Vibration signal reading system and vibration signal reading method of axial symmetry gyroscope based on rotating carrier wave

Abstract

The invention discloses an axisymmetric gyroscope vibration signal reading method based on rotating carrier waves. A conventional vibration signal reading method comprises a time division multiplexing reading method and a dual-frequency carrier wave reading method, the time division multiplexing reading method realizes the time division multiplexing of an electrode, but due to the process limitation of a one-way electrode, only half of the electrode of the gyroscope is in a reading state, and the reading result is poor. A new error is also introduced into a circuit parameter of which the two electrodes are not completely symmetrical at the reading end; and in the reading mode of the double-frequency carrier, two carrier waves with different frequencies are used for modulating the two electrodes respectively to serve as excitation signals, the excitation signals are read out through one channel, but the carrier waves with different frequencies introduce a gain adaptation problem at the reading-out end, so that a new error amount is generated. According to the scheme, the vibration signal reading method of the axial symmetry gyroscope based on the rotating carrier wave is adopted, namely, a DDS digital generator is adopted to generate a single-frequency carrier wave cos [omega] ct and rotating decomposition carrier waves sin [omega] t and cos [omega] t respectively, and meanwhile, the problem that the single-frequency carrier wave can only generate an excitation signal with a fixed direction angle is solved. Rotation decomposition modulation is introduced to generate two paths of signals cos [omega] ctcos [omega] t and cos [omega] ctsin [omega] t, initial carrier signals are respectively modulated on sine and cosine signals which are changed by frequency [omega], an x electrode and a y electrode are respectively excited and then are read out by a front-end amplifier circuit, and one path of front-end processing circuit also avoids errors caused by asymmetry of parameters of two paths of front-end processing circuits. Vo is generated through a capacitance / voltage conversion circuit, and in order to restore an initial displacement signal, the read-out semaphore after two-time modulation uses two-time demodulation in demodulation, namely initial carrier demodulation and rotation carrier demodulation to respectively filter out omega c and omega frequencies, so as to extract initial displacement voltage signals Vx and Vy; errors caused by a time division multiplexing reading system do not exist, and the gain adaptation problem brought by carriers with different frequencies at the reading end in a dual-frequency carrier reading scheme is also avoided.

Description

Technical Field

[0001] The invention relates to a vibration signal reading method of an axisymmetric gyroscope based on a rotating carrier wave, and belongs to the technical field of gyroscopes. Background Art

[0002] Axisymmetric gyroscopes are a type of gyroscope with rotational symmetry. This type of gyroscope has good stability and control characteristics and is widely used in navigation, attitude control and other fields. With the rapid development of the semiconductor industry, it has always been a popular research direction in the field of gyroscopes due to its advantages of lightweight, low power consumption, low cost and high reliability, and has a very broad development prospect. Axisymmetric gyroscopes include hemispherical resonant gyroscopes, micro-hemispherical resonant gyroscopes, ring gyroscopes, fully symmetrical four-value gyroscopes, etc. The readout electrodes are arranged differentially, that is, a pair of electrodes that differ by 90 degrees in physical space are differential to each other, which greatly reduces the eccentricity of the electrodes. In the front-end readout system of its control system, differential capacitance detection is usually used. Conventional vibration signal readout methods include time-sharing readout method and dual-frequency carrier readout method. In the time-sharing readout scheme, since the axisymmetric gyroscope cannot realize bidirectional electrodes, usually only half of the electrodes are in the readout state, which makes it difficult to achieve symmetrical differential detection. At the same time, at the readout end, the readout signals of the x and y axes will pass through two independent signal processing circuits. Due to the parameter errors in the circuits, the asymmetry between the two will also cause large errors in the readout signals. In the dual-frequency carrier excitation scheme, two carriers of different frequencies are used to modulate the two electrodes as excitation signals respectively, and the signals are read out through one channel. Although the error is improved, the carriers of different frequencies bring new gain adaptation problems at the readout end. Summary of the invention

[0003] Technical issues: In the system of time-sharing readout solution, the axisymmetric gyroscope cannot be in the readout state all the time due to process limitations, and the asymmetry of the two circuit parameters at the readout end will cause large errors in the readout signal. In addition, the dual-frequency carrier solution causes gain adaptation problems due to the introduction of two carriers of different frequencies.

