L14: MPC-lite (Constrained Control)

Prerequisites: L13 | Effort: 90 min | Seborg: Chapter 20

---

Learning Objectives

1. ✅ Understand constraint handling
2. ✅ Implement rate limits (Δu max)
3. ✅ Simulate move suppression
4. ✅ Approximate MPC behavior with PID + constraints

---

Theory Recap: MPC Basics (Seborg Ch. 20)

Model Predictive Control: - Optimizes future control trajectory - Handles constraints explicitly - Used in refineries, chemicals

MPC-lite Approximation: - PID + rate limits - Output constraints - Constraint projection

Rate Limits:

Δu_max = 5% per minute (slow valve movement)
u[k] = u[k-1] + clamp(Δu, -Δu_max, Δu_max)

---

Odibi Hands-On

Example 1: Constrained Level Control

# constrained_level.yaml
# PID with rate limit: max 2% valve change per minute

Working example: /examples/cheme_course/L14_mpc_lite/constrained_level.yaml

---

Summary

• ✅ Constraints are critical in real plants
• ✅ MPC handles them optimally
• ✅ PID + rate limits approximates MPC

Next: L15: CSTR Digital Twin

---