Jayaraman Krishnasamy

Application of optimal trajectory algorithms to a solar-panel handling industrial manipulator: A case study

Several algorithms have been proposed in the last 25 years on the problem of generating time-optimal trajectories for robot manipulators along specified paths. This article describes an application of an optimal trajectory algorithm to an industrial manipulator used in the transfer of solar panel substrates between process modules. These manipulators operate in a vacuum environment and have constraints on substrate accelerations as well as available motor torques. The article shows that a trajectory profile optimized for both substrate acceleration and motor torques can reduce substrate transport time by 25 percent over the commonly used “S-curve” based algorithms.

Resonance-Induced Failure of Entrapment: Application to Industrial Parts Feeding

Parts feeders are devices used in automated assembly lines to present component parts to the assembly machinery in a consistent and predetermined orientation. The process of converting a randomly oriented set of parts (as obtained from a vendor) into an ordered array is called parts feeding. There are many different types of feeders and feeding techniques used in the industry. This paper deals with a particular feeding process referred to here as vibratory entrapment. It describes a particular cause of failure of vibratory entrapment, namely, resonance. Failure due to resonance was first observed in high-speed video images of the entrapment phenomenon. This paper provides a description of the mechanics of failure of entrapment due to resonance. The mechanics is introduced with the simple example of a ping-pong ball in a cup and extended to real parts in a parts feeder. Conditions for resonance are derived and experimentally verified for a simple part shape and vibration pattern.