A review of the current status and common key technologies for agricultural field robots

The arrival of the Industrial Revolution 4.0 and the quick advancement of artificial intelligence (AI), cloud computing, and internet of things (IoT) have led to the beginning of a new technological revolution in agriculture. As an important branch of agricultural robots, field robots have an irreplaceable role in guaranteeing food security, seizing the global agricultural high ground, and realizing sustainable agricultural development. In this study, we first clarified the definition of field robots and review the different development stages of agricultural robots. Secondly, we searched and screened 678 relevant literature from electronic databases such as Science Direct, Web of Science, etc., and quantitatively analyzed all the literature in terms of three dimensions: year of publication, country, and keywords. Then, we systematically provided the current research status of ploughing-seeding, weeding, monitoring, harvesting, and information-gathering, crop protection and agricultural fly robots. Furthermore, the global development of field robots shows a trend of rapid growth and technology upgrading, and we proposed the common key technologies of field robots, including intelligent sensing, smart decision-making and control, dexterous arm and hand operation, autonomous and stable walking, and Cloud-Edge-End fusion intelligent operation. Finally, we summarized the challenges faced by robots, such as low sensing accuracy, poor operability, and low operating efficiency. Therefore, we attempted to provide new opportunities for the future development of field robots, such as new technologies such as unstructured information analysis, 5G, AI, digital twins, robots swarms collaboration, and other technologies, which enable the realization of field operation scenarios with fully autonomous perception.