Modular 4WD agricultural robot for cutting, collection, and precision seeding: design and simulation-based evaluation

This paper presents a four-wheel differential-drive (4WD) autonomous platform that consolidates grass cutting, collection, leaf crushing, and precision seeding through modular, quick-release toolheads. A vertically stacked two-unit architecture separates the drive/blower subsystem in a steel-framed base from a high-capacity collection chamber; transparent panels aid inspection and service. System specifications are formalized, and operating energy budgets are modelled to predict runtimes across cutting (≈ 1.2 h), crushing (≈ 2.0 h), and seeding (≈ 8.0 h) modes. Coverage-path algorithms (zigzag, spiral, concentric) are simulated, with results confirming that the boustrophedon pattern achieves complete rectangular coverage with minimal redundancy. Robustness simulations quantify debris deflection (> 95% rejection), slope climb limits (≈ 25° at < 20% slip), and stone-ingestion probability (≈ 10%), validating operational resilience. Finite-element analysis of the steel and aluminum chassis demonstrates high safety factors (> 15) with negligible stress or deformation under representative static loads. Beyond robotic functions, composting pathways for collected biomass are outlined to close the loop on sustainability. While dynamic load events and hardware validation are deferred to future work, the results indicate that the proposed modular 4WD platform integrates cutting, collection, and seed delivery with serviceability, structural robustness, and environmental benefit, making it a promising candidate for campus and small-scale agricultural automation.