Article
Robotics
Bokman Lim, Byungjune Choi, Changhyun Roh, Seungyong Hyung, Yong-Jae Kim, Younbaek Lee
Summary: This letter introduces a parametric delayed output feedback controller for human-exoskeleton interactions during walking or running. The controller utilizes three adjustable parameters to generate various interaction torques and has been tested for reliability and efficacy. Results show that hip exoskeleton assistance can reduce metabolic cost during running, and different gait resistances can be provided using different time delays.
IEEE ROBOTICS AND AUTOMATION LETTERS
(2023)
Article
Construction & Building Technology
Dominic Jud, Simon Kerscher, Martin Wermelinger, Edo Jelavic, Pascal Egli, Philipp Leemann, Gabriel Hottiger, Marco Hutter
Summary: This article discusses the process of converting off-the-shelf construction machines into autonomous robotic systems, including the development of sensing equipment, actuation mechanisms, and controllers. Additionally, it highlights the potential of the autonomous walking excavator in real-world applications such as autonomous trench digging, assembly of dry stone walls, forestry work, and semi-autonomous teleoperation.
AUTOMATION IN CONSTRUCTION
(2021)
Article
Chemistry, Multidisciplinary
Sergio Hernandez-Mendez, Elvia Ruth Palacios-Hernandez, Antonio Marin-Hernandez, Ericka Janet Rechy-Ramirez, Hector Vazquez-Leal
Summary: This research introduces three coupled controllers for object manipulation using a robotic manipulator. The controllers employed in the study are a classic PID controller, a type-I controller, and a type-II fuzzy controller.
APPLIED SCIENCES-BASEL
(2021)
Article
Robotics
Antonio Prado, Sunil K. Agrawal
Summary: This study compares the effects of two types of vibratory inputs on gait. The results show that both continuous vibration and timed vibration can modify stride velocity and cadence. These effects depend on spatial and temporal parameters.
IEEE ROBOTICS AND AUTOMATION LETTERS
(2022)
Article
Robotics
Chinmay Jategaonkar, Yogesh Singh, Vineet Vashista
Summary: This study investigates the effect of ankle exoskeletons on ankle joint motion in healthy individuals, revealing the impact of residual damping on gait adaptation. It is significant for future exoskeleton design and rehabilitation paradigm decisions.
IEEE ROBOTICS AND AUTOMATION LETTERS
(2022)
Article
Computer Science, Artificial Intelligence
Adham Salih, Amiram Moshaiov
Summary: This paper investigates the topology and weight evolution of Neuro-Controllers (NCs) for developing motion controllers that can successfully handle multiple motion problems. By using a decomposition-based evolutionary algorithm, both specialized and non-specialized controllers are obtained. Experimental results demonstrate that the proposed approach achieves better results compared to other methods with the same number of evaluations.
NEURAL COMPUTING & APPLICATIONS
(2022)
Article
Automation & Control Systems
Marshall K. Ishmael, Dante Archangeli, Tommaso Lenzi
Summary: This article presents the design, development, and validation of an autonomous powered hip exoskeleton with high torque density. The exoskeleton is capable of assisting users in activities such as walking, running, and climbing stairs.
IEEE-ASME TRANSACTIONS ON MECHATRONICS
(2022)
Article
Multidisciplinary Sciences
Dave Schmitthenner, Anne E. Martin
Summary: This study inferred a human-like controller for a spring-loaded inverted pendulum (SLIP) model using experimental walking data and system identification techniques. Three methods were compared, with the linear system and SINDY system being the most accurate. The results suggest that nonlinear system identification techniques may not be necessary for studying unperturbed walking and that human control of normal walking may be approximately linear.
ROYAL SOCIETY OPEN SCIENCE
(2021)
Article
Chemistry, Multidisciplinary
Zhaolu Li, Yumin Song, Xiaoli Zhang, Xiafu Peng, Ning Xu
Summary: This paper designs a bionic-robot dog as an imitation of biological form and movement. The structural and motion characteristics of the bionic-dog model are studied by analyzing the physiological structure of dogs and capturing motion data. Experimental results show that the bionic-robot dog can perform stable fast-gait walking, slow-gait walking, and gait transitions.
APPLIED SCIENCES-BASEL
(2023)
Article
Robotics
Sangsin Park
Summary: The researcher presented and derived a closed-form solution for an optimal ZMP pattern, meeting ZMP boundary conditions and an additional constraint. The solution allows for generating a walking pattern for every step period and connecting seamlessly with previous patterns. Real-time adjustments to the walking pattern are demonstrated based on varying step lengths.
