FR2545210A1 - Device for generating signals which have a given relationship with each other and which change as a function of incoming data - Google Patents

Abstract

The generating device of the invention is particularly appropriate for supplying the control voltages of TACAN synchro transmitters actuating coded distance-indicator wheels. The pure binary ARINC signal is encoded into BCD 3, then loaded into counters 10, 11, 14, 15 receiving a 40 kHz clock signal, and each followed by two decoders 20, 21 to 24, 25 decoding the angles from 60 to 120 DEG (phase shift of the X and Y windings with respect to Z, which is earthed), these decoders being followed by sample-and-hold circuits 26 to 31, analogue multipliers 32 to 37 and power amplifiers 38 to 43. Application to TACAN indicators.

Description

OSITIVE SIGN DEVELOPMENT DISP FOR PRESENTS
BETWEEN A DETERMINED AND DEVELOPING RELATIONSHIP
BASED ON IN CIDENT DATA
The present invention relates to a device for developing signals sensing between them a determined relationship and evaluating as a function of incident data2 in particular for developing angular signals for synchro-transm etters.

The electrical on-board equipment of aircraft includes in particular TACA N indicators. Some of this equipment and indicators have been in service for more than twenty years, and it has been necessary to renovate them. In general, the refurbishment of devices of this kind must be carried out without modification of the cells which receive them, and in particular of the connectors and cables for connection to other equipment. Some components of this equipment, such as synchro transmitters are no longer manufactured currently, and it is preferable to manufacture electronic conversion circuits in their place which must be compatible with the elements situated upstream as well as those situated in the front
In the case of TACAN indicators, the elements located upstream (A RIN C decoder) provide their output information on a bus in binary code. The elements located downstream are remote displays, generally with needle for the deposit, and with coded wheels (drums with figures) for the distance.

For the generation of field information in synchro-transm ettor form, there are several solutions, in particular
Simple to use but expensive hybrid modules, and transcoding memory circuits and operational amplifiers, satisfactory from all points of view. On the other hand, it will be possible to generate distance information, which must generally be displayed by three coded wheels, the aforementioned circuits cannot be used because of prohibitive cost prices and technological difficulties.

One could use for this purpose for each of the two voltages Ux and
Uy to produce a BCD / decimal digital decoder followed by a resistor divider network supplying voltages having five different absolute values, followed by an analog mixer. Such a solution would be economical, but would not allow the wheel of the units to be rotated gradually.

 Similarly, when ron must generate two or more signals having a determined relationship between them, and evolving as a function of incident data, there are no simple and economical circuits having good resolution.

The subject of the present invention is a device making it possible to develop, from a signal with a reference waveform, two or more signals having between them a determined, fJxed or variable relation as a function of determined laws, these signals evcuing depending on incident data, this device being simple and inexpensive to produce, and having very good resolution of the signals produced
The present invention more particularly relates to a device making it possible to develop, from data presented in binary form, control voltages of synohro-transmitters.

 The processing device according to the invention includes in the hands a counter operating in the countdown mode and receiving on its loading inputs the incident data converted into an appropriate form, this counter being followed by at least two different decoders each decoding at least a value, the output of each of these decoders being connected to the blocking control input of a sampler-blocker whose output is connected to a first input of a mathematical operator circuit and whose second input receives the signal with reference waveform which is also sent to all the sample-and-hold units, all of said counters receiving a clock signal whose period is a sub-multiple of that of the reverence waveform signal, and their module being equal to the ratio of the period of the reference waveform signal to the period of the clock signal.

 In the case where the incident data is presented in coded form in the form of a first code such as the pure binary code, and where the values of the n signals to be produced must between presented in decimal form, the processing device according to the invention comprises , downstream of a circuit for converting data from the first code to binary coded decimal code, for each decade of the n signals to be produced, that of the units preferably being associated with a decade of tenths of units and if necessary of hundredths of units, a programmable decimal moduio counter followed by at least one decoding circuit, each decoding circuit being followed by a sampler-blocker, a mathematical operator and, where appropriate, an amplifier.

