JPH0332801B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field to Which the Invention Pertains] The present invention receives a transmitted optical signal, operates by the energy of this optical signal, and
This invention relates to a photoresponsive device that outputs a pneumatic signal corresponding to the signal included in the photoresponse device.

[Prior art] Conventionally, optical signals are transmitted via optical fibers,
A system in which the receiving end converts the signal into an electrical signal and processes the signal is well known, but the receiving end is operated by the energy of the transmitted optical signal and generates a pneumatic signal according to the operation signal included in the optical signal. There has never been a device that can output this.

In order to realize such a device, it is necessary to minimize power consumption at the receiving end.
It is also necessary to shorten the response time.

[Object of the present invention]

The present invention aims to realize a light-responsive device that operates using the energy of a transmitted optical signal, has low power consumption, and has a fast response time.

[Summary of the invention]

The device according to the present invention includes a photoelectric conversion means that receives an optical signal sent from a transmission end side via an optical fiber, and operates using the electric power obtained from this photoelectric conversion means, and converts pulse-shaped signals contained in the optical signal. a pulse width signal converter that receives a signal, processes the signal, and outputs a pulse width signal corresponding to the operating signal; and a first air switch that has one end connected to the air pressure supply source and the other end connected to the tank. , and a second air switch with one end open and the other end connected to the tank, and the first and second air switches have on and off times corresponding to the pulse width signal from the pulse width signal converter. A distinctive feature of the structure is that it is controlled.

〔Example〕

FIG. 1 is a block diagram showing an example of a device according to the present invention. In this diagram, TR is the transmitting end, AC is the operating end, and OF is the transmitting end TR and the operating end AC.
It is an optical fiber that connects the

At the transmitting end TR, 1 is connected to one end of the optical fiber OF, for example, a laser diode (LD).
A light source such as 2 is a switch that turns this light source on and off, and is driven by a pulse signal as described above.

FIG. 2 is a waveform diagram showing an example of the form of an optical signal transmitted from the transmitting end TR via the optical fiber OF. As shown in this figure, a continuous optical signal (power light) and a pulse-like signal generated by continuing this optical signal are transmitted from the transmitting end TR.

Here, the pulsed signal consists of three pulses p ₁ ,
The operation signal is composed of p ₂ and p ₃ , and pulses p ₁ and p ₃
The time T _S between pulses p 1 and p 2 contains information on the reference pulse width, and the time t _x between pulses p ₁ and p ₂ contains information on the pulse width, that is, the manipulated variable. Therefore,
On the receiving end side, the operation signal can be obtained by measuring T _S and t _x and calculating t _x /T _S.

In this example, each of the pulses p ₁ to _{p 3} is generated by cutting off the power light, and it is desirable that the pulse width of these pulses be as narrow as possible. Further, each pulse may be generated by reducing the intensity (amplitude) of the power light, or may have a wavelength different from that of the power light.

Returning to Figure 1, at the operating end (receiving end) AC,
3 is a photoelectric conversion unit, which includes a photocell 30 that receives light emitted from the other end of the optical fiber OF;
It is composed of a resistor 31, a capacitor 32, and a regulator 33. Reference numeral 4 denotes a pulse width signal converter that is operated by being supplied with electric power obtained from the photoelectric converter 3, to which a pulsed signal included in the optical signal is applied via a capacitor 40, and this signal is processed and operated. Outputs a pulse width signal corresponding to the amount. Note that here, the capacitor 40 constitutes a signal extraction means for extracting a pulsed signal contained in a continuous optical signal, and the pulse width signal converter 4 constitutes a signal extraction means for extracting a pulsed signal contained in a continuous optical signal. A signal processing circuit 41 that measures the inter-pulse times t _x and T _S of a pulse-like signal, performs t _x /T _S , and outputs a corresponding signal e _{i ;} The feedback signal e _f
The circuit includes an addition circuit 42 which calculates the deviation ε from the deviation signal ε, and a pulse width signal generation circuit 43 which outputs a pulse width signal corresponding to the deviation signal ε.

Reference numerals 5 and 6 denote first and second pneumatic switches which are turned on and off in accordance with the pulse width signal from the pulse width signal converter 4, and here include diaphragms 51 and 61 that are displaced by air pressure. The ones that are used are used. 7 is a pneumatic pressure supply source, 8 is a tank, 80 is an output terminal, and 9 is a pneumatic-electrical conversion means, which generates an electrical signal e _f corresponding to the output pneumatic pressure of the tank 8.
is negatively fed back to the pulse width signal converter 4.

