CN115032460A - Novel equivalent inductance detection method and system - Google Patents
Novel equivalent inductance detection method and system Download PDFInfo
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- CN115032460A CN115032460A CN202210640022.9A CN202210640022A CN115032460A CN 115032460 A CN115032460 A CN 115032460A CN 202210640022 A CN202210640022 A CN 202210640022A CN 115032460 A CN115032460 A CN 115032460A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
- G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
- G01R27/26—Measuring inductance or capacitance; Measuring quality factor, e.g. by using the resonance method; Measuring loss factor; Measuring dielectric constants ; Measuring impedance or related variables
- G01R27/2611—Measuring inductance
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
- G01B7/02—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring length, width or thickness
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
- G01B7/30—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring angles or tapers; for testing the alignment of axes
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Abstract
The invention relates to the technical field of sensors, in particular to a novel method and a novel system for detecting equivalent inductance, wherein an induction coil is printed on a PCB (printed Circuit Board), a detection circuit comprises a signal driving circuit and a frequency detection circuit, the induction coil is electrically connected with the detection circuit, the wiring of the induction coil enables the direction of a magnetic field generated by current to be consistent, the signal driving circuit comprises a signal feedback amplifying circuit, an excitation capacitor, an inductor and a capacitor inductor to form LC oscillation, the frequency detection circuit comprises a counter and a clock, the signal driving circuit discharges to the induction coil in a capacitor energy storage mode to form an LC oscillation circuit, the frequency detection circuit records the number of pulses of the LC oscillation in a specified time window, the invention detects the equivalent inductance value of the induction coil through a unique algorithm of a second-order circuit equation and a circuit structure and a device for realizing the algorithm, the sensitivity is high, the micro-power consumption and micro-signal detection circuit can be applied to the working environment of micro-power consumption and micro-signals, and is simple in circuit and high in accuracy.
Description
Technical Field
The invention relates to the technical field of sensors, in particular to a novel method and a system for detecting equivalent inductance.
Background
The angular position sensor can detect the rotation angular displacement of the detected target; the angular position sensor is mainly used in the industries of flow meters, industrial machine tools and robots. The metal displacement sensor is mainly applied to the industries of industrial machine tools, robots and industrial Internet of things.
At present, angular displacement and displacement sensors in the industry mainly use a grating, and the detection method generally detects the amplitude of LC oscillation or the change of frequency, but the amplitude change is difficult to detect in the process of micro-signals and micro-power consumption, and the frequency detection has weak anti-interference performance and is greatly influenced by temperature drift.
Based on the reasons, the invention designs a novel equivalent inductance detection method and a novel equivalent inductance detection system, which are used for detecting the equivalent inductance value of the output signal of the induction coil, are suitable for the working environments of micro power consumption and micro signals, can be applied to sensor products of angular displacement and metal displacement, and are convenient to produce, high in accuracy and strong in anti-interference performance.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides a novel method and a novel system for detecting equivalent inductance, which are used for detecting the equivalent inductance value of an output signal of an induction coil, are suitable for the working environment of micro power consumption and micro signals, can be applied to sensor products of angular displacement and metal displacement, and are convenient to produce, high in accuracy and strong in anti-interference performance.
In order to achieve the above object, the present invention provides a novel equivalent inductance detection system, which includes a PCB, an induction coil, a capacitor, a detection circuit, a signal driving circuit, a frequency detection circuit, a counter and a clock, wherein the induction coil is printed on the PCB, the detection circuit includes the signal driving circuit and the frequency detection circuit, the induction coil is electrically connected to the detection circuit, the magnetic field generated by the current is made to have the same direction by the routing of the induction coil, the signal driving circuit includes a signal feedback amplifying circuit, an excitation capacitor and an inductor, the capacitor and the inductor form LC oscillation, and the frequency detection circuit includes the counter and the clock.
The counter is a high-precision low-temperature drift counter, and the clock is a high-precision low-temperature drift clock or a high-precision low-temperature drift and low-jitter clock.
The signal driving circuit is an LC oscillating circuit, the circuit design impedance is a non-damping parameter which is an ideal condition, electronic devices are all provided with internal resistance, energy is increased through a feedback amplifying circuit, and the non-damping condition of self-resonance is simulated.
