Hur får man system att uppföra sig som man vill? Reglerteknik och intressanta tillämpningar Carl-Fredrik Lindberg,

Single and Double Inverted Pendulum Movie found on internet 2

Automatic Control (“Reglerteknik” in Swedish) 3 ●Automatic control gives: ●Stability ●Fast disturbance rejection ●Small variations in controlled variables ●Etc. Modeling the tank dynamics Tuning the PID controller

How a control engineer sees the world 4 Set- points Measurement noise Measureable disturbances Non measureable disturbances Controller Process Feedback Feed- forward Control signals Σ Measured outputs

Automatic Control 5 ●Modeling ●Physical models, grey-box, black-box, … ●Controller design ●Feedback, feedforward, stability, performance, robustness, adaptive, … ●Estimation ●States, model parameters, … ●Diagnostics ●Fault detection and isolation, … ●Optimization

Project examples 6

EM Stabilizer in Galvanizing Lines 7 Stabilization of strip gives reduced zinc over-coating

EM Stabilizer in Galvanizing Lines 8 Improved strip position damping with EM Stabilizer

EM Control 9 Simulation of the flow Validation of model with PIV measurements in water model Continuous casting process Water model Control of the steel flow in the mold gives higher steel quality

Paper Machine Steam Energy Fingerprint 10 By quantifying steam flows and identifying energy waste, suggestions on how to improve energy efficiency are given

Arc Furnace Control 11 By control, optimization and EMS, the yield, energy efficiency and productivity is increased

SVC Voltage Control with Feedforward Improved disturbance rejection after TSC switching 12

Wireless Control ●New possibilities with wireless control ●Increased flexibility to install sensors ●Cost for wiring disappears ●Large challenges ●Reliability ●Latency ●Safety ●Co-existence with other wireless systems ●90% of the communication could often be saved by smarter sampling ●Different sampling strategies have been developed ●Sample as seldom as possible without losing control performance ●Taking into account that information packages may be delayed or lost 13

Diagnostics Control loop diagnostics ●On-line methods which automatically alarms for poor control loop performance. ●Examples ●Detection of oscillations and changed signal variance. ●Control performance measurements, Harris index etc. ●Classification of some faults, e.g. valve stiction, external disturbances. 14 Process section diagnostics ●Faults are both detected and isolated ●Fault examples: ●Detection of bias in a sensor ●Detection of clogging of a valve ●Detection of erosion in a pump ●Track heat transfer rate in heat exchanger ●Benefits: ●Early detection gives higher availability ●Reduced maintenance costs. ●Avoids wrong dosing when sensor has drifted. Example of fault isolation. The red bar indicates the most probable faulty signal.

Waste Water Treatment Some examples from my Ph.D. 15 Control of dissolved oxygen concentration Estimation of dissolved oxygen dynamics Adaptive control of external carbon flow rate

Thank you! Questions? 16