Method and system for detecting and measuring braking force of vehicle braking system using photonic sensors incorporated in brake caliper

Abstract

To measure a braking force and / or a torque applied by brake calipers of a vehicle braking system directly, accurately, and reliably.SOLUTION: A method for detecting and measuring a braking force and / or a braking torque by a braking system with a brake caliper 10 includes the steps of: incorporating deformation and / or strain sensor 2 of fiber Bragg grating type at each predetermined position in material of the body of the brake caliper 10; detecting, by the sensor 2, local deformation and / or strain acting at each position and generating a first photonic signal L; generating, by an optical reading / interrogation unit 4 optically connected to the sensor 2, a first electrical signal E; and processing the first electrical signal E to acquire a measurement of the braking force and / or the braking torque.SELECTED DRAWING: Figure 4C

Description

[Technical Field]

[0001] The present invention relates to a method and system for detecting and measuring braking force in a vehicle braking system by means of a photonic sensor (ie, a fiber optic sensor) integrated into the brake caliper.

[0002] The invention further relates to a brake caliper equipped with a sensor to enable the aforementioned method to be carried out. [Background technology]

[0003] When controlling, monitoring and operating a braking system, such as an electronically controlled disc brake system, it is very useful to know as accurately as possible in real time the braking force or torque value applied by the brake calipers of the braking system during braking.

[0004] However, it is difficult to directly, accurately, and reliably measure the braking force and / or torque applied by the brake calipers of a braking system.

[0005] To this end, it would be desirable to be able to incorporate a force sensor into the brake caliper itself that is capable of detecting and providing such information.

[0006] However, the force sensors available in the prior art are not suitable for incorporation into the body of a brake caliper because they are not sufficiently miniaturized and compact, or they cannot be easily connected to the outside for actuation and / or reading, or they are too sensitive to temperature changes and therefore are not suitable for operation in environments exposed to significant temperature and climate changes, such as a brake caliper.

[0007] At least some of the aforementioned drawbacks apply to known force sensors that are based, for example, on piezoelectric or piezoresistive phenomena.

[0008] Taking this into account, it is possible to try to indirectly estimate and / or calculate the values ​​of the braking force and / or torque based on the detection of other quantities or based on the detection of forces performed externally with respect to the brake caliper, but this causes further drawbacks due to the fact that such estimations or calculations do not fully meet the necessary accuracy requirements.

[0009] Although the sensor technology field offers a wide range of solutions, to the applicant's knowledge, there is currently no sensor solution that can be incorporated into a brake caliper and that detects with high accuracy and reliability the braking force and / or torque applied directly or indirectly by the brake caliper in real time during braking.

[0010] In fact, known solutions either provide sensors that cannot be integrated into the brake caliper from a practical point of view (because they are not compact enough or are too complex) or provide indirect measurements that do not allow obtaining braking force and / or torque with sufficient accuracy.

[0011] Therefore, there is a need for a force sensor or sensor for detecting other quantities related to braking force and / or torque that is compact, miniaturized, easy to operate / read, and can be practically incorporated into the body of the brake caliper without affecting it, and at the same time can accurately and reliably determine the braking force and / or torque applied by the brake caliper.

[0012] As noted above, such needs are not fully met by the solutions currently available from the prior art. Summary of the Invention

[0013] The object of the present invention is to provide a method for detecting and measuring the braking force and / or braking torque resulting from the actuation of a vehicle friction braking system, with detection performed at least in the brake calipers of the brakes, which system makes it possible to at least partially overcome the aforementioned disadvantages described with reference to the prior art and to meet the aforementioned requirements particularly felt in the relevant technical field.

[0014] This and other objects are achieved by a method for detecting and measuring braking forces and / or torques according to claim 1.

[0015] Some preferred embodiments of such a method are the subject of dependent claims 2-16.

[0016] A further object of the present invention is to provide a similar method for detecting and measuring the braking force and / or torque resulting from the operation of a friction brake, by detection performed on at least one suspension part of the vehicle to which the brake caliper is connected.

[0017] This object is achieved by a method according to claim 17 or claim 18.

[0018] A further object of the present invention is to provide a brake caliper with a sensor for a vehicle brake system, equipped to be able to carry out the aforementioned method for detecting and measuring braking force and / or braking torque according to claims 1 to 16.

[0019] These and other objects are achieved by a brake caliper with a sensor according to claim 19.

[0020] Some preferred embodiments of such a caliper are the subject of dependent claims 20 to 32.

[0021] It is a further object of the present invention to provide a system for detecting and measuring braking force and / or braking torque using at least one caliper with a sensor as claimed in claims 19 to 32.

[0022] This and other objects are achieved by a system for detecting and measuring braking force and / or braking torque according to claim 33.

[0023] Some preferred embodiments of such a system are the subject of dependent claims 34 to 39.

[0024] It is a further object of the present invention to provide a braking system that uses at least one of the aforementioned sensored brake calipers or that uses the aforementioned system for detecting and measuring braking force and / or braking torque.

[0025] These and other objects are achieved by a braking system according to claim 40.

[0026] Further features and advantages of the method and system according to the invention will become apparent from the following description of preferred embodiments thereof, given as non-limiting examples, with reference to the attached drawings, in which: FIG. [Brief explanation of the drawings]

[0027] [Figure 1] FIG. 1 illustrates, using a functional block diagram, different embodiments of a brake caliper with a sensor and a system for detecting and measuring braking force and / or braking torque according to the present invention. [Figure 2] FIG. 2 illustrates, using a functional block diagram, different embodiments of a brake caliper with a sensor and a system for detecting and measuring braking force and / or braking torque according to the present invention. [Figure 3]FIG. 3 illustrates, using functional block diagrams, different embodiments of a brake caliper with a sensor and a system for detecting and measuring braking force and / or braking torque according to the present invention. [Figure 4A] FIG. 4A illustrates, using functional block diagrams, different embodiments of a brake caliper with a sensor and a system for detecting and measuring braking force and / or braking torque according to the present invention. [Figure 4B] FIG. 4B illustrates, using functional block diagrams, different embodiments of a brake caliper with a sensor and a system for detecting and measuring braking force and / or braking torque according to the present invention. [Figure 4C] FIG. 4C illustrates, using functional block diagrams, different embodiments of a brake caliper with a sensor and a system for detecting and measuring braking force and / or braking torque according to the present invention. [Figure 5A] FIG. 5A illustrates, using functional block diagrams, different embodiments of a brake caliper with a sensor and a system for detecting and measuring braking force and / or braking torque according to the present invention. [Figure 5B] FIG. 5B illustrates, using functional block diagrams, different embodiments of a brake caliper with a sensor and a system for detecting and measuring braking force and / or braking torque according to the present invention. [Figure 6] FIG. 6 illustrates, using functional block diagrams, different embodiments of a brake caliper with a sensor and a system for detecting and measuring braking force and / or braking torque according to the present invention. [Figure 7] FIG. 7 shows a perspective view of a further embodiment of a brake caliper with a sensor according to the invention. [Figure 8] FIG. 8 shows a perspective view of a further embodiment of a brake caliper with a sensor according to the invention. [Figure 9A]FIG. 9A shows some details of a system for detecting and measuring braking force and / or braking torque, according to an embodiment of the present invention, and in particular an embodiment of a sensor included in such a system. [Figure 9B] FIG. 9 shows some details of a system for detecting and measuring braking force and / or braking torque, according to an embodiment of the present invention, and in particular an embodiment of sensors included in such a system. [Figure 9C] FIG. 9C shows some details of a system for detecting and measuring braking force and / or braking torque, according to an embodiment of the present invention, and in particular an embodiment of a sensor included in such a system. [Figure 10A] FIG. 10A shows some details of a system for detecting and measuring braking force and / or braking torque, according to an embodiment of the present invention, and in particular an embodiment of a sensor included in such a system. [Figure 10B] FIG. 10B shows some details of a system for detecting and measuring braking force and / or braking torque, according to an embodiment of the present invention, and in particular an embodiment of a sensor included in such a system. [Figure 11] FIG. 11 shows some details of a system for detecting and measuring braking force and / or braking torque, according to an embodiment of the present invention, and in particular an embodiment of a sensor included in such a system. [Figure 12] FIG. 12 is a functional block diagram of respective implementation options for the optical reading / interrogation unit included in the above-described system for detecting and measuring braking force and / or braking torque. [Figure 13] FIG. 13 is a functional block diagram of respective implementation options for the optical reading / interrogation unit included in the above-described system for detecting and measuring braking force and / or braking torque. [Figure 14]FIG. 14 is a functional block diagram of respective implementation options for the optical reading / interrogation unit included in the above-described system for detecting and measuring braking force and / or braking torque. [Figure 15] FIG. 15 shows an embodiment of a braking system according to the present invention including a plurality of the aforementioned sensored calipers. [Figure 16] FIG. 16 shows an embodiment of a braking system according to the present invention including a plurality of the sensored calipers described above. DETAILED DESCRIPTION OF THE INVENTION

[0028] With reference to Figures 1 to 3, 4A, 4B, 4C, 5A, 5B and 6 and 12 to 16, a method for detecting and measuring the braking force and / or braking torque BF / BT resulting from the operation of a vehicle friction braking system 1000 is described, with detection performed in at least one brake caliper 10 of the braking system.

[0029] The method comprises the step of incorporating at least one deformation and / or strain sensor 2 into a portion of the material M of the body of said at least one brake caliper 10 at a respective predetermined fixed position, at a location that is subject to deformation due to reaction forces exerted on the brake caliper in the form of a braking force and / or braking torque BF / BT, such that the deformation and / or strain S acting locally at said location where the at least one deformation and / or strain sensor 2 is located is representative of the braking force and / or braking torque BF / BT.

[0030] Said at least one deformation and / or strain sensor 2 is an optical fiber strain sensor 2 of the fiber Bragg grating type.

[0031] Next, the method includes detecting a local deformation and / or strain S acting at the respective location by each of said at least one optical fiber strain sensor 2 and generating a respective at least one first photonic signal L indicative of the detected deformation and / or strain S.

[0032] Next, the method includes receiving, by an optical reading / interrogation unit 4 optically connected to said at least one optical fiber strain sensor 2, said at least one first photonic signal L, and generating, by the optical reading / interrogation unit 4, at least one first electrical signal E representative of the detected local deformation and / or strain S based on said received at least one first photonic signal L.

[0033] The method finally comprises the step of processing said at least one first electrical signal E representative of the deformation and / or strain S to obtain a measure of the braking force and / or braking torque BF / BT.

