EP2119661B1 - Device for measuring a horizontal deflection of a load bearer swinging on support ropes - Google Patents

Description

The invention relates to a device for measuring a horizontal deflection of a pendulum suspended on suspension cables lifting device.

Suspended suspension cables suspended on suspension ropes are well known and serve, for example, for storing and retrieving piece goods in high-bay warehouses. The load-carrying means is in this case suspended on a suspension via usually four support cables, wherein the support cables are each connected at an upper suspension point with the suspension and at a lower suspension point with the load-receiving means. In order to move the load-carrying means horizontally, the suspension is horizontally movable via a suitable drive means. In the vertical direction, the load-receiving means is usually traversed by the fact that the support cables are synchronously wound or unwound by means of suitable take-up devices.

During horizontal and / or vertical movement of the load-handling device, the load-bearing device is accelerated or decelerated with a time delay due to its inertia with respect to the suspension, as a result of which oscillating movements of the load-bearing device can occur. In particular, when picking up a load and when delivering a load, for example, during storage a piece goods in a compartment of a shelf storage, it is necessary that the load-carrying means is substantially at rest, so no longer performs any oscillations. To avoid disturbances when picking up or releasing a load, it is therefore necessary to measure the horizontal deflection of the load receiving means, in particular to be able to determine whether the load receiving means is at rest, so that the intake or delivery of a load can take place. Moreover, it is desirable to avoid oscillations even during a horizontal and / or vertical movement of the load handling device.

It is a pendulum damping device of the company CePLuS GmbH in Magdeburg known in which are used for measuring the horizontal deflection of the lifting device cameras, which are arranged on the suspension of the lifting device and measure horizontal movements of the lifting device. In order to enable such a measurement, reflectors are arranged on the load receiving means, wherein the camera arranged on the suspension is directed downwards and determines the position of the reflector relative to the suspension. From the output signals of the camera, the deflection of the lifting device is determined.

A disadvantage of the known device is that it is relatively expensive to build. Another disadvantage of the known device is that the measurement of the horizontal deflection of the lifting device can not be done with a sufficient temporal resolution, in particular to detect and compensate occurring during a horizontal and / or vertical movement of the lifting device pendulum vibrations relatively high frequency.

A similar device is also through DE 198 36 103 A1 known.

By DE 201 08 207 U1 (corresponding DE 101 22 142 A1 and EP 1 390 286 A1 ) is a device for measuring a horizontal deflection of a pendulum suspension suspended on lifting cables load receiving means relative to a suspension of the lifting device known. The known device has at least two cable length sensors which are operatively connected to an electronic data processing means, wherein the ropes of the at least two rope length sensors are arranged between the suspension of the load receiving means and the load receiving means such that a computing unit connected to the electronic data processing means the horizontal deflection of the load receiving means determined in relation to the position of the suspension over the length of the respective ropes of the rope length sensors.

By EP 0 846 648 A1 is a device of the type mentioned in the preamble of claim 1 is known.

The invention has for its object to provide a device referred to in the preamble of claim 1 species, which is simplified compared to the known device in the structure and which allows a measurement of the horizontal deflection of a lifting device with high accuracy.

This object is achieved by the teaching defined in claim 1.

The basic idea of the teaching according to the invention is to measure the horizontal deflection of the load-carrying device directly on one of the support cables. It is based on the knowledge that the horizontal distance of a carrying cable from a point located in a vertical plane passing through the load receiving means changes during a pendulum movement, if this point lies in the vertical direction between the upper suspension points and the lower suspension points of the lifting device. On this basis, the invention provides distance measuring means for measuring the horizontal distance of at least one of the supporting cables to a reference point located in the vertical direction between an upper suspension point and a lower suspension point of the lifting device.

Since, according to the invention, the measurement of the horizontal deflection of the lifting device can take place directly on one of the suspension cables, the device according to the invention is simplified in its construction.

In addition, the teaching of the invention allows a precise and timely measurement of the horizontal deflection of the lifting device.

