scholarly journals V2SOM: A Novel Safety Mechanism Dedicated to a Cobot’s Rotary Joints

Robotics ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 18 ◽  
Author(s):  
Younsse Ayoubi ◽  
Med Laribi ◽  
Said Zeghloul ◽  
Marc Arsicault
Keyword(s):  
Good Control ◽  
Variable Stiffness ◽  
Human Robot Interaction ◽  
Industrial Robots ◽  
Necessary Condition ◽  
Physical Interaction ◽  
Robot Interaction ◽  
Internal Damage ◽  
Low Stiffness ◽  
The Impact

Unlike “classical” industrial robots, collaborative robots, known as cobots, implement a compliant behavior. Cobots ensure a safe force control in a physical interaction scenario within unknown environments. In this paper, we propose to make serial robots intrinsically compliant to guarantee safe physical human–robot interaction (pHRI), via our novel designed device called V2SOM, which stands for Variable Stiffness Safety-Oriented Mechanism. As its name indicates, V2SOM aims at making physical human–robot interaction safe, thanks to its two basic functioning modes—high stiffness mode and low stiffness mode. The first mode is employed for normal operational routines. In contrast, the low stiffness mode is suitable for the safe absorption of any potential blunt shock with a human. The transition between the two modes is continuous to maintain a good control of the V2SOM-based cobot in the case of a fast collision. V2SOM presents a high inertia decoupling capacity which is a necessary condition for safe pHRI without compromising the robot’s dynamic performances. Two safety criteria of pHRI were considered for performance evaluations, namely, the impact force (ImpF) criterion and the head injury criterion (HIC) for, respectively, the external and internal damage evaluation during blunt shocks.

scholarly journals Safe pHRI via the Variable Stiffness Safety-Oriented Mechanism (V2SOM): Simulation and Experimental Validations

2020 ◽  
Vol 10 (11) ◽  
pp. 3810
Author(s):  
Younsse Ayoubi ◽  
Med Amine Laribi ◽  
Marc Arsicault ◽  
Saïd Zeghloul
Keyword(s):  
Dynamic Performance ◽  
Variable Stiffness ◽  
Human Robot Interaction ◽  
Necessary Condition ◽  
Internal Damage ◽  
New Device ◽  
Head Injury Criterion ◽  
Low Stiffness ◽  
Experimental Validations ◽  
The Impact

Robots are gaining a foothold day-by-day in different areas of people’s lives. Collaborative robots (cobots) need to display human-like dynamic performance. Thus, the question of safety during physical human–robot interaction (pHRI) arises. Herein, we propose making serial cobots intrinsically compliant to guarantee safe pHRI via our novel designed device, V2SOM (variable stiffness safety-oriented mechanism). Integrating this new device at each rotary joint of the serial cobot ensures a safe pHRI and reduces the drawbacks of making robots compliant. Thanks to its two continuously linked functional modes—high and low stiffness—V2SOM presents a high inertia decoupling capacity, which is a necessary condition for safe pHRI. The high stiffness mode eases the control without disturbing the safety aspect. Once a human–robot (HR) collision occurs, a spontaneous and smooth shift to low stiffness mode is passively triggered to safely absorb the impact. To highlight V2SOM’s effect in safety terms, we consider two complementary safety criteria: impact force (ImpF) criterion and head injury criterion (HIC) for external and internal damage evaluation of blunt shocks, respectively. A pre-established HR collision model is built in Matlab/Simulink (v2018, MathWorks, France) in order to evaluate the latter criterion. This paper presents the first V2SOM prototype, with quasi-static and dynamic experimental evaluations.

scholarly journals A Stiffness Variable Passive Compliance Device with Reconfigurable Elastic Inner Skeleton and Origami Shell

2020 ◽  
Vol 33 (1) ◽  
Author(s):  
Zhuang Zhang ◽  
Genliang Chen ◽  
Weicheng Fan ◽  
Wei Yan ◽  
Lingyu Kong ◽  
...  
Keyword(s):  
Variable Stiffness ◽  
Rehabilitation Robotics ◽  
Human Robot Interaction ◽  
Main Concept ◽  
Robot Interaction ◽  
Switching Speed ◽  
Leaf Springs ◽  
Stiffness Variation ◽  
Low Stiffness ◽  
Large Deflection Problem

Abstract Devices with variable stiffness are drawing more and more attention with the growing interests of human-robot interaction, wearable robotics, rehabilitation robotics, etc. In this paper, the authors report on the design, analysis and experiments of a stiffness variable passive compliant device whose structure is a combination of a reconfigurable elastic inner skeleton and an origami shell. The main concept of the reconfigurable skeleton is to have two elastic trapezoid four-bar linkages arranged in orthogonal. The stiffness variation generates from the passive deflection of the elastic limbs and is realized by actively switching the arrangement of the leaf springs and the passive joints in a fast, simple and straightforward manner. The kinetostatics and the compliance of the device are analyzed based on an efficient approach to the large deflection problem of the elastic links. A prototype is fabricated to conduct experiments for the assessment of the proposed concept. The results show that the prototype possesses relatively low stiffness under the compliant status and high stiffness under the stiff status with a status switching speed around 80 ms.

