Posture analysis and application of a bionic pectoral foil

Biological fish propelled by wide paired pectoral foils is attractive for the special characteristics as their nature samples. Advantages and limitations of two groups of the bionic flatten pectoral foils classified by actuation arrangement are summarized. Key flapping properties of cow-nosed ray affecting its driving performance are obtained. Simplified driving method and typical theoretical postures for the designed bionic wide pectoral foil is analyzed and verified through experiments. A bionic fish based on this kind of foil has been developed and tested in air and water. Various postures designed imitating cow-nosed ray in air have also been verified. Furthermore, the swimming performance tests in water show that the bionic fish can achieve maximum forward swim speed of 0.7 times of body length per second and an excellent turning maneuverability with a small radius.