H∞ 2DOF control for the motion of a magnetic suspension positioning stage driven by inverter-fed linear motor

Kang, B.J.; Hung, Li-Han; Kuo, Shih-Kang; Lin, Shao Chieh; Liaw, C.M.

doi:10.1016/s0957-4158(02)00037-5

Cited by 18 publications

(5 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A precision stage is, for example, described in [3], and an overview of used stage technology over the years can be found in [4]. A wide range of stage control methods is described, for example using and design methods in [5] and [6]. In addition to a feedback controller, the stages use a feedforward controller that determines the required force to accelerate the stage according to its position setpoint profile, without having to create a controller error first.…”

Section: Wafer Stagementioning

confidence: 99%

Adaptive Feedforward for a Wafer Stage in a Lithographic Tool

Butler

2013

IEEE Trans. Contr. Syst. Technol.

View full text Add to dashboard Cite

The wafer stage and reticle stage in a lithographic tool, used to manufacture integrated circuits (ICs), operate at nanometer accuracy during a scanning motion. The position accuracy and settling time after accelerating to the scanning velocity are largely determined by the feedforward controller. The feedforward controller calculates the required force for the stage to move according to its position profile by multiplying the reference acceleration with the known stage mass. Two effects limit the accuracy directly after the acceleration phase. First, the actual stage acceleration in response to the controller-calculated force depends on the position of the stage in its working range. A variation of 0.1% is observed. Second, dynamic resonances in the stage response require a higher-order feedforward model. Combined, these effects result in a 20-30 nm peak position error. This brief investigates online adaptation of the feedforward mass parameter, with the aim of reducing the position-dependent stage behavior. Adaptation of only the feedforward mass is shown not to be able to compensate for stage dynamics, additionally requiring a higher-order feedforward element. From the control force and the measured motion response, the feedforward mass parameter is estimated on line. Least-squares estimation is fast enough to update the mass parameter during the acceleration phase, which takes less than 100 ms. This brief addresses a number of practical aspects and shows that adaptive feedforward estimation in combination with higher-order feedforward reduces the peak position error consistently by creating position-independent behavior.

show abstract

Section: Wafer Stagementioning

confidence: 99%

Adaptive Feedforward for a Wafer Stage in a Lithographic Tool

Butler

2013

IEEE Trans. Contr. Syst. Technol.

View full text Add to dashboard Cite

show abstract

“…• The system dynamics can be clearly separated into an unstable rigid body part dominant in the low frequency band (below 1) and a x 1 -position dependent stable flexible part dominant in the frequency band [1,3] which is symmetric in magnitude to the x 1 = 0 position (phase has a 180 • drop at x 1 = 0 due to sign change). • In the diagonal channels, rigid body dynamics correspond to a second order integrator, while in the offdiagonal channels, due to the decoupling, only a small proportional term can be observed.…”

Section: A First-principle Modelingmentioning

confidence: 99%

LPV identification of high performance positioning devices

Tóth

Wal

Heuberger

et al. 2011

Proceedings of the 2011 American Control Conference

View full text Add to dashboard Cite

High performance positioning devices exhibit position dependent dynamics in the form of varying flexible modes, which are expected to dominate the dynamic behavior in the new generation of lightweight positioning structures.To handle such position-dependent behavior, the framework of Linear Parameter-Varying (LPV) systems offers powerful tools in terms of control synthesis with many successful practical applications. However, to achieve the desired performance, a low complexity but accurate LPV model of the underlying plant is of crucial importance. Obtaining LPV models for positioning devices based on first principle laws is a rigorous and costly process often resulting in models with inadequate accuracy. Therefore a data driven-modeling approach using Orthonormal Basis Functions (OBF's) is studied for the controloriented modeling of xy-positioning table dynamics. Through a simulation study it is demonstrated that the proposed modeling procedure, using only measurement data, can provide models whose accuracy is very close to the analytic models derived with the full knowledge of the system.

show abstract

“…Yang D designed an adaptive backstepping controller for the active magnetic bearing to reduce the uncertainties of system parameters. 10 Also, modern control methods are applied to maglev systems, such as the H-infinity control method, 11,12 the fuzzy control method, 13 and the sliding model control method. 14,15 Sun proposed a permanent magnetic levitation (PML) system with the variable magnetic flux, which could avoid adhering by adjusting to zero levitation force.…”

Section: Introductionmentioning

confidence: 99%

Research of permanent magnetic levitation system: Analysis, control strategy design, and experiment

Zhao

Sun

Jin

et al. 2022

Proceedings of the Institution of Mechanical Engineers, Part C:

View full text Add to dashboard Cite

Aiming to realize levitation for a novel permanent magnetic levitation system, this paper proposes a double control strategy. The coupled dynamic model with two subsystems was established at first. According to the analysis of stable levitation, four joint control strategies of air gap length and rotation angle were designed. Then, the controller parameters tuning was implemented utilizing the improved PSO (particle swarm optimization) algorithm with non-linear inertia weight. At last, step response simulations and experiments were carried out to compare the performance of the proposed four control strategies. Results demonstrate the validity of PSO using for tuning proportional-integral-derivative (PID) parameters. In addition, the parallel double PD controller and cascade double PD controller both have better dynamic performance but more significant steady-state error. When using PID control for the air gap, the error could be eliminated. Compared with the parallel PID-PD control strategy, the cascade control is competitive in terms of 0.03 s rising time, 4.3 s settling time, and 24% peak overshoot.

show abstract

H∞ 2DOF control for the motion of a magnetic suspension positioning stage driven by inverter-fed linear motor

Cited by 18 publications

References 14 publications

Adaptive Feedforward for a Wafer Stage in a Lithographic Tool

Adaptive Feedforward for a Wafer Stage in a Lithographic Tool

LPV identification of high performance positioning devices

Research of permanent magnetic levitation system: Analysis, control strategy design, and experiment

Contact Info

Product

Resources

About