Exploiting Morphology of a Soft Manipulator for Assistive Tasks

Abstract

The idea of using embodied intelligence over traditional well-structured design and control formulations has given rise to simple yet elegant applications in the form of soft grippers and compliant locomotion-based robots. Real-world applications of soft manipulators are however limited, largely due to their low accuracy and force transmission. Nonetheless, with the rise of robotic appliances in the field of human-robot interaction, their advantages could outweigh their control deficiencies. In this context, the embodied intelligence could play an important role in developing safe and robust controllers. In this paper, we present a three module soft manipulator to experimentally demonstrate how its morphological properties can be exploited through interactions with the external environment. In particular, we show how to improve the pose accuracy in an assistive task using a simple control algorithm. The soft manipulator takes advantage of its inherent compliance and the physical constraints of the external environment to accomplish a safe interactive task with the user. There exists a continuous and mutual adaptation between the soft-bodied system and the environment. This feature can be used in tasks where the environment is unstructured (e.g. specific body region), and the adaptability of the interaction is entirely dependent on the morphology and control of the system. Experimental results indicate that significant improvements in the tracking accuracy can be achieved by a simple yet appropriate environmental constraint.