Design and Analysis of a Novel Primary and Secondary Embedded Deployable Offshore Cage

Cage aquaculture is an important strategic direction for marine aquaculture, which plays an important role in expanding aquaculture space and protecting the offshore ecological environment. First, based on the concept of embedded deployable mechanisms, a novel embedded deployable offshore cage driven by cables is proposed. Over-constrained spatial mechanisms and planar compliant mechanisms are respectively adopted as the primary and secondary cages while the secondary cages are embedded in the primary cage. A closed-loop cable-driven module is designed to deploy the cage through the pull and release of the cable. Then, due to the kinematic characteristics of threefold-symmetric Bricard mechanism with three symmetric planes intersecting at a determined line, the determined line is regarded as the central line of the driven mechanism. Finally, the relationship between the input angle and the output angle is obtained from the kinematic equations of the primary cage frame, then the relationship between the driven angle and corresponding open state of the cage frame can be derived by geometric projection.