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@article{J20a,
title = {Finite-Time Learning Control Using Frequency Response Data with Application to a Nanopositioning Stage},
author = {R. Rozario and A. J. Fleming and T. Oomen},
url = {http://www.precisionmechatronicslab.com/wp-content/uploads/2019/10/J20a-Prepress.pdf},
doi = {10.1109/TMECH.2019.2931407},
year = {2020},
date = {2020-01-01},
journal = {IEEE/ASME Transactions on Mechatronics},
volume = {Early Access},
abstract = {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. This paper aims 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},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@inproceedings{C19h,
title = {Image-Guided Locomotion of a Pneumatic-Driven Peristaltic Soft Robot},
author = {M. S. Xavier and A. J. Fleming and Y. K. Yong},
url = {http://www.precisionmechatronicslab.com/wp-content/uploads/2019/12/ROBIO-241-Final-paper-IEEE-certified.pdf},
year = {2019},
date = {2019-12-06},
booktitle = {Proceedings - IEEE International Conference on Robotics and Biomimetics},
address = {Dali, Yunnan, China},
abstract = {In this work, a pneumatic-driven peristaltic soft robot with pressure feedback control and image-guided tracking is developed. Locomotion is achieved in tube-like environments by mimicking the peristaltic motion of earthworms. The soft actuators are made of silicone rubber with 3D molding and fiber reinforcements. Pressure control is performed using custom made syringe pumps and on/off controllers in Arduino. Realtime visual tracking is accomplished in OpenCV with a colorbased approach. The soft robot has a stroke of 30-35mm for each cycle of actuation. This pneumatic soft robot shows great potential for application in minimally invasive surgery due to its compliance and biocompatibility.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}

@inproceedings{Ruppert2019b,
title = {Characterization of Active Microcantilevers Using Laser Doppler Vibrometry},
author = {M. G. Ruppert and N. F. S. D. Bem and A. J. Fleming and Y. K. Yong},
year = {2019},
date = {2019-11-18},
booktitle = {18th Asian Pacific Vibration Conference},
address = {Sydney, Australia},
abstract = {Active atomic force microscope cantilevers with on-chip actuation and sensing provide several advantages over passive cantilevers which rely on piezoacoustic base-excitation and the optical beam deflection measurement. Most importantly, these cantilevers provide clean frequency responses, the possibility of down-scaling and parallelization to cantilever arrays as well as the absence of optical interferences. In this paper, we demonstrate the analysis and calibration steps for three active cantilever geometries with integrated piezoelectric actuation. For this purpose, laser Doppler vibrometry (LDV) is used to experimentally obtain the deflection mode shapes of the first three eigenmodes, calibrate actuation gains, and to determine the dynamic modal stiffnesses using the Brownian spectrum of the cantilever. The experimental values are compared with finite element simulations.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}

@inbook{Ruppert2019b,
title = {Dynamics and Control of Active Microcantilevers},
author = {M. G. Ruppert and S. O. R. Moheimani},
editor = {Baillieul, John and Samad, Tariq},
url = {https://rd.springer.com/referenceworkentry/10.1007%2F978-1-4471-5102-9_184-2},
doi = {10.1007/978-1-4471-5102-9_184-2},
isbn = {978-1-4471-5102-9},
year = {2019},
date = {2019-11-16},
booktitle = {Encyclopedia of Systems and Control},
volume = {2},
publisher = {Springer London},
abstract = {The microcantilever is a key precision mechatronic component of many technologies for characterization and manipulation of matter at the nanoscale, particularly in the atomic force microscope. When a cantilever is operated in a regime that requires the direct excitation and measurement of its resonance frequencies, appropriate instrumentation and control is crucial for high-performance operation. In this entry, we discuss integrated cantilever actuation and present the cantilever transfer function model and its properties. As a result of using these active cantilevers, the ability to control the quality factor in order to manipulate the cantilever tracking bandwidth is demonstrated.},
keywords = {},
pubstate = {published},
tppubtype = {inbook}
}

@inproceedings{C19g,
title = {Experimental Characterisation of Hydraulic Fiber-Reinforced Soft Actuators for Worm-Like Robots},
author = {M. S. Xavier and A. J. Fleming and Y. K. Yong},
url = {http://www.precisionmechatronicslab.com/wp-content/uploads/2019/11/TF1-029-Final.pdf},
year = {2019},
date = {2019-11-06},
booktitle = {International Conference on Control, Mechatronics and Automation},
address = {Delft, Netherlands},
abstract = {This article describes the design and fabrication of fiber-reinforced soft actuators for a snake-like robot designed to operate inside constrained tubes. The actuators include bending, extension and torsion. These actuators were experimentally characterised using water as the driving fluid with the aid of a water pressure sensor connected to Arduino and video recordings. It is shown that fiber wrapping, geometry of cross-section and elastomer selection are the main parameters affecting the levels of extension, bending and torsion of these actuators. Then, multi-material soft actuators are developed and used to present a soft robot capable of crawling a pipe, a mechanism that could be explored in steerable catheters,endoscopes and pipe inspection devices.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}

@article{Wang2019b,
title = {Scan Rate Adaptation for AFM Imaging Based on Performance Metric Optimisation},
author = {K. Wang and M. G. Ruppert and C. Manzie and D. Nesic and Y. K. Yong },
url = {https://ieeexplore.ieee.org/document/8867937},
doi = {10.1109/TMECH.2019.2947203},
year = {2019},
date = {2019-10-14},
journal = { IEEE/ASME Transactions on Mechatronics},
abstract = {Constant-force contact-mode atomic force microscopy (AFM) relies on a feedback control system to regulate the tip-sample interaction during imaging. Due to limitations in actuators and control, the bandwidth of the regulation system is typically small. Therefore, the scan rate is usually limited in order to guarantee a desirable image quality for a constant-rate scan. By adapting the scan rate online, further performance improvement is possible, and the conditions to this improvement has been explored qualitatively in a previous study for a wide class of possible scan patterns. In this paper, a quantitative assessment of the previously proposed adaptive scan scheme is investigated through experiments that explore the impact of various degrees of freedom in the algorithm. Further modifications to the existing scheme are proposed and shown to improve the closed-loop performance. The flexibility of the proposed approach is further demonstrated by applying the algorithm to tapping-mode AFM.},
note = {early access},
keywords = {},
pubstate = {published},
tppubtype = {article}
}