The invention belongs to the technical field of
underwater bio-mimetic robotic fishes, and particularly relates to ostraciidae-imitating autonomous robotic fish capable of achieving sink-and-swim motion. By adopting a
gravity center adjusting method and a method of water suction and
discharge, high speed
underwater submerging and surfacing motion of the robotic fish is achieved, wherein the robotic fish can depend on a pectoral and a
tail fin to propel and adjusts an
angle of inclination through a heavy block to achieve the high-speed
underwater submerging and surfacing motion, and further, submerging and surfacing motion of the robotic fish under a low-speed condition can be achieved through changing of the gravity of the robotic fish. Compared with a former mechanism, the adjusting range and the
degree of precision of the robotic fish are greatly improved, the motion of direct swimming, steering, upward floating, diving and the like of the bio-mimetic robotic fish at various speeds can be achieved, and the capability of underwater motion of the robotic fish is improved. An upper shell body is divided into an upper shell body upper cover and an upper shell body connecting piece, the upper shell body connecting piece is connected with a lower shell body, the joint of the upper shell body connecting piece and the lower shell body is smeared with 703
silicone rubber, and static seal is formed between the two shell bodies. Deep-groove ball bearings are arranged at the two ends of a
ball screw, a limiting switch and an
encoder are arranged on a mechanism support, and the
encoder is connected with the
ball screw. Data of the movement condition of a balancing weight is sent back through the
encoder, and a
closed loop with a high precision is achieved. The situation that a
fish head can adjust an
angle of inclination of a fish body according to needs to reach to a set depth is guaranteed through the design.