Weak Vibration Deformation Detection Circuit

Abstract

A weak vibration deformation detection circuit of the present invention includes a photodiode circuit, an amplifier circuit, a differentiator circuit, a shaping circuit, and a gating circuit connected in sequence; parallel light rays are incident on a linear array silicon photodiode circuit through a lens; weak electrical signals are buffer-amplified and primarily amplified by the amplifier circuit part; the differentiator circuit part outputs to the shaping circuit part after receiving the amplified signals from the previous-stage amplifier circuit; after receiving the electrical signals transmitted by the differentiator circuit, the shaping circuit obtains a difference signal and outputs it; the driving signal output by the shaping circuit is used in cooperation with a gating logic gate circuit with different periodic pulse signals to obtain pulse signals with different time intervals and periodic outputs, and the pulse signals are converted into vibration deformation intensity pulses; the vibration intensity or deformation amount information is deduced by determining the deformation or vibration amplitude using the output pulse intensity. The circuit of the present invention has low implementation complexity, and the detection results are sensitive and accurate, and it is applicable to various industrial sites.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic circuits and signal processing, and particularly relates to a weak vibration deformation detection circuit. Background Art

[0002] Vibration deformation often occurs in the ground, bridges, and machinery. Weak vibration deformation signals contain rich characteristic information, such as ground settlement trends, mechanical failures, etc., so it is necessary to extract and analyze them. During the extraction of weak signals, sometimes the signals are very weak and are extremely vulnerable to external interference and are submerged in strong noise; sometimes the amplitude change range of the measured signal is very large, which brings great difficulties to signal acquisition; sometimes the signal duration is very short and is not enough to trigger the action of the backend acquisition and analysis system; traditional detection methods based on images, remote sensing, and GNSS often have poor real-time performance and limited scenarios. Therefore, in view of the characteristics of weak vibration deformation signals in terms of energy, time, timeliness, and scenarios, a detection circuit with fast shaping, sensitive response, high real-time performance, and rich applicable scenarios is proposed.

[0003] The linear array silicon photodiode has a wide spectral range from ultraviolet to near-infrared. Since all pixels can store charge readout with reverse bias, it has the ability of high sensitivity and low light quantity detection, and the crosstalk between pixels is reduced, maintaining the purity of the signal. The linear array silicon photodiode is mainly used for low light quantity detection. Different detection instruments composed of the linear array silicon photodiode and its processing circuit are widely used in various industrial fields. Summary of the Invention

[0004] Aiming at the defects of weak energy, short duration, and poor real-time performance of traditional detection methods for weak vibration deformation signals in the ground, bridges, and machinery, the present invention proposes a detection circuit and device combined with a photoelectric array diode, which can well solve the demand for real-time and highly sensitive detection of weak vibration deformation in different scenarios.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A weak vibration deformation detection circuit includes a photodiode circuit, an amplifier circuit, a differentiator circuit, a shaping circuit, and a gating circuit connected in sequence;

[0007] Parallel light rays are incident on the linear array silicon photodiode circuit through a lens; the linear array silicon photodiode changes the intensity of the received light into a weak change in the electrical signal, and at the same time transmits this weak electrical signal to the amplifier circuit;

[0008] The weak electrical signal is buffer-amplified and primarily amplified by the amplifier circuit part, so as to amplify the change signal to an electrical signal level that can be preprocessed by the subsequent differentiator circuit;

[0009] After receiving the amplified signal from the pre - amplifier circuit, the differentiator circuit extracts the sudden change part of the input waveform and outputs it to the shaping circuit part;

[0010] After receiving the electrical signal transmitted by the differentiator circuit, the shaping circuit compares this instantaneous change with the set reference value, outputs the obtained difference signal, and thus drives the Darlington tube at the subsequent stage;

[0011] The driving signal output by the shaping circuit is used in cooperation with the strobe logic gate circuit with pulse signals of different periods to obtain pulse signals with different time intervals and periods of output, thereby converting the pulse signal into a vibration deformation intensity pulse;

[0012] The vibration intensity or deformation amount information is deduced by using the output pulse intensity to determine the deformation or vibration amplitude.

