CN107907914B

CN107907914B - Measurement circuit of true geography three-component magnetometer

Info

Publication number: CN107907914B
Application number: CN201711434898.3A
Authority: CN
Inventors: 章雪挺; 许欢
Original assignee: Hangzhou Dianzi University
Current assignee: Hangzhou Dianzi University
Priority date: 2017-12-26
Filing date: 2017-12-26
Publication date: 2023-10-20
Anticipated expiration: 2037-12-26
Also published as: CN107907914A

Abstract

The invention relates to a measurement circuit of a true geographic three-component magnetometer. The invention comprises a power supply circuit, a sensor signal acquisition circuit, a main control circuit, a serial port gesture measurement circuit, an RTC clock circuit, a data transmission circuit, an SD card storage circuit, a file management circuit and an external interface circuit. The sensor signal acquisition circuit comprises a digital-to-analog conversion circuit, an X-axis analog signal addition circuit, a Y-axis analog signal addition circuit and a Z-axis analog signal addition circuit. The invention adopts the fluxgate sensor of Bartington company in UK, combines the characteristics of high sensitivity, high resolution, low power consumption and the like of the fluxgate sensor, and realizes the measurement of three components of geomagnetic field in real geographic environment based on the design of a measuring circuit by adding a serial port gesture measuring module.

Description

Measurement circuit of true geography three-component magnetometer

Technical Field

The invention belongs to the technical field of magnetic field measurement, and particularly relates to a measurement circuit of a true geographic three-component magnetometer.

Background

The magnetic field environment measurement has wide application in many fields such as ship demagnetization, control instruments, aerospace, geological exploration, industrial automation, nondestructive detection, magnetic navigation and the like. In order to meet the requirements of exploration, prospecting and other businesses and promote the development of geology and marine exploration, people put forward higher requirements on magnetic detection. The fluxgate three-component instrument is an instrument for realizing measurement by utilizing a three-component fluxgate sensor. In the prior art, only three components of a magnetic field under an instrument coordinate system are measured, and in actual application, the magnetic field components under a real geographic environment often need to be referenced, so that the problem of coordinate axis conversion is involved when the magnetometer measures the geomagnetic field. Furthermore, the magnetic field is a continuously variable quantity, so that the change trend of the magnetic field needs to be known in actual research and detection, and the observed quantity needs to be stored and backed up in real time in the measuring process. Therefore, the fluxgate three-component instrument which has high precision and good real-time storage and is used for three components of a magnetic field in a real geographic environment is developed and plays an important role in the fields of geological exploration and the like.

Disclosure of Invention

The invention aims to provide a measuring circuit of a true geographic three-component magnetometer.

The invention comprises a power supply circuit, a sensor signal acquisition circuit, a main control circuit, a serial port gesture measurement circuit, an RTC clock circuit, a data transmission circuit, an SD card storage circuit, a file management circuit and an external interface circuit. The signal output end of the sensor signal acquisition circuit is connected with the signal input end of the external interface circuit in a unidirectional signal manner, and the signal end of the sensor signal acquisition circuit is connected with the first signal end of the main control circuit in a bidirectional signal manner; the signal output end of the external interface circuit is connected with the signal input end of the file management circuit in a unidirectional signal manner, the signal input end of the external interface circuit is connected with the first signal output end of the main control circuit in a unidirectional signal manner, and the signal end of the external interface circuit is connected with the signal end of the data transmission circuit in a bidirectional signal manner; the second signal output end of the main control circuit is connected with the signal input end of the SD card storage circuit in a unidirectional signal mode, the signal input end of the main control circuit is connected with the signal output end of the RTC clock circuit in a unidirectional signal mode, and the second signal end of the main control circuit is connected with the signal end of the serial port gesture measuring circuit in a bidirectional signal mode.

The power supply circuit comprises a +15V voltage stabilizing circuit, -15V voltage stabilizing circuit, +5V voltage stabilizing circuit, +4.5V reference voltage circuit, +3.3V voltage stabilizing circuit, +3.3V switching power supply circuit and +2.5V reference voltage circuit; the +15V voltage stabilizing circuit and the-15V voltage stabilizing circuit supply power for the fluxgate sensor, the +5V voltage stabilizing circuit provides high-stability voltage for the data transmission circuit and obtains +4.5V and +2.5V with smaller ripple waves with the linear circuit, wherein the +4.5V reference voltage circuit is used for providing high-precision reference voltage for the triaxial analog signal adding circuit in the sensor signal acquisition circuit, and the +2.5V reference voltage circuit is used for providing stable reference voltage for the digital-analog conversion circuit in the sensor signal acquisition circuit; the +3.3V voltage stabilizing circuit and the +3.3V switching circuit are used for providing stable voltage for the main control circuit, the serial port gesture measuring circuit, the RTC clock circuit, the SD card storage circuit and the file management circuit;

the +15V voltage stabilizing circuit and the-15V voltage stabilizing circuit comprise a switching power supply chip U1 and capacitors C1-C3; one end of the capacitor C1 and the 2 pin of the switching power supply chip U1 are connected and then grounded, and the other end of the capacitor C1 and the 1 pin of the switching power supply chip U1 are connected and then connected with a +24V power supply; one end of the capacitor C2 is connected with the 3 pin of the switching power supply chip U1 and is used as a +15V power supply output end; the other end of the capacitor C2, one end of the capacitor C3 and the pin 4 of the switching power supply chip U1 are connected and then grounded; the other end of the capacitor C3 is connected with the 5 pin of the switching power supply chip U1 and is used as a power supply output end of-15V; the switching power supply chip U1 adopts a DC-DC switching power supply chip of a Texas instrument;

The +5V voltage stabilizing circuit comprises a switching power supply chip U2, polar capacitors Cp1-Cp4, resistors R1-R4, an inductor L1, capacitors C4-C6 and a light emitting diode D1; the 7 pin of the switching power supply chip U2, one end of the resistor R1, the positive electrode of the polar capacitor Cp2 and the positive electrode of the polar capacitor Cp3 are connected with a +24V power supply; the negative electrode of the polar capacitor Cp1, the negative electrode of the polar capacitor Cp2 and the negative electrode of the polar capacitor Cp3 are respectively grounded; the other end of the resistor R1 and the 5 pin of the switching power supply chip U2 are connected with one end of the resistor R2; the other end of the resistor R2 and the 6 pin of the switching power supply chip U2 are connected and then grounded; one end of the capacitor C4 is connected with the 1 pin of the switching power supply chip U2, the other end of the capacitor C4, one end of the inductor L1 and the cathode of the diode D1 are connected with the 8 pin of the switching power supply chip U2; the anode of the diode D1 is grounded; the other end of the inductor L1, one end of the resistor R3, the positive electrode of the polar capacitor Cp4, one end of the capacitor C5 and one end of the capacitor C6 are connected to serve as +5V power supply output ends; the other end of the resistor R3 and one end of the resistor R4 are connected with the 4 pin of the switching power supply chip U2; the negative electrode of the polar capacitor Cp4 and the other end of the resistor R4 are connected and then grounded, and the other end of the capacitor C5 and the other end of the capacitor C6 are respectively grounded; the remaining pins of the switching power supply chip U2 are suspended; the switching power supply chip U2 adopts a switching power supply chip TPS5420 of Texas instruments;

The +4.5V reference voltage circuit comprises a reference voltage chip U6, an operational amplifier chip U7, an inductor L2, a polar capacitor Cp8, capacitors C19-C24 and resistors R20-R21; one end of the inductor L2, the positive electrode of the polar capacitor Cp8 and one end of the capacitor C19 are connected with the 2 pin of the reference voltage chip U7; the other end of the inductor L2 is connected with the +5V voltage stabilizing output end of the +5V voltage stabilizing circuit; the negative electrode of the polar capacitor Cp8, the other end of the capacitor C19 and the pin 4 of the reference voltage chip U6 are connected and grounded; one end of the resistor R20 is connected with the 6 pin of the reference voltage chip U6, the other end of the resistor R20 and one end of the capacitor C21 are connected with the 3 pin of the operational amplifier chip U7, and the other end of the capacitor C21 is grounded; one end of the capacitor C20 is connected with the 5 pin of the reference voltage chip U6, and the other end of the capacitor C20 is grounded; the 4 pin of the operational amplifier chip U7 is grounded; one end of the capacitor C22 and the 7 pin of the operational amplifier chip U7 are connected and then connected with the +5V voltage stabilizing output end of the +5V voltage stabilizing circuit, and the other end of the capacitor C22 is grounded; one end of the resistor R21 is connected with the 6 pin of the operational amplifier chip U7, the other end of the resistor R21, one end of the capacitor C23 and one end of the capacitor C24 are connected, and the other end of the capacitor C23 and the other end of the capacitor C24 are respectively grounded as +4.5V reference voltage output ends; the rest pins of the reference voltage chip U6 and the operational amplifier chip U7 are suspended; the reference voltage chip U6 adopts a reference voltage chip REF5045 of a Texas instrument; the operational amplifier chip U7 adopts a precision operational amplifier chip OPA376 of Texas instruments;

The +3.3V voltage stabilizing circuit comprises a voltage stabilizing power supply chip U10, a polar capacitor Cp10 and capacitors C34-C36; the positive electrode of the polar capacitor Cp10, one end of the capacitor C34 and the 3 pin of the regulated power supply chip U10 are connected with the power supply VDD, and the negative electrode of the polar capacitor Cp10 and the other end of the capacitor C34 are respectively grounded; the 1 pin of the regulated power supply chip U10 is grounded; one end of a capacitor C35 and one end of a capacitor C36 are connected with the 2 pin of the regulated power supply chip U10 and serve as a +3.3V voltage output end of a +3.3V voltage stabilizing circuit, and the other end of the capacitor C35 and the other end of the capacitor C36 are grounded respectively; the regulated power supply chip U10 adopts a regulated power supply chip LM1117;

the +3.3V switching power supply circuit comprises a switching power supply chip U11, capacitors C37-C40, a resistor R23 and a light-emitting diode D3; one end of the capacitor C38, one end of the capacitor C37 and 3 pins and 4 pins of the switching power supply chip U11 are connected and then connected with a +5V voltage stabilizing output end of the +5V voltage stabilizing circuit, the other end of the capacitor C37 and 2 pins of the switching power supply chip U11 are connected and then grounded, and the other end of the capacitor C38 and 1 pin of the switching power supply chip U11 are connected and then grounded; one end of a capacitor C39, one end of a capacitor C40, one end of a resistor R23, a pin 5 and a pin 6 of a switching power supply chip U11 are connected and then connected with a voltage stabilizing output end of +3.3V of a +3.3V voltage stabilizing circuit, the other end of the capacitor C39 and the other end of the capacitor C40 are respectively grounded, the other end of the resistor R23 is connected with an anode of a light emitting diode D3, and a cathode of the light emitting diode D3 is grounded; the remaining pins of the switching power supply chip U11 are suspended; the switching power supply chip U11 adopts a switching power supply chip TPS7350 of Texas instruments;

