Spherical Wrist Manipulator Local Planner for Redundant Tasks in Collaborative Environments

Area of Science:

• Robotics
• Human-Robot Interaction
• Control Systems

Background:

• Industrial robots lack safe Human-Robot Interaction (HRI).
• Redundant manipulators offer potential for enhanced motion and dexterity.
• Existing collision avoidance methods have limitations in ensuring comprehensive safety.

Purpose of the Study:

• To propose a novel local path planner for redundant spherical wrist manipulators.
• To improve safety in Human-Robot Interaction (HRI) for industrial and medical applications.
• To optimize robot motion and dexterity through joint redundancy.

Main Methods:

• Developed an intuitive parametrization for end-effector (EE) angular motion, decoupling wrist joint rotation.
• Implemented a decentralized linear system with closed-loop control architecture.
• Integrated a novel collision avoidance strategy using a repulsive vector considering the entire manipulator surface.

Main Results:

• The planner successfully executed simulated paths with a maximum error of 0.25°.
• Demonstrated effective obstacle avoidance in dynamic scenarios.
• Time and frequency domain analysis confirmed planner performance in parametrizing redundant tasks.

Conclusions:

• The proposed local path planner enhances safety in Human-Robot Interaction (HRI).
• The planner effectively controls redundant spherical wrist manipulators for optimized motion and dexterity.
• This approach offers a significant advancement for safe robotic applications in industrial and medical fields.