Researchers at the State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, have developed an optimized variable-stiffness actuator (VSA) that uses an inverse proportional function curve groove (IPFC-VSA) to improve stiffness control in collaborative robots. The design addresses the trade-off between intrinsic safety and operational efficiency by enabling precise stiffness adjustment across a wide range.
Key takeaways
- Uses a leaf spring as the elastic element; a screw-driven roller moves along an inverse proportional curve to change the spring's effective length, adjusting stiffness.
- Optimization via genetic algorithm reduced stiffness curve nonlinearity from 78.1% to 2.34% in simulation; prototype experiments show nonlinear error ≤4%.
- Stiffness is decoupled from deflection angle, improving controllability and accuracy. The actuator offers a large stiffness range (min ≤500 N·m/rad, max ≥11,000 N·m/rad) and rapid stiffness change.
- Simulated head-collision tests confirm that adjusting joint stiffness can achieve intrinsic safety during impacts.
This design enhances stiffness controllability, making intermediate stiffness values practical for balancing safety and performance in human-robot collaboration. It is particularly relevant for collaborative robot joints requiring both high-speed precision and safe physical interaction.
Source: 《机器人》期刊 (robot.sia.cn) · Published 2026-05-12 · “基于反比例函数曲线滑槽的变刚度驱动器优化设计”