Multi-legged steering and slipping with low DoF hexapod robots

Area of Science:

• Robotics
• Biomechanics
• Mechanical Engineering

Background:

• Hexapedal robots offer inherent stability due to their posture and multi-legged support.
• Achieving insect-like agility and maneuverability, particularly steering, remains a significant engineering challenge for hexapods, especially those with underactuated legs.

Purpose of the Study:

• To formally define steering in the context of multi-legged robots.
• To investigate the difficulties in steering robots with six or more underactuated legs.
• To explore the role of leg slipping in enhancing steering capabilities.

Main Methods:

• Formal definition of steering for multi-legged robots.
• Analysis of steering limitations in underactuated hexapods.
• Experimental validation of steering performance with intentional slipping.

Main Results:

• Steering is shown to be impossible for many hexapods with underactuated legs without slipping.
• Experimental results highlight the necessity of controlled slipping for optimizing steering ability.
• Conventional non-slip contact models may underestimate the performance envelope of these robots.

Conclusions:

• A formal definition of steering clarifies its complexity in underactuated hexapods.
• Intentional slipping is a critical factor for achieving effective steering in such robots.
• Non-holonomic multi-legged slipping models are proposed as more suitable than dynamic models for representing these robots.