[0013] On the other hand, the present invention also discloses a weak vibration deformation detection method, which adopts the weak vibration deformation detection circuit as described above, and includes the following steps.

[0014] Step 1: Install the device. Place the light source and the linear array silicon photodiode on both sides of the surface to be inspected respectively. The light source generates parallel light rays through the optical structure. Through the adjustment mechanism, the parallel light rays are incident on the linear array silicon photodiode through the lens and are completely received by it;

[0015] Step 2: When there is no vibration deformation on the surface to be inspected or the vibration deformation amount does not reach the threshold value, the parallel light rays generated by the light source are completely absorbed by the linear array silicon photodiode. The linear array silicon photodiode is in the conducting state. In this state, the subsequent processing circuit is in a stable state for a long time, the strobe logic is blocked, and no detection pulse is output;

[0016] Step 3: When the vibration deformation occurring on the surface to be inspected reaches the threshold value, the parallel light rays generated by the light source are partially or completely blocked, causing partial or complete instantaneous cut - off of the linear array silicon photodiode. This instantaneous state is detected and amplified by the subsequent circuit, the strobe logic is opened, and the vibration deformation intensity pulse is output.

[0017] As can be seen from the above technical solutions, the present invention is composed of a photoelectric receiving circuit, an amplification module, a differentiator circuit, a shaping circuit, and a strobe circuit. The present invention utilizes the characteristics of high sensitivity and high isolation degree between pixels of the linear array silicon photodiode to extract the sudden and high - frequency characteristics of the weak vibration deformation signal on the surface to be inspected in real - time through the hardware circuit, and outputs the detection synchronization pulse under the cooperation of the strobe logic.

[0018] The weak vibration deformation detection circuit and device proposed by the present invention innovatively introduce a photoelectric array diode device in the circuit, and combine analog and digital devices, making full use of the high-speed operation characteristics of the analog-digital hybrid circuit to meet the requirements of the device for vibration measurement accuracy, reliability, cost, etc. All functions realized by this circuit can be achieved by basic operational amplifiers, high-speed comparators, and digital gate logic chips, without the participation of chips such as single-chip microcomputers (MCUs) that contain arithmetic units and controllers. Under the condition of meeting the high speed and stability of data processing, the device cost is greatly reduced. The measurement channels of the entire circuit can be flexibly expanded both in terms of quantity and accuracy, which greatly facilitates the use in occasions with different requirements for measurement range and accuracy.

[0019] By taking advantage of the characteristics of high sensitivity and high isolation degree between pixels of the linear array silicon photodiode, the present invention extracts the burst and high-frequency characteristics of the weak vibration deformation signal on the surface to be detected through a hardware circuit in real time. With the cooperation of the gating logic, a detection synchronization pulse is output, enabling the detection of weak vibration deformation signals in the ground, bridges, and machinery. Compared with the defects of poor real-time performance of traditional detection methods, it well solves the demand for real-time and highly sensitive detection of weak vibration deformation in different scenarios.

[0020] According to the design of the present invention, a weak vibration deformation detection circuit and device are realized. The circuit has low implementation complexity, and the detection results are sensitive and accurate, especially suitable for various industrial sites. Brief Description of the Drawings

[0021] Figure 1 It is the hardware framework diagram of the processing circuit in the embodiment of the present invention;

[0022] Figure 2 It is the schematic diagram of the processing circuit principle in the embodiment of the present invention;

[0023] Figure 3 It is the schematic diagram of the working principle of the device in the embodiment of the present invention;

[0024] Figure 4 It is the volt-ampere characteristic diagram of the linear array silicon photodiode;

[0025] Figure 5 It is the circuit diagram of the linear array silicon photodiode;

[0026] Figure 6 It is the output change diagram of the linear array silicon photodiode;

[0027] Figure 7 It is the weak signal amplification circuit;

[0028] Figure 8 It is the differential circuit;

[0029] Figure 9is a signal shaping circuit;

[0030] Figure 10 is an AND gate pulse gating signal;

[0031] Figure 11 is a gating circuit. Specific embodiments

[0032] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention.

