Special Session O-9/P-5
Biomimetic Design and Motion Control in Autonomous and Remotely Operated Underwater Vehicles
O-9/P-5:IL02 Robotic Fish Development for the Next Generation Underwater Vehicle
IKUO YAMAMOTO, Nagasaki University, Graduate School of Engineering, Nagasaki, Japan
The author has developed many kinds of robotic fishes based on elastic oscillating fin propulsion system from 1989. The presentaion describes past, present, and future robotic fish technologies, and applications of robotic fish technologies to various fields. Firstly, the history of the developed life-like robotic fish, such as sea bream in 1995, coelacanth in 1997, carp in 2000, shark ray in 2004 etc. is mentioned. The developed robotic fishes are basically propelled by vertical tail fin and operated by servo motors. Secondly, the life-like robotic dolphin was newly developed in 2013. The author developed tethered whale robot with horizontal tail fin propelled by hydraulic actuator in 1990s, however, the robotic dolphin is untethered and higher length,that is more than 1m,and has characteristic of fast cruising and higher maneuverability with horizontal tail fin propelled by servo motors. Thirdly, new application fields of robotic fish technologies, such as medical forceps and extractors, space robots which went to International Space Station and swam in the space, and current power plant using oscillating fin propulsion system for new offshore sustainable energy are described.Finally, robotic fish technologies for the next generation underwater vehicle are summarized.
O-9/P-5:IL07 An Octopus-inspired Robot
M. CIANCHETTI, C. LASCHI, The BioRobotics Institute, Scuola Superiore Sant’Anna, Pisa, Italy
Robotics can count on a 60-year history of successes based on the wise use of rigid links and materials, where well established control theories and techniques have been widely validated so to provide robots with high accuracy and reliability. On the other side, the growing need for robots in service tasks, working in unstructured environments and in contact with humans, is leading to the introduction of new technologies based on soft and compliant materials. The fundamental role covered by softness is clear in natural organisms, thus it is very meaningful to look at Nature for drawing inspiration. Among the other animals, the octopus is for sure the most paradigmatic example and the best model to understand how soft materials can be exploited to interact safely, but effectively with the environment. This approach allowed the development of a series of soft-bodied underwater devices and robots where dexterity, adaptability and robustness are achieved thanks to a smart combination of material properties and morphologies (embodied intelligence) which can be exploited for reacting to the environment, compensating external forces, and ultimately simplifying control.
O-9/P-5:IL08 Bionic Sonar Structure and Skin Material inspired by Dolphins
QIJUN LIU, ZHIMING LIU, JIE YU, ZIXUAN ZHANG, WENJIAN WU, National University of Defense Technology, Changsha, Hunan, China
The bio-sonar of dolphin is much better than artificial sonars in many aspects, especially in its abilities of materials distinguishing and seabed penetrating. We have researched four species in odontocete. The data of CT scanning over heads was processed, their physiological structures of respiratory systems were dissected, and mechanical properties of related organs and tissues were measured. Based on above results, a hypothesis of phonic mechanism which is similar with a reed whistle was proposed, and a bionic structure of simulation device was also designed and assembled. Fortunately, it could emit ultrasonic waves with frequencies as happens in dolphin. Dolphin is the fastest mammals in the ocean. Bionic researches on their abilities of drag reduction and noise control have been carried out. The bionic dolphin skin designed by us was composed of three compliant layers corresponding to epidermis, dermis and fat layer of dolphin skin. The intermediate layer with well-organized micro-papillae and ridges was fabricated by imprinting the featured faces of dolphins’ epidermis with compliant polymers. The soft-lithographic imprinting approach could be applied to obtain bionic epidermis of dolphin skins with high accuracy and large-areas.
O-9/P-5:IL10 Inspired by Fish: Evolving, Building, and Controlling Flapping Flexible Propulsive Structures for Aquatic Robots
J.H. LONG Jr., Vassar College, Poughkeepsie, New York, USA
Fish are not perfect machines. But they are diverse in terms of their evolved body morphologies and propulsive mechanisms. Thus they offer proof-of-concept for multiple types of non-rotary propulsion, notably undulatory and oscillatory flapping. Key to the control of flapping locomotion is the ability to control shape, stiffness of the propulsive element, and amplitude and frequency of the motor inputs. We combine kinematic studies of swimming fish with biomechanical tests of their bodies and skeletal elements using biorealistic motion inputs. Supplied with the resulting viscoelastic mechanical properties, we build simplified biomimetic flippers, bodies, and backbones. We test those propulsors in self-propelled robots. Using evolutionary techniques and autonomous robots, we search for shapes, mechanical properties, sensor inputs, and motor control networks that solve problems involving navigational behavior.
This work is supported by the National Science Foundation of the United States, INSPIRE grant 1344227.
O-9/P-5:IL11 Propulsive Performance of Dolphin Based on Numerical Simulation of Standing Swimming
K. ISOGAI, Kyushu University, Fukuoka, Japan
In the standing swimming of dolphins, which is often seen in aquariums, the total weight of the body is supported by the caudal fin in the water. It is clear that the thrust generated by the fanning motion of the caudal fin is equal to the body weight. In the study reported in this paper, a numerical simulation of the flow around the caudal fin (of the bottlenose dolphin) using the 3D Navier–Stokes code for the standing swimming condition was conducted and the necessary power was computed. The power thus determined is about 3–4 times larger than the power necessary for the cruising swimming condition, determined by the performances observed to date for trained dolphins in aquariums. With this necessary power, we have estimated the maximum speed the dolphin can attain, using the 3D MDLM (modified doublet lattice method) coupled with an optimum design method and the 3D Navier–Stokes code, obtaining about 13 m/s, which is considerably higher than values observed in aquariums. In addition to these computations conducted with the assumption of rigid fin, the similar computations in which the flexibility of the fin is taken into account have also been conducted. The results show that the power mass ratio is 62.2 W/kg which is 2.6 times larger than that of human athlete.