An integrated power, energy, and thermal management strategy using cascaded Control for off-road autonomous hybrid vehicles

Off-road hybrid vehicles operating in unstructured and thermally harsh environments require supervisory controllers capable of managing highly transient power demands while ensuring energy efficiency and component longevity. This paper presents a cascaded control strategy for integrated power, energy, and thermal management (IPETM) that addresses this multi-timescale challenge. The real-time framework combines a long-horizon optimizer that jointly minimizes fuel consumption and battery degradation with a fast compensatory controller that mitigates transient power fluctuations and uncertainties. Hardware-in-the-loop (HIL) testing using the actual vehicle control hardware and a high-fidelity virtual vehicle model demonstrates that the proposed approach maintains constraint-compliant operation under model and preview uncertainties. Benchmarking across nominal and extreme temperature off-road driving conditions shows that the IPETM strategy substantially reduces capacity degradation by ∼ 70 % relative to a real-time, long-horizon benchmark, without a significant increase in fuel consumption. Moreover, it achieves performance comparable to a synthesized short-update long-horizon controller that is computationally infeasible for real-time implementation and requires detailed future-demand previews. Sensitivity studies on control weights and update frequency further establish practical configuration guidelines. Overall, the results demonstrate that the proposed IPETM framework bridges the gap between real-time implementable and ideal optimization-based controllers, providing a computationally tractable and robust solution for integrated power, energy, and thermal management in autonomous hybrid off-road vehicles.