System and method for spatially detecting any foreign matter within a product based on the dielectric properties of the product

Abstract

A system for spatially detecting any foreign matter within a product based on the dielectric properties of the product comprises: a conveyor device adapted to convey the product through a scanning area along a passing direction within a predetermined passing time interval through the scanning area; a plurality of antennas arranged transversely with respect to the passing direction, each of the plurality of antennas being adapted to operate within a microwave range, each of the plurality of antennas being adapted to transmit an electromagnetic scanning signal, the electromagnetic scanning signal being adapted to propagate in the scanning area to diffuse within the product; a processing device adapted to generate a first set of values ​​representing the dielectric properties of the product based on at least one diffuse electromagnetic signal received by at least one of the plurality of antennas, the processing device being adapted to compare the first set of values ​​with a second set of values ​​representing the dielectric properties of the product in the absence of any foreign matter, each of the plurality of antennas being adapted to transmit the electromagnetic scanning signal at least once within the passing time interval according to a predetermined transmission frequency.

Description

Technical Field

[0001] The present invention relates to a system for spatially detecting any foreign matter in a product. Specifically, described herein is a system and method for spatially detecting any foreign matter in the product based on the dielectric properties of the product itself. Such products can be, for example, liquid or solid foods contained in glass or plastic containers (e.g., such as cans, bottles, vials, etc.), for example, ketchup, jam, milk, meat, etc. Such products can also be cosmetics (e.g., soap bars), or medicines contained in suitable glass, paper or plastic containers. The present invention can be used, for example, to facilitate the production of such products in factories, so as to automatically detect and / or reject any products containing foreign matter (e.g., such as bone fragments, glass fragments, rubber, stones, plastics or insects) or, for example, any products affected by inhomogeneity due to the presence of a large amount of air in the product itself. Background Art

[0002] The non-invasive identification of any foreign matter within a packaged product, without touching or altering the product itself, is particularly useful in avoiding the risk of consumer injury, while protecting manufacturers from legal expenses, costs incurred to recall entire batches of products, and loss of consumer confidence. Foreign matter still represents a risk to producers due to the limitations of currently used methods. For example, metal detectors can only detect conductive materials, X-rays cannot detect low-density plastics or small fragments of wood or glass, besides being hazardous to operators as they are ionizing radiation, while infrared-based technologies suffer from limited penetration and high absorption due to the presence of water in many of the products that need to be analyzed.

[0003] Unlike the most commonly used techniques, the technology of detecting / locating objects incorporated into structures with the help of electromagnetic waves in the microwave range (300 MHz to 300 GHz), also known as microwave imaging (MWI), does not discriminate according to density but according to the dielectric properties of the material constituting the product (for example, permittivity). This method makes it possible to overcome the limitations of X-ray devices, since it allows the detection of low-density plastics and glass, as long as there is a minimum dielectric contrast with the product content. Measurements carried out with contrast values ​​of approximately 10% have demonstrated its effectiveness. Moreover, the final cost of such a microwave device will be lower than that of an X-ray system, taking into account that no expensive dedicated sources and receivers are required. In fact, the components required to generate and capture microwaves are readily available on the telecommunications technology market.

[0004] In the 2017-2018 academic year at the Polytechnic Institute of Turin, Alessandro Giordano and Professor Francesca Vipiana presented a paper entitled “Microwave Imaging Technology for Food Contamination Monitoring”. https: / / webthesis.biblio.polito.it / 7482 / ) describes a microwave-based detection / localization system that allows the inspection of foods packed in glass jars, in particular marmalade and hazelnut paste. The system comprises an array of antennas arranged around the product to be inspected. Such antennas emit low-power electromagnetic signals at frequencies in the microwave range that can diffuse in the inspected product in order to provide a map of the dielectric properties of this product. By analyzing this map, any foreign matter inside the product can be identified.

[0005] The above mentioned MWI systems known in the art have a number of disadvantages, which will be exemplified below.

[0006] The first disadvantage relates to the fact that the map of the dielectric properties of the product is a two-dimensional map, therefore such a system does not allow non-invasive inspection of the product as a whole, i.e. the above mentioned system cannot provide a three-dimensional map of the dielectric properties of the product; this results in an inefficient non-invasive inspection system.

