Effect of Binder Content on Hybrid Magnetic Tool Behavior

This paper proposes the use of a hybrid magnetic tool, consisting of magnetic particles bonded with water-soluble glue, to improve both surface roughness and form accuracy of brittle materials such as ceramics. As the binder gradually dissolves into the lubricant, the bonded hybrid magnetic tool transforms to a particle brush in a magnetic field, increasing the deformability of the tool and its ability to conform to the target surface. This paper describes the effects of the tool transformation — from a bonded tool to a particle brush — on the characteristics of finished yttrium aluminum garnet (YAG) laser ceramics. The bonded tool removes material to flatten and smooth the target surface at the start of the process, gradually transitions to a particle brush (starting at the tool periphery), and finally smooths the surface as a flexible particle brush. The tool deformability and transition speed are adjustable by the binder content.

Where to Grasp a Tool?

Biomechanical and environmental constraints limit body movements and tool use actions. However, in the case of tool use, such constraints can often be overcome by adjusting a tool’s tool transformation to the requirements of the intended tool use action. The research presented here examined whether participants grasped a lever at different positions, thus modifying the lever’s tool transformation, to accommodate speed and accuracy requirements of different tasks. Participants were asked to quickly track a sequence of targets with the lever. If accuracy requirements were high, participants compensated for limits in the accuracy of hand movements by grasping the lever at a position that enabled precise control of the lever. If accuracy requirements were low, participants compensated for limits in hand speed by grasping the lever at a position that enabled fast lever movements with comparatively slow hand movements. This task-dependent grasp selection was only present after participants had practiced the tasks. The data show that in addition to adapting to fixed tool transformations, participants also actively controlled tool transformations to facilitate tool use actions.

A Robotic Tool Transformation Teacher

The objective of this project was to design and build a system for teaching robot tool transformations. A PUMA and an Adept One robot were used for testing the feasibility of the system. The Tool Transformation Teacher provides for both the manual and programmed control of a robotic manipulator with respect to a tool coordinate system, thus increasing robot flexibility.