[0034] According to a preferred embodiment, the method comprises the further step of incorporating at least one temperature sensor 5 (again, the temperature sensor 5 is an optical fiber temperature sensor 5 of the fiber Bragg grating type) in said portion of the material M of the body of the brake caliper 10, and by means of each of the at least one temperature sensor 5 detecting a temperature T value present at the respective location and generating at least one electrical signal Et indicative of the temperature based on the at least one second photonic signal Lt received.

[0035] The method further comprises receiving said at least one second photonic signal Lt by an optical reading / interrogation unit 4 optically connected to said at least one temperature sensor 5, and generating by the optical reading / interrogation unit 4 at least a second electrical signal Et representative of the temperature based on the received at least second photonic signal Lt.

[0036] In this case, the processing step comprises processing said at least one first electrical signal E and at least one second electrical signal Et to obtain measured values ​​of the braking force and / or braking torque BF / BT, taking into account temperature compensation.

[0037] It should be noted that the aforementioned term "incorporating" into a portion of material M (of the body of the brake caliper) can also be understood as "inserting" or "integrating" or "encapsulating" the sensors, i.e., positioning the sensors so that they are biased by deformations or strains acting on said portion of material M of the brake caliper body.

[0038] The aforementioned fiber Bragg grating optical sensors (hereinafter also referred to as "FBG sensors") are a type of deformation and / or strain sensor known per se.

[0039] FBG sensors are known to be very sensitive and versatile optical devices for measuring various physical parameters such as strain and temperature. In their simplest form, FBG sensors are obtained by a spatially periodic modulation of the refractive index inscribed in the core of an optical fiber (this can be obtained, for example, through the phenomenon of photosensitivity or using femtosecond optical pulses).

[0040] The FBG sensor is λB=2n eff It exploits the existence of a resonance condition that reflects incident light at the so-called "Bragg wavelength" λB, defined as Λ, where n eff is the effective refractive index of the fundamental mode of the optical fiber, and Λ is the spatial pitch (periodicity) of the grating. formula [1]:

[0041] The working principle of FBG sensors is that changes in either the effective refractive index or the grating pitch caused by external effects such as strain or temperature result in a respective shift in the operating wavelength, Δλ B This is based on the following characteristics (wavelength that can be derived from Bragg's formula 1).

[0042]

number

[0043] where Δλ B =λ-λ B is the reference Bragg wavelength λ B where k is a scale factor and α is the change in Bragg wavelength with respect to T is the thermo-optic coefficient. The Bragg wavelength shift has a linear dependence on the longitudinal strain ε with a sensitivity value of about 1.2 pm / με and a temperature change of about 11 pm / °C for silicon fibers in the 1550 nm range.

[0044] As mentioned above, it is appropriate to compensate the strain results obtained by the FBG sensor 2 embedded in the material M for temperature changes under the operating conditions. Such compensation can be achieved by expanding the above-mentioned Equation 1 to Equation 2:

[0045]

number

[0046] where ε=ε M +ε T contains two contributions: one due to pure mechanical strain and one due to thermal expansion ε T is the contribution caused by (α SP is the thermal expansion coefficient of the material). B Let T0 denote the reference Bragg wavelength and the reference temperature, and let λ and T denote the real-time values ​​of wavelength and temperature, which are expressed by Equation 3.

[0047]

number

[0048] From this equation, the pure mechanical force ε M can be obtained as the following equation 4.

[0049]

number

[0050] (ε M (This is input into the above equation to obtain the correction value for ). Real-time temperature values ​​are obtained via an additional FBG sensor (i.e., temperature sensor 5) that is enclosed in a loose tube placed close to the FBG strain sensor 2.

[0051] According to an implementation option, the aforementioned at least one temperature sensor 5 is made by a fiber Bragg grating made in a fiber or optical fiber different from the fiber in which the at least one deformation and / or strain sensor 2 is made. Furthermore, the fiber Bragg grating of the at least one temperature sensor 5 is arranged so as to be insensitive to thermal and mechanical deformations of the caliper body material.

[0052] FBG sensors are "passive" sensors; that is, they do not require a power supply and are activated by illuminating them by sending optically active radiation of an appropriate wavelength (e.g., the Bragg wavelength) into the optical fiber section containing the grating within the sensor. In response, the FBG sensor reflects or transmits an optical (i.e., photonic) signal, which depends not only on the incident radiation but also on the strain state experienced by the grating itself. Such a photonic signal can be a transmitted optical signal (i.e., optical spectrum) or a reflected optical signal (i.e., optical spectrum), depending on the different implementation options presented below.

[0053] According to this method embodiment (schematically shown in FIG. 1 ), the optical fiber strain sensor 2 is connected to an optical reading / interrogation unit 4 by means of a first connecting optical fiber 31. Furthermore, the optical reading / interrogation unit 4 is configured to activate said optical fiber strain sensor 2 by transmitting optically active radiation OA via said first connecting optical fiber 31. Furthermore, said first photonic signal L comprises a first optical spectrum L reflected by the Bragg grating type strain sensor 2, which reaches the optical reading / interrogation unit 4 via said first connecting optical fiber 31.

[0054] According to an implementation option (shown in FIG. 4B), the at least one temperature sensor 5 is made by a fiber Bragg grating made in the same optical fiber in which the at least one deformation and / or strain sensor 2 is made and arranged so as to be insensitive to the thermal and mechanical deformations of the material of the caliper body. Furthermore, the optical fiber temperature sensor 5 is connected to the optical reading / interrogation unit 4 by said first connecting optical fiber 31.

[0055] In this case, the optical reading / interrogation unit 4 is configured to activate the optical fiber temperature sensor 5 by transmitting optically active radiation OAt via a first connecting optical fiber 31 (wavelength-multiplied with the optically active radiation OAt of the strain sensor). The second photonic signal Lt comprises a second optical spectrum Lt reflected by the temperature sensor 5 (wavelength-multiplexed with the first optical spectrum L reflected by the strain sensor 2), which reaches the first optical reading / interrogation unit 4 via the connecting optical fiber 31.

[0056] According to another embodiment of the method (schematically shown in FIG. 2 ), the optical fiber strain sensor 2 is connected to an optical reading / interrogation unit 4 by a first input connecting optical fiber 32 and a second output connecting optical fiber 33. Furthermore, the optical reading / interrogation unit 4 is configured to activate said optical fiber strain sensor 2 by transmitting optically active radiation OA via the first input connecting optical fiber 32. Furthermore, said first photonic signal L comprises a first optical spectrum L transmitted by the fiber Bragg grating type strain sensor 2, which reaches the optical reading / interrogation unit 4 via the second connecting optical fiber 33.

[0057] According to an implementation option (shown in Fig. 4A), the at least one temperature sensor 5 is made by a fiber Bragg grating made in the same optical fiber in which the at least one deformation and / or strain sensor 2 is made, positioned so as to be insensitive to the thermal and mechanical deformations of the material of the caliper body. Furthermore, the optical fiber temperature sensor 5 is connected to the optical reading / interrogation unit 4 by the aforementioned first input connection optical fiber 32 and second output connection optical fiber 33.

[0058] In this case, the optical reading / interrogation unit 4 is configured to activate the optical fiber temperature sensor 5, which transmits optically active radiation OAt via a first input connection optical fiber 32 (wavelength multiplexed with the optically active radiation OAt of the strain sensor). The second photonic signal Lt comprises the second optical spectrum Lt transmitted by the temperature sensor 5 (wavelength multiplexed with the first optical spectrum L transmitted by the strain sensor 2), which reaches the optical reading / interrogation unit 4 via said second output connection optical fiber 33.

[0059] According to this method embodiment (schematically shown in the implementation options of Figures 3 and 4C), the optical fiber temperature sensor 5 is connected to the optical reading / interrogation unit 4 by means of a third connecting optical fiber 34. The optical reading / interrogation unit 4 is configured to activate the optical fiber temperature sensor 5 by transmitting optically active radiation OAt via said third connecting optical fiber 34. Furthermore, said second photonic signal Lt comprises a second optical spectrum Lt reflected by the fiber Bragg grating type temperature sensor 5, which reaches the optical reading / interrogation unit 4 via the third connecting optical fiber 34.

[0060] According to implementation options, each connection between each fiber from which a fiber Bragg grating type sensor is obtained and the respective connecting optical fiber to the optical reading / interrogation unit is made by a fiber splice or a detachable photonic connecting element (optical connector).

[0061] According to one embodiment of the method, a plurality of optical fiber strain sensors 2 are provided and used advantageously.

[0062] In this embodiment (schematically shown in FIGS. 5A and 5B), the incorporating step comprises incorporating a plurality of deformation and / or strain sensors 2a, 2b, 2c made by respective Bragg gratings, each associated with a respective central operating wavelength λa, λb, λc, said Bragg gratings being made of one or more optical fiber elements, each of said one or more optical fiber elements being incorporated in a predefined, constant spatial deployment state at a respective location in said portion of body material M of the brake caliper.

[0063] Furthermore, the step of generating each at least one photonic signal comprises generating a plurality of respective first photonic signals La, Lb, Lc, and the step of receiving comprises receiving said plurality of first photonic signals La, Lb, Lc from the optical reading / interrogation unit 4.

[0064] The step of generating at least one first electrical signal E by the optical reading / interrogation unit 4 includes generating a respective plurality of first electrical signals Ea, Eb, Ec based on the received plurality of first photonic signals La, Lb, Lc.

[0065] The processing step comprises processing the several first electrical signals Ea, Eb, Ec to obtain measurements of the braking force and / or braking torque BF / BT.

[0066] According to implementation options, each of the one or more optical fiber elements comprises a plurality of deformation and / or strain sensors 2a, 2b, 2c obtained at different stretches of the optical fiber element and associated with different respective operating wavelengths λa, λb, λc.

[0067] In this case, the method further includes transmitting, via a connecting optical fiber 33, respective optically active radiations OAa, OAb, and OAc at respective different operating wavelengths λa, λb, and λc to the different plurality of sensors and / or strain elements by optical read / interrogation element 4 using wavelength division multiplexing (WDM) transmission techniques. Next, the method receives, via a connecting optical fiber 33, respective optical spectra reflected by each of the plurality of deformation and / or strain sensors 2a, 2b, and 2c by demultiplexing using wavelength division multiplexing WDM techniques. Here, each of the aforementioned reflected optical spectra corresponds to a respective first photonic signal La, Lb, and Lc.

[0068] According to an implementation option of the method, the material M from which part of the material of the brake caliper 10 is made and into which at least one deformation and / or strain sensor 2 is integrated is aluminum or cast iron or titanium or magnesium or aluminum alloy or CFRP composite material.

[0069] The brake calipers to which this method can be applied are fixed or floating monoblocks or assemblies.

