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Harvard Forest REU Symposium Abstract 2014

  • Title: Simplicity and robustness: Keys to designing an aerial tram for autonomous above canopy data collection
  • Author: Bruce C McAlister (University of Massachusetts - Amherst )
  • Abstract:

    In collecting data above forest canopies, either data can be collected frequently at a single location by sensors mounted on a tower, or infrequently measured by hand across transects.The Harvard Forest aerial tram combines both the frequency of data collection from a tower with the mobility of people to measure daily and seasonal variations. The base station computer for the tram system uses python scripts running on Windows to send commands to the tram and control motion via a stepper motor. Onboard the tram a BeagleBoard XM running python scripts in Linux communicates over a wireless IEEE 802.11n link to relay data and commands between a Campbell Scientific CR1000 datalogger and the base station computer. Because of the need for the system to run continuously and without monitoring, we aimed to achieve simplicity and robustness in our designs. To this end a virtual router was implemented in the control computer to host the communication network without the need for a separate router; a simple two-pronged charging interface for the tram's internal battery was fabricated, and the motor drive sheave was redesigned to provide location control via the motor. Parts were fabricated from common materials to make modification and repair of the tram simple and fast. The project is ongoing and will continually receive improvements to both its hardware and software. The refinements implemented this summer have added robustness and adapted the tram to operating at its field site in the Harvard Forest.

  • Research Category: Forest-Atmosphere Exchange; Group Projects