In the first pneumatic switch 5, a pipe 52 corresponding to the input end of the switch is connected to the pneumatic supply source 7, and a pipe 53 corresponding to the output end is connected to the tank 8. By doing so, the connection between the tubes 52 and 53 is turned on and off. One end of the pipe 54 to which the switch control air pressure for displacing the diaphragm 51 is guided,
A nozzle 55 is connected and opposes a flapper 56 which is displaced in response to the pulse width signal Td ₁ from the pulse width signal converter 4 .

In the second pneumatic switch 6, a pipe 62 corresponding to the input end of the switch is open, and a pipe 63 corresponding to the output end is connected to the tank 8. Further, a nozzle 65 is connected to one end of the pipe 64 through which the switch control air pressure is guided, and this nozzle 65 is connected to a flapper 66 that is displaced in response to the pulse width signal Td ₂ from the pulse width signal converter 4.
is against.

Note that the nozzles 55 and 65 are connected to an air pressure supply source 7.
Air pressure from the air is supplied through throttles 57 and 67. Further, the flappers 56 and 66 are constructed of, for example, pulse motors, and are displaced in the direction of the arrow for a time corresponding to the pulse width.

The operation of the device configured as described above is as follows.

An optical fiber is connected from the transmitting end TR to the operating end AC side.
Through the OF, as shown in FIG. 2, an optical signal containing pulses with information in the intervals between the pulses is transmitted. The photoelectric conversion section 3 of the operating end AC converts the transmitted optical signal into an electrical signal and supplies it as operating power to the pulse width signal converter 4. The pulse signal is transmitted to the pulse width signal converter 4 via a capacitor 40 is applied to In this pulse width signal converter 4, the signal processing circuit 41 includes, for example, a logic circuit, a counter, and a sample-and-hold circuit, and the interval between each pulse t _x ,
While measuring T _S , it calculates t _x /T _S and outputs a signal e _i corresponding to the result of this calculation. Further, the pulse width generation circuit 43 inputs the deviation ε between the signal e _i from the signal processing circuit 41 and the feedback signal e _f , and generates a pulse interval signal in the opposite direction of the pulse interval Td with a deviation ε For example, the signals shown in FIG. 3 A and B are outputted from the two output terminals.

The pulse interval signal with pulse interval Td ₁ shown in A is:
The flapper 56 of the first pneumatic switch 5 is displaced in the direction of the arrow by the pulse P _H , and returned to its original position by the pulse P _L. Therefore, the flapper 56 is displaced in the direction of the arrow during Td _1. Similarly, the pulse interval signal with a pulse interval Td ₂ shown in B causes the flapper 66 of the second pneumatic switch 6 to be displaced in the direction of the arrow during Td ₂ . direction. When the flaps 56, 66 are displaced in the direction of the arrow, the opposing nozzle back pressure becomes low, and the first and second pneumatic switches 5, 6 are turned on for the respective pulse intervals Td ₁ , Td ₂ .

Fig. 4 is a diagram showing a simplified connection diagram of the first and second pneumatic switches, pneumatic pressure supply source 7, and tank 8, and Fig. 5 is an equivalent diagram of Fig. 4 using an electric circuit. It is a circuit diagram.

In these figures, if P _S is the output pressure of the pneumatic supply source 7, R ₁ and R ₂ are the resistances of the pipes 52, 53, 62, and 63, and C is the capacity of the tank 8, the output air pressure P _O of the tank 8 is , is expressed by the following equation.

When pressurizing, P _O = P _S {1- _exp (-Td ₁ / R ₁ C)} When reducing pressure, R _O = P _{S exp} (-Td ₂ / R ₂ C) Therefore, the output air pressure P _O is Pulse interval signal
Td ₁ and Td ₂ , that is, they correspond exactly to the input electrical signal e _i .

The output air pressure P _O is converted into an electric signal e _f by the pneumatic-electric conversion means 9, and the pulse width signal generation circuit 43 outputs a pulse width signal such that e _i =e _f . As a result, the output air pressure from tank 8
P _O quickly follows and is maintained to accurately correspond to the electrical signal e _i , ie, the manipulated variable.

