JPS5934013B2 - Majority decision method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a majority decision method for the same type of information, which is necessary when a plurality of electronic computers, various control devices, etc. are operated in parallel to improve reliability.

Systems that require high reliability are required to have a fail-safe function that always operates to the safe side in the event of a failure. is necessary.

In other words, such an element is called an asymmetric error element. For example, a relay is also an asymmetric error element, and since it always recovers in the event of a failure such as a power cut, this characteristic can be used to configure a highly reliable system equipped with a fail-safe function. be able to.

However, general electronic circuits do not use asymmetric error elements, but instead employ special circuit systems that place emphasis on reliability. It is difficult to fail-safe, and it is also uneconomical, so we install multiple identical devices to form a multiplexed system, run them in parallel, and monitor the same type of information that is generated. By using majority decision using the information as regular information, fail-safe operation is achieved and high reliability of the entire system is achieved.

FIG. 1 is a basic circuit diagram showing a conventional majority decision method using relays required in such a case. Each of the relays R1 to R3 is operated, and a circuit for operating the relay R is configured by the closing contacts R1 to R3 of each relay R1 to R3.

Therefore, if any two of relays R1-R3 operate, relay R will also operate, but if only one of relays R1-R3 operates, relay R will not operate.
The operating status of relay R indicates whether information that should be adopted as a majority decision has occurred.

However, even when extracting one piece of information from each of the three information sources IG1 to 1G3, at least four relays are required as shown in Figure 1, and when extracting even more information as shown in Figure 2, A huge number of relays are required, resulting in an increase in the space for accommodating the relays, an increase in the number of man-hours required for maintenance and inspection of the relays, etc., resulting in extremely uneconomical results, resulting in disadvantages that make the system unsuitable for practical use.

The present invention has the purpose of fundamentally eliminating such drawbacks of the conventional technology, and converts the same kind of information generated from a multiplex system into AC signals of different frequencies, mixes these AC signals, and then envelopes them. After extracting the frequency component of the line, the beat frequency is detected via a low-frequency wave generator, and based on the presence or absence of this beat frequency component, a majority decision is made that indicates that the two parties are the same, at least if the same information of the three parties is not included. This provides an extremely effective majority decision method for obtaining output.

The present invention will be described in detail below with reference to figures showing embodiments, but first, the principle will be described.

Figure 3 is a block diagram showing the basic principle, and the oscillator 08
The AC signals of different frequencies generated by C1 and 08C2 are mixed by mixer MIX, and then sent to detector D.
After performing envelope detection in ET, low-pass filter L
Beat frequency components are extracted by PF.

Now, the AC signal from oscillator 08C1 is A1CO3ω1
AC signal from t1 oscillator 08C2 A2CO5ω2t
Then, the output of mixer MIX is A1CO3ω1t+A
2CO3ω2t, and the result is obtained as follows.

Here, if the base of the right triangle is A and the opposite side is B, then the hypotenuse can be found from l. Considering ACO3(IZ) 1 +Bs1r+ωI, however, φ-tan'(B/A) Therefore, ( If we treat equation 1) in the same way as equation (2), we get: Then, the detector DET performs envelope detection to extract the frequency component of the envelope, and then the low-pass filter LPF extracts the high frequency component. When removed, the beat frequency component indicated by the envelope is obtained as shown in equation (3), and its frequency becomes (ω2-ω1)/2π.

Furthermore, when the output of oscillator 08C1 disappears, (3
) is A1-0, and the envelope detection output becomes JA22, which makes it clear that it becomes a simple direct current.

Therefore, the output OUT in FIG. 3 is the oscillator 08C0,0
Occurs only when 8C2 AC signal output is occurring,
The logical product based on each AC signal output t of the oscillators 08C1 and 08C2 is obtained from the output OUT, and by the disappearance of the detection output at the output OUT, it is possible to know that the output from one of the oscillators 08C1 and 08C2 has disappeared. can.

FIG. 4 is a block diagram of the basic configuration with an additional oscillator 08C3, which operates in the same way as in FIG.
~08C3 each oscillation frequency is set to ω1. Assuming ω2°ω3, the output of the mixer MIX can be obtained from the following, similar to equations (1) to (3).

Here, if we set , then from Equation (4), we obtain, where , and the component shown in Equation (5) is detected by envelope detection.

Therefore, if high frequencies are removed by the low-pass filter LPF as in Fig. 3, ω1/2π, ω2/2π, ω3
A beat frequency component is obtained based on each frequency of Aπ, and a beat frequency component is generated when at least two of the oscillators 08C1 to 08C3 are outputting an AC signal, whereas only one outputs an AC signal. Even if a beat frequency component occurs, it is determined that two of the three sources are generating the same information, and a majority decision can be made based on the output OUT.

