DE102008038286A1 - Method for weighing empty packaging, particularly bottles or cans, involves recording type of empty packaging, where accepted empty weight of empty packaging, corresponding to recorded type, is determined in time-dependent manner - Google Patents

Abstract

The method involves recording a type of empty packaging (2). An accepted empty weight of the empty packaging, corresponding to the recorded type, is determined in a time-dependent manner, where the empty packaging is rejected, when the accepted empty weight is exceeded. The rejection or separate handling of the empty packaging is determined. Independent claims are included for the following: (1) a software, particularly a data structure with the software code sections; and (2) a device for weighing empty packaging, particularly bottles or cans.

Description

FIELD OF THE INVENTION

The The invention relates generally to the weighing of empties, so bottles and / or cans, in the case of empties return and concerns in particular a method for weighing empties with variable accuracy.

BACKGROUND OF THE INVENTION

In reverse vending machines, the assumed empties with the help of a conveyor device, as this example in the DE 103 53 537 B4 the Applicant is described, while capturing its weight and at the same time detects the type of empties, for example by means of an attached to the empties identification feature, such as a bar code or other optical coding. In order to achieve the highest possible take-back volumes, the fastest possible but reliable detection of the weight of the empties is of great importance.

Based on the information collected for the empties, a decision can then be made as to how the empties are to be further processed. Such a device is for example from the WO 02/089078 A1 in which a sorting station is controlled on the basis of the detected identification feature.

The 1 shows a typical weighing operation in a reverse vending machine according to the prior art. The 1 shows the time dependence of the recorded weight of an empties. Since the empties are usually inserted more or less through an acceptance opening of the reverse vending machine, or the conveyor of the reverse vending machine causes oscillations, this leads to oscillations in the detection of the weight of the empties, which are attenuated due to the system characteristics of balance or scale and conveyor. The balance is characterized by a zero weight T (also called TARA), which is deducted from the recorded weight, or is not taken into account. After several oscillations, they are sufficiently damped to determine the net weight (NW) of the empties. This state is determined by means of a termination criterion, which is based on the measured time dependence of the weight of the empties. In the 1 is the occurrence of the condition of a sufficient measurement accuracy of the weight of the empties indicated by the vertical dashed line.

The The present invention now proceeds from a weighing method for each type of empties a maximum allowable Curb weight is set, resulting from the target curb weight of a completely emptied empties plus a maximum residual quantity calculated on liquid in the empties. For example can be set to reject the empties or Alternatively, separately treated (for example by Sorting out) when the empties are still more than ten percent of his maximum capacity is filled. In order to may be an undesirable contamination of the reverse vending machine and / or downstream handling stations reliable be avoided.

SUMMARY OF THE INVENTION

task It is the object of the present invention to provide a method and an apparatus to provide for the emptying of empties of the aforementioned type, whereby a quick but reliable decision allows is to decide whether to refuse an empties to be recorded or separately.

These The object is achieved by a method according to claim 1, a software or data structure according to claim 10 and by a Apparatus according to claim 11, further advantageous embodiments are the subject of the dependent claims.

Consequently The present invention is based on a method for weighing empties, in particular bottles and / or cans, in which the Type of empties recorded and in accordance with the detected type set a maximum permissible empty weight of the empties becomes; the weight of the empties is recorded; and further determined will reject that empties or treat them separately is when it is determined from the weight recorded that the maximum permissible empty weight is exceeded.

According to the The present invention, in the method, the weight of the empties time-dependent, becomes out of the time dependency of the detected weight, the accuracy of the detection of the weight the empties are estimated and will be the capture of the weight the empties are canceled when it is determined that the so-valued Accuracy of detecting the weight of the empties sufficient is to the reassignment or special treatment the empties.

The present invention is therefore based on the finding that for a reliable decision whether to reject the empties just to be detected or to treat separately, an exact gram-accurate detection of the weight of the empties is not required, but that it out is sufficient, with sufficient probability to make a statement as to whether the termination criterion of a maximum allowable residual filling with liquid is met or not. In particular, for large empty containers, so with a large maximum capacity, such a decision can be made after one or a few oscillations in the temporal dependence of the detected weight, ie at a time when the actual weight of the empties is not determined with sufficient accuracy However, with sufficient probability, a determination can be made that the maximum permissible residual filling is not exceeded. In particular, for large empty containers, but in principle for arbitrarily large empty containers, thus resulting in accordance with the invention significant speed advantages in the detection and evaluation of the weight of the empties to be detected, resulting in significantly higher return volumes of reverse vending machines.

