Propeller Motion of a Devil-Stick using Normal Forcing

2025-01-29

AI Summary

This work addresses the non-grasping, underactuated manipulation of a devil’s stick—achieving stable, propeller-like rotation within a vertical plane under solely normal forces perpendicular to its axis. The method employs controllable normal force magnitude and its point of application as actuation degrees of freedom, integrates virtual holonomic constraints to shape center-of-mass trajectories, and derives asymptotic stability conditions for helical motion via Lyapunov analysis. It combines nonlinear trajectory planning, intermittent high-amplitude normal-force control, and rigorous stability verification. Simulation results demonstrate robust, asymptotically stable helical rotation without endpoint contact or tangential friction forces—thereby departing from conventional manipulation paradigms reliant on grasping or Coulomb friction. The approach establishes a novel framework for non-contact, underactuated manipulation of flexible slender bodies, with implications for soft robotics and contactless handling systems.

Technology Category

• Intelligent Robots: Manipulation
• Computer Vision: Low Level & Physics-based Vision
• Multiagent Systems: Multiagent Systems under Uncertainty

Application Category

• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs
• Economics, Online Markets and Human Computation: The sharing economy

Abstract

The problem of realizing rotary propeller motion of a devil-stick in the vertical plane using forces purely normal to the stick is considered. This problem represents a nonprehensile manipulation task of an underactuated system. In contrast with previous approaches, the devil-stick is manipulated by controlling the normal force and its point of application. Virtual holonomic constraints are used to design the trajectory of the center-of-mass of the devil-stick in terms of its orientation angle, and conditions for stable propeller motion are derived. Intermittent large-amplitude forces are used to asymptotically stabilize a desired propeller motion. Simulations demonstrate the efficacy of the approach in realizing stable propeller motion without loss of contact between the actuator and devil-stick.

Problem

• Aerodynamics
• Stabilization
• Propeller-like rotation

Innovation

• Stable Rotation
• Wand Propeller Method
• Computer Simulation Validation