[0004] Technical solution: To solve the above technical problems, a method for reading vibration signals of an axisymmetric gyroscope based on a rotating carrier is invented. In this solution, a DDS digital generator is used to generate an initial carrier and a rotating decomposed carrier respectively, and the initial carrier is decomposed into the x direction and the y direction. By means of rotating carrier modulation, the initial carrier is modulated on the frequency of the rotating carrier, and carrier extraction at any angle can be achieved. Then, the two axial carriers are used to excite the x electrode and the y electrode of the gyro resonator respectively. At this time, the gyro resonator structure is equivalent to a common capacitor plate. By extracting the slight change in surface capacitance, it is picked up and read by a front-end amplifier circuit, and converted into a read signal quantity V through a capacitance / voltage conversion circuit. o, the readout signal contains ω d ,ω,ω c As well as combined harmonic components and higher harmonic components. d is the gyro resonant frequency, which is the frequency component that needs to be retained. Read the signal V o First, the initial carrier demodulation module is used to remove the ω c and its higher harmonic components, and then demodulated in two ways through the rotating carrier demodulation module to remove ω and its higher harmonic components and retain the frequency ω d , and finally extract the original displacement signal V containing the x electrode x And the original displacement signal V of the y electrode y .

[0005] In order to achieve the above-mentioned purpose, the technical scheme of the present invention is as follows: a vibration signal reading system of an axisymmetric gyroscope based on a rotating carrier, the system comprises a gyro resonator, a DDS initial carrier signal generator, a DDS rotating carrier cosine signal generator, a DDS rotating carrier sine signal generator, a front-end amplifier module, a capacitance / voltage conversion circuit module, an initial carrier demodulation module, and a rotating carrier demodulation module. First, the DDS initial carrier signal generator generates an initial carrier cosω c t, at the same time, the DDS rotating carrier sine signal generator generates the rotating carrier sinωt of the y-axis, and the DDS rotating carrier cosine signal generator generates the rotating carrier cosωt of the x-axis. Then, the initial carrier cosω c t, modulated with the rotating carrier cosωt of the x-axis and the rotating carrier sinωt of the y-axis respectively, the initial carrier cosω c Under the action of the rotating carrier cosωt of the x-axis and the rotating carrier sinωt of the y-axis, a direction of the rotating carrier frequency ω can be generated. c The changing x-channel carrier signal cosω c tcosωt and the carrier signal cosω of the y path c tsinωt, in order to realize the generation of excitation signals at any angle. Further, the generated x-channel carrier signal cosω c tcosωt and the carrier signal cosω of the y path c tsinωt, respectively excites the x-electrode and y-electrode of the gyro resonator, and the resulting surface capacitance change is amplified by the front-end amplifier circuit and converted into a voltage value V through the capacitance / voltage conversion circuit o . At this time, it contains ω d ,ω,ω c And combined harmonic components and higher harmonic components. Voltage V o First, the initial carrier cosω generated by the DDS initial carrier signal generator is passed through the initial carrier demodulation module.c t as the demodulated signal, removing ω c The x-path uses the rotating carrier cosωt of the x-axis generated by the DDS rotating carrier cosine signal generator as the demodulation signal to remove ω and its higher harmonic components and retain the frequency ω. d ; The y-path uses the y-axis rotating carrier sinωt generated by the DDS rotating carrier sinusoidal signal generator as the demodulation signal, removes ω and its higher harmonic components, and retains the frequency ω d , and finally extract the original displacement signal V containing the x electrode x And the original displacement signal V of the y electrode y In the link of generating the excitation carrier, a DDS carrier signal generator is used to generate the initial carrier, which avoids the gain adaptation problem caused by the dual-frequency carrier mode in the front-end amplifier circuit of the gyro resonator. At the same time, a rotating carrier signal generator is introduced to generate the rotating carrier cosωt of the x-axis and the rotating carrier sinωt of the y-axis. c t are modulated on the sine and cosine waveforms with a frequency of ω. At this time, the x-channel carrier signal cosω c tcosωt and the carrier signal cosω of the y path c tsinωt can realize signal excitation at any angle. In addition, in the front-end amplifier module, one amplifier circuit is used to extract the tiny capacitance changes on the surface of the gyroscope resonator. Compared with the two-channel amplifier circuit structure, this design effectively solves the problem of incomplete circuit parameter symmetry.

[0006] A vibration signal reading method of an axisymmetric gyroscope based on a rotating carrier wave, the method comprising the following steps:

[0007] Step 1) The DDS initial carrier signal generator generates the initial carrier cosω c t, the DDS rotating carrier sine signal generator generates a rotating carrier sinωt, and the DDS rotating carrier cosine signal generator generates a rotating carrier cosωt.

