WO2007121620A1

WO2007121620A1 - A contactless read out sensor for mechanical character wheel counter

Info

Publication number: WO2007121620A1
Application number: PCT/CN2006/001122
Authority: WO
Inventors: Ange Zhang
Original assignee: Ange Zhang
Priority date: 2006-04-24
Filing date: 2006-05-29
Publication date: 2007-11-01
Also published as: CN1835002A; CN1835002B

Abstract

A contactless read out sensor for mechanical character wheel counter in which a theory about light reaction is utilized to convert light signals into electrical signals coded data, hence realizes readout an indication value of the character wheel of the mechanical character wheel counter in the form of noncontact. A phototriode (1) and a light emitting diode (2) and a signal processing circuit are installed at a circuit board on the upside of a bracket (5). There is a fiber fixing hole (7) underneath the bracket. The fiber (4) is connected between the phototriode (1) and the light emitting diode (2) and the fiber fixing hole (7) and served for an optical path. The character wheel is installed under the bracket and reflecting light strips are attached to the character wheel, to read out a coded data of the phototriode in scanning form; then look up a check list for the character wheel (8) number and the coded data by means of a singlechip, and the coded data is converted into a indication number of the character wheel counter, and output through a serial communication port.

Description

Technical field:

The present invention relates to the field of data recognition technology in measurement technology, and more specifically to a mechanical character wheel counter non-contact reading sensor and a method of designing the same.

Background technique:

Mechanical rotary counters are widely used in water meters, electric meters, gas meters, odometers and other accumulative measuring instruments. Due to their simple structure and reliable operation, they are an irreplaceable measurement in a considerable period of history. the way. However, due to the development of technology, many places require that the measuring instrument can electronically output the measurement results for remote transmission or directly to the computer for data processing, and such instruments do not have corresponding electronic digital output devices.

Summary of the invention:

SUMMARY OF THE INVENTION It is an object of the present invention to provide a mechanical character wheel counter non-contact reading sensor which utilizes the principle of light reflection to convert a reflected light signal into a light signal according to the intensity of the light reflected signal of the reflective strip mounted on the surface of the character wheel. The electrical signal corresponding to the rotation angle of the character wheel encodes data, thereby realizing the function of reading the indicated value of the mechanical character wheel counter wheel in a non-contact manner. It comprises a character wheel, a fiber fixing hole, a bracket, a reflective strip, a circuit fiber, a light emitting diode, a phototransistor and a signal processing circuit, and is characterized in that: the upper circuit board of the bracket (5) ( ^; ι is equipped with a phototransistor (1), illuminating Diode (2) and signal processing circuit, the bracket (5) is provided with a fiber fixing hole (7') [ ^: 'phototransistor (1) and the light-emitting diode (2) and the fiber fixing hole (7) of the bracket (5) The optical fiber (4) is used as the optical channel, and two optical fibers are arranged side by side in each of the optical fiber fixing holes (7), one of which is connected to the phototransistor, one is connected to the light emitting diode, and the lower part of the bracket (5) is provided with a character wheel. (8), the character wheel (8) is affixed with a reflective strip (6). The signal circuit includes a single-chip control circuit and a multi-switch circuit as shown in Figure 7. The output of the phototransistor is connected to the input of the multiplexer. The A, B, and C terminals of the MCU control circuit are connected to the address selection terminals A, B, and C of the multiplexer, and the multiplexer 3⁄4 output terminal X is connected to the AD-IN terminal of the MCU control circuit, and the C0N1 terminal of the MCU control circuit is connected. With glowing two The cathode of the tube is connected, and the control circuit of the single chip first lowers the C0N1 end to make the LED illuminate the reflective strip on the character wheel. The MCU sequentially controls the A, B, and C address selection ends of the multi-way switch by the AD method. The IN terminal reads the output signal of the corresponding phototransistor into the encoded data in the single-chip microcomputer, and then converts the encoded data into a character wheel counter indicating number by the single-character word wheel digital and encoded data comparison table, and outputs it through the serial communication socket.

