David N. Rocheleau

System for interactive assembly modelling

A technique is developed that allows a designer to interactively create an assembly of components by specifying mating conditions between the individual components. Once the relationships between components via the mating conditions are established, each components location and orientation in the final assembly is computed. The joint information for a kinematic and dynamic analysis can be derived from the mating conditions, therefore this work may be extended to incorporate this analysis. Through this development, it will no longer be necessary for a designer to specify cumbersome and error prone transformation matrices to create an assembly. The designer will also be able to perform a kinematic or a dynamic analysis directly from an assembly model if the joint information can be automatically derived.

Designing effective writing and presentation assignments for Freshman engineering students

When the University of South Carolina College of Engineering (USA) created its new freshman year experience course in 1997, it established a Freshman Writing Program to integrate communications and writing skills into the curriculum. This paper describes how one component of the Freshman Writing Program, staffed by consultants in the Colleges communications and writing centers, is assistance to engineering faculty in structuring appropriate writing and oral presentation assignments for the course.

Fabrication of Biomimetic Scaffolds with Well-Defined Pore Geometry by Fused Deposition Modeling

A method for fabrication of a scaffold by fused deposition modeling is provided. The method includes forming a sacrificial mold with fused deposition modeling, the sacrificial mold comprising a dissolvable material. The method further includes infusing the sacrificial mold with a biodegradable composition and applying a solvent to the biodegradable composition infused sacrificial mold to dissolve the sacrificial mold and leave a scaffold formed from the biodegradable composition.

Design for Improved Trans-Tibial Prosthetic Devices Using Four Bar Mechanisms

Currently available prosthetic devices for trans-tibial (below the knee) amputees allow a great deal of mobility, but they do not allow amputees to walk with a normal gait. Most designs utilize passive elements to approximate the complex nonlinear response of the foot and ankle. This paper outlines early work in the design of a hybrid passive/active prosthesis that uses the inherent nonlinearity of a four bar mechanism and the power of numerical optimization to more closely duplicate the function of the human foot/ankle complex during walking.© 2005 ASME

Habitat for Humanity freshman design and build experience

The University of South Carolina has developed a new course that not only tackles the issue of retention from a student study skills point of view, but introduces the students to the world of engineering through a freshman design and build experience. The new course weaves together student success strategies, teamwork, and community service, by leading students through a Habitat for Humanity design project. The aim of the course is to excite freshman engineering students about the field of engineering by having them experience first hand what engineers do-design, create, build, and deliver solutions-while producing a design artifact that contributes to the local community. The paper illustrates how establishing a partnership with a local chapter of Habitat for Humanity (HFH) can provide a number of worthwhile design projects that freshman can easily tackle. The paper describes the successful implementation of constructing seven utility-tool-sheds for completed Habitat for Humanity homes. The team building process, the establishment of a freshman design and build shop, a spirited design competition, and the logistics of organizing such a project for 246 freshman engineering students are all described. The paper tells the story of how sixty teams participated in the project, and how the sheds were built on campus in a modular fashion, and then transported out to the Habitat site in an attempt to erect all sheds in a single hour. The paper then closes by suggesting other Habitat for Humanity projects involving playground equipment and pedestrian bridges that are planned for the future.

Planar surface reconstruction using circle generator laser light

A method is presented for finding the spatial position and orientation of a planar surface using a laser light source that generates structured light in the form of concentric circles. The purpose of the work is to provide the foundation for mapping regular and irregular surfaces for use in spatial surface reconstruction. The results of this work will lead to practical applications in the evaluation of pre- and post-surface deformation, and the reconstruction and representation of higher ordered surfaces. The latter having application as an alternative approach for capturing surfaces in direct geometric terms as opposed to the copious data discretization methods employed in surface reconstruction today.

Modeling Balance of Plant Components for a PEM Fuel Cell

To integrate a fuel cell into a vehicle platform many subsystems must be engineered to support the electrical power production of the fuel cell plant. These subsystems include the control of fuel and air supply as well as managing thermal and water throughput in the fuel cell stack. For the fuel cell plant to operate at optimum performance, one must examine the individual components that make up the “balance of plant” of the fuel cell system. Specifically, the power used to run the system must be scrutinized with the power produced by the system. Knowing how individual balance of plant components perform is the first step in design and optimization studies, as well as automated control system development. To address these issues, this paper examines how balance of plant components and subsystems affect parasitic power consumption, fuel cell power production, membrane hydration, hydrogen usage, and water production.Copyright

A Mechanical and Electrical Engineering Interdisciplinary Capstone Design Project

Since Spring 2000, and running every semester, the University of South Carolina Department of Mechanical Engineering and Department of Electrical Engineering have collaborated on a capstone senior design project. In the beginning, the collaboration was between a junior level mechanical engineering class and the electrical engineering senior capstone design class. The collaboration has evolved and is currently between both departments’ senior capstone design classes. This paper outlines the growth of the collaboration from inception to current state with focus on the recent history of the collaboration. In its current embodiment students from mechanical engineering design, develop, construct and deliver a robotic vehicle platform for electrical engineering students to place a microcontroller for use in the autonomous control of the robotic platform. The integrated and completed robotic platform is used in the Southeastern Conference IEEE student competition held each Spring. The collaboration is considered successful by both departments and is used as a key example of an interdisciplinary design effort between the two departments for ABET review considerations.Copyright

Development of a Variable Dynamic Automotive Suspension Model Using Virtual Test Bed

This paper is concerned with the development of a fully dynamic automotive suspension model in Virtual Test Bed (VTB), a dynamic system simulation environment developed by the University of South Carolina Department of Electrical Engineering for modeling multi-technical dynamic systems. VTB is normally used to prototype large scale electrical systems, but as shown in this paper, it can also be used to accurately simulate dynamic mechanical devices. Mathematical equations governing vehicle dynamic motion were developed and converted into C++ code. This code was then converted into a VTB model using Microsoft C++. A model of a full car passive suspension system was developed in VTB around this model, in which all dimensions, spring and damper constants, and vehicle path can be changed easily, without recoding the model itself. The model was then compared to a previously validated model created in Matlab Simulink. The results of this comparison, as well as validation with experimental data from a quarter-car suspension system, showed that VTB is a valid platform for modeling dynamic mechanical systems, and could be used to model active vehicle suspension as well.Copyright

Dynamic Modeling of an Overhead Valve Engine CAM-Follower System Using a Resistive Companion Dynamic Simulation Solver

A computer simulation model of the valve train of a Honda GX30 engine was modeled using Virtual Test Bed (VTB), a resistive companion dynamic simulation solver. Traditionally VTB has been exclusive to solving electrical system models but using the resistive companion equivalence of through and across variables, it can be applied to mechanical systems. This paper describes a dynamic simulation of an overhead valve engine cam-follower system using the VTB software application. The model was created to show valve train position, velocity and acceleration to aid in development of a camless engine being developed at the University of South Carolina. The mathematical model was created using governing dynamic equations. Using C++ programming, the mathematical model was transformed into a Virtual Test Bed model. The VTB model successfully shows valve train component position, velocity and acceleration. The significance of this work is its novelty in using the Virtual Test Bed environment to handle dynamic modeling of mechanical systems, whereas to date, VTB has been primarily focused on resistive companion modeling of power electronic systems. This work provides the foundation for using VTB to tackle more complex mechanical models.Copyright