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Andrew J Fleming - One of the best experts on this subject based on the ideXlab platform.
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five axis bimorph monolithic Nanopositioning Stage design modeling and characterization
Sensors and Actuators A-physical, 2021Co-Authors: Meysam Omidbeike, Yuen Kuan Yong, Steven Ian Moore, Andrew J FlemingAbstract:Abstract The article describes the design and modeling of a five-axis monolithic Nanopositioning Stage constructed from a bimorph piezoelectric sheet. Six-axis motion is also possible but requires 16 amplifier channels rather than 8. The nanopositioner is ultra low profile with a thickness of 1 mm. Analytical modeling and finite-element-analysis accurately predict the experimental performance. The Stage was conservatively driven with 33% of the maximum voltage, which resulted in an X and Y travel range of 6.22 μm and 5.27 μm respectively; a Z travel range of 26.5 μm; and a rotational motion of 600 μrad and 884 μrad about the X and Y axis respectively. The first resonance frequency occurs at 883 Hz in the Z axis. Experimental atomic force microscopy is performed using the proposed device as a sample scanner.
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model free multi variable learning control of a five axis Nanopositioning Stage
International Conference on Advanced Intelligent Mechatronics, 2021Co-Authors: Thijs Sieswerda, Andrew J Fleming, Tom OomenAbstract:This article compares the performance of recently introduced learning control methods on a 5-axis Nanopositioning Stage. Of these methods, the Smoothed Model-Free Inversion-based Iterative Control (SMF-IIC) method requires no modeling effort for effective tracking of repetitive trajectories and is readily applicable to multi-variable systems. Experimental results show that the tracking performance of the SMF-IIC method is similar to traditional learning control methods when applied to a single axis of the Nanopositioning Stage. The SMF-IIC method is also found to be effective for reference tracking of two axes simultaneously.
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sensing and decentralized control of a five axis monolithic Nanopositioning Stage
IFAC-PapersOnLine, 2020Co-Authors: Meysam Omidbeike, Yuen Kuan Yong, Andrew J FlemingAbstract:Abstract This article describes the design and calibration of a five degree-of-freedom linear and angular displacement sensor utilizing piezoresistive strain gages. A simple decentralized controller is then implemented to follow linear and angular reference signals. The foremost difficulty with piezoresistive sensors is their high-temperature sensitivity. In addition, they are sensitive to motion in multiple degrees of freedom, which must be decoupled before use as a displacement sensor. A new sensing design is proposed which provides decoupled measurements of linear and angular displacements in multi-axis monolithic Nanopositioning Stages. The proposed method employs system identification and feedforward techniques to calibrate each axis and minimize cross-coupling.
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finite time learning control using frequency response data with application to a Nanopositioning Stage
IEEE-ASME Transactions on Mechatronics, 2019Co-Authors: Robin De Rozario, Andrew J Fleming, Tom OomenAbstract:Learning control enables significant performance improvement for systems that perform repeating tasks. Achieving high tracking performance by utilizing past error data typically requires noncausal learning that is based on a parametric model of the process. Such model-based approaches impose significant requirements on modeling and filter design. The aim of this paper is to reduce these requirements by developing a learning control framework that enables performance improvement through noncausal learning without relying on a parametric model. This is achieved by explicitly using the discrete Fourier transform to enable learning by using a nonparametric frequency response function model of the process. The effectiveness of the developed method is illustrated by application to a Nanopositioning Stage.
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a five axis monolithic Nanopositioning Stage constructed from a bimorph piezoelectric sheet
2019 International Conference on Manipulation Automation and Robotics at Small Scales (MARSS), 2019Co-Authors: Meysam Omidbeike, Yuen Kuan Yong, Steven Ian Moore, Andrew J FlemingAbstract:The paper describes design, modeling and control of a five-axis monolithic Nanopositioning Stage constructed from a bimorph piezoelectric sheet. In this design, actuators are created by removing parts of the sheet using ultrasonic machining. The constructed nanopositioner is ultra-compact with a thickness of 1 mm. It has a X and Y travel range of 15.5 µm and 13.2 µm respectively; a Z travel range of 26 µm; and a rotational motion about the X- and Y-axis of 600 µrad and 884 µrad respectively. The first resonance frequency occurs at 883 Hz in the Z-axis, and the second and third resonance frequency appears at 1850 Hz, rotating about the X- and Y-axis. A decentralized control strategy is implemented to track Z, θx and θ y motions. The controller provides good tracking and significantly reduces cross-coupling motions among the three degrees-of-freedom.
Limin Zhu - One of the best experts on this subject based on the ideXlab platform.
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a novel compliant Nanopositioning Stage driven by a normal stressed electromagnetic actuator
IEEE Transactions on Automation Science and Engineering, 2021Co-Authors: Li Chen, Limin Zhu, Yuhan Niu, Xu Yang, Wule Zhu, Zhiwei ZhuAbstract:This article reports on the design, modeling, control, and testing of a novel compliant Nanopositioning Stage driven by a self-developed normal-stressed electromagnetic actuator. To facilitate the parameter selection for the Stage to achieve the desired stroke and natural frequency, an analytical model of both the electromagnetic circuit and flexure mechanism is established, which is then systematically verified through finite element analysis. By combining a proportional--integral--differential (PID)-based main controller with a system dynamics inversion-based feedforward compensator, a closed-loop control system for the Stage is constructed with the main controller being tuned through Bode's ideal transfer function-based loop-shaping method. The experimental result shows that a stroke of ± 95 μ m and a first natural frequency of 743 Hz are achieved for the designed Stage. Finally, taking advantage of the constructed control system, the Nanopositioning capability is demonstrated by finely tracking the harmonic and nanostair commands.
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fractional repetitive control of Nanopositioning Stages for tracking high frequency periodic inputs with nonsynchronized sampling
Review of Scientific Instruments, 2019Co-Authors: Limin ZhuAbstract:The repetitive control (RC) has been employed for high-speed tracking control of Nanopositioning Stages due to its abilities of precisely tracking periodic trajectories and rejecting periodic disturbances. However, in digital implementation, the sampling frequency should be integer multiple of the tracking frequency of the desired periodic trajectory. Otherwise, the rounding error would result in a significant degradation of the tracking performance, especially for the case of high input frequencies. To mitigate this rounding effect, the fractional repetitive control (FRC) technique is introduced to control the Nanopositioning Stage so as to precisely track high-frequency periodic inputs without imposing constraints on the sampling frequency of the digital control system. The complete procedure of controller design and implementation is presented. The techniques to deal with the problems of non-minimum phase system and fractional delay points number are described in detail. The proposed FRC is plugged into the proportional-integral control, and implemented on a custom-built piezo-actuated Nanopositioning Stage. Validation experiments are conducted, and the results show that the tracking errors caused by the rounding effect in the traditional RC approach are almost completely eliminated, when tracking sinusoidal waveforms with frequencies from 1000 Hz to 1587.3 Hz under the sampling frequency of 50 kHz, where the fractional parts being rounded vary from 0 to 0.5.
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high speed tracking of a Nanopositioning Stage using modified repetitive control
IEEE Transactions on Automation Science and Engineering, 2017Co-Authors: Meiju Yang, Limin ZhuAbstract:In this paper, a modified repetitive control (MRC) based approach is developed for high-speed tracking of Nanopositioning Stages. First, the hysteresis nonlinearity is decomposed as a periodic disturbance over a linear system. Then, the MRC technique is utilized to account for the periodic disturbances/errors caused by the hysteresis and dynamics behaviors. The developed approach provides a simple and effective hysteresis compensation strategy, avoiding the constructions of hysteresis model and its inversion. Besides, with improved loop-shaping properties, the MRC can alleviate the nonperiodic disturbance amplification problem of the conventional repetitive control. Finally, the effectiveness and performance of the developed MRC-based approach are verified by the experimental results on a custom-built piezo-actuated Stage in terms of hysteresis compensation, disturbance rejection and tracking accuracy.
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design and analysis of a high speed xyz Nanopositioning Stage
International Conference on Manipulation Manufacturing and Measurement on Nanoscale, 2015Co-Authors: Meiju Yang, Limin ZhuAbstract:This paper presents the design and analysis of a high-speed XYZ Nanopositioning Stage. The developed Stage is composed of a parallel-kinematic XY Stage and a Z Stage which is nested within the end-effector of the XY Stage. To achieve high resonance frequencies, four special flexure modules with large stiffness are employed for the XY Stage. These modules are arranged symmetrically to reduce cross-coupling between X- and Y-axis. For the Z Stage, a symmetrical leaf flexure parallelogram mechanism is adopted, which has high resonance frequencies and no cross-coupling. Static and dynamic analysis are performed respectively to establish analytical models for the developed XYZ Stage. Based on these models, the dimensions of the Stage are optimized to maximize the first resonance frequency of the X-and Y-axis. Then, finite-element analysis (FEA) is conducted to validate the performance of the developed XYZ Nanopositioning Stage. The FEA results reveal that the workspace of the Stage is 9.2 µm × 9.2 µm × 3.1 pm and the first resonance frequencies of the Stage in three axes are 7.3 kHz, 7.3 kHz and 46.2 kHz, respectively, which agrees with the analytical results.
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a rate dependent prandtl ishlinskii model for piezoelectric actuators using the dynamic envelope function based play operator
Frontiers in Mechanical Engineering, 2015Co-Authors: Meiju Yang, Limin ZhuAbstract:In this paper, a novel rate-dependent Prandtl-Ishlinskii (P-I) model is proposed to characterize the rate-dependent hysteresis nonlinearity of piezoelectric actuators. The new model is based on a modified rate-dependent play operator, in which a dynamic envelope function is introduced to replace the input function of the classical play operator. Moreover, a dynamic density function is utilized in the proposed P-I model. The parameters of the proposed model are identified by a modified particle swarm optimization algorithm. Finally, experiments are conducted on a piezo-actuated Nanopositioning Stage to validate the proposed P-I model under the sinusoidal inputs. The experimental results show that the developed rate-dependent P-I model precisely characterize the rate-dependent hysteresis loops up to 1000 Hz.
Yuen Kuan Yong - One of the best experts on this subject based on the ideXlab platform.
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five axis bimorph monolithic Nanopositioning Stage design modeling and characterization
Sensors and Actuators A-physical, 2021Co-Authors: Meysam Omidbeike, Yuen Kuan Yong, Steven Ian Moore, Andrew J FlemingAbstract:Abstract The article describes the design and modeling of a five-axis monolithic Nanopositioning Stage constructed from a bimorph piezoelectric sheet. Six-axis motion is also possible but requires 16 amplifier channels rather than 8. The nanopositioner is ultra low profile with a thickness of 1 mm. Analytical modeling and finite-element-analysis accurately predict the experimental performance. The Stage was conservatively driven with 33% of the maximum voltage, which resulted in an X and Y travel range of 6.22 μm and 5.27 μm respectively; a Z travel range of 26.5 μm; and a rotational motion of 600 μrad and 884 μrad about the X and Y axis respectively. The first resonance frequency occurs at 883 Hz in the Z axis. Experimental atomic force microscopy is performed using the proposed device as a sample scanner.
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sensing and decentralized control of a five axis monolithic Nanopositioning Stage
IFAC-PapersOnLine, 2020Co-Authors: Meysam Omidbeike, Yuen Kuan Yong, Andrew J FlemingAbstract:Abstract This article describes the design and calibration of a five degree-of-freedom linear and angular displacement sensor utilizing piezoresistive strain gages. A simple decentralized controller is then implemented to follow linear and angular reference signals. The foremost difficulty with piezoresistive sensors is their high-temperature sensitivity. In addition, they are sensitive to motion in multiple degrees of freedom, which must be decoupled before use as a displacement sensor. A new sensing design is proposed which provides decoupled measurements of linear and angular displacements in multi-axis monolithic Nanopositioning Stages. The proposed method employs system identification and feedforward techniques to calibrate each axis and minimize cross-coupling.
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a five axis monolithic Nanopositioning Stage constructed from a bimorph piezoelectric sheet
2019 International Conference on Manipulation Automation and Robotics at Small Scales (MARSS), 2019Co-Authors: Meysam Omidbeike, Yuen Kuan Yong, Steven Ian Moore, Andrew J FlemingAbstract:The paper describes design, modeling and control of a five-axis monolithic Nanopositioning Stage constructed from a bimorph piezoelectric sheet. In this design, actuators are created by removing parts of the sheet using ultrasonic machining. The constructed nanopositioner is ultra-compact with a thickness of 1 mm. It has a X and Y travel range of 15.5 µm and 13.2 µm respectively; a Z travel range of 26 µm; and a rotational motion about the X- and Y-axis of 600 µrad and 884 µrad respectively. The first resonance frequency occurs at 883 Hz in the Z-axis, and the second and third resonance frequency appears at 1850 Hz, rotating about the X- and Y-axis. A decentralized control strategy is implemented to track Z, θx and θ y motions. The controller provides good tracking and significantly reduces cross-coupling motions among the three degrees-of-freedom.
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multivariable model less feedforward control of a monolithic Nanopositioning Stage with fir filter inversion
2019 International Conference on Manipulation Automation and Robotics at Small Scales (MARSS), 2019Co-Authors: Meysam Omidbeike, Arnfinn A Eielsen, Yuen Kuan Yong, Andrew J FlemingAbstract:A model-less approach for inversion of the dynamics of multivariable systems using FIR filters is described. Inversion-based feedforward techniques have been widely used in the literature to achieve high-performance output tracking. The foremost difficulties associated with plant inversions are model uncertainties and non-minimum phase zeros. Various model-based methods have been proposed to exclude non-minimum phase zeros when inverting both single-input and single-output (SISO), and multiple-input and multiple-output (MIMO) systems. However, these methods increase the model uncertainty as they are no longer exact. To overcome these difficulties a model-less approach using FIR filters is presented. The results when applying the feedforward FIR filter to a multivariable Nanopositioning system is presented, and they demonstrate the effectiveness of the feedforward technique in reducing the cross-coupling and achieving significantly improved output tracking.
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tracking control of a monolithic piezoelectric Nanopositioning Stage using an integrated sensor
IFAC-PapersOnLine, 2017Co-Authors: Meysam Omidbeike, Yuen Kuan Yong, Yik R Teo, Andrew J FlemingAbstract:Abstract This article describes a method for tracking control of monolithic Nanopositioning systems using integrated piezoelectric sensors. The monolithic nanopositioner is constructed from a single sheet of piezoelectric material where a set of flexures are used for actuation and guidance, and another set are used for position sensing. This arrangement is shown to be highly sensitive to in-plane motion (in the x- and y-axis) and insensitive to vertical motion, which is ideal for position tracking control. The foremost difficulty with piezoelectric sensors is their low-frequency high-pass response. In this article, a simple estimator circuit is used to allow the direct application of integral tracking control. Although the system operates in open-loop at DC, dynamic command signals such as scanning trajectories are accurately tracked. Experimental results show significant improvements in linearity and positioning error.
Po-huan Chou - One of the best experts on this subject based on the ideXlab platform.
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intelligent integral backstepping sliding mode control using recurrent neural network for piezo flexural Nanopositioning Stage
Asian Journal of Control, 2016Co-Authors: Faa-jeng Lin, Shih Yang Lee, Po-huan ChouAbstract:In this study, an intelligent integral backstepping sliding-mode control IIBSMC system using a recurrent neural network RNN is proposed for the three-dimensional motion control of a piezo-flexural Nanopositioning Stage PFNS. First, the dynamic model of the PFNS is derived. Then, an integral backstepping sliding-mode control IBSMC system is proposed for the tracking of the reference contours. The steady-state response of the control system can be improved effectively due to the addition of the integrator in the IBSMC. Moreover, to relax the requirements of the bound and discard the switching function in the IBSMC, an IIBSMC system using an RNN estimator is proposed to improve the control performance and the robustness of the PFNS. The RNN estimator is proposed to estimate the lumped uncertainty, including the system parameters and external disturbance, online. Furthermore, the online tuning law for the training of the parameters of the RNN is derived using the Lyapunov stability theorem. In addition, a robust compensator is proposed to confront the minimum reconstructed error occurring in the IIBSMC system. Finally, some experimental results for the tracking of various contours are given to demonstrate the validity of the proposed IIBSMC system. From the performance measurements of the proportional-integral control, sliding mode control, IBSMC, and IIBSMC systems, the proposed IIBSMC system has the lowest maximum, average, and standard deviation of the position tracking errors for three-dimensional motion control of the PFNS.
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computed force control system using functional link radial basis function network with asymmetric membership function for piezo flexural Nanopositioning Stage
Iet Control Theory and Applications, 2013Co-Authors: Faa-jeng Lin, Shih Yang Lee, Po-huan ChouAbstract:A computed force control system using functional link radial basis function network with asymmetric membership function (FLRBFN-AMF) for three-dimension motion control of a piezo-flexural Nanopositioning Stage (PFNS) is proposed in this study. First, the dynamics of the PFNS mechanism with the introduction of a lumped uncertainty including the equivalent hysteresis friction force are derived. Then, a computed force control system with an auxiliary control is proposed for the tracking of the reference contours with improved steady-state response. Since the dynamic characteristics of the PFNS are non-linear and time varying, a computed force control system using FLRBFN-AMF is designed to improve the control performance for the tracking of various reference trajectories, where the FLRBFN-AMF is employed to estimate a non-linear function including the lumped uncertainty of the PFNS. Moreover, by using the asymmetric membership function, the learning capability of the networks can be upgraded and the number of fuzzy rules can be optimised for the functional link radial basis function network. Furthermore, the adaptive learning algorithms for the training of the parameters of the FLRBFN-AMF online are derived using the Lyapunov stability theorem. Finally, some experimental results for the tracking of various reference contours of the PFNS are given to demonstrate the validity of the proposed control system.
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Intelligent nonsingular terminal sliding-mode control using MIMO elman neural network for piezo-flexural Nanopositioning Stage
IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control, 2012Co-Authors: Faa-jeng Lin, Shih Yang Lee, Po-huan ChouAbstract:The objective of this study is to develop an intelligent nonsingular terminal sliding-mode control (INTSMC) system using an Elman neural network (ENN) for the threedimensional motion control of a piezo-flexural Nanopositioning Stage (PFNS). First, the dynamic model of the PFNS is derived in detail. Then, to achieve robust, accurate trajectory-tracking performance, a nonsingular terminal sliding-mode control (NTSMC) system is proposed for the tracking of the reference contours. The steady-state response of the control system can be improved effectively because of the addition of the nonsingularity in the NTSMC. Moreover, to relax the requirements of the bounds and discard the switching function in NTSMC, an INTSMC system using a multi-input-multioutput (MIMO) ENN estimator is proposed to improve the control performance and robustness of the PFNS. The ENN estimator is proposed to estimate the hysteresis phenomenon and lumped uncertainty, including the system parameters and external disturbance of the PFNS online. Furthermore, the adaptive learning algorithms for the training of the parameters of the ENN online are derived using the Lyapunov stability theorem. In addition, two robust compensators are proposed to confront the minimum reconstructed errors in INTSMC. Finally, some experimental results for the tracking of various contours are given to demonstrate the validity of the proposed INTSMC system for PFNS.
Jingyan Dong - One of the best experts on this subject based on the ideXlab platform.
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development of a high bandwidth xy Nanopositioning Stage for high rate micro nanomanufacturing
IEEE-ASME Transactions on Mechatronics, 2011Co-Authors: Sebastian Polit, Jingyan DongAbstract:This paper presents the design analysis fabrication and testing of a high-bandwidth piezo-driven parallel kinematic Nanopositioning XY Stage. The monolithic Stage design has two axes and each axis is composed of a doubly clamped beam and a parallelogram hybrid flexure with compliant beams and circular flexure hinges. The doubly clamped beam that is actuated by a piezoelectric actuator acts as a linear prismatic axis. The parallelogram hybrid flexures are used to decouple the actuation effect from the other axis. The mechanism design decouples the motion in the X- and Y-directions and restricts parasitic rotations in the XY plane while allowing for an increased bandwidth with linear kinematics in the operating region. Kinematic and dynamic analysis shows that the mechanical structure of the Stage has decoupled motion in XY-direction while achieving high bandwidth and good linearity. The Stage is actuated by piezoelectric stack actuators, and two capacitive gauges were added to the system to build a closed-loop positioning system. The results from frequency tests show that the resonant frequencies of the two vibrational modes are over 8 kHz. The Stage is capable of about 15 μm of motion along each axis with a resolution of about 1 nm. Due to parallel kinematic mechanism design, a uniform performance is achieved across the workspace. A PI controller is implemented for the Stage and a closed-loop bandwidth of 2 kHz is obtained.
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design of a high bandwidth xy Nanopositioning Stage for high throughput micro nano manufacturing
ASME 2010 International Mechanical Engineering Congress and Exposition, 2010Co-Authors: Sebastian Polit, Jingyan DongAbstract:A high natural frequency (open-loop bandwidth) is a critical requirement for nanopositioners in high-throughput nanomanufacturing and nano-metrology applications. This paper presents the design and analysis of a high-bandwidth Nanopositioning XY Stage. The monolithic Stage design has two axes and each axis is comprised of a doubly-clamped beam and a parallelogram hybrid flexure with complaint beams and circular flexure hinges. The doubly-clamped beam that is actuated by a piezoelectric actuator acts as a linear prismatic axis. The parallelogram hybrid flexures are used to decouple the actuation effect from the other axis. The mechanism design decouples the motion in the X and Y directions and restricts parasitic rotations in the XY plane while allowing for an increased bandwidth with linear kinematics in the operating region (or workspace). Kinematic and dynamic analysis shows that the mechanical structure of the Stage has decoupled motion in XY direction, while achieving high bandwidth and good linearity. Finite element analysis is adapted to verify the dynamic responses from theoretical analysis. The Stage is actuated by piezoelectric stack actuators, and two capacitive gauges were added to the system to build a closed-loop positioning system. The results from frequency test show that the resonation frequencies of the two vibrational modes are over 8K Hz. The Stage is capable of about 15 microns of motion along each axis with a resolution of about 1 nanometer. Due to parallel kinematic mechanism design, a uniform performance is achieved across the workspace. A PI controller is implemented for the Stage and a high closed-loop bandwidth is obtained.Copyright © 2010 by ASME
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a soi mems based 3 dof planar parallel kinematics Nanopositioning Stage
Sensors and Actuators A-physical, 2008Co-Authors: Deepkishore Mukhopadhyay, Jingyan Dong, Eakkachai Pengwang, Placid M FerreiraAbstract:Abstract This paper presents the design, kinematic and dynamic analysis, fabrication and characterization of a monolithic micro/Nanopositioning three degrees-of-freedom (DOF) (XYθ) Stage. The design of the proposed MEMS (micro-electro-mechanical system) Stage is based on a parallel-kinematic mechanism (PKM) scheme that allows for translation in the XY plane and rotation about the Z axis, an increased motion range, and linear kinematics in the operating region (or work area) of the Stage. The truss-like structure of the PKM results in higher modal frequencies by increasing the structural stiffness and reducing the moving mass of the Stage. The Stage is fabricated on a silicon-on-insulator (SOI) wafer using surface micromachining and deep reactive ion etching (DRIE) processes. Three sets of electrostatic linear comb drives jointly actuate the mechanism to produce motion in the X, Y and θ (rotation) directions. The fabricated Stage provides a motion range of 18 μm and 1.72° at a driving voltage of 85 V. The resonant frequency of the Stage under ambient conditions is 465 Hz. Additionally a high Q factor (∼66) is achieved from this parallel-kinematics mechanism design.
