Published Paper Details:

Indian agriculture continues to depend heavily on manual labour and small fuel-powered implements for repetitive field operations such as soil digging, weed removal and crop cutting. Rising fuel prices, seasonal labour scarcity and the emissions associated with small engine-driven machinery have created a need for low-cost, energy-autonomous field equipment suited to small and medium landholdings. This paper presents the design, implementation and experimental evaluation of a solar-powered multipurpose agricultural robot that performs movement, digging and cutting operations under wireless remote control. The implemented prototype harvests energy through a 12 V, 5 W photovoltaic panel that charges a 12 V, 1.2 Ah rechargeable battery; a three-terminal series regulator derives the 5 V logic rail while the battery rail supplies the actuators directly. An ATmega328P microcontroller, operating with a 16 MHz crystal oscillator and an external reset network, interprets commands received through a 433 MHz RF receiver and drives two L293D H-bridge motor drivers. The first driver controls four base motors arranged as left and right traction groups; the second operates the cutter and shaft actuators. The operator unit comprises four push buttons, a parallel-to-serial encoder and a 433 MHz transmitter with antenna. Testing of the assembled prototype reported a battery charging time of 4-5 hours of sunlight, 6-8 hours of continuous operation, a stable radio link over 50-100 m in open field with less than 1% signal loss, a base traversal speed of approximately 0.2 m/s, cutter and shaft speeds of 200-300 rpm, and a 70% reduction in manual labour on the test plots, with zero fuel consumption throughout. The results demonstrate the feasibility of solar-assisted, RF-controlled multipurpose field robots for small-scale agriculture.