Liquid floated gyroscope signal conversion circuit, conversion device and conditioning conversion method

Abstract

The invention provides a liquid floated gyroscope signal conversion circuit, conversion device and conditioning conversion method, and the conversion circuit comprises a differential amplification circuit, a phase-sensitive demodulation circuit, a DC amplification filter circuit, an AC output circuit, an anti-reverse connection filter circuit and a secondary power supply circuit. The phase-sensitive demodulation circuit and the direct-current amplification filter circuit are used for performing phase demodulation and conditioning processing on the gyro output signal, outputting a direct-current output signal which is used for measurement of signal acquisition equipment and has small scale factor discreteness, independently performing voltage following processing on the gyro output signal, and outputting an alternating-current output signal; the alternating current signal and the direct current signal are output in parallel and do not influence each other, so that the output signal of the gyroscope body is truly restored, the signal output quality is improved, and the testing efficiency of measuring the angular rate of rotation of the carrier along the gyroscope sensitive axial direction by applying the liquid floated gyroscope is greatly improved.

Description

Technical Field

[0001] The invention belongs to the technical field of inertial sensors, and in particular relates to a liquid floating gyro signal conversion circuit, a conversion device and a conditioning conversion method. Background Art

[0002] The liquid-floating gyroscope can measure the angular velocity of the carrier rotating along the sensitive axis of the gyroscope, and can convert the angular velocity into an AC voltage signal proportional to it, and also has a self-test function. In the process of developing, producing, accepting and using the liquid-floating gyroscope, the AC signal output by the gyroscope body is weak and easily interfered by the outside world, and the power, amplitude, AC and DC characteristics of the signal often do not meet the use requirements. Therefore, it is necessary to process the AC signal output by the gyroscope body so that the signal has the characteristics of high precision, low distortion and anti-interference.

[0003] The traditional way to measure the AC signal output by the liquid-floating gyroscope is to use the test equipment to directly measure it at the signal output end of the liquid-floating gyroscope. This method will introduce external interference signals, and because there is a phase difference between the gyroscope body signal and the excitation signal, it will cause the demodulation efficiency to decrease, causing the DC signal after interference demodulation to have a large discrete scale factor due to the different phase differences, and the conventional signal conversion circuit cannot solve this problem. Summary of the invention

[0004] The purpose of the present invention is to solve the problem that the existing liquid-floating gyroscope output signal measurement method will introduce interference, and the scale factor of the DC output signal after interference demodulation is highly discrete, and provide a liquid-floating gyroscope signal conversion circuit, a conversion device and a conditioning conversion method. The gyroscope output signal is processed by a differential amplifier circuit, a phase-sensitive demodulation circuit, a DC amplifier filter circuit, an AC output circuit, an anti-reverse connection filter circuit, and a secondary power supply circuit. The quality of the output signal can truly restore the output signal of the gyroscope body, the circuit has strong anti-interference ability, and the AC and DC signals are output in parallel without affecting each other, which greatly improves the test efficiency.

[0005] To achieve the above purpose, the technical solution provided by the present invention is:

[0006] A liquid floating gyro signal conversion circuit, comprising a differential amplifier circuit, a phase-sensitive demodulation circuit, a DC amplifier filter circuit, an AC output circuit, an anti-reverse connection filter circuit and a secondary power supply circuit;

[0007] The differential amplifier circuit is used to convert the gyro differential signal output by the liquid floating gyro into a single-ended signal with GND as a reference;

[0008] The phase-sensitive demodulation circuit is used to perform phase demodulation on the converted single-ended signal with GND as reference, so that the positive and negative half-wave signals in the single-ended signal are completely demodulated, and is used to convert the phase-demodulated signal into a DC signal;

[0009] The DC amplification and filtering circuit is used to amplify and isolate the DC signal output by the phase-sensitive demodulation circuit, and convert it into a DC output signal matching the polarity of the liquid-floating gyroscope; the DC output signal is used for measurement by external test equipment;

[0010] The AC output circuit is used to perform voltage following processing on the converted single-ended signal with GND as reference to obtain an AC output signal for measurement by an external test device;

[0011] The anti-reverse connection filter circuit is used to condition the power supply signal of the external power supply and supply it to the differential amplifier circuit, phase-sensitive demodulation circuit, DC amplifier filter circuit, AC output circuit and secondary power supply circuit, and can prevent the circuit from being damaged due to reverse connection of the positive and negative poles of the power supply.

[0012] Furthermore, the differential amplifier circuit includes a resistor R6*, a capacitor C6, a capacitor C21 and an operational amplifier N2, wherein the in-phase input terminal and the inverting input terminal of the operational amplifier N2 are respectively connected to the wiring port J2 and the wiring port J4; one end of the capacitor C6 is connected to the positive power supply port of the operational amplifier N2, and the other end is grounded; one end of the capacitor C21 is connected to the negative power supply port of the operational amplifier N2, and the other end is grounded; both ends of the resistor R6* are connected to two gain adjustment ports on the same side of the operational amplifier N2; the reference end of the operational amplifier N2 is grounded; the resistor R6* is used to adjust the circuit gain, and the operational amplifier N2 realizes the conversion of the gyro differential signal output by the liquid-floating gyroscope body into a single-ended signal with GND as a reference.

