JPH0710983Y2 - Vehicle detection receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a receiver for receiving a vehicle detection signal transmitted from substantially the center of a blocked section in both ends of the blocked section in a non-insulated track circuit. It is a thing.

[Conventional technology]

In a non-insulated track circuit, an AC signal of a specific frequency is transmitted by a transmitter from approximately the center of the block section formed by dividing it, and each AC signal is received at each end of the block section and then each reception signal is received. A means for detecting the presence of a vehicle in a closed section by the logical sum of outputs is generally used.

[Problems to be solved by the invention]

However, in the past, receivers were provided for each of the boundaries of the block section, and the increase in the number of receivers increased the equipment cost, and the maintenance and inspection man-hours correspondingly increased. Has occurred.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention comprises the following means.

That is, the AC signal of a specific frequency transmitted from approximately the center of the block section formed by partitioning the non-insulated track circuit consisting of a pair of non-insulated rails is received from each output at each end boundary of the block section from the AC It is provided with a wave device for extracting each signal, a multiplier for multiplying each output of each wave device with each other, and a detection circuit for detecting the output of the multiplier.

[Action]

Therefore, a wave filter extracts an AC signal of a specific frequency from each output received at each boundary at both ends of the closed section, and these are multiplied by a multiplier. If the detection circuit detects this, the vehicle in the closed section can be detected.

〔Example〕

Hereinafter, the details of the present invention will be described with reference to the drawings showing embodiments.

FIG. 1 is a block diagram showing a non-insulated track circuit (hereinafter, track circuit) 3 consisting of a pair of non-insulated tracks (hereinafter, track) 1 and 2.
And the closed section (hereinafter referred to as section) 1T to 3T is formed, and when attention is paid to section 2T, the current limit is set by the transmitter (hereinafter referred to as TX) 11 from the transmission point Ps set at the center of this section. Specific frequency f _{2 with} respect to the track circuit 3 via the resistor R for
While transmitting an AC signal obtained by modulating the carrier wave of the carrier with a modulation signal of a predetermined frequency, at both end boundaries A and B of the section 2T, by the loop-shaped coils L ₁ and L ₂ arranged along the rails 1 and ₂ , It is supposed that the AC signals that pass through the rails 1 and 2 are detected by electromagnetic coupling, and each of them receives power.

A TX similar to TX11 is also provided in sections 1T and 3T, carrier frequencies of these are defined as f ₁ and f ₃ , respectively, and the frequency of the signal is different for each section.

The AC signal of each frequency is received by the coils L ₁ and L ₂ ,
To the bandpass filters (hereinafter, BPF) 12 and 13 that pass the frequency f ₂ through the matching transformers MT ₁ and MT ₂ having two secondary windings and the resistance attenuators ATT ₁ and ATT ₂ for level setting. Given, where only the AC signal of frequency f ₂ is extracted into each,
It becomes a modulated signal by demodulation by demodulators (hereinafter, DEM) 14 and 15, and logarithmic compression is performed by logarithmic amplifiers (hereinafter, LGA) 61 and 62 that form a multiplier (hereinafter, MUL) 16 and then adders (hereinafter, , AD) 63 and after the logarithmic compression is restored by the antilogarithmic amplifier (hereinafter, ALA) 64, the power is amplified to a desired power by the power amplifier (hereinafter, PA) 17 that constitutes the detection circuit. The rectifier (REC) 18 produces a direct current, which drives the relay MR.

Therefore, V _1, V ₂ each output voltage of DEM14,15, each LGA61,62
The output voltage of V _o1 , V _o2 and the gain of each LGA 61, 62 are K _1, and the following equation holds.

_{V o1 = K 1 · l og} V 1 ...... (1) V o2 = K 1 · l og V 2 ...... (2) Further, the output voltage Vt of AD63 is given by the following equation.

Restoring a logarithmic compression by _{Vt = K 1 (l og V} 1 + l og V 2) = K 1 · l og V 1 · V 2 ...... (3) the Vt ALA64, the gain of ALA64
When K ₂ is set, the output voltage Vot of this is given by the following equation.

Vot = K ₁ · K ₂ · V ₁ · V ₂ = K · V ₁ · V ₂ (4) However, K = K ₁ · K ₂ , but in MUL16, V ₁ and V ₂ are mutually When either one becomes zero or becomes a very small value, Vot becomes the same, and the result equal to the logical sum of V ₁ and V ₂ is obtained, and accordingly PA17, The output of REC18 decreases and the relay MR is restored.
When the vehicle presence line of 2T is shown and the same vehicle absence line is shown during the operation of the relay MR, the vehicle detection in the section 2T can be performed by this.

Incidentally, if the coil L _1, the output voltage of the L ₂ each v _1, v ₂ and due to the AC signal of frequency f _2, V _1, V ₂ are proportional to v _1, v _2, respectively, from the interval 1T When the vehicle enters the section 2T, due to the short axis of the axle, the AC signal of the frequency f ₂ cannot be communicated to the rails 1 and 2 at the portion facing the coil L _1, and v ₁ is lowered, and this state is also the transmission point Ps. Continue until the vehicle passes.

