Variable-stiffness flexible bionic fish model based on internal fluid pressure adjustment

Abstract

The invention provides a variable-stiffness flexible bionic fish model based on internal fluid pressure adjustment. The model comprises a fish head portion, a fish body and a tail fin. A pneumatic power control unit is installed in the fish head portion. The fish body comprises four internal taper pneumatic muscles and a nested series-parallel unit. The nested series-parallel unit is taken as a spine and a skeleton of a bionic fish. The four internal taper pneumatic muscles are located in the nested series-parallel unit respectively. A front end of each internal taper pneumatic muscle is connected to the fish head portion, and a tail end is connected to the tail fin through a rigid fixing component. The pneumatic power control unit is connected to the nested series-parallel unit and the four internal taper pneumatic muscles respectively. The pneumatic power control unit adjusts an internal intensity of pressure of the internal taper pneumatic muscles so as to realize fish body swinging and torsion or changes an average intensity of pressure so that rigidity of a tail portion of the fish body changes. The model is flexible, according to a swimming speed, tail portion rigidity can be adjusted and the model is energy-saving and high-efficient.

Description

technical field [0001] The invention mainly relates to the field of underwater bionic robots, in particular to a flexible bionic fish model with variable stiffness based on internal fluid pressure regulation. Background technique [0002] The current research on the swimming mechanism of BCF fish shows that: 1. There is muscle tissue attached to the spine of the fish, which drives the fish tail to swing in the water, generating an inverse Karman vortex street, and uses the reaction force generated by it to push the fish body forward; 2. The fish tail Four large muscle groups are distributed around part of the spine. When the fish swims, it adjusts its own tension to change the stiffness of the fish tail. Because different swimming speeds require different stiffnesses, the natural frequency of the body and the swing frequency of the tail can reach the same level. 3. The four muscle groups around the spine can bend themselves in all directions by contracting the fish tail, gen...

AI Technical Summary

Problems solved by technology

However, this structure cannot meet the flexibility of the robot fish in the water, the turning radius is too large, and it is difficult to adjust the stiffness of the fish tail according to the swimming speed of the fish. The propulsion efficiency is not as high as that of a real fish, and further research and experiments are needed.

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