Study Of Attitude Measurement On Spinning Projectile Based On Magnetic Sensors Unit

Acquisition a variety of projectile flight attitude parameters has an important signification no matter for projectile design, projectile aerodynamics or fuze design. So it is important to test the projectile flight attitude accurately, which can accelerate the research course and improve the performance of weapon.With the contimuous improvement of geomagnetism theory and the sensors, microprocessors, calculate algorithm sophisticated increasingly, use magnetic detection to measure the component of geomagnetic field on the projectile coordinate can obtain the attitude angles by calculation. The magnetic detection has become the hotspot in the current attitude test and navigation research area because of its advantages such as good invisibility, high reliabity, high antidisturbance performance, high-g resistance.A measurement scheme based on the magnetic sensors unit is designed for measuring the spinning projectile attitude. The configuration of the sensors and the calculation algorithm are discussed, the hardware and software design are accomplished based on the simulation; the half size hardware-in-loop simulation is carried out for verifying effectiveness of this scheme, all the work done in this dissertation provides a helpful attempt of the application of magnetic sensors measurement unit. In the end, in allusion to the projectile which has the linear acceleration, a kalman filter composed of magnetic sensors and micro-inertial sensors is discussed; the performance of the filter is verified by simulation. Main research work can be summed up in the following five aspects:(1) Two schemes are put forward for high-spinning projectile attitude measurement, which are applicable to the carrier that has linear acceleration. The characteristics of the sheme are:the magnetic field strength is not need to know; only scalar calculation in attitude measurement; suitable for day/night and all weather conditions.(2) Real-time data acquisition system applies to test in missile-borne or rotary table. The mode of wireless transmission is adopted apply in rotary table experiment; the mode of data storage and data recovery is applyed in missile-borne experiment.(3) The error sources of measurement unit are analyzed, the compensating arrangement of soft and hard iron effect arc discussed emphatically. A 12-position calibrating method without north reference for magnetic compass is adopted for some application which has condition for up direction rotation. The effectiveness of this method is verified by rotate table experiment.(4) The EMC procedures of the measurement unit are designed. Preprocessing the geomagnetism signal based on wavelet analysis theory in order to provide valuable data for attitude calculation. The hardware-in-the-loop experiment is accomplished using rotary table, and the data is solved and anlysized. The result indicates that the error of the estimate attitude angles in the range of 1°(5) The kalman filters composed of magnetic sensors and micro-inertial sensors are researched, especially for the projectile which has swing and linear acceleration. The performance of the two filters are verified and compared by simulation.