[0033] As Figure 1 shown, the weak vibration deformation detection circuit described in this embodiment includes: This is the hardware framework diagram of the processing circuit of the device of the present invention. After the input signal passes through the photodiode receiving circuit, the amplifying circuit, the differentiating circuit, the shaping circuit, and the gating circuit in sequence, the burst and high-frequency characteristics of the weak vibration deformation signal on the surface to be detected are extracted in real time through the hardware circuit. With the cooperation of the gating logic, a detection synchronization pulse is output.

[0034] As Figure 2 shown, this is the schematic diagram of the specific implementation of the processing circuit of the present invention. It can be seen that parallel light rays are incident on the linear array silicon photodiode circuit part through the lens. The linear array silicon photodiode changes the intensity of the received light into a weak change in the electrical signal. At the same time, this weak electrical signal is transmitted to the amplifying circuit part. The weak electrical signal is buffer-amplified and primarily amplified by the amplifying circuit part, so as to amplify the change signal to the electrical signal level that can be preprocessed by the subsequent differentiating circuit. After receiving the amplified signal from the previous-stage amplifying circuit, the differentiating circuit part extracts the mutation part of the input waveform and outputs it to the shaping circuit part. The reference value and reference waveform of the shaping circuit part are preset during circuit design. After receiving the electrical signal transmitted by the differentiating circuit, the shaping circuit compares this instantaneous change with the set reference value, and outputs the obtained difference signal, thereby driving the subsequent Darlington tube. The Darlington tube can amplify very small signals in a highly sensitive amplifying circuit, and this signal is the output of the shaping circuit. The driving signal output by the shaping circuit is used in cooperation with the gating logic gate circuit with different periodic pulse signals to obtain pulse signals with different time intervals and periods output, so as to convert the pulse signal into a vibration deformation intensity pulse. The vibration deformation intensity or deformation amount and other information are calculated by using the output pulse intensity to determine the deformation or vibration amplitude.

[0035] As Figure 3As shown in the figure, it is the working principle diagram of the detection device formed by the application of the weak vibration deformation detection circuit according to the embodiment of the present invention. The light source generates parallel light rays through the optical structure. Through the adjustment mechanism, the parallel light rays can be incident on the linear array silicon photodiode after passing through the lens and be completely received by it. The processing circuit detects the change of the weak optoelectronic signal and converts it into an electrical signal that can be output, so as to easily convert the weak vibration deformation into a measurable electrical signal, and then obtain rich characteristics of the weak signal, such as ground settlement trend, mechanical failure, etc.

[0036] The following specifically describes the detection device formed by the application of the weak vibration deformation detection circuit according to the embodiment of the present invention respectively:

[0037] The first step: Install the device. Place the light source (and the optical structure) and the linear array silicon photodiode (and the processing circuit) on both sides of the surface to be inspected respectively. The light source can generate parallel light rays through the optical structure. Through the adjustment mechanism, the parallel light rays can be incident on the linear array silicon photodiode after passing through the lens and be completely received by it.

[0038] It can be interpreted as: The device consists of two parts, the light source (and the optical structure) and the linear array silicon photodiode (and the processing circuit). The surface to be inspected is placed between the two parts; the light source generates parallel light rays through the collimating lens, and the parallel light rays are emitted through the filter and irradiate the surface to be inspected; adjust the device so that the parallel light rays pass through the surface to be inspected, enter the receiving lens, and then the light rays converge on the linear array silicon photodiode;

[0039] The linear array silicon photodiode is a semiconductor device that converts optical signals into electrical signals. The linear array silicon photodiode works under reverse voltage. When there is no light illumination, the reverse current is very small (generally less than 0.1 microampere). When there is light illumination, the diode conducts.