A novel equivalent inductance detection method comprises the following steps:
s1-1: the signal driving circuit discharges to the induction coil in a capacitance energy storage mode to form an LC oscillating circuit, and the frequency detection circuit detects that the number of pulses of LC oscillation is recorded within a specified time window;
s1-2: the signal driving circuit excites the capacitor and the inductor to form LC oscillation through the signal feedback amplifying circuit, and self-resonance is formed through the feedback amplifying circuit to simulate undamped constant-amplitude LC oscillation.
S2-1: the counter counts the pulse number of LC oscillation, and the clock controls the start and stop of the counter; the timing frequency of the clock is at least 4 times of the LC oscillation frequency.
S2-2: the clock is used for timing the time window for controlling the counter to start and stop counting; the counter is used for counting pulses of the simulated self-resonance LC oscillation signals;
s2-3: the clock timing is divided into 2 consecutive time periods T1 and T2; t1 is used for monitoring LC oscillation starting time, T2 is used for counting LC pulses, and T1 and T2 are seamlessly connected;
s2-4: when the time is T1, the clock continues timing, the time window is T2, and meanwhile, the counter starts to count the pulses of the LC oscillation signals;
s2-5: when the time T2 is up, the counter stops counting, and meanwhile the drive circuit stops LC oscillation;
s2-6: the frequency of LC oscillation can be calculated through the pulse number recorded in a specified time window, and the equivalent inductance value can be calculated through the frequency;
the specific algorithm in S2-6 is as follows:
the initial value of the capacitor voltage is: u. of C (0 + )＝u C (0 - )＝U 0
The initial value of the inductor current is: i all right angle L (0 + )＝i L (0 - )＝0
The resulting circuit equation is: -u C +u R +u L ＝0
The circuit current is:
to obtain
The resulting circuit equation is:
is characterized by
When R is 0, a is 0,
the correspondence at this time is:
it can be seen that u c (t) and i L And (t) are all sine functions, the amplitude of the sine functions does not attenuate along with time, the response of the circuit is constant-amplitude oscillation response which is called the natural frequency of the system, and when the excitation of the circuit is the sine function of the same frequency, the circuit resonates.
The clock is a low temperature drift, low "jitter" clock of at least 32.768K.
Compared with the prior art, the invention detects the equivalent inductance value of the output signal of the induction coil through the unique algorithm of the second-order circuit equation and the circuit structure and the device for realizing the algorithm, has high sensitivity, can be suitable for the working environment of micro power consumption and micro signals, and has simple circuit and high accuracy.
Drawings
FIG. 1 is a schematic diagram of a second order circuit of the algorithm of the present invention.
FIG. 2 is a graph showing the response curve of the discharge process of the present invention.
FIG. 3 is a schematic view of the detection system of the present invention.
FIG. 4 is a diagram illustrating a detection state according to the present invention.
Detailed Description
The invention will now be further described with reference to the accompanying drawings.
Referring to fig. 1 to 4, the invention provides a novel equivalent inductance detection system, which comprises a PCB, an induction coil, a capacitor, a detection circuit, a signal driving circuit, a frequency detection circuit, a counter and a clock, wherein the induction coil is printed on the PCB, the detection circuit comprises the signal driving circuit and the frequency detection circuit, the induction coil is electrically connected with the detection circuit, the wiring of the induction coil enables the direction of a magnetic field generated by current to be consistent, the signal driving circuit comprises a signal feedback amplification circuit, an excitation capacitor and an inductor, the capacitor and the inductor form LC oscillation, and the frequency detection circuit comprises the counter and the clock.
The counter is a high-precision low-temperature drift counter, and the clock is a high-precision low-temperature drift clock.
The working principle of the system is as follows:
referring to fig. 3 to 4, a specific waveform signal is input to the induction coil or discharged, and a high-precision clock is started for timing, a partial circuit in the detection circuit receives an output signal of the circuit part of the induction coil, the detection circuit processes and calculates the output signal of the circuit part of the induction coil, the frequency of the calculated signal is processed, the signal driving circuit discharges to the induction coil, and the induction coil can generate a magnetic line perpendicular to the plane of the induction coil. This causes the metalized region to cut the magnetic field lines to generate Foucault current (Foucault current), which hinders the magnetic flux change and further causes the equivalent inductance of the oscillator circuit to change. The metal object is close to or far from the induction coil, and the projection area of the metal object projected onto the induction coil changes, so that the change of the equivalent induction value is influenced, and the pulse number in the detected time window changes.
