DE102020125845A1 - Method for determining an operating condition of a vehicle tire, evaluation unit, vehicle and method for controlling the vehicle - Google Patents

Abstract

The invention relates to a method for determining an operating state of a tire (4) of a vehicle using at least one gas sensor arranged on the vehicle, with at least the following steps:- detecting gaseous substances (Sn; n=1,2,3,... ) in a sensor environment of the gas sensor;- determining whether at least one indicator substance (SI) can be detected as a gaseous substance (Sn) in the sensor environment of the gas sensor, the at least one indicator substance (SI) depending on a tire temperature (T4) such is secreted from the tire (4) so that the indicator substance (SI) can only be detected if an operating state to be determined is present as a result of a change in the tire temperature (T4) in the sensor environment (U);- creating a detection result if an indicator substance (SI) can be detected in the sensor environment (U); and- determining and/or outputting the operating state of the tire (4) as a function of the detection result.

Description

The invention relates to a method for determining an operating state of a tire of a vehicle, an evaluation unit, a vehicle and a method for controlling the vehicle.

In connection with automated or autonomous driving, more and more tasks are being transferred from the driver to the respective automated or autonomous system. For this purpose, the human senses are simulated by monitoring systems in the vehicle that have sensors, for example with the help of cameras and image processing systems.

However, certain states of the vehicle are difficult to detect, especially while driving, for example if they affect the chassis, the drive or the wheels of the vehicle, for example overheating of the engine or the brakes or the tires. Normally, such operating states can be detected by the driver, for example by smelling, since gaseous substances escape in such operating states, which can be perceived through the nose. If no driver is present in an automated vehicle or if the driver is not attentive, this sensory perception cannot be used. A visual perception is usually only given when it is too late, i.e. when a tire is already on fire, for example. It is therefore desirable that a critical operating condition, which can lead to a burning tire, for example, can be recognized at an early stage.

Gas sensors are already known from the prior art, for example from CN 206339536 U . In KR 100559320 B1 is also described as using gas sensors inside or outside the vehicle to detect dangerous substances outside or a gaseous substance due to a fire outside or inside the vehicle. In US2011089255A1 it is described that when a foul smell is detected in the vehicle environment, a specific gaseous substance is released in the vehicle in order to compensate for the foul smell.

In DE 10 2018 116 282 A1 also describes detecting odors or gaseous substances and, depending on this, using a fingerprint composition to conclude that a component of the vehicle has failed or is about to fail and thus to a (pre)critical operating state. For example, gaseous substances are used that are produced when conventional rubber is burned, such as sulfur dioxide. The disadvantage here is that such gaseous substances are not only produced when rubber is burned. Rather, the respective gaseous substance can also occur naturally, ie without a (pre)critical operating state of the respective component being present. In US10118577B1 is also described to monitor whether a space in the vehicle is occupied by a person or an object, with odors in particular being detected by a gas sensor.

The object of the invention is to specify a method with which an operating state of a tire can be specified in a simple and reliable manner. The object of the invention is also to specify an evaluation unit for a vehicle and a method for controlling the vehicle.

This object is achieved by two methods, an evaluation unit and a vehicle according to the independent claims. The dependent claims indicate preferred developments.

• - Detektieren von gasförmigen Stoffen in einer Sensorumgebung des Gassensors;
• - Ermitteln, ob in der Sensorumgebung des Gassensors als gasförmiger Stoff mindestens ein Indikatorstoff nachgewiesen werden kann, wobei der mindestens eine Indikatorstoff in Abhängigkeit einer Reifen-Temperatur derartig aus dem Reifen abgesondert wird, dass sich der Indikatorstoff lediglich bei Vorliegen eines zu ermittelnden Betriebszustandes, vorzugsweise ausschließlich bei Vorliegen eines vorkritischen und/oder eines kritischen Betriebszustandes, infolge einer Veränderung der Reifen-Temperatur in der Sensorumgebung nachweisen lässt (und sonst, z.B. in einem unkritischen Betriebszustand, nicht), so dass eindeutig auf den zu detektierenden Betriebszustand geschlossen werden kann, wenn ein Nachweis des Indikatorstoffes in der Sensorumgebung erfolgt ist (oder gerade nicht erfolgt ist);
• - Erstellen eines Detektionsergebnisses, wenn ein Indikatorstoff in der Sensorumgebung nachgewiesen werden kann; und
• - Ermitteln und/oder Ausgeben des Betriebszustandes des Reifens in Abhängigkeit des Detektionsergebnisses.

