Method for monitoring and / or identifying a degradation in a distance-measuring system of an infrastructure system
Patent Information
- Application Number
- EP2024718054
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2023-04-01
- Filing Date
- 2024-03-28
- Publication Date
- 2026-02-11
AI Technical Summary
Existing methods fail to distinguish between degradation of infrastructure systems and restrictions in visibility, as both can cause similar effects on distance measuring systems, making it difficult to determine the cause of deviations from expected measurement results under adverse conditions.
A method that uses a distance-measuring system with a laser diode arrangement to emit electromagnetic waves, where the wavelength can be changed, allowing for repeated measurements with different wavelengths to differentiate between degradation and restricted visibility by comparing results to a distribution curve, indicating degradation if measurements remain consistently off-range and visibility restriction if results change with wavelength variations.
Effectively identifies and distinguishes between infrastructure system degradation and visibility restrictions, ensuring accurate fault detection and maintenance by differentiating between real faults and natural events affecting measurement accuracy.
Smart Images
Figure EP2024058441_10102024_PF_FP_ABST
Abstract
Description
[0001] Method for monitoring and / or detecting degradation of a distance measuring system of an infrastructure facility
[0002] The invention relates to methods for monitoring and / or detecting degradation of a distance measuring system of an infrastructure facility.
[0003] From the generic document DE 10 2021 002 099 A1 a method for monitoring and / or detecting a sensor system of a vehicle and / or a vehicle by means of an infrastructure system is known, wherein in order to achieve further optimization in the said field(s), it is proposed that the visibility conditions are additionally determined by means of the infrastructure system, for which purpose the method steps are carried out and / or applied analogously to the detection of a degradation of the transmitting device.
[0004] In general, it can be stated that infrastructure facilities are becoming increasingly important, or rather, instead of the previous preferred monitoring functions and information provision functions, infrastructure facilities will in future increasingly be designed to communicate with vehicles passing through the infrastructure, so that, for example, a bidirectional exchange of information / data between an infrastructure facility and the vehicles passing through the infrastructure is enabled.
[0005] Sensors are used in vehicles and their correct functioning must be ensured.
[0006] DE 10 2016 000 532 A1 proposes calibrating a vehicle device, such as a speedometer, using a traffic monitoring device.
[0007] From document DE 10 2018 106 594 A1, a method for monitoring and / or detecting a sensor system of a vehicle is known. This method comprises a step of determining a parameter value using a response signal, and a step of determining a monitoring signal assignable to the sensor system using the parameter value and a predetermined reaction value. As further disclosed in document DE 10 2018 106594 A1, the method may comprise a transmission step in which at least one signal causing the excitation event is transmitted using the excitation signal. Such a signal may be an acoustic and / or an electromagnetic signal. A suitable transmission device, for example a light source, may be used to transmit such a signal. In this way, the excitation event can be triggered very quickly and easily.For example, in the transmission step, a light pulse can be transmitted in the direction of the vehicle as the electromagnetic signal. Such a light pulse can, for example, simulate an oncoming vehicle, so that the response reaction can be a reaction of the vehicle's adaptive vehicle lighting. A light curtain or radiation wave curtain appearing in front of the vehicle can also be transmitted as the electromagnetic signal. For this purpose, a laser, for example, can be suitably controlled using the excitation signal. In this way, an obstacle located in front of the vehicle can be simulated, so that the response reaction can be a braking maneuver or a steering maneuver of the vehicle.
[0008] Since the future development trend is towards autonomous or semi-autonomous ferry operations, it must be ensured that the technology involved, particularly in the form of sensors, functions as error-free as possible with a very high level of reliability. This does not only include the vehicle-side sensors, but also, in particular, the sensors of stationary and / or mobile monitoring devices, by means of which a vehicle-side sensor system is monitored.
[0009] The solution to the document DE 10 2018 106 594 A1 implicitly assumes that the functionality of the monitoring device used functions 100% within the specified parameters, or the observer remains in the dark as to how it is technically guaranteed that the monitoring device functions 100% within the specified parameters over its service life and / or functions perfectly even under adverse environmental conditions.
[0010] As is known from DE 102018214831 A1, laser diodes in optical systems, for example, are often operated at their maximum load, which can often lead to aging effects or degradation over their lifetime. During degradation, the luminous flux (lumens) of the laser diode typically decreases continuously over time, so that the originally specified parameters can drift away over the lifetime and negatively impact the correct functioning of the optical system.
