Temperature monitoring device, temperature monitoring method and temperature monitoring system

Abstract

A temperature monitoring device according to the invention comprises a control system (100) adapted to generate a substantially periodic control waveform applied to a control input of a light source (111) with a tunable wavelength connected to a fiber interferometer (112), wherein a measuring fiber (120) is connected in an arm of one of the fiber interferometers (112) and the interferometer (111) output is connected to a detector (113), the output of the detector (113) being connected to a signal processing module (101) adapted to identify temperature changes as a function of the fiber length, characterized in that the coherence length of the light source (111) is longer than 0.5 m and the period of the periodic waveform is shorter than or equal to 20 s, the difference between the minimum and maximum wavelengths is higher than 3 pm, and the fiber is adapted to be placed near an energy-discharging device in a vehicle during its operation. A temperature monitoring method according to the invention is characterized in that the temperature is determined by cumulatively taking into account changes detected at measurement points on the measuring fiber of the device using the device according to the invention. A temperature monitoring system according to the invention is characterized in that the measuring fiber of the device according to the invention is placed near an energy-discharging device in a vehicle.

Description

Technical Field

[0001] The object of the present invention is a temperature monitoring device, a temperature monitoring method and a temperature monitoring system. The invention is particularly useful for early detection of vehicle fire risks, in particular in the engine compartment or in an electrical storage compartment, in particular for batteries. Background Art

[0002] Numerous solutions for distributed temperature measurement using optical fibers are known in the prior art. These solutions are based on, among other physical phenomena, the Rayleigh scattering, Raman scattering, and Brillouin scattering.

[0003] Rayleigh scattering is the scattering of light under the influence of inhomogeneities of the environment in which it propagates. One drawback of techniques involving the exploitation of this phenomenon is the lack of absolute information on temperature changes in the environment under investigation.

[0004] The Raman effect is used to measure temperature using the analysis of the difference between the Stokes and anti-Stokes intensities as a function of fiber length. This analysis of light intensity allows for the determination of absolute temperature, but unfortunately, has relatively low resolution, on the order of 1 meter, as a function of fiber length. Furthermore, using the Raman effect to monitor temperature requires either very sensitive detectors or extensive averaging, as the effect is quite weak.

[0005] Measuring temperature using the Brillouin effect involves analyzing the propagation frequency of acoustic waves generated in an optical fiber excited by intense light.

[0006] In the international patent application with invention publication number WO2006027369 entitled “Calibrating an optical fmcw backscattering measurement system” filed on March 16, 2006, an optical temperature monitoring system operating based on the Rayleigh effect is disclosed, with a light source having a wavelength tuned with a sawtooth waveform, wherein the temperature change as a function of the length of the optical fiber is measured based on the detection and analysis of the reflected wave of the interference source wave.

[0007] In the European patent application with invention publication number EP3246683 entitled “Optical health monitoring for aircraft overheat and fire detection” dated May 17, 2017, a method for detecting overheating and fire risks by monitoring temperature using optical fibers involving temperature measurement, detecting whether a threshold is exceeded, and generating an alarm in such a case is disclosed. Summary of the Invention

[0008] The object of the present invention is to provide a device suitable for temperature monitoring in vehicle engines, in particular cars and buses, which enables detection of vehicle component faults associated with changes, in particular temperature increases.

[0009] The temperature monitoring device according to the present invention comprises a control system adapted to generate a substantially periodic control waveform applied to a control input of a light source having a tunable wavelength connected to a fiber interferometer, wherein the measurement fiber is connected in one of the arms of the fiber interferometer. The interferometer output is connected to a detector having an output connected to a signal processing module adapted to identify temperature changes as a function of the fiber length. The light source coherence length is longer than 0.5 m, preferably 2 m, and preferably greater than 20 m. The substantially periodic control waveform has a period of less than 20 s, preferably less than 10 s, or even less than 4 s. Using periodic waveforms with such periods and their corresponding source wavelength tuning, respectively, of ≥3 pm, ≥8 pm, and ≥17 pm, allows for spatial measurement resolutions of less than 50 cm, 20 cm, and 10 cm, respectively. The optical fiber is suitable for placement near energetic devices in a vehicle during operation. This means, among other things, that its housing must withstand temperatures of at least 70°C without damage and should be selected to protect it from damage or degradation, at least up to the normal operating temperature of components located adjacent to the optical fiber.