[0013] Further, the phase-sensitive demodulation circuit includes a full-wave phase-sensitive demodulation circuit and a demodulation reference circuit, and the full-wave phase-sensitive demodulation circuit includes an inverting proportional amplifier circuit and a switch circuit;

[0014] The demodulation reference circuit is used to convert the excitation signal generated by the external excitation circuit into a reference signal;

[0015] The inverting proportional amplifier circuit is used to reversely amplify the single-ended signal output by the differential amplifier circuit with GND as the reference;

[0016] The switch circuit is used to switch on or off under the control of a reference signal, and convert the positive half-wave or negative half-wave of the amplified single-ended signal with GND as reference into a positive or negative direct current signal.

[0017] Further, the demodulation reference circuit includes a resistor R1*, a resistor R3, a resistor R4, a potentiometer RP1, a capacitor C1, an operational amplifier U3C, a diode D1 and a diode D2; after the resistor R1* and the potentiometer RP1 are connected in parallel, one end is connected to a wiring port J1, and the other end is connected to the inverting input end of the operational amplifier U3C and one end of the capacitor C1, and the other end of the capacitor C1 is connected to the non-inverting input end of the operational amplifier U3C and the ground wire GND; the output end of the operational amplifier U3Cd is connected in series with the diode D2 and the resistor R3 in sequence; after the diode D1 and the resistor R4 are connected in parallel, the positive electrode of the diode D1 is grounded, the negative electrode is connected between the resistor R3 and the resistor R4, and is connected to the input end of the switch circuit; the wiring terminal J1 is connected to an external excitation circuit, and the phase of the demodulated reference signal relative to the gyro differential signal can be controlled by adjusting the resistance values ​​of the resistor R1* and the potentiometer RP1;

[0018] The inverting proportional amplifier circuit includes a resistor R7, a resistor R5, an operational amplifier U3A, a capacitor C18 and a capacitor C20; the input end of the resistor R7 is connected to the output end of the differential amplifier circuit, and the output end is connected to the inverting input end of the operational amplifier U3A; the two ends of the resistor R5 are respectively connected to the output end and the inverting input end of the operational amplifier U3A; one end of the capacitor C18 and the capacitor C20 are respectively connected to the ground wire GND, and the other ends are respectively connected to the positive power supply end and the negative power supply end of the operational amplifier U3A; the resistor R7 and the resistor R5 are used to adjust the circuit gain, and the operational amplifier U3A is used to reversely amplify the single-ended signal output by the differential amplifier circuit with GND as the reference;

[0019] The switch circuit comprises an analog switch S1, a capacitor C4, a capacitor C5 and a capacitor C22; the analog signal positive power input terminal VS+ and the analog signal negative power input terminal VS- of the analog switch S1 are connected to the ground line GND via the capacitor C4 and the capacitor C22 respectively; the normally closed terminal, the normally open terminal and the logic level input terminal are connected to the output terminal of the reverse proportional circuit, the output terminal of the differential amplifier circuit and the cathode of the diode D1 in the demodulation reference circuit respectively; the ground terminal of the analog switch S1 is connected to the ground wire, the logic level positive power input terminal is connected to the ground via the capacitor C5, and the output terminal of the analog switch S1 is connected to the input terminal of the DC amplifier filter circuit;

[0020] The analog signal positive power input terminal VS+ of the analog switch S1 is also connected to the input terminal of the secondary power supply circuit, the analog signal negative power input terminal VS- is also connected to the negative power output terminal of the anti-reverse connection filter circuit, and the logic level positive power input terminal is also connected to the output terminal of the secondary power supply circuit.

[0021] Furthermore, the secondary power supply circuit is used to supply power to the analog switch S1 in the switching circuit separately; the secondary power supply circuit includes capacitor C3, capacitor C2 and voltage regulator U2; one end of capacitor C2 and capacitor C3 are respectively connected to the ground wire GND, and the other end is respectively connected to the input terminal Vi and output terminal Vo of the voltage regulator U2, the input terminal Vi is also connected to the analog signal positive power input terminal VS+ of the analog switch S1, and the output terminal Vo is also connected to the logic level positive power input terminal of the analog switch S1; the ground end of the voltage regulator U2 is connected to the ground wire GND.

[0022] Furthermore, the DC amplification and filtering circuit includes a resistor R2, a resistor R9, a resistor R10, a resistor R12, a resistor R13, a capacitor C25, a capacitor C19 and an operational amplifier U3D; one end of the resistor R9 is connected to the output end of the switch circuit, and the other end is connected in series with the resistor R10 and then connected to the in-phase input end of the operational amplifier U3D; the resistors R2, R12 and R13 are connected in series in sequence and then connected to the ground line GND, and the inverting input end of the operational amplifier U3D is connected between the resistor R12 and the resistor R13; one end of the capacitor C25 is connected between the resistor R9 and the resistor R10, and the other end is connected to the input end of the resistor R2; one end of the capacitor C19 is connected to the resistor R10 and the operational amplifier R13 to adjust the circuit gain;

[0023] The resistor R9, the resistor R10, the capacitor C19, the capacitor C25 and the operational amplifier U3D form a common-phase amplification low-pass filter, so that the polarity of the DC signal mediated and output by the phase-sensitive demodulation circuit is consistent with the polarity of the liquid floating gyroscope.

