Authors:
Ran Zhao
1
and
Daniel Sidobre
2
Affiliations:
1
CNRS and Univ. de Toulouse, France
;
2
Univ. de Toulouse, France
Keyword(s):
Obstacle Avoidance, Velocity Obstacles, Trajectory Time-scaling, Local Replanning.
Related
Ontology
Subjects/Areas/Topics:
Informatics in Control, Automation and Robotics
;
Mobile Robots and Autonomous Systems
;
Robotics and Automation
Abstract:
In various circumstances, planning at trajectory level is very useful to generate flexible collision-free motions for autonomous robots, especially when the system interacts with humans or human environment. This paper presents a simple and fast obstacle avoidance algorithm that operates at the trajectory level in real-time. The algorithm uses the Velocity Obstacle to obtain the boundary conditions required to avoid a dynamic obstacle, and then adjust the time evolution using the non-linear trajectory time-scaling scheme. A trajectory local replanning method is applied to make a detour when the static obstacles block the advance path of the robot, which leads to failure of implementing time-scaling approach. Cubic polynomial functions are used to describe trajectories, which brings sufficient flexibility in terms of providing higher order smoothness. We applied this algorithm on reaching tasks for a mobile robot. Simulation results demonstrate that the technique can generate collisio
n-free motion in real time.
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