RU2719557C1 - Method of transmitting and receiving data through an air gap based on inductively coupled circuits excited by rectangular pulses of different polarity, and a device for realizing said - Google Patents

Abstract

FIELD: measurement technology.SUBSTANCE: invention relates to telemetry, in particular to a method of transmitting and receiving data from working members of rotating assemblies and mechanisms. Method is characterized by that two short heteropolar rectangular-shaped pulses are used to excite a rotating contour of inductively coupled loops, and for reconstruction, a combination of threshold processing with memory elements on triggers is used. Differential excitation pulses cause on the secondary circuit a signal close to bipolar signal, which is processed by two comparators with heteropolar thresholds, which are equal in absolute value. To eliminate crushing due to interference of the device output signal, triggers are used.EFFECT: disclosed method increases noise immunity of transmitted data.2 cl, 3 dwg

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.

To transmit information from sensors located on rotating nodes and mechanisms, different communication methods are used between the rotating and stationary parts of the measuring equipment [1].

Modern non-contact methods of communication with rotating equipment can be divided into two large groups. One group includes methods involving the transmission of data over a radio channel by modulating a parameter of a carrier high-frequency signal. Another group includes methods that allow pulsed signals to be transmitted through the air gap.

The methods of the first group are represented by devices that are usually called radio telemetry systems (RTS). RTS can differ from each other in the way of organizing radio communications between the rotating and stationary parts of the system.

In the methods of the first group, inductive coupling between the transmitting and receiving elements of the system is widely used for transmitting data through the air gap, through which, for example, a carrier wave with a frequency of 13.56 MHz, modulated by digitized signals from sensors on the rotating part, is received and demodulated in the stationary part measuring equipment [2]. The disadvantage of this method is the use of radio channel elements in the information transmission path: modulator, demodulator and filter, which complicate the device, introduce additional errors, slow down the transmission rate of one bit of the data code, and with another method of signal transmission - in pulsed form - can be excluded. In addition, as noted by the developers of the RTS [2] (p. 24), the radio channel is not perfect in terms of noise immunity. The effect of interference on a low-power radio signal will lead to a distortion of code combinations, which will be detected on the stationary part of the system by well-known cyclic control methods. As a result, the distorted code combination will be excluded from consideration, but instead, it will be necessary to obtain a new data value, and this will lead to a decrease in the system transmission rate and to an increase in the error of signal recovery from its samples.

The methods of the second group are represented by devices in which there is no high-frequency carrier of code data packets transmitted from the rotating part of the system to its stationary part [1], and, as a result, they lack the above-mentioned disadvantages of the RTS. In particular, one of the methods of this group [1] (p. 17-21) assumes that data is transmitted through the air gap by exciting, with rectangular short pulses, the required amplitude of the primary rotating loop of inductively coupled circuits (ICC). On the secondary fixed circuit, separated from the rotating circuit by an air gap, signals are formed that are suitable for deciding what was transmitted in this category of the code - zero or one. The method is simple and reliable, but the signal received at its implementation at the ICS output is a superposition of two ICS responses to different-polarity jumps in the excitation current (respectively, to the leading and trailing edges of a rectangular pulse), and therefore has a longer duration, which can be shortened with another method pulsed excitation ISK - using exponential pulses.

Closest to the proposed method (prototype) is a method of transmitting data through an air gap [3], which consists in the fact that the informational code parcels received on the rotating part of the measuring system are fed through a repeater (amplifier parcels in power) to a differentiating circuit, cut off by a limiter of two bipolar pulses of an exponential shape, a pulse of one polarity, for example negative, and a pulse of another polarity, for example positive, is fed to the driver Nogo excitation signal of the primary circuit is inductively coupled circuits. As a result of such excitation of the circuits by a signal of an exponential shape, a short signal is generated at the output of the stationary circuit separated by an air gap from the rotating one, having a positive half wave and noticeably inferior negative amplitude half wave to it, which is suitable for deciding on the transmitted code discharge value.

The disadvantage of this method (prototype) is the low noise immunity due to the fact that the amplitude of the signals at the output of the coupled circuits formed under the influence of pulses of exponential form exciting the primary circuit of the ICD turns out to be small. Moreover, the known method behind the scenes assumes that the restoration of a signal received on a fixed circuit is based on its threshold processing and the use of its second half-wave for this purpose is not proposed. You can significantly increase the amplitude of the second half-wave of signals transmitted through the air gap, making it practically equal to the amplitude of their first half-wave, and take it into account when restoring code parcels on a par with the first half-wave, if you use a different method of exciting coupled circuits, supplementing it with an adequate recovery method, practically preserving while the advantage of the prototype is its high performance.