[0007] Another disadvantage is the fact that a two-dimensional map of the dielectric properties of a product can only identify the material of the foreign body, localizing the foreign body in a two-dimensional cross section of the product. However, such a two-dimensional map of the dielectric properties of the product cannot determine the size of the foreign body, nor the precise location of the foreign body within the product. This results in the inability to perform effective subsequent statistical analysis to reduce or eliminate the causes of the presence of foreign bodies in the products manufactured along the production line.

[0008] A further disadvantage relates to the fact that the above mentioned MWI systems cannot be easily installed in industrial production lines. Summary of the invention

[0009] It is therefore an object of the present invention to solve these and other problems encountered by the prior art, in particular by providing a system and method for spatially detecting any foreign matter within a product based on the dielectric properties of the product itself, which makes it possible to inspect the entire product in a non-invasive manner by determining a three-dimensional map of the dielectric properties of the product.

[0010] Another object of the present invention is to provide a system and method for spatially detecting any foreign matter within a product based on the dielectric properties of the product itself, which enables effective a posteriori statistical analysis to reduce or completely eliminate the causes of the presence of foreign matter in products manufactured along the production line.

[0011] It is a further object of the present invention to provide a system and method for spatially detecting in real time any foreign matter within a product being manufactured along an industrial production line based on the dielectric properties of the product itself.

[0012] The invention described herein includes systems and methods for spatially detecting any foreign matter within a product based on the dielectric properties of the product itself by determining in real time the dielectric contrast between the product contents and any foreign matter.

[0013] Further advantageous features of the invention are set forth in the appended claims, which are an integral part of the present description. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention will now be described in detail by way of some non-limiting exemplary embodiments thereof, with particular reference to the accompanying drawings, in which:

[0015] - Figure 1 Schematically illustrates an example of a system for spatially detecting any foreign matter within a product according to an embodiment of the present invention;

[0016] - Figure 2 Shown in Figure 1 An exemplary structural diagram of an antenna array used in a system of

[0017] - Figure 3 Shows Figure 1 An illustrative block diagram of a system;

[0018] - Figure 4 Shown is a reference Figure 1 An illustrative flow chart of a method for spatially detecting any foreign matter within a product by a system. DETAILED DESCRIPTION

[0019] Reference Figure 1 , schematically shows a system 100 for spatially detecting any foreign bodies in one or more products 135, the one or more products having a generally cylindrical or parallelepiped shape, such as, for example, vials, flasks, bottles or cans containing food, cosmetics, pharmaceuticals or chemical products made of glass, paper, plastic or other suitable materials. The system 100 comprises, for example, a production unit 160, a first storage unit 171, a second storage unit 172, a conveyor device 150, at least one of a plurality of antennas 200 adapted to operate in the microwave range and a discarding unit 175 for discarding at least one product 135 comprising one or more foreign bodies.

[0020] The production unit 160 is adapted to produce at least one product 135, such as, for example, a glass jar containing jam. The production unit 160 may include an actuator device adapted to perform production processes, such as, for example, washing and filling glass containers, in order to produce the product 135. During these production processes, foreign matter (such as, for example, glass fragments), for example generated by a wrongly broken container, may be dangerously contained in the at least one product 135. The production unit 160 may include an actuator device for removing the at least one product 135; the actuator device may include a servo mechanism driven by an electric motor and / or a hydraulic system.

[0021] According to the invention, the first storage unit 171 is adapted to store at least one product 135 that has not been checked, i.e. a product 135 for which it cannot be excluded a priori that it does not contain at least one foreign body. The first storage unit 171 and the production unit 160 may be operatively connected in such a way that at least one product 135 can be moved from the production unit 160 to the first storage unit 171. The first storage unit 171 may comprise an actuator device for removing at least one product 135; the actuator device may comprise a servo mechanism driven by an electric motor and / or a hydraulic system.

[0022] The second storage unit 172 is adapted to store at least one product 135 that has been checked according to the present invention. The second storage unit 172 may include actuator means for moving in at least one product 135 whose absence of any foreign matter has been verified; the actuator means may include a servo mechanism driven by an electric motor and / or a hydraulic system.

[0023] The conveyor belt device 150 is adapted to pass through the scanning area S ( Figure 2 The product 135 is conveyed through the scanning area S along the passing direction L within a predetermined passing time interval T (as can be seen in FIG. 1 ). For example, the conveyor device 150 can convey at least one product 135 to be inspected from the first storage unit 171 to the second storage unit 172, wherein the product 135 is moved at a constant speed of about 0.5 m / s. The conveyor device 150 can be connected to the first storage unit 171 and the second storage unit 172 when in operation, and can include, for example, a belt, a chain, etc. made of rubber and / or metal. The conveyor device 150 may include a servo mechanism driven by a motor and / or a hydraulic system.

