RU2710301C1 - Method of transmitting and receiving data through an air gap with short pulses and a device for its implementation - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: invention relates to telemetry, in particular, to transmission and reception of pulse signals through an air gap, and can be used in systems for transmitting and receiving data from working members of rotating assemblies and mechanisms. On rotary part of device pulses of bits of information code are used to excite primary circuit of inductively coupled circuits, secondary circuit of which is separated from it by an air gap and is located on fixed part of device, characterized by that short of excitation pulses are formed from bits of code, as compared to their duration, positive and negative half-waves of reaction to them in fixed part of device are integrated by first and second integrators, which zero at the end of each digit of data code, obtained integrals are compared on two comparators with identical in absolute value, but different sign by threshold, value of which is selected proceeding from the shape of short pulses and operating mode of connected loops, signals from outputs of comparators are supplied to inputs of the AND element, at the output of which recovered values of bits of the data code transmitted through the air gap are obtained.

EFFECT: technical result consists in improvement of noise immunity of transmitted data.

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Description

The invention relates to the field of television measurements, in particular to the transmission of pulsed signals through an air gap and can be used in systems for transmitting and receiving telemetric information from working bodies of rotating units and mechanisms.

Currently used methods and devices for transmitting and receiving data through the air gap are based either on the use of a radio channel or on the transmission of pulsed signals. In the latter case, the contactless transmission path is simplified by eliminating the components of the radio channel (modulator, demodulator, filter, etc.) from it and, on the whole, its reliability increases [1].

In turn, data transmission in pulsed form has several realizations. Among them, it should be distinguished methods that use the transmission of data by short pulse packets through inductively coupled circuits (ICC) [2, 3]. These methods are aimed at increasing the data transfer rate. Short-duration excitation signals of the rotating circuit of the ISK, corresponding to a unit in the discharge of the data code, can have a rectangular shape [1, p. 20], exponential [2], acute-angled [3] or other shape. The reaction of the stationary circuit of the ISK to them in the general case consists of several half-waves. The first half-wave of the reaction, which has a large amplitude compared to subsequent half-waves, allows us to establish the fact of the transmission of unity or zero in the discharge of the code in the stationary part of the equipment.

However, the aforementioned methods are more focused on data transmission through the air gap and behind the scenes suggest the use of a threshold method for recovering code messages, as simpler. But it is known that methods that use an integrated estimate over the entire observation interval of a signal (for example, [4], p. 109) are more effective in evaluating the value of a received signal. Therefore, by combining the advantages of transmission methods with short pulses with an integrated assessment of the response of ISK to them in stationary equipment, it is possible to increase the noise immunity of the method of transmitting and receiving data through the air gap.

Closest to the proposed method (prototype) is the method presented in the device for transmitting and receiving information from rotating objects [5]. The known method assumes that on the rotating part of the information-measuring system of information packages form sufficiently short excitation pulses of the primary circuit of the ISK formed by the windings of the air transformer and passive RC elements. Under the influence on an immovable circuit, separated from the rotating circuit by an air gap, adequate reactions are formed. The restoration of the packages is carried out using a threshold-regenerative element (comparator), the first input of which serves the signal transmitted through the gap, and the second signal is the threshold signal received from the filter output. The method is oriented to transmitting signals with time-pulse modulation, but it can also be used to transmit signals with code-pulse modulation.

The disadvantage of this method is the low noise immunity due to the threshold method of processing received parcels. It is possible to increase the noise immunity of this simple method by implementing in it an additional integral method for evaluating the received bits of the information code.

The essence of the proposed method is as follows.

For each unit bit of the information code, a short pulse of inductance of the primary circuit of inductively coupled circuits is generated on the rotating part of the measuring system for each unit discharge of the information code. A short pulse can have a rectangular, exponential or other shape. This impulse causes a corresponding reaction of the secondary circuit of the ISK located in the stationary part of the system and separated from the rotating circuit by an air gap. A characteristic feature of the reaction is that it consists of several half-waves of positive and negative polarity. The number of half-waves depends on the operating mode of the ISK. In the regime boundary between the aperiodic and the oscillatory, there are two such half-waves. In weakly oscillating modes, a third half-wave appears. Studies have shown that the integrals of the positive and negative half-waves in the boundary mode coincide in absolute value. This is in good agreement with the well-known energy conservation law. The same is true for other modes and, accordingly, for a different number of half-waves. Therefore, the values of the integrals for the positive and negative half-waves of the ISK reaction are calculated. Since in the absence of half-waves when transmitting zero in the code, the integrals from the interference signal present in the channel will also be the same in absolute value, then a threshold symptom should be taken into account, but after integration. For this purpose, the values of the integrals are compared with the value of the threshold R. For this, the positive integral is fed to the first input of one comparator, the second input of which is the level + P. The negative integral is fed to the second input of another comparator, the first input of which is the level -P. The first comparator will fix the level of the logical unit at its output when the positive integral becomes greater than threshold R. The other comparator will produce a single signal if the negative integral falls below the threshold -P. Using a logical element And, to the inputs of which signals from the outputs of the named comparators are supplied, a signal is generated that corresponds to the accepted value of the discharge of the data code. Integrators zero at the end of each interval corresponding to the duration of one bit of code. The choice of the threshold value P is carried out based on the shape of the exciting signal (the integral value depends on it), the operating mode of the detector (determines the number of half waves in the reaction), and the level of interference in the channel.

