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Article
Publication date: 5 June 2019

Hongjun Xing, Kerui Xia, Liang Ding, Haibo Gao, Guangjun Liu and Zongquan Deng

The purpose of this paper is to enable autonomous door-opening with unknown geometrical constraints. Door-opening is a common action needed for mobile manipulators to…

Abstract

Purpose

The purpose of this paper is to enable autonomous door-opening with unknown geometrical constraints. Door-opening is a common action needed for mobile manipulators to perform rescue operation. However, it remains difficult for them to handle it in real rescue environments. The major difficulties of rescue manipulation involve contradiction between unknown geometrical constraints and limited sensors because of extreme physical constraints.

Design/methodology/approach

A method for estimating the unknown door geometrical parameters using coordinate transformation of the end-effector with visual teleoperation assists is proposed. A trajectory planning algorithm is developed using geometrical parameters from the proposed method.

Findings

The relevant experiments are also conducted using a manipulator suited to extreme physical constraints to open a real door with a locked latch and unknown geometrical parameters, which demonstrates the validity and efficiency of the proposed approach.

Originality/value

This is a novel method for estimating the unknown door geometrical parameters with coordinate transformation of the end-effector through visual teleoperation assists.

Details

Assembly Automation, vol. 39 no. 3
Type: Research Article
ISSN: 0144-5154

Keywords

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Article
Publication date: 11 March 2014

Wei Wang, Gang Wang and Chao Yun

Calibrating kinematic parameters is one of the efficient ways to improve the robot's positioning accuracy. A method based on the product-of-exponential (POE) formula to…

Abstract

Purpose

Calibrating kinematic parameters is one of the efficient ways to improve the robot's positioning accuracy. A method based on the product-of-exponential (POE) formula to calibrate the kinematic parameters of serial industrial robots is proposed. The paper aims to discuss these issues.

Design/methodology/approach

The forward kinematics is established, and the general positioning error model is deduced in an explicit expression. A simplified model of robot's positioning error is established as both the error of reference configuration and the error of rigid displacement of the base coordinating system with respect to the measuring coordinating system are equivalently transferred to the zero position errors of the robot's joints. A practical calibration model is forwarded only requiring 3D measuring based on least-squares algorithm. The calibration system and strategy for calibrating kinematic parameters are designed.

Findings

By the two geometrical constrains between the twist coordinates, each joint twist only has four independent coordinates. Due to the equivalent error model, the zero position error of each joint can cover the error of reference configuration and rigid displacement of the robot base coordinating system with respect to the measuring coordinating system. The appropriate number of independent kinematic parameters of each joint to be calibrated is five.

Originality/value

It is proved by a group of calibration experiments that the calibration method is well conditioned and can be used to promote the level of absolute error of end effector of industrial robot to 2.2 mm.

Details

Industrial Robot: An International Journal, vol. 41 no. 2
Type: Research Article
ISSN: 0143-991X

Keywords

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Article
Publication date: 22 November 2018

Chen Shen, Youping Chen, Bing Chen and Yu Qiao

This paper aims to propose a novel robot kinematic calibration method based on the common perpendicular line (CPL) model to improve the absolute accuracy of industrial robots.

Abstract

Purpose

This paper aims to propose a novel robot kinematic calibration method based on the common perpendicular line (CPL) model to improve the absolute accuracy of industrial robots.

Design/methodology/approach

The deviation between the nominal and actual twists is considered the CPL transformation, which includes the rotation about the CPL and the translation along the CPL. By using the invariance of the reciprocal product of the two spatial lines, the previous deviation was analyzed in the neighbor space of the base frame origin. In this space, the line vector of the CPL contained only four independent parameters: two orientation elements and two moment elements. Thus, the CPL model has four independent parameters for the revolute joint and two parameters for the prismatic joint.

Findings

By simulations and experiment conducted on a SCARA robot and a 6-DOF PUMA robot, the effectiveness of the novel method for calibration of industrial robot is validated.

Originality/value

The CPL model avoided the normalization and orthogonalization in the iterative identification procedure. Therefore, identifying the CPL model was not only simpler but also more accurate than that of the traditional model. In addition, the results of the CPL transformation strictly conformed to the constraints of the twist.

