A double-layer sensing system combining thin-film resistor and acoustic emission networks towards an in situ real-time quantitative monitoring of hypervelocity impact

Massive orbital debris consisting of remnants from previous missions orbit the Earth. The acquisition of data pertaining to the orbital debris is of paramount importance for the development and validation of debris environment models. In this study, a novel in situ real-time quantitative hybrid perception method for hypervelocity impact (HVI) from space debris is proposed, integrating a thin-film resistive grid with acoustic emission (AE) technology. The thin-film resistive grid is fabricated by etching a cross-shaped array of micrometer-scale resistive wires on the respective sides of a polyimide film. In the event of the film being penetrated by debris and the resistive wires being broken, the electrical resistance status of the wires can then be used to determine the location and size of the debris. Following the penetration of the thin-film layer, the debris strike a second aluminum plate equipped with an AE sensor array. The arrival times of the acoustic signals are processed using a hyperbolic localization algorithm to determine the HVI location. By correlating the time and location data from both layers, the velocity and direction of HVI can be derived. This facilitates the quantitative perception of multiple debris parameters. Then, the HVI numerical simulations, which combine smooth particle hydrodynamics and finite element method, are performed to validate the effectiveness of the proposed perception approach. Finally, a physical prototype of the in situ debris detector is developed for experimental validation. Two ground-based two-stage light gas guns are used to propel several projectiles with diameters ranging from hundreds of micrometers to several millimeters. The average absolute errors for the three tested cases are 0.10 km/s for the projectile velocity, 1.0° for the impact angle, and 0.30 cm for the HVI location at the aluminum plate, demonstrating the effectiveness for multi-parameter perception of space debris.