Initial Alignment Of Fog Strap-Down System Of Track Inspection Car

Track inspection car is the equipment which is used in ride quality test of highspeed railway. It has the character of continuous measure determining benchmark by itself high efficiency test. The hardcore of this equipment is fiber optic gyro (FOG) strap-down initial measure system which gets geometry character of railway through dealing acceleration and angular velocity output by FOG.The test precision of initial measure system cannot exceed the precision limited by alignment error, so initial alignment is a very important problem in develop and application of the system. The main problem studied in this paper is initial alignment of the system and trying to obtain high precision and high reliabilityinitial alignment method.The main work done by this paper are:1. Expatiated the principle of FOG and strap-down inertial system and investigated the typical arithmetic of the attitude matrix.2. Deducted the initial alignment error model of strap-down inertial system founding on the basic theory of it.3. Obtained satisfactory alignment result through noise reduction of FOG signal using the advantage of time-domain and frequency-domain localization of wavelet transform and provided a effective method for practical measurement.