The +2.5V reference voltage circuit comprises a reference voltage chip U15, an operational amplifier chip U16, an inductor L3, a polar capacitor Cp13, capacitors C56-C61 and resistors R33-R34; one end of the inductor L3, the positive electrode of the polar capacitor Cp13 and one end of the capacitor C56 are connected with the 2 pin of the reference voltage chip U15, the other end of the inductor L3 is connected with the +5V voltage stabilizing output end of the +5V voltage stabilizing circuit, and the negative electrode of the polar capacitor Cp13, the other end of the capacitor C56 and the 4 pin of the reference voltage chip U15 are grounded after being connected; one end of the resistor R33 is connected with the 6 pin of the reference voltage chip U15, the other end of the resistor R33 and one end of the capacitor C58 are connected with the 3 pin of the operational amplifier chip U16, and the other end of the capacitor C58 is grounded; one end of the capacitor C57 is connected with the 5 pin of the reference voltage chip U15, and the other end of the capacitor C57 is grounded; the 4 pin of the operational amplifier chip U16 is grounded; one end of the capacitor C59 and the 7 pin of the operational amplifier chip U16 are connected and then connected with the +5V voltage stabilizing output end of the +5V voltage stabilizing circuit, and the other end of the capacitor C59 is grounded; one end of the resistor R34 is connected with the 6 pin of the operational amplifier chip U16, the other end of the resistor R34, one end of the capacitor C60 and one end of the capacitor C61 are connected, and the other end of the capacitor C60 and the other end of the capacitor C61 are respectively grounded as +2.5V reference voltage output ends; the other pins of the reference voltage chip U15 and the operational amplifier chip U16 are suspended; reference voltage chip U15 uses reference voltage chip REF5045 of Texas instruments; the op-amp chip U16 employs a texas instrument precision op-amp chip OPA376.

The sensor signal acquisition circuit comprises an X-axis analog signal addition circuit, a Y-axis analog signal addition circuit and a Z-axis analog signal addition circuit; three axial analog signal addition circuits with similar structures are used for converting the voltage value of the sensor output signal into the voltage value acceptable by the analog-to-digital conversion circuit;

the X-axis analog signal adding circuit comprises an operational amplifier chip U3, resistors R5-R9, capacitors C7-C10 and a polar capacitor Cp5; one end of a resistor R5, one end of a resistor R6 and one end of a resistor R7 are connected with a pin 3 of the operational amplifier chip U3, the other end of the resistor R5 is connected with a +4.5V reference voltage output end of a +4.5V reference voltage circuit, the other end of the resistor R6 is connected with one end of a capacitor C7 and used as an X-axis magnetic field signal input end, and the other end of the capacitor C7 is connected with the other end of the resistor R7 and grounded; the 4 pin of the operational amplifier chip U3 is grounded; the 1 pin and the 2 pin of the operational amplifier chip U3 are connected and then connected with a power supply V_Back; one end of the capacitor C8, the positive electrode of the polar capacitor Cp5 and the 8 pin of the operational amplifier chip U3 are connected with the +5V voltage stabilizing output end of the +5V voltage stabilizing circuit, and the other end of the capacitor C8 is connected with the negative electrode of the polar capacitor Cp5 and grounded; one end of the pin 6, pin 7 and capacitor C10 of the operational amplifier chip U3 is connected with the output end of the X-axis analog signal adding circuit and connected with the pin 6 of the universal socket P2; one end of a capacitor C9 and one end of a resistor R8 are connected with the pin 5 of the operational amplifier chip U3, the other end of the capacitor C9 is grounded, the other end of the resistor R8 and one end of the resistor R9 are connected with the other end of the capacitor C10, and the other end of the resistor R9 is connected with a power supply V_Back; the operational amplifier chip U3 adopts a precision operational amplifier chip OPA2376 of Texas instruments;

The Y-axis analog signal adding circuit comprises an operational amplifier chip U4, resistors R10-R14, capacitors C11-C14 and a polar capacitor Cp6; one end of a resistor R10, one end of a resistor R11 and one end of a resistor R12 are connected with a pin 3 of an operational amplifier chip U4, the other end of the resistor R10 is connected with a +4.5V reference voltage output end of a +4.5V reference voltage circuit, the other end of the resistor R11 is connected with one end of a capacitor C11 and is used as an input end of a Y-cycle magnetic field signal, and the other end of the capacitor C11 is connected with the other end of the resistor R12 and grounded; the 4 pin of the operational amplifier chip U4 is grounded; the 1 pin and the 2 pin of the operational amplifier chip U4 are connected and then connected with a power supply V_Back; one end of the capacitor C12, the positive electrode of the polar capacitor Cp6 and the +5V voltage stabilizing output end of the +5V voltage stabilizing circuit are connected with the 8 pin of the operational amplifier chip U4, and the other end of the capacitor C12 is connected with the negative electrode of the polar capacitor Cp6 and grounded; one end of a pin 6 and a pin 7 of the operational amplifier chip U4 and one end of a capacitor C14 are connected and serve as an output end of the Y-axis analog signal addition circuit, and the pin 4 of the power strip P2 is connected; one end of the capacitor C13 and one end of the resistor R13 are connected with the pin 5 of the operational amplifier chip U4, the other end of the capacitor C13 is grounded, the other end of the resistor R13 and one end of the resistor R14 are connected with the other end of the capacitor C14, and the other end of the resistor R14 is connected with the power supply V_Back; the operational amplifier chip U4 adopts a precision operational amplifier chip OPA2376 of Texas instruments;

The Z-axis analog signal adding circuit comprises an operational amplifier chip U5, resistors R15-R19, capacitors C15-C18 and a polar capacitor Cp7; one end of the resistor R15, one end of the resistor R16 and one end of the resistor R17 are connected with the 3 pin of the operational amplifier chip U5; the other end of the resistor R15 is connected with the +4.5V reference voltage output end of the +4.5V reference voltage circuit; the other end of the resistor R16 is connected with one end of the capacitor C15 and is used as an input end of the Z-axis magnetic field signal; the other end of the capacitor C15 is connected with the other end of the resistor R17 and grounded; the 4 pin of the operational amplifier chip U5 is grounded; the 1 pin and the 2 pin of the operational amplifier chip U5 are connected and then connected with a power supply V_Back; one end of the capacitor C16, the positive electrode of the polar capacitor Cp7 and the +5V voltage stabilizing output end of the +5V voltage stabilizing circuit are connected with the 8 pin of the operational amplifier chip U5, and the other end of the capacitor C16 is connected with the negative electrode of the polar capacitor Cp7 and grounded; one end of a pin 6 and a pin 7 of the operational amplifier chip U5 and one end of a capacitor C18 are connected and serve as an output end of the Z-axis analog signal addition circuit, and a pin 2 of the power strip P2 is connected; one end of a capacitor C17 and one end of a resistor R18 are connected with the pin 5 of the operational amplifier chip U5, the other end of the capacitor C17 is grounded, the other end of the resistor R18 and one end of a resistor R19 are connected with the other end of the capacitor C18, and the other end of the resistor R19 is connected with a power supply V_Back; the operational amplifier chip U5 adopts a precision operational amplifier chip OPA2376 of Texas instruments;

The digital-to-analog conversion circuit comprises an analog-to-digital conversion chip U14, polar capacitors Cp11-Cp12, resistors R29-R32, capacitors C48-C55 and a crystal oscillator X3; one end of the capacitor C48, the positive electrode of the polar capacitor Cp11 and the 1 pin of the analog-digital conversion chip U14 are connected with the +5V voltage stabilizing output end of the +5V voltage stabilizing circuit; the other end of the capacitor C48 and the negative electrode of the polar capacitor Cp11 are connected with each other and grounded; the 4 pin of the analog-to-digital conversion chip U14 is connected with the +2.5V reference voltage output end of the +2.5V reference voltage circuit; 3 feet, 6 feet, 7 feet, 9 feet, 11 feet, 13 feet, 5 feet and 2 feet of the analog-digital conversion chip U14 are grounded; one end of the capacitor C49 and the 8 pin of the analog-to-digital conversion chip U14 are connected and then used as an input end VXToADC of the digital-to-analog conversion circuit, the input end VXToADC is connected with the 6 pin of the universal socket P2, and the other end of the capacitor C49 is grounded; one end of the capacitor C50 and the 10 pins of the analog-digital conversion chip U14 are connected and then used as an input end VYTOADC of the digital-analog conversion circuit, the 4 pins of the power strip P2 are connected, and the other end of the capacitor C50 is grounded; one end of the capacitor C51 and the 12 pin of the analog-digital conversion chip U14 are connected and then used as an input end VZToADC of the digital-analog conversion circuit, the 2 pin of the power strip P2 is connected, and the other end of the capacitor C51 is grounded; the 14 pin of the analog-to-digital conversion chip U14 is connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit; one end of the resistor R29 is connected with the 24 pin of the analog-digital conversion chip U14, and the other end of the resistor R29 is connected with the 52 pin of the main control circuit; one end of the resistor R30 is connected with the 23 pin of the analog-digital conversion chip U14, and the other end of the resistor R30 is connected with the 54 pin of the main control circuit; one end of the resistor R31 is connected with the pin 22 of the analog-digital conversion chip U14, and the other end of the resistor R31 is connected with the pin 53 of the main control circuit; one end of the resistor R32 is connected with the 21 pin of the analog-digital conversion chip U14, and the other end of the resistor R32 is connected with the 56 pin of the main control circuit; the 20 pin of the analog-digital conversion chip U14 is grounded; one end of the crystal oscillator X3 and one end of the capacitor C54 are connected with the 19 pin of the analog-digital conversion chip U14; one end of the capacitor C55 and the other end of the crystal oscillator X3 are connected with the 18 pin of the analog-digital conversion chip U14; the other end of the capacitor C54 is connected with the other end of the capacitor C55 and then grounded; the 17 pin of the analog-digital conversion chip U14 is grounded; one end of the capacitor C52, the positive electrode of the polar capacitor Cp12, the 15 pin and the 16 pin of the analog-digital conversion chip U14 are connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit; the other end of the capacitor C52 is connected with the negative electrode of the polar capacitor C12 and then grounded; other pins of the analog-digital conversion chip U14 are suspended; the analog-to-digital conversion chip U14 adopts a 24-bit analog-to-digital conversion chip ADS1256 of Texas instruments.

