Optimal design and experimental verification of a four-claw seedling pick-up mechanism using the hybrid PSO-SA algorithm

Aim of study: To develop a novel four-claw seedling pick-up mechanism to integrate penetration and clamping into one process, realizing picking up seedlings stably and efficiently. Material and methods: A brushless DC servo motor characterized by small size, large torque, and high control precision was adopted to realize precise control for speed and clamping force through control algorithms. An optimization model was derived according to the requirements of picking up seedlings. The parameter optimization of the seedling pick-up mechanism is a complex multi-parameter and nonlinear optimization problem. The hybrid PSO-SA algorithm was used to solve the model, and the optimal parameters of the mechanism were obtained. Main results: The dynamic simulation was conducted, and the results showed that the optimized mechanism could meet the trajectory, acceleration, and clamping force requirement for picking up seedlings. The performance tests showed that the success ratio in picking up seedlings reached 84.46%, indicating the feasibility of the four-claw seedling pick-up mechanism for automatic transplanting machines. Research highlights: The four-claw seedling pick-up mechanism can be used in the automatic transplanting machine. Additionally, the hybrid PSO-SA algorithm can achieve promising results in solving the optimization problem of the seedling pick-up mechanism.