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1 – 10 of over 1000
Article
Publication date: 17 October 2016

Yifan Jiang, Xiang Huang and Shuanggao Li

The purpose of this paper is to propose an on-line iterative compensation method combining with a feed-forward compensation method to enhance the assembly accuracy of a…

Abstract

Purpose

The purpose of this paper is to propose an on-line iterative compensation method combining with a feed-forward compensation method to enhance the assembly accuracy of a metrology-integrated robot system (MIRS).

Design/methodology/approach

By the integration of a six degrees of freedom (6DoF) measurement system (T-Mac), the robot’ movement can be tracked with real-time measurement. With the on-line measured data, the proposed iterative compensation for absolute positioning and the feed-forward compensation for relative linear motion are integrated into the assembly process to improve the assembly accuracy.

Findings

It is found that the MIRS exhibits good performance in both accuracy and efficiency with the application of the proposed compensation method. With the proposed assembly process, a component can be automatically aligned to the target in seconds, and the assembly error can be decreased to 0.021 mm for position and 0.008° for orientation on average.

Originality/value

This paper presents a 6DoF MIRS for high-precision assembly. Based on the system, a novel on-line compensation method is proposed to enhance the assembly accuracy. In this paper, the assembly accuracy and the corresponding distance parameter are given by a series of experiments as reference for assembly applications.

Details

Industrial Robot: An International Journal, vol. 43 no. 6
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 1 February 1997

Rolf Bernhardt

States that manufacturing lines cannot be used for production during commissioning and that it is therefore always the goal to reduce the necessary efforts to a maximum extent…

Abstract

States that manufacturing lines cannot be used for production during commissioning and that it is therefore always the goal to reduce the necessary efforts to a maximum extent. Starts with a description of the state‐of‐the‐art in this field based on the situation in the automotive industry. Additionally lists RTD fields to overcome these problems. Goes on to present methods and software tools aiming at a tremendous decrease in efforts required today.

Details

Industrial Robot: An International Journal, vol. 24 no. 1
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 1 March 2014

Nancy Chun Feng, Qianhua (Q.) Ling, Daniel Gordon Neely and Andrea Alston Roberts

Research in nonprofit accounting is steadily increasing as more data is available. In an effort to broaden the awareness of the data sources and ensure the quality of nonprofit…

Abstract

Research in nonprofit accounting is steadily increasing as more data is available. In an effort to broaden the awareness of the data sources and ensure the quality of nonprofit research, we discuss archival data sources available to nonprofit researchers, data issues, and potential resolutions to those problems. Overall, our paper should raise awareness of data sources in the nonprofit area, increase production, and enhance the quality of nonprofit research.

Details

Journal of Public Budgeting, Accounting & Financial Management, vol. 26 no. 3
Type: Research Article
ISSN: 1096-3367

Article
Publication date: 1 December 1997

Grier C.I. Lin and Tien‐Fu Lu

Presents an on‐line calibration methodology for robot relative positioning inaccuracy. This methodology eliminates the need for time‐consuming off‐line calibrations relying on…

388

Abstract

Presents an on‐line calibration methodology for robot relative positioning inaccuracy. This methodology eliminates the need for time‐consuming off‐line calibrations relying on accurate models and complicated procedures. To realize this methodology, a vision system, a 3D force/torque sensor, and control strategies involving Neural Networks (NNs) were incorporated with an industrial robot.

Details

Industrial Robot: An International Journal, vol. 24 no. 6
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 30 September 2020

Wei Jiang, Dehua Zou, Xiao Zhou, Gan Zuo, Gao Cheng Ye and Hong Jun Li

The purpose of this study is to solve the key technical problems of the practical application of electric robots. The UHV multi-split transmission line power cable operation robot…

Abstract

Purpose

The purpose of this study is to solve the key technical problems of the practical application of electric robots. The UHV multi-split transmission line power cable operation robot is an important equipment to ensure the reliable operation of high voltage lines and is a useful exploration to realize high-quality power transmission. As the robot system platform equipment mature and operation environment gradually become more complex, the double arm coordination motion control in extreme environment becomes one of the main bottleneck for its practical in power system.