According to the invention, a method for determining an operating state of a tire of a vehicle using at least one gas sensor arranged on the vehicle, in particular a molecular mass sensor, is provided, which has at least the following steps:

• - Detecting gaseous substances in a sensor environment of the gas sensor;
• - Determine whether at least one indicator substance can be detected as a gaseous substance in the sensor environment of the gas sensor, with the at least one indicator substance being separated from the tire as a function of a tire temperature in such a way that the indicator substance only changes when an operating state to be determined is present, preferably only in the presence of a pre-critical and/or a critical operating state as a result of a change in the tire temperature in the sensor environment (and not otherwise, e.g. in a non-critical operating state), so that the operating state to be detected can be clearly inferred if the indicator substance has been detected (or has not just been detected) in the sensor environment;
• - Creating a detection result if an indicator substance can be detected in the sensor environment; and
• - Determining and / or outputting the operating state of the tire depending on the detection result.

This makes use of the fact that the tire separates out certain clearly identifiable indicator substances during warm-up, which only occur when the respective operating state is present, since chemical and physical changes in the material of the tire only result from the warm-up. As a result, gaseous substances are separated from selected aromatic substances in the material of the tire, which can be perceived as indicator substances outside the tire. Therefore, when detected by the gas sensor, these indicator substances can advantageously be used as indicators that can directly and unambiguously indicate the operating condition of the tire.

Only the gaseous substances are understood as indicator substances, which are separated from the tire exclusively under certain (pre)critical conditions or exclusively in certain (pre)critical operating states that are predetermined by the tire temperature and from which a somehow kind of dependency on the tire temperature results. If an indicator substance is detected in the sensor environment, an operating condition of the tire can then be clearly derived, since the indicator substance is not secreted naturally, i.e. if the respective (pre)critical operating condition of the tire is not present. For example, gaseous substances that are always separated out regardless of temperature and to which no operating state can be clearly assigned per se, such as plasticizers (sulphur dioxide), are not indicator substances within the meaning of the invention.

Preferably, tire-specific indicator substances are used, with a tire-specific indicator substance being either added specifically as an additional substance to the tire compound during or after manufacture of the tire or already being part of a conventional tire compound. As a result, a gaseous substance can be used as the indicator substance, which is only excreted from the tire in the relevant operating states, so that when the indicator substance is detected in the sensor environment, it can be assumed with a high degree of probability that it comes from the tire.

If a tire has warmed up, for example due to active heating up through internal material friction or passive heating up via the rim or a surface on which the tire rolls, this can be detected via the indicator substances before the tire starts to burn. Instability of the tire, for example in the sidewalls, due to material changes at high temperatures can also be detected early in this way. In the cases mentioned, a certain pre-critical or critical operating state can be clearly determined from the indicator substance that can only then be detected, wherein without such a detection a non-critical operating state or precisely no pre-critical or critical operating state exists.

The cause of active heating can be, for example, insufficient tire pressure for the current vehicle weight, e.g. due to excessive loading or a drop in tire pressure. As a result, the tire heats up due to the load and pressure, cf.

• - dass ein Indikatorstoff in der Sensorumgebung nachgewiesen ist, und/oder
• - eine Indikatorstoff-Konzentration eines in der Sensorumgebung nachgewiesenen Indikatorstoffes. Durch das Detektionsergebnis kann also in der einfachsten Ausbildung zunächst lediglich ausgegeben werden, dass überhaupt einer der Indikatorstoffe nachgewiesen wurde und/oder ergänzend auch in welcher Menge bzw. Konzentration, woraus sich nachfolgend unterschiedliche Möglichkeiten der Ermittlung des dem Indikatorstoff zugeordneten Betriebszustandes ergeben.

For this purpose, it is preferably specifically provided that the detection result contains

• - that an indicator substance is detected in the sensor environment, and/or
• - an indicator substance concentration of an indicator substance detected in the sensor environment. In the simplest embodiment, the detection result can initially only indicate that one of the indicator substances was detected at all and/or additionally in what quantity or concentration, which subsequently results in different possibilities for determining the operating state assigned to the indicator substance.

It can preferably be provided that the operating state of the tire is determined as a function of at least one indicator temperature, with each indicator substance being assigned at least one indicator temperature, and/or as a function of the indicator substance concentration of the detected indicator substance.

According to the first embodiment, it is provided that the indicator temperature indicates the tire temperature from which the indicator substance can be detected at all by the gas sensor or the tire temperature from which it is released. The operating state of the tire is thus derived as a function of the indicator temperature assigned to the respective indicator substance when it follows from the detection result that an indicator substance is present in the sensor environment. So if a certain indicator substance is detected, the tire temperature can be inferred in a simple manner or that a certain tire temperature has been exceeded, and it can already follow from this whether a potentially (pre)critical operating condition exists or not.

According to a further embodiment, it is provided that the at least one indicator temperature indicates the tire temperature from which the indicator substance concentration of the respective indicator substance measured by the gas sensor reaches or exceeds a fixed indicator substance concentration threshold value. In this case, the operating state of the tire also follows from an indicator temperature assigned to the indicator substance, this only being present when the at least one indicator substance concentration threshold value is reached or exceeded.

