. The code mark pattern 80 may be mounted freely stretched in the shaft 4, but it may also be attached to shaft walls or guide rails of the elevator installation 10. The sensor device 81 and the evaluation unit 82 are mounted on the car 1. The sensor device 81 is thus moved together with the car 1 and thereby scans the code marks of the code mark pattern without contact. For this purpose, the sensor device 81 in the small Distance led to the code mark pattern 80. For this purpose, the sensor device 81 is attached to the car 1 via a holder perpendicular to the travel path. According to Fig. 1 If the sensor device 81 is fastened to the car roof, it is, of course, entirely possible to fasten the sensor device 81 laterally or at the bottom to the car 1. The sensor device 81 forwards the sampled information to the evaluation unit 82. The evaluation unit 82 translates the sampled information into an absolute position indication which is understandable for an elevator control 11. About a suspension cable 9 this absolute position information is forwarded to the elevator control 11. The elevator controller 11 uses this absolute position indication for a variety of purposes. For example. It is used to control the travel curve of the car 1, such as the use of deceleration and acceleration measures. It also serves to control the shaft end delay, to monitor the shaft end limitation, to the floor detection, to accurately position the car 1 in floors 40.1 to 40.7, and of course to measure the speed of the car first

With knowledge of the present invention, the expert can of course implement other elevator systems with other types of drive such as hydraulic drive, etc. or elevators without counterweight, as well as a wireless transmission of position information to an elevator control.

The Fig. 2 to 10B show the construction of parts of devices 8 for determining the car position with a code mark pattern 80 and a sensor device 81, which comprises a number of sensors 85, 85 ', which are integrated in a - dash-dotted line - sensor housing 81.1.

Fig. 2 shows an embodiment of a device 8 for determining the car position from the prior art of the patent specification WO03011733A1 , Schematically illustrated are a stationary mounted in the shaft, oriented in the direction of travel of the car 1 Kodemarkenmuster 80 with Kodemarken 83, a sensor device 81 with the sensor housing 81.1 integrated, the Kodemarkenmuster 80 scanning sensors 85, 85 ', and an evaluation unit 82nd The sensor device 81 includes a single sensor array arranged in two sensor rows 86 and 86 ', wherein each of the sensor rows 86, 86' has a number n of sensors 85 and 85 'with a sensor length LS1. In the present example, 13 sensors each are shown. However, the number n of sensors is freely selectable depending on the travel length, the desired path resolution and possibly other conditions. The distances between the sensors correspond to the length λ 1, or half the length λ 1/2 of the code marks 83. The code marks 83 consist of sections of a magnetizable band, wherein the sections towards the sensors form south magnetic poles or north poles, the be detected by the sensors as a bit value "0" or as a bit value "1". The order of the south and north poles corresponds to the bit sequence of a pseudorandom coding, which ensures that after each shift of the sensor device by the length of a code mark a new and over the entire length of travel only once occurring n-digit (here 13- digit), which is detected by the n consecutive sensors of the sensor device and is assigned by an evaluation unit 82 a unique position of the car 1.

The two sensor rows 86 and 86 'of the sensor device 81 with the respective associated sensors 85 and 85' are mutually offset in the travel direction (y direction) by half a pole pitch, ie by half the length λ1 of a code mark 83. It is thereby achieved that in each possible cabin position, the sensors of one of the rows of sensors lie in the region above the middle of the code marks and in each case detect clear south and north poles. Before each position reading clock, the evaluation unit 82 determines that of the two rows of sensors which has sensors in the vicinity of a zero crossing between alternating magnetic poles of the code marks 83 and then reads in the values of the sensors of the other sensor row.
The sensors 85 and 85 'are arranged in two parallel rows of sensors 86 and 86', because two sensors each with a given length LS1 can not fit within the relatively short length λ1 of the code marks 82.