The main control circuit comprises a main control chip U12, resistors R24-R25, capacitors C41-C44 and a crystal oscillator X2; one end of a capacitor C41 and one end of a crystal oscillator X2 are connected with the 12 pin of the main control chip U12, one end of a capacitor C42 and the other end of the crystal oscillator X2 are connected with the 13 pin of the main control chip U12, the other end of the capacitor C41 and the other end of the capacitor C42 are grounded, and the 94 pin of the main control chip U12 is grounded through a resistor R24; one end of the resistor R25 and one end of the capacitor C43 are connected with the 14 pin of the main control chip U12, the other end of the resistor R25 is connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit, and the other end of the capacitor C43 is grounded; one end of the capacitor C44 is connected with the 6 pin of the main control chip U12, and the other end of the capacitor C44, the 50 pin, the 75 pin, the 100 pin, the 28 pin, the 11 pin and the 22 pin are connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit; the 20 feet, 49 feet, 74 feet, 99 feet, 10 feet and 19 feet of the main control chip U12 are grounded; the main control chip U12 is connected with one end of a resistor R29 in the analog-digital conversion circuit, the 53 pin is connected with one end of a resistor R31 in the analog-digital conversion circuit, the 54 pin is connected with one end of a capacitor R30 in the analog-digital conversion circuit, the 83 pin is connected with the 12 pin of the universal socket P2, the 56 pin is connected with one end of the resistor R32 in the analog-digital conversion circuit, the 30 pin is connected with the 5 pin of the SD card memory circuit, the 31 pin is connected with the 7 pin of the SD card memory circuit, the 32 pin is connected with the 3 pin of the SD card memory circuit, the 68 pin is connected with the 8 pin of the universal socket P2, the 69 pin is connected with the 10 pin of the socket P2, the 72 pin is connected with the 2 pin of the plug-in device SWD, the 76 pin is connected with the 3 pin of the plug-in device SWD, the 78 pin is connected with the 2 pin of the serial port gesture measurement circuit, the 79 pin is connected with the 3 pin of the universal socket P2, the 1 pin is connected with the 3 pin of the RTC clock circuit, the 2 is connected with the 15 pin of the SD card memory circuit, the 4 pin is connected with the 3 pin of the RTC clock circuit, and the 21 pin is connected with the +3.3V voltage stabilizing output terminal of the circuit; the remaining pins of the main control chip U12 are suspended; the main control chip U12 adopts STM32F103RCT6 chips of an intentional semiconductor.

The serial port gesture measurement circuit comprises a serial port gesture measurement chip U17, a capacitor C62 and a polar capacitor Cp14; the 7 pins, the 8 pins and the 4 pins of the serial port gesture measurement chip U17 are respectively grounded; one end of the capacitor C62, the positive electrode of the polar capacitor Cp14 and the 1 pin of the serial port gesture measurement chip U17 are connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit, and the other end of the capacitor C62 and the negative electrode of the polar capacitor Cp14 are respectively grounded; the 2 pin of the serial port gesture measurement chip U17 is connected with the 78 pin of the main control circuit; the 3 pin of the serial port gesture measurement chip U17 is connected with the 79 pin of the main control circuit; the pins 4, 7 and 8 of the serial port gesture measurement chip U17 are grounded; other pins of the serial port gesture measurement chip U17 are suspended; the serial port attitude measurement chip U17 adopts a LEADIY-M3 chip of soft core micro-technology; the serial port attitude measurement circuit converts three components of a magnetic field under a carrier coordinate system, which is measured by the magnetometer, into three components of the magnetic field under a real geographic environment by measuring a real-time attitude angle of the magnetometer.

The RTC clock circuit comprises a clock chip U13, resistors R26-R28, capacitors C45-C46 and a button cell B1; one end of the capacitor C45, one end of the resistor R26 and the 2 pin of the clock chip U13 are connected and then connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit, the other end of the capacitor C45 is grounded, and the other end of the resistor R26 and the 3 pin of the clock chip U13 are connected and then connected with the 1 pin of the main control circuit; the 5 pin, the 6 pin, the 7 pin, the 8 pin, the 9 pin, the 10 pin, the 11 pin, the 12 pin and the 13 pin of the clock chip U13 are grounded; one end of the resistor R27 and the 15 pin of the clock chip U13 are connected and then connected with the 2 pin of the main control circuit, one end of the resistor R28 and the 16 pin of the clock chip U13 are connected and then connected with the 4 pin of the main control circuit, and the other end of the resistor R27 and the other end of the resistor R28 are connected and then connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit; one end of the capacitor C46 and the positive electrode of the button battery B1 are connected with the 14 pin of the clock chip U13, the other end of the capacitor C46 is grounded, and the negative electrode of the button battery B1 is grounded; the remaining pins of the clock chip U13 are suspended; the clock chip U13 adopts a DS3231SN chip of a wetting semiconductor; the RTC clock circuit is used for calibrating the measurement time and keeping the synchronization of the measurement time and the standard time.

The data transmission circuit comprises a multichannel RS-232 line driver/receiver U8, capacitors C25-C29 and a polar capacitor Cp9; the 1 pin and the 3 pin of the multichannel RS-232 circuit driver/receiver U8 are respectively connected with two ends of a capacitor C25, the 4 pin and the 5 pin are respectively connected with two ends of a capacitor C26, the 15 pin is directly grounded, the 10 pin is used as the 8 pin of the signal output connection socket P2, the 9 pin is used as the 10 pin of the signal input connection socket P2, the 6 pin is grounded through a capacitor C29, the 2 pin is grounded through a capacitor C28, one end of the capacitor C27, the positive electrode of a polar capacitor Cp9 and the 16 pin are connected and then connected with the +5V voltage stabilizing output end of the +5V voltage stabilizing circuit, the other end of the capacitor C27 and the negative electrode of the polar capacitor Cp9 are connected and then grounded, the 7 pin is connected with the 4 pin of a wire holder P1, the 8 pin is connected with the 3 pin of the wire holder P1, and the other pins of the multichannel RS-232 circuit driver/receiver U8 are suspended; the multichannel RS-232 line driver/receiver U8 uses a texas instruments MAX3232 chip.

The SD card memory circuit comprises an SDCard-U18, a capacitor C63 and resistors R35-R36; one end of the capacitor C63 and the 4 pin of the SDCard-U18 are connected and then connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit, and the other end of the capacitor C63 and the 6 pin of the SDCard-U18 are connected and then grounded; one end of the resistor R35 and the 3 pin of the SDCard-U18 are connected and then connected with the 32 pin of the main control circuit, the other end of the resistor R35 and one end of the resistor R36 are connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit, and the other end of the resistor R36 and the 7 pin of the SDCard-U18 are connected and then connected with the 31 pin of the main control circuit; the 5 pin of the SDCard-U18 is connected with the 30 pin of the main control circuit, and the 2 pin is grounded; the remaining pins of SDCard-U18 are suspended.

The file management circuit comprises a file management control chip U9, capacitors C30-C33, a resistor R22, a light-emitting diode D2 and a crystal oscillator X1; one end of the capacitor C30 is connected with the 2 pin of the file management control chip U9, and the other end of the capacitor C30 is connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit; the 5 pins of the file management control chip U9 are connected with the 12 pins of the universal power strip P2, and the 6 pins are connected with the 14 pins of the universal power strip P2; one end of the capacitor C31 and the 9 pin of the file management control chip U9 are connected and then connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit, and the other end of the capacitor C31 is grounded; the 10 pins of the file management control chip U9 are connected with the 7 pins of the wire holder P1, and the 11 pins are connected with the 6 pins of the wire holder P1; the 12 pins of the file management control chip U9 are grounded; the 13 pins and the 14 pins of the file management control chip U9 are respectively connected with the two ends of the crystal oscillator X1; one end of the capacitor C32, one end of the capacitor C33 and the 28 pin of the file management control chip U9 are connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit; the other end of the capacitor C32 and the other end of the capacitor C33 are respectively grounded; the cathode of the light emitting diode D2 is connected with 24 pins of the file management control chip U9, the anode of the light emitting diode D2 is connected with one end of a resistor R22, and the other end of the resistor R22 is connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit; the 23 pin, the 21 pin and the 20 pin of the file management control chip U9 are respectively grounded; the 19 pin of the file management control chip U9 is connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit; other pins of the file management control chip U9 are suspended; the file management control chip U9 adopts a CH376S chip; the file management circuit improves the data reading and writing speed and enriches the functions of file management and reading and writing.

The external interface circuit comprises a wiring seat circuit, a universal socket circuit and a connector circuit;

the wire holder circuit comprises a wire holder P1, a diode D4 and a polar capacitor Cp15; the anode of the diode D4 is connected with the 1 pin of the wiring seat P1, and the cathode of the diode D4 is connected with the power supply DC24V; the 2 pins and the 8 pins of the wire holder P1 are grounded, the 3 pin is connected with the 8 pin of the data transmission circuit, the 4 pin is connected with the 7 pin of the data transmission circuit, the 6 pin is connected with the 11 pin of the file management circuit, and the 7 pin is connected with the 10 pin of the file management circuit; the positive electrode of the polar capacitor Cp15 is connected with the 5 pin of the wire holder P1, and the negative electrode of the polar capacitor Cp15 is grounded;

the universal power strip circuit comprises a universal power strip P2; the general power strip P2 is characterized in that 3 pins, 5 pins, 7 pins, 9 pins, 11 pins, 13 pins, 15 pins, 17 pins and 19 pins are grounded, 16 pins, 18 pins and 20 pins are connected with a +5V power supply, 2 pins are connected with 7 pins of a Z-axis analog signal addition circuit, 12 pins of a digital-to-analog conversion circuit, 4 pins are connected with 7 pins of a Y-axis analog signal addition circuit, 10 pins of a digital-to-analog conversion circuit, 6 pins are connected with 7 pins of an X-axis analog signal addition circuit, 8 pins of a digital-to-analog conversion circuit, 10 pins of a data transmission circuit, 68 pins of a main control circuit, 9 pins of a data transmission circuit, 69 pins of a main control circuit, 5 pins of a 12 pins file management circuit, 83 pins of a main control circuit, 14 pins of a file management circuit, 6 pins of a main control circuit and 80 pins of the main control circuit;

The connector circuit comprises a connector SWD; the 1 pin of the connector SWD is connected with a +3.3V power supply, the 2 pin is connected with the 72 pin of the main control circuit, the 3 pin is connected with the 76 pin of the main control circuit, and the 4 pin is grounded.

