EP1256502B1 - Protection against accident and fire for vehicles - Google Patents

Abstract

Device for technical monitoring of vehicles has two detectors (M, R, M, L) on both sides of a carriageway or arranged symmetrically relative to a vehicle, a detector unit that determines a difference from the values measured using the two detectors and a warning device for alerting a driver when a threshold value is exceeded. An Independent claim is made for a method for technical monitoring of a motor vehicle with the following steps simultaneous measurement of noise or temperature arising from the tires, wheels, running gear, etc. on both sides of a vehicle, calculation of the difference between the measured values and stopping of a vehicle when the difference exceeds a threshold value.

Description

The invention relates to an apparatus and a method for the prevention of accidents by road, rail and air vehicles. A device for the technical inspection of vehicles is z. B. known from DE-A1-19826220. Accidents of road, rail and air vehicles can be caused by human or technical failure. The technical causes include, for example, faults in brakes, tires, wheels, wheel rims, wheel bearings and engines. In the past it has been proven that these errors have particularly fatal consequences when they occur in tunnels and on bridges, because there are only insufficient escape possibilities. But even on supposedly safe routes devastating consequences in technical damage can not be ruled out. An example of this is the derailment of a train and subsequent collision with a bridge pier.

In the case of aircraft, the required take-off distance and the speed required for take-off can be calculated precisely, depending on take-off weight and meteorological influences. However, the crew is unable to determine during the launch whether a damaged wheel bearing or a hanging brake will affect the calculated values dangerously. A number of total losses has already occurred because by these causes after the retraction of the chassis, a tire has been overheated, burst and destroyed vital hydraulic lines. Another problem is that a large area of the aircraft during the start, ie in a phase in which the start can still be canceled, in flames, without the crew can determine this, because the corresponding sensors are only in the cool area of the engine, such as the accident of Concorde in Paris.

The invention has for its object to prevent the above-mentioned accidents in an improved manner.

The invention is solved by a method as well as by a device having the features of the independent claims. Advantageous embodiments emerge from the dependent claims.

To achieve the object of the invention, a device for the technical inspection of vehicles is provided which has two mounted on both sides of a roadway detectors. The detectors are positioned so that physical properties can be measured on two devices mounted symmetrically on the vehicle. Such devices are for example tires and wheel bearings on a car. A physical property within the meaning of the invention is, for example, the development of noise or the temperature occurring during the tire or the wheel bearing.

The device comprises an evaluation unit, with the a difference between two values measured simultaneously by the two detectors is evaluated.

A warning device is provided in the device which emits a warning signal when the evaluation results in the exceeding of a predetermined threshold value. The warning signal is transmitted, for example, to the vehicle driver. This may be associated with the request to stop his vehicle. A traffic light switching to red when the threshold value is exceeded can be a warning device in the sense of the invention.

Microphones for noise measurement and / or temperature measuring devices are in one embodiment of the invention as. Detectors used.

If the detectors are provided independently of the vehicle at typical danger spots, so advantageously all vehicles are checked, which approach the danger point. A tunnel represents a typical danger point in the sense of the invention, since an accident in a tunnel is associated with particularly great dangers for the other road users. The device is therefore preferably before entering a tunnel or underpass or before or at the beginning of a runway for aircraft. The device is in the context of the invention "before" such a danger spot attached when checked by this attachment, the vehicles that are likely to pass the danger point actually. Are there, for example, before entering a tunnel or more branching roads that are not in the Lead tunnel in, so the device is to install behind these branching roads. However, a diversion may still be provided before the tunnel to redirect defective vehicles over this.

According to the invention occurring during the movement of a vehicle physical properties such as temperatures and / or noise in two symmetrically mounted on the vehicle facilities are measured. Tires, wheels, wheel bearings, exhausts and / or engines represent such facilities. The difference between two of the simultaneously measured physical properties is determined.

The vehicle is stopped when the difference exceeds a predetermined threshold and thus indicates a defect.

Before the occurrence of an accident, the damage occurring to the vehicle regularly announces by a local temperature increase or change the driving noise. Temperature and noise can be measured relatively easily without contact. The problem, however, is that different operating conditions may cause the normal operating noise or operating temperatures to vary widely. Therefore, a simple measurement without reference is unsuitable. Usually, however, the above-mentioned vehicles are symmetrical. The errors almost never occur symmetrically. By a symmetrical measurement, it is thus possible to obtain a reference signal. If one now compares the measurement data obtained by "symmetrical" measurement, one has the possibility of using the difference to decide if a dangerous operating condition when. Vehicle is present. The comparison is advantageously carried out by difference signal formation (eg at temperatures), since this is particularly simple.

