Abstract:
Intelligent fruit harvesting is a key area of research in agricultural automation; howerver, it is constrained by factors such as complex and variable lighting conditions in the field, difficulties in target recognition, the fragility of the fruit, and significant individual variations, traditional rigid harvesting robots are prone to causing fruit damage in practical applications. Robotic compliance technology utilises the compliant characteristics of actuators and control systems to ensure stable grasping whilst preserving the fruit integrity. This paper provides a systematic review of research progress in compliant technology for fruit harvesting from the perspectives of actuator hardware and control algorithms: at the actuator level, it focuses on analysing the working principles and structural characteristics of elastic joint actuators and soft actuators; at the control level, it reviews classical compliant control methods and data-driven intelligent compliant control strategies, and, drawing on case studies of fruit harvesting such as apples and strawberries, analyses the application of these technologies in fruit contact, separation, and post-harvest handling, including short-distance placement and collection. Finally, the key challenges were summarized for the large-scale application of compliant harvesting, and the future development directions were outlined for the research and application of fruit harvesting robots.