Scalable Identification of Physics-Based and Neural Dynamics from Partial Measurements
Organizations: Department of Electrical Engineering, Chalmers University of Technology, Gothenburg, Sweden · Department of Mechanical Engineering, Imperial College London, London, United Kingdom
Abstract
We present a scalable method for identifying nonlinear dynamics from partial measurements, supporting physics-based, neural-network, and gray-box models. We use the Prediction Error Method (PEM) coupled with state estimation performed by a Moving Horizon Estimation (MHE) scheme, which can account directly for general nonlinear dynamics. This results in a bi-level optimization problem that scales poorly with increasing model parameters. To improve computational efficiency, we derive a reformulation that avoids explicit parameter-wide sensitivity matrices and exploits the temporal structure of the underlying optimization problem. Numerical comparisons show up to a speedup in hypergradient evaluation. Racing-vehicle simulations demonstrate accurate prediction and physical-parameter recovery in tire-force identification. Real-world data show that the gray-box model improves prediction accuracy with a neural residual while retaining physical interpretability.
Figures & tables
| Method | One-Step Prediction Error | Average Relative Physical-Parameter Error | Training Time | |
| Train | Validation | |||
| Ground True Parameters | – | |||
| SUBNET | – | 2 min | ||
| Joint-MHE | 7 min | |||
| EKF PEM | 1 min | |||
| EKF PEM (adaptive) | 26 min | |||
| Method | One-Step Prediction Error | Training Time | |
|---|---|---|---|
| Train | Validation | ||
| SUBNET | 3 min | ||
| Joint-MHE | 4 min | ||
| EKF PEM | 1 min | ||
| EKF PEM (adaptive) | 4 min | ||
| PEM-MHE (physics-only) | 2 h 50 min | ||
Nonlinear System Identification
Nonlinear system identification infers mathematical models and parameters of nonlinear dynamics from observed inputs, states, and outputs.
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