A New Form of Pendulous Integrating Gyro Accelerometer's (PIGA's) Statical Error Model
Zheng Yuanxi Xu Qiang (Beijing Control Device Research Institute)
The object of study in this paper is PIGA which is one kind of inertial sensors commonly used in missiles and aerospace vehicles. We apply the Euler equation to formulate the complete dynamic equation for the rotor, inner gimbal unit and outer gimbal unit of PIGA which has a nonorthogonal angular error ε. On the basis of general structural parameters, machining accuracy, circuit control accuracy and neglecting the small quantities of 10~(-6) order of magnitude, we reduce the complete dynamic equation to the equation of motion of inner gimbal at statical condition, i.e. statical harmonic error model of PIGA.Utilizing the six position test method we can obtain the output angular rate curves which verify the existence of the harmonic terms. All the coefficients of the error model can be identified by the least square method.