Details

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

Keywords

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Article
Publication date: 1 February 1992

E. Niedermayr and N. Roth

Describes an innovative error compensation method to improve the static positioning accuracy of industrial robots or other servo‐driven manipulation devices. As well as…

Abstract

Describes an innovative error compensation method to improve the static positioning accuracy of industrial robots or other servo‐driven manipulation devices. As well as the theoretical formulation, shows experimental results for quantitative estimation and verification of the method. Outlines integration concepts for this error compensation technique within commercial robot controllers.

Details

Kybernetes, vol. 21 no. 2
Type: Research Article
ISSN: 0368-492X

Keywords

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Article
Publication date: 1 June 2000

C.G. Guo and G.H. Xu

Some of the fundamental problems associated with the aerodynamic configuration of a single‐rotor remotely piloted helicopter are discussed in this paper. A method for…

Abstract

Some of the fundamental problems associated with the aerodynamic configuration of a single‐rotor remotely piloted helicopter are discussed in this paper. A method for selecting the aerodynamic shape of a fuselage and determining the locations and parameters of a horizontal stabilizer and a tail rotor in the preliminary design analysis is given. The application of this method to a remotely piloted single main rotor and tail rotor helicopter developed at the Nanjing University of Aeronautics and Astronautics is described. A raindrop shaped fuselage is chosen for the remotely piloted helicopter and the low drag characteristics of the fuselage are demonstrated from the wind‐tunnel experimental data. The experimental results on the pitching moment characteristics of the horizontal stabilizer are also presented and analyzed. The design considerations of the horizontal stabilizer and tail rotor of the helicopter are discussed in detail.

Details

Aircraft Engineering and Aerospace Technology, vol. 72 no. 3
Type: Research Article
ISSN: 0002-2667

Keywords

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Article
Publication date: 2 February 2015

Hou Yukan, Li Yuan, Zhang Jie, Wen-Bin Tang and Jiang Shoushan

The purpose of this study is to present a new and relatively inexpensive method for posture evaluation of the positioning of the wing-body assembly. Positioning is an…

Abstract

Purpose

The purpose of this study is to present a new and relatively inexpensive method for posture evaluation of the positioning of the wing-body assembly. Positioning is an essential process to guarantee alignment accuracy in an assembly line.

Design/methodology/approach

The studied method includes a structural set-up and a software algorithm used to process a set of experimental input data to compute the actual position of the wing with respect to the ideal position, which is proposed considering measurement uncertainty, the deviation caused by large errors in measurement points and the different tolerance requirements.

Findings

The studied method has been found to be simple and effective in addition to being highly accurate. Compared with most of the current methods that have been developed with optical equipment, it is more cost- and space-efficient. The automation process determines how much operation time will be saved.

Practical implications

The studied method has been applied in an actual assembly line, and the economic and time savings illustrate its benefits.

Originality/value

This method provides an attractive wing-body assembly solution for those enterprises that want to find a low-cost option or have limited measuring space for optical equipment. It can also be the basis for the accurate assembly of other large parts for aircraft and other vessels.

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Article
Publication date: 1 August 2000

Bryan Greenway

Discusses robot accuracy and repeatability and the mechanical and control aspects of robots that lead to errors occuring in static positioning and dynamic path following…

Abstract

Discusses robot accuracy and repeatability and the mechanical and control aspects of robots that lead to errors occuring in static positioning and dynamic path following. Outlines the steps that should be taken to minimise errors and concludes that robot users should encourage manufacturers to utilize the ISO and ANSI standards when measuring and presenting robot capabilities. This will not only give users the ability to objectively compare systems, but also push robot manufacturers to develop a better understanding of the products they are selling.

Details

Industrial Robot: An International Journal, vol. 27 no. 4
Type: Research Article
ISSN: 0143-991X

Keywords

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Article
Publication date: 20 June 2019

Shiwei Wang, Qingxuan Jia, Gang Chen and Dan Liu

This paper aims to present a complete relative pose error model for robot calibration, considering both the relative distance error and the relative rotation error of the…

Abstract

Purpose

This paper aims to present a complete relative pose error model for robot calibration, considering both the relative distance error and the relative rotation error of the robot end-effector, which can improve calibration accuracy.