[0040] Figure 4 is the volt-ampere characteristic of the linear array silicon photodiode; The second step: When there is no vibration deformation or the vibration deformation amount on the surface to be inspected does not reach the threshold value, the parallel light rays generated by the light source are completely absorbed by the linear array silicon photodiode, and the linear array silicon photodiode is in a conducting state. In this state, the subsequent processing circuit is in a stable state for a long time, the gating logic is blocked, and no detection pulse is output.

[0041] It can be interpreted as: When there is no vibration deformation or the vibration deformation amount on the surface to be inspected does not reach the threshold value, the parallel light rays generated by the light source are completely absorbed by the linear array silicon photodiode, and the linear array silicon photodiode is in a conducting state; since the linear array silicon photodiode is in a conducting state, the subsequent processing circuit is in a stable state for a long time. At this time, the optoelectronic diode amplifier circuit outputs a high level, the differentiating circuit is in a steady state, and the shaping circuit outputs a low level; since the output of the shaping circuit is a low level, the gating circuit composed of logic gates is blocked by the low level and no detection pulse is output;

[0042] Figure 5 is a linear array silicon photodiode circuit; as Figure 5 shown, it is a linear array silicon photodiode circuit, where the operating state of point a conforms to the following formula:

[0043] U 1＝ IR 1＝ UR 1 / ( R 1+ R 2)

[0044] Through the voltage division formula, the voltage output by the linear array silicon photodiode can be obtained as: U1 = 12 × 5.1 / (5.1 + 5.1) = 6V.

[0045] When no deformation occurs, that is, the diode between point a and point b is conducting, the voltage at point b is pulled down to 6V due to the conduction voltage drop of the diode. At this time, the conduction current is 10mA, flowing through resistor R3, and almost no voltage drop is generated. At this time, the voltage at point c is 6V;

[0046] When deformation occurs, that is, the diode between point a and point b is cut off. Due to the cut-off of the diode, point b is equivalent to an open circuit, and the voltages at point b and point c are 0V.

[0047] Since the circuit is in a stable state for a long time, there is no change in the input and output of the subsequent circuit.

[0048] Step 3: When the vibration deformation occurring on the surface to be inspected reaches the threshold, the parallel light rays generated by the light source are partially or completely blocked, causing partial or complete instantaneous cut-off of the linear array silicon photodiode. This instantaneous state is detected and amplified by the subsequent circuit.

[0049] It can be interpreted as: when the vibration deformation occurring on the surface to be inspected reaches the threshold, the parallel light rays generated by the light source are partially or completely blocked, causing partial or complete instantaneous cut-off of the linear array silicon photodiode; due to the partial or complete instantaneous cut-off of the linear array silicon photodiode, the subsequent processing circuit breaks the long-term stable state. At this time, the output of the photodiode amplifier circuit changes from high level to low level. The differential circuit extracts the instantaneous change state, and the shaping circuit outputs a high level; since the output of the shaping circuit is a high level, the gating circuit composed of logic gates is opened, and a detection synchronization pulse is output;

[0050] Figure 6 is the output change diagram of the linear array silicon photodiode; as Figure 6 shown, it is the output change diagram of the linear array silicon photodiode, which describes the detection voltage situation of point c in the linear array silicon photodiode output under stable illumination, no illumination, and changing illumination Figure 5 conditions.

[0051] When there is no deformation and the light is stable, the voltage detected at point c is stable at Vt, and there is no change in the subsequent circuit; when the light is blocked or there is no light, the voltage drops to 0V. In an ideal state, when the light changes from strong to weak, the voltage jump curve in the figure can be obtained, that is, the voltage jump.

