Vibro-tactile Haptic Guidance for Human-Robot Interaction and Cooperation tasks
Evaluation of a predictive approach in steering the human locomotion via haptic feedback
2015 IEEE/RSJ International Conference Intelligent Robots and Systems
In this paper, we present a haptic guidance policy to steer the user along predefined paths, and we evaluate a predictive approach to compensate actuation delays that humans have when they are guided along a given trajectory via sensory stimuli. The proposed navigation policy exploits the nonholonomic nature of human locomotion in goal directed paths, which leads to a very simple guidance mechanism. The proposed method has been evaluated in a real scenario where seven human subjects were asked to walk along a set of predefined paths, and were guided via vibrotactile cues. Their poses as well as the related distances from the path have been recorded using an accurate optical tracking system. Results revealed that an average error of 0.24 m is achieved by using the proposed haptic policy, and that the predictive approach does not bring significant improvements to the path following problem for what concerns the distance error. On the contrary, the predictive approach achieved a definitely lower activation time of the haptic interfaces.
Author = {Aggravi, M. and Scheggi, S. and Prattichizzo, D.},
Title = {Evaluation of a predictive approach in steering the human locomotion via haptic feedback},
BookTitle = {{Proc. IEEE/RSJ Int. Conf. Intelligent Robots and Systems}},
Address = {Hamburg, Germany},
Year = {2015}
Pages = {597--602},
Doi = {10.1109/IROS.2015.7353433}, }
Haptic Wrist Guidance Using Vibrations for Human-Robot Teams
2016, IEEE International Symposium on Robot and Human Interactive Communication
Human-Robot teams can efficiently operate in several scenarios including Urban Search and Rescue (USAR). Robots can access areas too small or deep for a person, can begin surveying larger areas that people are not permitted to enter and can carry sensors and instruments. One important aspect in this cooperative framework is the way robots and humans can communicate during rescue operation. Vision and audio modalities may result not efficient in case of reduced visibility or high noise. A promising way to guarantee effective communications between robot and human in a team is the exploitation of haptic signals. In this work, we present a possible solution to let a robot guide the position of a human operator’s hand by using vibrations. We demonstrate that an armband embedding four vibrating motors is enough to guide the wrist of an operator along a predefined path or in a target location. The results proposed can be exploited in human-robot teams. For instance, when the robot detects the position of a sensible target, it can guide the wrist of the operator in such position following an optimal path.
Author = {Aggravi, M. and Salvietti, G. and Prattichizzo, D.},
BookTitle = {{Proc. IEEE International Symposium on Robot and Human Interactive Communication (Ro-Man)}},
Title = {{Haptic Wrist Guidance Using Vibrations for Human-Robot Teams}},
Address = {New York, USA},
Year = {2016},}
Teleoperation in cluttered environments using wearable haptic feedback
2017 IEEE/RSJ International Conference Intelligent Robots and Systems
Robotic teleoperation in cluttered environments is attracting increasing attention for its potential in hazardous scenarios, disaster response, and telemaintenance. Although haptic feedback has been proven effective in such applications, commercially-available grounded haptic interfaces still show significant limitations in terms of workspace, safety, transparency, and encumbrance. For this reason, we present a novel robotic teleoperation system with wearable haptic feedback for telemanipulation in cluttered environments. The slave system is composed of a soft robotic hand attached to a 6-axis force sensor, which is fixed to a 6-degrees-of-freedom robotic arm. The master system is composed of two wearable vibrotactile armbands and a Leap Motion. The armbands are worn on the upper arm and forearm, and convey information about collisions on the robotic arm and hand, respectively. The position of the manipulator and the grasping configuration of the robotic hand are controlled by the user’s hand pose as tracked by the Leap Motion. To validate our approach, we carried out a human-subject telemanipulation experiment in a cluttered scenario. Twelve participants were asked to teleoperate the robot to grasp an object hidden between debris of various shapes and stiffnesses. Haptic feedback provided by our wearable devices significantly improved the performance of the considered telemanipulation tasks. All subjects but one preferred conditions with wearable haptic feedback.