Advantageously, a sensitivity of the gas sensor can also be adjusted during the evaluation of the detection result, so that a corresponding detection result, from which a specific operating state for the tire follows, is only output from one or more specific indicator substance concentration threshold value(s). As a result, an at least rough subdivision of the operating states considered in each case can also take place. For example, an indicator substance that is already present in very small amounts at pre-critical tire temperatures and which may not yet be reliably or consistently detected and whose indicator substance concentration increases very sharply at critical tire temperatures can also be used to distinguish between pre-critical and critical operating states at the corresponding tire temperatures. This makes the detection more flexible, since one or more specified detection limits for the respective indicator substance must also be exceeded in order to determine an operating state.

It is preferably also provided that the at least one indicator temperature assigned to the respective indicator substance is determined in advance and stored. Accordingly, in previous calibrations, the indicator temperature can be determined as a function of the indicator substance concentration threshold, so that it can easily be referred to while driving.

A further embodiment preferably provides that a tire temperature is estimated from the indicator substance concentration of a detected indicator substance contained in the detection result and the operating state of the tire is determined as a function of this estimated tire temperature. This enables a more precise estimation of the tire temperature via the measured indicator substance concentration, with the relationship between the determined indicator substance concentration of a detected indicator substance and the tire temperature preferably being determined in advance and stored.

• - ein unkritischer, erster Betriebszustand ermittelt wird, wenn die Reifen-Temperatur des Reifens in einem unkritischen, ersten Temperatur-Bereich liegt, wobei der unkritische, erste Temperatur-Bereich vorzugsweise bei kleiner gleich 50°C liegt, und
• - ein vorkritischer, zweiter Betriebszustand ermittelt wird, wenn die Reifen-Temperatur des Reifens in einem vorkritischen, zweiten Temperatur-Bereich liegt, wobei der vorkritische, zweite Temperatur-Bereich vorzugsweise zwischen 51°C und 119°C liegt, und
• - ein kritischer, dritter Betriebszustand ermittelt wird, wenn die Reifen-Temperatur des Reifens in einem kritischen, dritten Temperatur-Bereich liegt, wobei der kritische, dritte Temperatur-Bereich vorzugsweise oberhalb von einschließlich 120°C liegt.

Provision is preferably also made for the operating state of the tire to be determined as a function of the temperature range in which the tire temperature of the tire lies, which is derived from the indicator substance concentration and/or from the indicator temperature. Temperature ranges for which the operating states of the tire are known can therefore preferably be defined in advance, so that a simple determination can take place. For example, it can be provided that

• - a non-critical, first operating state is determined when the tire temperature of the tire is in a non-critical, first temperature range, the non-critical, first temperature range preferably being less than or equal to 50° C., and
• - a pre-critical, second operating state is determined when the tire temperature of the tire is in a pre-critical, second temperature range, the pre-critical, second temperature range preferably being between 51° C. and 119° C., and
• - A critical, third operating state is determined when the tire temperature of the tire is in a critical, third temperature range, the critical, third temperature range preferably being above 120° C. inclusive.

A rough subdivision can thus already be made with three temperature ranges, which can be derived from the presence of an indicator substance and/or the indicator substance concentration of the indicator substance.

Preferably, it can additionally be provided that the operating state, which is derived from the indicator substance concentration, is checked for plausibility with the operating state, which is derived from the indicator temperature. As a result, the determination can be carried out more reliably and deviations can be determined.

In order to carry out the method according to the invention, the evaluation unit according to the invention is designed to record a detection signal from a gas sensor, in particular a molecular mass sensor. According to the invention, a vehicle, for example an autonomously operated vehicle and/or a multi-part vehicle, with vehicle axles, wheels with tires arranged on the vehicle axles and the evaluation unit according to the invention is also provided. the evaluation unit being connected to a gas sensor, in particular a molecular mass sensor, in a signal-conducting manner (wireless or wired), the gas sensor being designed to detect gaseous substances in a sensor environment, the gas sensor being aligned in such a way that the tires are in the sensor environment discharged gaseous matter can be detected, particularly while the vehicle is moving in a forward direction.

It is preferably provided that each wheel or each vehicle axle is assigned at least one gas sensor. In this way, advantageously, wheel-by-wheel or at least evidence-based assignment of the determined operating state can take place. However, only one gas sensor can be provided per vehicle, for example at the rear of the vehicle.

Provision is preferably also made for air ducts to be arranged between the tires and the gas sensor in order to conduct an air flow containing the gaseous substances into the area surrounding the sensor. As a result, the indicator substances separated from the vehicle tire can be guided in a targeted manner in the direction of the gas sensor in order to ensure detection under as many environmental conditions as possible.

According to the invention, a method for controlling a vehicle, in particular a vehicle according to the invention, is determined as a function of an operating state of a tire according to the method according to the invention described above, with an action being carried out depending on the determined operating state, which is selected from the group consisting of: adapt driving dynamics of the vehicle, activation of an optical and/or acoustic indicator device, for example a display, activation of a stability control system, activation of a driver assistance system, activation of a fire extinguishing device. This allows a targeted reaction to a potentially (pre)critical operating state of a tire, for example. The driving dynamics can preferably be adapted as a function of a change in the substance concentration for the indicator substance detected, so that a development over time of the separation of the indicator substance from the tire can also be observed.