The essence of the proposed method is as follows.

For each unit bit of the data code, a short pulse is formed on the rotating part of the measuring system, the duration of which is determined by the parameters of the original code message and associated loops. It is fed to the input of the driver of the positive excitation pulse of the primary circuit of the ISK, and also through the delay element for a time equal to the duration of the short pulse, to the input of the driver of the negative pulse of excitation of the same circuit. As a result of the described actions, if there is a unit in the data code, a signal is generated at the output of the fixed circuit, having a first and second half-wave with parameters close in amplitude. The positive half-wave of the received signal is compared with the selected threshold (usually half the half-wave amplitude) on the first comparator, and the negative half-wave is compared with the negative value of the previously mentioned threshold on the second comparator. At the outputs of the comparators, single signals are obtained at times when the half-waves exceed the threshold values in absolute value. Since the signal at the inputs of the comparators is distorted by interferences that cause a “bounce” of the signals at their outputs, the output signal of the first comparator is fed to the unit input to the first state of the first trigger, and the output signal of the second comparator through the logic element AND, to the second input of which the output of the first trigger is applied, - to the same input of the second trigger. Triggers cut off the "bounce" caused by interference. The "Reset" signal, formed at the end of each bit of the data code, triggers set to zero. As a result, if there is a unit in the code category, a single signal is obtained at the output of the second trigger. When the input signal is zero, the trigger remains in the zero state. The probability of distortion by interference of both half-waves (the proposed method) is much less than the probability of distortion of a positive half-wave (prototype). Therefore, the proposed method allows to increase the noise immunity of data transmission.

The principle of achieving the named technical result due to the implementation of the above actions with pulse signals that control the excitation of the primary circuit of the ISK so that the signals received on their secondary circuit allow a more reliable decision on the value of the transmitted discharge of the code is illustrated by figures 1 and 2.

In FIG. 1a, a rectangular kod pulse corresponding to a single bit of a data code is shown. Based on it, in the prototype for controlling the driver of the exciting effect supplied to the primary circuit of the ICD, an EXPI pulse of exponential shape is created (plot 1 in Fig. 1, b). The shaper amplifies it in power without changing its shape. In FIG. 1c, the GE signal (plot 1) is presented, which is generated at the output of the stationary circuit of the ISK in response to an excitation pulse of exponential shape. The signal has positive and negative half-waves, the latter being almost 2 times smaller in amplitude of the former (the ISK reaction was obtained for the coupling coefficient 0.5 between the loops, normalized duration 0.3 and unit amplitude of the exponential signal). In stationary equipment, the decision on the value of the transmitted code bit is taken, for example, by one of the threshold processing methods.

In the proposed method, a short rectangular pulse of positive polarity is generated on the rotating part of the system along the leading edge of the pulse kod corresponding to a single bit of the information code — the signal pr _p represented by diagram 2 in FIG. 1 b Its duration is 2 times less than the duration of the exponential pulse. This signal is fed to the driver of the positive excitation pulse of the primary circuit of the ISK, and also through the delay element for a time equal to the duration of the short pulse, to the driver of the negative excitation pulse of the same circuit - the signal pr _o (plot 3 in Fig. 1, b). Under the influence of rectangular pulses of positive and negative polarity on the fixed part of the system at the output of the secondary circuit of the ICD, separated by the air gap from the primary circuit, ideally the signal RB is generated, which is represented by diagram 2 in FIG. 1c (the operating mode of the ISK and the total normalized duration of the exciting signal are the same as with exponential excitation). The appearance of the received signal indicates the presence of two half-waves of the same polar amplitude. For other values of the coupling coefficient k between the circuits and the normalized duration τ of the exciting signal, this proximity is preserved. In Fig. 1, d, on the left, diagram 1 characterizes the dependence of the ratio of the module | m2rb | the amplitudes of the second half-wave to the amplitude m1rb of the first half-wave, and plot 2 — the ratio of m1rb to the amplitude mge of the ICS reaction to exponential excitation from the coupling coefficient k for the chosen τ = 0.3. Figure 1, d on the right shows the corresponding dependences on the duration τ for a fixed k = 0.5: plot 3 - for the ratio of the module | m2rb | the amplitudes of the second half-wave to the amplitude m1rb of the first half-wave, and plot 4, for the ratio of m1rb to the amplitude mge of the ICR reaction to exponential excitation. The signal received on the fixed part, distorted by the interference, has the form shown in FIG. 2a - signal smes. It is fed to the first and second comparators having thresholds + U ₀ and -U _0, respectively. The signals k1 and k2 at the outputs of these comparators are represented by diagrams 1 and 3 in FIG. 2, b. The output signal of the first comparator is used to set the first trigger Tg1, the output signal of which is represented by diagram 2 in FIG. 2, b. The signal from the output of the second comparator is fed to one input of the And element, to the other input of which the output of the first trigger is connected. The output of the element And (plot 4 in Fig. 2, b) is used to set the second trigger Tg2 to a single state, from the output of which (plot 5 of Fig. 2, b) a restored code bit is obtained. To restore the zero state of the triggers, the Reset signal is used, which is generated at the end of each bit of the data code and supplied to the corresponding inputs of the triggers — signal R (plot 6 in Fig. 2, b). From the figures it is seen that the fragmentation of the signals at the outputs of the comparators due to interference does not distort the restored signal at the receiving part. Therefore, the proposed method of transmitting data through the air gap has a higher noise immunity compared to the prototype, because in the prototype, the reconstructed signal is received at the output of the first comparator.

