JPS5845521A - Two-dimensional digital vibrometer - Google Patents

Abstract

PURPOSE:To detect the magnitude and the direction of oscillation, by irradiating the light to photodetectors, which are arranged one-dimensionally, through an optical mask, where the pattern which changes the incident light in accordance with the oscillation input is formed. CONSTITUTION:When an oscillation is applied to a casell, an oscillation system mass 12 is moved relatively to the case 11, and the pattern of the light of a light source 2 which is transmitted through an optical mask 13 to reach a photodetector array 14a of a photo detecting array circuit 14 is changed. The optical mask 13 consists of a light-transmissive part 13a and a light interceptive part 13b, and a fan-shaped pattern formed with a line (r), which is inclined at 45 deg. to a direction X of the one-dimensional arrangement of the photodetector array 14a, and a line (s) which intersects the line (r) at 90 deg. is used in the light interceptive part 13b. Thus, the variation to the pendulum motion at the intersection among the line (X), the line (r), and the line (s) is indicated as the sum and the difference between the relative variation in the X direction and the relative variation in the Y direction, and X and Y two-dimensional oscillation output is taken out.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a two-dimensional digital vibrometer that uses a one-dimensional array of light-receiving elements or a single light-receiving element.

FIG. 1 shows a schematic configuration of a two-dimensional digital vibrometer using a conventional light receiving element and light source.

In Fig. 1, 1 is a node with a circular cross section, 2 is a point light source that also serves as the mass of the vibration system, and 3 is a light receiving element array arranged in a plane. The stationary position of the light source 2 is used as a reference point, and a large number of light receiving elements are arranged concentrically at regular intervals in the radiation direction. Now, when there is a vibration input, the two-point light source 2 causes a relative displacement with respect to the light receiving element array 3, and it is possible to extract an electrical signal from the light receiving element where the light is incident. Size and direction can be detected.

Such a conventional vibrometer using a point light source has the disadvantage that, in order to detect two-dimensional signals, a special light receiving element array in which light receiving elements are arranged in a plane as described above is required.

The present invention has been developed in view of the above-mentioned drawbacks found in the conventional products.
The purpose of this project is to provide a two-dimensional digital vibrometer that can detect two-dimensional vibrations using a one-dimensional array of general-purpose light-receiving elements or a single light-receiving element using an optical mask. an optical mask formed with a pattern consisting of a light transmitting part and a light blocking part so as to be able to change the light incident on the light receiving elements in accordance with vibration input; The present invention provides a two-dimensional digital vibrometer characterized by comprising a light source that irradiates light onto an element array or a single light-receiving element through the optical mask.

2 to 5 show a first embodiment of the present invention, and in the figures, the same components as those of the conventional example are denoted by the same reference numerals. FIG. 2 is a schematic configuration diagram of the vibration meter according to the present invention, where 11 is a case, and 12 is a case 11 connected to the case 1 through a circular cross-section nose 1.
A box-shaped vibration system mass 13 is an optical mask attached to the bottom of the vibration system mass 12 hanging from the inner surface of the top plate of the
As shown in FIG. 3, this optical mask 13 has a portion 13a that transmits the light from the light source 2 provided in the vibration system mass 12, and a portion 13b that blocks the light from the light source 2, which are formed with a chisel turn to be described later. There is. Reference numeral 14 denotes a light-receiving array circuit which includes a one-dimensionally arranged light-receiving element array 14a and an attached circuit described later for extracting a video signal from the light-receiving element array. It is installed to face 2.

In the above configuration, when vibration is applied to the case 11, the vibration system mass 12 causes relative movement with respect to the case 11,
Therefore, the nometer of the light from the light source 2 that passes through the optical mask 13 and reaches the light receiving element array 14a of the light receiving array circuit 14 changes.

Now, as shown in FIG. 3, the light blocking portion 13b is formed by a line r having an angle of 45° with respect to the one-dimensional arrangement direction Consider the fan shape that is formed. Now, X-rays and #
The amount of change in the pendulum motion at the intersection with r + s is △A
, ΔB, the relative change amount in the X direction is ΔX, and the relative displacement amount in the Y direction perpendicular to the X direction is ΔY, then equation (1) holds true.

(The equation υ always holds true for the movement of the optical mask 13 in any direction as shown in FIGS. 4(a), (b), and (c).

△X+△Y-△A, △X-△Y=ΔB ・・・・・・
(1) Therefore, formula (1) immediately becomes (4do\A, +ΔBn/2 = △X, (8A-ΔB)
/2- △Y...(2) can be calculated to know the vibration input in both the X and Y directions.

