Design of Feedback Systems With Plant Input Rate Saturation via QFT Approach

[+] Author and Article Information
Wei Wu, Suhada Jayasuriya

Department of Mechanical Engineering, Texas A&M University, College Station, TX 77843-3123

J. Dyn. Sys., Meas., Control 128(3), 701-705 (Aug 17, 2005) (5 pages) doi:10.1115/1.2232693 History: Received November 05, 2004; Revised August 17, 2005

In this paper, a synthesis approach for input rate saturation compensation of feedback systems is presented. Uncertain, stable plants of type greater than or equal to 1 are considered. Based on Horowitz’s original design for input amplitude saturation (Horowitz, I., 1983) and extensions developed in (Wu, W., and Jayasuriya, S., 1999; Wu, W., and Jayasuriya, S., 2001; Wu, W., 2000) an independent loop around the rate saturating element is introduced for saturation compensation by means of the third DOF (degree of freedom) saturation compensator, H(s). First, the structure of the additional loop transmission is constructed to generate the desired response behavior on a systems recovery from saturation. Second, robust stability and robust performance under the addition of H(s) are investigated. The circle criterion, describing function, and nonovershooting conditions are utilized to generate design constraints. In the end, all design constraints involving saturation compensation are expressed as frequency domain bounds, and the synthesis of saturation compensator H(s) follows from loop shaping methods such as QFT. The proposed approach guarantees input/output stability under saturation for the plant class considered.

Copyright © 2006 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.



Grahic Jump Location
Figure 1

3DOF loop including rate saturation model

Grahic Jump Location
Figure 2

Step responses for example 1

Grahic Jump Location
Figure 3

Unstable step response for example 1

Grahic Jump Location
Figure 4

Nichols’ chart of Ln without H(s)

Grahic Jump Location
Figure 5

Nichols’ chart of Ln with H(s)

Grahic Jump Location
Figure 6

Frequency response of Ln(s)∕(1+Ln(s))

Grahic Jump Location
Figure 7

Frequency response of Tcy∕(1+Ln(s))

Grahic Jump Location
Figure 8

Step responses with H(s)

Grahic Jump Location
Figure 9

Step responses without H(s)



Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In