Passivity-based control of human-robotic networks with inter-robot communication delays and experimental verification

Abstract

Abstract-In this paper, we present experimental studies on a cooperative control system for human-robotic networks with inter-robot communication delays. We first design a cooperative controller to be implemented on each robot so that their motion are synchronized to a reference motion desired by a human operator, and then point out that each robot motion ensures passivity. Inter-robot communication channels are then designed via so-called scattering transformation which is a technique to passify the delayed channel. The resulting robotic network is then connected with human operator based on passivity theory. In order to demonstrate the present control architecture, we build an experimental testbed consisting of multiple robots and a tablet. In particular, we analyze the effects of the communication delays on the human operator's behavior.

Passivity-Based Decentralized Control of Multi-Robot Systems With Delays Using Control Barrier Functions

“…Theorem 6 (See [24] and [26]). Given a dynamical system in control affine form (9), where x ∈ R n and u ∈ R m denote the state and the input, respectively, f and g are locally Lipschitz, and a set Ω ⊂ R n defined by a continuously differentiable function h as in (10), any Lipschitz continuous controller u such that (11) holds renders the set Ω forward invariant and asymptotically stable, i. e.,…”

“…Here, the so-called scattering transformation is introduced in order to stabilize a system in the presence of any, although constant, communication delay. On a similar line of inquiry, in [10], the authors employ the scattering transformation to make the interconnection of a network of robots with a human operator passive under constant time delays. It is worthwhile noticing that scattering-based approaches are suitable to make robots achieve synchronization tasks (such as consensus).…”

A Safety and Passivity Filter for Robot Teleoperation Systems

“…Passivity-based approaches, as well as other energy-based methods, for the control of robotic systems are considered in [4,12,26,28,15]. In [6], the authors introduce the concept of energy tanks, which is then extended in [20,21,19,7].…”