[0008] Step 2) Convert the carrier signal cosω c t is decomposed by the rotating carrier and modulated with the rotating carrier cosωt of the x-axis and the rotating carrier sinωt of the y-axis respectively to generate the x-channel carrier signal cosω c tcosωt and the carrier signal cosω of the y path c tsinωt. Among them, ω cis the frequency of the single-channel initial carrier, ω is the carrier frequency of the rotational decomposition, cosωt represents the carrier decomposed to the x-axis, and sinωt represents the carrier decomposed to the y-axis. In order to solve the problem that the initial carrier of the single-channel frequency cannot generate an excitation signal with an angle direction change, a rotating carrier signal is added to convert the initial carrier signal cosω c t modulates the sine and cosine signals with a frequency ω. At this time, the excitation signals of the two channels are cosω c tcosωt,cosω c The tsinωt combination generates excitation signals in different angular directions.

[0009] Step 3) The two carrier signals generated, that is, the carrier signal cosω of x c tcosωt and the carrier signal cosω of the y path c tsinωt excites the x-electrode and y-electrode of the gyro resonator respectively, causing a slight capacitance change on the surface of the gyro resonator structure, which is picked up and read out by the front-end amplifier circuit and converted into V by the capacitance / voltage conversion circuit. o , which contains ω d ,ω,ω c As well as combined harmonic components and higher harmonic components.

[0010] Step 4) Read out the signal V o Perform initial carrier demodulation and use the initial carrier signal generated by the DDS initial carrier signal generator, i.e. cosω c t is multiplied by the readout signal and filtered out through a low-pass filter. c and its high-frequency harmonic frequency components.

[0011] Step 5) The signal after the initial carrier demodulation is subjected to rotation carrier demodulation, and the x-axis rotation decomposition signal, i.e., cosωt, generated by the DDS rotating carrier cosine signal generator is multiplied with the signal after the initial carrier demodulation, and ω and its high-frequency harmonic frequency components are filtered out through a low-pass filter; the y-axis rotation decomposition signal, i.e., sinωt, generated by the DDS rotating carrier sine signal generator is multiplied with the signal after the initial carrier demodulation, and ω and its high-frequency harmonic frequency components are filtered out through a low-pass filter, and finally the signal containing the resonant frequency ω is retained. d The initial x electrode displacement signal V x and the initial y electrode displacement signal V y .

[0012] Furthermore, in step 1), the DDS digital generator is a direct frequency synthesizer that can output the required sine and cosine signals according to the input voltage signal. In this system, the DDS needs to generate two signals with different frequencies, namely, an initial carrier signal cosω ct and the rotating carrier signals cosωt and sinωt, with frequencies ω respectively c and ω, where ω c The single-channel carrier signal frequency is used to avoid the gain adaptation problem caused by the multi-frequency carrier in the front-end amplifier circuit, and the size of ω affects the rotation rate of the initial carrier. The carrier generated by DDS not only provides the excitation signal of the gyro resonator, but also provides the demodulation signal cosω for the initial carrier demodulation module. c t, the DDS rotating carrier signal generator provides demodulation signals cosωt and sinωt for the rotating carrier demodulation module. In addition, ensure that ω can be successfully filtered out in the subsequent filter demodulation module. c And the ω frequency component and its higher harmonic components, ω c And the size of ω must be greater than the resonant frequency ω d At least one order of magnitude, and ω c It needs to be greater than ω by at least one order of magnitude, so that the spectrum of the modulated signal is far away from the resonant frequency ω d , while leaving enough frequency space for filter design.

[0013] Further, step 2) converts the carrier signal cosω c t is decomposed by the rotating carrier and modulated with the rotating carrier cosωt of the x-axis and the rotating carrier sinωt of the y-axis respectively to generate the x-channel carrier signal cosω c tcosωt and the carrier signal cosω of the y path c tsinωt. Among them, ω c is the frequency of the single-channel initial carrier, ω is the carrier frequency of the rotational decomposition, cosωt represents the carrier decomposed to the x-axis, and sinωt represents the carrier decomposed to the y-axis. In order to solve the problem that the initial carrier of the single-channel frequency cannot generate an excitation signal with an angle direction change, a rotating carrier signal is added to convert the initial carrier signal cosω c t modulates the sine and cosine signals with a frequency ω. At this time, the excitation signals of the two channels are cosω c tcosωt,cosω c The tsinωt combination generates excitation signals in different angular directions.