[0052] The voltage state output by the linear array silicon photodiode changes from high to low. This change information is output to the inverting input terminal of the AD823AR for buffer amplification. After pre-amplification by the AD823AR, it is output to the LM2902 for further amplification. After two-stage amplification, the weak change amount can be converted into an electrical signal that can be processed by the subsequent circuit.

[0053] Figure 7 is a weak signal amplification circuit; as Figure 7 shown, it is a weak signal amplification circuit. The function of this circuit is to amplify the voltage of the weak change signal. It is mainly composed of the integrated operational amplifier AD823AR and LM2902N, etc. The weak change signal output by the linear array silicon photodiode enters the circuit through the resistor and is input to the inverting input terminal of the AD823AR at point V1, outputting an inverted signal, and then input to the inverting input terminal V2 of the LM2902 through the coupling circuit and output again. This output signal is in phase with the input signal.

[0054] An AC negative feedback network composed of a feedback resistor, an adjustable resistor, a capacitor, etc. is connected between the input and output of the entire circuit. By adjusting the resistance value, the gain of the circuit can be changed, which is beneficial to the stability of the circuit and reduces distortion.

[0055] After the change signal is amplified by the amplification circuit, it is output to the subsequent differential circuit for signal processing. The function of the differential circuit is to eliminate the invariant quantity and highlight the change quantity. The output waveform of the circuit only reflects the mutation part of the input waveform, that is, there is an output only when the partial or all instantaneous cut-off of the linear array silicon photodiode causes a mutation in the input waveform. There is no output for the constant part.

[0056] Figure 8 is a differential circuit; as Figure 8 shown, it is a differential circuit. The magnitude of the output voltage of this circuit is determined by the change amount of the input voltage, that is, when the input voltage changes faster, the output voltage is larger, and when the input voltage remains unchanged, the output voltage is basically 0.

[0057] The series connection of capacitor C and resistor R is used as the input terminal. Due to the existence of capacitor C and resistor R in the circuit, there is a charging and discharging process under the action of the applied voltage.

[0058] The current passing through capacitor C and resistor R9 is equal, and the voltages at the non-inverting and inverting terminals of the operational amplifier are equal. If V3 is a suddenly applied DC voltage, then the output Vout corresponds to a pulse with a direction opposite to that of V3. The characteristic of a differentiating circuit is that it can prominently reflect the jumping part of the input signal. Based on this characteristic, this circuit can convert the jumping part in the light intensity signal into sharp pulses for utilization.

[0059] Figure 9 is a signal shaping circuit; as Figure 9 shown, it is a shaping circuit composed of an operational amplifier and a Darlington transistor. Its high-voltage output characteristic and cathode clamping diode can convert inductive loads. The main function of this circuit is to amplify the current of the pulse signal of the differentiating circuit and increase the driving ability.

[0060] When a part or all of the linear array silicon photodiode is instantaneously cut off, causing a sudden change in the input waveform, the differentiating circuit changes accordingly. By comparing this instantaneous change with a set reference value, the subsequent Darlington transistor is driven. The Darlington transistor amplifies very tiny signals in a highly sensitive amplifier circuit, and then extracts weak vibration or deformation signals. The electrical signal and a pulse signal with a fixed period are input to an AND gate.

[0061] Figure 10 is the AND gate pulse gating signal; as Figure 10 shown, it is a schematic diagram of the waveform of the pulse gating signal composed of an AND gate. VI is the generated jumping signal, VB is the pulse width of the gated signal, VA is the fixed-frequency pulse signal input to different paths. VO is the finally output pulse signal. By setting the pulse width of the gating signal, pulse signals output from different paths are obtained, and then the required information is obtained.

[0062] Figure 11 is the gating circuit; as Figure 11 shown, it is the circuit diagram of the pulse gating signal composed of AND gates. This circuit is composed of multiple AND gate circuits, and the main function of the circuit is to extract pulse signals of different intensities.