Fig. 3 shows an enlarged side view A2 of in Fig. 2 illustrated code mark pattern 80 and positioned above the code mark pattern 80 sensor device 81 of the device 8 according to the cited prior art. Visible are the applied on a support 84 magnetized code marks 83, which according to WO03011733A1 have a relatively small length λ1 of 4 mm. As a result of the relatively small distances between adjacent north and south poles, the magnetic fields influence each other such that the detectable from the sensors as a unique signal magnetic field strengths reach only relatively low heights above the code marks. The limits of detectable magnetic field strengths in the direction of the track of the code marks are indicated as parabolic curves Λ1 and are also referred to as boundaries of a confidence interval, all possible position of the sensors in relation to the code marks, in which the sensors can safely and reliably scan the code marks with sufficiently strong sensor signals. In the cited prior art, therefore, the sensors 85, 85 'integrated in the sensor housing 81.1 must be guided such that their distance β1max to the code marks 83 does not exceed 3 mm during travel of the cabin, with the result that the sensors Guide between the sensor device and the code mark pattern 80 requires considerable effort.

Fig. 4 shows a cross-section viewed in the longitudinal direction (y-direction) of the code mark pattern 80 by a code mark 83 and the above arranged sensor device 81 according to the cited prior art. Two sensors 85 and 85 'integrated in the sensor housing 81.1 with their active sensor surfaces 850 and 850' can also be seen. The illustrated curve Δ1 of the limits of the magnetic field strengths which can be clearly recognized by the sensors transversely to the track of the code marks (confidence region in the transverse direction) indicates that the magnetic field strength of the code marks also decreases considerably in the region of the side edges of the code marks. Out Fig. 4 It can easily be seen that even with a relatively small lateral offset Δx (approximately 1 mm in the x-direction) between the sensor device 81 and the approximately 10 mm wide code mark pattern 80, one of the active sensor surfaces 850, 850 'leaves the region of detectable magnetic field strength, as a result a correct reading of the position of the car 1 is made impossible. This is likewise to be prevented only by a high-quality guidance of the sensor device 81 with respect to the code mark pattern 80.

Fig. 5 shows a first inventive embodiment of a device 8 for determining the cabin position. Again shown a stationary mounted in the elevator shaft single-track code mark pattern 80 with code marks 83 of length λ 2, a sensor device 81 with a number in a sensor housing 81.1 of integrated, the code mark pattern 80 are scanningly sensors 85, 85 ', and an evaluation unit 82. According to the invention includes the sensor device 81 two complete sensor groups 87 and 88, each having two sensor rows 87.1, 87.1 'and 88.1, 88.1', each of which comprises a number of sensors 85 and 85 '. The sensors 85 'are arranged offset in the direction of travel relative to the sensors 85 by half the length λ2 / 2 of the code marks 83. Each of the two complete sensor groups 87, 88 has substantially the same functions as the sensor group according to the prior art described above. Both sensor groups 87, 88 scan the code marks 83 redundantly, ie, each of them is independent of the other able to capture the complete information about the current position of the car 1 and to deliver to the evaluation unit, if the active sensor surfaces 850th '850' of their sensors 85, 85 'are located within the limits of detectable magnetic field strength above the code marks.
Furthermore, at the in Fig. 5 illustrated embodiment, the length λ2 of the code marks 83 - in comparison with those of the cited prior art - has been extended from about 4 mm to 5 to 10 mm.

Fig. 6 shows an enlarged side view A5 of in Fig. 5 The illustrated code mark pattern 80 and the sensor device 81 positioned above the code mark pattern 80 of the first embodiment of the device 8 according to the invention.

Evident are the extended in comparison with the prior art code marks 83, which now have a length λ2 of at least 5 mm, preferably 6 to 10 mm. Despite the mutual influences of adjacent south and north poles, the larger lengths of the code marks allow magnetic fields to develop in the region of their centers whose detectable limits reach much greater heights above the code marks, typically heights of 10 mm and more. This makes it possible to vary the distances between the active sensor surfaces 850, 850 'and the code marks 83 from about 1 mm to a maximum distance β2max of more than 5 mm during elevator operation. It makes sense that the sensor device (81) is guided above the code marks (83) so that a maximum distance between the sensors (85, 85 ') and the code marks (83) of 75% of the width δ of the code marks (83) can not be exceeded.