[0024] Will refer to Figure 2The plurality of antennas 200 described in detail are arranged transversely with respect to the passing direction L of the scanning area S. Each antenna 210 of the plurality of antennas 200 is adapted to operate in the microwave range and is adapted to transmit an electromagnetic scanning signal adapted to propagate within the scanning area S to diffuse in the product 135 passing through the scanning area S. In one embodiment of the invention, the antennas 210 of the plurality of antennas 200 may all be identical. The plurality of antennas 200 may be connected to the conveyor device 150 when in operation, for example to move the at least one product 135 to be inspected from the first storage unit 171 to the second storage unit 172.

[0025] The discarding unit 175 is adapted to discard at least one product 135 containing one or more foreign objects during movement along the conveyor device 150. The discarding unit 175 is located downstream of the plurality of antennas 200 and may be located upstream of the second storage unit 172. The discarding unit 175 may include: signaling means for indicating that at least one foreign object in the product 135 is detected, such as, for example, audible and / or visual signaling means; for transmitting the at least one product 135 whose presence has been verified to a Figure 1 An actuator device for the discharge zone not shown in the figure; the actuator device may include a servo mechanism driven by an electric motor and / or a hydraulic system.

[0026] However, the production unit 160 may not even be comprised in the system 100 : this is the case when the products 135 comprised in the first storage unit 171 are manufactured at a different location than the location where the system 100 described herein is used.

[0027] Figure 2 Shown in Figure 1 1 is an illustrative block diagram of a plurality of antennas 200 (also referred to as an antenna array) used in the system 100. Each antenna 210 of the plurality of antennas 200 is adapted to transmit or receive at least one electromagnetic signal within the electromagnetic spectrum range from 300 MHz to 300 GHz, i.e., each antenna 210 of the plurality of antennas 200 is adapted to operate in the microwave range.

[0028] The multiple antennas 200 are arranged transversely with respect to the penetration direction L of the scanning area S, and include at least three antennas 210 adapted to at least partially surround the product 135, and the at least three antennas 210 are arranged in such a way that the product 135 can be driven by the drive device 150 to move along the penetration direction L, for example at a speed of 0.5m / s.

[0029] In one embodiment of the present invention, the antennas 210 of the plurality of antennas 200 may be arranged to form an arc or a circumference in a plane transverse to the passing direction L. In this embodiment of the present invention, the scanning area S may be defined as a spatial area centered in the arc or the circumference formed by the arrangement of the antennas 210, the spatial area having an extension along the passing direction L equal to a first dimension of the product 135 along the passing direction L plus a first protection length, the spatial area having an extension along a direction perpendicular to the passing direction L equal to a second dimension of the product 135 along a direction perpendicular to the passing direction L plus a second protection length, and the height of the spatial area being defined by the arc or the circumference formed by the arrangement of the antennas 210. For example, assuming that the product 135 has a cylindrical shape with a diameter of 8 cm, the first and second dimensions of the product 135 will match the diameter, i.e., 8 cm. The first and second protection lengths may be defined as two fractions of the first and second dimensions of the product 135, for example, 1 / 2 and 1 / 4, respectively. Thus, the scanning area S will be defined by a spatial portion of 12 cm x 10 cm, wherein the height is defined by an arc or circumference formed by the arrangement of the antennas 210. In another embodiment of the invention, the antennas 210 of the plurality of antennas 200 may be arranged in such a way as to form a dotted line or a rectangular or trapezoidal perimeter in a plane transverse to the passing direction L. To this end, in both embodiments of the invention, the antennas 210 may be housed in a support structure. Such a structure may be anchored to a lateral support mounted on the conveyor device 150. In both of the above-mentioned embodiments of the invention, the transverse plane may be substantially perpendicular to the passing direction L.

[0030] In another embodiment of the present invention, the scanning area S may be defined by the overlap of the radiation patterns of the antennas 210 in the plurality of antennas 200, so that the power radiated by the antennas 210 in the plurality of antennas 200 in the scanning area S will exceed a predetermined power value. Figure 2 As shown, in one embodiment of the present invention, the scanning area S can be defined by the space portion between the antennas 210 included in the multiple antennas 200 and defined by the size of the antenna 210 itself, wherein the power radiated by each antenna 210 in the multiple antennas 200 exceeds a predetermined power value.

