Machinery Noise Radiation from Shell Structures: Active, Passive and Adaptive-Passive Control

Hood Technology proposes to identify the "best" combination of active and passive control approaches for radiation of machinery noise from shell structures. Hood wishes to exploit the best features of passive approaches: 1. The capability to generate the control forces passively, through reactive storage of energy for a half cycle. 2. The absolute stability. 3. The low power consumption. Hood wishes to maintain as much as possible the best features of fully active approaches: 1. The ability to adapt. 2. The ability to respond to distant performance measures, and to globally coordinate the actuators. Hood believes that an adaptive-passive approach, in which the reactive control element or array of elements respond passively but are adaptively tuned by a distributed active supervisory system, offers the best combination for these problems. Hood anticipates suffering a marginal performance sacrifice compared to a fully active approach, but enjoying a major reduction in system complexity, increased reliability, and a decrease in cost.