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1 – 10 of over 1000Juliang Xiao, Fan Zeng, Qiulong Zhang and Haitao Liu
This paper aims to propose a forcefree control algorithm that is based on a dynamic model with full torque compensation is proposed to improve the compliance and flexibility of…
Abstract
Purpose
This paper aims to propose a forcefree control algorithm that is based on a dynamic model with full torque compensation is proposed to improve the compliance and flexibility of the direct teaching of cooperative robots.
Design/methodology/approach
Dynamic parameters identification is performed first to obtain an accurate dynamic model. The identification process is divided into two steps to reduce the complexity of trajectory simplification, and each step contains two excitation trajectories for higher identification precision. A nonlinear friction model that considers the angular displacement and angular velocity of joints is proposed as a secondary compensation for identification. A torque compensation algorithm that is based on the Hogan impedance model is proposed, and the torque obtained by an impedance equation is regarded as the command torque, which can be adjusted. The compensatory torque, including gravity torque, inertia torque, friction torque and Coriolis torque, is added to the compensation to improve the effect of forcefree control.
Findings
The model improves the total accuracy of the dynamic model by approximately 20% after compensation. Compared with the traditional method, the results prove that the forcefree control algorithm can effectively reduce the drag force approximately 50% for direct teaching and realize a flexible and smooth drag.
Practical implications
The entire algorithm is verified by the laboratory-developed six degrees-of-freedom cooperative robot, and it can be applied to other robots as well.
Originality/value
A full torque compensation is performed after parameters identification, and a more accurate forcefree control is guaranteed. This allows the cooperative robot to be dragged more smoothly without external sensors.
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Davood Ghorbanzadeh, Atena Rahehagh and Mohsen Sharbatiyan
Online brand communities (OBCs) and their role in determining consumer behavior is gathering interest of theorists and practitioners. This study examines the role of OBCs in…
Abstract
Purpose
Online brand communities (OBCs) and their role in determining consumer behavior is gathering interest of theorists and practitioners. This study examines the role of OBCs in influencing the level of involvement leading to perceived sport team brand equity (STBE) of sports fans from a social exchange theory perspective. The role of self-congruity as a moderator is examined to determine the differences in the level of involvement and attachment of fans in OBCs.
Design/methodology/approach
Based on quantitative research and convenience sampling, data for the study were collected from 394 football fans who were existing members of OBCs. The research model is tested using partial least square structural equation modeling.
Findings
The results show a direct and significant impact of brand involvement on brand attachment. Consumer brand engagement (CBE) mediates the relationship between brand attachment and STBE. While self-congruence does moderate the effects between brand involvement and brand attachment.
Originality/value
The study reveals the role of community related factors on sports fans’ perceived STBE. The study also provided a novel approach to examine sport fan behavior in social media through the lens of social exchange theory. Finally, it is providing a novel approach in examining role of OBCs in influencing behavior of sports team fans towards the team and brand.
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Hong Fan and Liqiang Chen
The purpose of this paper is to investigate the effects of political connections on the association between firms' business strategy and their tax aggressiveness in an emerging…
Abstract
Purpose
The purpose of this paper is to investigate the effects of political connections on the association between firms' business strategy and their tax aggressiveness in an emerging economy such as China.
Design/methodology/approach
The authors study a large sample of Chinese public firms from 2011 to 2017 using a panel regression model. In addition, a change analysis, an instrument variable test and alternative measures/samples are implemented as robustness tests.
Findings
Firms adopting innovative business strategy are more tax aggressive overall. However, innovative firms with political connections are less tax aggressive compared to those without political connections.
Originality/value
This paper contributes to the understanding of firms' tax behaviors in an emerging economy setting. It suggests that there are costs associated with political connections, such as foregone tax saving opportunities, which are understudies in the prior literature.