Title = {Teleoperation in cluttered environments using wearable haptic feedback}, Author = {Bimbo, Joao and Pacchierotti, Claudio and Aggravi, Marco and Tsagarakis, Nikos and Prattichizzo, Domenico},
Booktitle = {2017 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)},
Pages = {3401--3408},
Year = {2017},
Organization = {IEEE},
Doi = {10.1109/IROS.2017.8206180},
Haptic Guidance in Dynamic Environments Using Optimal Reciprocal Collision Avoidance
2018, IEEE Robotics and Automation Letters
Human guidance in situations where the users cannot rely on their main sensory modalities, such as assistive or search-and-rescue scenarios, is a challenging task. In this paper, we address the problem of guiding users along collision-free paths in dynamic environments, assuming that they cannot rely on their main sensory modalities. In order to safely guide the subjects, we adapt the Optimal Reciprocal Collision Avoidance to our specific problem. The proposed algorithm takes into account the stimuli which can be displayed to the users and the motion uncertainty of the users when reacting to the provided stimuli. The proposed algorithm was evaluated in three different dynamic scenarios. A total of 18 blindfolded human subjects were asked to follow haptic cues in order to reach a target area while avoiding real static obstacles and moving users. Three metrics such as time to reach the goal, length of the trajectories, and minimal distance from the obstacles are considered to compare results obtained using this approach and experiments performed without visual impairments. Experimental results reveal that blindfolded subjects are successfully able to avoid collisions and safely reach the targets in all the performed trials. Although in this paper we display directional cues via haptic stimuli, we believe that the proposed approach can be general and tuned to work with different haptic interfaces and/or feedback modalities.
@article{baldi2018haptic, Title = {Haptic guidance in dynamic environments using optimal reciprocal collision avoidance},
Author = {Baldi, Tommaso Lisini and Scheggi, Stefano and Aggravi, Marco and Prattichizzo, Domenico},
Journal = {{IEEE Robotics and Automation Letters}},
Volume = {3},
Number = {1},
Pages = {265--272},
Year = {2018},
Publisher = {{IEEE}},
Doi = {10.1109/LRA.2017.2738328},
Multi-robot systems
Design and Evaluation of a Wearable Haptic Device for Skin Stretch, Pressure, and Vibrotactile Stimuli
2018, IEEE Robotics and Automation Letters
This paper presents a wearable haptic device for the forearm and its application in robotic teleoperation. The device is able to provide skin stretch, pressure, and vibrotactile stimuli. Two servo motors, housed in a 3D printed lightweight platform, actuate an elastic fabric belt, wrapped around the arm. When the two servo motors rotate in opposite directions, the belt is tightened (or loosened), thereby compressing (or decompressing) the arm. On the other hand, when the two motors rotate in the same direction, the belt applies a shear force to the arm skin. Moreover, the belt houses four vibrotactile motors, positioned evenly around the arm at 90 degrees from each other. The device weights 220 g for 115×122×50 mm of dimensions, making it wearable and unobtrusive. We carried out a perceptual characterization of the device as well as two human-subjects teleoperation experiments in a virtual environment, employing a total of 34 subjects. In the first experiment, participants were asked to control the motion of a robotic manipulator for grasping an object; in the second experiment, participants were asked to teleoperate the motion of a quadrotor fleet along a given path. In both scenarios, the wearable haptic device provided feedback information about the status of the slave robot(s) and of the given task. Results showed the effectiveness of the proposed device. Performance on completion time, length trajectory, and perceived effectiveness when using the wearable device improved of 19.8%, 25.1%, and 149.1% than when wearing no device, respectively. Finally, all subjects but three preferred the conditions including wearable haptics.
