WO2022087699A1

WO2022087699A1 - Method, mechanical device and equipment for measuring the mass or weight of ferromagnetic bodies

Info

Publication number: WO2022087699A1
Application number: PCT/BR2021/050466
Authority: WO
Inventors: Andre Garcia Lima SUETTI
Original assignee: Tmd Friction Do Brasil S.A.
Priority date: 2020-10-27
Filing date: 2021-10-22
Publication date: 2022-05-05
Also published as: BR102020022034A2; CN116670468A

Abstract

The invention proposes weighing techniques, primarily for weighing bodies that have ferromagnetic characteristics. For application to ferromagnetic bodies, the invention also discloses a solution for determining the magnetic susceptibility of said bodies, which is particularly useful for the analysis of bodies made of composite materials. The invention also provides a solution for weighing bodies that are in motion, such as parts being conveyed on a belt. To do so, the invention proposes mechanical devices that are simple, reliable, cheap, and easy to produce, used in conjunction with the proposed methods and equipment. The invention differs from the prior art by proposing an improvement to traditional weighing, and also discloses two novel concepts related to the problem. With regard to the improvement to traditional weighing, an attract/measure/release solution is proposed, and with regard to novel weighing concepts, electromagnetic equivalency and mass measurement by natural frequency are disclosed.

Description

METHOD, MECHANICAL DEVICE AND EQUIPMENT FOR MEASURING MASS OR WEIGHT OF FERROMAGNETIC BODIES

[001] The invention deals with a method, a mechanical device and an equipment for measuring mass or weight, magnetic susceptibility or amount of ferromagnetic material or amount of iron in ferromagnetic bodies, as well as qualification, classification and selection of said ferromagnetic bodies, which offers techniques aimed at weighing, mainly the weighing of bodies that have ferromagnetic characteristics. When applied to ferromagnetic bodies, the invention also presents a solution for determining the magnetic susceptibility of said bodies, being particularly useful in the analysis of bodies made of composite materials. It also provides mechanisms for weighing bodies that are in motion, such as parts being transported on a conveyor belt. Therefore, the invention proposes simple, reliable, cheap and easy-to-produce mechanical devices to be used in conjunction with the proposed methods and equipment. The invention proposes three new concepts interrelated with weighing: the so-called attract-measure-release solution, the solution here called electromagnetic equivalence and the one here called mass measurement by natural frequencies.

FIELD OF THE INVENTION

[002] The Method, mechanical device and equipment for measuring physical parameters of ferromagnetic bodies, objects of the present invention, fall within the technical weighing sector, the sector of determination of the composition of bodies of solid materials and the sector of measurements of ferromagnetic characteristics of solids through experiments, for any industrial area.

PURPOSE OF THE INVENTION

[003] The method, mechanical device and equipment for measuring physical parameters of ferromagnetic bodies, objects of the present invention, aim to propose to the relevant market a solution for the determination of the magnetic susceptibility of said bodies of solid materials, being particularly useful in analysis of bodies made of composite materials. It is also an object of the invention to weigh bodies that are in motion, such as parts being transported on a conveyor belt. To this end, the invention proposes simple, reliable, cheap and easy to use mechanical devices. production to be used in conjunction with the proposed methods and equipment, replacing traditional mechanical scales.

FUNDAMENTALS OF THE INVENTION AND STATE OF THE ART

[004] The design of the invention involves old weighing concepts. The following paragraphs refer to widespread foundations in the state of the art, but fundamental to the design of the invention.

[005] First, the concepts of mass and weight are differentiated. Mass is a scalar quantity that refers to the natural tendency of a body to oppose changes from its original state of rest or motion. Weight P is a force, therefore, a vector quantity, which relates mass m to the local acceleration of gravity g, through the application of Newton's second law:

P = mg (1 )

[006] In the International System of Units, masses are measured in kilograms (kg) and accelerations are measured in meters per second squared (m/s ² ). Consequently, weights are measured in kilogram meters per second squared (kg m / s ² ), a unit also known as the newton (N). The weighing scales ("scales") known in the state of the art depend on the gravitational field to which they are subjected. Therefore, traditional scales measure weight, not mass. This fact is confirmed by the basic premise that the measurement direction of traditional scales is, necessarily, the same direction as the acceleration of gravity: vertical.

[007] Although the above definitions are quite clear and known for centuries, it is common for the concepts of mass and weight to be confused often. The confusion is intensified by the use of the kilogram-force (kgf) unit for weight measurement, which resembles the kilogram (kg), unit of mass. However, such confusion usually does not have serious consequences, since, by definition, a body of mass 1 kg has a weight of 1 kgf on planet Earth. The vast majority of engineering applications are restricted to Earth, which has an approximately constant gravity of 9.81 m/s ² . Therefore, through Equation 1, it is deduced that a body of mass 1 kg has a weight of 9.81 N or, by definition, 1 kgf. Such clarification of mass and weight is of particular relevance in the explanation of Variant C of the present invention, shown below.

[008] With reference to weighing concepts, Figure 1 illustrates the primitive conception of a scale, composed of a lever system (1 ). The balance consists of two plates (2) suspended each on one side (3) of said lever (1), the two sides (3) of the lever having generally equal distances to the fulcrum (4). The working principle is based on equalizing the torque generated by the two sides (3) of the lever (1) at the fulcrum point (4), by adjusting the weights contained in the two plates (2), by checking the perfect horizontality of the lever (1), a condition that represents a zero torsional moment at the fulcrum (4). For this purpose, the body to be weighed (“body”) (5) is placed on one of the plates (2) and, on the other plate (2), weights (6) of known values are placed.

[009] The evolution of the mechanical balance passes through Gilles de Roberval who, in 1669, invented a mechanism shown in Figure 2, particularly relevant also for the Variant C of the present invention, which will be seen below. In general terms, said mechanism (7) uses a geometric concept to reduce the influence of the positioning of the body (5) on the plate (2) of the balance. In the simple lever weighing concept, shown in Figure 1, the body (5) has a lower weight if it is placed closer to the fulcrum (4) and greater weight if it is placed further away from the fulcrum (4). Figure 2 shows the solution presented by Roberval, in which the simple lever (1) is replaced by a parallelogram mechanism (7) with two fulcrums (4) and with joints (8) in the column of the plates (2), which guarantees a vertical movement of the plates (2) and, consequently, eliminates the variation in weight due to the positioning of the body (5). Still on mechanical balances, Richard Salter, in 1770, invented the spring balance, which, based on the theory of elasticity, more specifically on Hooke's law in its minimum form, correlates the deformation of a spring with the weight of the body to be weighed. . Despite being initially applied to mechanical balances, the concepts explored by Roberval and Salter served as the basis for many current concepts of electronic balances.

[0010] Load cell scales (“cell scales”) are electromechanical devices that emerged as a result of the invention of the strain gauge load cell which, in turn, emerged from the union of relevant inventions: the already explained concept of the scale of Salter, the Wheatstone bridge, the strain gauge and, occasionally, the Roberval mechanism. In general terms, the Wheatstone bridge, invented in the 19th century by Samuel Hunter Christie and improved by Sir Charles Wheatstone, allows the reading of very small variations in resistance in a resistor or in a resistive circuit. The strain gauge, in turn, was invented in 1938 by Edward E. Simmons and Arthur C. Ruge, and consists of gluing an electrically resistive filament to a mechanical structure, where such a resistive filament changes its electrical resistance proportionally to the deformation of the mechanical structure to which it is adhered. As the resistance variation is extremely small, it is common practice to use Wheatstone bridges to read the resistance of extremometers. Extensometric load cells in their essence are, therefore, mechanical structures (springs with relatively small deformations) to which strain gauges are attached that are electrically connected to a Wheatstone bridge, generating a signal proportional to the force applied to the mechanical structure.

[0011] The application of the Roberval mechanism in load cells (9) is shown in Figure 3, where the articulated fulcrums (4) are replaced by thin regions (10) of the mechanical structure, as well as the joints of the dish column ( 8) are replaced by thin regions (11) close to the column (12) of application of the force to be measured. Usually, strain gauges (13) are attached to regions (10,11 ) that are equivalent to fulcrums and joints as they are regions subject to greater deformation. Note, therefore, that the column (12) has an approximately vertical movement, as it occurs in the columns of the plates of the traditional Roberval mechanism, in Figure 2.

[0012] It is not clear in the literature when load cells were applied specifically in scales, although the deduction of this application is almost obvious. However, in the 1970s and 1980s, companies such as Toledo and Mettler patented some of the first types of scales with specific characteristics (US4236222, US3939332, US3962570, US3962569, US3984667, US3986012, US4181946, US4204197, US4236222, US4316).

[0013] Electromagnetic compensation scales use a completely different concept to carry out weighing. Figure 4 presents the basic concept (14), which was initially protected by Lee Cahn in 1963 (US3224517) where, in general terms, an electromagnet (15) generates a force to suspend the plate (2) on which the body is placed. (5), in order to reestablish the position of the plate (2) without load. A positioning sensor (16) informs the control module (17) when the position is re-established. The electrical power consumed by the electromagnet (15) when the position is re-established is proportional to the weight of the body (5) in addition to the plate (2). A more recent application of the electromagnetic compensation technique is found in US2012181094A1. [0014] Current common scales, whether based on strain gauge load cells or on electromagnetic compensation, require the body to be placed on the scale plate, which makes it difficult to use these scales to weigh bodies in motion. However, the state of the art includes some inventions aimed at this end: patents such as CN106768248A, CN109186723A and US3101800A have the objective of weighing bodies in motion, but still require the body to rest on a plate or equivalent; patents such as CA2229237A1 and US5856637A contemplate a connection device between a conveyor belt and the equivalent scale plate, in order to physically decouple the belt from the scale; patents such as RU2013127573A and JP2002277309A refer to mats transformed into scales.

[0015] It is not contemplated in the state of the art a solution that attracts the body from the surface that transports it, measures its weight or mass and releases it through a mechanically simple, stationary device, without joints.

PROBLEM TO BE SOLVED

[0016] The present invention contemplates a solution to the problem, through the design of devices with few components, without moving parts, cheap to be designed, optionally based on electromagnetic attraction and easily adaptable to conveyor surfaces that are already designed or installed. When the device uses electromagnetic attraction, a premise for the application is that the body to be weighed has a ferromagnetic composition. By way of nomenclature, “Variant A” is the application of the “attract-measure-release” concept associated with weighing per load cell.

[0017] In addition to being a solution for weighing moving parts, the invention addresses two new weighing concepts that are interrelated to the initial problem: the first new concept is based on electromagnetism, but it is not based on restoring the position of the pan, as is the case with electromagnetic balance scales, but it is based on an electromagnetic force directly equivalent to the weight of the body. This new weighing concept is called electromagnetic equivalence. When the “attract-me-and-release” concept is applied to the so-called electromagnetic equivalence, it is called “Variant B”.

[0018] The second proposed new weighing concept, totally different from what is known in the state of the art, is called here mass measurement by frequencies natural, and is based on the analysis of vibrations of a mechanical system composed of a structure specially designed for this purpose fixed to the body. When applying the concept “attract-measure-release” to the measurement by natural frequencies, it is called “Variant C”. The main advantage of measuring mass by natural frequencies lies in the dynamic application of the invention: while traditional weighing concepts are negatively affected by a possible vibration of the body or the set, weighing by natural frequencies is positively affected by such a circumstance: it is necessary the system vibrates to carry out the weighing. Another relevant advantage of measuring by natural frequencies is that, unlike weighing concepts, it does not weigh the body, it measures the mass of the body, which means that both variations in the gravitational field and the direction of device positioning do not influence the result. measurement, making it suitable for applications in unknown gravitational fields and even in the absence of gravitational fields.

[0019] Unlike Variants A and B, mass measurement by natural frequencies does not necessarily require a device that performs the attract-measure-release method. In this case, it is called “Variant D”.

[0020] Other technical problems that can be solved with the present invention deal with the determination of the magnetic susceptibility of bodies, as well as the determination of the amount of ferromagnetic material of bodies, mainly bodies constituted by composite materials. Documents such as JPH07306185A and JPA63217266 deal with these topics in a completely different way than proposed here. The present invention addresses solutions based on the union of concepts proposed here: the concept of load cell weighing in addition to electromagnetic equivalence (“Variant E”) and the concept of mass measurement by natural frequencies in addition to electromagnetic equivalence (“Variant E”) F”).

[0021] Another technical problem of possible application of the invention is the analysis of parts produced on the production line, and any of the Variants can be used to qualify, classify or select the parts according to the measurement result.

DESCRIPTION OF THE FIGURES

[0022] Reference is made to the Figures that accompany this descriptive report, for a better understanding and illustration of the same, where you can see:

[0023] Figure 1 refers to the state of the art exemplifying the primitive balance. [0024] Figure 2 refers to the state of the art exemplifying the traditional Roberval mechanism.

[0025] Figure 3 refers to the state of the art exemplifying the Roberval mechanism applied to a contemporary load cell.

[0026] Figure 4 refers to the state of the art, exemplifying the balance by electromagnetic compensation.

[0027] Figure 5 shows the side view in section of the basic scheme of Variant A, of the invention proposed here.

[0028] Figure 6 presents the dynamic mechanical system equivalent to the basic scheme of Variant A.

[0029] Figure 7 shows the side view in section of a functional version of Variant A.

[0030] Figure 8 shows the isometric sectional view of the device shown in Figure 7.

[0031] Figure 9 outlines the actuation timeline of the device shown in Figure 7.

[0032] Figure 10 shows the side cut view of the basic scheme of Variant B. [0033] Figure 11 outlines the timeline of the application of PWM (pulse width modulation) applied to Variant B of the invention proposed here.

[0034] Figure 12 shows a side view of a functional version of Variant C of the invention proposed herein.

[0035] Figure 13 shows the front view of the device shown in Figure 12.

[0036] Figure 14 presents the isometric view of the device shown in Figure 12.