JOURNAL OF FIELD ROBOTICS
(2022)
Article
Computer Science, Artificial Intelligence
Jesus Hernandez-Barragan, Jorge D. Rios, Javier Gomez-Avila, Nancy Arana-Daniel, Carlos Lopez-Franco, Alma Y. Alanis
Summary: This study introduces an adaptive neural PD controller for position tracking of a mobile manipulator, trained with the EKF algorithm. The controller dynamically adjusts gains to eliminate steady-state error and improve performance, showing faster learning speeds and convergence times compared to traditional PID controllers.
PEERJ COMPUTER SCIENCE
(2021)
Article
Physics, Multidisciplinary
Gokhan Yalniz, Bjorn Hof, Nazmi Burak Budanur
Summary: The turbulent dynamics in simulations of the three-dimensional Navier-Stokes equations can be described as transient visits to unstable time-periodic solutions. By reducing the original system to a 17-node Markov chain, accurate long-term averages of the system's observables as weighted sums over periodic orbits can be reproduced.
PHYSICAL REVIEW LETTERS
(2021)
Article
Robotics
Karam Almaghout, Bahram Tarvirdizadeh, Khalil Alipour, Alireza Hadi
Summary: This paper presents a clinical rehabilitation robotic system for training the knee joint, taking into account the occurrence of undesirable movements. The system measures interaction torques exerted by involuntary movements and uses a PD-RBF neural network for control. Experimental results show that the admittance PD-RBF controller has superior performance compared to other controllers.
Article
Engineering, Biomedical
Marshall K. K. Ishmael, Andrew Gunnell, Kai Pruyn, Suzi Creveling, Grace Hunt, Sarah Hood, Dante Archangeli, K. Bo Foreman, Tommaso Lenzi
Summary: This study investigates the biomechanics of individuals with above-knee amputations walking with and without a unilateral powered hip exoskeleton. The findings suggest that assisting the residual limb can reduce the energy consumption of the residual hip, which is important for understanding walking economy in individuals with disabilities.
IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING
(2023)
Article
Robotics
Vighnesh Vatsal, Guy Hoffman
Summary: Wearable robotic arms can expand a user's workspace and capabilities, but may also subject them to significant physical loads. This study introduces a framework aimed at minimizing muscle loads by incorporating a biomechanical cost term into the motion planning process. By utilizing locally-optimized initialization paths, mean human muscle fiber forces can be reduced by up to 23.47% compared to linearly interpolated trajectories.
IEEE ROBOTICS AND AUTOMATION LETTERS
(2021)
Article
Automation & Control Systems
Shishir Kolathaya, Aaron D. Ames
NONLINEAR ANALYSIS-HYBRID SYSTEMS
(2017)
Article
Automation & Control Systems
Aaron D. Ames, Paulo Tabuada, Austin Jones, Wen-Loong Ma, Matthias Rungger, Bastian Schuermann, Shishir Kolathaya, Jessy W. Grizzle
NONLINEAR ANALYSIS-HYBRID SYSTEMS
(2017)
Article
Robotics
Wen-Loong Ma, Noel Csomay-Shanklin, Shishir Kolathaya, Kaveh Akbari Hamed, Aaron D. Ames
Summary: This research introduces a novel framework that views rigid-body systems as a collection of lower-dimensional systems coupled via reaction forces. Stabilizing each subsystem coupled through passive dynamics ensures convergence for each control subsystem. Stability conditions are guaranteed for each control subsystem by formulating coupled control Lyapunov functions using the notion of input-to-state stability.
IEEE ROBOTICS AND AUTOMATION LETTERS
(2021)
Article
Robotics
Lokesh Krishna, Guillermo A. Castillo, Utkarsh A. Mishra, Ayonga Hereid, Shishir Kolathaya
Summary: In this work, we demonstrate robust walking in the bipedal robot Digit on uneven terrains by learning a single linear policy. The proposed control pipeline includes a high-level trajectory modulator for shaping foot trajectories and a low-level gait controller for regulating torso and ankle orientation. The linear policy used has only 13 learnable parameters, guaranteeing sample efficient learning and providing simplicity and interpretability of the policy. This work shows no loss of performance when facing challenging terrains and can be directly transferred to hardware.
IEEE ROBOTICS AND AUTOMATION LETTERS
(2022)
Article
Automation & Control Systems
Andrew Singletary, Shishir Kolathaya, Aaron D. Ames
Summary: The article introduces a method based on control barrier functions to ensure the safety of robotic systems. By combining kinetic energy with traditional CBF forms, the model dependence and conservativeness are minimized. The method is demonstrated in simulation on two robotic platforms.
IEEE CONTROL SYSTEMS LETTERS
(2022)
Article
Automation & Control Systems
Shishir Kolathaya
Summary: This letter investigates the stability properties of Proportional-Derivative (PD) controlled underactuated robotic systems for trajectory tracking applications, revealing that PD control laws can yield desirable tracking guarantees for a subclass of robotic systems. However, caution is advised as some systems may lead to instability with PD tracking control laws.
