SYSTEM AND METHOD FOR THE SPATIAL DETECTION OF ANY FOREIGN BODY WITHIN A PRODUCT BASED ON THE DIELECTRIC CHARACTERISTICS OF THE PRODUCT

Abstract

The present invention relates to a system (100) for spatially detecting any foreign body within a product (135) based on the dielectric characteristics of the product (135), the system (100) comprising: conveying means (150) adapted to transport the product (135) through a scanning region (S) along a crossing direction (L), in a predefined crossing time interval (T) to cross the scanning region (S); a plurality of antennas (200) arranged transversely to the crossing direction (L), 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 region (S), to diffuse into the product (135);processing means (250) adapted to generate a first set of values ​​indicative of the dielectric characteristics 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 ​​indicative of the dielectric characteristics of the product (135) in the absence of any foreign body, wherein each antenna (210) of the plurality of antennas (200) is adapted to transmit the electromagnetic scanning signal at least once in the crossing time interval (T), according to a predefined transmission frequency.

Description

The present invention relates to a system for spatially detecting any foreign body within a product, according to the preamble of claim 1. In particular, a system and method for spatially detecting any foreign body within a product are described herein, based on the dielectric characteristics of the product itself. The products may be, for example, liquid or solid food products, such as tomato sauce, jam, milk, meat, etc., contained in glass or plastic containers, such as jars, bottles, vials, etc. The products may also be cosmetic products, such as soap bars, or pharmaceutical products contained in suitable glass, paper, or plastic containers.The invention can be advantageously used, for example, in a plant for the production of such products to automatically detect and / or reject any product containing foreign bodies, such as, for example, bone fragments, glass fragments, rubber, stones, plastic or insects, or affected by a lack of homogeneity due, for example, to the presence of abundant air in the product itself. II IU Non-invasive identification of any foreign bodies within packaged products, without contact or alteration of the product itself, is especially useful for preventing the risk of consumer injury, while simultaneously protecting manufacturers from legal expenses, the costs of recalling entire product batches, and loss of customer confidence. Foreign bodies still pose 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, and are also harmful to operators as they are ionizing radiation, while infrared-based techniques suffer from limited penetration and high absorption due to the presence of water in many of the products that need to be analyzed. Unlike more commonly used technologies, the technique of detecting / locating objects embedded in structures using electromagnetic waves in the microwave range (300 MHz - 300 GHz), also known as Microwave Imaging (MWI), does not discriminate based on density, but rather on the dielectric properties, such as electrical permittivity, of the material that makes up the product. This approach overcomes the limitations of Microwave detection systems (MIS) are superior to X-ray devices because they allow the detection of low-density plastics and glass, provided there is a minimum dielectric contrast with the product's contents. Measurements performed with a contrast value of around 10% have demonstrated their effectiveness. Furthermore, the final cost of such a microwave device would be lower than that of X-ray systems, given that there is no need for expensive, dedicated sources and receivers. In fact, the components required to generate and capture microwaves are readily available in the telecommunications market. The thesis entitled "Microwave Imaging Technology for Food Contamination Monitoring," presented in the 2017-2018 academic year at the Polytechnic Institute of Turin by Alessandro Giordano, supervising Professor Francesca Vipiana (https: / / webthesis.biblio.polito.it / 7482 / ), describes a microwave-based detection / location system for inspecting food, specifically orange marmalade and hazelnut spread, contained in glass jars. This system consists of a series of antennas arranged around the product to be inspected. These antennas emit a low-power electromagnetic signal at a frequency in the microwave range, which diffuses into the product under examination to provide a map of its dielectric properties. By analyzing this map, it is possible to identify any contaminants. II IU foreign body inside the product. The MWI system mentioned above, which is known in the art, suffers from a number of drawbacks, which will be illustrated below. A primary drawback is related to the fact that the product's dielectric properties map is two-dimensional, so the system does not allow for a non-invasive inspection of the entire product; that is, the aforementioned system cannot provide a three-dimensional map of the product's dielectric properties; this results in an inefficient non-invasive inspection system. Another drawback is that a two-dimensional map of a product's dielectric properties only allows for the identification of the foreign body material, locating it within a two-dimensional section of the product. However, this map cannot determine the foreign body's dimensions or its exact position within the product. This makes it impossible to perform effective subsequent statistical analysis to reduce or eliminate the causes of foreign bodies in products manufactured along a production line. Another drawback is related to the fact that the aforementioned MWI system cannot II IU can be easily installed on an industrial production line. Therefore, an object of the present invention is to solve these and other problems suffered by the prior art, in particular by providing a system and a method for spatially detecting any foreign body within a product on the basis of the dielectric characteristics of the product itself, thereby allowing the product to be inspected in its entirety in a non-invasive manner by determining a three-dimensional map of the dielectric properties of the product. Another object of the present invention is to provide a system and method for spatially detecting any foreign body within a product based on the dielectric characteristics of the product itself, thereby enabling effective post-production statistical analysis to reduce, or completely eliminate, the causes of the presence of foreign bodies