An Analytic Approach to Cascade Control Design for Hydraulic Valve-Cylinder Drives

Research output: Contribution to book/anthology/report/conference proceedingArticle in proceedingResearchpeer-review

1 Citation (Scopus)

Abstract

Motion control design for hydraulic drives remains to be a complicated task, and has not evolved on a level with electrical drives. When considering specifically motion control of hydraulic drives, the industry still prefers conventional linear control structures, often combined with feed forward control and possibly linear active damping functionalities. However difficulties often arise due to the inherent and strong nonlinear nature of hydraulic drives, with the more dominant being nonlinear valve flow- and oil stiffness characteristics, and furthermore the volume expansion/retraction when considering cylinder drives. A widely used approach with electrical drives is state controller cascade control, that may by successfully applied to manipulate the drive dynamics in order to achieve high bandwidths etc., due to the nearly constant parameter-nature of such drives. Such properties are however, unfortunately not present in valve-operated hydraulic drives.
This paper considers a cascade control approach for hydraulic valve-cylinder drives motivated by the fact that this may be applied to successfully suppress nonlinearities. The drive is pre-compensated utilizing a pressure updated inverse valve flow relation, ideally eliminating the system gain variation, and the linear model equations for the pre-compensated system is used for the cascade control design. The cascade design does not utilize e.g. bode plots, root loci etc., and is based on an analytic approach, emphasizing the exact influence of each control parameter, resulting in an easily comprehensible control structure. Two versions of this cascade control approach is presented, with the first utilizing pressure-, piston velocity- and piston position feedback, and the second utilizing only pressure- and piston position feedback. The latter may be especially interesting in an industrial context, as this does not use the velocity feedback, which is rarely available here. Furthermore, the position control loop is designed analytically to guarantee a user defined gain margin. The proposed control design approach is verified through simulations, and results demonstrate the announced properties.
Original languageEnglish
Title of host publicationProceedings of 2016 9th FPNI Ph.D Symposium on Fluid Power
Number of pages9
PublisherAmerican Society of Mechanical Engineers
Publication dateOct 2016
Article numberFPNI2016-1521
ISBN (Print)978-0-7918-5047-3
DOIs
Publication statusPublished - Oct 2016
Event9th FPNI Ph.D. Symposium on Fluid Power - Florianópolis, Brazil
Duration: 26 Oct 201628 Oct 2016

Conference

Conference9th FPNI Ph.D. Symposium on Fluid Power
CountryBrazil
CityFlorianópolis
Period26/10/201628/10/2016
SponsorFederal University of Santa Catarina (UFSC), Fluid Power Net International (FPNI)

Fingerprint

Cascades (fluid mechanics)
Hydraulics
Hydraulic drives
Pistons
Motion control
Feedback
Root loci
Feedforward control
Position control
Damping
Stiffness
Bandwidth
Controllers

Keywords

  • Cascades (Fluid dynamics)
  • Design
  • Valves
  • Cylinders

Cite this

Schmidt, L., Hansen, A. H., Andersen, T. O., & Pedersen, H. C. (2016). An Analytic Approach to Cascade Control Design for Hydraulic Valve-Cylinder Drives. In Proceedings of 2016 9th FPNI Ph.D Symposium on Fluid Power [FPNI2016-1521] American Society of Mechanical Engineers. https://doi.org/10.1115/FPNI2016-1521
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title = "An Analytic Approach to Cascade Control Design for Hydraulic Valve-Cylinder Drives",
abstract = "Motion control design for hydraulic drives remains to be a complicated task, and has not evolved on a level with electrical drives. When considering specifically motion control of hydraulic drives, the industry still prefers conventional linear control structures, often combined with feed forward control and possibly linear active damping functionalities. However difficulties often arise due to the inherent and strong nonlinear nature of hydraulic drives, with the more dominant being nonlinear valve flow- and oil stiffness characteristics, and furthermore the volume expansion/retraction when considering cylinder drives. A widely used approach with electrical drives is state controller cascade control, that may by successfully applied to manipulate the drive dynamics in order to achieve high bandwidths etc., due to the nearly constant parameter-nature of such drives. Such properties are however, unfortunately not present in valve-operated hydraulic drives.This paper considers a cascade control approach for hydraulic valve-cylinder drives motivated by the fact that this may be applied to successfully suppress nonlinearities. The drive is pre-compensated utilizing a pressure updated inverse valve flow relation, ideally eliminating the system gain variation, and the linear model equations for the pre-compensated system is used for the cascade control design. The cascade design does not utilize e.g. bode plots, root loci etc., and is based on an analytic approach, emphasizing the exact influence of each control parameter, resulting in an easily comprehensible control structure. Two versions of this cascade control approach is presented, with the first utilizing pressure-, piston velocity- and piston position feedback, and the second utilizing only pressure- and piston position feedback. The latter may be especially interesting in an industrial context, as this does not use the velocity feedback, which is rarely available here. Furthermore, the position control loop is designed analytically to guarantee a user defined gain margin. The proposed control design approach is verified through simulations, and results demonstrate the announced properties.",
keywords = "Cascades (Fluid dynamics), Design, Valves, Cylinders",
author = "Lasse Schmidt and Hansen, {Anders Hedegaard} and Andersen, {Torben O.} and Pedersen, {Henrik Clemmensen}",
year = "2016",
month = "10",
doi = "10.1115/FPNI2016-1521",
language = "English",
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Schmidt, L, Hansen, AH, Andersen, TO & Pedersen, HC 2016, An Analytic Approach to Cascade Control Design for Hydraulic Valve-Cylinder Drives. in Proceedings of 2016 9th FPNI Ph.D Symposium on Fluid Power., FPNI2016-1521, American Society of Mechanical Engineers, 9th FPNI Ph.D. Symposium on Fluid Power, Florianópolis, Brazil, 26/10/2016. https://doi.org/10.1115/FPNI2016-1521