• 1 eine schematische Ansicht eines Fahrzeuges;
• 2 eine schematische Schnittansicht durch einen Reifen gemäß 1;
• 3 ein Flussdiagramm eines erfindungsgemäßen Verfahrens.

The invention is explained in more detail below using an exemplary embodiment. Show it:

• 1 a schematic view of a vehicle;
• 2 a schematic sectional view through a tire according to FIG 1 ;
• 3 a flowchart of a method according to the invention.

In 1 a vehicle 1 is shown schematically, which has a plurality of wheels 2 which, according to the detailed view in 2 each have a rim 3 in the usual form, on which a tire 4 is mounted. The rim 3 and the tire 4 delimit a tire interior 5 , a specific tire internal pressure p5 prevailing in the tire interior 5 , which pressure can be variably adjusted via a tire valve 6 .

The tire 4 is built up in layers and in particular has a tread strip 4a with a profile 4b, one or more belt layers 4c with steel cords and a carcass 4d. The tread strip 4a and the carcass 4d are also composed of several layers in order to develop certain running properties of the tire 4.

The tires 4 actively heat up while the vehicle 1 is being driven, since the individual layers of the tire 4 move against one another and heat is thus generated by friction. Furthermore, the tires 4 can be heated passively, e.g. via the rim 3 or via the ground on which the tire 4 rolls, insofar as the rim 3 or the ground is heated up considerably.

In normal driving operation, the tire 4 normally heats up to a tire temperature T4 of up to 50°C. Normal driving operation means in particular that a tire internal pressure p5 is adapted to the vehicle weight G1 and no other unusual external influences, e.g. via the rim 3 or the ground, act on the tire 4. The respective tire 4 is operated in a normal or non-critical first operating state Z1 in which the tire temperature T4 is also in a non-critical first temperature range B1 of less than or equal to 50°C.

However, if certain framework conditions are present, it can happen that one or more tires 4 of the vehicle 1 are no longer operated in the non-critical first operating state Z1, but instead in a pre-critical or critical operating state Z2, Z3. A pre-critical or critical operating state Z2, Z3 can exist, for example, when the tire pressure p5 is too low for the current driving situation and/or the vehicle weight G1 is too high for the currently set tire pressure p5. Furthermore, the wheel rim 3 can heat up excessively due to a defect in the brakes of the vehicle 1, so that the tire 4 is also heated up passively. The ground on which the tire 4 rolls can also vary be very hot according to environmental conditions, which can have an indirect effect on the operating state Z1, Z2, Z3 of the tire 4.

In all of the scenarios mentioned, it can happen that the tire temperature T4 rises so sharply, either as a result of passive heating of the tire 4 from the outside or as a result of load and pressure as a result of so-called flexing work, that it is in a pre-critical second temperature range B2, for example between 51°C and 119°C, or in a critical third temperature range B3, for example above 120°C. In these temperature ranges B2, B3, in particular in the critical temperature range B3, the tire 4 can run off the rim 3, the tire 4 can be damaged, the tire 4 can melt or even the tire 4 can burn come.

If the tire temperature T4 of the tire 4 increases, in particular due to such a pre-critical or critical operating state Z2, Z3 in which the respective tire 4 is being operated, chemical and physical processes in the tire 4 result in increased exposure of different gaseous substances Sn, n=1, 2, 3 ..., which can also be perceived outside the tire 4. The type of gaseous substances Sn released is initially dependent on the respective tire 4 or the materials used in the tire 4.

• Dazu ist im Fahrzeug 1 ein Überwachungssystem 7 vorgesehen, das mindestens einen Gassensor 8, beispielsweise einen Molekülmassen-Sensor 8a, insbesondere einen QCM-Sensor (Quartz Crystal Microbalance) aufweist. Mit diesem können in einem ersten Schritt ST1 (s. 3) eines erfindungsgemäßen Verfahrens selektiv unterschiedliche gasförmige Stoffe Sn in einer Sensorumgebung U detektiert werden. Der Gassensor 8 ist dabei derartig am Fahrzeug 1 angeordnet, dass die Sensorumgebung U zumindest einen Teil eines Reifens 4 abdeckt. Vorzugsweise ist dabei jedem Rad 2 des Fahrzeuges 1 mindestens ein derartiger Gassensor 8 zugeordnet, um eine radindividuelle Betrachtung zu ermöglichen. Es sind aber auch andere Anordnungen möglich, beispielsweise auch achsweise oder in einem hinteren Bereich des Fahrzeuges 1.

