Congratulations to Chris on Defending the Ph.D. Dissertation!
Chris defended the dissertation titled "Advanced Control of Roll-to-Roll Mechanical Dry Transfer", delivering significant advances in R2R manufacturing control. Four key contributions structure the work: (1) an NLDI-based robust H∞-optimal controller for R2R mechanical dry transfer that rigorously accounts for process nonlinearities and disturbances while maintaining a state-feedback structure, outperforming linear-model controllers in experiments and offering better computational feasibility than PLDI formulations; (2) novel theoretical stability and H∞ performance results for uncertain APPLSs and APPLSs, with the switched H∞ controller applied to R2R mechanical dry transfer outperforming controllers that do not account for the peeling pattern; (3) a novel RLMPC algorithm for R2R peeling with an internal LTV model spanning the entire period that is updated online using system measurements and the nonlinear process model, significantly outperforming linear MPC while maintaining a 5 ms sampling rate; and (4) SQP ILC applied to R2R mechanical dry transfer, improving the feedforward control signal between transfer tasks using measurements and the nonlinear process model, significantly improving control performance relative to baseline controllers while maintaining minimal online computational burden. Together, these contributions advance both theoretical understanding and practical implementation of R2R manufacturing processes.
Updated 11/09/2025
Congratulations to Jiamin on Defending the Ph.D. Dissertation!
Jiamin defended the dissertation titled "Autonomous Steering and Event Detection: Modeling, Estimation, and Control in Drilling Engineering", delivering a comprehensive framework that advances both theory and practice in autonomous directional drilling. Six interconnected contributions structure the work: (1) a high-fidelity nonlinear delay differential equation model capturing floating stabilizers, bit tilt saturation, and bottom-hole assembly nonuniformity, validated with field data; (2) the first rigorous proof that the model's linear complementarity formulation always has a unique solution, ensuring deterministic simulation; (3) a nonlinear model predictive control architecture that leverages the validated model to enable reliable trajectory guidance; (4) computational acceleration via physics-based state reduction and SINDy-based surrogates, cutting solve times from minutes to under a second without sacrificing fidelity; (5) a multi-input economic MPC with sensor fusion that coordinates weight-on-bit and pad forces to achieve tracking and economic objectives under disturbances; and (6) an advanced hydraulic model paired with an unscented Kalman filter that detects kicks and washouts earlier than legacy approaches, providing reliable safeguards for drilling operations. Together, these contributions markedly enhance drilling efficiency, safety, and responsiveness under harsh downhole conditions.
Updated 11/09/2025
Chris Awarded Best Student Paper at MECC 2025!
Congratulations to Chris for receiving the Best Student Paper Award at the Modeling, Estimation, and Control Conference (MECC) 2025! His work on Model Predictive Path Integral (MPPI) control for Roll-to-Roll (R2R) manufacturing addresses many of the key challenges in R2R control, including nonlinearity, stochasticity, and scalability. A case study demonstrates that an MPPI controller with a non-differentiable cost function outperforms a linear MPC with a quadratic cost function in a simulation of a typical R2R line. Looking forward, as advanced manufacturing lines are increasingly equipped with modern GPUs, MPPI control represents a promising method for high-performance R2R manufacturing, offering both theoretical rigor and practical applicability.
Updated 11/09/2025
Congratulations to Yifan for successfully defending his dissertations!
Yifan's dissertation addresses the core challenges in drilling engineering, focusing on the nonlinear coupled tri-axial vibrations that significantly impact efficiency and safety. He developed a comprehensive drillstring dynamic modeling framework that includes vibration mechanism investigation and the design of surface and/or downhole vibration controllers. This physics-based model, grounded in directional drilling kinematics and field-consistent 12-DOF corotational beam elements, simulates various drilling scenarios to optimize operations. Yifan's work also explores different sensing-feedback-actuation systems to enhance control over drilling vibrations, offering a robust alternative to the current Soft-Torque/Soft-Speed systems. His research not only advances our understanding of drilling vibrations but also paves the way for future innovations in automated drilling technologies.
Updated 06/01/2025
Congratulations to Jiamin and Chris for passing their qualified exam and proposal defense!
