阅读说明：本技术 Gnss/mimu/气压高度计的组合导航系统及方法 (GNSS/MIMU/barometric altimeter combined navigation system and method ) 是由 陈帅 刘善武 顾得友 温哲君 王琛 谭聚豪 于 2019-10-25 设计创作，主要内容包括：本发明公开了一种GNSS/MIMU/气压高度计的组合导航系统及方法。该系统包括微处理器、大气压强传感器和GNSS/MIMU组合导航系统,其中GNSS/MIMU组合导航系统包括GNSS接收机、微惯导和上位机。首先大气压强传感器采集当前环境的气压和温度值,得到模拟的气压信号和温度信号,并经模数转换、过滤及校正处理后,得到校正的数字气压信号及温度信号；然后微处理器接收校正的数字温度信号及气压信号后,根据预设的海拔高度算法进行计算,得到海拔高度,并根据需要进行补偿；最后将计算得到的海拔高度推送给GNSS/MIMU组合导航系统,进行组合导航。本发明具有精度高、成本低、体积小、易嵌入且便于携带的优点。(The invention discloses a combined navigation system and method of a GNSS/MIMU/barometric altimeter. The system comprises a microprocessor, an atmospheric pressure sensor and a GNSS/MIMU integrated navigation system, wherein the GNSS/MIMU integrated navigation system comprises a GNSS receiver, a micro inertial navigation system and an upper computer. Firstly, an atmospheric pressure sensor acquires the air pressure and temperature value of the current environment to obtain a simulated air pressure signal and a simulated temperature signal, and the simulated air pressure signal and the simulated temperature signal are subjected to analog-to-digital conversion, filtering and correction processing to obtain a corrected digital air pressure signal and a corrected temperature signal; then after the microprocessor receives the corrected digital temperature signal and the corrected air pressure signal, the altitude is calculated according to a preset altitude algorithm to obtain the altitude, and compensation is carried out according to the requirement; and finally, pushing the calculated altitude to a GNSS/MIMU integrated navigation system for integrated navigation. The invention has the advantages of high precision, low cost, small volume, easy embedding and convenient carrying.)

1. The integrated navigation system of the GNSS/MIMU/barometric altimeter is characterized by comprising a microprocessor, an atmospheric pressure sensor and a GNSS/MIMU integrated navigation system, wherein the GNSS/MIMU integrated navigation system comprises a GNSS receiver, a micro inertial navigation unit and an upper computer;

the atmospheric pressure sensor is connected with the microprocessor and used for acquiring current air pressure and a current temperature value to obtain an analog air pressure signal and a temperature signal, performing analog-to-digital conversion and filtering processing on the obtained signal to obtain a filtered digital air pressure acquisition signal and a filtered digital temperature acquisition signal, and compensating and correcting the filtered digital air pressure acquisition signal and the filtered digital temperature acquisition signal;

the microprocessor is used for receiving the digital temperature acquisition signal and the digital air pressure acquisition signal which are corrected by the atmospheric pressure sensor, calculating the received corrected digital air pressure acquisition signal according to a preset altitude algorithm to obtain the altitude, and transmitting the calculated altitude data to the GNSS/MIMU combined navigation system after error compensation;

the GNSS/MIMU combined navigation system receives the initial height value by using the GNSS receiver, sends the initial height value to the microprocessor for processing, and then outputs the initial height value to the upper computer monitoring system, the micro inertial navigation system provides three-dimensional postures of a yaw angle, a pitch angle and a roll angle, speed and position information for the GNSS/MIMU combined navigation system, and the microprocessor provides the height value converted from atmospheric pressure.

2. The integrated GNSS/MIMU/barometric altimeter navigation system of claim 1, wherein the barometric pressure sensor comprises a sampling unit, an analog-to-digital converter, a control unit and an external interface circuit connected in sequence;

the sampling unit is used for acquiring the current air pressure and the current temperature in real time to form a simulated air pressure signal and a simulated temperature signal;

the analog-to-digital converter is used for performing analog-to-digital conversion on the simulated air pressure signal and the simulated temperature signal to obtain a digital air pressure signal and a digital temperature signal;

the control unit is used for filtering and compensating the digital air pressure signal and the temperature signal to obtain a corrected digital air pressure signal and a corrected temperature signal;

and the interface circuit is used for communication between the control unit and the microprocessor.