[0024] Furthermore, the anti-reverse connection filter circuit includes a capacitor C23, a capacitor C24, a diode D3 and a diode D4; the capacitor C23 and the capacitor C24 are connected in series, and the positive electrode of the capacitor C24 is connected to the negative electrode of the capacitor C23; the connection line between the capacitor C23 and the capacitor C24 outputs two paths, one path is grounded, and the other path is connected to a set wiring port J7, and the wiring port J7 is used to connect the power ground of the external power supply;

[0025] The cathode of the diode D3 is connected to the anode of the capacitor C23 and then connected to the input terminal Vi of the voltage regulator U2 in the secondary power supply circuit, the positive power supply port of the operational amplifier N2 in the differential amplifier circuit, the positive power supply port of the operational amplifier U3A in the phase-sensitive demodulation circuit, the positive power supply port of the DC amplifier filter circuit, and the positive power supply port of the AC output circuit; the anode of the diode D3 is connected to the wiring port J5, which is used to connect to the positive electrode of the external power supply;

[0026] The positive electrode of the diode D4 is connected to the negative electrode of the capacitor C24 and then connected to the negative power supply port of the operational amplifier N2 in the differential amplifier circuit, the negative power supply port of the operational amplifier U3A in the phase-sensitive demodulation circuit, the analog signal negative power supply input terminal VS- of the analog switch S1, the negative power supply port of the DC amplifier and filter circuit, and the negative power supply port of the AC output circuit; the negative electrode of the diode D4 is connected to the set wiring port J6, and the wiring port J6 is used to connect the negative electrode of the external power supply.

[0027] Furthermore, the AC output circuit includes a voltage follower U3B; the in-phase input terminal of the voltage follower U3B is connected to the output terminal of the differential amplifier circuit, and the output terminal of the voltage follower U3B is connected to the inverting input terminal of the voltage follower U3B, so as to convert the output signal of the differential amplifier circuit into an AC output signal; the output terminal of the voltage follower U3B is also connected to a set connection port J6, and the connection port J6 is connected to the signal input terminal of the external test equipment.

[0028] The method for conditioning and converting the output signal of a liquid-floating gyroscope based on the above-mentioned liquid-floating gyroscope signal conversion circuit comprises the following steps:

[0029] Step 1: Amplify and convert the gyro differential signal output by the liquid floating gyro, and output a single-ended signal with GND as the reference;

[0030] Step 2: performing phase demodulation on the single-ended signal with GND as reference, so that the positive and negative half-wave signals in the single-ended signal are completely output and converted into a DC signal;

[0031] At the same time, voltage following processing is performed on the single-ended signal with GND as reference to obtain an AC output signal for measurement by an external test device;

[0032] Step 3: Amplify and filter the DC signal output by phase demodulation in step 2 to obtain a DC output signal for measurement by external test equipment.

[0033] A liquid-floating gyro signal conversion device comprises an electrical connector XP1 and a printed circuit board; the liquid-floating gyro signal conversion circuit is fixedly arranged on the printed circuit board;

[0034] The electrical connector XP1 has multiple power interfaces and signal interfaces; one end of the power interface and the signal interface are respectively connected to the corresponding wiring ports in the liquid floating gyroscope signal conversion circuit; the other end of the power interface and the signal interface are used to connect to an external power supply, a liquid floating gyroscope output terminal and a test device.

[0035] The advantages of the present invention are:

[0036] The liquid-floating gyro signal conversion circuit of the present invention includes a differential amplifier circuit, a phase-sensitive demodulation circuit, a DC amplifier filter circuit, an AC output circuit, an anti-reverse connection filter circuit and a secondary power supply circuit. By performing multi-stage processing on the gyro output signal, the AC signal output by the gyro body is converted and output into AC and DC signals, and the AC and DC signals are output in parallel without affecting each other. The DC output signal has a small discreteness of the scale factor, and the signal output quality is improved while the gyro body output signal is truly restored. The test efficiency of the angular velocity of the carrier rotating along the sensitive axis of the gyro using the liquid-floating gyro is greatly improved. The specific advantages include:

[0037] 1. The differential amplifier circuit in the present invention amplifies the output signal of the gyroscope body, and effectively isolates the reverse interference of the subsequent conversion circuit on the weak signal of the gyroscope body, effectively suppresses the common-mode interference of the gyroscope body on the conversion circuit, and the polarity of the DC output signal can be adjusted by swapping the differential input, effectively isolating the interference between the liquid-floating gyroscope and the conversion circuit board of the present invention, and realizing the polarity adjustment of the DC output signal.

[0038] 2. The present invention adopts a voltage follower in the AC output circuit, which effectively isolates the input and output ends of the AC output circuit, avoids mutual interference, and ensures the purity of the demodulated input signal.

[0039] 3. The phase-sensitive demodulation circuit in the present invention adopts full-wave phase-sensitive demodulation, which can be adjusted according to the phase of the output signal of the gyroscope body, so as to adjust the demodulation efficiency to the optimal level, significantly reducing the discreteness of the DC output scale factor caused by the phase difference between the liquid-floating gyroscope body signal and the excitation signal, ensuring that the positive and negative half-wave signals of the gyroscope are completely demodulated, eliminating demodulation spikes, and improving the signal output quality.

[0040] 4. The DC amplification and filtering circuit in the present invention adopts a common-phase low-pass amplification filter, which effectively suppresses the interference between the front and back ends of this level of circuit, and ensures that the polarity of the self-test output signal is consistent with the polarity of the rotation output signal. It should be noted that the self-test output signal refers to the input of a specified current to the gyro torquer in order to realize the self-calibration and self-detection functions of the sensor, and the gyro outputs an output signal of a fixed size. The rotation output signal refers to the signal output when the gyro rotates along its sensitive axis. According to the technical requirements of the gyro, the polarities of these two output signals must be kept consistent.

[0041] 5. The anti-reverse connection filter circuit in the present invention adopts diode protection to ensure that the circuit will not be damaged when the positive and negative power supplies are connected reversely. At the same time, the ripple of the positive and negative power supplies can be suppressed, making the positive and negative power supplies purer.

