One of the most challenging tasks for mobile robots is to track mobile obstacles that surround them. This task is especially difficult in outdoor environments where a great variety of obstacles may induce the robot to take erroneous decisions. The mobile robot needs as much information as possible concerning the obstacle positions and speeds (direction and magnitude) in order to plan evasive ma...

Planning the motion of objects in contact is an important stage of the analysis of mechanical assembly tasks. This paper concerns with the case of a poly-hedron moving within a polyhedral environment. It presents an algorithm to plan the motion of a convex polyhedron translating and rotating in contact with a neither necessarily convex nor connected polyhedral obstacle. This algorithm uses a ne...

This paper considers the artificial potential field method combined with rotational vectors for a general problem of multi-unmanned aerial vehicle (UAV) systems tracking a moving target in dynamic three-dimensional environment. An attractive potential field is generated between the leader and the target. It drives the leader to track the target based on the relative position of them. The other ...

This paper presents an obstacle avoidance method for spacecraft relative motion control. In this approach, a connectivity graph is constructed for a set of relative framepoints,which formavirtual net centeredaroundanominal orbital position. The connectivity between points in the virtual net is determined based on the use of safe positively invariant sets for guaranteed collision freemaneuvering...

The paper demonstrates a following robot with omni-directional wheels, which is able to take action to avoid obstacles. The robot design is based on both fuzzy and extension theory. Fuzzy theory was applied to tune the PMW signal of the motor revolution, and correct path deviation issues encountered when the robot is moving. Extension theory was used to build a robot obstacle-avoidance model. V...

Effective target tracking and collision avoidance schemes are essential to the success of unmanned aerial vehicle (UAV) missions. In a dynamic environment, UAV path planning often relies on predicted obstacle and target motion. This paper presents an algorithm that predicts the trajectory of a moving object (target or obstacle) detected by a UAV. An extended Kalman filter is first employed to e...

Autonomous collision avoidance in vehicles requires an accurate seperation of obstacles from the background, particularly near the focus of expansion. In this paper, we present a technique for fast segmentation of stationary obstacles from video recorded by a single camera that is installed in a moving vehicle. The input image is divided into three motion segments consisting of the ground plane...

This paper considers the problem of autonomous robot navigation in dynamic and congested environments. The predictive navigation paradigm is proposed where probabilistic planning is integrated with obstacle avoidance along with future motion prediction of humans and/or other obstacles. Predictive navigation is performed in a global manner with the use of a hierarchical Partially Observable Mark...

During obstacle crossing, a minimal vertical distance between foot and obstacle (toe clearance) has to be preserved to avoid tripping. This study analyzed the control of an obstacle crossing task as a reaching motion with the foot when visual information was unavailable to blind and sighted participants. A major difference with upper limb reaching is that the lower limb task has to be integrate...