[0011] The (generic) documents cited as examples in the assessment of the prior art, as well as the following document DE 10 2006 052 770 B4, or the methods and devices disclosed therein, are an integral part of the present invention and are representative of other generic / generic documents.
[0012] In addition to technical problems, especially degradation, adverse environmental conditions, as already mentioned above, can also negatively influence the correct functioning of an optical system / laser system / lidar system.
[0013] Adverse environmental conditions include, in particular, weather-related influences such as fog, snowfall or heavy rain, which can have a severely negative impact on visibility and thus also on functionality.
[0014] A solution to the problem is already known from the generic document DE 10 2021 002 099 A1, although the observer remains somewhat unclear as to how a "degradation of the infrastructure facility" is to be distinguished from a "restriction of visibility".
[0015] Object of the invention:
[0016] The object of the invention can be seen in presenting a solution for an improved method for monitoring and / or detecting a degradation of a distance measuring system of an infrastructure facility.
[0017] Solution to the task:
[0018] The object is achieved by a method for monitoring and / or detecting degradation of a distance-measuring system of an infrastructure facility according to independent claim 1. Advantageous further developments are specified in the dependent claims, whereby combinations not described in detail or resulting logical developments obvious to the person skilled in the art are also included. Description of the invention:
[0019] In order to achieve further optimization in the field of monitoring and / or detecting a degradation of a distance-measuring system of an infrastructure facility, wherein the infrastructure facility is also designed to communicate with vehicles passing through the infrastructure, wherein the distance-measuring system of the infrastructure facility has a transmitting device and is designed to detect a degradation of the transmitting device, a method is proposed, wherein the method comprises at least the following steps: a) transmitting a transmitted signal with the transmitting device, b) detecting a received signal scattered back from the vehicle, c) determining the distance to the vehicle based on the received signal and d) determining a degree of degradation based on the determined distance to the vehicle and / or the received signal strength of the received signal, which is characterized in thatthat the transmitting device of the distance-measuring system of the infrastructure facility comprises a laser diode arrangement for emitting a transmission signal in the form of electromagnetic waves, in which the wavelength of the emitted electromagnetic wave is variable.
[0020] The actual problem that has not yet been solved is how to distinguish between a "degradation of the infrastructure" and a "restriction of visibility", since both events can have the same effect and therefore it is necessary to clarify in more detail, for example by means of evidence, which event is actually causal in the case of a deviation from / in relation to the expected distribution curve tolerance range.
[0021] A restriction of visibility or a restriction of visibility conditions (both expressions are synonymous) always occurs when, for example, adverse environmental conditions prevail. Adverse environmental conditions, in the context of the invention, are primarily understood to mean weather-related influences such as fog, snowfall, spray, or heavy rain. The cause of this is determined a) in the event of a deviation of the measurement results from an expected distribution curve tolerance range, orb) if the determined distance of the vehicle at the time of initial detection and / or the received signal strength of the received signal at a defined distance of the vehicle are not within the expected distribution curve tolerance range, this is of great importance for the operator of an infrastructure facility, since a "degradation of the infrastructure facility" is a real fault of the infrastructure facility which must be rectified by service, whereas a "restriction of visibility" is a natural event and not a fault of the infrastructure facility.
[0022] A "limited visibility" has a negative impact on the measurement results, although these negative effects are initially indistinguishable from, or comparable to, a "degradation of the infrastructure facility." In adverse or limited visibility conditions (e.g., fog, snowfall, spray, or heavy rain), the "detection range" decreases significantly. The light signals or laser beams are significantly attenuated in fog and high humidity / spray, which correspondingly reduces the range of a laser system (lidar system). This reduction in range due to limited visibility has the same effect, or leads to the same effect, or is comparable to, that of degradation of the transmitting device.The term “degradation of the transmitting device” is to be understood in the broadest sense also to mean a weakened receiving device, since such an error has the same effect.
[0023] In an advantageous embodiment of the invention, the method for monitoring and / or detecting a degradation of a distance-measuring system of an infrastructure facility is characterized in that an indication of a detection of a degradation is always recognized when the determined distance of the vehicle at the time of the initial detection and / or the received signal strength of the received signal at a defined distance of the vehicle are not within the expected distribution curve tolerance range.
