2012 BFY Abstract Detail Page

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Abstract Title: W00 - Using a Chaotic Pendulum to turn Sophomores into Experimentalists
Abstract: Quantifying the behavior of a nonlinear pendulum provides the setting for a semester long introduction to experimental methods. Students learn electronics, LabVIEW, data acquisition, and numerical analysis as they build stepper motor controllers, hardware timed data acquisition systems, and analysis software used to study the rich behavior of a chaotic pendulum.

The course is designed to build both the skills and confidence that students need to take on the ill-defined and difficult problems that they will see in the future. The first two thirds of the course is devoted to building the apparatus and controls, the data collection system, and writing the basic analysis software displaying Poincare' sections and bifurcation diagrams. The physics, technical topics and mathematical tools are presented as the topics become relevant. Homework problems and written work is assigned and tested on throughout the semester. Students work at their own stations but discuss problems with their peers in a collaborative environment. During the last third of the course students conduct individual explorations of different aspects of the chaotic pendulum. These investigations vary from measurements of Lyapunov exponents and correlation dimensions, to building FPGA stepper motor controllers, to studying chaotic magnetic dipole-dipole interaction. The semester concludes with a poster session where students present what they have been working on.

The apparatus consists of a pendulum operating in a variable magnetic potential. Driving torque is controlled by eddy forces, monitored by hall sensors and modulated by a stepper motor. Optical sensors provide information about position and driving phase. The system is relatively inexpensive which allows an entire course to be equipped at a reasonable cost. In this workshop I will introduce the hardware and software used in the course and discuss how they are used achieve our educational goals for the course.
Abstract Type: Workshop

Workshop Documents

Workshop Document: Download the Workshop Document

Author/Organizer Information

Primary Contact: Marty Johnston
Univ. of St. Thomas