[0037] Figure 15 illustrates the concept of “eight open at one end”, applied to the device shown in Figure 12.

[0038] Figure 16 illustrates the concept of “fork”, applied to the device shown in Figure 12.

[0039] Figure 17 presents the critical dimensions of the device shown in Figure 12.

[0040] Figure 18 shows a side view of a functional version of Variant D of the invention proposed herein.

[0041] Figure 19 presents the isometric view of the device shown in Figure 18. [0042] Figure 20 shows the side view of the device shown in Figure 18 in which a hammer exciter subsystem was added.

[0043] Figure 21 shows the front view of the device shown in Figure 20.

[0044] Figure 22 shows the rear view of the device shown in Figure 20.

[0045] Figure 23 presents a detail of Figure 20, showing the components in the excitation region.

[0046] Figure 24 shows the top view of a production line in which the equipment for analyzing parts was installed.

[0047] Figure 25 shows the positioning variation of the body of the example of embodiment of the invention.

GENERAL DESCRIPTION OF THE INVENTION

[0048] The method, mechanical device and equipment for measuring physical parameters of bodies, object of the present invention, is a method, a mechanical device and an equipment for measuring mass or weight, magnetic susceptibility or quantity of ferromagnetic material or amount of iron in bodies, as well as qualification, classification and selection of said bodies.

[0049] When applied to a ferromagnetic body, the method for measuring the mass or weight of a ferromagnetic body (5), comprises the steps of: 1 - actuation of one or a plurality of actuator electromagnets (20), resulting in attraction electromagnetic, from the bottom up, of the body (5) by the electromagnet(s) actuator(s) (20); 2 - crimping of the body (5) against the electromagnet(s) actuator(s) (20) or against one or a plurality of impact heads (21), due to the electromagnetic force exerted by the electromagnet(s) actuator(s)( es) (20); 3 - measurement of the mass or weight of the body itself (5), containing the reading of a signal correlated with the mass or weight of the body (5); 4 - deactivation of the actuator(s) electromagnet(s) (20); and 5 - fall of the body (5) due to the weight of the body (5), conceptualizing the term “attract-mede-release”.

[0050] Also when applied to a ferromagnetic body, the method for determining the magnetic susceptibility or for determining the amount of ferromagnetic material or for determining the amount of iron in a ferromagnetic body (5) comprises the steps of: 1 - activation of a or a plurality of actuator electromagnets (20), resulting in electromagnetic attraction, from below, of the body (5) by the actuator electromagnet(s) (20); 2 - body crimping (5) against the actuator(s) electromagnet(s) or against one or a plurality of head(s) impact (20), due to the electromagnetic force exerted by the electromagnet(s) actuator(s) (20); 3 - measurement of mass or weight of the body (5), containing the reading of a signal correlated with the mass or weight of the body (5); 4 - gradual decrease of the electromagnetic force of the actuator(s) electromagnet(s) (20) until said electromagnetic force is less than the weight force of the body (5); 5 - reading of the instantaneous power or voltage applied to the electromagnet(s) actuator(s) (20) at the final instant of step 4; and 6 - fall of the body (5) due to the weight of the body (5).

[0051] Step 3, referring to the measurement of mass or weight itself of the body (5), may contain the reading of a signal correlated with the mass or weight of the body (5), said signal coming from one or a plurality of load cells (19), arranged vertically in series with the body (5) and, when in plurality, parallel to each other, or said signal can be obtained by gradually decreasing the electromagnetic force applied to the electromagnet(s)( s) actuator(s) (20), until the weight force, exerted naturally by the body (5), is greater than the electromagnetic force exerted by the actuator(s) electromagnet(s) (20), causing the electromagnetic release of the body (5) simultaneously with reading of the instantaneous power or voltage applied to the electromagnet(s) actuator(s) (20).

[0052] Still in relation to step 3, referring to the measurement of mass or weight of the body itself (5), such measurement can be obtained through statistical regression that uses, as explanatory variables, natural frequencies of a mechanical system (45) which is composed of a mechanical device (40) and the body (5) crimped to said mechanical device (40).

[0053] The method for qualification, classification or selection of a ferromagnetic body (5) comprises the steps of the method described above, also containing the steps of: 1 - analysis of the result of said measurement, through comparison with pre- established, comparison with statistical data from previously measured bodies or artificial neural network algorithm; and 2 - optionally manipulating the bodies based on the result of said analysis.

[0054] The Mechanical Device (18) for measuring the weight of a ferromagnetic body (5), where the weight measurement is obtained by processing a signal coming from one or a plurality of load cells (19), arranged vertically in series with the body (5) and, when in plurality, parallel to each other, it comprises: one or a plurality of load cells (19); one or a plurality of actuator electromagnets (20); none, one or a plurality of impact heads (21); and none, one or a plurality of damping elements (22).

[0055] The Mechanical device (33) for measuring the weight of a ferromagnetic body (5) obtained by gradually decreasing the electromagnetic force applied to the electromagnet(s) actuator(s) (20), until the weight force, exerted naturally by the body (5), is greater than the electromagnetic force exerted by the electromagnet(s) actuator(s) (20), causing the electromagnetic release of the body (5) at the same time as reading the power or instantaneous voltage applied to the actuator(s) electromagnet(s) (20); comprises: one or a plurality of actuator electromagnets (20); one or a plurality of presence sensors (34); and none, one or a plurality of impact heads (21).

[0056] The Mechanical Device (40) for measuring the mass of the ferromagnetic body (5), containing the reading of a signal correlated with the mass or weight of the ferromagnetic body (5), obtained through statistical regression that uses, as variables explanatory, natural frequencies of a mechanical system (45) with the ferromagnetic body (5) attached to said mechanical device (40), has one or a plurality of actuating electromagnets, as well as none, one or a plurality of impact heads, forming a mechanical system that has the concomitance of: at least one mode of vibration whose natural frequency is, at the same time, more affected by the mass variation of said body and less affected by the positioning of said body, compared to natural frequencies of other modes mechanical system vibration; and at least one mode of vibration whose natural frequency is, at the same time, more affected by the variation in positioning of said body and less affected by the variation of mass of said body, compared to natural frequencies of other vibration modes of the mechanical system.

[0057] The mechanical device (40) is still composed of spools (41) and structure (42), in such a way that, when it has a ferromagnetic body (5) fixed at its end, it forms a mechanical system (45) that has, concomitantly: the natural frequency of the first bending vibration mode in the yz plane more influenced by the mass of the ferromagnetic body (5) embedded in the end of said device (40) than by the positioning of the ferromagnetic body (5) embedded in the end of the said device (40), compared to natural frequencies of other vibration modes of said mechanical system (45); and the natural frequency of the first torsion mode in the xz plane more influenced by the positioning of the ferromagnetic body (5) crimped at the end of said device (40) than by the mass of the ferromagnetic body (5) crimped at the end of said device (40), compared to natural frequencies of other vibration modes of said mechanical system (45). [0058] The Mechanical Device (40), may also have, in addition, a subsystem that performs the function of a modal hammer, consisting of a support (47), elastic beam (48), optional mechanical stop (49) and hammer head (50 ).

