Review and Prospect for Vegetable Grafting Robot and Relevant Key Technologies

Grafting is an effective way to overcome the obstacles of continuous soil cropping and improve the tolerance of plants to abiotic and biotic stresses. An automatic grafting robot can effectively improve the grafting efficiency and survival rate of grafted seedlings, which is an important demand for the commercialization and promotion of vegetable planting. Based on the six main grafting technologies, this paper deeply summarized and analyzed the research status, technical characteristics, and development trends of vegetable grafting robots developed by various countries in the world. At the same time, it focused on the design methods and characteristics of key components such as seedling picking device, clamping device, and cutting device of vegetable grafting robots in detail. Then, the application of machine vision in the grafting robot was compared from the aspects of seed information feature recognition, automatic seedling classification, seedling state detection, and auxiliary grafting. It also was pointed out that machine vision technology was the only way to realize the fully automated grafting of vegetable grafting robots. Finally, several constraints, such as the limited grafting speed of vegetable grafting robots were pointed out, and the future development direction of grafting robots was predicted. As a result, it is believed that the intelligence degree of vegetable grafting robots needs to be improved, and its research and development fail to integrate with the seedling biotechnology, which leads to its poor universality. In the future, improving machine vision, artificial intelligence, and automation technology will help the development of high-performance universal grafting robots.