[0010] Preferably, the measuring fiber is a single-mode fiber.Such a solution allows a simple implementation of the algorithm while at the same time not requiring additional systems for implementing single-mode operation.

[0011] Instead, the connection between the interferometer and the measurement fiber runs via a single-mode excitation system.

[0012] Furthermore, alternatively, there is at least one mode filter, or device ensuring single mode operation between the light source and the detector.

[0013] The presence of at least one polarizer or polarization splitter between the light source and the detector ensures operation with a single light polarization and avoids the use of polarization splitting systems and the separate detection of their orthogonal states.

[0014] Preferably, the measurement fiber is a polarization maintaining fiber, which ensures operation with a single light polarization without additional systems.

[0015] Preferably, the detector is characterized by being equal to or less than 60 pW*Hz -1 / 2 The equivalent noise power is less than 20 pW*Hz-1 / 2, which simplifies the implementation of the control algorithm and reduces the risk of errors.

[0016] Preferably, the signal processing system is connected to the detector via an analogue to digital converter having a resolution of at least 6 bits and a sampling rate of 20 kHz or more, which simplifies the implementation of the control algorithm and provides sufficient resolution.

[0017] Preferably, the apparatus comprises an ambient temperature sensor connected to the control system.

[0018] The reflectivity-reducing component can, in particular, comprise a damping component.

[0019] The method for monitoring the temperature of a vehicle using a temperature sensor according to the present invention involves detecting a temperature exceeding a specified threshold value and generating an alarm signal if this value is exceeded. The method is characterized by using a device according to the present invention to detect a temperature exceeding the specified value. A measuring fiber is placed near an energy-dissipating component in the vehicle, an initial temperature is set, and then, during subsequent light source tuning cycles, it is used to iteratively monitor temperature changes along the measuring fiber, cumulatively updating the current value at at least one measurement point within the length of the measuring fiber and then comparing it to the threshold value.

[0020] Preferably, the measuring fiber is placed in the vehicle near at least one component from the group consisting of a fuel pump, fuel manifold, turbocharger, exhaust manifold, alternator, starter, air compressor, oil pump, oil sump, heater unit, AC compressor, electronic control system, wiring harness, battery, and fuel cell, with at least one measuring point located near at least one of these components. Monitoring these components, in particular, allows for the detection of temperature increases associated with a fire risk or faults requiring intervention.

[0021] Equipping the measuring fiber with a scale indicating the distance to the starting point of the measuring fiber or to at least one measuring point makes it easier to position the measuring fiber in the vehicle and to assign the measuring points to the vehicle components. This scale can be a marking on an additional component bundled with the fiber or on its outer surface.

[0022] Preferably, the initial temperature is determined by an automatic readout of an ambient temperature sensor.

[0023] Preferably, the initial temperature is input into the control system via its interface.

[0024] Preferably, the alarm signal generated is selected depending on which point of the measuring optical fiber the temperature exceeds the threshold value.

[0025] A system according to the invention for monitoring the temperature of a vehicle component comprises an optical fiber device for measuring temperature placed near at least one component of the vehicle, distinguished by the fact that the optical fiber device for measuring temperature is a device according to the invention.

[0026] Preferably, the system comprises a digital system suitable for automatically implementing the method according to the invention.The system can be integrated with the control system of the device according to the invention.