[0031] Each antenna 210 of the plurality of antennas 200 is adapted to operate in the microwave range. Each antenna 210 is adapted to send an electromagnetic scanning signal that propagates in the scanning area S and diffuses in the product 135, i.e., the electromagnetic scanning signal diffuses in at least one portion of the product 135.

[0032] Specifically, the product 135 is adapted to pass through the scanning area S and completely pass through the scanning area within a predetermined passing time interval T. The passing time interval T may depend on the movement speed of the product 135 conveyed by the conveyor device 150 and the size of the scanning area S. As the product 135 passes through the scanning area S within the passing time interval T, each antenna 210 of the plurality of antennas 200 is adapted to transmit an electromagnetic scanning signal at least once according to a predetermined transmission sequence. The electromagnetic scanning signal sequentially transmitted by each antenna 210 diffuses in the product 135, that is, the electromagnetic scanning signal diffuses in at least one portion of the product. Therefore, at least one diffuse electromagnetic signal is received by the remaining antennas 210 that are not transmitting. Using a set of diffuse electromagnetic signals, a three-dimensional map of the dielectric properties of the product 135 can be determined. The frequency and power of the electromagnetic scanning signal depend on the size and dielectric properties of the contents of the product 135 to be analyzed; the conductivity of the material contained in the product 135 is particularly important for ensuring that the electromagnetic scanning signal fully penetrates into the product 135.

[0033] The transmission sequence of the plurality of antennas 200 can be defined, for example, as a progressive transmission based on a predetermined order of the antennas 210 in the plurality of antennas 200. For example, assuming that the antennas 210 are arranged along a line, the transmission sequence can start from the first antenna at one end of the line and can end at the last antenna at the other end of the line. In other embodiments of the present invention, other scanning sequences can be considered based on the geometry of the product 135 and / or the geometry of the scanning area S.

[0034] Figure 3 Shows Figure 1 The system 100 may include an interfacing device 220, a communication device 230, a memory device 240, and a processing device 250, which may be interconnected via a communication bus 201 during operation.

[0035] The docking device 220 is adapted to manage the plurality of antennas 200. The docking device 220 may, for example, comprise: a device adapted to send and receive electromagnetic signals in the microwave range; and a corresponding control unit and / or servo mechanism, driven by a motor, adapted to spatially orient the antennas 210 of the plurality of antennas 200 so as to optimize the sending and receiving of electromagnetic signals in the scanning area S. The docking device 220 may, for example, comprise a sensor device (such as a photoelectric cell, an RFID sensor, a camera, etc.) for detecting the presence of the product 135 at the entrance of the scanning area S.

[0036] The communication means 230 are adapted to output from the system 100 a method for spatially detecting any foreign matter within the product 135 (which is the subject of the present invention, as will be described below with reference to Figure 4 The flow chart of the present invention is described by way of example). The communication device 230 may, for example, include a communication unit adapted to communicate with a remote management system and / or a server. The communication unit may, for example, include an Ethernet interface, a WiFi interface, a GSM, UMTS, an LTE interface, etc. The communication unit may establish a connection with an external device (e.g., such as a computer, a smart phone, a tablet computer, etc.) for managing or monitoring the system 100. The communication device 230 may allow a user to interact with the system 100. For example, the communication device 230 may include an output device and an input device, for example, a display and an alphanumeric keyboard, respectively, or alternatively, a touch screen display display displaying an alphanumeric keyboard and interactive symbols. In another embodiment of the present invention, the communication device 230 may include a communication port (e.g., such as an RS232 or USB interface, etc.) to connect to a terminal outside the system 100. The terminal outside the system 100 may, for example, be a smart phone controlled by a user or an operator.

[0037] The memory device 240 allows the storage of information input to and / or output from the system 100 and instructions for implementing the present embodiment of the invention; the memory device 240 may include, for example, a flash-type solid-state memory. The information may include a set of values ​​and / or parameters for implementing the method of spatially detecting any foreign matter in the product 135 that is the subject of the present invention, such as, for example, the operating state of the plurality of antennas 200 and / or the values ​​of a plurality of physical quantities (e.g., the speed at which the product 135 passes through the scanning area S, the frequency and power of the electromagnetic scanning signal, etc.). Figure 4 The flowchart of FIG. 2 details the instructions stored in the memory device 240 .

[0038] The processing device 250 allows processing of information and instructions stored in the memory device 240 and / or received via the docking device 220 and the communication device 230, and may include, for example, an ARM processor, an Arduino microcontroller, a processor with an x86 or x64 architecture, etc.

