RU2304061C1 - Automatic cab signaling adaptive signal receiver - Google Patents

Abstract

FIELD: railway transport; signaling and communication.

SUBSTANCE: invention relates to continuously controlled cab signaling systems. Proposed adaptive receiver contains series-connected coded signal reception unit, analog-to-digital converter implementing Fourier transfer function, first on-line storage, averaged signal spectrum forming unit and second on-line storage, correlative comparator, control pulse shaper, switch element and correlative identificator of automatic cab signaling signal spectrum which is output of adaptive receiver. First and second outputs of second on-line storage are connected, accordingly, to first and second inputs of correlative comparator. Output of clock-pulse generator is connected to control inputs of first on-line storage, averaged signal spectrum forming unit, second on-line storage and correlative comparator.

EFFECT: improved reliability of identification of signals of continuously controlled cab signaling system at external interference and instability of carrier frequency of coded signals.

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Description

The invention relates to the field of railway automation and telemechanics and can be used in continuous automatic locomotive signaling systems, in particular, in continuous automatic locomotive signaling signal receivers installed in the driver's cab.

A known signal receiver of continuous automatic locomotive signaling (ALSN), designed for continuous reception in the driver's cab of the code (signal) indications of traffic lights - green (W), yellow (W) or red-yellow (QL). The formation of the numerical code of each of these indications is carried out by coding equipment, consisting of a code path transmitter (KPT) and a transmitter relay. The signals transmitted to the rail circuit are received on the locomotive by the receiving coils, amplified and converted by the locomotive receiver into a train of pulses corresponding to the original code combination transmitted by the CBT. The decoder decodes the accepted code combination and, depending on its type, provides ignition of the corresponding fire of a locomotive traffic light (Kravtsov Yu.A., Nesterov V.L., Lekuta G.F. et al. "Railway Automation and Telemechanics Systems", textbook for universities under Edited by Kravtsov, Yu.A., Moscow: Transport, 1996, p. 144-145).

The presence of interference in the rail circuit causes distortion of the received code combinations, which leads to erroneous decoding, i.e. to malfunctions of the ALSN. Improving the stability of the operation of an automatic locomotive signaling can be achieved by using an adaptive receiver in which the recognition of a signal coming from a rail line is carried out by comparing a given set of characteristic parameters of its envelope with the parameters of already received signals recorded in random access memory, as well as with characteristic parameters of model signals Z, F and QOL stored in read-only memory.

As a prototype, a device has been adopted that can be used in continuous automatic locomotive signaling systems. The known device provides reception of signals transmitted to the rail circuit, the received signals are amplified and converted into a pulse sequence corresponding to the original code combination, using the following means. The device contains a series-connected filter, a sampling unit, the second input of which receives a signal specifying the sampling frequency, an amplitude-to-digital converter, a time window generating unit, a buffer unit, a fast Fourier transform unit, a second buffer unit, a Fourier transform data processing unit, a third buffer a unit, a signal selector, and means for calculating the values of the converted signals and identification, the outputs of which are connected to a message former connected to the display (US 4965757, G01R 23/16, 10.23.90).

A disadvantage of the known technical solution is the inability to recognize signals in the event of a deviation of the carrier frequency from a given value. Even its small deviations (comparable to 1/2 the resolution of the Fourier converter) can lead to incorrect identification of asymmetric signals. To ensure correct signal recognition in this case, a change in the algorithm for converting and identifying recognized signals will be required, which will complicate the implementation of the device. Its disadvantage, in addition, is the instability of work in the conditions of interference; the device is not protected from playing distorted (incorrectly received) code combinations and does not contain a node for their suppression.

The technical result consists in increasing the reliability of recognition of signals of automatic locomotive signaling of continuous operation under the influence of external noise and instability of the carrier frequency of the code signals, protection against the reproduction of distorted signals and stability.

