Design and Modeling of Variable Stiffness Joints Based on Compliant Flexures

2010 ◽  
Author(s):  
Gianluca Palli ◽  
Claudio Melchiorri ◽  
Giovanni Berselli ◽  
Gabriele Vassura
Keyword(s):  
Compliant Mechanism ◽  
Variable Stiffness ◽  
Human Robot Interaction ◽  
Robot Interaction ◽  
Control Laws ◽  
Compliant Behavior ◽  
Stiffness Profile ◽  
And Performance ◽  
Definition Of ◽  
Selection Of

The development of safe and dependable robots for physical human-robot interaction is actually changing the way robot are designed introducing several new technological issues. Outstanding examples are the adoption of soft covers and compliant transmissions or the definition of motion control laws that allow a compliant behavior in reaction to possible collisions, while preserving accuracy and performance during the motion in the free space. In this scenario, a growing interest is devoted to the study of variable stiffness joints. With the aim of improving the compactness and the flexibility of existing mechanical solutions, a variable stiffness joint based on the use of compliant flexures is investigated. The proposed concept allows the implementation of a desired stiffness profile and range along with the selection of the maximum joint deflection. In particular, this paper reports a systematic procedure for the synthesis of a fully-compliant mechanism used as a non-linear transmission, together with a preliminary design of the overall joint.

Design of a Variable Stiffness Actuator Based on Flexures

2011 ◽  
Vol 3 (3) ◽  
Author(s):  
Gianluca Palli ◽  
Giovanni Berselli ◽  
Claudio Melchiorri ◽  
Gabriele Vassura
Keyword(s):  
Compliant Mechanism ◽  
Variable Stiffness ◽  
Human Robot Interaction ◽  
Experimental Characterization ◽  
Robot Interaction ◽  
Trade Off ◽  
Variable Stiffness Actuator ◽  
Robotic Devices ◽  
Stiffness Profile ◽  
Variable Stiffness Actuators

Variable stiffness actuators can be used in order to achieve a suitable trade-off between performance and safety in robotic devices for physical human–robot interaction. With the aim of improving the compactness and the flexibility of existing mechanical solutions, a variable stiffness actuator based on the use of flexures is investigated. The proposed concept allows the implementation of a desired stiffness profile and range. In particular, this paper reports a procedure for the synthesis of a fully compliant mechanism used as a nonlinear transmission element, together with its experimental characterization. Finally, a preliminary prototype of the overall joint is depicted.

Affective Goal and Task Selection for Social Robots

2009 ◽  
pp. 74-87 ◽  
Author(s):  
Matthias Scheutz ◽  
Paul Schermerhorn
Keyword(s):  
Decision Making ◽  
Real World ◽  
Social Robots ◽  
Human Robot Interaction ◽  
Robot Interaction ◽  
Task Selection ◽  
Resource Limitations ◽  
Effective Decision ◽  
Effective Decision Making ◽  
Selection Of

Effective decision-making under real-world conditions can be very difficult as purely rational methods of decision-making are often not feasible or applicable. Psychologists have long hypothesized that humans are able to cope with time and resource limitations by employing affective evaluations rather than rational ones. In this chapter, we present the distributed integrated affect cognition and reflection architecture DIARC for social robots intended for natural human-robot interaction and demonstrate the utility of its human-inspired affect mechanisms for the selection of tasks and goals. Specifically, we show that DIARC incorporates affect mechanisms throughout the architecture, which are based on “evaluation signals” generated in each architectural component to obtain quick and efficient estimates of the state of the component, and illustrate the operation and utility of these mechanisms with examples from human-robot interaction experiments.

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.

scholarly journals Soft Robotics with Variable Stiffness Actuators: Tough Robots for Soft Human Robot Interaction

Soft Robotics ◽  
2015 ◽  
pp. 231-254 ◽  
Author(s):  
Sebastian Wolf ◽  
Thomas Bahls ◽  
Maxime Chalon ◽  
Werner Friedl ◽  
Markus Grebenstein ◽  
...  
Keyword(s):  
Variable Stiffness ◽  
Human Robot Interaction ◽  
Soft Robotics ◽  
Robot Interaction ◽  
Variable Stiffness Actuators

Determination of Variable Stiffness of a Human Elbow for Human-Robot Interaction

2014 ◽  
Author(s):  
Michael Boyarsky ◽  
Megan Heenan ◽  
Scott Beardsley ◽  
Philip Voglewede
Keyword(s):  
Experimental Data ◽  
Disturbance Rejection ◽  
Variable Stiffness ◽  
Important Variable ◽  
Human Motion ◽  
Human Robot Interaction ◽  
Robot Interaction ◽  
Constant Stiffness ◽  
Stiffness Model ◽  
Motor Model

This paper aims to emulate human motion with a robot for the purpose of improving human-robot interaction (HRI). In order to engineer a robot that demonstrates functionally similar motion to humans, aspects of human motion such as variable stiffness must be captured. This paper successfully determined the variable stiffness humans use in the context of a 1 DOF disturbance rejection task by optimizing a time-varying stiffness parameter to experimental data in the context of a neuro-motor Simulink model. The significant improved agreement between the model and the experimental data in the disturbance rejection task after the addition of variable stiffness demonstrates how important variable stiffness is to creating a model of human motion. To enable a robot to emulate this motion, a predictive stiffness model was developed that attempts to reproduce the stiffness that a human would use in a given situation. The predictive stiffness model successfully decreases the error between the neuro-motor model and the experimental data when compared to the neuro-motor model with a constant stiffness value.

