Sorting machine

Description

SORTING MACHINE Scope The present invention relates to a sorting machine, according to the preamble of independent claim No. 1. The sorting machine in question belongs to the sector of the production of machines for classifying products, which are advantageously used to identify within a bulk product certain solid elements that must be separated. Advantageously, the sorting machine in question is suitable for handling small bulk products, particularly those smaller than about 15 mm (down to even 1-2 mm). The sorting machine in question is intended, in particular, to be used in the agri-food industry, for example, to separate nuts from their corresponding shells before packaging, in the waste recovery and recycling industry, for example, to separate waste made from different plastic materials, or in any other sector where it is necessary to separate solid elements in a bulk product from each other based on their external appearance and / or their particular chemical-physical properties. State of the art Automatic sorting machines are known on the market, which serve to separate, within a product composed of several objects, certain objects that must be selected or discarded. As is well known, sorting machines are typically equipped with conveyors that move a flow of bulk product containing various solid elements that must be differentiated and separated. This bulk product may include, for example, nuts (such as peanuts, almonds, and walnuts, which must be separated from their shells before packaging), or cereals, or it may include waste products of different materials (for example, plastic), which must be separated from each other to allow for their proper disposal or recycling. For example, the means of transport include one or more hoppers through which the product is introduced into the interior of the machine itself via a system of ramps until it reaches the collection tanks. The sorting machines also include an optical detection system designed to capture and analyze images of the bulk product flow, in order to distinguish in the bulk product the solid elements that must be separated or discarded. This detection system allows sending control signals, based on the information obtained from the acquired images, to expulsion means (such as solenoid valves) that can be activated to remove the selected solid elements from the bulk product, for example, by emitting jets of compressed air. In more detail, in order to distinguish and separate from the bulk product the solid elements that have a similar color in the visible light spectrum, the optical detection system of the sorting machines of known type includes color cameras capable of detecting images of the product in the visible spectrum and infrared cameras, capable of detecting chemical-physical characteristics of the bulk product that are not detectable or easily detectable by analyzing the actual colors of the product itself. For this purpose, the sorting machines are equipped with optical emitters that emit white light (for the detection of real colors using color cameras), and other optical emitters that emit infrared light (for the detection of infrared images using infrared cameras). In particular, the use of multispectral cameras, both color and infrared, for product image detection is well known. However, these cameras do not always provide sufficiently accurate information (especially in terms of spectral resolution in the spectral bands of interest). Likewise, optical emitters, particularly infrared ones, are also not capable of illuminating products with the entire spectral band of interest. The use of hyperspectral cameras is also known, which provide a much higher spectral resolution than standard hyperspectral cameras (since they are able to distinguish even more than one hundred adjacent spectral bands) and therefore allow the analysis of products across virtually the entire spectral band of interest. However, for hyperspectral cameras to perform the aforementioned analyses, the products must be illuminated with radiation that presents a substantially continuous spectrum within the bands in which these cameras operate. In fact, if the lights used to irradiate the products exhibit discontinuities in their spectral band, the hyperspectral camera (even with very high spectral resolution) would not be able to generate images for the wavelengths that fall within those discontinuities in the emitted light. To provide this continuous band lighting, halogen or incandescent lamps are used, which are now hard to find and very expensive, or wide-spectrum LEDs, also very expensive. Description of the invention In this situation, the problem from which the present invention starts is, therefore, to eliminate the drawbacks of the previously mentioned known technique, by providing a sorting machine that allows for a precise spectral analysis of the products (particularly in the infrared spectrum) and that, at the same time, is economical to manufacture. Another objective of the present invention is to provide a sorting machine that operates efficiently. Another objective of the present invention is to provide a sorting machine that is completely reliable from an