[0042] In addition, the conversion circuit of the present invention adopts common discrete components, the components are autonomous and controllable, and the types and quantities of components are optimized to the minimum, achieving the best cost-effectiveness, and significantly reducing costs compared to traditional technologies.

[0043] The conversion circuit can be adapted to the output signal conversion of various types of liquid floating gyroscope bodies, has a wide application range and is highly practical.

[0044] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a block diagram of the liquid floating gyro signal conversion circuit of the present invention;

[0046] Figure 2 It is a circuit connection diagram of a differential amplifier circuit, a phase-sensitive demodulation circuit, a DC amplifier and filter circuit, and an AC output circuit in a liquid floating gyro signal conversion circuit of the present invention;

[0047] Figure 3 It is a circuit diagram of a reverse connection prevention filter circuit in a liquid floating gyro signal conversion circuit of the present invention;

[0048] Figure 4 It is a circuit diagram of a secondary power supply circuit in a liquid floating gyro signal conversion circuit of the present invention;

[0049] Figure 5 It is a schematic diagram of the liquid floating gyro signal conversion device of the present invention. DETAILED DESCRIPTION

[0050] Embodiments of the present invention are described in detail below. The embodiments are exemplary and intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0051] Reference Figure 1-Figure 2 An embodiment of the present invention provides a liquid floating gyroscope signal conversion circuit, including a differential amplifier circuit, a phase-sensitive demodulation circuit, a DC amplifier filter circuit, an AC output circuit, an anti-reverse connection filter circuit and a secondary power supply circuit.

[0052] The differential amplifier circuit is used to convert the gyro differential signal output by the liquid-floating gyro body into a single-ended signal with GND as a reference. The differential amplifier circuit includes a resistor R6*, a capacitor C6, a capacitor C21 and an operational amplifier N2, wherein the in-phase input terminal of the operational amplifier N2 is connected to a set wiring port J2, and the inverting input terminal is connected to a set wiring port J4, and the wiring port J2 and the wiring port J4 are respectively connected to two output terminals of the liquid-floating gyro; one end of the capacitor C6 is connected to the positive power supply port of the operational amplifier N2, and the other end is grounded; one end of the capacitor C21 is connected to the negative power supply port of the operational amplifier N2, and the other end is grounded; the reference terminal 1 of the operational amplifier N2 is grounded; the two ends of the resistor R6* are connected to the gain adjustment port 2 and the gain adjustment port 3 on the same side of the operational amplifier N2; the resistor R6* plays a role in adjusting the circuit gain, the capacitor C6 and the capacitor C21 play a filtering role, and the operational amplifier N2 plays a role in converting the signal.

[0053] The phase-sensitive demodulation circuit is used to demodulate the single-ended signal output by the differential amplifier circuit with GND as the reference into a DC signal. The phase-sensitive demodulation circuit has the functions of full-wave phase-sensitive demodulation and demodulation reference signal phase adjustment. The phase-sensitive demodulation circuit includes a full-wave phase-sensitive demodulation circuit and a demodulation reference circuit. The full-wave phase-sensitive demodulation circuit consists of an inverting proportional amplifier circuit and a switching circuit.

[0054] The inverting proportional amplifier circuit includes resistor R7, resistor R5, operational amplifier U3A, capacitor C18 and capacitor C20. One end of resistor R7 is connected to the output end of the differential amplifier circuit, and the other end is connected to the inverting input end of the operational amplifier U3A; one end of resistor R5 is connected to the inverting input end of the operational amplifier U3A, and the other end is connected to the output end of the operational amplifier U3A; the non-inverting input end of the operational amplifier U3A is connected to GND; one end of capacitor C18 and capacitor C20 are respectively connected to the positive power supply end and the negative power supply end of the operational amplifier U3A, and the other ends of capacitors C18 and C20 are respectively connected to GND; resistors R7 and R5 play a role in adjusting the gain, and the operational amplifier U3A plays a role in inverting amplification. The output end of the inverting proportional amplifier circuit is connected to the input end of the switch circuit.

[0055] The switch circuit is composed of an analog switch S1, a capacitor C4, a capacitor C5, and a capacitor C22. The output end of the operational amplifier U3A in the inverting proportional amplifier circuit is connected to the normally closed end 1 of the analog switch S1, and the normally open end 2 of the analog switch S1 is connected to the output end of the operational amplifier N2. One end of the capacitor C4 and the capacitor C22 are connected to the ground wire GND respectively, and the other end is connected to the analog signal positive power input end VS+ and the analog signal negative power input end VS- of the analog switch S1 respectively; one end of the capacitor C5 is connected to the ground wire GND, and the other end is connected to the logic level positive power input end 4 of the analog switch S1; the output end of the analog switch S1 is connected to the ground wire GND, the logic level input end 3 of the analog switch S1 is connected to the cathode of the diode D1 in the demodulation reference circuit, and the output end of the analog switch S1 is connected to one end of the resistor R9 in the DC amplifier filter circuit. The analog switch S1 is used to turn on or off under the control of the reference signal output by the demodulation reference circuit, and convert the positive half-wave and negative half-wave of the single-ended signal amplified by the inverting proportional amplifier circuit into DC signals with positive and negative polarities respectively. The specific working process is as follows: when the phase difference between the input signal of the full-wave phase-sensitive demodulation circuit and the reference signal output by the demodulation reference circuit is 0°, the positive half-wave signal in the input signal of the full-wave phase-sensitive demodulation circuit is converted into a negative half-wave signal through the inverting proportional amplifier circuit, and is transmitted to the output end by the normally closed end 1 of the analog switch S1, and the negative half-wave signal is transmitted to the output end by the normally open end 2 of the analog switch S1. In one sine wave cycle, the output end of the analog switch S1 obtains two consecutive negative half-waves; when the phase difference between the input signal of the full-wave phase-sensitive demodulation circuit and the reference signal output by the demodulation reference circuit is 180°, the positive half-wave signal is transmitted to the output end by the normally open end 2 of the analog switch S1, and the negative half-wave signal is converted into a positive half-wave signal through the inverting proportional amplifier circuit and is transmitted to the output end by the normally closed end 1 of the analog switch S1. In this way, in one sine wave cycle, the output end of the analog switch obtains two consecutive positive half-waves. Capacitors C4, C5, and C22 play a filtering role.