We are thrilled to announce two research projects that have successfully passed their proposal defenses. Chris has made significant strides in the "Modeling and Control of Roll-to-Roll Mechanical Peeling," a project that promises to advance the field of Roll-to-Roll (R2R) manufacturing. Meanwhile, Jiamin has excelled in "Autonomous Steering and Event Detection: Modeling, Estimation, and Control in Drilling Engineering," a study poised to enhance the efficiency and safety of drilling operations. Congratulations to both Chris and Jiamin for passing their proposal defense and qualified exam!
Updated 06/01/2025
Chris and Dr. Chen to Present at ACC 2025 in Denver!
Congratulations to Chris and Dr. Chen! Their paper, "Nonlinear Model Predictive Control for Roll-to-Roll Mechanical Transfer of Printed Electronics and 2D Materials", has been accepted for presentation at the American Control Conference (ACC) 2025 in Denver. The work introduces a fast, accurate nonlinear model and MPC framework for precise control of roll-to-roll (R2R) mechanical peeling—an advanced technology enabling continuous, etchant-free transfer of printed electronics and 2D materials. A case study on CVD graphene dry transfer highlights the approach’s effectiveness in managing nonlinear dynamics and constraints for high-quality manufacturing.
Updated 06/01/2025
Shihao will present at NAMRC at Clemson University!
We are pleased to announce that Shihao will be presenting his paper on first-principles modeling of adhesion dynamics in roll-to-roll (R2R) lamination of PET-EVA-PET composites at the North American Manufacturing Research Conference (NAMRC) at Clemson University. The work develops an explicit adhesion-force model by linking interface temperature, compression force, and web speed with a coupled heat-transfer and contact mechanics framework. The model is validated against experimental peeling-force data, showing strong agreement and providing practical maps for optimizing manufacturing settings. This research offers valuable insights and tools for enhancing process efficiency and product quality in flexible-electronics and photovoltaic manufacturing.
Updated 06/01/2025
Congratulations to Nick for successfully defending his dissertations!
Nick has developed a groundbreaking methodology to enhance the value and efficiency of Distributed Energy Resources (DER) in power systems. His work presents a novel framework that balances the costs and constraints of DER owners with the maximization of social welfare, marking a significant leap in energy resource management. Additionally, Nick's research includes innovative methods for assessing DER's techno-economic potential and generating realistic electricity market price scenarios. Nick's contributions to the field are poised to influence future developments in energy distribution and management.
Updated 1/24/2024
News
Congratulations to Jian for successfully defending his dissertations!
Jian's dissertation advances our understanding of bit forensics and its automation processes. He developed a comprehensive framework that effectively utilizes computer vision and machine learning techniques. This framework, enriched with mechanical domain knowledge, automates the detection, integration, and analysis of PDC drill bit damage. His approach not only streamlines the bit forensics process but also markedly improves its efficiency. Jian will be joining WeRide.AI as a Planning and Control Software Engineer, where he will apply his expertise to advance the field of autonomous driving.
Updated 1/7/2024
Jiamin's Paper Selected as Finalist for Best Student Paper at MECC 2023!
We are delighted to announce that Jiamin's paper, presented at the Modeling, Estimation, and Control Conference (MECC 2023), has been selected as one of the top five finalists for the Best Student Paper Award. The paper distinguishes itself with three groundbreaking contributions: It provides the first-ever empirical evidence highlighting the critical importance of floating stabilizers, a phonomenon often overlooked in prior research. Furthermore, the paper generalizes a novel model that successfully adapts to beams with varying cross-sectional areas. Lastly, this model demonstrates an unprecedented capability to accurately mimic borehole propagation. We are proud of Jiamin's outstanding achievements and look forward to continued innovation from our research group.
Updated 10/7/2023
Our Paper Accepted by MECC 2023 and ALDSC!
We are delighted to announce several notable achievements from our group that will be highlighted at the upcoming 3rd Modeling, Estimation, and Control Conference (MECC 2023).
Firstly, we are pleased to share that our paper, titled "Experimentally Validated Nonlinear Delayed Differential Approach to Model Borehole Propagation for Directional Drilling," has been accepted by both MECC 2023 and the joint journal ASME Letters in Dynamic Systems and Control (ALDSC). The paper will be presented by Jiamin at South Tahoe Events Centre, Lake Tahoe, Nevada, between October 2-5 during the conference. Furthermore, the full paper will be published in ALDSC. Congratulations to Jiamin and Mathew, and we extend our sincere thanks to Halliburton for their support.
Secondly, doctoral student Christopher Martin will present another paper at MECC 2023, titled "A Dynamic System Model for Roll-to-Roll Dry Transfer of Two-Dimensional Materials and Printed Electronics." The first author of this work is Dr. Qishen Zhao, and the paper was previously published in the Journal of Dynamic Systems, Measurement, and Control in 2022. This paper presents the first comprehensive dynamic system model for R2R peeling, an emerging technology in the field of advanced flexible materials.
Updated 08/14/2023
Best Paper Award for Our Team!
We are thrilled to announce that the paper titled "Virtual Power Injection for Optimal Adjustment of Droop-Controlled Inverters," co-authored by Kaden and Matt, has received the best paper award by the 2023 11th International Conference on Smart Grid （icSmartGrid）. This esteemed recognition highlights the innovative work and dedication of our team members. The paper is now being submitted to a journal for possible publication. Special thanks to Matt and Kaden for their extraordinary efforts!
Updated 08/14/2023
M. K. Cheong, K. E. Plewe, D. Chen, and P. Du, "Virtual Power Injection for Optimal Adjustment of Droop-Controlled Inverters," in 2023 11th International Conference on Smart Grid (icSmartGrid), pp. 1-9, IEEE, 2023.
A. M. Keller, T. Feng, N. Demirer, R. Darbe, and D. Chen, "Rate of penetration estimation downhole with machine learning for drilling position control," Geoenergy Science and Engineering, vol. 224, p. 211593, 2023.
Y. Zhang, P. Ashok, D. Chen, and E. van Oort, "A Control-Oriented Lumped Parameter Drillstring Dynamic Model for Real-Time Vibration Mitigation and Drilling Optimization," in SPE/IADC International Drilling Conference and Exhibition, OnePetro, 2023.
J. Chu, P. Ashok, D. Chen, and E. van Oort, "Automatic Drill Bit Dull Grading Report Generation to Address the Revised IADC Dull Grading Schema," in SPE/IADC Drilling Conference and Exhibition, p. D021S018R003, SPE, 2023.
M. S. Khaled, N. Wang, P. Ashok, D. Chen, and E. van Oort, "Strategies for Prevention of Downhole Tool Failure Caused by High Bottomhole Temperature in Geothermal and High-Pressure/High-Temperature Oil and Gas Wells," SPE Drilling & Completion, vol. 38, no. 02, pp. 243-260, 2023.
Q. Zhao, C. Martin, N. Hong, D. Chen, and W. Li, "A Real-Time Supervisory Control Strategy for Roll-to-Roll Dry Transfer of 2D Materials and Printed Electronics," IEEE/ASME Transactions on Mechatronics, 2023.
N. Hong, Q. Zhao, D. Chen, K. M. Liechti, and W. Li, "A method to estimate adhesion energy of as-grown graphene in a roll-to-roll dry transfer process," Carbon, vol. 201, pp. 712-718, 2023.
Updated 01/23/2023
Congrats to Kaden Plewe on joining Sandia National Laboratories!
Congrats to our lab member, Kaden Plewe, on joining Sandia National Laboratories to work with the CSP team. He will be working at the National Solar Thermal Test Facility (NSTTF) in Albuquerque, NM on projects related to developing next-generation CSP and CST technology that will aid decarbonization on multiple fronts and increase the resiliency of power grids. Learn more about the team he is working with and current projects here.
Updated 03/12/2023
Congratulations to Mathew for successfully defending his dissertations!
Mathew's research advances our knowledge of directional drilling and its precise control. He investigates methods to overcome the challenges brought by difficulty of measuring deep subsurface parameters and improve the accuracy and reliability of automated directional drilling. The algorithm proposed by him is able to estimate time-varying model parameters in real-time using only measurements commonly obtained while drilling. Based on that, he designed a stochastic model predictive controller, optimal in open-loop and approximately optimal in closed-loop and with minimal violation of state constraints, to incorporate information of the model uncertainty into the control framework, which significantly improves the control performance computationally efficiency.
