Design Of 9-Axis Electronic Compass

As a posture sensor,electronic compass has the characteristics of high accuracy,small volume,and low power consumption.It is widely used in military fields such as missile control,navigation,aerospace,and other military fields.With the advancement of science and technology,the cost of electronic compass has gradually decreased,and the application of civilian fields in automotive navigation and mining exploration has continued to expand.Today,a series of smart products such as unmanned aerial vehicles,balance cars,and smartphones have integrated electronic compass,and the application of electronic compass has penetrated into people’s lives.The design of domestic electronic compass products has always relied mainly on imported geomagnetic sensors,acceleration sensors,and other chips.Not only is the price high,but also the use of chips will be limited in some high-end products.Promoting the localization rate of electronic compass products is a current trend.The traditional electronic compass designed using 3-axis geomagnetic sensors and 3-axis acceleration sensors is mainly used to measure the attitude of static carriers.Due to the poor dynamic performance of acceleration sensors,this 6-axis electronic compass is not suitable for the attitude measurement of dynamic carriers.Based on the above issues,this paper proposes to design a 9-axis electronic compass using a domestic 3-axis geomagnetic sensor,a 3-axis acceleration sensor,and a 3-axis gyroscope sensor,which is characterized by high accuracy,low cost,and portability.The design of domestic electronic compass products has always rely on imported geomagnetic sensors,acceleration sensors and other chips.Not only is the price high,but the use of chips will also be limited in some high-end products.Promoting the domestic rate of electronic compass products is currently a trend of the current trend.The electronic compass designed by the traditional 3-axis graphic sensor and the 3-axis acceleration sensor is mainly used in the posture of measured the static carrier.Due to the poor dynamic performance of the acceleration sensor,this 6-axis electronic compass is not suitable for the gesture measurement of the dynamic carrier.Based on the above problems,this paper proposes a 9-axis electronic compass that applies a domestic 3-axis magnetic sensor,a 3-axis acceleration sensor and combined with the 3-axis gyroscope sensor,and has the characteristics of high accuracy,low cost,and easy carrying.The main research work of this article is as follows:(1)Use the magnetic sensor,acceleration sensor and gyroscope sensor as the data collection module of the electronic compass,and add the power module,microcontroller module and display module to complete the entire function of the electronic compass hardware circuit.Use Cadence software for circuit principles and PCB design,and finally,in order to facilitate the installation and use of the compass,use Solidworks software to design a packaging shell for the electronic compass.(2)Electronic compass lower machine software uses the Keilu Vision5 development platform for development,azimuth calculation principle based on rotation matrix and quaternion and combines the calculation method of the Calman filtering and planar circumferential calibration,implemented functions such as data acquisition,data filtering,error compensation for geomagnetic data,azimuth calculation,and data output.Finally,a humanmachine interaction interface was designed to achieve the function of displaying three azimuth data and sensor data.(3)The accuracy of the electronic compass was tested using a three-axis turntable.The static measurement results showed that the measurement error of the roll angle was less than0.5°,the measurement error of the pitch angle was less than 0.6°,and the measurement error of the heading angle was less than 0.7°.The dynamic measurement results show that the measurement errors of the three azimuth angles are all less than 0.8°,indicating that the accuracy of the electronic compass meets the design requirements.Fix the electronic compass and measure its output stability based on the amplitude of output azimuth jitter.According to the range of azimuth jitter of the electronic compass within 60 seconds that is less than 0.05°,it is concluded that the electronic compass has good output stability.Using a high and low temperature box to provide different environmental temperatures for the electronic compass,the accuracy of the electronic compass was tested,and it was found that the electronic compass can achieve measurement errors within 1°C in temperature environments ranging from-20°C to 40°C.