[0056] The demodulation reference circuit is composed of an RC circuit, a comparator, and a rectifier circuit. The wiring port J1 is connected to the excitation signal, one end of the resistor R1* is connected to the wiring terminal J1, and the other end is connected to the inverting input terminal of the operational amplifier U3C. One end of the potentiometer RP1 is connected to the wiring terminal J1, and the other end and the adjustment end are both connected to the inverting input terminal of the operational amplifier U3C; the two ends of the capacitor C1 are respectively connected to the in-phase input terminal and the inverting input terminal of the operational amplifier U3C; the in-phase input terminal of the operational amplifier U3C is connected to the ground wire GND. The anode of the diode D2 is connected to the output terminal of the operational amplifier U3C, and the cathode is connected to one end of the resistor R3. The other end of the resistor R3 is respectively connected to the cathode of the diode D1 and one end of the resistor R4; the anode of the diode D1 and the other end of the resistor R4 are connected to the ground wire GND. Resistor R1*, potentiometer RP1, and capacitor C1 form an RC circuit to adjust the phase. By adjusting the size of resistor R1* and potentiometer RP1, the phase of the demodulated reference signal relative to the gyro signal can be controlled. Diode D2 has a rectifying effect, diode D1 has a signal shaping effect, and resistors R3 and R4 have a voltage dividing effect.

[0057] The DC amplifier filter circuit is used to convert the DC signal outputted by the phase-sensitive demodulation circuit after demodulation into a DC output signal. The DC amplifier filter includes a resistor R2, a resistor R9, a resistor R10, a resistor R12, a resistor R13, a capacitor C25, a capacitor C19 and an operational amplifier U3D. Resistors R9 and R10 are connected in series, and the input end of resistor R9 is connected to the analog switch output end 1 in the phase-sensitive demodulation circuit; resistors R2, R12, and R13 are connected in series in sequence, and the inverting input end of the operational amplifier U3D is connected between resistors R12 and R13; one end of capacitor C25 is connected between resistors R9 and R10, and the other end is connected to the input end of resistor R2; one end of capacitor C19 is connected between resistor R10 and the in-phase input end of the operational amplifier U3D, and the other end is connected to the ground wire GND; the in-phase input end of the operational amplifier U3D is connected to the output end of resistor R10, and the inverting input end of the operational amplifier U3D is connected between resistor R12 and resistor R13; the output port of the operational amplifier U3D is connected to the wiring port J3, and the wiring port J3 is connected to the signal input end of the test equipment. Resistors R2, R12, and R13 play a role in adjusting the gain, resistors R9, R10, capacitors C19, and C25 play a role in filtering, and the operational amplifier U3D plays an amplifying role. The DC amplification and filtering circuit adopts a common-phase amplification low-pass filter to ensure that the polarity of the self-test output signal is consistent with the polarity of the liquid floating gyro output signal, saving the number of components and having the functions of amplification and interference isolation.

[0058] The AC output circuit is used to convert the single-ended signal output by the differential amplifier circuit with GND as the reference into a measurable AC output signal. The AC output circuit includes a voltage follower U3B, the in-phase input terminal of the voltage follower U3B is connected to the output terminal of the operational amplifier N2 in the differential amplifier circuit, and the output terminal of the voltage follower U3B is connected to the inverting input terminal of the voltage follower U3B, so as to realize the conversion of the output signal of the differential amplifier circuit into a measurable AC output signal while having the function of isolating interference. The output terminal of the AC output circuit is connected to the wiring port J6, and the wiring port J6 is connected to the signal input terminal of the external test equipment. The voltage follower U3B plays the role of isolating interference and signal transmission.

[0059] Reference Figure 3 The anti-reverse connection filter circuit is used to power the differential amplifier circuit, phase-sensitive demodulation circuit, DC amplifier filter circuit, AC output circuit and secondary power supply circuit, and can prevent the positive and negative power supplies from being reversed, avoiding damage to the circuit when the positive and negative poles of the power supply are reversed, and can suppress the positive and negative power supply ripples, making the positive and negative power supplies purer.