[0063] Since the intensity of each path of signal is related to the light intensity, by controlling the periods of different input pulse signals, the working time intervals and periods of the gating logic gates are made different, so that the amplitude change of vibration is converted into an electrical signal, and then pulses of the vibration deformation intensity are output. The vibration intensity or deformation amount and other information are deduced by using the output pulse intensity to determine the deformation or vibration amplitude.

[0064] Through the above steps, a weak vibration deformation detection circuit and device utilize the characteristics of high sensitivity and high isolation between pixels of a linear array silicon photodiode to extract the burst and high-frequency characteristics of the weak vibration deformation signal on the surface to be detected in real time through a hardware circuit. With the cooperation of the gating logic, a detection synchronization pulse is output, realizing the detection of weak vibration deformation signals in the ground, bridges, and machinery. Compared with the defects such as poor real-time performance of traditional detection methods, it well solves the demand for real-time and highly sensitive detection of weak vibration deformation in different scenarios.

[0065] According to the design of the present invention, a weak vibration deformation detection circuit and device are realized. The circuit has low implementation complexity, and the detection results are sensitive and accurate, especially suitable for various industrial sites.

[0066] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0067] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A weak vibration deformation detection circuit, comprising a photodiode circuit, an amplifier circuit, a differentiator circuit, a shaping circuit, and a gating circuit connected in sequence; Characterized in that, Parallel light rays are incident on a linear array silicon photodiode circuit through a lens; the linear array silicon photodiode changes the intensity of the received light into a weak change in the electrical signal, and at the same time transmits this weak electrical signal to the amplifier circuit; The weak electrical signal is buffer-amplified and primarily amplified by the amplifier circuit part, so as to amplify the change signal to an electrical signal level that can be preprocessed by the subsequent differentiator circuit; After receiving the amplified signal from the previous-stage amplifier circuit, the differentiator circuit part extracts the mutation part of the input waveform and outputs it to the shaping circuit part; After receiving the electrical signal transmitted by the differentiator circuit, the shaping circuit compares this instantaneous change with the set reference value, and outputs the obtained difference signal, thereby driving the subsequent Darlington tube; The driving signal output by the shaping circuit is used in cooperation with a gating logic gate circuit with different periodic pulse signals to obtain pulse signals with different time intervals and periods of output, thereby converting the pulse signals into vibration deformation intensity pulses; The deformation or vibration amplitude is determined by using the output pulse intensity, thereby calculating the vibration intensity or deformation amount information.

2. The weak vibration deformation detection circuit according to claim 1, Characterized in that: The amplifier circuit includes a buffer amplification AD823AR module and a signal primary amplification LM2902 module.

3. A weak vibration deformation detection method, adopting the weak vibration deformation detection circuit according to any one of claims 1-2, Characterized in that: It includes the following steps, Step 1: Install the device, place the light source and the linear array silicon photodiode on both sides of the surface to be inspected respectively. The light source generates parallel light rays through an optical structure. Through the adjustment mechanism, the parallel light rays are incident on the linear array silicon photodiode through the lens and are completely received by it; Step 2: When there is no vibration deformation or the vibration deformation amount on the surface to be inspected does not reach the threshold value, the parallel light rays generated by the light source are completely absorbed by the linear array silicon photodiode, and the linear array silicon photodiode is in a conducting state. In this state, the subsequent processing circuit is in a stable state for a long time, the gating logic is blocked, and no detection pulse is output; Step 3: When the vibration deformation occurring on the surface to be inspected reaches the threshold value, the parallel light rays generated by the light source are partially or completely blocked, causing partial or complete instantaneous cut-off of the linear array silicon photodiode. This instantaneous state is detected and amplified by the subsequent circuit, the gating logic is opened, and vibration deformation intensity pulses are output.

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