 In the case where the incident data is presented in a coded form if a first code, and for which the values of n signals to be produced must be presented in analog form, the device of the invention comprises a circuit for converting the first code into pure binary code, the outputs of which are linked to the loading inputs of the counter which is modulo 2P, p being an integer, the outputs of counting states of this counter being connected to n sets of at least one decoder each .

 The present invention will be better understood on reading the detailed description of an embodiment taken as a nonlimiting example and illustrated by the appended drawing, the single figure of which is a block diagram of this embodiment.

 The embodiment described below relates to aircraft TACAN indicators, but it is understood that the invention applies to all cases where two or more signals have to be developed from incident data presenting a determined relationship between them, and evolving according to these data. The realization of the devices making it possible to implement all these cases will be obvious to those skilled in the art on reading the description given below of the preferred embodiment of the invention, the explanation of its operation, and the suggested variants. The device 1 for developing synchro-transmitter control signals (not shown) is intended to be connected to a digital bus 2 standardized A RIN C on which information appears in pure binary form, for example the distance from the aircraft with a beacon in the sdL The device 1 has six output terminals respectively referenced XU, YU, XD, YD and XC, YC on which appear the voltages X and Y, defined below, for controlling the synchro-transm etters actuating respective coded wheels, mechanically independent between aliases (not shown either), units, tens and hundreds of a distance indicator, graduated in nautical miles. It is however understood that the invention is not limited to such types of distance indicators, and can be applied for example to indicators comprising a different number of coded wheels, or else comprising a display device with hands moving in front of a graduated dial.

 A natural binary / binary decimal coded conversion circuit 3 is connected to bus 2. This circuit 3 can either be made up of specific integrated circuits, or be produced in a manner known per se using programmable logic networks. Circuit 3 has four series of outputs, referenced 4 to 7 and corresponding respectively to tenths, units, tens and hundreds of nautical miles, each coded in parallel B C D.

 The outputs 4 and 5 of circuit 3 are connected via registers 8 and 9 respectively to the data inputs of counters 10 and 11, while its outputs 6 and 7 are connected via registers 12, 13 to the data inputs of two counters 14, 15 respectively. The clock signal inputs of registers 8, 9, 12 and 13 are connected to a terminal 16 on which a clock signal is sent, the frequency of which is the frequency of appearance of the binary distance words on the bus 2. The inputs CI for validation of the counters 14 and 15 are connected to the CO overflow output of a counter 17, the data inputs of which are at logic "O" level. The validation input of counter 10 is connected to the CO overflow output of counter 11. All digital counters 10, 11, 14, 15 and 17 operate in down counting mode and are modtilo 10. The signal inputs d 'clock of these five counters are all connected to the output of an oscillator 18 controlled by nominal frequency voltage 40 kHz whose control input is connected to a terminal 19 receiving, from a device not shown, m signal with reference waveform. In the present case, the signal arriving at terminal 19 is the sinusoidal voltage of the calculation power supply sector at 400 Hz of the aircraft.

 According to a variant of the invention, instead of using the mains voltage at 400 Hz, a stable and good quality oscillator is used, operating at the frequency of 40 kHz, the output of which is directly connected to the signal inputs. clock of the aforementioned five counters, and at the input of a frequency divider by 100 followed by an appropriate filter whose output is connected to terminal 19, the oscillator 18 then being eliminated.

 The counting state outputs of counters 10 and 11 are connected to both a first decoder circuit 20 and to a second decoder circuit 21. The counting state outputs of counter 14 are connected as well as those of counter 17 to both to a third decoder circuit 22 and to a fourth decoder circuit 23. The counting state outputs of counter 15 are connected, as well as those of counter 17, both to a fifth decoder circuit 24 and to a sixth decoder circuit 25 .