[0060] The anti-reverse connection filter circuit includes a capacitor C23, a capacitor C24, a diode D3 and a diode D4. The capacitor C23 and the capacitor C24 are connected in series, and the positive electrode of the capacitor C24 is connected to the negative electrode of the capacitor C23; the connection line between the capacitor C23 and the capacitor C24 outputs two paths, one path is grounded, and the other path is connected to the set wiring port J7, and the wiring port J7 is used to connect the power ground of the external power supply as a reference for the single-ended signal. The positive electrode of the diode D3 is connected to the set wiring port J5, and the wiring port J5 is used to connect the positive electrode of the external power supply. After the negative electrode of the diode D3 is connected to the positive electrode of the capacitor C23, a positive voltage VP is output, and the positive voltage VP is connected to the input end of the voltage regulator U2 in the secondary power supply circuit, the positive power supply port of the operational amplifier N2 in the differential amplifier circuit, the positive power supply port of the operational amplifier U3A in the phase-sensitive demodulation circuit, and the positive power supply port of the DC amplifier filter circuit and the positive power supply port of the AC output circuit. The cathode of diode D4 is connected to the wiring port J8, which is used to connect to the cathode of external power supply to receive negative power supply. The anode of diode D4 is connected to the cathode of capacitor C24 to output negative voltage VN, which is connected to the negative power port of operational amplifier N2 in differential amplifier circuit, the negative power port of operational amplifier U3A in phase-sensitive demodulation circuit, analog signal negative power input terminal VS- of analog switch, negative power port of DC amplifier filter circuit and negative power port of AC output circuit. Diode D3 and diode D4 play a unidirectional isolation role, and capacitor C23 and capacitor C24 play a filtering role.

[0061] Reference Figure 4, the secondary power supply circuit is used to provide a working voltage to the analog switch S1 in the switch circuit alone. The secondary power supply circuit includes a capacitor C3, a capacitor C2 and a voltage regulator U2. One end of the capacitor C2 and the capacitor C3 are respectively connected to the ground line GND, and the other end is respectively connected to the input terminal Vi and the output terminal Vo of the voltage regulator U2, the input terminal Vi is also connected to the analog signal positive power input terminal VS+ of the analog switch S1, and the output terminal Vo is also connected to the logic level positive power input terminal 4 of the analog switch S1. The ground end of the voltage regulator U2 is connected to the ground line GND. The voltage regulator U2 plays a voltage conversion role.

[0062] Reference Figure 5 The liquid floating gyro signal conversion circuit of the present invention is fixed on the printed circuit board, and through the external electrical connector XP1, a liquid floating gyro signal conversion circuit board is formed. The electrical connector XP1 has multiple interfaces, one end of the interface is respectively connected to the wiring ports J1-J8 in the conversion circuit, and the other end of the interface is respectively connected to the external power supply, the output end of the liquid floating gyro, and the external test equipment. Specifically, each component in the circuit is fixed on the printed circuit board by welding.

[0063] The process of conditioning and converting the liquid floating gyro signal using the conversion circuit of the present invention is as follows:

[0064] Step 1, the liquid-floating gyro outputs a gyro differential signal and transmits it to a differential amplifier circuit; the differential amplifier circuit performs amplification conversion based on the received gyro differential signal, and outputs a single-ended signal with GND as a reference as an input signal for a phase-sensitive demodulation circuit and an AC output circuit;

[0065] Step 2: The phase-sensitive demodulation circuit performs phase demodulation on the single-ended signal with GND as reference that is amplified and converted in step 1, so that the positive and negative half-wave signals in the single-ended signal are completely output and converted into a DC signal.

[0066] The principle of phase-sensitive demodulation circuit for phase demodulation of the output single-ended signal is as follows: full-wave phase-sensitive demodulation is to convert the input single-ended signal into a DC signal proportional to it. When the phase difference between the input signal of the full-wave phase-sensitive demodulation circuit and the demodulation reference signal is 0°, the positive half-wave signal is converted into a negative half-wave signal through the inverting proportional amplifier circuit and transmitted to its output end by the normally closed terminal 1 of the analog switch S1, and the negative half-wave signal is transmitted to its output end by the normally open terminal 2 of the analog switch S1; in one sine wave cycle, the output end of the analog switch S1 obtains two consecutive negative half-waves. When the phase difference between the input signal of the full-wave phase-sensitive demodulation circuit and the demodulated reference signal is 180°, the positive half-wave signal is transmitted to the output end by the normally open terminal 2 of the analog switch S1, and the negative half-wave signal is converted into a positive half-wave signal through the inverting amplifier circuit and transmitted to its output end by the normally closed terminal 1 of the analog switch S1, so that in one sine wave cycle, the output end of the analog switch S1 obtains two consecutive positive half-waves. When the phase difference between the input signal of the full-wave phase-sensitive demodulation circuit and the demodulation reference signal is neither 0° nor 180°, within a sine wave cycle, the signal obtained at the output end of the analog switch S1 is not the two standard continuous positive half-wave signals or negative half-waves mentioned above, and the waveform of the output signal will be distorted. In view of this phenomenon, an RC circuit (composed of resistor R1*, potentiometer RP1, and capacitor C1) is added to the demodulation reference circuit. By adjusting the RC circuit, the phase difference between the reference signal and the input signal of the full-wave phase-sensitive demodulation circuit is changed to ensure that the demodulated output signal is not distorted. The RC circuit plays a role in adjusting the phase. The low-pass makes the phase of the output signal lag behind the phase of the input signal, and the high-pass makes the phase of the output signal lead the phase of the input signal. In this embodiment, the low-pass connection method is adopted, and the positions of the resistor and the capacitor are swapped, that is, the high-pass connection method. In specific operation, the time constant of the RC circuit can be adjusted while checking whether the output waveform is distorted until the demodulated output waveform is normal.

[0067] At the same time, the AC output circuit performs voltage following processing on the single-ended signal with GND as reference that is amplified and converted and output in step 1, and obtains an AC output signal for measurement by an external test device.

[0068] Step 3, the DC amplifying and filtering circuit amplifies and filters the DC signal output after phase demodulation in step 2 to obtain a DC output signal with low discreteness of the scale factor as a measurement signal for the external test equipment.

