Development of an electrically actuated automatic levelling system for agricultural transport platforms based on three-point mechanism and fuzzy PID

Operating agricultural transport platforms on hilly and unstructured terrain presents significant challenges in stability and safety due to centre-of-gravity shifts and uneven ground excitation. This paper proposes a compact hydraulics-free automatic levelling system based on an electrically actuated three-point support mechanism. To address the nonlinear and coupled characteristics of the system, a fuzzy self-tuning PID control strategy is developed to achieve coordinated roll–pitch regulation with real-time adaptive gain adjustment. Unlike conventional hydraulic or fixed-parameter PID approaches, the proposed method improves adaptability under varying terrain disturbances. The system is implemented on an embedded platform and validated through prototype experiments under slope angles ranging from 3° to 12°. Results show that the levelling error is maintained within ±0.2°, while the settling time is reduced by 51.9% compared with conventional PID control, with significantly reduced overshoot. These results demonstrate that the proposed system provides an effective and practical solution for improving the stability and safety of agricultural transport platforms in complex terrain.