in products manufactured along a production line. It is a further object of the present invention to provide a system and method for spatially detecting in real time any foreign body within a product being manufactured along an industrial production line based on the dielectric characteristics of the product itself. The invention described herein consists of a II IU system and a method for spatially detecting any foreign body within a product based on the dielectric characteristics of the product itself, determining in real time the dielectric contrast between the contents of the product and any foreign body. Other advantageous features of the present invention are set forth in the appended claims, which are an integral part of this description. The invention will now be described in detail through some examples of non-limiting embodiments thereof, with special reference to the accompanying drawings, where: - Figure 1 schematically shows an example of a system for spatially detecting any foreign body within a product according to an embodiment of the present invention; Figure 2 shows an illustrative structural diagram of an array of antennas used in the system of Figure 1; Figure 3 shows an illustrative block diagram of the system in Figure 1; Figure 4 shows an illustrative flowchart of a method for spatially detecting any foreign body within a product, with reference to the system in Figure 1. > your NCNNC With reference to Figure 1, a system 100 is schematically shown for spatially detecting any foreign body within one or more products 135 having a substantially cylindrical or parallelepiped shape, such as, for example, vials, bottles, or jars made of glass, paper, plastic, or other suitable materials, containing food, cosmetic, pharmaceutical, or chemical products. The system 100 comprises, for example, a production unit 160, a first storage unit 171, a second storage unit 172, conveying means 150, at least a plurality of antennas 200 adapted to operate in the microwave range, and a rejection unit 175 for rejecting at least one product 135 comprising one or more foreign bodies. Production unit 160 is adapted to produce at least one product 135, such as, for example, a glass jar containing jam. Production unit 160 may comprise actuating means adapted to carry out production processes, such as, for example, washing and filling glass containers, to create product 135. During these production processes, foreign bodies such as glass fragments, for example, from containers being destroyed incorrectly, may be dangerously included in at least one product 135. Production unit 160 may comprise actuating means to remove the II IU > your NCNNC 8 less a product 135; the actuating means may comprise servomechanisms driven by electric motors and / or hydraulic systems. The first storage unit 171 is adapted to store at least one product 135 that has not yet been inspected according to the present invention, i.e., a product 135 for which it cannot be ruled out a priori that it does not contain at least one foreign body. The first storage unit 171 and the production unit 160 can be operationally connected such 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 include actuating means for removing at least one product 135; the actuating means may include servomechanisms driven by electric motors and / or hydraulic systems. The second storage unit 172 is adapted to store at least one product 135 that has been inspected according to the present invention. The second storage unit 172 may comprise actuating means for introducing at least one product 135 that has been verified to be free of foreign bodies; the actuating means may comprise servomechanisms driven by electric motors and / or hydraulic systems. The 150 conveyors are adapted for II IU II IU transporting product 135 through a scan region S (visible in Figure 2) along a crossing direction L, within a predefined crossing time interval T for crossing the scan region S. For example, the conveyor means 150 can transport at least one product 13b to be inspected from the first storage unit 171 to the second storage unit 172, moving the product 135 at a constant speed on the order of 0.5 m / s. The conveyor means 150 can be operationally connected to the first storage unit 171 and the second storage unit 172, and can comprise, for example, belts, chains, etc., made of rubber and / or metal. The conveyor means 150 can comprise servomechanisms driven by electric motors and / or hydraulic systems. The plurality of antennas 200, which will be described in detail with reference to Figure 2, are arranged transversely to the crossing direction L of the scan region 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 scan signal adapted to propagate in the scan region S, to diffuse into the product 135 that passes through the scan region 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 operatively connected to the means 150 II IU conveyors, for example, to make at least one product 135 be inspected to move from the first storage unit 171 to the second storage unit 172. The rejection unit 17b is adapted to reject at least one product 135, containing one or more foreign bodies, moving along the conveyor means 150. The rejection unit 175 is located downstream of the plurality of antennas 200 and possibly upstream of the second storage unit 172. The rejection unit 175 may include signaling means to indicate the detection of at least one foreign body in the product 135, such as, for example, audible and / or visual signaling devices; drive means for transporting to a discharge area, not shown in Figure 1, at least one product 135 for which the presence of at least one foreign body has been verified; the drive means may include servomechanisms driven by electric motors and / or hydraulic systems. However, the production unit 160 may not even be included in system 100: this is the case when the products 135 contained in the first storage unit 171 have been manufactured in a different location, other than the one used in system 100 described herein. II IU Figure 2 shows an illustrative structural diagram of the plurality of antennas 200, also called the antenna series, used in the system 100 of Figure 1. Each antenna 210 of the plurality of antennas 200 is adapted to transmit or receive at least one electromagnetic signal, in the range of the electromagnetic spectrum 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. The plurality of antennas 200 are arranged transversely to the crossing direction L of the scanning region S, and comprise at least three antennas 210 adapted to surround, at least partially, the product 135, the at least three antennas 