Design/methodology/approach

This paper summarizes the key technologies related to power cable robots, and aims at key technical indicators such as operation reliability, operation efficiency and operation quality in the robot’s practical process. The dynamic evolution mechanism of the robot’s mechanical configuration, the multi-physics information fusion algorithm in extreme environments, the robot’s autonomous positioning and its error compensation control, the robot’s robust motion control in extreme environments and the dual-arm force-position hybrid coordination control and the dynamic distribution and elimination mechanism of internal forces in the closed chain between robots and operating objects, all the research methods and solutions of the key technologies are proposed, respectively.

Findings

Finally, a new control architecture for power cable robots in the background of the Ubiquitous Power Internet of Things is proposed so as to manage the operation and maintenance of electric power systems. The above key technologies are a new exploration of the operation and maintenance management of EHV (Extra High Voltage) multi-split transmission lines which have laid a solid theoretical foundation for the power cable robot.

Originality/value

High voltage transmission line is the main channel of power transmission. It is an important means to improve the integration of operation and maintenance management of power system to use robot instead of manual inspection and maintenance of power line, in the promotion and application of electric robot. The authors pay attention to the practicability, and the breakthrough of key technologies of robot is the premise of the practicability of robot. In this paper, the robot operation and control in multi-task and complex scenes are studied. The research and implementation of the main key technologies, such as the dynamic evolution mechanism of robot configuration, the coupling and fusion law of multi physical fields in the extreme electric power environment, the autonomous positioning control of manipulator, the robust control of robot in the super electromagnetic field environment and the cooperative operation control of multi manipulator, are discussed.

Details

Industrial Robot: the international journal of robotics research and application, vol. 48 no. 1
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 11 May 2010

Veran V. Vasić, Darko P. Marčetić, Slobodan N. Vukosavić and Đura V. Oros

The purpose of this paper is to propose an analytical method for prediction of self‐sustained oscillations that might happen during low‐cost induction motor drive application…

Abstract

Purpose

The purpose of this paper is to propose an analytical method for prediction of self‐sustained oscillations that might happen during low‐cost induction motor drive application. This forecast is needed to avoid unwanted oscillations that can be encountered for in fan, compressor and pump drives utilizing open‐loop frequency‐controlled three‐phase induction motor drives.

Design/methodology/approach

The paper presents the model of the induction motor drive system that includes inverter switches dead‐time and allows discontinuous current of front‐end rectifier. Stability analysis of proposed model was performed by tracing the eigenvalues of the overall system matrix.

Findings

Discontinuous rectifier current at light loads and the dead‐time of the inverter switches are the main sources of undesired low‐frequency self‐sustained speed oscillations in open‐loop controlled induction motor drives. The evaluated risk prediction is a function of drive and motor parameters and load level.

Originality/value

The proposed induction motor drive system model highlights the direct connection between the self‐sustained speed oscillations and the system parameters like inverter dead time, dc capacitor values, motor parameters and motor load level. Good accuracy of instability prediction is verified by dynamic simulation and by extensive experimentation.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 29 no. 3
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 30 October 2018

Jiabo Zhang, Xibin Wang, Ke Wen, Yinghao Zhou, Yi Yue and Jizhi Yang

The purpose of this study is the presentation and research of a simple and rapid calibration methodology for industrial robot. Extensive research efforts were devoted to meet the…

Abstract

Purpose

The purpose of this study is the presentation and research of a simple and rapid calibration methodology for industrial robot. Extensive research efforts were devoted to meet the requirements of online compensation, closed-loop feedback control and high-precision machining during the flexible machining process of robot for large-scale cabin.

Design/methodology/approach

A simple and rapid method to design and construct the transformation relation between the base coordinate system of robot and the measurement coordinate system was proposed based on geometric constraint. By establishing the Denavit–Hartenberg model for robot calibration, a method of two-step error for kinematic parameters calibration was put forward, which aided in achievement of step-by-step calibration of angle and distance errors. Furthermore, KUKA robot was considered as the research object, and related experiments were performed based on laser tracker.

Findings

The experimental results demonstrated that the accuracy of the coordinate transformation could reach 0.128 mm, which meets the transformation requirements. Compared to other methods used in this study, the calibration method of two-step error could significantly improve the positioning accuracy of robot up to 0.271 mm.

Originality/value

The methodology based on geometric constraint and two-step error is simple and can rapidly calibrate the kinematic parameters of robot. It also leads to the improvement in the positioning accuracy of robot.

