Wisconsin Alumni Research Foundation

Information Technology
Information Technology
SISO Model Predictive Controller
WARF: P04113US

Inventors: James Rawlings, Gabriele Pannocchia, Nabil Laachi

The Wisconsin Alumni Research Foundation (WARF) is seeking commercial partners interested in developing a fast, easily tuned controller specifically tailored to SISO processes.
Overview
Currently, most single-input, single-output (SISO) systems use a proportional, integral, derivative (PID) controller. The PID controller is simple, fast, and easily implemented on simple computing hardware; however, it is also difficult to tune; falls short in setpoint tracking accuracy and disturbance rejection; lacks robustness when the system and system model are mismatched; and has difficulty handling system constraints.

Most large-scale processes with multiple-inputs, multiple-outputs (MIMO) systems use model-based control methods such as linear quadratic (LQ) control or model predictive control (MPC). Model-based control methods explicitly optimize the process, can handle complex multivariable processes and account for constraints; however, they are slow, difficult to implement on simple computing hardware and hard to tune.
The Invention
UW-Madison researchers have developed a fast, easily tuned controller specifically tailored to SISO processes. The controller combines the best features of model-based control methods and PID controllers and performs better than PID controllers on all SISO processes.

This offset-free, constrained, linear quadratic (CLQ) controller has three modules: a state and disturbance estimator, a target calculation and a constrained dynamic optimization. Each of the modules is implemented efficiently so that the overall CLQ algorithm has little computational cost and can be applied using simple hardware and software.
Applications
  • Controling SISO processes
Key Benefits
  • Fast execution – makes control decisions quickly
  • Easily tuned
  • Can be implemented on simple computing hardware
  • Optimizes control behavior
  • Superior to PID controllers on all SISO processes
  • Especially exceeds performance of PID controllers for systems with large time delays; setpoints that are or become unreachable due to constraints on the manipulated variable; complex, high-order dynamics; or significant measurement and process noise
Additional Information
For More Information About the Inventors
For current licensing status, please contact Emily Bauer at [javascript protected email address] or 608-960-9842

WARF