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.

Multiple sensors based obstacle detection system

Abstract: A mobility assistive device that can assist to navigate in the environment and keep away from collisions with obstacles could help reduce health costs and enhance the quality of care and independence of the elderly. Traditionally mobility assistive devices have been electromechanical devices which have the main function to provide physical support for the elderly whilst moving around such as canes and wheelchairs. Application of microcontrollers and wireless communication to mobility assistive devices have increased the functionality of these devices in terms of obstacle detection and information processing, and have brought exciting new concepts, which make these devices to be hand free and small. The proposed system is based on optical and ultrasonic sensors which can detect a wide range of obstacles, such as small objects on the walkway (e.g., toys), large static obstructions (e.g., building wall), as well as stairs and uneven surfaces, and warns the wearer several times before making contact with the object (e.g., 1.5m, 1.0m and 0.5m).

Motion planning for mobile robots in dynamic environments using a potential field immune network

Abstract: This paper proposes a potential field immune network (PFIN) for dynamic motion planning of mobile robots in an unknown environment with moving obstacles and a fixed/moving goal. The velocity obstacle method is utilized to determine the imminent collision obstacle. Subsequently, PFIN is implemented to guide robots to avoid collision with the most dangerous objects at every time instant. The overall response of the immune network is calculated with the aid of fuzzy logic and genetic algorithms. Simulation results are presented to verify the effectiveness of the proposed architecture in dynamic environments with single and multiple fixed/moving obstacles.

Obstacle detection method and system, particularly for systems for assisting the parking of vehicles

Abstract: An obstacle detection method and system, particularly for car parking systems comprising emitting ultrasound signals at a plurality of sensors, receiving echo signals returned by at least one obstacle, performing a parametric evaluation of the received signals, determining, for each sensor, the distance between the sensor and an obstacle detected by it, associating with each sensor a value of the distance from the obstacle detected by it; determining a value corresponding to the minimum detected distance and replacing it with the sum value between a minimum distance and a priority threshold value; assigning to the sensor that detected the minimum distance a priority status; and defining a sensor polling cycle that polls more frequently a priority status sensor than non-prioritized sensors.

Stereo-based all-terrain obstacle detection using visual saliency

Abstract: This paper proposes a hybridization of two well-known stereo-based obstacle detection techniques for all-terrain environments. While one of the techniques is employed for the detection of large obstacles, the other is used for the detection of small ones. This combination of techniques opportunistically exploits their complementary properties to reduce computation and improve detection accuracy. Being particularly computation intensive and prone to generate a high false-positive rate in the face of noisy three-dimensional point clouds, the technique for small obstacle detection is further extended in two directions. The goal of the first extension is to reduce both problems by focusing the detection on those regions of the visual field that detach more from the background and, consequently, are more likely to contain an obstacle. This is attained by means of spatially varying the data density of the input images according to their visual saliency. The second extension refers to the use of a novel voting mechanism, which further improves robustness. Extensive experimental results confirm the ability of the proposed method to robustly detect obstacles up to a range of 20 m on uneven terrain. Moreover, the model runs at 5 Hz on 640 × 480 stereo images. © 2010 Wiley Periodicals, Inc. © 2011 Wiley Periodicals, Inc.