The outputs of the decoder circuits 20 to 25 are respectively connected to the blocking control input of sampler-blockers referenced 26 to 31, the inputs of which are all connected to terminal 19. The outputs of the sampler-blockers 26 to 31 are each connected to a first input of an analog multiplier, these multipliers being respectively referenced 32 to 37.The outputs of the multipliers 32 to 37 are respectively connected via appropriate power amplifiers, referenced 38 to 43, to output terminals referenced
XU, YD, XD, YC, XC, which are themselves connected, in a manner not shown, to the windings Y and X of synchro-transmitters actuating separately the coded wheels of the units (indices U), hundreds (indices D), and hundreds (indices C), distance display (it is recalled that the envelopes of the voltages in these windings Y and X are respectively phase-shifted by # / 3 and 2 # / 3 relative to that of the voltage in the winding ent Z connected to ground).

 We will now explain the operation of the device 1 described above.

The purpose of the device 1 is to provide each of the synchro-transmitters actuating the coded wheels of the distance indicator with the
same control voltages they previously received from synchro-transmitters-transmitters which have been replaced by electronic circuits. These electronic circuits provide, among other things, distance information in natural binary form, available on bus 2.

Consequently, the device 1 must synthesize, from the distance information in binary form, control voltages for the synchro-transmitters.

soit, si on considère le montage équivalent en triangle, l'enroulement Z étant relié à la masse::

équations dans lesquelles U est l'amplitude maximale de la tension des enroulements statoriques du synchro-transmetteur (11,8 volts efficaces selon la norme A RIN C 407), w est la pulsation de la tension d'excitation de son rotor (2# x 400 pour une frvsquence de 400 Hz), et a est le décalage angulaire du rotor par rapport à une position quelconque de ce rotor prise comme référence (par exemple la position pour laquelle la roue codée qu'il entraîne indique le chiffre "0").According to standard A RIN C 407, and If we consider a star-mounted circuit of the windings of a synchro-transmitter, the voltages at the terminals of the stator windings X, Y, Z of this synchro-transmitter are of the form :

or, if we consider the equivalent assembly in triangle, winding Z being connected to ground:

equations in which U is the maximum amplitude of the voltage of the stator windings of the synchro-transmitter (11.8 volts rms according to standard A RIN C 407), w is the pulsation of the excitation voltage of its rotor (2 # x 400 for a frequency of 400 Hz), and a is the angular offset of the rotor with respect to any position of this rotor taken as reference (for example the position for which the coded wheel which it drives indicates the number "0" ).

 The voltages synthesized by circuit 1 will be of the form e indicated in the equations Il below 5.

For this purpose, the binary distance information of the bus 2 is converted by the device 3 into binary decimal coded form. To rotate the wheel of the units practically gradually, the distance unit information is produced with a resolution of one tenth of a unit (thus, even If the aircraft in question is moving at low speed, the pilot can easily and quickly see if the distance to a fixed beacon increases or decreases)
As soon as a distance information arrives on the bus 2, it is converted by the device 3, and immediately after the end of the transmission of this information a clock signal arrives on the terminal 16, thus transferring the binary value coded an decimal (available on outputs 4 to 7) of this information at the inputs of counters 10, 11, 14 and 15. Counters 10 and 11 on the one hand, counters 14 and 15 with counter 17 on the other hand counting down from of the value of this information one hundred periods of the clock signal at 40 kHz during one period of the signal at 400 Hz applied to terminal 19 which reaches the inputs of the samplers 26 to 31, and the inputs of the multipliers 32 to 37. Thus, during a period of the signal at 400 Hz, the counters 10 and 11 as well as 14 with 17 and 15 with 17 produce a hundred different counting states. If the information present on the outputs 4 to 7 of the device 3 are zero, it that is, if the distance information is a thousand, the comp tors 10, 11, 14, 15 and 17 count down, from the moment they are loaded by registers 8, 9, 12, 13, from the states (in decimal notation) "00" (that is to say "100"), "99", "98" ... until "01", "00", and start again: "99", "98", etc ...

