Active Control Approach to Temporal Acoustic Cloaking

TL;DR

This paper introduces a linear, active control method for implementing a temporal acoustic cloak that can hide events in time without altering the physical medium, demonstrated through simulation.

Contribution

It presents a novel, fully linear, active control approach for temporal acoustic cloaking, avoiding medium modification and allowing reprogrammable cloaking parameters.

Findings

Successful simulation of a one-dimensional water channel cloak

Real-time reprogramming of cloaking parameters demonstrated

Active control approach avoids physical medium alteration

Abstract

We propose a realization of a transformation-based acoustic temporal cloak using an active closed-loop control approach to an equivalent electromagnetic problem. Unlike the more common spatial cloaks the goal of which is hiding fixed objects from detection, the goal of the temporal cloak is hiding the occurrence of events during a finite period of time. In electromagnetic systems, in which events represent, for example, leakage of signals from transmission lines or optical fibers, temporal cloaking solutions usually rely on nonlinear phenomena related to the fibers properties, or on modulating the properties of the propagation medium itself. In particular, the transformation-based solution requires modulating the constitutive parameters of the medium both in space and time. Our control approach is fully linear, where the required change in the medium parameters is programmed into the controllers and created by external actuators in real-time. This cloaking system keeps the physical medium unchanged, and enables to reprogram the cloaking parameters upon request. We demonstrate our solution in a simulation of a one-dimensional water channel.