Assessment of Pointshell Shrinking and Feature Size on Virtual Manual Assembly

Abstract

This paper investigates the effect of pointshell shrinking and feature size on manual assembly operations in a virtual environment with haptic force feedback. Specific emphasis is on exploring methods to improve voxelbased modeling to support manual assembly of low clearance parts. CAD parts were created, voxelized and tested for assembly. The results showed that pointshell shrinking allows the engineer to assemble parts with a lower clearance than without pointshell shrinking. Further results showed that assemble-ability is dependent on feature size, particularly part diameter and clearance. In a pin and hole assembly, as the pin diameter increases, for a given percent clearance, assembling low clearance features becomes difficult. An empirical equation is developed to guide the designer in selecting an appropriate voxel size based on feature size. These results advance the effort to improve manual assembly operations via haptic feedback in the virtual environment. ABSTRACTThis paper investigates the effect of pointshell shrinking and feature size on manual assembly operations in a virtual environment with haptic force feedback. Specific emphasis is on exploring methods to improve voxel-based modeling to support manual assembly of low clearance parts. CAD parts were created, voxelized and tested for assembly. The results showed that pointshell shrinking allows the engineer to assemble parts with a lower clearance than without pointshell shrinking. Further results showed that assemble-ability is dependent on feature size, particularly part diameter and clearance. In a pin and hole assembly, as the pin diameter increases, for a given percent clearance, assembling low clearance features becomes difficult. An empirical equation is developed to guide the designer in selecting an appropriate voxel size based on feature size. These results advance the effort to improve manual assembly operations via haptic feedback in the virtual environment

Immersive Computing Technology to Investigate Tradeoffs Under Uncertainty in Disassembly Sequence Planning

“…Voxel-based methods, such as Voxmap pointshell, have proven especially effective in simulating full 6DOF haptic interactions [20], but the reliance on using approximate geometry for collision detection presents a challenge when faced with assembly of low clearance parts. Faas and Vance [21] present a method of pointshell shrinking to support low clearance virtual assembly tasks, and Seth et al [22] developed a tiered approach using both exact and approximate geometry to support low clearance assembly.…”