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A Nonlinear PID Autotuning Algorithm

Taylor, James H. and Åström, Karl Johan LU (1986) American Control Conference, 1986 p.2118-2123
Abstract
A nonlinear autotuning regulator algorithm is obtained via a direct combination of the Åström-Hägglund algorithm for the linear case [1] with the sinusoidal-input describing function (SIDEF) approach to nonlinear compensator synthesis of Taylor and Strobel [2]. The basic approach for linear autotuning proceeds as follows: a. install a relay with hysteresis in series with the unknown plant to be controlled; close a unitygain feedback loop around this combination; b. choose several values of hysteresis so that this system exhibits limit cycles; the frequencies and amplitudes of the oscillation at the output of the plant determine points on the plant Nyquist plot; and c. given points on the plant Nyquist plot, set the PID controller gains... (More)
A nonlinear autotuning regulator algorithm is obtained via a direct combination of the Åström-Hägglund algorithm for the linear case [1] with the sinusoidal-input describing function (SIDEF) approach to nonlinear compensator synthesis of Taylor and Strobel [2]. The basic approach for linear autotuning proceeds as follows: a. install a relay with hysteresis in series with the unknown plant to be controlled; close a unitygain feedback loop around this combination; b. choose several values of hysteresis so that this system exhibits limit cycles; the frequencies and amplitudes of the oscillation at the output of the plant determine points on the plant Nyquist plot; and c. given points on the plant Nyquist plot, set the PID controller gains using an appropriate tuning algorithm (e.g., Ziegler-Nichols). This approach produces good results if the plant is liner or nearly so; however, if the plant behavior is strongly amplitude-dependent, there are likely to be problems with implementing this algorithm. The nonlinear autotuning regulator algorithm which extends the above approach to handle situations where the plant behavior is strongly amplitude-dependent is based on the SIDF approach. In essence, SIDF input/output (I/O) models of the compensated nonlinear system are exploited to directly synthesize a compensator nonlinearity that eliminates or reduces the amplitude dependence of the open-loop I/O relation. The nonlinear synthesis portion of this algorithm is reasonably simple to implement, has been shown to be effective [2], and should be of practical utility. An example application to a precision position control system is provided as an illustration. (Less)
Please use this url to cite or link to this publication:
author
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organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
host publication
Proceedings of the 1986 American Control Conference : Seattle Sheraton Hotel and Towers, Seattle, WA, June 18-20, 1986 - Seattle Sheraton Hotel and Towers, Seattle, WA, June 18-20, 1986
pages
2118 - 2123
publisher
IEEE - Institute of Electrical and Electronics Engineers Inc.
conference name
American Control Conference, 1986
conference location
Seattle, Washington, United States
conference dates
1986-06-18 - 1986-06-20
external identifiers
  • scopus:0022593576
DOI
10.23919/ACC.1986.4789280
language
English
LU publication?
yes
id
5e43a5b3-8ea8-41f6-9111-cc8c9663bf18 (old id 8517851)
date added to LUP
2016-04-04 12:55:18
date last changed
2021-01-03 06:09:17
@inproceedings{5e43a5b3-8ea8-41f6-9111-cc8c9663bf18,
  abstract     = {{A nonlinear autotuning regulator algorithm is obtained via a direct combination of the Åström-Hägglund algorithm for the linear case [1] with the sinusoidal-input describing function (SIDEF) approach to nonlinear compensator synthesis of Taylor and Strobel [2]. The basic approach for linear autotuning proceeds as follows: a. install a relay with hysteresis in series with the unknown plant to be controlled; close a unitygain feedback loop around this combination; b. choose several values of hysteresis so that this system exhibits limit cycles; the frequencies and amplitudes of the oscillation at the output of the plant determine points on the plant Nyquist plot; and c. given points on the plant Nyquist plot, set the PID controller gains using an appropriate tuning algorithm (e.g., Ziegler-Nichols). This approach produces good results if the plant is liner or nearly so; however, if the plant behavior is strongly amplitude-dependent, there are likely to be problems with implementing this algorithm. The nonlinear autotuning regulator algorithm which extends the above approach to handle situations where the plant behavior is strongly amplitude-dependent is based on the SIDF approach. In essence, SIDF input/output (I/O) models of the compensated nonlinear system are exploited to directly synthesize a compensator nonlinearity that eliminates or reduces the amplitude dependence of the open-loop I/O relation. The nonlinear synthesis portion of this algorithm is reasonably simple to implement, has been shown to be effective [2], and should be of practical utility. An example application to a precision position control system is provided as an illustration.}},
  author       = {{Taylor, James H. and Åström, Karl Johan}},
  booktitle    = {{Proceedings of the 1986 American Control Conference : Seattle Sheraton Hotel and Towers, Seattle, WA, June 18-20, 1986}},
  language     = {{eng}},
  pages        = {{2118--2123}},
  publisher    = {{IEEE - Institute of Electrical and Electronics Engineers Inc.}},
  title        = {{A Nonlinear PID Autotuning Algorithm}},
  url          = {{http://dx.doi.org/10.23919/ACC.1986.4789280}},
  doi          = {{10.23919/ACC.1986.4789280}},
  year         = {{1986}},
}