Height-Adjustable AGV With Adaptive Suspension for Challenging Terrains

This paper presents the design, analysis, and validation of a one-third-scale four-wheel-drive autonomous ground vehicle (AGV) prototype engineered for operation in unstructured and unpredictable environments such as agricultural fields, off-road terrain, and disaster zones. The prototype integrates a chassis height-adjustment mechanism actuated by a linear actuator and a passive suspension system designed for compliance and stability. A 3D-printed carbon fiber-reinforced chassis is planned for the full-scale version to ensure high strength-to-weight performance. Kinematic modeling of the height-adjustment linkage is conducted to evaluate singularities, actuator stroke limits, and safe operating ranges. Torque analysis is performed to appropriately size the wheel motors based on rolling resistance forces. The suspension system is analyzed through empirical and theoretical methods, including tire stiffness estimation, ride rate, wheel rate, spring stiffness, damping coefficient, and shear stress constraints. An Arduino-based microcontroller governs the control system, supported by dual ultrasonic sensors for obstacle detection and clearance estimation. The prototype demonstrates the ability to adaptively adjust chassis height or reroute based on obstacle height in real-time. Field testing confirms successful integration of mechanical, electrical, and control subsystems for terrain-aware navigation. These results serve as a foundation for scaling up to a full-sized AGV with advanced sensing, sensor fusion, and control strategies for autonomous deployment in complex environments.