The invention realizes a measuring circuit of a true geographic three-component magnetometer. The characteristics of low power consumption, good stability, high precision, small volume and the like of the fluxgate sensor are utilized. In the sensor signal acquisition circuit, an analog signal addition circuit is designed for converting the voltage value of the sensor output signal into a voltage value acceptable by an analog-to-digital conversion circuit. In the serial port attitude measurement circuit, an attitude measurement chip LEADIY-M3 with complete functions is selected to realize real-time attitude information of the magnetometer, and the attitude measurement chip LEADIY-M is used for transforming three components of a magnetic field under a measured carrier coordinate system to obtain geomagnetic field components under a real geographic environment. By designing the RTC clock circuit, the time calibration is more accurate, and the synchronization of the measurement time and the standard time is maintained. In the file management circuit, a file management control chip CH376S supporting a USB interface is selected, so that file management and read-write functions are enriched.

Drawings

FIG. 1 is an overall block diagram of the circuit of the present invention;

FIGS. 2-7 are circuit diagrams of power supply circuits; wherein FIG. 2 is a circuit diagram of a +15V voltage stabilizing circuit and a-15V voltage stabilizing circuit, FIG. 3 is a circuit diagram of a +5V voltage stabilizing circuit, FIG. 4 is a circuit diagram of a +4.5V reference voltage circuit, FIG. 5 is a circuit diagram of a +3.3V voltage stabilizing circuit, FIG. 6 is a circuit diagram of a +3.3V switching power supply circuit, and FIG. 7 is a circuit diagram of a +2.5V reference voltage circuit;

FIGS. 8-11 are circuit diagrams of a sensor signal acquisition circuit; wherein fig. 8 is a circuit diagram of an X-axis analog signal addition circuit, fig. 9 is a circuit diagram of a Y-axis analog signal addition circuit, fig. 10 is a circuit diagram of a Z-axis analog signal addition circuit, and fig. 11 is a circuit diagram of a digital-to-analog conversion circuit;

FIG. 12 is a circuit diagram of a master circuit;

FIG. 13 is a circuit diagram of a serial port attitude measurement circuit;

FIG. 14 is a circuit diagram of an RTC clock circuit;

FIG. 15 is a circuit diagram of a data transmission circuit;

FIG. 16 is a circuit diagram of an SD card memory circuit;

FIG. 17 is a circuit diagram of a file management circuit;

FIGS. 18-20 are circuit diagrams of external interface circuits; fig. 18 is a circuit diagram of a wire holder circuit, fig. 19 is a circuit diagram of a general strip circuit, and fig. 20 is a circuit diagram of a connector circuit.

Detailed Description

The invention is further analyzed in connection with the following figures.

As shown in FIG. 1, the measuring circuit of the true geographic three-component magnetometer comprises a main control circuit I, a power supply circuit II, a sensor signal acquisition circuit III, an external interface circuit IV, a data transmission circuit V, an SD card storage circuit VI, a serial port gesture measuring circuit VII, an RTC clock circuit VIII and a file management circuit IX.

The power supply circuit II comprises a +15V voltage stabilizing circuit, -15V voltage stabilizing circuit, +5V voltage stabilizing circuit, +4.5V reference voltage circuit, +3.3V voltage stabilizing circuit, +3.3V switching power supply circuit and +2.5V reference voltage circuit;

as shown in fig. 2, the +15v voltage stabilizing circuit and the-15v voltage stabilizing circuit comprise a switching power supply chip U1 and capacitors C1-C3; one end of the capacitor C1 and the 2 pin of the switching power supply chip U1 are connected and then grounded, and the other end of the capacitor C1 and the 1 pin of the switching power supply chip U1 are connected and then connected with a +24V power supply; one end of the capacitor C2 is connected with the 3 pin of the switching power supply chip U1 and is used as a +15V power supply output end; the other end of the capacitor C2, one end of the capacitor C3 and the pin 4 of the switching power supply chip U1 are connected and then grounded; the other end of the capacitor C3 is connected with the 5 pin of the switching power supply chip U1 and is used as a power supply output end of-15V; the switching power supply chip U1 adopts a DC-DC switching power supply chip of Texas instruments.

As shown in fig. 3, the +5v voltage stabilizing circuit includes a switching power supply chip U2, polar capacitors Cp1-Cp4, resistors R1-R4, an inductor L1, capacitors C4-C6, and a light emitting diode D1; the 7 pin of the switching power supply chip U2, one end of the resistor R1, the positive electrode of the polar capacitor Cp2 and the positive electrode of the polar capacitor Cp3 are connected with a +24V power supply; the negative electrode of the polar capacitor Cp1, the negative electrode of the polar capacitor Cp2 and the negative electrode of the polar capacitor Cp3 are respectively grounded; the other end of the resistor R1 and the 5 pin of the switching power supply chip U2 are connected with one end of the resistor R2; the other end of the resistor R2 and the 6 pin of the switching power supply chip U2 are connected and then grounded; one end of the capacitor C4 is connected with the 1 pin of the switching power supply chip U2, the other end of the capacitor C4, one end of the inductor L1 and the cathode of the diode D1 are connected with the 8 pin of the switching power supply chip U2; the anode of the diode D1 is grounded; the other end of the inductor L1, one end of the resistor R3, the positive electrode of the polar capacitor Cp4, one end of the capacitor C5 and one end of the capacitor C6 are connected to serve as +5V power supply output ends; the other end of the resistor R3 and one end of the resistor R4 are connected with the 4 pin of the switching power supply chip U2; the negative electrode of the polar capacitor Cp4 and the other end of the resistor R4 are connected and then grounded, and the other end of the capacitor C5 and the other end of the capacitor C6 are respectively grounded; the remaining pins of the switching power supply chip U2 are suspended; the switching power supply chip U2 adopts a switching power supply chip TPS5420 of Texas instruments.

As shown in fig. 4, the +4.5v reference voltage circuit includes a reference voltage chip U6, an operational amplifier chip U7, an inductor L2, a polar capacitor Cp8, capacitors C19-C24, resistors R20-R21; one end of the inductor L2, the positive electrode of the polar capacitor Cp8 and one end of the capacitor C19 are connected with the 2 pin of the reference voltage chip U7; the other end of the inductor L2 is connected with the +5V voltage stabilizing output end of the +5V voltage stabilizing circuit; the negative electrode of the polar capacitor Cp8, the other end of the capacitor C19 and the pin 4 of the reference voltage chip U6 are connected and grounded; one end of the resistor R20 is connected with the 6 pin of the reference voltage chip U6, the other end of the resistor R20 and one end of the capacitor C21 are connected with the 3 pin of the operational amplifier chip U7, and the other end of the capacitor C21 is grounded; one end of the capacitor C20 is connected with the 5 pin of the reference voltage chip U6, and the other end of the capacitor C20 is grounded; the 4 pin of the operational amplifier chip U7 is grounded; one end of the capacitor C22 and the 7 pin of the operational amplifier chip U7 are connected and then connected with the +5V voltage stabilizing output end of the +5V voltage stabilizing circuit, and the other end of the capacitor C22 is grounded; one end of the resistor R21 is connected with the 6 pin of the operational amplifier chip U7, the other end of the resistor R21, one end of the capacitor C23 and one end of the capacitor C24 are connected, and the other end of the capacitor C23 and the other end of the capacitor C24 are respectively grounded as +4.5V reference voltage output ends; the rest pins of the reference voltage chip U6 and the operational amplifier chip U7 are suspended; the reference voltage chip U6 adopts a reference voltage chip REF5045 of a Texas instrument; the operational amplifier chip U7 uses the fine operational amplifier chip OPA376 of texas instruments.

As shown in fig. 5, the +3.3v voltage stabilizing circuit includes a voltage stabilizing power supply chip U10, a polarity capacitor Cp10, and capacitors C34-C36; the positive electrode of the polar capacitor Cp10, one end of the capacitor C34 and the 3 pin of the regulated power supply chip U10 are connected with the power supply VDD, and the negative electrode of the polar capacitor Cp10 and the other end of the capacitor C34 are respectively grounded; the 1 pin of the regulated power supply chip U10 is grounded; one end of a capacitor C35 and one end of a capacitor C36 are connected with the 2 pin of the regulated power supply chip U10 and serve as a +3.3V voltage output end of a +3.3V voltage stabilizing circuit, and the other end of the capacitor C35 and the other end of the capacitor C36 are grounded respectively; the regulated power supply chip U10 employs a regulated power supply chip LM1117.

As shown in fig. 6, the +3.3v switching power supply circuit includes a switching power supply chip U11, capacitors C37-C40, a resistor R23, and a light emitting diode D3; one end of the capacitor C38, one end of the capacitor C37 and 3 pins and 4 pins of the switching power supply chip U11 are connected and then connected with a +5V voltage stabilizing output end of the +5V voltage stabilizing circuit, the other end of the capacitor C37 and 2 pins of the switching power supply chip U11 are connected and then grounded, and the other end of the capacitor C38 and 1 pin of the switching power supply chip U11 are connected and then grounded; one end of a capacitor C39, one end of a capacitor C40, one end of a resistor R23, a pin 5 and a pin 6 of a switching power supply chip U11 are connected and then connected with a voltage stabilizing output end of +3.3V of a +3.3V voltage stabilizing circuit, the other end of the capacitor C39 and the other end of the capacitor C40 are respectively grounded, the other end of the resistor R23 is connected with an anode of a light emitting diode D3, and a cathode of the light emitting diode D3 is grounded; the remaining pins of the switching power supply chip U11 are suspended; the switching power supply chip U11 is a texas instrument switching power supply chip TPS7350.