Fig. 7A FIG. 15 shows a cross-section, viewed in the longitudinal direction (y direction) of the code mark pattern 80, through a code mark 83 of a code mark pattern 80 and the sensor device 81 arranged above it in accordance with FIG Fig. 5 illustrated first embodiment of the invention. In this cross section, four sensors 85, 85 'integrated in the sensor housing 81.1 with their active sensor surfaces 850, 850' can be seen. The distance between the sensor surfaces and the code marks is compared to the device according to the prior art by about 50%, ie from about 4 mm to about 6 mm, increased. The two sensors 85, 85 'shown to the left of the center belong to the sensor group 87 and the two sensors 85, 85' shown to the right of the middle belong to the sensor group 88, the two sensor groups being transversely to the track of the code marks by a distance U (in the x direction ) spaced apart from each other. In the in Fig. 7A shown position of the sensor housing 81.1 are all active sensor surfaces 850, 850 'of the sensors within the symbolized by the curve .DELTA.B2 limit of the sensors clearly detectable magnetic field strength (confidence in the transverse direction). Each of the two sensor groups 87 and 88 can detect the complete coded information about the current position of the car 1 in this centered position of the sensor housing 81.1 relative to the track of the code marks 83 and forward it to the evaluation unit. As related to Fig. 2 The sensors 85 and 85 'belonging to one of the two sensor groups 87 and 88 are offset relative to one another in the travel direction y by half the length λ 2/2 of the code marks and, in the embodiment described here, in two sensor rows 87.1, 87.1', respectively 88.1, 88.1 'are arranged per sensor group 87, 88. This arrangement was chosen because the ratio between the length λ2 of the code marks 83 and the length LS2 of the sensors' does not allow a series arrangement of the sensors 85 and 85 in this embodiment.

Fig. 7B shows shows the cross section according to Fig. 7A , wherein the sensor device 81 is positioned offset by Δx transversely to the direction of travel with respect to the track of the code mark pattern 80. In the case of the offset shown by more than 30% of the width δ of the code marks, the sensor surfaces of the sensors 85, 85 'of the sensor group 88 are outside the limit of the magnetic field strengths detectable for the sensors by the curve .DELTA.2 and are therefore no longer effective. However, the sensor surfaces of the sensors 85, 85 'of the sensor group 87 are still within the aforementioned limit and give the sensor device and thus the entire The device according to the invention still has full functionality even with the extreme displacement shown.
The evaluation unit 82 combines the different information that the two sensor groups deliver in the situation shown to information that represents the effective current position of the car (1).
It can easily be seen that with the sensor arrangement shown, the requirements for the guidance system which guides the sensor unit 81 with respect to the code mark pattern 80 can be greatly reduced.

Figure 8 shows a second inventive embodiment of a device 8 for determining the cabin position. Shown in turn are a stationary mounted in the elevator shaft single-track code mark pattern 80 with code marks of length λ3, a sensor device 81 with a number in a sensor housing 81.1 integrated, the Kodemarkenmuster 80 scanning sensors 85, 85 ', and an evaluation unit 82. According to the invention also contains this sensor device 81st two complete sensor groups 87, 88. Each of the two sensor groups comprises sensors 85 and sensors 85 'offset relative to them in the travel direction y by half the length ( λ3 / 2) of a code mark, with each one of the sensor groups 87, 88 in the present embodiment variant associated sensors 85 and 85 'are arranged on a single sensor track 87.1, 88.1. The latter is possible in this case, because the ratio between the length λ3 of the code marks 83 and the length LS3 of the sensors permits a series arrangement of the sensors 85 and 85 '.
Each of the two complete sensor groups 87, 88 has substantially the same functions as the sensor group according to the prior art described above and is able to provide the complete information about the to detect current position of the car 1, provided that the active sensor surfaces 850, 850 'of their sensors 85, 85' are within the limits of detectable magnetic field strength on the code marks. In the embodiment of the invention described here, the length λ3 of the code marks 83 has been extended from approximately 4 mm to 6 to 10 mm in comparison with those of the cited prior art.