[0070] According to one embodiment of the method, the incorporating step includes first incorporating at least one deformation and / or strain sensor 2 into a preformed frame and / or package 7 having a predefined shape and dimensions (e.g., as shown in FIGS. 9A, 9B, 10A, and 10B). Furthermore, the incorporating step includes incorporating said preformed frame or package 7 (e.g., as shown in FIGS. 7 and 8) into the body of the brake caliper 10 at a certain predefined position within the brake caliper mold and / or molded casing during the manufacture of the brake caliper 10, thereby partially or completely incorporating each of said at least one deformation and / or strain sensors 2 into a desired portion of the material M of the brake caliper body.

[0071] The preformed frame 7 will now be described in more detail with reference to Figures 9A, 9B, 9C, 10A and 10B.

[0072] 9A, 9B, and 9C show implementation options (corresponding to the functional diagram shown in FIG. 4C) that provide a through optical fiber with input and output sections, including separate fibers dedicated to the strain sensor 2 and the temperature sensor 5.

[0073] According to this mounting option, the pre-formed frame 7 comprises an aluminum housing 73 configured to contain one or more stretches of optical fiber containing one or more fiber optic strain sensors 2. A recess 71 is provided in the housing 73 for fixing the optical fiber in place "in sight" using a suitable adhesive or binder.

[0074] In this mounting option, the preform frame 7 has two capillary tubes 78 (e.g., made of stainless steel) adapted to house and protect the connecting optical fibers 32, 33 emerging from the preform frame, and a further output capillary tube 79 adapted to contain the connecting optical fiber 34 dedicated to the temperature sensor 5.

[0075] The optical fiber containing the strain sensor is pre-assembled and secured to the aluminum housing 73 by a binder or adhesive 77 (e.g., cement-based adhesive) (as shown in the cross-section of Figure 9B). The strain sensor 2 (shown in Figure 9B) is exposed in a fusing process and embedded in the aluminum that forms the caliper body.

[0076] 10A and 10B show an implementation option (corresponding to the functional diagram shown in FIG. 3) providing an optical fiber containing a strain sensor 2 and another optical fiber dedicated to a temperature sensor 5.

[0077] 10A and 10B show an implementation with a single truncated optical fiber. Here, a preformed frame includes an aluminum housing 73 configured to contain an optical fiber stretch containing one or more optical fiber strain sensors 2, where a recess 71 is provided for fixing the optical fiber "in line of sight." In a variation of this embodiment, a second truncated optical fiber containing an FBG temperature sensor is integrated into the housing 73.

[0078] In this mounting option, the preformed frame 7 includes a capillary tube 78 (e.g., stainless steel) adapted to house and protect the connecting optical fibers 31, 34 exiting the preformed frame, and another output capillary tube 79 adapted to contain the connecting optical fiber 34 dedicated to the temperature sensor 5.

[0079] The optical fiber containing the strain sensor is pre-assembled and fixed in an aluminum housing 73 by a binder or adhesive 77 (e.g., cement-based adhesive) (as shown in cross section in Figure 9B).

[0080] The temperature measurement sensor 5, enclosed in its own capillary tube 79, is encapsulated in a separate loose steel tube within the housing 73 so as to be unaffected by thermal stresses in the material and insensitive to thermal and mechanical deformations of the caliper body material. The loose steel tube containing the temperature sensor 5 is also fixed within the aluminum housing 73 by a binder or adhesive 77 (e.g., cementitious adhesive).

[0081] According to the mounting option, as shown in FIG. 11, some preformed frames (e.g., preformed frame 7 according to the mounting option shown in FIGS. 9A, 9B, and 9C, and preformed frame 7′ according to the mounting option shown in FIGS. 10A and 10B) can be integrated using a mounting bracket before being integrated into the caliper.

[0082] Next, at least one preformed frame 7', 7' (in any of the implementation options described above) is fixed in the desired position within the body of the brake caliper.

[0083] For example, FIG. 7 shows four sensor assemblies 2 of different types, i.e., two pairs of sensor assemblies. Each pair includes a sensor assembly 2' with a single fiber structure mounted on a preformed frame 7 (for reflected photonic signals, as in the embodiment options of FIGS. 10A and 10B ) and a sensor assembly 2 with a through structure with a first optical fiber 32 and a second optical fiber 33 mounted on a preformed frame 7 (for transmitted signals, as in the embodiment options of FIGS. 9A, 9B, and 9C ). In the embodiment shown in FIG. 7 , all sensor assemblies further provide a third optical fiber 34 for a temperature sensor. Therefore, all sensor assemblies are integrated into symmetrical lateral positions of the brake caliper body.

[0084] 8 shows another implementation example, where at least one sensor assembly 2 consists of separate fibers 32, 33 that are integrated low in the brake caliper between two fixtures (thus, depending on the illumination direction, one of the two fibers acts as the input fiber and the other fiber acts as the output with the transmitted photonic signal).

[0085] Additionally or alternatively, at least one sensor assembly 2' of single fiber configuration (31) may be provided integrated into the brake caliper portion for fixing (two such sensor assemblies 2' are shown in FIG. 8, positioned at the bottom of each of the two caliper portions for fixing).

[0086] Additionally or alternatively, at least one sensor assembly 2″ can be provided with a single fiber configuration 31 embedded in a brake caliper portion for the purpose of fixing at a 45° angle to the vertical through the center of the fixing hole (FIG. 8 shows two such sensor assemblies 2″ arranged in two respective caliper portions for fixing).

[0087] According to one embodiment of the method, the step of incorporating at least one deformation and / or strain sensor 2 into the body of the brake caliper comprises welding optical fibers, wherein said at least one deformation and / or strain sensor 2 is provided on a predefined portion of the surface of the brake caliper body.

[0088] According to an implementation option of the aforementioned embodiment, the aforementioned welding is carried out by ultrasonic additive manufacturing (UAM), which is known per se, and which allows the sensor to be integrated into the metal body of the caliper by means of a metal layer.

[0089] According to another implementation option of the aforementioned embodiment, the aforementioned welding is performed by laser technology known per se, which is able to perform direct welding of the fibers in the caliper body.

[0090] The above-described embodiments provide the technical advantage that simpler and more cost-effective structural variations of the sensor can be used, as it does not need to be designed to withstand the temperatures of the melting process and subsequent heat treatment, but does not need to be designed to withstand lower temperatures due to the process features described above.

[0091] From the above, it is clear that the most diverse implementation options of this method are possible and are included in the present invention, which provides for the incorporation of any number of sensors and / or assemblies of optical fiber deformation and / or strain sensors 2 at any position of the brake caliper, with the only constraint that this does not in any way change the function of the brake caliper itself.

[0092] According to one embodiment of the method, the aforementioned steps of receiving and generating are performed by a single optical reading / interrogation unit 4 integrated into and / or housed in the brake caliper 10 .

[0093] According to one embodiment of the method, the steps of the method are performed by a plurality of brake calipers 10 of disc brake calipers of a braking system of a vehicle.

[0094] In this case, according to an implementation option, the aforementioned steps of receiving and generating are performed by a single optical reading / interrogation unit 4 operably connected to all brake calipers 10 of said plurality of disc brake calipers of the vehicle braking system. According to another implementation option, the aforementioned steps of receiving and generating are performed by a plurality of optical reading / interrogation units 4, each operably connected to one or more brake calipers 10 of said plurality of disc brake calipers.

[0095] According to one embodiment, the method comprises a step of transmitting said at least one first electrical signal E and / or second electrical signal Et to the control unit 20 before the processing step.

[0096] According to a possible embodiment, one or more optical reading / interrogation units 4 and one or more control units 20 are installed in one, two or four vehicle control units.

[0097] In this case, according to an implementation option, the processing step includes calculating the braking force and / or torque BF / BT by the processor of the control unit 20 based on said at least one first electrical signal E by means of one or more algorithms executed by one or more software programs.

[0098] According to another implementation option, the processing step includes calculating the brake force and / or torque BF / BT by a processor of the control unit 20 based on the first electrical signal E and the second electrical signal Et by one or more algorithms executed by one or more software programs based on:

[0099] According to a further implementation option, the step of processing includes calculating, by a processor of the control unit 20, the braking force and / or torque BF / BT based on said plurality of first electrical signals Ea, Eb, Ec and said at least one second electrical signal Et by one or more algorithms executed by one or more software programs based on:

[0100] According to a more specific implementation option, the calculation step comprises calculating the clamping force and / or brake torque BF / BT by a predetermined non-linear relationship between the brake force and / or torque and the deformation and / or strain detected by at least one deformation and / or strain sensor 2 at the respective position integrated in the brake caliper.

[0101] Such a predetermined non-linear relationship may be represented, for example, by a computerized model or look-up table stored accessible by the processor of the control unit 20 .

[0102] The aforementioned predetermined non-linear relationship is determined, for example, by a testing and / or characterization and / or calibration step performed before using the brake caliper 10 after at least one deformation and / or strain sensor 2 has been incorporated into the brake caliper 10.

[0103] According to implementation examples, the aforementioned steps of testing and / or characterization and / or calibration may include functional and / or structural simulations, for example calculations based on the Finite Element Method (FEM).

[0104] The aforementioned calculations and processing allow for the definition of a nonlinear relationship between strain measurements at one or more points on the caliper and the braking force / torque, thereby allowing the braking force / torque to be estimated based on the strain measurements performed.

[0105] According to one embodiment of the method, the processing step includes obtaining dynamic measurements of the trend of the brake force and / or torque BF / BT in real time based on the detected deformation and / or the change in the detected deformation and / or strain over time.

[0106] According to an implementation option, the method comprises a further step of detecting a possible malfunction of the optical fiber sensor 2 .

[0107] It should be noted that the above method, in all its various embodiments, can be applied mutatis mutandis by detecting the stresses / strains acting not only on the brake caliper but also (or exclusively) on the suspension part of the vehicle to which the brake caliper is connected.

[0108] Thus, a method is described for detecting and measuring the braking force and / or braking torque resulting from the actuation of a friction brake by detection performed in at least one suspension part of the vehicle to which the brake caliper is connected.

[0109] Such a method includes the step of incorporating at least one deformation and / or strain sensor at a predefined fixed location in a portion of material of the suspension portion of the vehicle that deforms due to a reaction force applied to the suspension portion of the vehicle by a brake caliper during a braking event with the braking force and / or torque, such that the deformation and / or strain acting locally at the location where the at least one deformation and / or strain sensor is located represents the braking force and / or braking torque.

[0110] Said at least one deformation and / or strain sensor is a fiber optic strain sensor of the fiber Bragg grating type.