operational point of view. Brief description of the drawings The technical features of the present invention, in accordance with the aforementioned objectives, are clearly derived from the content of the claims set forth below, and their advantages will become more evident in the detailed description that follows, made with reference to the accompanying drawings, which represent some merely illustrative and non-limiting embodiments, in which: - Figure 1 shows a perspective view of a sorting machine according to the present invention; - Figure 2 shows a schematic side section view of the sorting machine that is the subject of the present invention; - Figure 3 shows a schematic representation of the emitting media, according to a first embodiment of the sorting machine in question; - Figure 4 shows a detail of the emitting media from Figure 3; - Figure 5 shows a schematic representation of the emitting media, according to a second embodiment of the sorting machine in question; - Figure 6 shows a detail of the emitting media from Figure 5; - Figure 7 shows the spectral intensity of the individual spectral bands of the infrared LEDs of the emitting media; - Figure 8 shows the spectral intensity of a continuous infrared spectral band acquired as a result of the individual spectral bands in Figure 7. Detailed description of an example of a preferred embodiment With reference to the attached figures, a sorting machine according to the present invention has been indicated with 1. Advantageously, the sorting machine 1 in question is intended to be used, in different application areas, to select certain elements in a product made up of a set of solid elements, in particular of very similar shape and / or color. In more detail, the sorting machine 1 in question is intended to be used in the food industry, in particular to identify in a bulk product (particularly granular), such as nuts (peanuts, walnuts, almonds), seeds, cereals or the like, elements that must be discarded before packaging the product, which may be, for example, nut shells, residues from food processing or other inedible foreign bodies. Furthermore, the sorting machine 1 in question can be used in the waste recovery industry, in particular to identify elements of certain materials (e.g., different types of plastic) for their proper disposal or recycling. With reference to the diagram in Figure 2, the sorting machine 1 comprises transport means 2, which define a feed path A, along which at least one bulk product comprising several solid elements to be sorted can be conveyed. Furthermore, these means of transport 2 are configured to advance the bulk product by gravity at least in one analysis section A' of the advance path A. In more detail, the sorting machine 1 in question comprises a support frame 17, which carries the transport means 2 and defines within it an operating volume 18 traversed, at least partially, by the forward path A. Advantageously, the transport means 2 comprise at least one hopper 13, which is located upstream of the forward path A and is suitable for supplying the bulk product to the forward path A. In particular, the hopper 13 is mounted on the support frame 17 and is provided with an open upper end 19, through which the bulk product is advantageously supplied to the sorting machine 1 in question, and a lower end 20 that communicates with the operating volume 18, in order to supply said bulk product on the forward stroke A. Furthermore, the transport means 2 advantageously comprise at least one ramp 12 positioned along the forward path A upstream of the analysis section A' and, preferably, located within the operating volume 18 defined by the support frame 17 downstream of the hopper 13. Advantageously, this ramp 12 is capable of being crossed by the bulk product and of being discharged by gravity along the analysis section A'. In particular, the ramp 12 extends along a proper development direction, which is preferably substantially rectilinear and inclined with respect to a vertical direction, in order to define a rectilinear section of the forward path A, between a first end 21 operationally connected to the lower end of the hopper 13 and a second opposite end 22, from which the analysis section A' develops in the air. Preferably, the transport means 2 also comprise a vibrating feeder 23 interposed between the hopper 13 and the ramp 12 (in particular between the lower end 20 of the hopper 13 and the first end 21 of the ramp 12) and designed to advance the bulk product from the same hopper 13 to the ramp 12, along which the bulk product descends by the force of gravity to be distributed and advanced along the forward path A. The sorting machine 1 in question includes an optical detection system 3, which is advantageously designed to detect in the bulk product that advances along the forward path A, the solid elements that must be removed. The aforementioned optical detection system 3 comprises emitting means 4, which are configured to emit electromagnetic radiations capable of impacting the bulk product towards the analysis section A' of the forward path A. Furthermore, the optical detection system comprises at least one optical sensor 5, which is oriented towards the