Search results

1 – 10 of over 10000
Per page
102050
Citations:
Loading...
Access Restricted. View access options
Article
Publication date: 18 June 2020

Mervin Joe Thomas, Mithun M. Sanjeev, A.P. Sudheer and Joy M.L.

This paper aims to use different machine learning (ML) algorithms for the prediction of inverse kinematic solutions in parallel manipulators (PMs) to overcome the computational…

289

Abstract

Purpose

This paper aims to use different machine learning (ML) algorithms for the prediction of inverse kinematic solutions in parallel manipulators (PMs) to overcome the computational difficulties and approximations involved with the analytical methods. The results obtained from the ML algorithms and the Denavit–Hartenberg (DH) approach are compared with the experimental results to evaluate their performances. The study is performed on a novel 6-degree of freedom (DoF) PM that offers precise motions with a large workspace for the end effector.

Design/methodology/approach

The kinematic model for the proposed 3-PPSS PM is obtained using the modified DH approach and its inverse kinematic solutions are determined using the Levenberg–Marquardt algorithm. Various prediction algorithms such as the multiple linear regression, multi-variate polynomial regression, support vector, decision tree, random forest regression and multi-layer perceptron networks are applied to predict the inverse kinematic solutions for the manipulator. The data set required to train the network is generated experimentally by recording the poses of the end effector for different instantaneous positions of the slider using the concept of ArUco markers.

Findings

This paper fully demonstrates the possibility to use artificial intelligence for the prediction of inverse kinematic solutions especially for complex geometries.

Originality/value

As the analytical models derived from the geometrical method, Screw theory or numerical techniques involve approximations and needs more computational power, it is not advisable for real-time control of the manipulator. In addition, the data set obtained from the derived inverse kinematic equations to train the network may lead to inaccuracies in the predicted results. This error may generate significant deviations in the end-effector position from the desired position. The present work attempts to resolve this issue by proposing a camera-based approach that uses ArUco library and ML algorithms to create the data set experimentally and predict the inverse kinematic solutions accurately.

Details

Industrial Robot: the international journal of robotics research and application, vol. 47 no. 5
Type: Research Article
ISSN: 0143-991X

Keywords

Access Restricted. View access options
Article
Publication date: 27 September 2018

Saijal Kizhakke Kodakkattu, Prabhakaran Nair and Joy M.L.

The purpose of this study is to obtain optimum locations, peak deflection and chord of the twin trailing-edge flaps and optimum torsional stiffness of the helicopter rotor blade…

156

Abstract

Purpose

The purpose of this study is to obtain optimum locations, peak deflection and chord of the twin trailing-edge flaps and optimum torsional stiffness of the helicopter rotor blade to minimize the vibration in the rotor hub with minimum requirement of flap control power.

Design/methodology/approach

Kriging metamodel with three-level five variable orthogonal array-based data points is used to decouple the optimization problem and actual aeroelastic analysis.

Findings

Some very good design solutions are obtained using this model. The best design point in minimizing vibration gives about 81 per cent reduction in the hub vibration with a penalization of increased flap power requirement, at normal cruise speed of rotor-craft flight.

Practical implications

One of the major challenges in the helicopters is the high vibration level in comparison with fixed wing aircraft. The reduction in vibration level in the helicopter improves passenger and crew comfort and reduces maintenance cost.

Originality/value

This paper presents design optimization of the helicopter rotor blade combining five design variables, such as the locations of twin trailing-edge flaps, peak deflection and flap chord and torsional stiffness of the rotor. Also, this study uses kriging metamodel to decouple the complex aeroelastic analysis and optimization problem.

Details

Aircraft Engineering and Aerospace Technology, vol. 90 no. 6
Type: Research Article
ISSN: 1748-8842

Keywords

Access Restricted. View access options
Book part
Publication date: 23 February 2016

Abstract

Details

Communication and Information Technologies Annual
Type: Book
ISBN: 978-1-78560-785-1

Access Restricted. View access options
Book part
Publication date: 29 November 2019

Bettina C.K. Binder

Many large companies in Europe include mainly men in supervisory boards and the women quota is often lower than 20%. In Germany an optional women quota of 30% in supervisory…

