Method for determining a wheel diameter in a rail vehicle

Abstract

The invention relates to a method for determining a wheel diameter in a rail vehicle. The wheel diameter of a rail vehicle wheel is determined manually. A digital twin is used to estimate wear of the wheel diameter. The digital twin is based on stored values ​​of the determined wheel diameter and on continuously updated operating data of the rail vehicle.

Description

The invention relates to a method for determining a wheel diameter in a rail vehicle.In railway technology, in particular in the case of a driven rail vehicle, diameters of wheels of the rail vehicle are regularly measured and associated values are manually input in an electronic control system of the rail vehicle. At the same time, rotational speeds of the wheels are detected during operation of the rail vehicle and associated values are likewise supplied to a control system or a control technology of the rail vehicle.The control system uses the manually input wheel diameters and the speeds to calculate a speed of the railway vehicle. The speed calculated in this way is a safety-critical value which is used as a basis for safety functions of the rail vehicle.The wheel diameter to be determined changes due to mechanical loads during operation of the rail vehicle and also due to maintenance measures carried out.Due to dynamic metal-metal contact during operation, a wheel profile is subject to wear which can be divided into two portions. A first portion is caused by the rolling motion of the wheel, which is associated with slip and microsliding. This wear component is manifested on the one hand in a geometric change in the wheel profile which is "deformed" compared to the profile prescribed in standards.A second component is caused by a correction of the profile changes, which takes place by way of an underground wheelset rotation (re-profiling). In this case, wheel material is removed in a defined manner during operation in order to restore or maintain a wheel profile conforming to the norm. Both portions lead to a reduction in the wheel diameter.It is known to determine the wheel diameter and its profile regularly with the aid of specially trained maintenance personnel. In this case, associated parameters of the individual wheel are measured with millimeter precision and manually. If these parameters reach predetermined limit values, re-profiling is planned for the associated wheel.This procedure is complicated and error-prone due to the "human factor": inaccurate measurements, incorrect inputs or forgotten inputs influence, on the one hand, the safety-critical determination of the speed of the rail vehicle and, on the other hand, the operating safety of the wheel in a disadvantageous and immediate manner.This procedure is also expensive: because of the use of measuring instruments in determining the wheel parameters, a workshop stay of the rail vehicle for several hours is necessary. The downtime of the rail vehicle thus generated has a disadvantageous effect for the operator as well as for the manufacturer of the rail vehicle. The need for specially trained maintenance personnel also causes increased costs.It is therefore the object of the present invention to specify an improved method for detecting a wheel diameter in a rail vehicle, which method can be carried out reliably, with high precision and in a cost-saving manner.This object is achieved by the features of claim 1. Advantageous further developments are specified in the dependent patent claims.The invention relates to a method for determining a wheel diameter in a rail vehicle.In this case, a wheel diameter of a wheel of the rail vehicle is manually determined.Digital twin is used to estimate wheel diameter wear.The digital twin is based here on stored values of the determined wheel diameter and on constantly updated operating data of the rail vehicle.In an advantageous development, the wheel diameter is determined manually after re-profiling of the wheel has been carried out.In an advantageous development, the manually determined wheel diameter is stored on the side of the rail vehicle in an associated train safety system.In an advantageous development, the manually determined wheel diameter is transmitted from the rail vehicle to a fixed control point, which is referred to as the land side.In an advantageous development, the manually determined wheel diameter is transmitted from the rail vehicle to the stationary monitoring point with the aid of a radio communication system.In an advantageous development, the digital twin is used on the side of the fixed control point in order to estimate the wear of the wheel diameter.In an advantageous development, the digital twin is based on the stored values of the wheel diameter which are stored in the traction securing system or on the side of the fixed monitoring point.In an advantageous development, the digital twin is based on continuously updated operating data of the rail vehicle, in particular on a travel distance travelled by the rail vehicle, and / or on wheel data, in particular on previously known wear data and / or on previously known wheel materials.In an advantageous development, the digital twin is based on data from train protection systems and / or on data from train influencing systems. This makes it possible to determine the current wheel diameter or the wheel diameter wear more accurately and preferably in real time.This includes, for example, the known "European Train Control System, ETCS". The European Train Control System (ETCS) is a system for signal control and train monitoring in the European rail network. It collects and transmits a variety of data to improve the safety and efficiency of train traffic. The data provided by ETCS include:Speed restrictions: ETCS informs trains about the permissible maximum speed on different route sections.Route information: The system passes on data about the route topology, such as curves, slopes, slopes and points positions.Signals and signal status: ETCS transmit information about light signals and their status to indicate to the train drivers whether they are allowed to continue driving or stop.Braking curves and braking distances: It provides information about the braking curves and required braking distances in order that trains can stop in good time.Train position and speed: ETCS tracks the exact position and speed of the trains to avoid collisions and to regulate the train distance.Safety-relevant data: this includes information about construction sites, temporary speed limits or other safety-relevant events on the route.functions for train control: ETCS can also provide functions for train control and train guidance, in order to activate automatic braking or train stops in cases of emergency, for example.In summary, ETCS operates as an integral part of