Minh Tuan Hua

• Hua, Minh Tuan; Poursina, Mohammad; Vu, Viet Hung & Sanfilippo, Filippo (2026). Dynamic Modeling and Analysis of Robotic Manipulators With Mixed Rigid–Elastic Joints. IEEE Access. 14, p. 33966–33995. doi: 10.1109/ACCESS.2026.3668125. Full text in Research Archive
• Hua, Minh Tuan; Gravdahl, Jan Tommy & Sanfilippo, Filippo (2025). Adaptive Cartesian Position Control with a Switching Strategy for Robotic Manipulator with Mixed Rigid-Elastic Joints. Proceedings of IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS). ISSN 2153-0858. 2025, p. 7398–7405. doi: 10.1109/iros60139.2025.11247250. Full text in Research Archive Show summary

  With the increasing demand for safe and efficient human-robot interaction in industrial applications, robotic manipulators with mixed rigid-elastic joints have gained significant attention, yet their control remains challenging due to inherent parameter uncertainties and complex dynamics. In this paper, an adaptive Cartesian position control for robotic manipulators with mixed rigid-elastic joints is presented. Adaptive controllers are designed to deal with uncertainties in the parameters of the motors, while robust control signals effectively cope with uncertainties of the links and stiffness of the elastic joints. Furthermore, a switching strategy between Cartesian space position control and joint space position control when the end-effector comes into the vicinity of the target point is proposed. This switching strategy helps to keep the pose of the robotic manipulator stable when the end-effector has approached the target point. Simulation results on a 6-DOF robotic manipulator demonstrate that the proposed control scheme can achieve the desired accuracy in position and maintain a stable pose when the end-effector reaches the target.

• Hua, Minh Tuan; Gravdahl, Jan Tommy & Sanfilippo, Filippo (2025). Impedance Control for Robots with Mixed Rigid-Elastic Joints Using Sliding Mode Control. In IEEE (Eds.), 2025 European Control Conference (ECC). IEEE (Institute of Electrical and Electronics Engineers). ISSN 9783907144121. p. 2914–2920. doi: 10.23919/ecc65951.2025.11187019. Full text in Research Archive
• Sanfilippo, Filippo; Tataru, Marius; Hua, Minh Tuan; Johansson, Inge Johan Straumsøy & Andone, Diana (2025). Gamifying Cultural Immersion: Virtual Reality (VR) and Mixed Reality (MR) in City Heritage. IEEE Transactions on Games (TG). ISSN 2475-1502. 17(4), p. 893–911. doi: 10.1109/TG.2025.3553712. Full text in Research Archive Show summary

  The exploration of city culture and heritage has gone through a fundamental transition in today's digital world, boosted by the introduction of extended reality (XR) technologies, such as virtual reality (VR), mixed reality (MR), and augmented reality. These developments have provided new opportunities for individuals to profoundly engage with historical narratives and artistic expressions inherent in urban environments. Despite these technical advancements, a critical research gap remains in properly combining these immersive technologies with gamification principles to improve cultural exploration. This study seeks to fill this gap by studying the integration of gamification into XR settings, with the goal of increasing participant engagement, cooperation, and interaction while digging into the various layers of a city's history and artistic heritage. Two complementary use cases are presented: one centred on VR and the other on MR, both of which provide unique immersive experiences customized to exploring city culture. Gamification ideas are implemented into these use cases, with game elements used to encourage user involvement and participation within historical and artistic settings. Students are actively involved in the development of cultural heritage applications, highlighting the value of educational engagement. To assess the success and validity of this approach, a system usability scale (SUS) questionnaire is distributed to users participating in these immersive experiences. The survey findings evaluate user perceptions, satisfaction levels, and the effectiveness of gamification aspects in improving their understanding and connection to the city's heritage. The VR application received a score of 71.77 (out of 100), while the MR application received a score of 65.94 (out of 100), both being very close to the average SUS score of 68. Moreover, to improve the rigour of our evaluation, the user engagement scale short form (UES-SF) is also incorporated. The UES results indicate that participants felt more immersed in the MR application (4.33) compared to the VR application (3.57). This difference may be attributed to the MR application's ability to integrate interactive elements with the real-world environment, enhancing the sense of presence and relevance for users. Both applications had similar perceived usability scores, while the MR app slightly outperformed the VR app in aesthetics and rewarding factors, suggesting a better overall user experience.