[0014] Furthermore, in step 3), the excitation mode of the axisymmetric gyroscope is electrostatic excitation of a flat capacitor, and its excitation is only related to the voltage on the electrode. In terms of the readout signal, a slight change of the capacitor is extracted from the resonator structure, and the capacitance change ΔC of each mode is only positively correlated with the displacement of the corresponding mode, so it can be set:

[0015]

[0016] where ω dis the resonant frequency of the gyro resonator, and the readout current can be calculated according to the formula:

[0017]

[0018] The displacement signals of the x-electrode and y-electrode are read out by one front-end circuit at the same time, avoiding the error introduced by the asymmetric parameters of the two front-end processing circuits. The signal is amplified by the front-end amplifier and then converted into a voltage signal V by the capacitor / voltage conversion circuit. o , which contains the modulation signals of the x-electrode and the y-electrode, and ω d ,ω,ω c As well as the combined harmonic components and higher harmonic components, the harmonic components included are ω c +ω+ω d ,ω c +ω-ω d ,ω c -ω+ω d ,ω c -ω-ω d .

[0019] In step 3), the x-channel carrier signal cosω is generated. c tcosωt and the carrier signal cosω of the y path c tsinωt excites the x-electrode and y-electrode of the gyro resonator respectively, causing a slight capacitance change on the surface of the gyro resonator shell, which is picked up and read out by the front-end amplifier circuit, ensuring that it can be amplified to the level that can be recognized by the subsequent initial carrier demodulation and rotating carrier demodulation modules without distortion as much as possible, and converted into a readout signal quantity V through the capacitance / voltage conversion circuit. o , read out the signal which contains ω d ,ω,ω c And the combined harmonic components and higher harmonic components, where ω d is the resonant frequency of the gyro resonator. In the front-end readout system of this system, only one front-end amplification processing circuit is used, and the readout signal contains the original displacement signals of the x-electrode and the y-electrode at the same time, avoiding the readout signal error problem caused by the asymmetric parameters of the dual-channel readout circuit.

[0020] The x-channel carrier signal cosω will be generated c tcosωt and the carrier signal cosω of the y path c tsinωt excites the x-electrode and y-electrode of the gyro resonator respectively, causing a slight capacitance change on the surface of the gyro resonator shell, which is picked up and read out by the front-end amplifier circuit, ensuring that it can be amplified to the level that can be recognized by the subsequent initial carrier demodulation and rotating carrier demodulation modules without distortion as much as possible, and converted into a readout signal quantity V through the capacitance / voltage conversion circuit. o , read out the signal which contains ωd ,ω,ω c And the combined harmonic components and higher harmonic components, where ω d is the resonant frequency of the gyro resonator. In the front-end readout system of this system, only one front-end amplification processing circuit is used, and the readout signal contains the original displacement signals of the x-electrode and the y-electrode at the same time, avoiding the readout signal error problem caused by the asymmetric parameters of the dual-channel readout circuit.

[0021] Further, in step 4), the signal V is read out o After two modulations, two modulation frequencies are introduced, namely the frequency ω introduced by carrier modulation. c The frequency ω introduced by the rotating carrier decomposition modulation contains the harmonic component ω c +ω+ω d ,ω c +ω-ω d ,ω c -ω+ω d ,ω c -ω-ω d Therefore, two demodulations are required to retain the resonant frequency ω in the initial displacement signal. d . Read signal V o First, it is demodulated by the initial carrier module to filter out ω c The initial carrier signal generated by the DDS initial carrier signal generator is cosω c t and readout signal V o By multiplying, the carrier cosω can be filtered out. c t frequency component, and for 2ω c High-frequency harmonic components, etc., can be removed from the original signal by using only a low-pass filter. c The influence of the component, at this time, the component contained in the signal after the initial carrier demodulation module is: ω+ω d With ω-ω d .

[0022] Further, step 5) performs a rotational carrier demodulation on the signal after the initial carrier demodulation, and uses the x-axis rotational decomposition signal generated by the DDS rotating carrier cosine signal generator, i.e., cosωt, to multiply the signal after the initial carrier demodulation, and passes through a low-pass filter to filter out ω and its high-frequency harmonic frequency components; uses the y-axis rotational decomposition signal generated by the DDS rotating carrier sine signal generator, i.e., sinωt, to multiply the signal after the initial carrier demodulation, and passes through a low-pass filter to filter out ω and its high-frequency harmonic frequency components, and finally retains the signal containing the resonant frequency ω d The initial x electrode displacement signal V x and the initial y electrode displacement signal V y .