Design/methodology/approach

In this paper, the relative distance error model and the relative rotation error model of robot calibration are derived by ignoring high-order nonlinear errors, and the two models form into a complete relative pose error model. Besides, mathematical expectation of the nonlinear errors is calculated, indicating that they have little influence on calibration accuracy.

Findings

Comparative experiments have indicated that the proposed complete relative pose error model does better in robot calibration than only the distance error model.

Originality/value

The main contribution of this paper lies in the derivation of the relative rotation error model, which helps to form a complete relative pose error model for calibration. The proposed method improves calibration accuracy, with avoiding identifying the transformation matrix between the measurement system frame and the robot base frame.

Details

Industrial Robot: the international journal of robotics research and application, vol. 46 no. 5
Type: Research Article
ISSN: 0143-991X

Keywords

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Article
Publication date: 7 April 2015

Zivana Jakovljevic, Petar B. Petrovic, Dragan Milkovic and Miroslav Pajic

The purpose of this paper is to provide a method for the generation of information machines for part mating process diagnosis. Recognition of contact states between parts…

Abstract

Purpose

The purpose of this paper is to provide a method for the generation of information machines for part mating process diagnosis. Recognition of contact states between parts during robotized part mating represents a significant element of the system for active compliant robot motion. All proposed information machines for contact states recognition will recognize one of the possible contact states even when irregular events in the process occur, and the active motion planner will continue to send commands to robot controller according to the planned trajectory.

Design/methodology/approach

The presented framework is based on the general theory of automata and formal languages. Starting from possible regular contact states transitions in part mating, the authors create an automaton for diagnostics, which, besides regular, accepts all irregular (observable and unobservable) process sequences.

Findings

Contact states do not appear arbitrarily during regular processes, but in certain context. Theory of automata represents a solid basis for contextual recognition and diagnosis of irregularities in part mating.

Research limitations/implications

The proposed methodology is elaborated and experimentally verified using an example of cylindrical part mating, and stick-slip effect as an observable irregularity. The future work will address the generation of diagnosers for other types of part mating tasks and extension of the set of observable irregularities.

Practical implications

The process diagnosis increases the robustness of active compliant motion system.

Originality/value

Although very important feedback information provider for active motion planner, part mating process monitoring was not frequently addressed in the past. In this paper, the authors propose a methodology for generation of part mating process diagnoser that is based on general automata theory.

Details

Assembly Automation, vol. 35 no. 2
Type: Research Article
ISSN: 0144-5154

Keywords

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Article
Publication date: 12 August 2014

Zhangjun Jin, Cijun Yu, Jiangxiong Li and Yinglin Ke

The purpose of this paper is to propose a robot-assisted assembly system (RAAS) for the installation of a variety of small components in the aircraft assembly system. The…

Abstract

Purpose

The purpose of this paper is to propose a robot-assisted assembly system (RAAS) for the installation of a variety of small components in the aircraft assembly system. The RAAS is designed to improve the assembly accuracy and increase the productive efficiency.

Design/methodology/approach

The RAAS is a closed-loop feedback system, which is integrated with a laser tracking system and an industrial robot system. The laser tracking system is used to evaluate the deviations of the position and orientation of the small component and the industrial robot system is used to locate and re-align the small component according to the deviations.

Findings

The RAAS has exhibited considerable accuracy improvement and acceptable assembly efficiency in aircraft assembly project. With the RAAS, the maximum position deviation of the component is reduced to 0.069 mm and the maximum orientation deviation is reduced to 0.013°.

Social implications

The RAAS is applied successfully in one of the aircraft final assembly projects in southwest China.

Originality/value

By integrating the laser tracking system, the RAAS is constructed as a closed-loop feedback system of both the position and orientation of the component. With the RAAS, the installation a variety of small components can be dealt with by a single industrial robot.

Details

Industrial Robot: An International Journal, vol. 41 no. 5
Type: Research Article
ISSN: 0143-991X

Keywords

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