• Sanfilippo, Filippo; Salvietti, Gionata; Blažauskas, Tomas; Gabriele, Guido; Zafar, Maria & Hua, Minh Tuan [Show all 14 contributors for this article] (2025). Integrating VR, AR, and Haptics in Basic Surgical Skills Training: A Review and Perspective. IEEE Access. 13, p. 99203–99220. doi: 10.1109/ACCESS.2025.3574265. Full text in Research Archive Show summary

  Traditional surgical training faces challenges related to sustainability, cost, and ethical considerations. Limited access to resources, ethical concerns about cadaver-based learning, limited availability of surgical cases, and the high costs associated with hands-on training impede the effectiveness and accessibility of surgical education. Despite these challenges, the need for direct tactile experience remains critical, as it fosters the development of essential motor skills and tactile abilities vital for surgical practice. However, advancements in immersive technologies such as virtual reality (VR), augmented reality (AR), and haptics offer a promising solution to address these challenges. VR and AR technologies offer realistic, controlled environments where learners can visualise anatomical structures and practice surgical procedures without risks. The integration of haptic feedback in these immersive simulations further enriches the learning process by adding the sense of touch and physical interaction, aiding in mastering critical surgical skills. The incorporation of immersive technologies in surgical training presents an opportunity to address the constraints of conventional methods. These technologies offer the possibility of creating platforms that replicate real-life surgical scenarios, allowing learners to hone their skills and build confidence in a safe and controlled environment. Moreover, immersive learning offers an ethical alternative to cadaver-based training and extends access to training materials irrespective of geographical limitations. Such an approach allows for step-based training, where students may begin acquiring skills through immersive learning, then move to special surgical simulators, and finally to patients. This article deals with the impact of immersive technologies such as VR, AR, and haptics on reshaping conventional surgical training, by focusing specifically on basic surgical skills. Targeting educators, medical experts, and involved parties, the article aims to stimulate additional exploration and adoption of immersive technologies to elevate surgical competencies and patient care standards.

• Hua, Minh Tuan; Sveen, Emil Mühlbradt; Schlanbusch, Siri Marte & Sanfilippo, Filippo (2024). Robust-Adaptive Two-Loop Control for Robots with Mixed Rigid-Elastic Joints. In NN, . (Eds.), International Conference on Intelligent Robots and Systems (IROS). IEEE (Institute of Electrical and Electronics Engineers). ISSN 9798350377705. p. 11332–11339. doi: 10.1109/IROS58592.2024.10802178. Full text in Research Archive Show summary

  In robotics, while rigid joints are common due to their accuracy and fast response ability, elastic joints are wellknown for their safety when interacting with the environment. To harmonise the advantages of these joint types, robots with mixed rigid-elastic joints can be considered. In this paper, a robust-adaptive two-loop control algorithm is proposed to control this type of hybrid robots when there are uncertainties in system parameters. In the outer loop, a robust control algorithm is proposed to deal with the uncertainties in the parameters of the joint dynamics, together with an adaptive controller for the rigid joints. In the inner loop, another robust control algorithm is proposed to handle the uncertainties in system parameters of the elastic joint’s motor contribution, and a similar adaptive control algorithm is presented to manipulate the elastic joints’ motors. The stability of the system is assured by Lyapunov’s stability theory. Finally, simulations are conducted to verify the proposed control algorithm.

• Hua, Minh Tuan; Park, Jong Hyeon & Sanfilippo, Filippo (2024). Modelling and Control of a Hybrid Robotic Arm with Mixed Rigid-Elastic Joints, 2024 IEEE 19th Conference on Industrial Electronics and Applications (ICIEA). IEEE (Institute of Electrical and Electronics Engineers). ISSN 9798350360868. doi: 10.1109/ICIEA61579.2024.10665130. Full text in Research Archive
• Sanfilippo, Filippo; Økter, Martin Bjaadal; Dale, Jørgen; Hua, Minh Tuan & Ottestad, Morten (2024). Revolutionising Prosthetics and Orthotics with Affordable Customisable Open-Source Elastic Actuators. In NN, . (Eds.), International Conference on Automation, Robotics and Applications (ICARA). Institute of Electrical and Electronics Engineers (IEEE). ISSN 9798350394252. p. 57–63. doi: 10.1109/ICARA60736.2024.10553120. Full text in Research Archive Show summary

