Feedback и Feedforward
Цель: Изучить тему «Feedback и Feedforward» 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
Feedback waits until disturbance affects controlled variable, then corrects. Feedforward measures disturbance before output changes and calculates compensating action.
Example heat exchanger: feedback uses outlet temperature. Feedforward additionally measures inlet flow/temperature and adjusts steam proactively.
Limitation
Feedforward requires measurable disturbance and reasonable process model. Unmeasured errors remain, so practical system often combines feedforward + feedback trim.
Практическая работа
For tank level with variable inlet flow, compare feedback manipulating outlet valve and feedforward based on measured inlet flow. Explain combination.
Самопроверка
• How feedback reacts?
• How feedforward differs?
• What requirement for feedforward?
• Why combine both?
• What happens with model error?
Что нужно запомнить
- Feedback waits until disturbance affects controlled variable, then corrects.
- Feedforward measures disturbance before output changes and calculates compensating action.
- Example heat exchanger: feedback uses outlet temperature.
- Feedforward additionally measures inlet flow/temperature and adjusts steam proactively.
- Feedforward requires measurable disturbance and reasonable process model.