the train control system to ensure safe and efficient train travel by providing important information to the train drivers and the landing gear in real time.This also includes, for example, the known "punctiform tension influencing, PZB". Point train control (PZB) is a train control system used in Germany and some other countries to ensure safety in train traffic. Unlike the ETCS, which is a comprehensive system, the PZB operates with a limited number of data and functions to control train traffic. The PZB provides mainly the following data:Signals and signal information: The PZB uses magnets or induction loops on the track to transmit information about signals. It detects the signal position and informs the operator of the next signal and the allowed speed.Speed monitoring: It monitors the speed of the train and compares it with the allowed speeds on the section of the track. If the train exceeds the speed limit, the PZB may engage and trigger automatic forced braking.Braking curves and brake path monitoring: Similar to ETCS, the PZB can monitor the brake path and, if appropriate, activate the brakes in order to stop the train in good time if the speed regulations are not taken into account.Stop signals: The PZB also monitors stop signals to ensure that the train stops in time if a stop is required.In summary, the PZB is an older train control system compared to ETCS and provides a basic but effective safety control for train traffic by supporting the operator and intervening in the case of speed limits being exceeded or signals being ignored in order to avoid accidents.This also includes, for example, the known "linear train influencing, LZB". Linear train control (LZB) is a train control system used in some countries, especially in Germany, to control train traffic and to ensure safety. Similar to ETCS and PZB, the LZB provides a series of data to assist in train control and monitoring:Speed control: The LZB monitors the speed of the train and gives the operator information about the permissible speed on the route section. It may also automatically control the train speed to meet the maximum speed specified.Data transmission and reception: The LZB operates via data transmission systems between the route signal system and the train. It receives information about signal position and speed regulations and transmits these to the locomotive driver.Automatic braking: Similar to other train control systems, the LZB may trigger automatic braking if the train operator ignores speed limits or ignores signals.Route Monitoring: The LZB monitors the route and can provide the train driver with indications of disturbances or speed changes that can occur on the route.In comparison with PZB, LZB offers more advanced control of the train movements, in that, in addition to purely monitoring signals and speeds, it also offers the possibility of automatically regulating the train speed and of assisting the operator in compliance with the regulations.The same coverages are ETCS, PZB and LZB in these points:Speed Monitoring: All three systems monitor the speed of the train and inform the operator of the permissible speed on a specific route section. They can also intervene to trigger automatic braking if the speed limit is not adhered to.Signal monitoring: They all provide functions for monitoring signals, whether the display of signal status or the warning of the operator of stop signals or signals with specific instructions.Safety-relevant monitoring: All three systems are designed to transmit safety-relevant information, such as, for example, indications of faults on the route, construction sites or other events which could influence the pulling movement.At least the speed of the vehicle as well as the braking are the parameters that are transmitted in the digital twin. As a result, the stored or estimated values for the wheel diameter are secured or constantly updated.In an advantageous development, wear of the wheel diameter during operation of the rail vehicle is continuously estimated by the digital twin and compared with the values stored on the side of the rail vehicle or on the side of the control point.This makes it possible to detect irregularities or excessive wear of the wheel diameter in a wide range of advance.By the present invention, wheel diameters are determined without errors and continuously with the aid of highly accurate estimation.The present invention reduces down times required to date in the determination of the wheel diameters and the use of personnel required to date.The present invention makes it possible to determine an inspection or maintenance requirement widely beforehand, which increases its planability and feasibility.The invention is explained in more detail below with the aid of a drawing. The single FIG. 1 shows a flow chart for the invention.A wheel diameter DMAN of a wheel of a rail vehicle is manually determined and prepared for use with a digital twin DZWI.The digital twin DZWI is used to estimate wear VERS of the wheel diameter.The digital twin DZWI is based here on stored values of the determined wheel diameter DMAN and on constantly updated operating data of the rail vehicle.The constantly updated operating data of the rail vehicle are obtained with the aid of one or more train influencing systems.In particular, advanced train control systems, such as the ETCS, PZB or LZB systems described above, play a decisive role in data acquisition with respect to speed and brakes, which are integrated into the digital twin DZWI or used by it.The digital twin DZWI accommodates predictive calculations that allow interpretation for the future. A main function of the digital twin is to calculate predictive analyses for the wear on the basis of the collected operating data in order to make a statement as to how far a rail vehicle under consideration can still travel with its current wheels.As soon as maintenance personnel in a workshop make real measurements of the wheels, these values are fed into the train influencing systems (here ETCS, PZB or LZB).This is generally effected via service lap tops or directly via displays on board the vehicles.This is basically similar to the process of re-profiling the wheels, where the updated data is input to the systems to ensure their precise and secure functionality.An exchange of measurement data between the digital twin DZWI and the systems for influencing the train is decisive in order to continuously obtain accurate information about the state of the wheels and in order to ensure that the systems are always up-to-date.By integrating this information in real time, the systems can on the one hand further improve the safety and efficiency of train traffic by enabling precise predictions, while on the other hand and at the same time ensuring the integrity of the wheels and other important components.

