METHOD FOR CHECKING COMPLETENESS

A method for checking completeness, in a first step, passes a first object to a measuring station, wherein the measuring station has at least one ultrasonic sensor that is fixed in place, and in a second step, measures the first object using ultrasound, wherein an image of the object is created by an artificial intelligence. In a third step, the artificial intelligence compares the image obtained with a reference image, wherein the reference image is derived from a predetermined, complete object.

CROSS REFERENCE TO RELATED APPLICATIONS

Applicant claims priority under 35 U.S.C. § 119 of German Application No. 10 2017 108 501.7 filed Apr. 21, 2017, the disclosure of which is incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a method for checking completeness of objects.

2. Description of the Related Art

Methods for checking completeness serve for quality assurance. In this regard, a check is undertaken as to whether all the integral parts required for a process to take place properly are present. In general, this check of completeness is a check of presence, in which it is checked whether all the integral parts of an object, for example of a component or of a module, are present at the correct location. In this regard, the object is recorded using multiple cameras or color sensors, for example. Subsequently, an image of the object is created by means of image processing methods, and it is checked whether this image agrees with a predetermined image of a complete object.

Computers having great computing power are required for such image processing methods.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to make available a method for checking completeness, in which computers can be used that possess only very low computing power.

These and other objects are accomplished in accordance with the invention.

Therefore the invention relates to a method for checking completeness, which method comprises multiple consecutive steps. In a first step, a first object is passed to a measuring station, wherein the measuring station has at least one ultrasonic sensor that is fixed in place. If a more precise image of the object is supposed to be obtained, the measuring station can also contain more than just one ultrasonic sensor, for example 2 to 8 ultrasonic sensors.

Subsequently, in a second step, the first object is measured by means of the ultrasonic sensors in the measuring station, wherein signals are obtained that are made available to an artificial intelligence for further processing. This artificial intelligence creates an image of the object from these signals. This artificial intelligence can be implemented on a computer, for example; this computer can be a simple personal computer (PC), for example.

Finally, in a third step, the artificial intelligence compares the image of the object that was obtained with a reference image, wherein the reference image has been derived from at least one predetermined object. This predetermined object is, for example, a complete object, in other words an object that has all the required integral parts, but not any unnecessary parts. Optionally, in order to improve the reference image, derivations of incomplete objects can also be used in addition.

This method is advantageous in that the artificial intelligence creates an image of the object from the ultrasonic sensor data, which image can be compared with the reference image easily and quickly, without this artificial intelligence having to demonstrate great computing power. For this reason, even a PC or microcontroller can be used as the artificial intelligence.

In an advantageous embodiment, a second object is passed to the measuring station as soon as the first object has been measured. In this way, multiple objects, for example, can be made available, one after the other, on a transport apparatus, for example a conveyor belt, which transports the objects in the direction of the measuring station. As soon as an object has been measured, it is moved out of the measuring station again, and an object situated behind it is moved into the measuring station and measured there.

After the first object has been removed and the subsequent second object to be measured has been passed to the measuring station, the second object is measured using ultrasound. The signals obtained are passed on to an artificial intelligence. From these signals, the artificial intelligence creates an image of the object. In a further step, the artificial intelligence compares the image obtained with the reference image.

In a further preferred embodiment, in a fourth step, in other words after the object has been removed from the measuring station, this object is sorted out if the image obtained does not agree with the reference image. If the image obtained for the object does agree with the reference image, then the object is transported to a further station. This station can be a packaging station in which the object is packaged. This station can also be a processing station in which the object is processed further.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1ashows a schematic representation of a predetermined object1, i.e. of an object that is complete. This object1comprises a basic body2, in which four similar components3to6are disposed. This object1is measured by means of ultrasound, so that an image of this object1is obtained.

