WO2011038439A1

WO2011038439A1 - Conveyance device and method for testing whether a minimum distance between two objects to be conveyed is maintained

Info

Publication number: WO2011038439A1
Application number: PCT/AT2010/000364
Authority: WO
Inventors: Christoph Wolkerstorfer; Josef Reischl
Original assignee: Tgw Mechanics Gmbh
Priority date: 2009-10-02
Filing date: 2010-10-01
Publication date: 2011-04-07
Also published as: EP2483184A1; WO2011038440A1; AT508865B1; AT508865A1; CN102648137A; DE202010018479U1; AT509818A1; AT508864B1; CN102648137B; EP2483183A1; AT508864A1

Abstract

The invention relates to a conveyance device (1) comprising several drives (2, 2a..2c) arranged successively in the direction of conveyance (z, z1, z2) and used to transport objects (22a..22d) at an actual speed. Said conveyance device (1) comprises means for determining a desired position of an object (22a..22d) using a desired speed of the drives (2, 2a..2c) and the time which has elapsed after passing a reference point (p), or using a desired path which is predefined by the drives (2, 2a..2c) and which is traversed after passing a reference point (p). Said conveyance device (1) comprises a control/regulation element for controlling or regulating a desired distance between two objects (22a..22d) using the mentioned desired position. According to the invention, said conveyance device (1) also comprises at least one sensor (17, 18, 23) which is provided for detecting a first range (A) and a second range (B), the second detection range (B) being arranged in the direction of conveyance (z, z1, z2) behind the first detection range (A) at a first distance (x, x1, x2). Said conveyance device (1) also comprises means for testing whether at least one distance (x, x1, x2) is maintained between two objects (22a..22d) transported by said conveyance device (1) using a signal emitted by the at least one sensor (17, 18, 23) in such a manner that a positive result is signalled when the objects (22a..22d) pass both detection ranges (A, B), the two detected ranges being at least free of objects (22a..22d) for a short time or at least partially covered such that at least the first distance (x, x1, x2) can be determined. The invention also relates to a method for testing whether the first distance (x, x1, x2) between two objects (22a..22d) transported by the conveyance device (1) is maintained.

Description

Conveying device and method for checking compliance with a minimum distance between two conveyed objects

The invention relates to a conveyor, comprising a plurality of locally in a conveying direction successive drives for the transport of objects with an actual speed, means for determining a desired position of an object by means of a target speed of the drives and the time since passing a reference point has elapsed, or by means of a predetermined by the drives desired path, which is traversed since passing a reference point, and a control / regulation for controlling or regulating a desired distance between two objects from said target position. Furthermore, the invention relates to a method for checking whether a minimum distance is maintained between two objects transported with a conveyor, wherein the objects are transported by means of several, in a conveying direction locally behind one another drives with an actual speed, a desired position of an object by means of a desired speed of the drives and the time which has elapsed since passing a reference point, or by means of a predetermined by the drives desired path, which is traversed since passing a reference point is determined, and a target distance between two objects is controlled or regulated on the basis of said desired position.

Conveyors are now widely used and, for example, from any warehouse, no production facility and no postal or baggage distribution system indispensable. They are used for the comfortable conveying and sorting of sometimes very heavy loads. Over time, many types of conveyors have evolved that are optimized for a particular application. Very often conveyors are designed as roller conveyors in which the conveyed is transported by individual, with the conveyed temporarily in contact, rollers. A likewise common type is a conveyor belt or a conveyor chain.

Fig. 1 shows an example of a conveyor 1 according to the prior art, specifically a roller conveyor. In this case, a plurality of drives 2 a, 2 b and 2 c between two rail-like frame parts 3 and 4 are arranged locally one behind the other. In the example shown there is a Drive 2a..2c in each case from a motor roller 5 and an auxiliary roller 7 connected thereto via a belt 6. If the drives 2a..2c are now activated, that is to say set in rotation, a conveyed item is transported in the conveying direction z in a manner known per se , Fig. 2 further shows the structure of a motor roller 5 according to the prior art. This comprises a fixed to the frame parts 3 and 4 and thus stationary axis 8. On the axis 8, two bearings 9 and 10 are arranged, which carry the outer shell 11. On the axis 8, the stator winding 12 is further arranged. On the outer shell 11 are two covers 13 and 14 for protecting the interior of the motor roller 5 against dust. Finally, a drive control 15, which is electrically connected to the stator winding 12, is arranged in the motor roller 5. A connection cable 16, which is connected to the drive control 15, is guided through a hole in the axis 8 (not shown) to the outside. Via the connecting cable 16, the drive controller 15 receives commands from a higher-level control (not shown). This control can selectively control individual motor rollers 5 and thus drives 2a..2c, ie, cause them to a certain speed, acceleration or deceleration, and thus convey a conveyed product flexibly via the conveyor device 1. In this case, a rotary field in the stator winding 12 is generated by the drive control 15, which then drives the outer jacket 11. The motor used is a brushless motor, which is actually a synchronous machine, which is driven by direct current and an inverter, and is used in modern conveyor systems for energy-related reasons and also because of the noise pollution If, for example, a single object is transported which covers five rolls in the conveying direction, then a zone can be formed which comprises, for example, six rollers within which rollers are driven Zone moves along with the conveyed object, so that in the present example only six rolls are always in operation, no matter how long the conveyor is. For example, US Pat. No. 6,729,463 shows a conveying device with flexible, in particular also "traveling" zones. The conveyor includes a zone address interface to which a plurality of motors are coupled to configure at least one zone control unit. With this arrangement, it is possible to control any, consecutive motors. With the help of sensors, which each consist of a transmitting and a receiving element and are each provided with an engine, the position of a subsidized object can be determined. Since conveyor systems can take on immense proportions, a large number of such transmitter / receiver pairs is therefore necessary. The conveyor system according to the prior art is therefore expensive and prone to errors due to the large number of sensors.