[0027] According to the invention, a computer program product suitable for temperature monitoring comprises an instruction set for a control system of the device according to the invention, with which the implementation of the method according to the invention is carried out. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The object of the invention is presented as an embodiment in the accompanying drawings, in which Figure 1a depicts a block diagram of an apparatus according to an embodiment of the present invention, Figure 1b depicts a block diagram of an apparatus according to an alternative embodiment of the present invention, Figure 2 depicts a flow chart of a method according to an embodiment of the present invention, Figure 3 Depicts a table with operating temperatures and temperature thresholds of components in an embodiment of a system according to the present invention, and Figure 4 Depicted is a table listing the maximum theoretical spatial resolution that may be achieved for selected pairs of preferred values ​​for source tuning time and tuning range. DETAILED DESCRIPTION

[0029] According to an embodiment of the present invention, Figure 1a The device of the block diagram depicted in FIG1 is equipped with a tunable light source 111 controlled by a control system 100. The wavelength of the light generated by light source 111 is tuned. Due to the simplicity of implementing the temperature change measurement method, the best results have been achieved with linear tuning, sawtooth tuning, or triangular tuning. However, solutions with other periodic waveforms are possible. The source is connected to an interferometer 112, where it is separated. In FIG1 , light propagation is indicated by a double line with arrows, showing a simplified propagation direction.

[0030] Part of the light constituting the reference beam is directed to detector 113 directly or via a reference arm (not shown in the figure), while another part is directed to measuring fiber 120 and constitutes the measuring beam. The measuring beam aimed at the measuring fiber is subjected to Rayleigh scattering throughout its length. As a result of this scattering, the light returns to interferometer 112, which directs the light to detector 113. In detector 113, interference of the reference beam is observed, with the light from the measuring beam scattered at various points in the measuring fiber. For some applications, it is reasonable to use two or more detectors and add their output signals. This is a particularly useful approach if the applied fiber does not maintain polarization.

[0031] The temperature change at the point where the light is scattered results in a change in the signal detected by the detector 113. The signal from the detector 113 is passed to the processing module 101 where the temperature change ΔT of the measurement point is determined based on the change in the signal.

[0032] The signal processing module 101 is connected to the control system 100. The control system 100 is connected to a tunable light source 111. It is thus possible to synchronize the signal processing with the source tuning and to mark the position of measurement points along the length of the measurement fiber 120. The signal connections are marked in FIG1 by single lines.

[0033] Each point in the measurement fiber 120 can be considered a source of backward-directed light. The beat frequency of the signal from such a source with the reference signal is proportional to the distance along the fiber. This serves as the basis for determining the position of a given measurement point relative to the fiber's origin. Temperature measurement involves analyzing the inverse Fourier transform at a specific segment of the fiber. The phase of the observed beat changes under the influence of temperature, which unambiguously indicates a temperature change. Therefore, the concept of a measurement point implies a fiber segment with a length equal to the spatial resolution, where temperature changes are interpreted as the average temperature change over the length of the analyzed segment. Spatial resolution also influences the ability to distinguish components. If necessary, it is possible to artificially extend fiber segments between measurement points, i.e., to place segments longer than necessary, as well as to place them multiple times near the same component.

[0034] By using a device that reduces the reflectivity from component 121, in particular an attenuation component that reduces the signal strength returning at the end of the measuring fiber, the operation of the system is improved. Such a component prevents reflections of strong signals from the end of the fiber and translates into an improved signal-to-noise ratio. It is advantageous to provide at least 6 dB of reflection attenuation. This function can be achieved, for example, by: an angled physical connector (APC), or by terminating the fiber with an angled cut covered with a material having a refractive index similar to that of glass, or by using an attenuator or optical isolator. By using a reflection attenuation system of 20 dB or more, a significant improvement in measurement accuracy has been achieved. A device that provides 60 dB of attenuation has significantly simplified the implementation of the method according to the present invention.

[0035] The light source coherence length 111 should be at least twice as long as the measurement fiber 120. Coherence lengths suitable for monitoring a vehicle's engine compartment or battery compartment typically range from 1 m to 1 km. This means that the light source 111 should have a bandwidth of at most 70 MHz, preferably less than 1 MHz. Best results have been achieved with sources having a bandwidth of less than 100 kHz. The above frequency bands correspond to coherence lengths that satisfy the coherence length conditions specified in the claims for a central wavelength of 1550 nm.