3. The integrated GNSS/MIMU/barometric altimeter navigation system of claim 1, wherein the barometric pressure sensor is a type BMP280 barometric pressure sensor.

4. The integrated GNSS/MIMU/barometric altimeter navigation system according to claim 1, wherein said microprocessor is a single chip microcomputer of model STM32F103ZET 6.

5. The integrated GNSS/MIMU/HE system of claim 1, wherein the host computer is a computer with monitoring software for real-time viewing of output information of the integrated GNSS system.

6. A combined navigation method of GNSS/MIMU/barometric altimeter is characterized by comprising the following steps:

firstly, a sampling unit of an atmospheric pressure sensor acquires the air pressure and temperature value of the current environment to obtain an analog air pressure signal and a temperature signal, and the analog air pressure signal and the temperature signal are subjected to analog-to-digital conversion, filtering and correction to obtain a corrected digital air pressure signal and a corrected temperature signal;

then, after receiving the corrected digital temperature signal and the corrected air pressure signal, the microprocessor calculates according to a preset altitude algorithm to obtain the altitude, if the GNSS receiver is arranged at a position which is not on the same horizontal plane as the air pressure sensor, a height difference is generated between the GNSS receiver and the air pressure sensor, and compensation is carried out according to the height difference;

finally, the calculated altitude is pushed to a GNSS/MIMU integrated navigation system for integrated navigation; the integrated navigation system provides attitude information of yaw, pitch and roll angles, speed information of east, north and sky speeds, and position information of latitude, longitude and altitude for the carrier.

7. The integrated GNSS/MIMU/barometric altimeter navigation method according to claim 6, wherein said calculating according to a preset altitude algorithm obtains altitude, and the specific formula is:

wherein H is the altitude to be determined, P_HFor this high atmospheric pressure, the air specific gas constant R is 287.05287m²/(K·s²) Acceleration of gravity g in free fall_n＝9.80665(m/s²) Vertical rate of change of temperature β, T_b、H_b、P_bThe lower limit values of the atmospheric temperature, the standard atmospheric pressure altitude and the atmospheric pressure of the corresponding layer in the height stratification respectively adopted by the international standard atmosphere.

Technical Field

The invention relates to the technical field of integrated navigation, in particular to an integrated navigation system and method of a GNSS/MIMU/barometric altimeter.

Background

The GNSS/MIMU integrated navigation system, especially the low-cost GNSS/MIMU integrated navigation system, has become an international research hotspot as an important component in the field of navigation. The main purpose of combining the GNSS and the inertial navigation into a system is to improve the precision and the reliability of the navigation, and the combined mode overcomes the respective defects, makes up for the shortages, ensures that the integrated navigation precision is higher than the precision of the independent work of the two systems, realizes the real-time and high-precision navigation positioning in a complex environment with strong interference, and is a relatively perfect navigation system. However, the earth is opaque to electromagnetic wave signals of navigation satellites, so the elevation precision factor VDOP value is usually always larger than the horizontal position precision factor HDOP, which results in that the positioning result of the GNSS receiver in the vertical direction is not ideal in the horizontal direction, and the measurement precision of the GNSS/MIMU integrated navigation system is directly affected.

The abbreviation atmospheric pressure, is the atmospheric pressure acting on a unit area, equal to the weight of a vertical column of air extending upward to the upper boundary of the atmosphere per unit area. The barometric pressure is related to conditions such as height, temperature and the like, and generally, the barometric altimeter is manufactured according to the principle as the altitude gradually decreases. In the current application occasion, the mechanical barometer has a large proportion, and although the integrated navigation system based on the barometer is a multi-purpose digital barometer, the integrated navigation system still serves as an independent module to be matched with a GNSS receiver, an MIMU and the like in the application of an unmanned aerial vehicle and the like, so that the problems of large volume and high power consumption exist.

Disclosure of Invention

The invention aims to provide a combined navigation system and method of a GNSS/MIMU/barometric altimeter, which has high precision, small volume and low power consumption.

