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

Abstract--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 paper, we present the creation of a 2-DOF malleable robot, detailing the design of joints and malleable link, along with its modelling 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. ECONFIGURABLE robot systems provide several key potential advantages over traditional robots, including of the robot (such as locomotion), albeit with a decrease in increased task versatility by adapting to better suit tasks, the performance for a specific task compared to a specialised and reduced robot cost due to a smaller total number of robot. While the majority of reconfigurable robots are modular, modules, such as links and joints. As such, there has been reconfiguration can also be achieved by locking aspects of significant research into the development of reconfigurable the robot. Examples include directly locking revolute joints to robots, with the most popular approach utilising modularity reduce the DOF of the robot [11], and locking passive cylindrical as the method of reconfiguration, as this allows for the joints carefully positioned to directly vary the Denavit-interchangeability of parts, leading to self-repair [1], [2].