[0069] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should be included in the protection scope of the present invention.

Claims

1. A liquid floating gyro signal conversion circuit, characterized in that: It includes a differential amplifier circuit, a phase-sensitive demodulation circuit, a DC amplifier filter circuit, an AC output circuit, an anti-reverse connection filter circuit and a secondary power supply circuit; The differential amplifier circuit is used to convert the gyro differential signal output by the liquid floating gyro into a single-ended signal with GND as a reference; The phase-sensitive demodulation circuit is used to perform phase demodulation on the converted single-ended signal with GND as reference, so that the positive and negative half-wave signals in the single-ended signal are completely demodulated, and is used to convert the phase-demodulated signal into a DC signal; The DC amplification and filtering circuit is used to amplify and isolate the DC signal output by the phase-sensitive demodulation circuit, and convert it into a DC output signal matching the polarity of the liquid-floating gyroscope; the DC output signal is used for measurement by external test equipment; The AC output circuit is used to perform voltage following processing on the converted single-ended signal with GND as reference to obtain an AC output signal for measurement by an external test device; The anti-reverse connection filter circuit is used to condition the power supply signal of the external power supply and supply it to the differential amplifier circuit, phase-sensitive demodulation circuit, DC amplifier filter circuit, AC output circuit and secondary power supply circuit, and can prevent the circuit from being damaged due to reverse connection of the positive and negative poles of the power supply.

2. The liquid floating gyro signal conversion circuit according to claim 1, characterized in that: The differential amplifier circuit includes a resistor R6*, a capacitor C6, a capacitor C21 and an operational amplifier N2, wherein the in-phase input terminal and the inverting input terminal of the operational amplifier N2 are respectively connected to the wiring port J2 and the wiring port J4; one end of the capacitor C6 is connected to the positive power supply port of the operational amplifier N2, and the other end is grounded; one end of the capacitor C21 is connected to the negative power supply port of the operational amplifier N2, and the other end is grounded; both ends of the resistor R6* are connected to two gain adjustment ports on the same side of the operational amplifier N2; the reference end of the operational amplifier N2 is grounded; the resistor R6* is used to adjust the circuit gain, and the operational amplifier N2 realizes the conversion of the gyro differential signal output by the liquid-floating gyro body into a single-ended signal with GND as a reference.

3. The liquid floating gyro signal conversion circuit according to claim 2, characterized in that: The phase-sensitive demodulation circuit includes a full-wave phase-sensitive demodulation circuit and a demodulation reference circuit, and the full-wave phase-sensitive demodulation circuit includes an inverting proportional amplifier circuit and a switch circuit; The demodulation reference circuit is used to convert the excitation signal generated by the external excitation circuit into a reference signal; The inverting proportional amplifier circuit is used to reversely amplify the single-ended signal output by the differential amplifier circuit with GND as the reference; The switch circuit is used to switch on or off under the control of a reference signal, and convert the positive half-wave or negative half-wave of the amplified single-ended signal with GND as reference into a positive or negative direct current signal.

4. The liquid floating gyro signal conversion circuit according to claim 3, characterized in that: The demodulation reference circuit comprises a resistor R1*, a resistor R3, a resistor R4, a potentiometer RP1, a capacitor C1, an operational amplifier U3C, a diode D1 and a diode D2; after the resistor R1* and the potentiometer RP1 are connected in parallel, one end is connected to a wiring port J1, and the other end is connected to the inverting input end of the operational amplifier U3C and one end of the capacitor C1, and the other end of the capacitor C1 is connected to the non-inverting input end of the operational amplifier U3C and the ground wire GND; the output end of the operational amplifier U3Cd is connected in series with the diode D2 and the resistor R3 in sequence; after the diode D1 and the resistor R4 are connected in parallel, the positive electrode of the diode D1 is grounded, the negative electrode is connected between the resistor R3 and the resistor R4, and is connected to the input end of the switch circuit; the wiring terminal J1 is connected to an external excitation circuit, and the phase of the demodulated reference signal relative to the gyro differential signal can be controlled by adjusting the resistance values ​​of the resistor R1* and the potentiometer RP1; The inverting proportional amplifier circuit includes a resistor R7, a resistor R5, an operational amplifier U3A, a capacitor C18 and a capacitor C20; the input end of the resistor R7 is connected to the output end of the differential amplifier circuit, and the output end is connected to the inverting input end of the operational amplifier U3A; the two ends of the resistor R5 are respectively connected to the output end and the inverting input end of the operational amplifier U3A; one end of the capacitor C18 and the capacitor C20 are respectively connected to the ground wire GND, and the other ends are respectively connected to the positive power supply end and the negative power supply end of the operational amplifier U3A; the resistor R7 and the resistor R5 are used to adjust the circuit gain, and the operational amplifier U3A is used to reversely amplify the single-ended signal output by the differential amplifier circuit with GND as the reference; The switch circuit comprises an analog switch S1, a capacitor C4, a capacitor C5 and a capacitor C22; the analog signal positive power input terminal VS+ and the analog signal negative power input terminal VS- of the analog switch S1 are connected to the ground line GND via the capacitor C4 and the capacitor C22 respectively; the normally closed terminal, the normally open terminal and the logic level input terminal are connected to the output terminal of the reverse proportional circuit, the output terminal of the differential amplifier circuit and the cathode of the diode D1 in the demodulation reference circuit respectively; the ground terminal of the analog switch S1 is connected to the ground wire, the logic level positive power input terminal is connected to the ground via the capacitor C5, and the output terminal of the analog switch S1 is connected to the input terminal of the DC amplifier filter circuit; The analog signal positive power input terminal VS+ of the analog switch S1 is also connected to the input terminal of the secondary power supply circuit, the analog signal negative power input terminal VS- is also connected to the negative power output terminal of the anti-reverse connection filter circuit, and the logic level positive power input terminal is also connected to the output terminal of the secondary power supply circuit.