Updated 01/23/2023
Y. Zhang, H. Zhang, D. Chen, P. Ashok, and E. van Oort, "Comprehensive review of high frequency torsional oscillations (HFTOs) while drilling," Journal of Petroleum Science and Engineering , p.111161, Nov 4, 2022, doi: 10.1016/j.petrol.2022.111161
MS. Khaled, D. Chen, P. Ashok and E. van Oort, "Drilling Heat Maps for Active Temperature Management in Geothermal Wells," In SPE Annual Technical Conference and Exhibition, OnePetro, Sep 26, 2022, doi: 10.2118/210306-MS
AM. Keller, V. Pho, N. Demirer, R. Darbe, and D. Chen, "Estimation for Predictive Control and Human-in-the-Loop Operation of Rotary Steerable Systems," Journal of Dynamic Systems, Measurement, and Control,, Vol. 144, Iss. 9, pp. 091005 (10 pages), doi: 10.1115/1.4054885
Q. Zhao, C. Martin, D. Chen, and W. Li, "MODEL BASED REPETITIVE CONTROL FOR PEELING FRONT GEOMETRY CONTROL IN A ROLL-TO-ROLL PEELING PROCESS," In Proceedings of the 2022 International Symposium on Flexible Automation, Jul 2022
Q. Zhao, N. Hong, D. Chen, and W. Li, "A Dynamic System Model for Roll-to-Roll Dry Transfer of Two-Dimensional Materials and Printed Electronics." , Journal of Dynamic Systems, Measurement, and Control, Vol. 144, Iss. 7, pp. 071004 (8 pages), Jul 2022, doi: 10.1115/1.4054187
K. Plewe, JN. Sment, MJ. Martinez, CK. Ho, and D. Chen, "Transient thermal performance of high-temperature particle storage bins," In AIP Conference Proceedings, Vol. 2445, Iss. 1, pp. 160013, May 2022, AIP Publishing LLC, doi: 10.1063/5.0085649
Q. Gu, AH. Fallah, A. Ambrus, T. Feng, D. Chen, P. Ashok, and E. van Oort, "Computationally efficient simulation of non-isothermal two-phase flow during well construction using a new reduced drift-flux model," Applied Thermal Engineering, Vol. 206, pp. 118077, Apr 2022, doi: 10.1016/j.applthermaleng.2022.118077
I. Feng, S. Gul, D. Chen, and E. van Oort, "Model Predictive Control for Automated Drilling Fluid Maintenance," In IADC/SPE International Drilling Conference and Exhibition, OnePetro, Mar 1, 2022, doi: 10.2118/208769-MS
Y. Zhang, Z. Yan, P. Ashok, D. Chen, and E. van Oort, "Drilling Hard Abrasive Rock Formations with Differential Hydraulic Hammers: Dynamic Modeling of Drillstring Vibrations for ROP Optimization," In IADC/SPE International Drilling Conference and Exhibition, OnePetro, Mar 1, 2022, doi: 10.2118/208670-MS
C. Martin, Q. Zhao, S. Bakshi, D. Chen, and W. Li, "H∞ Optimal Control for Maintaining the R2R Peeling Front," In IFAC-PapersOnLine, Vol. 55, Iss. 37, pp. 663-668, Jan 1, 2022, doi: 10.1016/j.ifacol.2022.11.258
N. Hong, D. Kireev, Q. Zhao, D. Chen, D. Akinwande, and W. Li, "Roll-to-Roll Dry Transfer of Large-Scale Graphene," Advanced Materials, Vol. 34, Iss. 3, pp. 2106615, Nov 9, 2021, doi: 10.1002/adma.202106615
Updated 01/23/2023
Christopher Martin Awarded NFT Graduate Research Fellowship
Congratulations to lab member Christopher Martin for his successful NFT GRFP proposal! This fellowship will provide him with funding and resources to pursue his research interests over the next three years.
Christopher's research will lay a theoretical groundwork for roll-to-roll printing processes in the field of flexible electronics. Modeling the dynamics associated with the peeling interactions in the roll-to-roll process and sequentially using those models to control the system with a high tolerance is a critical step in advancing this technology. The research proposed by Chris and Dr. Chen will increase the quality of flexible electronics produced in a fully roll-to-roll transfer printing process while supporting a higher throughput rate.
After graduating, Christopher intends to pursue a full-time faculty position where he can continue developing theoretical tools that are used to produce technologies that benefit society.