 The decoding values of the decoders 20 to 25 are adjusted to ensure the aforementioned offset of 600 between the envelopes of the control voltages of the windings X and Y of the same synchro-transmitter.

Thus, for a period of the reference signal at 400 Hz, which corresponds to a complete revolution of the rotor of a synchro-transmitter, we have seen that one can obtain a hundred different counting states of the counters, one of these commanding states, after decoding, the corresponding sampler-blocker.

 This amounts to saying that an increment between two successive counting states corresponds to a rotation of 3.6 of the rotor of a synchrotransmitter. To obtain the envelope of the control voltage of an erroillemant Y, phase-shifted by # / @ - 600 relative to the reference voltage (ground), it is necessary to count seventeen increments of 3.6 = 61.2 (value closest to 600), and to obtain the envelope of the control voltage of a winding X, phase shifted by 120, it is necessary to count 33 increments of 3.6 = 118.8 (value closest to 1200 ). Since the counters operate in countdown mode, decoders such as 20 and 21 will be respectively set to values 83 (100-17) and 67 (100-33). Of course If we wanted to get a better approximation of these values of 60 and 120, it would suffice to modify the circuit 3 so that it can command an additional counter of hundredths of a unit, arranged in cascade with the counter 10; the increments would then be 0.360, and if we wanted to further improve the resolution, we would take into account the thousandths of a unit. As soon as the counting states of the corresponding counters arrive at these values, the decoders teis that 20 and 21 are sent by the samplers, such as 26 and 27 respectively, sample values proportional to sin # / 3 and sin 2 # / 3 respectively which are multiplied in multipliers such as 32, 33 by the reference voltage which is of the form : U sin wt. The synchrotransmitters then position all of the coded wheels so that they indicate the value zero.

If the distance information is not ne, a non-zero value is available on bus 2, and device 3 converts it into a corresponding binary decimal coded value which is loaded into counters 8, 9, 12, 13 on a active edge of the clock signal applied to terminal 16. The counters then count down from these loaded values to zero (or 100) then continue to count down through the values 99, 98, ... etc. When they reach the values 83 then 67, the decoders such as 20 and 21 cause the samplers such as 26 and 27 to transmit the values of the samples of the reference signal at 400 Hz as it occurs at these times, these values being proportional to sin (a + and sin (a + the angle a being a function of said distance information. These sample values multiply the reference signal at 400 Hz, and we obtain on outputs Y and X for each synchro -transmitters of units, tens and hundreds of voltages of the form:

The coded wheels of units, tens, and hundreds of nautical miles of the TA CAN distance indication then indicate the instantaneous distance (at the moment when the aircraft's TACAN received an appropriate signal from a beacon on the ground) from the aircraft to the beacon with which it is in communication.

 The invention is not limited to application to TACON devices, and can be implemented in any device having to develop two or more signals having a determined relationship between them and evolving according to incident data.

 This incidental data is firstly converted into values which can be loaded into counters operating in the countdown mode. Of course, the counting period (to be able to take account of a maximum value to be loaded into the counters) of the counters must be less than the period of time separating the arrival of two consecutive data. The modulo of the counters must be equal to the ratio between the frequency of the clock signals sent to the counters and the frequency of the signal with reference waveform (applied to good 19).

A decoding device is used for each of the signals to be produced.

This decoding device can decode one or more different values, and the decoding value (s) can (can) be fixed or be controlled by an external signal. This decoding device may consist of a read only memory (a fixed decoding value) or of several (selection of a fixed value from among several, depending on external criteria), or of random access memories (evolving decoding value) .

 The signal with reference waveform is not necessarily a sinusoid, but can also be a particular signal such as an exponential, gaussian signal, etc. The operating devices 32 to 37 are not necessarily multipliers, but may be, in other applications, mathematical operators such as adders, accumulators, dividers, etc.