[0111] Next, the method includes detecting, by each of the at least one optical fiber strain sensors, a local deformation and / or strain acting at the respective location, and then generating at least one first photonic signal for each of the detected deformations and / or strains; then receiving, by an optical reading / interrogation unit optically connected to the at least one optical fiber strain sensor, said at least one first photonic signal; then generating, by the optical reading / interrogation unit, at least one first electrical signal representative of the locally detected deformation and / or strain based on the received at least one first photonic signal; and finally processing said at least one first electrical signal representative of the deformation and / or strain to obtain a measurement of the braking force and / or braking torque.

[0112] According to an implementation option of the aforementioned method, the at least one deformation and / or strain sensor arranged in the suspension is further configured to detect a further force acting on the suspension element.

[0113] 1-14, the sensored brake caliper 10 for the braking system of the vehicle 1000 will now be described.

[0114] Such a sensored brake caliper 10 comprises a brake caliper body 1 , at least one deformation and / or strain sensor 2 and a brake caliper 10 with first photonic connection means 3 .

[0115] The brake caliper comprises a brake caliper body 1 made of a material that is susceptible to deformation by reaction forces applied to the brake caliper in the form of braking forces and / or torques during a braking event. The brake caliper body 1 comprises a portion of said material M, the deformation and / or strain S of which locally represents the braking force and / or braking torque BF / BT applied to the braking system.

[0116] At least one deformation and / or strain sensor 2 is integrated in a portion of the material susceptible to deformation M at a respective predetermined fixed position and comprises at least one optical fiber strain sensor of the Fiber Bragg Grating type (FBG sensor), which is configured to detect deformation and / or strain S acting locally at the respective position and to generate a respective at least one first photonic signal L representative of the detected deformation and / or strain S.

[0117] The first photonic connection means 3 is connected to said optical fibre strain sensor 2 and is connected to an optical reading / interrogation unit 4 and is configured to transmit said at least one first photonic signal L.

[0118] According to one embodiment, the sensored caliper 10 further comprises at least one temperature sensor 5 integrated into the aforementioned portion of the material M of the brake caliper body at a predefined fixed position near the optical fiber strain sensor 2. This comprises at least one optical fiber temperature sensor of the fiber Bragg grating type. The temperature sensor is configured to detect a temperature value T present at the respective position and to generate at least a respective second photonic signal Et representative of the detected temperature.

[0119] The sensor caliper 10 further comprises second photonic connection means 6 connected to the optical fiber temperature sensor 5 and connected to the optical reading / interrogation unit 4 and configured to transmit said at least one second photonic signal Lt.

[0120] According to one embodiment, the sensored caliper 10 further comprises an optical reading / interrogation unit 4 which can be connected to a remote control unit 20 external to the brake caliper.

[0121] The optical reading / interrogation unit 4 (as shown in the above description describing the method according to the invention) is optically connected to the first photonic connection means 3 and is configured to activate said at least one optical fiber strain sensor 2 to transmit a first optically active radiation OA and to receive at least one first photonic signal L.

[0122] Furthermore, the optical reading / interrogation unit 4 is configured to generate, based on the received at least one first photonic signal L, at least one first electrical signal E representative of the detected deformation and / or strain S. Said at least second electrical signal E is configured to be transmitted to the remote control unit 20.

[0123] Thus, in the above embodiment, the optical reading / interrogation unit 4 (according to any of the embodiments described above in the method description) is integrated into the sensored brake caliper 10 .

[0124] In particular, according to an implementation option of the brake caliper with sensor, the optical reading / interrogation unit 4 is further connected to a second photonic connection means 6 and configured to activate an optical fiber temperature sensor 5 which transmits a second photoactive radiation OAt and also receives at least a second photonic signal Lt.

[0125] In this case, the optical reading / interrogation unit 4 is further configured to generate at least a second electrical signal Et representative of the detected temperature based on the received at least second photonic signal Lt, and the at least second electrical signal Et is configured to be transmitted to the remote control unit 20.

[0126] According to an implementation option, the first photonic connection means 3 comprises a first connecting optical fiber 31 configured to transmit a first optically active radiation OA from the optical reading / interrogation unit 4 to the at least one optical fiber strain sensor 2 and to transmit a first photonic signal L having a first reflected optical spectrum L from the at least one optical fiber strain sensor 2 towards the optical reading / interrogation unit 4.

[0127] According to an additional implementation option of the sensored brake caliper, the optical reading / interrogation unit 4 is further configured to activate the at least one optical fiber strain sensor 2 by transmitting a first optical activation radiation OA.

[0128] According to an implementation option, the first photonic connection means 3 comprises a first input connection optical fiber 32 configured to transmit a first optically active radiation OA from the optical reading / interrogation unit 4 to the at least one optical fiber strain sensor 2, and further comprises an output connection optical fiber 33 adapted to transmit a first photonic signal L comprising a first transmitted optical spectrum L from the at least one optical fiber strain sensor 2 towards the optical reading / interrogation unit 4.

[0129] According to one embodiment, the at least one temperature sensor 5 is made by a fiber Bragg grating made in the same optical fiber in which the at least one deformation and / or strain sensor 2 is made and arranged so as to be insensitive to heat and to mechanical deformations of the material of the caliper body.

[0130] In this case, according to an implementation option (shown in FIG. 4B), the optical fiber temperature sensor 5 is connected to the optical reading / interrogation unit 4 by a first connecting optical fiber 31. The optically active radiation OAt is transmitted wavelength-multiplexed with the optically active radiation OAt of the strain sensor via the first connecting optical fiber 31. A second photonic signal Lt, comprising the second optical spectrum Lt reflected by the temperature sensor 5, wavelength-multiplexed with the first optical spectrum reflected by the strain sensor 2, reaches the optical reading / interrogation unit 4 via the first connecting optical fiber 34.

[0131] According to another implementation option (shown in FIG. 4A), the optical fiber temperature sensor 5 is connected to the optical reading / interrogation unit 4 by a first input connection optical fiber 32 and a second output connection optical fiber 33. The optically active radiation OAt is wavelength multiplexed with the optically active radiation OAt of the strain sensor and transmitted via the first input connection optical fiber 32. The second photonic signal Lt transmitted by the temperature sensor 5 is wavelength multiplexed with the first optical spectrum L transmitted by the strain sensor 2 and reaches the optical reading / interrogation unit 4 via the second output connection optical fiber 33.

[0132] According to a further implementation option, said second photonic connection means 6 comprises a third connecting optical fiber 34 configured to transmit the second optically active radiation OAt from the optical reading / interrogation unit 4 to the optical fiber temperature sensor 5 and to transmit a second photonic signal Lt having a second reflected optical spectrum Lt from the optical fiber strain sensor 5 towards the optical reading / interrogation unit 4.

[0133] According to an implementation example, each connection between each fiber from which a fiber Bragg grating type sensor is obtained and the connecting optical fiber to the optical reading / interrogation unit 4 is made by a fiber splice or a detachable photonic connection element (optical connector).

[0134] According to one embodiment, the sensored caliper 10 comprises a plurality of deformation and / or strain sensors 2a, 2b, 2c made by respective Bragg gratings, each associated with a respective central operating wavelength (λa, λb, λc). The aforementioned Bragg gratings are obtained by one or more optical fiber elements, each of which is integrated into the aforementioned portion of material M of the body of the brake caliper 10, at a respective position and in a respective predefined, constant space.

[0135] Each of said deformation and / or strain sensors 2a, 2b, 2c is configured to generate a respective photonic signal of a plurality of first photonic signals La, Lb, Lc.

[0136] The optical reading / interrogation unit 4 receives the aforementioned plurality of first electrical signals La, Lb, Lc, generates a respective plurality of first photonic signals Ea, Eb, Ec received based on the plurality of first photonic signals La, Lb, Lc, and transmits such a plurality of first electrical signals Ea, Eb, Ec to the control unit 20.

[0137] According to implementation options, each of the one or more optical fiber elements includes a plurality of deformation and / or strain sensors 2a, 2b, 2c obtained at different stretches of the optical fiber element and associated with different respective operating wavelengths λa, λb, λc.

[0138] The optical reading / interrogation unit 4 is further configured to transmit the respective optically active radiations OAa, OAb, OAc at respective operating wavelengths λa, λb, λc to the plurality of deformation and / or strain sensors 2a, 2b, 2c by wavelength division multiplexing (WDM) transmission techniques, and to receive and distinguish respective reflected light spectra corresponding to respective first photonic signals La, Lb, Lc by each of the plurality of deformation and / or strain sensors 2a, 2b by using demultiplexing by wavelength division multiplexing (WDM) techniques.

[0139] According to one embodiment, the sensored brake caliper 10 further comprises at least one preformed frame and / or housing 7 having a predetermined shape and dimensions that is assembled into the sensored caliper 10 during manufacturing of the sensored caliper.

[0140] Such at least one preformed frame and / or housing 7 includes at least one deformation and / or strain sensor 2, so that each of said at least one deformation and / or strain sensor 2 is incorporated into a desired portion of the material M of the sensor-equipped caliper body.

[0141] Some examples of preformed frames or packages 7 are shown in Figures 9A, 9B, 10A and 10B and have already been described before the description of the method according to the invention.

[0142] According to an implementation option, the sensored caliper 10 further comprises an optical fiber welded to the surface of the brake caliper body, with at least one deformation and / or strain sensor 2 and / or at least one temperature sensor 5 integrated into such optical fiber.

[0143] 12-14, further exemplary details are provided with reference to the reading / interrogation unit 4 as an example.

[0144] According to an embodiment of the sensored brake caliper 10 , the optical reading / interrogation unit 4 comprises a broadband optical radiation source 40 , an optical circulator 46 and at least one photoelectron spectrometer receiver 41 .

[0145] The broadband optical radiation source 40 is configured to transmit one first optically active radiation OA or a plurality of second optically active radiations OAa, OAb, OAc and / or one second optically active radiation OAt.

[0146] At least one photoelectron spectrometer receiver 41 is configured to select one or more wavelengths to be received and is also configured to receive the first photonic signal L or the plurality of first photonic signals La, Lb, Lc and convert them into a first electrical signal E or a plurality of first electrical signals Ea, Eb, Ec, and / or receive the second photonic signal Lt and convert it into a second electrical signal Et.

[0147] In this embodiment, a wavelength domain (WDND) multiplexed FBG sensor is interrogated using a broad spectrum source and spectrometer based technique (as shown in Figure 12).

[0148] The broad-spectrum light source may include, for example, a superluminescent diode or a spontaneous emission light source (such as a semiconductor optical amplifier or an erbium-doped optical fiber amplifier), which is used (via the input port and the through port 46 of the optical circulator) to illuminate the FBG sensors 2a, 2b, 2c, which are characterized by having reflectivity peaks at different wavelengths (λa, λb, λc) that are not overlapped with each other.

