Guolei Wang, Qiankun Yu, Tianyu Ren, Xiaotong Hua and Ken Chen
To paint large workpieces automatically, painting manipulators with hollow wrists must be transported by mobile platforms to different positions because of their limited…
Abstract
Purpose
To paint large workpieces automatically, painting manipulators with hollow wrists must be transported by mobile platforms to different positions because of their limited workspaces. This paper aims to provide a visualization method for finding appropriate base positions (BPs) and maximum painting areas for manipulators.
Design/methodology/approach
This paper begins by analyzing the motion characteristics of manipulators possessing a spherical wrist and summarizing them into three constraints – positioning, orientation and singularity avoidance. The hollow wrist is simplified and considered as spherical by introducing the concepts of an inner wrist center and an outer wrist center. Taking the three constraints into consideration, the boundaries of the manipulating space are formulated analytically. Finally, to verify the method, the space obtained is applied to determine the maximum painting areas for flat, cylindrical and conical surfaces. Experiments of robotic painting were used to confirm the results.
Findings
Compared with previous studies, the maximum areas obtained using the proposed method increased by 17-131 per cent with an algorithm of lower complexity, and the process remained visually intuitive, thereby demonstrating that the method of manipulating space is more effective.
Originality/value
Such a method allows individuals to visualize the entire painting area at the current BP, thereby maximizing painting areas or optimizing BPs. It opens a black box that is the relationship between BPs and blocks. The method can also be used to choose the best configuration for painting manipulators, select the end-effector structure parameters, split surfaces into blocks, etc.
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Tianyu Ren, Yunfei Dong, Dan Wu and Ken Chen
The purpose of this paper is to present a simple yet effective force control scheme for collaborative robots by addressing the problem of disturbance rejection in joint torque…
Abstract
Purpose
The purpose of this paper is to present a simple yet effective force control scheme for collaborative robots by addressing the problem of disturbance rejection in joint torque: inherent actuator flexibility and nonlinear friction.
Design/methodology/approach
In this paper, a joint torque controller with an extended state observer is used to decouple the joint actuators from the multi-rigid-body system of a constrained robot and compensate the motor friction. Moreover, to realize robot force control, the authors embed this controller into the impedance control framework.
Findings
Results have been given in simulations and experiments in which the proposed joint torque controller with an extended state observer can effectively estimate and compensate the total disturbance. The overall control framework is analytically proved to be stable, and further it is validated in experiments with a robot testbed.
Practical implications
With the proposed robot force controller, the robot is able to change its stiffness in real time and therefore take variable tasks without any accessories, such as the RCC or 6-DOF F/T sensor. In addition, programing by demonstration can be realized easily within the proposed framework, which makes the robot accessible to unprofessional users.
Originality/value
The main contribution of the presented work is the design of a model-free robot force controller with the ability to reject torque disturbances from robot-actuator coupling effect and motor friction, applicable for both constrained and unconstrained environments. Simulation and experiment results from a 7-DOF robot are given to show the effectiveness and robustness of the proposed controller.
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Yunfei Dong, Tianyu Ren, Ken Chen and Dan Wu
This paper aims to improve the accuracy of robot payload identification and decrease the complexity in its industrial application by developing a new method based on the actuator…
Abstract
Purpose
This paper aims to improve the accuracy of robot payload identification and decrease the complexity in its industrial application by developing a new method based on the actuator current.
Design/methodology/approach
Instead of previous general robot dynamic modeling of the actuators, links, together with payload inertial parameters, the paper discovers that the difference of the actuator torque between the robot moving along the same trajectory with and without carrying payload can be described as a function of the payload inertial parameters directly. Then a direct dynamic identification model of payload is built, a set of specialized novel exciting trajectories are designed for accurate identification and the least square method is applied for the estimation of the load parameters.
Findings
The experiments confirm the effectiveness of the proposed method in robot payload identification. The identification accuracy is greatly improved compared with that of existing methods based on the actuator current and is close to the accuracy of the methods that direct use the wrist-mounted force-torque sensor.
Practical implications
As the provided experiments indicate, the proposed method expands the application range and greatly improves the accuracy, hence making payload identification fully operational in the industrial application.
Originality/value
The novelty of such an identification method is that it does not require the rotor inertias and inertial parameters of links as a prior knowledge, and the specially designed trajectories provide completed decoupling of the load parameters.