[0059] Finally, the invention encompasses an Equipment (52) configured to carry out the above-described method, equipment which comprises the Mechanical Device (18) for measuring the weight of a ferromagnetic body (5) or the Mechanical Device (33) for measuring the weight of a ferromagnetic body (5) or the Mechanical Device (40) for measuring the mass of a ferromagnetic body (5), also containing control hardware and software (54) and optional body manipulator (55).

DETAILED DESCRIPTION OF THE INVENTION

[0060] As presented in the solutions proposed by the present invention, six variants of the invention are addressed, being that:

[0061] “Variant A” is the application of the concept “attract-measure-release” associated with weighing by load cell, and can be used when the body to be weighed has a ferromagnetic composition;

[0062] “Variant B” is the application of the “attract-me-and-release” concept associated with electromagnetic equivalence weighing, used when the body has a ferromagnetic composition;

[0063] “Variant C” is the association of the concept “attract-measure-release” to the measurement of mass by natural frequencies, also applied to ferromagnetic bodies. [064] “Variant D” is the application of measurement by natural frequencies without the need for the concomitant application of the concept “attract-measure-release” and, consequently, without the need for the body to have ferromagnetic characteristics.

[0064] the "Variant E" consists of the addition of a weighing per load cell in addition to the concept of electromagnetic equivalence, mentioned above, in order to obtain information on the magnetic susceptibility of the body; and

[0065] Like the "Variant E", the "Variant F" also aims to obtain information on the magnetic characteristics of the body, however, through the junction of mass measurement by natural frequencies and the concept of electromagnetic equivalence.

Variant A [0066] Figure 5 shows the basic schematic view of Variant A, which consists of a mechanical arrangement (18) vertically in series of a load cell (19), an actuator electromagnet (20) and its respective and optional impact head (21 ). Optionally, there may be a damping element (22) in parallel with the load cell (19). Such a mechanical arrangement is fixed to an inertial support (23) and intends to weigh a body (5) that has ferromagnetic properties.

[0067] To make the measurement, the actuator electromagnet (20) is electrically activated and this attracts the body (5), impacting it and setting it against the actuator electromagnet (20) or against the optional impact head (21) ). After said crimping of the body, the electrical signal of the load cell (19) is read through the application of extensometric methods known in the state of the art, weighing the body (5). The activation of the actuator electromagnet (20) and the reading of the load cell signal (19) are performed by an electro-electronic hardware (24). Methods and best practices for load cell based weighing, such as tare subtraction, calibration, etc., are well known. such methods being applicable to Variant A.

[0068] As the purpose is to measure a static load, one should avoid the use of piezoelectric load cells which, although very rigid, are more apt to measure dynamic forces. For static loads, it is common to apply strain gauge load cells, as described in the fundamentals of the invention. However, strain gauge cells have a stiffness constitution proportional to their measurement range, which makes them, inevitably, an element that favors the occurrence of vibrations in the system. It is known that vibrations are undesirable in the measurement of static loads and, to circumvent the problem, Variant A can contain a damping element (22) parallel to the load cell (19) in order to dissipate the energy of the impact of the body (5 ) and consequently minimize or eliminate vibration.

[0069] The easiest way to design the actuator electromagnet (20), as well as its activation, is to define the application voltage to be required by a known electromagnet, given by (adapted from Physics, Chapter 32 Electromagnetic Induction - Robert Katz Publications):

where U is the voltage of a to be applied to the actuator electromagnet (20) (V); A is the cross-sectional area of the actuator electromagnet coil (20) (m ² ); R is resistance of said coil ( ); n is the number of turns of the actuator electromagnet (20); d is the gap between the body (5) and the face of the actuator electromagnet (20) or the optional impact head (21) (m); ch_ is the thickness of the optional impact head (21) (m); m _p is the mass of the body (5) (kg); g is the acceleration due to gravity (m/s ² ); p is the magnetic constant (adopted 4x^x10 ^-7 ) and ô is a factor for adjusting the body type (5). Such a factor is a dimensionless number between 0 and 1, where oferrite is 1, and is correlated with the magnetic susceptibility of the body to being attracted. From the definition of the application voltage, it is analyzed whether the actuator electromagnet (20) supports such a voltage for the suspension time of the body (5) and weight reading. [0070] The time ti of suspension of the body (5) can be obtained, approximately, by

where F _e is the force that the actuator electromagnet (20) applies to the body (5) at the initial moment of suspension, given by

[0071] From the point of view of mechanical vibrations, a dynamic system that can represent the basic version of Variant A is found in Figure 6. As can be seen, the proposal for a one-degree-of-freedom system is minimized. The load cell (19) is considered to be a purely elastic, massless element with stiffness constant k _c . The optional damper element (22) has a damping constant c and the vibrating mass m _t is given by the sum of the masses of the actuator electromagnet (20) and the optional impact head (21) m _ec in addition to the mass m _p of the body (5 ).

[0072] The dimensioning of the optional damping element (22) is such that it makes the system critically damped: it is desired that the system does not vibrate and stabilizes itself as quickly as possible, for later weight measurement. For this, the necessary damping constant c is found from

[0073] Also to circumvent the vibration problem, the device can be stiffened to receive the impact of the body. A proposal in this direction is seen in the functional device shown in Figure 7 and Figure 8. In such figures, the components already mentioned above can be found, in addition to one or more pre-tensioning electromagnets (25), a plunger (26), a or more optional ferromagnetic elements (27) and a stator (28). In conventional weighing systems, it is common to adopt more than one load cell to circumvent body positioning problems, a solution optionally applicable to the proposed inventive concept.

[0074] The stator (28) is mounted on an inertial support (23). Fixed to the stator (28), is the pretensioner electromagnet (25) and one or more load cells (19). The plunger (26) is floating within the system, and holds the actuator electromagnet (20), the optional ferromagnetic element (27) and the damper ring (29). The optional ferromagnetic element (27) is required when the plunger (26) is made of a non-ferromagnetic material. The actuation time line follows the diagram in Figure 9, where the time runs from left to right and the actuation (30) of the pre-tensioner electromagnet (25), the actuation (31) of the actuator electromagnet (20) and the measurement (32) of weight.

[0075] The process describes the steps: 1 - the pretensioner electromagnet (25) is energized, attracting the piston (26) against the stator (28) on its conical faces, making the system rigid in the vertical direction , mainly from the bottom to the top; 2 - the actuator electromagnet (20) is energized, which attracts and sets the body (5) against the actuator electromagnet itself (20) or against the optional impact head (21); 3 - after crimping the body (5), the pretensioner electromagnet (25) is de-energized, causing the mass of the plunger (26) and all that is crimped to it (27;29;20;5 ) rest on the load cell(s) (19); 4 - the weight measurement is carried out by reading the signal(s) of the load cell(s) (19); 5 - the actuator electromagnet (25) is de-energized, allowing the body (5) to fall.