Details

Industrial Robot: An International Journal, vol. 45 no. 6
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 17 May 2023

Lulu Huang, Xiang Huang and Shuanggao Li

Large size of aircraft assembly tooling structure and complex measurement environment exist. The laid enhanced reference points (ERS) are subject to a combination of nonuniform…

Abstract

Purpose

Large size of aircraft assembly tooling structure and complex measurement environment exist. The laid enhanced reference points (ERS) are subject to a combination of nonuniform temperature fields and measurement errors, resulting in increased measurement registration errors. In view of the nonuniform temperature field and measurement errors affecting the ERS point registration problem, the purpose of this paper is to propose a neural network-based ERS point registration compensation method for large-size measurement fields under a nonuniform temperature field.

Design/methodology/approach

The approach is to collect ERS point information and temperature data, normalize the collected data to complete the data structure design and complete the construction of the neural network prediction model by data training. The data learning is performed to complete the prediction model construction, and the prediction model is used to complete the compensation analysis of ERS points. Finally, the algorithm is verified through experiments and engineering practice.

Findings

Experimental results show that the proposed neural network-based ERS point prediction and compensation method for nonuniform temperature fields effectively predicts ERS point deformation under nonuniform temperature fields compared with the conventional method. After the compensation analysis, the registration error is effectively reduced to improve registration accuracy. Reducing the combined effect of environmental nonuniform temperature field and measurement error has apparent advantages.

Originality/value

The method reduces the registration error caused by combining a nonuniform temperature field and measurement error. It can be used for aircraft assembly site prediction and registration error compensation analysis, which is essential to improve measurement accuracy further.

Details

Robotic Intelligence and Automation, vol. 43 no. 2
Type: Research Article
ISSN: 2754-6969

Keywords

Article
Publication date: 15 July 2022

Lulu Huang, Xiang Huang and Shuang-Gao Li

The size of the aircraft tooling structure is huge, and the ambient temperature is difficult to maintain a constant state. Aiming at the influence of current temperature, this…

Abstract

Purpose

The size of the aircraft tooling structure is huge, and the ambient temperature is difficult to maintain a constant state. Aiming at the influence of current temperature, this paper aims to propose a compensation method for registration error of large-scale measurement fields based on multi-temperature sensors.

Design/methodology/approach

In this method, an enhanced reference points (ERS)–temperature regression model is constructed from ERS and temperature data. The ERS offsets compensation model is established by solving the offset through the regression model, and the ERS offset compensation analysis is carried out.

Findings

The experimental results show that the proposed registration error compensation algorithm has obvious advantages over traditional methods in reducing the influence of ambient temperature and improving the measurement accuracy by reducing the registration error.

Originality/value

This method reduces registration error caused by the influence of ambient temperature and is used for aircraft measurements in different temperature environments.

Details

Sensor Review, vol. 42 no. 5
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 26 November 2019

Pu Zhao and Yunfei Zhou

Manipulators are often subjected to joint flexibility caused by various causes in industrial applications, such as shaft windup, harmonic drives and bearing deformation. However…

Abstract

Purpose

Manipulators are often subjected to joint flexibility caused by various causes in industrial applications, such as shaft windup, harmonic drives and bearing deformation. However, many industrial robots are only equipped with motor-side encoders because link-side encoders and torque transducers are expensive. Because of joint flexibility and resulted slow response rate, control performance of these manipulators is very limited. Based on this, the purpose of this paper is to use easy-to-install and cheap accelerometers to improve control performance of such manipulators.

Design/methodology/approach

First, a novel tip-acceleration feedback method is proposed to avoid amplifications of approximation errors caused by inversion of the Jacobian matrix. Then, a new control scheme, consisting an artificial neural network, a proportional-derivative (PD) controller and a reference model, is proposed to track motor-side position and suppress link-side vibration.

Findings

By using the proposed tip-acceleration feedback method, each link’s vibration can be suppressed correlatively. Through the networks, smaller motor-side tracking errors can be obtained and unknown dynamics can be compensated. Tracking and convergence performance of the network-based system can be improved by using the additional PD controller.

Originality/value

The originality is based on using accelerometers to improve link-side vibration suppression and control performance of flexible-joint manipulators. The previously used methods need expensive link-side sensors or accurate robot model, which is unavailable for many industrial robots only equipped with motor-side encoders. The report proposed a novel acceleration feedback method and used networks to solve such problems.

Details

Industrial Robot: the international journal of robotics research and application, vol. 47 no. 1
Type: Research Article
ISSN: 0143-991X

Keywords

1 – 10 of over 1000