JPS6120438A - Optical sensor multiplexing device - Google Patents

Abstract

PURPOSE:To multiplex optically sensor information by one optical fiber by connecting many optical sensors in a shape of a loop through the optical fiber, executing a sensitization in accordance with an on/off operating state of each optical sensor, and executing a weighting to its photosensitive quantity. CONSTITUTION:By an E/Q converting part 101 in a collecting device 10, a light of a light quantity determined by its input voltage Es is sent out serially to optical sensors 131, 132-13N through optical fibers 120, 121, 122-12N from an optical connector 103, inputted to an optical/electric converting part 102 in the collecting device 10 from an optical connector 104 after making the round, converted to a voltage from a light and outputted as ER. Each optical sensor controls a light quantity by the respective specified light quantity variation rates (extinction rates) kappa1, kappa2...kappan (0<kappai<1) from a state that the extinction is not executed in accordance with its operating state. In accordance with an operation of each optical sensor, the extinction is executed by weighting which follows 1-1/a, 1-(1/a)<2>,...1-(1/a)<n> (provided that a>1) with respect to the power series 1/a, (1/a)<2>,...(1/a)<n>.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a multiplexing device for optical sensor information using optical fibers.

(Prior technology) The mechanical displacement of a sensor that detects temperature, pressure, position, etc. is used to control the light transmitted from an optical fiber, and the light itself is used as a response signal without the need for electrical processing. The return type optical sensor does not require a power supply line or an electric signal line, and has advantages such as electromagnetic interference, safety, and wire savings.

FIGS. 2 and 3 show typical conventional methods for collecting sensor information via optical fibers when there are a large number of optical sensors of this type.

The first method is to connect the optical sensors 331, 332 to 33N to the collecting device 30 using two optical fibers 321, 341, respectively, as shown in FIG.

322.342 to 32N, 34N are connected in a star shape, and the electric/optical converter (hereinafter referred to as rE/Q converter) in the collecting device 30, respectively, soB: toz~, 90
In this method, optical sensor information is collected via N and optical/electrical converters (hereinafter referred to as rQ/E converters) 311, 312 to 31N.

The second method is to connect a collection device and a group of optical sensors in a loop using optical fibers and collect sensor information using a wavelength multiplexing method. For example, as shown in FIG.
Broadband wavelength light is transmitted from the light emitting unit 401 in the optical sensor 43 through optical fibers 420, 421, 422 to 42N.
1,432,433 to 4.7 NK, and each optical sensor transmits a unique wavelength λ1. λ2~λ. Select and absorb
After passing through the optical sensors 431 to 43N, the light receiving unit 402 of the collecting device 40 detects the wavelengths λ1 to λ. This method separates the light, detects the amount of each separated light, and identifies each optical sensor and its operation.

(Problems to be Solved by the Invention) According to the conventional technology, the first method requires one pair of optical fibers, optical connectors, wires, and Q/E converters for each optical sensor, so it is small and lightweight. The second method has the disadvantage of being difficult and expensive to implement, and the second method requires a large number of optical fibers, optical connectors,
However, optical sensors that selectively absorb specific wavelengths are extremely expensive, the wavelength band of optical fibers is narrow, and there are restrictions on the selection of wavelength bands for light emitting elements and light receiving elements. These have the disadvantage that multiplexing is limited.

(Means for Solving the Problems) The present invention has been made by focusing on such conventional problems, and optical sensors are connected in a loop using optical fibers, and light passes through each optical sensor. The amount of passing light is controlled according to the operation of the sensor.

The amount of transmitted light to be controlled is weighted like a power series for each sensor. At this time, the weighting for each sensor is, for example, 1-+/a, 1-(1/a)2.1-(1/a) )
3.1-(1/a)".

(Function) Next, the function will be explained with reference to FIGS. 1(a) and 1(b). After the optical signal inputted from the collecting device 10 goes through the optical sensors connected in a loop, the optical signal inside the collecting device 10 This electric signal ER, which is converted into an electric signal E3 by an electric converter, is input to a comparator 20 and compared with a reference voltage 231 generated from a reference voltage generator 230, and the value is the same as that of the electric signal ER. Or, if the voltage value of ER is low, that is, it is determined that there is dimming, and the logic " ] " is output, and if the voltage value of ER is higher than the reference voltage 231, that is, it is determined that there is no dimming, and the logic "0#" is output. .