According to the invention, the distance measuring means can measure the distance of the associated carrying cable to a reference point movable relative to the load receiving means, provided that the relative movement between the point and the load receiving means is taken into account in the evaluation compensatory, as a result, the actual Change in the distance between the reference point and the support cable is determined. An advantageous development of the teaching according to the invention provides that the distance measuring means measure the horizontal distance of the associated support cable to a reference point fixed to the load-receiving means. In this embodiment, the evaluation of the measurement results is simplified because in the evaluation of a relative movement between the reference point and the load-carrying means does not have to be considered.

In principle, the distance measuring means can be arranged on the suspension of the load-receiving means. Another advantageous development of the teaching of the invention provides that the distance measuring means are arranged on the load-receiving means. In this embodiment, a particularly compact and mechanically maintenance-friendly design of the device results because only one access to the load handling device is required during maintenance.

An extremely advantageous development of the teaching according to the invention provides that the distance measuring means have optical measuring means. In this embodiment, the distance measurement can be carried out in time with high resolution, so that the control of the load receiving means associated drive means by which the load receiving means is horizontally and / or vertically movable, can be carried out with a correspondingly high temporal resolution. Instead of optical measuring means and other non-contact measuring means may be used, for example, ultrasonic measuring means, provided adequate measurement accuracy and freedom from interference in the measurement is ensured.

In the aforementioned embodiment, the be formed optical measuring means in a variety of ways. For example, it is possible to measure the horizontal deflection of the load-carrying means by means of a type of autofocus device known from photographic cameras, which is arranged on the load-receiving means and focused on the carrying cable. Changes in a pendulum movement of the horizontal distance of the support cable from the autofocus device, it focuses on, from output signals of the autofocus device, the respective horizontal distance of the auto 'focus device to the support cable and thus the respective deflection of the lifting device can be determined. An advantageous development of the embodiment with the optical measuring means provides that these at least one laser, which irradiates at least one connected to the associated support cable reflection element, and at least one receiver, which receives from the reflection element reflected laser light. From output signals of the receiver, the respective horizontal deflection of the load receiving means can be determined, for example, due to the running time of the laser light between the laser, the reflection element and the receiver.

An advantageous development of the aforementioned embodiment provides that the distance measuring means comprise at least one laser rangefinder, in particular at least one laser interferometer. Such laser rangefinders are well known to the skilled person with regard to their construction and their function and are therefore not explained in detail here.

In order to increase the accuracy of the measurement in the embodiments with the reflection element, provides an advantageous development that the reflection element based on the cable axis of the associated Supporting cables is connected to the support cable substantially against rotation. In this way, measurement errors are avoided, which could result from the fact that the reflection element is rotated about the cable axis of the supporting cable.

Another development of the teaching according to the invention provides that the distance measuring means have mechanical measuring means.

In the aforementioned embodiment, the mechanical measuring means may preferably comprise at least one cable length sensor connected to the load receiving means, the measuring cable of which is connected to the associated carrying cable. A suitable rope length sensor can, for example, have a measuring cable which can be developed on or from a winding element, wherein the winding element is arranged on the load receiving means in the vertical direction between an upper suspension point and a lower suspension point of the load receiving means. In a horizontal deflection of the lifting device, the rope from the winding element off or wound onto this, the resulting change in the Meßseillänge between the supporting cable and the winding element can be measured. Corresponding rope length sensors are produced, for example, by BR Electronic GmbH. A particular advantage of this embodiment is that it is particularly simple in construction, since a single rope length sensor is sufficient to measure the horizontal deflection of the lifting device. In addition, this embodiment is robust in construction. Furthermore, it is advantageous that the measuring cable may have a relatively small length, so that, for example due to temperature changes occurring elongations of the measuring cable in view of the measurement accuracy negligible are.

