Restoring lighting quality in highway tunnels during luminaire malfunction conditions: An optimization-based luminous flux redistribution strategy

The enclosed lighting environment in highway tunnels exacerbates accident risks. Prolonged operation of light emitting diode (LED) luminaires commonly results in lumen depreciation, and the associated random failure rate escalates with the extent of this decay, posing a significant threat to driving safety within tunnels. This study proposes a tunnel lighting optimization framework that integrates a hybrid intelligent algorithm, combining particle swarm optimization-differential evolution-simulated annealing (H-PDS) with three-dimensional (3D) illuminance modeling. Based on dual standards from the Chinese JTG/T D70/2-01-2014 (JTG) and the international commission on illumination (CIE), an innovative 3D illuminance field model incorporating luminaire pitch angle correction is developed. This model utilizes coordinate transformation matrices to analyze the impact of installation position, offering enhanced accuracy over conventional models. To address the multi-peak optimization problem inherent in tunnel lighting, a hierarchical H-PDS algorithm is designed. Its global layer utilizes particle swarm optimization (PSO) for a coarse search of the solution space. The local layer incorporates differential evolution (DE) combined with the metropolis criterion from simulated annealing (SA) to effectively escape local optima. Concurrently, a constraint layer dynamically regulates the luminous flux boundaries. Experimental results indicate that, under a single-luminaire failure condition, the proposed framework enhances overall uniformity and lane centerline longitudinal uniformity by more than 7% and 12%, respectively, thereby effectively counteracting the uniformity degradation induced by lumen depreciation. This study contributes theoretical methodologies and technical tools for enhancing reliability and enabling dynamic control of tunnel lighting systems, offering significant practical engineering value in reducing accidents associated with dark adaptation.