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Updated 07/28/2022
N. Hong, D. Kireev, Q. Zhao, D. Chen, D. Akinwande, and W. Li, "Roll-to-Roll Dry Transfer of Large-scale Graphene," Advanced Materials, pp. 2106615, Nov 9, 2021
O. Erge, Q. Gu, D. Chen, and E. van Oort, "MPD Choke Control Considering the Thixotropic Gelation Behavior of Drilling Fluids," Journal of Petroleum Science and Engineering, pp. 109793, Nov 2, 2021
A. Fallah, Q. Gu, D. Chen, P. Ashok, and E. van Oort, "Globally Scalable Geothermal Energy Production Through Managed Pressure Operation Control of Deep Closed-Loop Systems," Energy Conversion and Management Journal, Vol. 236, pp. 114056, May 15, 2021
S. Bakshi, T. Feng, Z. Yan, Z. Ma, and D. Chen, "Energy-Conscientious Trajectory Planning for an Autonomous Mobile Robots in an Asymmetric Task Space," Journal of Intelligent & Robotic Systems, Vol. 101, Iss. 1, pp.1-14
Q. Gu, A. Fallah, T. Feng, S. Bakshi, D. Chen, P. Ashok, D. Moore, and E. van Oort, 2021, "A Novel Dilution Control Strategy for Gas Kick Handling and Riser Gas Unloading Mitigation in Deepwater Drilling," Journal of Petroleum Science and Engineering, p. 107973 (January 2021)
Updated 01/30/2022
NSF REU supplemental funding has been awarded to support undergraduate research in the modeling and control of roll-to-roll manufacturing. View the Award Posting for more information.
Updated 01/30/2022
Automated Guided Vehicles Capstone Project
A group of ECE students successfully completed their capstone project on "Controlling A Group of Automated Guided Vehicles."
Updated 01/30/2022
New DOE funding to support testing at Sandia's NSTTF
Research that will be lead by Dr. Chen and Kaden Plewe was recently awarded DOE funding to support high-temperature particle thermal storage testing at the National Solar Thermal Test Facility (NSTTF). This testing will be used to validate our thermal storage models for Sandia's Gen3 Particle Pilot Plant. See the NSTTF Funding Post for more information.
Updated 06/08/2021
Congratulations to Qifan and Amir for successfully defending their dissertations!
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An Advanced Hydraulic-Thermal Model for Drilling & Control of Geothermal Wells
Amir’s work advances our knowledge in the field of oil & gas and geothermal drilling operations. He developed an advanced model that characterizes the hydraulic and thermal dynamics with a high temporal resolution, making it possible to identify the complex physics associated with multi-stage drilling procedures. In addition to advancing fundamental knowledge in this area, Amir’s work sets a platform for improving the safety and reliability of drilling procedures.
Amir will be joining Xecta Digital Labs in Houston, TX to work as a full-time Senior Research Engineer. His primary focus will be on developing physics- and ML-based models for drilling automation and optimization.
A Comprehensive Deepwater Well Control System for Riser Gas Unloading Mitigation
Qifan’s research advances our knowledge of off-shore drilling with the development of new models, control algorithms, and event detection methods. His control algorithm increases the speed and safety of drilling operations by detecting and responding to deep-water disturbance events efficiently and reliably. In addition to detecting these events, a classification procedure provides a way for operators to better understand drilling procedures in real-time and to adapt accordingly, which increases safety, reliability, and efficiency.
Qifan will be joining Apple to work as a Hardware Test Engineer, contributing to the quality control of Apple products.
Updated 06/07/2021
Gen 3 Particle Pilot Plant Awarded Phase III DOE Funding
Sandia National Laboratories was recently awarded $25 million by the DOE to fund the Phase III testing and construction of the Gen 3 Particle Pilot Plant. Our lab is working with SNL to develop component and system-level models, perform component-level testing, and develop operational controls for the G3P3 project. For more info visit the SNL G3P3 Website or watch the video below, where Cliff Ho (G3P3 PI) introduces the novelty of the G3P3 system.
Updated 04/14/2021
Welcome to a New Lab Member
Joey Huang has joined our lab as an undergraduate researcher from the CS department. He will be conducting research on the control of automated ground vehicles, further developing our research in the field of path planing and optimization.
Updated 04/14/2021
Updated 01/27/2021
Our paper on “Risk-Aware Path Planning with Uncertain Human Interactions” has been accepted by ACC 2021, congratulations to Jian, Soovadeep, and Zeyu!