FIG. 6 is a block diagram showing an example of the pulse width signal generation circuit 43 in FIG. 1. Here, a comparator CO ₁ inputs the deviation ε between e _i and e _f , an integrator INT integrates the deviation ε via a switch S ₁ ,
A comparator CO ₂ inputs the output of this integrator INT, and a monomultiplier inputs this output via switch S ₅ .
Logic circuit that inputs the output of MM ₁ , MM ₂ , comparator CO ₁ and controls each switch S ₁ to _{S 5} , feedback signal
Input e _f and nonlinear output via switches S ₂ and S ₃
It is composed of nonlinear circuits NL ₁ and NL ₂ that output e _r and _−er to the input terminal of an integrator INT.

FIG. 7 is a waveform diagram showing an example of the operating waveforms of each part of this circuit.

Each switch _S1 to _S5 is driven by a logic circuit LG as shown in Fig. 7,
The output terminals of MM ₁ and MM ₂ output pulse width signals having pulse intervals Td ₁ and Td ₂ related to the deviation signal ε, as shown in FIG. Note that in each of the nonlinear circuits NL ₁ and NL ₂ , the deviation ε and the amount of pressure change in the output air pressure P _O are not linearly related, but change depending on the direction of pressure change and the output at that time. It was established to compensate.

In the above embodiment, the pneumatic-electrical converter 9 is provided so that the electrical signal e _f corresponding to the output air pressure P _O is negatively fed back to the pulse width signal converter. good. Further, the pulse width signal converter is not limited to one including the circuit shown in FIG. 6, but may be one using a microcomputer or the like, for example. Furthermore, the pneumatic switch is not limited to one that includes a diaphragm that is displaced by back pressure from the nozzle wrapper; for example, a solenoid valve may be used.

[Effects of the present invention] As explained above, according to the present invention, a light-responsive device can be realized which consumes less power, operates only by transmitted optical signals, and therefore does not need to transmit electrical signals. can. Further, by providing a negative feedback loop including a pneumatic-electric conversion means, responsiveness can be increased, and a pneumatic pressure signal that accurately corresponds to the manipulated variable can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a configuration block diagram showing an example of the device according to the present invention, FIG. 2 is a waveform diagram showing an example of the form of an optical signal transmitted from the transmitting end in the device shown in FIG. 1, and FIG. The waveform diagram of the pulse width signal obtained from the pulse width signal converter in FIG.
5 is a simplified diagram of the main parts in the figure, FIG. 5 is an equivalent circuit thereof, FIG. 6 is a configuration block diagram showing an example of a pulse width signal generation circuit, and FIG. 7 is a waveform showing an example of operating waveforms of each part in FIG. 6. It is a diagram. TR...Transmission end, AC...Operation end, OF...Optical fiber, 3...Photoelectric conversion section, 4...Pulse width signal converter, 5, 6...Pneumatic pressure switch, 7...Pneumatic pressure supply source, 8... ...Tank, 9...Pneumatic-electrical conversion means.

Claims (1)

[Claims] 1. A light-responsive device comprising a transmitting end and a receiving end connected to each other via an optical fiber, and outputting a pneumatic signal based on information contained in an optical signal sent from the transmitting end. The transmitting end includes means for outputting a continuous optical signal with a constant intensity;
The intensity of this continuous optical signal is reduced for a short time so that a pulsed signal is included in the continuous light, and the interval between at least two pulses of the pulsed signal is adjusted according to the amount of operation to be transmitted. the receiving end receives continuous optical signals sent from the transmitting end via the optical fiber, and also includes means for storing the obtained power. a photoelectric conversion section including a signal extraction section for extracting a pulse-like signal contained in a continuous optical signal; a signal processing circuit that inputs a pulse signal, measures the time interval between the two pulse signals, and outputs a signal related to the manipulated variable; a pulse-width signal converter for converting a signal related to a manipulated variable from a pulse-width signal into a pulse-width signal; a first pneumatic switch having one end connected to an air pressure source and the other end connected to a tank; and a second air switch connected to the tank, and the on/off times of the first and second air switches are controlled by the pulse width signal from the pulse width signal converter. A photoresponsive device characterized by: 2 The pulse width signal converter generates a pulse width signal that turns on and off the first and second air switches so that the difference signal between the electrical signal corresponding to the output air pressure signal and the signal related to the manipulated variable becomes zero. A photoresponsive device according to claim 1, which outputs.