[0039] Reference Figure 4 , the following will refer to Figure 1 System 100 describes an exemplary method for spatially detecting any foreign matter within product 135.

[0040] In step 400, a phase of initializing the system 100 is performed to put the system in a working state. During this step, for example, the processing device 250 verifies the working state of the components of the system 100, such as, for example, the production unit 160, the first storage unit 171, the second storage unit 172, the conveyor device 150, the plurality of antennas 200, the waste unit 175, the docking device 220, the communication device 230, the memory device 240, etc.

[0041] At step 410, the processing device 250 is configured to perform a conveying phase. During this phase, the processing device 250 controls the conveyor device 150, which conveys the product 135 through the scanning area S along the passing direction L within a predetermined passing time interval T. The passing time interval T through the scanning area S may depend on the movement speed of the product 135 and the size of the scanning area S. The movement speed of the product 135 may be, for example, a substantially constant speed of about 0.5 m / s. During this phase, the processing device 250 may receive information from the sensor device of the docking unit 220 indicating the presence of the product 135 at the entrance of the scanning area S. The processing device 250 may then initialize a timer TM, which counts the passing time interval T required for the product 135 to pass through the scanning area S.

[0042] At step 420, the processing device 250 is configured to perform a scanning phase. During this phase, the processing device 250 controls the docking device 220 in such a way that each antenna 210 of the plurality of antennas 200, which are arranged transversely with respect to the passing direction L, transmits an electromagnetic scanning signal in the microwave range. In this way, the electromagnetic scanning signal propagates in the scanning area S to diffuse within the product 135, i.e., the electromagnetic scanning signal diffuses in at least one portion of the product 135. During the scanning phase, each antenna 210 of the plurality of antennas 200 transmits an electromagnetic scanning signal at least once within a passing time interval T according to a predetermined transmission sequence.

[0043] For example, the product 135 conveyed by the conveyor device 150 and entering the scanning area S triggers a timer TM that counts the time interval T required for the product 135 to pass through the scanning area S. As the product 135 passes through the scanning area S, each antenna 210 in the plurality of antennas 200 is adapted to transmit an electromagnetic scanning signal at least once according to a predetermined transmission sequence. When the timer TM reaches the value of the time interval T, the transmission sequence stops, and the value of the time interval T has been determined based on the movement speed of the product 135 and the size of the scanning area S, so that the product 135 can be completely scanned within the time interval T.

[0044] For example, the transmission sequence is defined a priori based on the geometry of the product 135 and / or the geometry of the scanning area S. For example, referring to Figure 2 , assuming that the plurality of antennas 200 include six antennas 210 sequentially arranged from left to right with respect to the passing direction L, the transmission sequence during the passing time interval T required for the product 135 to pass through the scanning area S may be:

[0045] (1, 2, 3, 4, 5, 6, 6, 5, 4, 3, 2, 1, 1, 2, 3, 4, 5, 6, 6, 5, 4, 3, 2, 1).

[0046] Each antenna 210 numbered "1" to "6" in the plurality of antennas 200 sequentially transmits a scanning signal within a transmission time interval t that is shorter than the passing time interval T; for example, the transmission time interval t of each antenna 210 can be defined as being shorter than or equal to the passing time interval T divided by the number of elements in the transmission sequence (24 in this example). The transmission time interval t can be, for example, approximately 10 ms. The electromagnetic scanning signal sequentially transmitted by each antenna 210 (starting from the first antenna "1" to the last antenna "6") diffuses within the product 135, that is, the electromagnetic scanning signal diffuses in at least one portion of the product. Therefore, if the first antenna "1" is a transmitting antenna, the remaining non-transmitting antennas 210 (for example, "2" to "6") receive at least one diffuse electromagnetic signal. The frequency and power of the electromagnetic scanning signal depend on the size and dielectric properties of the contents of the product 135 to be analyzed; the conductivity of the material contained in the product 135 is particularly important for ensuring that the electromagnetic scanning signal fully penetrates into the product 135. In other embodiments of the present invention, other scanning sequences may be considered, for example, such as: (1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6)

[0048] (6, 5, 4, 2, 1, 6, 5, 4, 2, 1, 6, 5, 4, 2, 1, 6, 5, 4, 2, 1, 6, 5, 4, 2, 1), etc.

