Study on automatic attachment switching technology used for emergency rescue equipment

To tackle the challenge of low efficiency in switching attachments for emergency rescue equipment, this paper proposes an automatic attachment switching integrated technical framework based on a streamlined three-stage, five-step switching strategy, an AprilTag-based method for acquiring attachment pose and segmented trajectory planning. To meet the rapid switching requirements of emergency rescue equipment attachment, the automatic attachment switching process is divided into three stages (Attachment Disassembly, Location Searching, and Attachment Assembly), which are further divided into five sequential steps. The rapid automatic attachment pose acquisition is achieved through AprilTag. A kinematic model of a 7-degree-of-freedom (7-DOF) redundant mechanical arm for emergency rescue equipment is established using the Modified Denavit-Hartenberg (MDH) method. The relationship between hydraulic cylinder position and joint angle is derived. The inverse kinematics of the mechanical arm is addressed through the gradient projection method, optimizing the process to circumvent joint limits. Given the necessity for trajectory smoothness in the efficient switching of large hydraulic mechanical arms, the motion characteristics of each step are thoroughly analyzed, leading to the development of a smooth segmented trajectory planning scheme. Simulation and experimental validation of the proposed automatic attachment switching technology demonstrate its capability to achieve swift and precise switching between the bucket and gripper, with an impressive average switching time of just 14.35 s. The findings of this research offer crucial theoretical insights for designing trajectory planning strategies for emergency rescue equipment, significantly enhancing the operational capabilities in emergency rescue situations.