In addition, the materials in the tire 4 also change in such a way that from certain tire temperatures T4 substances Sn are released or separated more easily or more frequently, which are otherwise stably integrated in the material at low tire temperatures T4 and therefore cannot be perceived from the outside . The type and a substance concentration KSn of the released substances Sn are therefore also dependent on the tire temperature T4. In this way, at least some of the separated gaseous substances Sn, which have a dependency on the tire temperature T4 and which are only separated out in the pre-critical or the critical temperature range B2, B3, can be used as indicators to determine whether a Tire 4 is operated in a pre-critical or critical operating state Z2, Z3 or in the pre-critical or critical temperature range B2, B3:

• For this purpose, a monitoring system 7 is provided in the vehicle 1, which has at least one gas sensor 8, for example a molecular mass sensor 8a, in particular a QCM sensor (Quartz Crystal Microbalance). With this, in a first step ST1 (s. 3 ) A method according to the invention selectively different gaseous substances Sn are detected in a sensor environment U. The gas sensor 8 is arranged on the vehicle 1 in such a way that the area around the sensor U covers at least part of a tire 4 . Each wheel 2 of the vehicle 1 is preferably assigned at least one such gas sensor 8 in order to enable wheel-specific consideration. However, other arrangements are also possible, for example by axle or in a rear area of vehicle 1.

The arrangement of the gas sensor 8 should preferably be selected in such a way that the individual released substances Sn can still get into the sensor environment U while driving. The gas sensor 8 or the sensor environment U should therefore lie in an air flow 9 in which the exiting gaseous substances Sn move in a forward direction VR while the vehicle 1 is traveling. An arrangement of the gas sensor 8 close to the tires "behind" the vehicle axles 10 is suitable for this purpose, ie lying behind the respective vehicle axle 10 in the forward direction VR viewed from a front side of the vehicle 1 (cf. 1 ). In addition, air ducts 9a can also be attached, which direct the air flow 9 to the gas sensors 8 in a targeted manner.

The gas sensor 8 is connected to an evaluation unit 11 (wired or wireless), which is designed to record and analyze a detection signal SD emitted by the gas sensor 8 . The detection signal SD is dependent on the respectively detected gas in the sensor environment U. The gaseous substances Sn released by the tire 4 can thus be inferred from the detection signal SD. Depending on the gas sensor 8, both the presence or the pure detectability of a specific gaseous substance Sn and the substance concentration KSn of the respective substance Sn and thus also a change in substance concentration dKSn can be determined.

This enables a time-resolved monitoring of the operating state Z1, Z2, Z3 in which the tire 4 is operated or in which temperature range B1, B2, B3 the tire temperature T4 lies, without using a sensor that measures the temperature directly. For this purpose, in a second step ST2 of the method according to the invention, the evaluation unit 11 uses the detection signal SD to check whether certain indicator substances SI can be detected among the detected gaseous substances Sn.

These indicator substances SI are distinguished, for example, by the fact that an indicator temperature TI can be assigned to them, from which point these indicator substances SI are demonstrably released from the tire 4 and therefore in front of the gas sensor 8 in general can be detected. According to one embodiment, the detection signal SD can only be monitored for the presence or the detectability of a specific indicator substance SI as a gaseous substance Sn.

However, one or more indicator temperatures TI can also be assigned to an indicator substance SI as a function of an indicator substance concentration threshold value WKSI. If an indicator substance concentration KSI determined by the gas sensor 8, i.e. the substance concentration KSn of a specific indicator substance SI, exceeds the respectively specified indicator substance concentration threshold value WKSI, the indicator substance SI is additionally detected for the respectively associated indicator temperature TI. As a result, further subdivisions can be made within the pre-critical or the critical temperature range B2, B3. Any indicator temperatures TI assigned to an indicator substance SI are generally in the precritical or in the critical temperature range B2, B3, since the indicator substance SI is not released in the non-critical temperature range B1 and therefore cannot be detected by the gas sensor 8 either .

Benzothiazole Sla, for example, can be detected as an indicator substance SI in conventional tires 4, with this initially being released only slightly and not reliably detectably from a tire temperature T4 of just above 50° C., i.e. in the pre-critical temperature range B2, and in tires -Temperatures T4 from approx. 100°C, i.e. in the critical temperature range B3, increased or released in higher, reliably detectable indicator substance concentrations KSI. At least one indicator temperature TI of approx. 100° C. can therefore be assigned to the indicator substance SI benzothiazole Sla. For this purpose, a corresponding indicator substance concentration threshold value WKSI can be assigned to benzothiazole Sla as indicator substance SI, when this value is reached or exceeded, benzothiazole Sla as indicator substance SI is present in a reliably detectable or so high indicator substance concentration KSI that is normally present in the assigned indicator substance temperature TI of approx. 100°C. It is assumed here that the indicator substance concentration KSI of the indicator substance SI benzothiazole Sla also increases as the tire temperature T4 increases. In this way, further indicator substance concentration threshold values WKSI can also be defined, which are assigned correspondingly to further indicator temperatures TI.

