Yue Qiao, Wang Wei, Yunxiang Li, Shengzui Xu, Lang Wei, Xu Hao and Re Xia
The purpose of this paper is to introduce a motion control method for WFF-AmphiRobot, which can effectively realize the flexible motion of the robot on land, underwater and in the…
Abstract
Purpose
The purpose of this paper is to introduce a motion control method for WFF-AmphiRobot, which can effectively realize the flexible motion of the robot on land, underwater and in the transition zone between land and water.
Design/methodology/approach
Based on the dynamics model, the authors selected the appropriate state variables to construct the state space model of the robot and estimated the feedback state of the robot through the maximum a posteriori probability estimation. The nonlinear predictive model controller of the robot is constructed by local linearization of the model to perform closed-loop control on the overall motion of the robot. For the control problem of the terminal trajectory, using the neural rhythmic movement theory in bionics to construct a robot central pattern generator (CPG) for real-time generation of terminal trajectory.
Findings
In this paper, the motion state of WFF-AmphiRobot is estimated, and a model-based overall motion controller for the robot and an end-effector controller based on neural rhythm control are constructed. The effectiveness of the controller and motion control algorithm is verified by simulation and physical prototype motion experiments on land and underwater, and the robot can ideally complete the desired behavior.
Originality/value
The paper designed a controller for WFF-AmphiRobot. First, when constructing the robot state estimator in this paper, the robot dynamics model is introduced as the a priori estimation model, and the error compensation of the a priori model is performed by the method of maximum a posteriori probability estimation, which improves the accuracy of the state estimator. Second, for the underwater oscillation motion characteristics of the flipper, the Hopf oscillator is used as the basis, and the flipper fluctuation equation is modified and improved by the CPG signal is adapted to the flipper oscillation demand. The controller effectively controls the position error and heading angle error within the desired range during the movement of the WFF-AmphiRobot.
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Xu Hao, Lang Wei, Yue Qiao, Shengzui Xu, Jian Bin Liao, Yu Xi, Wang Wei and Zhi-Wei Liu
The computing power of the legged robot is not enough to perform high-frequency updates for the full-body model predictive control (MPC) of the robot, which is a common problem…
Abstract
Purpose
The computing power of the legged robot is not enough to perform high-frequency updates for the full-body model predictive control (MPC) of the robot, which is a common problem encountered in the gait research of the legged robot. The purpose of this paper is to propose a high-frequency MPC control method for the bounding gait of a parallel quadruped robot.
Design/methodology/approach
According to the bounding gait characteristics of the robot, the quadruped robot model is simplified to an equivalent plane bipedal model. Under the biped robot model, the forces between the robot’s feet and the ground are calculated by MPC. Then, the authors apply a proportional differential controller to distribute these forces to the four feet of the quadruped robot. The robot video can be seen at www.bilibili.com/video/BV1je4y1S7Rn.
Findings
To verify the feasibility of the controller, a prototype was made, and the controller was deployed on the actual prototype and then fully analyzed through experiments. Experiments show that the update frequency of MPC could be stabilized at 500 Hz while the robot was running in the bounding gait stably and efficiently.
Originality/value
This paper proposes a high-frequency MPC controller under the simplified model, which has a higher working efficiency and more stable control performance.
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Fusheng Liu, Zhihang He, Yue Qiao, Xinxin Liu, Xuelong Li, Wang Wei, Bo Su and Ruina Dang
The purpose of this paper is specifically to provide a more intelligent locomotion planning method for a hexapod robot based on trajectory optimization, which could reduce the…
Abstract
Purpose
The purpose of this paper is specifically to provide a more intelligent locomotion planning method for a hexapod robot based on trajectory optimization, which could reduce the complexity of locomotion design, shorten time of design and generate efficient and accurate motion.
Design/methodology/approach
The authors generated locomotion for the hexapod robot based on trajectory optimization method and it just need to specify the high-level motion requirements. Here the authors first transcribed the trajectory optimization problem to a nonlinear programming problem, in which the specified motion requirements and the dynamics with complementarity constraints were defined as the constraints, then a nonlinear solver was used to solve. The leg compliance was taken into consideration and the generated motions were deployed on the hexapod robot prototype to prove the utility of the method and, meanwhile, the influence of different environments was considered.
Findings
The generated motions were deployed on the hexapod robot and the movements were demonstrated very much in line with the planning. The new planning method does not require lots of parameter-tuning work and therefore significantly reduces the cycle for designing a new locomotion.