The technical solution for realizing the purpose of the invention is as follows: the integrated navigation system of the GNSS/MIMU/barometric altimeter is characterized by comprising a microprocessor, an atmospheric pressure sensor and a GNSS/MIMU integrated navigation system, wherein the GNSS/MIMU integrated navigation system comprises a GNSS receiver, a micro inertial navigation unit and an upper computer;

the atmospheric pressure sensor is connected with the microprocessor and used for acquiring current air pressure and a current temperature value to obtain an analog air pressure signal and a temperature signal, performing analog-to-digital conversion and filtering processing on the obtained signal to obtain a filtered digital air pressure acquisition signal and a filtered digital temperature acquisition signal, and compensating and correcting the filtered digital air pressure acquisition signal and the filtered digital temperature acquisition signal;

the microprocessor is used for receiving the digital temperature acquisition signal and the digital air pressure acquisition signal which are corrected by the atmospheric pressure sensor, calculating the received corrected digital air pressure acquisition signal according to a preset altitude algorithm to obtain the altitude, and transmitting the calculated altitude data to the GNSS/MIMU combined navigation system after error compensation;

the GNSS/MIMU combined navigation system receives the initial height value by using the GNSS receiver, sends the initial height value to the microprocessor for processing, and then outputs the initial height value to the upper computer monitoring system, the micro inertial navigation system provides three-dimensional postures of a yaw angle, a pitch angle and a roll angle, speed and position information for the GNSS/MIMU combined navigation system, and the microprocessor provides the height value converted from atmospheric pressure.

Furthermore, the atmospheric pressure sensor comprises a sampling unit, an analog-to-digital converter, a control unit and an external interface circuit which are connected in sequence;

the sampling unit is used for acquiring the current air pressure and the current temperature in real time to form a simulated air pressure signal and a simulated temperature signal;

the analog-to-digital converter is used for performing analog-to-digital conversion on the simulated air pressure signal and the simulated temperature signal to obtain a digital air pressure signal and a digital temperature signal;

the control unit is used for filtering and compensating the digital air pressure signal and the temperature signal to obtain a corrected digital air pressure signal and a corrected temperature signal;

and the interface circuit is used for communication between the control unit and the microprocessor.

Further, the air pressure sensor adopts a BMP280 type air pressure sensor.

Further, the microprocessor adopts a single chip microcomputer with the model number of STM32F103ZET 6.

Furthermore, the upper computer is a computer carrying monitoring software and is used for checking the output information of the integrated navigation system in real time.

A combined navigation method of GNSS/MIMU/barometric altimeter includes the following steps:

firstly, a sampling unit of an atmospheric pressure sensor acquires the air pressure and temperature value of the current environment to obtain an analog air pressure signal and a temperature signal, and the analog air pressure signal and the temperature signal are subjected to analog-to-digital conversion, filtering and correction to obtain a corrected digital air pressure signal and a corrected temperature signal;

then, after receiving the corrected digital temperature signal and the corrected air pressure signal, the microprocessor calculates according to a preset altitude algorithm to obtain the altitude, if the GNSS receiver is arranged at a position which is not on the same horizontal plane as the air pressure sensor, a height difference is generated between the GNSS receiver and the air pressure sensor, and compensation is carried out according to the height difference;

finally, the calculated altitude is pushed to a GNSS/MIMU integrated navigation system for integrated navigation; the integrated navigation system provides attitude information of yaw, pitch and roll angles, speed information of east, north and sky speeds, and position information of latitude, longitude and altitude for the carrier.

Further, the altitude is calculated according to a preset altitude algorithm, and the altitude is obtained according to a specific formula:

wherein H isAltitude to be determined, P_HFor this high atmospheric pressure, the air specific gas constant R is 287.05287m²/(K·s²) Acceleration of gravity g in free fall_n＝9.80665(m/s²) Vertical rate of change of temperature β, T_b、H_b、P_bThe lower limit values of the atmospheric temperature, the standard atmospheric pressure altitude and the atmospheric pressure of the corresponding layer in the height stratification respectively adopted by the international standard atmosphere.

Compared with the prior art, the invention has the following remarkable advantages: (1) the atmospheric pressure sensor, the microcontroller and the GNSS/MIMU integrated navigation system are all designed by adopting modular structures, so that the whole integrated system has the advantages of small volume, portability, low cost and easy plugging; (2) the air pressure sensor has the functions of filtering and correcting, and improves the precision of data acquired and processed by the microprocessor, thereby improving the precision of final positioning.

Drawings

FIG. 1 is a schematic block diagram of a GNSS/MIMU/barometric altimeter integrated navigation system according to the present invention.