  Collaborative robots, also known as cobots, have become progressively popular as they are designed to safely work alongside humans or in shared environments. The adoption of compliant actuators, which avoid damage in the event of an unintentional collision, is an important feature of their design. In prosthetic and orthotic applications, the use of compliant actuators, which minimise damage in the case of an inadvertent contact, is critical to ensuring safety and comfort for the user. In dynamic settings, elastic actuators are preferred over rigid ones, however most compliant cobots are currently too expensive or complex to construct for prosthetic and orthotic applications. To address this challenge, this study presents a low-cost sensorised elastic actuator design for prosthetics and orthotics. This is presented as an educational framework. The design is modular and can be quickly customised using 3D printing technology, allowing for efficient and cost-effective fabrication. Both the hardware and software are open-source, enabling easy access for students, researchers and practitioners. The design also allows for the introduction of impedance and admittance control techniques, providing even greater versatility to the system.

• Sanfilippo, Filippo; Økter, Martin Bjaadal; Dale, Jørgen; Hua, Minh Tuan; Zafar, Muhammad Hamza & Ottestad, Morten (2024). Open-source design of low-cost sensorised elastic actuators for collaborative prosthetics and orthotics. HardwareX. 19. doi: 10.1016/j.ohx.2024.e00564. Full text in Research Archive
• Hua, Minh Tuan; Poursina, Mohammad & Sanfilippo, Filippo (2024). Dynamic Modelling of Mixed Rigid-Flexible Joint Robotic Manipulator Using Recursive Newton-Euler Formulation, 2024 10th International Conference on Automation, Robotics and Applications (ICARA). IEEE (Institute of Electrical and Electronics Engineers). ISSN 9798350394245. p. 165–171. doi: 10.1109/ICARA60736.2024.10553136. Full text in Research Archive Show summary

  Rigid joints have good position control accuracy due to their stiffness. On the other hand, elastic joints are advantageous when interacting with the environment due to their compliance characteristics. Most of the current robot arms use all rigid joints or all elastic joints in their designs. This work presents a highly efficient approach to formulate both inverse and forward dynamics of robots with mixed rigid-elastic joints using recursive Newton-Euler algorithm. To simplify the modelling process, a unified rigid body is proposed, where the link and all motors attached to it are unified as a whole unyielding entity. In addition, the effect of gear ratio is considered in the development of this modelling approach. Successively, an inverse dynamics controller is presented. Finally, simulations are conducted based on the proposed modelling method and the inverse dynamics control algorithm.

• Hua, Tuan; Langås, Even Falkenberg; Zafar, Muhammad Hamza & Sanfilippo, Filippo (2023). From rigid to hybrid/soft robots: Exploration of ethical and philosophical aspects in shifting from caged robots to human-robot teaming. In Yu, Wen (Eds.), 2023 IEEE Symposium Series on Computational Intelligence (SSCI). IEEE (Institute of Electrical and Electronics Engineers). ISSN 9781665430654. p. 1794–1799. doi: 10.1109/SSCI52147.2023.10372032. Full text in Research Archive Show summary

  This paper delves into the ethical, philosophical, and practical dimensions associated with the transition from caged robots to human-robot teaming (HRT). By exploring the evolving dynamics between humans and robots, this paper examines the ethical challenges, philosophical implications, and practical considerations that arise as collaboration and integration between humans and robots deepen. It emphasises the need for responsible design, implementation, and ethical frameworks to guide the development and deployment of human-robot teams. Particular focus is put into the ethical ramifications of choosing between rigid and soft actuators. The study underscores the significance of employing admittance and impedance control techniques to regulate interaction forces and compliance between humans and robots. By analysing the ethical implications of utilising soft actuators, the paper emphasises the potential advantages, such as enhanced safety and reduced risk of harm during close human-robot collaboration.

