1. Concept of Adaptive Control: Adaptive control is a sophisticated control strategy where the controller's parameters (like $K_p, T_i, T_d$) are not fixed. Instead, the system continuously monitors the process performance and "adapts" by automatically re-tuning itself to maintain optimal performance under changing conditions.
2. How it Differs from Others:
• Feed-forward: Anticipates disturbances before they affect the process but does not change its own tuning parameters.
• Ratio Control: Maintains a fixed relationship between two flows.
• Adaptive Control: Actually "learns" or adjusts its internal logic to keep the system optimized.
3. Types of Adaptive Control: Common types include Model Reference Adaptive Control (MRAC) and Self-Tuning Regulators (STR). These are essential in high-performance applications like aerospace (where air density changes with altitude) or chemical reactors (where catalyst activity declines over time).