forward path A, in particular towards the analysis section A' of the forward path A itself. Said optical sensor 5 is configured to capture electromagnetic radiation from the bulk product irradiated by the emitting means 4 and to transduce said electromagnetic radiation into corresponding measurement signals. In more detail, the optical detection system 3 is arranged along the forward path A, in particular below the ramp 12 of the transport means 2, in order to detect the bulk product in free fall from the same ramp 12 along the analysis section A' with the solid elements to be selected spaced apart. Furthermore, the optical detection system 3 is preferably arranged within the operating volume 18 defined inside the support frame 17, such that, in particular, the support frame 17 itself protects the optical detection system 3 from light from the external environment, which could otherwise interfere with the electromagnetic radiation emitted by the emitting means 4 and the electromagnetic radiation from the irradiated bulk product that is to be detected by the optical sensor 5. The sorting machine 1 further comprises an electronic control unit 6, which is operatively connected to the optical sensor 5 to receive the measuring signals and is configured to emit command signals, and ejection means 7, which are connected to the electronic control unit 6 to receive said command signals. These command signals are intended to order the ejection means 7 to remove certain solid elements of the bulk product from the forward path A. Preferably, the ejection means 7 comprise several nozzles 16 oriented towards the analysis section A' of the feed path A and configured to emit a jet of compressed air to remove solid elements from the feed path A based on the measurement signals provided by the optical detection system 3. In particular, the nozzles 16 of the ejection means 7 are arranged side by side along a transverse (preferably orthogonal) alignment direction Z with respect to the feed path A (e.g., horizontal) and, preferably, substantially parallel to the inclined plane on which the ramp 12 of the transport means 2 is developed. Advantageously, the nozzles 16 are arranged below the optical detection system 3 and are actuated, based on the command signals sent by the electronic control unit 6, each by means of a corresponding solenoid valve, to emit a jet of compressed air towards the free-falling bulk product flow along the analysis section A' of the forward path A. In particular, each nozzle 16 is operationally associated with a specific point in the analysis section A' (for example, according to a specific position grid), so that the operation of each nozzle 16 generates an airflow that impacts the elements passing through that specific point in the analysis section A'. In this way, the solid elements that must be separated from the rest of the bulk product are reached by the jet of compressed air emitted by one of the nozzles 16 of the ejection means 7 and are effectively diverted from the forward path A while they are in free fall from the ramp 12 along the analysis section A'. Advantageously, the transport means 2 further comprise at least a first collection compartment 14, capable of receiving the bulk product coming from the forward path A, and at least a second collection compartment 15, capable of receiving the solid elements removed from the forward path A by the ejection means 7. In more detail, the first collection compartment 14 is arranged below the ramp 12 of the transport means 2, substantially at the end of the analysis section A', so that said first collection compartment 14 receives the bulk product falling freely from the ramp 12 that has not been removed from the forward path A by the ejection means 7. Furthermore, the second collection compartment 15 is arranged adjacent to the first collection compartment 14, so that the second collection compartment 15 receives the solid elements that have been hit by the jet of compressed air emitted by one of the nozzles 16 of the expulsion means 7 and thus diverted from the forward path A. Conveniently, the sorting machine 1 in question can comprise several forward paths A (defined, for example, by corresponding hoppers 13, vibrating feeders and ramps 12) with their corresponding first and second collection compartments 14, 15, in order to sort several bulk products, even simultaneously. With reference to the diagrams in Figures 3-6, the emitting means 4 comprise at least one row 41 of LEDs arranged in alignment along an alignment direction X orthogonal to the forward path A and, more specifically, horizontal. These LEDs are configured to emit electromagnetic radiation towards the analysis section A' in order to irradiate the bulk product. Advantageously, the row 41 of LEDs is arranged on a corresponding support bar 42, which extends along the alignment direction X and is preferably mounted on the support frame 17, in particular within the operating volume 18 of the sorting machine 1. Advantageously, as illustrated in the example in Figure 2, the emitting means 4 comprise several rows 41 of LEDs, which are arranged on opposite sides of the forward path A (e.g., behind and in front of the analysis section