A Comparative Study on the Effect of Mechanical Compliance for a Safe Physical Human–Robot Interaction

2020 ◽  
Vol 142 (6) ◽  
Author(s):  
Yu She ◽  
Siyang Song ◽  
Hai-Jun Su ◽  
Junmin Wang
Keyword(s):  
Impact Force ◽  
Variable Stiffness ◽  
Human Robot Interaction ◽  
Design Parameters ◽  
Robot Dynamics ◽  
Robot Interaction ◽  
Promising Alternative ◽  
Mechanical Compliance ◽  
Maximum Impact Force ◽  
The Impact

Abstract In this paper, we study the effects of mechanical compliance on safety in physical human–robot interaction (pHRI). More specifically, we compare the effect of joint compliance and link compliance on the impact force assuming a contact occurred between a robot and a human head. We first establish pHRI system models that are composed of robot dynamics, an impact contact model, and head dynamics. These models are validated by Simscape simulation. By comparing impact results with a robotic arm made of a compliant link (CL) and compliant joint (CJ), we conclude that the CL design produces a smaller maximum impact force given the same lateral stiffness as well as other physical and geometric parameters. Furthermore, we compare the variable stiffness joint (VSJ) with the variable stiffness link (VSL) for various actuation parameters and design parameters. While decreasing stiffness of CJs cannot effectively reduce the maximum impact force, CL design is more effective in reducing impact force by varying the link stiffness. We conclude that the CL design potentially outperforms the CJ design in addressing safety in pHRI and can be used as a promising alternative solution to address the safety constraints in pHRI.

Design and Prototype of a Tunable Stiffness Arm for Safe Human-Robot Interaction

2016 ◽  
Author(s):  
Yu She ◽  
Hai-Jun Su ◽  
Cheng Lai ◽  
Deshan Meng
Keyword(s):  
Impact Velocity ◽  
Robot Manipulator ◽  
Variable Stiffness ◽  
Human Robot Interaction ◽  
Robot Interaction ◽  
Injury Criteria ◽  
Straight Beam ◽  
Head Injury Criteria ◽  
The Impact ◽  
Tunable Stiffness

In this paper, we present a tunable stiffness robot link for safe human-robot interaction. Stiffness of a manipulator determines the injury levels of a human from an impact between robots and operators, given a specific impact velocity. Compliance of a robot manipulator includes joint compliance and link compliance. Variable stiffness design from the viewpoint of actuators have been widely studied, while adjustable stiffness robotic link in the application of human robot interaction is rare in literatures. This paper details the design of a tunable stiffness robotic manipulator via four bar linkages which are actuated by servo motors. A 3D model of the morphing beam is constructed, and a robot which is made up of 3 morphing arms is designed. Prototypes using 3D printer are fabricated. Numerous tests have been done, and the results show that the stiffness is able to change 3.6 times given a morphing angle of π/4. Given an impact velocity of 2.2 m/s, the impact tests show that the acceleration has a 19.4% decrease comparing the curved beam and straight beam, and the head injury criteria (HIC) significantly decreases from 210.3 m5/2s−4 to 150.3 m5/2s−4, which is much safer to the operators. This paper explores the research of tunable stiffness on robotic links in the application of human robot interaction, expanding the research arena with regarding to human safe robot design.

scholarly journals ELSA in Industrial Robotics

2020 ◽  
Vol 1 (4) ◽  
pp. 179-186
Author(s):  
Matthew Studley ◽  
Alan Winfield
Keyword(s):  
Manufacturing Industry ◽  
Industrial Revolution ◽  
Human Life ◽  
Human Robot Interaction ◽  
Industrial Robots ◽  
Robot Interaction ◽  
Industrial Robotics ◽  
Primary Focus ◽  
Legal Frameworks ◽  
The Impact

Abstract Purpose of Review Industry is changing; converging technologies allow a fourth Industrial Revolution, where it is envisaged that robots will work alongside humans. We investigate how the research community is responding to the ethical, legal, and social aspects of industrial robots, with a primary focus on manufacturing industry. Recent Findings The literature shows considerable interest in the impact of robotics and automation on industry. This interest spans many disciplines, which is to be expected given that the ELS impacts of industrial robotics may be profound in their depth and far-reaching in their scope. Summary We suggest that the increasing importance of human-robot interaction (HRI) reduces the differentiation between industrial robotics and other robotic domains and that the main challenges to successful adoption for the benefit of human life are above all political and economic. Emerging standards and legal frameworks may scaffold this success, but it is apparent that getting it wrong might have repercussions that last for generations.