210 being arranged in such a way that the product 135 can be moved along the crossing direction L, driven by the drive means 150, for example, at a speed of 0.5 m / s. In one embodiment of the invention, the antennas 210 of the plurality of antennas 200 can be arranged to form an arc, or a circle, in a plane transverse to the crossing direction L. In this embodiment of the invention, the scanning region S can be defined as a spatial region centered on the arc, or the circle, formed by the arrangement of the antennas 210, having an extent along the crossing direction L that is equal to a first dimension of the product 135, along the crossing direction. II IU L, plus a first length of the protective device, the space region having an extension along the direction perpendicular to the crossing direction L that is equal to a second dimension of the product 135, along the direction perpendicular to the crossing direction L, plus a second length of the protective device, the height of the space region being delimited by the arc, or circumference, formed by the arrangement of the antennas 210. For example, assuming that the product 135 is cylindrical with a diameter of 8 cm, both the first and second dimensions of the product 135 will coincide with the diameter, i.e., 8 cm. The first length of the protective device and the second length of the protective device can be defined as two fractions of the first and second dimensions of the product 135, for example, 1 / 2 and 1 / 4, respectively.Consequently, the scanning region S will be defined by the spatial portion of 12 cm x 10 cm, with a height delimited by the 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 can be arranged so as to form a dotted line, or a rectangular or trapezoidal perimeter, in the plane transverse to the crossing direction L. For this purpose, in both embodiments of the invention, the antennas 210 can be housed in a support structure. The structure can be anchored to allow the NCNNC to pass through the scanning region S, traversing it completely in a predefined crossing time interval T. The crossing time interval T can depend on the speed of movement of the product 135 being transported by the conveying means 150 and on the dimensions of the scanning region S.As product 135 passes through the scan region S, during the crossing time interval T, each antenna 210 of the plurality of antennas 200 is configured to transmit the electromagnetic scan signal at least once, according to a predefined transmission sequence. The electromagnetic scan signal transmitted sequentially by each antenna 210 diffuses into product 135, that is, it diffuses into at least a portion of it. Consequently, at least one diffuse electromagnetic signal is received by the remaining antennas 210, which are not transmitting. Using this set of diffuse electromagnetic signals, it is possible to determine a three-dimensional map of the dielectric properties of product 135.The frequency and power of the electromagnetic scanning signal depend on the size and dielectric characteristics of the contents of product 135 to be analyzed; the conductivity of the material contained in product 135 is particularly important to ensure sufficient penetration of the electromagnetic scanning signal into product 135. The transmission sequence through the plurality of II IU II IU antennas 200 can be defined, for example, as a progressive transmission based on a predefined order of the antennas 210 from the plurality of antennas 200. For example, assuming that the antennas 210 are arranged along a line, the transmission sequence can start from a first antenna located at one end of the line and can end with a last antenna located at the other end of the line. In other embodiments of the invention, other scanning sequences can be considered based on the geometry of the product 135 and / or the geometry of the scanning region S. Figure 3 shows an illustrative block diagram of system 100 from Figure 1. System 100 may comprise interface media 220, communication media 230, memory media 240, and processing media 250, which may be operationally interconnected via a communication bus 201. The interface means 220 are adapted to manage the plurality of antennas 200. The interface means 220 may comprise, for example, devices adapted to transmit and receive electromagnetic signals in the microwave range and respective control units and / or servomechanisms, driven by electric motors, adapted to spatially orient the antennas 210 of the plurality of antennas 200 to optimize the transmission and reception of electromagnetic signals in the scanning region S. The means II IU 220 interface may comprise, for example, sensor media such as photocells, REID sensors, video cameras, etc., to detect the presence of product 135 at the entrance of the scanning region S. The communication means 230 are adapted to transmit from the system 100 information obtained by the spatial foreign body detection method in a product 135, which is the subject of the present invention, as will be described below by way of example with reference to the flowchart in Figure 4. The communication means 230 may comprise, for example, a communication unit adapted to communicate with a remote management system and / or server. The communication unit may comprise, for example, an Ethernet interface, a Wi-Fi interface, a GSM, UMTS, LTE interface, etc. The communication unit may establish a connection with an external device for managing or monitoring the system 100, such as, for example, a computer, a smartphone, a tablet, etc. The communication means 230 may allow a user to interact with the system 100.For example, the communication means 230 may comprise output and input means, such as a display and an alphanumeric keyboard, respectively, or alternatively, a touchscreen displaying an alphanumeric keyboard and interactive symbols. In another embodiment of the invention, the communication means 230 may comprise a communication port, such as an RS232 or USB interface, etc., for connection to a terminal external to the system 100. The terminal external to the system 100 may be, for example, a smartphone controlled by a user or operator. The memory media 240 allows for the storage of information entered and / or emitted from the system 100 and instructions that implement the present embodiment of the invention; the memory media 240 may comprise, for example, a flash solid-state memory. The information may include a set of values ​​and / or parameters useful for implementing the method for spatially detecting any foreign body within a product 135, which is the subject of the present invention, such as, for example, the