[0076] [077] It should be noted that the gap between the plunger (26) and the load cell(s) (19), during step 2 or between the plunger (26) and the stator (28) , during the measurement, is considerably small, enough to disengage the piston (26) from the stator (28) during the measurement. This ensures that the impact on the load cell(s) (19) in step 4 is small and the system oscillates with a small and rapidly dissipating amplitude. The association of the plurality of load cells (19) is considered, when there is, as a single elastic element, so that the system can still be simplified to one degree of freedom. The need for a dedicated damping element is eliminated, the main function of the damping ring (29) being to distribute the weight among the plurality of cells (19). The conical shape of the interface between the stator (28) and the piston (26) guarantees positioning in the horizontal plane, with the objective of minimizing positioning variations that negatively influence the weighing.

Variant B

[0077] Variant B aims to weigh ferromagnetic bodies that have equal magnetic susceptibilities, such as, for example, equal parts being produced on a production line. Figure 10 schematizes a functional device (33) of Variant B, consisting of the actuator electromagnet (20), the optional impact head (21) and the presence sensor (34), which detects the part attached to the actuator electromagnet (20) or fixed to the optional impact head (21 ).

[0078] The actuation time line consists of: 1 - Energize the actuator electromagnet (20) with sufficient power to attract the body (5) and crimp it against the actuator electromagnet (20) or against the optional impact head ( 21 ); 2 - Gradually reduce the power applied to the actuator electromagnet (20), until the weight of the body (5) is greater than the electromagnetic force exerted by the actuator electromagnet (20) against the body (5), causing the body ( 5) disengage the actuator electromagnet (20) or the optional impact head (21) and start a free fall, instant detected by the presence sensor (34).

[0079] Since the magnetic susceptibility of the bodies (5) to be weighed is equal, the power (or voltage, if the circuit resistance is constant) applied to the actuator electromagnet (20) at the instant of disengagement is proportional to the weight of the body (5).

[0080] The control of the power applied to the actuator electromagnet (20) is given by a control system (35) and can be done in several ways, the most common being: through a direct current drive, through a alternating current frequency or, preferably, using a PWM command (pulse width modulation). As an illustration, Figure 11 shows the time line of a PWM actuation of Variant B. The abscissas represent the time from left to right and the ordinates refer to the voltage applied to the actuator electromagnet (20). In a first phase (36), the actuator electromagnet (20) is activated, which attracts the body (5) until the moment of crimping (37). The moment of crimping (37) can be determined by time or by reading the presence sensor (34). after the crimping, there is a gradual decrease (38) in the pulse width of the actuator electromagnet (20) actuation, until the weight of the body (5) is greater than the electromagnetic force exerted by the actuator electromagnet (20) on the body (5) , instant (39) in which the presence sensor (34) detects the disengagement of the body. It is noteworthy that Figure 11 is schematic with respect to the number of pulses, since, usually, the pulse frequency of a PWM is in the order of kHz, which would make the image shown in the diagram of Figure 11 incomprehensible because it contains pulses. too much. The control system (35) is able to identify the pulse width at the moment when the presence sensor (34) detects the disengagement of the body (5). The easiest way to estimate the weight of the body (5) is through a proportionality to the pulse width at the moment of disengagement (39).

[0081] Due to different magnetic susceptibilities of bodies with different constitutions, the system must be calibrated using bodies similar to those that will be weighed during use. Using this previous calibration, the proportionality between the pulse width at the time of disengagement (39) and the body weight (5) is obtained. Optionally, the weight estimate can be obtained through statistical regressions, which tends to provide better accuracy than simple proportionality.

Variant C

[0082] While the free vibration generated by the impact of the body against the actuator electromagnet or against the optional impact head is harmful to the weight reading in Variant A, Variant C aims to use exactly this vibration to estimate the mass of the body. As a background, consider the one-degree-of-freedom mechanical system of Figure 6, where kcc represents the stiffness of a generic structure without damping. Therefore, c = 0. It is possible to find the mass m _p of the body if the mass m _ec of the actuator electromagnet and the optional impact head, the stiffness k _cc of the structure and the natural angular frequency o)„ of the system are determined, a once

[0083] You can develop a structure with known stiffness and measure the natural frequency of the system, looking for the change in the natural frequency that m _p causes when fixed to the system. It is noteworthy that, unlike Variant A and Variant B, Variant C does not measure weight, but mass. [0084] Although the minimal model above illustrates the initial idea, the direct application is technically unfeasible even in the theoretical phase, since the physical assembly is a continuous system, with infinite degrees of freedom, making the positioning of the body very relevant. in estimating its mass. It is also well known that some modes of vibration are more affected than others by the variation of body mass. With these issues in mind, it is proposed to develop a device that has one or more vibration modes that have their natural frequencies that change in favor of m _p detection while having other vibration modes sensitive to m _p positioning. In other words, a structure is proposed that has modes of vibrations within the spectral region of measurement that have respective natural frequencies that are: heavily influenced by the variation of the body's mass and little influenced by its positioning; and little influenced by the variation of body mass and heavily influenced by its positioning.

[0085] Bringing these two characteristics together in a single device, it is proposed to identify the natural frequencies of the modes of interest and estimate the body mass through a multivariable statistical regression, in which the natural frequencies are the explanatory variables.

[0086] Figure 12, Figure 13 and Figure 14 show a device (40) developed in order to meet these characteristics. This is an example that can be taken as a functional solution, not limited to the only plausible constructive solution: there are numerous other conceptions that meet the objectives of the invention. Attention is drawn to the definition of the x, y and z coordinates in Figure 14, necessary for the explanation.

[0087] In said functional example, the device (40) is fixed to an inertial support (23) by the four spools (41) that act as fulcrums. The spools suspend the structure (42), which has a geometry in the shape of an “8 open at one end”, illustrated by the thick line (43) of Figure 15, forming a “fork” facing downwards - the thick line (44) of the Figure 16 -, which supports an actuator electromagnet (20) with its respective and optional impact head at each of its ends. When the body (5) is crimped for weight measurement, it closes the “8” shape, forming the so-called mechanical system (45).

[0088] The technical reasons behind the device geometry (40) are: [0089] The slender shape of the fork favors the emergence of the first bending vibration mode in the yz plane, which is sensitive to the body's mass variation (5). Such a mode of vibration can be considered as a one-degree-of-freedom mechanical system in which the relation m _p = k / c is valid, where k is the stiffness constant in the vibration direction and co is the angular natural frequency to be measured. Therefore, we expect an approximate and inversely quadratic relationship between the mass of the body (5) and the natural frequency in the first bending vibration mode in the yz plane

[0090] The structure (42) has several triangular weight reliefs that, for reasons of mechanical strength, serve to form a mesh of trusses in the xz plane, aiming to stiffen the structure (42) in the xz plane while keeping it flexible in the yz plane . The functional reason behind this manipulation of stiffness is to distance the natural frequencies of the first bending modes in the xz and yz planes, reducing the natural frequency of the first bending modes in the yz plane, as well as favoring its amplitude. There are also thin regions that connect the structure (42) to the crimping region on the spools (41), in order to favor the amplitude of the compression vibration mode in the z direction.