In addition, until the vehicle moves from the power transmission point Ps to the section 3T, the AC signal cannot be transmitted to the rails 1 and 2 in the portion facing the coil L _{2 in} the same manner, and v ₂ is reduced. While the vehicle is in line, either v ₁ or v ₂ will drop, and the relay MR will be restored accordingly.

FIG. 2 shows a vehicle detection characteristic, in which the vehicle V is a section from the boundary A.
When entering 2T, v ₁ drops sharply, and this state is maintained up to the transmission point Ps, but if it passes this, v ₁ will gradually rise due to the influence of the impedance of rails 1 and 2.

In addition, v ₂ shows the opposite tendency to v _1, and gradually decreases as the vehicle V approaches the power transmission point Ps, while it rapidly increases as it advances from the boundary B to the section 3T.

Meanwhile, v _1, v Vot by V _1, V ₂ of the product to comply to _2, v is a logic sum of the reduction range of reduced range and v ₂ of _1, the boundary A, v _1, v change of ₂ in the B In order to maintain the lowered state between the boundaries A and B as it is, the detection level L _{D at} which the relay MR restores or operates is set as shown in the figure, so that the boundary A is set at the detection point P _D and the boundary B. The vehicle V in the section 2T can be accurately detected with the detection limit point P _L.

Therefore, MUL16 or relay MR is shared and boundaries A and B are
Compared to the case where a receiver for each section 2T (hereinafter, RX) is provided for each, the simplification of the configuration realizes reduction of equipment cost, maintenance and man-hours.

Note that the matching transformer MT _1, 2 winding in MT _2, RX ₂ for interval 2T
Those which are not connected to the resistive attenuators ATT ₁ and ATT ₂ constituting the above are connected to similar RX ₁ and RX ₃ for the sections 1T and 3T, respectively.

However, depending on the relationship between frequencies f _{1 to} f ₃ , high-pass filters or low-pass filters may be used instead of BPFs 12 and 13, and DEMs 14 and 15 are omitted unless carrier modulation is performed. This is also the case when MUL16, PA17, and REC18 are replaced with other configurations having equivalent functions.

Further, although the power reception at the boundaries A and B is the current power reception by the coils L ₁ and L ₂ , it may be voltage power reception or voltage / current power reception depending on the situation, and it is the same even if these are individually provided for each section. Various modifications such as the above are possible.

[Effect of device]

As is apparent from the above description, according to the present invention, a signal of a specific frequency transmitted from the center of the block section is extracted at each end of the block section, and the extracted signals are logarithmically compressed and then added. Since an addition logarithm operation is performed on the addition result, the multiplication process can be performed by the adder, and the signals extracted from both ends of the closed section can be treated as substantially one signal by performing the multiplication. A single receiver can receive both ends of the boundary and output a logical sum of the received outputs, reducing equipment costs, maintenance, and inspection man-hours, and sending vehicle detection signals from the center of the section to both ends of the section. When receiving individually at the boundary, a great effect is obtained.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, FIG. 1 is a configuration diagram, and FIG. 2 is a diagram showing vehicle detection characteristics. 1,2 …… Railway (non-insulated track), 3 …… Track circuit (non-insulated track circuit), 11 …… TX (transmitter), 12,13 …… BPF (band wave filter), 16 …… MUL ( Multiplier), 17 ... PA (power amplifier), 18 ... REC (rectifier), MR ... relay, 1T-3T ...
… Section (closed section), L ₁ , L ₂ …… Coil.

Claims (1)

[Scope of utility model registration request] 1. An AC signal of a specific frequency transmitted from substantially the center of a closed section formed by dividing a non-insulated track circuit consisting of a pair of non-insulated rails into a signal received at each end of the closed section. A vehicle detection receiver for detecting the presence or absence of a vehicle on the non-insulated rail based on a first filter (12), a second filter (13), a first demodulator (14), and a second filter. Demodulator (15), first logarithmic amplifier (61), second logarithmic amplifier (62), adder (63), antilogarithmic amplifier (64), rectifier (18), and relay (MR), the first and second filters pass a signal from the transmitter, and the first and second demodulators output the outputs of the first and second filters. Demodulating, wherein the first logarithmic amplifier is The second logarithmic amplifier amplifies the signal received at the other end of the closed section based on the logarithmic characteristic, and the adder is An output signal of the first logarithmic amplifier and an output signal of the second logarithmic amplifier are added, the antilogarithmic amplifier amplifies the adder output signal based on an antilogarithmic characteristic, and the rectifier has the antilogarithmic value. An amplifier output signal is rectified, and the relay detects the presence or absence of a vehicle on the non-insulated track by being energized or deenergized depending on the presence or absence of a rectifier output signal. Receiver.