SU390672A1 - BIBLIO '.; - Google Patents

Description

one

The invention relates to railway automatics devices and is intended for the non-contact automatic detection of overheating of axle-trains.

Device for automatic detection of superheated books is known, including track reading chambers, wheelset sensors, amplifiers, memory control units, a decision block with an amplitude discriminator, amplifier, adder and threshold element.

In order to improve accuracy and noise immunity, the proposed device is equipped with a differential amplifier, logic elements “Р1ЛИ, an inverter and a nonlinear element, hncchem the output of the differential amplifier is connected in parallel to the inputs of the logic element“ Р1ЛИ and an inverter whose output is connected to the second input of the element “OR, and its output through a non-linear element is connected to one of the inputs of the adder.

FIG. 1 shows a diagram of the proposed device, where Y and 2 are rail sensors for the passage of wheel sets, 3 is a reading camera with a receiver of infrared signals; 4 - amplifier of thermal signals of axle boxes, 5 and 6 - triggers, 7 - control unit; eight -

memory block; .9 n W - key diagrams “And, 11 and 12 — memory elements, 13 — decisive block, 14 — amplitude discriminator, J5 — add-on with gain factor

one

(.IH-), 16 - adder, 17 - threshold

element, 18 - d, ifferred amplifier, 19 - inverter, 20 - logical s. kema OR, 21 - nonlinear element with a given characteristic.

FIG. 2 shows a time diagram of the downturn of the device, explaining the principle of its operation; in fig. 3 - the calculated surface of the optimal threshold, dividing the area of existence of a normal greyupi-1x with an emergency heating box, where X is the maximum amnlitude of two

compared signals (f7 «aito), Y - relative amplitudes of a larger signal to a smaller one ((7 max / / mpV), Z - difference of amplitudes of a large and small signal (/ max- (Umni). Iri of the first oscillator on

a rail sensor / aisle of wheel pairs at its output appears a signal (Fig. 2, a), which flips trigger 5 of control unit 7. Trigger 5 switches and prepares the triggering of key circuits

"And 9 and 10 of the memory block 5. Iri passing the first wheelset between the rail sensors / and 2 bolometer of the readout chamber 3" examines the rear (as the train moves) wall of the axle box. The heat signal produced by the bolometer from the output of amplifier 4 is fed to the inputs of memory elements L and 12, but is memorized by memory element 11. After finishing the inspection of the first wheel set, it passes under sensor 2 and the electrical signal from it (Fig. 2, b) again triggers trigger 5, returning it to its original state. At the same time, flip-flop 6 is transferred, the signal from the output of which (Fig. 2, d) will prepare circuits for storing the amplitude of the signal by memory element 12. This completes the memorization operation and the amplitude of the signal of the axle box of the first wheel set. When the second wheel enters the sensor 1 of the wheel pair, trigger 5 switches again, and the key device JO connects to the input of amplifier 4 a memory element 12 that will "remember the amplitude of the second axle box signal from the same side of the train. Upon completion of the operation of storing the amplitudes of two adjacent signals of the axlebox of the car, the decision block 13 begins to work, which makes a decision about the state of the axle box.

In accordance with theoretical calculations, the decision block detects overheated axles on the surface of the optimal threshold shown in FIG. 3. Its analytical expression is:

Up

1 n something (1 + 1)

Ho

where. Uo - the value of the threshold ratio of the amplitudes of the signals when the magnitude of the amplitude of the larger of the compared signals x,

n is a constant coefficient that determines the horizontal asymptote of the optimal threshold curve at

Z const;

/ Po is the coefficient determining the vertical asymptote of the optimal threshold curve;

p - coefficient with size 1} To compose a decision block algorithm that implements the detection of superheated boxes over the surface of the optimal por / X

ha, taking into account the fact that Y -: -, ner L / MIInSU. MIN

The new equation will be as follows:

(1 + 1)

1 then (+ /)

Lj instant

/ rt / mas C / m and k

nx

Adding and rel in the right side of the equality unit, and then, multiplying the left and right sides by f /.- na-c, after conversion we get:

--- I ma, with | I -) l + M "Kc4-f /" - H4-t / Z

 , + and, + and,

where (U2 then / -.

Analyzing this expression, we see that the decision block, which detects overheated axial boxes on three grounds, must contain a threshold element with a response threshold (L-something) and an adder, on which the four voltage values are summed:

LI - {Smart „. Il + ---); L2

L / 3 - iL / MiiH; U.Uz.

Signals from memory elements 11 and 12 are simultaneously sent to amplitude discriminator 14, which extracts a signal with a larger amplitude (f / max), a differential amplifier 18 and an adder 16. The output signal from the discriminator passes through amplifier 15 with an amplification factor ( ) also goes to the adder

16. Differential amplifier 18 forms the difference of the amplitudes of the two matched signals, which is fed to the inputs of the inverter 19 and the logic element OR 20. The output of the OR 20 circuit is the magnitude of the difference of the amplitudes of the compared signals, depending on which output of the nonlinear element with the characteristic

Uf bij: Ui -l, the voltage UA LZ is generated.

Thus, at the output of the adder we have

f /, 1 J

 P

+ f; .MaKC-f (y.MHH-f,

What was required to get. Threshold element 17 is triggered by

when the measured signs of the signs of detection, y, z together give a point on or above the surface of the optimal threshold, i.e., in the region of the maximum probability of being overheated

bush

The advantages of the proposed device include the ease of its adjustment under the conditions of operation (setting the calculated threshold for triggering the threshold element and

amplification), as well as the possibility of its technical implementation with the help of typical logic elements.

Subject invention

A device for automatic detection of overheated railway axle boxes containing track reading chambers, wheelset sensors, amplifiers, memory control units, a resolver unit with amplitude discriminator, L-driver, adder and threshold element, characterized in that, in order to improve accuracy and noise immunity, it is equipped with a differential amplifier, OR logic gates, an inverter and a nonlinear element, with the output of the differential amplifier connected to a parallel moves the logic element "OR and inverter, whose output is connected to the second input element" OR, and its output via a nonlinear element soedipen to one input of the adder.

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