[0049] At step 430, the processing device 250 is configured to perform an analysis phase. During this phase, the processing device 250 generates a first set of values ​​representing dielectric properties of the product 135 based on at least one diffuse electromagnetic signal received by at least one antenna 210 of the plurality of antennas 200. During this phase, the processing device 250 compares the first set of values ​​with a second set of values ​​representing dielectric properties of the product 135 in the absence of any foreign matter.

[0050] For example, assuming that the plurality of antennas 200 includes N antennas 210, the first set of values ​​can be determined by means of respective electromagnetic signals diffused by the scanned product 135, each diffuse electromagnetic signal being received by each antenna 210 in the plurality of antennas 200. In addition to the self-interaction term in the case where the transmitting antenna and the receiving antenna coincide, the first set of values ​​including N antennas 210 can be determined among all possible pairs of antennas 210. 2 - a first interaction matrix of N interactions, the first interaction matrix being represented, for example, by means of complex numbers, as both the phase and the amplitude of such received electromagnetic signals. The first interaction matrix represents a first set of values ​​representing the dielectric properties of the product 135. Similarly, a second set of values ​​can be determined by means of individual electromagnetic signals diffused by the product 135 in the absence of any foreign matter, the individual diffused electromagnetic signals being received by individual antennas 210 of the plurality of antennas 200. In addition to the self-interaction terms, a matrix including N 2 - a second interaction matrix of N interactions, said second interaction matrix being represented, for example by means of complex numbers, as both the phase and the amplitude of such received electromagnetic signal. The second interaction matrix represents a second set of values ​​representing the dielectric properties of said product 135 in the absence of any foreign matter. The second set of values ​​may be predetermined during the initialization phase described in step 400 and stored in the memory device by said processing means 250. Likewise, the first set of values ​​may be stored in the memory device 240 by said processing means 250 during the analysis phase described herein.

[0051] The processing device 250 compares the first set of values ​​with the second set of values, for example, by the difference between the first interaction matrix and the second interaction matrix, thereby obtaining a differential interaction matrix representing the dielectric properties of one or more foreign objects that may be present in the scanned product. Similarly, the differential interaction matrix can also be stored in the memory device 240 by the processing device 250.

[0052] The processing means 250 may decompose the differential interaction matrix into eigenvectors by using an algorithm based on truncated singular value decomposition known from the previously mentioned literature. This transformation makes it possible to filter the useful information, thereby eliminating the noise components that can be identified by applying the algorithm. By using the Born approximation, the incoming electromagnetic scanning signal and the total electromagnetic field in the scanning area S can be considered to be approximately equivalent; based on this consideration, the measured electromagnetic field changes (i.e. the differential interaction matrix) can be assumed to be linearly dependent on the changes in the dielectric properties within the volume of the product 135, which may be caused by the presence of at least one foreign body. This makes it possible to determine a three-dimensional map of the dielectric properties of the volume of the inspected product 135 from the differential interaction matrix, thereby constructing a three-dimensional tomographic image of the scanned product 135.

[0053] In step 440, the processing device 250 verifies whether the product 135 contains at least one foreign object inside. To this end, for example, the processing device 250 can check whether all values ​​of the differential interaction matrix are not empty. If this is the case, the processing device 250 will perform step 450, otherwise the processing device 250 will perform step 460.

[0054] In step 450, the processing device 250 outputs signal notification information via the communication device 230. For example, the signal notification information can be displayed on a screen so that an operator can monitor the presence of one or more foreign objects in one or more products 135 in real time. Such signal notification information can trigger the actuator device of the discard unit 175 to discard those products 135 containing at least one foreign object. For example, the products 135 can be discarded with the help of a pneumatic cylinder, which will cause the discarded products 135 to fall into a collection chamber. Such signal notification information can be sent to a management system of the system 100, even a remote management system, for example, via a communication interface such as Wi-Fi, GSM, ETHERNET, etc. The processing device 250 can store the values ​​of the differential interaction matrix in the memory device 240 in order to collect information about the size, location and type of foreign objects detected in one or more products 135. This is useful for analyzing the reasons for the presence of one or more foreign objects in one or more products 135. Subsequently, the processing device 250 will perform step 460.

[0055] At step 460 , the processing device 250 checks, for example by means of a sensor such as a video camera, a photoelectric cell, etc., whether there are any other products 135 that need to be scanned. If so, the processing device will perform step 410 , otherwise the processing device will perform step 470 .

