2024
14.
Fangzhou Xia*; Ivo W Rangelow; Kamal Youcef-Toumi
Active Probe Atomic Force Microscopy: A Practical Guide on Precision Instrumentation Book
Springer, 2024, ISBN: 978-3-031-44232-2.
Abstract | Links | BibTeX | Tags: Actuator, Atomic Force Microscopy, Design, Education, Experimentation, Instrumentation, Mechatronics, MEMS, Modeling & Simulation, Motion Control, Nanorobotics, Piezoelectricity, Review, Sensor, Signal Processing, Theory
@book{2023AFMbook,
title = {Active Probe Atomic Force Microscopy: A Practical Guide on Precision Instrumentation},
author = {Fangzhou Xia* and Ivo W Rangelow and Kamal Youcef-Toumi},
url = {https://link.springer.com/book/10.1007/978-3-031-44233-9},
doi = {https://doi.org/10.1007/978-3-031-44233-9},
isbn = {978-3-031-44232-2},
year = {2024},
date = {2024-02-06},
urldate = {2023-10-01},
publisher = {Springer},
abstract = {From a perspective of precision instrumentation, this book provides a guided tour to readers on exploring the inner workings of atomic force microscopy (AFM). Centered around AFM, a broad range of mechatronic system topics are covered including mechanics, sensors, actuators, transmission design, system identification, signal processing, dynamic system modeling, controller. With a solid theoretical foundation, practical examples are provided for AFM subsystem level design on nano-positioning system, cantilever probe, control system and system integration. This book emphasizes novel development of active cantilever probes with embedded transducers, which enables new AFM capabilities for advanced applications. Full design details of a low-cost educational AFM and a Scale Model Interactive Learning Extended Reality (SMILER) toolkit are provided, which helps instructors to make use of this book for curriculum development. This book aims to empower AFM users with deeper understanding of the instrument to extend AFM functionalities for advanced state-of-the-art research studies. Going beyond AFM, materials presented in this book are widely applicable to precision mechatronic system design covered in many upper-level graduate courses in mechanical and electrical engineering to cultivate next generation instrumentalists.},
keywords = {Actuator, Atomic Force Microscopy, Design, Education, Experimentation, Instrumentation, Mechatronics, MEMS, Modeling & Simulation, Motion Control, Nanorobotics, Piezoelectricity, Review, Sensor, Signal Processing, Theory},
pubstate = {published},
tppubtype = {book}
}
From a perspective of precision instrumentation, this book provides a guided tour to readers on exploring the inner workings of atomic force microscopy (AFM). Centered around AFM, a broad range of mechatronic system topics are covered including mechanics, sensors, actuators, transmission design, system identification, signal processing, dynamic system modeling, controller. With a solid theoretical foundation, practical examples are provided for AFM subsystem level design on nano-positioning system, cantilever probe, control system and system integration. This book emphasizes novel development of active cantilever probes with embedded transducers, which enables new AFM capabilities for advanced applications. Full design details of a low-cost educational AFM and a Scale Model Interactive Learning Extended Reality (SMILER) toolkit are provided, which helps instructors to make use of this book for curriculum development. This book aims to empower AFM users with deeper understanding of the instrument to extend AFM functionalities for advanced state-of-the-art research studies. Going beyond AFM, materials presented in this book are widely applicable to precision mechatronic system design covered in many upper-level graduate courses in mechanical and electrical engineering to cultivate next generation instrumentalists.
13.
Yip Fun Yeung; Fangzhou Xia*; Mikio Furokawa; Takayuki Hirano; Kamal Youcef-Toumi
SymPO:One-Pass Fault Prediction For Non-Stationary Dynamics Journal Article Forthcoming
In: IEEE Transactions on Neural Network and Learning Systems (under review), Forthcoming.
BibTeX | Tags: Automation, Intelligence, Mechatronics, Method, Modeling & Simulation, Signal Processing, Theory
@article{2024IEEETNNLS,
title = {SymPO:One-Pass Fault Prediction For Non-Stationary Dynamics},
author = {Yip Fun Yeung and Fangzhou Xia* and Mikio Furokawa and Takayuki Hirano and Kamal Youcef-Toumi},
year = {2024},
date = {2024-01-01},
urldate = {2024-01-01},
journal = {IEEE Transactions on Neural Network and Learning Systems (under review)},
keywords = {Automation, Intelligence, Mechatronics, Method, Modeling & Simulation, Signal Processing, Theory},
pubstate = {forthcoming},
tppubtype = {article}
}
12.
Abhishek Patkar; Qinghui Meng*; Hanrui Wang; Fangzhou Xia*; Kamal Youcef-Toumi
Time Delay based Neural Network Control of Permanent Magnet Synchronous Motors Journal Article Forthcoming
In: IEEE Transactions on Power Electronics (under review), Forthcoming.
BibTeX | Tags: Automation, Design, Experimentation, Instrumentation, Intelligence, Mechatronics, Modeling & Simulation, Motion Control, Theory
@article{2024IEEETPEL,
title = {Time Delay based Neural Network Control of Permanent Magnet Synchronous Motors},
author = {Abhishek Patkar and Qinghui Meng* and Hanrui Wang and Fangzhou Xia* and Kamal Youcef-Toumi},
year = {2024},
date = {2024-01-01},
urldate = {2024-01-01},
journal = {IEEE Transactions on Power Electronics (under review)},
keywords = {Automation, Design, Experimentation, Instrumentation, Intelligence, Mechatronics, Modeling & Simulation, Motion Control, Theory},
pubstate = {forthcoming},
tppubtype = {article}
}
2023
11.
Lois Wampler^; Fangzhou Xia^*; Yip Fun Yeung; Takayuki Hirano; Ali Alshehri; Mikio Furokawa; Kamal Youcef-Toumi
A Doppler Radar with a Sweeping Lock-in Demodulator for Machine Vibration Sensing Journal Article
In: IEEE Sensors Journal, 2023.
Abstract | Links | BibTeX | Tags: Automation, Experimentation, Instrumentation, Mechatronics, Modeling & Simulation, Sensor, Signal Processing, Theory
@article{2023IEEESensors,
title = {A Doppler Radar with a Sweeping Lock-in Demodulator for Machine Vibration Sensing},
author = {Lois Wampler^ and Fangzhou Xia^* and Yip Fun Yeung and Takayuki Hirano and Ali Alshehri and Mikio Furokawa and Kamal Youcef-Toumi},
doi = {10.1109/JSEN.2023.3325820},
year = {2023},
date = {2023-10-31},
urldate = {2023-10-31},
journal = {IEEE Sensors Journal},
abstract = {Data-driven predictive maintenance of modern machinery has the potential to increase equipment lifespan and decrease manufacturing costs. Vibration analysis can effectively diagnose potential problems in machines. A Doppler radar can be used as a sensor that provides non-contact, inexpensive real-time machine vibration data collection without necessitating line-down time. Implementation with Software Defined Radio (SDR) allow easy adjustment of excitation signals based on application needs. Conventional Fast Fourier Transformation based vibration analysis requires large amounts of data to achieve high spectral resolution needed for fault detection, which can be inefficient and computationally too expensive. In this work, we propose to use a sweeping lock-in amplifier to achieve high frequency resolution with small amounts of data by processing windowed sections of Doppler-shifted radio signals. This algorithm can reliably measure the Doppler shift frequency corresponding to the travelling speed of a moving object and identify the frequency of oscillating target with small amplitude, with the latter widely present in machine vibration. The distinguishing condition of the two cases is mathematically derived. The proposed algorithm is studied in simulation with triangular displacement waveform for simplicity of analysis and sinusoidal waveform for generic applications. For experimental verification, speaker vibration at a known frequency is analyzed to achieve an accuracy of 0.025 Hz within the known vibration frequency. This method is robust to the presence of noise frequencies and capable of detecting multiple frequencies.},
keywords = {Automation, Experimentation, Instrumentation, Mechatronics, Modeling & Simulation, Sensor, Signal Processing, Theory},
pubstate = {published},
tppubtype = {article}
}
Data-driven predictive maintenance of modern machinery has the potential to increase equipment lifespan and decrease manufacturing costs. Vibration analysis can effectively diagnose potential problems in machines. A Doppler radar can be used as a sensor that provides non-contact, inexpensive real-time machine vibration data collection without necessitating line-down time. Implementation with Software Defined Radio (SDR) allow easy adjustment of excitation signals based on application needs. Conventional Fast Fourier Transformation based vibration analysis requires large amounts of data to achieve high spectral resolution needed for fault detection, which can be inefficient and computationally too expensive. In this work, we propose to use a sweeping lock-in amplifier to achieve high frequency resolution with small amounts of data by processing windowed sections of Doppler-shifted radio signals. This algorithm can reliably measure the Doppler shift frequency corresponding to the travelling speed of a moving object and identify the frequency of oscillating target with small amplitude, with the latter widely present in machine vibration. The distinguishing condition of the two cases is mathematically derived. The proposed algorithm is studied in simulation with triangular displacement waveform for simplicity of analysis and sinusoidal waveform for generic applications. For experimental verification, speaker vibration at a known frequency is analyzed to achieve an accuracy of 0.025 Hz within the known vibration frequency. This method is robust to the presence of noise frequencies and capable of detecting multiple frequencies.
10.
Jiajie Qiu^; Hongjin Kim^; Fangzhou Xia*; Kamal Youcef-Toumi
Multi-axis Active Vibration Suppression for Wafer Transfer Systems Best Paper Proceedings Article
In: IEEE/ASME Advanced Intelligent Mechatronics, 2023.
Abstract | Links | BibTeX | Tags: Actuator, Automation, Design, Experimentation, Instrumentation, Mechatronics, Modeling & Simulation, Motion Control, Theory
@inproceedings{2023AIM,
title = {Multi-axis Active Vibration Suppression for Wafer Transfer Systems},
author = {Jiajie Qiu^ and Hongjin Kim^ and Fangzhou Xia* and Kamal Youcef-Toumi},
url = {https://ieeexplore.ieee.org/document/10196218},
year = {2023},
date = {2023-06-27},
urldate = {2023-06-27},
booktitle = {IEEE/ASME Advanced Intelligent Mechatronics},
abstract = {Vibration suppression is critical in precision mechatronic systems for nanofabrication. For automated wafer handling in semiconductor plants, Overhead Hoist Transport (OHT) vehicles transport wafers carried in Front Opening Unified Pods (FOUPs); while the wafers are transported in a FOUP, semiconductor chips are at risk of damage by excited small particles due to mechanical vibration. Active suppression of the FOUP vibrations has been proposed to improve the production yield. However, there are two main challenges that make it a non-trivial problem. First, moving FOUPs carried by the OHT vehicles have no external anchoring point as a momentum source for control efforts. Second, no sensor attachment is permitted on mass-production FOUPs, which makes feedback control more challenging without measurement. Since the goal is to suppress the large FOUP acceleration peaks instead of eliminating all vibration, an inertia-based counterbalancing system is designed to address these challenges. To validate this idea, a custom testbed is designed for multi-axis vibration generation and suppression. A Disturbance Observer-Based Controller (DOBC) is developed and implemented on the hardware. During the experiment, 38 percent of the OHT hand unit vibration (and 42 percent of FOUP vibration) suppression is achieved in the OHT travel direction. Moreover, multi-axis FOUP-level acceleration-peak reduction is achieved to verify the effectiveness of the proposed method. },
keywords = {Actuator, Automation, Design, Experimentation, Instrumentation, Mechatronics, Modeling & Simulation, Motion Control, Theory},
pubstate = {published},
tppubtype = {inproceedings}
}
Vibration suppression is critical in precision mechatronic systems for nanofabrication. For automated wafer handling in semiconductor plants, Overhead Hoist Transport (OHT) vehicles transport wafers carried in Front Opening Unified Pods (FOUPs); while the wafers are transported in a FOUP, semiconductor chips are at risk of damage by excited small particles due to mechanical vibration. Active suppression of the FOUP vibrations has been proposed to improve the production yield. However, there are two main challenges that make it a non-trivial problem. First, moving FOUPs carried by the OHT vehicles have no external anchoring point as a momentum source for control efforts. Second, no sensor attachment is permitted on mass-production FOUPs, which makes feedback control more challenging without measurement. Since the goal is to suppress the large FOUP acceleration peaks instead of eliminating all vibration, an inertia-based counterbalancing system is designed to address these challenges. To validate this idea, a custom testbed is designed for multi-axis vibration generation and suppression. A Disturbance Observer-Based Controller (DOBC) is developed and implemented on the hardware. During the experiment, 38 percent of the OHT hand unit vibration (and 42 percent of FOUP vibration) suppression is achieved in the OHT travel direction. Moreover, multi-axis FOUP-level acceleration-peak reduction is achieved to verify the effectiveness of the proposed method.
9.
Fangzhou Xia*; Shane Lovet; Eyan Forsythe; Malek Ibrahim; Kamal Youcef-Toumi
AFM SMILER: A Scale Model Interactive Learning Extended Reality Toolkit for Atomic Force Microscopy based on Digital Twin Technology Journal Article
In: IEEE Transactions on Mechatronics (in preparation), 2023.
Abstract | Links | BibTeX | Tags: Atomic Force Microscopy, Design, Education, Experimentation, Instrumentation, Intelligence, Mechatronics, MEMS, Modeling & Simulation, Nanorobotics, Sensor, Theory
@article{2023IEEETM,
title = {AFM SMILER: A Scale Model Interactive Learning Extended Reality Toolkit for Atomic Force Microscopy based on Digital Twin Technology},
author = {Fangzhou Xia* and Shane Lovet and Eyan Forsythe and Malek Ibrahim and Kamal Youcef-Toumi},
url = {https://ieeexplore.ieee.org/abstract/document/10136835},
doi = {10.1109/TMECH.2023.3274695},
year = {2023},
date = {2023-06-01},
urldate = {2023-01-01},
journal = {IEEE Transactions on Mechatronics (in preparation)},
abstract = {Atomic force microscope (AFM) is a precision mechatronic system for nanoscale imaging of surfaces. Due to limited instrument access and lack of visualization techniques, understanding its principles can be challenging. Digital twin technology allows the creation of virtual representations of physical systems, which can be particularly useful to address challenges in AFM education. To realistically simulate nanoscale physics, we first developed new efficient algorithms for four virtual scale models, including cantilever mechanics, probe transducers, controller tuning, and contact mechanics. Second, three simulated experiment interactive learning modules are developed for instrument operation, including virtual imaging, system overview, and imaging modalities. In the end, three hardware systems are integrated for an extended reality experience, including a macroscopic AFM scale model, a haptic device for probe-sample interaction force feedback and an upgraded low-cost educational AFM for nanoscale imaging and instrumentation. This completes the eight total modules for the AFM SMILER: A Scale Model Interactive Learning Extended Reality toolkit. Preliminary studies shows the toolkit being helpful for AFM education. In addition to mechatronics and nanotechnology education, techniques developed in this work can be generally applied to computationally efficient realistic digital twin creation.},
keywords = {Atomic Force Microscopy, Design, Education, Experimentation, Instrumentation, Intelligence, Mechatronics, MEMS, Modeling & Simulation, Nanorobotics, Sensor, Theory},
pubstate = {published},
tppubtype = {article}
}
Atomic force microscope (AFM) is a precision mechatronic system for nanoscale imaging of surfaces. Due to limited instrument access and lack of visualization techniques, understanding its principles can be challenging. Digital twin technology allows the creation of virtual representations of physical systems, which can be particularly useful to address challenges in AFM education. To realistically simulate nanoscale physics, we first developed new efficient algorithms for four virtual scale models, including cantilever mechanics, probe transducers, controller tuning, and contact mechanics. Second, three simulated experiment interactive learning modules are developed for instrument operation, including virtual imaging, system overview, and imaging modalities. In the end, three hardware systems are integrated for an extended reality experience, including a macroscopic AFM scale model, a haptic device for probe-sample interaction force feedback and an upgraded low-cost educational AFM for nanoscale imaging and instrumentation. This completes the eight total modules for the AFM SMILER: A Scale Model Interactive Learning Extended Reality toolkit. Preliminary studies shows the toolkit being helpful for AFM education. In addition to mechatronics and nanotechnology education, techniques developed in this work can be generally applied to computationally efficient realistic digital twin creation.
8.
Yip Fun Yeung*; Fangzhou Xia; Juliana Covarrubias; Mikio Furokawa; Takayuki Hirano; Kamal Youcef-Toumi
Robotic Method and Instrument to Efficiently Synthesize Faulty Conditions and Mass-Produce Faulty-Conditioned Data for Rotary Machines Proceedings Article
In: IEEE International Conference on Robotics and Automation (ICRA), 2023.
Abstract | Links | BibTeX | Tags: Actuator, Automation, Design, Experimentation, Instrumentation, Intelligence, Mechatronics, Motion Control, Theory
@inproceedings{2023ICRA,
title = {Robotic Method and Instrument to Efficiently Synthesize Faulty Conditions and Mass-Produce Faulty-Conditioned Data for Rotary Machines},
author = {Yip Fun Yeung* and Fangzhou Xia and Juliana Covarrubias and Mikio Furokawa and Takayuki Hirano and Kamal Youcef-Toumi},
url = {https://ieeexplore.ieee.org/document/10161055},
year = {2023},
date = {2023-05-29},
urldate = {2023-05-29},
booktitle = {IEEE International Conference on Robotics and Automation (ICRA)},
abstract = {Condition synthesis is vital for generating data for fault detection and diagnosis studies. Traditional methods rely heavily on human labor. This study proposes a robotic method and its instrument to efficiently synthesize faulty conditions and mass-produce data to develop fault detection and diagnosis algorithms. The first contribution is the formalization of a new approach called Robotic Condition Synthesis, which shifts the traditionally labor-intensive task of condition synthesis to a robot-based force control task. The second contribution is developing a new robotic manipulator, which is more effective than current lab-grade robots for the tasks involved in the Robotic Condition Synthesis. The third contribution is empirical evidence of the superiority of this new robot in performing the Robotic Condition Synthesis tasks. This study also explores the potential of the new robot by conducting a three-dimensional system identification of a rotordynamic plant, which lays the foundation for more advanced Robotic Condition Synthesis policies in the future.},
keywords = {Actuator, Automation, Design, Experimentation, Instrumentation, Intelligence, Mechatronics, Motion Control, Theory},
pubstate = {published},
tppubtype = {inproceedings}
}
Condition synthesis is vital for generating data for fault detection and diagnosis studies. Traditional methods rely heavily on human labor. This study proposes a robotic method and its instrument to efficiently synthesize faulty conditions and mass-produce data to develop fault detection and diagnosis algorithms. The first contribution is the formalization of a new approach called Robotic Condition Synthesis, which shifts the traditionally labor-intensive task of condition synthesis to a robot-based force control task. The second contribution is developing a new robotic manipulator, which is more effective than current lab-grade robots for the tasks involved in the Robotic Condition Synthesis. The third contribution is empirical evidence of the superiority of this new robot in performing the Robotic Condition Synthesis tasks. This study also explores the potential of the new robot by conducting a three-dimensional system identification of a rotordynamic plant, which lays the foundation for more advanced Robotic Condition Synthesis policies in the future.
7.
Jiajie Qiu^; Hongjin Kim^; Fangzhou Xia*; Kamal Youcef-Toumi
Disturbance Rejection Control for Active Vibration Suppression of OHT Wafer Transfer Vehicles Journal Article
In: Machines, vol. 11, no. 2, pp. 125, 2023.
Abstract | Links | BibTeX | Tags: Actuator, Automation, Design, Experimentation, Instrumentation, Mechatronics, Modeling & Simulation, Motion Control, Theory
@article{2023Machines,
title = {Disturbance Rejection Control for Active Vibration Suppression of OHT Wafer Transfer Vehicles},
author = {Jiajie Qiu^ and Hongjin Kim^ and Fangzhou Xia* and Kamal Youcef-Toumi},
url = {https://www.mdpi.com/2075-1702/11/2/125},
doi = {10.3390/machines11020125},
year = {2023},
date = {2023-01-01},
urldate = {2023-01-01},
journal = {Machines},
volume = {11},
number = {2},
pages = {125},
abstract = {In modern semiconductor fabrication plants, automated Overhead Hoist Transport (OHT) vehicles transport wafers in Front Opening Unified Pods (FOUPs). Even in a cleanroom environment, small particles excited by the mechanical vibration of the FOUP can still damage the chips if such particles land on the critical area of the wafers. To minimize the vibration excitation force transferred to the FOUP, this research focuses on controlling the vibration displacement level of an OHT Hand Unit—interface between the OHT vehicle and the FOUP. However, since the OHT vehicle and the FOUP keep traveling, the target system is floating and there exists no external anchoring point for a controlling force source. In addition, no sensor attachments are permitted on mass-production FOUPs, which makes this vibration level suppression problem more challenging. In this research, a custom testbed is designed to replicate the acceleration profile of the OHT vehicle under its travel motion. Then, system modeling and identification is conducted using simulation and experiment to verify the fabricated testbed design. Finally, a Disturbance Observer-Based Controller (DOBC) is developed and implemented on a custom active vibration suppression actuator with inertia force-based counterbalancing to reduce peak vibration amplitude from 870 µm to 230 µm.},
keywords = {Actuator, Automation, Design, Experimentation, Instrumentation, Mechatronics, Modeling & Simulation, Motion Control, Theory},
pubstate = {published},
tppubtype = {article}
}
In modern semiconductor fabrication plants, automated Overhead Hoist Transport (OHT) vehicles transport wafers in Front Opening Unified Pods (FOUPs). Even in a cleanroom environment, small particles excited by the mechanical vibration of the FOUP can still damage the chips if such particles land on the critical area of the wafers. To minimize the vibration excitation force transferred to the FOUP, this research focuses on controlling the vibration displacement level of an OHT Hand Unit—interface between the OHT vehicle and the FOUP. However, since the OHT vehicle and the FOUP keep traveling, the target system is floating and there exists no external anchoring point for a controlling force source. In addition, no sensor attachments are permitted on mass-production FOUPs, which makes this vibration level suppression problem more challenging. In this research, a custom testbed is designed to replicate the acceleration profile of the OHT vehicle under its travel motion. Then, system modeling and identification is conducted using simulation and experiment to verify the fabricated testbed design. Finally, a Disturbance Observer-Based Controller (DOBC) is developed and implemented on a custom active vibration suppression actuator with inertia force-based counterbalancing to reduce peak vibration amplitude from 870 µm to 230 µm.
2022
6.
Chen Yang*; Fangzhou Xia; Yi Wang; Kamal Youcef-Toumi
Comprehensive study of charge-based motion control for piezoelectric nanopositioners: Modeling, instrumentation and controller design Journal Article
In: Mechanical Systems and Signal Processing, vol. 166, pp. 108477, 2022, ISSN: 0888-3270.
Abstract | Links | BibTeX | Tags: Actuator, Experimentation, Instrumentation, Mechatronics, Modeling & Simulation, Motion Control, Piezoelectricity, Theory
@article{2021_MSSP,
title = {Comprehensive study of charge-based motion control for piezoelectric nanopositioners: Modeling, instrumentation and controller design},
author = {Chen Yang* and Fangzhou Xia and Yi Wang and Kamal Youcef-Toumi},
url = {https://www.sciencedirect.com/science/article/pii/S0888327021008219},
doi = {https://doi.org/10.1016/j.ymssp.2021.108477},
issn = {0888-3270},
year = {2022},
date = {2022-01-01},
urldate = {2022-01-01},
journal = {Mechanical Systems and Signal Processing},
volume = {166},
pages = {108477},
abstract = {High performance motion control of piezoelectric nanopositioners is crucial for a wide range of applications. The primary challenges stem from several aspects, including hysteresis and creep effects, along with the lightly damped mechanical resonance. In view of these issues, this paper proposes a comprehensive charge-based motion control solution, including a generalized electromechanical model, a charge controller with non-resistive DC stabilization and a robust charge control (RCC) strategy. The advantages of charge-based control in system identification and controller design are clearly indicated. Towards this solution, a generalized model of piezoelectric nanopositioner is first proposed, showing the effectiveness of charge control approach in the presence of arbitrarily complicated mechanical dynamics. Furthermore, we present a charge controller with a simple configuration, which eliminates the frequency-dependent performance of classical controller design. This guarantees consistently high control performance over the full operating bandwidth. Finally, to deal with the mechanical resonance and remaining nonlinearities and uncertainties, we propose a control strategy that combines charge control and robust feedback control into a single framework. Superior tracking and damping control performance of the proposed solution is confirmed by extensive experimental validations.},
keywords = {Actuator, Experimentation, Instrumentation, Mechatronics, Modeling & Simulation, Motion Control, Piezoelectricity, Theory},
pubstate = {published},
tppubtype = {article}
}
High performance motion control of piezoelectric nanopositioners is crucial for a wide range of applications. The primary challenges stem from several aspects, including hysteresis and creep effects, along with the lightly damped mechanical resonance. In view of these issues, this paper proposes a comprehensive charge-based motion control solution, including a generalized electromechanical model, a charge controller with non-resistive DC stabilization and a robust charge control (RCC) strategy. The advantages of charge-based control in system identification and controller design are clearly indicated. Towards this solution, a generalized model of piezoelectric nanopositioner is first proposed, showing the effectiveness of charge control approach in the presence of arbitrarily complicated mechanical dynamics. Furthermore, we present a charge controller with a simple configuration, which eliminates the frequency-dependent performance of classical controller design. This guarantees consistently high control performance over the full operating bandwidth. Finally, to deal with the mechanical resonance and remaining nonlinearities and uncertainties, we propose a control strategy that combines charge control and robust feedback control into a single framework. Superior tracking and damping control performance of the proposed solution is confirmed by extensive experimental validations.
2021
5.
Chen Yang*; Nicolas Verbeek; Fangzhou Xia; Yi Wang; Kamal Youcef-Toumi
Modeling and Control of Piezoelectric Hysteresis: A Polynomial-Based Fractional Order Disturbance Compensation Approach Journal Article
In: IEEE Transactions on Industrial Electronics, vol. 68, no. 4, pp. 3348-3358, 2021.
Abstract | Links | BibTeX | Tags: Actuator, Experimentation, Instrumentation, Mechatronics, Modeling & Simulation, Motion Control, Piezoelectricity, Theory
@article{2020IEEETIE,
title = {Modeling and Control of Piezoelectric Hysteresis: A Polynomial-Based Fractional Order Disturbance Compensation Approach},
author = {Chen Yang* and Nicolas Verbeek and Fangzhou Xia and Yi Wang and Kamal Youcef-Toumi},
url = {https://ieeexplore.ieee.org/document/9027124},
year = {2021},
date = {2021-01-01},
urldate = {2021-01-01},
journal = {IEEE Transactions on Industrial Electronics},
volume = {68},
number = {4},
pages = {3348-3358},
publisher = {IEEE},
abstract = {Piezoelectric hysteresis is a critical issue that significantly degrades the motion accuracy of piezo-actuated nanopositioners. Such an issue is difficult to be precisely modeled and compensated for, primarily due to its asymmetric, rate, and input amplitude-dependent characteristics. This article proposes a novel method to deal with this challenge. Specifically, a polynomial-based fractional order disturbance model is proposed to accommodate and characterize the complex hysteresis effect. In this model, the rate dependence is captured by a general method of implementing curve fitting in Bode magnitude plot. The inverse model for control purposes is immediately available from the original one. The proposed method does not require expensive computational resources. In fact, this article shows that this controller can be easily implemented in an analog manner, which brings the advantages of high bandwidth and low cost. Extensive modeling and tracking experiments are carried out to demonstrate the effectiveness of the proposed method. It is shown that the piezoelectric hysteresis nonlinearity can be significantly suppressed over a wide bandwidth.},
keywords = {Actuator, Experimentation, Instrumentation, Mechatronics, Modeling & Simulation, Motion Control, Piezoelectricity, Theory},
pubstate = {published},
tppubtype = {article}
}
Piezoelectric hysteresis is a critical issue that significantly degrades the motion accuracy of piezo-actuated nanopositioners. Such an issue is difficult to be precisely modeled and compensated for, primarily due to its asymmetric, rate, and input amplitude-dependent characteristics. This article proposes a novel method to deal with this challenge. Specifically, a polynomial-based fractional order disturbance model is proposed to accommodate and characterize the complex hysteresis effect. In this model, the rate dependence is captured by a general method of implementing curve fitting in Bode magnitude plot. The inverse model for control purposes is immediately available from the original one. The proposed method does not require expensive computational resources. In fact, this article shows that this controller can be easily implemented in an analog manner, which brings the advantages of high bandwidth and low cost. Extensive modeling and tracking experiments are carried out to demonstrate the effectiveness of the proposed method. It is shown that the piezoelectric hysteresis nonlinearity can be significantly suppressed over a wide bandwidth.
4.
Chen Yang*; Nicolas Verbeek; Fangzhou Xia; Yi Wang; Kamal Youcef-Toumi
Statically Stable Charge Sensing Method for Precise Displacement Estimation of Piezoelectric Stack-Based Nanopositioning Journal Article
In: IEEE Transactions on Industrial Electronics, vol. 68, no. 9, pp. 8550-8560, 2021.
Abstract | Links | BibTeX | Tags: Actuator, Experimentation, Instrumentation, Mechatronics, Modeling & Simulation, Motion Control, Piezoelectricity, Theory
@article{2020IEEETIE_2,
title = {Statically Stable Charge Sensing Method for Precise Displacement Estimation of Piezoelectric Stack-Based Nanopositioning},
author = {Chen Yang* and Nicolas Verbeek and Fangzhou Xia and Yi Wang and Kamal Youcef-Toumi},
url = {https://ieeexplore.ieee.org/abstract/document/9177358},
year = {2021},
date = {2021-01-01},
urldate = {2021-01-01},
journal = {IEEE Transactions on Industrial Electronics},
volume = {68},
number = {9},
pages = {8550-8560},
publisher = {IEEE},
abstract = {Piezoelectric self-sensing is a promising displacement estimation technique that has captured a broad range of attention since its origin. However, one long-standing and critical issue associated with this technique is its unstable static performance. This issue significantly undermines the sensing accuracy and the long-term reliability, which are primary concerns in industrial applications. In this article, we show that this challenging issue can be finally solved. The proposed solution consists of two steps. First, we develop a novel charge sensing circuit that provides an explicit access to observe any disturbance that might impact the static sensing. Second, by introducing cascaded observers, a self-improvement sensing scheme is developed. High accuracy displacement estimate can, thus, be reconstructed by fusing the reference signal, the observed disturbance, and the original sensing signal together. Experimental validations demonstrate the expected stable performance. The root-mean-square sensing errors are well below 1%. The developed self-sensing technique is a competitive solution for nanopositioning applications, also due to its self-contained, immunity to environmental disturbance, and plug-and-play features.},
keywords = {Actuator, Experimentation, Instrumentation, Mechatronics, Modeling & Simulation, Motion Control, Piezoelectricity, Theory},
pubstate = {published},
tppubtype = {article}
}
Piezoelectric self-sensing is a promising displacement estimation technique that has captured a broad range of attention since its origin. However, one long-standing and critical issue associated with this technique is its unstable static performance. This issue significantly undermines the sensing accuracy and the long-term reliability, which are primary concerns in industrial applications. In this article, we show that this challenging issue can be finally solved. The proposed solution consists of two steps. First, we develop a novel charge sensing circuit that provides an explicit access to observe any disturbance that might impact the static sensing. Second, by introducing cascaded observers, a self-improvement sensing scheme is developed. High accuracy displacement estimate can, thus, be reconstructed by fusing the reference signal, the observed disturbance, and the original sensing signal together. Experimental validations demonstrate the expected stable performance. The root-mean-square sensing errors are well below 1%. The developed self-sensing technique is a competitive solution for nanopositioning applications, also due to its self-contained, immunity to environmental disturbance, and plug-and-play features.
2020
3.
Fangzhou Xia*; Chen Yang; Yi Wang; Kamal Youcef-Toumi
Model and Controller Design for High-speed Atomic Force Microscope Imaging and Autotuning Proceedings Article
In: ASPE Spring Topical Meeting on Design and Control of Precision Mechatronic Systems, American Society for Precision Engineering 2020.
Abstract | Links | BibTeX | Tags: Atomic Force Microscopy, Automation, Instrumentation, Mechatronics, Modeling & Simulation, Motion Control, Theory
@inproceedings{2020ASPE,
title = {Model and Controller Design for High-speed Atomic Force Microscope Imaging and Autotuning},
author = {Fangzhou Xia* and Chen Yang and Yi Wang and Kamal Youcef-Toumi},
url = {https://zenodo.org/record/5048303#.Y5icmnbMJD8},
year = {2020},
date = {2020-01-01},
urldate = {2020-01-01},
booktitle = {ASPE Spring Topical Meeting on Design and Control of Precision Mechatronic Systems},
organization = {American Society for Precision Engineering},
abstract = {Atomic Force Microscope (AFM) is a powerful nano-scale surface measurement instrument. However, significant operator experience is needed for successful imaging under various conditions. Parameters of the PID controller for probe deflection or oscillation regulation are tuned by the operator based on visual inspection of the trace and retrace tracking performance. With the development of high-speed AFM and for the purpose of operation overhead reduction, automated parameter tuning of the controller is needed. In this work, we propose a series of control and image improvement methods starting first with an automated PID controller tuning and adjustment method. The imaging speed can also be adjusted based on an error metric. Second, three methods including location-based scanning, line-based feedforward and error-corrected line scan, are proposed for image-level performance improvement. Third, in cases where topography variation and material properties are non-uniform across the sample surface, the controller needs to adapt to such changes on the fly to maintain stability and good tracking performance. Considering the complexity in contact mechanics and the requirement of high-bandwidth real-time operation, a single neuron PID is designed for model-free adaptive tracking. With a lumped parameter AFM model created in Matlab Simulink, the proposed algorithms are evaluated in simulation to demonstrate their effectiveness. With the proposed architecture, the methods can be used individually or together based on application to improve imaging performance.},
keywords = {Atomic Force Microscopy, Automation, Instrumentation, Mechatronics, Modeling & Simulation, Motion Control, Theory},
pubstate = {published},
tppubtype = {inproceedings}
}
Atomic Force Microscope (AFM) is a powerful nano-scale surface measurement instrument. However, significant operator experience is needed for successful imaging under various conditions. Parameters of the PID controller for probe deflection or oscillation regulation are tuned by the operator based on visual inspection of the trace and retrace tracking performance. With the development of high-speed AFM and for the purpose of operation overhead reduction, automated parameter tuning of the controller is needed. In this work, we propose a series of control and image improvement methods starting first with an automated PID controller tuning and adjustment method. The imaging speed can also be adjusted based on an error metric. Second, three methods including location-based scanning, line-based feedforward and error-corrected line scan, are proposed for image-level performance improvement. Third, in cases where topography variation and material properties are non-uniform across the sample surface, the controller needs to adapt to such changes on the fly to maintain stability and good tracking performance. Considering the complexity in contact mechanics and the requirement of high-bandwidth real-time operation, a single neuron PID is designed for model-free adaptive tracking. With a lumped parameter AFM model created in Matlab Simulink, the proposed algorithms are evaluated in simulation to demonstrate their effectiveness. With the proposed architecture, the methods can be used individually or together based on application to improve imaging performance.
2019
2.
Fangzhou Xia*; Chen Yang; Yi Wang; Kamal Youcef-Toumi
Bandwidth Based Repetitive Controller Design for a Modular Multi-actuated AFM Scanner Proceedings Article
In: IEEE American Control Conference (ACC), pp. 3776-3781, 2019, ISSN: 0743-1619.
Abstract | Links | BibTeX | Tags: Atomic Force Microscopy, Instrumentation, Mechatronics, Modeling & Simulation, Motion Control, Piezoelectricity, Theory
@inproceedings{2019ACC_1,
title = {Bandwidth Based Repetitive Controller Design for a Modular Multi-actuated AFM Scanner},
author = {Fangzhou Xia* and Chen Yang and Yi Wang and Kamal Youcef-Toumi},
url = {https://ieeexplore.ieee.org/document/8814642},
doi = {10.23919/ACC.2019.8814642},
issn = {0743-1619},
year = {2019},
date = {2019-07-01},
urldate = {2019-07-01},
booktitle = {IEEE American Control Conference (ACC)},
pages = {3776-3781},
abstract = {High-Speed Atomic Force Micrscopy (HSAFM) enables visualization of dynamic processes and helps with understanding of fundamental behaviors at the nano-scale. Ideally, the HSAFM video frames should have high fidelity, high resolution, and a wide scanning range. Unfortunately, it is very difficult for scanners to simultaneously achieve high scanning bandwidth and large range. Since the first bending mode of large piezos is a major limiting factor, we propose an alternative design by stacking multiple short range piezo actuators. This approach allows significant increase of scanner bandwidth (over 20 kHz) while maintaining large travel range (over 20 μm). The modular design also facilitates the easy adjustment of scanner travel range. In this paper, we first discuss the design and assembly of this scanner. We then present the modeling and control of this multi-actuated scanner. A comparative study is then given on the performance of different controllers. These include a PID controller, a LQR based controller and a bandwidth based repetitive controller. The proposed algorithm provides significant improvement in tracking performance when utilized with the scanner using optimized input trajectories.},
keywords = {Atomic Force Microscopy, Instrumentation, Mechatronics, Modeling & Simulation, Motion Control, Piezoelectricity, Theory},
pubstate = {published},
tppubtype = {inproceedings}
}
High-Speed Atomic Force Micrscopy (HSAFM) enables visualization of dynamic processes and helps with understanding of fundamental behaviors at the nano-scale. Ideally, the HSAFM video frames should have high fidelity, high resolution, and a wide scanning range. Unfortunately, it is very difficult for scanners to simultaneously achieve high scanning bandwidth and large range. Since the first bending mode of large piezos is a major limiting factor, we propose an alternative design by stacking multiple short range piezo actuators. This approach allows significant increase of scanner bandwidth (over 20 kHz) while maintaining large travel range (over 20 μm). The modular design also facilitates the easy adjustment of scanner travel range. In this paper, we first discuss the design and assembly of this scanner. We then present the modeling and control of this multi-actuated scanner. A comparative study is then given on the performance of different controllers. These include a PID controller, a LQR based controller and a bandwidth based repetitive controller. The proposed algorithm provides significant improvement in tracking performance when utilized with the scanner using optimized input trajectories.
2018
1.
Chen Yang*; Changle Li; Fangzhou Xia; Yanhe Zhu; Jie Zhao; Kamal Youcef-Toumi
Charge controller with decoupled and self-compensating configurations for linear operation of piezoelectric actuators in a wide bandwidth Journal Article
In: IEEE Transactions on Industrial Electronics, vol. 66, no. 7, pp. 5392-5402, 2018.
Abstract | Links | BibTeX | Tags: Atomic Force Microscopy, Experimentation, Instrumentation, Mechatronics, Motion Control, Piezoelectricity, Theory
@article{2018IEEETIE,
title = {Charge controller with decoupled and self-compensating configurations for linear operation of piezoelectric actuators in a wide bandwidth},
author = {Chen Yang* and Changle Li and Fangzhou Xia and Yanhe Zhu and Jie Zhao and Kamal Youcef-Toumi},
url = {https://ieeexplore.ieee.org/document/8466119},
year = {2018},
date = {2018-01-01},
urldate = {2018-01-01},
journal = {IEEE Transactions on Industrial Electronics},
volume = {66},
number = {7},
pages = {5392-5402},
publisher = {IEEE},
abstract = {Charge control is a well-known sensorless approach to operate piezoelectric actuators, which has been proposed for more than 30 years. However, it is rarely used in industry because the implemented controllers suffer from the issues of limited low-frequency performance, long settling time, floating-load, and loss of stroke, etc. In this paper, a novel controller circuit dedicated to overcome these issues is presented. In the proposed scheme, a grounded-load charge controller with decoupled configuration is developed, which separates high-frequency and low-frequency paths, thus achieving arbitrarily low transition frequency without increasing the settling time. Based on this, a self-compensating configuration is further proposed and integrated into the controller circuit, which makes full use of controller output to improve its own control performance at low frequencies. Experimental results show that the presented charge controller can effectively reduce more than 88% of the hysteretic nonlinearity even when operating close to the transition frequency. To demonstrate its practical value, we then integrate it into a custom-designed high-speed atomic force microscope system. By comparing images obtained from using voltage drive and charge controller, it is clear that the piezoelectric hysteresis has been significantly reduced in a wide bandwidth.},
keywords = {Atomic Force Microscopy, Experimentation, Instrumentation, Mechatronics, Motion Control, Piezoelectricity, Theory},
pubstate = {published},
tppubtype = {article}
}
Charge control is a well-known sensorless approach to operate piezoelectric actuators, which has been proposed for more than 30 years. However, it is rarely used in industry because the implemented controllers suffer from the issues of limited low-frequency performance, long settling time, floating-load, and loss of stroke, etc. In this paper, a novel controller circuit dedicated to overcome these issues is presented. In the proposed scheme, a grounded-load charge controller with decoupled configuration is developed, which separates high-frequency and low-frequency paths, thus achieving arbitrarily low transition frequency without increasing the settling time. Based on this, a self-compensating configuration is further proposed and integrated into the controller circuit, which makes full use of controller output to improve its own control performance at low frequencies. Experimental results show that the presented charge controller can effectively reduce more than 88% of the hysteretic nonlinearity even when operating close to the transition frequency. To demonstrate its practical value, we then integrate it into a custom-designed high-speed atomic force microscope system. By comparing images obtained from using voltage drive and charge controller, it is clear that the piezoelectric hysteresis has been significantly reduced in a wide bandwidth.
Dr. Fangzhou Xia
Research Scientist
Mechanical Engineering Department
Physics Department
Massachusetts Institute of Technology