[0024] In an advantageous embodiment of the invention, the method for monitoring and / or detecting a degradation of a distance-measuring system of an infrastructure facility is characterized in that each measuring point of the distance-measuring system (or the received signal strength) is assigned to a typical distance by means of a distribution curve, wherein a shift of the distribution curve (away from the expected tolerance range) in the direction of a smaller distance is an indication of an aging effect or degradation in the transmitter and / or receiver.
[0025] In an advantageous embodiment of the invention, the method for monitoring and / or detecting a degradation of a distance-measuring system of an infrastructure facility is characterized in that, if there is an indication of a detection of a degradation based on the method steps carried out by means of a first wavelength, the method steps are carried out at least once more based on a wavelength that is different from the first wavelength.
[0026] In an advantageous embodiment of the invention, the method for monitoring and / or detecting a degradation of a distance-measuring system of an infrastructure facility is characterized in that the laser diode arrangement for emitting a transmission signal consists of a single laser diode and / or a laser diode array, wherein the wavelength of the emitted electromagnetic waves is variable.
[0027] In an advantageous embodiment of the invention, the method for monitoring and / or detecting a degradation of a distance-measuring system of an infrastructure facility is characterized in that the laser diode arrangement for emitting a transmission signal consists of at least two single laser diodes and / or at least two laser diode arrays that can be activated independently of one another, wherein the wavelengths of the independently emitted electromagnetic waves are different from one another.
[0028] In an advantageous embodiment of the invention, the method for monitoring and / or detecting a degradation of a distance-measuring system of an infrastructure facility is characterized in that the indication of a detection of a degradation is positively confirmed if the method steps carried out by means of a first wavelength and a wavelength changed compared to the first wavelength produce identical to almost identical results in relation to the distribution curve and / or to each other.In an advantageous embodiment of the invention, the method for monitoring and / or detecting a degradation of a distance-measuring system of an infrastructure facility is characterized in that the indication of a detection of a degradation is negated, and instead of a detection of a degradation, an indication of a restriction of the visibility conditions is detected if the method steps carried out by means of a first wavelength and a wavelength changed compared to the first wavelength produce deviating results in relation to the distribution curve and / or to one another.
[0029] In an advantageous embodiment of the invention, the method for monitoring and / or detecting a degradation of a distance-measuring system of an infrastructure facility is characterized in that the indication of a detection of a degradation is positively confirmed if the method steps carried out by means of a first wavelength and a wavelength changed compared to the first wavelength produce deviating results in relation to the distribution curve and / or to each other.
[0030] In an advantageous embodiment of the invention, the method for monitoring and / or detecting a degradation of a distance-measuring system of an infrastructure facility is characterized in that the indication of a detection of a degradation is negated, and instead of a detection of a degradation, an indication of a restriction of the visibility conditions is detected if the method steps carried out by means of a first wavelength and a wavelength changed compared to the first wavelength produce identical to almost identical results in relation to the distribution curve and / or to one another.
[0031] Knowing the cause of the measurement results, i.e., the determined distance of the vehicle at the time of initial detection and / or the received signal strength at a defined vehicle distance, not being within the expected distribution curve tolerance range, is very important, as it is determined whether "degradation of the infrastructure" or "restricted visibility" is the cause. This is because "degradation of the infrastructure" is a genuine fault of the infrastructure that requires maintenance, whereas "restricted visibility" is a natural phenomenon and not a fault of the infrastructure. In other words:
[0032] A differentiation regarding the "detection of degradation" and the "detection of a restriction of visibility" is advantageous or of great importance for the operator of the infrastructure facility, since although these events can (and do) produce identical results, a "degradation of the infrastructure facility" is a real fault of the infrastructure facility that must be remedied by service, whereas a "restriction of visibility" is a natural event and not a fault of the infrastructure facility.
[0033] For the sake of clarity, it should be noted that the phrase “identical to almost identical results in relation to the distribution curve and / or to each other” is to be understood as meaning that the two measurements with different wavelengths are very close to each other in terms of results, but in relation to the distribution curve, both measurements have a certain or significant (but almost identical) distance to the distribution curve.
[0034] Deviating from the above, the wording “differing results in relation to the distribution curve and / or to each other” is to be understood in such a way that the two measurements with different wavelengths are NOT very close to each other in terms of results, or show a certain or significant difference, and also in relation to the distribution curve at least the first measurement has a certain different distance to the distribution curve.
[0035] As the two preceding paragraphs show, in relation to the distribution curve, at least the first of the two measurements with different wavelengths always shows a certain distance from the distribution curve, since otherwise there would (would) be no repeated measurement at all with a wavelength different from the first wavelength.
