Meeting Abstract
Siphonophores are colonial organisms that are capable of rapid movement and changes in direction. This capability is possible due to the distribution of thrust production of the bulk body among multiple jetting propulsion units along the length of the body central stem. In particular, species under the genus Nanomia utilize muscular control of the jetting unit outlet to direct the water jet during contraction. By including multiple distributed thrust units with directional control, a larger number of distinct forces can be imparted along the body to finely control the colony kinematics and heading. Understanding the fundamental colonial coordination, control, dynamics, and fluid motion would help in further understanding the growth and behavior of siphonophores in live environments. This study focuses on the characterization of the coordinated movements for velocity and heading control gaits. Preliminary measurements and classifications were developed using shadowgraph and fluorescent dye footage of siphonophores in captivity and open water, respectively. These characterizations were used for the design and preliminary control implementation of a Nanomia-mimetic robot. Parameterized modifications of the gait frequency and patterns, as well as the number of propulsion units in the colony, were iterated to determine the effect of gait generation variables on the colony velocity and heading response. These responses were combined to develop an optimized control scheme for rapid colonial locomotion control. Future plans for adaptive control of the colony using neural networks with distributed control, which mimics the minimal control network of Nanomia, will be discussed in an effort to automate jetting unit addition and autotomy.
