A Compliant Connection Strategy Based on Variable Stiffness Charging Arms

The paper primarily focuses on the variable stiffness charging arm of a variable stiffness charging robot system. This component is crucial for the entire system as it directly impacts the safe and efficient interaction between the robot and the vehicle charging interface. Firstly, by establishing the forward and inverse kinematic models of the variable stiffness charging arm, the system ensures accurate control over the position and orientation of the arm's end effector. Additionally, a combination of static initial values and a PID controller is introduced to achieve precise control of the arm's movements. Secondly, due to the presence of system errors, a spiral search algorithm is employed in conj unction with the passive compliance of the variable stiffness charging arm to achieve accurate positioning of the charging socket. Finally, considering the variable stiffness characteristics of the charging arm, the paper introduces a multi-level stiffness adjustment strategy based on force sensing. By real-time sensing of the force information at the end of the variable stiffness charging arm, the system can dynamically adjust the stiffness level. This allows the arm to be more compliant and safe when making contact with the vehicle charging socket, while also adjusting stiffness according to different charging stages to enhance efficiency and stability.