operating status of the plurality of antennas 200 and / or values ​​of various physical quantities, for example, the speed of the product 135 through the scanning region S, the frequency and power of the electromagnetic scanning signal, etc. The instructions stored in the memory media 240 will be described in detail below with reference to the flowchart in Figure 4. The processing media 250 enable the processing of information and instructions stored in the memory media 240 and / or received through the interface media 220 and communication media 230, and may comprise, for example, II IU an ARM processor, an Arduino microcontroller, a processor with x86 or x64 architecture, etc. With reference to Figure 4, the following will describe an exemplary method for spatially detecting any foreign body within a product 135 with reference to system 100 of Figure 1. In step 400, an initialization phase of system 100 is carried out to bring it into operation. During this stage, for example, the processing means 250 verify the operational status of the elements of system 100, such as, for example, the production units 160, first storage unit 171, second storage unit 172, conveyor means 150, plurality of antennas 200, rejection unit 175, interface means 220, communication means 230, memory means 240, etc. In step 410, the processing means 250 are configured to execute a transport phase. During this phase, the processing means 250 control the conveyor means 150 that transport product 135 through the scan region S along the crossing direction L, within the predefined crossing time interval T. The crossing time interval T for crossing the scan region S may depend on the movement speed of product 135 and the dimensions of the scan region S. The movement of product 135 can be, for example, a substantially constant speed on the order of 0.5 m / s. During this phase, the processing means 250 can receive, from the sensor means of the interface unit 220, information indicating the presence of product 135 at the entrance of the scan region S. The processing means 250 can then initialize a timer TM to count the crossing time interval T required for product 135 to cross the scan region S. In step 420, the processing means 250 are configured to perform a scanning phase. During this phase, the processing means 250 control the interface means 220 such that the electromagnetic scanning signal, in the microwave range, is transmitted by each antenna 210 of the plurality of antennas 200, the plurality of antennas 200 being arranged transversely to the crossing direction L. In this way, the electromagnetic scanning signal propagates in the scanning region S to diffuse into product 135; that is, the electromagnetic scanning signal is diffused into at least a portion of product 135. During the scanning phase, each antenna 210 of the plurality of antennas 200 transmits the electromagnetic scanning signal at least once within the crossing time interval T, according to the predefined transmission sequence. II IU II IU For example, product 135, being transported by conveyor means 150 and entering scan region S, activates timer TM to count the crossing time interval T required for product 135 to cross scan region S. As product 135 passes through scan region S, each antenna 210 of the plurality of antennas 200 is configured to transmit the electromagnetic scanning signal at least once according to a predefined transmission sequence. The transmission sequence stops when timer TM reaches the crossing time interval value T, which has been determined based on the speed of movement of product 135 and the dimensions of scan region S, so that product 135 can be fully scanned within the crossing time interval T. The transmission sequence is defined a priori, for example, based on the geometry of the product 135 and / or the geometry of the scan region S. For example, with reference to Figure 2, assuming that the plurality of antennas 200 comprises six antennas 210 arranged from left to right with respect to the crossing direction L, the transmission sequence during the crossing time interval T required for the product 135 to cross the scan region S can be: (1,2,3,4,5,6,6,5,4,3,2,1,1,2,3,4,5,6,6,5,4,3,2,1). II IU Each antenna 210 of the plurality of antennas 200, numbered 1 through 6, sequentially transmits the scan signal for a transmission time interval t shorter than the crossover time interval T. For example, the transmission time interval t for each antenna 210 can be defined to be shorter than or equal to the crossover time interval T divided by the number of elements in the transmission sequence, which in this example is 24. The transmission time interval t can be on the order of, for example, 10 ms. The electromagnetic scan signal transmitted sequentially by each antenna 210, starting from the first antenna 1 and ending with the last antenna 6, is diffused in the product 135, that is, it is diffused in at least a portion of it. Consequently, at least one diffuse electromagnetic signal is received by the remaining non-transmitting antennas 210, for example, 2 through 6 if the first antenna 1 is the transmitter.The frequency and power of the electromagnetic scanning signal depend on the size and dielectric characteristics of the contents of product 135 to be analyzed; the conductivity of the material contained in product 135 is particularly important to ensure sufficient penetration of the electromagnetic scanning signal into product 135. In other embodiments of the invention, other scanning sequences may be considered, such as, for example: > your NCNNC 22 (1,2,3,4,5,6,1,2,3,4,5,6,1,2,3,4,5,6,1,2,3,4,5,6), (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. In step 430, the processing means 250 are configured to perform an analysis phase. During this phase, the processing means 250 generate a first set of values ​​indicative of the dielectric characteristics of product 135 based on at least one diffuse electromagnetic signal received by at least one antenna 210 from the plurality of antennas 200. During this phase, the processing means 250 compare the first set of values ​​with a second set of values ​​indicative of the dielectric characteristics of product 135 in the absence of foreign bodies. Assuming, for example, that the plurality of antennas 200 comprises a number N of antennas 210, the first set of values ​​can be determined by means of each electromagnetic signal broadcast by the scanned product 135, each electromagnetic signal broadcast by each antenna 210 of the plurality of antennas 200 being received. Excluding the self-interaction terms, which is the case when the transmitting antenna and the receiving antenna