Authors

Abstract

To overcome the challenges associated with complex seedling-to-haulage rope connections, low manual unlocking efficiency, and poor reusability in current kelp harvesting operations, a PLC-controlled rapid disengagement technology for kelp seedling ropes was proposed. The proposed technology employs a button-type locking structure with self-locking functionality, coupled with a magnetically controlled disengagement device, to achieve automated unfastening of seedling ropes without damaging the suspension rope. The paper presents the structural composition and operating principle of the locking structure. A three-dimensional force model during the disengagement process was established based on rotational torque and frictional force balance, and the constraint mechanism for posture correction of the lock within the flared guiding channel was analyzed. To address the force characteristics of the seedling rope during the disengagement process, a dual-fingered pusher structure was designed. The use of an involute trajectory enabled stable extraction of the rope from the locking groove. In terms of control, a Delta PLC was employed as the central controller, and an execution system comprising an electric push rod, proximity sensors, magnetic adsorption module, and rope-pulling motor was developed to achieve automated control of lock correction, magnetic positioning, unlocking, and rope disengagement. Key parameters such as the locking button force, rope-pulling force, and motor power were determined and optimized through theoretical modeling and bench-scale testing. Experimental results indicated that the system achieved the highest disengagement success rate of 96.67% when the guiding slot clearance was 14 mm, the haulage rope speed was 40 mm/s, and the pusher length was 45 mm, demonstrating stable and reliable device performance.

Abstract in Chinese

针对当前海带收获作业中苗绳与绠绳连接方式复杂、人工解扣效率低及不可重复使用等问题，提出了一种基于PLC控制的海带苗绳快速脱扣技术。该技术通过锁定功能的按钮式锁扣，配套开发磁吸控制脱扣装置，实现苗绳在不破坏吊绳的前提下的自动化解扣。论文提出了锁扣的结构组成与工作原理，基于旋转扭矩、摩擦力平衡和弹性势能理论，建立了脱扣过程中的三维受力模型，分析了扩口式导向槽中锁扣姿态矫正的约束机制。针对拨绳过程中苗绳的受力特点，设计了双拨指结构，结合渐开线轨迹实现苗绳从挂接槽中稳定拨出。控制系统方面，采用台达PLC作为主控核心，搭建了由电动推杆、接近开关、磁吸模块、拨绳电机等构成的执行系统，完成从锁扣矫正、磁吸定位到解锁拨绳的自动控制流程。通过理论建模与台架试验，对锁扣按钮受力、拨绳拨力及电机功率等关键参数进行了计算与优化。试验结果表明，当导向槽间隙为14 mm、绠绳速度为40 mm/s、拨指长度为45 mm时，系统脱扣成功率最高达96.67%，装置运行稳定可靠。