The electric signal ER is input to the selector 221 and the DC amplifier 21, and the output of the DC amplifier 211 is input to the selector 22.
1 is input. The selector 22 includes the comparator 20.
1 output is connected, and this comparator output is the logic
``In other words, if there is dimming, the dimming amount of the sensor is DC amplified by the DC amplifier 21, the voltage A side that cancels the dimming amount is selected, and inputted to the comparator 202. Also, the output of the comparator is the logic voltage. 0'', that is, no dimming, selects the input side B of the DC amplifier 21 and inputs it to the comparator 202, which compares it with the reference voltage 232 generated from the reference voltage generator 230. , the input voltage is the reference voltage 23
If the input voltage is lower than or equal to 2, it outputs a logic "1", and if the input voltage is high, it outputs a logic ''On'.

After that, perform the same operation and set the output terminal to ``1'''' or 0''''.
Output.

(Embodiment) FIG. 1(b) is a block diagram showing an embodiment of the present invention, and FIG. 1(2) is a circuit diagram for identifying the sensor of the present invention and identifying its operation.

In FIG. 1(b), 10 is a collection device that performs E/Q and vE conversion, 101 and 102 are VQ and Q/E converters, 1.91 to 13N are optical sensors, 120 to 12N are optical fibers, and 7 os , J o4 is an optical connector.

The η converter 101 in the collecting device 10 serially sends out the light amount determined by the input voltage Es from the optical connector 103 to the optical sensors 131, 132-13N via the optical fibers 120, 12, 122-12N, - The postpartum light is input from the optical connector 104 to the conversion unit 102 in the collection device 10, where the light is converted into voltage and output as El.

Each optical sensor changes from a non-attenuated state to a specific light intensity change rate (attenuation rate) of 1°, 2...n, depending on its operating state.
To control the light amount by (0 kuniku 1), if the loop total dimming amount when all the sensors are not dimming is (however, 1), then the received voltage E with respect to the sending voltage E6
R is as shown in the following formula.

ER=ni・η1・η.・(ni1・ni2...etc.) Es
Equation 1 (where η1.ηa: Elo, conversion coefficient of 07'E conversion section) where 1. If 2 is 1 when 2 is in the transmitting state, then the curtain series 1/a, (j/a)2 . …(1/
a) 1- +/a for n, 1- (1/a)2
．． ...If the light is attenuated by a known means with weighting according to 1-(1/a)n (where a>1), the total amount of light attenuation is the multiplicative product of any combination of motion sensors. The motion sensor can be identified by detecting , and when all sensors are in a dimmed state, the multiplicative product is the result of subtracting the curtain series from 1 as described above, even if the total number of sensors n increases. For example, when a=2, the convergence value of n-+ω is about 0.288, and there is no exponential decrease in the amount of detected light, so multiplexing can be greatly improved. a) is an embodiment according to the present invention, where a=2. n=4
In other words, the identification circuit is E8. in FIG. 1(b) when four sensors control the light intensity in a power series of 2. E
Connect to R terminal.

201 to 204 are comparison circuits that compare ER and a reference voltage, 211 to 213 are DC amplifiers, 221 to 223 are selectors, and 230 is a reference voltage generator that generates a reference voltage for comparison with respect to the weighting of each sensor. occurs.

To explain the operation of this circuit, the input voltage Es is as shown in Figure 1 (
The sensor is identified by signal processing from the input voltage ER which is E/Q converted by the E10 conversion unit 101 of the collection device 10 of b) and φ converted by the sensor postpartum conversion unit 102.

The input voltages of each of the comparison circuits 201 to 204 and the reference voltage 231 generated from the reference voltage generation circuit 230 are set to A. E
s+232 becomes 3/4. E8,233 is 7/8x. E8
．． z a 4 on 15/16. When the input voltage is equal to or lower than the reference voltage, a logic pass 1'' is output, and when it is higher, a logic pass 0'' is output to the respective terminals 2-24.

The DC amplifiers 211 to 213 each weight the input voltage by 1''/'a + 1-(1/a)2.1 (+
/a) Reciprocal of 3, i.e. 2, 4/3 for a = 2
, is amplified 8/7 times and added to the next stage selectors 221 to 223 in a canceled form. In the selectors (analog switches) 221 to 223, the comparison circuits 201 to 2 in the previous stage
When the output of 03 is logic "1", the DC amplifiers 211-2
13 output voltages are selected and the comparison circuits 201 to 203 are selected.
If the output of
The input side of 213 (voltage before amplification) is selected and applied to the next stage comparison circuit. Note that this operation is performed in descending order of light attenuation rate. It will be held on 2nd... and 4th.

