Three dimensional multi-rigid-body modeling of a vibratory micro-pin feeder bowl

The use of micro-scale metallic pins in small engineering devices poses numerous problems due to their physical size and the dominant forces which act on micro-scale objects. Assembly of devices with micro-scale parts is problematic because the components are below the practical threshold of unaided human manipulation and most robotic manipulation. The use of tweezers and microscopes to aid human assembly is possible but challenging because the micro-scale pins tend to adhere to tweezers. Previous work has found that vibratory feeder-bowls provide a feasible means to singulate and orient micro-scale pins by overcoming the adhesive forces that plague other manipulation techniques. The analysis and prediction of the behavior of vibratory feeder bowls for micro-scale components has previously been limited to two dimensions. To advance the understanding of vibratory feeder bowls for micro-pins, a three dimensional simulation has been developed that predicts the pin capture rates as a function of the physical properties of the feeder bowl and bodies. This model is based on an impulse-momentum contact model and it incorporates traditional macro-scale forces such as gravity, air-drag, and friction as well as micro-scale interactions such as magnetic and electrostatic forces. In comparison to prior experimental pin capture rates, the three dimensional simulation produced more accurate results than the existing two dimensional simulation. Finally, the simulation was used to conduct a parametric study to characterize the effects that varying system parameters have on the performance of the feeder bowl