Development of Adaptive-Limb Transformable Robot for Portable and Replaceable End-Effectors with Compact Lock-Spin Mechanisms
Jin Hirai, Takuma Hiraoka, Masanori Konishi, Hiromi Tada, Kunio Kojima, Kei Okada
AI summary
Problem
Transformable robots struggle to expand their task range because carrying and replacing multiple end-effectors on-site typically requires bulky external devices or lacks continuous rotational functionality.
Approach
The authors design a bipedal robot with a 7-DoF limb that reaches its own body to swap end-effectors, utilizing a novel compact Lock-Spin mechanism that integrates an air cylinder inside a hollow motor to enable precise, torque-transmitting, continuous rotation.
Key results
- 7-DoF limb enables on-site end-effector replacement without external devices
- Compact Lock-Spin mechanism transmits continuous torque within a 58.2 mm housing
- High replacement success rate maintained across angular misalignments up to 8 degrees
- Robot switches between walking, wheeled locomotion, and manipulation using swapped tools
Why it matters
Enables agile, multi-tasking mobile robots for disaster response and uneven terrain where rapid tool swapping and adaptive locomotion are critical.
Abstract
Transformable robots adapt to various environments by changing their shape or functionality. The robots are able to further expand their task range by replacing their end-effectors (EEs). In this letter, we propose an adaptive-limb transformable robot capable of replacing multiple types of mounted EEs. First, 7 degrees of freedom (DoF) limbs can reach multiple types of EEs mounted on the front body surface, and replace them using that single limb without relying on external devices. Second, we develop a compact Lock-Spin mechanism that integrates a locking mech- anism into the rotor of the motor to enable continuous rotation. Experimental results demonstrate that the proposed transformable robot can replace EEs on-site and that this replacement enables locomotion and manipulation adapted to the environment.