The Scalability Trap: A Systematic Review of Mobility Constraints in Mid-size Unmanned Ground Vehicles
Journal
Journal of Intelligent & Robotic Systems
ISSN
9210296
Date Issued
2026-09-10
Type
Article
Abstract
The deployment of Unmanned Ground Vehicles in unstructured environments is currently polarized between lightweight scouting platforms and heavy industrial machinery, leaving a significant void in the functional capabilities of mid-sized robotic systems. This systematic review investigates the architectural constraints of the mid-size category, strictly defined in this work by a total Gross Vehicle Weight (GVW) ranging from 100 to 1000 kg through a Comparative Boundary Analysis of 24 empirical studies. By stratifying the literature into lightweight, mid-size, and heavy-duty clusters, the analysis identifies a Scalability Trap where kinematic principles effective at small scales become energetically prohibitive when upscaled. Specifically, the review demonstrates that the resistive turning moment inherent to skid-steering architectures scales linearly with mass, rendering differential drive mechanisms increasingly inefficient and prone to immobilization as payload scales in highly deformable soils. Furthermore, the synthesis of suspension dynamics reveals that rigid chassis designs in this intermediate class struggle to manage dynamic vertical forces, leading to high-frequency sensor noise and intermittent traction loss that pneumatic tyre compliance cannot mitigate. Algorithmically, the review establishes that reactive kinematic controllers frequently diverge under the inertial non-linearities of this mass regime during high-speed or transient maneuvers, necessitating predictive dynamic frameworks capable of explicitly managing actuator saturation and stochastic wheel slip. Despite these architectural and algorithmic limitations, empirical evidence confirms the agronomic superiority of the mid-size class, which delivers measurable crop yield improvements relative to conventional tractors by preserving soil porosity through reduced ground pressure. Consequently, this study concludes that the future of field robotics depends on shifting from rigid, skid-steered prototypes to morphologically adaptive systems utilizing 4-Wheel Steering, passive articulation, and predictive traction control to unlock the operational potential of the mid-size sector. © The Author(s) 2026.