In FIG. 3 is a structural diagram of a device for implementing the proposed method of transmitting data through an air gap using inductively coupled circuits excited by an acute-angled pulse, and FIG. 1 and 2 are diagrams explaining his work.

To achieve a technical result, which consists in increasing the noise immunity of transmitting bits of a data code, to a device containing on its rotating part a driver of a positive excitation pulse, the output of which 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 is separated from the primary circuit air gap, a short-pulse shaper, a delay element and a negative-pulse shaper are introduced on the rotating part excitation, and on the fixed part - two comparators, two triggers, element I. The input of the short-pulse driver is the input of the device, its output is connected to the input of the driver of the positive excitation pulse and to the input of the delay element, the output of which is connected to the input of the driver of the negative excitation pulse, output which is connected to the primary circuit. The secondary circuit is connected to the first input of the first comparator, the output of which is connected to the input of the unit in the unit of the first trigger, and the second input of the second comparator, the output of which through the element And is connected to the same input of the second trigger. A positive threshold voltage is applied to the second input of the first comparator, and a negative threshold voltage of the same absolute value is supplied to the first input of the second comparator. The output of the first trigger is connected to the second input of element I. The reset signal is sent to the inputs of the zero setting of both triggers at the end of each bit of the data code. The output of the second trigger is the output of the device.

A device for implementing the proposed method of transmitting data through the air gap comprises a rotating part 1, a fixed part 2 and an air gap 3. The rotating part 1 contains a short pulse shaper 4, a positive excitation pulse shaper 5, a primary circuit 6 of inductively coupled circuits 8, a delay element 9, shaper 10 of the negative excitation pulse. The fixed part 2 contains the first 11 and second 12 comparators, the element And 13, the first 14 and second 15 triggers.

The input of the device is the input of the shaper 4 of the short pulse located on the rotating part 1, which receives the bits of the data code. Its output is connected to the input of the delay element 9 and to the input of the positive excitation pulse generator 5, the output of which is connected to the primary circuit 6 of inductively coupled circuits 8. The output of the delay element is connected to the input of the negative excitation pulse generator 10, the output of which is connected to the primary circuit. The secondary circuit 7, located on the fixed part 2, separated from the rotating part 1 by an air gap 3, is connected to the first input of the first 11 comparator and to the second input of the second 12 comparator. The output of the first comparator is connected to the installation input to the unit of the first 14 trigger, the output of which is connected to the And 13 element, to the other input of which the output of the second 12 comparator is connected, and its output is connected to the installation input to the unit of the second 15 trigger, the output of which is the device output. A positive threshold voltage is applied to the second input of the first comparator, and negative, equal in absolute value to the positive, to the first input of the second comparator. At the end of each digit of the code, the “Reset” signal is sent to the inputs of the zero trigger set.