Abstract

Many large companies in Europe include mainly men in supervisory boards and the women quota is often lower than 20%. In Germany an optional women quota of 30% in supervisory boards was proposed for capital-market-oriented companies in 2016. Some assume that without a gender quota the earnings of enterprises would shrink as male and female members in supervisory teams do not work in such a harmonized and structured way. Others think that a women quota in supervisory boards should be requested by law and should not remain optional. In this context, conducting research and analyzing the impact of the women’s presence in supervisory boards on the success of companies appear as a necessary topic. The present chapter looks at the companies of EURO STOXX 50 in the year 2015 and their success and tries to establish whether this success can be related to the percentage of female members in supervisory positions. It replicates in this way the study of Binder, Alonso-Almeida, and Bremser (2016) which analyzed the relationship between female’s representation in the management board (executive board) and firm performance (measured by earnings before taxes – EBT) of the EURO STOXX 50 companies in 2014. It is in the same time an extension of the original study as the supervisory board is brought under scrutiny.

Details

The Cross-Disciplinary Perspectives of Management: Challenges and Opportunities
Type: Book
ISBN: 978-1-83867-249-2

Keywords

Available. Open Access. Open Access
Article
Publication date: 7 October 2020

Intan Azurin Zainee and Fadilah Puteh

As the new emerging workforce, Generation Y (Gen Y) is said to be demanding, influential and possessing strong bargaining power. This study examines the impact of corporate social…

17648

Abstract

Purpose

As the new emerging workforce, Generation Y (Gen Y) is said to be demanding, influential and possessing strong bargaining power. This study examines the impact of corporate social responsibility (CSR) on employee retention among Gen Y in the accounting profession. CSR is widely researched subject due to its applicability in multidisciplinary fields and industries. This research intends to investigate the nexus between CSR and human capital disciplines. It employs Carroll's pyramid of CSR as the main theoretical framework to establish its relationship with talent retention among Gen Y employees. This study has a threefold aim: (1) to determine the level of CSR awareness, (2) to determine the relationship between CSR dimensions and talent retention and (3) to examine the effect of CSR dimensions on talent retention.

Design/methodology/approach

The paper opted for an exploratory study using the structured questionnaire. A total of 377 Gen Y accountants who are currently working in accounting firms located in Klang Valley, Malaysia, were involved as respondents. Data were analyzed using descriptive, correlation and regression analyses to answer the research objectives.

Findings

The paper provided empirical insights about the impact brought by CSR practices in financial-based firms on employee retention. It was found that all CSR elements, as suggested by Carroll, have a significant relationship with employees’ retention. The interaction between the CSR elements and employee retention accounts for 16% of the research model. Based on the multiple regression analysis, it was found that only two CSR elements are the significant predictors of employee retention among Gen Y in the case of financial-based firms in Malaysia.

Research limitations/implications

This research covers Gen Y employees in accounting firms; thus, generalization is not applicable to other generations. Besides, the predictors of the research study utilize Carroll’s pyramid of CSR. Therefore, future research studies are encouraged to validate the research model into other sectors. Other models of CSR could also be used.

Practical implications

This paper includes implication for the organization to understand employee retention practices on Gen Y who are currently dominating the workforce.

Originality/value

This paper fulfills an identified need to study how CSR practices could enhance employee retention among Gen Y in the organization.

Details

Revista de Gestão, vol. 27 no. 4
Type: Research Article
ISSN: 1809-2276

Keywords

Access Restricted. View access options
Article
Publication date: 6 March 2024

Ruoxing Wang, Shoukun Wang, Junfeng Xue, Zhihua Chen and Jinge Si

This paper aims to investigate an autonomous obstacle-surmounting method based on a hybrid gait for the problem of crossing low-height obstacles autonomously by a six wheel-legged…

199

Abstract

Purpose

This paper aims to investigate an autonomous obstacle-surmounting method based on a hybrid gait for the problem of crossing low-height obstacles autonomously by a six wheel-legged robot. The autonomy of obstacle-surmounting is reflected in obstacle recognition based on multi-frame point cloud fusion.

Design/methodology/approach

In this paper, first, for the problem that the lidar on the robot cannot scan the point cloud of low-height obstacles, the lidar is driven to rotate by a 2D turntable to obtain the point cloud of low-height obstacles under the robot. Tightly-coupled Lidar Inertial Odometry via Smoothing and Mapping algorithm, fast ground segmentation algorithm and Euclidean clustering algorithm are used to recognize the point cloud of low-height obstacles and obtain low-height obstacle in-formation. Then, combined with the structural characteristics of the robot, the obstacle-surmounting action planning is carried out for two types of obstacle scenes. A segmented approach is used for action planning. Gait units are designed to describe each segment of the action. A gait matrix is used to describe the overall action. The paper also analyzes the stability and surmounting capability of the robot’s key pose and determines the robot’s surmounting capability and the value scheme of the surmounting control variables.