The proposed method allows to eliminate the disadvantage of the known method, namely, to increase the noise immunity of data transmission and reception through the air gap with the help of ICDs excited by short pulses, the output signal of which in the fixed part of the measuring system is subjected to integral and threshold processing in order to recover code messages.

The principle of achieving the named technical result due to the implementation of the above actions with the signal transmitted through the air gap is illustrated by figures 1 and 2.

In the known device (prototype), information packages are fed to a signal conditioner, which creates a short pulse, the location of which is determined by the parameter of the package, for example, its amplitude. So they form a signal with time-pulse modulation. In FIG. 1a, a similar pulse pri of a rectangular shape is shown. It is fed to the primary (rotating) circuit of the ISK formed by the windings of an air transformer and RC elements. In FIG. Figure 1b shows the signal g generated at the output of the stationary circuit of the ISK in response to the pulse of the driver. The signal has positive and negative half-waves. In stationary equipment, the transmitted impulse is detected using a threshold regenerative circuit (comparator). To increase the noise immunity in the prototype, a filter is used that monitors the voltage of low-frequency noise and uses it as a threshold level in the comparator. Thus, in the prototype, the negative wave of the ISK reaction is not used (cut off by the comparator). Note that the method used in the prototype for the transmission and reception of pulsed signals with time-pulse modulation, will remain operational when using signals with code-pulse modulation.

In the proposed method, a short pulse, for example, a rectangular pulse, similar to the pulse pri shown in FIG. 1, is generated for each unit bit of the data code on the rotating part of the system. 1a (the impulse can be Gaussian, sinusoidal, exponential, acute-angled and others). The zero bit of the code corresponds to a pause at the output of the corresponding shaper. Such a signal is used to excite the primary circuit of the ISK. Under its influence on the stationary part of the system, at the output of the secondary circuit of the ISK, separated by an air gap from the primary circuit, a signal g is generated, shown in FIG. 1 b If a signal of this kind is detected on the secondary circuit, then this means that a unit was transmitted in this category of the code, and in its absence, zero. The type of signal at the output of the ISK for all variants of the excitation signal is the same - the signal consists of at least two half-waves, positive and negative, and the integrals from them are equal in absolute value. As an example in FIG. 1c shows the values of the above integrals for the reaction g of the ISK to a short rectangular pulse of normalized duration (to the natural frequency of the oscillations of the circuits in 1 Hz) of 0.4 s duration, exciting the ISK with the same contours and a coupling coefficient between them equal to 0.5, in the boundary mode with a normalized amplitude of 1 V input exposure [1, p. 19]. The signal at the output of the fixed circuit may be distorted by noise, for example a normal view, as shown in FIG. 2a - signal smes. The positive values of the signal distorted by the interference are integrated by the first integrator, the signal int1 at the output of which is shown in FIG. 2, b line double thickness. Negative values of the signal smes are integrated by a second integrator, the output signal int2 of which is shown in FIG. 2, b is a solid thin line. Separation of positive and negative values is realized using the first comparator and two keys, one of which passes the signal values to the first integrator when a unit corresponding to the positive values in the smes signal is formed at the direct output of the first comparator. The second key, controlled by the inverse output of the first comparator, passes negative values to the second integrator. When transmitting a unit in the code category (fragment 1 in Fig. 2, b), the integrators return values equal in absolute value. Obviously, if zero is transmitted in the discharge of the code (fragment 0 in Fig. 2, b), then both integrators will also give the same values in absolute value. Therefore, when restoring the premises, the integral value is also taken into account. With the selected form of a short excitation pulse, the reaction to it is known, and hence the value of the integral. It is logical to assume that if both integrals exceed some threshold P in absolute value, then one is present in this category of code. The signal int1 from the output of the first integrator is fed to the first input of the second comparator, to the second input of which a threshold + P is supplied. The signal int2 from the output of the second integrator is connected to the second input of the third comparator, the first input of which serves the threshold -P. The threshold levels in FIG. 2b are shown by dashed lines. The signal k2 from the output of the second comparator (plot 2 in Fig. 2, c) and the signal k3 from the output of the third comparator (plot 3 in Fig. 2, c) are fed to the inputs of the logic element I. At the output of the element And receive the signal vp of the restored packages, represented by diagram 4 in FIG. 2, c. The threshold P is selected based on the shape of the short pulse of excitation of the ISK, the mode of their operation and the level of interference in the channel. In order to ensure normal functioning, at the end of each interval of the code discharge transmission, the integrators signal sbros, represented by diagram 1 in FIG. 2, c. The sbros signal resets the integrators, preparing them for the integration of the next discharge. The proposed method, due to the combination of ICS excitation with short pulses used to transmit signals through the air gap and integrated threshold assessment of the received signals, is less sensitive to instantaneous distortions in the useful signal due to interference. Therefore, the proposed method of transmitting and receiving data through the air gap with short pulses has a higher noise immunity compared to the prototype.

