In this paper, we study variational point-obstacle avoidance problems on complete Riemannian manifolds. The problem consists of minimizing an energy functional depending the velocity, covariant acceleration and a repulsive potential function used to avoid static obstacle given by point in manifold, among set admissible curves. We derive dynamical equations for stationary paths problem, particul...

Models and control strategies for dynamic obstacle avoid­ ance in visual guidance of mobile robot are presented. Characteristics that distinguish the visual computation and motion-control requirements in dynamic environments from that in static environments are discussed. Objectives of the vision and motion planning are formulated as: 1) finding a collision-free trajectory that takes account of...

The Rayleigh conjecture about convergence up to the boundary of the series representing the scattered field in the exterior of an obstacle D is widely used by engineers in applications. However this conjecture is false for some obstacles. AGR introduced the Modified Rayleigh Conjecture (MRC), which is an exact mathematical result. In this paper we review the theoretical basis for the MRC method...

Time to Contact (TTC) is a biologically inspired method for obstacle detection and reactive control of motion that does not require scene reconstruction or 3D depth estimation. TTC is a measure of distance expressed in time units. Our results show that TTC can be used to provide reactive obstacle avoidance for local navigation. In this paper we describe the principles of time to contact and sho...

The goal of this study was to determine if prolonged exposure to perceptual-motor mismatch increased adaptability and retention of balance in older adults. Sixteen adults, aged 66 to 81 years, were randomized to one of two groups: either the control group (n=8) or the experimental group (n=8). Both groups first completed six trials of walking an obstacle course. Participants then trained twice ...

In the first part of the present paper, a novel communication scheme of an autonomous robot team via Bluetooth radio is investigated. In the presented solution, an autonomous unit is equipped with two independent Bluetooth radios and so a relatively fast communication is possible in the team in a static (i.e. no ad-hoc) networking topology. The performance of such a network was tested by implem...

the aim of this research was to examine the effect of a training interventionprogram on fall-related motor performance in the male elderly with no regularphysical activities. for this purpose, 39 out of 130 participants in screen test wereselected and assigned to training group (n=20) and control group (n=19). subjectsaged between 60 and 70 in experimental were 73.68% and in the control group43...

We present an abstract framework for irreversible rate independent evolution processes of quasi-static nature. The main tool relies on the minimizing movement theory. In particular situations, stability and energy inequality of Mielke’s type are satisfied. Several examples are given, among which the obstacle erosion.

{ This paper describes the Bremen Autonomous Wheelchair project. It shows that common static re strategies for ultrasonic sensors are inherently unsafe and proposes a new adaptive re strategy which delivers a complete coverage of the environment of the robot. Furthermore, a new obstacle avoidance approach for shared-control robotics systems is described in detail.

Highway obstacle detection is a challenging problem. Highways present an unknown and dynamic environment with real-time constraints. In addition, the high speeds of travel force a system to detect objects at long ranges. Although there are a number of methods that can successfully detect moving vehicles, the more difficult problem of finding small, static road debris such as tires or crates rem...