Claims

Method for determining a wheel diameter in a rail vehicle, - in which a wheel diameter of a wheel of a rail vehicle is manually determined, - in which a digital twin is used to estimate wear of the wheel diameter, - in which the digital twin is based on stored values of the determined wheel diameter and on constantly updated operating data of the rail vehicle.Method according to claim 1, wherein the wheel diameter is determined manually after re-profiling of the wheel has been carried out.Method according to Claim 1 or 2, in which the manually determined wheel diameter is stored on the side of the rail vehicle in an associated train safety system.Method according to one of the preceding claims, in which the manually determined wheel diameter is transmitted from the rail vehicle to a fixed monitoring point which is referred to as the land side.Method according to Claim 4, in which the manually determined wheel diameter is transmitted from the rail vehicle to the fixed monitoring point with the aid of a radio communication system.Method according to Claim 4 or 5, in which the digital twin is used on the side of the fixed monitoring point in order to estimate the wear of the wheel diameter.Method according to one of the preceding claims, in which the digital twin is based on stored values of the wheel diameter which are stored in the traction protection system or on the side of the fixed monitoring point.Method according to one of the preceding claims, in which the digital twin is based on continuously updated operating data of the rail vehicle, in particular on a travel distance travelled by the rail vehicle, and / or on wheel data, in particular on previously known wear data and / or on previously known wheel materials.Method according to one of the preceding claims, in which the digital twin is based on data from train protection systems and / or train influencing systems.Method according to Claim 9, in which data of the system ETCS or PZB or LZB are used.Method according to one of the preceding claims, in which the digital twin continuously estimates wear on the wheel diameter during operation of the rail vehicle and compares it with the values stored on the side of the rail vehicle or on the side of the control point.

Images