According to the invention, it is basically sufficient if it is established on the basis of output signals of the device according to the invention that the horizontal deflection of the load receiving means is substantially equal to zero, ie the load receiving means is substantially at rest. In this rest position then loads can be absorbed or delivered. In such an embodiment, the process for receiving or delivering a load is only started when the load-carrying means is at rest. However, an extremely advantageous development of the teaching according to the invention provides that the distance measuring means are in a data transmission connection with a control device such that the control device controls a load receiving means associated drive means by which the load receiving means is horizontally and / or vertically movable in response to output signals of the distance measuring , The control device can in this case be formed in particular by an electronic data processing device, for example a control computer. An advantageous development of the aforementioned embodiment provides that the control device controls the drive means such that during horizontal and / or vertical movement of the load receiving means pendulum movements are at least partially minimized during horizontal or vertical movement. In this embodiment, in particular, a trajectory, which passes through the load receiving means between a load receiving location and a load discharge location, and optionally additionally the speed at which the load receiving means travels through the trajectory, be chosen so that oscillations are minimized. In this way, storage and retrieval operations by means of the load handling means are designed to save time, whereby the storage and retrieval performance of the load handling device can be significantly increased.

The invention will be explained in more detail with reference to the attached highly schematic drawing, are shown in the embodiments of a device according to the invention. All the features described in the drawing and claimed in the claims, taken alone and in any combination with each other form the subject of the invention, regardless of their summary in the claims and their dependency and regardless of their description or representation in the drawing.

Fig. 1

eine Seitenansicht zur Verdeutlichung des grundsätzlichen Aufbaus eines an Tragseilen pendelbar aufgehängten Last- aufnahmemittels,

Fig. 2

eine Seitenansicht eines ersten Ausfüh- rungsbeispieles einer erfindungsgemäßen Vorrichtung im Bereich des Lastaufnahme- mittels und

Fig. 3

in gleicher Darstellung wie Fig. 2 ein zweites Ausführungsbeispiel einer erfin- dungsgemäßen Vorrichtung.

It shows:

Fig. 1

a side view to illustrate the basic structure of a pendulum suspended on suspension cables load-receiving means,

Fig. 2

a side view of a first embodiment of a device according to the invention in the field of Lastaufnahme- means and

Fig. 3

in the same representation as Fig. 2 A second embodiment of an inventive device.

In the figures of the drawing, the same or corresponding components are provided with the same reference numerals.

In Fig. 1 is a load-bearing device in a side view 2, which is suspended from four suspension cables, of which in Fig. 1 only two support cables 4, 6 can be seen. The other suspension cables are arranged offset perpendicular to the plane of the support cables 4, 6. Subsequently, only the support cables 4, 6 are explained in detail. The other suspension cables are constructed accordingly.

The support cables 4, 6 are connected at lower suspension points 8, 10 with the load-receiving means and at upper suspension points 12, 14 with a suspension, which is designed as a movable carriage 16 in this embodiment.

The load receiving means 2 is associated with a drive means by means of which the carriage 16 in the direction of a double arrow 18 is movable. If required according to the respective requirements, the carriage 16 can additionally be moved perpendicular to the plane of the drawing. By means of the carriage 16, the load-receiving means 2 is thus movable in the horizontal direction. For vertical movement of the load receiving means 2 are by means of the drive means winding drums 20, 22 rotatably driven, which serve for winding or unwinding of the support cables 4, 6. The drive means drives the winding drums 20, 22 so synchronously that the load receiving means 2 is vertically movable, without performing tilting movements.

Fig. 1 represents the load-receiving means 2 in a position in which it is horizontally deflected relative to a rest position, the support cables 4, 6 are thus α inclined relative to the vertical at an angle. How out Fig. 1 it can be seen, the horizontal distance A, for example, of the support cable 4 changes from a lying in a vertical plane reference point P at a horizontal deflection of the lifting device 2, provided that this reference point P lies in the vertical direction between the upper suspension points 12, 14 and the lower suspension points 8, 10. In contrast, this distance A does not change if the reference point P in a plane defined by the upper suspension points 12, 14 level 26 (in Fig. 1 symbolized by a dot-dash line) or lies in a plane defined by the lower suspension points 8, 10 level 28.

