EP2809862A1

EP2809862A1 - Determining a position by measuring forces

Info

Publication number: EP2809862A1
Application number: EP13710352.9A
Authority: EP
Inventors: Uwe Krause
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 2012-03-15
Filing date: 2013-03-12
Publication date: 2014-12-10
Also published as: DE102012204080A1; US20150033876A1; WO2013135704A1; CN104169512A; CN104169512B

Abstract

The invention relates to a device and a method for determining the position of an object (1) which can be moved in a linear manner. The device comprises a contact unit (4) which is coupled to the object (1) such that the contact unit provides a force signal (F) that is dependent on the position of the object (1), a force detecting unit (8) for detecting the force signal (F) provided by the contact unit (4), and an evaluating unit (9) for evaluating the force signal (F) detected by the force detecting unit (8). The position of the object (1) is ascertained using an evaluation function (F(X)) during the evaluation process, said evaluation function describing a dependence of the force signal (F) on the position of the object (1).

Description

description

The invention relates to a device and a method for determining a position of a linearly movable object, in particular a sliding door or an elevator door.

Various such devices and methods are already known.

For example, DE 10 2009 042 800 A1 discloses a system comprising a drive unit and a sensor with which the position of an element moved by the drive unit can be determined. The sensor is a rangefinder for measuring a distance between the sensor and the movable element, from which a position of the movable element is determined. DE 10 2006 040 232 A1 discloses a door drive for an au ^¬ automatic door with a brushless electric motor and a drive device for controlling and / or regulating the electric motor. The drive device comprises an angle transmitter operating according to a magnetic principle for generating an angle signal proportional to the angle of rotation of the motor.

DE 10 2007 060 343 AI discloses a monitoring device for monitoring the movement of a wing of a gear ^¬ nen gate with a position detection device for detecting a position of the wing. The position detecting means includes a distance measuring device for measuring a distance of a wing portion from a stationary portion using a wave transmission. From the patent application with the application number 102011003399.8 a method for determining a position of at least one by means of a drive belt of a drive unit be ^¬ wegbaren element is known. This is the drive belt stretched over a measurement interval with a given force by one path change. From the measuring interval, the force and a modulus of elasticity and a cross section of the drive ^¬ belt an effective length of the drive belt is determined and from the effective length, the position is determined.

The invention has for its object to provide an alternative method and an alternative device for determining a position of a linearly movable object.

The object is achieved according to the invention with respect to the device by the features of claim 1 and in terms of Ver ^¬ driving by the features of claim 10. Advantageous embodiments of the invention are the subject of the dependent claims.

An inventive apparatus for determining a position of a linearly movable object comprises a contact in- uniform, which is so coupled to the object that it provides a dependent of the position of the object power signal, a power detection unit for detecting the force signal provided by the Kon ^¬ clock unit and an evaluation unit for evaluating the force signal detected by the force detection unit.

Such a device requires no moving and wear-prone components in the measuring system and therefore has the advantage of being particularly wear-resistant and functional. Further, the device requires power only when a position of the object is also read out, and is therefore efficient in terms of power consumption and power consumption. Furthermore, the device in Wesentli ^¬ surfaces can be arranged in a space which is traversed by the object, so that the device advantageously requires hardly any additional space. In a first embodiment of the invention, the contact unit comprises a spring element, which is coupled to a first end of the object and with a second end to the force detection ^¬ unit, so that the length of the spring element depends on the position of the object. The force sensing ^¬ unit recorded as a force signal a restoring force of the spring element.

This embodiment provides a very simple and cost-effective implementation of the invention.

In this embodiment, the spring element is arranged, for example, such that it runs along the direction of movement of the object, or it is guided over a deflection device.

Both alternatives advantageously make it possible to fix a direction of the restoring force of the spring element. A particularly simple design can be used Krafter--making unit in particular, as these need not be designed for Rich ^¬ directional changes of the restoring force.

Alternatively, in the above embodiment, the

Force detection unit rotatably mounted or designed to detect a direction-dependent force signal.

