48 results found
© 2018 IEEE. Inspired by teleost fish scale, this paper investigates the possibility of implementing stiffness control as a new source of robots dexterity and flexibility control. Guessing about the possibility of biological scale jamming in real fish, we try to understand the possible underlying actuation mechanism of such behavior by conducting experiments on a Cyprinus carpio fish skin sample. Bulking tests are carried out on an encapsulated skin sample, in thin latex rubber, for unjammed and vacuum jammed cases. For the first time, we observed biological scale jamming with very small hysteresis due to the unique scale morphology and jammed stacking formation. We call this unique feature 'Geometrical Jamming' where the resisting force is due to the stacking formation rather than the interlocking friction force. Inspiring by this unique morphology and helical arrangement of the scale, in this research, we investigate different possible design and actuation mechanisms for an integrable scale jamming interface for stiffness control of continuum manipulators. A set of curved scales are 3D printed which maintain a helix formation when are kept in place and jammed with two thin fishing steel wires. The non-self locking jagged contact surfaces replicate inclined stacking formation of the jammed fish scale resulting in the same reversible low hysteresis characteristics, in contrast to the available interlocking designs. The effectiveness of the designs are shown for uniaxial elongation experiments and the results are compared with similar research. The contact surfaces, in our design, can be lubricated for further hysteresis reduction to achieve smooth, repeatable and accurate stiffness control in dynamic tasks.
Ranasinghe A, Dasgupta P, Nagar A, et al., 2018, Human Behavioral Metrics of a Predictive Model Emerging During Robot Assisted Following Without Visual Feedback, IEEE Robotics and Automation Letters, Vol: 3, Pages: 2624-2631
He L, Herzig N, de Lusignan S, et al., 2018, Granular Jamming Based Controllable Organ Design for Abdominal Palpation., Pages: 2154-2157, ISSN: 1557-170X
Medical manikins play an essential role in the training process of physicians. Currently, most available simulators for abdominal palpation training do not contain controllable organs for dynamic simulations. In this paper, we present a soft robotics controllable liver that can simulate various liver diseases and symptoms for effective and realistic palpation training. The tumors in the liver model are designed based on granular jamming with positive pressure, which converts the fluid-like impalpable particles to a solid-like tumor state by applying low positive pressure on the membrane. Through inflation, the tumor size, liver stiffness, and liver size can be controlled from normal liver state to various abnormalities including enlarged liver, cirrhotic liver, and multiple cancerous and malignant tumors. Mechanical tests have been conducted in the study to evaluate the liver design and the role of positive pressure granular jamming in tumor simulations.
Sadati SMH, Sullivan L, Walker ID, et al., 2018, Three-Dimensional-Printable Thermoactive Helical Interface With Decentralized Morphological Stiffness Control for Continuum Manipulators, Pages: 2283-2290
Herzig N, Maiolino P, Iida F, et al., 2018, A Variable Stiffness Robotic Probe for Soft Tissue Palpation, IEEE Robotics and Automation Letters, Vol: 3, Pages: 1168-1175
Sadati SMH, Naghibi SE, Walker ID, et al., 2018, Control Space Reduction and Real-Time Accurate Modeling of Continuum Manipulators Using Ritz and Ritz-Galerkin Methods, IEEE ROBOTICS AND AUTOMATION LETTERS, Vol: 3, Pages: 328-335, ISSN: 2377-3766
Cotugno G, Konstantinova J, Althoefer K, et al., 2018, Modelling the structure of object-independent human affordances of approaching to grasp for robotic hands., PLoS One, Vol: 13
Grasp affordances in robotics represent different ways to grasp an object involving a variety of factors from vision to hand control. A model of grasp affordances that is able to scale across different objects, features and domains is needed to provide robots with advanced manipulation skills. The existing frameworks, however, can be difficult to extend towards a more general and domain independent approach. This work is the first step towards a modular implementation of grasp affordances that can be separated into two stages: approach to grasp and grasp execution. In this study, human experiments of approaching to grasp are analysed, and object-independent patterns of motion are defined and modelled analytically from the data. Human subjects performed a specific action (hammering) using objects of different geometry, size and weight. Motion capture data relating the hand-object approach distance was used for the analysis. The results showed that approach to grasp can be structured in four distinct phases that are best represented by non-linear models, independent from the objects being handled. This suggests that approaching to grasp patterns are following an intentionally planned control strategy, rather than implementing a reactive execution.