A'), and / or at different heights (e.g., to irradiate the analysis section A' from above and below). These rows 41 of LEDs are mounted on corresponding support bars 42. Optionally, the emitting means 4 may include optical means (such as lenses and mirrors) that allow the electromagnetic radiation beams emitted by the LEDs to be properly conditioned.For example, the emitting means 4 may include a reflective mirror (with a parabolic or elliptical cross-section) arranged on the support bar 42 and positioned so as to intercept the electromagnetic radiations emitted by the LEDs and reflect them towards the analysis section A' of the forward path A, in order, for example, to concentrate them in correspondence with a focus line parallel to the alignment direction X. The emitting media 4 are designed to emit infrared radiation and, advantageously, also radiation in the visible spectrum (as discussed in more detail later). Infrared radiation is used to irradiate the bulk product passing through the analysis section A' of the conveyor path A, so that corresponding infrared images of the bulk product can be acquired by the optical sensor 5. Specifically, this infrared radiation has a spectrum that extends at least within a certain continuous infrared spectral band. This infrared spectral band is continuous in that it has no gaps from its lower to its upper limit. Advantageously, the continuous infrared spectral band extends, at least partially, within the SWIR spectrum. In particular, the SWIR spectrum is understood to be between 900 nm and 3000 nm. Preferably, the continuous infrared spectral band extends, at least partially, in the range of 900 nm to 1800 nm. Advantageously, the continuous infrared spectral band extends, at least partially, into the near-infrared (NIR) spectrum. Specifically, the NIR spectrum is understood to be between 700 nm and 900 nm. Advantageously, the continuous infrared spectral band extends, at least partially, in the range from 700 nm to 3000 nm. Advantageously, the continuous infrared spectral band has a wavelength of at least 300 nm, preferably at least 600 nm. For example, the continuous infrared spectral band extends continuously from at least 1000 nm to 1600 nm (with a wavelength of 600 nm). According to another embodiment example, the continuous infrared spectral band extends continuously from at least 750 nm to 1700 nm (with a length of 950 nm). The emitting media 4 (and, specifically, its LEDs) are designed to emit the aforementioned continuous infrared spectral band using the configuration described below. With reference to the diagram in Figure 3, the row 41 of LEDs is organized into several groups 43 of LEDs, arranged side by side along the X-axis, such that each group 43 comprises a corresponding section of the row 41 of LEDs. The LEDs in each group 43 comprise several infrared LEDs 44 configured to emit infrared radiation in corresponding spectral bands different from infrared. Figure 7 shows an example of the different spectral bands of the infrared LEDs in a group 43. The sum of the different spectral bands of the 44 infrared LEDs completely covers at least the aforementioned continuous infrared spectral band, so that when activated simultaneously, the 44 infrared LEDs emit a set of infrared radiations that extends across the entire interval of the continuous infrared spectral band, without interruption. Therefore, the electronic control unit 6 of the sorting machine 1 is designed to simultaneously activate the infrared LEDs 44 of each group 43, so that they emit this set of infrared radiations to obtain the continuous infrared spectral band. An example of this continuous spectral band is illustrated in Figure 8. In particular, the electronic control unit 6 is designed to operate all LED groups simultaneously. Advantageously, the spectral band of each infrared LED 44 is partially overlapped with the spectral band of at least the adjacent infrared LEDs 44 in the corresponding group 43, so that in the transition zone between the spectral band of one of the infrared LEDs 44 and that of the adjacent infrared LED 44 there is at least a stretch of overlap between both spectral bands, thus ensuring the absence of interruptions in the continuous infrared spectral band. In particular, as shown, for example, in Figure 7, each spectral band has at least one peak, from which it descends with two side flanks, which preferably each extend at least to the peak of the spectral band of the corresponding adjacent infrared LED 44. The number of infrared LEDs 44 in each group 43 and the spectral bands of each of them are designed based on the specific infrared analysis that the sorting machine 1 must perform. Advantageously, each group 43 of LEDs comprises at least two infrared LEDs and, preferably, at least three infrared LEDs. For example, with reference to the embodiments in Figures 3-6, each group 43 of LEDs comprises three infrared LEDs 44. Advantageously, with reference to Figure 4, each group of LEDs is designed to illuminate a corresponding sector S of the analysis section A' parallel to the alignment direction X of the 41st row of LEDs. Therefore, this sector S, preferably horizontal, extends orthogonally to the forward