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All Outputs (41)

Realizing low-impedance rendering in admittance-type haptic interfaces using the input-to-state stable approach (2017)
Journal Article
Nabeel, M., Jafari, A., & Ryu, J. H. (2017). Realizing low-impedance rendering in admittance-type haptic interfaces using the input-to-state stable approach. Proceedings of the ... IEEE/RSJ International Conference on Intelligent Robots and Systems. IEEE/RSJ International Conference on Intelligent Robots and Systems, 2017-September, 914-919. https://doi.org/10.1109/IROS.2017.8202254

© 2017 IEEE. This paper proposes an approach to enlarge the impedance range of admittance-type haptic interfaces. Admittance-type haptic interfaces have advantages over impedance-type haptic interfaces in the interaction with high impedance virtual e... Read More about Realizing low-impedance rendering in admittance-type haptic interfaces using the input-to-state stable approach.

The Input-to-State Stable (ISS) approach for stabilizing haptic interaction with virtual environments (2017)
Journal Article
Jafari, A., Nabeel, M., & Ryu, J. H. (2017). The Input-to-State Stable (ISS) approach for stabilizing haptic interaction with virtual environments. IEEE Transactions on Robotics, 33(4), 948-963. https://doi.org/10.1109/TRO.2017.2676127

© 2004-2012 IEEE. Passivity has been a major criterion for designing a stable haptic interface due to its numerous advantages. However, passivity-based controllers have suffered from the design conservatism of the passivity criterion, particularly wh... Read More about The Input-to-State Stable (ISS) approach for stabilizing haptic interaction with virtual environments.

Multi degree-of-freedom successive stiffness increment approach for high stiffness haptic interaction (2016)
Presentation / Conference
Singh, H., Jafari, A., & Ryu, J. (2016, November). Multi degree-of-freedom successive stiffness increment approach for high stiffness haptic interaction. Paper presented at Asia Haptics, Kashiwanoha, Japan

In haptic interaction, stability and the object’s hardness perception are of great significance. Although numerous studies have been done for stable haptic interaction, however, most of them sacrifice the actual displayed stiffness as a cost of stabi... Read More about Multi degree-of-freedom successive stiffness increment approach for high stiffness haptic interaction.

Stable and transparent teleoperation over communication time-delay: Observer-based input-to-state stable approach (2016)
Journal Article
Jafari, A., Nabeel, M., Singh, H., & Ryu, J. (2016). Stable and transparent teleoperation over communication time-delay: Observer-based input-to-state stable approach. IEEE Haptics Symposium : [proceedings]. IEEE Haptics Symposium, 2016-April, 235-240. https://doi.org/10.1109/HAPTICS.2016.7463183

In this paper, an observer-based input-to-state stable approach is proposed to stabilize teleoperation systems over communication time-delay with better transparency compared with passivity approaches. In this paper, input-to-state stable approach is... Read More about Stable and transparent teleoperation over communication time-delay: Observer-based input-to-state stable approach.

Independent force and position control for cooperating manipulators handling an unknown object and interacting with an unknown environment (2016)
Journal Article
Ryu, J. H., Jafari, A., & Jee-Hwan, R. (2016). Independent force and position control for cooperating manipulators handling an unknown object and interacting with an unknown environment. Journal of The Franklin Institute, 353(4), 857-875. https://doi.org/10.1016/j.jfranklin.2015.12.010

© 2016 The Franklin Institute. Published by Elsevier Ltd. All rights reserved. This paper presents a unified framework for system design and control in cooperative robotic systems. It introduces a highly generalized cooperative system configuration t... Read More about Independent force and position control for cooperating manipulators handling an unknown object and interacting with an unknown environment.

Increasing the impedance range of admittance-type haptic interfaces by using Time Domain Passivity Approach (2015)
Journal Article
Hwang, J. H., Nabeel, M., Lee, J., Mehmood, U., Jafari, A., & Ryu, J. H. (2015). Increasing the impedance range of admittance-type haptic interfaces by using Time Domain Passivity Approach. Proceedings of the ... IEEE/RSJ International Conference on Intelligent Robots and Systems. IEEE/RSJ International Conference on Intelligent Robots and Systems, 2015-December, 585-590. https://doi.org/10.1109/IROS.2015.7353431

© 2015 IEEE. This paper proposes a method to increase the impedance range of admittance-type haptic interfaces. Admittance-type haptic interfaces are used in various applications that typically require interaction with high impedance virtual environm... Read More about Increasing the impedance range of admittance-type haptic interfaces by using Time Domain Passivity Approach.