coincide, it is possible to determine, among all possible pairs of antennas 210, a first interaction matrix comprising N2-N interactions expressed as the phase and amplitude of the received electromagnetic signals, for example, by means of numbers II IU II IU complexes. The first interaction matrix represents the first set of values ​​indicative of the dielectric characteristics of product 135. Likewise, the second set of values ​​can be determined by each electromagnetic signal diffused by product 135 in the absence of foreign bodies, each diffuse electromagnetic signal received by each antenna 210 of the plurality of antennas 200. Excluding self-interaction terms, it is possible to determine, among all possible pairs of antennas 210, a second interaction matrix comprising N²-N interactions expressed as both the phase and amplitude of the received electromagnetic signals, for example, by means of complex numbers. The second interaction matrix represents the second set of values ​​indicative of the dielectric characteristics of product 135 in the absence of foreign bodies.The second set of values ​​can be predetermined during the initialization phase described in step 400 and stored by the processing medium 250 in the memory medium. Likewise, during the analysis phase described herein, the first set of values ​​can be stored by the processing medium 250 in the memory medium 240. The processing means 250 compare the first set of values ​​and the second set of values, for example, by the difference between the first interaction matrix and the second interaction matrix, thus obtaining a differential interaction matrix indicative of the dielectric characteristics of one or more foreign bodies that may be present in the scanned product. Likewise, the differential interaction matrix can also be stored by the processing means 250 in the memory means 240. The processing means 250 can decompose the differential interaction matrix into eigenvectors using an algorithm based on the decomposition of truncated singular values, as described in the aforementioned document. This transform allows the useful information to be filtered out by canceling a noise component that can be identified by applying the algorithm. Using Bom's approximation, the incident electromagnetic scan signal and the total electromagnetic field in the scan region S can be considered approximately equivalent. Based on this consideration, it can be assumed that the variation of the measured electromagnetic field, i.e., the differential interaction matrix, depends linearly on the variation of the dielectric properties within the volume of product 135, which can be caused by the presence of at least one foreign body.This allows us to determine, from the differential interaction matrix, a three-dimensional map of the dielectric properties of the volume of product 135 under examination, thus constructing a three-dimensional tomography of the scanned product 135. II IU II IU In step 440, the processing means 250 checks whether product 135 contains at least one foreign body internally. For this purpose, for example, the processing means 250 can check whether all values ​​in the differential interaction matrix are non-zero. If so, the processing means 250 will execute step 450; otherwise, it will execute step 460. In step 450, the processing means 250 transmit signaling information via the communication means 230. For example, the signaling information can be displayed on a screen, allowing an operator to monitor in real time the presence of one or more foreign bodies in one or more products 135. This signaling information can activate actuating means of the rejection unit 175 to reject those products 135 that contain at least one foreign body. For example, products 135 can be rejected by means of a pneumatic cylinder that will cause the rejected products 135 to fall into a collection compartment. The signaling information can be sent to a system management system 100, including a remote one, for example, via communication interfaces such as Wi-Fi, GSM, or Ethernet.The processing media 250 can store the differential interaction matrix values ​​in the memory media 240 to gather information about the dimensions, position, and type of foreign body detected in one or more products 135. This is useful for analyzing the causes of the presence of one or more foreign bodies in one or more products 135. Subsequently, the processing media 250 will execute step 460. In step 460, the processing means 250 check, for example, by means of sensors such as video cameras, photocells, etc., whether there are other products 135 that need to be scanned. If so, the processing means will execute step 410; otherwise, they will execute step 470. In step 470, the processing media 250 execute all the operations necessary to complete the operations of system 100. During this step, the processing media 250 may signal the inoperative status of system 100, for example, by means of visual indicators, for example, LED indicator lights and / or audible indicators, for example, buzzers or speakers. The advantages of the present invention are evident from the above description. The system and method for spatial detection of foreign bodies within a product, the subject of the present invention, advantageously allows for a non-invasive inspection of the entire product, determining a three-dimensional map of the dielectric properties of the product. Another advantage of the present invention lies in the II IU II IU The fact that any foreign body within a product is detected based on the dielectric characteristics of the product itself, which allows the collection of information, such as: dimensions, position and type of foreign bodies contained in the product, so that an effective analysis can be carried out to reduce, or completely eliminate, the causes of the presence of foreign bodies in products manufactured along a production line. Another advantage of the present invention lies in the fact that it provides a system and a method that allows the spatial detection, in real time, of any foreign body within a product based on the dielectric characteristics of the product itself by appropriately configuring the number of antennas in the antenna plurality and the transmission sequence of the electromagnetic scanning signals of the antennas. Of course, without prejudice to the principle of the present invention, the embodiments and implementation details may vary widely from those described and illustrated herein, merely by way of non-limiting example, without thereby departing from the scope of protection of the present invention as set forth in the attached claims.