The horizontal deflection of the load receiving means 2 can thus be measured by the present invention, the horizontal distance, for example, the support cable 4 is measured from the reference point P in the vertical direction between the upper suspension point 12 and the lower suspension point 8 and between the upper suspension point 14 and the lower Suspension point 10 is located.

In Fig. 1 a first embodiment of a device according to the invention 30 is shown, the distance measuring means for measuring the horizontal distance A at least one of the support cables, in the illustrated embodiment of the support cable 4, to the vertical between the upper suspension point 12 and the lower suspension point 8 and the upper suspension point 14 and the lower suspension point 14 of the lifting device 2 adjacent reference point P has. In the illustrated embodiment, the distance measuring means comprise optical measuring means in the form of a laser rangefinder 32. The laser rangefinder 32 is disposed on the load receiving means 2 in the vertical direction to the plane 28 spaced so that the reference point P lies in the vertical direction between the upper suspension point 12 and the lower suspension point 8. The laser rangefinder 32 has a laser, which irradiates a arranged on the support cable 4 reflection element 34, from which the laser light is reflected onto a receiver of the laser rangefinder 32. The reflection element 34 is arranged on a flat iron 36, with one end of the support cable 4 is connected and the other end is pivotally connected to the load-receiving means 2, so that the flat iron 36 forms an imaginary extension of the support cable 4. The flat iron 36 is connected against rotation with the support cable 4 and thus follows only the pendulum movement of the support cable 4 in the horizontal axis. Thus, the laser rangefinder 32 measures the horizontal distance A between the support cable 4 and the point P and thus the deflection of the load receiving means 2 relative to the in Fig. 2 unrecognizable suspension of the lifting device 2. The laser rangefinder 32 is in data transmission connection with a in Fig. 1 only schematically indicated control device 38, by means of which the load receiving means 2 associated drive means (see above to Fig. 1 ) is controllable.

• Das Lastaufnahmemittel 2 nimmt bei Betrieb an einem Aufnahmeort eine Last auf, wobei die Aufnahme und spätere Abgabe der Last in dem Fachmann allgemein bekannter Weise erfolgen und daher hier nicht näher erläutert wird. Um die Last zu einem Abgabeort zu transportieren, steuert die Steuerungseinrichtung 38 die dem Lastaufnahmemittel 2 zugeordnete Antriebseinrichtung derart an, daß das Lastaufnahmemittel 2 in horizontaler und/oder vertikaler Richtung verfahren wird. Aufgrund der Massenträgheit des Lastaufnahmemittels 2 mit darauf aufgenommener Last folgt das Lastaufnahmemittel 2 Bewegungen des Schlittens 10 zeitlich verzögert, wobei Pendelbewegungen und damit eine periodische Auslenkung des Lastaufnahmemittels 2 relativ zu dem Schlitten 16 entstehen können.

The operation of the device 30 according to the invention is as follows:

• The load-receiving means 2 receives a load during operation at a pick-up location, the pick-up and subsequent discharge of the load occurring in a manner well-known to those skilled in the art and therefore not explained in detail here. In order to transport the load to a delivery location, the control device 38 controls the drive device associated with the load receiving means 2 such that the load receiving means 2 is moved in the horizontal and / or vertical direction. Due to the inertia of the load-receiving means 2 with the load picked up on it, the load-carrying means 2 follows movements of the carriage 10 delayed, with oscillations and thus a periodic deflection of the lifting device 2 may arise relative to the carriage 16.

In horizontal displacements of the load receiving means 2 decreases or increases the distance of the support cable 4 from the reference point P. This distance is measured by means of the laser rangefinder 32 and output signals of the laser rangefinder are supplied to the control device 38. The control device 38 controls in response to the output signals of the laser rangefinder 32 to the load receiving means 2 associated drive means. The trajectory along which the load receiving means 2 moves along the trajectory and the speed with which the load receiving means 2 moves can be chosen, for example and in particular, such that oscillating movements of the load receiving means 2 are minimized at least in sections along the trajectory. However, the control can also be such that oscillations between a recording and a delivery point of the load in favor of a higher speed between these places are deliberately accepted and pendulum movements are corrected, for example, or shortly before reaching the Lastabgabeortes by appropriate control of the drive device. In this way, the performance of the load receiving means 2 can be substantially increased during the storage and retrieval of loads. The required measurement of the respective deflection of the load receiving means 2 by means of the device 30 according to the invention in a simple and fast way with high accuracy.