An Analytic Approach to Cascade Control Design for Hydraulic Valve-Cylinder Drives. / Schmidt, Lasse; Hansen, Anders Hedegaard; Andersen, Torben O.; Pedersen, Henrik Clemmensen.

Proceedings of 2016 9th FPNI Ph.D Symposium on Fluid Power. American Society of Mechanical Engineers, 2016. FPNI2016-1521.

Research output: Contribution to book/anthology/report/conference proceedingArticle in proceedingResearchpeer-review

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AU - Schmidt, Lasse

AU - Hansen, Anders Hedegaard

AU - Andersen, Torben O.

AU - Pedersen, Henrik Clemmensen

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N2 - Motion control design for hydraulic drives remains to be a complicated task, and has not evolved on a level with electrical drives. When considering specifically motion control of hydraulic drives, the industry still prefers conventional linear control structures, often combined with feed forward control and possibly linear active damping functionalities. However difficulties often arise due to the inherent and strong nonlinear nature of hydraulic drives, with the more dominant being nonlinear valve flow- and oil stiffness characteristics, and furthermore the volume expansion/retraction when considering cylinder drives. A widely used approach with electrical drives is state controller cascade control, that may by successfully applied to manipulate the drive dynamics in order to achieve high bandwidths etc., due to the nearly constant parameter-nature of such drives. Such properties are however, unfortunately not present in valve-operated hydraulic drives.This paper considers a cascade control approach for hydraulic valve-cylinder drives motivated by the fact that this may be applied to successfully suppress nonlinearities. The drive is pre-compensated utilizing a pressure updated inverse valve flow relation, ideally eliminating the system gain variation, and the linear model equations for the pre-compensated system is used for the cascade control design. The cascade design does not utilize e.g. bode plots, root loci etc., and is based on an analytic approach, emphasizing the exact influence of each control parameter, resulting in an easily comprehensible control structure. Two versions of this cascade control approach is presented, with the first utilizing pressure-, piston velocity- and piston position feedback, and the second utilizing only pressure- and piston position feedback. The latter may be especially interesting in an industrial context, as this does not use the velocity feedback, which is rarely available here. Furthermore, the position control loop is designed analytically to guarantee a user defined gain margin. The proposed control design approach is verified through simulations, and results demonstrate the announced properties.

AB - Motion control design for hydraulic drives remains to be a complicated task, and has not evolved on a level with electrical drives. When considering specifically motion control of hydraulic drives, the industry still prefers conventional linear control structures, often combined with feed forward control and possibly linear active damping functionalities. However difficulties often arise due to the inherent and strong nonlinear nature of hydraulic drives, with the more dominant being nonlinear valve flow- and oil stiffness characteristics, and furthermore the volume expansion/retraction when considering cylinder drives. A widely used approach with electrical drives is state controller cascade control, that may by successfully applied to manipulate the drive dynamics in order to achieve high bandwidths etc., due to the nearly constant parameter-nature of such drives. Such properties are however, unfortunately not present in valve-operated hydraulic drives.This paper considers a cascade control approach for hydraulic valve-cylinder drives motivated by the fact that this may be applied to successfully suppress nonlinearities. The drive is pre-compensated utilizing a pressure updated inverse valve flow relation, ideally eliminating the system gain variation, and the linear model equations for the pre-compensated system is used for the cascade control design. The cascade design does not utilize e.g. bode plots, root loci etc., and is based on an analytic approach, emphasizing the exact influence of each control parameter, resulting in an easily comprehensible control structure. Two versions of this cascade control approach is presented, with the first utilizing pressure-, piston velocity- and piston position feedback, and the second utilizing only pressure- and piston position feedback. The latter may be especially interesting in an industrial context, as this does not use the velocity feedback, which is rarely available here. Furthermore, the position control loop is designed analytically to guarantee a user defined gain margin. The proposed control design approach is verified through simulations, and results demonstrate the announced properties.

KW - Cascades (Fluid dynamics)

KW - Design

KW - Valves

KW - Cylinders

U2 - 10.1115/FPNI2016-1521

DO - 10.1115/FPNI2016-1521

M3 - Article in proceeding

SN - 978-0-7918-5047-3

BT - Proceedings of 2016 9th FPNI Ph.D Symposium on Fluid Power

PB - American Society of Mechanical Engineers

ER -

Schmidt L, Hansen AH, Andersen TO, Pedersen HC. An Analytic Approach to Cascade Control Design for Hydraulic Valve-Cylinder Drives. In Proceedings of 2016 9th FPNI Ph.D Symposium on Fluid Power. American Society of Mechanical Engineers. 2016. FPNI2016-1521 https://doi.org/10.1115/FPNI2016-1521