Claims

1. A spatial detection system for foreign bodies within a product based on the dielectric characteristics of the product, the system being characterized in that it comprises: - conveying means adapted to transport the product through a scanning region (S) along a crossing direction (L), in a predefined crossing time interval (T) to cross the scanning region (S); a plurality of antennas arranged transversely to the crossing direction (L), wherein each antenna of the plurality of antennas is adapted to operate in the microwave range, and wherein each antenna is adapted to transmit an electromagnetic scanning signal adapted to propagate in the scanning region (S), to diffuse into the product;- processing means adapted to generate a first set of values ​​indicative of the dielectric characteristics of the product based on at least one diffuse electromagnetic signal received by at least one antenna of the plurality of antennas, the processing means being adapted to compare the first set of values ​​with a second set of values ​​indicative of the dielectric characteristics of the product in the absence of foreign bodies, II IU wherein each antenna of the plurality of antennas is adapted to transmit the electromagnetic scan signal at least once in the crossing time interval (T), according to a predefined transmission sequence.; 2. The system according to claim 1, characterized in that the plurality of antennas comprises at least three antennas adapted to surround, at least partially, the product.

3. The system according to claim 1 or 2, characterized in that the antennas of the antenna plurality are arranged to form an arc, or a circle, in a plane transverse to the crossing direction (L).

