Using light underwater : devices, algorithms and systems for maritime persistent surveillance

[摘要] (cont.) In this application the robot and the sensor nodes can be fitted with our novel imaging sensor, capable of taking underwater color-accurate photographs for reef health assessment and species identification. Compared to existing techniques, our approach: (1) simplifies the deployment of sensors through sensor self-localization, (2) provides sensor status information and thus enables the user to capture rare events or to react to sensor failure, (3) provides the user real time data and thus enables adaptive sampling, (4) simplifies mobile sensing underwater by providing position information to underwater robots, (5) collects new types of data (accurate color images) through the use of new sensors. We present several innovations that enable our approach: (1) an adaptive illumination approach to underwater imaging, (2) an underwater optical communication system using green light, (3) a low power modulation and medium access protocol for underwater acoustic telemetry, (4) a new AUV design capable of hovering and of efficiently transporting dynamic payloads. We present the design, fabrication and evaluation of a hardware platform to validate our approach. Our platform includes: (1) AquaNet, a wireless underwater sensor network composed of AquaNodes, (2) Amour, an underwater vehicle capable of autonomous navigation, data muling, docking and efficient transport of dynamic payloads and (3) AquaLight an underwater variable-spectrum Xenon strobe which enables underwater color accurate photography. We use this platform to implement and experimentally evaluate our algorithms and protocols.

[发布机构] Massachusetts Institute of Technology