As shown in fig. 7, the +2.5v reference voltage circuit includes a reference voltage chip U15, an operational amplifier chip U16, an inductance L3, a polarity capacitance Cp13, capacitances C56-C61, and resistors R33-R34; one end of the inductor L3, the positive electrode of the polar capacitor Cp13 and one end of the capacitor C56 are connected with the 2 pin of the reference voltage chip U15, the other end of the inductor L3 is connected with the +5V voltage stabilizing output end of the +5V voltage stabilizing circuit, and the negative electrode of the polar capacitor Cp13, the other end of the capacitor C56 and the 4 pin of the reference voltage chip U15 are grounded after being connected; one end of the resistor R33 is connected with the 6 pin of the reference voltage chip U15, the other end of the resistor R33 and one end of the capacitor C58 are connected with the 3 pin of the operational amplifier chip U16, and the other end of the capacitor C58 is grounded; one end of the capacitor C57 is connected with the 5 pin of the reference voltage chip U15, and the other end of the capacitor C57 is grounded; the 4 pin of the operational amplifier chip U16 is grounded; one end of the capacitor C59 and the 7 pin of the operational amplifier chip U16 are connected and then connected with the +5V voltage stabilizing output end of the +5V voltage stabilizing circuit, and the other end of the capacitor C59 is grounded; one end of the resistor R34 is connected with the 6 pin of the operational amplifier chip U16, the other end of the resistor R34, one end of the capacitor C60 and one end of the capacitor C61 are connected, and the other end of the capacitor C60 and the other end of the capacitor C61 are respectively grounded as +2.5V reference voltage output ends; the other pins of the reference voltage chip U15 and the operational amplifier chip U16 are suspended; reference voltage chip U15 uses reference voltage chip REF5045 of Texas instruments; the op-amp chip U16 employs a texas instrument precision op-amp chip OPA376.

The sensor signal acquisition circuit III comprises an X-axis analog signal adding circuit, a Y-axis analog signal adding circuit and a Z-axis analog signal adding circuit;

as shown in fig. 8, the X-axis analog signal adding circuit includes an operational amplifier chip U3, resistors R5-R9, capacitors C7-C10, and a polar capacitor Cp5; one end of a resistor R5, one end of a resistor R6 and one end of a resistor R7 are connected with a pin 3 of the operational amplifier chip U3, the other end of the resistor R5 is connected with a +4.5V reference voltage output end of a +4.5V reference voltage circuit, the other end of the resistor R6 is connected with one end of a capacitor C7 and used as an X-axis magnetic field signal input end, and the other end of the capacitor C7 is connected with the other end of the resistor R7 and grounded; the 4 pin of the operational amplifier chip U3 is grounded; the 1 pin and the 2 pin of the operational amplifier chip U3 are connected and then connected with a power supply V_Back; one end of the capacitor C8, the positive electrode of the polar capacitor Cp5 and the 8 pin of the operational amplifier chip U3 are connected with the +5V voltage stabilizing output end of the +5V voltage stabilizing circuit, and the other end of the capacitor C8 is connected with the negative electrode of the polar capacitor Cp5 and grounded; one end of the pin 6, pin 7 and capacitor C10 of the operational amplifier chip U3 is connected with the output end of the X-axis analog signal adding circuit and connected with the pin 6 of the universal socket P2; one end of a capacitor C9 and one end of a resistor R8 are connected with the pin 5 of the operational amplifier chip U3, the other end of the capacitor C9 is grounded, the other end of the resistor R8 and one end of the resistor R9 are connected with the other end of the capacitor C10, and the other end of the resistor R9 is connected with a power supply V_Back; the operational amplifier chip U3 adopts a precision operational amplifier chip OPA2376 of Texas instruments;

As shown in fig. 9, the Y-axis analog signal adding circuit includes an operational amplifier chip U4, resistors R10 to R14, capacitors C11 to C14, and a polar capacitor Cp6; one end of a resistor R10, one end of a resistor R11 and one end of a resistor R12 are connected with a pin 3 of an operational amplifier chip U4, the other end of the resistor R10 is connected with a +4.5V reference voltage output end of a +4.5V reference voltage circuit, the other end of the resistor R11 is connected with one end of a capacitor C11 and is used as an input end of a Y-cycle magnetic field signal, and the other end of the capacitor C11 is connected with the other end of the resistor R12 and grounded; the 4 pin of the operational amplifier chip U4 is grounded; the 1 pin and the 2 pin of the operational amplifier chip U4 are connected and then connected with a power supply V_Back; one end of the capacitor C12, the positive electrode of the polar capacitor Cp6 and the +5V voltage stabilizing output end of the +5V voltage stabilizing circuit are connected with the 8 pin of the operational amplifier chip U4, and the other end of the capacitor C12 is connected with the negative electrode of the polar capacitor Cp6 and grounded; one end of a pin 6 and a pin 7 of the operational amplifier chip U4 and one end of a capacitor C14 are connected and serve as an output end of the Y-axis analog signal addition circuit, and the pin 4 of the power strip P2 is connected; one end of the capacitor C13 and one end of the resistor R13 are connected with the pin 5 of the operational amplifier chip U4, the other end of the capacitor C13 is grounded, the other end of the resistor R13 and one end of the resistor R14 are connected with the other end of the capacitor C14, and the other end of the resistor R14 is connected with the power supply V_Back; the operational amplifier chip U4 adopts a precision operational amplifier chip OPA2376 of Texas instruments;

As shown in fig. 10, the Z-axis analog signal adding circuit includes an operational amplifier chip U5, resistors R15 to R19, capacitors C15 to C18, and a polar capacitor Cp7; one end of the resistor R15, one end of the resistor R16 and one end of the resistor R17 are connected with the 3 pin of the operational amplifier chip U5; the other end of the resistor R15 is connected with the +4.5V reference voltage output end of the +4.5V reference voltage circuit; the other end of the resistor R16 is connected with one end of the capacitor C15 and is used as an input end of the Z-axis magnetic field signal; the other end of the capacitor C15 is connected with the other end of the resistor R17 and grounded; the 4 pin of the operational amplifier chip U5 is grounded; the 1 pin and the 2 pin of the operational amplifier chip U5 are connected and then connected with a power supply V_Back; one end of the capacitor C16, the positive electrode of the polar capacitor Cp7 and the +5V voltage stabilizing output end of the +5V voltage stabilizing circuit are connected with the 8 pin of the operational amplifier chip U5, and the other end of the capacitor C16 is connected with the negative electrode of the polar capacitor Cp7 and grounded; one end of a pin 6 and a pin 7 of the operational amplifier chip U5 and one end of a capacitor C18 are connected and serve as an output end of the Z-axis analog signal addition circuit, and a pin 2 of the power strip P2 is connected; one end of a capacitor C17 and one end of a resistor R18 are connected with the pin 5 of the operational amplifier chip U5, the other end of the capacitor C17 is grounded, the other end of the resistor R18 and one end of a resistor R19 are connected with the other end of the capacitor C18, and the other end of the resistor R19 is connected with a power supply V_Back; the operational amplifier chip U5 adopts a precision operational amplifier chip OPA2376 of Texas instruments;

As shown in FIG. 11, the digital-to-analog conversion circuit comprises an analog-to-digital conversion chip U14, polar capacitors Cp11-Cp12, resistors R29-R32, capacitors C48-C55 and a crystal oscillator X3; one end of the capacitor C48, the positive electrode of the polar capacitor Cp11 and the 1 pin of the analog-digital conversion chip U14 are connected with the +5V voltage stabilizing output end of the +5V voltage stabilizing circuit; the other end of the capacitor C48 and the negative electrode of the polar capacitor Cp11 are connected with each other and grounded; the 4 pin of the analog-to-digital conversion chip U14 is connected with the +2.5V reference voltage output end of the +2.5V reference voltage circuit; 3 feet, 6 feet, 7 feet, 9 feet, 11 feet, 13 feet, 5 feet and 2 feet of the analog-digital conversion chip U14 are grounded; one end of the capacitor C49 and the 8 pin of the analog-digital conversion chip U14 are connected and then connected with the 6 pin of the universal socket P2, and the other end of the capacitor C49 is grounded; one end of the capacitor C50 and the pin 10 of the analog-digital conversion chip U14 are connected and then are connected with the pin 4 of the power strip P2, and the other end of the capacitor C50 is grounded; one end of the capacitor C51 and the pin 12 of the analog-digital conversion chip U14 are connected and then are connected with the pin 2 of the power strip P2, and the other end of the capacitor C51 is grounded; the 14 pin of the analog-to-digital conversion chip U14 is connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit; one end of the resistor R29 is connected with the 24 pin of the analog-digital conversion chip U14, and the other end of the resistor R29 is connected with the 52 pin of the main control circuit; one end of the resistor R30 is connected with the 23 pin of the analog-digital conversion chip U14, and the other end of the resistor R30 is connected with the 54 pin of the main control circuit; one end of the resistor R31 is connected with the pin 22 of the analog-digital conversion chip U14, and the other end of the resistor R31 is connected with the pin 53 of the main control circuit; one end of the resistor R32 is connected with the 21 pin of the analog-digital conversion chip U14, and the other end of the resistor R32 is connected with the 56 pin of the main control circuit; the 20 pin of the analog-digital conversion chip U14 is grounded; one end of the crystal oscillator X3 and one end of the capacitor C54 are connected with the 19 pin of the analog-digital conversion chip U14; one end of the capacitor C55 and the other end of the crystal oscillator X3 are connected with the 18 pin of the analog-digital conversion chip U14; the other end of the capacitor C54 is connected with the other end of the capacitor C55 and then grounded; the 17 pin of the analog-digital conversion chip U14 is grounded; one end of the capacitor C52, the positive electrode of the polar capacitor Cp12, the 15 pin and the 16 pin of the analog-digital conversion chip U14 are connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit; the other end of the capacitor C52 is connected with the negative electrode of the polar capacitor C12 and then grounded; other pins of the analog-digital conversion chip U14 are suspended; the analog-to-digital conversion chip U14 adopts a 24-bit analog-to-digital conversion chip ADS1256 of Texas instruments.

As shown in FIG. 12, the main control circuit I comprises a main control chip U12, resistors R24-R25, capacitors C41-C44 and a crystal oscillator X2; one end of a capacitor C41 and one end of a crystal oscillator X2 are connected with the 12 pin of the main control chip U12, one end of a capacitor C42 and the other end of the crystal oscillator X2 are connected with the 13 pin of the main control chip U12, the other end of the capacitor C41 and the other end of the capacitor C42 are grounded, and the 94 pin of the main control chip U12 is grounded through a resistor R24; one end of the resistor R25 and one end of the capacitor C43 are connected with the 14 pin of the main control chip U12, the other end of the resistor R25 is connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit, and the other end of the capacitor C43 is grounded; one end of the capacitor C44 is connected with the 6 pin of the main control chip U12, and the other end of the capacitor C44, the 50 pin, the 75 pin, the 100 pin, the 28 pin, the 11 pin and the 22 pin are connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit; the 20 feet, 49 feet, 74 feet, 99 feet, 10 feet and 19 feet of the main control chip U12 are grounded; the main control chip U12 is connected with one end of a resistor R29 in the analog-digital conversion circuit, the pin 53 is connected with one end of a resistor R31 in the analog-digital conversion circuit, the pin 54 is connected with one end of a capacitor R30 in the analog-digital conversion circuit, the pin 83 is connected with the pin 12 of the universal socket P2, the pin 56 is connected with one end of the resistor R32 in the analog-digital conversion circuit, the pin 30 is connected with the pin 5 of the SD card memory circuit, the pin 31 is connected with the pin 7 of the SD card memory circuit, the pin 32 is connected with the pin 3 of the SD card memory circuit, the pin 68 is connected with the pin 8 of the universal socket P2, the pin 69 is connected with the pin 10 of the socket P2, the pin 72 is connected with the pin 2 of the plug SWD, the pin 76 is connected with the pin 3 of the plug SWD, the pin 78 is connected with the pin 2 of the serial port gesture measurement circuit, the pin 79 is connected with the pin 3 of the universal socket P2, the pin 1 is connected with the pin 3 of the RTC clock circuit, the pin 2 is connected with the pin 15 of the plug 4; the remaining pins of the main control chip U12 are suspended; the main control chip U12 adopts STM32F103RCT6 chips of an intentional semiconductor.

