Control Architecture for Human-Like Motion With Applications to Articulated Soft Robots

Abstract

Human beings can achieve a high level of motor performance that is still unmatched in robotic systems. These capabilities can be ascribed to two main enabling factors: (i) the physical proprieties of human musculoskeletal system, and (ii) the effectiveness of the control operated by the central nervous system. Regarding point (i), the introduction of compliant elements in the robotic structure can be regarded as an attempt to bridge the gap between the animal body and the robot one. Soft articulated robots aim at replicating the musculoskeletal characteristics of vertebrates. Yet, substantial advancements are still needed under a control point of view, to fully exploit the new possibilities provided by soft robotic bodies. This paper introduces a control framework that ensures natural movements in articulated soft robots, implementing specific functionalities of the human central nervous system, i.e., learning by repetition, after-effect on known and unknown trajectories, anticipatory behavior, its reactive re-planning, and state covariation in precise task execution. The control architecture we propose has a hierarchical structure composed of two levels. The low level deals with dynamic inversion and focuses on trajectory tracking problems. The high level manages the degree of freedom redundancy, and it allows to control the system through a reduced set of variables. The building blocks of this novel control architecture are well-rooted in the control theory, which can furnish an established vocabulary to describe the functional mechanisms underlying the motor control system. The proposed control architecture is validated through simulations and experiments on a bio-mimetic articulated soft robot.

Soft Robots: Implementation, Modeling, and Methods of control

“…Certain study instances of electro-ribbon actuators are promising in soft robotics but difficult to control because of pull-in unsteadiness. There is a relatively small contraction range for feedforward control: Suphapol Diteesawat et al have handled minor contractions below the pull-in voltage threshold and complete contractions [89]. An alternative perspective demonstrates how we might acquire helpful information from soft-arm compliant behavior.…”

Developing and testing a remotely operated vehicle with a seven-function manipulator

“…Thus, there will be a great difference in the control hardware architecture. In terms of control software architecture, there are hierarchical control architectures, reactive control architectures, subsumption control architectures, and hybrid control architectures [14][15][16] . Among them, the hierarchical control architecture is an architecture based on the principle of reducing intelligence and increasing precision.…”