Updated 01/27/2021
Dr. Chen received an award from the NSF to conduct research on “Modeling and Control of a Roll-to-Roll Manufacturing Process for Dry Transfer of Two-Dimensional Materials and Printed Electronics”
Updated 01/27/2021
S. Bakshi, T. Feng, Z. Yan, Z. Ma, and D. Chen, “Energy-Conscientious Trajectory Planning for an Autonomous Mobile Robots in an Asymmetric Task Space,” Journal of Intelligent & Robotic Systems
Q. Gu, A. Fallah, T. Feng, S. Bakshi, D. Chen, P. Ashok, D. Moore, and E. van Oort, 2021, “A Novel Dilution Control Strategy for Gas Kick Handling and Riser Gas Unloading Mitigation in Deepwater Drilling,” Journal of Petroleum Science and Engineering, p. 107973 (January 2021), DOI: https://doi.org/10.1016/j.petrol.2020.107973
A. Fallah, Q. Gu, Z. Ma, A. Karimi Vajargah, D. Chen, P. Ashok, E. van Oort, and R. May, “Temperature Dynamics and Its Effects on Gas Influx Handling During Managed Pressure Drilling Operations,” accepted, Journal of Natural Gas Science and Engineering
Kaden Plewe, J. N. Sment, M. J. Martinez, C. K. Ho, and D. Chen, “Transient Thermal Performance of High-Temperature Particle Storage Bins,” 26th SolarPACES Conference, Albuquerque, Nex Mexico, September 29 – October 2, 2020
Q. Zhao, T. Feng, W. Li, and D. Chen, "Power Management for a Fuel Cell/Battery/Supercapacitor Hybrid Locomotive,” Proceedings of ASME Dynamic Systems and Control conference, Pittsburgh, Pa, October 4 – 7, 2020
Jian Chu, Hansen Qin, Zeyu Yan, Soovadeep Bakshi , and D. Chen, “An Integrated Hardware and Software Platform for Control of Automatic Ground Vehicles,” Proceedings of ASME Dynamic Systems and Control conference, Pittsburgh, Pa, October 4 – 7, 2020
A. Fallah, Q. Gu, D. Chen, P. Ashok, and E. van Oort, A. Karimi Vajargah and R. Banirazi, “Hole Cleaning Case Studies Analyzed with a Transient Cuttings Transport Model,” Proceedings of 2020 SPE Annual Technical Conference and Exhibition, Virtual, October 27-29, 2020
Q. Shen, D. Chen, and W. Li, “Controlling Peeling Front Geometry in a Roll-to-Roll Thin Film Transfer Process,” Proceedings of 2020 MSEC Manufacturing Science & Engineering Conference, Cincinnati, OH, June 22-26, 2020
Updated 01/27/2021
Dr. Alex Headly Awarded Faculty Position at The University of Memphis
Our group alumnus, Dr. Alex Headley, will join the Department of Mechanical Engineering at The University of Memphis as an Assistant Professor in Fall 2020.
Updated 03/29/2020
Congratulations to Soovadeep for successfully defending his dissertation!
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On-Demand Planning of a School of Autonomous Mobile Robots for Prioritized Task Completion
Soovadeep's work has advanced the field of planning and control for autonomous mobile robots by introducing novel algorithms that optimally cluster AMRs to navigate the task space in an economical and energy-efficient way. His algorithms support real-time route planning with an emphasis on task priority─something that existing state-of-the-art methods overlook─and have paved the way for major improvements in the efficiency and effectiveness of real-world autonomous processes. During his time at UT, Soovadeep has also made significant contributions in medical signal processing, modeling of physical systems, and drilling optimization.
Beyond his fundamental contributions to the field of Mechanical Engineering, Soovadeep has been a critical player in the Cockrell School of Engineering through his numerous teaching positions, peer-to-peer interactions, and mentorships. His time spent at UT will surely go on to impact the reality and standards of what it means to study science and engineering here.
After graduating, Soovadeep is joining the Level 5 (Autonomous Driving) team at Lyft as a Hardware Engineer in Motion Controls, where he will work on vehicle modeling, HIL simulation, and control design, testing and verification. He will be based out of their Palo Alto office.
Updated 03/07/2020