Emerald | Industrial Robot: An International Journal | Table of Contents

Robotic vision boosts automotive industry quality and productivity

literatinetwork@emeraldinsight.com (Robert Bogue) — Fri, 16 Aug 2013 00:00:00 +0100

Abstract

Purpose - This paper aims to provide a background to the use of robots by the automotive industry and describe a number of applications which illustrate the capabilities and importance of robotic machine vision technology. Design/methodology/approach - Following an historical background to the use of robots by the automotive industry, this paper discusses a selection of applications which involve the use of robotic machine vision. Brief conclusions are drawn. Findings - This shows that robotic vision technology is playing an important and growing role within the automotive industry and can yield improved product quality and greater productivity.Originality/value - This paper illustrates how robots equipped with machine vision are contributing to the automotive industry’s needs for greater productivity and improved quality.

Ease of programming and sophisticated sensors see robots advancing in transport logistics, palletizing, order picking and assembly.

literatinetwork@emeraldinsight.com (Richard Bloss) — Fri, 16 Aug 2013 00:00:00 +0100

Abstract

Purpose - Review of the many recent innovations such as 3D vision, hydrogen power and autonomous mobility in robot technology such as logistics, order filling, product handling, and assembly for more efficient handling of products in warehouse as well as manufacturing situations.Design/methodology/approach - In-depth interviews conducted with both the exhibitors and integrators of robots at the recent dual Automate-Promat shows.Findings - Robot developments, such as easier programming, cheaper, more autonomous, and more versatile (two armed) units continue to address a rapidly increasing number of applications to move products in warehouse and manufacturing environments, assemble orders, perform product assembly tasks, automated measurements and conduct inspection and other quality guarantee tasks.Practical implications - Robot advances such as lower prices, much easier programming, better versatility and more autonomy are opening many new applications to robotic answers. Hydrogen power can make mobile robots run longer between energy recharging for more up time.Originality/value - Readers will learn how others are rapidly applying robots to many new applications, saving money, getting a fast return on their investment and solving many old material handling and manufacturing problems even if they did not attend the PROMAT/AUTOMATE 2013 exhibition in Chicago.

Improving Wafer Handling Performance in Semiconductor Manufacturing

literatinetwork@emeraldinsight.com (Heping Chen, Ben Mooring, Hongtai Cheng) — Fri, 16 Aug 2013 00:00:00 +0100

Abstract

Purpose - The electronics industries are relying increasingly on robotics for their production. Wafer handling robots are used to transfer wafers between wafer processing stations. A pick-measure-place method is typically utilized to transfer wafers accurately. The measurement step is performed using an aligner, which is time-consuming. To increase wafer transfer efficiency, it is desirable to speed up the measurement process or place it in parallel with other operations. To solve the problem, optic sensors are installed at each station to estimate the wafer eccentricity on-the-fly. The eccentricity values are then applied to control the robot to place the wafer directly onto another station accurately without using the aligner. However, current methods face problems to achieve high accuracy requirements to meet the electronic manufacturing needs. In this paper, a technique is developed to improve the wafer handling performance in semiconductor manufacturing.Design/methodology/approach - The kinematics model of the wafer handling robot is developed. Two sensor location calibration algorithms are proposed. Method I is based on the wafer handling path. Method II uses the offset paths from the wafer handling path. The results from these two methods are compared. To compute the wafer eccentricity on-the-fly, a wafer eccentricity estimation technique is developed. Findings - The developed methods are implemented using a wafer handling robotic system in semiconductor manufacturing. The wafer eccentricity estimation errors are greatly reduced using the developed methods. The experimental results demonstrate that Method II achieves better results and can be used to improve the wafer handling accuracy and efficiency. Research limitations/implications - The proposed technique is implemented and tested many times on a wafer handing robotic system. The notch alignment in the wafer handling needs further research. Practical implications - The developed method is validated using a system in semiconductor manufacturing. Hence the developed method can be directly implemented in production if the notch of a wafer can be identified. Originality/value - This paper provides techniques to improve the wafer handling accuracy in semiconductor manufacturing . Compared with the results using other methods, Method II greatly increases the wafer handling accuracy to satisfy the semiconductor manufacturing needs.

A Method for Integrating Ethics into the Design of Robots.

literatinetwork@emeraldinsight.com (Aimee van Wynsberghe) — Fri, 16 Aug 2013 00:00:00 +0100

Abstract

Purpose - The purpose of this paper is to explore a methodology for incorporating ethics into the design process and resulting prototype of robots.Design/methodology/approach - The methodology explored in this work is called the "Care-Centered Value Sensitive Design" (CCVSD) Approach. The CCVSD provides both an outline of the components demanding ethical attention as well as a step-by-step manner in which such considerations may proceed throughout the design process of a robot: beginning from the moment of idea generation to the design of various prototypes. Findings - In this paper, the CCVSD approach is used to explore the design of a novel robot for the testing of urine in pediatric patients – the "wee-bot" robot. Creating the "wee-bot" robot using the CCVSD model aims at placing the value and safety of the nurse as a high priority – in line with the safety and wellbeing of the patient - rather than disregarding it for the exclusive well-being of the patient. Practical implications - The design and development of the robot targets contextual needs with an in-depth understanding of the relationship between the technical content of the robot and the manifestation of values in context.Originality/value - The paper presents a novel approach for the future design of robots along with an original idea for a service robot in the healthcare domain.

