This Invention is related to a wheel sensor monitoring method and to a sensor environment monitoring method and a to a system executing such a method.

There are known methods of measurement sensor monitoring, including railway vehicle wheel sensors and methods of sensor environment monitoring including measurement and recording of sensor working conditions, such as internal temperature, vibrations inside the sensor and relationships between electric signals inside the sensor, as well as conditions in the environment of the sensor, such as ambient temperature and relative humidity.

There are also known evaluation systems evaluating information provided by the sensor, resulting in information about the technical condition of the sensor and about its working conditions, useful for forecasting the technical condition of the sensor and for its remaining lifetime.

There are known evaluation methods used to detect wheel presence and to monitor the technical condition of the wheel sensor, which independently receive the wheel presence signal and a signal reflecting technical condition of the sensor.

This invention is related to development of a solution which ensures quasi-continuous monitoring that allows to observe working conditions of a wheel sensor. This objective was achieved through simultaneous sending signals from measurement sensors which detect the observed parameters and from the wheel sensor to an evaluation system. The system monitors the wheel sensor and its environment including measurement and recording of wheel sensor working conditions, it is used to form a set of diagnostic information variable, which over time is used to create a diagnostic signal that is sent to the evaluation system. This system also receives the wheel presence signal. It is characterised in that according to the invention a diagnostic signal and a wheel presence signal are sent simultaneously and automatically to the evaluation system, in constant or variable intervals. A frequency band higher than the frequency band used by the wheel presence signal is used to send the diagnostic signal. Then the diagnostic signal and the wheel presence signal are added together to form a resulting signal.

Potential, mutual interference of the diagnostic signal and the wheel presence signal is eliminated by adding these signals only at times ti, when the frequency band used by the output signal at time ti is significantly lower, preferably 10 times lower, than the lower boundary of the frequency band used by the signal at time ti. The resulting signal is then sent through the current loop to the evaluation system and the resulting signal is decomposed using top bandwidth filtration and bottom bandwidth filtration. We thus obtain a separate secondary wheel presence signal, and the secondary diagnostic signal is sent to the diagnostic module, while the secondary wheel presence signal is sent to the wheel detection module. The separated signals are then analysed using a known method. Permitted frequency bands are controlled during the signal adding operation. If the wheel presence signal exceeds the permitted frequency band, this is detected on the basis of identification of a momentary wheel presence signal change that is faster than the momentary signal change corresponding to the permitted frequency band; this prevents the signals from being added together.

Preferably, the sensor vibration levels indicating train travel in direct vicinity of the sensor are also controlled, in order to eliminate interferences during the signal adding.

A wheel sensor monitoring system including a wheel detection system, a wheel sensor interior monitoring system with sensors for, preferably, temperature, vibration, humidity and a wheel sensor environment monitoring system and an evaluation system is characterised in that it also Includes a voltage/current conversion system. The wheel detection system is connected to an input of the voltage/current conversion system through the first resistor. The wheel sensor interior monitoring system is also connected to an input of the voltage/current detection system, through the second resistor and through a converter, preferably a modem.

The output of the voltage/current conversion system is connected with the top bandwidth filter system and with the bottom bandwidth filter system. The top bandwidth filter system is connected with the wheel sensor monitoring evaluation system through a converter, preferably a modem. The bottom bandwidth filter system is connected with the wheel detection evaluation system.

An external wheel sensor environment monitoring system is preferably connected to the wheel sensor interior monitoring system using a serial interface, preferably using galvanic separation.

Use of the invention ensures quasi-continuous monitoring of sensor technical condition, its working conditions and conditions of its environment in order to forecast the future technical condition of the sensor, thus improving safety of railway traffic and the availability of traffic control equipment. Automatically obtained information can also be used in railway line maintenance based on prevention.

The invention is better explained using a description of an embodiment and using a drawing, in which Fig. 1 presents the general diagram of the method and Fig. 2 presents a general diagram of the system.

As Fig. 2 shows, the wheel sensor monitoring system includes a wheel detection system UDK, a wheel sensor internal monitoring system UMC and sensors: C_Z1 for temperature measurements, C_Z2 for vibration measurements, C_Zn for humidity measurements and an evaluation system UO.

The system also includes a voltage/current conversion system KUI with wheel detection system UDK, which is connected to its input via the first resistor R1, and a wheel sensor Interior monitoring system UMC connected via the second resistor R2 and via converter K1 comprising a modem.

The output of the voltage/current conversion system KUI is connected to the top bandwidth filter system FGP and the bottom bandwidth filter system FDP. The top bandwidth filter system FGP is connected with the monitoring evaluation system UM_UO via converter K2, comprising a modem K2. The bottom bandwidth filter system FDP is connected with the wheel detection evaluation system UDK_UO.

Working conditions of the wheel sensor are measured and recorded automatically, in constant intervals Tdi, using the following sensors: for temperature measurements C_Z1, for vibration measurements C_Z2 and for humidity measurements C_Zn. The obtained measurement results are used to form a set of diagnostic information ZDti in the wheel sensor internal monitoring system UMC.

The set of diagnostic information ZDti is used to form a diagnostic signal SD that is sent to the evaluation system UO as shown in Fig. 1, with the evaluation system also receiving the wheel presence signal X from the wheel detection system UDK. The diagnostic signal SD is sent using a frequency band higher than the frequency band used to send the wheel presence signal X and the diagnostic signal SD is added to the wheel presence system X to obtain the resulting signal Y.

Potential mutual interference of the diagnostic signal SD with the wheel presence signal X is eliminated in such a way that these signals are added only at times ti, namely when the frequency band used by the output signal Y at time ti is 10 times lower than the bottom boundary of the frequency band used by the diagnostic signal SD.

The resulting signal Y is sent further using a current loop to the evaluation system UO, and this resulting signal Y is decomposed using top bandwidth filtration FG and bottom bandwidth filtration FD.

We obtain a separate secondary diagnostic signal SD_UO^∼SD and a separate secondary wheel presence signal X_UO^∼X. The secondary diagnostic signal SD_UO^∼SD is sent to the diagnostic module MD and the secondary wheel presence signal X_UO^∼X is sent to the wheel detection module MW.

The separated signals are further analysed in a known manner and diagnostic information useful in forecasting of sensor technical condition and its remaining lifetime is obtained. Additionally, the obtained information may be used to evaluate degradation of railway infrastructure manifesting through increased vibration levels recorded in the sensor.

The system is executed as in Example 1 with the exception that an external wheel sensor environment monitoring system UMZ is connected to the wheel sensor internal monitoring system UMC which uses a serial interface with galvanic separation. It enables access to diagnostic information related to the track infrastructure, for example about increased track temperature, related to technical condition of equipment installed within the tracks, for example incorrect junction and junction drive operation, as well as related to the environment of the track infrastructure, as relative humidity and temperature requiring the junction to be heated. This information does not require any additional expenses for dedicated transmission infrastructure thanks to the use of the wheel sensor and its connection with the evaluation system.