• Hua, Tuan; Sanfilippo, Filippo & Hao, Nguyen Vinh (2022). A Novel Adaptive Sliding Mode Controller for a 2-DOF Elastic Robotic Arm. Robotics. 11(2). doi: 10.3390/robotics11020047. Full text in Research Archive Show summary

  Collaborative robots (or cobots) are robots that are capable of safely operating in a shared environment or interacting with humans. In recent years, cobots have become increasingly common. Compliant actuators are critical in the design of cobots. In real applications, this type of actuation system may be able to reduce the amount of damage caused by an unanticipated collision. As a result, elastic joints are expected to outperform stiff joints in complex situations. In this work, the control of a 2-DOF robot arm with elastic actuators is addressed by proposing a two-loop adaptive controller. For the outer control loop, an adaptive sliding mode controller (ASMC) is adopted to deal with uncertainties and disturbance on the load side of the robot arm. For the inner loops, model reference adaptive controllers (MRAC) are utilised to handle the uncertainties on the motor side of the robot arm. To show the effectiveness of the proposed controller, extensive simulation experiments and a comparison with the conventional sliding mode controller (SMC) are carried out. As a result, the ASMC has a 50.35% lower average RMS error than the SMC controller, and a shorter settling time (5% criterion) (0.44 s compared to 2.11 s).

• Sanfilippo, Filippo; Hua, Tuan Minh & Bos, Steven (2020). A comparison between a two feedback control loop and a reinforcement learning algorithm for compliant low-cost series elastic actuators. In Bui, Tung X. (Eds.), Proceeding of the 53rd Hawaii International Conference on System Sciences (HICSS 2020). AIS Electronic Library University of Hawai'i at Manoa Hamilton Library 2550 McCarthy Mall Honolulu, HI 96822. ISSN 9780998133133. p. 881–890. doi: 10.24251/hicss.2020.110. Full text in Research Archive Show summary

  Highly-compliant elastic actuators have become progressively prominent over the last years for a variety of robotic applications. With remarkable shock tolerance, elastic actuators are appropriate for robots operating in unstructured environments. In accordance with this trend, a novel elastic actuator was recently designed by our research group for Serpens, a low-cost, open-source and highly-compliant multi-purpose modular snake robot. To control the newly designed elastic actuators of Serpens, a two-feedback loops position control algorithm was proposed. The inner controller loop is implemented as a model reference adaptive controller (MRAC), while the outer control loop adopts a fuzzy proportional-integral controller (FPIC). The performance of the presented control scheme was demonstrated through simulations. However, the efficiency of the proposed controller is dependent on the initial values of the parameters of the MRAC controller as well as on the effort required for a human to manually construct fuzzy rules. An alternative solution to the problem might consist of using methods that do not assume a priori knowledge: a solution that derives its properties from a machine learning procedure. In this way, the controller would be able to automatically learn the properties of the elastic actuator to be controlled. In this work, a novel controller for the proposed elastic actuator is presented based on the use of an artificial neural network (ANN) that is trained with reinforcement learning. The newly designed control algorithm is extensively compared with the former approach. Simulation results are presented for both methods. The authors seek to achieve a fair, non-biased, risk-aware and trustworthy comparison.

• Hua, Tuan; Sanfilippo, Filippo & Helgerud, Erlend (2019). A robust two-feedback loops position control algorithm for compliant low-cost series elastic actuators. IEEE International Conference on Systems, Man, and Cybernetics (SMC). ISSN 2163-9590. p. 2384–2390. doi: 10.1109/SMC.2019.8913845. Full text in Research Archive Show summary

  Elastic joints are considered to outperform rigid joints in terms of peak dynamics, collision tolerance, robustness, and energy efficiency. Therefore, intrinsically elastic joints have become progressively prominent over the last years for a variety of robotic applications. In this article, a two-feedback loops position control algorithm is proposed for an elastic actuator to deal with the influence from external disturbances. The considered elastic actuator was recently designed by our research group for Serpens, a low-cost, open-source and highly-compliant multi-purpose modular snake robot. In particular, the inner controller loop is implemented as a model reference adaptive controller (MRAC) to cope with uncertainties in the system parameters, while the outer control loop adopts a fuzzy proportional-integral controller (FPIC) to reduce the effect of external disturbances on the load. The advantage of combining the FPIC and the MRAC controllers is the possibility of achieving independence with respect to imprecise system parameters. A mathematical model of the considered elastic actuator is also presented to validate the proposed controller through simulations. The operability of the presented control scheme is demonstrated. In closed-loop the load swing is rapidly confined and eliminated thereafter.

