Richard Stamper

The purpose of this research is to design a new tracking system for solar panels using the idea of discrete-position tracking. Compared with the traditional fixed solar panel, discreteposition trackers have a higher gain of harvesting solar radiation with smaller misalignment angles. Also, since we are trying to design the a passive tracker with solely mechanical structure to do the kinetics, a discrete-position tracker can decrease the cost of the maintenance to a huge extent in contrast to both one-axis and two-axis continuous tracking systems. The majority of the cost of maintaining a continuous tracker is the motor or hydraulic ram. These devices not only are relatively expensive but also do not adapt robust to different weather condition. Therefore, the major part of this summer research is to develop the algorithm of calculating the gain of discrete-position tracker for solar panels comparing with fixed tracker and continuous tracker. The report will introduce the background i...

This paper presents a novel three degree of freedom parallel manipulator that employs only revolute joints and constrains the manipulator output to translational motion. Closed-form solutions are developed for both the inverse and forward kinematics. It is shown that the inverse kinematics problem has up to four real solutions, and the forward kinematics problem has up to 16 real solutions.

Pin loosening is a frequent complication associated with the use of halo orthoses. Efforts to reduce pin loosening incidence include increasing the number of halo pins, increasing the torque specification, and proactively retightening the halo pins. Although these approaches lower pin loosening incidence rates, none addresses the cause of pin loosening, which is the inability of current halo ring designs to accommodate changes in geometry of the skull. A novel four-pin adaptive halo ring is introduced that can accommodate changes in geometry of the skull and provide a nearly constant pin force. To quantify pin loosening in a halo ring, tests were performed using a fixture that was capable of simulating the changes in skull geometry that are responsible for pin loosening. Both the four-pin adaptive halo and a conventional halo were tested. After 1.1mm of radial recession of the skull at the pin site, the average halo pin force in the conventional halo decreased by 78% while the avera...

Two optimization studies on the design of a three degree of freedom translational parallel platform are conducted and the results are compared. The objective function of the first study maximizes total volume of the manipulator workspace without regard to the quality of the workspace. The second study optimizes the total volume of well conditioned workspace by maximizing a global condition