Title = {{Design and evaluation of a wearable haptic device for skin stretch, pressure, and vibrotactile stimuli}},
Author = {Aggravi, Marco and Paus{\'e}, Florent and Giordano, Paolo Robuffo and Pacchierotti, Claudio},
Journal = {{IEEE Robotics and Automation Letters}},
Volume = {3},
Number = {3},
Pages = {2166--2173},
Year = {2018},
Publisher = {{IEEE}},
Doi = {10.1109/LRA.2018.2810887}
Heterogeneous Human-Robot Team
Cooperative human-robot haptic navigation
2014, IEEE International Conference on Robotics and Automation
This paper proposes a novel use of haptic feedback for human navigation with a mobile robot. Assuming that a path-planner has provided a mobile robot with an obstacle- free trajectory, the vehicle must steer the human from an initial to a desired target position by only interacting with him/her via a custom-designed vibro-tactile bracelet. The subject is free to decide his/her own pace and a warning vibrational signal is generated by the bracelet only when a large deviation with respect to the planned trajectory is detected by the vision sensor on-board the robot. This leads to a cooperative navigation system that is less intrusive, more flexible and easy-to-use than the ones existing in literature. The effectiveness of the proposed system is demonstrated via extensive real-world experiments.
Title = {Cooperative human-robot haptic navigation},
Author = {Scheggi, Stefano and Aggravi, Marco and Morbidi, Fabio and Prattichizzo, Domenico},
Booktitle = {{2014 IEEE International Conference on Robotics and Automation (ICRA)}}, Pages = {2693--2698},
Year = {2014},
Organization = {{IEEE}},
Doi = {10.1109/ICRA.2014.6907245},
Cooperative Navigation for Mixed Human–Robot Teams Using Haptic Feedback
2016 IEEE Transactions on Human-machine Systems
In this paper, we present a novel cooperative navigation control for human-robot teams. Assuming that a human wants to reach a final location in a large environment with the help of a mobile robot, the robot must steer the human from the initial to the target position. The challenges posed by cooperative human-robot navigation are typically addressed by using haptic feedback via physical interaction. In contrast to that, in this paper we describe a different approach, in which the human-robot interaction is achieved via wearable vibrotactile armbands. In the proposed work the subject is free to decide her/his own pace. A warning vibrational signal is generated by the haptic armbands when a large deviation with respect to the desired pose is detected by the robot. The proposed method has been evaluated in a large indoor environment, where fifteen blindfolded human subjects were asked to follow the haptic cues provided by the robot. The participants had to reach a target area, while avoiding static and dynamic obstacles. Experimental results revealed that the blindfolded subjects were able to avoid the obstacles and safely reach the target in all of the performed trials. A comparison is provided between the results obtained with blindfolded users and experiments performed with sighted people.
Author = {Scheggi, S. and Aggravi, M. and Prattichizzo, D.},
Title = {{Cooperative Navigation for Mixed Human-Robot Teams Using Haptic Feedback}},
Journal = {{IEEE Transactions on Human-Machine Systems}},
Volume = {47},
Number = {4},
Pages = {462--473},
Year = {2016},
Doi = {10.1109/THMS.2016.2608936}
Other researches
A remote vibrotactile guidance system for blind and visually impaired
Trained guide dogs and white canes still remain the primary mobility aids for visually impaired. However, they are limited in guiding the user toward a desired location, especially in unknown domains. In this paper we present a remote guidance system which provides the visually impaired with vibrotactile directional cues to properly move in environments in which they are not familiar with. The user is equipped with a webcam, two vibrotactile bracelets and a white cane which is used to avoid potential obstacles. The video captured by the webcam is streamed to a remote operator who can properly guide the impaired person by activating the vibrotactile stimulations. The proposed approach has been validated on a group of blind subjects in an outdoor urban scenario. Experimental results revealed that the proposed system can be an effective solution in terms of intuitiveness and acceptability.
DALI: A Smart Walking Assistant for Safe Navigation in Complex Indoor Environments
2015, Book chapter Ambient Assisted Living, Volume 11 of the series Biosystems & Biorobotics
Indoor navigation can be a challenging issue for people afflicted by cognitive impairments. The project Devices for Assisted Living (DALi) is a research initiative sponsored by the European Commission under the FP7 programme with the goal of developing a robotic wheeled walker assisting disabled people in indoor scenarios where crowd, obstacles and multiple points of interest may confuse or in- timidate the users. The walking assistant, called c-Walker, is designed to monitor the environment, to detect possible hazards and to decide the best path across the space, thus guiding the user safely towards the wanted destination.
Author = {Aggravi, M. and Colombo, A. and Fontanelli, D. and Giannitrapani, A. and Macii, D. and Moro, F. and Nazemzadeh, P. and Palopoli, L. and Passerone, R. and Prattichizzo, D. and Rizano, T. and Rizzon, L. and Scheggi, S.},
Title = {A Smart Walking Assistant for Safe Navigation in Complex Indoor Environments},
BookTitle = {Ambient Assisted Living},
Pages = {487--497},
Publisher = {Springer International Publishing},
Year = {2015}
Object motion-decoupled internal force control for a compliant multifingered hand
2012, IEEE International Conference on Robotics and Automation
Compliance in multifingered hand improves grasp stability and effectiveness of the manipulation tasks. Compliance of robotic hands depends mainly on the joint control parameters, on the mechanical design of the hand, as joint passive springs, and on the contact properties. In object grasping the primary task of the robotic hand is the control of internal forces which allows to satisfy the contact constraints and consequently to guarantee a stable grasp of the object. When compliance is an essential element of the multifingered hand, and the control of the internal forces is not designed to be decoupled from the object motion, it happens that a change in the internal forces causes the object trajectory to deviate from the planned path with consequent performance degradation. This paper studies the structural conditions to design an internal force controller decoupled from object motions. The analysis is constructive and a controller of internal forces is proposed. We will refer to this controller as object motion- decoupled control of internal forces. The force controller has been successfully tested on a realistic model of the DLR Hand II. This controller provides a trajectory interface allowing to vary the internal forces (and to specify object motions) of an underactuated hand, which can be used by higher-level modules, e.g. planning tools.
Author = {Prattichizzo, D. and Malvezzi, M. and Aggravi, M. and Wimboeck, T.},
BookTitle = {{IEEE International Conference on Robotics and Automation (ICRA)}},
Title = {Object motion-decoupled internal force control for a compliant multifingered hand},
Address = {St. Paul, MN, USA},
Year = {2012},
Pages = {1508--1513}
Hand-Tool-Tissue Interaction Forces in Neurosurgery for Haptic Rendering
2015, Medical & Biomedical Computing & Engineering
Haptics provides sensory stimuli displaying the interaction with virtual or tele-manipulated objects. The haptic feedback can be provided to the user via tactile information and via kinesthetic feedback. Here we focused on measuring the interaction forces during neurosurgical tasks performed on a brain phantom, with the aim of understanding which could be the best haptic feedback in a real tele-operation scenario. We instrumented three neurosurgical tools using Force Sensitive Resistors, for measuring the contact forces exerted by surgeons to tools. A load cell placed under a brain phantom measured the tool-tissue forces. Three neurosurgeons were asked to perform typical actions on the phantom. The measured surgeon-tool contact forces ranges, i.e., 0.01 - 3.49 N for the thumb and 0.01 - 6.6 N for index and middle fingers, fit the range of the cutaneous sensitivity of the human finger pad. The measured tool-tissue interaction forces were from six to eleven times lower with respect to the contact forces, i.e., 0.01 - 0.59 N. Eventually, we believe that convey only the cutaneous component of the haptic feedback would transmit a sensation comparable to that present when both cutaneous and kinesthetic feedback are given. Additionally, this approach does not compromise the stability of the haptic feedback loop.
Author = {Aggravi, M. and De Momi, E and DiMeco, F. and Cardinale, F. and Casaceli, G. and Riva, M. and Ferrigno, G. and Prattichizzo, D.},
Title = {{Hand-Tool-Tissue Interaction Forces in Neurosurgery for Haptic Rendering}},
Journal = {{Medical & Biological Engineering & Computing}},
Publisher = {Springer},
doi = {10.1007/s11517-015-1439-8},
issn = {0140-0118},
Year = {2015}