Topic
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.
Papers published on a yearly basis
Papers
More filters
••
TL;DR: It is suggested that the non-parallel obstacle layouts (especially the concave layout) with larger longitudinal distance between obstacles are more beneficial to pedestrian movement, when there are obstacles in corridors.
Abstract: Previous research on the effect of obstacles on crowd dynamics primarily focused on relationships between the scale or position of obstacles and pedestrian movement behavior. However, the influence of different obstacle layouts on pedestrian flow in corridors has not been well investigated. Here, we conducted an experimental study on the effect of three obstacle layouts (i.e., parallel, convex and concave layouts) on pedestrian flow in corridors, creating seven scenarios for unidirectional flow and four scenarios for bidirectional flow at low and high crowd densities. The image processing method is employed to collect pedestrian trajectories. Accordingly, typical phenomena, speed, density and flow rate are obtained. It was found that in comparison with the parallel layout, average speed at high crowd density increases approximately 19% in non-parallel layouts when the distance between obstacles is 1.6 m, while the decrease rate of average passing time reaches 17%. The relationship between group speed and time is U-shaped, and group speed is reduced sharply in the parallel layout. Congestion is the severest in the parallel layout in bidirectional flow, i.e. the largest density in the parallel layout is 16% higher than that in non-parallel layouts when the longitudinal distance between obstacles is 1.6 m. Congestion is alleviated with the increasing longitudinal distance between obstacles in the non-parallel layouts. Flow rate in the non-parallel layouts (especially in the concave layout) is greater than that in the parallel layout. These results suggest that the non-parallel obstacle layouts (especially the concave layout) with larger longitudinal distance between obstacles are more beneficial to pedestrian movement, when there are obstacles in corridors. It is hoped that this study will be helpful in crowd management and pedestrian facility design.
36 citations
••
TL;DR: In this paper, the existence of a continuous solution to a nonlinear parabolic obstacle problem with a continuous time-dependent obstacle is shown, and the solution is constructed by an adaptation of the Schwarz alternating method.
35 citations
••
TL;DR: In this paper, an obstacle system with 14 factors is established based on literature review and expert consultation according to characteristics of China firstly, namely economic, technical, social and political obstacles are further evaluated by expert opinions.
35 citations
•
14 Jul 2017
TL;DR: In this paper, an obstacle detection method, a device, an apparatus and a storage medium is presented. But the method comprises steps of acquiring acquired acquired 3D point cloud in a running process of an unmanned vehicle, projecting the 3d point cloud to two-dimensional grids and acquiring feature information of each grid; inputting the feature information from each grid into a prediction model obtained through the pre-training and obtaining an obstacle prediction parameter of the grid; and according to the obstacle prediction parameters, carrying out grid clustering so as to obtain the obstacle detection result.
Abstract: The invention discloses an obstacle detection method, a device, an apparatus and a storage medium. The method comprises steps of acquiring acquired 3D point cloud in a running process of an unmanned vehicle; projecting the 3D point cloud to two-dimensional grids and acquiring feature information of each grid; inputting the feature information of each grid into a prediction model obtained through the pre-training and obtaining an obstacle prediction parameter of each grid; and according to the obstacle prediction parameter of each grid, carrying out grid clustering so as to obtain an obstacle detection result. According to the invention, accuracy of detection results can be improved.
35 citations
•
TL;DR: A new technique is proposed which can detect an obstacle, judge its distance and measure the size of the obstacle using one camera and one ultrasonic sensor.
Abstract: Different types of sensors are often fused to acquire information which cannot be acquired by a single sensor. Sensor fusion is particularly applicable for mobile robots for object detection and navigation. The techniques that have been developed so far for detecting an obstacle are costly. Hence, a new technique is proposed which can detect an obstacle, judge its distance and measure the size of the obstacle using one camera and one ultrasonic sensor. The technique is cheap in terms of sensor cost and in terms of computational cost. General Terms Robotics, robot navigation.
35 citations