• Adaptive Control of a Nanopositioning Device 

      Eielsen, Arnfinn Aas; Gravdahl, Jan Tommy (Journal article; Peer reviewed, 2012)
      High-bandwidth tracking control is desirable in many nanopositioning applications, including scanning probe microscopy. Typical nanopositioner designs have several sources of uncertainty which can degrade control performance, ...
    • Adaptive feed-forward hysteresis compensation for piezoelectric actuators 

      Eielsen, Arnfinn Aas; Gravdahl, Jan Tommy; Pettersen, Kristin Ytterstad (Journal article; Peer reviewed, 2012)
      Piezoelectric actuators are often employed for high-resolution positioning tasks. Hysteresis and creep nonlinearities inherent in such actuators deteriorate positioning accuracy. An online adaptive nonlinear hysteresis ...
    • Analog Robust Repetitive Control for Nanopositioning Using Bucket Brigade Devices 

      Eielsen, Arnfinn Aas; Gravdahl, Jan Tommy; Leang, Kam K. (Journal article; Peer reviewed, 2014)
      In many applications of nanopositioning, such as scanning probe microscopy, tracking fast periodic reference trajectories with high accuracy is highly desirable. Repetitive control is a simple and effective control scheme ...
    • Comparison of Adaptive Controllers for a Servomechanism 

      Eielsen, Arnfinn Aas (Master thesis, 2007)
      Electric motors with metal graphite brushes experience a change in contact resistance depending on current load. This varying resistance leads to varying gain in the motor, since the proportion of power dissipated due to ...
    • Damping and Tracking Control Schemes for Nanopositioning 

      Eielsen, Arnfinn Aas; Vagia, Marialena; Gravdahl, Jan Tommy; Pettersen, Kristin Ytterstad (Journal article; Peer reviewed, 2013)
      Fast and accurate tracking of reference trajectories is highly desirable in many nanopositioning applications, including scanning probe microscopy. Performance in common positioning stage designs is limited by the presence ...
    • Design of a nonlinear damping control scheme for nanopositioning 

      Vagia, Marialena; Eielsen, Arnfinn Aas; Gravdahl, Jan Tommy; Pettersen, Kristin Ytterstad (Journal article; Peer reviewed, 2013)
      The application of a nonlinear control law for vibration damping on a typical nanopositioning system is investigated. The nonlinear control law is an augmentation of the linear integral force feedback scheme, where the ...
    • Fixed-Structure, Low-Order Damping and Tracking Control Schemes for Nanopositioning 

      Eielsen, Arnfinn Aas; Vagia, Marialena; Gravdahl, Jan Tommy; Pettersen, Kristin Ytterstad (Journal article; Peer reviewed, 2013)
      Fast and accurate tracking of periodic reference trajectories is highly desirable in many nanopositioning applications, including scanning probe microscopy. Performance in common positioning stage designs is limited by the ...
    • H_inf Reduced Order Control for Nanopositioning: Numerical Implementability 

      Ragazzon, Michael Remo Palmén; Eielsen, Arnfinn Aas; Gravdahl, Jan Tommy (IFAC Proceedings series;, Journal article; Peer reviewed, 2014)
      In this paper we discuss how model reduction affects the stability and computational complexity of controllers for nanopositioning systems. A robust H∞ multiple-input multiple-output controller is designed and implemented ...
    • Low-order continuous-time robust repetitive control: Application in nanopositioning 

      Eielsen, Arnfinn Aas; Gravdahl, Jan Tommy; Leang, Kam K. (Journal article; Peer reviewed, 2015)
      A low-order repetitive control (RC) design in continuous-time for nanopositioning applications is presented. It focuses on achieving high performance and sufficient robustness to uncertainties. The design is mainly ...
    • Nanopositioning in Atomic Force Microscopes: Robust Control Design, Order Reduction and Numerical Implementability 

      Ragazzon, Michael Remo Palmén (Master thesis, 2013)
      This thesis can be divided into two overall topics. The first concerns control design for nanopositioning devices, and specifically an Atomic Force Microscope (AFM). The second topic concerns the implementability issues ...
    • On implementation of the Preisach model identification and inversion for hysteresis compensation 

      Stakvik, Jon Åge; Ragazzon, Michael Remo Palmén; Eielsen, Arnfinn Aas; Gravdahl, Jan Tommy (Peer reviewed; Journal article, 2015)
      A challenge for precise positioning in nanopositioning using smart materials is hysteresis, limiting posi-tioning accuracy. The Preisach model, based on the delayed relay operator for hysteresis modelling, isintroduced. ...
    • Topics in Control of Nanopositioning Devices 

      Eielsen, Arnfinn Aas (Doktoravhandlinger ved NTNU, 1503-8181; 2012:315, Doctoral thesis, 2012)
      Nanopositioning concerns motion control with resolution down to atomic scale. Positioning devices with such a capability have applications in numerous areas in industry and science. Examples include scanning probe microscopy, ...
    • Topography and force imaging in atomic force microscopy by state and parameter estimation 

      Ragazzon, Michael Remo Palmén; Gravdahl, Jan Tommy; Pettersen, Kristin Ytterstad; Eielsen, Arnfinn Aas (Journal article; Peer reviewed, 2015)
      A novel imaging method for atomic force microscopy based on estimation of state and parameters is presented. The cantilever dynamics is modeled as a linear system augmented by the tip-sample interaction force. The states ...