Nested optimization of an elevator andits gain-scheduled LQG controller

Hosam K. Fathy, Scott A. Bortoff, G. Scott Copeland, Panos Y. Papalambros, A. Galip Ulsoy

Research output: Chapter in Book/Report/Conference proceedingConference contribution

12 Scopus citations


This paper studies the combined optimization of an elevator.s design (plant) and LQG controller for ride comfort. Elevator dynamics and primary vibration sources (drive motor torque ripple and guide rail irregularity) are modeled using an object-oriented language. The resulting model is nonlinear. Elevator vibrations are minimized with respect to both the design and the LQG controller. LQG gains are scheduled versus cab mass and height for robustness. Sequential plant/control optimization produces an optimal ride only when the torque ripple is the dominant disturbance. Otherwise, passive vibration reduction decreases the controller.s authority over the vibrations, hence coupling the plant and control optimization problems. Combined plant/controller optimization, using a nested strategy, mitigates this coupling and finds the correct optimal system design.

Original languageEnglish (US)
Title of host publicationDynamic Systems and Control
PublisherAmerican Society of Mechanical Engineers (ASME)
Number of pages8
ISBN (Print)0791836290, 9780791836293
StatePublished - 2002

Publication series

NameASME International Mechanical Engineering Congress and Exposition, Proceedings

All Science Journal Classification (ASJC) codes

  • Mechanical Engineering


Dive into the research topics of 'Nested optimization of an elevator andits gain-scheduled LQG controller'. Together they form a unique fingerprint.

Cite this