[0036] In this embodiment, the tunable light source 111 has a power of 0 dBm, but good results have been obtained for sources with a power range between -5 dBm and 24 dBm.

[0037] The method according to the present invention is easy to implement if the source is linearly tuned from a well-known initial wavelength (preferably with an accuracy of at least 5 pm) to a known wavelength. The tuning range should exceed 50 pm. The accuracy of the initial setting of the tuning point affects the measurement uncertainty. An error of 1 pm translates into an erroneous reading of approximately 0.8 degrees Kelvin. In this embodiment, the light source 111 is adapted to perform wavelength tuning in a continuous manner, with a range of at least 1 nm.

[0038] In applications where only a few measurement points are required or where monitoring of larger devices is involved, light sources with significantly narrower tuning ranges (even up to 3 pm) can occasionally be used. The maximum theoretical spatial resolution values ​​for typical pairs of tuning time and tuning range are listed in Figure 4 It should be noted that the values ​​actually achievable under real operating conditions occasionally deviate significantly (even by more than an order of magnitude) from the theoretical values. This proves that the redundant system design is sound.

[0039] The measurement fiber 120 should be suitable for addressing a module. It should preferably be a single-mode fiber at the operating wavelength, preferably with a high aperture (i.e., equal to or greater than 0.12). Such an aperture ensures a sufficient level of reverse signal and a permissible level of bending losses. Good results have been achieved with single-mode fiber meeting the requirements of ITU-T Recommendation G.652.

[0040] The fiber optic jacket should be suitable for long-term operation at temperatures up to 85°C. It can be made of, for example, polyamide, aluminum, copper, organically modified ceramic (Ormocer), or gold. In some applications, it is necessary to limit the jacket to the most durable coating that offers a temperature resistance of at least 200°C. For example, copper-based jackets offer a temperature resistance of up to 400°C, while gold-based jackets offer a temperature resistance of up to 600°C.

[0041] In this embodiment, the detector 113 has a power of 8 pW*Hz. -1 / 2The equivalent noise power and 3dB frequency band from 0 to 80kHz of the analog to digital converter. The signal processing system 101 is connected to the detector 113 via an analog to digital converter, and the analog to digital converter has a resolution of at least 8 bits and a sampling rate of at least 0.5MHz. The experiments carried out show that these (or better) parameters of the detector and the converter allow for sufficiently fast and sufficiently accurate signal measurement, so that temperature information can be obtained based on its change using a relatively simple and easily implemented algorithm. The use of a detector with lower equivalent noise power and / or a wider bandwidth and a converter with higher resolution and / or a faster sampling rate will improve the parameters of the device and system according to the present invention.

[0042] Figure 1b Instead of, or in addition to, using single mode fiber, a higher order mode filter 114 may be introduced into the measurement path between the light source 111. It will operate best if placed near the detector 113.

[0043] Another possible alternative solution is to selectively increase the loss of higher order modes before the multimode fiber, or by using special excitation of the multimode fiber in order to efficiently propagate the 1st mode.

[0044] Additionally, a single-mode excitation system 115 may be used between the interferometer and the measurement fiber.

[0045] An alternative to using a polarized light source is to equip the device with a polarizer 116 between the light source 111 and the detector 113. In such a system, it is possible to obtain operation in a system that does not automatically maintain polarization if a polarization splitter and a detector that detects orthogonal polarizations are used, making it possible to obtain a signal by summing the signals from the two orthogonal polarizations.

[0046] In an alternative embodiment, it is possible to use polarization-maintaining fibers that allow the polarization component (polarizer or polarization splitter) to be eliminated from the system. Polarization-maintaining fibers that can be used include, for example, PANDA fibers and bow-tie fibers, or elliptical core fibers known from the prior art (e.g., from the publication entitled "Polarization-maintaining fibers and their applications", Noda J. et al., 1986, Journal of Lightwave Technology, Vol. 4, No. 8).

[0047] The use of an additional ambient temperature sensor 130 connected to the control system 100 facilitates determining an initial temperature T0 for which the current temperature is updated by determining subsequent changes in ΔT. Alternatively or in addition, a system allowing user input of temperature values ​​or a signal receiver from an external device independent temperature sensor may be used.

