RVP

PWC


Projects

The following projects include both ongoing and past work.

Urban Robotics Project Buffinton, Shooter 2008-2010

The Urban Robotics project is a collaborative project between Bucknell University and The Florida Institute for Human and Machine Cognition (IHMC).  The project was started by Professors Keith Buffinton and Steven Shooter in 2008 and is funded by The Office of Naval Research.  The two main systems developed for this project are the Bipedal Walking Robot and the Urban Warrior (also known as the tBot).  Research at Bucknell has been strongly focused on the Biped and bipedal walking.  Current work on the Biped has been divided into subsystems including head designs for vision and pressure-sensing feet.

All of these projects are meant to work toward a common goal of producing a system that can perform efficiently and effectively in an urban environment.

Pulse-width Control Buffinton 2004-2007

A 1988 publication by researchers at the University of California at Berkeley describes a remarkably effective algorithm for point-to-point position control of rigid-body plants that are subject to mechanical friction, including stiction. This Pulse Width Control (PWC) algorithm is applied only when the plant is close enough to its desired position that stiction forces come into play. When stiction sticks the plant, the algorithm applies a series of fixed-height rectangular force pulses in a feedback fashion to move the plant to its desired position. For point-to-point position control of a rigid-body plant, this algorithm guarantees limit-cycle-free operation and zero steady-state position error, even when the plant parameters, including the stiction and Coulomb friction levels, are not known exactly.

This project seeks to take results of the Berkley PWC algorithm to the next level, i.e., to a state of maturity sufficient to attract industrial partners to a subsequent project that will see adaptive PWC with piecewise-linear-gain PWC laws applied to industrial robots and machine tools in bona fide industrial settings.