at A method according to the invention is the process of weighing the Empties are assigned an operation to record the type of empties. For this purpose, an identification feature of the empties, for example an optical feature, a barcode, an optical coding or the like, or the type of empties based on others Characteristics, such as shape, size, color, transparency, Material or the like of the empties, detected without contact become. For the thus-detected empties are in correspondence the type from a database stored in a memory Target empty weight, ie empty weight with completely empty Container, and the associated maximum residual filling of such a container type and read out the respective maximum permissible curb weight of the identified type empties calculated or fixed.

at In addition, according to the method, the weight of the empties becomes time-dependent which usually causes muffled oscillations a measured signal for the detected weight leads. From the time dependence of the recorded weight is based predetermined criteria, as exemplified below, estimated the accuracy of the detection of the weight of the empties. According to the invention, the detection of the weight of the empties canceled, if for the just to be detected Empties are found that the accuracy of the detection of Weight of the empties is sufficient to the rejection or separate handling of the empties.

expedient the measured values of the weight of the empties are continuously digitized and the thus digitized weight readings to estimate the Accuracy of capturing the weight of the empties analyzed. For example, from the time course of the measured Weight force revealed that the oscillations of the weight already sufficiently strongly damped, so that with sufficient Probability can be assumed that the aforementioned Maximum permissible empty weight of empties not exceeded is. This can be determined, for example, when the digitized Weight readings at any time or with a predetermined overwhelming Probability smaller than the aforementioned maximum allowable Curb weight.

According to one Another embodiment will be digitized from the aforementioned Weight readings minima and maxima determined. Based on these maxima and minima then a statement can be made how strong the Oscillations of the scale system have already subsided, resulting in for example, by continuous comparison of immediately consecutive Maxima and minima can be determined. If it is determined that the oscillation amplitude of the weight measurements is sufficient has subsided to ensure that during a vibration cycle all digitized weight readings or a predeterminable fraction thereof smaller than the aforementioned maximum allowable empty weight of the empties are, the weighing process can aborted and a decision on the rejection or separate handling of the empties with sufficient probability to be hit.

According to one Another embodiment is from the aforementioned maxima and minima of the weight readings a running average, then based on the accuracy of the detection of the weight of the empties is estimated. For example, as Abort criterion be selected so that the determined running average or running mean plus one more size less than the maximum permissible empty weight of the empties is.

These another size can be, for example, from the vibration amplitude a current vibration cycle, as determined from the last two Maxima and minima are determined, derived, for example with multiplied by a predefinable percentage, the smaller than 100 percent.

According to a further embodiment, the aforementioned further variable is derived from a standard deviation, that is to say a statistical variable which is determined from a predetermined number of previous detections of the weight of empties. For this purpose, a predetermined number of correspondingly executed previous weight measurements may be used. Alternatively, NEN for the balance system also once, for example, at system startup or production, a predetermined number of reference weighing operations are performed, resulting in, for example, statements about the damping in the balance system and the like.

According to one Another embodiment is in addition to the detection The type of empties determines whether the empties are a means of closure whose weight then in the affirmative case from a database is read out and in the calculation of the aforementioned maximum permissible empty weight of the empties becomes.

Further Aspects of the present invention relate to software, in particular data structure, for example stored on any Media or downloadable over a data network or executable online by connecting to a data network, wherein the software comprises software code sections which, when used by a processor unit, causing it to to carry out the aforementioned method of weighing, as well as a corresponding device for weighing empties, preferably in the form of a reverse vending machine for empties Installation at any location, for example in a supermarket.

FIGURE OVERVIEW

following the invention will be described by way of example and with reference are described on the accompanying drawings, from which provide further features, advantages and tasks to be solved become. Show it:

1 the time dependency of the weight force detected by an empties in a method according to the prior art;

2 the temporal dependence of the gravitational force detected by empties for a method according to the present invention;

3 in a schematic block diagram, an apparatus for weighing empties according to the present invention;

4 a schematic flow diagram of a method for weighing empties according to the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

A method for weighing empties according to the present invention is exemplified in the 3 represented situation, according to which an empties 2 , For example, a bottle or can, which is completely or almost completely emptied, using a conveyor 4 , For example, a conveyor belt and / or a suitable arrangement of conveyor rollers, in a reverse vending machine to an identification feature detection device 6 and a balance 5 is moved past. As the empties 2 through an acceptance opening of the reverse vending machine 1 more or less on the conveyor belt 4 is raised and / or due to mechanical oscillations of the conveyor belt 4 and the scales 5 in itself, according to the 2 for the time dependence of the weight w (t) like this by the balance 5 ( 3 ), a damped vibration behavior is detected. A reverse vending machine, as it is used to carry out the method according to the invention, is characterized by a comparatively high zero or dead weight of the balance (also called TARA), which may for example be in the range of 12 to 14 kilograms and in the 2 indicated by the double arrow T. The detected weight w (t) oscillates more or less regularly around the net weight NW of the empties to be determined. The upper dashed line in the 2 indicates the maximum permissible empty weight of the empties, above which a rejection or separate handling of the empties is determined (for example, sorting into a special return area). This maximum permissible unladen weight L is calculated from the nominal empty weight known for the respective type of empties when the container is completely emptied plus a maximum permissible residual filling which is calculated from the maximum capacity of the respective empties type multiplied by a predetermined percentage. For example, in a method according to the present invention, it may be determined that empties containers filled to more than ten percent are rejected or treated separately.