In FIG. 3 shows a structural diagram of a device for implementing the proposed method of transmitting and receiving data through the air gap with short pulses, and in figures 1 and 2 are diagrams explaining its operation.

To achieve a technical result, which consists in increasing the noise immunity of transmitting and receiving bits of a data code, to a device containing a short pulse shaper on its rotating part, the input of which is the input of the device, and its output is connected to the primary circuit of inductively coupled circuits, the secondary circuit of which is located on the fixed part of the device and separated from the primary circuit by an air gap, connected to the input of the first comparator, two keys, two inter Gratora, second and third comparators, and element I. The first comparator uses a zero threshold, its input is connected to the inputs of the first and second keys, its direct output is connected to the control input of the first key, and the inverse output is connected to the control input of the second key. The output of the first key is connected to the input of the first integrator, the output of which is connected to the first input of the second comparator, the threshold + P is applied to the second input of which. The output of the second key is connected to the input of the second integrator, the output of which is connected to the second input of the third comparator, the first input of which has a threshold -P. The control inputs of both integrators give a signal "Reset". The outputs of the second and third comparators are connected to the inputs of the element And, the output of which is the output of the device.

A device for implementing the proposed method for transmitting and receiving data through the air gap with short pulses contains a rotating part 1, a fixed part 2 and an air gap 3. The rotating part 1 contains a shaper 4 of short pulses and a primary circuit 5 of inductively coupled circuits 7. The fixed part 2 of the device, separated from the rotating part 1 by the air gap 3, contains a secondary circuit 6 of inductively coupled circuits 7, the first comparator 8, the first 9 and second 10 keys, the first 11 and second 12 integrators, the second comparator p 13, the third comparator 14, the element And 15.

The input of the device is the input of the shaper 4 short pulses located on the rotating part 1, which receives the bits of the data code. Its output is connected to the primary circuit 5 of inductively coupled circuits 7. The output of the inductively connected circuit 2 of the secondary circuit 6 of the inductively coupled circuits 7, separated from the primary circuit 5 by an air gap 3, is connected to the input of the first comparator 8, having a zero comparison threshold, and also the inputs of the first 9 and second 10 keys, the outputs of which are connected respectively to the inputs of the first 11 and second 12 integrators. The output of the first integrator 11 is connected to the first input of the second comparator 13, to the second input of which a threshold + P is applied. The output of the second integrator 12 is connected to the second input of the comparator 14, the first input of which has a threshold -P. The control inputs of both integrators give a signal "Reset". The outputs of the second 13 and third 14 comparators are connected to the inputs of the element And 15, the output of which is the output of the device.