Findings

The experimental verification is carried out on the robot laboratory platform (BIT-6NAZA). The obstacle recognition method can accurately detect low-height obstacles. The robot can maintain a smooth posture to cross low-height obstacles, which verifies the feasibility of the adaptive obstacle-surmounting method.

Originality/value

The study can provide the theory and engineering foundation for the environmental perception of the unmanned platform. It provides environmental information to support follow-up work, for example, on the planning of obstacles and obstacles.

Details

Robotic Intelligence and Automation, vol. 44 no. 1
Type: Research Article
ISSN: 2754-6969

Keywords

Access Restricted. View access options
Article
Publication date: 13 November 2018

Umberto Visconti, WonJong Eun, JiSoo Sim, SangWoo Lee and SangJoon Shin

The purpose of this paper is to present the design, analysis and experiments of the active trailing-edge flap (Seoul National University Flap, SNUF) for vibration reduction in the…

324

Abstract

Purpose

The purpose of this paper is to present the design, analysis and experiments of the active trailing-edge flap (Seoul National University Flap, SNUF) for vibration reduction in the helicopter rotor prior to the small-scale blades planned to test in a whirl tower.

Design/methodology/approach

The predictions of the hinge moment in both steady and unsteady flows were obtained through computational fluid dynamics calculations. When compared with the results originated from analytical formulations, the proposed method showed improved prediction capabilities. To validate the deflection of the flap under the centrifugal load by rotating, static analysis was conducted using both contact and rotating condition of MSC NASTRAN. The corresponding experiment also was performed using the vertical frame for simulating the effect of the centrifugal force.

Findings

The hinge moment of the flap is predicted through unsteady analysis in the actuation frequency of 3/rev. The material of the guide in the flap mechanism was selected through static analysis under both contact and rotating condition. Finally, reduction of the deflection occurred because of the load in the axial direction of the hinge like the centrifugal load.

Practical implications

The important aspects, such as design, analysis, and experiments for the active trailing-edge flap were shown.

Originality/value

This paper showed the relationship of the displacement, block force and voltage of the piezo-actuator, combined with the hinge moment predicted. The methodology and the experiment were presented for simulating the centrifugal force acting on the flap.

Details

Aircraft Engineering and Aerospace Technology, vol. 91 no. 1
Type: Research Article
ISSN: 1748-8842

Keywords

Access Restricted. View access options
Article
Publication date: 5 April 2022

Zhimin Pan, Yu Yan, Yizhou Huang, Wei Jiang, Gao Cheng Ye and Hong Jun Li

The purpose of this paper is to achieve optimal climbing control of the gas-insulated switchgear (GIS) robot, as the authors know that the GIS inspection robot is a kind of…

213

Abstract

Purpose

The purpose of this paper is to achieve optimal climbing control of the gas-insulated switchgear (GIS) robot, as the authors know that the GIS inspection robot is a kind of artificial intelligent mobile equipment which auxiliary or even substitute human labor drive on the inner wall of the gas-insulated metal enclosed switchgear. The GIS equipment fault inspection and maintenance can be realized through the robot manipulator on the mobile platform and the camera carried on the fuselage, and it is a kind of intelligent equipment for operation. To realize the inspection and operation of the GIS equipment pipeline without blind spots, the robot is required to be able to travel on any wall inside the pipeline, especially the top of the pipeline and both right and left sides of the pipeline, which requires the flexible climbing of the GIS inspection robot. The robot device has a certain adsorption function to ensure that the robot is fully attached to the wall surface. At the same time, the robot manipulator can be used for collision-free obstacle avoidance operation planning in the narrow operation space inside the GIS equipment.

Design/methodology/approach

The above two technologies are the key that the robot completes the GIS equipment inspections. Based on this, this paper focuses on modeling and analysis of the chassis adsorption characteristics for the GIS inspection robot. At the same time, the Denavit Hartenberg (D-H) coordinate model of the robot arm system has been established, and the kinematics forward and inverse solutions of the robot manipulator system have been derived.

Findings

The reachable working space point cloud diagram of the robot manipulator in MATLAB has been obtained based on the kinematics analysis, and the operation trajectory planning of the robot manipulator using the robot toolbox has been obtained. The simulation results show that the robot manipulator system can realize the movement without collision and obstacle avoidance. The space can cover the entire GIS pipeline so as to achieve no blind area operation.