Originality/value
A locomotion generation method based on trajectory optimization was constructed for a 12-degree of freedom hexapod robot. The variable stiffness compliance of legs was considered to improve the accuracy of locomotion generation. And also, different from some simulation work before, the authors have designed the locomotion in three cases and constructed field tests to demonstrate its utility.
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Yanzhang Yao, Wei Wang, Yue Qiao, Zhihang He, Fusheng Liu, Xuelong Li, Xinxin Liu, Dehua Zou and Tong Zhang
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.
Abstract
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.
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Hui Chen, Qiao-zhuan Liang and Yue Zhang
The current research studies are inconclusive about the positive or negative effects of group faultlines, especially in the Chinese context. To address this issue, this study aims…
Abstract
Purpose
The current research studies are inconclusive about the positive or negative effects of group faultlines, especially in the Chinese context. To address this issue, this study aims to adopt an interactive perspective to explore the group interaction process. Specifically, this study proposes a new construct “interactive faultlines” to integrate overall faultlines and separate faultlines, and based on categorization-elaboration model (CEM), develops an integrated moderated mediation model to examine when and how interactive faultlines facilitate or inhibit group creativity.
Design/methodology/approach
This study tests the model with the samples of 405 employees from 95 groups in China, carrying out confirmatory factor analysis, regression analysis and process.
Findings
This study finds that the indirect effect of informational faultlines on group creativity through information elaboration is positive when social faultlines are low, but negative when social faultlines are high.
Practical implications
This research provides some practical implications on how to manage group compositions and coordinate group interaction process to make full use of the potential benefits of diverse information and avoid the possible detriment from social categorization.
Originality/value
This study adopts an interactive perspective to consider informational faultlines and social faultlines simultaneously, and constructs a focal concept “interactive faultlines.” Based on CEM, it also offers a fine-grained picture of the double-edged relationship between informational faultlines and group creativity by identifying social faultlines as a moderator and information elaboration as a mediator, which advances knowledge about the linkages between interactive faultlines and group creativity. Particularly, this study is rooted in the Chinese context and brings in indigenous attributes derived from an analysis of Eastern cultures to elucidate the particular effect of informal social connections.
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The paper aims to identify the relationship between institutional logics and corporate finance in the context of China. It models the institutional logics and outlines why and how…
Abstract
Purpose
The paper aims to identify the relationship between institutional logics and corporate finance in the context of China. It models the institutional logics and outlines why and how they impact the capital structure. The study aims to expand the domain of corporate finance by introducing the institutional effects.
Design/methodology/approach
The paper employs the ownership and region to proxy institutional logics, and a time dummy for their evolution and tests how they shape firms' capital structure through panel data regression.
Findings
The paper finds that capital structures in firms dominated by state logic are less heterogeneous but the heterogeneities of all firms' increase over time and the capital structures in firms dominated by state logic deviate more from the optimality but those of all firms approach the optimality as time goes by. I also document that the institutional logics affect the corporate financing decisions through the selection of chief executive officers (CEOs).
Research limitations/implications
The paper demonstrates how state and market institutions are embodied in firms and how their evolution requires firms to adapt, and it proposes a brand-new insight into the marketization process of China.
Practical implications
The paper finds that the firms are unable to acquire optimal capital structure because of the institutional pressure and derive some implications on managerial practice of Chinese firms.
Originality/value
The paper analyses and examines the impacts of the institutional logics on corporate financing decisions as well as the potential channel, enhancing the understanding of the institutions and firms' responses.
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Xueyan Zhang, Xiaohu Zhou, Qiao Wang, Zhouyue Wu and Yue Sui
Based on social influence theory, this paper aims to explore the influence of academic entrepreneurs on team innovation activities. The innovation behavior of academic team…
Abstract
Purpose
Based on social influence theory, this paper aims to explore the influence of academic entrepreneurs on team innovation activities. The innovation behavior of academic team members is the key behavior in academic entrepreneurial activities. As a special entrepreneurial group, academic entrepreneurs' political skills play an important role in stimulating team innovative behaviors.
Design/methodology/approach
This paper adopts a multi-level study design and takes as samples the paired data of 91 academic entrepreneurial teams (n = 475). Based on team cognition, it constructs a model of the influence mechanism of academic entrepreneurs' political skills on team innovation behavior and explores the mechanism of transactive memory system in this influence effect. The authors use HLM and PROCESS macro to test our multilevel model.
Findings
The results show that academic entrepreneurs' political skills positively impact team innovation behavior, and a transactive memory system plays a mediating role between them. Team psychological safety significantly enhances the positive relationship of both academic entrepreneurs' political skills and a transactive memory system with team innovation behavior. Moreover, with enhanced perceptions of team psychological safety, academic entrepreneurs' political skills are more likely to improve team innovation behavior through the transactive memory system.
