UAV-based Wireless Sensor Network in Orchards. Southern California Conferences for Undergraduate Res

Abstract

A promising technology for the acquisition of ground data (e.g. plant and environmental data) at a low-cost, is wireless sensor networking (WSN). In this paper, a WSN was developed to collect ground sensors data in an orchard and transmit them wirelessly to an Unmanned Aerial Vehicle (UAV). Each affordable ground-based Data Acquisition System (DAS) contains: (i) a microprocessor (arduino mega), (ii) Series 2 Zigbee protocol XBees, (iii) a SD memory card (only for the “router”), (iv) temperature and humidity micro-sensors, and (v) a micro-camera. Several DASs were placed around a specified area each containing a XBee. These XBees were configured using the latest X-CTU program to be “end-points”. The “end-points” have the ability to sleep in order to save energy and are only woken up when transferring its information from its specific sensor to another single XBee configured as a “coordinator” or “master” in the network thus making the others “slaves”. The “coordinator” receives all the various information coming from every “end-point” and stores it into an SD card. Additionally, an autonomous multirotor hexacopter (UAV) was used to collect the ground-based WSN data. The UAV carries another XBee configured as a “router”. Once the UAV is within proximity of the “coordinator”, all the information stored inside the SD card is then transferred up to the UAV’s XBee and stored into the flight controller’s micro SD. The UAV is programmed to sustain a steady altitude until all the information is passed from the “coordinator” to the “router”. After the transfer is complete the UAV then returns “home”. This system was tested in an open field and in an orchard. The purpose of this project was to develop a low-cost system capable of giving farmers and/or businesses the ability to collect data from remote large areas at sufficient spatial and temporal resolution.