[0091] Weight relief is also important for the sensitivity of the system (45) to body mass variation (5): if the structure (42) has a lot of mass, the body (5) represents a smaller percentage of the mass of the system (45) that is vibrating. Regarding the material to be used for the construction of the structure (42), light and rigid metals such as titanium are suggested, as well as a manufacturing process by electro-erosion, laser cutting or water jet cutting;

[0092] Regarding the structures with relief that simulate the Roberval mechanism seen in the fundamentals of the invention, it was exposed that its purpose is to make the deformation in the fulcrums and pivots less susceptible to the positioning of the load. For the present development, a structure based on the Roberval mechanism is proposed, however, modified to obtain the inverse function: it is desired that the device (40) has a vibration mode that is highly affected by the positioning of the body's mass. (5). The spools (41 ) - suggestively made of a low-density metal, such as aluminum - perform a similar function to the fulcrums (4) in the Roberval balance (7), having a cylindrical axis shape, favoring the torsional vibration mode in the xz plane in which the upper spools (41) twist axially in the same direction as the respective lower spools (41). Such a mode characterizes an opposite movement of the two fork legs (44). As has been said, although the inspiration for the development of this mode comes from the Roberval balance, an opposite result is sought: the natural frequency of the torsion mode in the xz plane is sensitive to the positioning of the body (5). Such sensitivity is due to the change in the center of mass along the x direction. In didactic terms, for different positioning of the body (5), the movement of each fork leg (44) is partially determined by the restriction caused by the crimping of the body (5) against the actuator electromagnets (43) or against the optional impact head. , with the body's center of mass (5) being deposited in only one of the legs, significantly influencing its natural frequency.

[0093] It is desired that the natural frequencies of the device (40) be low such that they are far from the free-free natural frequencies of the body (5).

[0094] To achieve the objectives described above, the critical dimensions are recommended based on Figure 18, which are: a - as large as the body (5) allows; - as small as possible, limited for structural reasons; c - as large as possible, limited by the minimum frequency that the acquisition system accurately reads, because the first natural frequency of bending in the yz plane is inversely proportional to this dimension; d - as small as possible, limited by the minimum frequency that the acquisition system accurately reads, because the first natural frequency of bending in the yz plane is proportional to this dimension; e, e - large enough that the first mode of vibration is bending in the yz plane.

[0095] For a measuring range from 250x10' ³ kg to 450x10' ³ kg with a body (5) of dimensions 60x10 ^-3 mx 60x10' ³ mx 25x10' ³ m in x, y and z, respectively, the dimensions are suggested approximate: a = 52x10 ^-3 m, (z>b = 2.5x10' ³ m with 1 .5x10' ³ m transition radius, c = 160x10' ³ m, d = 8x10' ³ m and e = 15x10' ³ m .

[0096] Regarding the identification of the natural frequencies of the vibration modes of interest, this can be done through any method of modal analysis of the state of the art.

[0097] However, a good compromise between cost, ease of implementation and satisfaction of the results involves the following techniques: sensing via microphone, positioned close to the structure; the signal acquisition system through an analog-to-digital converter; the definition of the sampling frequency by the Nyquist criterion; spectral processing through fast Fourier transform; and super spectral resolution through cubic spline. [0098] It is proposed the development of a software dedicated to the identification of the natural frequencies of the system, being part of the proposed device.

[0099] The application of multivariable regression that estimates the body mass (5) through the natural frequencies of the system (45) can also be called calibration. Such calibration is described by the steps of: 1 - a sample of bodies (5) is selected that cover the measurement range as much as possible; 2 - each body (5) of said sample is weighed on a calibrated balance, recording the respective masses of each body (5). Such a set of masses is the independent variable of the regression; 3 - each body (5) is subjected to impact and crimped to the device (40), recording the natural frequencies of the vibration modes of interest. Such natural frequencies are the explanatory variables of the regression. Several submissions of each element are suggested, so that a variation of positioning is contemplated; and 4 - a statistical regression method available in the state of the art is performed using the independent variable and the explanatory variables, in order to estimate the mass of each body (5) of said sample; the parameters and the equation resulting from the regression are recorded.

[00100] Such parameters and equation are now used to estimate the mass of the new bodies (5) to be measured, characterizing the use of the proposal.

[00101] It is proposed the development of a source code dedicated to the said statistical regression, and such source code can be contained in the software used to detect the natural frequencies of the system. Such software can also be the same that estimates the mass of the bodies (5) during the use of the proposal.

Variant D

[00102] As explained in the grounds of the invention, Variant D is based on Variant C, with the following conceptual difference: it is not necessary for the device to attract the body electromagnetically and, consequently, it is not necessary for the body to have a ferromagnetic composition.

[00103] For a vertical measurement similar to the traditional process of scales in general, in which the body is placed on the measuring device, we propose the device 45 seen in Figure 18 and Figure 19. As can be seen, it rotates the system (40) of Variant C by 180 degrees around the y-axis and the actuator electromagnets (20) are eliminated. [00104] Optionally, a tray (46) is added to facilitate the placement of the body. Regarding such a tray (46), it can be: 1 - flexible so that it does not close the “eight open at one end” format, from the point of view of modal analysis. That is, flexible so as not to significantly influence the torsional vibration mode in the xz plane, making the body responsible for performing the function of closing the “open eight at one end” shape; and 2 - magnetized to facilitate the crimping of the body, when it is ferromagnetic, in order to guarantee a vibration without slipping between the body and the tray (46); designed in such a way that it does not have natural frequencies that are confused with the natural frequencies useful for the measurement; and 3 - made with high damping material or receive coatings that aim to dampen its vibration, in order to minimize the influence of its natural frequencies on the measurement.

[00105] As in Variant C, the measurement requires that the natural frequencies of the system be excited. Such excitation can be generated by the impact of the body itself against the device (45) or by some external mechanism, such as an appropriate modal hammer, a dynamic exciter or by piezoelectric elements.

[00106] When opting for an excitation other than the impact of the body itself, it is recommended that the excitation be in a direction that favors the amplitude of all vibration modes to be used in the estimation of the body's mass. For the case of the device (45) suggested in Figure 18 and Figure 19, the ideal direction is given by a vector inclined at 45° in the xz and yz planes.

[00107] A subsystem with the function of said modal hammer is shown in Figure 20, Figure 21, Figure 22 and Figure 23. Such subsystem is composed of a support (47) that is worn somewhere inert, such as the non-vibrating part of the spools (41 ). At the other end of the support (47) the end of an elastic beam (48) is crimped, as well as an optional mechanical stop (49). At the other end of such an elastic beam, a hammer head (50) is crimped. To provide better repeatability in impacts, the structure (42) can have a bulge (51) that forms a face perpendicular to the impact direction (such bulge (51) is also useful for other types of excitation, such as by dynamic exciter or by piezoelectric elements). The use of such a subsystem consists of simply pulling and releasing the hammering head (50) or the elastic beam (48) in the opposite direction to the structure (42), imposing an initial displacement on the elastic beam (48) and, consequently, on the head. hammer (50), which will vibrate freely due to the elasticity of the elastic beam (48). When there is the optional mechanical stop (49), the pull must be up to the contact of the hammer head (50) or the elastic beam (48) with the mechanical stop (49). The free vibration of the hammer head (50) implies an impact of the hammer head (50) against the structure (42) or against its optional bulge (51). The modal excitation of the mechanical system, required for the measurement of body mass, is therefore given by said impact. The proposed subsystem offers the benefit of being coupled to the device and allows the excitation always in the ideal direction. The optional mechanical stop (49) provides protection to the elastic beam (48) against excessive displacement during pulling, in addition to guaranteeing excitations with force repeatability.

Variant E and Variant F

[00108] Variant E and Variant F deal with devices that aim to estimate the magnetic susceptibility of ferromagnetic bodies. For most engineering materials, especially composite materials of homogeneous constitution, the magnetic susceptibility is directly related to the amount of ferromagnetic material contained in the material, if bodies of the same geometry are considered. Examples of homogeneously constituted composite materials include friction materials used in brake pads and linings, while the clearest example for ferromagnetic material is iron itself. Therefore, Variant E and Variant F are also aimed at estimating the amount of iron contained in the body and can be particularly useful in reverse engineering practices of brake linings and pads.

[00109] Either a weighing as described in Variant A or a mass measurement as described in Variant C, where the main concept of Variant B is added, which refers to the detection of the power applied to the actuator electromagnet at the moment of disengagement from the body. The concomitance of Variant A with Variant B is called Variant E and the concomitance of Variant C with Variant B is called Variant F. The mechanical arrangement of Variant E is identical to that of Variant A, with the exception that presence sensor (34) is required, and the mechanical arrangement of Variant F is identical to that of Variant C, with the exception that the presence sensor (34) is required.

[00110] To calibrate the system to estimate the magnetic susceptibility (or amount of iron) of bodies of the same geometry, a method based on statistical regression is proposed: 1 - the weight or mass reading is calibrated according to the techniques described in Variant A and Variant C, for Variant E and Variant F, respectively; 2 - a sample of bodies is selected that covers the range of magnetic susceptibility (or amount of iron) as much as possible; 3 - the magnetic susceptibility (or amount of iron) of each sample body is obtained through theoretical calculation or practical measurement, using any means known in the state of the art. Such a set of magnetic susceptibilities is the independent variable of the regression; 4 - each body is subjected to the crimping and unsetting of the actuator electromagnet, recording the power applied to the actuator electromagnet at the time of disengagement. Such power is the explanatory variable of the regression. It should be noted that a well-defined and repeatable positioning of the body under the actuator electromagnet offers better results; 5 - a statistical regression method available in the state of the art is performed using the independent variable and the explanatory variable, in order to estimate the magnetic susceptibility (or amount of iron) of each body of said sample; and 6 - the parameters and the equation resulting from the regression are recorded.

[00111] Such parameters and equation are now used to estimate the magnetic susceptibility (or amount of iron) of the new bodies to be measured.

Application of the invention on a production line

[00112] The ease of implementation of Variant A, Variant B, Variant C, Variant E and Variant F in production lines is notorious, such as, for example, by means of simple fixing of the respective devices in inertial structures on belts that transport parts . Given this facility, Figure 24 proposes equipment (52) for qualification, classification or selection of produced parts (53). Such equipment (52) consists of devices (18 or 33 or 40), control hardware and software (54) and an optional parts handler (55). Such manipulator (55) is able to divert the flow of the parts (53), according to the result of the measurement or the result of said analysis. [00113] Through such equipment (52), it is possible, for example, to analyze the statistical trend of production and, when the manipulator (55) is present, it is possible to classify pieces (53) between compliant and non-compliant, classify pieces ( 53) in various categories or select parts (53) with specific characteristics. It is proposed that the said qualification, classification or selection of parts be based on a simple comparison with pre-established values, as well as with statistical data of previously measured parts, as well as an artificial neural network algorithm.

EXAMPLE OF EMBODIMENT OF THE INVENTION

[00114] The successful applicability of Variant A and Variant B and, consequently, of Variant E is clear to a person skilled in the art, so that examples of embodiment would not add to the matter. The explanatory reinforcement therefore falls on the estimation of mass by natural frequencies, so that the example discussed in this section applies to Variant C and, consequently, to Variant D and Variant F. [00115] The device (40) described in variant C with the dimensions of Paragraph [0095] is proposed. It is desired that the device (40) measures four different types of bodies (5), called PN1, PN2, PN3 and PN4, which are parts produced on an industrial production line. Such pieces are represented by steel parallelepipeds with 60x10 ^-3 mx 60x10 ^-3 m in x and y. The range of possible masses of each type of part can be found in Table 1, as well as the respective required resolutions:

Table 1

[00116] Resolutions are defined as 10% of the possible mass range, according to quality system manuals such as the MSA (Measurement System Analysis) of ISO QS 9000. As can be seen in Table 1, the heaviest part possible has a mass of 382.6x10' ³ kg (PN2), the lightest part has a mass of 297.7x10' ³ kg (PN4) and the smallest resolution is 0.69x10' ³ kg (PN2). Therefore, a measurement range is defined with a certain safety margin from 250x10' ³ kg to 450x10' ³ kg with a resolution of 0.69x10 ^-3 kg, which implies 290 graduations.

[00117] An analysis is proposed via simulations using the Finite Element Method. Eight thicknesses are defined for the aforementioned steel parallelepipeds, generating the bodies Ci to Cs, according to Table 2.

Table 2

[00118] As can be seen, the definition of thickness is given in four regions Ri, R2, Ra and R4, which include the extremes of the range (Ri, and R4) and intermediate regions (R2, and R3), equally spaced in pasta. A pair of bodies is proposed for each region, such that they are separated in mass according to the proposed resolution - 0.69x10' ³ kg. Sampling the full range is particularly important to avoid the need for undesired model extrapolation. Attention is also drawn to the minuscule difference in thickness in each pair of bodies, in the order of 20x10' ⁶ m (two hundredths of a millimeter).

[00119] With respect to the positioning variation, three positions are defined in the x direction, called Po, P2 and P4, with Po centered, P2 = 2x10' ³ m and P4 = 4x10' ³ m, as shown in Figure 25.

[00120] The analysis is performed using the Finite Element Method of the device with the eight bodies Ci to Cs fixed in each of the three positions Po, P2 and P4, generating 24 simulations. As a result, the frequencies fi, fs and fe are obtained, which refer to the natural frequencies of the vibration modes of bending in x, torsion in y and compression in z, respectively, according to Table 3.