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. If the discharge of the information code contains one (Fig. 1, a), then a short pulse is generated along the leading edge of the code pulse in the shaper 4, under the influence of which the positive excitation pulse shaper 5 generates a rectangular pulse of positive polarity (plot 2 in Fig. 1, b) supplied to the primary circuit 6 of inductively coupled circuits 8. A rectangular pulse of negative polarity is applied to it (plot 3 in Fig. 1, b), formed from a short pulse delayed by its duration by an element aderzhki 5, generator excitation pulse 10 negative. In response to two bipolar excitation signals on the secondary circuit 7 located on the stationary part 2, separated from the rotating part 1 by the gap 3, ideally, the signal represented by plot 2 in FIG. 1, c. The same signal, distorted by interference, is shown in FIG. 2 a. It is processed by the first 11 and second 12 comparators with thresholds + U ₀ and -U _0, respectively (Fig. 2, a). If the signal mixture with noise exceeds the threshold + U ₀ or falls below the threshold -U ₀ , then a single signal is generated at the output of the first or second comparator (diagrams 1 and 3 in Fig. 2, b). The first of them will set the first 14 trigger to a single state (plot 2 in Fig. 2, b), and the second through element I 13 (plot 4 in Fig. 2, b), if one is fixed in the first trigger, the second 15 trigger ( diagram 5 in Fig. 2, b). The "Reset" signal applied to the zero inputs of these triggers at the end of each bit of the code brings the triggers to their initial state.

The technical result of the proposed method for transmitting and receiving data through an air gap based on inductively coupled circuits excited by rectangular pulses of different polarity, and a device for its implementation, is achieved by increasing the noise immunity of the transmission of bits of the data code by approximating the response of the circuits to the bipolar signal, due to the found method of their excitation, and the use of memory elements in the restoration of premises.

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. Manner Product Brochure. URL: http://manner-sensortelemetrie.ru/-dokumentaciya/Brochure-production-MANNER(Rus).pdf (accessed: 08/10/2019).

3. 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.

METHOD FOR TRANSMITTING AND RECEIVING DATA THROUGH AIR GAP BASED ON INDUCTIVELY CONNECTED CIRCUITS EXCITED BY RECTANGULAR PULSES OF DIFFERENT POLARITY, AND A DEVICE FOR ITS IMPLEMENTATION

The symbols for FIG. 3:

1 - rotating part;

2 - fixed part;

3 - air gap;

4 - shaper short pulse;

5 - shaper of a positive pulse of excitation;

6 - primary circuit;

7 - secondary circuit;

8 - inductively coupled circuits;

9 - delay element;

10 - driver of a negative excitation pulse;

11 - the first comparator;

12 - second comparator;

13 - the element And;

14 - the first trigger;

15 - second trigger.

Claims (2)

1. The method of transmitting and receiving data through an air gap based on inductively coupled circuits excited by rectangular pulses of different polarity, which consists in the fact that on the rotating part pulses of single 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 air gap and is located on the fixed part, characterized in that a pulse is formed from the code discharge short compared to the discharge duration, from which it is obtained a positive polarity excitation pulse is generated, and a negative polarity excitation pulse is obtained from a short pulse delayed for the duration of the signal, the signal from the secondary circuit is compared on one comparator with a positive threshold depending on the signal parameters, and on the other comparator with a corresponding negative threshold, the output signal of the first comparator used to set the first trigger to the unit, and the output signal of the second comparator is combined according to the And scheme with the output signal of the first trigger and they are used to set the second trigger to the unit, at the end of each bit of the code the triggers are reset to zero, the output of the second trigger 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 based on inductively coupled circuits excited by rectangular pulses of different polarity, containing on the rotating part a driver of a positive excitation pulse connected to the input of the primary circuit of inductively coupled circuits, the secondary circuit of which is located on the fixed part separated from the rotating part by an air gap, characterized in that a short pulse former is introduced into it on the rotating part , the delay element and the driver of the negative excitation pulse, and on the rotating part - the first and second comparators, the first and second triggers and the I element, the input of the device is the input of the shaper of the short pulse, the output of which is connected to the input of the driver of the positive excitation pulse and is connected to the delay element the input of the driver of the negative excitation pulse, the output of which is connected to the input of the primary circuit, the output of the secondary circuit is connected to the first input of the first and second input the second comparator, to the other inputs of which threshold voltages + U ₀ and -U ₀ are applied, the value of which is determined by the signal parameters, the output of the first comparator is connected to the input of setting the single state of the first trigger, and the output of the second through the And element, controlled by the output of the first trigger, with the input of setting the single state of the second trigger, the output of which is the output of the device, both triggers are reset to zero by the "Reset" signal applied to their second inputs at the end of each bit of the data code s.

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