IEEE CONTROL SYSTEMS LETTERS
(2021)
Proceedings Paper
Automation & Control Systems
Sagar Gubbi, Shishir Kolathaya, Bharadwaj Amrutur
2020 6TH INTERNATIONAL CONFERENCE ON CONTROL, AUTOMATION AND ROBOTICS (ICCAR)
(2020)
Proceedings Paper
Computer Science, Artificial Intelligence
Shishir Kolathaya, Sushant Veer
2019 IEEE/RSJ INTERNATIONAL CONFERENCE ON INTELLIGENT ROBOTS AND SYSTEMS (IROS)
(2019)
Proceedings Paper
Computer Science, Artificial Intelligence
Shishir Kolathaya, Ashish Joglekar, Suhan Shetty, Dhaivat Dholakiya, Abhimanyu, Aditya Sagi, Shounak Bhattacharya, Abhik Singla, Shalabh Bhatnagar, Ashitava Ghosal, Bharadwaj Amrutur
2019 28TH IEEE INTERNATIONAL CONFERENCE ON ROBOT AND HUMAN INTERACTIVE COMMUNICATION (RO-MAN)
(2019)
Proceedings Paper
Computer Science, Artificial Intelligence
Shounak Bhattacharya, Abhik Singla, Abhimanyu, Dhaivat Dholakiya, Shalabh Bhatnagar, Bharadwaj Amrutur, Ashitava Ghosal, Shishir Kolathaya
2019 28TH IEEE INTERNATIONAL CONFERENCE ON ROBOT AND HUMAN INTERACTIVE COMMUNICATION (RO-MAN)
(2019)
Proceedings Paper
Automation & Control Systems
Abhik Singla, Shounak Bhattaeharya, Dhaivat Dholakiya, Shalabh Bhatnagar, Ashitava Ghosal, Bharadwaj Amrutur, Shishir Kolathaya
2019 INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION (ICRA)
(2019)
Article
Robotics
Shishir Kolathaya, William Guffey, Ryan W. Sinnet, Aaron D. Ames
IEEE ROBOTICS AND AUTOMATION LETTERS
(2018)
Proceedings Paper
Automation & Control Systems
Ayonga Hereid, Shishir Kolathaya, Aaron D. Ames
2016 IEEE 55TH CONFERENCE ON DECISION AND CONTROL (CDC)
(2016)
Article
Automation & Control Systems
Shishir Kolathaya, Aaron D. Ames
IEEE CONTROL SYSTEMS LETTERS
(2019)
Article
Automation & Control Systems
Xiaoyu Luo, Chengcheng Zhao, Chongrong Fang, Jianping He
Summary: This paper investigates the problem of false data injection attacks in multi-agent dynamical systems and proposes FDI attack set selection algorithms to maximize the convergence error by finding the optimal subset of compromised agents.
Article
Automation & Control Systems
Nitin K. Singh, Abhisek K. Behera
Summary: In this paper, a twisting observer is proposed for robustly estimating the states of a second-order uncertain system. The observer approximates the unknown sign term for the non-measurable state with a delayed output-based switching function, and achieves the desired steady-state accuracy by controlling the delay parameter. The application of the observer to output feedback stabilization is also discussed.
Article
Automation & Control Systems
Alexander Aleksandrov
Summary: This paper investigates the absolute stability problem for positive Persidskii systems with delay, proposes a special construction method for diagonal Lyapunov-Krasovskii functionals, and derives a criterion for the existence of such functionals guaranteeing the absolute stability, as well as obtaining sufficient conditions for a family of time-delay Persidskii systems to construct a common diagonal Lyapunov-Krasovskii functional. The efficiency of the developed approaches is demonstrated through four examples.
Article
Automation & Control Systems
Noureddine Toumi, Roland Malhame, Jerome Le Ny
Summary: This paper addresses large multi-agent dynamic discrete choice problems using a linear quadratic mean field games framework. The model incorporates the features where agents have to reach a predefined set of possible destinations within a fixed time frame and running costs can become negative to simulate crowd avoidance. An upper bound on the time horizon is derived to prevent agents from escaping to infinity in finite time. The existence of a Nash equilibrium for infinite population and its epsilon-Nash property for a large but finite population are established. Simulations are conducted to explore the model behavior in various scenarios.
Article
Automation & Control Systems
Philippe Schuchert, Vaibhav Gupta, Alireza Karimi
Summary: This paper presents the design of fixed-structure controllers for the As2 and Asw synthesis problem using frequency response data. The minimization of the norm of the transfer function between the exogenous inputs and performance outputs is approximated through a convex optimization problem involving Linear Matrix Inequalities (LMIs). A general controller parametrization is used for continuous and discrete-time controllers with matrix transfer function or state-space representation. Numerical results show that the proposed data-driven method achieves performance equivalent to model-based approaches when a parametric model is available.