path A along which the bulk product is intended to descend. In particular, the radiation emitted by some of the infrared LEDs 44 of a group 43 may also be of interest to the adjacent sector S (which is illuminated by the adjacent group 43 of LEDs). Each infrared LED 44 is designed to emit a beam of radiation that is capable of irradiating at least the entire corresponding sector S, overlapping, in said sector S, with the beam of each other infrared LED 44 of the corresponding group 43. Thus, sector S (and therefore the bulk product passing through it) is irradiated by all the spectral bands of the infrared LEDs 44 and, therefore, in said sector S, these spectral bands overlap, achieving irradiation of sector S with the aforementioned continuous spectral band of infrared. Advantageously, the infrared LEDs 44 of each group 43 are arranged at a distance from the analysis section A' of the forward path A, and in particular from the corresponding sector S of the latter, and are designed to emit a radiation beam with an opening angle such that the beam of each infrared LED 44 completely irradiates the sector S associated with the corresponding group 43 of LEDs. Furthermore, advantageously, the distance between the 44 infrared LEDs (along the X alignment direction) and the beam opening angle of each of them are such that there are no parts of the sector that are not irradiated by all 44 infrared LEDs. According to the present invention, the optical sensor 5 of the sorting machine comprises at least one hyperspectral camera 51, which has a spectral range covering at least the continuous infrared spectral band generated by the infrared LEDs 44 of the emitting means 4. Thus, the hyperspectral camera 51 allows the electronic control unit 6 to acquire hyperspectral images of the bulk product in the analysis zone A' irradiated by infrared radiation. The information contained in these hyperspectral images is used by the electronic control unit 6 to identify the elements of the bulk product that must be discarded and to control the ejection means 7 accordingly. Preferably, the optical sensor 5 comprises several hyperspectral cameras 51, arranged, for example, on opposite sides of the forward path A, in particular in front of and behind the latter, as in the example in Figure 2. Advantageously, the hyperspectral camera 51 has a spectral range defined by several adjacent and preferably uniformly distributed resolution spectral bands. Each resolution hyperspectral band covers a specific interval of the hyperspectral camera's spectral range (and, therefore, a specific interval of the continuous infrared spectral band of the radiation used to irradiate the bulk product elements). Thus, each resolution spectral band can provide information about the bulk product that is detectable when it is irradiated by radiation within that resolution spectral band. Advantageously, the hyperspectral camera 51 comprises several dozen spectral resolution bands, specifically at least one hundred, adjacent to each other (without interruptions across the spectral range). In this way, the hyperspectral camera 51 enables a substantially continuous analysis of the spectral properties of the bulk product. Advantageously, the hyperspectral camera has a spectral resolution of less than or equal to 10 nm FWHM, preferably less than or equal to 5 nm FWHM, and even more preferably less than or equal to 3 nm FWHM. This spectral resolution corresponds to the width of each spectral resolution band. Advantageously, the electronic control unit 6 makes it possible to identify the solid elements that must be selected and discarded with respect to the bulk product flow (thus generating the command signals to operate the ejection means 7) based on the information acquired by the hyperspectral camera 51, which refers to the bulk product passing along the analysis section A' and irradiated by the infrared LEDs 44 of the emitting means 4. Advantageously, the hyperspectral camera 51 is designed to detect, for each resolution spectral band of its spectral range, the corresponding electromagnetic radiations coming from the irradiated bulk product and to generate the corresponding measurement signals. Furthermore, the electronic control unit 6 advantageously comprises a processing module 61, which is designed to generate, from the measurement signals, the corresponding images of the bulk product. Therefore, the image generated by each resolution spectral band provides the infrared optical properties of the bulk product in that spectral band. Advantageously, the electronic control unit 6 is provided with at least one thresholding software, of a known type (and therefore not discussed here), which defines the criteria by which the electronic control unit 6 itself determines, based on the measurement signals acquired (i.e., in particular, the images processed by the processing module 11), the solid elements to be removed and, consequently, the command signals to be sent to the ejection means 7. Advantageously, the images of the bulk product are intended to be processed as computer data by the software of the electronic control unit 6, in order to determine the command signals to be sent to the ejection means 7. In