Kalman Filter Based Digital Air Data Computer Implement Methods

Air Data Computer(ADC) is one of the important airborne instrumentation systems,it ues the pressure and temperature sensor measure some original parameters,calculate the pressure altitude, indicate airspeed, atmospheric static temperature, mach number, vertical speed etcs informations,and sent to the airplane dictate system.Integrity and accurate air data provide indispensability information to airplane,it not only meet the use request in the condition airplane in lots of enviro nment,and have necessary function when the aircraft execute task,as well as provide necessary information display,b ut also to improve aircraft maneuverability, safety and economy plays an important role.This dissertation based on the basic principle of digital air data computer,architecture and project implementation of digital air data computer system, use Kalman filter algorithm improves the pressure altitude and vertical speed anti-jamming capability,and write the corresponding DSP program. The major contents are as follows:1.Learn the basic components of the air data computer is the basis for building the system. This dissertation introduces the air parameters basic concepts and the corresponding calculation.Given the structure of the system, including the sensor module, a timing control module and a digital signal processing module processors,as well as input and output interfaces, self-test and fault output module and power module, and describes in detail the function of each module.2. Kalman filter is applied to the air data computer system.Given the basic principle and the basic model of Kalman filter,for the actual situation of the system,after simulation analysis we choose the constant velocity model,But when the vertical speed mutated always lead to the Kalman filter value have larger error.Therefore,introduce the forgetting factor in Kalman filter,and describe several methods to calculate forgetting factor,After simulation analysis and comprehensive consideration,select the new information covariance method to calculate forgetting factor.3.Completed the system project,mainly include: Given the structure of the system,seen the TMS320C5410 A DSP as implementation platform,design the software process,include initialization of DSP internal data,send and receive data,data processing and Kalman filtering;Given the system test method,including external source testing and analog sources testing, for pressure altitude, vertical speed, Mac h number selected the appropriate test methods, The results shows that implement methods of the digital air data computer,be capable to achieve project targets and have good results.