Table 3

[00121] For the example in question, it is suggested to estimate the mass of the body through the application of a polynomial of the form

where the parameters assume the values A = 3732,940; B = 37.2469; C = -4.01983; D = -3.62683; E = ^{-684.829x10'3} ; F = ^1.37654x10'3 ; G = ^1.05097x10'3 ; H = ^1.35054x10'3 . The criterion for acceptance of the proposal is given by the simple analysis of residues: for any element, a residue smaller than the stipulated resolution of 0.69x10' ³ kg is desired. Table 4 presents the estimates and the residues, where a maximum residue of 0.13x10' ³ kg can be seen, which validates the good applicability of the proposal. By way of reflection, applying only one natural frequency among fi, fa and fó in any type of regression known from the state of the art generates residues that are even greater than the resolution.

Table 4

Claims

27 CLAIMS

1. METHOD FOR MEASURING PHYSICAL PARAMETERS OF BODIES, being the method intended for the measurement of mass or weight of a ferromagnetic body (5), characterized by comprising steps that include:

- actuation of one or a plurality of actuator electromagnets (20), resulting in electromagnetic attraction, from the bottom up, of the body (5) by the actuator electromagnet(s) (20);

- body crimping (5) against the electromagnet(s) actuator(s) (20) or against one or a plurality of impact heads (21), due to the electromagnetic force exerted by the electromagnet(s) actuator(s) ) (20);

- measurement of mass or weight itself of the body (5), containing the reading of a signal correlated with the mass or weight of the body (5);

- deactivation of the actuator(s) electromagnet(s) (20); and

- fall of the body (5) by force of the weight of the body (5).

2. METHOD FOR MEASURING PHYSICAL PARAMETERS OF BODIES, being the method intended for determining the magnetic susceptibility or for determining the amount of ferromagnetic material or for determining the amount of iron in a ferromagnetic body (5), characterized by comprising the steps that include :

- body crimping (5) against the actuator(s) electromagnet(s) or against one or a plurality of impact head(s) (20), due to the electromagnetic force exerted by the electromagnet(s) actuator(s) (20);

- measurement of mass or weight of the body (5), containing the reading of a signal correlated with the mass or weight of the body (5);

- gradual decrease of the electromagnetic force of the actuator(s) electromagnet(s) (20) until said electromagnetic force is less than the weight force of the body (5);

- reading of the instantaneous power or voltage applied to the electromagnet(s) actuator(s) (20) at the final instant of step 4; and

- fall of the body (5) by force of the weight of the body (5).

3. METHOD, being the method intended to measure the weight of a body (5), or intended to determine the magnetic susceptibility or intended to determine the amount of ferromagnetic material or intended to determine the amount of iron in a ferromagnetic body (5) , according to Claim 1 or 2, characterized in that the weight measurement of the mass measurement step is obtained by processing a signal coming from one or a plurality of load cells (19), arranged vertically in series with the body ( 5) and, when in plurality, parallel to each other;

4. METHOD, being the method intended for measuring the weight of a body (5), according to Claim 1, characterized in that the weight measurement of the mass measurement step is obtained by the gradual decrease of the electromagnetic force applied to the electromagnet(s) (s) actuator(s) (20), until the weight force, exerted naturally by the body (5), is greater than the electromagnetic force exerted by the electromagnet(s) actuator(s) (20), causing the electromagnetic release of the body (5) simultaneously with reading of the power or instantaneous voltage applied to the electromagnet(s) actuator(s) (20);

5. METHOD, being the method intended for measuring the mass of a body (5), or being the method intended for determining magnetic susceptibility or intended for determining the amount of ferromagnetic material or intended for determining the amount of iron in a ferromagnetic body (5), according to Claim 1 or 2, characterized in that the mass measurement of the mass measurement step is obtained through statistical regression that uses, as explanatory variables, natural frequencies of a mechanical system (45) that is composed of a mechanical device (40) and the body (5) crimped to said mechanical device (40).

6. METHOD, being the method intended for the qualification, classification or selection of bodies (5), comprising measurement of said bodies (5), according to Claim 1 or 2, characterized by also comprising the steps of: analysis of the result of said measurement, through comparison with pre-established values, comparison with statistical data of previously measured bodies or algorithm of artificial neural networks; and optional manipulation of bodies based on the result of said analysis.

7. MECHANICAL DEVICE FOR MEASURING PHYSICAL PARAMETERS OF BODIES, the mechanical device (18) being configured to carry out the measurement of weight through the processing of a signal coming from one or a plurality of cells of load (19), characterized in that it comprises: one or a plurality of load cells (19); one or a plurality of actuator electromagnets (20); none, one or a plurality of impact heads (21); and none, one or a plurality of damping elements (22).

8. Mechanical device according to Claim 7, configured to be instantly stiffened, characterized in that it comprises one or a plurality of pre-tensioning electromagnets (25), a piston (26), none, one or a plurality of ferromagnetic elements ( 27) and a stator (28).

9. MECHANICAL DEVICE FOR MEASURING PHYSICAL PARAMETERS OF BODIES, the mechanical device (33) being configured to perform weight measurement through the gradual decrease of the electromagnetic force applied to the electromagnet(s) actuator(s) (20), characterized comprising: one or a plurality of actuator electromagnets (20); one or a plurality of presence sensors (34); and none, one or a plurality of impact heads (21).

10. MECHANICAL DEVICE FOR MEASURING PHYSICAL PARAMETERS OF BODIES, being the mechanical device characterized by the fact that, when it has a body fixed to itself, it forms a mechanical assembly that has the concomitance of: at least one mode of vibration whose natural frequency it is, at the same time, more affected by the mass variation of said body and less affected by the positioning of said body, compared to natural frequencies of other modes of vibration of the mechanical system; and at least one mode of vibration whose natural frequency is, at the same time, more affected by the variation in positioning of said body and less affected by the variation of mass of said body, compared to natural frequencies of other vibration modes of the mechanical system.

11. MECHANICAL DEVICE, the mechanical device being configured to perform measurement of physical parameters of bodies according to Claim 9, characterized by also having one or a plurality of actuating electromagnets, as well as none, one or a plurality of heads of impact.

12. MECHANICAL DEVICE, being the mechanical device (40), composed of spools (41) and structure (42), according to claim 9 or 10, characterized in that, when it has a body (5) embedded in its end, forms a mechanical system (45) that has, at the same time: the natural frequency of the first bending vibration mode in the yz plane (Figure 14) more influenced by the mass of the body (5) crimped at the end of said device (40) than by positioning the body (5) crimped at the end of said device (40), compared to natural frequencies of other vibration modes of said mechanical system (45); and the natural frequency of the first twisting mode in the xz plane (Figure 14) is more influenced by the positioning of the body (5) crimped at the end of said device (40) than by the mass of the body (5) crimped at the end of said device ( 40), compared to natural frequencies of other vibration modes of said mechanical system (45).

13. MECHANICAL DEVICE, being the mechanical device, according to Claim 9 or 10, characterized by having, in addition, a subsystem that performs the function of modal hammer, composed of support (47), elastic beam (48), optional backrest mechanical (49) and hammer head (50).

14. EQUIPMENT FOR MEASURING PHYSICAL PARAMETERS OF BODIES, the equipment (52) being configured to perform the measurement of physical parameters of ferromagnetic bodies, characterized by comprising mechanical devices and also control hardware and software (54) and optional body manipulator (55).