Individual Differences in Human-Robot Interaction in a Military Multitasking Environment

2011 ◽  
Vol 5 (1) ◽  
pp. 83-105 ◽  
Author(s):  
Jessie Y. C. Chen
Keyword(s):  
Task Performance ◽  
Attentional Control ◽  
Target Recognition ◽  
Human Robot Interaction ◽  
Automated Systems ◽  
Robot Interaction ◽  
Military Vehicle ◽  
And Performance ◽  
Modality Preference ◽  
And Robotics

A military vehicle crew station environment was simulated and a series of three experiments was conducted to examine the workload and performance of the combined position of the gunner and robotics operator in a multitasking environment. The study also evaluated whether aided target recognition (AiTR) capabilities (delivered through tactile and/or visual cuing) for the gunnery task might benefit the concurrent robotics and communication tasks and how the concurrent task performance might be affected when the AiTR was unreliable (i.e., false alarm prone or miss prone). Participants’ spatial ability was consistently found to be a reliable predictor of their targeting task performance as well as their modality preference for the AiTR display. Participants’ attentional control was found to significantly affect the way they interacted with unreliable automated systems.

Physical human-robot interaction: Dependability, safety, and performance

2008 ◽  
Author(s):  
Antonio Bicchi ◽  
Michele Bavaro ◽  
Gianluca Boccadamo ◽  
Davide De Carli ◽  
Roberto Filippini ◽  
...  
Keyword(s):  
Human Robot Interaction ◽  
Robot Interaction ◽  
And Performance

scholarly journals Calibrating intuitive and natural human–robot interaction and performance for power-assisted heavy object manipulation using cognition-based intelligent admittance control schemes

2018 ◽  
Vol 15 (4) ◽  
pp. 172988141877319 ◽  
Author(s):  
S M Mizanoor Rahman ◽  
Ryojun Ikeura
Keyword(s):  
Predictive Control ◽  
Optimization Algorithm ◽  
Weight Perception ◽  
Robotic System ◽  
Human Robot Interaction ◽  
Admittance Control ◽  
Robot Interaction ◽  
Heavy Object ◽  
Control Scheme ◽  
And Performance

In the first step, a one degree of freedom power assist robotic system is developed for lifting lightweight objects. Dynamics for human–robot co-manipulation is derived that includes human cognition, for example, weight perception. A novel admittance control scheme is derived using the weight perception–based dynamics. Human subjects lift a small-sized, lightweight object with the power assist robotic system. Human–robot interaction and system characteristics are analyzed. A comprehensive scheme is developed to evaluate the human–robot interaction and performance, and a constrained optimization algorithm is developed to determine the optimum human–robot interaction and performance. The results show that the inclusion of weight perception in the control helps achieve optimum human–robot interaction and performance for a set of hard constraints. In the second step, the same optimization algorithm and control scheme are used for lifting a heavy object with a multi-degree of freedom power assist robotic system. The results show that the human–robot interaction and performance for lifting the heavy object are not as good as that for lifting the lightweight object. Then, weight perception–based intelligent controls in the forms of model predictive control and vision-based variable admittance control are applied for lifting the heavy object. The results show that the intelligent controls enhance human–robot interaction and performance, help achieve optimum human–robot interaction and performance for a set of soft constraints, and produce similar human–robot interaction and performance as obtained for lifting the lightweight object. The human–robot interaction and performance for lifting the heavy object with power assist are treated as intuitive and natural because these are calibrated with those for lifting the lightweight object. The results also show that the variable admittance control outperforms the model predictive control. We also propose a method to adjust the variable admittance control for three degrees of freedom translational manipulation of heavy objects based on human intent recognition. The results are useful for developing controls of human friendly, high performance power assist robotic systems for heavy object manipulation in industries.

scholarly journals MODELING AND TESTING PROXEMIC BEHAVIOR FOR HUMANOID ROBOTS

2012 ◽  
Vol 09 (04) ◽  
pp. 1250028 ◽  
Author(s):  
ELENA TORTA ◽  
RAYMOND H. CUIJPERS ◽  
JAMES F. JUOLA ◽  
DAVID VAN DER POL
Keyword(s):  
Target Location ◽  
Personal Space ◽  
Humanoid Robots ◽  
Human Robot Interaction ◽  
Bayesian Filtering ◽  
Mathematical Form ◽  
Robot Interaction ◽  
Verbal Interactions ◽  
Definition Of ◽  
Robotic Architecture

Humanoid robots that share the same space with humans need to be socially acceptable and effective as they interact with people. In this paper we focus our attention on the definition of a behavior-based robotic architecture that (1) allows the robot to navigate safely in a cluttered and dynamically changing domestic environment and (2) encodes embodied non-verbal interactions: the robot respects the users personal space (PS) by choosing the appropriate distance and direction of approach. The model of the PS is derived from human–robot interaction tests, and it is described in a convenient mathematical form. The robot's target location is dynamically inferred through the solution of a Bayesian filtering problem. The validation of the overall behavioral architecture shows that the robot is able to exhibit appropriate proxemic behavior.

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