[0149] The photonic signals La, Lb, Lc, each with a different wavelength, are retro-reflected by the FBG sensor (in the example shown in FIG. 12) and coupled to the spectrometer 41 via the output port of the optical circulator 46 .

[0150] The spectrometer 41 is a dispersive element, typically a phase grating volume, that can spatially separate the different spectral components of the signal. These spatially separated signal components are coupled to an array of optical receivers that can generate signals having intensity values ​​corresponding to various wavelengths.

[0151] Each optical receiver is sensitive to optical radiation corresponding to a well-defined spectral region, and therefore has the potential to reconstruct the entire spectrum of the spectral range of interest.

[0152] According to another embodiment of the sensored brake caliper 10 (shown in FIG. 13), the optical reading / interrogation unit 4 comprises an adjustable optical radiation source 42 , an optical circulator 46 , and a photoelectron spectrometer receiver 43 .

[0153] The adjustable optical radiation source 42 is configured to transmit at a given time a desired optical radiation OAn among the possible first optically active radiations OAa, OAb, OAc at a respective wavelength λn or a second optically active radiation OAt at a wavelength λt.

[0154] The emitted optical radiation OAn illuminates the optical fiber containing the FBG sensor (by way of the input and through ports of the optical circulator 46) and determines the response by the FBG sensor sensitive to wavelength λn, which generates a retroreflected photonic signal Ln, which is coupled to the photodiode receiver 43 via the output port of the optical circulator 46.

[0155] The photodiode optoelectronic receiver 43 is configured to receive the aforementioned first retro-reflective photonic signal Ln and convert it into a first electrical signal En (or similarly to receive the second photonic signal Lt and convert it into said second electrical signal Et).

[0156] In this embodiment, wavelength-domain (WDM) multiplexed FBG sensors are interrogated using tunable laser and photodiode-based techniques.

[0157] According to various implementation options, the tunable optical radiation source 42 is a tunable laser that can be used in an "agile tunable" or "swept wavelength" mode known per se.

[0158] According to another embodiment of the sensored caliper 10 (shown diagrammatically in FIG. 14), the optical reading / interrogation unit 4 is made entirely by a single photonic integrated circuit using PIC technology. In this case, such single integrated photonic circuit includes a broadband optical radiation source 40, at least one wavelength optical filtering element 44, and at least one optoelectronic photodiode receiver 43.

[0159] The broadband optical radiation source 40 is configured to transmit one first optically active radiation OA and / or a plurality of second optically active radiations OAa, OAb, OAc, and / or one second optically active radiation OAt.

[0160] The optical radiation emitted by the input and through ports of the optical circulator 46 (which in the example of FIG. 14 include optical radiation OAa, OAb, and OAc) illuminates the optical fiber containing the FBG sensor, which reflects the respective photonic signals La, Lb, and Lc. The photonic signal WDM given by the sum of the signals La, Lb, and Lc as a whole is transmitted via the output port of the optical circulator 46 to the input of at least one filter optical element 44, each at its own distinct wavelength.

[0161] The at least one wavelength optical filtering element 44 can be tuned around the wavelength of the queried fiber Bragg grating to select a respective photonic signal (photonic signal Lb at wavelength λb in the example of FIG. 14). The at least one optical filtering element 44 that is tunable can be tuned around different wavelengths to select photonic signals reflected by any FBG sensor sequentially or at different times, depending on what is desired.

[0162] At least one optoelectronic photodiode receiver 43 is configured to receive a photonic signal selected from the aforementioned photonic signals and convert it into one or more electrical signals, and / or, if selected, to receive a second photonic signal Lt and convert it into a second electrical signal Et.

[0163] With reference to the above description of the different embodiments of the reading / interrogating unit 4 (in light of Figures 12 to 14), exactly the same description applies mutatis mutandis if three FBG sensors comprise two FBG strain sensors and one FBG temperature sensor, or if only one optical fiber strain sensor and one FBG temperature sensor are provided, or if any number of optical fiber strain sensors and one FBG temperature sensor are provided.

[0164] Depending on the implementation options, the brake caliper body is made of aluminum or cast iron. More specifically, the part of the material of the brake caliper in which at least one deformation and / or strain sensor is integrated is made of aluminum or cast iron, or generally aluminum alloy or CFRP composite material.

[0165] As mentioned above, a distinctive feature of the technical solution described here is that deformation and / or strain sensors are integrated into the body of the brake caliper itself and detect the deformations and strains applied to the brake caliper body during braking. This clearly distinguishes the solution described here from a structural and functional point of view from technical solutions that integrate force sensors into wearable parts of the brake caliper, such as brake pads.

[0166] According to another possible embodiment, the brake caliper with sensor is either a fixed brake caliper or a floating brake caliper.

[0167] A system 100 for detecting and measuring the braking force and / or braking torque BF / BT resulting from the operation of a vehicle braking system by detection performed in at least one brake caliper 10 of the braking system will now be described with reference to Figures 1 to 5.

[0168] Such a system 100 comprises at least one sensored caliper 10 according to any of the above-mentioned embodiments, an optical reading / interrogation unit 4 optically connected to the first photonic connection means 3 of the sensored caliper to receive said at least one first photonic signal L and a remote control unit 20.

[0169] The aforementioned optical reading / interrogation unit 4 is configured to generate, based on the received at least one first optical signal L, at least one first electrical signal E representative of the detected deformation and / or strain S.

[0170] A remote control unit 20 external to the sensored caliper 10 is connected to the optical reading / interrogation unit 4 to receive the at least one first electrical signal and is configured to process said at least one first electrical signal E representative of the deformation and / or strain S and obtain and provide measurements of the braking force and / or braking torque BF / BT.

[0171] According to an implementation option of such a system, the sensored brake caliper 10 further comprises a fiber optic temperature sensor 5 .

[0172] In this case, the optical reading / interrogation unit 4 is also connected to the second photonic connection means 6 of the sensor caliper for receiving the at least one second photonic signal Lt, and is configured to generate, based on the at least second photonic signal Lt, at least one second electrical signal Et indicative of the detected temperature, and to transmit the at least one second electrical signal Et to the remote control unit 20.

[0173] The remote control unit 20 is further configured to process the at least one second electrical signal Et and obtain a measurement of the braking force and / or braking torque BF / BT based on the at least one first electrical signal E and the at least second electrical signal Et.

[0174] According to an implementation option of the system (for example shown in Figure 6), the optical reading / interrogation unit 4 is integrated into and / or housed in the sensored caliper 10. In this case, an electrical signal E is output from the sensored caliper and transferred to a remote control unit.

[0175] According to another implementation option of the system (shown in different variants in Figures 1 to 5), the optical reading / interrogation unit 4 is external to the sensored brake caliper 10. In this case, the photonic signal L is emitted from the sensored caliper into a fiber and directed towards the optical reading / interrogation unit 4.

[0176] According to an embodiment of the system 100, the optical reading / interrogation unit 4 is further configured to activate each of the fiber Bragg type optical fiber strain 2 and / or temperature 5 sensors included in the sensored caliper 10, thereby transmitting the first optically active radiation OA and / or the second optically active radiation OAt.

[0177] According to an implementation option of the system, the optical reading / interrogation unit 4 is configured to transmit respective optically active radiation OAa, OAb, OAc at respective active wavelengths λa, λb, λc to the plurality of deformation and / or strain sensors 2a, 2b, 2c, and to receive and distinguish respective reflected light spectra La, Lb, Lc by each of the plurality of deformation and / or strain sensors using multiplexing using wavelength division multiplexing (WDM) transmission techniques.

[0178] According to different implementation options of the system 100, it comprises, outside the brake caliper 10, an optical reading / interrogation unit 4 according to any one of the design variants of the optical reading / interrogation unit 4 shown above.

[0179] In particular, according to an implementation option of the system 100 , the optical reading / interrogation unit 4 comprises a broadband optical radiation source 40 , an optical circulator 46 , and at least a photoelectron spectrometer receiver 41 .

[0180] The broadband optical radiation source 40 is configured to transmit one first optically active radiation OA or a plurality of second optically active radiations OAa, OAb, OAc and / or one second optically active radiation OAt.

[0181] At least an optoelectronic receiver equipped with a spectrometer 41 is configured to select the wavelength and / or wavelengths to be received and also to receive said first photonic signal L or said plurality of first photonic signals La, Lb, Lc and convert them into a first electrical signal E or a plurality of first electrical signals Ea, Eb, Ec, and / or to receive said second photonic signal Lt and convert it into a second electrical signal Et.

[0182] According to another implementation option of the system 100 , the optical reading / interrogation unit 4 comprises an adjustable optical radiation source 42 , an optical circulator 46 and at least one photodiode photoelectron spectrometer receiver 43 .

[0183] The adjustable optical radiation source 42 is configured to transmit, at a desired time, a desired optically active radiation OAn among the possible first optically active radiations OAa, OAb, OAc at a respective wavelength λn, or a second optically active radiation OAt at a wavelength λt.

[0184] The emitted optical radiation OAn illuminates an optical fiber containing an FBG sensor (by way of the input and through ports of the optical circulator 46) and determines the response by the FBG sensor sensitive to wavelength λn, which generates a reflecting photonic signal Ln that is coupled to a photodiode receiver 43 via the output port of the optical circulator 46.

[0185] At least one photodiode optoelectronic receiver 43 is configured to receive the aforementioned first retro-reflected photonic signal Ln and convert it into said first electrical signal En (or similarly to receive the second photonic signal Lt and convert it into a second electrical signal Et).

[0186] According to another implementation option of the system 100, the optical reading / interrogation unit 4 is made entirely by a single photonic integrated circuit using PIC (Photonic Integrated Circuit) technology, in which case such single integrated photonic circuit includes a broadband optical radiation source 40, at least one wavelength optical filtering element 44, and at least one optoelectronic photodiode receiver 43.

[0187] The broadband optical radiation source 40 is configured to transmit one first optically active radiation OA or a plurality of second optically active radiations OAa, OAb, OAc and / or one second optically active radiation OAt.

[0188] The optical radiation emitted by the input and through ports of the optical circulator 46 (which in the example of FIG. 14 include optical radiation OAa, OAb, and OAc) illuminates optical fibers containing FBG sensors, which each reflect a photonic signal La, Lb, and Lc. The photonic signal WDM, given as a whole by the sum of the signals La, Lb, and Lc, is transmitted via the output port of the optical circulator 46 to the input of at least one filter optical element 44, each at its own different wavelength.

[0189] At least one wavelength optical filtering element 44 can be tuned around the wavelength of the queried fiber Bragg grating to select a respective photonic signal (photonic signal Lb at wavelength λb in the example of FIG. 14). The optical filtering element 44, being tunable, can be tuned to different wavelengths to select the photonic signals reflected by any one of the FBG sensors sequentially or at different times as desired.