A novel equivalent inductance detection method comprises the following steps:
s1-1: the signal driving circuit discharges to the induction coil in a capacitive energy storage mode to form an LC oscillating circuit, and the frequency detection circuit detects that the number of LC oscillating pulses is within a specified time window and records the number of the LC oscillating pulses;
s1-2: the signal driving circuit excites the capacitor and the inductor to form LC oscillation through the signal feedback amplifying circuit, and self-resonance is formed through the feedback amplifying circuit to simulate undamped constant-amplitude LC oscillation.
S2-1: the counter counts the pulse number of LC oscillation, and the clock controls the start and stop of the counter; the timing frequency of the clock is at least more than 4 times of the LC oscillation frequency;
s2-2: the clock is used for timing the time window for controlling the counter to start and stop counting; the counter is used for counting pulses of the simulated self-resonance LC oscillation signals;
s2-3: the clock timing is divided into 2 consecutive time periods T1 and T2; t1 is used for monitoring LC oscillation starting time, T2 is used for counting LC pulses, and T1 and T2 are seamlessly connected;
s2-4: when the time is T1, the clock continues timing, the time window is T2, and meanwhile, the counter starts to count the pulses of the LC oscillation signals;
s2-5: when T2 is reached, the counter stops counting, and meanwhile the drive circuit stops LC oscillation;
s2-6: the frequency of LC oscillation can be calculated by the pulse number recorded in a predetermined time window, and the equivalent inductance value can be calculated by the frequency.
The specific algorithm in S2-6 is as follows:
the initial value of the capacitor voltage is: u. of C (0 + )＝u C (0 _ )＝U 0
The initial value of the inductor current is: i.e. i L (0 + )＝i L (0 _ )＝0
The resulting circuit equation is: -u C +u R +u L ＝0
The circuit current is:
to obtain
The resulting circuit equation is:
is characterized by
When R is 0, a is 0,
the correspondence at this time is:
it can be seen that u c (t) and i L And (t) are all sine functions, the amplitude of the sine functions does not attenuate along with time, the response of the circuit is constant-amplitude oscillation response which is called the natural frequency of the system, and when the excitation of the circuit is the sine function of the same frequency, the circuit resonates.
The clock is a low temperature drift, low "jitter" clock of at least 32.768K.
Example (b):
referring to fig. 1 to 2, the present invention provides a novel equivalent inductance detection method, including a PCB, an induction coil, a capacitor, a detection circuit, a signal driving circuit, a frequency detection circuit, a counter and a clock, wherein the induction coil is printed on the PCB, the detection circuit includes the signal driving circuit and the frequency detection circuit, the induction coil is electrically connected to the detection circuit, the routing of the induction coil makes the magnetic field direction generated by the current consistent, the signal driving circuit includes a signal feedback amplifying circuit, an excitation capacitor and an inductor and forms LC oscillation, and the frequency detection circuit includes the counter and the clock.
Specifically, when the detected metal object is far away from the induction coil, the trigger starts to trigger, the capacitor discharges to the induction coil inductor, the driving circuit drives the LC to vibrate, and the high-precision clock is started to start timing T11; after the time T11 is up, starting timing T12, and simultaneously starting a counter to count LC oscillation pulse signals; and after the time T12 is up, stopping counting, timing and oscillation. The number of pulses of LC oscillations recorded within the T12 time window was C11.
Specifically, when a detected metal object approaches an induction coil, a trigger starts to trigger, a capacitor discharges to the induction coil, a driving circuit drives LC to vibrate, and a high-precision clock is started to start timing T21; after the time T21 is up, starting timing T22, and simultaneously starting a counter to count LC oscillation pulse signals; and after the time T22 is up, stopping counting, timing and oscillation. The number of pulses of LC oscillations recorded within the T22 time window was C22.
The values of C11 and C22 must be different, whereas the values of C11 and C22 are different because the equivalent inductance value varies due to the distance and proximity of the metal object.
The above is only a preferred embodiment of the present invention, and is only used to help understand the method and the core idea of the present invention, and the protection scope of the present invention is not limited to the above embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and adaptations to those skilled in the art without departing from the principles of the present invention should also be considered as within the scope of the present invention.
