Development of Autonomous Robot Osteotomy for Mandibular Ramal Bone Harvest and Evaluation of Its Accuracy: A Phantom Mandible-Based Trial

An autonomous robot osteotomy using direct coordinate determination for registering was developed, and the accuracy of the designed osteotomy along the preprogrammed plan was evaluated. Furthermore, the accuracy of the robotic and manual osteotomy was compared in regard to cut position, length, angle and depth. A light-weight robot was used in this study, with an electric gripper. Twenty stone models were used to evaluate accuracy of osteotomy and sixteen mandible phantoms were used to simulate the ramal bone harvest osteotomy for comparison between robotic and manual surgery. In the stone model experiment, the absolute mean values for osteotomy errors for position, length, angle, and depth were 0.93 ± 0.45 mm, 0.81 ± 0.34 mm, 1.26 ± 1.35°, and 1.19 ± 0.73 mm, respectively. In the mandible phantom model experiment, the robotic surgery showed lower errors for position, length and angle (0.70 ± 0.34 mm, 0.35 ± 0.19 mm and 1.32 ± 0.96°) and somewhat higher errors for depth (0.59 ± 0.46 mm) than manual surgery (1.83 ± 0.65 mm, 0.62 ± 0.37 mm, 5.96 ± 3.47° and 0.40 ± 0.31 mm). This study may provide a basis for developing clinical application of an autonomous robot osteotomy.

SYSTEM BASED COMPONENT IDENTIFICATION USING COORDINATE DETERMINATION IN MIXED REALITY

The maintenance of an industrial plant is mainly based on analogue and manual methods and processes. In the future, the maintenance data of the real object should be determined digital and transferred to a PDM system in real time. This is made possible with a digital method of component identification. This publication presents a system-based component identification using Mixed Reality. Coordinates are determined by the terminal device and compared with a reference structure. After successful identification, maintenance data can be determined and automatically transferred to a PDM System.

INVESTIGATION OF THE RESIDUAL TROPOSPHERIC ERROR INFLUENCE ON THE COORDINATE DETERMINATION ACCURACY IN A SATELLITE LANDING SYSTEM

This paper presents the results of the investigation of the residual tropospheric error influence on coordinate determination in a GNSS landing system. The ICAO recommended methodology for residual tropospheric error calculation is taken as a basis for the present research. Special attention is paid to the troposphere refractivity index and troposphere scale height, which are derived from the well-known troposphere refraction MOPS model. A computer simulation is performed for them for the whole year and the northern hemisphere latitudes. Hardware in the loop simulation has been performed to complement the computer simulation study and investigate the situation with the residual tropospheric error calculation for the experimental GNSS satellites configuration. The experimental measurement session with a duration of about 9 hours is recorded to obtain the configuration of real navigation satellites The residual tropospheric error in meters is calculated for each navigation satellite visible during the experiment. The authors investigate the residual tropospheric error influence on the accuracy of the coordinates determined in the GNSS landing system.

New Research on Gravity Field in Lithuanian Territory

New research of Lithuanian territory gravity field was started in 2016 with aim to improve accuracy of quasigeoid as well as accuracy of normal heights determined by methods of satellite geodesy. Obtained data could be used in the research of geophysics, geodynamics as well as in performing the precise navigation. Quartz automatic gravimeters Scintrex CG-5 are planned to be used for the survey consisting of 30000 points. Method of gravity measurements was worked out. RMS error of gravity determined with this method does not exceed 60 @Gal. Coordinates and heights of measured points are determined with GNSS using LitPOS network and LIT15G quasigeoid model. RMS error of coordinate determination does not exceed 0,20 m, for normal heights – 0,15 m. Method of gravity anomalies determination and their accuracy estimation was prepared.