Stable bilateral teleoperation with input-to-state stable approach (2015)
Conference Proceeding
Jafari, A., Nabeel, M., & Ryu, J. (2015). Stable bilateral teleoperation with input-to-state stable approach

Passivity has been the most often used constraint for the controller design of bilateral teleoperation systems. However passivity has been suffering from its own design conservatism since this is a sufficient condition for stability and representing... Read More about Stable bilateral teleoperation with input-to-state stable approach.

Network formulation and stability improvement of a bilateral teleoperation system with admittance-type master interfaces (2015)
Conference Proceeding
Nabeel, M., Jafari, A., & Ryu, J. H. (2015). Network formulation and stability improvement of a bilateral teleoperation system with admittance-type master interfaces. https://doi.org/10.1109/AIM.2015.7222796

© 2015 IEEE. This paper introduces a network formulation of bilateral teleoperation systems with admittance-type master interfaces to improve their stability range with Time Domain Passivity Approach (TDPA). Since traditional network representation o... Read More about Network formulation and stability improvement of a bilateral teleoperation system with admittance-type master interfaces.

Stable admittance type haptic interaction based on time domain passivity approach (2015)
Journal Article
Jafari, A., Totorkulov, K., & Ryu, J. (2015). Stable admittance type haptic interaction based on time domain passivity approach

In this paper, we propose a stable and high transparent admittance haptic display even in free space haptic rendering. Because considering admittance haptic rendering as a one-port network is not enough to detect the active energy, new representation... Read More about Stable admittance type haptic interaction based on time domain passivity approach.

Input-to-state stable approach to release the conservatism of passivity-based stable haptic interaction (2015)
Journal Article
Jafari, A., & Ryu, J. H. (2015). Input-to-state stable approach to release the conservatism of passivity-based stable haptic interaction. IEEE International Conference on Robotics and Automation, 2015-June(June), 285-290. https://doi.org/10.1109/ICRA.2015.7139013

© 2015 IEEE. Passivity has been a major criterion on designing a stable haptic interface due to many advantages. However, passivity has been suffering from its intrinsic conservatism since it only represents a small set of the whole stable region. Th... Read More about Input-to-state stable approach to release the conservatism of passivity-based stable haptic interaction.

6-DOF extension of memory-based passivation approach for stable haptic interaction (2014)
Journal Article
Jafari, A., & Ryu, J. H. (2015). 6-DOF extension of memory-based passivation approach for stable haptic interaction. Intelligent Service Robotics, 8(1), 23-34. https://doi.org/10.1007/s11370-014-0161-y

© 2014, Springer-Verlag Berlin Heidelberg. This paper extends previously proposed memory-based passivity approach (MBPA) to 6 degrees-of-freedom (DOF) haptic interactions. By introducing 6-DOF virtual proxy and virtual object, connected with haptic i... Read More about 6-DOF extension of memory-based passivation approach for stable haptic interaction.

Hybrid force-motion control of coordinated robots interacting with unknown environments (2014)
Journal Article
Jafari, A., & Ryu, J. H. (2014). Hybrid force-motion control of coordinated robots interacting with unknown environments. https://doi.org/10.1109/ICCAS.2014.6987966

© 2014 Institute of Control, Robotics and Systems (ICROS). This paper presents a unified framework for system design and control in cooperative robotic systems. It introduces a highly general cooperative system configuration involving any number of m... Read More about Hybrid force-motion control of coordinated robots interacting with unknown environments.