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Rongwei Ren, Lei Yu and Yunxia Zhu
This paper aims to study the evolution of innovation-based dynamic capabilities in informal copycat-style firms. As a kind of informal economical organizations, copycat-style…
Abstract
Purpose
This paper aims to study the evolution of innovation-based dynamic capabilities in informal copycat-style firms. As a kind of informal economical organizations, copycat-style firms in many emerging economies play an important role in their development of the economics. The development of Shanzhai firms, Chinese-style copycat firms, from imitation to innovation has become an important micro-foundation of China’s economic growth and the manufacturing development. With the cluster development of the Chinese mobile phone industry as the macro and industrial environment background, this paper chose Beijing Tianyu Communication Equipment Co. Ltd as the typical example of innovation in Shanzhai firms and studied the evolution of innovation-based dynamic capabilities in this company.
Design/methodology/approach
This paper chose Beijing Tianyu Communication Equipment Co. Ltd as the typical example of innovation in Shanzhai firms and studied the evolution of innovation-based dynamic capabilities in this company by adopting the leading-edge dynamic capability theory, innovation theory and industrial cluster theory. The authors further discussed how to improve the dynamic capabilities in Shanzhai firms in China.
Findings
It is finally suggested that Shanzhai firms should reduce innovation failures and lower damage degree of dynamic capabilities through consistent innovation and paying attention to their innovation improvement.
Originality/value
It will be very significant to research the survival or diminishing of Shanzhai firms from a theoretical perspective, which will eventually enhance property right protection and innovation development in China.
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Jun Wen, Carol Chunfeng Wang, Edmund Goh, Zhaohui Su and Tianyu Ying
This paper explores the role of traditional Chinese medicine (TCM) as a tourism recovery drawcard to boost China's inbound tourism after COVID-19.
Abstract
Purpose
This paper explores the role of traditional Chinese medicine (TCM) as a tourism recovery drawcard to boost China's inbound tourism after COVID-19.
Design/methodology/approach
This paper employed a mixed method involving a cross-disciplinary literature review along with reflections from experts in TCM and health communication to inform tourism management. Specifically, this paper examines TCM and its potential benefits as a medical tourism drawcard to combat COVID-19. The selected literature focusses on the image and merits of TCM to frame how this medical philosophy can be used to position China as a tourist destination. Reflections on the use of TCM as a tourism marketing tool can guide promotional strategies from the Chinese government and destination managers during and after COVID-19.
Findings
The Chinese government, the tourism industry (e.g. destination managers), the media and tourists must focus on three aspects of the role of TCM: to provide medical benefits to travellers amid COVID-19 and beyond, elevate China as a destination for global medical tourists and be leveraged as a tool for economic recovery.
Practical implications
The paper builds a tourism recovery framework for stakeholders to adopt tailored TCM communication strategies to boost its inbound tourism programme.
Originality/value
This paper is the first academic paper to review TCM comprehensively and critically in relation to China tourism and post-COVID-19 recovery measures.
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Changyu Wang, Tianyu Yuan, Jiaojiao Feng and Xinya Peng
The purpose of this study is to explore the relationship between information overload and employees' workplace anxiety in the context of enterprise social media (ESM).
Abstract
Purpose
The purpose of this study is to explore the relationship between information overload and employees' workplace anxiety in the context of enterprise social media (ESM).
Design/methodology/approach
This study built a theoretical model to analyze the relationships among employees' perceptions of information overload on ESM, supervisor-subordinate instrumental and expressive ties on ESM and workplace anxiety. PLS-SEM was used to test the model through 219 questionnaires collected online.
Findings
The results revealed that information overload on ESM plays a positive role in employees' workplace anxiety. Supervisor-subordinate instrumental ties based on ESM can weaken the relationship between information overload and employees' workplace anxiety, but expressive ties can strengthen the positive relationship between information overload and workplace anxiety.
Originality/value
Little is known about whether information overload on ESM will affect employees' workplace anxiety and how leaders can mitigate this effect through ESM. Hence, this study developed a theoretical model and conducted an empirical study to open up a research opportunity to examine the relationships among information overload on ESM, supervisor-subordinate instrumental and expressive ties on ESM and employees' workplace anxiety. The study also has the potential to guide organizations in fine-tuning their social media usage strategies.
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Tianyu Yan, Weizhe Yang, Yanyan He and Qinglong Gou
This study aims to investigate the effect of the reference quality on the optimal production strategy of a component manufacturer (CM), which mainly concerns whether to sell its…
Abstract
Purpose
This study aims to investigate the effect of the reference quality on the optimal production strategy of a component manufacturer (CM), which mainly concerns whether to sell its high quality self-branded products and whether to supply critical components to a competitive original equipment manufacturer (OEM) who produces low quality products.
Design/methodology/approach
The study considers a supply chain comprising an OEM, a CM and a third-party component manufacturer (TCM), who produces components with uncertain quality. The OEM selects a supplier between the CM and the TCM to produce products. Anticipating the OEM’s supplier selection, the CM chooses among three alternative production strategies. For each alternative strategy of the CM, the authors derive the equilibrium solutions between the OEM and the CM with or without the reference quality effect. Then, the authors obtain the effect of the reference quality on the CM by comparing the CM’s optimal strategy between the two situations.