[0056] At step 470, the processing device 250 performs all operations necessary to complete the operation of the system 100. During this step, the processing device 250 may signal the inoperative state of the system 100, for example, by means of a visual indicator (e.g., an LED indicator) and / or an audible indicator (e.g., a buzzer or a speaker).

[0057] From the above description, the advantages of the present invention are obvious.

[0058] The system and method for spatially detecting any foreign matter inside a product that is the subject of the present invention advantageously allow non-invasive inspection of the product as a whole, determining a three-dimensional map of the dielectric properties of such a product.

[0059] Another advantage of the present invention lies in the fact that any foreign matter within a product is detected based on the dielectric properties of the product itself, making it possible to collect information such as the size, location and type of foreign matter contained in the product, so that an effective analysis can be carried out, thereby reducing or completely eliminating the causes of the presence of foreign matter in products manufactured along the production line.

[0060] Another advantage of the present invention lies in the fact that it provides a system and method that enables spatial and real-time detection of any foreign matter within a product based on the dielectric properties of the product itself by properly configuring the number of antennas in a plurality of antennas and the transmission sequence of the electromagnetic scanning signals of the antennas.

[0061] Of course, without prejudice to the principle of the invention, the forms of implementation and implementation details may vary widely with respect to those described and illustrated herein merely by way of non-limiting examples, without departing from the scope of protection of the invention as set forth in the appended claims.

Claims

1. A system (100) for spatially detecting any foreign matter within a product (135) based on the dielectric properties of the product (135), the system (100) include: - a conveyor belt device (150) adapted to convey the product (135) through the scanning area (S) along a passing direction (L) within a predetermined passing time interval (T) through the scanning area (S); a plurality of antennas (200) arranged transversely with respect to the passing direction (L) and comprising N antennas (210), wherein each antenna (210) of the plurality of antennas (200) is adapted to operate in the microwave range, and wherein each antenna (210) is adapted to transmit an electromagnetic scanning signal adapted to propagate in the scanning area (S) so as to diffuse within the product (135); - processing means (250) adapted to generate a first set of values ​​representative of the dielectric properties of the product (135) based on at least one diffuse electromagnetic signal received by at least one antenna (210) of the plurality of antennas (200), the processing means (250) being adapted to compare the first set of values ​​with a second set of values ​​representative of the dielectric properties of the product (135) in the absence of any foreign matter, Each antenna (210) in the plurality of antennas (200) is adapted to transmit the electromagnetic scanning signal at least once within the passing time interval (T) according to a predetermined transmission sequence, and the system is characterized in that: The first set of values ​​is determined by means of the electromagnetic signal diffused by the scanned product (135), each electromagnetic signal being received by each antenna (210) of the plurality of antennas (200), and determining, among all possible pairs of antennas (210), N including the electromagnetic signal diffused by the scanned product (135), each electromagnetic signal being received by each antenna (210) of the plurality of antennas (200), excluding the self-interaction term when the transmitting antenna and the receiving antenna coincide. 2 - N first interaction matrices representing interactions of phase and amplitude of said at least one diffuse electromagnetic signal, The second set of values ​​is determined by means of the electromagnetic signal diffused by the scanned product (135) in the absence of any foreign matter, each electromagnetic signal being received by each antenna (210) of the plurality of antennas (200), and, except for the self-interaction term when the transmitting antenna and the receiving antenna coincide, determining among all possible pairs of antennas (210) a plurality of electromagnetic signals comprising N 2 - N second interaction matrices representing interactions of said phase and said amplitude of said at least one diffuse electromagnetic signal, And the processing device (250) is adapted to compare the first set of values ​​and the second set of values ​​by the difference between the first interaction matrix and the second interaction matrix, so as to obtain a differential interaction matrix representing the dielectric properties of one or more foreign objects that may be present in the scanned product (135).

2. The system (100) according to claim 1, in, The plurality of antennas (200) includes at least three antennas (210) adapted to at least partially surround the product (135).

3. The system (100) according to claim 1 or 2, in, The antennas (210) of the plurality of antennas (200) are arranged to form an arc or a circumference in a plane transverse to the passing direction (L).

4. The system (100) according to claim 3, in, The scanning area (S) is defined as a spatial area centered in the arc or the circumference formed by the arrangement of the antenna (210), the spatial area having an extension along the passing direction (L), which is equal to a first dimension of the product (135) along the passing direction (L) plus a first protection length, and wherein the spatial area has an extension along a direction perpendicular to the passing direction (L), which is equal to a second dimension of the product (135) along a direction perpendicular to the passing direction (L) plus a second protection length, and the height of the spatial area is defined by the arc or the circumference formed by the arrangement of the antenna (210).