Characterized a rear ^¬ force can be detected by the force detection unit, the direction of which changes during the movement of the object. This advantageously allows egg ne direct connection of the object by the force detection unit ^¬ without having to fix the direction of the restoring force. The contact unit can therefore consist only in this embodiment of the spring element and thus be ^{¬ be} particularly easy.

In a second embodiment of the invention, the contact unit has a mass which is coupled via a cable to the object. In this case, the cable is connected via a deflection element. leads, so that acts on the deflecting a dependent of the position of the object force, and the force sensing ^¬ unit detects as a force signal acting on the deflecting force.

This embodiment of the invention has the advantage over the above-mentioned first embodiment that no spring element is used, the spring constant of which changes over time, so that the evaluation of the force signal does not have to be adapted to the changing properties of the contact unit.

In a third embodiment of the invention, the contact unit comprises a belt drive for driving the object, and a gekop ^¬ pelte to the belt drive and the force detection unit connecting unit.

In a fourth embodiment of the invention, the contact unit comprises a tension spring coupled to the force detection unit, by means of which the object is moved.

In all embodiments of the invention, the contact unit may each comprise a drive unit of the object, i. an already existing component. This advantageously reduces the additional components required for determining the position. For example, the spring element of the first embodiment or the mass and the rope of the second embodiment can be designed and arranged such that exert the spring force of the spring element or the weight of the mass a useful force for moving the object.

In the inventive method for determining a position of a linearly movable object by means of a device according to the invention by means of the standardized Krafterfassungsein- a signal supplied by the contact unit power signal ^¬ he summarizes and evaluated captured by the Krafterfas ^¬ sungseinheit force signal by means of the evaluation unit. The position of the object is determined by means of an evaluation function, which describes a dependence of the force signal on a coordinate indicating the position of the object.

In the method, the position of the object is thus determined on the basis of an evaluation function which assigns a force signal to the position of the object. In this way, a Posi ^¬ tion of the object even after a manual movement of the object during a power failure from the force signal from ^¬ be passed.

The evaluation function is preferably experimentally ermit ^¬ telt.

As a result, the evaluation function can be reliably determined under real conditions.

In a further embodiment of the method, test positions of the object are specified and the force signal is continuously recorded at the test positions and compared with the values of the evaluation function for the test positions. The evaluation function will be updated if their values are different to the test ^¬ positions of the captured test positions for the force signals. This makes it advantageous to use the evaluation function to adapt än ^¬-reducing properties of the inventive device, for example a varying spring constant of the spring element in the first embodiment of the apparatus.

As a result of the continuous checking of the evaluation function at predetermined positions of the object, reliably necessary adjustments of the evaluation function can be reliably detected and, in addition, a temporal change of the properties of the device can be documented and analyzed.

The above-described characteristics, features and advantages of this invention and the manner in which it achieves will be more clearly and clearly understood in connection with the following description of exemplary embodiments, which are explained in more detail in connection with the drawings. Showing:

1A shows schematically a first device for determining a position of a sliding door in an open position of the sliding door, FIG 1B schematically shows the device shown in FIG 1A at a closed position of the sliding door,

FIG. 1C schematically illustrates an evaluation function for determining a position of the sliding door by means of the device shown in FIGS. 1A and 1B,

2A schematically shows a second device for determining a position of a sliding door with an open position of the sliding door,

2B schematically shows the device shown in FIG 2A at a closed position of the sliding door,

2C schematically shows an evaluation function for determining a position of the sliding door by means of the device shown in FIGS. 2A and 2B,

3A shows schematically a third device for determining a position of a sliding door with an opened position of the sliding door,

3B shows schematically the device shown in FIG. 3A with a closed position of the sliding door, FIG. 3C shows schematically an evaluation function for determining a position of the sliding door by means of the device shown in FIGS. 3A and 3B, 4A schematically shows a fourth device for determining a position of a sliding door with an open position of the sliding door, FIG 4B schematically shows the device shown in FIG 4A at a closed position of the sliding door, and

4C schematically shows an evaluation function for determining a position of the sliding door by means of the device shown in FIGS. 4A and 4B.