Correction
Automation & Control Systems
Zhijun Guo, Gang Chen
Article
Automation & Control Systems
Matteo Della Rossa, Thiago Alves Lima, Marc Jungers, Raphael M. Jungers
Summary: This paper presents new stabilizability conditions for switched linear systems with arbitrary and uncontrollable underlying switching signals. The study focuses on two specific settings: the robust case with completely unknown and unobservable active mode, and the mode-dependent case with controller depending on the current active switching mode. The technical developments are based on graph-theory tools and path-complete Lyapunov functions framework, enabling the design of robust and mode-dependent piecewise linear state-feedback controllers using directed and labeled graphs.
Article
Automation & Control Systems
Elena Petri, Romain Postoyan, Daniele Astolfi, Dragan Nesic, W. P. M. H. (Maurice) Heemels
Summary: This study investigates a scenario where a perturbed nonlinear system transmits its output measurements to a remote observer via a packet-based communication network. By designing both the observer and the local transmission policies, accurate state estimates can be obtained while only sporadically using the communication network.
Article
Automation & Control Systems
Jonas Krook, Robi Malik, Sahar Mohajerani, Martin Fabian
Summary: This paper proposes a method to synthesise controllers for cyber-physical systems subjected to disturbances, such that the controlled system satisfies specifications given as linear temporal logic formulas. The approach constructs a finite-state abstraction of the original system and synthesises a controller for the abstraction. It introduces the robust stutter bisimulation relation to account for disturbances and uncertainty, ensuring that related states have similar effects under the same controller. The paper demonstrates that the existence of a controller for the abstracted system implies the existence of a controller for the original system enforcing the linear temporal logic formula.
Article
Automation & Control Systems
Clement Chahbazian, Karim Dahia, Nicolas Merlinge, Benedicte Winter-Bonnet, Aurelien Blanc, Christian Musso
Summary: The paper derives a recursive formula of the Fisher information matrix on Lie groups and applies it to nonlinear Gaussian systems on Lie groups for testing. The proposed recursive CRLB is consistent with state-of-the-art filters and exhibits representative behavior in estimation errors. This paper provides a simple method to recursively compute the minimal variance of an estimator on matrix Lie groups, which is fundamental for implementing robust algorithms.
Article
Automation & Control Systems
Yiheng Fu, Pouria Ramazi
Summary: This study investigates the characteristics of decision fluctuations in heterogeneous populations and explores the uncertainties in imitation behavior. The findings are important for understanding the bounded rationality nature of imitation behaviors.
Article
Automation & Control Systems
Lars A. L. Janssen, Bart Besselink, Rob H. B. Fey, Nathan van de Wouw
Summary: This paper introduces a mathematical relationship between the accuracy of reduced-order linear-time invariant subsystem models and the stability and accuracy of the resulting reduced-order interconnected linear time-invariant model. This result can be used to directly translate the accuracy characteristics of the reduced-order subsystem models to the accuracy properties of the interconnected reduced-order model, or to translate accuracy requirements on the interconnected system model to accuracy requirements on subsystem models.
Article
Automation & Control Systems
Piyush Gupta, Vaibhav Srivastava
Summary: We study the optimal fidelity selection for a human operator servicing tasks in a queue, considering the trade-off between high-quality service and penalty due to increased queue length. By modeling the operator's cognitive dynamics and task fidelity, we determine the optimal policy and value function numerically, and analyze the structural properties of the optimal fidelity policy.
Article
Automation & Control Systems
Lukas Schwenkel, Alexander Hadorn, Matthias A. Mueller, Frank Allgoewer
Summary: In this work, the authors study economic model predictive control (MPC) in periodic operating conditions. They propose a method to achieve optimality by multiplying the stage cost by a linear discount factor, which is easy to implement and robust against online changes. Under certain assumptions, they prove that the resulting linearly discounted economic MPC achieves optimal asymptotic average performance and guarantees practical asymptotic stability of the optimal periodic orbit.
Article
Automation & Control Systems
Taher Ebrahim, Sankaranarayanan Subramanian, Sebastian Engell
Summary: We propose a robust nonlinear model predictive control algorithm for dynamic systems with mixed degrees of freedom. This algorithm optimizes both continuous and discrete manipulated variables, enhancing closed-loop performance. Our approach relies on a computationally efficient relaxation and integrality restoration strategy and provides sufficient conditions to establish recursive feasibility and guarantee robust closed-loop stability. The effectiveness of the approach is demonstrated through two nonlinear simulation examples.