As shown in fig. 13, the serial port posture measurement circuit vii includes a serial port posture measurement chip U17, a capacitor C62, and a polarity capacitor Cp14; the 7 pins, the 8 pins and the 4 pins of the serial port gesture measurement chip U17 are respectively grounded; one end of the capacitor C62 and the positive electrode of the polar capacitor Cp14 are connected with the 1 pin of the serial port gesture measurement chip IC16, and the other end of the capacitor C62 and the negative electrode of the polar capacitor Cp14 are respectively grounded; the 2 pin of the serial port gesture measurement chip U17 is connected with the 78 pin of the main control circuit; the 3 pin of the serial port gesture measurement chip U17 is connected with the 79 pin of the main control circuit; other pins of the serial port gesture measurement chip U17 are suspended; the serial port attitude measurement chip U17 adopts a LEADIY-M3 chip of soft core micro-technology.

As shown in fig. 14, the RTC clock circuit viii includes a clock chip U13, resistors R26-R28, capacitors C45-C46, and a button cell B1; one end of the capacitor C45, one end of the resistor R26 and the 2 pin of the clock chip U13 are connected and then connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit, the other end of the capacitor C45 is grounded, and the other end of the resistor R26 and the 3 pin of the clock chip U13 are connected and then connected with the 1 pin of the main control circuit; the 5 pin, the 6 pin, the 7 pin, the 8 pin, the 9 pin, the 10 pin, the 11 pin, the 12 pin and the 13 pin of the clock chip U13 are grounded; one end of the resistor R27 and the 15 pin of the clock chip U13 are connected and then connected with the 2 pin of the main control circuit, one end of the resistor R28 and the 16 pin of the clock chip U13 are connected and then connected with the 4 pin of the main control circuit, and the other end of the resistor R27 and the other end of the resistor R28 are connected and then connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit; one end of the capacitor C46 and the positive electrode of the button battery B1 are connected with the 14 pin of the clock chip U13, the other end of the capacitor C46 is grounded, and the negative electrode of the button battery B1 is grounded; the remaining pins of the clock chip U13 are suspended; the clock chip U13 adopts DS3231SN chip which is a semiconductor.

As shown in fig. 15, the data transmission circuit v includes a multi-channel RS-232 line driver/receiver U8, capacitors C25-C29, and a polarity capacitor Cp9; the 1 pin and the 3 pin of the multichannel RS-232 circuit driver/receiver U8 are respectively connected with two ends of a capacitor C25, the 4 pin and the 5 pin are respectively connected with two ends of a capacitor C26, the 15 pin is directly grounded, the 10 pin is used as the 8 pin of the signal output connection socket P2, the 9 pin is used as the 10 pin of the signal input connection socket P2, the 6 pin is grounded through a capacitor C29, the 2 pin is grounded through a capacitor C28, one end of the capacitor C27, the positive electrode of a polar capacitor Cp9 and the 16 pin are connected and then connected with the +5V voltage stabilizing output end of the +5V voltage stabilizing circuit, the other end of the capacitor C27 and the negative electrode of the polar capacitor Cp9 are connected and then grounded, the 7 pin is connected with the 4 pin of a wire holder P1, the 8 pin is connected with the 3 pin of the wire holder P1, and the other pins of the multichannel RS-232 circuit driver/receiver U8 are suspended; the multichannel RS-232 line driver/receiver U8 uses a texas instruments MAX3232 chip.

As shown in FIG. 16, the SD card memory circuit VI comprises SDCard-U18, capacitor C63, and resistors R35-R36; one end of the capacitor C63 and the 4 pin of the SDCard-U18 are connected and then connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit, and the other end of the capacitor C63 and the 6 pin of the SDCard-U18 are connected and then grounded; one end of the resistor R35 and the 3 pin of the SDCard-U18 are connected and then connected with the 32 pin of the main control circuit, the other end of the resistor R35 and one end of the resistor R36 are connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit, and the other end of the resistor R36 and the 7 pin of the SDCard-U18 are connected and then connected with the 31 pin of the main control circuit; the 5 pin of the SDCard-U18 is connected with the 30 pin of the main control circuit, and the 2 pin is grounded; the remaining pins of SDCard-U18 are suspended.

As shown in fig. 17, the document management circuit ix includes a document management control chip U9, capacitors C30-C33, a resistor R22, a light emitting diode D2, and a crystal oscillator X1; one end of the capacitor C30 is connected with the 2 pin of the file management control chip U9, and the other end of the capacitor C30 is connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit; the 5 pins of the file management control chip U9 are connected with the 12 pins of the universal power strip P2, and the 6 pins are connected with the 14 pins of the universal power strip P2; one end of the capacitor C31 and the 9 pin of the file management control chip U9 are connected and then connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit, and the other end of the capacitor C31 is grounded; the 10 pins of the file management control chip U9 are connected with the 7 pins of the wire holder P1, and the 11 pins are connected with the 6 pins of the wire holder P1; the 12 pins of the file management control chip U9 are grounded; the 13 pins and the 14 pins of the file management control chip U9 are respectively connected with the two ends of the crystal oscillator X1; one end of the capacitor C32, one end of the capacitor C33 and the 28 pin of the file management control chip U9 are connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit; the other end of the capacitor C32 and the other end of the capacitor C33 are respectively grounded; the cathode of the light emitting diode D2 is connected with 24 pins of the file management control chip U9, the anode of the light emitting diode D2 is connected with one end of a resistor R22, and the other end of the resistor R22 is connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit; the 23 pin, the 21 pin and the 20 pin of the file management control chip U9 are respectively grounded; the 19 pin of the file management control chip U9 is connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit; other pins of the file management control chip U9 are suspended; the file management control chip U9 adopts a CH376S chip.

The external interface circuit IV comprises a wiring seat circuit, a universal socket circuit and a connector circuit;

as shown in fig. 18, the wire holder circuit includes a wire holder P1, a diode D4, and a polar capacitor Cp15; the anode of the diode D4 is connected with the 1 pin of the wiring seat P1, and the cathode of the diode D4 is connected with the power supply DC24V; the 2 pins and the 8 pins of the wire holder P1 are grounded, the 3 pin is connected with the 8 pin of the data transmission circuit, the 4 pin is connected with the 7 pin of the data transmission circuit, the 6 pin is connected with the 11 pin of the file management circuit, and the 7 pin is connected with the 10 pin of the file management circuit; the positive electrode of the polar capacitor Cp15 is connected with the 5 pin of the wire holder P1, and the negative electrode of the polar capacitor Cp15 is grounded;

as shown in fig. 19, the universal serial bus circuit includes a universal serial bus P2; the general power strip P2 is characterized in that 3 pins, 5 pins, 7 pins, 9 pins, 11 pins, 13 pins, 15 pins, 17 pins and 19 pins are grounded, 16 pins, 18 pins and 20 pins are connected with a +5V power supply, 2 pins are connected with 7 pins of a Z-axis analog signal addition circuit, 12 pins of a digital-to-analog conversion circuit, 4 pins are connected with 7 pins of a Y-axis analog signal addition circuit, 10 pins of a digital-to-analog conversion circuit, 6 pins are connected with 7 pins of an X-axis analog signal addition circuit, 8 pins of a digital-to-analog conversion circuit, 10 pins of a data transmission circuit, 68 pins of a main control circuit, 9 pins of a data transmission circuit, 69 pins of a main control circuit, 5 pins of a 12 pins file management circuit, 83 pins of a main control circuit, 14 pins of a file management circuit, 6 pins of a main control circuit and 80 pins of the main control circuit;

As shown in fig. 20, the connector circuit includes a connector SWD; the 1 pin of the connector SWD is connected with a +3.3V power supply, the 2 pin is connected with the 72 pin of the main control circuit, the 3 pin is connected with the 76 pin of the main control circuit, and the 4 pin is grounded.

Because the circuit adopts the MAG03MCL100 fluxgate sensor of Bartington company in UK, the sensor converts the magnetic signal into the voltage signal to be output, the voltage range is between minus 10V and 10V, and the high-precision analog-to-digital conversion chip in the market can only convert the voltage value of 0 and 5V, three axial analog signal addition circuits with the same structure are designed for converting the voltage value of the signal output by the sensor into the voltage value acceptable by the analog-to-digital conversion circuit. And designing a serial port attitude measurement circuit for measuring the attitude information of the magnetometer in real time and converting the three components of the magnetic field under the measured carrier coordinate system into geomagnetic field components under the real geographic coordinate system through a coordinate transformation matrix.

The circuit related by the invention is a three-component magnetometer measuring circuit under the true geography, and the measuring circuit has wide application range, and can be used for aerospace and complex submarine environment. The circuit can measure the three-component vector magnetic field value under the true geographic coordinate system in real time, provides accurate original data for drawing magnetic anomaly imaging, and is beneficial to the development of detection and search technologies.