scholarly journals Ethics of Corporeal, Co-present Robots as Agents of Influence: a Review

2021 ◽  
Author(s):  
AJung Moon ◽  
Shalaleh Rismani ◽  
H. F. Machiel Van der Loos
Keyword(s):  
Artificial Intelligence ◽  
Physical Environment ◽  
Ethical Issues ◽  
Human Robot Interaction ◽  
Physical Interaction ◽  
Ethical Challenges ◽  
Natural Tendency ◽  
Ai Ethics ◽  
Recent Trends ◽  
The Impact

Abstract Purpose of Review To summarize the set of roboethics issues that uniquely arise due to the corporeality and physical interaction modalities afforded by robots, irrespective of the degree of artificial intelligence present in the system. Recent Findings One of the recent trends in the discussion of ethics of emerging technologies has been the treatment of roboethics issues as those of “embodied AI,” a subset of AI ethics. In contrast to AI, however, robots leverage human’s natural tendency to be influenced by our physical environment. Recent work in human-robot interaction highlights the impact a robot’s presence, capacity to touch, and move in our physical environment has on people, and helping to articulate the ethical issues particular to the design of interactive robotic systems. Summary The corporeality of interactive robots poses unique sets of ethical challenges. These issues should be considered in the design irrespective of and in addition to the ethics of artificial intelligence implemented in them.

A Quasi-Static Model for Studying Physical Interaction Between a Soft Robotic Digit and a Human Finger

2018 ◽  
Author(s):  
Mahdi Haghshenas-Jaryani ◽  
Muthu B. J. Wijesundara
Keyword(s):  
Human Performance ◽  
Theoretical Models ◽  
Element Model ◽  
Human Robot Interaction ◽  
Physical Interaction ◽  
Robotic Hand ◽  
Robot Interaction ◽  
Interaction Forces ◽  
Comparison Of The Results ◽  
Human Finger

This paper presents the development of a framework based on a quasi-statics concept for modeling and analyzing the physical human-robot interaction in soft robotic hand exoskeletons used for rehabilitation and human performance augmentation. This framework provides both forward and inverse quasi-static formulations for the interaction between a soft robotic digit and a human finger which can be used for the calculation of angular motions, interaction forces, actuation torques, and stiffness at human joints. This is achieved by decoupling the dynamics of the soft robotic digit and the human finger with similar interaction forces acting on both sides. The presented theoretical models were validated by a series of numerical simulations based on a finite element model which replicates similar human-robot interaction. The comparison of the results obtained for the angular motion, interaction forces, and the estimated stiffness at the joints indicates the accuracy and effectiveness of the quasi-static models for predicting the human-robot interaction.

scholarly journals Towards natural handshakes for social robots: human-aware hand grasps using tactile sensors

2018 ◽  
Vol 9 (1) ◽  
pp. 221-234 ◽  
Author(s):  
João Avelino ◽  
Tiago Paulino ◽  
Carlos Cardoso ◽  
Ricardo Nunes ◽  
Plinio Moreno ◽  
...  
Keyword(s):  
Human Subjects ◽  
Tactile Feedback ◽  
Human Robot Interaction ◽  
Physical Interaction ◽  
Tactile Sensors ◽  
Cultural Backgrounds ◽  
Robot Interaction ◽  
Human Interactions ◽  
Hand Grip ◽  
Fundamental Part

Abstract Handshaking is a fundamental part of human physical interaction that is transversal to various cultural backgrounds. It is also a very challenging task in the field of Physical Human-Robot Interaction (pHRI), requiring compliant force control in order to plan the arm’s motion and for a confident, but at the same time pleasant grasp of the human user’s hand. In this paper,we focus on the study of the hand grip strength for comfortable handshakes and perform three sets of physical interaction experiments between twenty human subjects in the first experiment, thirty-five human subjects in the second one, and thirty-eight human subjects in the third one. Tests are made with a social robot whose hands are instrumented with tactile sensors that provide skin-like sensation. From these experiments, we: (i) learn the preferred grip closure according to each user group; (ii) analyze the tactile feedback provided by the sensors for each closure; (iii) develop and evaluate the hand grip controller based on previous data. In addition to the robot-human interactions, we also learn about the robot executed handshake interactions with inanimate objects, in order to detect if it is shaking hands with a human or an inanimate object. This work adds physical human-robot interaction to the repertory of social skills of our robot, fulfilling a demand previously identified by many users of the robot.

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