In addition, JP 7206132 shows a roller conveyor in which the conveyed material is measured with the aid of a light barrier arranged at the beginning of the roller conveyor. During transport of the conveyed material via the rollers, the position of the latter is continuously determined on the basis of the speed specified by the drives and used for the individual control of the motor rollers. A disadvantage of JP 7206132 is that faults on the conveyor are not recognized due to the lack of sensors. Thus, too large or too small distances between the objects to be conveyed, which arise for example due to the fact that there is a slip between the objects to be conveyed and the conveyor rollers, are not recognized. Likewise, objects removed or added or fallen by the conveyor on the conveyor route (possibly unauthorized) remain undetected.

While the solution disclosed in US Pat. No. 6,729,463 is impractical because of the large number of sensors (in particular in the case of large systems), the solution disclosed in JP 7206132 also appears because of the many undetected disturbances that are constantly occurring in practice not very effective. In particular, there is a lack of a secure method for determining the existence of a minimum distance between two objects of extraction, without, however, requiring a plethora of sensors.

The object of the invention is therefore to provide a conveyor or a method, which or which verifies compliance with a minimum distance between two conveyor objects with a small number of sensors. The object of the invention is achieved with a conveyor of the type mentioned, additionally comprising:

at least one sensor, which is provided for detecting a first area and a second area, wherein the second detection area is arranged in the conveying direction at a first distance behind the first detection area, and

Means for checking whether at least the first distance is maintained between two objects transported with the conveyor, with the aid of a signal of the at least one sensor, such that a positive result is signaled if, during the passing of the objects, both detection areas are free of objects at least in the short term are or are at least partially occupied only in such a way that the presence of at least the first distance can be concluded.

The object of the invention is further achieved by a method of the type mentioned above, in which a signal of at least one sensor, which is provided for detecting a first area and a second area, is evaluated in such a way that a positive result is reported, if during the passing of the objects, both detection areas are at least short-term free of objects or at least partially occupied in such a way that at least a minimum distance can be concluded, the second detection area, seen in the conveying direction, being at a first distance behind the first Detection area is arranged.

In this way, a conveyor or a method is provided, which or which verifies compliance with a minimum distance between two conveyor objects with a small number of sensors. For the implementation of the invention, only the provision of two detection areas, which are arranged one behind the other in a test distance in the conveying direction, is necessary. If, during the passing of the objects, both detection areas are free of objects, at least in the short term, at least a predetermined minimum distance exists between two objects. Alternatively, the detection areas can also be partially occupied only in such a way that the presence of the distance can be concluded. Slippage between the drives and the conveyed objects, as well as removed or added objects, does not affect the result of the test. Consequently, in a conveyor in which the desired position of an object by means of a desired speed or a desired path of the drives are determined to simple Way can be determined whether the actual distance between the objects actually corresponds to at least a desired distance. The disadvantages of the prior art are thus overcome with little technical effort. Finally, the invention can also be seen to recognize the necessity of a test facility for the object distance for a conveying device in which these object distances can be controlled or regulated per se.

For checking the two detection areas, a single sensor can now be provided which is able to scan both detection areas at the same time. Alternatively, the detection areas can also be scanned sequentially. If this takes place sufficiently quickly with respect to the conveying speed, the sequential scanning has only a negligible effect on the method according to the invention or the conveying device according to the invention. Of course, per each detection area, a sensor can be provided, so two sensors.

As the distance between the detection areas, the minimum distance to be checked is preferably provided. With an ideal digital sensor, the signal level will change when the object occupies half the detection area. The center distance of the two detection ranges then corresponds to the minimum distance to be checked. These conditions are not always available, so that the distance should be adjusted accordingly in deviations from the ideal conditions in a conventional manner. Furthermore, it is also conceivable that sensors are used with an analog output signal. In this case, the output signal should be evaluated accordingly. If the analog sensor delivers, for example, a linear output signal which depends linearly on the fraction of the occupied detection range, then a minimum distance exists if the center distance of the two detection ranges corresponds to the minimum distance to be checked and the sum of the relative sensor signals is 100%. In this case, a coverage area of 50% each is occupied, or one is 40% and the other 60% occupied, etc. If the areas are occupied to a lesser extent, there is even a larger distance between the subsidized objects. Advantageous embodiments and modifications of the invention will become apparent from the dependent claims and from the description in conjunction with the figures of the drawing. It is expedient for the conveying device to form a subsection of a conveying system which comprises a plurality of conveying devices located locally one behind the other in the conveying direction. Often conveyors are divided into several sections to simplify the operation of the system. The invention can now be advantageously used to produce clarity between the subsections in that at the interface between see two sections for the examination of a minimum distance between the subsidized objects is taken care, so that at least at the beginning of a sub-section ordered conditions.

It is also favorable if the first distance is smaller than the desired distance between two objects. In this way, a reliable statement can be made as to whether the required minimum distance between two objects is maintained.

It is also favorable if the desired speed of at least one drive is adjustable individually and differently from the desired speeds of the other drives. In this way, the objects on the conveyor can be moved individually. The conveyor is thus particularly flexible.

It is also favorable if a sensor is provided for detecting one area each. In this way, the conveyor can be made fault-tolerant insofar as the failure of a single sensor usually does not lead to the failure of the entire system.

It is advantageous if the second detection area is arranged in the conveying direction at the end of the conveyor. With this measure, the presence of a minimum distance between the same can be checked again at the end of a conveyor, ie before the conveyed objects leave the conveyor. The result can be transmitted to a subsequent conveyor or manipulation unit, which can initiate appropriate countermeasures in the event of a fault. The second detection area must be included not be located at the last possible location of the conveyor. It is sufficient if the said detection range is located in the end region of the conveyor.