Fig. 9 shows an enlarged side view A8 of in Fig. 8 The code mark pattern 80 and the sensor device 81 of the second embodiment of the device 8 are shown above the code mark pattern 80. The code marks 83, which are lengthened compared to the prior art, now have a length λ3 of at least 6 mm, preferably 7 to 10 mm exhibit. Despite the mutual influence of adjacent south and north poles, the larger lengths of the code marks allow magnetic fields to form near their centers whose detectable limits (curves Λ3) reach much greater heights above the code marks, typically at heights of more than 10 mm , This makes it possible to vary the distances between the active sensor surfaces 850, 850 'and the code marks 83 from about 1 mm to a maximum distance β3max of more than 6 mm during elevator operation. Effectively, the maximum distance β3max can reach up to 100% of the width δ of the code marks.

Out Fig. 9 It can also be seen that, in the present relationship between the length λ3 of the code marks 83 and the length LS3 of the sensors 85, 85 ', the sensors 85 and 85' associated with a sensor group 87, 88 are all in one Sensor row and can be integrated with sufficient distance in the sensor housing 81.1.

Fig. 10A FIG. 12 shows a cross-section, viewed in the longitudinal direction (y-direction) of the code mark pattern 80, through a code mark 83 of a code mark pattern 80 and the sensor device 81 arranged above it, corresponding to FIG Fig. 8 illustrated second embodiment of the invention. In this cross section, two sensors 85, 85 'integrated in the sensor housing 81.1 with their active sensor surfaces 850, 850' can be seen. The left of the center shown sensor 85, 85 'belongs to the sensor group 87 and the right center shown sensors 85, 85' belongs to the sensor group 88, wherein the two sensor groups by a distance U across the track of the code marks (in the x direction) from each other are spaced. In the in Fig. 10A are shown, all active sensor surfaces 850, 850 'of the sensors 85, 85' within the symbolized by the curve .DELTA.3 limit of the sensors clearly recognizable by the sensors magnetic field strength across the track of the code marks (cross-sectional confidence) ,
In the embodiment described here, the respective sensors 85 and 85 'belonging to one of the two sensor groups 87 and 88 are offset relative to one another in the travel direction y by half the length λ3 / 2 of the code marks (as in connection with FIG Fig. 2 justified) and arranged in each case in a single sensor row 87.1, or 88.1 per sensor group 87, 88. This arrangement can be realized in the present embodiment, because the ratio between the length λ3 of the code marks 83 and the length LS3 of the sensors permits a series arrangement of the sensors 85 and 85 'of each sensor group 87, 88. With this arrangement of Sensors in this embodiment, the measured transversely to the travel distance between the active sensor surfaces 850, 850 'of the outer sensors much lower than in the device according to the Fig. 5 to 7B , This makes it possible to realize even greater distances between the active sensor surfaces 850, 850 'and the code marks 83.
Each of the two sensor groups 87 and 88 can detect the complete coded information about the current position of the car 1 in this centered position of the sensor housing 81.1 relative to the track of the code marks 83 and forward it to the evaluation unit.

Fig. 10B shows shows the cross section according to Fig. 10A , wherein the sensor device 81 is positioned offset by Δx transversely to the direction of travel with respect to the track of the code marks 83. In the case of the extreme offset shown by more than 30% of the width δ of the code marks, the sensor surfaces 850, 850 'of the sensors 85, 85' of the sensor group 88 are outside the limit of the magnetic field strengths detectable by the sensors .DELTA.33 and are therefore no longer effective. However, the sensor surfaces of the sensors 85, 85 'of the sensor group 87 are still within the stated limit and still give the sensor device and thus the entire device according to the invention full functionality even with the extreme displacement shown.
The evaluation unit 82 combines the different information that the two sensor groups deliver in the situation shown to information that represents the effective current position of the car (1).
It can easily be seen that with the sensor arrangement shown, an optimum ratio between the maximum permissible Distance of the sensor surfaces to the code marks and the allowable displacement of the sensor device relative to the track of the code marks can be adjusted, and thereby the requirements for the accuracy of the guide system, which leads the sensor unit 81 against the code mark pattern 80 can be greatly reduced.

