Design and Experimental Validation of an Active Suspension Backpack Based on Ground Reaction Force Analysis

This study proposes a design and evaluation method for active suspension backpacks based on ground reaction force analysis. First, a single-degree-of-freedom doublemass model of the human body-backpack system was established, and a systematic analysis of ground reaction forces was conducted under various stiffness, damping, load mass, and walking speed conditions. Theoretical analysis indicates that when the suspension backpack stiffness is lower than the resonance stiffness, and the damping is small, the ground reaction force reaches its minimum value. The optimal stiffness value is not zero stiffness. Based on theoretical analysis, a variable-parameter active suspension backpack system was designed, which enables precise adjustment of system stiffness and damping through motor control. The experimental results show that when the backpack operates in reverse mode, the load is opposite to the human body movement, reducing the peak ground reaction force by 7.16%, 11.18%, and 13.26% compared to the constant force suspension backpack (CF mode), ordinary backpack (OB mode), and locked backpack (LOCK mode), respectively, verifying the accuracy of the theoretical model. The reverse mode suspension backpack can effectively reduce ground reaction forces, providing new ideas for suspension backpack applications.