University of Hawaii

Electrical Engineering

Development of a Low-Cost Three-Axis Anemometer for Analysis of Various Wind Phenomena

Date: 2015-08-13           Add to Google Calendar
Time: 2pm-4pm
Location: Holmes Hall 388
Speaker: John Hirano, candidate for PhD

 The work I have conducted toward my Ph.D. is anchored in the research and development of a low-cost three-axis anemometer. As part of the Renewable Energy Island Sustainability group, I was responsible for investigating the feasibility of a distributed wind turbine as part of a renewable energy portfolio for Holmes Hall. As part of the study, I investigated the optimal placement for the wind turbines using numerical models of the wind flow, which showed us the effects of the architectural topology on wind flow. But we wanted to compare the numerical models to real-time data with a high spatial resolution. Due to the lack of affordable options of anemometers for this purpose, we began the development of our own low-cost three-axis anemometer.

The development of a low-cost three-axis anemometer has taken my research through various approaches to the design and several prototypes. The core technology is an implementation of guided-parallel beam structures and infrared (IR) sensor technology. Three parallel beam structures are oriented and designed to decompose the wind force along each axis. The IR sensor pair converts the physical displacement to a electronic voltage to determine the velocity of the wind. The drawbacks to an openly exposed IR sensor is the errors that may occur due to misalignment and external infrared light sources. These challenges are addressed through the profiling of the IR sensors and evaluating methods for mitigating the effects of external interference. This process lead to the development of a new force transducer to convert the displacement of the parallel suspensions to a force measurement.

The developed force transducer uses principles of total internal reflection and frustrated total internal reflection to measure the amount of force applied to the transducer. The force transducer uses Polydimethylsiloxane (PDMS) as the material for the optical waveguide. I will show that the optically-based force transducer performs with similar characteristics as available force sensors and can be implemented into a low-cost three-axis anemometer.