Neural network-based intelligent path tracking for nonlinear predictive control in wheeled robots
摘要
This paper proposes an adaptive Neural Network–based Nonlinear Model Predictive Control (NN–NMPC) framework to enhance the path tracking accuracy and computational efficiency of a four-wheeled mobile robot in dynamic environments. The NMPC gain matrices are tuned online using a compact 4 × 5 multilayer perceptron, trained on 18,360 input–output samples with up to 29-step future reference data and noise augmentation for robustness. Experimental evaluations over velocities from 0.5 m/s to 1.5 m/s demonstrate a 25% average tracking accuracy improvement, 30% reduction in computation time, and final positional error decrease from 0.10 m to 0.07 m compared to a fixed-gain NMPC. On complex sigma-shaped paths, the proposed method halves solution time (from 8.34 s to 5.61 s) without performance loss. Speed sensitivity tests show RMSE rising from 0.095 m to 0.132 m and noise robustness declining from 0.88 to 0.80 as speed increases, while computation time remains constant (≈ 1.5 s). In obstacle-avoidance scenarios, the NN–NMPC with probabilistic collision-avoidance constraints maintain over 95% collision-free confidence and reduces peak deviation by up to 3 × compared to baseline NMPC under noisy perception. Real-world implementation using a Pixy2 vision system (5.5 mm static accuracy at 2 m) and ARM–U2D2 processing confirms the controller’s real-time feasibility and robustness. These results establish NN–NMPC as a strong candidate for intelligent, high-speed navigation in wheeled robotics.