Transcript Document
Rig Jig: An Optimization of Forward Thrust Abstract Automated systems have greatly improved and simplified mankind’s activities. The Rig Jig sensor system is a setup combining both aspects of sailing and an automated feedback mechanism. The model is a proof of concept, showing that a sensor system is capable of measuring the data necessary to control a sailboat, and that software is capable of implementing a working feedback control that can optimize the efficiency of forward movement of a sailboat. The primary goal is to show a relationship between the forces affecting the vessel and the forward thrust, and to use those measurements to maximize sailing efficiency. Overview Data Processing The Rig Jig Model consists of sixteen strain gauges, a signal conditioning circuit, a digital subsystem, a MATLAB data processing program, and a Graphical User Interface. The strain gauges are divided into four Wheatstone bridges, whose output corresponds to either a forward or side force. The goal is to maximize the outputs of the forward force, while minimizing the torque and yawing motion of the vessel. All calculations are performed in MATLAB. The four sensor outputs are plotted simultaneously and a mathematical model runs to find the best boom angle. The Graphical User Interface also allows the sailor to input multiple variables that could affect performance. Sensors System Flow Chart Transducers Results Amplifier and PIC Authors Jean-Benoit Daumerie, EE ’07 Scott Harrington, EE ’07 Nadya Sosonkin, EE ‘07 Feedback Algorithm Data Processing Advisors Dr. Stephen Judd Dr. Jorge Santiago Special Thanks Mr. Salvador Castro Brian Edwards Robert Callan Demo Schedule April 19, 2007 10:00-11:30, 1:00-2:00 Department of Electrical and Systems Engineering Results Sixteen strain gauges are mounted on individual aluminum transducers. As they are strained or stressed, the resistance changes, providing a different output voltage which can later be converted into forces. Signal Conditioning The AD627 instrumentation amplifier serves to transform the low voltage output from the Wheatstone bridge into a higher voltage that can be converted into a digital component in the PIC microcontroller. The PIC then sends the digital readings to MATLAB for calculations. In addition, the PIC serves to control the SERVO motor adjusting the boom angle, essential for the feedback mechanism. During operation, MATLAB takes the data and optimizes performance by determining the best boom position. The graph below shows a sample of different wind angles and the expected outputs for different boom angles. As seen, for each different wind angle, there is a prominent maximum at a specific boom position.