In a further advantageous embodiment of the invention, the second detection area is arranged at a second distance, which corresponds to at least one length of an object - in each case in the conveying direction - arranged before the end of the conveyor. In this version, the first and the second detection range are arranged so far before the end of the conveyor that the conveyor itself can still make a correction of too small or too large a distance. In an advantageous embodiment of the invention, therefore, the control / regulation is prepared to the target distance between two objects upon receipt of a negative result or in the absence of a positive result by increasing / decreasing the relative speed of the first object / second object seen in the conveying direction relative to the second object / restore the first object. If, for example, too small a distance is detected between the objects to be conveyed, then the object to be conveyed, which has already passed the mentioned detection areas, can be accelerated slightly by the drives which are currently associated with the object to be conveyed in order to restore the required minimum distance. A subsequent conveying or manipulation unit can therefore assume that the required minimum clearances are met at the transfer point. This is of great advantage, in particular, when conveying devices and / or manipulators from different manufacturers are combined to form a conveyor system, since it can not be assumed a priori that each conveyor or each manipulator objects between which a certain distance is no longer present , can still handle correctly. It is particularly advantageous in the aforementioned variant, when a third detection area is arranged in the conveying direction at the end of the conveyor. In the variant set out last, it can not be assumed with the utmost certainty that the required minimum clearances can be restored, since even in this end region of the conveyor slip between the drives and the conveyed objects can not be completely ruled out. Therefore, a third detection area is arranged at the end of the conveyor. In a particularly advantageous embodiment of the invention, the control scheme is prepared to the second object upon receipt of a negative result or in the absence of a positive result in the first or stopping the second detection area until the first object passes through a third detection area arranged in the conveying direction after the first or second detection area. In this variant, a subsequent object is stopped until the object leaves the conveyor in the end region. Depending on the required level of security, the subsequent object can already be moved further if the object begins to leave the end area at the third detection area or only when it has actually left the end area.

It is favorable if a fourth detection area is arranged at the reference point. In principle, a drive, for example via the current absorbed by the motor, can also determine whether an object is in its conveying area or not. Even with very light objects to be conveyed even small fluctuations in current can lead to misinterpretations about the presence of an object. For this reason, an additional detection area is provided so that the position of the objects from the reference point can be determined more reliably.

It is furthermore advantageous if at least a fifth detection area, viewed in the conveying direction, is arranged in front of the first detection area and behind the fourth detection area. Conveyors can sometimes be very long, so that the position of objects due to measurement tolerances can no longer be determined with sufficient accuracy. Also removed or added, or fallen from the conveyor objects remain undetected for a relatively long time. For this reason, additional detection areas are provided in the course of the conveyor, in which it is checked whether the actual conditions on the conveyor still sufficiently accurately correspond to the expected conditions. In a further particularly advantageous embodiment of the invention, the distance between the objects is additionally determined on the basis of the desired speed of the drives and the time span or the desired path during which the fifth detection range is free when passing objects. If the actual distance between the objects does not correspond to the nominal distance, corrective measures can be initiated. It is advantageous if the control / regulation is prepared to the target distance between two objects:

by increasing / decreasing the relative speed of the first object / second object seen in the conveying direction relative to the second object / first object. if the determined distance is smaller than the nominal distance or

by decreasing / increasing the relative speed of the first object / second object seen in the conveying direction relative to the second object / first object, if the determined distance is greater than the desired distance.

In this way, faults in the operation of the conveyor can be detected and resolved relatively early, so that disturbances that are considered isolated even perhaps harmless in itself, not accumulate and may possibly lead to a total failure of the conveyor. It should be noted at this point that the variant of the invention just described also form the subject matter of an independent invention, ie can also provide a valuable contribution to ensuring a trouble-free operation of a conveying device without the first and second detection area according to the invention. A further advantageous embodiment of the invention comprises:

a second set of detection areas, which are arranged in reverse order and

Means for activating the second set upon reversal of the conveying direction. In this way, the conveyor can be operated in both conveying directions by simply switching to another set of detection areas. In particular, the detection areas are arranged in mirror image.

It is also advantageous if the conveying device according to the invention comprises means for reversing the order of the detection regions upon reversal of the conveying direction. In this variant, the system does not switch over to another set of detection ranges, but the detection ranges are rearranged according to the conveying direction. For example, sensors can be moved or pivoted to other detection areas. With the help of this variant of the invention, a change of the conveying direction is also feasible.

In a further advantageous variant of the invention, a Einschleuse- or ejection device or a switch is arranged between the first and second detection area. In this way, it is possible to check whether there is a distance between two conveyed objects. which corresponds to the length of a Einschleuse- or Ausschleusevorrichtung or a switch. This can significantly contribute to a trouble-free operation of the conveyor, as input or ejection operations or switching of switches can be done without interference.

It is advantageous if

a first detection area is arranged at the beginning of each partial branch of the conveyor, when the conveyor is brought together by a plurality of partial branches, respectively

a second detection area is arranged at the end of each partial branch of the conveyor, when the conveyor is divided into several sub-branches. In this variant, a detection area is arranged on each branch of a branch, be it caused by a Einschleuseoder ejection device or a switch, so that the relevant elements can always be kept free even when driving through various branches. At a simple branch, for example, three detection areas are needed, which are used depending on the direction in which the branch is traversed.

It is particularly advantageous if the first distance between the first and second detection regions and / or the second distance between the second and third detection regions is adjustable. In this way, compliance with different distances between the objects, which can also be different sizes, can be realized. This is particularly advantageous if objects of different types are conveyed on the same conveyors. For example, in the promotion of fragile material usually a greater distance between the objects is provided as a more robust Good.

It is advantageous if:

a plurality of first and / or second detection regions, which are arranged at different first distances in the conveying direction, and - means for selecting a first and second detection range are provided based on a set first distance.

In this variant, two suitable detection areas each are selected from a plurality of detection areas. Beween, for example, three detection areas Distances of 10 cm and 20 cm provided, so minimum distances of 10, 20 and 30 cm can be adjusted. Of course, this principle can also be extended to a higher number of detection ranges. It is also advantageous if:

a plurality of second and / or third detection areas, which are arranged in the conveying direction at different second intervals, and

Means are provided for selecting a second and third detection range based on a set second distance.

This variant is advantageously suitable for conveying devices with which objects of different sizes are often conveyed. In this case, the previously described principle is applied to the second and the third detection range.

