Modeling multi-legged robot locomotion with slipping and its experimental validation

TL;DR

This paper introduces a novel algorithm for modeling and predicting the locomotion of multi-legged robots with slipping, validated through experimental measurements, enabling reliable motion planning even with multiple slipping contacts.

Contribution

It presents a new contact force prediction algorithm based on a kinematic and friction law approach for multi-legged robots with slipping contacts.

Findings

Accurate measurement of foot contact forces in a hexapedal robot.

Algorithm can predict body velocity and contact forces during slipping.

Simulation of motion plans with multiple slipping legs is computationally efficient.

Abstract

Multi-legged robots with six or more legs are not in common use, despite designs with superior stability, maneuverability, and a low number of actuators being available for over 20 years. This may be in part due to the difficulty in modeling multi-legged motion with slipping and producing reliable predictions of body velocity. Here we present a detailed measurement of the foot contact forces in a hexapedal robot with multiple sliding contacts, and provide an algorithm for predicting these contact forces and the body velocity. The algorithm relies on the recently published observation that even while slipping, multi-legged robots are principally kinematic, and employ a friction law ansatz that allows us to compute the shape-change to body-velocity connection and the foot contact forces. This results in the ability to simulate motion plans for a large number of potentially slipping legs. In homogeneous environments, this can run in (parallel) logarithmic time of the planning horizon