Design of a lightweight robotic arm for kiwifruit pollination

Robotic simulation is an important method for verifying robot design parameters and the feasibility of various schemes. We simulated and analysed the effectiveness of the design parameters of a robotic arm for kiwifruit pollination and verified the rationality of the robotic arm’s movement during pollination. First, the basic parameters and working space of the robotic arm for kiwifruit pollination were identified based on a trellis system that supports kiwifruit vines. MATLAB software was employed for the simulation to prove that the working space of the lightweight robotic arm for pollination can satisfy the operating requirements. Appropriate joint motors were selected based on the maximum theoretical torque on each joint of the robotic arm obtained through the analysis. SolidWorks software was used to verify the strength of the robotic arm materials and joint connectors, and the operating environment of the robotic arm and MATLAB software were applied to simulate and analyse the feasibility of trajectory planning for pollination. Based on the simulation results, we built a prototype of the robotic arm and a motion control system. The experiment indicated that the maximum operating speed of this lightweight pollination robotic arm was ωmax = 0.105 rad/s, the pollination success rate was 85%, the average pollination time of a single flower was 5 s, and the pollination efficiency was 78 min/mu, which was significantly higher than the 86 min/mu of artificial brush pollination. The lightweight pollination robotic arm satisfied the automatic operation requirements of kiwifruit pollination.