[0036] The invention is explained in more detail below using Figures 1 to 4 as examples. The figures and the values mentioned or derived therein (if any) are only examples and serve to facilitate understanding.
[0037] All figures are only schematic representations (not to scale). They show schematically:
[0038] Figure 1: a schematic representation of an excitation event for monitoring a sensor system of a vehicle, based on the prior art according to the document DE 10 2018 106 594 A1;
[0039] Figure 2: a principle representation of an evaluation option, based on the
[0040] State of the art according to document DE 10 2018 214 831 A1 ;
[0041] Figure 3: a schematic flow diagram;
[0042] Figure 4: a schematic diagram of possibilities to use one or more
[0043] Laser diodes of a laser diode arrangement are able to generate different wavelengths or to vary the emitted electromagnetic wave, according to document DE 102006 052 770 B4;
[0044] To avoid repetitions, especially repetitions of technical descriptions, the above-mentioned
[0045] (generic / generic) documents, or the methods and devices / solutions disclosed therein, which are a full part of the present invention.
[0046] Figure 1 shows a schematic representation of an excitation event for monitoring a vehicle's sensor system, based on the prior art according to document DE 10 2018 106 594 A1. As can be seen from Figure 1, an infrastructure facility (112) is located at the edge of a roadway (130) on which a vehicle (100) travels. The vehicle (100) is equipped with a sensor system (104), designed as an optical environment detection system (in particular a camera), in order to monitor the traffic space in the direction of travel. Furthermore, the vehicle (100) is provided with an (optical or radio-based) communication interface (107) in order to be able to send or transmit a response signal (120) or communication signal (120) to the receiving device (118) of the infrastructure facility (112).As can be further seen from Figure 1, the (optical or radio-based) communication interface (107) is connected internally to the vehicle with an internal vehicle interface (108) or vehicle bus connection (108) with the sensor system (104). As can be further seen from Figure 1, the infrastructure system (112) has a transmitting device (114) in order to generate / transmit signals (116), for example in the form of an “invisible” laser curtain as an excitation event (102), or as a communication signal, or as a signal for a communication / communication interface. The infrastructure system (112) can also be generally referred to as a device (110), whereby for reasons of clarity, the “inner workings” (e.g. internal interfaces) of the infrastructure system (112) are not shown in detail. Likewise, the process of calibration orthe exact process of monitoring and / or detecting a sensor system (104) of a vehicle (100) with the aid of an infrastructure system (112) is not described in more detail, since this is already disclosed in detail in the generic document DE 10 2018 106 594 A1.
[0047] As can also be seen from Figure 1, the transmitting device (114) located in the infrastructure system (112) can also be designed as a bidirectional transceiver in order to receive the transmitted signal (116) (e.g., laser pulse(s)) and the received signal (117) backscattered by the vehicle (100) and to provide them internally for further processing. Alternatively, the transmitted signal (116) and the received signal (117) backscattered by the vehicle (100) can also be received by the receiving device (118) in order to provide them internally for further processing.
[0048] As can be further seen from Figure 1, the vehicle (100) passes the infrastructure facility (112) when the vehicle (100) continues its travel (in the direction of travel of the vehicle (100)) past the infrastructure facility (112) located at the side of the road. Driving underneath, for example, a road-spanning infrastructure facility also constitutes a passing.
[0049] Figure 2 shows a schematic diagram of an evaluation option based on the prior art according to DE 10 2018 214 831 A1. As can be seen from Figure 2, the results (in the form of points) of several (distance) measurements are shown, which were generated, for example, by the distance-measuring system (114, 118). Each measurement point of the distance-measuring system (114, 118) (or the received signal strength) is assigned to a typical distance using a distribution curve. Furthermore, the two variants (V1 and V2) for degradation detection are shown in a highly simplified manner using the white arrows.
[0050] The term "distance-measuring system (114, 118)" is to be understood as a system function which arises from the fact that a signal (116) is transmitted by means of the transmitting device (114) of the infrastructure facility (112), wherein the transmitted signal (116) is "reflected" by the vehicle (100) and is received as a backscattered received signal (117) by a receiving device (118) or transmitting / receiving device (114), wherein the distance (a) I the distance (a) between the vehicle and the infrastructure can be physically determined based on a runtime evaluation (time between transmission and reception).
