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Model Predictive Control Implementation with LabVIEW

Yurong Kimberly Wang, Ph.D.Principal Control Systems Engineer

Tyco Electronics

Wilsonville, Oregon

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Tyco Electronics / Precision Interconnect

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Precision Interconnects

• COMFORT, MODULUS3, BLUE RIBBON, BASIS, ERGOLINE, LIFELIC, AND SLIMLINE ARE TRADE MARKS

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Coax Manufacturing Processes

• Dielectric layer • Taping or Extrusion

• Shield layer• Braiding or Serving

• Jacket layer• Taping or Extrusion

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Taped or Extruded Coax

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Coax Property

)ln(96.59

d

D

kZo

• C: capacitance (pF/Foot)

• Td: time delay (ns/Foot)

• Z0: impedance (Ohm)

• k: dielectric constant

• D: outer diameter (Mil)

• d: center conductor diameter (Mil)

• Formulae

)ln(

95.16

dDk

C

kTd 016.1

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Process Control Challenge• Multiple Outputs

• Capacitance, Diameter, Time delay, Impedance, …

• Multiple Inputs• Screw speed, line speed, barrel temperatures, tape tensions, …

• Long and Variable Time Delays• Variable line speeds and sensor to actuator distances

• Input and Output Constraints• Input and output upper and lower spec limits

• Nonlinearity• Variety of operating conditions

• Disturbances• Center conductor variation, tape thickness variation, …

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Model Predictive Control (MPC) Law

• Model-based multi-variable control

• Optimal control law with I/O constraints

• Nonlinear control with model mismatch

• Long and variable time delay process

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MPC System and Optimization

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MPC Sampling Instants

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System ArchitectureProduction

QualityEngineers

Production

Plant Managers

Production

ProcessEngineers

Production

Manufacturing Engineers

Manufacturing Information Server

Business NetworkReport Program for Data Analysis

Production

RemoteUsersInternet

Control Network

Local Control Module

Local Control Module

Local Control Module

Business Network

OPC Client & Server for Data Logging

OPC Client & Server for Data Sharing

Production

LabVIEWHMI & MPC Control

Figure 1. System Architecture

Local Control Module

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LabVIEW Project Explorer

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LabVIEW – Based Application• LabVIEW Professional Development• LabVIEW Real-Time Module• Data Logging and Supervisory Control Module• Simulation Module• Control Design Toolkit• Advanced Signal Processing Toolkit• Database Connectivity Toolkit• Internet Connectivity Toolkit• Report Generation Toolkit• Compact FieldPoint Hardware and Device Drivers

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LabVIEW MPC Implementation

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LabVIEW MPC Code

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LabVIEW MPC ApplicationManual to auto control with disturbance rejection

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MatLABTM MPC – Initial Approach

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MatLAB MPC Script Node

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MatLAB MPC ApplicationManual to auto control with disturbance rejection

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Polymer Extrusion MPC HMI

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MPC Output Weighting Effect

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Manufacturing Benefit• Consistent product quality

Multi-variable auto-controlled product quality

• Productivity improvement Unmanned overnight MPC control with alarm monitoring Production speed auto ramp with feedforward compensation

• Equipment cost reduction Inner tape layer diameter gauge elimination

• Sensor fault detection Controller acting up with sensor fault readings

• Labor cost reduction Coax quality on-line prediction and off-line test reduction

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Reference Material

• LabVIEW Model Predictive Control Module User Manual by National Instruments

• MatLAB Model Predictive Control Toolbox User Manual by MathWorks

• Advanced Control Unleashed by Terrence L. Blevins, Gregory K. McMillan, Willy K. Wojsznis,

and Michael W. Brown, ISA• Models Unleashed – Virtual Plant and Model Predictive Control

Applications, A Pocket Guide by Gregory K. McMillan, Robert A. Cameron, ISA

• Dual-Target Predictive Control for Food Extrusion by Y. Wang and J. Tan, Control Engineering Practice 8 (2000)