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• Hua, Tuan; Sanfilippo, Filippo & Hao, Nguyen Vinh (2021). An Adaptive Sliding Mode Controller for a 2-DOF Elastic Robotic Arm. Full text in Research Archive Show summary

  Collaborative robots (or cobots) are robots that can safely operate together or interact with humans in a shared environment. They have steadily been more prevalent in recent years. The use of compliant actuators is critical in the design of cobots. In fact, this form of actuation system can potentially mitigate the damage caused by unexpected collision. As a result, when working in a complex setting, elastic joints are thought to outperform rigid joints. In this paper, a two-loop adaptive controller is proposed to deal with the control task of a 2-DOF robot arm with elastic actuators. For the outer control loop, an adaptive sliding mode controller (ASMC) is proposed to deal with uncertainties and disturbance on the load side of the robot arm. For the inner loop, model reference adaptive controllers (MRAC) are proposed to handle the uncertainties on the load side of the robot arm. Simulation experiments are conducted to verify the efficiency of the proposed two-loop controller.

• Sanfilippo, Filippo; Hua, Tuan & Bos, Steven (2020). A comparison between a two feedback control loop and a reinforcement learning algorithm for compliant low-cost series elastic actuators. Full text in Research Archive
• Hua, Minh Tuan (2026). Modelling and Control of Robotic Manipulators with Mixed Rigid- Elastic Joints. Universitetet i Agder. ISSN 9788284273327. Full text in Research Archive Show summary

  Stive ledd brukes ofte i tradisjonelle design av robotmanipulatorer fordi de gir rask respons og høy posisjonsnøyaktighet. De er egnet for anvendelser der hastighet og nøyaktighet er de viktigste hensynene. Imidlertid er de ofte innelukket på grunn av den potensielle risikoen for menneskers helse og omgivelsene. På den annen side verdsettes elastiske ledd for sin iboende sikkerhet ved interaksjon med omgivelsene. De har imidlertid treg respons og kan avvike fra ønsket posisjon når en kollisjon oppstår. For å kombinere fordelene og redusere ulempene ved begge leddtyper kan robotmanipulatorer med blandede stive–elastiske ledd vurderes. Posisjonsreguleringsalgoritmer fungerer godt i frie rom, der robotmanipulatoren kan bevege seg fritt. Imidlertid kan posisjonsregulering føre til for store kontaktkrefter når en kollisjon oppstår. Kraftreguleringsalgoritmer fungerer derimot godt i begrensede rom, der robotmanipulatoren er i tett kontakt med omgivelsene. Imidlertid har kraftregulering dårlig posisjonsnøyaktighet. Impedansregulering er velkjent som en metode for å regulere forholdet mellom kontaktkraft og posisjonsfeil. Ved å ta i bruk impedansregulering kan sikkerheten forbedres ikke bare gjennom maskinvare, men også gjennom programvare. Hovedmålet med dette arbeidet er å forbedre sikkerheten i menneske–robotinteraksjon. Spesielt utvikles en robotmanipulator med blandede stive–elastiske ledd, og det utvikles reguleringsalgoritmer, inkludert impedansregulering. Arbeidet har tre hovedbidrag. For det første utledes den matematiske modellen for denne typen robotmanipulator. Egenskapene til den matematiske modellen analyseres. For det andre utvikles dedikerte reguleringsalgoritmer. Målet med de foreslåtte reguleringsalgoritmene er å sikre sikkerhet når robotmanipulatoren samhandler med omgivelsene. Til slutt designes en prototype av en robotmanipulator med blandede stive–elastiske ledd. Robotmanipulatoren har seks ledd. De tre første leddene er stive, og de tre siste leddene er elastiske. Delene til robotmanipulatoren er 3Dprintet og montert. Denne prototypen brukes til å teste de foreslåtte reguleringsalgoritmene. Dette arbeidet gir en systematisk utledning av den dynamiske modellen for robotmanipulatorer med blandede stive–elastiske ledd. Et annet viktig vitenskapelig bidrag ligger i utviklingen av reguleringsalgoritmer tilpasset manipulatorer med blandede stive–elastiske ledd. I motsetning til konvensjonell impedansregulering utviklet for fullt stive systemer, tar de foreslåtte strategiene eksplisitt hensyn til leddenes elastisitet i regulatorutformingen. Ved å forbedre sikkerheten under fysisk interaksjon støtter den foreslåtte tilnærmingen en bredere bruk av roboter i industri, helsevesen og hjemmemiljøer. Integrasjonen av elastisitet og impedansregulering bidrar til sikrere systemer for menneske–robot-interaksjon.

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