The design of a compliant underwater angle sensor to investigate the kinematics of burrowing razor clams

Abstract

This paper presents the detailed design process for a compliant underwater angle sensor to be used in analyzing the precise burrowing motions of razor clams in order to aid in the development of intelligent anchoring devices. The angle sensor was developed using a set of specific functional requirements, theoretical kinematic and structural models, and an iterative prototyping process. The resulting sensor is a device that can measure the angle between the two halves of a clam's shell versus time using a thermal-centric strain gauge configuration. The device is saltwater compatible, does not hinder the motions of the clam and only increases the axial drag on the clam by 2.3 to 5.5%. Data can now be collected using this sensor that will be important to creating a strategy for the coordination of the movements of a robotic anchor that would improve upon existing anchoring technologies for marine applications ranging from small boats, to Autonomous Underwater Vehicles (AUVs), to spy equipment.