Next, FIG. 5 shows an example of a circuit block configuration for extracting digital signals from the above-mentioned apparatus. In FIG. 5, 14 is the same as shown in FIG. 2, a one-dimensionally arranged light receiving element array 4a, and a video signal corresponding to the amount of light irradiated to each element by sequentially scanning each element of the light receiving element array 14H. 21 is a clock oscillation circuit, 22 is a control circuit for controlling the sequence of the circuit system, and 23 is a video signal. A level setting circuit 24 sets a predetermined threshold value for the signal and sends it out at a digital logic level of %0//, 1#, and 24 is a video signal level 11 that is sent out in series from the level setting circuit 23.
25 is an initial value setting circuit that manually sets binary data corresponding to the initial position of the optical mask (position of vibration input 0); 26 is 2 This is an arithmetic circuit that performs arithmetic operations on the output data of the advance counter 24 and the set value of the initial value setting circuit 25 and outputs ΔX or ΔY.

Next, the operation will be explained. In response to the clock output φθ of the clock oscillation circuit 21, the control circuit 22 outputs a scanning start signal S for the light receiving element array and a scanning clock output φ1. The light receiving element array 14a is sequentially scanned from the tip by this signal and sent to the video signal total level setting circuit 23 according to the position of the optical mask 13. The level setting circuit 23 is connected to the light receiving element 11〃 in the light transmitting part 1'3a of the optical mask 13, and s□ to the light receiving element in the light blocking part 1'3a of the optical mask 13.
The threshold is set to a logic level of /l. 2
The advance counter 24 counts the level of %1 in the first half and the edge half of one scan of the light receiving element array 14a. Synchronization with scanning is achieved by control signals from the control circuit 22.

The initial value setting circuit 25 is set with initial values corresponding to the first half and the second half of scanning, respectively.

After the counter 24 finishes counting, the arithmetic circuit 26 performs an arithmetic operation on the data and the initial value selected and fetched from the initial value setting circuit 25, depending on whether the data is the first half or the second half of the scan, and calculates ΔX. , ΔY are also output to each other. The arithmetic circuit 26 has a function of temporarily holding A and ΔB'z in the middle of the ΔX and ΔY calculations, and performs the calculations while the timing with the shear array scanning and the like is controlled by the control circuit 22.

Note that mechanical performance such as the natural frequency of the pendulum system is determined by the performance required as a vibration meter and the arrangement interval of each element constituting the light receiving element array 14a'.

Furthermore, the function remains the same even if the light receiving element array is attached to the pendulum or the light source and optical mask are attached to the case.

As explained above, in the first embodiment, since an optical mask is used, the X
, Y2-dimensional vibration output can be obtained.

In addition, since this device recognizes the A area as opposed to the conventional point light source that recognizes the electrical point on the coordinate plane, the light from the optical mask is applied to the midpoint between the elements that make up the light receiving element array. A signal can be detected even if the boundary between the transparent part and the blocking part is located.

Furthermore, as explained above, it is possible to perform signal processing that focuses only on the amount of change in the five positions. Therefore, within the allowable dynamic range of the device, There is no problem even if the relative position initially deviates. The actual assembly of the device is extremely easy, as all you need to do is pay attention to the relative angles between the optical mask and the light-receiving element.

In the first embodiment, an optical mask is described in which the light transmitting part and the light blocking part are formed by two orthogonal straight lines, but as shown in FIG. 67.5?An optical mask 13' provided with a light transmitting part 13''a, a blocking part 13'b, and a semi-transmissive part 13'C divided by lines @r, t, and g' intersecting at an angle of 90°. Vibration can be detected even at intermediate angles in the orthogonal X and Y directions.In this case, the threshold level setting circuit 23 for the video signal shown in FIG. It is configured so that it can be distinguished into three stages according to each area of 13'.

His signal processing circuit is also configured to adapt to the input signal. Optical mask 13' shown in FIG.
When using , straight lines X, r, t as shown in Figure 7
, S'' and the amount of change ΔA, ΔC2ΔB/(In FIG. 7, the symbols (a), (b), and (c) are expressed by the following equation for the displacement of the optical mask ΔY.

ΔA=ΔX+△Y, △C=△p+(ΔX−△Y), Δ
B'=△X...(3) Therefore, according to equation (3), △A-△X=△Y, △C-ΔX+ΔY=ΔP...
... Obtain (4).

Here, 8P is the optical mask 13' and the light receiving element array 1 on P@ in the angular direction inclined at 45 degrees with respect to both the X and Y axes.
This is the relative displacement with respect to 4a.

As explained above, the light transmission level of the optical mask,
By changing the boundary in various ways, it is possible to detect a signal depending on the purpose of measurement. The boundary line may be a curved line, in which case it will have non-linear characteristics.

Furthermore, as shown in FIG. 8, a concentric optical mask 1
3) It is possible to manufacture a so-called omnidirectional vibration meter that has the same vibration detection sensitivity in all two-dimensional directions.

