Robot-Assisted Underwater Acoustic Imaging for Bridge Scour Evaluation (AS-8)

Bridge scour is the engineering term for the erosion of soil surrounding a bridge foundation (piers and abutments) caused by complex water current. Scour and other hydraulic induced failures accounted for 58% of over 1,500 bridge collapses in the U.S [Zhang2018]. Monitoring with fixed and/or portable instrumentations is one of the most effective measures in mitigating scour hazards. However, fixed instrumentation with sensors installed prior to flood events can only detect scour in the area instrumented and is susceptible to the harsh environment during a flood event. On the other hand, deploying portable instrumentation (e.g., radar, sonar) using surface boat or radio-controlled boat during a severe flood event is very difficult due to safety consideration and/or water conditions. Leveraging the achievement in developing wall-climbing robots over last few years, the research team proposes a solution to deploy a portable sonic imaging instrument using a wall-climbing robot from bridge pier and deploy the instrument into water to assess scour hazard around the bridge foundation. The wall-climbing robot is expected to climb down along the pier and rest above water level. A delivery system will be designed and installed on the robot to deploy the scanning sonar instrument into the water for inspection and visualization of the bridge scour and retrieve back when the 3D sonic imaging job is done. The project is an integral part of the research effort in developing reliable and field deployable robots for bridge inspection. The combination of wall-climbing robot, delivery system and sonic imaging can directly be applied in assessment of bridge scour, which will meet the INSPIRE UTC goal of making inspection and maintenance more reliable and cost-effective. Approach and Methodology: This project will investigate the design options of the delivery system by considering the size and weight of the sonic instrument, the capability of the wall-climbing robot to be outfitted, and the typical scenario of bridge scour (e.g., underwater depth) to determine the design requirements and specs. The design options of the instrument delivery system to be investigated include the cable winch system, telescopic rod, and Rolatube concept. The winch system is easy to deliver the instrument into water and retrieve back using cable. However, the flexible cable impose challenges to control the position of the instrument in rapid water current during flood event. The telescopic rode is easy to expend, stiff enough to keep position of the instrument in water, but difficult to shorten the length through automatic control. Overall Objectives: This project will produce a working prototype of a delivery system to be outfitted in the payload compartment of the Rise-Rover wall-climbing robot. It will be able to carry a portable sonic imaging instrument on the tip of the RolaTube in coiled state. After the robot reach the location close to water level on a pier, the instrument can be deployed into water for bridge scour assessment by unrolling the tape/band that then forms a long and stiff tube. The underwater depth of the instrument can be controlled by the delivery system by expanding or contracting the length of the tube. While the robot circle around the pier, the instrument can perform underwater survey and visualization of the bridge scour using the scanning sonar instrument. Scope Year-1: (1) to design and prototype a dual-chamber climbing robot that can move on the curve/flat surfaces of concrete piers, (2) to integrate the side-scan sonar and the altimeter with the climbing robot, and test the system’s maneuverability and stability as well as the sensors’ performance in application settings, and (3) to demonstrate the field performance of the integrated system at a bridge site.


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Filing Info

  • Accession Number: 01847975
  • Record Type: Research project
  • Source Agency: Inspecting and Preserving Infrastructure through Robotic Exploration University Transportation Center
  • Files: UTC, RIP
  • Created Date: Jun 4 2022 12:26PM