Dual-Branch Fusion Network: Precise Decoding of Lower Limb Multi-Joint Torque

To address the critical challenge of providing accurate, real-time lower-limb joint torque estimation across diverse locomotion conditions for adaptive human-exoskeleton interaction.

We developed a novel dual-branch architecture that synergizes temporal convolutional networks (TCN) and transformers to process surface electromyography and kinematic data. The TCN captures local temporal dynamics, while the transformer extracts global dependencies. A joint-specific task-aware residual fusion mechanism was introduced to dynamically synthesize these features, employing residual enhancement to adapt precisely to the distinct biomechanics of individual joints.

Validated across twelve diverse locomotion patterns, the framework achieved root mean square errors (Nm/kg) and Pearson correlation coefficients of 0.1655/0.9904 (ankle), 0.1405/0.9588 (knee), and 0.1975/0.9698 (hip). It maintained a 4.2912 ms latency and showed strong adaptability on public datasets.

The proposed method effectively balances high estimation accuracy with the strict computational efficiency needed for real-time applications, successfully addressing previous issues in adapting to dynamic environments.

This work advances biomedical engineering by providing a fast, reliable solution for adaptive exoskeleton torque control, significantly enhancing seamless and natural human-robot interaction in assistive exoskeleton technologies.