Development of a novel intelligent control system for an autonomous multiple codend opening/closing mechanism in sampling nets

• A novel electromagnetic induction-based control system was developed for autonomous multiple codend release in sampling nets. • A dual-mode intelligent control architecture was designed to support both autonomous and acoustic communication control. • The functionality and reliability of the multiple codend release mechanism and intelligent control system were validated through testing and sea trials. Quantitative sampling of ichthyoplankton is a critical tool for estimating recruitment abundance and supporting the sustainable management of fishery resources. This study introduces a novel multiple codend release mechanism utilizing an electromagnetic induction device as part of an autonomous multiple codend opening/closing system for sampling nets. The electromagnetic induction mechanism operates solely on the principle of electromagnetism to open and close codends, significantly reducing the reliance on mechanical components compared to traditional motor-triggered systems. Furthermore, an intelligent control system integrating automatic and remote modes via acoustic communication has been developed, allowing researchers to select the appropriate mode based on varying operational conditions and requirements. These advancements demonstrated strong stability and reliability in both controlled tests and sea trials. Collectively, the newly developed multiple codend release mechanism and intelligent control system offer a foundational reference for enhancing the efficiency and adaptability of multiple sampling nets.