Obstacle avoidance for kinematically redundant robots using distance algorithm

The redundancy of robot manipulators plays an important role in increasing their flexibility and versatility, especially in an environment with obstacles. In this paper, the redundancy is utilized for enabling collision-free motion for a given trajectory of a manipulator end-effector. Manipulator links and obstacles are approximated by polytopes that are described by their vertices. The distance algorithm, which allows computation of the distance information between polytopes in R/sup m/, is used to obtain distance information between robot and obstacles. Three kinds of method based on the distance information-gradient projection method, obstacle avoidance force method, obstacle avoidance velocity method-are proposed to calculate the joint trajectory that enable a manipulator to perform a desired end-effector motion and avoid obstacles. A simple numerical example involving a two-dimensional five degree-of-freedom manipulator working among obstacles is described.

Authors

• Chi Youn Chung
• Bum Hee Lee
• Jung-Hoon Lee

Keywords

• Robotics and automation
• Tires
• Programmable control
• Service robots
• Robot sensing systems
• Manipulator dynamics
• Linear programming
• Mathematical model
• Euclidean distance
• Redundancy
• Obstacle Avoidance
• Distance Algorithm
• Polytope
• Performance Indicators
• Shortest Distance
• Repulsive Forces
• Euclidean Norm
• Jacobian Matrix
• Pseudo-inverse
• Sensor Devices
• Nearest Point
• Distance Information
• Norm Minimization
• Joint Velocity
• Joint Force
• Joint Acceleration
• Gradient Projection Method
• Artificial Potential Field