4. The system according to claim 3, characterized in that the scanning region (S) is defined as a spatial region centered on the arc, or circumference, formed by the arrangement of the antennas, having an extension along the crossing direction (L) that is equal to a first dimension of the product, along the crossing direction (L), plus a first length of the protective device, and wherein the spatial region has an extension along the direction perpendicular to the crossing direction (L) that is equal to a second dimension of the product, along the direction perpendicular to the crossing direction (L), plus a second length of the protective device, the height of the spatial region being delimited by the arc, or circumference, formed by the arrangement of the antennas.

5. The system in accordance with one or more of claims 1 to 4, characterized in that the frequency and power of the electromagnetic scanning signal depend on the size, dielectric characteristics and electrical conductivity of the product contents.

6. The system in accordance with one or more of claims 1 to 5, characterized in that the transmission sequence of the plurality of antennas is defined as a progressive transmission according to a predefined order of the antennas of the plurality of antennas.

7. The system according to one or more of claims 1 to 6, characterized in that the crossing time interval (T) is determined on the basis of a product movement speed and the dimensions of the scanning region (S), so that the product can be fully scanned within the crossing time interval (T).

8. The system according to one or more of claims 1 to 7, characterized in that each antenna of the plurality of antennas is adapted to transmit or receive at least one electromagnetic signal in the electromagnetic spectrum band between 300 MHz and 300 GHz.

9. The system in accordance with one or more of claims 1 to 6, characterized in that it comprises memory means adapted to store the first set of values ​​and / or the second set of values.

10. A method for spatially detecting any foreign body within a product based on the dielectric characteristics of the product, the method being characterized in that it comprises: - a transport phase, in which the transporting means carry the product through a scanning region (S) along a crossing direction (L), in a predefined crossing time interval (T) to cross the region (S); - a scanning phase, in which an electromagnetic scanning signal, in the microwave range, is transmitted by each antenna of a plurality of antennas arranged transversely to the crossing direction (L), and in which the electromagnetic scanning signal propagates in the scanning region (S), to diffuse into the product;an analysis phase, where the processing means generate a first set of values ​​indicative of the dielectric characteristics of the product based on at least one diffuse electromagnetic signal received by at least one antenna of the plurality of antennas, and where the processing means compare the first set of values ​​with a second set of values ​​indicative of the dielectric characteristics of the product in the absence of foreign bodies, the method wherein, during the scanning phase, each antenna of the plurality of antennas transmits the electromagnetic scanning signal at least once in the crossing time interval (T), according to a predefined transmission sequence.

11. The method according to claim 10, characterized in that the plurality of antennas comprises at least three antennas that surround, at least partially, the product.

12. The method according to claims 10 or 11, characterized in that the antennas of the antenna plurality are arranged to form an arc, or a circle, in a plane transverse to the crossing direction (L).

13. The method according to claim 12, characterized in that the scanning region (S) is defined as a spatial region centered on the arc, or circumference, formed by the arrangement of the antennas, having an extension along the crossing direction (L) that is equal to a first dimension of the product, along the crossing direction (L), added to a first length of the protective device, and wherein the spatial region has an extension along the direction perpendicular to the crossing direction (L) that is equal to a second dimension of the product, along the direction perpendicular to the crossing direction (L), added to a second length of the protective device, the height of the spatial region being delimited by the arc, or circumference, formed by the arrangement of the antennas.

14. The method according to one or more of claims 10 to 13, characterized in that the frequency and power of the electromagnetic scanning signal are defined by the size, dielectric characteristics and electrical conductivity of the product content.

15. The method according to one or more of claims 10 to 14, characterized in that the transmission sequence of the plurality of antennas is defined as a progressive transmission according to a predefined order of the antennas of the plurality of antennas.

16. The method according to one or more of claims 10 to 15, characterized in that the crossing time interval (T) is defined on the basis of a product movement speed and the dimensions of the scanning region (S), so that the product can be fully scanned within the crossing time interval (T).

17. The method according to one or more of claims 10 to 16, characterized in that each antenna of the plurality of antennas transmits or receives at least one electromagnetic signal in the electromagnetic spectrum band II IU between 300 MHz and 300 GHz.

18. The method according to one or more of claims 10 to 17, characterized in that it comprises a storage phase in which the processing means 5 store the first set of values ​​and / or second set of values ​​in memory means.

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