Error analysis of motion transmission mechanisms : design of a parabolic solar trough

Abstract

This thesis presents the error analysis pertaining to the design of an innovative solar trough for use in solar thermal energy generation fields. The research was a collaborative effort between Stacy Figueredo from Prof. Alexander Slocum's Precision Engineering Research Group at MIT and a team of students from the 2.752 Mechanical Engineering course and resulted in a final design that uses two linear actuators to rotate a monolithic parabolic trough over a 2600 range. A measure of efficiency, based on the geometric tracing of incident and reflected rays under different parabola deformations, was developed and used to determine the impact of several key parameters on the accuracy of the system. The resulting error analysis demonstrated the substantial influence of the crank arm length and actuator precision on the overall system efficiency and set an upper bound of 1 degree in permissible angular error in order to maintain 80% efficiency under sustained wind loading.