To the code mark pattern:

The code mark pattern 80 consists of a plurality of code marks 83 applied to a carrier 84. Advantageously, the code marks have high coercivities. The carrier 84 is, for example, a steel strip of 1 mm carrier thickness and 10 mm carrier width. The code marks 83 may, for example, be sections of a plastic strip containing magnetizable particles. The brand thickness can be, for example, 1 mm and the brand width δ = 10 mm. The code marks 83 are arranged on the carrier 84 in the longitudinal direction y in succession at equal intervals and form the same length rectangular sections. The longitudinal direction y corresponds to the travel direction y according to Fig. 1 , The code marks 83 are magnetized as either South Pole or North Pole. Advantageously, they are magnetized to saturation. For iron as the magnetic material of the code marks, the saturation magnetization is 2.4T. The code marks have a given signal strength, for example, they are manufactured with a certain magnetization of +/- 10mT. A south pole forms a negative magnetic field and a north pole a positively oriented magnetic field. Of course, with knowledge of the present invention, differently dimensioned code mark patterns with wider or narrower brand widths as well as thicker or thinner mark thicknesses can be used. In addition to iron as a magnetic material for the Kodemarken also any other industrially proven and use inexpensive magnetic materials, for example, rare earths such as neodymium, samarium, etc., or magnetic alloys or oxidic materials or polymer-bonded magnets, etc.

On the Branding Dimension: The differences of the code mark patterns 80 in the embodiments of the car position determining means 8 are that in the embodiment of the prior art Fig. 2 the brand length λ1 = 4 mm, while in the further development according to Fig. 5, 6,7 and in the inventive embodiment according to Fig. 8, 9, 10th the brand length λ2> 5 mm (preferably 6 mm or 7 mm). The code marks 83 in the further development and in the embodiment according to the invention are thus longer than the code marks 83 from the prior art.

The sensor device 81 : The sensor device 81 scans the magnetic fields of the code marks 83 as seen in the longitudinal direction y with a large number of sensors 85, 85 'arranged at the same distance from one another. The sensors 85, 85 'used in the three embodiments of the car position detecting means 8 are identical in mechanical dimensions and sensitivity. Preferably cost-effective and easily controllable and readable Hall sensors are used for the sensors 85, 85 '. The sensors 85, 85 'form, for example, equal length rectangular sections with a broad side of 3 mm and a narrow side of 2 mm. For example. are the sensors 85, 85 'supported sensors in which a carrier limits the broad side and the narrow side and the actual sensor surface 850, 850' has a significantly smaller dimension of eg. 1 mm ² . For Hall sensors, the sensor surface is 850, 850 'typically centrally located in the interior of the sensors. The sensors 85, 85 'detect via the sensor surface 850, 850' the magnetic fields of the code marks 83 as sensor signals. The stronger the signal strength of the code marks 83, the stronger the sensor signal of the sensors 85, 85 '. Typical sensitivities of Hall sensors are 150V / T. The sensors 85, 85 'output binary information for the magnetic marks of the code marks 83 detected as analog voltages. For a south pole, they output a bit value "0" and for a north pole they output a bit value "1". With knowledge of the present invention, however, the skilled person can also use other magnetic sensors such as coils. He can also use different sized sensors with wider or narrower broadsides, as well as wider or narrower narrow sides. Also, the skilled person can use more sensitive, or less sensitive Hall sensors.

For Coding : The code mark pattern 80 has a binary pseudorandom coding . The binary pseudorandom coding comprises sequences arranged consecutively with n bit values "0" or "1". Each farther back of one bit value in the binary pseudorandom coding introduces a new n-ary sequence with bit values "0" or "1". Such a sequence of n consecutive bit values is called a codeword. For example. a codeword with a 13-digit sequence is used. With simultaneous scanning of thirteen consecutive code marks 83 of the code mark pattern 80, the 13-digit sequence is read out unambiguously and without repetition of code words. Accordingly, the sensor device 81 for reading the code words comprises thirteen sensors 85, 85 '. With knowledge of the present invention, the The skilled person will of course realize sensor devices with more or less long codewords and correspondingly more or fewer sensors. It is also possible to realize a so-called Manchester coding, which results from the fact that in a pseudo-randomly coded bit sequence, after each south pole code mark an inverse north pole code mark is added and vice versa. The thus enforced zero crossings of the magnetic field after at most every second code mark are used in particular for the application of an interpolation device, which enables a higher resolution of the position measurement. For the interpolation device, additional sensors are integrated in the sensor device. However, the interpolation method is not relevant in the context of the invention. The combination of the pseudorandom coding with the Manchester coding described has the consequence that the sensors of the sensor device must be arranged with a pitch which corresponds to a double length of the code marks (2λ).