[0051] As can be further schematically seen in Figure 2 (already documented in DE 10 2018 214 831 A1), the aging effect or degradation, i.e., a weakening of the transmitting unit and / or a reduction in the reception sensitivity of the receiving unit of the distance-measuring system, can be determined based on the first detection of the object, i.e., the initial detection. According to this fact, the degradation or aging effect can be reliably detected or detected during the vehicle's service life using two variants (V1, V2).
[0052] As can be seen schematically from Figure 2, in the first variant (V1) there is a shift in the distribution curve of the values (W1) in the direction of detection at a shorter distance when there is a “degradation in the transmitting device (114)” (in the broadest sense this is also a weakened receiving device (114, 118)), so that the initial detection when a vehicle is detected for the “first time” shifts towards a shorter distance.
[0053] As can be further schematically seen in Figure 2 (already documented in document DE 10 2018 214 831 A1), the aging effect / a "degradation of the transmitting device (114)" can also occur according to the second variant (V2) as an alternative or in addition to the first variant (V1). In variant (V2), a statistical evaluation is performed such that a typical distance with a corresponding distribution can be derived based on a defined received signal strength.
[0054] In both variants (V1, V2) this means (conversely) that if the distribution curve shifts (away from the expected tolerance range) towards a smaller distance, there is an aging effect or degradation in the transmitter and / or receiver.
[0055] A further functional explanation / figure description is omitted here, as this is already disclosed in detail in the generic document DE 10 2018 214 831 A1. A key difference between the present application and document DE 10 2018 214 831 A1 is that the "distance-measuring system (114, 118)" is located in an infrastructure system (112), for example, in a stationary infrastructure system (112) and / or a mobile infrastructure system integrated into a surveillance vehicle, whereas in document DE 10 2018 214 831 A1 the "distance-measuring system" is located in a vehicle (which follows a vehicle traveling ahead, so that in document DE 10 2018 214 831 A1 the distance between the two vehicles is determined).
[0056] In the light of the invention, the tolerance range is to be understood as the range which, in a fault-free state and with unrestricted visibility, corresponds to an expected target result (TARGET-E) of received signal strength (y) at a corresponding distance (a, x), wherein the expected target result (TARGET-E) is provided with a corresponding tolerance band to compensate for measurement tolerances.
[0057] The symbol (*1) in Figure 2 shows a typical distance at which a vehicle is detected for the “first time” (with a low reception signal strength) when a vehicle (100) approaches the infrastructure facility (112).
[0058] The symbol (*2) in Figure 2 shows a typical distance that results at a defined reception signal strength when a vehicle (100) approaches the infrastructure facility (112).
[0059] In the light of the invention, the expression "substantial agreement of the results" or "within the expected tolerance range" is to be understood as a range which corresponds approximately to less than or equal to 10% (or 20%) of permissible deviation, or when the deviation of the results from each other (or as expected) is not greater than 10% (or 20%).
[0060] The expression "greater deviation of the results" "outside the expected tolerance range" is to be understood in the light of the invention as a range which corresponds approximately to greater than or equal to 20% (or 30%) of permissible deviation, or when the deviation of the results from each other (or as expected) is greater than 20% (or 30%).
[0061] Figure 3 shows a schematic flow diagram of the method according to the invention, from which the result derivation (cause-indicator determination) can be seen with regard to the cause decision of a "degradation" or "restriction of visibility" if the determined distance (a) of the vehicle (100) at the time of the initial detection and / or the received signal strength of the received signal (117) at a defined distance (a) of the vehicle (100) are not in the expected distribution curve tolerance range.
[0062] As can be seen from Figure 3, method steps a) to d) are carried out at a first wavelength by the distance-measuring system of the infrastructure facility (112). If the measured values are within the expected distribution curve tolerance range, there is no indication of an aging effect or degradation in the distance-measuring system of the infrastructure facility (112), or no indication of this is detectable, so the process of "detecting a degradation of the transmitting device (114)" can be completed / terminated.
[0063] As can be further seen from Figure 3, the process steps a) to d) are repeated if the measured values with the first wavelength are not within the expected distribution curve tolerance range, whereby in the repeating process steps a) to d) a different wavelength than the first wavelength is used.
[0064] This is followed by a comparison of the measured values resulting from the measurements of process steps a) to d) with different wavelengths, whereby the type of wavelength change (variable according to Figure 4a OR different according to Figure 4b) plays a decisive role.