Depending on this substance-selective detection of a specific indicator substance SI, a detection result D can be output in a third step ST3. This indicates in particular that a specific indicator substance SI could be detected for the indicator temperature TI assigned to it (ST3.1). It then also follows from the detection result D that the tire temperature T4 has reached or exceeded the correspondingly assigned indicator temperature TI. This can then be used, for example, to classify one of the above-mentioned temperature ranges B1, B2, B3, with reaching or exceeding the at least one indicator temperature TI in any case being a pre-critical or a critical temperature range B2, B3 and with a Falling below the non-critical temperature range B1. At least the pre-critical and the critical temperature range Bk, k=2, 3, .

If there are several indicator substances SI of this type, the detection result D can also be used to output the detection (or non-detection) of further indicator substances SI, so that it is also possible to use a number of indicator temperatures TI accordingly, for example in order to achieve a more reliable classification in the temperature allow areas Bk. The indicator temperature TI of the respective indicator substances SI can be determined in previous tests and stored in the evaluation unit 11 .

From the detection result D, the operating state Z1, Z2, Z3 of the respective tire 4 can be directly inferred in a fourth step ST4 via the indicator temperature TI and/or the respective temperature range Bk. The operating states Zm, m=1, 2, 3, ... can also be subdivided more finely depending on the application, i.e. m>3.

According to a further embodiment, the indicator substance concentration KSI of a specific detected indicator substance SI can also be analyzed directly in the evaluation unit 11 without determining one or more indicator temperatures Ti in an intermediate step. A detected indicator substance SI can, for example, also be directly assigned a preferably continuous relationship between the respective indicator substance concentration KSI and the tire temperature T4, which can be determined beforehand, for example. In this embodiment, the indicator substance concentration KSI can then be used to infer the tire temperature T4 in fine steps, it being assumed that the indicator substance concentration KSI also increases as the tire temperature T4 increases.

In this embodiment, the detection result D output in the third step ST3 does not indicate that an indicator temperature TI has been reached and the respective indicator substance SI is present (ST3.1), but how much of a certain indicator substance SI could be detected (ST3.2), from which the tire temperature T4 follows directly in fine steps. From this, for example, taking into account the corresponding temperature ranges Bk in the fourth step ST4, the operating state Zm of the respective tire 4 can be inferred.

In the method according to the invention, the operating state Zm of the tire 4 can thus be determined in general via an indicator substance SI, for which it is within the pre-critical and/or the critical temperature range B2, B3 with regard to its detectability at specific indicator temperatures TI (step ST3. 1) and/or with regard to its indicator substance concentration KSI there is a connection with the tire temperature T4.

In addition, both versions for determining the detection result D can also be used for a plausibility check if, for example, the indicator temperature TI assigned to a specific detected indicator substance SI is compared with the tire temperature T4, which is derived from the indicator substance concentration KSI of an indicator substance SI that has also been detected follows.

• Ist das Fahrzeug 1 beispielsweise ein autonom betriebenes Fahrzeug 1a einer höheren Autonomiestufe, für die ein Fahrer zur ständigen Überwachung nicht anwesend oder nicht ständig aufmerksam sein muss, so kann eine Fahrdynamik F1 des Fahrzeuges 1 in Abhängigkeit des Steuersignals SA automatisiert bzw. autonom angepasst werden. Dazu kann ein automatisierter Eingriff in das Bremssystem 20 und/oder das Antriebssystem 21 des autonom betriebenen Fahrzeuges 1a vorgesehen sein. Dadurch kann eine Fahrzeug-Geschwindigkeit vlst des autonom betriebenen Fahrzeuges 1a reduziert werden. Dies kann insbesondere auch in Abhängigkeit davon geschehen, welche Räder 2 des autonom betriebenen Fahrzeuges 1a betroffen sind.

Depending on the operating state Zm determined in the fourth step ST4, a control signal SA can then be output, which can be used in a control method according to the invention. The control signal SA is used to control the vehicle 1 in accordance with the present tire temperature T4 or the present operating state Zm. The control signal SA can be used in different ways depending on the application:

• If the vehicle 1 is, for example, an autonomously operated vehicle 1a with a higher level of autonomy, for which a driver does not have to be present or constantly attentive for constant monitoring, the driving dynamics F1 of the vehicle 1 can be adjusted automatically or autonomously depending on the control signal SA. For this purpose, an automated intervention in the brake system 20 and/or the drive system 21 of the autonomously operated vehicle 1a can be provided. As a result, a vehicle speed vlst of the autonomously operated vehicle 1a can be reduced. This can also happen depending on which wheels 2 of the autonomously operated vehicle 1a are affected.

The actuation can take place in such a way that, for example, at tire temperatures T4 in the second pre-critical temperature range B2 or in the pre-critical operating state Z2, no intervention takes place, but rather this is only prepared. In addition, the substance concentration change dKSn can be used. If this rises sharply for an indicator substance SI, for example, it is to be expected that the respective tire temperature T4 could soon enter the third critical temperature range B3, so that a reduction in the vehicle speed vlst of the autonomously operated vehicle can already be done in advance 1a such a situation can be prevented. The control signal SA can therefore also be adjusted accordingly as a function of the change in substance concentration dKSn for the indicator substance SI.