Originality/value

Finally, the GIS inspection robot physical prototype system has been developed through system integration design, and the inspection, maintenance operation experiment has been carried out in the actual GIS equipment. The entire robot system can complete the GIS equipment inspection operation soundly and improve the operation efficiency. The research in this paper has important theoretical significance and practical application value for the optimization design and practical research of the GIS inspection robot system.

Details

Industrial Robot: the international journal of robotics research and application, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0143-991X

Keywords

Access Restricted. View access options
Article
Publication date: 14 March 2023

Caixia Chao, Xin Mei, Yongle Wei and Lijin Fang

This paper aims to design a walking-clamp mechanism for the inspection robot of transmission line. The focus for this design is on climbing ability and obstacle-crossing ability…

138

Abstract

Purpose

This paper aims to design a walking-clamp mechanism for the inspection robot of transmission line. The focus for this design is on climbing ability and obstacle-crossing ability with a goal to create a novel walking-clamp mechanism that can clamp not only the line but also the obstacle.

Design/methodology/approach

A novel clamping jaw used in the walking-clamp mechanism is proposed. The clamping wheel is mounted on the lower end of clamping jaw to reduce the friction between the clamping jaw and the line, and the top end of clamping jaw is designed as a hook structure to clamp the obstacle. The working principle and force states of the walking-clamp mechanism clamping the line and obstacle are analyzed, and the simulation and prototype experiments are carried out.

Findings

The experimental results show that this mechanism can clamp the obstacle steadily, and the clamping forces of the front and back pairs of clamping jaws are almost equal during robot walking along the catenary-shaped line. It is in agreement with the theoretical analysis, and it demonstrates that this mechanism can meet the working requirements of inspection robot.

Practical implications

This novel mechanism can be used for inspection robot of transmission line, and it is beneficial for robot to complete long-distance inspection works.

Social implications

It stands to reduce costs related to inspection and improve the inspection efficiency.

Originality/value

Innovative features include its structure, working principle and force states.

Details

Industrial Robot: the international journal of robotics research and application, vol. 50 no. 4
Type: Research Article
ISSN: 0143-991X

Keywords

Access Restricted. View access options
Article
Publication date: 12 March 2018

K.R. Kadam and S.S. Banwait

Different groove angles are used to study performance characteristics of two-axial groove journal bearing. In this study two grooves are located at ±90º to the load line. The…

147

Abstract

Purpose

Different groove angles are used to study performance characteristics of two-axial groove journal bearing. In this study two grooves are located at ±90º to the load line. The various angles of grooves have been taken as 10° to 40° in the interval of 5°. Different equations such as Reynolds equation, three-dimensional energy equation and heat conduction equation have been solved using finite element method and finite difference method. Pressure distribution in fluid is found by using Reynolds equation. The three-dimensional energy equation is used for temperature distribution in the fluid film and bush. One-dimensional heat conduction equation is used for finding temperature in axial direction for journal. There is a very small effect of groove angle on film thickness, eccentricity ratio and pressure. There is a drastic change in attitude angle and side flow. Result shows that there is maximum power loss at large groove angle. So the smaller groove angle is recommended for two-axial groove journal bearing.

Design/methodology/approach

The finite element method is used for solving Reynolds equation for pressure distribution in fluid. The finite difference method is adopted for finding temperature distribution in bush, fluid and journal.

Findings

Pressure distribution in fluid is found out. Temperature distribution in bush, fluid and journal is found out. There is a very small effect of groove angle on film thickness, eccentricity ratio and pressure.

Research limitations/implications

The groove angle used is from 10 to 40 degree. The power loss is more when angle of groove increases, so smaller groove angle is recommended for this study.

Practical implications

The location of groove angle predicts the distribution of pressure and temperature in journal bearing. It will show the performance characteristics. ±90° angle we will prefer that will get before manufacturing of bearing.

Social implications

Due to this study, we will get predict how the pressure and temperature distribute in the journal. It will give the running condition of bearing as to at what speed and load we will get the maximum temperature and pressure in the bearing.

Originality/value

The finite element method is used for solving the Reynolds equation. Three-dimensional energy equation is solved using the finite difference method. Heat conduction equation is also solved for journal. The C language is used. The code is developed in C language. There are different equations which depend on each other. The temperature is dependent on pressure viscosity of fluid, etc. so C code is preferred.

1 – 10 of over 10000
Per page
102050