Design And Realization Of Strapdown AHRS Based On DSP Navigation Computer

As an important airborne equipment,Strapdown Inertial Attitude and Heading Reference System(AHRS) is in matter of flight safety.Smaller volume, lower cost, higher accuracy and reliability are theprimary demands to develop AHRS. New-style electronic technique such as DSP creates preconditionfor system miniaturization. One small airborne AHRS with DSP was designed, software wasresearched to improve the system accuracy, the hardware was realized for smller volume by this paper.The research result was well and was valuable for both military and engineering application.Firstly, A high performance micro-navigation computer based on DSP was designed to meet thedemand of the Attitude and Heading Reference System for processing ability, size and applicability.The DSP chip TMS320C6713was used as the processor and the CPLD was used as the controller ofthe extended peripheral interfaces, the DSP micro navigation computer can accomplish real-time datatransmission, real-time control signals outputs, strap-down inertial navigation algorithm and filteringalgorithm, etc.Secondly, Depending on the system performance requirements, strapdown AHRS core algorithmwas deeply studied. Centering on how to improve the accuracy of strapdown AHRS effectively,kalman damp algrorithm was deeply studied by this paper. The result kalman damp algrorithm provedcan effectively inhibit the Schuler cycle oscillation and Foucault oscillation cycle, to avoid the attitudedrift by mathematical algorithms, error analysis, simulation and experimental testing.The headingerror accumulation and divergence over time by the Strapdown Algorithm, and can not meet theSystem accuracy requirements,so add magnetic sensors to ARHS, Magnetic heading accuracy is notvery satisfactory.Therefore, magnetic heading error correction algorithm and compensation algorithmwere deeply studied and adaptive second-order magnetic heading correction algorithm was proposed,Experiments show that this algorithm was very flexible and engineering value.Thirdly, on the basis of the core algorithm research, software code was designed andstandardized. Firstly, the software modules of strapdown solver、kalman damp algrorithm andmagnetic heading correction and compensation was designed by this paper.Then according to systemsecurity and reliability of the design requirements, software modules of BIT was designed. Lastly，According to the software coding standard, the software code were standardize. The system softwarereached the ultimate accuracy and reliability.Finally, on the basis of hardware and software research, a AHRS was designed，built and examined. Strapdown AHRS was designed and realized Successfully. A lot of statictesting,positioning test, dynamic test, high and low temperature testing and vibration testing weredone to test the system performance.A lot of engineering problems in the system test were solved.Theresults showed that strapdown AHRS has high precision, stable and reliable performance.