In tunnel kilns and roller kilns when firing clay bricks, fine ceramics, temperature is usually controlled through multiple consecutive zones along the kiln length. Each zone is equipped with its own temperature controller, but strong thermal coupling exists between neighboring zones due to heat conduction, radiation, and kiln atmosphere flow. Consequently, temperature fluctuations in one zone inevitably disturb adjacent zones, making kiln temperature control a nonlinear, multi-variable, and time-delay–dominated system.

Conventional PID control uses fixed parameters (Kp, Ki, Kd) tuned for a specific operating condition. While simple and widely applied, traditional PID struggles in continuous multi-zone kilns. Changes in production load, kiln speed, fuel quality, or product type often lead to oscillation, overshoot, and repeated manual retuning. Moreover, fixed-parameter PID does not effectively compensate for inter-zone thermal interaction, resulting in unstable temperature profiles and higher energy consumption.

Fuzzy PID control combines classical PID structure with fuzzy logic reasoning. Instead of constant gains, fuzzy rules dynamically adjust PID parameters based on real-time temperature deviation and its rate of change. This allows aggressive control during large disturbances and softer control near the setpoint, improving overall stability.

Comparision between Fix PID and Fuzzy PID
Unikiln adopts an AI PID Temperature Controller based on fuzzy logic, specifically developed for continuous multi-zone kiln systems. Practical operation has demonstrated that this approach significantly reduces temperature fluctuation and overshoot between zones. At the same time, smoother thermal profiles lower specific energy consumption and improve product consistency. In addition, adaptive fuzzy tuning minimizes the need for frequent manual parameter adjustment, simplifying commissioning and long-term operation.

AI PID Temperature Controller based on Fuzzy Logic
By embedding process experience and adaptive intelligence into temperature control, fuzzy PID provides a more robust and energy-efficient solution than conventional PID for modern tunnel and roller kilns.