This study presents an innovative adaptive non-linear fractional-order PID (FOPID) tuning
methodology for a flow meter controller in a desalination plant, integrating a hybrid Particle Swarm
Optimization (PSO) and Deep Q-Network (DQN)-based Reinforcement Learning (RL) strategy with
a dynamic weighting mechanism to optimize control of non-linear systems with time delays and
disturbances. By utilizing fractional-order parameters, the PSO-DQN-RL framework ensures global
optimization and real-time adaptability under fluctuations in operational parameters. Results
demonstrate superior performance over traditional methods and advanced techniques such as Genetic
Algorithms (GA), Fuzzy Logic Controller (FLC), Neural Network-based PID (NN-PID), and PSO, offering
faster response times, reduced overshoot, and minimal steady-state error compared to the slower and
less precise outcomes of FLC, the static limitations of PSO, the rigid parameter settings of GA, and the
inconsistent performance of NN. The hybrid method’s enhanced robustness and dynamic parameter
evolution surpass the modest adaptability of PSO. Despite its computational complexity, the offlineonline
balance and real-time GUI enable scalable deployment, positioning this scientifically novel
approach as a benchmark for FOPID tuning in various applications.