It should be noted at this point that the variants mentioned for the conveyor device according to the invention and the resulting advantages are equally related to the method according to the invention and vice versa.

The above embodiments and further developments of the invention can be combined in any manner.

For a better understanding of the invention, this will be explained in more detail with reference to the following figures.

Each shows in a highly schematically simplified representation:

1 shows a roller conveyor in a perspective view according to the prior art.

2 shows a section through a schematically illustrated motor roller of a roller conveyor according to the prior art;

3 is a schematic representation of an exemplary conveyor according to the invention; the conveyor of Figure 3 at different times.

8 shows an exemplary pulse sequence recorded in a detection area;

FIG. 9 shows a set of first and second detection areas; FIG.

10 shows an exemplary conveying device for two different conveying directions;

11 shows an exemplary sensor for scanning a plurality of detection areas;

Fig. 12 is a conveyor with an input / ejection device and

Fig. 13 shows a conveyor, in which the inventive arrangement of detection areas is provided repeatedly.

By way of introduction, it is stated that in the variously described embodiments, identical parts are provided with the same reference numerals or the same component designations, wherein the disclosures contained in the entire description can be mutatis mutandis transferred to like parts with the same reference numerals or component names. Also, the location information chosen in the description, such as top, bottom, side, etc. related to the immediately described and illustrated figure and are to be transferred to the new situation mutatis mutandis when a change in position. Furthermore, individual features or combinations of features from the illustrated and described different embodiments may represent for themselves, inventive or inventive solutions.

The embodiments show possible embodiments of a conveyor according to the invention, it being noted at this point that the invention is not limited to the specifically illustrated embodiments thereof, but rather also various combinations of the individual embodiments are possible with each other and this possibility of variation due to the teaching of technical action representational invention in the skill of those skilled in this technical field. So there are also all conceivable variants, which can be achieved by combinations ner details of the illustrated and described embodiment are possible, includes the scope of protection.

FIG. 3 now shows an exemplary conveying device 1, here in the form of a roller conveyor, with a plurality of drives 2 arranged locally one behind the other in a conveying direction and individually controllable drives 2. A drive 2 can be formed from a motor roller 5 or as shown in FIG , For example, from a motor roller 5 and one or more driven with a belt 6 auxiliary roller (s) 7. It is conceivable, of course, that a drive consists of a (more or less short) conveyor belt. For example, a conveyor belt can be tensioned via the motor roller 5 and the auxiliary roller 7 in FIG. 1, if this is advantageous due to the nature of the objects to be conveyed. Of course, the length of the conveyor belt can be made larger. Equally, of course, a conveyor chain can be provided. In the rear region of the conveyor 1, a first detection area A and a second detection area B are arranged behind it in a first distance x seen in the conveying direction z. In the present example, each detection area is monitored by its own sensor. The first detection area A is therefore associated with the first sensor 17, the second detection area B with the second sensor 18. At the end of the conveyor 1 there is a third detection area C or a third sensor 19.

The third detection area C is arranged behind the second detection area B in a second distance y, as seen in the conveying direction z. At a reference point p at the beginning of the conveyor, a fourth detection area D or a fourth sensor 20 is located between the fourth detection area D and the first detection area A, finally a fifth detection area E or a fifth sensor 21 is located.

For the sake of simplicity, it is assumed for the following considerations that the sensors 17..21 are light barriers. However, this is by no means mandatory as will be explained later. In Fig. 3 unspecified local control units along the conveyor 1 are arranged, which receive commands of a higher-level control and redistribute them to the drives 2. The function of the arrangement shown in FIG. 3 is as follows.

At the beginning of the conveyor 1 different objects are stored at different times, which are conveyed in sequence by the drives 2. Fig. 4 shows the conveyor 1 of FIG. 3 at a later time. On the conveyor 1 are at this time the objects 22a, 22b, 22c and 22d. When passing the reference point p or the fourth detection range D, the objects 22a..22d were measured by the fourth sensor 20 with regard to their length and with regard to the distance between them. For example, the first object 22a has a length 1. Alternatively or additionally, the force emitted by the first drive 2, for example in the form of the current absorbed by the motor, can be used to determine the said lengths and distances. Fluctuations in the motor current indicate when an object 22a..22d is being conveyed by the relevant drive 2 or not. In a particularly advantageous embodiment, the information from the fourth sensor 20 and from the first drive 2 are compared with one another in order to largely avoid errors in the initial detection of the objects 22a, 22d.

A target position of an object 22a..22d can now with the aid of a target speed of the drives 2 and the time which has elapsed since passing the reference point p, or with the aid of a predetermined by the drives 2 target path, which pass since the reference point p is traversed, are determined. With this information and the length of an object 22a..22d, for example, the length 1 of the first object 22a, those drives 2 can now be determined in a conventional manner, which are currently in contact with an object 22a..22d and driven accordingly become. In order to avoid collisions, a control of the conveyor 1 in this example provides protection zones around the objects 22a, 22d, each of which is slightly larger than the objects 22a, 22d (shown in dashed lines). This results in a predetermined by the controller target distance between the objects 22a..22d, which is controlled or regulated accordingly, most easily by the fact that all drives 2 specify the same target speed. The promotion of objects 22a..22d with the aid of individually controllable drives 2 is known in principle and will therefore not be explained in detail here. In any case, it is clear that the actual speed or actual position of an object 22a..22d does not necessarily coincide with the desired speed or the desired position of the respective object 22a..22d. For example, a drive 2 can slip through during the acceleration of an object 22a..22d and thus counteract an accurate position determination via the setpoint speed or the desired path of the drives. Likewise, an object 22a..22d may slip over a drive 2 during deceleration or be advanced by subsequent objects 22a..22d. Finally, an object 22a..22d can be removed from the conveyor 1 at all or fall off it, or an object 22a..22d is added. In practical operation of a conveyor system 1, all this can easily occur.

As can be seen in FIG. 4, the mentioned protection zone between the first object 22a and the second object 22b is observed, but the second object 22b and the third object 22c are in contact with each other, a minimum distance is not present here.

In Fig. 5, which shows the conveyor 1 at a later time, the first object 22a has already passed the first detection area A and the second detection area B. As can be easily seen from FIG. 5, both detection areas A, B are free of objects 22a, 22b at short notice, so that the result of the check as to whether a minimum distance x has been maintained is positive. Depending on the design of the control of the system 1 can now be provided that positive and negative, only negative or positive results are reported active. If not both positive and negative results are reported, e.g. even the absence of a negative result can be considered a positive result. In any case, there is still no need for action in FIG. 5 to correct the distance between the first and second objects 22a and 22b. The objects 22a..22d are therefore simply moved on uniformly.

6 shows the conveyor 1 at a time when the first object 22a has already almost left the conveyor 1 and to which the third object 22c, which is in fact applied to the second object 22b, occupies both detection areas A and B. As is readily apparent from Fig. 6, when passing the second and third objects 22b and 22c, there is no timing at which both detection areas A and B are free of objects 22b and 22c. According to the invention it is now found that a required minimum distance between the second and the third object 22b and 22c is not present. Accordingly, the second object 22b is accelerated to restore the required distance. Alternatively or additionally, the third object 22c may also be delayed. The third detection area C has not yet been used in the previous example. His

Function will now be explained with reference to FIG. 7, which shows the conveyor 1 at a time when, starting from the state shown in FIG. 6, the second object 22b has been returned to the third detection area C and the third object 22c has returned to the first detection area A. Alternatively, if the distance y is chosen to be sufficiently large, the third object 22c may also be retracted only in front of the second detection area B. The first object 22a has now left the area of the conveyor 1 at all, the fourth object 22d remains in a waiting position.

The third object 22c is now stopped at the first detection area A until the second object 22b passes the third detection area C. It can be provided that the third object 22c is not moved further until the second object 22b has left the third detection area C or already when the second object 22b begins to move. Of course, intermediate solutions are conceivable. Instead of simply accelerating or decelerating objects 22a, 22d, as in FIG. 6, and trusting that the required distances will be corrected accordingly, this variant of the invention actually ensures that such a distance is also maintained. This even if there should be slip between the objects 22a..22d and the drives 2. Of course, the method explained for any number of objects 22a..22d, between which a required minimum distance x is not met, applicable.

Optionally, the occurrence of too small a distance can also be displayed on a control panel of the conveyor system 1. It is also conceivable that when a too small distance from a "normal operation" in a "disturbance operation" is switched in which additional precautions are taken. For example, the conveying speed can be reduced on the entire conveyor or on only a part thereof. Do not become too small distances x more detected, then it can be switched back to normal operation.

In the following, the function of the fifth detection area E will be explained. It may be that the required distances are not met even before the detection area E. In this case, both too large distances may exist (reduce the capacity of the conveyor) or too small (can cause interference). With the aid of the fifth detection area E, the distance between two objects 22a and 22b is now determined from the target speed of the drives 2 and the time span or the desired path during which the fifth detection area E is free of objects 22a..22d, determined. An incorrect distance can be corrected in sequence by appropriate control of the drives 2. Of course, any number of fifth detection areas E can be provided.

In addition to incorrect distances but also missing or added objects can be detected. As mentioned, yes, at the beginning of the conveyor 1, it is determined which objects 22a, 22d (i.e., objects of which length) are being transported at which intervals. Therefore, at the output of a digital fourth sensor 20, a pulse train corresponding to the conveyed objects 22a..22d would be output. FIG. 8 shows such an exemplary pulse sequence, here in a diagram voltage U over time t. It is conceivable, of course, that instead of a time signal, a path signal of a drive 2 is used to generate the pulse sequence shown. In this case, a plot of voltage U across the path would result. Instead of the voltage U, of course, any other suitable property of a sensor output can be used. If the transport of the objects 22a..22d now proceeds error-free, the same pulse sequence is received in the fifth detection range E as in the fourth detection range D, only with a time delay. However, if the pulse sequences deviate from one another, the transport of the objects 22a..22d has not occurred without errors. Advantageously, one will tolerate a degree of deviation before an alarm is triggered or other countermeasures are taken. Depending on the set threshold, the system reacts more or less sensitively.

There are several possibilities for comparing the pulse sequences. For example, the correlation of the pulse sequences detected by the regions D and E may be formed become. It is also conceivable that the pulse lengths and / or pulse pauses (depending on the design of the logic so the object lengths / distances or distances / object lengths) are evaluated.

The method explained for the detection range E can, of course, also be carried out at the detection range A or B, in addition to the method described in FIGS. 3 to 6. In this way, a particularly comprehensive control of the flow of funding can be realized. However, the method carried out on the detection area E can also be carried out independently of the method provided for the detection areas A and B and thus form the subject of an independent invention.

At this point, it is once again made clear that from the fact that a detection area A..E is occupied by an object 22a..22d, no conclusions can be drawn on its own which object 22a..22d currently has a detection area A..E covered. This information is obtained from the position determination of the objects 22a..22d with the aid of the reference point p. Accordingly, an alarm can be issued or other measures can be initiated if a gap between two objects 22a..22d is to pass a detection range A..E at a certain time, but this is actually not the case. This applies both to the method described by the coverage areas A and B and to the method described by the coverage area E.

9 now shows a possibility for arranging a plurality of first and / or second detection regions which are arranged at different first distances, from which a specific first and second detection region is selected according to a set distance. Specifically, three detection areas are provided at intervals of x1 and x2. Depending on which distance is to be checked, certain area pairs are selected. If the ranges AI and Bl are selected, the minimum distance xl + x2 can be checked. If A2 and B2 are selected, the minimum distance x2 can be checked, and if A3 and B3 are selected, the minimum distance xl can be checked. Of course, the illustrated principle can be extended to any number of detection ranges, or be applied to the distance y.