The invention integrally solves the problems that the amplitude or frequency change of LC oscillation is detected in the prior art, but the amplitude change is difficult to detect in the micro-signal and micro-power consumption, the frequency detection has weak anti-interference performance and is greatly influenced by temperature drift, the equivalent inductance value of the output signal of the induction coil is detected by the algorithm of a second-order circuit and the corresponding system design, the invention can be applied to the working environment of the micro-power consumption and the micro-signal, and the circuit is simple and easy to realize, has high accuracy, precision and sensitivity and strong anti-interference performance, can be applied to the sensor products of angular displacement and metal displacement and is convenient to produce.
Claims (5)
1. The utility model provides a novel detect equivalent inductance system, its characterized in that, includes PCB circuit board, induction coil, electric capacity, detection circuitry, signal drive circuit, frequency detection circuit, counter and clock, induction coil prints on the PCB circuit board, detection circuitry includes signal drive circuit and frequency detection circuit, induction coil with detection circuitry electric connection, induction coil's walking line makes the magnetic field direction that electric current produced unanimous, signal drive circuit includes signal feedback amplifier circuit, excitation electric capacity and inductance, and electric capacity and inductance form LC and vibrate, frequency detection circuit includes counter and clock.
2. The novel system for detecting equivalent inductance of claim 1, wherein the counter is a high-precision low-temperature drift counter, and the clock is a high-precision low-temperature drift clock.
3. A novel method for detecting equivalent inductance according to the system of claim 1, comprising the steps of:
s1-1: the signal driving circuit discharges to the induction coil in a capacitive energy storage mode to form an LC oscillating circuit, and the frequency detection circuit detects that the number of LC oscillating pulses is within a specified time window and records the number of the LC oscillating pulses;
s1-2: the signal driving circuit excites the capacitor and the inductor to form LC oscillation through the signal feedback amplifying circuit, and self-resonance is formed through the feedback amplifying circuit to simulate undamped constant-amplitude LC oscillation.
S2-1: the counter counts the pulse number of LC oscillation, and the clock controls the start and stop of the counter; the timing frequency of the clock is at least more than 4 times of the LC oscillation frequency.
S2-2: the clock is used for timing a time window for controlling the counter to start and stop counting; the counter is used for counting pulses of the simulated self-resonance LC oscillation signals;
s2-3: the clock timing is divided into 2 consecutive time periods T1 and T2; t1 is used for monitoring LC oscillation starting time, T2 is used for counting LC pulses, and T1 and T2 are seamlessly connected;
s2-4: when the time is T1, the clock continues timing, the time window is T2, and meanwhile, the counter starts to count the pulses of the LC oscillation signals;
s2-5: when the time T2 is up, the counter stops counting, and meanwhile the drive circuit stops LC oscillation;
s2-6: the frequency of LC oscillation can be calculated by the pulse number recorded in a predetermined time window, and the equivalent inductance value can be calculated by the frequency.
4. A novel method for detecting equivalent inductance according to the system of claim 3, wherein the specific algorithm in S2-6 is as follows:
the initial value of the capacitor voltage is: u. u C (0 + )＝u C (0 _ )＝U 0
The initial value of the inductor current is: i.e. i L (0 + )＝i L (0 _ )＝0
The resulting circuit equation is: -u C +u R +u L ＝0
The circuit current is:
to obtain
The resulting circuit equation is:
is characterized by
When R is equal to 0, the compound is,
the correspondence at this time is:
it can be seen that u c (t) and i L (t) are all sine functions, the amplitude of the sine functions does not attenuate along with time, the response of the circuit is constant-amplitude oscillation response, the constant-amplitude oscillation response is called the natural frequency of the system, and when the excitation of the circuit is the sine function with the same frequency, the circuit generates resonance.
5. A novel system for detecting equivalent inductance as claimed in claim 3, wherein said clock is a low temperature drift, low "jitter" clock of at least 32.768K.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210640022.9A CN115032460A (en) | 2022-06-08 | 2022-06-08 | Novel equivalent inductance detection method and system |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210640022.9A CN115032460A (en) | 2022-06-08 | 2022-06-08 | Novel equivalent inductance detection method and system |
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| Publication Number | Publication Date |
|---|---|
| CN115032460A true CN115032460A (en) | 2022-09-09 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202210640022.9A Withdrawn CN115032460A (en) | 2022-06-08 | 2022-06-08 | Novel equivalent inductance detection method and system |
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| CN (1) | CN115032460A (en) |
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- 2022-06-08 CN CN202210640022.9A patent/CN115032460A/en not_active Withdrawn
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Application publication date: 20220909 |