Abstract: In view of the phenomenon that firefighters are required to lift the water gun hose for a long time in the current firefighting work scene and are prone to physical fatigue, a firefighting water gun exoskeleton was developed for the firefighting work scene. After the preliminary completion of the force structure design of the exoskeleton, in order to verify the reliability of the exoskeleton at work, ABAQUS finite element simulation software was used to carry out the stress and strain analysis. The finite element calculation results show that, due to the large impact load will be generated at the moment when the water gun is opened, the maximum stress of the exoskeleton under the impact of the water gun will be generated. The maximum stress of the dangerous parts of the exoskeleton under the working state is 1.639×10^-2 MPa, and the maximum deformation is 4.835×10^-3 mm. All the values are within the reasonable and safe range. After verifying the high reliability of the exoskeleton, the overall design is carried out, and the stress structure and non stress functional parts are elaborated in detail to improve the design. In the physical test, compared with the firefighting operation without wearing exoskeleton, the fireman obviously felt the lower load on the forearm used to lift the water gun while wearing exoskeleton, and the force sensation of the left and right muscles of the body was improved more evenly. Using biomechanical analysis, the force distribution of multiple joints and muscle parts in the human body during firefighting operations before and after wearing exoskeletons was analyzed. The results showed that after wearing exoskeletons, the joint force distribution improved and muscle activation decreased.

Key words: firefighting equipment, upper limb exoskeleton, finite element simulation, reliability analysis, biomechanical simulation