This post is an excerpt from the journal ISA Transactions. All ISA Transactions articles are free to ISA members, or can be purchased from Elsevier Press.

Abstract: The four-way proportional directional control valve has been widely used as the main stage spring constant for the two-stage proportional control valve (PDV). Since a tradeoff should be made between manufacturing costs and static performance, two symmetry dead zones are introduced in the main stage spring constant: the center dead zone caused by the center floating position and the intermediate dead zone caused by the intermediate position. Though the intermediate dead-zone is much smaller than the center dead zone, it has significant effect on the dynamic position tracking performance. In this paper, the cascade dead zones problem in a typical two-stage PDV is analyzed and a cascade dead zones model is proposed for the main stage spring constant. Then, a cascade dead zones inverse method is improved with gain estimation and dead zone detection to compensate the dead zone non-linearity. Finally, a digital controller is designed for verification. The comparative experimental results indicate that it is effective to reduce the large position tracking error when the proposed method is applied.

 Free Bonus! To read the full version of this ISA Transactions article, click here.

Enjoy this technical resource article? Join ISA and get free access to all ISA Transactions articles as well as a wealth of other technical content, plus professional networking and discounts on technical training, books, conferences, and professional certification.

Click here to join ISA ... learn, advance, succeed!

2006-2018 Elsevier Science Ltd. All rights reserved.