Malleable Robots: Reconfigurable Robotic Arms With Continuum Links of Variable Stiffness

Through the implementation of reconfigurability to achieve flexibility and adaptation to tasks by morphology changes rather than by increasing the number of joints, malleable robots present advantages over traditional serial robot arms in regards to reduced weight, size, and cost. While limited in degrees of freedom (DOF), malleable robots still provide versatility across operations typically served by systems using higher DOF than required by the tasks. In this article, we present the creation of a 2-DOF malleable robot, detailing the design of joints and malleable link, along with its modeling through forward and inverse kinematics, and a reconfiguration methodology that informs morphology changes based on end effector location—determining how the user should reshape the robot to enable a task previously unattainable. The recalibration and motion planning for making robot motion possible after reconfiguration are also discussed, and thorough experiments with the prototype to evaluate accuracy and reliability of the system are presented. Results validate the approach and pave the way for further research in the area.