Findings
First, the reference quality has opposite effects on the CM’s production strategy depending on the competition results. A high reference quality effect motivates the CM to solely sell the self-branded products if the OEM can always enter the final product market when purchasing from the TCM, and to sell both self-branded products and components if the OEM cannot enter the market when using the TCM’s low quality components. Second, the reference quality effect motivates the OEM to accept a higher wholesale price from the CM. Third, the reference quality effect can make the CM benefit from a more stable TCM in competition.
Originality/value
This paper first considers the impact of the reference quality effect on the CM’s production strategy. By considering consumers’ behavior in a co-opetitive supply chain, this paper contributes to both literature and practice.
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Hanan Lu, Qiushi Li, Tianyu Pan and Ramesh Agarwal
For an axial-flow compressor rotor, the upstream inflow conditions will vary as the aircraft faces harsh flight conditions (such as taking off, landing or maneuvering) or the…
Abstract
Purpose
For an axial-flow compressor rotor, the upstream inflow conditions will vary as the aircraft faces harsh flight conditions (such as taking off, landing or maneuvering) or the whole compressor operates at off-design conditions. With the increase of upstream boundary layer thickness, the rotor blade tip will be loaded and the increased blade load will deteriorate the shock/boundary layer interaction and tip leakage flows, resulting in high aerodynamic losses in the tip region. The purpose of this paper is to achieve a better flow control for tip secondary flows and provide a probable design strategy for high-load compressors to tolerate complex upstream inflow conditions.
Design/methodology/approach
This paper presents an analysis and application of shroud wall optimization to a typical transonic axial-flow compressor rotor by considering the inlet boundary layer (IBL). The design variables are selected to shape the shroud wall profile at the tip region with the purpose of controlling the tip leakage loss and the shock/boundary layer interaction loss. The objectives are to improve the compressor efficiency at the inlet-boundary-layer condition while keeping its aerodynamic performance at the uniform condition.
Findings
After the optimization of shroud wall contour, aerodynamic benefits are achieved mainly on two aspects. On the one hand, the shroud wall optimization has reduced the intensity of the tip leakage flow and the interaction between the leakage and main flows, thereby decreasing the leakage loss. On the other hand, the optimized shroud design changes the shock structure and redistributes the shock intensity in the spanwise direction, especially weakening the shock near the tip. In this situation, the shock/boundary layer interaction and the associated flow separations and wakes are also eliminated. On the whole, at the inlet-boundary-layer condition, the compressor with optimized shroud design has achieved a 0.8 per cent improvement of peak efficiency over that with baseline shroud design without sacrificing the total pressure ratio. Moreover, the re-designed compressor also maintains the aerodynamic performance at the uniform condition. The results indicate that the shroud wall profile has significant influences on the rotor tip losses and could be properly designed to enhance the compressor aerodynamic performance against the negative impacts of the IBL.
Originality/value
The originality of this paper lies in developing a shroud wall contour optimization design strategy to control the tip leakage loss and the shock/boundary layer interaction loss in a transonic compressor rotor. The obtained results could be beneficial for transonic compressors to tolerate the complex upstream inflow conditions.
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Siyue Chen, Gengzhi Huang, Hongou Zhang, Yuyao Ye and Qitao Wu
Institutional factors play an important and complex role in Chinese outward foreign direct investment (OFDI) location choices that do not seem to be influenced by a host country’s…
Abstract
Purpose
Institutional factors play an important and complex role in Chinese outward foreign direct investment (OFDI) location choices that do not seem to be influenced by a host country’s high political risks. Moreover, the location choice for OFDI is key to corporate strategic decision-making on internationalization. Therefore, this study aims to examine the direct investments of Chinese multinational enterprises (MNEs) in Laos.
Design/methodology/approach
Combining the purposive sampling strategy and snowball sampling method, the authors interviewed nine market- and resource-seeking Chinese enterprises in Laos. Drawing from the mainstream eclectic paradigm and the theory of new institutional economics, the authors analyzed two key variables – enterprise investment motivation and enterprise heterogeneity.
Findings
Chinese MNEs are not insensitive to the regressive institutional quality of host countries; the relationship effect and institutional distance are the location decision pathways along with which institutional factors influence Chinese multinationals’ investments in Laos; political stability is necessary for Chinese-funded enterprises to invest in Laos and the degree of corruption is an overestimated institutional preference factor.
Originality/value
The relationship effect is introduced into the analysis framework as an intermediate variable that influences the decision of MNEs to invest in countries with underdeveloped institutions. It verifies the significant roles of bilateral political relations and network relations in the OFDI location decisions of state-owned and private enterprises, respectively.