In a further improved embodiment, statistical methods such as e.g. Statistical Process Control (SPC) applied to differential signals. This works particularly reliably for recurring similar DUTs.

Alternatively, more expensive processes such as e.g. an evaluation of the symmetrically determined signals by a neural network can be applied. Such a method is to be used in particular for the evaluation of sound measurement values.

The measurement is carried out stationary. The stationary measurement is to be preferred, if particularly dangerous tracks are to be universally secured. Examples of this are entrances into a tunnel or a runway of an airport. All vehicles are then checked that enter a tunnel or that want to take off from a runway, regardless of the individual safety features of the respective vehicle.

For example, bearing noise and / or temperatures occurring are measured externally and without contact. At the entrance to a tunnel, sensors for the non-contact measurement of the temperatures and / or the sound generated by passing vehicles are set up on the left and right of a vehicle lane. Be strong'different Registered measuring signals, this may for example be caused by a defective wheel bearing. A warning signal is then output and the affected vehicle is stopped manually or by means of a traffic light system.

In this way, further abnormalities on wheels and wheel rims in rail vehicles when driving through a test section - and evaluation of the temperature difference signal can be determined by means of SPC, which indicate a defect.

Tire, wheel and bearing temperatures, as well as the temperature of individual parts of the cargo in road vehicles can be determined when driving through a test section. By subtracting the measured temperatures with or without statistical evaluation, faults or damage occurring on the aforementioned parts can be detected early.

Engine and exhaust gas temperatures in aircraft can be specifically measured. By subtraction of thermal images with or without evaluation by a neural network then represents the value that is used to identify incidents.

Engine noise in aircraft and evaluation of the sound emission by means of a neural network can also be used.

Chassis and / or wheel bearing temperatures of aircraft before and during take-off can be measured symmetrically to obtain information regarding possible defects.

In addition, the speed of the invention is preferred and accelerate or decelerate the vehicles. It is then checked, for example, whether temperatures that occur in tires or wheel bearings, move in the normal context. Otherwise, a warning signal is issued.

This embodiment differs from the aforementioned in that no reference signal is measured. Instead, absolute values are evaluated and a warning signal is issued if a fault is suspected as a result. The warning signal is forwarded either to the vehicle driver and / or to an external location, from which the necessary protective measures are initiated manually or automatically.

An acceleration or deceleration is measured, as this causes typical changes in the operating state. These are to be considered in the evaluation or evaluation.

If a train slows down, the temperatures measured at the first axis at a measuring point are relatively cool. If the last car of a train finally passes the measuring point, then there is a clear increase in temperature compared to the first axis. This temperature increase from axis to axis of subsequent wagons is determined. If the rise shows an outlier, this is a sign of the existence of a fault. The warning signal is then output. In this embodiment of the invention, therefore, a temperature profile is determined and determined abnormalities as a measure of interference.

The invention is used stationary. The stationary version is especially designed so that These can be brought to a different location from the weight and the technical effort at any time. The cost of stationary measuring equipment is extremely low because a single plant can inspect many thousands of vehicles daily. In addition, complete coverage of all road, rail and runway users is only possible with a stationary system.

It is advantageous to equip high-speed lines of an operator of a rail network at a distance of 150 kilometers with a meter. For all other routes of such an operator, the distance is selected so that even short-distance trains are detected by the measurement.

At sporadic intervals, it often happens that slipped cargo triggers catastrophic accidents in rail traffic. Since the acceleration values and the centrifugal force in rail traffic are relatively low, the cargo rarely shifts abruptly, but rather in sections. By timely detection of the danger, such an accident can be prevented. If, for example, the measurement and / or image acquisition are carried out obliquely from above, not only the evaluation of, for example, temperature differences but also the vertical geometry of the vehicle and / or the charge can be determined. This measurement simultaneously checks whether parts of the load have slipped and protrude laterally beyond the prescribed width.

Stationary equipped with the device according to the invention measuring points in front of the entrances to the stations and ferries are advantageous because there the uncoupling of a defective vehicle causes the least problems. Further measuring points are to be provided, in particular, against slow-moving traffic, and hiking construction sites. These measuring points must be placed far enough in front of the corresponding danger spot that the driver is prompted to brake by means of a radio signal and can reduce the speed with normal braking, provided that he has not initiated any delay at this point. If he does not respond to this signal, it goes out after a short time delay another signal, which is switched so that then an automatic braking is initiated. With the use of the device according to the invention, the heavy railway accident in Brühl, Germany, could have been prevented.

