In this paper, we propose a novel approach to reactive obstacle avoidance for nonholonomic systems. The method is based on the deformation of an initial trajectory computed by a motion planner. The deformation we perform keeps the nonholonomic constraints of the system satisfied. The deformation algorithm is based on a potential field generated by obstacles. We applied this approach to the mobi...

Planning trajectories for nonholonomic systems is difficult and computationally expensive. When facing unexpected events, it may therefore be preferable to deform in some way the initially planned trajectory rather than to re-plan entirely a new one. We suggest here a method based on affine transformations to make such deformations. This method is exact and fast: the deformations and the result...

In this thesis the potential of visual servoing techniques for vertical take-off and landing (VTOL) UAV platforms is explored. An overview of UAV applications and state-of-theart quadrotors is provided, backed up by the necessary theoretical background. Visual servoing based solutions of the important flight tasks (such as vertical take-off and landing, obstacle avoidance and attitude estimatio...

Potential field methods are rapidly gaining popularity in obstacle avoidance applications for mobile robots and manipulators. While the potential field principle is particularly attractive because of its elegance and simplicity, substantial shortcomings have been identified as problems that are inherent to this principle. Based upon mathematical analysis, this paper presents a systematic critic...

Helicopter crews are required to carry out a wide range of duties most of which involve operational safety. One particular flight safety problem that has relevance to a variety of different types of rotorcraft is assisting the pilot in obstacle avoidance. Obstacles, in this context, may typically include other aircraft, terrain features, buildings, bridges, overhead cables and poles. The proble...

Whether a task can be completed after a failure of one of the degrees-of-freedom of a redundant manipulator depends on the joint angle at which the failure takes place. It is possible to achieve fault tolerance by globally planning a trajectory that avoids unfavorable joint positions before a failure occurs. In this paper, we present a trajectory planning algorithm that guarantees fault toleran...

Given two compact, simply connected manifolds with boundary, and a navigation function (NF) on each manifold, this paper presents a simple composition law that yields a new NF on the cross product space. The method provides tunable “hooks” for shaping the new potential function while still guaranteeing obstacle avoidance and essentially global convergence. The composition law is associative, an...

We describe a vision-based obstacle avoidance system for off-road mobile robots. The system is trained from end to end to map raw input images to steering angles. It is trained in supervised mode to predict the steering angles provided by a human driver during training runs collected in a wide variety of terrains, weather conditions, lighting conditions, and obstacle types. The robot is a 50cm ...

Today’s world contain of a large variation of people. Mostly disability person is depends upon other for their living. But in the today’s fast developing world, people is busy in work so that they don’t have enough time for physically challenged people.The main aim this system physically challenged people can move inside the home without any trouble. In this system voice recognition system used...