In Fig. 3 is a second embodiment of a Inventive device 30, which differs from the embodiment according to FIG Fig. 1 characterized in that the measuring means comprise mechanical measuring means which have a rope length sensor 40, the measuring cable 42 is connected to the associated supporting cable 4. The rope length sensor 40 has a winding element 44, from which the measuring cable 42 can be unwound or wound up on a horizontal deflection of the load receiving means 2. Based on the change of the effective length L of the measuring cable 42 thus the horizontal distance between the reference point P and the measuring cable 4 can be measured.

In the illustrated embodiments, horizontal deflections of the load receiving means 2 are detected parallel to the drawing plane by the distance measuring means according to the invention. If required in accordance with the respective requirements, horizontal deflections of the lifting device perpendicular to the drawing plane can additionally be detected by using additional distance measuring means which are offset by 90 ° from the distance measuring means shown and thus a horizontal deflection of the load receiving means 2 perpendicular to the drawing plane detected.

According to the invention, the measuring direction, ie the direction in which, for example, the laser beam of a laser rangefinder or a measuring cable of a rope length sensor runs, lie horizontally. According to the invention, however, the measuring direction can also be inclined to the horizontal. In this case, for example, the laser beam of a laser rangefinder or the course of a measuring cable of a rope length sensor is inclined to the horizontal. In this case, in turn, the horizontal distance of the associated support cable is measured to a reference point as a result, and to a reference point, in the vertical direction between the upper suspension point and the lower suspension point of the lifting device and in a horizontal plane passing through a point at which, for example, the laser beam impinges on the supporting cable or at which the measuring cable is connected to the supporting cable.

Claims (9)

1. Device for measuring a horizontal deflection of a load bearing means (2) suspended in a pendular manner on support cables (4, 6) relative to a suspension (16) of the load bearing means,
   comprising distance measuring means for measuring the horizontal distance of at least one of the support cables (4) to a reference point (P) lying in vertical direction between an upper suspension point (12) or (14) and a lower suspension point (8) or (10) of the load bearing means (2), wherein the distance measuring means comprise optical measuring means,
   characterised in that
   the optical measuring means comprise at least one laser which radiates at least one reflection element (34) connected to the assigned support cables and at least one receiver which receives laser light reflected by the reflection element (34).
2. Device according to claim 1, characterised in that the distance measuring means measure the horizontal distance (A) of the assigned support cable (4) to a reference point (P) that is fixed relative to the load bearing means (2).
3. Device according to claim 1 or 2, characterised in that the distance measuring means are arranged on the load bearing means (2).
4. Device according to claim 1, characterised in that the optical measuring means comprise at least one laser distance measuring device (32), in particular at least one laser interferometer.
5. Device according to claim 1 or 4, characterised in that the reflection element (34) is connected in relation to the cable axis of the assigned support cable (4) essentially non-rotationally to the support cable (4).
6. Device according to one of the preceding claims, characterised in that the distance measuring means comprise mechanical measuring means.
7. Device according to claim 6, characterised in that the mechanical measuring means comprise at least one cable length transmitter (40) connected preferably with the load bearing means (2), the measuring cable (42) of which is connected to the assigned support cable (4).
8. Device according to one of the preceding claims, characterised in that the distance measuring means are in data transmission connection with a control device (38) such that the control device controls a drive device assigned to the load bearing means (2), by means of which drive device the load bearing means (2) can be moved horizontally and/or vertically, depending on output signals of the distance measuring means.
9. Device according to claim 8, characterised in that the control device (38) controls the drive device such that during the horizontal and/or vertical movement of the load bearing means (2) pendular movements are minimised at least in sections during the horizontal and/or vertical movement.

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