[0190] The optoelectronic photodiode receiver 43 is configured to receive and convert selected photonic signals from among the aforementioned photonic signals into one or more electrical signals, and / or, if selected, to receive and convert a second photonic signal Lt into a second electrical signal Et.

[0191] With reference to the above description of the different embodiments of the reading / interrogating unit 4 (in light of Figures 12 to 14), exactly the same description applies mutatis mutandis if three FBG sensors comprise two FBG strain sensors and one FBG temperature sensor, or if only one optical fiber strain sensor and one FBG temperature sensor are provided, or if any number of optical fiber strain sensors and one FBG temperature sensor are provided.

[0192] Referring to FIG. 15, a further embodiment of a system 100 for detecting and measuring braking force and / or braking torque BF / BT will now be described.

[0193] In this case, the system 100 comprises a plurality of sensored calipers (101-104) belonging to the braking system of a vehicle and a single optical reading / interrogation unit 4 operably connected to each sensored caliper 101, 102, 103, 104 of said plurality of sensored calipers.

[0194] The optical reading / interrogation unit 4 is configured to transmit respective optically active radiation OA1 to OA4 to the optical fiber strain sensors 101 to 104 and to receive respective photonic signals L1 to L4 (either reflected or transmitted according to a selected configuration) from such different optical fiber strain sensors.

[0195] The optical reading / interrogation unit 4 is also configured to generate a plurality of respective electrical signals E1-E4 based on the photonic signals L1-L4 received from the plurality of sensored brake calipers 101-104.

[0196] 15, there are four brake calipers connected to the optical reading / interrogation unit 4. In other embodiments, the number may be different from four (e.g., two or six).

[0197] According to another embodiment, the system 100 comprises a plurality of optical reading / interrogation units 4 each operatively connected to one or more of the brake calipers 10 of the aforementioned plurality of disc brake calipers.

[0198] For example, Figure 16 shows one preferred option with four reader / interrogation units 4, each operably connected to a respective brake caliper. Another preferred option (not shown) provides for the presence of two readers, each connected to two brake calipers.

[0199] According to one embodiment of the system 100, the remote control unit 20 includes at least one processor having stored thereon one or more pieces of software configured to execute an algorithm for calculating braking force and / or torque based on the received at least one first electrical signal E, or based on the received at least one first electrical signal and the received second electrical signal Et, or based on the plurality of first electrical signals Ea, Eb, Ec and the second electrical signal Et.

[0200] The present invention further includes a braking system for a vehicle 1000 including a plurality of sensored brake calipers 10 according to any one of the sensored caliper embodiments described above.

[0201] The present invention further includes a braking system of the vehicle 1000, which includes a system for measuring braking force and / or braking torque according to an embodiment of a system for detecting and measuring braking force and / or braking torque (resulting from implementation of the braking system).

[0202] The objects of the invention are fully achieved by the illustrated method and system thanks to its functional and structural features.

[0203] In fact, the technical solution described here comprises one or more photonic sensors that can be easily and effectively integrated into the caliper (fixed or floating) of a friction brake in order to indirectly, accurately and reliably measure the braking force caused by the actuation of the brake or the torque generated by the clamping of the brake caliper on the brake disc.

[0204] The fiber optic sensitive element consists of a single sensor or multiple strain sensors based on fiber Bragg grating (FBG) technology.

[0205] Advantageously, at least one temperature sensor, also of the FBG technology type, is further provided.

[0206] The fiber optic sensor element can be pre-formed for easy incorporation into the brake caliper during manufacture.

[0207] The placement of a pre-formed frame containing the photonic sensors allows for the correct placement of strain sensors at desired locations on the brake caliper body, enabling the detection of strain acting on the brake caliper at multiple locations in response to braking forces.

[0208] Advantageously, the possibility of detecting strain at multiple locations allows for a more accurate, albeit indirect, determination of braking force and / or torque.

[0209] The system consists of the aforementioned sensored brake caliper, which includes a fiber optic sensor optically connected to a reading / interrogation unit (which can be remote or integrated into the brake caliper) for the conversion of strain information into an optical-to-electrical signal (advantageously based on WDM technology).

[0210] The reader / interrogator units are based on various electro-optical technologies.

[0211] Advantageously, such a reading / interrogation unit can be achieved by silicon-based photonic technologies (e.g., PIC - Photonics Integrated Circuit), which makes it possible to make such a unit by integrating it into a sensored brake caliper or even into an existing electronic control unit.

[0212] Thus, the control unit of the system can determine the braking force and / or torque over a wide operating range, with temperature compensation.

[0213] Furthermore, the system control unit can calculate detailed information such as brake caliper temperature based on the output of the sensored caliper in order to optimize braking operation by controlling brake application (e.g., by detecting vibrations and actively damping them), or it can continuously read the sensor output at a high sampling rate and calculate brake torque in real time.

[0214] Additionally, multiple sensored calipers can be conveniently connected to a single reading / interrogation unit. Further advantages of using fiber-optic sensors for dynamically measuring the brake

[0215] Further advantages of using fiber optic sensors to dynamically measure braking force are the ability to use passive sensors (no power source required), high robustness and reliability in harsh environments, electromagnetic immunity, high sensitivity (to detect very small and very large forces), and wide bandwidth.

[0216] Those skilled in the art will be able to make numerous modifications and adaptations to the above-described embodiments, or to substitute functionally equivalent elements to meet their foreseeable needs, without departing from the scope of the appended claims. All features described above as belonging to one possible embodiment may be implemented independently of other described embodiments.

Claims

1. 1. A method for detecting and measuring a braking force and / or a braking torque (BF / BT) resulting from the operation of a braking system (1000) of a vehicle, the detection being performed in at least one brake caliper (10) of the braking system, comprising: - incorporating at least one deformation and / or strain sensor (2) into a part of the material (M) of the body of said at least one brake caliper (10) at each predetermined position, said brake caliper being susceptible to deformation due to a reaction force exerted on said brake caliper by said braking force and / or braking torque (BF / BT), so that a deformation and / or strain (S) acting locally at said position where said at least one deformation and / or strain sensor (2) is located is representative of said braking force and / or braking torque (BF / BT), said at least one deformation and / or strain sensor (2) being an optical fiber strain sensor (2) of the fiber Bragg grating type; detecting, by each of said at least one optical fiber strain sensor (2), said local deformation and / or strain (S) acting at each said location, and generating at least one first photonic signal (L) representative of said detected deformation and / or strain (S); The at least one first photonic signal (L1) is received by an optical reading / interrogation unit (4) optically connected to the at least one optical fiber strain sensor (2). generating, by said optical reading / interrogation unit (4), at least one first electrical signal (E) representative of said locally detected deformation and / or strain (S) based on said at least one first photonic signal (L); processing said at least one first electrical signal (E) representative of said deformation and / or strain (S) to obtain a measurement of said braking force and / or braking torque (BF / BT).

2. - incorporating at least one temperature sensor (5) in said portion of material (M) of the body of said brake caliper (10), said at least one temperature sensor (5) being a fiber optic temperature sensor (5) of the fiber Bragg grating type; detecting, by each of said at least one temperature sensor (5), a temperature value (T) present at each of said locations, and generating a respective at least one second photonic signal (Lt) representative of said detected temperature value (T); receiving said at least one second photonic signal (Lt) by said optical reading / interrogation unit (4) optically connected to said at least one temperature sensor (5); generating, by said optical reading / interrogation unit (4), based on said at least second optical signals (Lt) received, at least one second electrical signal (Et) representative of said temperature; 2. The method of claim 1, wherein the processing step comprises processing the at least one first electrical signal (E) and the at least one second electrical signal (Et) to obtain a measurement of the brake force and / or brake torque (BF / BT) taking into account temperature compensation.

3. said at least one temperature sensor (5) is made by a fiber Bragg grating made in a different optical fiber with respect to the fiber in which said at least one deformation and / or strain sensor (2) is made, the fiber Bragg grating of the at least one temperature sensor (5) is arranged to be insensitive to thermal and mechanical deformations of the material of the caliper body; the optical fiber temperature sensor (5) is connected to the optical reading / interrogation unit (4) by a third connecting optical fiber (34); the optical reading / interrogation unit (4) is configured to activate the optical fiber temperature sensor (5) by transmitting optically active radiation (OAt) through the third connecting optical fiber (34); 3. The method of claim 2, wherein the second photonic signal (Lt) is transmitted through the fiber Bragg grating. The second optical spectrum (Lt) reaches the optical reading / interrogation unit (4) via the third connecting optical fiber (34).

4. the optical fiber strain sensor (2) is connected to the optical reading / interrogation unit (4) by a first connecting optical fiber (31); the optical reading / interrogation unit (4) is configured to activate the optical fiber strain sensor (2) by transmitting optically active radiation (OA) through the first connecting optical fiber (31); 4. The method according to claim 1, wherein the first photonic signal (L) comprises a first optical spectrum (L) reflected by the strain sensor (2) of the fiber Bragg grating type, the first optical spectrum (L) reaching the optical reading / interrogation unit (4) via the first connecting optical fiber (31).

5. the at least one temperature sensor (5) is made by a fiber Bragg grating made of the same optical fiber as the at least one deformation and / or strain sensor (2) is made of and is arranged so as to be insensitive to thermal and mechanical deformations of the material of the caliper body; the optical fiber temperature sensor (5) is connected to the optical reading / interrogation unit (4) by the first connecting optical fiber (31); the optical reading / interrogation unit (4) is configured to activate the optical fiber temperature sensor (5) by sending optically active radiation (OAt) wavelength-amplified at the optically active radiation of the strain sensor via the first connecting optical fiber (31); 5. The method of claim 4, wherein the second photonic signal (Lt) is reflected by the temperature sensor (5) of the fiber Bragg grating type and comprises a second optical spectrum (Lt) wavelength-multiplexed with the first optical spectrum (L) reflected by the strain sensor (2), the second optical spectrum (Lt) reaching the optical reading / interrogation unit (4) via the first connecting optical fiber (34).

6. the optical fiber strain sensor (2) is connected to the optical reading / interrogation unit (4) by a first input connection optical fiber (32) and a second output connection optical fiber (33); the optical reading / interrogation unit (4) is configured to activate the optical fiber strain sensor (2) by transmitting optically active radiation (OA) through the first input connection optical fiber (32); 4. The method of claim 1, wherein the first photonic signal (L) comprises a first optical spectrum (L) transmitted by the fiber Bragg grating type strain sensor (2), the first optical spectrum (L) reaching the optical reading / interrogation unit (4) via the second connecting optical fiber (33).

