Researchers have developed a multimodal wheel-footed robot, named Sirius, that combines the efficiency of wheeled locomotion with the terrain adaptability of legged robots. The robot features a novel switching mechanism that allows seamless transitions between wheeled and footed modes, addressing limitations of existing designs that struggle with complex terrains or require drastic posture changes. The mechanism uses a linear actuator and spring-loaded flange slider to engage or disengage the foot from the wheel hub, ensuring stable contact without relative slip.
Key takeaways
- Sirius has 8 degrees of freedom per side (hip roll/pitch, knee, ankle, and switching joint), with knee motors relocated to the torso via a four-bar linkage to reduce leg inertia.
- A whole-body dynamics model, based on single rigid-body assumptions, supports model predictive control (MPC) and whole-body controllers for both wheeled and footed modes.
- Two wheel-foot balance transition strategies were designed for switching from wheeled balance to bipedal standing, with constraints analyzed.
- In experiments, pitch and yaw angles were maintained within ±0.1 rad on complex terrains; static switching completed within 8 seconds and dynamic switching within 4 seconds.
The results demonstrate that the proposed structure and control strategies achieve high performance and environmental adaptability, offering a practical solution for robots needing efficient locomotion across varied industrial or outdoor settings.
Source: 《机器人》期刊 (robot.sia.cn) · Published 2026-05-12 · “轮足机器人切换机构设计与切换策略”