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Bo Zeng, Hongwei Liu, Hongzhou Song, Zhe Zhao, Shaowei Fan, Li Jiang, Yuan Liu, Zhiyuan Yu, Xiaorong Zhu, Jing Chen and Ting Zhang
The purpose of this paper is to design a multi-sensory anthropomorphic prosthetic hand and a grasping controller that can detect the slip and automatically adjust the grasping…
Abstract
Purpose
The purpose of this paper is to design a multi-sensory anthropomorphic prosthetic hand and a grasping controller that can detect the slip and automatically adjust the grasping force to prevent the slip.
Design/methodology/approach
To improve the dexterity, sensing, controllability and practicability of a prosthetic hand, a modular and multi-sensory prosthetic hand was presented. In addition, a slip prevention control based on the tactile feedback was proposed to improve the grasp stability. The proposed controller identifies slippages through detecting the high-frequency vibration signal at the sliding surface in real time and the discrete wavelet transform (DWT) was used to extract the eigenvalues to identify slippages. Once the slip is detected, a direct-feedback method of adjusting the grasp force related with the sliding times was used to prevent it. Furthermore, the stiffness of different objects was estimated and used to improve the grasp force control. The performances of the stiffness estimation, slip detection and slip control are experimentally evaluated.
Findings
It was found from the experiment of stiffness estimation that the accuracy rate of identification of the hard metal bottle could reach to 90%, while the accuracy rate of identification of the plastic bottles could reach to 80%. There was a small misjudgment rate in the identification of hard and soft plastic bottles. The stiffness of soft plastic bottles, hard plastic bottles and metal bottles were 0.64 N/mm, 1.36 N/mm and 32.55 N/mm, respectively. The results of slip detection and control show that the proposed prosthetic hand with a slip prevention controller can fast and effectively detect and prevent the slip for different disturbances, which has a certain application prospect.
Practical implications
Due to the small size, low weight, high integration and modularity, the prosthetic hand is easily applied to upper-limb amputees. Meanwhile, the method of the slip prevention control can be used for upper-limb amputees to complete more tasks stably in daily lives.
Originality/value
A multi-sensory anthropomorphic prosthetic hand is designed, and a method of stable grasps control based on slip detection by a tactile sensor on the fingertip is proposed. The method combines the stiffness estimation of the object and the real-time slip detection based on DWT with the design of the proportion differentiation robust controller based on a disturbance observer and the force controller to achieve slip prevention and stable grasps. It is verified effectively by the experiments and is easy to be applied to commercial prostheses.
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Bo Zeng, Shaowei Fan, Li Jiang and Hong Liu
This paper aims to present the design and experiment of a modular multisensory prosthetic hand for applications. Design and experiment of a modular multisensory hand for…
Abstract
Purpose
This paper aims to present the design and experiment of a modular multisensory prosthetic hand for applications. Design and experiment of a modular multisensory hand for prosthetic applications.
Design/methodology/approach
This paper reveals more details focusing on the appearance, mechanism design, electrical design and control of the prosthetic hand considering anthropomorphism, dexterity, sensing and controllability. The finger is internally integrated with the actuator, the transmission mechanism, the sensors and the controller as a modular unit. Integrated with multiple sensors, the prosthetic hand can not only perceive the position, the contact force and the temperature of the environment like a human hand but also provide the foundation for the practical control.
Findings
The experiments show that the prosthetic hand can accurately control the contact force to achieve stable grasps based on the sensors feedback and a simple and effective force-tracking impedance control algorithm. In addition, the experiments based on the cosmesis validate not only the cosmesis functionality but also the control performance for a prosthesis–cosmesis system.
Practical implications
Because of the small size, low weight, high integration, modularity and controllability, the prosthetic hand is easily applied to upper-limb amputees. Meanwhile, the finger as a modular unit is easy to be fixed, maintained and applied to a partial upper-limb amputee.
Originality/value
Each modular finger of the prosthetic hand integrated with the actuator, the transmission mechanism, the sensors and the controller as a whole can independently control the position and the force. The cosmetic glove design can provide pretty appearance without compromising the control performance.
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Keywords
Qiong Wu, Zhiwei Zeng, Jun Lin and Yiqiang Chen
Poor medication adherence leads to high hospital admission rate and heavy amount of health-care cost. To cope with this problem, various electronic pillboxes have been proposed to…
Abstract
Purpose
Poor medication adherence leads to high hospital admission rate and heavy amount of health-care cost. To cope with this problem, various electronic pillboxes have been proposed to improve the medication adherence rate. However, most of the existing electronic pillboxes use time-based reminders which may often lead to ineffective reminding if the reminders are triggered at inopportune moments, e.g. user is sleeping or eating.
Design/methodology/approach
In this paper, the authors propose an AI-empowered context-aware smart pillbox system. The pillbox system collects real-time sensor data from a smart home environment and analyzes the user’s contextual information through a computational abstract argumentation-based activity classifier.
Findings
Based on user’s different contextual states, the smart pillbox will generate reminders at appropriate time and on appropriate devices.
Originality/value
This paper presents a novel context-aware smart pillbox system that uses argumentation-based activity recognition and reminder generation.
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Anam and M. Israrul Haque
The rapid increase in analytics is playing an essential role in enlarging various practices related to the health sector. Big Data Analytics (BDA) provides multiple tools to…
Abstract
The rapid increase in analytics is playing an essential role in enlarging various practices related to the health sector. Big Data Analytics (BDA) provides multiple tools to store, maintain, and analyze large sets of data provided by different systems of health. It is essential to manage and analyze these data to get meaningful information. Pharmaceutical companies are accumulating their data in the medical databases, whereas the payers are digitalizing the records of patients. Biomedical research generates a significant amount of data. There has been a continuous improvement in the health sector for past decades. They have become more advanced by recording the patient’s data on the Internet of Things devices, Electronic Health Records efficiently. BD is undoubtedly going to enhance the productivity and performance of organizations in various fields. Still, there are several challenges associated with BD, such as storing, capturing, and analyzing data, and their subsequent application to a practical health sector.
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Jinyu Yang, Jun Lian and Xing Liu
The purpose of this paper is to study the impact of political connections and institutional environment differences on private enterprises' acquiring bank loans, and to analyze…
Abstract
Purpose
The purpose of this paper is to study the impact of political connections and institutional environment differences on private enterprises' acquiring bank loans, and to analyze the governance effect of bank debts and its impact on firm value.
Design/methodology/approach
Choosing private listed enterprises in China as samples, this study builds equation models and uses the three‐stage least squares estimation method to estimate these models.
Findings
The results show that: political connections influence lending policies of banks; the politically connected private enterprises could acquire more loans from banks. In poorer institutional environment, political connections can help private enterprises to acquire more bank loans; building political connections is an informal substitute mechanism for private enterprises to overcome the drawbacks of market institutions. The bank loans have governance effects on politically connected private enterprises and can increase firm value; the allocation of bank loans through political connections is efficient.
Originality/value
This study provides a meaningful perspective for understanding the impact of political connections on firm value and allocation of social resources.
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Fan Zeng, Beshah Ayalew and Mohammed Omar
The purpose of this paper is to present a new closed‐loop radiative robotic paint curing process that could replace less efficient and bulky convection‐based paint curing…
Abstract
Purpose
The purpose of this paper is to present a new closed‐loop radiative robotic paint curing process that could replace less efficient and bulky convection‐based paint curing processes in automotive manufacturing.
Design/methodology/approach
The proposed robotic paint curing processes uses an Ultraviolet LED panel for a heat source, an infra‐red camera for non‐contact thermal signature feedback of cure level, and a robot control strategy that incorporates the cure‐level information in an inverse dynamics control of the robotic manipulator. To demonstrate the advantage of the closed‐loop process in improving cure uniformity, detailed models and discussions of the irradiation process, the robotics and the control strategy are presented.
Findings
A simulation‐based comparison of the closed‐loop robotic curing with the open‐loop robotic curing clearly shows the benefits of using thermal signature feedback in improving cure level uniformity.
Originality/value
This is a new approach proposed to exploit immerging technology and improve the efficiency of energy use in an automotive manufacturing process without sacrificing product quality.
Details