Dynamic Coupling and Indirect Control of Jointed Robots Rolling Atop A Moving Platform

2026-04-23

AI Summary

This study investigates locomotion of a wheeled, underactuated two-link robot on a freely moving platform driven solely by internal joint actuation, elucidating the dynamic coupling between multiple robots and the platform. Leveraging Lagrangian mechanics, a system dynamics model is formulated to analyze fish-like swimming behaviors induced by joint oscillations. The work proposes a novel control strategy that indirectly governs the trajectory of the unactuated robot exclusively through platform acceleration. This approach achieves, for the first time, precise regulation of both direction and path for an underactuated robot without direct joint actuation. Numerical simulations confirm the effectiveness of the method in executing orbital motion around a fixed point and sustained directional locomotion.

Technology Category

• Intelligent Robots: Motion and Path Planning
• Humans and AI: Human-Aware Planning and Behavior Prediction
• Multiagent Systems: Multiagent Systems under Uncertainty

Application Category

• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Systems and Infrastructure for Web, Mobile and WoT: Applied ML and AI for Web-based mobile applications
• Economics, Online Markets and Human Computation: Economics and fairness of platforms and recommendation systems

Abstract

An asymmetric two-link robot supported atop a flat platform by wheels that roll and pivot freely, but do not slip laterally, will develop forward momentum if the joint between the links is actuated internally. In particular, oscillations in the joint angle will generate undulatory locomotion suggesting fishlike swimming. If two such robots surmount a common platform that's free to translate with its own inertial dynamics, then the individual robots' dynamics will be coupled so that the locomotion of either robot is affected by that of the other. We develop a mathematical model for this system and present simulations demonstrating its behavior. We then consider a single robot with an unactuated joint rolling atop a platform that moves under control, and show that actuation of the platform is sufficient to dictate the robot's behavior. In particular, with the acceleration of the platform as an input, the robot's heading can be made to track a chosen function of time. This is sufficient to guarantee that the robot can be induced to orbit a fixed point on the platform or to locomote persistently in a desired direction.

Problem

• dynamic coupling
• indirect control
• jointed robots
• moving platform
• undulatory locomotion

Innovation

• indirect control
• dynamic coupling
• underactuated robotics
• undulatory locomotion
• moving platform