关键词: 平粮机械臂, 七自由度, 运动学分析, 平粮方法, 路径规划

Abstract: In response to the problems of traditional manual grain leveling operations that are time‑consuming, labor‑intensive, and pose safety hazards, and in response to the shortcomings of existing tracked and truss grain leveling equipment and methods such as large operating space, low efficiency, and high energy consumption, a seven degree of freedom robotic arm has been designed to achieve automatic leveling of the grain surface in tall bungalows. Each joint of the manipulator is mainly driven by a digital hydraulic cylinder. MCU is selected to control the digital hydraulic cylinder of each joint. At the same time, the standard D-H parameter table of the manipulator is established, and the three‑dimensional simulation model is established through MATLAB Robotics Toolbox. Geometric method and Newton Raphson algorithm based on object Jacobi are used to solve the Inverse kinematics of the manipulator, and Monte Carlo method is used to simulate and analyze the workspace. The fifth order Polynomial interpolation and T-type interpolation are used to simulate its motion trajectory, and the RRT* algorithm is used to plan the obstacle avoidance path. The results show that the working space of the robotic arm can cover the positions of grain to be leveled in the bungalow warehouse, and the motion trajectory is stable and reliable, meeting the required work requirements. At the same time, the T-shaped interpolation method can reduce the joint acceleration of the robotic arm to 0 rad/s when its motion trajectory is between 4 and 6 seconds. The RRT* algorithm enables the robotic arm to accurately avoid grain piles that do not require operation within a height range of 4-8 meters. The analysis results can provide basic support for the development of high‑altitude grain leveling equipment and the construction of intelligent control platforms in the future.

Key words:  grain leveling manipulator, seven degrees of freedom, kinematics analysis, grain leveling method, path planning