10 now shows a variant of the invention in which a second set of detection areas A..E is arranged in the reverse order, which in case of reversal of the conveyor direction z can be activated. 10 shows a conveying device 1 with a total of 7 detection areas A1..E2, the indices indicating the use of the areas A1..E2 for the respective conveying direction. A first set for the first conveying direction zl is formed as usual by the detection areas AI .. El (see also FIGS. 3 to 6). When the conveying direction is reversed, that is to say in the conveying direction z2, the detection area C1 becomes Dl, the areas A1 and B1 are not required, the areas A2 and B2 are added, the detection area D1 becomes C2, and the area El becomes E2.

In a variant of the invention, a separate sensor is assigned to each detection area A1..E2, for example a light barrier or a capacitive distance sensor, which is activated as required. Advantageously, the sensors can then be connected to the conveyor 1 fixed.

Alternatively, the detection ranges A..E can also be shifted accordingly.

Fig. 11 shows one of several possibilities. In this case, the first and the second detection range A and B are detected by a single sensor 23, or scanned. By way of example, the sensor 23 is a laser which is arranged above the conveying device 1 and can be pivoted. It is sufficient if instead of the whole device only the laser beam can be deflected in a conventional manner by means of a mirror. The laser beam can now be moved back and forth between the first and second detection areas A and B, or it can also be scanned line by line. Modern laser deflection units are usually so fast that the time delay between detection of the first area A and the second area B for the invention has only a marginal effect. For the interests of the invention can therefore be assumed as a rule of a quasi-simultaneous detection. By known per se laser distance measurement, which is in principle possible without a dedicated reflector, it can now be determined whether objects 22a..22d are in the detection area A, B, since the distance measured by the sensor 23 upon entry of an object 22a. .22d changes abruptly into the detection range (strictly speaking, this only applies to objects 22a..22d of a certain height, ie not flat objects 22a..22d - unless the sensor 23 measures A..E when the detection range is empty the conveyor 1 through, for example, the laser can scan the space between two rollers 5 and 6). Of course, reflectors can also be provided for detection areas A and B. although the danger of pollution and breakage is always present in the harsh operating environment. Advantageously, even flat objects 22a..22d are thus detected in any case. In the same way, other sensors 23 can be used, which can detect their surroundings in a beam shape. Examples include ultrasonic distance sensors and radar distance sensors or a video camera with attached image processing. Of course, these can also be provided for the detection of several areas A..E and of course several such sensors can be provided. The particular advantage of this variant of the invention is that the detection ranges A..E can be very flexible, both in terms of their shape and size and their position. Objects 22a, 22d of different sizes with different distances and different conveying directions z can therefore be taken into account particularly easily. By appropriate reprogramming, eg the deflection unit of the laser beam, the detection ranges A..E can be easily rearranged under changed operating conditions.

In Fig. 11, the sensor 23 is located only at a small height above the conveyor 1. It is also conceivable, however, that the sensor 23 is at a greater distance to the conveyor device 1. For example, the sensor 23 may be mounted on the ceiling of a hall in which the conveyor 1 is located. In this case, for example, the sensor 23 may also detect the fourth detection range D at a relatively steep angle. From the position shown in FIG. 11, this is possible only at a very shallow angle, which greatly increases the probability of error detections.

Finally, the shifting of detection areas A..E can also be effected simply by displacing the sensors 17..21 themselves along the conveyor device 1. For example, light barriers are conceivable that can be moved by means of a carriage in the conveying direction z, for example by means of a spindle or a toothed belt. Here are many design options conceivable that tap the expert due to his expertise in a simple way. FIG. 12 now shows a variant of the invention in which an infeed or outfeed device 24 is arranged between the first and second detection areas A, B. In this case, a detection area is arranged on each partial branch, here it is the first detection area A, the second detection area B and the sixth detection area F. If conveying is carried out in the conveying direction z, then only the first and second detection areas A and B are in operation , which take over the already explained function. If an object 22a..22d is now ejected, the function of the detection area B is adopted from the sixth detection area F. If an object 22a..22d is introduced, on the other hand, the sixth detection area F assumes the function of the first detection area A. If the conveying direction z is reversed, the conditions are correspondingly reversed. Of course, the principle shown can equally be applied to a switch. Advantageously, it can thus be checked whether there is such a distance between two objects that the entry or exit area or the area of a point is free of objects 22a, 22d.

In the following, some "traditional" operating modes of a conveyor 1 are explained:

1) Dusting operation: Here, the objects 22a... 22d are simply jammed at the end of the conveying device, that is to say they are pushed against each other in such a way that they are shown in dashed lines in the figures

Protected zones lie against each other. Alternatively, it is also conceivable that the objects 22a..22d are jammed so that they touch each other. In this case, subsequent objects 22a..22d can also be expelled on idling drives by utilizing their kinetic energy and can be driven onto already jammed objects 22a..22d. In this case, it is expedient to stop the first object 22a, 22d already slightly in front of the detection areas A, B, or C, so that it is not unintentionally pushed past the detection areas A, B or C by subsequent objects 22a, 22c. Optionally, the drives 2 in the storage zone can also be controlled so that they apply a holding force on the objects 22a..22d.

2) Single outlet: The objects 22a..22d jammed at the end of the conveyor 1 are now separated again by the objects 22a..22d being moved one after the other, ie with a time delay, by the conveyor device 1. 3) Block exit: Here the jammed objects 22a..22d are treated as a block and processed as a whole. The objects 22a..22d are therefore set in motion simultaneously. By different speeds for the objects 22a..22d, the distances between them can also be increased slightly. In order to avoid high current peaks when starting a plurality of drives 2, they can also be controlled a little time offset. This operating mode then resembles the single run-out.

The positions of the objects 22a..22d or the distances between them can in the different modes in a conventional manner by means of a target speed of the drives 2 and the time which has elapsed since passing a reference point p, or with the aid of one of the drives 2 predetermined desired path, which is traversed since passing a reference point p determined. According to the invention, compliance with the distances is then tested as already described. However, a particular advantage of the invention consists in the fact that the separation of the objects is possible in principle only with the aid of the detection areas A and C or B and C. In this way, an emergency operation of the conveyor 1 can be maintained even if the above-mentioned position and distance determination on the reference point p is not possible because e.g. important components have failed. If necessary, this emergency operation can also be maintained during the replacement of defective components. The conveyor 1 according to the invention is thus not only particularly safe but also particularly fault-tolerant.

