Enabling physical human/dual-arm collaboration to resist random impacts: An improved shear-thickening fluid controller

Physical human–robot collaboration (pHRC) has gained significant traction in industrial settings due to its exceptional flexibility and adaptability. However, robots often face unexpected nonlinear and random impact disturbances during task execution, which pose risks such as human injury and robotic instability. To address these challenges, this paper proposes a novel control strategy based on improved shear-thickening fluid control (ISFC) for enhancing human–robot cooperation. Drawing inspiration from the unique properties of shear-thickening fluids, ISFC is designed to ensure stable collaboration between humans and robots while effectively mitigating the effects of random impacts. Furthermore, an ISFC-based framework is introduced for human/dual-arm robot collaboration. Comprehensive simulations and experimental evaluations are conducted to validate the effectiveness and advantages of the proposed approach. The experimental results show that compared with the traditional linear admittance control (L-AC) and SFC, ISFC not only has excellent impact resistance (peak velocity<0.1 m/s under 30 N impacts) but also overcomes the stability defects of SFC in low-speed operation, reducing the convergence time by 94.1% (from 8.29 s to 0.50 s) and residual displacement by 49.3% (from 13.21 mm to 6.7 mm). In dual-arm collaboration, the position synchronization error remains below 8 mm. These improvements provide a new idea for the application of human–robot collaboration.