Depending on the maximum capacity of the respective empty container, the target empty weight NW and the maximum permissible empty weight L differ more or less clearly. If the empties are, for example, a PET bottle with a nominal empty weight NW of, for example, 40 grams but a maximum capacity of 1.5 liters, then the difference L-NW is significantly greater than for a PET bottle with one maximum capacity of, for example, only 0.2 liters. Based on this knowledge, the present invention is based significantly. In particular, in a method according to the present invention, a statement about the accuracy of the current measurement of the weight of the empties is made from the time dependence of the weight w (t), for example based on the comparison of successive maxima and minima statistical variable derived therefrom, for example standard deviation, a mean time derived therefrom and / or further statistical variables.

According to the 2 From this fact, in one possible embodiment of the present invention, assuming that the further oscillations are attenuated to an average value NW somewhere in the range between L and T, it is already possible for that first oscillation cycle to be attenuated. a first statement be made that the permissible unladen weight L is not exceeded. According to the 2 If the maximum and minimum of the second oscillation cycle are already completely within the range between L and T. According to another embodiment, it is thus already determined during the second oscillation cycle, for example at the illustrated time t2, that the maximum permissible unladen weight L is not exceeded. From the 2 It becomes clear that at this point in time it is not possible to make a sufficiently accurate statement about the actual weight of the currently collected empties. According to a further embodiment of a method according to the invention, even further oscillation cycles can be awaited, for example, until the time t1 to wait, to which the current oscillation amplitude is already strongly attenuated, so that it can be stated with even higher probability that the currently detected empties the maximum permissible empty weight L does not exceed.

According to one Another embodiment may consist of the maxima and minima from w (t) a running average can be calculated and decided that the maximum permissible empty weight L is not exceeded is when the distance of this running average to the maximum permissible empty weight L is sufficiently large. This "sufficient" measures, for example at the vibration amplitude of a current vibration cycle, as shown by the read out maxima and minima determined from a previously known or also for each weighing process certain or estimated Damping of the weighing system and / or other statistical Sizes, in particular, as a statistical Standard deviation can be used. This can according to others Embodiments of a predetermined number of previous Measurements of the weight of empties or even those for the currently to be detected empties measured oscillations determined become.

According to the 3 includes a reverse vending machine 1 According to the present invention, further, a control or processing unit 8th and one of these associated memory 9 in which a database or a data structure is stored in which each possible type of empties a target empty weight with fully emptied container, a maximum capacity, the weight of a closure means of the respective empties type and possibly other sizes are stored. According to the 3 detects the identification feature detecting means 6 For example, an optical scanner, a rf scanner or an opto-electronic or otherwise non-contact detection unit, which on the container 2 provided identification feature 3 and / or other properties of the container 2 , such as size, color, diameter, etc., within the detection range 7 , At the same time, the scale detects 5 the temporal dependence of the weight of the container 2 as exemplified in the 2 represented, digitizes these weight readings and passes them to the control or processing unit 8th ,

An exemplary method according to the present invention will be described in more detail below with reference to FIGS 4 explained. In step S1, the target empty weight of the currently detected container is determined. For this purpose, that of the detection device 6 detected identification feature information and / or other sizes, as stated above, from the processor unit 8th evaluated and the respective container corresponding sizes from the associated database 9 read. In the reverse vending machine, information is thus available for the container currently to be detected both with regard to the desired empty weight when the container is completely emptied and with respect to the maximum capacity of the respective container type. In step S2, the balance is detected 5 the weight of the container is continuous. On the basis of the digitized measured values thus acquired, in the optional step S3, minima and maxima in the temporal dependence of the weight force (cf. 2 ). In step S4, the accuracy of weight detection for the currently-to-be-detected type of container is then estimated, as stated above. Subsequently, it is queried in step S5 whether the weighing accuracy thus estimated is sufficient for the current weighing process in order to determine with a sufficiently high degree of certainty that the currently detected empty container should be rejected or treated separately. If it is determined in the step S5 that the current weighing accuracy is not yet sufficient, the process returns to the step S2, otherwise, it goes to the step S6 in which the output of the detected weight is made. It should be noted that in the method according to the invention, not necessarily the exact weight of the container type currently to be detected is output, but that it is quite sufficient to output a control signal or a data structure which is the return automatic instructs to reject the empties currently to be collected (for example, when the maximum permissible residual charge is exceeded) or to treat them separately. Finally, in the method in step S7, a further handling of the empties, in particular rejection or separate treatment.

