Development and evaluation of drone mounted sprayer for pesticide applications to crops
Application of crop protection materials is one of the crucial operations in agriculture to meet ever demanding food production. The drone mounted sprayer mainly consists of BLDC motors, LiPo (Lithium polymer) batteries, peticide tank, pump, and supporting frame. Six BLDC motors were mounted to hexa-copter frame to lift of 5 kg payload capacity. Two LiPo batteries of 6 cells — 8000mAh were used to supply the necessary current required for the propulsion system. A 5 liter capacity conical-square shaped fluid tank was used to hold the pesticide solution. A 12 V DC motor coupled with pump was used to pressurize spray liquid and then to atomize in to fine spray droplets by means of four nozzles. A suitable aluminium supporting frame was used to mount the spray liquid tank, sprayer motor, spray and supporting legs (landing gears) for safe take-off and landing. The entire drone mounted sprayer operation controlling with the help of transmitter at ground level, HD FPV camera also provide at front down side of drone sprayer unit to monitoring the live spaying operation. 1.08 ha h−1, respectively at a forward speed of 3.6 km h−1 and 1m height of spray. The cost of operation for groundnut and paddy crops using drone mounted sprayer has been worked out 345 and Rs. 367 Rs ha−1 respectively. The spray uniformity was increased with increase in height of spray and operating pressure. A VMD and NMD of spray droplet size were measured and it was found to be 345 and 270 μm, respectively in lab condition. This sprayer is very useful where human interventions are not possible for spraying of chemicals on crops including rice fields and orchard crops as well as crops under terrain lands. This technology greatly helpful for small farming community in reducing cost of pesticide application and environmental pollution but also biological efficacy of application technology.
Proposal of Continuous Remote Control Architecture for Drone Operations
Drones have been considered for use in various fields according to the performance improvement and the price down of devices. They are expected for some applications: disaster relief, farm field, security field, transportation field, etc. Some companies will employ the autopilot system for their business. However, they have to switch to manual operation in case of emergency due to the autopilot safety is not guaranteed. Therefore, a pilot must connect with the drone continuously by the network for remote monitoring. Cellular network systems are the candidate networks for remote monitoring. However, typical design of cellular networks does not assume user equipment devices in the air because antennas of cellular networks are usually aimed downward to reduce inter-cell interference. This means that drones may fly out a communication area of cellular networks. Therefore, business drones must communicate with some cellular networks to keep continuous communication. However, IP-based application will disconnect due to change of cellular networks. As a result, practical business drones’ operations require a continuous communication mechanism. This paper proposes a continuous remote control architecture for drone operations to improve safety of the autopilot function. The proposed architecture employs NTMobile technology as a seamless mobility protocol supporting continuous communication. Additionally, it also employs IP-based remote control application to control drones remotely. The evaluation system can acquire sensor information and exchange control information continuously when drones switch access networks. The proposed architecture can be a fundamental framework to realize a wide area drone operation service.
Development of a PWM precision spraying controller for unmanned aerial vehicles
This paper presents a new Pulse Width Modulation (PWM) controller for Unmanned Aerial Vehicle (UAV) precision sprayer for agriculture using a TL494 fixed-frequency pulse width modulator together with a data acquisition board and developed software. An UAV can be remotely controlled or flown autonomously by pre-programmed flight plans. The PWM controller was implemented through the guidance system on the UAV with control commands sent between the UAV helicopter and the ground control station via a wireless telemetry system. The PWM controller was tested and validated using LabVIEW 8.2. Several analyses were performed in a laboratory to test different control signals. The results show that the PWM controller has promise as a higher precision technique for spray applications, which will improve efficiency of pesticide application, especially in crop production areas.