Geometric design of part feeders

Abstract

This thesis presents solutions for problems derived from industrial assembly and robotic manipulation. The basic tasks in a factory are manufacturing the parts, and combining them into the desired product. In automating these tasks, we want to use robot manipulators that require little or no human intervention.

We explore devices that deliver parts in a uniform orientation to robots. Such a device is called a partfeeder. Part feeders are used to improve the efficiency in an industrial assembly line: robots to which the parts are fed in a uniform orientation can easily process these parts without having to sense their initial orientations.

In practice, the problem of part feeding is usually solved using trial-and-error approaches which are time consuming and error prone. We show how to systematically design part feeders using techniques from computational geometry.

We consider four different feeders. The first feeder consists of a sequence of fences which are mounted across a conveyor belt. The fences brush the part as it travels down the belt thus reorienting it. The second feeder is a pulling finger which applies a sequence of pull operations that reorients flat parts with elevated edges. The third feeder deals with three-dimensional parts. It is a sequence of (tilted) plates with fences which reorients a three-dimensional polyhedral part as it travels down the plates. The fourth feeder in this thesis is the vibratory bowl feeder.

This thesis gives insight into the geometrical nature of part feeding problems. The results have implications for practical design of part feeding devices, and experimental results can be used as input for future research in geometric feeding.