Collision avoidance

About: Collision avoidance is a research topic. Over the lifetime, 8014 publications have been published within this topic receiving 111414 citations.

Collision avoidance method for mobile robot considering motion and personal spaces of evacuees

Abstract: In the case of disasters such as earthquakes or Nuclear/Biological/Chemical(NBC) terrorist attacks, mobile robots, called “rescue robots,” that can work in dangerous environments instead of rescue crews in rescue missions, can be of great help. However, realizing such robot systems requires many types of technologies. In particular, path planning is an important technology that provides a mobile robot with autonomous navigation to a target destination with collision avoidance. To avoid evacuees, the robot should consider the motion of people in the near future. In this research, we propose a collision avoidance method that estimates the motions and personal spaces of the evacuees. The method consists of three steps: “estimation,” “conversion,” and “planning.” In the estimation step, the future positions of evacuees are estimated by considering their planned motions and personal spaces. Then, in the conversion step, a time axis is added to construct a 3D time-space coordinate system. Finally, in the planning step, a distance-time transform is applied to plan a safe 3D path from the robot's current position to the desired goal. The proposed method has been implemented on our rescue robot simulator, and some simulation experiments were conducted to verify its usefulness.

On‐line path planning strategy integrated with collision and dead‐lock avoidance schemes for wheeled mobile robot in indoor environments

Abstract: Purpose – This paper aims to present a hybrid path planning algorithm which is designed for use of autonomous vehicles in indoor environments. The approach mainly contributes the ability of generating a safe and smooth collision avoidance path for attaining a desired position in an unknown and obstructed environment.Design/methodology/approach – The hybrid planner is based on potential field method and Voronoi diagram approach, and it is represented with the ability of concurrent map building and autonomous navigation.Findings – The possibility of controlling the look‐ahead distance allows the mobile robot to smartly control the velocity for creating a smooth trajectory autonomously. The dead‐lock problem is solved by defining necessary sub‐goals between targets on the constructed map.Originality/value – The system controller (look‐ahead control) with the potential field method allows the robot to generate a smooth and safe path for an expected position. Only essential exploration of unknown environment i...

Multi-Ship Collision Avoidance Decision-Making Based on Collision Risk Index

Abstract: Most maritime accidents are caused by human errors or failures. Providing early warning and decision support to the officer on watch (OOW) is one of the primary issues to reduce such errors and failures. In this paper, a quantitative real-time multi-ship collision risk analysis and collision avoidance decision-making model is proposed. Firstly, a multi-ship real-time collision risk analysis system was established under the overall requirements of the International Code for Collision Avoidance at Sea (COLREGs) and good seamanship, based on five collision risk influencing factors. Then, the fuzzy logic method is used to calculate the collision risk and analyze these elements in real time. Finally, decisions on changing course or changing speed are made to avoid collision. The results of collision avoidance decisions made at different collision risk thresholds are compared in a series of simulations. The results reflect that the multi-ship collision avoidance decision problem can be well-resolved using the proposed multi-ship collision risk evaluation method. In particular, the model can also make correct decisions when the collision risk thresholds of ships in the same scenario are different. The model can provide a good collision risk warning and decision support for the OOW in real-time mode.

Unmanned aircraft collision detection and resolution: Concept and survey

Abstract: The utilization of unmanned aerial vehicles requires the ability to navigate in urban or unknown terrain where many moving and/or stationary obstacles of different types and sizes may endanger the safety of the mission. Large efforts have been addressed to resolve conflicts to unmanned aircraft. This paper explores the fundamental concept and presents an up-to-date survey of the collision sensing, detection and resolution methods those deployed for aircraft, especially for unmanned aerial vehicles. The collision avoidance concept is demonstrated through proposing generic functions carried by collision avoidance systems with special emphasis on the context aware implementation. These functions are then presented together with design factors that are used then to classify major collision avoidance methods.

Closed loop motion planning and control for mobile robots in uncertain environments

Abstract: In this paper we present an extension to the navigation function methodology [Rimon, E. and Koditschek, D.E., 1992], [Tanner, H.G., et al., 2001] to the case where unmodelled obstacles are introduced in the workspace. A feedback control law is derived, based on the navigation function built on the initial workspace. Global convergence and collision avoidance properties are established. The derived closed form control law is suitable for real time implementation. Collision avoidance and global convergence properties are verified through computer simulations.