DamBotTM: An Unmanned Amphibious Vehicle for Earth Dam Outlet Inspection

Abstract

The US Army Corps of Engineers (USACE) owns, maintains and operates several hundred locks and dams across the United States. A large portion of these structures have met or exceeded their design life, therefore the need to perform detailed inspections regularly has become increasingly important. Some of the challenges for inspection personnel are the hazardous conditions associated with entering dam outlet works, and the need to conduct the inspection within a short time frame so that the dam can resume normal operations and maintain downstream water levels. These subterranean conduits are classified as confined spaces and can be several hundred meters long, have flowing water, and in some instances have toxic gases present. The USACE Engineer Research and Development Center (ERDC) has developed an unmanned amphibious vehicle, called DamBot™, to enter these outlet works with a sensor suite and perform first-look inspections of the conduit and closure gates. In order to carry out these inspections, DamBot™ is equipped with cameras and LiDARs to capture 360 degrees situational awareness around the platform, and a five-meter robotic arm with nine degrees of freedom to perform up close inspection of closure gates, which can be over six meters tall. Additionally, the DamBot™ is able to capture data of the entire conduit during inspections, collecting a dataset that provides a comprehensive picture of the infrastructure. DamBot™ uses techniques such as simultaneous localization and mapping (SLAM) to assure positional accuracy of data collection in these GPS denied environments. These datasets can be post-processed into 3D models and can be used for structural health monitoring by way of change detection when compared with previous inspections. DamBot™ has been successfully demonstrated at several active USACE projects, and this paper will detail the specifications of the system and discuss the results of field demonstrations, lessons learned, and future improvements to the system.