The number of phototransistors and light-emitting diodes is determined according to different application requirements. The more the phototransistor, the smaller the volume of the sensor, and corresponding to the number of different phototransistors, the adjacent two optical fibers have a certain angle between the fixed holes; the present invention The calculation method and steps of the proposed angle between two adjacent fiber fixing holes are as follows:

(1) According to the design requirements, select the number N of phototransistors corresponding to each character wheel;

(2) The angle between two adjacent fiber fixing holes

XN];

(3) The number of optical fiber fixing holes and the number of phototransistors N phase;

After determining the angle between the number of phototransistors and the adjacent two fixed holes of the optical fiber, there is a set of black and white reflective strips of a specific length corresponding thereto. The calculation method and steps of the lengths of the reflective strips are as follows -

(1) The length of the reflective segment and the non-reflective segment is the angular amount of the circle of the character wheel;

(2) The length of each segment is the angle and α determined by a _MK = 360X (K ± l / M) ÷ [(N - 3) ' N]. =360÷ (N-3) The combination of angles determined, where Κ=], 2, 3··· (Ν-1), M^3V3⁄4-N, N is the number of phototransistors.

(3) The sum of the angles of all the reflective segments and the non-reflective segments is equal to 360 degrees V

(4) When the verification character wheel rotates one week, all data read by the photoelectric sensor has no duplicate data;

(5) Corresponding the data determined in (4) with the character wheel indicator number of the character wheel counter to form a table of numbers and coded data, and storing the comparison table at the signal shown in FIG. Inside the microcontroller.

(6) Using the signal processing circuit shown in Figure 7 to read out the 3⁄4 out signal of the sensor, and obtain the corresponding character wheel indication number by checking the word wheel digital and the encoded data comparison table, and the MCU control circuit is passed through the string of 6 The line mode output word wheel indicates the number. :'" ^Ί ''

The invention has the advantages that: the data can be remotely transmitted, the lotus power supply is not needed, the accuracy is high, the use is convenient, the service life is long, and the accumulated error is not generated, and the non-contact type reading of the mechanical character wheel counter indication value is realized. Features.

BRIEF DESCRIPTION OF THE DRAWINGS:

Fig. 1 is a schematic structural view of a sensor embodiment 1 of the present invention. ; ' '

2 is a schematic view showing the angular distribution between the fixing holes of the optical fiber of Embodiment 1 in the sensor of the present invention.

Fig. 3 is a schematic view showing a reflective strip of the embodiment 1 of the sensor of the present invention. '

Fig. 4 is a schematic structural view of a sensor embodiment 2 of the present invention. ' :

Fig. 5 is a schematic view showing the angle distribution of the optical fiber fixing hole of the embodiment 2 in the sensor of the present invention.

Fig. 6 is a schematic view showing the distribution of a reflective strip of Embodiment 2 of the sensor of the present invention.

Figure 7 is a diagram showing the signal processing circuit of Embodiment 1 and Embodiment 2 in the sensor of the present invention.

detailed description:

Example 1:

Applied on 8 phototransistor sensors.

Bracket and board design:

(1) Determine the number of phototransistors corresponding to each character wheel N=8 (see Figure 1); (2) Calculate the angle between the adjacent two fiber fixing holes:

=360÷[(8-3) Χ8]= 9 degrees;

(3) The number of fiber fixing holes is 8 and the interval angle is 9 degrees (see Figure 2);

According to the above method, the fiber positioning holes (7) on the bracket (5) and the bracket (5) are designed and 8 phototransistors are mounted on the circuit board (3) (see Fig. 1). Reflective strip design:

(2) Calculation of length per segment - α _ΗΚ =360 X (K+l/M) ÷[ (N_3) xN]

a ₀ =360 ÷ (N- 3) . N=8; M=5; K=l, 2, 3, 4, 5, 6, 7:

a _5] = 360 X (1+1/5) ÷ [ (8-3) x8]= 10.8

5 ₂ = 19.8

a 28.8

a ₅₄ = 37.8

a ₅₅ = 46.8

a _M = 55.8

a ₅₇ = 64.8

a _O =360 ÷ (N-3) -360/5=72

The set of segment lengths is {10.8" , 19.8 ^U , 28. S, 37.8" , 46.8" , 55.8"·, 64.8", 72' }

(3) The length of the segment that satisfies the condition that the sum of the angles of all the reflective segments and the non-reflective segments is equal to 360 degrees is:

72+72+37.8+37.8+28.8+28.8+19.8+19.8+10.8+10.8+10.8+10.8=360

(4) When the verification character wheel rotates one week, all data read by the photoelectric sensor has no duplicate data:

When the length combinations of the segments are combined in the following order, the output signals of the phototransistors have no duplicate data. {72°, 72°, 37.8. 19.8. 28.8°, 10.8 19.8. , 37.8 ⁰ , 10.8. 28.8. 10.8. 10.8. } (see Figure 3)

(5) The verification method is as follows:

All the light-emitting diodes (2) emit light, respectively detecting the output level of the phototransistor (1). When the fiber positioning hole (7) is located above the reflective section, the output level of the phototransistor (1) is 1, 'When the fiber positioning hole output level (7) is positioned above the non-reflective section, the phototransistor (1) of the output level to 0, all the photoelectric ^three-pole tube (1) according to D7 of FIG. 1, D6, D5, D4, D3, The order of D2, Dl, and DO is arranged into a hexadecimal coded data. When the character wheel rotates one week, the photoelectric The encoded data output by the triode in sequence is as follows:

0 1 3 7 F IF 3F 7F FF FE FC F8 FO EO El CI C3 83 87 86

6 E C 1C 18 38 30 31 71 61 63 62 E2 C2 C6 C4 84 8C 88 89

9 19 11 13 33 23 27 67 47 4F CF 8F 9F 9E IE 3E 3C 3D 7D 79

7B FB F3 F7 E7 EF EE CE DE DC DD 9D BD B9 BB BA 3A 7A 72 76

74 F4 E4 EC E8 C8 D8 DO 90 BO AO 20 60 40 CO 80

There is no duplicate data in all 96 encoded data, which proves that the segment lengths shown in (Figure 3) are a set of valid combinations. While the above data is generated by rotating the word wheel for one week, the following table of characters and coded data is also generated.

The word wheel digital and coded data comparison table is stored in the single chip microcomputer, and the signal processing circuit of FIG. 7 is used to read the coded data of the sensor, and the corresponding character wheel number is obtained by checking the word wheel digital and the coded data comparison table, which is controlled by the single chip control circuit. The communication socket outputs the character wheel indication number in a serial manner, and realizes the function of reading the mechanical character wheel counter indication value in a non-contact manner. '

Example 2:

Applied on 7 phototransistor sensors.

Bracket and board design:

(1) Determine the number of phototransistors corresponding to each character wheel N=7 (see Figure 4); (2) Calculate the angle between the adjacent two fiber fixing holes:

α = 360 ÷ [(7-3) x7]= 360 + 28=12.9 degrees;

C3) The number of fiber fixing holes is 7 and the interval angle is 12.9 degrees (see Figure 5);

According to the above method, the fiber positioning holes (7) on the bracket (5) and the out bracket (5) and the seven phototransistors on the circuit board (3) are designed (see Fig. 4). Reflective strip design:

(2) Calculation of each length:

α _ΜΚ =360 X (Kl/M) ÷ [ (N- 3) N]

a ₀ =360 ÷ (N-3)

N=7; M=3; K=l, 2, 3, 4, 5, 6:

A ₃₁ = 360 X (1-1/3) ÷ [ (7-3) X7]=8.6 _;

a:«= 21.4;

a ₃₃ = 34.3;

a 47.1;

a 60.0;

a ₃₆ = 72.9;

0=360 ÷ (N-3) =360/4-90;

The segment length set is {8.6, 21.4, 34.3, 47.1, 60, 72.9, 90}

90+90+47.4+47.4+21.4+21.4+21.4+21.4=360

(4) When the verification word wheel rotates one revolution, all data read by the photoelectric sensor has no duplicate data - when the length combinations of the segments are combined in the following order, the output signal of the phototransistor has no duplicate data. {90°, 21.4. , 21.4. , 21.4°, 47.1°, 47.1°, 21.4. , 90. } (see Figure 6) ' ■

(5) The verification method is as follows:

All the light-emitting diodes (2) emit light, respectively detecting the output level of the phototransistor (1'Γ, when the fiber positioning hole (7) is located above the reflective section, the output level of the phototransistor (1) is 1, when the fiber When the positioning hole (7) is located above the non-reflective section, the output level of the phototransistor (1) is 0, and the output levels of all the phototransistors (1) are as shown in Figure 1, D6, D5, D4, D3, D2, Dl The order of the DOs is arranged in a hexadecimal coded data. When the word wheel is rotated one week, the coded data output by the phototransistor is as follows: . 0 1 3 7 F IF 3F 7F 7E 7C 7D 79 7B 73 72 76 66 64 6C 4C 48 58 18 10 30 31 21 61 63 43 42 46 6 4 CD 9 19 IB 13

33 37 27 67 6F 4F 4E 5E IE 1C 3C 38 78 70 60 40

There is no duplicate data in all 56 encoded data, which proves that the segment lengths shown in Figure 6 are combined into a set of valid combinations. While the above data is generated by rotating the word wheel for one week, the following table of characters and coded data is also generated.

The word wheel digital and coded data comparison table is stored in the single chip microcomputer, and the signal processing circuit of the sensor is used to read the coded data of the sensor, and the word wheel number of the ^ is obtained by checking the word wheel digital and the coded data comparison table, by the single chip control circuit The character wheel indicator number is serially output via the communication socket, and the function of reading the mechanical character wheel counter indication value in a non-connected manner is realized.

Claims

Rights request

1. A mechanical character wheel counter non-contact reading sensor comprising a character wheel (8), a fiber fixing hole (7), a bracket (5), a reflective strip (6), a circuit board (3), an optical fiber (4), The light emitting diode (2) and the phototransistor (1) are characterized in that: the upper circuit board (3) of the bracket (5) is provided with a phototransistor (1), a light emitting diode (2) and a signal processing circuit, and the bracket (5) is opened. The optical fiber fixing hole (7), the phototransistor (1) and the light-emitting diode and the fiber fixing hole (7) of the bracket (5) adopt an optical fiber (4) as an optical channel, and each fiber fixing hole (7) is juxtaposed Install 2 fibers, one of which is connected to the phototransistor (1), the i is connected to the LED (2), the lower part of the bracket (5) is equipped with a character wheel (8), and the character wheel (8) is affixed with a reflective strip ( 6).

2. A mechanical character wheel counter non-contact reading sensor according to claim 1, wherein: the center line of the optical fiber fixing hole (7) is evenly spaced at equal intervals from the word wheel in the normal direction of the outer circumference of the character wheel.

3. A mechanical character wheel counter non-contact reading sensor according to claim 1, wherein: the optical fiber (4) is connected between the phototransistor (1), the light emitting diode (2) and the fiber fixing hole (7). As a light channel.

4. A mechanical character wheel counter non-contact reading sensor according to claim 1, wherein: the reflective strip (6) on the character wheel (8) is formed by a black and white reflective segment and a non-reflective segment.

5. The mechanical character wheel counter non-contact reading sensor according to claim 1, wherein: the signal processing circuit comprises a single chip control circuit and a multi-way switch circuit, and an output end of the phototransistor is connected to the input end of the multi-way switch. The A, B, and C terminals of the MCU control circuit are connected to the address selection of the multiplexer 3⁄4 A, B, C. The output terminal X of the multiplexer is connected to the AD-IN terminal of the MCU control circuit, and the MCU controls the power. The C0N1 end is connected to the cathode of the LED, and the MCU control circuit first lowers the C0N1 end to make the LED illuminate the reflective strip on the character wheel, and the MCU sequentially controls the A, B, and C address selection ends of the multi-channel switch by scanning mode. The output signal of the corresponding phototransistor is read into the coded data by the AD-IN terminal, and the coded data is converted into the word wheel counter indication number by the single-character word wheel digital and coded data comparison table, and output through the serial communication socket. . '

6. The mechanical character wheel counter non-contact reading sensor according to claim 1, wherein: the number of the phototransistors (1) in the sensor and the fixing holes (7) of the optical fibers on the bracket (5) The following calculation methods and steps are used: ' ·'·'·

(1) selecting the number N of photoelectric three-tubes (1) corresponding to each character wheel according to design requirements;

(2) The angle between adjacent two fiber fixing holes <7) on the bracket (5) 'a = 360 ÷ [ (N-3) xN] _;

(3) The number of fiber fixing holes (7) of the bracket (5) is equal to the number N of the phototransistors (1); 7. The non-contact reading sensor for a mechanical character wheel counter according to claim 1 or 4, wherein: the angles of the black and white reflective segments and the non-reflective segments are as follows:

(1) The angle between the reflective segment and the non-reflective segment is increased by the angle of the circle of the character wheel;

(2) Each length is composed of an angle determined by 360 x (K±l/M) ÷ [ (N-3 ) XN] and an angle determined by 360 ÷ N, where K = 1, 2, 3 · ·'· (Ν-1), Μ=3, 4-Ν, Ν is the number of phototransistors.

(3) The sum of the angles of all the reflective segments and the non-reflective segments is equal to 360 degrees;

(4) When the verification word wheel is rotated one revolution, all data read by the photoelectric sensor has no duplicate data.

(5) Correspond to the data determined in (4) and the word wheel of the character wheel counter [words to form a table of numbers and coded data.

(6) Using the sensor signal processing circuit shown in Fig. 7 to read the coded data of the device, and obtain the word wheel indication number by checking the word wheel digital and the coded data comparison table, and outputting the word serially by the single chip control circuit via the communication socket. The wheel indicates the number.