In this case, only one light-receiving element may be used, but the initial relative positions of the optical mask 13 and the light-receiving element 14' must be such that the light-receiving element is located at the center of the concentric circles forming the optical mask.

Note that 13'a, . . . 13〃e represent concentric areas in which the light transmittance gradually changes. A level setting circuit 23'a that sets a threshold value and outputs a logic level ^ON2%1.

23'b...23'e are made to correspond.

To determine the vibration level, it is sufficient to detect the logic output of the -6 level setting circuit. The light transmission level of the optical mask can be subdivided depending on the size of the light receiving element and its resolution.

As explained above, since the two-dimensional digital vibrometer according to the present invention uses an optical mask, two-dimensional X and Y vibration outputs can be obtained from a one-dimensionally arranged general-purpose light receiving element array. In addition, since this device recognizes a heron region, as opposed to recognizing an electric point on a coordinate plane using a conventional point light source, an optical mask is placed on the midpoint between the elements that make up the light receiving element array. A signal can be detected even if the boundary between the light transmitting part and the light blocking part is located. Furthermore, it is possible to perform signal processing that focuses only on the amount of change in position, and therefore, within the allowable dynamic range of the device, the relative positions of the optical mask and the light-receiving element array in the X and Y directions are initially shifted. It does not matter if this occurs. Finally, the actual device assembly work is extremely easy, as all you need to do is pay attention to the relative angle between the optical mask and the light-receiving element. Furthermore, by varying the light transmission level of the optical mask and its boundary a, it is possible to detect a signal depending on the purpose of measurement.

Note that since the present invention essentially detects a two-dimensional displacement vector or its absolute value, it can be used in various devices that require a two-dimensional displacement detection function.

[Brief Description of the Drawings] The drawings are provided to explain the present invention.
A schematic configuration diagram of a dimensional digital vibration meter, FIGS. 2 to 5 show the first embodiment of the present invention, and FIG. 2 is a partially vertical front view schematically showing the vibration meter according to the present invention. Figure 3 is a diagram explaining the correspondence between the optical mask and the light receiving element array, Figures 4 (a), (b) and (c) are diagrams explaining the operation, Figure 5 is a block configuration diagram of the digital signal extraction circuit, and Figure 6 is a diagram similar to FIG. 3 showing another embodiment of the optical mask, FIG. 7 is an explanatory diagram of the operation by the optical mask of FIG. 6, and FIG. 8 is an explanatory diagram showing still another embodiment of the optical mask. be. 2... Light source, 12... Vibration system mass, 13... Optical mask, 13a... Light transmitting part, 13b... Light blocking part, 14... Light receiving array circuit, 14a...・Photodetector array patent applicant: Oki Electric Industry Co., Ltd. Agent Patent attorney: Yoshi 1) Sei Takashi Figure 3X Figure 4× (α) (b)
(C) Figure 6 Figure 7 Personal procedure amendment August 9, 1980 Kazuo Wakasugi, Commissioner of the Patent Office 1 Display of the case 1981 Patent application No. 143529 2 Name of the invention Two-dimensional digital vibration meter 3 Relationship with the case of the person who refused the amendment Patent applicant address 1-7-12 Toranomon, Minato-ku, Tokyo Name (
029) Oki Electric Industry Co., Ltd. Representative Nankai Hashimoto 4th generation Masato 105 Den (03) 508-9866
"Column for detailed explanation of the invention in the specification" 1. (1) Add "1ka" between [line] and "e" on page 2, line 17 of the specification. (2) Add r14aJ between "i" and "ka" on page 3, line 19 of the specification. (3) Add r14aJ between “i” and “no” on the 7th line of page 6 of the specification, and add “na” between “line” and “wa” on the 18th line of the same page. Join each. (4) Add "wa" between "hen" and "ra" on page 7, line 15 of the specification. (5) "ΔY" on the 10th line of the 9th page of the specification is corrected to "ΔV", and from the 17th line of the same page to the 19th line of the same page are corrected as follows. Note: Here, △X and △Y are the relative changes when △V is decomposed into components on the X axis and on the X axis, and △P is △V
The relative relationship between the optical mask 13' and the light-receiving element array 14a on the P-axis when decomposed into a component on the P-axis and a component on the X-axis in an angle direction inclined by 45 with respect to both the X and Y axes. It is the amount of change. (6) The words and phrases shown in the left column (incorrect) below on the following pages and lines in the specification will be corrected by showing them in the right column (correct). Page line Left column (incorrect) Right column (correct) P411
6th place Chemical P4117
9420 P4L20 104

Claims (1)

[Claims] an optical mask formed with a pattern consisting of a one-dimensionally arranged light-receiving element array or a single light-receiving element, and a light transmitting part and a light blocking part so that the light incident on them can be changed according to vibration input; A two-dimensional digital vibrometer comprising a light source that irradiates light onto a light receiving element array or a single light receiving element through the optical mask.