Corresponding parts are provided in all figures with the same reference numerals.

Figures 1A, 1B, 2A, 2B, 3A, 3B, 4A, 4B schematically show different devices for determining a position of a linearly movable object 1, which is a sliding door in this Ausführungsbei play ^¬, the linear, in Figures 1A between a 2A, 3A, 4A and a closed position shown in FIGS. 1B, 2B, 3B, 4B. The direction of movement of the sliding door defines the X-direction of a Cartesian Koordi ^¬ natensystems with coordinates X, Y, Z.

In the open position, the sliding door strikes against a first stop 2. In the closed position, the sliding door strikes a second stop 3. The various devices for determining the position of the sliding door each comprise a coupled to the sliding contact unit 4, and a ge of the contact unit 4 ^¬ coupled power acquisition unit 8. The contact unit 4 is in each case so coupled to the sliding door and the force detection unit 8 that they have a from the position of the sliding ^¬ door dependent force signal F delivers. The force signal F is detected by the force detection unit 8. As Krafterfas ^¬ sungseinheit 8 there may be a suitable conventional power be used, for example, a force transducer with a strain gauge or a spring with potentio- metric, incremental or magnetic force detection. The force signal F detected by the force detection unit 8 is in each case supplied to an evaluation unit 9 and evaluated by it for determining the position of the sliding door. For this purpose, an evaluation function F (X) is used which describes a dependence of the force signal F on the position of the sliding door.

The position of the sliding door is thereby indicated by the X-coordinate of that door edge of the sliding door which, in the open position of the sliding door, adjoins the first stop 2 (in FIGS. 1A, 1B, 2A, 2B, 3A, 3B, 4A, 4B, this is the left door edge, respectively). Xo indicates the position of the slider ^¬ betür in the open position. Χο + ΔΧ indicates the position of the sliding door in the closed position, ie ΔΧ is the distance of the closed sliding door from the first stop 2. Fo denotes the value F (Xo) of the evaluation function F (X) with the sliding door open. Fo + AF denotes the value F (Xo + AX) of the evaluation function F (X) with the sliding door closed. Figures IC, 2C, 3C, 4C schematically show Auswertefunkti ^¬ ones F (X) for the in Figures 1A, 1B, 2A, 2B, 3A, 3B, 4A, 4B devices shown.

In all illustrated embodiments Fo is the minimum of the evaluation function F (X) in the interval [Xo, Xo + AX]. This can be exploited in particular to detect errors of the respective device. If, for example, a detected force signal F is significantly smaller than Fo, this indicates a defect in the device.

The various devices shown in the figures differ essentially by the formation of the contact unit 4 and the associated evaluation function F (X). FIGS. 1A and 1B show a device whose contact unit 4 has a spring element 5.1, for example a rubber rope, and a deflection device 5.2 designed as a deflection roller. The spring element 5.1 is coupled to a first end connected to the sliding door and with a second end to the Krafterfas ^¬ sungseinheit. 8 In this case, the spring element 5.1 is guided over the deflection device 5.2, so that the spring element 5.1 runs between the sliding door and the deflection device 5.2 in the X direction and between the deflection device 5.2 and the force detection unit 8 in a Z direction perpendicular thereto.

During a movement of the sliding door from the open to the closed position, the spring element 5.1 is stretched and delivers as a force signal F dependent on the elongation restoring force. This force signal F is detected by the Krafterfas ^¬ sungseinheit. 8

In the embodiment shown in Figures 1A and 1B, a linear relationship between the length and the restoring force of the spring element 5.1 has been adopted according to the Hooke's law. Since in this embodiment, the change in length of the spring element 5.1 is equal to the distance of the sliding door from the first stop 2, the evaluation function F (X) is also linear. In particular, the evaluation function F (X) is therefore monotonically and thus enables unambiguous position of the sliding door zuzuord ^¬ NEN a sensed force signal F. Figures 2A and 2B show a device whose contact unit 4 consists only of a spring element 5.1, which is coupled with ei ^¬ nem first end to the sliding door and with a second end to the force detection unit 8. In contrast to the exemplary embodiment illustrated in FIGS. 1A and 1B, in this case the spring element 5.1 connects the spring element

Sliding door and the force detection unit 8 miteinan ^¬ directly, without being guided over a deflecting 5.2. This simplifies the structure with respect to the exemplary embodiment illustrated in FIGS. 1A and 1B.

However requires in Figures 2A and 2B layout shown arrangement is that the force detection unit is arranged rotatably gela ^¬ siege or for detection of a directional force signal F 8, because in this arrangement, the angle between the spring element 5.1 and the X-direction during the Movement of the sliding door changes.

The angle change also causes the corresponding evaluation function F (X) shown in Figure 2C to be non-linear, even if the length and restoring force of the spring element 5.1 are linearly dependent on each other according to Hook's law.

Instead, the slope of the evaluation function F (X) increases with X, so that the resolution of the evaluation of the force signal F improves towards the closed position of the sliding door. Also in this embodiment, the evaluation ^¬ function F (X) monotonically and thus enables a sensed force signal F clearly a position of the sliding door zuzuord ^¬ NEN.

FIGS. 3A and 3B show a device whose contact unit 4 has a mass 6.1, a cable 6.2 and a deflection element 6.3. The mass 6.1 is on the rope 6.2 to the

Sliding door coupled and guided over the deflection element 6.3, so that acts on the deflecting 6.3 dependent on the position of the sliding door force. The force detection unit 8 detects this force acting on the deflection element 6.3 as a force signal F. The direction and magnitude of this force Su ^¬ countries during a movement of the sliding door, since the angle between the X-direction and the change between the sliding door and the deflecting element 6.3. Also in this example approximately ^¬ exporting the power detection unit 8 is thus rotatably mounted or designed for detection of a directional force signal F. FIG. 3C schematically shows the evaluation function F (X) of the device illustrated in FIGS. 3A and 3B. Also in this embodiment, the evaluation function F (X) is monotone. FIGS. 4A and 4B show a device whose contact unit 4 has a belt drive 7.1 for driving the sliding door and a connecting unit 7.2 coupled to the belt drive 7.1 and the force detection unit 8.

The belt drive 7.1 comprises a drive belt 7.11, two pulleys 7.12 and a drive rod 7.13. The An ^¬ drive belt 11.7 runs over the pulleys 12.7 and is connected at one point to the drive rod 13.7, which in turn is connected to the sliding door.

The connecting unit 7.2 comprises a connecting rod 7.21, a linear guide 7.22 and a spring element 5.1. The connecting rod 7.21 is connected at a first end to the on ^¬ drive belt 7.11 and stored so that it is rotatable in the XZ plane. The second end of the connecting rod ^¬ 21.7 is guided by the linear guide 7:22 along the X-direction. The spring element 5.1 is at one end to the second end of the connecting rod is 7.21 and the at the end of which ^¬ coupled to the power detection unit 8 and ver ^¬ running in the X direction. Instead of a separate linear guide 7.22, the second end of the connecting rod 7.21 can also be performed with the help of the drive belt 7.11 along the X direction. The connecting rod 21.7 is connected to the drive belt 11.7 in such a way, the first end of the connecting ^¬ rod 21.7 during the movement of the sliding door from the open to the closed position first of a Po ^¬ sition between the two pulleys 07/12 on one of the pulleys 07/12 that to moved and then, just before reaching the closed position of the sliding door, around this pulley 7.12 is guided around. This returns the second End of the connecting rod 7.21 its direction of movement, just before the sliding door reaches the closed position.

During the movement of the sliding door from the open to the closed position, the expansion of the spring element 5.1 accordingly decreases initially to and shortly before reaching the closed position again. The force detection unit 8 detects as a force signal F, the restoring force of Fe ^¬ derelementes 5.1.

FIG. 4C shows schematically the resulting evaluation function F (X). Due to the decrease in the elongation of the spring element 5.1 shortly before reaching the closed position of the sliding door, the evaluation function F (X) is not monotonous in this exemplary embodiment. By the decrease of the force signal F shortly before reaching the closed position of the sliding door can reach the closed position of the

Sliding door can be identified safely. In all embodiments, the force signal F can either be a pure measurement signal for position determination or it can be generated by a useful force. In the first case, the force should be as small as possible in order not to exert any significant influence on the movement of the sliding door (eg Fo = I and Fo + AF = 1.5 N). A useful force, for example, be the spring force of a spring element 5.1 or the weight ^¬ force of the mass 6.1 to allow or support the opening of the sliding door. Analogously, the useful force can be a spring or weight force which enables or supports the closing of the sliding door.

Although the invention in detail by preferred execution ^¬ examples has been illustrated and described in detail, the invention is not limited by the disclosed examples and other variations can be derived therefrom by the skilled artisan without departing from the scope of the invention.

Claims

claims

A device for determining a position of a linearly movable object (1), the device comprising:

- a contact unit (4) which is ge ^¬ coupled in such a way to the object (1) that it provides a from the position of the object (1) dependent force signal (F),

a force detection unit (8) for detecting the force signal (F) delivered by the contact unit (4) and

- An evaluation unit (9) for evaluating the detected by the force ^¬ detection unit (8) force signal (F).

2. Apparatus according to claim 1,

characterized in that the contact unit (4) comprises a spring element (5.1) having a first end to the

Object (1) and with a second end to the force sensing ^¬ unit (8) is coupled, so that the length of Federelemen ^¬ tes (5.1) depends on the position of the object (1), and that the force detection unit (8) as a force signal (F) detects a restoring force of the spring element (5.1).

3. Apparatus according to claim 2,

characterized in that the spring element (5.1) via a deflection device (5.2) is guided.

4. Apparatus according to claim 2,

characterized in that the force detection unit (8) is rotatably mounted.

5. Apparatus according to claim 2,

characterized in that the force detection unit (8) is designed to detect a direction-dependent force signal (F).

6. Apparatus according to claim 1,

characterized in that the contact unit (4) has a ^mass (6.1), which is coupled to the object (1) via a cable (6.2), the cable (6.2) via a deflecting element (6.3) is guided, so that on the deflecting element (6.3) one of the position of the object (1) dependent force acts, and the force detection unit (8) as a force signal (F) detects the force acting on the deflecting element (6.3).

7. Apparatus according to claim 1,

characterized in that the contact unit (4) comprises a belt drive (7.1) for driving the object (1) and a to the belt drive (7.1) and the force detection unit (8) coupled connection unit (7.2).

8. Apparatus according to claim 1,

characterized in that the contact unit (4) comprises a to the force detection unit (8) coupled tension spring, by means of which the object (1) moves or the movement of Ob ^¬ jektes (1) is supported.

9. Apparatus according to claim 1,

characterized in that the contact unit (4) to the force detection unit (8) coupled mass (6.1) sums around ^¬ , with the weight of the movement of the object (1) allows or is supported.

10. A method for determining a position of a linearly movable object (1) by means of a device according to one of the preceding claims, wherein

- By means of the force detection unit (8) from the contact ^¬ unit (4) supplied force signal (F) is detected and

- by means of the evaluation unit (9) the sungseinheit of the Krafterfas- detected (8) force signal wherein the position of the object (1) based on an evaluation ^¬ function (F (X)) is determined is evaluated (F), that of a dependency Force signal (F) of a the position of the object (1) to ^¬ giving coordinate (X) describes.

11. The method according to claim 10,

characterized in that the evaluation function (F (X)) is determined experimentally.

12. The method according to claim 10 or 11,

characterized in that

- PrüfPositionen of the object (1) are given,

- The force signal (F) at the test positions continuously detected and with the values of the evaluation function (F (X)) for the

Test positions is compared and

- the evaluation function (F (X)) is updated if its values for the test positions deviate from the force signals (F) recorded at the test positions.