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.

An obstacle detecting device for a vehicle

Abstract: An obstacle detecting device for a vehicle comprises a pair of image sensors for taking an image of an object surrounding a vehicle, a display image plane for displaying an image data taken by said pair of image sensors as an image, and a plurality of windows designating regions of said image on said display image plane. The device further comprises an optical obstacle detecting device for detecting distances from said vehicle to said object in said regions of the image designated by said plurality of windows for the respective windows to thereby detect an obstacle, a laser radar device mounted on the vehicle for radiating a radar beam to the object surrounding the vehicle to thereby detect said obstacle, and an obstacle selecting device for selecting either the obstacle detected by said optical obstacle detecting device or the obstacle detected by said laser radar device mounted on the vehicle.

Obstacle detection device for vehicle

Abstract: An obstacle detection device for a vehicle includes an area determining section for determining a detection area extended forward of a running vehicle and provided for detecting an obstacle, a split section for splitting the area into a plurality of small split zones, a detecting section for detecting an obstacle in each of the small split zones, inferring section for an inferring a path of the vehicle in the obstacle detection area, and a judging section for judging a rank of danger of an obstacle in the detection area. The obstacle can be properly detected so that the vehicle can take a responsive and appropriate action for avoiding the obstacle.

Driving environment surveillance apparatus

Abstract: A driving environment surveillance apparatus is provided to specify a region where an obstacle is present depending upon an azimuth detected by an obstacle detecting unit so as to derive a two-dimensional image corresponding to the specified region from an image detecting unit, and to extract the obstacle from the two-dimensional image so as to calculate a size index of the obstacle, thereby detecting a relative distance or the azimuth to the obstacle from a vehicle with high accuracy and at a high speed.

Biologically-inspired dynamical systems for movement generation: Automatic real-time goal adaptation and obstacle avoidance

Abstract: Dynamical systems can generate movement trajectories that are robust against perturbations. This article presents an improved modification of the original dynamic movement primitive (DMP) framework by Ijspeert et al [1], [2]. The new equations can generalize movements to new targets without singularities and large accelerations. Furthermore, the new equations can represent a movement in 3D task space without depending on the choice of coordinate system (invariance under invertible affine transformations). Our modified DMP is motivated from biological data (spinal-cord stimulation in frogs) and human behavioral experiments. We further extend the formalism to obstacle avoidance by exploiting the robustness against perturbations: an additional term is added to the differential equations to make the robot steer around an obstacle. This additional term empirically describes human obstacle avoidance. We demonstrate the feasibility of our approach using the Sarcos Slave robot arm: after learning a single placing movement, the robot placed a cup between two arbitrarily given positions and avoided approaching obstacles.

Reconstruction of a two-dimensional binary obstacle by controlled evolution of a level-set

Abstract: We are concerned with the retrieval of the unknown cross section of a homogeneous cylindrical obstacle embedded in a homogeneous medium and illuminated by time-harmonic electromagnetic line sources. The dielectric parameters of the obstacle and embedding materials are known and piecewise constant. That is, the shape (here, the contour) of the obstacle is sufficient for its full characterization. The inverse scattering problem is then to determine the contour from the knowledge of the scattered field measured for several locations of the sources and/or frequencies. An iterative process is implemented: given an initial contour, this contour is progressively evolved such as to minimize the residual in the data fit. This algorithm presents two main important points. The first concerns the choice of the transformation enforced on the contour. We will show that this involves the design of a velocity field whose expression only requires the resolution of an adjoint problem at each step. The second concerns the use of a level-set function in order to represent the obstacle. This level-set function will be of great use to handle in a natural way splitting or merging of obstacles along the iterative process. The evolution of this level-set is controlled by a Hamilton-Jacobi-type equation which will be solved by using an appropriate finite-difference scheme. Numerical results of inversion obtained from both noiseless and noisy synthetic data illustrate the behaviour of the algorithm for a variety of obstacles.