Claims

1. The utility model provides a measurement circuit of true geography three-component magnetometer, includes power supply circuit, sensor signal acquisition circuit, master control circuit, serial ports gesture measurement circuit, RTC clock circuit, data transmission circuit, SD card memory circuit, file management circuit, external interface circuit, its characterized in that:

The sensor signal acquisition circuit comprises an X-axis analog signal addition circuit, a Y-axis analog signal addition circuit and a Z-axis analog signal addition circuit;

The Y-axis analog signal adding circuit comprises an operational amplifier chip U4, resistors R10-R14, capacitors C11-C14 and a polar capacitor Cp6; one end of a resistor R10, one end of a resistor R11 and one end of a resistor R12 are connected with a pin 3 of an operational amplifier chip U4, the other end of the resistor R10 is connected with a +4.5V reference voltage output end of a +4.5V reference voltage circuit, the other end of the resistor R11 is connected with one end of a capacitor C11 and is used as an input end of a Y-cycle magnetic field signal, and the other end of the capacitor C11 is connected with the other end of the resistor R12 and grounded; the 4 pin of the operational amplifier chip U4 is grounded; one end of a capacitor C12, the positive electrode of a polar capacitor Cp6 and the +5V voltage stabilizing output end of the +5V voltage stabilizing circuit are connected with the 8 pin of the operational amplifier chip U4, and the other end of the capacitor C12 is connected with the negative electrode of the polar capacitor Cp6 and grounded; one end of a pin 6 and a pin 7 of the operational amplifier chip U4 and one end of a capacitor C14 are connected and serve as an output end of the Y-axis analog signal addition circuit, and the pin 4 of the power strip P2 is connected; one end of the capacitor C13 and one end of the resistor R13 are connected with the pin 5 of the operational amplifier chip U4, the other end of the capacitor C13 is grounded, the other end of the resistor R13 and one end of the resistor R14 are connected with the other end of the capacitor C14, and the other end of the resistor R14 is connected with the power supply V_Back; the operational amplifier chip U4 adopts a precision operational amplifier chip OPA2376 of Texas instruments;

The digital-to-analog conversion circuit comprises an analog-to-digital conversion chip U14, polar capacitors Cp11-Cp12, resistors R29-R32, capacitors C48-C55 and a crystal oscillator X3; one end of the capacitor C48, the positive electrode of the polar capacitor Cp11 and the 1 pin of the analog-digital conversion chip U14 are connected with the +5V voltage stabilizing output end of the +5V voltage stabilizing circuit; the other end of the capacitor C48 and the negative electrode of the polar capacitor Cp11 are connected with each other and grounded; the 4 pin of the analog-to-digital conversion chip U14 is connected with the +2.5V reference voltage output end of the +2.5V reference voltage circuit; 3 feet, 6 feet, 7 feet, 9 feet, 11 feet, 13 feet, 5 feet and 2 feet of the analog-digital conversion chip U14 are grounded; one end of the capacitor C49 and the 8 pin of the analog-digital conversion chip U14 are connected and then connected with the 6 pin of the universal socket P2, and the other end of the capacitor C49 is grounded; one end of the capacitor C50 and the pin 10 of the analog-digital conversion chip U14 are connected and then are connected with the pin 4 of the power strip P2, and the other end of the capacitor C50 is grounded; one end of the capacitor C51 and the pin 12 of the analog-digital conversion chip U14 are connected and then are connected with the pin 2 of the power strip P2, and the other end of the capacitor C51 is grounded; the 14 pin of the analog-to-digital conversion chip U14 is connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit; one end of the resistor R29 is connected with the 24 pin of the analog-digital conversion chip U14, and the other end of the resistor R29 is connected with the 52 pin of the main control circuit; one end of the resistor R30 is connected with the 23 pin of the analog-digital conversion chip U14, and the other end of the resistor R30 is connected with the 54 pin of the main control circuit; one end of the resistor R31 is connected with the pin 22 of the analog-digital conversion chip U14, and the other end of the resistor R31 is connected with the pin 53 of the main control circuit; one end of the resistor R32 is connected with the 21 pin of the analog-digital conversion chip U14, and the other end of the resistor R32 is connected with the 56 pin of the main control circuit; the 20 pin of the analog-digital conversion chip U14 is grounded; one end of the crystal oscillator X3 and one end of the capacitor C54 are connected with the 19 pin of the analog-digital conversion chip U14; one end of the capacitor C55 and the other end of the crystal oscillator X3 are connected with the 18 pin of the analog-digital conversion chip U14; the other end of the capacitor C54 is connected with the other end of the capacitor C55 and then grounded; the 17 pin of the analog-digital conversion chip U14 is grounded; one end of the capacitor C52, the positive electrode of the polar capacitor Cp12, the 15 pin and the 16 pin of the analog-digital conversion chip U14 are connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit; the other end of the capacitor C52 is connected with the negative electrode of the polar capacitor C12 and then grounded; other pins of the analog-digital conversion chip U14 are suspended; the analog-to-digital conversion chip U14 adopts a 24-bit analog-to-digital conversion chip ADS1256 of a Texas instrument;

The main control circuit comprises a main control chip U12, resistors R24-R25, capacitors C41-C44 and a crystal oscillator X2; one end of a capacitor C41 and one end of a crystal oscillator X2 are connected with the 12 pin of the main control chip U12, one end of a capacitor C42 and the other end of the crystal oscillator X2 are connected with the 13 pin of the main control chip U12, the other end of the capacitor C41 and the other end of the capacitor C42 are grounded, and the 94 pin of the main control chip U12 is grounded through a resistor R24; one end of the resistor R25 and one end of the capacitor C43 are connected with the 14 pin of the main control chip U12, the other end of the resistor R25 is connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit, and the other end of the capacitor C43 is grounded; one end of the capacitor C44 is connected with the 6 pin of the main control chip U12, and the other end of the capacitor C44, the 50 pin, the 75 pin, the 100 pin, the 28 pin, the 11 pin and the 22 pin are connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit; the 20 feet, 49 feet, 74 feet, 99 feet, 10 feet and 19 feet of the main control chip U12 are grounded; the main control chip U12 is connected with one end of a resistor R29 in the analog-digital conversion circuit, the 53 pin is connected with one end of a resistor R31 in the analog-digital conversion circuit, the 54 pin is connected with one end of a capacitor R30 in the analog-digital conversion circuit, the 83 pin is connected with the 12 pin of the universal socket P2, the 56 pin is connected with one end of the resistor R32 in the analog-digital conversion circuit, the 30 pin is connected with the 5 pin of the SD card memory circuit, the 31 pin is connected with the 7 pin of the SD card memory circuit, the 32 pin is connected with the 3 pin of the SD card memory circuit, the 68 pin is connected with the 8 pin of the universal socket P2, the 69 pin is connected with the 10 pin of the socket P2, the 72 pin is connected with the 2 pin of the plug-in device SWD, the 76 pin is connected with the 3 pin of the plug-in device SWD, the 78 pin is connected with the 2 pin of the serial port gesture measurement circuit, the 79 pin is connected with the 3 pin of the universal socket P2, the 1 pin is connected with the 3 pin of the RTC clock circuit, the 2 is connected with the 15 pin of the SD card memory circuit, the 4 pin is connected with the 3 pin of the RTC clock circuit, and the 21 pin is connected with the +3.3V voltage stabilizing output terminal of the circuit; the remaining pins of the main control chip U12 are suspended; the main control chip U12 adopts an STM32F103RCT6 chip of an artificial semiconductor;

The serial port gesture measurement circuit comprises a serial port gesture measurement chip U17, a capacitor C62 and a polar capacitor Cp14; the 7 pins, the 8 pins and the 4 pins of the serial port gesture measurement chip U17 are respectively grounded; one end of the capacitor C62, the positive electrode of the polar capacitor Cp14 and the 1 pin of the serial port gesture measurement chip U17 are connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit, and the other end of the capacitor C62 and the negative electrode of the polar capacitor Cp14 are respectively grounded; the 2 pin of the serial port gesture measurement chip U17 is connected with the 78 pin of the main control circuit; the 3 pin of the serial port gesture measurement chip U17 is connected with the 79 pin of the main control circuit; the pins 4, 7 and 8 of the serial port gesture measurement chip U17 are grounded; other pins of the serial port gesture measurement chip U17 are suspended; the serial port attitude measurement chip U17 adopts a LEADIY-M3 chip of soft core micro-technology;

the RTC clock circuit comprises a clock chip U13, resistors R26-R28, capacitors C45-C46 and a button cell B1; one end of the capacitor C45, one end of the resistor R26 and the 2 pin of the clock chip U13 are connected and then connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit, the other end of the capacitor C45 is grounded, and the other end of the resistor R26 and the 3 pin of the clock chip U13 are connected and then connected with the 1 pin of the main control circuit; the 5 pin, the 6 pin, the 7 pin, the 8 pin, the 9 pin, the 10 pin, the 11 pin, the 12 pin and the 13 pin of the clock chip U13 are grounded; one end of the resistor R27 and the 15 pin of the clock chip U13 are connected and then connected with the 2 pin of the main control circuit, one end of the resistor R28 and the 16 pin of the clock chip U13 are connected and then connected with the 4 pin of the main control circuit, and the other end of the resistor R27 and the other end of the resistor R28 are connected and then connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit; one end of the capacitor C46 and the positive electrode of the button battery B1 are connected with the 14 pin of the clock chip U13, the other end of the capacitor C46 is grounded, and the negative electrode of the button battery B1 is grounded; the remaining pins of the clock chip U13 are suspended; the clock chip U13 adopts a DS3231SN chip of a wetting semiconductor;

The data transmission circuit comprises a multichannel RS-232 line driver/receiver U8, capacitors C25-C29 and a polar capacitor Cp9; the 1 pin and the 3 pin of the multichannel RS-232 circuit driver/receiver U8 are respectively connected with two ends of a capacitor C25, the 4 pin and the 5 pin are respectively connected with two ends of a capacitor C26, the 15 pin is directly grounded, the 10 pin is used as the 8 pin of the signal output connection socket P2, the 9 pin is used as the 10 pin of the signal input connection socket P2, the 6 pin is grounded through a capacitor C29, the 2 pin is grounded through a capacitor C28, one end of the capacitor C27, the positive electrode of a polar capacitor Cp9 and the 16 pin are connected and then connected with the +5V voltage stabilizing output end of the +5V voltage stabilizing circuit, the other end of the capacitor C27 and the negative electrode of the polar capacitor Cp9 are connected and then grounded, the 7 pin is connected with the 4 pin of a wire holder P1, the 8 pin is connected with the 3 pin of the wire holder P1, and the other pins of the multichannel RS-232 circuit driver/receiver U8 are suspended; the multichannel RS-232 line driver/receiver U8 adopts a MAX3232 chip of Texas instruments;

the SD card memory circuit comprises an SDCard-U18, a capacitor C63 and resistors R35-R36; one end of the capacitor C63 and the 4 pin of the SDCard-U18 are connected and then connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit, and the other end of the capacitor C63 and the 6 pin of the SDCard-U18 are connected and then grounded; one end of the resistor R35 and the 3 pin of the SDCard-U18 are connected and then connected with the 32 pin of the main control circuit, the other end of the resistor R35 and one end of the resistor R36 are connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit, and the other end of the resistor R36 and the 7 pin of the SDCard-U18 are connected and then connected with the 31 pin of the main control circuit; the 5 pin of the SDCard-U18 is connected with the 30 pin of the main control circuit, and the 2 pin is grounded; the remaining pins of the SDCard-U18 are suspended;