The technical result is achieved by the fact that in the adaptive signal receiver of the automatic locomotive signaling, comprising a block for receiving code signals from a rail circuit, the input of which is connected to the receiving coils, and its output - with the input of an amplitude-to-digital converter, a clock generator, a series-connected converter that implements a Fourier transform function, a first random access memory, an average signal spectrum forming unit, and a second random access memory, a correlation comparison device, a control pulse generator, a key element and a correlation identifier of the signal spectra of the automatic locomotive signaling, while the first and second outputs of the second random access memory are connected respectively to the first and second inputs of the comparison correlation device, the output of which is connected to the control input through a control pulse generator a key element connected between the second output of the second random access memory and the input of the correlation identifier of the signal spectra of the automatic locomotive signaling, the output of the clock generator is connected to the control inputs of the first random access memory, the unit for generating the averaged signal spectrum, the second random access memory and the correlation comparison device, the output of the correlation identifier of the signal spectra of the automatic locomotive signaling is the output of the adaptive receiver signals of automatic locomotive alarm.

The above set of features characterizing the proposed receiver, allows for high reliability of recognition of signals of continuous automatic locomotive signaling under the influence of external noise and instability of the carrier frequency of code signals, as well as to suppress distorted (incorrectly received) signals. Each of the signals received by the receiver Z, G and QOL is a cyclically repeating sequence of pulses, on each period T of which the number of pulses, their duration and the duration of the pauses between them are determined by the type of signal. As the characteristic parameters of the sequences Z, G, and KZ, we use the characteristics of their expansion into a generalized Fourier series, and, in particular, their amplitude spectrum obtained on the basis of the discrete Fourier transform (DFT) of the signal envelope over the period T (Baskakov S.I. and signals. Moscow. State Unitary Enterprise Publishing House "Higher School", 2005, p. 389-395).

The drawing shows a functional diagram of an adaptive receiver of signals of an automatic locomotive alarm.

The adaptive receiver of automatic locomotive signaling signals contains a block 1 for receiving code signals from a rail circuit, the input of which is connected to the receiving coils (not shown in the drawing), and its output (the output of the detector of this block) is connected to the input of the amplitude-to-digital converter 2 connected to the input a transducer 3 that implements the Fourier transform function, the output of the transducer 3 is connected to the input of the first random access memory 4 connected to the block 5 for generating an averaged spectrum of signals the output of which is connected to the input of the second random access memory 6, the outputs of the second random access memory 6 are connected respectively to the first and second inputs of the correlation comparison device 7, the output of which is connected via the driver 8 to the control input of the key element 9 connected between the second output of the second random access memory 6 and the input of the correlation identifier 10 of the signal spectra of the automatic locomotive signaling, clock output of the generator 11 is connected to the control inputs of the first random access memory 4, unit 5 forming an averaged spectrum signal, the second random access memory 6 and the correlation comparison unit 7, the output of the correlation identifier 10 spectra automatic locomotive alarm signal is output adaptive receiver automatic locomotive alarm signals.

Adaptive receiver signals automatic locomotive alarm operates as follows.

The signals of the automatic locomotive signaling are perceived by the receiving coils connected to the input of the code signal receiving unit 1. In block 1, the received signals are amplified and detected. From the detector output (the output of the code signal receiving unit 1), the pulse train (envelope of the received signal) u (t) at the output of unit 1, obtained on the basis of the frequency-manipulated harmonic signal U (ωt) received at its input, is input to the analog-digital input converter 2, in which the signal is digitized. Next, the resulting discrete sequence is fed to the input of the transducer 3, in which it is subjected to the Fourier transform and mathematical processing. The result of this transformation is the amplitude spectrum F _{N of the} signal, the set of N values of which is one-to-one associated with the shape of the envelope of the ALSN signal. F _{N is} taken as its characteristic parameter (image) of the original signal.

последовательностей, поступивших в приемник на очередном такте τ_k=nT, k=0, 1, 2, ..., а в блоке 5 формирования усредненного спектра сигналов производится вычисление и формирование их усредненной по n величины

для всех N составляющих амплитудных спектров [F_N]^(j).In the first random access memory 4, n images are stored

the sequences received at the receiver at the next clock time τ _k = nT, k = 0, 1, 2, ..., and in block 5 of the formation of the averaged spectrum of signals, the calculation and generation of their value averaged over n

for all N components of the amplitude spectra [F _N ] ^(j) .

The duration of all clock cycles τ _{k + 1} = τ _k = nT, k = 0, 1, 2, ... is the same and is set by a clock generator 11, which is connected to the control inputs of the first random access memory 4, block 5 of the formation of the averaged spectrum of signals, the second random access memory 6 and correlation device 7 comparison.