[0023] Compared with the prior art, the advantages of the present invention are as follows: Due to process limitations, the vibration signal readout method of the axisymmetric gyroscope under the time-sharing multiplexing scheme has only half of the electrodes working in the readout state, which makes it difficult to achieve symmetrical differential detection, and at the readout end, the readout signals of the x and y axes will pass through two independent signal processing circuits. Due to the parameter errors in the circuits, the asymmetry between the two will also cause large errors in the readout signals. The readout scheme under the dual-frequency carrier uses two carrier signals of different frequencies to respectively excite the two electrodes and read out through one channel. Although this improves the error, carriers of different frequencies will have different frequency responses, which introduces new gain adaptation problems at the readout end. This scheme adopts a vibration signal readout method for an axisymmetric gyroscope based on a rotating carrier, that is, a DDS digital generator is used to generate a single-frequency carrier cosω respectively. c t and the rotational decomposition carrier sinωt and cosωt. At the same time, in order to solve the problem that a single-frequency carrier can only generate an excitation signal with a fixed direction angle, the rotational decomposition modulation is introduced to generate two signals cosω c tcosωt and cosω c tsinωt, the initial carrier signal is modulated on the sine and cosine signals that change with frequency ω, and the x and y electrodes are stimulated respectively, and then read out by a front-end amplifier circuit. One front-end processing circuit also avoids the error introduced by the two front-end processing circuits due to parameter asymmetry. Then, V is generated through the capacitor / voltage conversion circuit o , and the read signal after two modulations, in order to restore the initial displacement signal, two demodulations are used in the demodulation, namely the initial carrier demodulation and the rotating carrier demodulation to filter out ω respectively c and ω frequency to extract the initial displacement voltage signal V x and V y Not only does it eliminate the errors caused by the time-division multiplexing readout system, it also avoids the gain adaptation problem caused by the different frequency carriers at the readout end in the dual-frequency carrier readout scheme. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A block diagram of the system implementation of the present invention;

[0025] Figure 2 It is a principle block diagram of the rotation decomposition carrier module of the present invention;

[0026] Figure 3 It is a waveform diagram of the rotational decomposition carrier module of the present invention;

[0027] Figure 4 It is a block diagram of the implementation of the initial carrier demodulation module of the present invention;

[0028] Figure 5This is an implementation block diagram of the rotary carrier demodulation module of the present invention. DETAILED DESCRIPTION

[0029] In order to deepen the understanding of the present invention, the present embodiment is described in detail below with reference to the accompanying drawings.

[0030] Embodiment 1: A vibration signal reading system of an axisymmetric gyroscope based on a rotating carrier wave, such as Figure 1 As shown, the system includes a gyro resonator, a DDS initial carrier signal generator, a DDS rotating carrier cosine signal generator, a DDS rotating carrier sine signal generator, a front-end amplifier module, a capacitance / voltage conversion circuit module, an initial carrier demodulation module, and a rotating carrier demodulation module. The initial carrier signal cosω is generated by the DDS digital generator. c t and the rotating carrier signals cosωt and sinωt, the initial carrier signal cosω c After t is modulated with the rotating carrier cosωt of the x-axis and the rotating carrier sinωt of the y-axis respectively, an x-channel carrier signal cosω in any direction can be generated. c tcosωt and the carrier signal cosω of the y path c Furthermore, the two carrier signals generated are used to stimulate the x-electrode and y-electrode of the gyro resonator respectively, and the surface capacitance change generated is detected by an amplifier circuit and converted into V by a capacitance / voltage conversion circuit. o , which contains ω d ,ω,ω c As well as combined harmonic components and higher harmonic components. After the initial carrier demodulation, the ω c The rotating carrier demodulation is divided into two paths for demodulation, removing ω and its higher harmonic components, and finally retaining the frequency ω d , which contains the original displacement signal V of the x electrode x And the original displacement signal V of the y electrode y .