To the confidence interval: The magnetic fields are represented by curved arrows above the code marks. The signal strength of the code marks 83 is strongest in the middle of the code marks 83 and decreases towards the edges of the code marks 83. Also, the signal strength of the code marks 83 decreases away from the code marks 83 a certain distance away. An area with sufficiently strong magnetic fields above the code marks 83, in which the code marks 83 can be scanned reliably and reliably by the sensor device 81, is called a confidence interval. The confidence interval is determined by the signal strength of the code marks 83, the dimension of the code marks 83 and by the sensitivity of the sensors 85, 85 '. The sensor surfaces 850, 850 'of the sensors 85, 85' must have a clearance of, for example, +/- 1 mm in the confidence interval to provide valid information. The curve Λ1 limits the confidence interval in the longitudinal direction y of the device 8 for determining the car position according to the prior art Fig. 2, 3, 4 , The curves Λ2, Λ3 limit the confidence interval in the longitudinal direction y of the devices 8 for determining the car position in accordance with the Fig. 5 - 10B illustrated inventive embodiments.

In the embodiment according to the prior art ( Fig. 2, 3, 4 ), the lengths λ1 of the code marks 83 are smaller than the lengths λ2, λ3 in the embodiments according to the invention Fig. 5 - 10B , For this reason, the height of the curve Λ1 is lower than the height of the curves Λ2, Λ3. The shorter code marks 83 according to the prior art Fig. 2, 3, 4 have a lower effective signal strength and thus a lower confidence level. The losses of the signal strength of the code marks 83 with a short mark length λ1 = 4 mm according to Fig. 2, 3, 4 are so high that the sensors 85, 85 'at a low distance of only 3 mm above the code marks 83 must be arranged. The arrangement of the sensors 85, 85 'according to Fig. 2, 3, 4 is thus limited by the signal strength, since the sensor surfaces 850, 850 'have to lie with a clearance of +/- 1 mm in the confidence interval.

In contrast, in the two embodiments according to the invention Fig. 5 - 10B the brand length λ2, λ3 greater than 5 mm, preferably 6 - 10 mm, so that losses of the signal strength of the code marks 83 are avoided, which manifests itself in a larger confidence range. This large confidence range allows the sensors 85 not in a limited by the signal strength distance, but in a determined by the guide system distance above the code marks 83 to order. Thus, the sensors 85, 85 'can be arranged at a great distance of more than 6 mm above the code marks 83. Further extension of the brand length causes no further increase in the confidence interval.
From the Fig. 4 . 7A . 10A It can be seen that also given transverse to the track of the code marks given confidence areas, the height decreases with decreasing distance to the edges of the code marks 83. In the mentioned Fig. 4 . 7A . 10A These confidence intervals in the transverse direction are symbolized in each case by the curves Λ1, or Λ2, Λ3, which mark the boundaries of the magnetic field strength uniquely recognizable by the sensors.

Of course, with knowledge of the present invention, those skilled in the art can realize other code mark patterns and correspondingly designed sensor devices. For example, more than two parallel arranged sensor groups could be integrated into the sensor device to further increase the allowable offset between the sensor device and the code mark pattern.
Other physical principles for representing length coding are also conceivable. For example. For example, the code marks may have different dielectric numbers read by a capacitive-effect sensing device. Also, a reflective code mark pattern is possible in which, depending on the value of the individual code marks, more or less reflected light is detected by a sensor device detecting reflected light.