непрерывно поступают с выхода блока 5 формирования усредненного спектра сигналов на вход второго оперативного запоминающего устройства 6. Второе оперативное запоминающее устройство 6 работает циклически и хранит усредненные значения амплитудных спектров (образы) огибающих

и

, полученные для каждых двух смежных тактов работы устройства - последующего τ_k+1 и предыдущего τ_k и поступающие соответственно на второй и первый входы корреляционного устройство сравнения 7. Корреляционное устройство сравнения 7 на каждом такте производит сравнение этих образов. При их совпадении формирователь 8 импульса управления формирует сигнал логической 1, а при несовпадении - сигнал логического 0.Values

continuously come from the output of block 5 forming an averaged spectrum of signals to the input of the second random access memory 6. The second random access memory 6 is cyclical and stores the average values of the amplitude spectra (images) of the envelopes

and

obtained for every two adjacent clock cycles of the device - the subsequent τ _{k + 1} and the previous τ _k and received respectively at the second and first inputs of the correlation comparison device 7. The correlation comparison device 7 at each cycle compares these images. When they coincide, the driver 8 of the control pulse generates a signal of logical 1, and if they do not match, a signal of logical 0.

- образа независимо от того, какой группой КПТ генерируется текущее сигнальное показание, и идентифицирует

- образа как З, Ж или КЖ сигнальное показание, которое отражается на подключенном к выходу корреляционного идентификатора 10 локомотивном светофоре. При отсутствии совпадения формирователь 8 импульса управления формирует сигнал логического 0, ключевой элемент 9 при этом запирается,

- образ на вход корреляционного идентификатора 10 не поступает и на его выходе формируется признак отсутствия сигнального показания (белый огонь).The presence of a consistent chain of coincidences is evidence of stable adaptive reception and decoding of the next ALSN signal indication. Generated by the driver 8 of the control pulse, the coincidence signal corresponding to logical 1 opens a key element 9 connecting the second output of the second random access memory 6 with the input of the correlation identifier 10 of the signal spectra. The correlation identifier 10 of the signal spectra contains a read-only memory (ROM) in which the characteristic parameters of the standard signal readings Z, F and QOL are recorded for two groups of code transmitters that are currently used in operation: KPT-5, KPT-8 with a duration of a signal reading of 1.6 s and KPT-7, KPT-9 with a duration of a signal reading of 1.9 s. The device is invariant to the type of CBT, performs a correlation analysis of the input received at its input.

- an image regardless of which CBT group generates the current signal indication, and identifies

- an image as З, Ж or КЖ signal indication, which is reflected in the locomotive traffic light connected to the output of the correlation identifier 10. If there is no match, the driver 8 of the control pulse generates a logic 0 signal, the key element 9 is locked,

- the image at the input of the correlation identifier 10 is not received and at its output a sign of the absence of a signal indication (white light) is formed.

Thus, the use of the proposed adaptive receiver of signals of an automatic locomotive signaling, providing high noise immunity, prevents distortion of the signal reading, thereby increasing traffic safety.

Claims (1)

An adaptive receiver for automatic locomotive signaling signals, comprising a block for receiving code signals from a rail circuit, the input of which is connected to the receiving coils, and its output is connected to the input of an analog-to-digital converter, characterized in that a clock generator, a series-connected converter that implements the function, is introduced into it Fourier transform, the first random access memory, the formation unit of the averaged spectrum of signals and the second random access memory, correlation device The comparison property, the control pulse generator, the key element and the correlation identifier of the signal spectra of the automatic locomotive signaling, while the input of the converter that implements the Fourier transform function is connected to the output of the analog-to-digital converter, the first and second outputs of the second random access memory are connected to the first and second the inputs of the correlation comparison device, the output of which is connected to the control input through a control pulse shaper a key element connected between the second output of the second random access memory and the input of the correlation identifier of the signal spectra of the automatic locomotive signaling, the output of the clock generator is connected to the control inputs of the first random access memory, the unit for generating the averaged signal spectrum, the second random access memory and the correlation comparison device, the output of the correlation ID of signal spectra of an automatic locomotive signal tion of the receiver is the output of an adaptive automatic locomotive alarm signals.