Variable Cut-Off Frequency Observer-Based Positioning for Ball-Beam Systems without Velocity and Current Feedback Considering Actuator Dynamics

Yonghun Kim, Seok Kyoon Kim, Choon Ki Ahn

Research output: Contribution to journalArticlepeer-review

10 Citations (Scopus)


This paper develops an observer-based positioning scheme for ball-beam systems considering actuator dynamics. The practical constraints are handled systematically, including the mechanical dynamical nonlinearities, mismatched load disturbances, and parameter uncertainties. This result provides contributions as follows. First, parameter-independent observers exponentially estimate the ball velocity, motor speed, and its acceleration to remove the velocity, motor speed, and current feedback. Second, the auto-tuner automatically adjusts the desired closed-loop input-output behaviors to update its cut-off frequency in the transient operations. Third, observer-based active damping injection reduces the closed-loop ball position and actuator speed dynamics to 1 by pole-zero cancellation. Finally, disturbance observers act as a dynamic compensator by estimating the disturbances from model-plant mismatches such as dynamic nonlinearities, mismatched load disturbances, and parameter variations. The experimental study verifies the applicability of the proposed technique using the Quanser Ball-Beam hardware driven by an SRV02 servomotor.

Original languageEnglish
Article number9245593
Pages (from-to)396-405
Number of pages10
JournalIEEE Transactions on Circuits and Systems I: Regular Papers
Issue number1
Publication statusPublished - 2021 Jan

Bibliographical note

Funding Information:
Manuscript received July 28, 2020; revised September 21, 2020; accepted October 12, 2020. Date of publication October 30, 2020; date of current version December 21, 2020. This work was supported in part by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education under Grant 2018R1A6A1A03026005, in part by the Korea Agency for Infrastructure Technology Advancement (KAIA) funded by the Ministry of Land, Infrastructure and Transport under Grant TL20HBST-B158067-01, and in part by the NRF funded by the Korea Government (Ministry of Science and ICT) under Grant NRF-2020R1A2C1005449. This article was recommended by Associate Editor A. Oliveri. (Corresponding authors: Seok-Kyoon Kim; Choon Ki Ahn.) Yonghun Kim is with the Center of Echo-Friendly and Smart Vehicles, Korea Advanced Institute of Science and Technology, Daejeon 34051, South Korea (e-mail:

Publisher Copyright:
© 2004-2012 IEEE.


  • Ball balancing
  • auto-tuner
  • disturbance observer
  • positioning
  • state estimation

ASJC Scopus subject areas

  • Electrical and Electronic Engineering


Dive into the research topics of 'Variable Cut-Off Frequency Observer-Based Positioning for Ball-Beam Systems without Velocity and Current Feedback Considering Actuator Dynamics'. Together they form a unique fingerprint.

Cite this