[0048] The temperature monitoring method according to the invention can be used to detect fire risks by monitoring the temperature in the engine compartment or the battery compartment and by specifying a single threshold value for all measuring points. In such a case, the threshold value is selected from the range of 130°C to 220°C; in this embodiment, it is 175°C. Such a range and value selection requires the use of a more durable housing for the measuring fiber; in this embodiment, a copper-based housing is used. If this value is exceeded, an alarm signal is generated. The use of the device according to the invention allows the indication of the measuring point at which the temperature threshold value is recorded together with the alarm signal. The temperature is monitored using a device according to the invention, the measuring fiber 120 of which is placed in the engine compartment or the battery compartment and in the vicinity of the energy-discharging components; the changes in the measuring points assigned to these components and located on the measuring fiber 120 are then cumulatively updated. This method of analysis requires setting an initial temperature. The initial temperature inside the engine compartment is input into the device according to the invention or is read from the ambient temperature sensor 130, alternatively a signal representing the temperature is received. In Figure 2 The initialization phase 200 in the flowchart shown in FIG. includes setting an initial temperature T0(d) for at least one point throughout the optical fiber. The initial temperature is set at phase 201. It can be manually entered, read from a sensor, averaged from a grid of sensors, or obtained from another independent source (such as a weather station). Then, during a scanning phase 202, the light source 111 is periodically tuned, varying its wavelength in a sawtooth waveform. This could also be a symmetrical waveform with a linear change in wavelength, or another waveform known from the prior art. In subsequent tuning cycles, indexed by a variable n, the temperature change ΔT along the measurement fiber 120 ΔT(d) is iteratively determined 203, and the current value at at least one measurement point within its length is cumulatively updated 204, replacing T(d, t=n)=T(d, t=n-1)+ΔT. In this embodiment, it is compared 205 to a threshold temperature value (175°C). If the temperature T(d, t=n) exceeds the threshold, an alarm is generated 206. Of added value is the ability to indicate the measurement point at which the value exceeds the threshold. The subsequent (n+1) scans are then performed. This method can be performed automatically under the control of the control system 100. It is then equipped with a memory containing a program for executing the method according to the invention using the device according to the invention. The device is then adapted to automatically detect temperature changes as a function of fiber length and time, and preferably generate an alarm.

[0049] In the current iteration and the reference (previous) iteration, the temperature change at a measurement point P located at a distance d from the starting point of the measuring fiber 120 is determined using the prior art OFDR (Optical Frequency Domain Reflectometry) method using the cross-correlation 2 of the signals (temperature change signals). These signals can be determined using the inverse complex Fourier transform of the signals from the investigation section of the optical fiber. Only the beat frequency band present at the detector, corresponding to the spatial resolution, is considered. The shift in the cross-correlation of the two measurements corresponds to the shift in the wavelength of the reproduced reference signal. Various techniques to this effect are presented in Jia Song's master's thesis entitled "Optical Frequency Domain Reflectometry: Sensing Range Extension and Enhanced Temperature Sensitivity", Carleton Institute of Physics, University of Ottawa, Ottawa, Canada, 2014. However, experts in the field can routinely propose other applicable methods for determining temperature using a measuring fiber excited by a light source with a periodically tuned wavelength.

