阅读说明：本技术 一种基于磁阻传感器的电子罗盘 (Electronic compass based on magnetoresistive sensor ) 是由 马驰 朱悦 张鹏 于 2018-08-07 设计创作，主要内容包括：一种基于磁阻传感器的电子罗盘,属于传感器检测技术领域,是主要由TMR传感器、放大电路、滤波电路、AD转换模块、微处理器、串口模块、上位机和三轴加速度计组成的,本发明的基于磁阻传感器的电子罗盘具有灵敏度高,线性度好,动态范围宽等特点,选择并采用椭球、椭圆拟合及最小二乘法算法进行数据修正和误差补偿,线性度良好。(The invention relates to an electronic compass based on a magnetoresistive sensor, which belongs to the technical field of sensor detection and mainly comprises a TMR sensor, an amplifying circuit, a filter circuit, an AD conversion module, a microprocessor, a serial port module, an upper computer and a three-axis accelerometer.)

1. The utility model provides an electron compass based on magnetic resistance sensor, is mainly by TMR sensor, amplifier circuit, filter circuit, AD conversion module, microprocessor, serial port module, host computer and triaxial accelerometer constitution, its characterized in that: the TMR sensor is connected with the amplifying circuit, the amplifying circuit is connected with the filter circuit, the filter circuit is connected with the AD conversion module, the AD conversion module is connected with the microprocessor, the microprocessor is connected with the serial port module, the serial port module is connected with an upper computer, and the triaxial accelerometer is connected with the microprocessor.

2. An electronic compass based on magnetoresistive sensors, as claimed in claim 1, characterized in that: the amplifier circuit adopts AD623, and the common mode voltage is +2.048V, and the magnification is 11 times, and the ADC adopts the AD7689 successive approximation type of charge redistribution of four channel positions. The filter circuit is a second-order passive filter circuit.

3. An electronic compass based on magnetoresistive sensors, as claimed in claim 1, characterized in that: the three-axis accelerometer adopts MMA8451Q, the accelerometer adopts +5V power supply, and a 4.7 muf fault removing capacitor is connected to the power supply and the ground terminal so as to reduce the noise of the power supply part. Through IIC bus interface and singlechip communication, MMA8451Q is as the slave unit, selects the address as 0x1C through pin SA0, according to IIC bus interface demand, pulls up SCL and SDA pin to VCC through 4.7K resistance.

Technical Field

The invention relates to an electronic compass based on a magnetoresistive sensor, and belongs to the technical field of sensor detection.

Background

The electronic compass is widely applied to the fields of aerospace, navigation surveying and mapping, integrated navigation, aircraft control and the like, has important influence on national economy and military development, and is a research hotspot at home and abroad in recent years; the current geomagnetic detection in the electronic compass is commonly used and has the sensor or fluxgate technology of effect, but the detection mode has the defects of low sensitivity, poor linearity, complex post circuit, large volume and the like. The invention develops an electronic compass based on a magnetic resistance sensor.

Disclosure of Invention

In view of the above-mentioned shortcomings, the present invention provides an electronic compass based on a magnetoresistive sensor.

The invention is realized by the following technical scheme: the utility model provides an electron compass based on magnetic resistance sensor, is mainly by TMR sensor, amplifier circuit, filter circuit, AD conversion module, microprocessor, serial port module, host computer and triaxial accelerometer constitution, its characterized in that: the TMR sensor is connected with the amplifying circuit, the amplifying circuit is connected with the filter circuit, the filter circuit is connected with the AD conversion module, the AD conversion module is connected with the microprocessor, the microprocessor is connected with the serial port module, the serial port module is connected with an upper computer, and the triaxial accelerometer is connected with the microprocessor.

The amplifier circuit adopts AD623, and the common mode voltage is +2.048V, and the magnification is 11 times, and the ADC adopts the AD7689 successive approximation type of charge redistribution of four channel positions. The filter circuit is a second-order passive filter circuit.

The three-axis accelerometer adopts MMA8451Q, the accelerometer adopts +5V power supply, and a 4.7 muf fault removing capacitor is connected to the power supply and the ground terminal so as to reduce the noise of the power supply part. Through IIC bus interface and singlechip communication, MMA8451Q is as the slave unit, selects the address as 0x1C through pin SA0, according to IIC bus interface demand, pulls up SCL and SDA pin to VCC through 4.7K resistance.

The invention has the advantages that: the electronic compass based on the magnetoresistive sensor has the characteristics of high sensitivity, good linearity, wide dynamic range and the like, and data correction and error compensation are carried out by selecting and adopting an ellipsoid, ellipse fitting and least square algorithm. The linearity is good.

Drawings

FIG. 1 is a schematic diagram of the system of the present invention.

In the figure, the TMR sensor 1, the TMR sensor 2, the amplifying circuit 3, the filter circuit 4, the AD conversion module 5, the microprocessor 6, the serial port module 7, the upper computer 8 and the three-axis accelerometer.

Detailed Description

The utility model provides an electron compass based on magnetic resistance sensor, is mainly by TMR sensor 1, amplifier circuit 2, filter circuit 3, AD conversion module 4, microprocessor 5, serial module 6, host computer 7 and triaxial accelerometer 8 constitute, its characterized in that: TMR sensor 1 is connected with amplifier circuit 2, and amplifier circuit 2 is connected with filter circuit 3, and filter circuit 3 is connected with AD conversion module 4, and AD conversion module 4 is connected with microprocessor 5, and microprocessor 5 is connected with serial port module 6, and serial port module 6 is connected with host computer 7, and triaxial accelerometer 9 is connected with microprocessor 5.

The amplifying circuit 2 adopts AD623, the common mode voltage is +2.048V, the amplification factor is 11 times, and the ADC adopts an AD7689 successive approximation type of charge redistribution of four channel positions. The filter circuit is a second-order passive filter circuit.

The triaxial accelerometer 9 adopts MMA8451Q, the accelerometer adopts +5V power supply, and a 4.7 muf fault removing capacitor is connected between a power supply and a ground terminal so as to reduce the noise of a power supply part. Through IIC bus interface and singlechip communication, MMA8451Q is as the slave unit, selects the address as 0x1C through pin SA0, according to IIC bus interface demand, pulls up SCL and SDA pin to VCC through 4.7K resistance.

When the device works, the electronic compass obtains the triaxial magnetic field component in a carrier coordinate system through sensing geomagnetic field information by the TMR sensor MMLP44F, acquires the gravity field information through the accelerometer, and calculates the attitude angle according to the information. And transforming the triaxial magnetic field component in the carrier coordinate system into a geographic coordinate system by combining geomagnetic field information and attitude angles, wherein the corrected geomagnetic field component is used for calculating an azimuth angle, and the microprocessor adopts STM32F103C8T 6. And data correction and error compensation are carried out by selecting and adopting an ellipsoid, ellipse fitting and least square algorithm, and a calculation result is output to a computer through a serial port to finish real-time graphic display and data storage.

It will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in the embodiments described above without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims.