ARES, a variable stiffness actuator with embedded force sensor for the ATLAS exoskeleton

2014 ◽  
Vol 41 (6) ◽  
pp. 518-526 ◽  
Author(s):  
M. Cestari ◽  
D. Sanz-Merodio ◽  
J.C. Arevalo ◽  
E. Garcia
Keyword(s):  
Design Methodology ◽  
Variable Stiffness ◽  
Force Sensor ◽  
Content Type ◽  
Torque Measurements ◽  
Variable Stiffness Actuator ◽  
Compact Design ◽  
Intrinsic Dynamic

Purpose – The purpose of this study is to present a variable stiffness actuator, one of whose main features is that the compliant elements simultaneously allow measuring of the torque exerted by the joint. Conceived as a force-controlled actuator, this actuator with Adjustable Rigidity and Embedded Sensor (ARES) is intended to be implemented in the knee of the ATLAS exoskeleton for children to allow the exploitation of the intrinsic dynamic during the locomotion cycle. Design/methodology/approach – A set of simulations were performed to evaluate the behavior of the actuator mechanism and a prototype of the variable impedance actuator was incorporated into the exoskeleton’s knee and evaluations of the torque measurements capabilities along with the rigidity adjustments were made. Findings – Mass and inertia of the actuator are minimized by the compact design and the utilization of the different component for more than one utility. By a proper match of the compliance of the joint and the performed task, good torque measurements can be achieved and no bandwidth saturation is expected. Originality/value – In the actuator, the compliant elements simultaneously allow measuring of the torque exerted by the join. By a proper match of the compliance of the joint and the performed task, good torque measurements can be achieved and no bandwidth saturation is expected.

Design and characterization of a T-shaped two-axis force sensor

Sensor Review ◽  
2019 ◽  
Vol 39 (6) ◽  
pp. 776-782
Author(s):  
Liang Zhong ◽  
Feifei Li ◽  
Yuxin Peng ◽  
Qiang Yang ◽  
Mingming Zhang ◽  
...  
Keyword(s):  
Design Methodology ◽  
Simple Structure ◽  
Force Sensor ◽  
The Other ◽  
Strain Gauges ◽  
Content Type ◽  
Sensor Head ◽  
Compact Size ◽  
Basic Performance

Purpose This paper aims to propose a type of T-shaped two-axis force sensor for measuring the forces in x- and z-axes. The developed sensor has a simple structure and can be effectively assembled into compact devices. Design/methodology/approach A T-shaped plate, with both ends fixed on a base, is used as the substrate of the sensor. Eight strain gauges are placed in the root of the plate or near the sensor head, which can construct two full Wheatstone bridges on the upper and lower surfaces of the plate. When the x- or z-axes forces are applied to the sensor head, different deformation can be generated to the strain gauges. Therefore, the two Wheatstone bridges can be constructed with a different configuration for measuring the forces in x- or z-axes, respectively. Findings A prototype was designed and constructed and experiments were carried out to test the basic performance of the sensor. It has been verified that the developed sensor could measure the x- and z-axes forces independently with a high resolution of 2.5 and 5 mN, respectively. Originality/value Only one thin plate was used in the design, the forces in x- and z-axes could be measured independently and simultaneously, which made the sensor with a simple structure and compact size. Experiments were also verified that there was no crosstalk error occurred in one axis when the force was applied to the other axis.

A novel series-parallel hybrid robot for climbing transmission tower

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yanzhang Yao ◽  
Wei Wang ◽  
Yue Qiao ◽  
Zhihang He ◽  
Fusheng Liu ◽  
...  
Keyword(s):  
Design Methodology ◽  
Parallel Robot ◽  
Robot Design ◽  
Transmission Tower ◽  
Content Type ◽  
Magnetic Attraction ◽  
Working Environments ◽  
Spline Curves ◽  
Parallel Hybrid ◽  
Compact Design

Purpose The purpose of this paper is to describe the design and development of a novel series-parallel robot, which aims to climb on the transmission tower. Design methodology approach This study introduces a hybrid robot, which consists of adsorption and two 3-degree of freedom (DOF) translation parallel legs connected by a body linkage. The DOF of the legs ensures that the robot can move on the climbing plane, also contribute to a compact design of the robot. An electromagnet is used to adsorb onto the transmission tower, simplifying the overall structure. Based on the robot design, this paper further defines its climbing gait and adopt the 6th B-spline curves for climbing trajectory planning under different working environments. Findings The developed prototype that implements the design of the robot, which was used in simulation and experiments, showing that the robot is capable of climbing in the test environments with the planned climbing gait. Originality value The hybrid robot is able to climb under varying degrees of inclinations and cross the obstacles, and the magnetic attraction can ensure stable climbing.

An extended DMP framework for robot learning and improving variable stiffness manipulation

2019 ◽  
Vol 40 (1) ◽  
pp. 85-94
Author(s):  
Feifei Bian ◽  
Danmei Ren ◽  
Ruifeng Li ◽  
Peidong Liang ◽  
Ke Wang ◽  
...  
Keyword(s):  
Design Methodology ◽  
Variable Stiffness ◽  
Admittance Control ◽  
End Effector ◽  
Content Type ◽  
Human Dose ◽  
Robot Cooperation ◽  
Electromyographic Signals ◽  
Reference Trajectories ◽  
Teaching By Demonstration

Purpose The purpose of this paper is to present a method which enables a robot to learn both motion skills and stiffness profiles from humans through kinesthetic human-robot cooperation. Design Methodology Approach Admittance control is applied to allow robot-compliant behaviors when following the reference trajectories. By extending the dynamical movement primitives (DMP) model, a new concept of DMP and stiffness primitives is introduced to encode a kinesthetic demonstration as a combination of trajectories and stiffness profiles, which are subsequently transferred to the robot. Electromyographic signals are extracted from a human’s upper limbs to obtain target stiffness profiles. By monitoring vibrations of the end-effector velocities, a stability observer is developed. The virtual damping coefficient of admittance controller is adjusted accordingly to eliminate the vibrations. Findings The performance of the proposed methods is evaluated experimentally. The result shows that the robot can perform tasks in a variable stiffness mode as like the human dose in the teaching phase. Originality Value DMP has been widely used as a teaching by demonstration method to represent movements of humans and robots. The proposed method extends the DMP framework to allow a robot to learn not only motion skills but also stiffness profiles. Additionally, the authors proposed a stability observer to eliminate vibrations when the robot is disturbed by environment.

A new variable stiffness robot joint

2015 ◽  
Vol 42 (4) ◽  
pp. 371-378 ◽  
Author(s):  
Yong Tao ◽  
Tianmiao Wang ◽  
Yunqing Wang ◽  
Long Guo ◽  
Hegen Xiong ◽  
...  
Keyword(s):  
Design Methodology ◽  
Dynamic Stiffness ◽  
Variable Stiffness ◽  
System Behavior ◽  
Pivot Point ◽  
Content Type ◽  
Wide Range ◽  
Variable Stiffness Actuators ◽  
Stiffness Adjustment ◽  
Elastic Elements

Purpose – This study aims to propose a new variable stiffness robot joint (VSR-joint) for operating safely. More and more variable stiffness actuators are being designed and implemented because of their ability to minimize large forces due to shocks, to safely interact with the user and their ability to store and release energy in passive elastic elements. Design/methodology/approach – The design of VSR-joint is compact and integrated highly and the operating is simply. The mechanics, the principle of operation and the model of the VSR-joint are proposed. The principle of operation of VSR-joint is based on a lever arm mechanism with a continuously regulated pivot point. The VSR-joint features a highly dynamic stiffness adjustment along with a mechanically programmable system behavior. This allows an easy adaption to a big variety of tasks. Findings – Preliminary results are presented to demonstrate the fast stiffness regulation response and the wide range of stiffness achieved by the proposed VSR-joint design. Originality/value – In this paper, a new variable stiffness joint is proposed through changing the cantilever arm to change the performance of the elastic element, which is compact, small size and simple adjustment.

A new variable stiffness actuator and its control method

2019 ◽  
Vol 46 (4) ◽  
pp. 553-560 ◽  
Author(s):  
Lei Zhang ◽  
Wendong Wang ◽  
Yikai Shi ◽  
Yang Chu ◽  
Xing Ming
Keyword(s):  
Control Method ◽  
Three Dimensional ◽  
Variable Stiffness ◽  
Magnetorheological Fluid ◽  
Human Robot Interaction ◽  
Crash Test ◽  
Three Dimensional Model ◽  
Content Type ◽  
Variable Stiffness Actuator

Purpose To achieve variable stiffness, this paper aims to design a flexible actuator with variable stiffness by using the magnetorheological effect of magnetorheological fluid. The variable stiffness actuator can well meet the safety requirements of human–robot interaction and be more adaptable to unknown or complex environments. The variable stiffness actuator designed in this study can realize the continuous and controllable change of stiffness compared with the existing actuator. Design/methodology/approach The principle of variable stiffness actuator is illustrated in detail; the three-dimensional model and mechanical model of the flexible actuator are provided. The magnetic field distribution of the actuator coil is analyzed, and the dynamic model of the actuator is provided. Findings Output torque test suggests that the magnetorheological fluid variable stiffness actuator (VSAMF) can output a stable torque which meets the designing requirements of the test; sinusoidal follow-up test shows that VSAMF can implement sinusoidal follow-up; variable stiffness test shows that VSAMF can achieve real-time variable stiffness adjustment; the crash test suggests that VSAMF can well protect machines when meeting obstacles. Originality/value In this paper, a new variable stiffness joint is proposed through changing the current to change the performance of the stiffness, and it can realize the continuous and controllable change of stiffness.

Design methodology of a novel variable stiffness actuator based on antagonistic-driven mechanism

2019 ◽  
Vol 233 (19-20) ◽  
pp. 6967-6984
Author(s):  
Yinghao Ning ◽  
Wenfu Xu ◽  
Hailin Huang ◽  
Bing Li ◽  
Fei Liu
Keyword(s):  
Sensitivity Analysis ◽  
Design Methodology ◽  
Design Method ◽  
Structural Parameters ◽  
Variable Stiffness ◽  
Compact Structure ◽  
Constant Stiffness ◽  
Return Journey ◽  
Variable Stiffness Actuator ◽  
Spring Mechanism

This paper concerns the construction of a novel variable stiffness actuator with antagonistic-driven mechanism (ADM-VSA). The ADM-VSA consists of two cam mechanisms and two constant stiffness spring mechanisms establishing the antagonistic structure to eliminate the empty return journey. The former with symmetrical cam profiles are designed for the movement of actuator, while the latter are explored substituting traditional springs of generating compliance for compact structure. To obtain desired performance of the actuator, the design methodology is developed for constructing the ADM-VSA, integrating the constant stiffness spring mechanism design method from four-bar mechanism to multi-bar mechanism, the comprehensive optimization of cam profiles and sensitivity analysis of structural parameters. The comprehensive optimization is conducted with different-order Bezier splines considering the torque, stiffness, and energy by friction simultaneously. The sensitivity analysis is performed to investigate the influence of structural errors on the performance of actuator, with new indexes decreasing the workload of calculation, and several guidelines for the design and manufacturing are achieved. Finally, a prototype is developed to verify the reliability of ADM-VSA and, further, proves the validity of proposed design methods.

scholarly journals Vulnerable adults in police custody

2019 ◽  
Vol 22 (1) ◽  
pp. 5-8
Author(s):  
Ian Cummins
Keyword(s):  
Design Methodology ◽  
Research Literature ◽  
Police Custody ◽  
England And Wales ◽  
Content Type ◽  
Increased Risk ◽  
Vulnerable Adults

Purpose The purpose of this paper is to discuss the recent National Appropriate Adult Network (NAAN) report on the role of the appropriate adult. Design/methodology/approach This paper is based on the NAAN report and a review of relevant policy and research literature. Findings There to Help 2 highlights that there are still significant gaps in the provision of appropriate adult schemes across England and Wales. These gaps potentially place vulnerable adults at increased risk. Originality/value This paper is a review of recent research.

Co-workers’ perceptions of and reactions to employee’s involuntary demotion

2019 ◽  
Vol 41 (4) ◽  
pp. 740-757 ◽  
Author(s):  
Sophie Hennekam ◽  
Subramaniam Ananthram ◽  
Steve McKenna
Keyword(s):  
Design Methodology ◽  
Emotional Responses ◽  
Emotional Reaction ◽  
Content Type ◽  
Informational Justice ◽  
Behavioural Responses ◽  
Behavioural Reaction ◽  
Three Stages ◽  
Depth Interviews ◽  
The Way

Purpose The purpose of this paper is to investigate how individuals perceive and react to the involuntary demotion of a co-worker in their organisation. Design/methodology/approach The authors draw on 46 semi-structured in-depth interviews (23 dyads) with co-workers of demoted individuals. Findings The findings suggest that an individual’s observation of the demotion of a co-worker has three stages: their perception of fairness, their emotional reaction and their behavioural reaction. The perception of fairness concerned issues of distributive, procedural, interpersonal and informational justice. The emotional responses identified were feelings of disappointment/disillusion, uncertainty, vulnerability and anger. Finally, the behavioural reactions triggered by their emotional responses included expressions of voice, loyalty, exit and adaptation. Originality/value Perceptions of (in)justice perpetrated on others stimulate emotional and behavioural responses, which impacts organisational functioning. Managers should therefore pay attention to the way a demotion is perceived, not only by those directly concerned, but also by co-workers as observers.

Consumer value creation through WhatsApp use

2019 ◽  
Vol 32 (4) ◽  
pp. 455-471
Author(s):  
Jorge Cruz-Cárdenas ◽  
Jorge Guadalupe-Lanas ◽  
Ekaterina Zabelina ◽  
Andrés Palacio-Fierro ◽  
Margarita Velín-Fárez ◽  
...  
Keyword(s):  
Latin American ◽  
Value Creation ◽  
Emotional Support ◽  
Design Methodology ◽  
Instant Messaging ◽  
Role Performance ◽  
Content Type ◽  
Consumer Value ◽  
Depth Interviews ◽  
Practical Implications

Purpose The purpose of this paper is to understand in-depth how consumers create value in their lives using WhatsApp, the leading mobile instant messaging (MIM) application. Design/methodology/approach The study adopts the perspective of customer-dominant logic (CDL) and uses a qualitative multimethod design involving 3 focus groups and 25 subsequent in-depth interviews. The research setting was Ecuador, a Latin American country. Findings Analysis and interpretation of the participants’ stories made it possible to identify and understand the creation of four types of value: maintaining and strengthening relationships; improving role performance; emotional support; and entertainment and fun. In addition, the present study proposes a conceptual model of consumer value creation as it applies to MIM. Practical implications Understanding the way consumers create value in their lives using MIM is important not only for organizations that offer MIM applications, but also for those companies that develop other applications for mobile phones or for those who wish to use MIM as an electronic word-of-mouth vehicle. Originality/value The current study is one of the first to address the topic of consumer behavior in the use of technologies from the perspective of CDL; this perspective enables an integrated qualitative vision of value creation in which the consumer is the protagonist.

scholarly journals Advantages and potential challenges of data management in e-maintenance

2019 ◽  
Vol 25 (3) ◽  
pp. 378-396 ◽  
Author(s):  
Arian Razmi-Farooji ◽  
Hanna Kropsu-Vehkaperä ◽  
Janne Härkönen ◽  
Harri Haapasalo
Keyword(s):  
Data Management ◽  
Design Methodology ◽  
Management Practices ◽  
Future Research ◽  
Conceptual Approach ◽  
Content Type ◽  
Different Types ◽  
Maintenance Systems ◽  
Industry Leader ◽  
Practical Implications

Purpose The purpose of this paper is twofold: first, to understand data management challenges in e-maintenance systems from a holistically viewpoint through summarizing the earlier scattered research in the field, and second, to present a conceptual approach for addressing these challenges in practice. Design/methodology/approach The study is realized as a combination of a literature review and by the means of analyzing the practices on an industry leader in manufacturing and maintenance services. Findings This research provides a general understanding over data management challenges in e-maintenance and summarizes their associated proposed solutions. In addition, this paper lists and exemplifies different types and sources of data which can be collected in e-maintenance, across different organizational levels. Analyzing the data management practices of an e-maintenance industry leader provides a conceptual approach to address identified challenges in practice. Research limitations/implications Since this paper is based on studying the practices of a single company, it might be limited to generalize the results. Future research topics can focus on each of mentioned data management challenges and also validate the applicability of presented model in other companies and industries. Practical implications Understanding the e-maintenance-related challenges helps maintenance managers and other involved stakeholders in e-maintenance systems to better solve the challenges. Originality/value The so-far literature on e-maintenance has been studied with narrow focus to data and data management in e-maintenance appears as one of the less studied topics in the literature. This research paper contributes to e-maintenance by highlighting the deficiencies of the discussion surrounding the perspectives of data management in e-maintenance by studying all common data management challenges and listing different types of data which need to be acquired in e-maintenance systems.

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