Design and Fabrication of a Multifunctional Agricultural Robot for Multiple Farm Operations Using Mechanical Components

Agricultural operations such as seed sowing, soil preparation, weeding, fertilizer application, spraying and field monitoring are traditionally performed using separate machines or manual labour. The use of separate agricultural implements increases operational time, labour requirements and equipment cost, particularly for small and fragmented farms. This research presents the design and fabrication of a compact, multifunctional agricultural robot capable of performing multiple agricultural operations using a common mobile platform and interchangeable mechanical attachments. The proposed robot consists of a mild-steel structural chassis, four-wheel drive mechanism, geared DC motors, chain-and-sprocket transmission, seed-metering mechanism, rotary mechanical weeder, fertilizer dispensing mechanism, spray unit and optional soil-monitoring arrangement. A modular attachment mechanism is incorporated so that individual agricultural tools can be mounted according to the required operation. The mechanical design was developed by considering vehicle mass, rolling resistance, field gradient, traction requirement, motor torque, shaft diameter, chain transmission and implement power requirements. The prototype is powered by a rechargeable battery and controlled using a microcontroller-based control system. The robot is designed for low-speed operation suitable for agricultural fields. Preliminary prototype evaluation is proposed for seed spacing accuracy, weeding efficiency, spraying coverage, field capacity, battery endurance and traction performance. Representative prototype calculations indicate that a compact four-wheel platform can provide adequate tractive effort while maintaining low soil disturbance. The proposed multifunctional design has the potential to reduce dependence on manual labour, decrease the need for multiple dedicated machines and provide an economical automation solution for small and medium-scale agricultural applications