Based On Small Dsp Strapdown Ahrs

A mini digital Attitude and Heading Reference System (AHRS) based on DSP is designed, which can be used on air-to-air missile with Strapdown Inertial Navigation System (SINS) as mid-course guidance. With TMS320F240 DSP chip as the core of hardware system, software and hardware designed and debuged for AHRS high-speed real time data process is realized.Firstly, the engineering background and significance in this field is analyzed, especially on the mechanism of AHRS; a simplificated error model of inertial device is constructed and validated. A proper attitude algorithm suited for DSP is selected by comparing and simulating all kinds of attitude algorithms, and completed AHRS arithmetic is complied.Then, DSP chip is chosen after the property of DSP structure system is analyzed. After comparing the principles of V/F , I/F type ADC with Σ-Δ type ADC, a conclusion is drawn that Σ-Δ type ADC can substitute for VF type ADC on engineering practice. Schematic circuit diagram of hardware system is obtained and a circuit board is made.Finally, through mixed program of assemble language and C program, software and hardware is debugged respectively in CCS'C2000.The result of debug shows that the selected ADC is fit for AHRS with the property of high transfer speed and high precision. For less computational complexity and higher real-time, algorithm can decrease error efficaciously.