Research on hybrid estimation algorithm for dynamic center-of-mass parameters of tracked agricultural transport...

To address dynamic centroid shift and reduced control accuracy caused by complex terrain and multi-device collaborative loading on tracked agricultural transport platforms, a hybrid estimation algorithm (CBA-IPSO-UKF) is proposed. This algorithm is designed for platforms operating in unstructured outdoor environments and combines a deep learning-based model with intelligent optimization techniques. First, the limitations of traditional UKF algorithms-which depend heavily on physical models and struggle with strong nonlinear disturbances-are overcome by developing a CNN-BiLSTM hybrid model with attention mechanisms. This model replaces conventional state and observation equations. Second, to reduce systematic errors from model mismatch, a constant-coefficient compensation vector is incorporated into the estimation framework. An improved particle swarm optimization algorithm, enhanced with genetic algorithm crossover and mutation operators, is used to optimize global parameters and minimize residuals. Real-vehicle data were collected from a self-developed tracked agricultural platform, resulting in a dataset of 18, 000 valid samples. Comparative experiments were carried out under typical circular driving conditions in unstructured environments. The results demonstrate that the proposed algorithm achieves high accuracy and steady-state performance in both attitude and velocity estimation. Specifically, the mean absolute errors for roll angle, pitch angle, and heading angle were 0.0917°, 0.1352°, and 3.1458°, respectively. The MAE for the three-axis velocities reached 0.0622 m/s, 0.0616 m/s, and 0.0209 m/s, respectively. These results show significant improvements over traditional algorithms like UKF and ACKF. This study offers both theoretical support and practical engineering solutions for real-time state perception and the stability control of autonomous operations in complex environments for intelligent agricultural machinery.