A NEW IMU-BASED METHOD FOR RELATIVE POSE DETERMINATION

摘要

An increasing number of precision measurement or detection sensors are distributed on the motion platforms and work jointly to improve the mission performance, which to a great extent depends on the accuracy of the local or relative pose between key sensors. Normally, an inertial measurement unit (IMU) is applied and is installed just at the sensor position to sense the local motion. Conventionally, two IMUs on two separate locations apply INS function for relative pose determination which needs a global coordinate system (usually the local level frame) as a transition. In this paper, we present a new inertial-based method to determine the relative pose of the two IMUs without the necessity of using the global frame. Firstly, relative attitude quaternion, relative velocity and relative position differential equations are derived and the solution for the equations is given. Then the relative attitude, velocity and position error propagation functions are presented, which can be estimated by filters if appropriate measurement exists. Finally, the technique of applying this method into transfer alignment (TA) is given and evaluated through mathematic simulation. Results show that this method can provide an accurate estimate of relative pose between critical positions with high accuracy.