[0031] Embodiment 2: A vibration signal reading method of an axisymmetric gyroscope based on a rotating carrier. Figure 1 As shown, the whole system includes a gyro resonator, a DDS initial carrier signal generator, a DDS rotating carrier cosine signal generator, a DDS rotating carrier sine signal generator, a front-end amplifier module, a capacitance / voltage conversion circuit module, an initial carrier demodulation module, and a rotating carrier demodulation module. The DDS initial carrier signal generator generates the initial carrier cosω c t, the DDS rotating carrier sine signal generator generates the carrier sinωt, and the DDS rotating carrier cosine signal generator generates the carrier cosωt. In addition, ensure that ω can be successfully filtered out in the subsequent filtering and demodulation module cAnd the ω frequency component and its higher harmonic components, ω c And the size of ω must be greater than the resonant frequency ω d At least one order of magnitude, and ω c It needs to be greater than ω by at least one order of magnitude, so that the spectrum of the modulated signal is far away from the resonant frequency ω d , leaving enough frequency space for the filter design. c t is decomposed by the rotating carrier and modulated with the rotating carrier cosωt of the x-axis and the rotating carrier sinωt of the y-axis respectively to generate the x-channel carrier signal cosω c tcosωt and the carrier signal cosω of the y path c tsinωt, the schematic diagram is as follows Figure 2 As shown. Among them, ω c is the frequency of the single-channel initial carrier, ω is the carrier frequency of the rotational decomposition, cosωt represents the carrier decomposed to the x-axis, and sinωt represents the carrier decomposed to the y-axis. In order to solve the problem that the initial carrier of the single-channel frequency cannot generate an excitation signal with an angle direction change, a rotating carrier signal is added to convert the initial carrier signal cosω c t modulates the sine and cosine signals with a frequency ω. At this time, the excitation signals of the two channels are cosω c tcosωt,cosω c The tsinωt combination generates excitation signals at different angles, and the waveforms are as follows: Figure 3 As shown. Further, the generated carrier signal is used to excite the x-electrode and y-electrode of the hemispherical gyroscope respectively. The excitation method of the axisymmetric gyroscope is electrostatic excitation of the plate capacitor, and its excitation is only related to the voltage on the electrode. In terms of the readout signal, the slight change of the capacitor is extracted from the resonator structure, and the capacitance change ΔC of each mode is only positively correlated with the displacement of the corresponding mode, so it can be set:

[0032]

[0033] where ω d is the resonant frequency of the gyro resonator, and the readout current can be calculated according to the formula:

[0034]

[0035] The displacement signals of the x-electrode and y-electrode are read out by one front-end circuit at the same time, avoiding the error introduced by the asymmetric parameters of the two front-end processing circuits. The signal is amplified by the front-end amplifier and then converted into a voltage signal V by the capacitor / voltage conversion circuit. o , which contains the modulation signals of the x-electrode and the y-electrode, and ω d ,ω,ω cAs well as the combined harmonic components and higher harmonic components, the harmonic components included are ω c +ω+ω d ,ω c +ω-ω d ,ω c -ω+ω d ,ω c -ω-ω d For the modulated signal V o , two modulation frequencies are introduced, namely the frequency ω introduced by carrier modulation c The frequency ω introduced by the rotating carrier decomposition modulation contains the harmonic component ω c +ω+ω d ,ω c +ω-ω d ,ω c -ω+ω d ,ω c -ω-ω d Therefore, two demodulations are required to retain the resonant frequency ω in the initial displacement signal. d . Read signal V o First, it is demodulated by the initial carrier module. The specific implementation principle is as follows Figure 4 As shown. To filter out ω c The initial carrier signal generated by the DDS initial carrier signal generator is cosω c t and readout signal V o By multiplying, the carrier cosω can be filtered out. c t frequency component, and for 2ω c High-frequency harmonic components, etc., can be removed from the original signal by using only a low-pass filter. c The influence of the component, at this time, the component contained in the signal after the initial carrier demodulation module is: ω+ω d With ω-ω d The signal after initial carrier demodulation is subjected to rotation carrier demodulation. The specific implementation principle is as follows: Figure 5 As shown, the x-axis rotation decomposition signal, i.e., cosωt, generated by the DDS rotating carrier cosine signal generator is multiplied with the demodulated signal of the initial carrier, and ω and its high-frequency harmonic frequency components are filtered out through a low-pass filter; the y-axis rotation decomposition signal, i.e., sinωt, generated by the DDS rotating carrier sine signal generator is multiplied with the demodulated signal of the initial carrier, and ω and its high-frequency harmonic frequency components are filtered out through a low-pass filter, and finally the signal containing the resonant frequency ω is retained. d The initial x electrode displacement signal V x and the initial y electrode displacement signal V y .

[0036] It should be noted that the above embodiments are not intended to limit the protection scope of the present invention, and equivalent changes or substitutions made on the basis of the above technical solutions all fall within the protection scope of the claims of the present invention.