7. the at least one temperature sensor (5) is made by a fiber Bragg grating made of the same optical fiber as the at least one deformation and / or strain sensor (2) is made of and is arranged so as to be insensitive to thermal and mechanical deformations of the material of the caliper body; the optical fiber temperature sensor (5) is connected to the optical reading / interrogation unit (4) by the first input connection optical fiber (32) and the second output connection optical fiber (33); the optical reading / interrogation unit (4) is configured to activate the optical fiber temperature sensor (5) by transmitting optical activity radiation (OAt) wavelength multiplexed with the optical activity radiation (OA) of the strain sensor via the first input connection optical fiber (32); 7. The method of claim 6, wherein the second photonic signal (Lt) is transmitted by the fiber Bragg grating type temperature sensor (5) and comprises a second optical spectrum (Lt) wavelength-amplified with the first optical spectrum (L) transmitted by the strain sensor (2), the second optical spectrum (Lt) reaching the optical reading / interrogation unit (4) via the second output connection optical fiber (33).

8. the incorporating step includes incorporating a plurality of deformation and / or strain sensors (2a, 2b, 2c) made by respective Bragg gratings each associated with a respective central operating wavelength (λa, λb, λc); the Bragg grating is obtained in one or more optical fiber elements; each of the one or more optical fiber elements being incorporated into the portion of the material (M) of the body of the brake caliper at a respective position and in a respective predefined state; The method further comprises: transmitting, by said optical reading / interrogation element (4), respective optically active radiations (OAa, OAb, OAc) at different respective operating wavelengths (λa, λb, λc) to said plurality of sensors and / or strain elements via said connecting optical fiber by wavelength division multiplexing (WDM) transmission technology; receiving, via said connecting optical fiber (33), and distinguishing by demultiplexing using wavelength division multiplexing techniques, each of the optical spectra reflected by each of said plurality of deformation and / or strain sensors (2 a, 2 b, 2 c), wherein each of said reflected optical spectra corresponds to a respective first photonic signal (La, Lb, Lc); the step of generating the at least one first electrical signal (E) by the optical reading / interrogation unit (4) comprises generating a plurality of first electrical signals (Ea, Eb, Ec) based on each of the plurality of first electrical signals (La, Lb, Lc); 8. The method of claim 1, wherein the step of processing comprises processing the plurality of first electrical signals (Ea, Eb, Ec) to obtain measurements of the braking force and / or braking torque (BF / BT).

9. The incorporating step comprises: - incorporating said at least one deformation and / or strain sensor (2) in a preformed frame and / or housing (7) having a preformed shape and dimensions; the body of the brake caliper (10), including incorporating the preformed frame (7) into a mold and / or mold enclosure of the brake caliper at a certain predefined position during the manufacture of the brake caliper (10); 9. The method according to any one of claims 1 to 8, wherein each of said at least one deformation and / or strain sensor (2) is partially or completely integrated into said desired portion of the material (M) of the body of the brake caliper.

10. the step of incorporating the at least one deformation and / or strain sensor (2) into the body of the brake caliper comprises welding an optical fiber; 9. The method according to any one of claims 1 to 8, wherein said at least one deformation and / or strain sensor (2) is obtained on a predefined portion of the surface of said brake caliper body.

11. The welding step includes: an ultrasonic additive manufacturing (UAM) ultrasonic technique adapted to incorporate the sensor into the metal body of the caliper by means of a metal layer; or The method of claim 10 performed by laser technology adapted to directly weld the fiber to the clamp.

12. 12. The method of any of claims 1 to 11, wherein the receiving and generating steps are performed by a single optical reading / interrogation unit (4) integrated into and / or housed in the brake caliper (10).

13. The steps of the method are performed by a plurality of brake calipers (10) of a disc brake caliper of a braking system of a vehicle, the receiving and generating steps are performed by a single optical reading / interrogation unit (4) operatively connected to all of the brake calipers (10) of the plurality of disc brake calipers of a vehicle braking system; or 12. The method of any of claims 1 to 11, wherein the receiving and generating steps are performed by a plurality of optical reading / interrogation units (4) each operatively connected to one or more brake calipers (10) of the plurality of disc brake calipers of a vehicle braking system.

14. Before the processing step, transmitting said at least one first electrical signal (E) and / or second electrical signal (Et) to a control unit (20); The steps of the process include:

14. The method of claim 1, further comprising calculating the braking force and / or braking torque (BF / VT) by a processor of the control unit (20) using one or more algorithms operated by one or more software programs based on the at least one first electric signal (E), or the at least one first electric signal (E) and the second electric signal (Et), or the plurality of first electric signals (Ea, Eb, Ec) and the at least one second electric signal (Et).

15. the calculating step comprises calculating the clamping force and / or brake torque (BF / BT) according to a predefined non-linear relationship between the braking force and / or brake torque and the deformation and / or strain detected by the at least one deformation and / or strain sensor (2) at each position integrated in the brake caliper, the predefined nonlinear relationship is represented by a computerized model or look-up table stored so as to be accessible by the processor of the control unit (20); 15. The method of claim 14, wherein the predefined non-linear relationship is determined by experimentation and / or characterization and / or calibration performed after the at least one deformation and / or strain sensor (2) is incorporated into the brake caliper (10) and before using the brake caliper.

16. 16. The method of claim 1, wherein the processing step includes obtaining a dynamic measurement of a real-time trend of the braking force and / or torque (BT / BF) based on the detected changes in deformation and / or strain over time.

17. A method for detecting and measuring a braking force and / or a braking torque resulting from the operation of a friction brake by detection performed on at least one suspension part of a vehicle to which a brake caliper is connected, comprising: - incorporating at least one deformation and / or strain sensor at each predefined fixed position in a portion of material of the suspension part of the vehicle that is subject to deformation due to a reaction force exerted by the brake caliper on the suspension part of the vehicle under said braking force during a braking event, wherein the deformation and / or strain acting locally at the position where the at least one deformation and / or strain sensor is located is representative of a braking force and / or braking torque, and wherein the at least one deformation and / or strain sensor is an optical fiber strain sensor of the fiber Bragg grating type; - detecting, by each of at least one optical fiber strain sensor, a local deformation and / or strain acting at a respective location, and generating a respective at least one first photonic signal representative of said detected deformation and / or strain; receiving the at least one first photonic signal by an optical reading / interrogation unit optically connected to the at least one optical fiber strain sensor; - generating, by an optical reading / interrogation unit, at least one first electrical signal representative of said locally detected deformation and / or strain based on said at least one first photonic signal received; processing said at least one first electrical signal representative of said deformation and / or strain to obtain a measure of said braking force and / or braking torque.

18. The method of claim 17 , wherein the at least one deformation and / or strain sensor disposed on the suspension is also configured to detect additional forces acting on the suspension element.

19. A brake caliper (10) with a sensor for a braking system for a vehicle (1000), comprising: a brake caliper comprising a brake caliper body (1) made of a material susceptible to deformation due to a reaction force applied to the brake caliper in response to a braking force and / or torque during a braking event, the brake caliper body (1) including a portion of the material (M), the deformation and / or strain (S) of the portion of the material (M) locally representing the braking force and / or braking torque (BF / BT) applied to a braking system; at least one deformation and / or strain sensor (2) incorporated in said portion of the deformable material (M) at each defined location, at least one deformation and / or strain sensor (2) that is an optical fiber strain sensor of a fiber Bragg grating type, configured to detect a deformation and / or strain (S) acting locally at a respective position and to generate at least one first photonic signal (L) representative of the detected deformation and / or strain (S); a sensored brake caliper (10) including a first photonic connection means (3) connected to said optical fiber strain sensor (2) and configured to be connected to an optical reading / interrogation unit (4) for transmitting said at least one first photonic signal (L).

20. at least one temperature sensor (5) integrated in the portion of the material of the body of the brake caliper that is susceptible to deformation (M) in the vicinity of the optical fiber strain sensors (2) and at each predetermined position, the at least one temperature sensor (5) being an optical fiber strain sensor of a fiber Bragg grating type, the at least one temperature sensor (5) being configured to detect a temperature (T) present at each location and to generate at least one second photonic signal (Et) indicative of the detected temperature; 20. The sensored brake caliper (10) according to claim 19, comprising second photonic connection means (6) connected to said optical fiber temperature sensor (5) and to an optical reading / interrogation unit (4) configured to transmit said at least second photonic signal (Lt).

21. an optical reading / interrogation unit (4) connectable to a remote control unit (20) external to the brake caliper, the optical reading / interrogation unit (4) is optically connected to the first photonic connection means (3) and is configured to activate the at least one optical fiber strain sensor (2) to transmit a first optically active radiation (OA) and to receive the at least one first photonic signal (L); the optical reading / interrogation unit (4) is configured to generate, based on the received at least one first photonic signal (L), at least one first electrical signal (E) representative of the detected deformation and / or strain (S); 21. The brake caliper (10) with sensor according to claim 19 or 20, wherein the at least one first electrical signal (E) is adapted to be transmitted to a remote control unit (20).

22. the optical reading / interrogation unit (4) is further connected to the second photonic connection means (6) and is configured to activate the optical fiber temperature sensor (5) to transmit a second optically active radiation (OAt) and to receive the at least second photonic signal (Lt); the optical reading / query unit (4) is further configured to generate, based on the received at least second photonic signal (Lt), at least a second electrical signal (Et) representative of the detected temperature; the at least second electrical signal (Et) is adapted to be transmitted to the remote control unit (20); A caliper (10) with a sensor according to claims 19 and 20.

23. the first photonic connection means (3) comprises a first connecting optical fiber (31) adapted to transmit the first optically active radiation (OA) from the optical reading / interrogation unit (4) to the at least one optical fiber strain sensor (2) and to transmit the first photonic signal (L) having a first reflected light spectrum (L) from the at least one optical fiber strain sensor (2) towards the optical reading / interrogation unit (4), or The first photonic connection means (3) comprises: a first input connection optical fiber (32) configured to transmit the first optically active radiation (OA) from the optical reading / interrogation unit (4) to the at least one optical fiber strain sensor (2); 23. The sensored caliper (10) of any of claims 19 to 22, comprising an output connection optical fiber (33) configured to transmit the first photonic signal (L) comprising a first transmitted light spectrum (L) from the at least one optical fiber strain sensor (2) towards a reading / interrogation unit (4).

