The case of large azimuth misalignment angles in a strapdown inertial navigation system (SINS) is analyzed, and a method of using the adaptive UPF for the initial alignment is proposed. The filter is based on the idea of a strong tracking filter; through the introduction of the attenuation memory factor to effectively enhance the corrections of the current information residual error on the syst...

Shearer dynamic positioning is a key factor for coal mine equipment automation, and it is feasible to shearer positioning using the strapdown inertial navigation system(SINS). Yet, it is very difficult to guarantee positioning accuracy by error influence. This paper provided a method for shearer positioning error analysis. Firstly, we built the shearer state equation and put forward a method ca...

To perform dynamic tumor tracking (DTT) for clinical applications safely and accurately, gimbaled head swing verification is important. We propose a quantitative gimbaled head swing verification method for daily quality assurance (QA), which uses feature point tracking and a web camera. The web camera was placed on a couch at the same position for every gimbaled head swing verification, and cou...

The initial attitude estimation of the airborne navigation system greatly affects the overall attitude accuracy. The initial alignment depends on the inertial measurement unit’s performance. In the case of the tactical grade inertial measurement unit, even though tilt angles can be estimated relatively accurately by using accelerometer outputs, it is difficult to determine the azimuth angle wit...

In-motion alignment of a SDINS/GPS integrated system, determining the angular relationship between the navigation frame and the body frame is a necessary process. This paper describes the in-motion alignment procedure for a low-cost GPS/INS integrated system using the Unscented Kalman Filter (UKF) and Central Difference Kalman Filter (CDKF). The UKF and CDKF are used to implement the in-motion ...

PURPOSE OF THE STUDY The aim of the study was to compare a radiographic position of the acetabular component with a position guided by the navigation system in final acetabular cup alignment. MATERIAL Between May and October 2005, 15 patients underwent implantation of a cementless acetabular component from the posterolateral minimally invasive approach with the use of kinematic navigation. ...

Implant alignment is an important factor affecting clinical results associated with total knee arthroplasty (TKA). No report exists showing the utility of an accelerometer-based portable navigation system among patients with marked femoral bowing. The aim of this study was to evaluate the accuracy of a portable navigation system for implant alignment in Asian patients with marked femoral bowing...

BACKGROUND Several reference axes are used to establish femoral rotational alignment during total knee arthroplasty, but debate continues with regard to which axis is most accurately and easily identified during surgery. Computer-assisted navigation systems have been developed in an attempt to more accurately and consistently align implants during total knee arthroplasty, but it is unknown if n...