[0065] As can be further seen from Figure 3, with a changed wavelength according to Figure 4a, a comparison of measured values resulting from the measurements of method steps a) to d) with different wavelengths is carried out, a) whereby in the case of equality or near agreement, an indication of the detection of degradation is concluded, b) whereas in the case of a lack of agreement or differences, instead of a detection of degradation, an indication of a restriction of the visibility conditions is recognized / concluded.
[0066] This decision logic is based on the realization that if a laser diode degrades, the measurement results remain consistently poor even at different wavelengths (they consistently deviate from the expected distribution curve tolerance range). However, if restricted visibility is the cause of the deviation from the expected distribution curve tolerance range, measurements at different wavelengths can certainly change the result. As can be seen from Figure 3, if the wavelength changes according to Figure 4b, a comparison of the measured values resulting from the measurements in process steps a) to d) with different wavelengths is carried out. a) If there is a lack of agreement ordifferences, an indication of a detection of degradation is inferred, b) whereas similarity or near agreement, instead of a detection of degradation, is recognized / inferred as an indication of a restriction of visibility.
[0067] This decision logic is based on the realization that in the case of degradation of a laser diode, the measurement results at different wavelengths (of different laser diodes) are different (deviating to a different extent from the expected distribution curve tolerance range), whereas in the case of restricted visibility as the cause of the deviation from the expected distribution curve tolerance range, measurements with different wavelengths usually result in consistent deviations, or the deviations will not be nearly as large as would be the case with degradation of one of the two laser diodes.
[0068] Figure 4 shows a schematic diagram of possibilities for generating different wavelengths by means of one or more laser diodes of a laser diode arrangement (115), or for varying the emitted electromagnetic wave.
[0069] The left illustration (Figure 4a) of Figure 4 shows a basic representation of a possibility for the targeted variation / influence of the laser wavelength of a laser diode arrangement.
[0070] The right illustration (Figure 4b) shows further possibilities for generating different wavelengths using a laser diode arrangement.
[0071] For the sake of clarification, it should be noted that the phrase “in which the wavelength of the emitted electromagnetic wave is variable” means that measurements are carried out with different wavelengths (based on a wavelength that is different from the first wavelength), wherein the wavelength change a) can be realized both by a laser diode arrangement (115), in which a change in the wavelength takes place by means of a laser diode with a variable wavelength according to Figure 4a, b) can be realized by a laser diode arrangement (115), in which the change in the wavelength takes place by means of several independently controllable laser diodes with different wavelengths according to Figure 4b.
[0072] The left-hand illustration (Figure 4a) of Figure 4 shows (as already described in DE 10 2006 052 770 B4) a basic representation of a possibility for the targeted variation / influence of the laser wavelength, as can be brought about by tempering (heating / cooling) the laser transmitting diode. As can be seen from Figure 4a, the temperature of the laser diode can be varied / influenced / changed by installing a) one or more heating elements (141), for example in the form of a resistor / multiple resistors, and / or b) one or more cooling elements (140), for example in the form of a Peltier element / multiple Peltier elements, near the laser diode / laser diode arrangement.
[0073] As is further stated in document DE 10 2006 052 770 B4, the wavelength of the laser diode can be varied by approximately 0.2 nm per degree Celsius by heating or cooling the laser diode.
[0074] The right-hand illustration (Figure 4b) of Figure 4 shows (as already described in DE 10 2006 052 770 B4) a basic illustration or visualization of further possibilities for generating different wavelengths using a laser diode array. As can be seen from Figure 4b, the physical body of the laser diode array contains two active laser elements with different wavelengths, which can be operated independently of one another depending on the internal electrical circuitry, either separately or anti-parallel (by applying the supply voltage in the corresponding flow direction). A configuration of a laser diode array with two active laser elements with different wavelengths is always a preferred configuration when a larger wavelength difference, ora greater variability between the individual wavelengths is sought, since using the method according to the left illustration (Figure 4a), due to temperature limits that must be observed, only a change in the wavelengths relative to each other (first wavelength AND deviating wavelength) with limited variability is possible.
[0075] All features and / or parts of the features of the dependent claims or the description may be applied and / or combined with (one or more of) the independent claims, even if this embodiment(s) is / are not explicitly described or shown as an example in the description. Likewise, the individual features of the independent claims may also be applied and / or combined with each other.