5. The system (100) according to claim 1, in, The frequency and power of the electromagnetic scanning signal depends on the size, dielectric properties and conductivity of the contents of the product (135).

6. The system (100) according to claim 1, in, The transmission sequence of the plurality of antennas (200) is defined as progressive transmission according to a predetermined order of antennas (210) in the plurality of antennas (200).

7. The system (100) according to claim 1, in, The passing time interval (T) is determined based on the moving speed of the product (135) and the size of the scanning area (S) so that the product (135) can be completely scanned within the passing time interval (T).

8. The system (100) according to claim 1, in, Each antenna (210) of the plurality of antennas (200) is adapted to transmit or receive at least one electromagnetic signal in an electromagnetic spectrum band between 300 MHz and 300 GHz.

9. A method for spatially detecting any foreign matter within a product (135) based on the dielectric properties of the product (135), the method include: - a conveying phase, in which a conveyor belt device (150) conveys the product (135) through the scanning area (S) along a passing direction (L) within a predetermined passing time interval (T) through the scanning area (S); - a scanning phase, wherein each antenna (210) of a plurality of antennas (200) arranged transversely with respect to the passing direction (L) transmits an electromagnetic scanning signal in the microwave range, and wherein the electromagnetic scanning signal propagates in the scanning area (S) so as to diffuse within the product (135); - an analysis phase, wherein the processing means (250) generates a first set of values ​​representative of the dielectric properties of the product (135) based on at least one diffuse electromagnetic signal received by at least one antenna (210) of the plurality of antennas (200), and wherein the processing means (250) compares the first set of values ​​with a second set of values ​​representative of the dielectric properties of the product (135) in the absence of any foreign matter, The method further comprises: during the scanning phase, each antenna (210) of the plurality of antennas (200) transmits the electromagnetic scanning signal at least once within the passing time interval (T) according to a predetermined transmission sequence, and the method is characterized in that: During the analysis phase, the first set of values ​​is determined by means of the electromagnetic signal diffused by the scanned product (135), each electromagnetic signal being received by each antenna (210) of the plurality of antennas (200), and determining, among all possible pairs of antennas (210), N values ​​comprising N 2 - N first interaction matrices representing interactions of phase and amplitude of said at least one diffuse electromagnetic signal, The second set of values ​​is determined by means of the electromagnetic signal diffused by the scanned product (135) in the absence of any foreign matter, each electromagnetic signal being received by each antenna (210) of the plurality of antennas (200), and, except for the self-interaction term when the transmitting antenna and the receiving antenna coincide, determining among all possible pairs of antennas (210) a plurality of electromagnetic signals comprising N 2 - N second interaction matrices representing interactions of said phase and said amplitude of said at least one diffuse electromagnetic signal, And the processing device (250) is adapted to compare the first set of values ​​and the second set of values ​​by the difference between the first interaction matrix and the second interaction matrix, so as to obtain a differential interaction matrix representing the dielectric properties of one or more foreign objects that may be present in the scanned product (135).

10. The method according to claim 9, in, The plurality of antennas (200) includes at least three antennas (210) at least partially surrounding the product (135).

11. The method according to claim 9 or 10, in, The antennas (210) of the plurality of antennas (200) are arranged to form an arc or a circumference in a plane transverse to the passing direction (L).

12. The method according to claim 11, in, The scanning area (S) is defined as a spatial area centered in the arc or the circumference formed by the arrangement of the antenna (210), the spatial area having an extension along the passing direction (L), which is equal to a first dimension of the product (135) along the passing direction (L) plus a first protection length, and wherein the spatial area has an extension along a direction perpendicular to the passing direction (L), which is equal to a second dimension of the product (135) along a direction perpendicular to the passing direction (L) plus a second protection length, and the height of the spatial area is defined by the arc or the circumference formed by the arrangement of the antenna (210).

13. The method according to claim 9, in, The frequency and power of the electromagnetic scanning signal are defined by the size, dielectric properties and conductivity of the contents of the product (135).

14. The method according to claim 9, in, The transmission sequence of the plurality of antennas (200) is defined as progressive transmission according to a predetermined order of antennas (210) in the plurality of antennas (200).

15. The method according to claim 9, in, The passing time interval (T) is defined based on the moving speed of the product (135) and the size of the scanning area (S) so that the product (135) can be completely scanned within the passing time interval (T).

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