[0050] It is recommended to place the measuring fiber 120 in the engine compartment of the vehicle so that it operates in the immediate vicinity of components that are prone to overheating and can cause fires under certain circumstances, such as, for example: fuel pumps, fuel manifolds, alternators, starters, electronic components of the engine, turbochargers, oil pans. The measuring points on the measuring fiber 120 are selected so that they are placed in the immediate vicinity of these components. Figure 3 The normal operating temperatures of the above-mentioned components are listed in the table shown in . Since these temperatures vary significantly, the fire detection specificity of the system according to the invention can be improved using the method according to the invention and the device according to the invention by using different threshold values ​​for different measuring points P1, P2, P3, P4, P5, P6, P7 of the measuring fiber 120, which are located at various distances from the starting point of the measuring fiber 120. Due to the significant spread of normal operating values, it is reasonable to use different threshold temperature values ​​for different measuring points. Figure 3 The values ​​used in this embodiment are also listed in the table shown in . The criterion of 30°C or more above the normal operating temperature is used. Other more complex criteria can also be proposed, depending on the requirements regarding system specificity and sensitivity in relation to fire risk detection. In particular, to improve specificity, it may be advisable to increase the threshold value with increasing ambient temperature. The choice of fiber optic housing depends on which vehicle components are to be monitored. For example, for monitoring the fuel manifold, generally only a measuring fiber optic with a resistance to temperatures above 70°C is required; monitoring a turbocharger requires a resistance to temperatures of at least 140°C, or higher in some models.

[0051] Each vehicle is individually selected to include the component group whose temperature is to be measured. In addition to the aforementioned, this group can also include the exhaust manifold, air compressor, oil pump, heater unit, AC compressor, wiring harness, and, in the case of electric and hybrid vehicles, the battery, fuel cell, and converter. It's also advisable to analyze energy-generating devices in the passenger area and areas prone to fire risks.

[0052] Preferably, the measuring fiber is equipped with a scale indicating the distance to the starting point of the measuring fiber or to at least one measuring point.Such a solution facilitates the placement of the measuring fiber in the vehicle and the assignment of the measuring points to the vehicle components.

[0053] The use of the system according to the invention makes it possible to detect fire risks and other harmful phenomena associated with temperature increases. In such cases, threshold values ​​relevant to the given phenomenon are used. For example, an exhaust system leak (for example, in the exhaust manifold or turbocharger area) associated with the discharge of hot flue gases constitutes a fault requiring independent intervention. In some cases, hot flue gases can also cause fires in nearby components. A blockage in the air system can increase the pressure in the air compressor and therefore the temperature, which can also lead to fires. A blockage in the pulleys can cause the V-belts to rub against the pulleys, which can lead to fires in these belts.

[0054] Depending on how the measuring fiber is placed, a single component can be assigned to one or more measurement points. By placing the measuring fiber multiple times near a given component (e.g., by winding it), the number of measurement points can be multiplied, and additional criteria for the temperature distribution at these points can be used.

[0055] The device, method, and system can also be used to detect faults associated with reduced device temperatures compared to normal operating temperatures. In such cases, a threshold temperature is determined near the lower range of normal operating temperatures, and conditions where the device's temperature falls below the threshold temperature are detected. Hybrid solutions are also possible, where two threshold temperatures are set and both operating temperatures above the first threshold temperature and below the second threshold temperature are detected, flagging both conditions with appropriate alerts.

[0056] Having read this description, an expert can routinely come up with many alternative solutions regarding the placement of the measuring fibers, the distribution of the measuring points, the threshold temperature values, or setting complex conditions for generating alarms related to the temperature distribution at the measuring points and their relationship to the threshold temperature.

[0057] Having reviewed the requirements and parameters indicated in this specification, a specialist can also routinely propose numerous structural solutions for the subassemblies of the device according to the invention, in particular various types of optical fibers and housings, as well as adequate detectors, light sources, or control systems. The control system can be analog, fully digital, or digital with analog peripherals for generating control waveforms. In particular, the use of signal processors and FPGA circuits is possible for this purpose.

[0058] The method according to the invention can be performed by an operator or in an automated manner.

[0059] These and other inventive execution variants are protected as defined in the appended patent claims.

[0060] The invention also has application in temperature control in battery cooling systems and temperature measurement in passenger spaces or energy resource management systems.

