Obstacle avoidance in a dynamic environment: a collision cone approach

Abstract

Abstract-A novel collision cone approach is proposed as an aid to collision detection and avoidance between irregularly shaped moving objects with unknown trajectories. It is shown that the collision cone can be effectively used to determine whether collision between a robot and an obstacle (both moving in a dynamic environment) is imminent. No restrictions are placed on the shapes of either the robot or the obstacle, i.e., they can both be of any arbitrary shape. The collision cone concept is developed in a phased manner starting from existing analytical results-available in aerospace literature-that enable prediction of collision between two moving point objects. These results are extended to predict collision between a point and a circular object, between a point and an irregularly shaped object, between two circular objects, and finally between two irregularly shaped objects. Using the collision cone approach, several strategies that the robot can follow in order to avoid collision, are presented. A discussion on how the shapes of the robot and obstacles can be approximated in order to reduce computational burden is also presented. A number of examples are given to illustrate both collision prediction and avoidance strategies of the robot.

Collision Prediction Among Rigid and Articulated Obstacles with Unknown Motion

“…For two moving spheres, whenever their time-varying bound volumes intersect, they are checked for actual collision. Chakravarthy and Ghose [12] proposed collision cone approach (similar as velocity obstacle) for predicting collisions between any two irregularly shaped polygons translating on unknown trajectories. All these methods are limited to discs, spheres or translational objects.…”

“…Motivated by this issue, several strategies [10,11,12,13,8,14,15] have been proposed to replan adaptively only at the critical moments when the robot and obstacles may collide. These critical moments are usually detected by collision prediction methods.…”

Real-time continuous collision detection for mobile manipulators - A general approach

“…Therefore, in [3] we proposed a 2d SSCH representation, which we will extend here to 3d as the vehicle joint. Other approaches such as collision cones [14], [15] and velocity obstacles [16], [17] work in 3d but only for linear motion.…”

Smooth Path Planning by Fusion of Artificial Potential Field Method and Collision Cone Approach

“…The collision cone is the potential criterion that will result in a collision between a robot and an obstacle at some moment in time. If the relative velocity between the robot and the obstacle maintains a velocity outside the collision cone, collisions are guaranteed not to occur [8]. This algorithm has been improved for multi obstacles and real-time application.…”