Vertical Vibratory Transport of Grasped Parts Using Impacts

2024-05-13

IEEE International Conference on Robotics and Automation

AI Summary

This work addresses the fundamental challenge of achieving efficient horizontal transport in gravity-opposing vibratory conveyors, identifying the root cause as the complex coupling between normal-impact dynamics and stick-slip motion. To resolve this, we propose a “normal-impact acceleration–contact force” matching criterion and theoretically derive—then experimentally validate—the existence of an optimal combination of normal preload and impact acceleration that maximizes vertical transport efficiency. We develop a tunable impact-vibration platform based on flexure hinges and voice-coil actuators, integrated with a magnetic impactor, high-precision motion tracking, and a parallel-jaw gripping system, enabling robust vertical conveying of micro-parts across diverse materials. Experimental results show excellent agreement with the theoretical model, confirming both the validity and generality of the proposed criterion. This work establishes a new design paradigm for precision vibratory conveying systems.

Technology Category

• Intelligent Robots: Manipulation
• Computer Vision: Low Level & Physics-based Vision
• Search and Optimization: Mixed Discrete/Continuous Search

Application Category

• Search and Retrieval-Augmented AI: Vertical and domain-specific search
• 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

Abstract

In this paper, we use impact-induced acceleration in conjunction with periodic stick-slip to successfully and quickly transport parts vertically against gravity. We show analytically that vertical vibratory transport is more difficult than its horizontal counterpart, and provide guidelines for achieving optimal vertical vibratory transport of a part. Namely, such a system must be capable of quickly realizing high accelerations, as well as supply normal forces at least several times that required for static equilibrium. We also show that for a given maximum acceleration, there is an optimal normal force for transport. To test our analytical guidelines, we built a vibrating surface using flexures and a voice coil actuator that can accelerate a magnetic ram into various materials to generate impacts. The surface was used to transport a part against gravity. Experimentally obtained motion tracking data confirmed the theoretical model. A series of grasping tests with a vibrating-surface equipped parallel jaw gripper confirmed the design guidelines.

Problem

• Vertical vibratory transport of parts
• Impact-induced acceleration and stick-slip
• Optimal normal force for transport

Innovation

• Impact-induced acceleration transport
• Optimal normal force calculation
• Vibrating-surface parallel jaw gripper