Tendon-driven robot arms optimized for torque and compact design
Design optimization of tendon-driven robots considering tendon wrapping and shortcut
Robotics
Summary
Designing robot arms that use tendons is tricky because making the arm strong usually makes it bulky. The authors developed a method that finds the best balance between strong joint movement and keeping the arm slim. They do this by choosing the best way to route tendons and place pulleys, including clever shortcuts to boost strength without extra thickness. Their results show new design patterns that might surprise many engineers and help build better, smaller robot arms.
What this means in practice
- •For robot designers: Create compact, high-torque tendon-driven robot arms using optimized tendon routing and pulley setups.
- •For prosthetic device developers: Design slimmer and more powerful prosthetic limbs by applying optimized tendon paths that balance strength and size.
Authors
Yuta Sahara, Kento Kawaharazuka, Kei Okada
Abstract
This study proposes a multi-objective optimization method for tendon-driven arm design, addressing the inherent trade-off between joint torque and arm thickness through tendon wrapping and shortcut effects. We formulate the problem to simultaneously maximize torque and minimize thickness, solved using NSGA-II. The algorithm optimizes tendon routing, pulley configurations, and attachment points. Results reveal Pareto-optimal designs with effective moment arm expansion via strategic shortcuts, providing practical guidelines for compact high-torque arms. The optimized configurations demonstrate non-trivial patterns beyond conventional design intuition, offering new insights for engineering efficient robotic systems.