Can, Erol

Radiation monitoring systems require high sensitivity, stability, and adaptability under dynamically changing environmental conditions. Conventional fixed-sensitivity sensor architectures often suffer from reduced accuracy under high radiation levels, increased noise effects at low radiation levels, and unnecessary energy consumption due to continuous high-sensitivity operation. This study proposes a novel hybrid adaptive control framework that integrates Proportional-Integral-Derivative (PID) control, Sugeno-type fuzzy logic inference, and threshold-based sensor switching within a unified architecture. The proposed method dynamically adjusts sensor sensitivity by evaluating both radiation intensity and PID error behavior. A mathematical control model defined as u(t) = alpha uPID(t)+beta uFLC(t)+gamma R(t)/Rmax is implemented to generate a continuous adaptive control signal for real-time sensor switching. Simulation results under four distinct operating conditions demonstrate that radiation intensity provides the dominant contribution for sensitivity transition, while PID error improves transient regulation and system response. A threshold-based switching mechanism (u(t)>uth = 4) effectively separates low- and high-sensitivity operating regions without causing instability. The results confirm that the proposed hybrid architecture improves responsiveness, robustness, and operational efficiency compared with fixed-sensitivity monitoring approaches. The main contribution of this study is the integration of continuous PID-fuzzy control regulation with discrete sensor selection in a single adaptive framework, providing a scalable solution for intelligent radiation sensing applications and next-generation monitoring systems.

Can, Erol

Space missions expose spacecraft electronics to complex space environments, including charged particle fluxes, solar wind plasma, and high-energy radiation, which can induce surface charging, electrostatic discharges (ESD), and single-event upsets (SEUs) in power conversion systems. Traditional mitigation strategies, such as radiation-hardened components and shielding, offer partial protection but incur significant mass and efficiency penalties and do not address transient plasma-induced disturbances. This study presents a physics-informed, plasma-resilient design methodology for DC–DC converters in deep-space applications. A comprehensive space-environment simulation framework is developed to model heliocentric plasma density, solar wind velocity, proton energy spectra, and surface charging, incorporating both low- and high-frequency fluctuations. Building on this, a radiation-aware, adaptive DC–DC converter topology is proposed, coupled with a model reference adaptive control (MRAC) architecture and disturbance observer, enabling real-time mitigation of plasma-induced voltage fluctuations, SEU step events, and input ripple. Simulation results demonstrate that the proposed approach maintains the output voltage close to the nominal value under the considered space-environment disturbances. The adaptive controller reduces the RMS voltage error from approximately 10.3–12.6 V in the uncontrolled system to approximately 1.86–1.91 V across the investigated operating scenarios while significantly suppressing transient deviations caused by plasma fluctuations and SEU events. Frequency-domain analysis confirms effective attenuation of low-frequency plasma-induced transients, while Lyapunov-based stability proofs ensure guaranteed closed-loop robustness. The integrated methodology enables reliable, efficient, and adaptive energy management for long-duration space missions, highlighting the importance of environment-aware hardware-control co-design for future deep-space spacecraft.