If a driver is present in the vehicle 1 and is alert, a display 12 can also be activated as a function of the control signal SA, on which the driver can see the respective operating state Zm of the respective tire 4 and/or the temperature range Bk and/or the tire Temperature T4 of the tire 4 is shown. A display can only be provided for the pre-critical temperature range B2 and for the critical temperature range B3 or only for specific tire temperatures T4, so that the driver can react independently accordingly. The substance concentration change dKSn of the respective indicator substance SI can also be taken into account. In addition or as an alternative, other optical and/or acoustic indication devices 13 can also be activated as a function of the control signal SA.

In a multi-part vehicle 1b consisting of a towing vehicle 1c and a trailer 1d, corresponding measures can be taken as a function of the control signal SA, in which case it can also be distinguished whether and which wheels 2 of the trailer 1d or of the towing vehicle 1c are affected.

In addition, the control signal SA can in all cases also be taken into account as a function of the vehicle speed vlst, a braking condition and other information relating to the respective vehicle 1, 1a, 1b, with this information being able to be provided via the CAN bus of the vehicle 2.

In addition, the control signals SA can be output to a stability control system 14 and/or a driver assistance system 15, which can adapt their control strategy as a function of the operating state Zm of the respective tire 2. For example, selective braking attacks on tires 4 in pre-critical or critical operating states Zm can be avoided if possible in order to prevent the tire temperatures T4 of these tires 4 from increasing even more.

A fire extinguishing device 16 close to the tire can also be activated as a function of the control signals SA if, for example, based on the determined operating state Zm or a determined tire temperature T4 or a determined indicator substance SI, there is a very high probability that a burning tire 4 is present.

Reference List

1

vehicle

1a

autonomous vehicle

1b

multi-part vehicle

1c

towing vehicle

1d

follower

2

wheel

3

rim

4

tires

4a

tread

4b

profiling

4c

belt layer

4d

carcass

5

tire interior

6

tire valve

7

surveillance system

8th

gas sensor

8a

molecular mass sensor

9

airflow

9a

air duct

10

vehicle axle

11

evaluation unit

12

screen

13

notification facility

14

stability control system

15

driver assistance system

16

fire extinguishing equipment

20

braking system

21

drive system

bk

k. temperature range

dKSn

Substance concentration change of the n. substance Sn

D

detection result

F1

Driving dynamics of the vehicle 1

G1

vehicle weight

KSn

Substance concentration of the nth substance Sn

ASI

tracer concentrations

p5

tire internal pressure

sn

n. gaseous substance

SA

control signal

SD

detection signal

S.I

indicator substance

Sia

benzothiazole

T4

tire temperature

ti

indicator temperature

u

sensor environment

WKSI

Tracer concentration threshold

maybe

vehicle speed

VR

forward direction

room

m. operating status

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• CN 206339536 U [0004]
• KR 100559320 B1 [0004]
• US2011089255A1 [0004]
• DE 102018116282 A1 [0005]
• US10118577B1 [0005]

Claims (20)