5. The liquid floating gyro signal conversion circuit according to claim 4, characterized in that: The secondary power supply circuit is used to supply power to the analog switch S1 in the switch circuit separately; the secondary power supply circuit includes capacitor C3, capacitor C2 and voltage regulator U2; one end of capacitor C2 and capacitor C3 are respectively connected to the ground wire GND, and the other end is respectively connected to the input terminal Vi and output terminal Vo of the voltage regulator U2, the input terminal Vi is also connected to the analog signal positive power input terminal VS+ of the analog switch S1, and the output terminal Vo is also connected to the logic level positive power input terminal of the analog switch S1; the ground end of the voltage regulator U2 is connected to the ground wire GND.

6. The liquid floating gyro signal conversion circuit according to claim 5, characterized in that: The DC amplification and filtering circuit comprises a resistor R2, a resistor R9, a resistor R10, a resistor R12, a resistor R13, a capacitor C25, a capacitor C19 and an operational amplifier U3D; one end of the resistor R9 is connected to the output end of the switch circuit, and the other end is connected in series with the resistor R10 and then connected to the in-phase input end of the operational amplifier U3D; the resistors R2, R12 and R13 are connected in series in sequence and then connected to the ground line GND, and the inverting input end of the operational amplifier U3D is connected between the resistor R12 and the resistor R13; one end of the capacitor C25 is connected between the resistor R9 and the resistor R10, and the other end is connected to the input end of the resistor R2; one end of the capacitor C19 is connected between the resistor R10 and the operational amplifier R13 and is used to adjust the circuit gain; The resistor R9, the resistor R10, the capacitor C19, the capacitor C25 and the operational amplifier U3D form a common-phase amplification low-pass filter, so that the polarity of the DC signal mediated and output by the phase-sensitive demodulation circuit is consistent with the polarity of the liquid floating gyroscope.

7. The liquid floating gyro signal conversion circuit according to claim 6, characterized in that: The anti-reverse connection filter circuit includes a capacitor C23, a capacitor C24, a diode D3 and a diode D4; the capacitor C23 and the capacitor C24 are connected in series, and the positive electrode of the capacitor C24 is connected to the negative electrode of the capacitor C23; the connection line between the capacitor C23 and the capacitor C24 outputs two paths, one path is grounded, and the other path is connected to a set wiring port J7, and the wiring port J7 is used to connect the power ground of the external power supply; The cathode of the diode D3 is connected to the anode of the capacitor C23 and then connected to the input terminal Vi of the voltage regulator U2 in the secondary power supply circuit, the positive power supply port of the operational amplifier N2 in the differential amplifier circuit, the positive power supply port of the operational amplifier U3A in the phase-sensitive demodulation circuit, the positive power supply port of the DC amplifier filter circuit, and the positive power supply port of the AC output circuit; the anode of the diode D3 is connected to the wiring port J5, which is used to connect to the positive electrode of the external power supply; The positive electrode of the diode D4 is connected to the negative electrode of the capacitor C24 and then connected to the negative power supply port of the operational amplifier N2 in the differential amplifier circuit, the negative power supply port of the operational amplifier U3A in the phase-sensitive demodulation circuit, the analog signal negative power supply input terminal VS- of the analog switch S1, the negative power supply port of the DC amplifier and filter circuit, and the negative power supply port of the AC output circuit; the negative electrode of the diode D4 is connected to the set wiring port J6, and the wiring port J6 is used to connect the negative electrode of the external power supply.

8. The liquid floating gyro signal conversion circuit according to claim 7, characterized in that: The AC output circuit includes a voltage follower U3B; the in-phase input terminal of the voltage follower U3B is connected to the output terminal of the differential amplifier circuit, and the output terminal of the voltage follower U3B is connected to the inverting input terminal of the voltage follower U3B, so as to convert the output signal of the differential amplifier circuit into an AC output signal; the output terminal of the voltage follower U3B is also connected to a set connection port J6, and the connection port J6 is connected to the signal input terminal of an external test device.

9. A method for conditioning and converting a liquid-floating gyroscope output signal based on a liquid-floating gyroscope signal conversion circuit according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step 1: Amplify and convert the gyro differential signal output by the liquid floating gyro, and output a single-ended signal with GND as the reference; Step 2: performing phase demodulation on the single-ended signal with GND as reference, so that the positive and negative half-wave signals in the single-ended signal are completely output and converted into a DC signal; At the same time, voltage following processing is performed on the single-ended signal with GND as reference to obtain an AC output signal for measurement by an external test device; Step 3: Amplify and filter the DC signal output by phase demodulation in step 2 to obtain a DC output signal for measurement by external test equipment.

10. A liquid floating gyro signal conversion device, characterized in that: It comprises an electrical connector XP1 and a printed circuit board; the liquid floating gyro signal conversion circuit as described in any one of claims 1 to 8 is fixedly mounted on the printed circuit board; The electrical connector XP1 has multiple power interfaces and signal interfaces; one end of the power interface and the signal interface are respectively connected to the corresponding wiring ports in the liquid floating gyroscope signal conversion circuit; the other end of the power interface and the signal interface are used to connect to an external power supply, a liquid floating gyroscope output terminal and a test device.

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