For this purpose, alternating voltage is applied to an ultrasonic transducer of an ultrasonic sensor, wherein the transducer preferably is a piezoelectric quartz or ceramic oscillator. The ultrasonic transducer is not shown, however, inFIG. 1a. The transducer is excited by means of the application of the alternating voltage so as to produce oscillations, so that ultrasonic waves are formed. These ultrasonic waves emitted by the ultrasonic sensor impact the object1and in turn are reflected by this object1. These reflected ultrasonic waves can in turn be received by the ultrasonic transducer. The electrical signals obtained as a result are subjected to pre-processing of an evaluation of frequency, phase or amplitude. Subsequently, the evaluation result is passed to an artificial intelligence, so that finally, an image of the object1is obtained. This image of the object1is used as a reference image. This reference image can then be compared with the images of other objects that also have been measured by means of ultrasound. Because ultrasonic measurements are known as such, these measurements will not be discussed in any further detail.

InFIG. 1b, a schematic representation of an object7to be measured is shown. This object7also has a basic body8in which multiple components9to11are disposed. In this basic body8, however, not four but rather only three components9to11are disposed, so that one component is missing and a gap12is formed. This object7is therefore not complete. If this object7is measured by means of ultrasound, an image is also obtained. This image is compared with the reference image. By means of the comparison of the recorded image with the reference image, it can therefore be determined that the object7is not complete. The incomplete object7can therefore be detected very easily and quickly, and can ultimately be sorted out or corrected. In this way, incomplete objects are prevented from being processed further, or—if these objects are end products—incomplete objects are prevented from leaving a production operation.

FIG. 2shows a perspective view of multiple objects20to23, which are disposed on a transport apparatus24. The transport apparatus24shown inFIG. 2is a conveyor belt, wherein only parts of the transport apparatus24are shown. In this regard, the objects20to23are transported in the direction of an arrow26and get into a measuring station25by way of an opening27. In this measuring station25, the objects are measured by means of ultrasonic sensors. The ultrasonic sensors are situated within the measuring station25, however, and for this reason these ultrasonic sensors cannot be seen inFIG. 2. The objects are transported out of the measuring station25once again by means of the transport apparatus24, through an opening that cannot be seen inFIG. 2, which lies opposite the opening27. For this reason, the object23has already left the measuring station25. In the measuring station25, there is also an object that is just being measured, but cannot be seen inFIG. 2.

The measuring station25is connected with an artificial intelligence29, preferably a computer, by way of at least one line28. The artificial intelligence29as well as the at least one line28are shown only schematically. If multiple lines are provided, then this connection can also be a line run. In this artificial intelligence29, the electrical signals obtained from the ultrasonic sensors are subjected to an evaluation of frequency, phase or amplitude, so that ultimately, an image of the object that is just being measured is obtained.

FIG. 3shows a section A-A through the measuring station25shown inFIG. 2, wherein the section was also passed through the transport apparatus24as well as through the objects20to23disposed on it. The measuring station25is connected with an artificial intelligence29by way of at least one line28.

The transport apparatus24is conducted through the measuring station25in the direction of the arrow26. In this regard, the objects20to22situated on the transport apparatus24can get into the measuring station25through the opening27.

In the measuring station25, there is an object30on the transport apparatus24, which object is being measured by means of ultrasound. In the measuring station25, two ultrasonic sensors31and32are provided for this purpose.

After the object30has been measured and the electrical signals have been sent to the artificial intelligence29by way of the at least one line28, the object30is moved out of the measuring station25once again. In this regard, the object30leaves the measuring station25by way of an opening33, which lies opposite the opening27.

Because measuring of the objects as well as data processing take place very quickly, it is not necessary for the movement of the transport apparatus24in the direction of the arrow26to be interrupted, so that the transport of the objects through the measuring station25can take place continuously.

Although a different structure of the measuring station25is also conceivable, the measuring station25according toFIGS. 2 and 3has a box-shaped structure, so that the measuring station25has a bottom34, wherein the transport apparatus24is affixed and moved above the bottom34. The bottom34is connected with a top35by way of side walls, wherein only the three side walls36,37, and40can be seen inFIG. 3. In this regard, it is possible that the top35is configured as a lid, wherein the lid35is removable, in order to carry out maintenance of the measuring station25, if necessary, without the measuring station25having to be removed completely.

