RI: Small: Fast, Cheap, and In Control: New Methods for Precision Navigation of Low-Cost Autonomous Underwater Vehicles for Ocean Science

一种新型的小型低成本无人水下机器人(UUV)正开始执行海洋、环境评估和国家安全任务，这些任务比大型高成本UUV、载人潜水器和人类潜水员等以前的方法更快、更便宜。小型低成本UUV的一个重要限制是其低成本导航系统，目前仅限于需要相对低精度导航的任务。该项目正在开发使用低成本传感器进行高精度导航的新方法，以显著提高低成本UUV的导航精度。该方法由三部分组成：(1)使用多普勒声纳速度测量和低成本低功率惯性测量单元来估计姿态；(2)开发基于非线性模型的状态估计器，采用航行器二阶对象动力学的完全非线性模型；(3)利用水声调制解调器网络提供同步的水声通信和声学距离和距离-速率数据，并将这些数据用于改进水下航行器导航。这些方法的实验验证包括用两个不同的试验台水下机器人进行全面的实验试验。成果的传播包括研究出版物和更广泛的公众宣传。该项目涉及对本科生和研究生的实践培训和指导。这些本科生将参与这项研究，并将在一个项目中担任导师，该项目通过约翰·霍普金斯大学校园里为期半天的周末项目，为巴尔的摩地区的中学女生提供入门工程经验。这项研究将使UUV能够执行需要高导航精度的任务，这些任务目前被认为与现有的低成本UUV不切实际或不可行。

A novel class of small low-cost unmanned underwater vehicles (UUVs) is beginning to perform oceanographic, environmental assessment, and national security missions that are faster and less expensive than previous methods such as large high-cost UUVs, human-piloted vehicles, and human divers. A significant limitation of small low-cost UUVs is their low-cost navigation systems which presently limit them to missions requiring comparatively low-precision navigation. This project is developing new methods for high-accuracy navigation with low-cost sensors to provide dramatically improved navigation accuracy for low-cost UUVs. The three-part approach (1) employs Doppler sonar velocity measurement and low-cost low-power inertial measurement units to estimate attitude; (2) develops nonlinear model-based state estimators employing a full nonlinear model of the vehicle's second order plant dynamics; and (3) utilizes underwater acoustic modem networks to provide simultaneous acoustic communication and acoustic range and range-rate data, and employ these data for improved underwater vehicle navigation. Experimental validation of these methods includes full-scale experimental trials with two disparate testbed underwater vehicles. Dissemination of the results includes research publications and more general public outreach. This project involves hands-on training and mentoring of undergraduate students and graduate students. The undergraduates will be involved in the research, and will also serve as mentors in a program which provides introductory engineering experiences for middle school girls in the Baltimore area through half-day weekend programs on the Johns Hopkins University campus. This research will enable UUVs to perform missions requiring high navigation accuracy that are presently considered either impractical or infeasible with existing low-cost UUVs.