, 2017, Trends in robot assisted endovascular catheterization technology: A review, Pages: 34-41
© 2017 IEEE. Thirty-Three years has passed since the first utilization of laparoscopic technology in surgery, yet the deployment of robots in endovascular catheterization process is currently still in its infancy. Following up some reviews by other researchers, this paper elaborates trends in robotic-Assisted endovascular catheterization through literature study of published articles since the last 4 years, direct observation of on going minimally invasive endovascular intervention surgery, and discussions with an interventional cardiologist. Some important facts have been identified such as, some commercial robots have been used In Vitro, and magnetic resonance compatible slave robots as well as methods for physician skill evaluation are under development. The existing issues include miniaturization of flexible robots, side contact force sensing device for catheters, and stable haptic feedback in master robot. Some examples of interesting topics for future research are more stable and robust haptic feedback, structure and mechanism of catheter, intra-cardiac sensors, estimation methods of catheter tip states (position, angle and contact force), modeling and control methods, image sensing technology which does not yield radiation exposure yet more economically affordable, and simulator with skill assessment algorithm.
Cotugno G, Althoefer K, Nanayakkara T, 2017, The Role of the Thumb: Study of Finger Motion in Grasping and Reachability Space in Human and Robotic Hands, IEEE TRANSACTIONS ON SYSTEMS MAN CYBERNETICS-SYSTEMS, Vol: 47, Pages: 1061-1070, ISSN: 2168-2216
Sornkarn N, Nanayakkara T, 2017, Can a Soft Robotic Probe Use Stiffness Control Like a Human Finger to Improve Efficacy of Haptic Perception?, IEEE TRANSACTIONS ON HAPTICS, Vol: 10, Pages: 183-195, ISSN: 1939-1412
, 2017, A biologically inspired multimodal whisker follicle, Pages: 3847-3852
© 2016 IEEE. Mammalian whisker follicle contains multiple sensory receptors strategically organized to capture tactile sensory stimuli of different frequencies via the vibrissal system. There have been a number of attempts to develop robotic whiskers to perform texture classification tasks in the recent past. Inspired by the features of biological whisker follicle, in this paper we design and use a novel soft whisker follicle comprising of two different frequency-dependent data capturing modules to derive deeper insights into the biological basis of tactile perception in the mammalian whisker follicle. In our design, the innervations at the Outer Conical Body (OCB) of a biological follicle are realized by a piezoelectric transducer for capturing high frequency components; whereas the innervations around the hair Papilla are represented by a hall sensor to capture low frequency components during the interaction with the environment. In this paper, we show how low dimensional information such as the principle components of co-variation of these two sensory modalities vary for different speeds and indentations of brushing the whisker against a surface. These new insights into the biological basis of tactile perception using whiskers provides new design guidelines to develop efficient robotic whiskers.
, 2017, Mechanics of continuum manipulators, a comparative study of five methods with experiments, Pages: 686-702, ISSN: 0302-9743
© Springer International Publishing AG 2017. Investigations on control and optimization of continuum manipulators have resulted in a number of kinematic and dynamic modeling approaches each having their own advantages and limitations in various applications. In this paper, a comparative study of five main methods in the literature for kinematic, static and dynamic modeling of continuum manipulators is presented in a unified mathematical framework. The five widely used methods of Lumped system dynamic model, Constant curvature, two-step modified constant curvature, variable curvature Cosserat rod and beam theory approach, and series solution identification are re-viewed here with derivation details in order to clarify their methodological differences. A comparison between computer simulations and experimental results using a STIFF-FLOP continuum manipulator is presented to study the advantages of each modeling method.
Konstantinova J, Cotugno G, Dasgupta P, et al., 2017, Palpation force modulation strategies to identify hard regions in soft tissue organs., PLoS One, Vol: 12
This paper presents experimental evidence for the existence of a set of unique force modulation strategies during manual soft tissue palpation to locate hard abnormalities such as tumors. We explore the active probing strategies of defined local areas and outline the role of force control. In addition, we investigate whether the applied force depends on the non-homogeneity of the soft tissue. Experimental results on manual palpation of soft silicone phantoms show that humans have a well defined force control pattern of probing that is used independently of the non-homogeneity of the soft tissue. We observed that the modulations of lateral forces are distributed around the mean frequency of 22.3 Hz. Furthermore, we found that the applied normal pressure during probing can be modeled using a second order reactive autoregressive model. These mathematical abstractions were implemented and validated for the autonomous palpation for different stiffness parameters using a robotic probe with a rigid spherical indentation tip. The results show that the autonomous robotic palpation strategy abstracted from human demonstrations is capable of not only detecting the embedded nodules, but also enhancing the stiffness perception compared to static indentation of the probe.
, 2016, Autonomous robotic palpation of soft tissue using the modulation of applied force, Pages: 323-328, ISSN: 2155-1774
© 2016 IEEE. Palpation or perception of tactile information from soft tissue organs during minimally invasive surgery is required to improve clinical outcomes. One of the methods of palpation includes examination using the modulation of applied force on the localized area. This paper presents a method of soft tissue autonomous palpation based on the mathematical model obtained from human tactile examination data using modulations of palpation force. Using a second order reactive auto-regressive model of applied force, a robotic probe with spherical indenter was controlled to examine silicone tissue phantoms containing artificial nodules. The results show that the autonomous palpation using the model abstracted from human demonstration can be used not only to detect embedded nodules, but also to enhance the stiffness perception compared to the static indentation of the probe.
, 2016, The efficacy of interaction behavior and internal stiffness control for embodied information gain in haptic perception, Pages: 2657-2662, ISSN: 1050-4729
© 2016 IEEE. Haptic perception in biological systems not only depends on the environmental conditions, but also on the behavioral state and the internal impedance of the embodiment because proprioceptive sensors are embedded in the muscle and tendons used for actuation. A simple example of such a phenomenon can be found when people are asked to palpate a soft tissue to identify a stiff-inclusion. People tend to perform a variety of palpation strategies depending on their previous knowledge and the desired information. Does this mean that the probing behavioral variables and internal muscle impedance parameters and their interaction with given environmental conditions play a role in the perception information gain during the estimation of soft tissue's properties? In this paper, we use a two-degree of freedom laboratory-made variable stiffness and indentation probe to investigate how the modulation of probing behavioral and internal stiffness variables can affect the accuracy of the depth estimation of stiff inclusions in artificial silicon phantom tissue using information gain metrics based on prior knowledge in form of memory primitives.
Sadati SMH, Shiva A, Ataka A, et al., 2016, A geometry deformation model for compound continuum manipulators with external loading, Proceedings - IEEE International Conference on Robotics and Automation, Vol: 2016-June, Pages: 4957-4962, ISSN: 1050-4729
© 2016 IEEE. The complexity of soft continuum manipulators with hybrid and tuneable structures poses a challenging task to achieve an inverse kinematics model which is both precise and computationally efficient for control and optimization purposes. In this paper, a new method based on the principle of virtual work and a geometry deformation approach is presented for the inverse kinematics model of the STIFF-FLOP arm which is a pneumatically actuated continuum manipulator. We propose a novel simplified and computationally efficient yet accurate analytical solution to analyse the static behaviour of a compound soft manipulator in the presence of external and body forces which is verified against experimental data, showing promising agreement with 10% mean error for planar movements. In the process, we present a new modelling approach for braided soft extensor actuators with no braid-surface relative slip constraint. For the first time, our model predicts a simple analytical solution for the cross section deformation which is essential to control soft manipulators with regional tunable stiffness structure.
Sornkarn N, Dasgupta P, Nanayakkara T, 2016, Morphological Computation of Haptic Perception of a Controllable Stiffness Probe, PLOS ONE, Vol: 11, ISSN: 1932-6203
, 2016, Stable Grip Control on Soft Objects With Time-Varying Stiffness, IEEE Transactions on Robotics, Vol: 32, Pages: 626-637, ISSN: 1552-3098
© 2016 IEEE. Humans can hold a live animal like a hamster without overly squeezing despite the fact that its soft body undergoes impedance and size variations due to breathing and wiggling. Although the exact nature of such biological motor controllers is not known, existing literature suggests that they maintain metastable interactions with dynamic objects based on prediction rather than reaction. Most robotic gripper controllers find such tasks very challenging mainly due to hard constraints imposed on the stability of closed-loop control and inadequate rates of convergence of adaptive controller parameters. This paper presents experimental and numerical simulation results of a control law based on a relaxed stability criterion of reducing the probability of failure to maintain a stable grip on a soft object that undergoes temporal variations in its internal impedance. The proposed controller uses only three parameters to interpret the probability of failure estimated using a history of grip forces to adjust the grip on the dynamic object. Here, we demonstrate that the proposed controller can maintain smooth and stable grip tightening and relaxing when the object undergoes random impedance variations, compared with a reactive controller that involves a similar number of controller parameters.
Ranasinghe A, Sornkarn N, Dasgupta P, et al., 2016, Salient Feature of Haptic-Based Guidance of People in Low Visibility Environments Using Hard Reins., IEEE Trans Cybern, Vol: 46, Pages: 568-579
This paper presents salient features of human-human interaction where one person with limited auditory and visual perception of the environment (a follower) is guided by an agent with full perceptual capabilities (a guider) via a hard rein along a given path. We investigate several salient features of the interaction between the guider and follower such as: 1) the order of an autoregressive (AR) control policy that maps states of the follower to actions of the guider; 2) how the guider may modulate the pulling force in response to the trust level of the follower; and 3) how learning may successively apportion the responsibility of control across different muscles of the guider. Based on experimental systems identification on human demonstrations from ten pairs of naive subjects, we show that guiders tend to adopt a third-order AR predictive control policy and followers tend to adopt second-order reactive control policy. Moreover, the extracted guider's control policy was implemented and validated by human-robot interaction experiments. By modeling the follower's dynamics with a time varying virtual damped inertial system, we found that it is the coefficient of virtual damping which is most sensitive to the trust level of the follower. We used these experimental insights to derive a novel controller that integrates an optimal order control policy with a push/pull force modulator in response to the trust level of the follower monitored using a time varying virtual damped inertial model.
, 2016, Kinematic analysis of the human thumb with foldable palm, Pages: 226-238, ISSN: 0302-9743
© Springer International Publishing Switzerland 2016. There have been numerous attempts to develop anthropomorphic robotic hands with varying levels of dexterous capabilities. However, these robotic hands often suffer from a lack of comprehensive understanding of the musculoskeletal behavior of the human thumb with integrated foldable palm. This paper proposes a novel kinematic model to analyze the importance of thumb-palm embodiment in grasping objects. The model is validated using human demonstrations for five precision grasp types across five human subjects. The model is used to find whether there are any co-activations among the thumb joint angles and muskuloskeletal parameters of the palm. In this paper we show that there are certain pairs of joints that show stronger linear relationships in the torque space than in joint angle space. These observations provide useful design guidelines to reduce control complexity in anthropomorphic robotic thumbs.
Afrisal H, Sadati SMH, Nanayakkara T, 2016, A Bio-Inspired Electro-Active Velcro Mechanism Using Shape Memory Alloy for Wearable and Stiffness Controllable Layers, 8th IEEE International Conference on Information and Automation for Sustainability (ICIAfS) - Interoperable Sustainable Smart Systems for Next Generation, Publisher: IEEE, ISSN: 2151-1802
Abad S-A, Sornkarn N, Nanayakkara T, 2016, The Role of Morphological Computation of the Goat Hoof in Slip Reduction, IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), Publisher: IEEE, Pages: 5599-5605
Li M, Konstantinova J, Secco EL, et al., 2015, Using visual cues to enhance haptic feedback for palpation on virtual model of soft tissue., Med Biol Eng Comput, Vol: 53, Pages: 1177-1186
This paper explores methods that make use of visual cues aimed at generating actual haptic sensation to the user, namely pseudo-haptics. We propose a new pseudo-haptic feedback-based method capable of conveying 3D haptic information and combining visual haptics with force feedback to enhance the user's haptic experience. We focused on an application related to tumor identification during palpation and evaluated the proposed method in an experimental study where users interacted with a haptic device and graphical interface while exploring a virtual model of soft tissue, which represented stiffness distribution of a silicone phantom tissue with embedded hard inclusions. The performance of hard inclusion detection using force feedback only, pseudo-haptic feedback only, and the combination of the two feedbacks was compared with the direct hand touch. The combination method and direct hand touch had no significant difference in the detection results. Compared with the force feedback alone, our method increased the sensitivity by 5%, the positive predictive value by 4%, and decreased detection time by 48.7%. The proposed methodology has great potential for robot-assisted minimally invasive surgery and in all applications where remote haptic feedback is needed.
Sadati SMH, Noh Y, Naghibi SE, et al., 2015, Stiffness Control of Soft Robotic Manipulator for Minimally Invasive Surgery (MIS) Using Scale Jamming, 8th International Conference on Intelligent Robotics and Applications (ICIRA), Publisher: SPRINGER-VERLAG BERLIN, Pages: 141-151, ISSN: 0302-9743
Morland MFE, Althoefer K, Nanayakkara T, 2015, Novel method to form adaptive internal impedance profiles in walkers, 2015 37TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC), Pages: 7764-7767, ISSN: 1557-170X
Ranasinghe A, Dasgupta P, Althoefer K, et al., 2015, Identification of Haptic Based Guiding Using Hard Reins., PLoS One, Vol: 10
This paper presents identifications of human-human interaction in which one person with limited auditory and visual perception of the environment (a follower) is guided by an agent with full perceptual capabilities (a guider) via a hard rein along a given path. We investigate several identifications of the interaction between the guider and the follower such as computational models that map states of the follower to actions of the guider and the computational basis of the guider to modulate the force on the rein in response to the trust level of the follower. Based on experimental identification systems on human demonstrations show that the guider and the follower experience learning for an optimal stable state-dependent novel 3rd and 2nd order auto-regressive predictive and reactive control policies respectively. By modeling the follower's dynamics using a time varying virtual damped inertial system, we found that the coefficient of virtual damping is most appropriate to explain the trust level of the follower at any given time. Moreover, we present the stability of the extracted guiding policy when it was implemented on a planar 1-DoF robotic arm. Our findings provide a theoretical basis to design advanced human-robot interaction algorithms applicable to a variety of situations where a human requires the assistance of a robot to perceive the environment.
Jiang A, Ranzani T, Gerboni G, et al., 2014, Robotic Granular Jamming: Does the Membrane Matter?, SOFT ROBOTICS, Vol: 1, Pages: 192-201, ISSN: 2169-5172
Calinon S, Bruno D, Malekzadeh MS, et al., 2014, Human-robot skills transfer interfaces for a flexible surgical robot, COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE, Vol: 116, Pages: 81-96, ISSN: 0169-2607
Konstantinova J, Li M, Mehra G, et al., 2014, Behavioral Characteristics of Manual Palpation to Localize Hard Nodules in Soft Tissues, IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING, Vol: 61, Pages: 1651-1659, ISSN: 0018-9294
Cianchetti M, Ranzani T, Gerboni G, et al., 2014, Soft Robotics Technologies to Address Shortcomings in Today's Minimally Invasive Surgery: The STIFF-FLOP Approach, SOFT ROBOTICS, Vol: 1, Pages: 122-131, ISSN: 2169-5172
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