24. said at least one temperature sensor (5) being made by a fiber Bragg grating made of the same optical fiber as the at least one deformation and / or strain sensor (2) being made of, and arranged so as to be insensitive to thermal and mechanical deformations of the material of the caliper body; the optical fiber temperature sensor (5) is connected to an optical reading / interrogation unit (4) by the first connecting optical fiber (31); the optically active radiation (OAt) is wavelength multiplexed with the optically active radiation (OA) of the strain sensor and transmitted through the first connecting optical fiber (31); the second photonic signal (Lt) is reflected by a temperature sensor (5) and comprises a second optical spectrum (Lt) wavelength multiplexed with the first optical spectrum (L); said second spectrum reaches said optical reading / interrogation unit (4) via said first connecting optical fiber (34); or The optical fiber temperature sensor (5) is connected to an optical reading / interrogation unit (4) by the first input connecting optical fiber (32) and the second output connecting optical fiber (33); the optically active radiation (OAt) is wavelength multiplexed with the optically active radiation (OA) of the strain sensor and transmitted to the first input connection optical fiber (32); 24. The caliper (10) with sensor of claim 23, wherein the second photonic signal (Lt) is transmitted by a temperature sensor (5), wavelength-multiplexed with the first optical spectrum (L) and reaches the optical reading / interrogation unit (4) via the second output connection optical fiber (33).

25. 23. The caliper (10) with sensor (10) of claim 22, wherein the second photonic connection means (6) comprises a third connecting optical fiber (34) configured to transmit the second optically active radiation (OAt) from the optical reading / interrogation unit (4) to the optical fiber temperature sensor (5) and to transmit a second photonic signal (Lt) having a second reflected optical spectrum (Lt) from the optical fiber strain sensor (5) towards the optical reading / interrogation unit (4).

26. 26. The caliper (10) with sensor of any of claims 23 to 25, wherein each connection between each fiber from which the fiber Bragg grating type sensor is obtained and a respective connecting optical fiber to the optical reading / interrogation unit (4) is made by a fiber splice or a detachable photonic connecting element or optical connector.

27. a plurality of deformation and / or strain sensors (2a, 2b, 2c), each of said plurality of deformation and / or strain sensors is fabricated by a respective Bragg grating associated with a respective central operating wavelength (λa, λb, λc); the Bragg grating is obtained in one or more optical fiber elements; the one or more optical fiber elements are part of the body material (M) of the brake caliper (10) and are incorporated at respective positions in a predefined positional relationship; each of said deformation and / or strain sensors (2a, 2b, 2c) is configured to generate a respective photonic signal of a plurality of first photonic signals (La, Lb, Lc); the optical reading / interrogation unit (4) transmits respective optically active radiations (OAa, OAb, OAc) at respective operating wavelengths (λa, λb, λc) to the plurality of deformation and / or strain sensors (2a, 2b, 2c) using wavelength division multiplexing (WDM) transmission technology, and receives and distinguishes respective reflected light spectra corresponding to respective first photonic signals (La, Lb, Lc) by each of the plurality of deformation and / or strain sensors (2a, 2b, 2c) by demultiplexing using wavelength division multiplexing (WDM) technology; 27. The sensored caliper (10) of any of claims 19 to 26, wherein the optical reading / interrogation unit (4) is configured to generate a respective plurality of first electrical signals (Ea, Eb, Ec) based on the received plurality of first photonic signals (La, Lb, Lc) and to transmit the plurality of first electrical signals (Ea, Eb, Ec) to a control unit (20).

28. a preformed frame and / or housing (7) having a predetermined shape and dimensions that is incorporated into the sensored caliper (10) during manufacture of the sensored caliper; said preformed frame and / or housing (7) containing at least one deformation and / or strain sensor (2); 28. The sensored caliper (10) according to any one of claims 19 to 27, wherein each of the at least one deformation and / or strain sensor (2) is integrated into a desired portion of the material (M) of the body of the sensored caliper.

29. further comprising an optical fiber welded to a surface of the brake caliper body; 28. The sensor-equipped caliper (10) of any one of claims 19 to 27, wherein the at least one deformation and / or strain sensor (2) and / or the at least one temperature sensor (5) are integrated in the optical fiber.

30. The optical reading / interrogation unit (4) comprises: a broadband optical radiation source (40) configured to transmit said at least one first optically active radiation (OA; OAa, OAb, OAc) and / or second optically active radiation (OAt); configured to select a wavelength and / or wavelengths to receive; configured to receive and convert each of said at least one first photonic signal (L; La, Lb, Lc) into said at least one first electrical signal (E; Ea, Eb, Ec); and / or 30. The sensored caliper (10) of any one of claims 19 to 29, comprising a photoelectron spectrometer receiver (41) that receives and converts the second photonic signal (Lt) into the second electrical signal (Et).

31. The optical reading / interrogation unit (4) comprises: an adjustable optical radiation source (42) configured to transmit at least one first optically active radiation (OA; OAa, OAb, OAc) and / or second optically active radiation (OAt) having a desired respective wavelength; 30. The sensored caliper (10) of any of claims 19 to 29, comprising a photodiode optoelectronic receiver (43) configured to receive the first photonic signal (L; La, Lb, Lc) and convert it into the first electrical signal (E; Ea, Eb, Ec) and to receive the second photonic signal (Lt) and convert it into the second electrical signal (Et).

32. Said optical reading / interrogation unit (4) is entirely made by a single integrated photonic circuit implementing PIC (Photonic Integrated Circuit) technology, said single integrated photonic circuit comprising: a broadband optical radiation source (40) configured to transmit said at least one first optically active radiation (OA; OAa, OAb, OAc) and / or second optically active radiation (OAt); at least one wavelength optical filtering element (44) that can be tuned around the wavelength of the interrogated fiber Bragg grating to select the respective photonic signal; 30. The sensored caliper (10) of any of claims 19 to 29, comprising a photodiode optoelectronic receiver (43) configured to receive a photonic signal selected from the at least one first photonic signal (L; La, Lb, Lc) and convert it into the first electrical signal (E; Ea, Eb) and / or to receive the second photonic signal (Lt) and convert it into the second electrical signal (Et).

33. A system (100) for detecting and measuring a braking force and / or a braking torque (BF / BT) resulting from the operation of a braking system of a vehicle by detection performed in at least one brake caliper (10), said system comprising: At least one sensored caliper (10) according to claim 22; an optical reading / interrogation unit (4) optically connected to the first photonic connection means (3) of the sensor caliper for receiving the at least one first photonic signal (L), the optical reading / interrogation unit (4) being configured to generate, based on the received at least one first photonic signal (L), at least one first electrical signal (E) representative of the detected deformation and / or strain (S); a remote control unit (20) external to the sensored caliper (10) connected to the optical reading / interrogation unit (4) for receiving the at least one first electrical signal, a remote control unit (20) for processing said at least one first electrical signal (E) representative of said deformation and / or strain (S) to obtain and provide measurements of said braking force and / or braking torque (BF / BT).

34. 24. A method for manufacturing a vehicle comprising: said optical reading / interrogation unit (4) is further connected to said second photonic connection means (6) of the sensor caliper to receive said at least one second photonic signal (Lt); the optical reading / interrogation unit (4) is configured to generate, based on the received at least second photonic signal (Lt), at least a second electrical signal (Et) representative of the detected deformation and / or strain, and to transmit the at least second electrical signal (Et) to the remote control device (20); 34. The system (100) of claim 33, wherein the remote control unit (20) is further configured to process the at least second electrical signal (Et) to obtain a measurement of the braking force and / or braking torque (BF / BT) based on the at least one first electrical signal (E) and the at least one second electrical signal (Et).

35. A system (100) according to claim 33 or 34, wherein the sensored caliper (10) is a sensored caliper according to any one of claims 22 to 32, and wherein the optical reading / interrogation unit (4) is integrated and / or housed in the sensored caliper (10).

36. 36. The system (100) of any of claims 33 to 35, wherein the optical reading / interrogation unit (4) is further configured to activate each of the strain (2) and / or temperature (5) sensors of the optical fiber Bragg type included in the sensor caliper (10) to transmit a first optically active radiation (OA) and / or a second optically active radiation (OAt).

37. 37. The system (100) according to claim 36, wherein the optical reading / interrogation unit (4) is further configured to transmit respective optically active radiations (OAa, OAb, OAc) to the plurality of deformation and / or strain sensors (2a, 2b) at respective operating wavelengths (λa, λb, λc) using wavelength division multiplexing (WDM) transmission techniques, and to receive and distinguish respective optical spectra (La, Lb, Lc) reflected by the plurality of deformation and / or strain sensors by demultiplexing via wavelength division multiplexing (WDM) techniques.

38. The optical reading / interrogation unit (4) comprises: a broadband optical radiation source (40) configured to transmit said at least one first optically active radiation (OA; OAa, OAb, OAc) and / or second optically active radiation (OAt); a photoelectron spectrometer receiver (41) configured to select one wavelength and / or multiple wavelengths to receive, and further configured to receive and convert each of said at least one first photonic signal (L; La, Lb, Lc) into said at least one first electrical signal (E; Ea, Eb, Ec) and / or receive and convert each of said second photonic signals (Lt) into said second electrical signal (Et), or The reading / interrogation unit (4) comprises: an adjustable optical radiation source (42) configured to transmit said at least one first optically active radiation (OA; OAa, OAb, OAc) and / or second optically active radiation (OAt) having a desired respective wavelength; a photodiode optoelectronic receiver (43) configured to receive and convert the first photonic signal (L; La, Lb, Lc) into the first electrical signal (E; Ea, Eb, Ec) and to receive and convert the second photonic signal (Lt) into the second electrical signal (Et); or, The optical reading / interrogation unit (4) is entirely made by a single integrated photonic circuit implementing PIC (Photonic Integrated Circuit) technology, the single integrated photonic circuit comprising: a broadband optical radiation source (40) configured to transmit said at least one first optically active radiation (OA; OAa, OAb, OAc) and / or second optically active radiation (OAt); at least one wavelength optical filtering element (44) tunable around the wavelength of the interrogated fiber Bragg grating to select the respective photonic signal; 38. The system (100) of any of claims 33 to 37, comprising a photodiode optoelectronic receiver (43) configured to receive a photonic signal selected from said at least one first photonic signal (L; La, Lb, Lc) and convert it into said first electrical signal (E; Ea, Eb), and / or, if selected, to receive said second photonic signal (Lt) and convert it into said second electrical signal (Et).

39. a plurality of calipers (10) with sensors belonging to the braking system of the vehicle; a single optical reading / interrogation unit (4) operatively connected to each sensored caliper (10) of said plurality of sensored calipers; or 39. The system (100) of any one of claims 33 to 38, comprising a plurality of optical reading / interrogation units (4) each operatively connected to one or more brake calipers (10) of the plurality of disc brake calipers of a vehicle braking system.

40. comprising a plurality of brake calipers (10) according to any one of claims 20 to 32, or a system (100) for detecting and measuring braking force and / or braking torque resulting from operation of said disc brake system, A braking system (1000) for a vehicle, wherein the system for detecting and measuring braking force and / or braking torque is according to any of claims 33 to 39.

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