Sliding mode hybrid impedance control of robot manipulators interacting with unknown environments using VSMRC method (2013)
Presentation / Conference
Jafari, A., Ryu, J., Rezaei, M., Monfaredi, R., Talebi, A., & Shiry Ghidary, S. (2013, October). Sliding mode hybrid impedance control of robot manipulators interacting with unknown environments using VSMRC method. Paper presented at The 44th IEEE International Symposium on Robotics (ISR 2013), Seoul, Korea

In the present paper, the objective of hybrid impedance control is specified and a robust hybrid impedance control approach is proposed. Based on the concept of hybrid control, the task space is decomposed into position and force controlled subspaces... Read More about Sliding mode hybrid impedance control of robot manipulators interacting with unknown environments using VSMRC method.

Transparency improved sliding-mode control design for bilateral teleoperation systems by using virtual manipulator concept (2013)
Journal Article
Jafari, A., & Ryu, J. H. (2013). Transparency improved sliding-mode control design for bilateral teleoperation systems by using virtual manipulator concept. IFAC-PapersOnLine, 3(PART 1), 21-26. https://doi.org/10.3182/20131111-3-KR-2043.00013

This paper proposes a new methodology for designing sliding mode bilateral controllers based virtual manipulator concept that aims to reach the most transparency considering parameter uncertainties and disturbances. This method shows a modified schem... Read More about Transparency improved sliding-mode control design for bilateral teleoperation systems by using virtual manipulator concept.

Successive stiffness increment approach for high stiffness haptic interaction
Presentation / Conference
Singh, H., Jafari, A., & Ryu, J. Successive stiffness increment approach for high stiffness haptic interaction. Paper presented at IEEE Eurohaptics 2016 Conference

This paper proposes a method to further enlarge the displayed stiffness range of the impedance-type haptic interfaces. Numerous studies have been done for a stable haptic interaction in a wide impedance range. However, most of the approaches sacrific... Read More about Successive stiffness increment approach for high stiffness haptic interaction.

Increasing the rate-hardness of haptic interaction: Successive force augmentation approach
Conference Proceeding
Singh, H., Jafari, A., & Ryu, J. (2017). Increasing the rate-hardness of haptic interaction: Successive force augmentation approach

There have been numerous approaches that have been proposed to enlarge the impedance range, however it is still a challenging issue to increase the rate-hardness of haptic interaction while maintaining stability. The actual perceived rate-hardness ha... Read More about Increasing the rate-hardness of haptic interaction: Successive force augmentation approach.

Independent force and position control for cooperating manipulators handling an unknown object interacting with an unknown environment
Presentation / Conference
Jafari, A., & Ryu, J. Independent force and position control for cooperating manipulators handling an unknown object interacting with an unknown environment. Paper presented at 44th International Symposium on Robotics (ISR) 2013

In this paper, we consider two manipulators grasping a rigid object in contact with a deformable working surface, whose real physical parameters are unknown. Dynamics of the closed chain mechanism is expressed based on the objects center of mass, and... Read More about Independent force and position control for cooperating manipulators handling an unknown object interacting with an unknown environment.

An adaptive hybrid force/motion control design for robot manipulators interacting in constrained motion with unknown non-rigid environments
Presentation / Conference
Jafari, A., Ryu, J., Rezaei, M., Monfaredi, R., Talebi, A., & Ghidary, S. An adaptive hybrid force/motion control design for robot manipulators interacting in constrained motion with unknown non-rigid environments. Paper presented at IEEE ISR 2013

In the present paper, the objective of hybrid control is specified and an adaptive hybrid force/motion control approach is proposed. Based on the concept of hybrid control, the task space is decomposed into position and force controlled subspaces. An... Read More about An adaptive hybrid force/motion control design for robot manipulators interacting in constrained motion with unknown non-rigid environments.

Multi degree-of-freedom input-to- state stable approach for stable haptic interaction
Presentation / Conference
Jafari, A., Nabeel, M., & Ryu, J. Multi degree-of-freedom input-to- state stable approach for stable haptic interaction. Paper presented at IEEE World Haptics Conference (WHC 2015), Chicago

Passivity has been the most often used constraint for the controller design of haptic interfaces. However, the designed controller based on passivity constraint has been suffering from its conservatism, especially when the user wants to increase the... Read More about Multi degree-of-freedom input-to- state stable approach for stable haptic interaction.