In order to simplify the equation, ・η, ・η in the above equation 1. section. Then, ER=.・to 2・to 3・to 4・E, so if a = 2 and n = 4, then ER=.・
(1-dedicated)・(1-('A)2)・(1-(sha)3)・
(1-('A)')・E8=to O-'A -3/4-7
/8-15/16- Es-2 formula, where 2. except for □. 3. The reduced voltage when all 4 are in the dimmed state is . °3/4・7/8・15/16・Es=0.61
To 5. E, Tonashi, and □ are the reduced voltage differences when the light is dimmed. This is a larger value than E8.

Therefore, the voltage of ER is the same as the reference voltage 231. If it is equal to or smaller than ES, add 2. 3. 1 can be determined as "1" regardless of 4.

That is, the reference voltage generation circuit 230 generates oE8 at IA of the reference voltage 231 based on E8, compares it with ER in the comparator circuit 20, and sets the state of 1 to 0 as BL to terminal 2. It can be output. On the other hand, as mentioned above.

The output of is also applied to the selector 22, as described above.

When is 1'', that is, when the value of ER is compared with the reference voltage of 23.
Select a signal in which the O value is doubled (reciprocal of 1-μ) using the DC amplifier 21 to cancel the attenuation, and the b1 is 0.
In this case, the voltage of the ER is directly selected and applied to the next stage comparison circuit 2θ2 to determine the error 2.

In this case, as in 1 above, except for 2 and 3. When all 4 are in the dimmed state, the input of the comparator circuit 202 is .・7
/8・15/16- B8 = 0.82. Es deni 2
Only in the dimmed state.・3/4Es=0.75. Therefore, the input voltage of the comparison circuit 202 is set to 3/4 of the reference voltage 232 generated by the reference voltage generation circuit 230. By comparing oE8 to Es=0.75, 3. Regardless of 4, the comparison circuit 202 can output 1'' or 0''.

Similarly, the comparison circuits 203 and 204 calculate the value of the reference voltage 233°234 generated from the reference voltage generation circuit 230,
On 7/8. Es, on 15/16. By comparing with Es, J+b4 can be sequentially output as ``°1'' or O''. In this embodiment, there are four sensors, but by adding a comparator circuit, a DC amplifier, a selector, a reference voltage generation circuit, etc., it is possible to identify more sensors and identify their operations.

As explained above, in this embodiment, a large number of optical sensors are connected in a loop via optical fibers, and the light is attenuated according to the on/off operating state of each optical sensor, and the amount of attenuation is weighted. Since the optical sensor is identified by this method, there is an advantage that sensor information can be optically multiplexed onto a single optical fiber using a simple principle.

(Effects of the Invention) As explained above, the present invention reduces the total amount of light attenuation of all sensors by weighting the amount of light attenuation and sets the curtain series as a difference from 1, thereby significantly reducing optical multiplexing. With a small number of optical fibers, optical connectors, and O/E conversion modules, sensor information can be collected efficiently, making it suitable for various control systems, measurement systems, factory Zorant, automobiles,
It can be used for multiplexing sensor inputs on airplanes, ships, etc.

[Brief explanation of the drawing]

FIG. 1(b) is a configuration diagram of an embodiment of the present invention, FIG. 1(a)
2 is a detailed explanatory diagram of the present invention, FIG. 2 is a conventional star connection type optical sensor data collection device, and FIG. 3 is a conventional wavelength multiplexing type loop type optical sensor data collection device. 10... Collection device, 10... Voltage-light converter (Elo),
102...Light-voltage converter (o,"g), 103,10
4... Optical connector, 131~13N... Optical sensor, 120~
12N...Optical fiber, 201-204...Comparison circuit, 2
11-213...DC amplifier, 221-223...Selector, 230...Reference voltage generator, 20-25...Terminal. 〕F4 Figure 2 S0 Figure 3 Procedural amendment (voluntary) 8 months 60・〃・11I3

Claims (2)

[Claims] (1) At least two or more optical sensors are connected in a loop via optical fibers, and the amount of light passing through each optical sensor is controlled according to power series weighting for each sensor according to the operation. An optical sensor multiplexing device that performs optical multiplexing. (2) Weighting for each sensor is 1-1/a, 1-(1/
a) ^2, 1-(1/a)^3...1-(1/a)^n(
However, a>1. ) The optical sensor multiplexing device according to claim 1, characterized in that: