Fangzhou Xia

@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}

}

@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}

}

@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}

}

@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}

}

@inproceedings{2019ACC_2,

title = {Design and Control of a Multi-Actuated Nanopositioning Stage with Stacked Structure},

author = {Chen Yang* and Fangzhou Xia and Yi Wang and Stephen Truncale and Kamal Youcef-Toumi},

url = {https://ieeexplore.ieee.org/document/8815299},

year  = {2019},

date = {2019-01-01},

urldate = {2019-01-01},

booktitle = {IEEE American Control Conference (ACC)},

pages = {3782-3788},

abstract = {A novel multi-actuated nanopositioning stage with stacked structure has been developed. The aim is to achieve both high bandwidth and large motion range. Symmetric flexures are designed to obtain equal stiffness along any direction in the lateral plane. With this design, the lateral stiffness and corresponding bending mode resonance frequency can be optimized. Both analytical model and finite element analysis are employed to predict the dominant resonance frequency. Experimental results indicate that the dominant resonance of nanopositioner is at 28.2 kHz, with a motion range of 16.5J.1m. A disturbance-observer-based controller is implemented to suppress the hysteretic nonlinearity. The new design and control system enable high-bandwidth and high-precision nanopositioning up to 2 kHz.},

keywords = {Actuator, Atomic Force Microscopy, Design, Experimentation, Instrumentation, Mechatronics, Modeling & Simulation, Motion Control},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{2018ACC,

title = {Design and Control of a Multi-actuated High-bandwidth and Large-range Scanner for Atomic Force Microscopy},

author = {Fangzhou Xia* and Stephen Truncale and Yi Wang and Kamal Youcef-Toumi},

url = {https://ieeexplore.ieee.org/document/8431801},

doi = {10.23919/ACC.2018.8431801},

issn = {2378-5861},

year  = {2018},

date = {2018-06-01},

urldate = {2018-06-01},

booktitle = {IEEE American Control Conference (ACC)},

pages = {4330-4335},

abstract = {Atomic force microscopes (AFMs) with high-speed and large-range capabilities open up possibilities for many new applications. It is desirable to have a large scanning range along with zooming ability to obtain high resolution and high frame-rate imaging. Such capabilities will increase the imaging throughput and allow more sophisticated observations at the nanoscale. Unfortunately, in-plane scanning of conventional piezo tube scanners typically covers a large range of hundreds of microns but has limited bandwidth up to several hundred Hertz. The main focus of this paper is the multi-actuated piezo scanner design and control algorithm to achieve high-speed tracking. Three design strategies for structure bandwidth and operational range consideration are presented and evaluated. The non-linear hysteresis effect of the piezo actuators is modeled using the Preisach hysteresis model. PID control, iterative learning control and repetitive control strategies were investigated in simulation. Based on the controllers performance, the repetitive controller is implemented on a high-speed FPGA device and experimentally verified. The new AFM scanner design is capable of 10 kHz tracking at 3 μm range and 200 Hz tracking at 100 μm range.},

keywords = {Atomic Force Microscopy, Experimentation, Instrumentation, Mechatronics, Modeling & Simulation, Motion Control, Piezoelectricity},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{2017ACC,

title = {Induced vibration contact detection for minimizing cantilever tip-sample interaction forces in jumping mode atomic force microscopy},

author = {Fangzhou Xia* and Iman Soltani Bozchalooi and Kamal Youcef-Toumi},

url = {https://ieeexplore.ieee.org/document/7963591},

year  = {2017},

date = {2017-01-01},

urldate = {2017-01-01},

booktitle = {IEEE American Control Conference (ACC)},

pages = {4141--4146},

organization = {IEEE},

abstract = {Minimizing tip-sample interaction force is crucial for the performance of atomic force microscopes when imaging delicate samples. Conventional methods based on jumping mode such as peak force tapping require a prescribed maximum interaction force to detect tip-sample contact. However, due to the presence of drag forces (in aqueous environments), noises and cantilever dynamics, the minimal detectable peak force can be large. This results in large tip-sample interaction forces and hence sample damage. To minimize this force, we propose a method based on induction of surface or probe vibrations to detect contact between cantilever probe tip and sample substrate. To illustrate the effectiveness of the method, we report experimental results for contact detection on a PS-LDPE-12M polymer sample. A topography tracking control algorithm based on the proposed contact detection scheme is also presented.},

keywords = {Atomic Force Microscopy, Experimentation, Instrumentation, Mechatronics, Modeling & Simulation, Motion Control, Signal Processing},

pubstate = {published},

tppubtype = {inproceedings}

}