Claims (10)

1. Elevator system (10) with at least one car (1) and at least one device (8) for the absolute measurement of a position of a car,

   - the device (8) having a codemark pattern (80), a sensor apparatus (81), and an analyzer (82) which analyzes the signals of the sensor apparatus (81),

   - the codemark pattern (80) being mounted along the length of the travel path of the car (1) and
   consisting of a multiplicity of codemarks (83) in the form
   of sections of a magnetizable tape which are magnetized as
   south pole or north pole and arranged in a single line,

   - the sensor apparatus (81) being mounted on the car (1) and scanning the codemarks (83) touchlessly by means of sensors (85, 85'),

   characterized in that
   the sensor apparatus (81) contains at least two sensor groups (87, 88) each with a plurality of sensors (85, 85') which are arranged one after the other in the direction of the line of the codemarks (83), the sensor groups (87, 88) scanning the codemarks redundantly and being separated by a distance U perpendicular to the line of the codemarks (83) so as to allow lateral displacements between the sensor apparatus and the line of the codemarks.
2. Elevator system (10) according to claim 1,
   characterized in that
   the distance U by which the sensor groups (87, 88) are separated from each other perpendicular to the line of the codemarks (83) is so chosen that at least the sensors (85, 85') of one of the two sensor groups (87, 88) deliver the complete information regarding the current position of the car (1) provided that, measured perpendicular to the line of the codemarks (83), the deviation of the current position of the sensor apparatus (81) from its centered position relative to the line of the codemarks (83) does not exceed a value of 25%, preferably 30%, of the width (δ) of the codemarks (83).
3. Elevator system (10) according to one of claims 1 or 2,
   characterized in that
   the distance U by which the sensor groups (87, 88) are separated from each other perpendicular to the line of the codemarks (83) is so chosen that the sensors of both sensor groups (87, 88) deliver the complete information regarding the current position of the car (1) provided that, measured perpendicular to the line of the codemarks (83), the deviation of the current position of the sensor apparatus (81) from its centered position relative to the line of the codemarks does not exceed a value of 10%, preferably 15%, of the width δ of the codemarks (83).
4. Elevator system (10) according to one of claims 1 to 3,
   characterized in that
   the respective sensors (85, 85') assigned to a sensor group (87, 88) are arranged in two sensor lines (87.1, 87.1', 88.1, 88.1') running parallel to the line of the codemarks (83) .
5. Elevator system (10) according to one of claims 1 to 4,
   characterized in that
   the respective sensors (85, 85') assigned to a sensor group (87, 88) are arranged in a single sensor line (87.1, 88.1) running parallel to the line of the codemarks (83).
6. Elevator system (10) according to one of claims 1 to 5, characterized in that the analyzer (82) which processes the signals of the sensors is so designed that when, as a result of a deviation of the current position of the sensor apparatus (81) from its centered position relative to the line of the codemarks, the two sensor groups (87, 88) deliver different information, the different information is combined into one information which represents the actual current position of the car (1).
7. Elevator system (10) according to one of claims 1 to 6,
   characterized in that
   the analyzer (82) which processes the signals of the sensors (85, 85') is so designed that it compares the signals received from the two sensor groups (87, 88) and saves or displays an information if the received signals deviate from each other over a defined period of time or during a defined number of trips of the car (1).
8. Elevator system (10) according to one of claims 1 to 7,
   characterized in that
   the codemark pattern (80) comprises a multiplicity of codemarks (83) with a mark length λ > 5 mm.
9. Elevator system (10) according to one of claims 1 to 8,
   characterized in that
   the sensors (85, 85') are guided above the codemarks (83) in such manner that a maximum distance between the sensors (85, 85') and the codemarks (83) of 100% of the width δ of the codemarks (83) is not exceeded.
10. Method for operating an elevator system (10) with at least one car (1) and at least one device (8) for absolute measurement of a car position,

    - a codemark pattern (80) comprising a multiplicity of codemarks (83) in the form of sections of a magnetizable tape which are magnetized as south poles or north poles and arranged in a single line being mounted along the length of the travel path of the car (1) and being scanned by a sensor apparatus (81) mounted on the car (1),

    - the car position being determined from the signals of the sensor apparatus (81) by an analyzer (82),

    characterized in that

    - the codemark pattern (80) is scanned by at least two sensor groups (87, 88) which are integrated in the sensor apparatus (81), each of which comprises a plurality of sensors (85, 85') which are arranged one after the other in the direction of the line of the codemarks (83) and which are separated from each other by a distance U perpendicular to the line of the codemarks so as to allow lateral displacements between the sensor apparatus and the line of the codemarks,

    - at least the sensors (85, 85') of one of the two sensor groups (87, 88) deliver the complete information about the current position of the car (1).

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