[0076] List of reference symbols:
[0077] 100 vehicles
[0078] 102 Excitation event
[0079] 104 Sensor technology
[0080] 107 Communication interface
[0081] 108 in-vehicle interface / bus connection
[0082] 110 Device
[0083] 112 Infrastructure facility
[0084] 114 Transmitting device (pattern and / or signal for communication / communication interface)
[0085] 115 laser diode array
[0086] 116 Signal (e.g. laser signal / electromagnetic signal)
[0087] 117 reception signal scattered back from the vehicle (100)
[0088] 118 Receiving device (communication interface)
[0089] 120 Response signal / communication signal
[0090] 130 roadway
[0091] 140 cooling element, e.g. Peltier element
[0092] 141 Heating element, e.g. resistance a Distance between infrastructure system and vehicle
[0093] TARGET RESULT / TARGET RESULT CURVE
[0094] W1 values of a distribution curve
[0095] W2 values of a distribution curve
[0096] V1 Variant 1
[0097] V2 Variant 2
Claims
1. A method for monitoring and / or detecting a degradation of a distance-measuring system of an infrastructure facility (112), wherein the infrastructure facility (112) is also designed to communicate with the vehicles (100) passing through the infrastructure, wherein the distance-measuring system of the infrastructure facility (112) has a transmitting device (114) and is designed to detect a degradation of the transmitting device (114), wherein the method comprises at least the following steps: a) transmitting a transmitted signal (116) with the transmitting device (114), b) detecting a received signal (117) scattered back from the vehicle (100), c) determining the distance (a) to the vehicle based on the received signal (117) and d) determining a degree of degradation based on the determined distance (a) to the vehicle (100) and / or the received signal strength of the received signal (117), characterized in that the transmitting device (114) of the distance-measuring system of the infrastructure facility has a laser diode arrangement for emitting a transmitted signal (116) in the form of electromagnetic waves, in which the wavelength of the emitted electromagnetic wave is variable.
2. Method according to claim 1, characterized in that an indication of a detection of degradation is always recognized when the determined distance (a) of the vehicle (100) at the time of the initial detection and / or the received signal strength of the received signal (117) at a defined distance (a) of the vehicle (100) are not in the expected distribution curve tolerance range.
3. Method according to one of claims 1 to 2, characterized in that by means of a distribution curve each measuring point of the distance-measuring system (114, 118) (or the received signal strength) is assigned to a typical distance, wherein a shift of the distribution curve (away from the expected tolerance range) in the direction of a smaller distance is an indication of an aging effect or degradation in the transmitter and / or receiver.
4. Method according to one of claims 1 to 3, characterized in that, if there is an indication of detection of degradation based on the method steps carried out by means of a first wavelength, the method steps are carried out at least once more based on a wavelength which is different from the first wavelength.
5. Method according to one of claims 1 to 4, characterized in that the laser diode arrangement for emitting a transmission signal (116) consists of a single laser diode and / or a laser diode array, wherein the wavelength of the emitted electromagnetic waves is variable.
6. Method according to one of claims 1 to 4, characterized in that the laser diode arrangement for emitting a transmission signal (116) consists of at least two single laser diodes and / or at least two laser diode arrays which can be activated independently of one another, wherein the wavelengths of the independently emitted electromagnetic waves are different from one another.
7. Method according to one of claims 1 to 5, characterized in that the indication of a detection of degradation is positively confirmed if the method steps carried out by means of a first wavelength and a wavelength changed compared to the first wavelength produce identical to almost identical results in relation to the distribution curve and / or to one another.
8. Method according to one of claims 1 to 5, characterized in that the indication of a detection of degradation is negated, and instead of a detection of degradation an indication of a restriction of the visibility conditions is recognized if the method steps carried out by means of a first wavelength and a wavelength changed compared to the first wavelength produce results that differ from one another in relation to the distribution curve and / or to one another.
9. Method according to one of claims 1 to 4 and 6, characterized in that the indication of a detection of degradation is positively confirmed if the method steps carried out by means of a first wavelength and a wavelength changed compared to the first wavelength produce results that differ from one another in relation to the distribution curve and / or to one another.
10. Method according to one of claims 1 to 4 and 6, characterized in that the indication of a detection of degradation is negated, and instead of a detection of degradation, an indication of a restriction of the visibility conditions is recognized if the method steps carried out by means of a first wavelength and a wavelength changed compared to the first wavelength produce identical to almost identical results in relation to the distribution curve and / or to one another.