1

Reverse vending device

2

Empties (Container)

3

identification feature

4

conveyor

5

Libra

6

Identifier detection means

7

detection range

8th

Controller / processor unit

9

Storage / database

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 10353537 B4 [0002]
• WO 02/089078 A1 [0003]

Claims (18)

Method for weighing empties, in particular of bottles and / or cans, in which captures a type of empties and in accordance with the detected type, a maximum allowable Empty weight (L) of the empties is determined (S1); the weight the empties are recorded; and it is determined that the empties be rejected or treated separately, if based of the detected weight is determined that the maximum permissible Curb weight is exceeded; in which method the Weight (w (t)) of the empties is detected time-dependent; out the time dependence of the detected weight accuracy the determination of the weight of the empties is estimated; and the collection of the weight of the empties is canceled if it is determined that the accuracy is sufficient to a rejection or separate handling of the empties set. Method according to claim 1, wherein measured values of the weight emptied continuously and the digitized weight readings to estimate the accuracy of the detection of the weight empties are analyzed. The method of claim 2, wherein from the digitized Weight readings to estimate the accuracy of the Recording the weight of the empties Minima and maxima of the weight readings be determined. The method of claim 3, wherein from the maxima and Minima a running average of the weight readings calculated will and the accuracy of detecting the weight of the empties estimated on the basis of the continuous average. Method according to claim 4, wherein the detection of the Weight of empties is canceled when a sum of one Target empty weight of the empties and the running mean value by one predetermined size is smaller than the maximum permissible empty weight (L) of the empties. The method of claim 5, wherein the predetermined Size calculated based on a standard deviation is made of a predetermined number of previous observations of the Weight of empties is determined. Method according to one of the preceding claims, wherein the type of empties based on an identification feature ( 3 ) of the empties ( 2 ) and / or detected without contact. Method according to one of the preceding claims, wherein the maximum permissible empty weight (L) is determined by: reading a database ( 9 ), in which for each possible type of empties an empty weight of the empties and their capacity are stored; and adding the thus-read curb weight and a predetermined fraction of the maximum capacity. Method according to Claim 8, in which the type of empties ( 2 ) is also detected, whether the empties have a closure means, and wherein for determining the maximum allowable empty weight (L) further the weight of the closure means from the database ( 9 ) and taken into account in the addition. Software, in particular data structure, with software code sections that are provided by a processor unit ( 8th ) can be carried out to carry out the method according to any one of the preceding claims. Device for weighing empties ( 2 ), in particular of bottles and / or cans, with a detection device ( 6 ) to a type of empties ( 2 ) capture; a balance ( 5 ) to continuously record the weight of the empties and output digitized weight readings; and a processor unit ( 8th ), which further processes the digitized weight readings and is adapted to set a maximum allowable empty weight (L) of the empties in accordance with the detected type of empties, and to designate that the empties be rejected or treated separately when using the determined weight is determined that the maximum permissible curb weight is exceeded; characterized in that an estimation means is provided to estimate from the time dependence of the detected weight the accuracy of the detection of the weight of the empties, and the processor unit ( 8th ), the determination of the weight of the empties terminates if it is determined that the accuracy is sufficient to determine a rejection or separate handling of the empties. Apparatus according to claim 11, wherein the estimating means from the digitized weight readings for estimation the accuracy of detecting the weight of the empties minima and Maxima of weight measurements determined. Apparatus according to claim 12, wherein the estimation means of the maxima and minima lau calculates the mean of the weight readings and estimates the accuracy of the weight reading of the empties based on the running average. Apparatus according to claim 13, wherein the processor unit ( 8th ) terminates the detection of the weight of the empties when a sum of a target empty weight of the empties and the running average by a predetermined size is smaller than the maximum permissible empty weight (L) of the empties. Apparatus according to claim 14, wherein the estimating means the predetermined size based on a Standard deviation calculated from a predetermined number previous estimates of the weight of empties. Device according to one of claims 11 to 15, wherein the detection device ( 6 ) the type of empties based on an identification characteristic ( 3 ) of the empties ( 2 ) and / or detected without contact. Device according to one of claims 11 to 16, wherein the processor unit ( 8th ) a memory with a database ( 9 ), wherein the processor unit ( 8th ) defines the maximum permissible empty weight (L) by: reading a database ( 9 ), in which for each possible type of empties an empty weight of the empties and their capacity are stored; and adding the thus-read curb weight and a predetermined fraction of the maximum capacity. Device according to claim 17, wherein the detection device ( 6 ) is further configured to detect whether the empties have a closure means, and wherein the processor unit ( 8th ) for determining the maximum allowable empty weight (L), and the weight of the closing means from the database ( 9 ) and considered in the addition.