Robotic dog mimics mammals for superior mobility on land and in water

Existing amphibious robots are largely inspired by reptiles or insects, and often face limitations in agility, dynamics, and load capacity. Basing the amphibious robot on the swimming style of dogs allows for it to easily transition between land and water and overcome many of the challenges faced by insect-inspired designs.

The amphibious robot paves the way for future applications in environmental research, military vehicles, rescue missions, and beyond.

To enhance its water mobility, the amphibious robotic dog features a unique paddling mechanism, modelled after the swimming motion of dogs. Careful engineering of its structure, including precise weight and buoyancy balance, ensures stable and effective aquatic performance.

The team developed and tested three distinct paddling gaits:

• Two doggy paddle-inspired approaches optimised for speed and propulsion
• A trot-like paddling style, designed for enhanced stability in water

Through extensive experimentation, the doggy paddle method proved superior for speed, achieving a maximum water speed of 0.576 kilometres per hour (kph), while the trot-like style prioritised stability. On land, the amphibious robotic dog reaches speeds of 1.26 kph, offering versatile mobility in amphibious environments.

"This innovation marks a big step forward in designing nature-inspired robots," says Yunquan Li, corresponding author of the study.

"Our robot dog's ability to efficiently move through water and on land is due to its bioinspired trajectory planning, which mimics the natural paddling gait of real dogs. The double-joint leg structure and three different paddling gaits address previous limitations such as slow swimming speeds and unrealistic gait planning, making the robotic dog much more effective in water."