John E. Sneckenberger

A Safety Control System for a Robotic Workstation

A three-level safety control scheme for a robotic workstation has been devised. In this control scheme, three levels of hazard detection and associated control strategies, which include both human sensory warnings and robot operational constraints, are employed. The hardware design that was developed to interface these sensors to the Rhino XR-2 robot controller as well as software in implementing a safety control scheme are discussed.

Design and Analysis of Hybrid Guideway Heating System for Morgantown Personal Rapid Transit

The Morgantown Personal Rapid Transit (M-PRT) system is a comfortable conveyance for travel in Morgantown, WV. One of its operating concerns is the increasing cost of heat to the guideway during winter. As the vehicles cannot run safely during snow, the system includes a guideway heating system to melt the ice from the guideway. To reduce the use of expensive natural gas, an interest has been expressed to define a hybrid heating system using an alternate fuel supply. Solid Oxide Fuel Cell (SOFC) was incorporated in the hybrid heating system. This hybrid heating system was designed, and then a detailed analysis was performed to ascertain the performance parameters like heat produced, thermal efficiency, cost of the system and the emissions involved. This high temperature fuel cell releases large amounts of usable heat in the form of exhaust gases. The exhaust gases are deprived of any undesired emissions that pollute the atmosphere. A USDOE EPSCoR WV State Implementation Award conducted by Advance Power Electricity Research Center (APERC) at West Virginia University provided support for conducting this research.© 2010 ASME

Trajectory Planning for Obstacle-Avoided Assembly of Planar Printed Circuit Boards

The use of robots to assemble Printed Circuit Boards represents a cost-effective, efficient approach to the electronics manufacturing industry. The ability to plan and simulate the assembly robot workcell operations early in the PCB design stages is essential. This concurrent engineering concept leads to the goal of reduction of design time by using an assembly planner and simulator to predict assembly workcell problems as early as possible in the product definitions stage. An assembly robot workcell trajectory planner and simulator were implemented to approach the goal. This paper addresses the issues of the development of such robot trajectory planner and simulator. The trajectory planner and simulator (TPS) can plan assembly paths for the assembly for a given PCB layout and assembly sequence with a collision avoidance algorithm implemented. TPS also provides the capability to graphically visualize workcell mechanics and to provide advisory information to the user for a PCB High Density Electronics assembly.

Chapter V Workcell Operations

The problems encountered in design, simulation, operation, and monitoring of manufacturing cells are analyzed by the papers included in this chapter. The authors of the first paper propose an algorithm to minimize the inter-cell traffic, whereas the second paper is concerned with cost considerations for cell design. Both address the important issues of the Group Technology approach to multi-product manufacturing settings.

Kinematic Error Budgeting to Obtain the Best Feasible Task Performance for a Specified SCARA Manipulator

The positioning accuracy of the end effector of a robot manipulator with respect to its workplace has become significantly more important as the number of industrial and commercial processes that require robotic assembly have increased. Various technical approaches have been proposed and/or investigated for increasing the accuracy of the robot’s end effector. It is well appreciated that geometric errors in the kinematic links and Joints of the robot manipulator are obvious contributors to the positioning error of the end effector. This paper develops the analytical assessment of the positioning error of the robot end effector caused by kinematic errors in the link/Joint parameters that describe the manipulator geometry. This assessment is performed for several point-to-point end effector tasks within the robot’s preferred workspace. A kinematic error budgeting program is used to determine the best feasible end effector performance for a given SCARA manipulator based on an error evaluation of the desired versus actual paths for specific link/Joint errors.

Chapter III Process Technology

The planning and performance evaluation of various manufacturing processes constitute the theme of the third chapter. The first paper discusses research efforts aimed at the development of interfaces for the smooth transition of information from automated design to the Computer-Aided Process Planning (CAPP) system and then directly to the automated shop floor equipment. The next paper reports on the application of nonlinear goal programming to electrical discharge machining of ceramic composites, implementing a modified search technique to obtain optimal operating conditions. The third paper presents basic concepts of expert systems and then illustrates them with the prototype expert system aiding the designer of a metal-forming process of axisymmetric bars with simple extrusion. The fourth paper presents a CAPP system for generating optimal process plans for robotic assembly which uses a feature data base and a connectivity data base to generate feasible assembly sequences, which results in robot arm trajectory plans. The automated assembly of printed circuit boards is considered in the fifth paper. The author provides an analysis of the combined effects of angular and linear errors on successful part registration during assembly.

The Effect of Robot Kinematic Parameter Errors on Joint Torques

Research on improving robot positioning accuracy due to link/joint parameter errors has concentrated mostly on the effects of these errors on the kinematic performance of the robot. This paper extends this error-related analysis to the dynamic performance of the robot, by presenting the deviations in robot manipulator torque for several cases in which link/joint kinematic parameter errors exist. The deviation in manipulator joint torque due to robot link/joint kinematic parameter errors was studied for a two-link revolute robot manipulator. Algorithms have been developed that successfully compute such joint torque deviations. A simple robot task cases was studied. The results shows the contribution of joint torque deviation due to the small kinematic parameter errors.

Chapter IV Product Engineering

Papers grouped in this chapter all present various solutions and systems of product design and engineering. The first paper describes the work in automating the design process with an artificial intelligence technique called Case-Based Reasoning, as applied to process planning, product redesign, and design testing. The system of computer-aided design of mechanical clutches is presented in the second paper, whereas the third paper presents an expert system (using the VP-Expert shell) for design of precise ball and roller bearings. The fourth paper discusses a two-stage design framework for design of spur gears. The two stages proposed are preliminary design and design optimization, and the paper focuses especially on the optimization stage. Then, the fifth paper presents an approach to computer-aided design of underground structures.

Chapter VIII Motion Specification

In the first paper, an approximate path planning algorithm first navigates a point robot in polygonal terrains and returns paths with suboptimal lengths. An innovative four-step trajectory planning algorithm is developed in the second paper for a 3-axis articulated robot in which precise joint-level control can be easily achieved, major mechanical vibration can be avoided, and a well tuned speed can be used to maintain the efficiency. Inverse and forward kinematics for the Stewart Platform-based Manipulator are presented in the third paper.

Chapter II Production Planning

Diverse aspects of production planning and related issues are addressed by the papers in this chapter. A taxonomy of event-driven Al-based expert systems is presented in the first paper. It focuses especially on the synergy between the use of such systems and the issues of deriving parallel algorithms for real-time applications. The second paper compares the new lot sizing policy methodology termed DLIC (Dynamic Least Incremental Cost) for variable demand pattern with the well known policies using a variety of demand patterns. The problem of real-time scheduling is addressed by the third paper. Specifically, the potential application of discrete event computer simulation to aid system control in real-time decision-making is analyzed.