Input, output, manipulated variable и disturbance
Цель: Изучить тему «Input, output, manipulated variable и disturbance» 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
Modeling begins with identification of variables. Manipulated variable u - то, что controller changes. Controlled output y/PV - то, что хотим regulate. Disturbance d - external input. Setpoint r - desired output.
Example heat exchanger
u = steam valve/flow, y = outlet temperature, d1 = inlet temperature, d2 = product flow. Если product flow increases, heating demand changes even without controller action.
SISO и MIMO
Single Input Single Output has one main manipulated and one controlled variable. Real plant often MIMO: several inputs influence several outputs. Changing reflux in distillation affects composition and levels indirectly.
Практическая работа
Для tank with inlet valve and outlet pump identify u, y, d in two different control strategies: regulate level via inlet vs via outlet.
Самопроверка
• Что такое manipulated variable?
• Что такое disturbance?
• Чем SISO отличается MIMO?
• Может ли одна variable быть disturbance в одном loop и manipulated в другом?
• Зачем четко определять variables before tuning?
Что нужно запомнить
- u = steam valve/flow, y = outlet temperature, d1 = inlet temperature, d2 = product flow.
- Если product flow increases, heating demand changes even without controller action.
- Single Input Single Output has one main manipulated and one controlled variable.
- Real plant often MIMO: several inputs influence several outputs.
- Changing reflux in distillation affects composition and levels indirectly.