Fruit output of China ranks first in the world.The fruit industry,as a labor-intensive industry,has a great demand for labor force.However,the shortage of labor force,high intensity of manual labor and low efficiency in the current market have become one of the important problems hindering the industrialization development of orchards.Therefore,realizing the mechanization of orchard production is a necessary means to liberate labor force and improve production efficiency.At the same time,due to the vigorous implementation of raw grass mowing technology in orchard soil management in China,orchard raw grass can regulate the moisture content in the soil,and weeds covered on the soil surface after mowing can be used as fertilizer for fruit tree.However,irregular mowing will have a lot of adverse effects on fruit trees and affect normal orchard management.Cutting weeds in orchard is an important task of orchard management.The level of agricultural mechanization in underdeveloped hilly areas has caused a lot of labor consumption on orchard management.At the same time,traditional chemical weeding greatly polluted orchard.Therefore,the mechanical stubble weeding in orchard plays an important role in protecting orchard soil.The realization of efficient mechanical weeding has become an urgent goal to be achieved in the process of orchard mechanization.Most orchards in China are located in hilly and mountainous areas with complex planting terrain conditions and imperfect road planning.Currently,weeding machines used in hilly orchards are generally flat orchards and field weeding machines.The artificial knap-type and hand-pushed weeding machines of flat orchards are time-consuming and laborious.Field weeding machines are driven by tractors,with high cost and large overall size,which are difficult to meet the requirements of mechanization of hilly orchards.Therefore,it is of great practical significance to study the mowing machine in hilly orchards to promote the development of fruit industry.Raw grass mowing is a modern orchard management mode widely promoted at home and abroad in recent years.The weeding performance of orchard mowing robot is closely related to the physical properties of weeds and design parameters of swinging blade.A mowing robot for hilly citrus orchards was designed based on a Y-type flapping blade mowing mechanism to solve the complex terrain conditions of citrus orchards in hilly areas and the difficulty of applying the existing weeding machinery.The kinematics model of single stalk cut by flapping knife was established with D-H method.The parameters of swinging blade designed were explored through single factor experiment of recutting rate.Results showed that the impact force of single weed stem was 74.25 N under the condition of no grass entanglement.The cutting path of blade was deduced.The recutting rate decreased with the increase of blade spacing,cutter shaft speed and forward speed of robot.