 In the case where the signals to be produced are analog signals such as those controlling a synchro-transmitter and display of heading, bearing or bearing, the incident signals, if they are in pure binary code, have no no need to be converted, and device 3 is useless.

The set of counters 10, 11, 14, 15, 17 is replaced by a single counter of modii [o 2P, for example p = 12 or 13. This counter is connected to two decoders decoding the same values as above, each of d 'them being connected to the blocking control input of a sampler-blocker. Circuit 18 has a frequency of 1.6384 MHz if p = 12 or 3.2768 M Hz if p = 13, in the case where the reference voltage of the sector is at 400 Hz.

Claims (12)

 1. Device for developing, from a reference waveform signal (19), at least two signals (XU, YU to XC, YC) having a determined relationship between them and evolving as a function of incident data (2), characterized by the fact that it comprises at least one counter (10, 11, 14, 15) operating in countdown mode and receiving on its loading inputs (4 to 7) the incident data converted into appropriate form , this counter being followed by at least two different decoders (20 to 25) each decoding at least one value, the output of each of these decoders being connected to the blocking control input of a sampler-blocker (26 to 31) the output of which is connected to a first input of a mathematical operating circuit, the second input of which receives the signal with reference waveform (19) which is also sent to all the sample-and-hold units, all of said counters receiving a signal d clock whose period is a submultiple of that of the signa l with reference waveform, and their mode being equal to the ratio of the period of the reference waveform signal to the period of the clock signal.  2. Elaboration device according to claim 1, characterized in that the signals to be elaborated have between them a fixed fixed relation.  3. Elaboration device according to claim 1, characterized in that the signals to be produced have a variable relationship between them as a function of determined laws.  4. Elaboration device according to any one of the preceding claims, characterized in that the decoding values of the decoders are fixed.  5. Elaboration device according to claim 4, characterized in that the decoders include read only memories.  6. Elaboration device according to any one of claims  1 to 3, characterized in that the decoding values of the decoders are controlled by an external signal.  7. Elaboration device according to claim 6, characterized in that the decoders comprise random access memories.  8. Elaboration device according to any one of the preceding claims, for which the incident data are presented in a form coded according to a first code, and for which the values of the n signals to be produced must be presented in analog form, characterized by the fact that it includes a circuit for converting the first code into pure binary code, the outputs of which are connected to the loading inputs of the counter which is of modulo 2p, p being an integer, the outputs of counting states of this counter being connected to n sets of at least one decoder each.  9. Elaboration device according to any one of claims  1 to 7, for which the incident data are presented in a form coded according to a first code, and for which the values of the n signals to be produced must be presented in decimal form, characterized in that it comprises a circuit (3) converting data from the first code into binary coded decimal code, and for each decade, that of the units (5) preferably being associated with a decade of tenths of units (4), and where appropriate, of hundredths of units, a programmable counter at  decimal moduio followed by at least one decoding circuit, each decoding circuit being followed by a sampler-blocker, a mathematic operator  matic, and if necessary an amplifier.  10. Processing device according to claim 9, in which the signals to be processed are the control signals for synchro- transmitters of aircraft TACAN distance indicators, characterized in that the waveform signal of reference is provided from the supply voltage at 400 Hz of the aircraft on-board network, that the counter clock signal has a frequency of 40 kHz and is synchronized with said supply voltage at 400 Hz, that the counters are of modulo 100, that the decoders decode the values 83 and 67 to respectively control the windings Y and X of the synchro-transmitters receivers each actuating a coded wheel of indication of distance, respectively of the units, tens, and hundreds of nautical miles, and that the mathematical operators are analog multipliers.  11. Elaboration device according to claim 10, characterized in that the clock signal of the counters is supplied by an oscillator at 40 kHz, this oscillator being followed by a frequency divider by 100 and a filter suitable for the output from which the reference waveform voltage is available.  12. Elaboration device according to any one of claims  characterized by the fact that the waveform signal of  reference is an exponential or gaussian function.