Claims

1. A temperature monitoring device having a detector (113) and a tunable wavelength light source (111) and a control system (100), the control system (100) being adapted to generate a substantially periodic control waveform applied to a control input of the tunable wavelength light source (111), wherein the tunable wavelength light source (111) is connected to a fiber interferometer (112), the fiber interferometer (112) having an arm including a measuring fiber (120), wherein the fiber interferometer (112) is connected to a detector (113), the detector (113) having an output connected to a signal processing module (101), the signal processing module (101) being adapted to identify temperature changes as a function of the fiber length, wherein the coherence length of the tunable wavelength light source (111) is longer than 0.5 m, and the period of the periodic waveform is shorter than or equal to 20 s, and the wavelength tuning range of the tunable wavelength light source (111) is higher than 3 pm, characterized in that The measuring optical fiber (120) is suitable for being placed near an energy-discharging device in a running vehicle and being subjected to the temperature of the energy-discharging device in the running vehicle, and is suitable for providing a Rayleigh scattered signal back to an interferometer (112).

2. The device according to claim 1, characterized in that The connection between the interferometer (112) and the measurement fiber (120) includes a single-mode excitation system (115).

3. The device according to claim 1, characterized in that At least one higher order mode filter (114) is interconnected between the light source (111) and the detector (113).

4. The device according to claim 1, characterized in that At least one polarizer (116) or polarization splitter is located between the light source (111) and the detector (113).

5. The device according to claim 1, characterized in that The detector (113) has a power equal to or less than 60 pW*Hz -1 / 2 The equivalent noise power.

6. The device according to claim 1, characterized in that It further has an analog-to-digital converter with a resolution of at least 6 bits and a sampling rate of at least 20 kHz, and the signal processing module (101) is connected to the detector (113) via the analog-to-digital converter.

7. The device according to claim 6, characterized in that It comprises an ambient temperature sensor (130) connected to a control system (100).

8. A method for temperature monitoring of a vehicle using a temperature sensor (130), comprising the steps of detecting (205) a temperature exceeding a specified threshold and generating (206) an alarm signal if said threshold is exceeded, characterized in that As defined in any one of claims 1 to 7, the step of detecting (205) a temperature exceeding a threshold value is performed with a sensor, and the measuring optical fiber (120) is arranged in the vicinity of the energy-releasing component in the vehicle, Set (201) the initial temperature, then, iteratively determining (203) a temperature change ΔT along the measuring optical fiber (120) in subsequent tuning cycles corresponding to a scanning (202) step of the tunable wavelength light source (111), and cumulatively updating (204) the current temperature value T(d, t=n) of at least one measuring point within the length of the measuring fiber using the determined temperature change ΔT(d) in subsequent tuning cycles to obtain a temperature value to be compared with the threshold value.

9. The method according to claim 8, characterized in that The measuring optical fiber (120) is disposed in the vicinity of at least one component selected from the group consisting of a fuel pump, a fuel manifold, a turbocharger, an exhaust manifold, an alternator, a starter, an air compressor, an oil pump, an oil pan, a heater unit, an AC compressor, an electronic control system, a wiring harness, a battery, and a fuel cell in a vehicle, and at least one measuring point is located in the vicinity of the at least one component.

10. The method according to claim 8, characterized in that The initial temperature is determined (201) by automatic reading of the ambient temperature sensor (130).

11. The method according to claim 8, characterized in that The initial temperature is input into the control system (100).

12. The method according to claim 8, characterized in that The generated alarm signal is selected depending on which point of the measuring optical fiber (120) is the point at which the temperature T(d, t=n) exceeds the threshold temperature.

13. A temperature monitoring system for a vehicle component, the vehicle component comprising a fiber optic device for measuring temperature placed near at least one component, characterized in that The optical fiber device is a temperature monitoring device as defined in any one of claims 1 to 7.

14. The system according to claim 13, wherein: The measurement fiber (120) operates in proximity to at least one component selected from the group consisting of a fuel pump, a fuel manifold, a turbocharger, an exhaust manifold, an alternator, a starter, an air compressor, an oil pump, an oil pan, a heater unit, an AC compressor, an electronic control system, an electrical wiring harness, a battery, and a fuel cell.

15. A computer program product suitable for temperature monitoring, characterized in that It comprises an instruction set for a control system (100) of a temperature monitoring device as defined in any one of claims 1 to 7, with which a method as defined in any one of claims 8 to 12 is executed.

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