Originality/value
The study explores the influence of transactive memory system on the relationship between academic entrepreneurs' political skills and team innovation behavior, with the team cognitive perspective derived from social influence theory. This provides authors with new insights on the complex dynamics at place in the team innovation process and offers implications for how we can fruitfully manage this process.
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In this chapter, the author compares two representations of the child from two famous films by the Fifth Generation’s top director in China, Chen Kaige, Yellow Earth (1984) and…
Abstract
In this chapter, the author compares two representations of the child from two famous films by the Fifth Generation’s top director in China, Chen Kaige, Yellow Earth (1984) and Together (2002). The girl’s story in the former and the boy’s story in the latter show respectively the dissolution of the Party/state as an extended family home, and it being replaced by the atomized, fluid, and flexible family home in the new state-led neo-liberal order. Compared with the girl, the boy in the new century tries to convey an equally lyrical articulation of the family/home, but differently, with a strong sense of his subjectivity. Thus, the boy’s voice in Together, self-reflective, artistically innovative, and affective, becomes a voice of resistance against authoritarian neoliberalism in post-socialist China.
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Mianzhi Yang, Qing Hui, Qingru Yang, Mengwei Fan and Xin Li
China has recently introduced a new audit law that aims to increase the scope of audit supervision and raise the standards for preventing risks in auditing national public…
Abstract
Purpose
China has recently introduced a new audit law that aims to increase the scope of audit supervision and raise the standards for preventing risks in auditing national public projects. This paper presents a systematic research study on the causes of audit risks in national public projects and discusses the process by which these causes contribute to the emergence of such risks. Furthermore, the paper investigates the core risk sources in various types of national construction project audit. This paper aims to provide theoretical support for auditors of national construction projects in risk avoidance when conducting audits.
Design/methodology/approach
In this study, the authors carefully selected five national public audit projects from China and performed a comprehensive analysis of 85 relevant audit documentation. The textual analysis was conducted using Nvivo12 software, and the grounded theory approach was adopted for generalization purposes.
Findings
Based on the research results, the findings suggest that there are five key causes contributing to the audit risk of national construction projects: professional competence, risk awareness, management capacity, level of attention and deliberate fraud. The most critical factor identified is management capability, with 59.93% of the data supporting this view. This conclusion was based on an analysis of state-owned enterprises, administrative organs and public institutions. Building upon this, a framework titled “the mechanism of audit risk factors with management capability as the core” was constructed.
Originality/value
This paper employs qualitative analysis methods to examine national construction projects in China, contributing new literature to the theoretical study of audit risk management. The article also provides practical recommendations for auditors on how to mitigate audit risks and improve the quality of audit services in national project governance.
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Hung Ngoc Phan and Satoko Okubayashi
Dehydrated bacterial cellulose’s (BC) intrinsic rigidity constrains applicability across textiles, leather, health care and other sectors. This study aims to yield a novel BC…
Abstract
Purpose
Dehydrated bacterial cellulose’s (BC) intrinsic rigidity constrains applicability across textiles, leather, health care and other sectors. This study aims to yield a novel BC modification method using glycerol and succinic acid with catalyst and heat, applied via an industrially scalable padding method to tackle BC’s stiffness drawbacks and enhance BC properties.
Design/methodology/approach
Fabric-like BC is generated via mechanical dehydration and then finished by using padding method with glycerol, succinic acid, catalyst and heat. Comprehensive material characterizations, including international testing standards for stiffness, bending properties (cantilever method), tensile properties, moisture vapor transmission rate, moisture content and regain, washing, thermal gravimetric analysis, derivative thermogravimetry, Fourier-transform infrared spectroscopy and colorimetric measurement, are used.
Findings
The combination of BC/glycerol/succinic acid dramatically enhanced porous structure, elongation (27.40 ± 6.39%), flexibility (flexural rigidity of 21.46 ± 4.01 µN m; bending modulus of 97.45 ± 18.20 MPa) and moisture management (moisture vapor transmission rate of 961.07 ± 86.16 g/m2/24 h; moisture content of 27.43 ± 2.50%; and moisture regain of 37.94 ± 4.73%). This softening process modified the thermal stability of BC. Besides, this study alleviated the drawbacks for washing (five cycles) of BC and glycerol caused by the ineffective affinity between glycerol and cellulose by adding succinic acid with catalyst and heat.
Originality/value
The study yields an effective padding process for BC softening and a unique modified BC to contribute added value to textile and leather industries as a sustainable alternative to existing materials and a premise for future research on BC functionalization by using doable technologies in mass production as padding.