Claims

1. A vibration signal reading system for an axisymmetric gyroscope based on a rotating carrier, characterized in that: The system includes a gyro resonator, a DDS initial carrier signal generator, a DDS rotating carrier cosine signal generator, a DDS rotating carrier sine signal generator, a front-end amplifier module, a capacitance / voltage conversion circuit module, an initial carrier demodulation module, and a rotating carrier demodulation module. First, the DDS initial carrier signal generator generates an initial carrier cosω c t, the DDS rotating carrier sine signal generator generates the rotating carrier sinωt of the y-axis, and the DDS rotating carrier cosine signal generator generates the rotating carrier cosωt of the x-axis. Then, the initial carrier cosω c t, modulated with the rotating carrier cosωt of the x-axis and the rotating carrier sinωt of the y-axis respectively, the initial carrier cosω c Under the action of the rotating carrier cosωt of the x-axis and the rotating carrier sinωt of the y-axis, the direction of the generated wave changes with the frequency ω of the rotating carrier. c The changing x-channel carrier signal cosω c tcosωt and the carrier signal cosω of the y path c tsinωt, in order to realize the generation of excitation signal at any angle, the generated x-channel carrier signal cosω c tcosωt and the carrier signal cosω of the y path c tsinωt, respectively excites the x-electrode and y-electrode of the gyro resonator, and the resulting change in the surface capacitance of the spherical shell is amplified by the front-end amplifier circuit and converted into a voltage value V through the capacitance / voltage conversion circuit o , which contains ω d ,ω,ω c As well as the combined harmonic components and higher harmonic components, the voltage V o First, the initial carrier demodulation module is used to remove the ω c and its higher harmonic components, and then demodulated in two ways through the rotating carrier demodulation module to remove ω and its higher harmonic components and retain the frequency ω d , and finally extract the original displacement signal V containing the x electrode x And the original displacement signal V of the y electrode y .

2. The vibration signal reading system of an axisymmetric gyroscope based on a rotating carrier according to claim 1, characterized in that: In the link of generating the excitation carrier, a DDS carrier signal generator is used to generate the initial carrier, generate the rotating carrier cosωt of the x-axis and the rotating carrier sinωt of the y-axis, and convert the initial carrier signal cosω c t are modulated on the sine and cosine waveforms with a frequency of ω. At this time, the x-channel carrier signal cosω c tcosωt and the carrier signal cosω of the y path c tsinωt can realize signal excitation at any angle.

3. A vibration signal reading method of an axisymmetric gyroscope based on a rotating carrier, characterized in that: The method comprises the following steps: Step 1) generating an initial carrier signal cosω by using a DDS initial carrier signal generator c t, the rotating carrier sinωt of the y-axis is generated by the DDS rotating carrier sine signal generator, and the rotating carrier cosωt of the x-axis is generated by the DDS rotating carrier cosine signal generator. Step 2) Initial carrier signal cosω c t is decomposed by the rotating carrier and modulated with the rotating carrier cosωt of the x-axis and the rotating carrier sinωt of the y-axis respectively to generate the x-channel carrier signal cosω c tcosωt and the carrier signal cosω of the y path c tsinωt, where ω is the frequency of the angle change, the initial carrier signal cosω c t are modulated on the sine and cosine waveforms with a frequency of ω to achieve carrier component extraction at any angle. Step 3) The two carrier signals generated, that is, the carrier signal cosω of x c tcosωt and the carrier signal cosω of the y path c tsinωt excites the x-electrode and y-electrode of the gyro resonator respectively, causing a slight capacitance change on the surface of the gyro resonator structure, which is picked up and read out by the front-end amplifier circuit and converted into V by the capacitance / voltage conversion circuit. o , which contains ω d ,ω,ω c As well as combined harmonic components and higher harmonic components, Step 4) Read out the signal V o Perform initial carrier demodulation and use the initial carrier signal generated by the DDS initial carrier signal generator, i.e. cosω c t is multiplied by the readout signal and filtered out through a low-pass filter. c and its high-frequency harmonic frequency components, Step 5) The signal after the initial carrier demodulation is subjected to rotation carrier demodulation, and the x-axis rotation decomposition signal, i.e., cosωt, generated by the DDS rotating carrier cosine signal generator is multiplied with the signal after the initial carrier demodulation, and ω and its high-frequency harmonic frequency components are filtered out through a low-pass filter; the y-axis rotation decomposition signal, i.e., sinωt, generated by the DDS rotating carrier sine signal generator is multiplied with the signal after the initial carrier demodulation, and ω and its high-frequency harmonic frequency components are filtered out through a low-pass filter, and finally the signal containing the resonant frequency ω is retained. d The initial x electrode displacement signal V x and the initial y electrode displacement signal V y .