particular, the images are not necessarily intended to be displayed, for example, by means of a monitor on the sorting machine 1. Advantageously, the electronic control unit 6 comprises one or more hardware devices, preferably one or more electronic boards, which, even more preferably, have installed specific processor modules (for example, one or more modules designed to analyze the measurement signals from the optical sensor 5) and / or operational modules (for example, one or more modules prepared to generate the control signals based on the analyzed measurement signals and to send said control signals to the ejection means 7), wherein said processor and / or operational modules are, in particular, in the form of integrated circuits (chips or microchips). For example, said electronic control unit 6 may be provided with a hardware device for controlling the emitting means 4, a hardware device for controlling the optical sensor 5 and a hardware device for controlling the ejecting means 7, which are preferably operatively connected to the same central control hardware device, in particular a PLC unit (in which the expression "PLC unit" should be understood as a unit of the "programmable logic controller" type). According to a particular embodiment, part of the electronic control unit 6 may be integrated (at least in part) into the hyperspectral camera 51, which in this case will be implemented as a smart camera. Advantageously, the emitting media 4 are designed to also emit electromagnetic radiation of visible light at least in a certain continuous spectral band of the visible spectrum. In particular, this continuous spectral band of the visible spectrum forms, together with the continuous spectral band of the infrared, a global continuous spectral band, i.e., a spectral band without breaks (gap) that extends across the visible spectrum and at least part of the infrared spectrum (defined by the continuous spectral band of the infrared). Preferably, this global continuous spectral band extends, at least partially, in the range of 400 nm to 1800 nm. For example, the continuous spectral band of infrared extends continuously from at least 450 nm to 1600 nm. Advantageously, with reference to the embodiment illustrated in Figures 5 and 6, each group 43 of LEDs comprises one or more luminous LEDs 45 capable of emitting visible light radiations suitable for illuminating the bulk product passing through the analysis zone A'. For example, each group 43 of LEDs comprises a white LED 45. According to a different embodiment, each group 43 of LEDs includes one or more LEDs 45 capable of emitting radiation within a limited band of the visible spectrum, for example, in the red, green, and / or blue. Advantageously, similarly to what was discussed above for the infrared LEDs 44, each light LED 45 is designed to emit a light beam that is capable of irradiating at least the entire corresponding sector S of the analysis zone A', overlapping, in said sector S, with the beam of the infrared LEDs 44 of the corresponding group 43 (as illustrated in the example in Figure 6). Thus, sector S (and therefore the product passing through it) is irradiated by all the spectral bands of the LEDs (infrared 44 and luminous 45) and, therefore, in said sector S, these spectral bands overlap, obtaining an irradiation of sector S with the aforementioned global continuous spectral band, thus allowing an efficient spectral analysis in both the visible and infrared spectrum. For this purpose, the optical sensor 5 is also sensitive to the visible spectrum to acquire images of the bulk product irradiated by the luminous LEDs 45 and to allow, in particular through the image processing module 61, the generation of visible images of the bulk product elements. For example, the 51 hyperspectral camera has a spectral range that also includes the visible spectrum to acquire visible images of the bulk product. According to a different embodiment (not illustrated in the accompanying figures), the optical sensor 5 of the sorting machine 1 comprises at least one separate color camera for capturing visible images of the bulk product. Advantageously, the hyperspectral camera 51 (and preferably the eventual color camera) has an acquisition frequency greater than 15 kHz, so it can acquire images of the bulk product elements (which descend along the feed path A at a speed generally of approximately 4 m / s) with good spatial resolution, even in the case of very small elements such as grains. For example, the hyperspectral camera is of the linear scanning (push-broom) type, which is itself a known type. The invention conceived in this way therefore achieves the intended purposes. In particular, the arrangement of the emitting media 4 organized in groups 43 of LEDs as previously described, allows the bulk product to be irradiated with a continuous (uninterrupted) spectrum in the spectral band (infrared) of interest, with a simple and economical configuration to implement and which, together with the hyperspectral camera 51, allows the efficient analysis of the optical characteristics of the bulk product, at least in the infrared. The invention conceived in this way therefore achieves the intended purposes.

