The problem of predicting ship squat in non-uniform water depth is studied in this paper. For transverse depth variations, calculations are done using slender-body shallow-water theory, as implemented in the code “ShallowFlow”. Examples are given for realistic ships transiting dredged channels, and the effect of channel width on ship squat is discussed. Further examples are given for ships tran...

A Rover’s wheel performance is one of the limiting factors in its ability to successfully traverse other planets. More research focusing on wheel materials, design, and optimized tread patterns needs to be conducted so that a rover can reach more of its potential. A wheel test bed is being fabricated to test new wheel designs and to collect data which will be used to map the relationship betwee...

The application of transient three-dimensional numerical code ITU-WAVE is presented for the prediction hydrodynamic characteristics floating bodies. time histories unsteady motions are directly with respect to Impulse Response Functions (IRFs). First-order steady forces wave-resistance, sinkage force and trim moment solved as steady-state limit surge radiation IRF. second-order mean using near-...

The application of mobile robots to field environments has enabled significant advances in such diverse areas as agriculture, defense and security, planetary surface exploration, and mining. To successfully deploy a robot in an unstructured, outdoor environment, roboticists should consider the interaction of the robot and terrain. Often, this interaction is assumed to follow a simple Coulomb fr...

External perception based on vision plays a critical role in developing improved and robust localization algorithms for mobile robots, as well as gaining important information about the vehicle and the traversed terrain. This paper presents two novel methods to improve mobility on rough terrains by using visual input. The first method consists of a stereovision algorithm for real-time 6-DoF ego...

A novel approach is proposed for the modeling of rigid-wheel and soft-soil interaction to efficiently compute normal and shear stress distributions in the contact area. The authors propose a velocity field in the vicinity of the contact area based on the physical nature of the problem. Thereupon, the incremental changes to the stress field are computed by resorting to elastoplasticity theory an...

Wheels of planetary rovers typically have grousers on their surface to provide grip for climbing in loose soil and scrambling over rough terrain. In this study, the influence of grousers on the traveling performances of wheeled rovers is evaluated in various soils. First, the influence of the number of grousers was quantitatively determined by conducting experiments using wheels with different ...

This is a retrospective study of the results of angle-stable plating of displaced 3- or 4- part fractures of the proximal humerus in 92 geriatric patients treated between 2/2000 and 2/2004. At final follow-up patients were clinically evaluated using the Constant-Murley score and were examined radiologically. The mean non-age-related Constant-Murley score was 69.8 points. A clear correlation was...

1 0-7803-8155-6/04/$17.00©2004 IEEE 2 IEEEAC paper #1121, Version 2, Updated July 29, 2003 Abstract—Future planetary exploration missions will require rovers to perform difficult tasks in rough terrain, with limited human supervision. Knowledge of terrain physical characteristics would allow a rover to adapt its control and planning strategies to maximize its effectiveness. This paper describes...