新型嵌套折展子母网箱机构研究

Research on the Novel Primary and Secondary Embedded Deployable Cage Mechanism

网箱养殖是海洋设施养殖的重要战略方向,针对现有深海网箱难以自适应调整养殖区域以优化生态环境、体积庞大难以运输等问题,提出了新型嵌套折展子母网箱机构,以空间折展机构为网箱支撑母框架,嵌套安装于母框架的平面柔性折展机构为子网箱框架,以闭环钢丝绳驱动网箱折展。研究构成网箱框架机构的三重对称Bricard机构折展关键状态尺度约束类型的演变,揭示机构折展过程中对称面相交共线的几何不变特性,构造以对称面交线为折展轴线的网箱折展驱动机构;进一步建立网箱框架机构运动学方程,通过对称面几何投影解析求解驱动杆转角与网箱折展状态的对应关系。所提出的具有大折展比的嵌套折展网箱机构为深海网箱的研制提供了新思路。

Cage aquaculture is an important strategic direction for marine aquaculture. Aiming at the problems that the existing offshore cages are difficult to adjust the breeding areas adaptively to optimize the ecological environment and the difficulty in transportation due to their large size,a novel primary and secondary embedded deployable offshore cage is proposed which the over-constrained spatial mechanisms and planar compliant mechanisms are respectively adopted as the primary and secondary cages. A closed-loop cable-driven module is designed to deploy the cage through the pull and release of the cable. Then,the evolution of the dimension constraint types of the threefold-symmetric Bricard mechanism which forms the primary cage mechanism is investigated. The geometric invariant characteristics that three symmetric planes intersecting at a determined line are revealed so that the cage driven mechanism with the symmetrically plane intersecting line as the axis of mechanism folding is constructed. Further,by establishing the kinematics equation of the primary cage mechanism,the relationship between the driven angle and corresponding open state of the cage can be derived from geometric projection on the symmetric planes. The novel primary and secondary embedded deployable cage mechanism with large deployable ratio can provide new thread for the design of offshore cages.