Method for determining an operating state (Zm; m=1,2,3...) of a tire (4) of a vehicle (1) using at least one gas sensor (8) arranged on the vehicle (1), with at least the following steps: - Detecting gaseous substances (Sn; n=1,2,3,...) in a sensor environment (U) of the gas sensor (8) (ST1); - Determine whether in the sensor environment (U) of the gas sensor (8) as a gaseous substance (Sn) at least one indicator substance (SI) can be detected (ST2), the at least one indicator substance (SI) depending on a tire temperature (T4 ) is separated from the tire (4) in such a way that the indicator substance (SI) can only be detected in the presence of an operating state (Z2, Z3) to be determined as a result of a change in the tire temperature (T4) in the sensor environment (U); - Creating a detection result (D) when an indicator substance (SI) in the sensor environment (U) can be detected (ST3); and - Determining and / or outputting the operating state (Zm) of the tire (4) depending on the detection result (D) (ST4). procedure after claim 1 , characterized in that the detection result (D) includes - that an indicator substance (SI) is detected in the sensor environment (U) (ST3.1), and/or - an indicator substance concentration (KSI) of an indicator substance in the sensor environment (U ) detected indicator substance (SI) (ST3.2). procedure after claim 2 , characterized in that the operating state (Zm) of the tire (4) is determined: - as a function of at least one indicator temperature (TI), each indicator substance (SI) being assigned at least one indicator temperature (TI), and/or - as a function of the indicator substance concentration (KSI) of the indicator substance (SI) detected in the sensor environment (U), with the operating state (Zm) to be determined being at least a pre-critical, second operating state (Z2) and/or a critical, third operating state (Z3 ) are provided. procedure after claim 3 , characterized in that the indicator temperature (TI) indicates the tire temperature (T4) from which the respective indicator substance (SI) can be detected by the gas sensor (8), so that the operating state (Zm) of the tire (4) in Dependence of the indicator temperature (TI) assigned to the respective indicator substance (SI) is determined if it follows from the detection result (D) that an indicator substance (SI) is present in the sensor environment (U) (ST3.1). procedure after claim 3 or 4 , characterized in that the at least one indicator temperature (TI) indicates from which tire temperature (T4) the gas sensor (8) measured indicator substance concentration (KSI) of the respective indicator substance (SI) has a specified indicator substance concentration Threshold value (WKSI) is reached or exceeded, so that the operating state (Zm) of the tire (4) follows from reaching or exceeding the at least one indicator substance concentration threshold value (WKSI). Procedure according to one of claims 3 until 5 , characterized in that the at least one indicator temperature (TI) assigned to the respective indicator substance (SI) is determined in advance and stored. Procedure according to one of claims 3 until 6 , characterized in that from the indicator substance concentration (KSI) of a detected indicator substance (SI) contained in the detection result (D), a tire temperature (T4) is estimated (ST3.2) and the operating state (Zm) of the tire (4) as a function of this estimated tire temperature (T4). procedure after claim 7 , characterized in that the relationship between the determined indicator substance concentration (KSI) of a detected indicator substance (SI) and the tire temperature (T4) is determined in advance and stored. Procedure according to one of claims 3 until 8th , characterized in that the operating state (Zm) of the tire (4) is determined as a function of the temperature range (Bk) in which the tire temperature (T4) of the tire (4) lies, which is derived from the indicator substance concentration ( KSI) and/or derived from the indicator temperature (TI). procedure after claim 9 , characterized in that the operating state (Zm), which is derived from the indicator substance concentration (KSI), is checked for plausibility with the operating state (Zm), which is derived from the indicator temperature (TI). procedure after claim 9 or 10 , characterized in that - a non-critical, first operating state (Z1) is determined when the tire temperature (T4) of the tire (4) is in a non-critical, first temperature range (B1), the non-critical, first temperature range (B1) is preferably less than or equal to 50°C, and - the pre-critical, second operating state (Z2) is determined when the tire temperature (T4) of the tire (4) is in a pre-critical, second temperature range (B2), the pre-critical, second temperature range (B2) being preferred is between 51°C and 119°C, and - the critical, third operating state (Z3) is determined when the tire temperature (T4) of the tire (4) is in a critical, third temperature range (B3), wherein the critical, third temperature range (B3) is preferably above 120° C. inclusive. Procedure according to one of claims 3 until 11 , characterized in that the indicator substance (SI) can be detected in the sensor environment (U) only when the pre-critical, second operating state (Z2) and/or when the critical, third operating state (Z3) is present. Method according to one of the preceding claims, characterized in that a tire-specific indicator substance (SI), for example benzothiazole (SIa), is used as the indicator substance (SI), the tire-specific indicator substance (SI; SIa) during or after the manufacture of the tire (4) is additionally introduced into the tire (4) in a targeted manner and/or is a natural part of the tire construction components (4a, 4b, 4c, 4d) of the tire (4). Evaluation unit (11) for carrying out a method according to one of the preceding claims, wherein the evaluation unit (11) is designed to record a detection signal (SD) from a gas sensor (8). Vehicle (1) with vehicle axles (10), wheels (2) arranged on the vehicle axles (10) with tires (4) and an evaluation unit (11). Claim 14 , wherein the evaluation unit (11) is connected to a gas sensor (8), in particular a molecular mass sensor (8a), in a signal-conducting manner, the gas sensor (8) being designed to detect gaseous substances (Sn) in a sensor environment (U), wherein the gas sensor (8) is aligned in such a way that gaseous substances (Sn) separated by the tires (4) can be detected in the sensor environment (U), in particular while the vehicle (1) is moving in a forward direction (VR). Vehicle (1) after claim 15 , characterized in that each wheel (2) or each vehicle axle (10) is assigned a gas sensor (8). Vehicle (1) after claim 15 or 16 characterized in that air ducts (9a) are arranged between the tires (4) and the gas sensor (8) for conducting an air flow (9) containing the gaseous substances (Sn) into the sensor surroundings (U). Vehicle (1) according to one of Claims 15 until 17 , characterized in that the vehicle (1) is an autonomously operated vehicle (1a) and/or a multi-part vehicle (1b). Method for controlling a vehicle (1), in particular a vehicle (1) according to one of Claims 15 until 18 , Depending on an operating state (Zm) of a tire (4) determined by a method according to one of Claims 1 until 13 , wherein depending on the determined operating state (Zm) an action is carried out, which is selected from the group consisting of: adapting a driving dynamics (F1) of the vehicle (1), activating an optical and / or acoustic indicator device (13), for example one Displays (12), control of a stability control system (14), control of a driver assistance system (15), control of a fire extinguishing device (16). procedure after claim 19 , characterized in that the driving dynamics (F1) depending on a substance concentration change (dKSn) for the indicator substance (SI) is adjusted.

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