For airports, the installation of one device per kilometer landing / runway and in special cases on the taxiways would be useful. In traffic, in addition to the above-mentioned installation options further installations on steep slopes would be advantageous. After all, many serious accidents have occurred in the past, involving in particular road trains and buses. Typically, these accidents have been caused by too late or incorrect shifting back to a low gear and the associated thermal overload of the wheel brakes. If the driver is warned early, then he can bring the vehicle to a halt even before the brakes have completely stopped. Again, these are the Cost of a stationary plant in relation to the number of measurements vanishingly small.

Trucks and their cargo should be inspected for possible heat radiation before entering a ferry, but also before being loaded onto "piggy-back trains", in order to prevent future fires such as those in the tunnel under the English Channel some time ago.

For manufacturing, sales and economic reasons, each individual device will be able to meet all the requirements for air, rail and road traffic.
Areas of application of the invention are therefore in particular:

Road transport:

Early detection of bearing damage, damage to the brake system, overheating of vehicle parts, tires and cargo.

Measuring points:

Sporadically on highways, punctually in front of the entrance to neuralgic areas, such as tunnels, railways, bridges, ferries, etc. and at the beginning of strong declines.

Measurement Methods:

Determine the operating condition by detecting the speed, acceleration and deceleration using non-contact measuring methods and, where this is not possible for reasons of space or traffic, of induction loops. Detection of the reference signal by symmetric Measurements using thermal imaging cameras, thermal and acoustic sensors. Evaluation of the measurement by differential signal generation, application by static process control (SPC) and the use of a neural network.

Warning Methods:

Acoustically, optically and by mechanical barrier of a road or roadway.

rail transport

Early detection of bearing damage and damage to the brake system, overheating of vehicle parts and cargo. Detection of overhanging cargo and prevention of excessive speed in hazardous areas

Measuring points:

Every 50 to 200 km, preferably every 150 km in the high-speed area, at significantly shorter distances on short distances, and additionally before danger and hiking construction sites, before entering main stations and critical areas such as tunnels, rail loading stations, bridges and ferries.

Measurement Methods:

As described in the road. In addition, wheel rims can be detected by inductive proximity sensors.

Warning Methods:

By radio directly to train driver and route clearance point. Acoustically, visually and by signals.

air traffic

The applications in the field of air traffic are largely identical to the possibilities of road and rail transport. However, they are limited to the geographical area of the airports.

Type of detector used, regardless of the type of traffic (air, rail, road) Mechanical sensors:

such as pressure sensors, which are triggered when passing over the bearing force of a tire.

Optical sensors:

such as photocells, which are triggered when passing through or image acquisition by cameras, which can be used as input signal for a neural network.

Inductive / electromagnetic sensors:

such as induction switches, which are triggered by the metal rim of the wheel of a rail vehicle.

Type of evaluation

Particularly in the evaluation of images, the use of neural networks makes sense, as it also the evaluation of the Picture of a complete vehicle allows. The above-mentioned sensors for identifying a single wheel can be dispensed with, for example. It is then evaluated only the difference between the two sides. In particular, neural networks are also able to detect construction-related differences such as the location of the exhaust system in trucks. In addition, it is then possible to identify sources of fire of cargoes.

In FIG. 1, a vehicle is sketched in plan view, which is provided with four wheels and drives into a measuring point at a speed v. The four wheels generate thermal images T ₁ (L), T ₂ (L), T ₁ (R) and T ₂ (R). The measuring point is equipped with several pressure sensors (D1, R), (D2, R), (D3, R), (D1, L), (D2, L), (D3, L) as well as a right and a left infrared camera (M , L) or (M, R). The pressure sensors (D1, R), (D2, R), (D3, R) and (D1, L), (D2, L), (D3, L) are arranged one behind the other with a respective distance d. A right first pressure sensor (D1, R) is assigned a first right transmitter (S1, R), a right second pressure sensor (D2, R) is a second right transmitter (S2, R), etc. Measured values are transmitted to an evaluation unit via the transmitters.

