Proportional control
Цель: Изучить тему «Proportional control» и закрепить её практическими заданиями и самопроверкой.
2 акад. часа чтение и разбор теории, решение задач, работа со схемой или виртуальным стендом и проверка понимания.
Основной материал
P-controller output changes proportional to error: u = bias + Kc*e (sign convention depends system). Higher Kc gives stronger reaction but too high gain causes oscillation/instability.
Proportional offset
For self-regulating process P-only often leaves steady-state error because nonzero output change requires nonzero error. Increasing gain reduces offset but may reduce stability margin.
Proportional band
Some controllers use PB instead of gain; relationship inverse. Need know controller convention.
Практическая работа
At Kc=2 %output/°C, error +5 °C gives +10 % output from bias. Compare Kc=5. Discuss sensitivity.
Самопроверка
• How P action responds to error?
• What happens when gain increases?
• What is offset?
• Why not infinite gain?
• What is proportional band concept?
Что нужно запомнить
- P-controller output changes proportional to error: u = bias + Kc*e (sign convention depends system).
- Higher Kc gives stronger reaction but too high gain causes oscillation/instability.
- For self-regulating process P-only often leaves steady-state error because nonzero output change requires nonzero error.
- Increasing gain reduces offset but may reduce stability margin.
- Some controllers use PB instead of gain; relationship inverse.