Design and simulation of a robotic arm imitating human arm motions for a spraying actuator arm

Aiming to address the issues of low positioning accuracy and high waste of spray application robots in China's facility agriculture, a robot capable of imitating manual spraying behavior is highly needed to enhance spraying precision and reduce pesticide waste. We have designed a robot equipped with a mechanical arm that can move up and down for spraying, aiming to achieve imitation of manual up-and-down spraying for facility-grown tomatoes and cucumbers. The robot is modeled in 3D using SW software. The kinematic equations of the actuator arm are established using the DH method, and the forward and inverse kinematics are analyzed numerically. MATLAB was employed for simulation purposes, and the Monte Carlo method was utilized to generate the workspace diagram, which demonstrated that the maximum workspace of the actuator arm in the vertical direction was 0.8 m. By integrating the joint space and Cartesian space trajectory planning method, the trajectory curves of the actuator arm were obtained in the simulation. The simulation results yielded the angular displacement, angular velocity, angular acceleration, and angular change curves for each joint, which further substantiated the rationality of the design by demonstrating the continuous and moderate nature of the curves' change. The continuous and gradual evolution of the curves serves to reinforce the rationale behind the design. The design is further validated by the continuous and gradual evolution of the curves. It provides a reference point for the construction of automated spraying robots.