Derivative control
Цель: Изучить тему «Derivative 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
D-action responds to rate of change of error or PV. It predicts trend: if temperature is rapidly approaching SP, derivative can reduce output before overshoot.
Noise sensitivity
Derivative amplifies high-frequency noise, because noise changes rapidly. Therefore measurement filtering and derivative implementation matter. Many industrial controllers use derivative on PV to avoid setpoint kick.
Practical use
D is useful for processes with significant inertia where prediction helps, but often omitted in noisy flow/pressure loops. PI is very common industrial structure.
Практическая работа
Compare clean slow temperature signal and noisy flow signal. Explain why derivative likely more useful in first.
Самопроверка
• What does D respond to?
• Why noise problem?
• What is derivative kick?
• Why PI common?
• Where D can help?
Что нужно запомнить
- It predicts trend: if temperature is rapidly approaching SP, derivative can reduce output before overshoot.
- Derivative amplifies high-frequency noise, because noise changes rapidly.
- Therefore measurement filtering and derivative implementation matter.
- Many industrial controllers use derivative on PV to avoid setpoint kick.
- D is useful for processes with significant inertia where prediction helps, but often omitted in noisy flow/pressure loops.