Note that the amplitude of the AC signal component generated by the oscillators 08C1 to 08C3 is involved in determining the amplitude of the composite wave, so
It may be determined according to various conditions, but in practice it may be set to A1, A2, and A3.

Furthermore, it is practically preferable to select the frequencies at approximately equal intervals of ω2-ω1 and ω3-ω2.

FIG. 5 is a circuit diagram of an embodiment based on the above principle, in which a phase-shifted CR oscillator is configured by resistors R1□ to R34, capacitors 011 to C34, and transistors Qll to Q31, and each oscillation frequency is different. In addition, the oscillation state is established by applying power to the inputs IN and N3 based on the same type of information from the three sources, and the AC signals generated from these oscillators 08C1 to 08C3 are as follows.
After being mixed by the resistors R1 to R3 constituting the mixer MIX, the diode D1. D
After the envelope is detected by the detector DET consisting of 2,
Beat frequency components are extracted in the low pass filter LPF.

In order to provide a fail-safe function, the low-pass filter LPF is composed of 4-terminal super-bass capacitors C2 and C3 and an inductance coil L, and the beat frequency component extracted by this is passed through the capacitor C4, It is amplified in an amplifier A consisting of resistors R4 to R6, a transistor Q, and a transformer T whose band characteristic is adapted to the beat frequency component, and is amplified by diodes D3 to D6.
, becomes direct current through a full-wave rectifier circuit REC using a capacitor C5, and operates a relay RL.

Here, if we consider the fail-safe function of the above-mentioned circuit, a failure in each element of the oscillators 08C1 to 08C3 will stop oscillation, and the resistors R1 to R3 of the mixer MIX will
If a disconnection occurs, the conditions are the same as stopping oscillation, and if a short circuit occurs, the mixing function is not lost and no trouble occurs.

Also, for the detector DET, the diode D1. If D2 is short-circuited or opened, no detection output is generated and the relay RL is restored.

In the low-pass filter LPF, super bus capacitors are used for capacitors C2 and C3, so if these are shorted or opened, the output disappears, and the inductance coil L
The same thing happens when the wire is disconnected.

However, if the inductance coil L is short-circuited, the ripple current from the detector DET will pass through, which is dangerous. However, the band characteristics of the transformer T adapt the amplification frequency band of the amplifier A to the beat frequency component, and 08
This danger can also be avoided by separating the oscillation wave numbers of C1 to 08C3 and the beat frequency.

Further, if a failure occurs in each element of the amplifier A and the rectifier circuit RFC, the relay RL is used to restore both, and a complete fail-sale function is realized.

FIG. 6 shows the majority decision circuits DMJ1 to D shown in FIG.
It is a block diagram of a situation in which MJn is combined with information sources 1G1 to 1G3, and the same type of information D1 to Dn generated from information sources I01 to 1G3 is determined by each majority decision circuit DMJ,
-DMJn, and relays RL1 to RLn corresponding to relay RL in FIG. 5 are operated based on the majority decision output.

In addition, in Fig. 5, taking into consideration the fail-safe function, Wien bridge type, Bartley type, etc. may be used as the oscillators 08C0 to 08C3, and the same effect can be obtained by using an active filter as the low-pass filter LPF and amplifier A. However, various modifications are possible, such as detecting the phase or frequency change of the mixed wave by frequency discrimination instead of envelope detection.

As is clear from the above explanation, according to the present invention, a majority decision system having a self-fail-safe function is realized with a simple and easily miniaturized configuration, and a predetermined purpose can be achieved in a purely electronic manner. A remarkable effect can be obtained in majority decision judgment for multiple systems of the same type of information.

[Brief explanation of drawings]

Figures 1 and 2 are circuit diagrams of a conventional example, Figure 3 is a block diagram showing the basic principle of the present invention, Figure 4 is a block diagram of the basic configuration, and Figure 5 is a circuit diagram showing an embodiment of the present invention. 6 is a block diagram of a situation in which the circuit of FIG. 5 and the information source are combined. IG1~1G3... Information source, 08C1~08C
3...Oscillator, MIX...Mixer, D
ET...Detector, LPF...Low pass filter, OUT...Output.

Claims (1)

[Claims] 1 Convert the same kind of information generated by the three sources from the multiplex system into AC signals with different frequencies, mix the AC signals, extract the frequency component of the envelope, and then send it to the A majority decision determination method characterized by detecting a beat frequency based on each frequency and obtaining a majority decision output indicating that at least two of the same information of the three are the same based on the presence or absence of the beat frequency component.