Research On Vehicle Integrated Navigation System Based On Single Axis Fiber Optic Gyro

The dual-antenna GPS navigation system can provide the speed,position and heading angle information required for land vehicle navigation,but the GPS signal is susceptible to interference and output frequency of the GPS signa is low,especially when the vehicle is turning,It is difficult to guarantee the accuracy of the vehicle’s heading angle information.while the fiber optic gyro strapdown inertial navigation system has many advantages such as small size,high sensitivity,high output frequency,etc.it can maintain a certain attitude angle accuracy in a short period of time,but the cost of land-based car navigation fiber optic gyro is higher,so This paper proposes a low-cost simplified inertial navigation system(RISS)design solution based on single-axis fiber optic gyro.The designed simplified inertial navigation system and dual-antenna GPS navigation system are used to construct a combined navigation system to increase the output frequency of navigation information while ensuring that the accuracy of the heading angle information output by the system is less than 0.5 ?,and the hardware and software design of the dual-antenna GPS / RISS integrated navigation system is implemented based on the TMS320C6713 DSP chip.The main research contents are as follows:First,the domestic and foreign simplified inertial navigation system design schemes were investigated,and the working principles of the two simplified inertial navigation systems were analyzed in detail.Based on the existing conditions in the laboratory,A new simplified inertial navigation system is designed using the inclination sensor,single-axis gyroscope and accelerometer.The working principle is analyzed in detail and the mechanics arrangement equation is established.The factors affecting the navigation performance of the simplified inertial navigation system are analyzed and derived in detail.The navigation error model is derived.The composition and positioning principle of the GPS system are studied,and the pseudo-range positioning method and the carrier phase positioning method are compared and analyzed.The dual-antenna GPS heading angle solution equation based on the carrier phase method is derived.Then study the principle of Kalman filtering,compare and analyze the advantages and disadvantages of direct filtering and indirect filtering,construct a dual-antenna GPS / RISS loose combined filtering algorithm model based on indirect method,and design a trajectory generator to generate trajectory parameters to simulate the integrated navigation algorithm.Research and simulation results show that the heading angle accuracy is significantlyimproved when dual antenna GPS is used.Secondly,the hardware implementation of the integrated navigation system based on DSP + FPGA and the writing of related software programs are introduced.The composition of the hardware system and the main functions of each part are introduced in detail.The control program and navigation solver program of the integrated navigation system are designed in the DSP development environment CCS3.3.Finally,a sports car experiment is designed.The orientation accuracy and installation error of the dual-antenna GPS are checked first,and then a sports car test is performed.The experimental results prove the correctness of the designed navigation algorithm.When the dual-antenna GPS is at 1 meter baseline,the heading accuracy of the integrated navigation system can reach 0.3?.