The device operates as follows. On the rotating part 1 at the input of the device receives the code sending data of a rectangular shape. Shaper 4 generates from them short excitation pulses of the primary circuit 5 of inductively coupled circuits 7, for example, such as shown in FIG. 1 a. Their action will cause a reaction on the secondary circuit 6 of ISK 7 (Fig. 1, b). The reaction is formed by positive and negative half-waves, the number of which depends on the operating mode of the ISK. In the boundary regime, for example, there are two such half-waves - positive and negative. The integrals of the positive and negative half-waves are equal in absolute value (Fig. 1, c). Therefore, it is necessary to calculate them. The direct output of the first comparator 8 controls the first key 9 so that the first integrator 11 receives positive values from the mixture smes (Fig. 2, a) of the useful signal and noise. As a result, the signal int1, shown in FIG. 2, b thickened line. The inverse output of the first comparator controls the passage of negative values of the smes signal through the second key 10 to the input of the second integrator 12, the output signal int2 of which is shown in FIG. 2, b is a solid thin line. In the same figure, the dotted lines represent the threshold values + P and -P used by the second 13 and third 14 comparators to obtain their output signals k2 and k3 shown in FIG. 2, in diagrams 2 and 3, respectively. At the output of element And 15, the restored code packets vp are generated, which are represented by diagram 4 in FIG. 2c, as a result of the coincidence of two events, the positive integral int1 exceeds the threshold + P and the negative integral int2 exceeds the threshold -P modulo. For the integrators to work correctly, it is necessary to reset their values at the end of each bit of code. This is done using the sbros signal shown in FIG. 2, in diagram 1, supplied to the input "Reset" of the device.

The technical result of the proposed method for transmitting and receiving data through the air gap with short pulses and a device for its implementation is that an increase in the noise immunity of the transmission and reception of bits of the data code is achieved due to the excitation of the rotating loop of the ISK with short pulses and the use of the integral signals generated on the fixed loop for processing and threshold recovery methods.

Literature

1. Measuring systems for rotating units and mechanisms / V.V. Karasev, A.A. Mikheev, G.I. Nechaev; Ed. G.I. Nechaeva. - M .: Energoatomizdat, 1996 .-- 176 p.

2. Zilotova MA, Karasev VV, Nikolaev A.V. A method of transmitting data through an air gap and a device for its implementation. RF patent No. 2565527. Bull. No. 29, 2015.

3. Karasev VV, Koltsov DB A method of transmitting data through an air gap using inductively coupled circuits excited by an acute-angled pulse, and a device for its implementation. RF patent No. 2674923. Bull. No. 35, 2018.

4. Penin P.I. Digital information transmission systems. Textbook for universities. - M .: Owls. Radio, 1976 .-- 368 p.

5. Karasev V.V., Matveev L.T., Nechaev G.I. Device for transmitting and receiving information from rotating objects. A.S. USSR No. 802983.

METHOD FOR TRANSMITTING AND RECEIVING DATA THROUGH THE AIR GAP BY SHORT PULSES AND A DEVICE FOR ITS

IMPLEMENTATION

The symbols for FIG. 3:

1 - rotating part;

2 - fixed part;

3 - air gap;

4 - shaper of short pulses;

5 - primary circuit;

6 - secondary circuit;

7 - inductively coupled circuits;

8 - the first comparator;

9 - the first key;

10 - the second key;

11 - the first integrator;

12 - second integrator;

13 - the second comparator;

14 - the third comparator;

15 - element I.

Claims (2)

1. The method of transmitting and receiving data through the air gap by short pulses, which consists in the fact that on the rotating part of the device pulses of bits of the information code are used to excite the primary circuit of inductively coupled circuits, the secondary circuit of which is separated from it by an air gap and is located on the fixed part of the device, characterized in that from the discharges of the code short excitation pulses are formed in comparison with their duration, positive and negative half-waves of reaction to them in a stationary Parts of the device are integrated by the first and second integrators, which zero at the end of each bit of the data code, the obtained integrals are compared on two comparators with thresholds identical in absolute value but different in sign, the value of which is selected based on the shape of short pulses and the operation mode of the coupled circuits, signals from the outputs of the comparators are fed to the inputs of the And element, the output of which receives the restored values of the bits of the data code transmitted through the air gap. 2. A device for implementing a method of transmitting and receiving data through an air gap in short pulses, comprising, on a rotating part, a driver of a pulse excitation signal, the input of which is an input of the device connected to the input of the primary circuit of inductively coupled circuits, the secondary circuit of which is connected to the input of the first comparator, located on the fixed part, separated from the rotating part by an air gap, characterized in that the first and second keys, the first and the second integrator, the second and third comparators and the AND element, the driver generates pulses short compared to the duration of the bits under the influence of the data code bits, the input of the first comparator using the zero threshold is connected to the key inputs, the direct output of the first comparator is connected to the control input of the first key, the output of which is connected to the input of the first integrator, the output of which is connected to the first input of the second comparator, to the second input of which a threshold + P is applied, the inverse output of the first comparator is connected connected to the control input of the second key, the output of which is connected to the input of the second integrator, the output of which is connected to the second input of the third comparator, the first input of which has a threshold -P, the control inputs of integrators are connected to the input "Reset" of the device, the signal of which resets the integrators at the end each bit of the code, the outputs of the second and third comparators are connected to the inputs of the element And, the output of which is the output of the device.

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