Obstacle

About: Obstacle is a research topic. Over the lifetime, 9517 publications have been published within this topic receiving 94760 citations. The topic is also known as: impediment & barrier.

Optimization based exploitation of the ankle elasticity of HRP-2 for overstepping large obstacles

Abstract: This paper proposes a new generic strategy to investigate the dynamic limits of the humanoid robot HRP-2 based on whole body optimal control optimization. In this study we exploit the intuitive access to complex motion characteristics, given by optimal control, to effectively resolve a major technical coupling effect, namely between the ankle elasticity and the stabilizing algorithms. Control efforts are reduced to get a clearer view of the actual system limits and to exploit its capacities at maximum. As showcase we decided to focus on a stepping motion over a cylindrical obstacle. This study is further supported by real experiments on the HRP-2 14 robotic platform and the present maximum of a dynamically overstepped obstacle was extended to 20cm (height) × 11cm (width) (including safety margin) without multi-contact support.

Real time planning and scheduling for a team of unmanned vehicles

Abstract: A method of implementing a plurality of unmanned vehicles over an obstacle field. The method includes obtaining a physical map of the obstacle field. Discretizing the physical map into traversable edges that avoid the obstacles, the traversable edges meeting at nodes. Replacing sections of the traversable edges that are beyond the maneuverability of the unmanned vehicles with traversable arcs. Determining traverse time parameters associated with paths through the obstacle fields, each path made up of select traversable edges and select traversable arcs and using the traverse time parameters in planning and scheduling the vehicles.

Method for estimating relative speed between vehicle and objective obstacle

Abstract: In estimating the relative speed between a vehicle and an objective obstacle, a plurality of objective obstacle data are labeled, and an objective obstacle data preestimated on the basis of the past objective data is compared with an objective obstacle newly provided, thereby judging whether or not there is the same obstacle for every label. With regard to the objective obstacle data decided as being the same, the amount of variation in distance is determined for every label by comparison of the last data and the now data and divided by a sampling time to provide a relative speed. Thus, noise data can be eliminated to reliably provide a relative speed between a subject vehicle and an existent objective obstacle.

Obstacle detection system

Abstract: A system (10) that incorporates inertial sensor information into optical flow computations to detect obstacles and to provide alternative navigational paths free from obstacles. The system (10) is a maximally passive obstacle detection system that makes selective use of an active sensor (52). The active detection (52) typically utilizes a laser. Passive sensor suite includes binocular stereo (54), motion stereo (56) and variable fields-of-view (57). Optical flow computations involve extraction, derotation and matching of interest points from sequential frames of imagery, for range interpolation of the sensed scene, which in turn provides obstacle information for purposes of safe navigation.

Method for implementing required navigational performance procedures

Abstract: A method (200) is disclosed for designing an RNP approach for an aircraft at a particular runway (90). The method includes selecting a runway (201), gathering obstacle data for the obstacle evaluation area (202), selecting a VEB method and terms (204), laying out a preliminary approach, inducing a missed approach segment (206), calculating a preliminary obstacle clearance surface (208), calculating a momentary descent segment using a physical model of the aircraft (210), adjusting the obstacle clearance surface so that no obstacles intersect the surface (212), and optionally optimizing the approach by departing from the operator's standard procedures (214). Preferably, the obstacle clearance surface is adjusted so that it just touches an obstacle, without any object intersecting the surface, thereby providing an optimal decision altitude.