InFIG. 4, inner workings of the measuring station25shown inFIG. 2are shown, wherein the top35was removed according toFIG. 3. In this way, the view is directly onto a top38of the transport apparatus24and thereby onto the bottom34of the measuring station25. For the sake of clarity, only parts of the transport apparatus24are shown. The object30that is being measured by means of ultrasound is situated on this top38of the transport apparatus24. For this purpose, the measuring station25has an ultrasonic sensor31,32,41,42on each side wall36,37,39,40, in each instance. Each of these ultrasonic sensors31,32,41,42emits ultrasonic waves, which are reflected by the object30and received by the transducers (which cannot be seen, because they are disposed in the ultrasonic sensors) disposed in the ultrasonic sensors31,32,41,42. The ultrasound recorded by the transducers is converted to electrical signals, which in turn are passed on to the artificial intelligence (cannot be seen inFIG. 4). In the artificial intelligence, finally, an image of the object30is produced from these electrical signals, wherein the image is compared with a reference image. By means of this comparison, it can be determined whether or not the object30is complete.

InFIG. 5, a variant of the measuring station shown inFIG. 4is shown. In the case of the measuring station43shown inFIG. 5, the view is onto a top44of a transport apparatus45, wherein the transport apparatus45is disposed above a bottom46of the measuring station43, so that it can move. For the sake of clarity, once again only parts of the transport apparatus45are shown. This measuring station43, too, has four side walls49to52, as well as a top, which is disposed on the side walls49to52, wherein the top in turn can be configured as a removable lid. Just like in the case of the measuring station according toFIG. 4, in the measuring station43according toFIG. 5the top has also been removed and therefore cannot be seen. The transport apparatus45transports objects in the direction of an arrow47into the measuring station43, and, after these objects have been measured, transports them out of this measuring station43once again. For this purpose, the measuring station43has two openings, as is also the case for the measuring station25according toFIGS. 2 to 4, but these openings cannot be seen inFIG. 5.

An object48is disposed on the top44of the transport apparatus45, which object is situated in the measuring station43and is being measured by means of ultrasound. For this purpose, two ultrasonic sensors53and54are provided, which are affixed on two opposite side walls50and52, respectively. Therefore the measuring station25ofFIGS. 2 to 4differs from the measuring station43ofFIG. 5only by the number of ultrasonic sensors.

Preferably, 2 to 10 and, particularly preferably, 2 to 4 ultrasonic sensors are provided in such a measuring station. By means of this number of ultrasonic sensors, a sufficiently precise image of an object can be obtained. In this regard, it is advantageous to provide more than one ultrasonic sensor, in particular if the object possesses a very complex structure.

InFIG. 6, a further variant of a schematically shown measuring station55is shown, which is disposed above a transport apparatus56. The measuring station55comprises three ultrasonic sensors, which are disposed on an underside63of the measuring station55and therefore cannot be seen. The measuring station55is connected with an artificial intelligence58by way of an electrical line57. On the transport apparatus56, only parts of which are shown, there are three objects59,60,61, which are being moved in the direction of an arrow62. The object60, which is situated below the measuring station55, is just being measured, whereas the object61has already been measured and is therefore being moved away from the measuring station55. The measuring station55can be attached, by way of a holder, which is not shown inFIG. 6, however, for example to a ceiling of a building (not shown), in which the measuring station55is situated. An advantage of this measuring station55is that it can be serviced very easily. For example, this measuring station55can simply be removed when it needs to be serviced, and can be replaced by a different measuring station.

InFIG. 7, the underside63of the measuring station55is shown, so that the three ultrasonic sensors64,65and66can be seen.

InFIGS. 1ato6, the objects were shown only schematically. It is understood that any conceivable objects can be measured by means of ultrasound, by means of the method. Thus, for example, these objects can be beverage boxes that must be filled with a specific number of bottles, or, alternatively, circuit boards that must be equipped with a specific number of components.

For measurement of objects, it is sufficient if the measuring station has only one ultrasonic sensor. In the case of very complex objects or if a precise image must be obtained, it is a possibility to provide more than just one ultrasonic sensor. Thus, the measuring station can have 2 to 8, preferably 2 to 4 ultrasonic sensors, for example, if necessary.