4. The vibration signal reading method of the axisymmetric gyroscope based on the rotating carrier according to claim 3 is characterized in that: Step 1) The DDS digital generator is a direct frequency synthesizer that can output the required sine and cosine signals according to the input voltage signal. The DDS needs to generate two signals with different frequencies, that is, to generate an initial carrier signal cosω c t and the rotating carrier signals cosωt and sinωt, with frequencies ω respectively c and ω, where ω c The single-channel carrier signal frequency, the DDS initial carrier signal generator provides the demodulation signal cosω for the initial carrier demodulation module c t, the DDS rotating carrier signal generator provides the demodulation signals cosωt and sinωt for the rotating carrier demodulation module, ensuring that ω can be successfully filtered out in the subsequent filtering demodulation module c And the ω frequency component and its higher harmonic components, ω c And the size of ω must be greater than the resonant frequency ω d At least one order of magnitude, and ω c It needs to be greater than ω by at least one order of magnitude, so that the spectrum of the modulated signal is far away from the resonant frequency ω d , while leaving enough frequency space for filter design.

5. The vibration signal reading method of the axisymmetric gyroscope based on the rotating carrier according to claim 3, characterized in that: Step 2) Convert the carrier signal cosω c t is decomposed by the rotating carrier and modulated with the rotating carrier cosωt of the x-axis and the rotating carrier sinωt of the y-axis respectively to generate the x-channel carrier signal cosω c tcosωt and the carrier signal cosω of the y path c tsinωt, where ω c is the frequency of the single-channel initial carrier, ω is the carrier frequency of the rotational decomposition, cosωt represents the carrier decomposed to the x-axis, sinωt represents the carrier decomposed to the y-axis, and the rotational carrier signal is added to convert the initial carrier signal cosω c t modulates the sine and cosine signals with a frequency ω, and the two excitation signals cosω c tcosωt,cosω c The tsinωt combination generates excitation signals in different angular directions.

6. The vibration signal reading method of the axisymmetric gyroscope based on the rotating carrier according to claim 3, characterized in that: In step 3), the excitation mode of the axisymmetric gyroscope is electrostatic excitation of a flat capacitor, and its excitation is only related to the voltage on the electrode. In terms of the readout signal, the slight change of the capacitor is extracted from the resonator structure. The capacitance change ΔC of each mode is only positively correlated with the displacement of the corresponding mode. Assume: where ω d is the resonant frequency of the gyro resonator, and the readout current is obtained according to the formula: The displacement signals of the x-electrode and the y-electrode are read out by a front-end circuit at the same time. The signal is processed and amplified by the front-end amplifier and then converted into a voltage signal V by the capacitor / voltage conversion circuit. o , which contains the modulation signals of the x-electrode and the y-electrode, and ω d ,ω,ω c As well as the combined harmonic components and higher harmonic components, the harmonic components included are ω c +ω+ω d ,ω c +ω-ω d ,ω c -ω+ω d ,ω c -ω-ω d .

7. The vibration signal reading method of the axisymmetric gyroscope based on the rotating carrier according to claim 3, characterized in that: In step 4), the read signal V after passing through the front-end circuit is o , a demodulation is performed through the initial carrier demodulation module, using the initial carrier signal generated by the DDS initial carrier signal generator, i.e., cosω c t and readout signal V o Multiply and filter out the carrier cosω c The frequency component of t, for 2ω c High-frequency harmonic components, etc., use a low-pass filter to filter out ω from the original signal c High frequency component, at this time, the filtered signal contains ω d , ω and combined harmonic components and higher harmonic components.

8. The vibration signal reading method of an axisymmetric gyroscope based on a rotating carrier according to claim 2, characterized in that: Step 5) The signal after initial carrier demodulation is divided into two paths for rotating carrier demodulation, that is, d ,ω and the combined harmonic components and higher harmonic components are demodulated. For x-channel, the DDS rotating carrier cosine signal generator is used to generate the signal cosωt, which is multiplied by the demodulated signal of the initial carrier, and then filtered out by a low-pass filter to remove ω and its high-frequency harmonic frequency components, retaining the resonant frequency ω d The x-axis displacement signal V x ; Use the DDS rotating carrier sinusoidal signal generator to generate a signal sinωt, which is multiplied by the demodulated signal of the initial carrier, and then filtered out ω and its high-frequency harmonic frequency components through a low-pass filter, retaining the resonant frequency ω d Y-axis displacement signal V y .

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