Initial alignment is always a key topic and difficult to achieve in an inertial navigation system (INS). In this paper a novel self-initial alignment algorithm is proposed using gravitational apparent motion vectors at three different moments and vector-operation. Simulation and analysis showed that this method easily suffers from the random noise contained in accelerometer measurements which a...

The initial alignment is vital to the strapdown inertial navigation system (SINS). In this work, an efficient initial alignment method for SINS based on a six-degree of freedom inertial measurements unit (IMU) is proposed. The three dimensional linear accelerations and angular rates are acquired from a data acquisition board which contains a low-cost IMU. Preprocess the gyro data and modeling t...

PURPOSE To verify the positional accuracy of a novel x-ray-image-based dynamic tumor-tracking (DTT) irradiation technique using the gimbaled MV x-ray head of a Vero4DRT (MHI-TM2000). METHODS Verification of the x-ray-image-based DTT was performed using three components: a three-dimensional moving phantom with a steel ball target, a laser displacement gauge, and an orthogonal kV x-ray imaging ...

An arithmetic of fast two-position initial alignment for Strapdown Inertial Navigation System (SINS) using Unscented Kalman Filter (UKF) is proposed in this paper to solve the initial alignment problems of SINS. Based on the analysis of initial alignment method of SINS, the nonlinear model for two-position attitude calculation is derived, and the two-position method is used to eliminate the con...

In this paper, an innovative inertial navigation system (INS) mechanization and the associated Kalman filter (KF) are developed to implement a fine alignment for the strapdown INS (SINS) on stationary base. The improved mechanization is established in the pseudo-geographic frame, which is rebuilt based on the initial position. The new mechanization eliminates the effects of linear movement erro...

A prospective study was performed to assess the intra-operative variation in femoral and tibial axis alignment during navigated total knee replacement. The intra-operative initial, trial and final mechanical axis alignments were recorded from the navigation system. The mean variation and correlation coefficient were calculated and analysed. There were 40 patients (24 females, 16 males), with ag...