Claims

1. Sorting machine (1), comprising: - transport means (2), which define a forward path (A) along which at least one bulk product composed of several solid elements to be sorted can advance,and are designed to advance said bulk product by gravity at least in an analysis section (A') of said feed path (A); - an optical detection system (3) comprising: - emitting means (4) comprising at least one row (41) of LEDs arranged in alignment along an alignment direction (X) orthogonal to said feed path (A) and designed to emit electromagnetic radiation suitable for impacting said bulk product towards the analysis section (A') of said feed path (A); - at least one optical sensor (5) oriented towards said feed path (A) and configured to capture electromagnetic radiation from said bulk product irradiated by said emitting means (4) and to transduce said electromagnetic radiation into corresponding measurement signals; - an electronic control unit (6) operatively connected to said optical sensor (5) to receive said measurement signals,and configured to emit command signals; - ejection means (7) operatively connected to said electronic control unit (6) to receive said command signals, which are suitable for ordering said ejection means (7) to remove certain solid elements of said bulk product from said forward path (A); wherein said emitting means (4) are designed to emit infrared radiation at least in a certain continuous spectral band of the infrared; wherein said row (41) of LEDs is arranged in several groups (43) of LEDs,arranged side by side along said alignment direction (X); the LEDs in each of said groups (43) comprise several infrared LEDs (44) wherein the spectral band of each of said infrared LEDs (44) partially overlaps the spectral band of at least the adjacent infrared LEDs (44) in the corresponding group (43); wherein said electronic control unit (6) is designed to simultaneously actuate said infrared LEDs (44); wherein said optical sensor (5) comprises at least one hyperspectral camera (51), having a spectral range covering at least said continuous infrared spectral band.

2. Sorting machine (1) according to claim 1,characterized in that each of said groups (43) of LEDs is designed to irradiate a corresponding sector (S) of said analysis section (A') parallel to said alignment direction (X); wherein each of said infrared LEDs (44) is designed to emit a radiation beam capable of irradiating at least said corresponding sector (S) and, in said sector (S), overlaps with the beam of each of the other said infrared LEDs (44) of the corresponding group (43).

3. Sorting machine (1) according to any of the preceding claims, characterized in that said hyperspectral camera (51) has a spectral resolution defined by several adjacent spectral resolution bands.

4. Sorting machine (1) according to claim 3,characterized in that the spectral range of said hyperspectral camera (51) comprises several dozen of said spectral resolution bands.

5. Sorting machine (1) according to claim 3 or 4, characterized in that: - said hyperspectral camera (51) is designed to generate, for each of said spectral resolution bands, corresponding measurement signals; - said electronic control unit (6) comprises a processing module (61), which is designed to generate, from said measurement signals, corresponding images of said bulk product.

6. Sorting machine (1) according to any of the preceding claims, characterized in that each group (43) of LEDs comprises at least two of said infrared LEDs (44) and, preferably, at least three of said infrared LEDs.

7. Sorting machine (1) according to any of the preceding claims,characterized in that said emitting means (4) are designed to emit visible light electromagnetic radiation at least in a certain continuous spectral band of the visible spectrum, which, together with said continuous infrared spectral band, forms an overall continuous spectral band; wherein said optical sensor (5) has a spectral resolution in the visible spectrum, for acquiring images of said bulk product irradiated by said visible light source.

8. Sorting machine (1) according to claim 7, characterized in that each of said LED groups (43) comprises one or more luminous LEDs (45) suitable for emitting said visible light electromagnetic radiation.

9. Sorting machine (1) according to any one of claims 7 to 8,characterized in that said hyperspectral camera (51) has a spectral range in the visible spectrum for acquiring images of said bulk product irradiated by said visible light electromagnetic radiation.

10. Sorting machine (1) according to any of the preceding claims, characterized in that said transport means (2) comprise at least one ramp (12) located along said forward path (A) upstream of said analysis section (A) and capable of being traversed by said bulk product and of gravity-discharging said bulk product along said analysis section (A').

11. Sorting machine (1) according to any of the preceding claims, characterized in that it comprises a support frame (17),which has said transport means (2) mounted on it and defines within it an operational volume (18) traversed at least partially by said forward path A and in which said optical detection system (3) is arranged.

12. Sorting machine (1) according to claims 10 and 11, characterized in that said ramp (12) is arranged within said operational volume (18).

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