The invention has been explained primarily with reference to detection ranges A..E. These can be scanned by various types of sensors. For example, light barriers with and without reflector, simple mechanical switches, which are actuated by the objects 22a..22d, ultrasonic sensors, lasers, radar sensors, capacitive sensors, video cameras with image processing, infrared sensors, but also Barcode readers, RFID readers, etc. are used (for bar code readers and RFID readers, it is advantageous if the objects 22a.22d carry their identification always in the same place, otherwise a correspondingly larger distance should be provided between the readers ). Of course, mixed forms of said sensors are also conceivable. The implementation of the method according to the invention can be carried out in hardware and / or software. For example, corresponding program steps and parameters are stored in a memory, which are read out and executed by a processor at runtime. Another possibility would be to use a PLC (programmable logic controller) for this purpose. It is also conceivable, for example, that the invention with the help of a

ASICs (Application Specific Integrated Circuit) is implemented. These are of course only a few examples of many ways in which the method according to the invention can be implemented and therefore serve merely to illustrate the invention. Of course, the invention is not bound to a roller conveyor. Rather, the invention can be used for example for conveyors, which promote the conveyed via belts or chains. The sub-area in which a drive transported a conveyed material is then different, usually larger. Also, the invention is not bound to a motor role as shown in Fig. 2. Rather, the drive of the rollers can also be done via (external) motors. Of course, the drive by means of electrical energy is not mandatory for the invention. Also conceivable are e.g. pneumatic or hydraulic drives. Finally, linear drives in the form of, for example, sliders or the like are conceivable. These can also be operated electrically, pneumatically or hydraulically.

For completeness, it is noted at this point that the shown arrangement of first and second detection areas A and B or the optional third to sixth detection areas C..F can be provided as often as desired on a conveyor. It is also possible that in the detection areas A..F multiple functions are performed. For example, the third detection area C can function as a fourth detection area D of a subsequent conveyor section, ie, in the third detection area C, a pulse sequence corresponding to FIG. 8 can also be detected in addition to the originally assigned function. This pulse train can additionally be detected in the first and / or second detection area A and B. FIG. 12 shows an example in which the first to third detection area (corresponding to the inventive variant according to claim 5) is provided several times on a conveyor device 1. In the conveying direction z, the detection ranges AI, Bl, Cl (at the same time fulfills the function of the fourth area in the next section D2), A2, B2, C2 (simultaneously fulfilling the function of the fourth area in the next section D3), and so on. Of course, other sequences are conceivable, especially mixed forms. For the sake of order, it should finally be pointed out that in order to better understand the construction of the conveyor device 1, this or its components have been shown partially unevenly and / or enlarged and / or reduced in size.

The task underlying the independent inventive solutions can be found in the description.

Above all, the individual embodiments shown in FIGS. 3 to 12 can form the subject of independent solutions according to the invention. The relevant tasks and solutions according to the invention are to be found in the detailed descriptions of these figures.

REFERENCE NUMBERS

1 conveyor

2, 2a..2c drive

3 left frame part

4 right frame part

5 motor role

6 straps

7 auxiliary roller

8 axis

9 left bearing

10 right camp

11 outer jacket

12 stator winding

13 left lid

14 right lid

15 drive control

16 connection cables

17 first sensor

18 second sensor

19 third sensor

20 fourth sensor

21 fifth sensor

22a..22e (conveyor) objects

23 lasers

24 input / output device

A first detection area

B second detection area

C third detection range

D fourth coverage area

E fifth detection range

F sixth detection range

1 object length

P reference point

t time

U voltage

x, xl, x2 first distance

y second distance

z, zl, z2 conveying direction

Claims

Patent claims

1. conveying device (1), comprising:

a plurality of drives (2, 2a..2c) located locally behind one another in a conveying direction (z, z1, z2) for transporting objects (22a..22d) at an actual speed,

Means for determining a desired position of an object (22a..22d) by means of a desired speed of the drives (2, 2a..2c) and the time which has elapsed since passing a reference point (p), or with the aid of a from the drives (2, 2a..2c) predetermined target path, which is traversed since passing a reference point (p), and a control / regulation for controlling or regulating a desired distance between two objects (22a..22d) based said target position,

marked by

at least one sensor (17, 18, 23), which is provided for detecting a first area (A) and a second area (B), wherein the second detection area (B) in the conveying direction (z, zl, z2) seen in a first distance (x, xl, x2) is disposed behind the first detection area (A), and

Means for checking whether at least the first distance (x, x1, x2) is maintained between two objects (22a, 22d) transported by the conveyor (1), with the aid of a signal from the at least one sensor (17, 18, 23) in such a way that a positive result is signaled if during the passing of the objects (22a..22d) both detection areas (A, B) are at least short-term free of objects (22a..22d) or at least partially occupied in such a way are that can be concluded on the existence of at least the first distance (x, xl, x2).

2. conveying device (1) according to one of the preceding claims, characterized in that the first distance (x, xl, x2) is smaller than the desired distance between two objects (22a..22d).

3. conveying device (1) according to one of claims 1 to 2, characterized in that the second detection area (B) in the conveying direction (z, zl, z2) seen at the end of the conveyor (1) is arranged.

4. conveying device (1) according to one of claims 1 to 2, characterized in that the second detection area (B) at a second distance (y) which corresponds to at least a length of an object (22a..22d) - respectively in the conveying direction (z, zl, z2) seen - is arranged in front of the end of the conveyor (1).

5. conveying device (1) according to claim 4, characterized in that a third detection area (C) in the conveying direction (z, zl, z2) seen at the end of the conveyor (1) is arranged.

6. conveying device (1) according to one of claims 1 to 5, characterized in that at least a fifth detection area (E) in the conveying direction (z, zl, z2) seen before the first detection area (A) and behind a at the reference point (p ) arranged fourth detection area (D) is arranged.

