Modeling and simulation of porpoising for a multilink dolphin robot

This paper analytically analyzes the porpoising behavior of dolphins and other cetaceans in the context of bio-robotics. Based on the conventional assumption that porpoising saves energy at high speed, the “crossover” speed is recalculated. A dynamic model for a multilink dolphin-like robot within the framework of multibody dynamics is created. Simulations using the dynamic model have been extensively performed in MATLAB/Simulink. In terms of simulation results obtained, the primary assumption has been validated and a newly possible main cause of porpoising´s energy economy is suggested that the route diversion action results in a significant speed increase while porpoising. Two contradictions between the observation and the theoretical prediction have been explained, agreeing well with the above finding.