The present invention relates to control systems of trains, particularly for transport of goods and comprising a plurality of locomotives.
In particular, the invention relates to an acoustic system and method for traction and braking control of a train.
The “Distributed Power” technique born in the American “AAR” railway world is well known in the art. Such technique consists in distributing several locomotives along a train of exceptional length and weight, as shown in
The purpose of the “Distributed Power” system is to better distribute traction and braking forces along the train, significantly reducing longitudinal forces that could trigger processes of derailment.
An accurate description of the distributed power system and its benefits is contained in WO2017025895, where the drawbacks of possible faults in the radio control system are also fully described and corrective solutions are claimed for operating the train in degraded conditions.
According to the report I00-002 “Sonar Transmission through the Train Brake System”, Hans Sandholt, Bengt Schmidtbauer, reporting the results of tests carried out in collaboration between the Swedish institute CHARMEC and the company SAB-WABCO Italia, today Faiveley Transport Italia, it is possible to transmit waves at subsonic frequencies along the brake line of a train up to 1.5 km long, at a maximum frequency between 5 Hz and 10 Hz.
US2002153765 claims propagation of negative and positive pressure pulses along the brake line of a railway train to transmit traction or braking commands. According to such method, it is not possible to continuously modulate traction or braking commands.
An object of the present invention is therefore to propose an acoustic system and method for the continuous traction and braking control of a train that allows an additional way of controlling a train.
The solution of the present disclosure consists in a further method, with respect to those already reported in WO2017025895, for controlling a train adopting Distributed Power technology, in the event of a fault in the radio control system.
The solution claimed herein uses the propagation of acoustic waves inside the general pipe.
Such result is obtained by means of an acoustic system for the traction and braking control of a train comprising a general brake pipe, a master vehicle comprising traction and braking devices, and at least one slave vehicle comprising traction and braking devices.
The acoustic system for the traction and braking control of a train includes:
The aforesaid and other objects and advantages are achieved, according to an aspect of the present invention, by an acoustic system and method as described and claimed herein. Preferential embodiments of the invention are also described defined in the dependent claims.
The functional and structural characteristics of some preferred embodiments of an acoustic traction and braking control system according to the present invention will now be described with reference to the drawings.
Before describing in detail a plurality of embodiments of the invention, it should be clarified that the invention is not limited in its application to the details of construction or to the configuration of the components provided in the following description or illustrated in the drawings. The invention may assume other embodiments and may be implemented or achieved in essentially different ways. It should also be understood that the phraseology and terminology have descriptive purposes and should not be construed as limiting. The use of “include” and “comprise” and their variations are to be understood as encompassing the elements stated hereinafter and the equivalents thereof, as well as additional elements and the equivalents thereof.
The present invention describes methodologies for the modulation of subsonic waves superposed at the pressure for transmitting information related to traction and braking commands along the brake line of a train.
Referring initially to
The acoustic system for traction-braking transmission control 1 includes a modulator device 303 associated with the master vehicle ML. The modulator device 303 receives at least one traction or braking request signal 302 and generates an electrical signal 308 adapted to energize an actuator 304. The actuator 304 transforms said electrical signal 308 into a respective acoustic signal 309 to be transmitted inside said general brake pipe 301.
In other words, the modulator device 303 receives information to be transmitted and performs a suitable modulation thereof, as described hereinafter, subsequently driving an actuator 304 which transforms the electrical signal 308 into an acoustic signal 309. The acoustic signal 309 is then propagated along the brake pipe 301.
For example, the traction or braking request signals 302 may be generated by means of traction and braking commands given by an engine driver by means of a special command lever or by automatic traction or braking systems.
The frequency value of said acoustic signal 309 is adjusted according to the amplitude value of the traction or braking request signal 302, in accordance with a predetermined trans-characteristic function.
For example, but not necessarily, the curve of the trans-characteristic function presents a non-linear trend within the existence range thereof.
The acoustic traction and braking control system 1 according to the present invention further comprises at least one transducer device 305, associated with said at least one slave vehicle SL, which detects the acoustic signal 309 and converts the instantaneous amplitude value of the acoustic signal 309 into an electrical signal 310 the frequency value of which is adjusted according to the frequency of the acoustic signal 309.
For example, the frequency of the electrical signal 310 coincides with the frequency of the acoustic signal 309.
Moreover, said acoustic traction and braking control system 1 includes at least one frequency demodulator 306 associated with said at least one slave vehicle SL, which generates a traction or braking management signal 307 the amplitude value of which is adjusted according to the frequency of the electrical signal 310. The traction or braking management signal 307 is transmitted by the frequency demodulator 306 to a traction and braking management system 311, associated with said at least one slave vehicle SL, for the management of traction and braking.
In other words, the transducer device 305, installed on one or more slave vehicles SL, may be an acoustic/electric transducer 305 arranged along said brake pipe 301 which transforms the acoustic signal received into an electrical signal 310 for frequency demodulators 306 charged with reconstructing the initial information and providing said information to a traction/braking management system 311.
If one intends to transmit information through the entire train, it is appropriate to use subsonic frequencies, as indicated in the cases “e”, “f”, “i” of
In such case, the most appropriate type of modulation is a modulation of a sinusoidal frequency, for example but not exclusively at 5 Hz, in a limited range of modulation, for example but not exclusively +/−1.5 Hz. Such a limited range of modulation allows in practice to transmit only traction and braking commands, for example but not exclusively as shown in
A frequency value equal to or less than 3.5 Hz represents the maximum braking request value, including emergency braking. A frequency value equal to or greater than 6.5 Hz represents the maximum traction request value. A variant is shown in
In order to make the system more insensitive to noise, a hysteresis may be inserted the value of which may be fixed or may be changed dynamically by the system according to the noise measured during operation. The curves of
In the same way, discontinuous and/or non-linear functions may be achieved, creating areas with lower gain (higher resolution) and areas with greater gain (lower resolution).
Observing
The acoustic traction and braking control system for acoustic traction-braking transmission may be used as a backup system to a radio traction-braking transmission system, in case of damage or malfunction of the radio traction-braking transmission system.
An acoustic traction and braking control method is moreover described, which includes the steps of:
Several aspects and embodiments of an acoustic traction and braking control system of a train according to the present invention have been described. It is understood that each embodiment may be combined with any other embodiment. The invention, moreover, is not limited to the described embodiments, but may vary within the scope of protection as described and claimed herein.
Number | Date | Country | Kind |
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102017000058879 | May 2017 | IT | national |
This application is a National Phase filing of PCT International Application No. PCT/IB2018/053774, having an International Filing Date of May 28, 2018, claiming priority to Italian Patent Application No. 102017000058879, having a filing date of May 30, 2017 each of which is hereby incorporated by reference in its entirety.
Filing Document | Filing Date | Country | Kind |
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PCT/IB2018/053774 | 5/28/2018 | WO | 00 |