FIG. 2 is a schematic structural diagram of a GNSS/MIMU/barometric altimeter integrated navigation system of the present invention.

Detailed Description

With reference to fig. 1-2, the integrated navigation system of GNSS/MIMU/altimeter of the present invention is characterized by comprising a microprocessor, an atmospheric pressure sensor and a GNSS/MIMU integrated navigation system, wherein the GNSS/MIMU integrated navigation system comprises a GNSS receiver, a micro inertial navigation unit and an upper computer;

the atmospheric pressure sensor is connected with the microprocessor and used for acquiring current air pressure and a current temperature value to obtain an analog air pressure signal and a temperature signal, performing analog-to-digital conversion and filtering processing on the obtained signal to obtain a filtered digital air pressure acquisition signal and a filtered digital temperature acquisition signal, and compensating and correcting the filtered digital air pressure acquisition signal and the filtered digital temperature acquisition signal;

the microprocessor is used for receiving the digital temperature acquisition signal and the digital air pressure acquisition signal which are corrected by the atmospheric pressure sensor, calculating the received corrected digital air pressure acquisition signal according to a preset altitude algorithm to obtain the altitude, and transmitting the calculated altitude data to the GNSS/MIMU combined navigation system after error compensation;

the GNSS/MIMU combined navigation system receives the initial height value by using the GNSS receiver, sends the initial height value to the microprocessor for processing, and then outputs the initial height value to the upper computer monitoring system, the micro inertial navigation system provides three-dimensional postures of a yaw angle, a pitch angle and a roll angle, speed and position information for the GNSS/MIMU combined navigation system, and the microprocessor provides the height value converted from atmospheric pressure.

As a specific embodiment, the atmospheric pressure sensor includes a sampling unit, an analog-to-digital converter, a control unit, and an external interface circuit, which are connected in sequence;

the sampling unit is used for acquiring the current air pressure and the current temperature in real time to form a simulated air pressure signal and a simulated temperature signal;

the analog-to-digital converter is used for performing analog-to-digital conversion on the simulated air pressure signal and the simulated temperature signal to obtain a digital air pressure signal and a digital temperature signal;

the control unit is used for filtering and compensating the digital air pressure signal and the temperature signal to obtain a corrected digital air pressure signal and a corrected temperature signal;

and the interface circuit is used for communication between the control unit and the microprocessor.

As a specific embodiment, the air pressure sensor is a BMP280 air pressure sensor.

As a specific embodiment, the microprocessor adopts a single chip microcomputer with the model number of STM32F103ZET 6.

As a specific embodiment, the upper computer is a computer carrying monitoring software and is used for viewing the output information of the integrated navigation system in real time.

A combined navigation method of GNSS/MIMU/barometric altimeter includes the following steps:

firstly, a sampling unit of an atmospheric pressure sensor acquires the air pressure and temperature value of the current environment to obtain an analog air pressure signal and a temperature signal, and the analog air pressure signal and the temperature signal are subjected to analog-to-digital conversion, filtering and correction to obtain a corrected digital air pressure signal and a corrected temperature signal;

then, after the microprocessor receives the corrected digital temperature signal and the corrected air pressure signal, calculation is carried out according to a preset altitude algorithm to obtain the altitude, if the GNSS receiver is placed at a position where the air pressure sensor is not located on the same horizontal plane, a height difference is generated between the GNSS receiver and the air pressure sensor, and output needs to be compensated in order to avoid the influence of the height difference on output precision.

And finally, pushing the calculated altitude to a GNSS/MIMU integrated navigation system for integrated navigation. At the moment, the combined navigation system can provide attitude information of yaw angle, pitch angle and roll angle, speed information of east speed, north speed and sky speed and more accurate position information of latitude, longitude and altitude for the carrier.

As a specific embodiment, the calculation is performed according to a preset altitude algorithm to obtain the altitude, and the formula is as follows:

wherein H is the altitude to be determined, P_HFor this high atmospheric pressure, the air specific gas constant R is 287.05287m²/(K·s²) Acceleration of gravity g in free fall_n＝9.80665(m/s²) Vertical rate of change of temperature β, T_b、H_b、P_bThe lower limit values of the atmospheric temperature, the standard atmospheric pressure altitude and the atmospheric pressure of the corresponding layer in the height stratification respectively adopted by the international standard atmosphere.

The invention is described in further detail below with reference to the figures and specific embodiments.