At time t ₀ acts according to Figure 2, the first pair of wheels, which generates the thermal images T ₁ (L) and T ₁ (R), on the first two pressure sensors (D1, R) and (D1, L) and a time measurement is in Gear set.

und $${\mathrm{v}}_{1,\mathrm{L}}=\left({\mathrm{t}}_{0,\mathrm{L}}-{\mathrm{t}}_{1,\mathrm{L}}\right)/\mathrm{d}$$

ermittelt. Stimmen die ermittelten Geschwindigkeiten überein, so ist dies für das System ein Indiz, dass es sich bei den erfassten Gegenständen tatsächlich um ein Radpaar handelt.According to FIG. 3, the aforementioned first pair of wheels is detected for the second time at time t _1, namely by the pressure sensors (D ₂ , R) as well as (D ₂ , L). The velocities v _{1, R} and v _{1, L} , with which the two detected objects move are calculated according to past time and distance covered $${\mathrm{<figure-callout\; id="1"\; label="v"\; filenames="imgf0003.png,imgf0004.png"\; state="\{\{state\}\}">v</figure-callout>}}_{1.\mathrm{R}}=\left({\mathrm{t}}_{0.\mathrm{R}}-{\mathrm{t}}_{\mathrm{i}.\mathrm{R}}\right)/\mathrm{d}$$

and $${\mathrm{<figure-callout\; id="1"\; label="v"\; filenames="imgf0003.png,imgf0004.png"\; state="\{\{state\}\}">v</figure-callout>}}_{1.\mathrm{L}}=\left({\mathrm{t}}_{0.\mathrm{L}}-{\mathrm{<figure-callout\; id="1"\; label="t"\; filenames="imgf0003.png,imgf0004.png"\; state="\{\{state\}\}">t</figure-callout>}}_{1.\mathrm{L}}\right)/\mathrm{d}$$

determined. If the determined speeds match, this is an indication to the system that the detected objects are actually a pair of wheels.

und $${\mathrm{v}}_{2,\mathrm{L}}=\left({\mathrm{t}}_{1,\mathrm{L}}-{\mathrm{t}}_{2,\mathrm{L}}\right)/\mathrm{d}$$

erneut ermittelt und miteinander verglichen. Stimmen die Geschwindigkeiten v_2,R und v_2,L wiederum überein, so werden die erfassten Gegenstände als vorderes Radpaar vom System identifiziert. Als zusätzliche Information, die diese Identifizierung bestätigt, kann in einer Ausgestaltung die Erfassung des hinteren Radpaares hinzugezogen werden. In dieser Ausgestaltung wird das vordere Radpaar als Radpaar erst dann identifiziert, wenn ein nachfolgendes Radpaar von den ersten beiden Drucksensoren (D1, R) und (D1, L) in einem für Kraftfahrzeuge typischen Abstand von wenigen Metern, so zum Beispiel von weniger als 6 Metern erfasst wird.At a subsequent time t ₂ , according to FIG. 4, the aforementioned first wheel pair is detected for the third time by the pressure sensors (D3, R) as well as (D3, L). For the first time, the second rear wheel pair acts on the pressure sensors (D1, L) and (D1, R). The speed of the wheels of the first pair of wheels are according to $${\mathrm{<figure-callout\; id="2"\; label="v"\; filenames="imgf0003.png"\; state="\{\{state\}\}">v</figure-callout>}}_{2.\mathrm{R}}=\left({\mathrm{<figure-callout\; id="1"\; label="t"\; filenames="imgf0003.png,imgf0004.png"\; state="\{\{state\}\}">t</figure-callout>}}_{1.\mathrm{R}}-{\mathrm{<figure-callout\; id="2"\; label="t"\; filenames="imgf0003.png"\; state="\{\{state\}\}">t</figure-callout>}}_{2.\mathrm{R}}\right)/\mathrm{d}$$

and $${\mathrm{<figure-callout\; id="2"\; label="v"\; filenames="imgf0003.png"\; state="\{\{state\}\}">v</figure-callout>}}_{2.\mathrm{L}}=\left({\mathrm{<figure-callout\; id="1"\; label="t"\; filenames="imgf0003.png,imgf0004.png"\; state="\{\{state\}\}">t</figure-callout>}}_{1.\mathrm{L}}-{\mathrm{<figure-callout\; id="2"\; label="t"\; filenames="imgf0003.png"\; state="\{\{state\}\}">t</figure-callout>}}_{2.\mathrm{L}}\right)/\mathrm{d}$$

reassessed and compared. If the velocities v _{2, R} and v _{2, L} coincide again, the detected objects are identified as the front pair of wheels by the system. As additional information confirming this identification, in one embodiment, the detection of the rear wheel pair may be consulted. In this embodiment, the front pair of wheels is identified as a pair of wheels only when a subsequent pair of wheels from the first two pressure sensors (D1, R) and (D1, L) in a typical for motor vehicles distance of a few meters, such as less than 6 Meters is detected.

In one embodiment, the movement type is evaluated as follows.

If v ₁ = v ₂ , then the vehicle will move smoothly.

If v ₁ > v ₂ , then the vehicle brakes.

If v ₁ <v _2, then accelerates the vehicle.

The measuring time t _{3 is} calculated on the basis of the driving behavior and the speed. When the time t ₃ is reached, the front wheel pair is at the same height as the infrared cameras (M, L) and (M, R).

If, in the aforementioned manner, objects moving through the pressure sensors have been identified as a pair of wheels, the thermal images T1 (L) and T1 (R) of the two infrared cameras (M, L) and (M, R) at time t ₃ first pair of wheels recorded symmetrically, as shown in Figure 5. The normalized mean value is calculated as follows: T _{1, n} = 2 * [T ₁ (R) -T ₁ (L)] / [T ₁ (R) + T ₁ (L)].

The time t ₃ has advantageously been calculated by the system beforehand on the basis of the determined speed together with a possibly determined acceleration or deceleration, so that the system "knows" with great accuracy the time at which the thermal images must be recorded.

FIG. 6 shows the plot of the determined normalized average values as a function of a consecutive numbering x. FIG. 6 clarifies that based on empirical values, a temperature difference threshold value OEG is determined which here corresponds to the dotted line. When the threshold value is exceeded, an alarm is triggered. According to FIG. 6, this is the case for the value T _{16, n} .

The thermal images taken at time t ₃ are also evaluated. First, difference images are determined. Examples of possible results are shown in FIGS. 7a to 7c.

As shown in Figure 7a, one tire is significantly warmer than the other, indicating too low a one-sided air pressure.

According to FIG. 7b, a brake has overheated because one rim flange is considerably hotter than the opposite one. According to Figure 7c, a bearing has overheated because the overheated area concentrates on the area of the axis compared to the reference value.

In addition to the relative measurements, the measured absolute temperature values can also be evaluated as a function of the speed and driving behavior. If the absolute measured values deviate from empirical values and a threshold value determined therefrom, an alarm is triggered.

Claims (8)

1. Apparatus for the technical examination of vehicles, comprising

   - two detectors (M, R, M, L) arranged at both sides of a track,

   - an evaluation unit by means of which a difference between two values that are simultaneously measured by the two detectors is evaluated,

   - a warning device that outputs a warning signal when it arises from the evaluation that a predetermined threshold value (OEG) has been exceeded.
2. Apparatus according to claim 1, wherein microphones and/or temperature measurement devices, which in particular serve the purpose of recording thermal images, are used as detectors.
3. Apparatus according to claim 1 or 2, wherein the apparatus is arranged in front of the entrance into a tunnel or an underpass or in front or at the start of a runway for aeroplanes.
4. Apparatus according to one of the preceding claims, wherein means 1 to i (S_i,R,D_i,R, S_i,R, D_i,R, S_i,L, D_i,L, S_i,L, D_i,L,) are provided for measuring speed and/or for measuring acceleration or deceleration of a vehicle, wherein in particular i = 1 is for a simple detection, i = 2 for a speed measurement and i = 3 for an acceleration measurement.
5. Apparatus according to one of the preceding claims, wherein means (S_1,R, D_1,R, S_1,R, D_1,L, S_1,L, D_1,L, S_1,L, D_1,L) are provided for measuring speed and/or for measuring the acceleration or deceleration of individual wheels of a vehicle.
6. Method for the technical examination of vehicles, comprising the steps of
   Simultaneous measuring of the temperatures and/or noises occurring at two devices that are symmetrically mounted on a moving vehicle, in particular tyres, wheels, wheel bearings, exhausts and/or engines mounted on a vehicle, by means of an apparatus according to claims 1, 2, 3
   Determining the difference between two of the temperatures or noises measured simultaneously
   Stopping the vehicle when the difference exceeds a predetermined threshold value.
7. Method according to the preceding claim, wherein the vehicle is stopped in front of the entrance into a tunnel, into an underpass or in front of or on a runway for aeroplanes when the threshold value is exceeded.
8. Method according to one of the two preceding claims, wherein the speeds, accelerations and/or decelerations of the vehicle or individual parts of the vehicle are measured and evaluated.

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