The file management circuit comprises a file management control chip U9, capacitors C30-C33, a resistor R22, a light-emitting diode D2 and a crystal oscillator X1; one end of the capacitor C30 is connected with the 2 pin of the file management control chip U9, and the other end of the capacitor C30 is connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit; the 5 pins of the file management control chip U9 are connected with the 12 pins of the universal power strip P2, and the 6 pins are connected with the 14 pins of the universal power strip P2; one end of the capacitor C31 and the 9 pin of the file management control chip U9 are connected and then connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit, and the other end of the capacitor C31 is grounded; the 10 pins of the file management control chip U9 are connected with the 7 pins of the wire holder P1, and the 11 pins are connected with the 6 pins of the wire holder P1; the 12 pins of the file management control chip U9 are grounded; the 13 pins and the 14 pins of the file management control chip U9 are respectively connected with the two ends of the crystal oscillator X1; one end of the capacitor C32, one end of the capacitor C33 and the 28 pin of the file management control chip U9 are connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit; the other end of the capacitor C32 and the other end of the capacitor C33 are respectively grounded; the cathode of the light emitting diode D2 is connected with 24 pins of the file management control chip U9, the anode of the light emitting diode D2 is connected with one end of a resistor R22, and the other end of the resistor R22 is connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit; the 23 pin, the 21 pin and the 20 pin of the file management control chip U9 are respectively grounded; the 19 pin of the file management control chip U9 is connected with the +3.3V voltage stabilizing output end of the +3.3V voltage stabilizing circuit; other pins of the file management control chip U9 are suspended; the file management control chip U9 adopts a CH376S chip;

2. A true geographic three component magnetometer measurement circuit as defined in claim 1 wherein: the +15V voltage stabilizing circuit and the-15V voltage stabilizing circuit comprise a switching power supply chip U1 and capacitors C1-C3; one end of the capacitor C1 and the 2 pin of the switching power supply chip U1 are connected and then grounded, and the other end of the capacitor C1 and the 1 pin of the switching power supply chip U1 are connected and then connected with a +24V power supply; one end of the capacitor C2 is connected with the 3 pin of the switching power supply chip U1 and is used as a +15V power supply output end; the other end of the capacitor C2, one end of the capacitor C3 and the pin 4 of the switching power supply chip U1 are connected and then grounded; the other end of the capacitor C3 is connected with the 5 pin of the switching power supply chip U1 and is used as a power supply output end of-15V; the switching power supply chip U1 adopts a DC-DC switching power supply chip of Texas instruments.

3. A true geographic three component magnetometer measurement circuit as defined in claim 1 wherein: the +5V voltage stabilizing circuit comprises a switching power supply chip U2, polar capacitors Cp1-Cp4, resistors R1-R4, an inductor L1, capacitors C4-C6 and a light emitting diode D1; the 7 pin of the switching power supply chip U2, one end of the resistor R1, the positive electrode of the polar capacitor Cp2 and the positive electrode of the polar capacitor Cp3 are connected with a +24V power supply; the negative electrode of the polar capacitor Cp1, the negative electrode of the polar capacitor Cp2 and the negative electrode of the polar capacitor Cp3 are respectively grounded; the other end of the resistor R1 and the 5 pin of the switching power supply chip U2 are connected with one end of the resistor R2; the other end of the resistor R2 and the 6 pin of the switching power supply chip U2 are connected and then grounded; one end of the capacitor C4 is connected with the 1 pin of the switching power supply chip U2, the other end of the capacitor C4, one end of the inductor L1 and the cathode of the diode D1 are connected with the 8 pin of the switching power supply chip U2; the anode of the diode D1 is grounded; the other end of the inductor L1, one end of the resistor R3, the positive electrode of the polar capacitor Cp4, one end of the capacitor C5 and one end of the capacitor C6 are connected to serve as +5V power supply output ends; the other end of the resistor R3 and one end of the resistor R4 are connected with the 4 pin of the switching power supply chip U2; the negative electrode of the polar capacitor Cp4 and the other end of the resistor R4 are connected and then grounded, and the other end of the capacitor C5 and the other end of the capacitor C6 are respectively grounded; the remaining pins of the switching power supply chip U2 are suspended; the switching power supply chip U2 adopts a switching power supply chip TPS5420 of Texas instruments.

4. A true geographic three component magnetometer measurement circuit as defined in claim 1 wherein: the +4.5V reference voltage circuit comprises a reference voltage chip U6, an operational amplifier chip U7, an inductor L2, a polar capacitor Cp8, capacitors C19-C24 and resistors R20-R21; one end of the inductor L2, the positive electrode of the polar capacitor Cp8 and one end of the capacitor C19 are connected with the 2 pin of the reference voltage chip U7; the other end of the inductor L2 is connected with the +5V voltage stabilizing output end of the +5V voltage stabilizing circuit; the negative electrode of the polar capacitor Cp8, the other end of the capacitor C19 and the pin 4 of the reference voltage chip U6 are connected and grounded; one end of the resistor R20 is connected with the 6 pin of the reference voltage chip U6, the other end of the resistor R20 and one end of the capacitor C21 are connected with the 3 pin of the operational amplifier chip U7, and the other end of the capacitor C21 is grounded; one end of the capacitor C20 is connected with the 5 pin of the reference voltage chip U6, and the other end of the capacitor C20 is grounded; the 4 pin of the operational amplifier chip U7 is grounded; one end of the capacitor C22 and the 7 pin of the operational amplifier chip U7 are connected and then connected with the +5V voltage stabilizing output end of the +5V voltage stabilizing circuit, and the other end of the capacitor C22 is grounded; one end of the resistor R21 is connected with the 6 pin of the operational amplifier chip U7, the other end of the resistor R21, one end of the capacitor C23 and one end of the capacitor C24 are connected, and the other end of the capacitor C23 and the other end of the capacitor C24 are respectively grounded as +4.5V reference voltage output ends; the rest pins of the reference voltage chip U6 and the operational amplifier chip U7 are suspended; the reference voltage chip U6 adopts a reference voltage chip REF5045 of a Texas instrument; the operational amplifier chip U7 uses the fine operational amplifier chip OPA376 of texas instruments.

5. A true geographic three component magnetometer measurement circuit as defined in claim 1 wherein: the +3.3V voltage stabilizing circuit comprises a voltage stabilizing power supply chip U10, a polar capacitor Cp10 and capacitors C34-C36; the positive electrode of the polar capacitor Cp10, one end of the capacitor C34 and the 3 pin of the regulated power supply chip U10 are connected with the power supply VDD, and the negative electrode of the polar capacitor Cp10 and the other end of the capacitor C34 are respectively grounded; the 1 pin of the regulated power supply chip U10 is grounded; one end of a capacitor C35 and one end of a capacitor C36 are connected with the 2 pin of the regulated power supply chip U10 and serve as a +3.3V voltage output end of a +3.3V voltage stabilizing circuit, and the other end of the capacitor C35 and the other end of the capacitor C36 are grounded respectively; the regulated power supply chip U10 employs a regulated power supply chip LM1117.

6. A true geographic three component magnetometer measurement circuit as defined in claim 1 wherein: the +3.3V switching power supply circuit comprises a switching power supply chip U11, capacitors C37-C40, a resistor R23 and a light-emitting diode D3; one end of the capacitor C38, one end of the capacitor C37 and 3 pins and 4 pins of the switching power supply chip U11 are connected and then connected with a +5V voltage stabilizing output end of the +5V voltage stabilizing circuit, the other end of the capacitor C37 and 2 pins of the switching power supply chip U11 are connected and then grounded, and the other end of the capacitor C38 and 1 pin of the switching power supply chip U11 are connected and then grounded; one end of a capacitor C39, one end of a capacitor C40, one end of a resistor R23, a pin 5 and a pin 6 of a switching power supply chip U11 are connected and then connected with a voltage stabilizing output end of +3.3V of a +3.3V voltage stabilizing circuit, the other end of the capacitor C39 and the other end of the capacitor C40 are respectively grounded, the other end of the resistor R23 is connected with an anode of a light emitting diode D3, and a cathode of the light emitting diode D3 is grounded; the remaining pins of the switching power supply chip U11 are suspended; the switching power supply chip U11 is a texas instrument switching power supply chip TPS7350.

7. A true geographic three component magnetometer measurement circuit as defined in claim 1 wherein: the +2.5V reference voltage circuit comprises a reference voltage chip U15, an operational amplifier chip U16, an inductor L3, a polar capacitor Cp13, capacitors C56-C61 and resistors R33-R34; one end of the inductor L3, the positive electrode of the polar capacitor Cp13 and one end of the capacitor C56 are connected with the 2 pin of the reference voltage chip U15, the other end of the inductor L3 is connected with the +5V voltage stabilizing output end of the +5V voltage stabilizing circuit, and the negative electrode of the polar capacitor Cp13, the other end of the capacitor C56 and the 4 pin of the reference voltage chip U15 are grounded after being connected; one end of the resistor R33 is connected with the 6 pin of the reference voltage chip U15, the other end of the resistor R33 and one end of the capacitor C58 are connected with the 3 pin of the operational amplifier chip U16, and the other end of the capacitor C58 is grounded; one end of the capacitor C57 is connected with the 5 pin of the reference voltage chip U15, and the other end of the capacitor C57 is grounded; the 4 pin of the operational amplifier chip U16 is grounded; one end of the capacitor C59 and the 7 pin of the operational amplifier chip U16 are connected and then connected with the +5V voltage stabilizing output end of the +5V voltage stabilizing circuit, and the other end of the capacitor C59 is grounded; one end of the resistor R34 is connected with the 6 pin of the operational amplifier chip U16, the other end of the resistor R34, one end of the capacitor C60 and one end of the capacitor C61 are connected, and the other end of the capacitor C60 and the other end of the capacitor C61 are respectively grounded as +2.5V reference voltage output ends; the other pins of the reference voltage chip U15 and the operational amplifier chip U16 are suspended; reference voltage chip U15 uses reference voltage chip REF5045 of Texas instruments; the op-amp chip U16 employs a texas instrument precision op-amp chip OPA376.

8. A true geographic three component magnetometer measurement circuit as defined in claim 1 wherein: the fluxgate sensor is a MAG03MCL100 fluxgate sensor of Bartington company in England.