7. conveyor (1) according to one of claims 1 to 6, characterized by a second set of detection areas (A..E), which are arranged in reverse order and

Means for activating the second set upon reversal of the conveying direction (z, zl, z2).

8. conveying device (1) according to one of claims 1 to 6, characterized by

Means for reversing the order of the detection areas (A..E) upon reversal of the conveying direction (z, zl, z2).

9. conveyor (1) according to one of claims 1 to 8, characterized in that between the first and second detection area (A, B) a Einschleuse- or Ausschleusevorrichtung (24) or a switch is arranged.

10. conveying device (1) according to claim 9, characterized in that

- Each a first detection area (A, F) is arranged at the beginning of each sub-branch of the conveyor (1), when the conveyor (1) is merged by a plurality of sub-branches, respectively

a second coverage area (B, F) at the end of each sub-branch of the funding Device (1) is arranged when the conveyor (1) is divided into several sub-branches.

11. conveying device (1) according to any one of the preceding claims, characterized in that the first distance (x, xl, x2) between the first and second detection area (A, B) and / or the second distance (y) between the second and third detection range (B, C) is adjustable.

12. conveying device (1) according to claim 11, characterized by

- A plurality of first and / or second detection areas (A, B), which in the conveying direction (z, zl, z2) seen at different first distances (x, xl, x2) are arranged, and

Means for selecting a first and second detection range (A, B) based on a set first distance (x, xl, x2).

13. conveying device (1) according to claim 11 or 12, characterized by

a plurality of second and / or third detection regions (B, C), which are arranged in the conveying direction (z, zl, z2) at different second distances (y), and

Means for selecting a second and third detection range (B, C) based on a set second distance (y).

14 conveyor (1) according to one of claims 1 to 13, characterized in that the control / regulation is prepared to the target distance between two objects (22a..22d) upon receipt of a negative result or in the absence of a positive result by increasing / Lowering the relative speed of the first object (22a) / second object (22b) seen in the conveying direction (z, zl, z2) with respect to the second object (22b) / first object (22a).

15. A conveyor (1) according to any one of claims 1 to 14, characterized in that the control is prepared to receive the second object (22b) upon receipt of a negative result or in the absence of a positive result in the first or second detection range (A, B) to stop until the first object (22a) in a conveyor direction (z, zl, z2) after the first or second detection area (A, B) arranged third detection area (C) passes.

16. Conveying device (1) according to one of the preceding claims, characterized in that the control / regulation is prepared in addition to the distance between the objects (22a..22d) based on the target speed of the drives (2, 2a. .2c) and the time span or the target path during which the fifth detection area (E) is free from passing through objects (22a..22d).

17. Conveying device (1) according to claim 16, characterized in that the

Control is prepared to set the desired distance between two objects (22a..22d):

by increasing / decreasing the relative speed of the first object (22a) / second object (22b) seen in the conveying direction (z, zl, z2) with respect to the second object (22b) / first object (22a), if the determined distance is smaller as the nominal distance or

by lowering / increasing the relative speed of the first object (22a) / second object (22b) seen in the conveying direction (z, zl, z2) with respect to the second object (22b) / first object (22a), if the determined distance is greater as the nominal distance.

18. Method for checking whether at least one distance (x, x1, x2) is maintained between two objects (22a, 22d) transported by a conveyor (1), wherein the objects (22a, 22d) are separated by means of a plurality of objects (22a, 22d) a conveying direction (z, z1, z2) of drives (2, 2a..2c) located one behind the other are transported at an actual speed,

a target position of an object (22a..22d) with the help of a target speed of the drives (2, 2a..2c) and the time which has elapsed since passing a reference point (p), or with the aid of one of the drives (2, 2a..2c) predetermined target path, which is traversed since passing a reference point (p), is determined and

a desired distance between two objects (22a, 22d) is controlled or regulated on the basis of said desired position,

characterized, in that a signal of at least one sensor (17, 18, 23), which is provided for detecting a first area (A) and a second area (B), is evaluated in such a way that a positive result is reported, if during the passing of the objects (22a..22d) both detection areas (A, B) are free of objects (22a..22d) at least in the short term, or are at least partially occupied only in such a way that the presence of at least the distance (x, xl, x2) can be closed, wherein the second detection area (B) in the conveying direction (z, zl, z2) seen at a first distance (x, xl, x2) behind the first detection area (A) is arranged.

19. The method according to claim 18, characterized in that the desired distance between two objects (22a..22d) upon receipt of a negative result or absence of a positive result by increasing / decreasing the relative speed of the in the conveying direction (z, zl, z2) seen first Object (22a) / second object (22b) relative to the second object (22b) / first object (22a) is restored.

20. The method according to claim 18, characterized in that the second object (22b) on receipt of a negative result or in the absence of a positive result at the first or second detection range (A, B) is stopped until the first object (22a) one in the conveying direction (z, zl, z2) after the first or second detection range (A, B) arranged third detection area (C) happens, wherein - each in the conveying direction (z, zl, z2) seen - the distance between the third detection area ( C) and the first and second detection area (A, B), in which the second object (22b) is stopped, at least the length of the first object (22a) corresponds.

21. Method according to one of the preceding claims, characterized in that, when two objects (22a..22d) pass through a fifth detection area (E) which, viewed in the conveying direction (z, z1, z2), precedes the first detection area (A). in addition, the distance between the objects (22a..22d) is determined based on the target speed of the drives (2, 2a..2c) and the time period or the target path, during which the fifth detection range (E) free of objects (22a..22d) is detected.

22. The method according to claim 21, characterized in that the desired distance between two objects (22a..22d): by raising / lowering the relative speed of the first object (22a) / second object (22b) seen in the conveying direction (z, zl, z2) from the second object (22b) / first object (22a), if the determined distance becomes smaller is as the nominal distance or

by decreasing / increasing the relative speed of the first object (22a) / second object (22b) seen in the conveying direction (z, zl, z2) with respect to the second object (22b) / first object (22a), if the determined distance is greater is the desired distance.