Characterization and experimental evaluation of gear transmission errors in an industrial robot

literatinetwork@emeraldinsight.com (Mohamed Slamani, Ilian A. Bonev) — Fri, 16 Aug 2013 00:00:00 +0100

Abstract

Purpose - This paper proposes a simple technique for assessing the effect of gear transmission errors in a six-axis industrial serial robot, as these errors can vitally affect the industrial robot’s positioning accuracy.Design/methodology/approach - The experimental procedure is developed using a laser interferometer system to measure bidirectional linear position errors for an ABB IRB 1600 industrial robot. A simple technique based on Fast Fourier Transformation (FFT) analysis is devised and implemented for the characterization, evaluation, and quantification of gear transmission errors. Structural deformation and backlash error are also discussed.Findings - We found that the major sources of error affecting the performance of the robot come from joints 2 and 3. We also found that eccentricity errors, structural deformations, and backlash are the most important sources of error affecting the accuracy and the repeatability of the industrial robot studied. Additional tests show that the robot’s first joint has relatively poor bidirectional repeatability.Practical implications - The usefulness of a laser tracker (or any other large range portable 3D measurement system) is questionable for assessing—let alone analyzing in depth—the gear transmission errors of some of today’s industrial robots. We demonstrate in this paper that a laser interferometer system can successfully measure gear transmission errors very accurately. The proposed methodology is simple, efficient, and easy to use for the characterization and quantification of the errors.Originality/value - This work is the first to detail the use of the laser interferometer system for the characterization of the gear transmission errors of an industrial robot. A methodology has been developed and implemented for very accurately quantifying the effects of gear transmission errors, structural deformations, and backlash. The proposed methodology greatly simplifies the measurement setup and accelerates error quantification.

Fuzzy Neural Control for Unmanned Robot applied to Automotive Test

literatinetwork@emeraldinsight.com (Gang Chen, Wei-gong Zhang, Xiao-na Zhang) — Fri, 16 Aug 2013 00:00:00 +0100

Abstract

Purpose - The paper aims to overcome the shortcomings that proportional-integral-derivative (PID) control for Unmanned Robot applied to Automotive Test (URAT) needs a priori manual retuning, has large speed fluctuations and is hard to adjust control parameters. A novel control approach based on fuzzy neural network applied to URAT was proposed.Design/methodology/approach - The multiple manipulator coordinated control model was established. After that the displacement of throttle mechanical leg, clutch mechanical leg, brake mechanical leg and shift mechanical arm for URAT was used as input of fuzzy neural network (FNN) model, and vehicle speed was used as output of FNN model. The number of membership functions was three, and the type of that was generalized bell membership function (gbellmf). The hybrid learning algorithm which combined with back propagation algorithm and least square method was applied to train the model. The Sugeno model was selected as fuzzy reasoning model.Findings - Experimental results demonstrated that compared with PID control method, the proposed approach can greatly improve the accuracy of vehicle speed tracking. The approach can accurately realize the vehicle speed tracking of given driving test cycle. Therefore, it can ensure the accuracy and effectiveness of automotive test results.Research limitations/implications - Different driving style has an effect on the test results. How to realize the simulation of driving style by means of URAT is an important work in future. Besides, the drivability of URAT which manipulates manual transmission or automatic transmission vehicles, is conducted in the future research. Furthermore, on the basis of the advantages of URAT, outdoor road automotive tests and autonomous driving with more complex outdoor environment using URAT are our future research.Practical implications - The paper provides effective methods for improving the accuracy of speed tracking and repeatability.Originality/value - After establishing the multiple manipulator coordinated control model, this paper proposes a novel control approach based on FNN for URAT.

Calibrating Distance Mapping of Non-SVP Catadioptric Camera of the Soccer Robot

literatinetwork@emeraldinsight.com (xiaoxiao zhu, Qixin Cao) — Fri, 16 Aug 2013 00:00:00 +0100

Abstract

Purpose - The purpose of the present paper is to propose a full model-based method for distance-mapping calibration for the non-SVP (non-single viewpoint) catadioptric camera of the Soccer Robot. The method should be easy to operate, efficient, accurate, and scalable to fit larger field sizes.Design/methodology/approach - The distance-mapping model was first constructed based on the imaging principle. We then calibrated the internal parameters using the mirror boundary and used the mirror center to choose the correct pose from two possible solutions. We then proposed a three-point method based on a unique solution case of the non-SVP P3P (perspective-three-point) problem to solve the external parameters. Lastly, we built the distance mapping by back-projection.Findings - The simulation experimental results have shown that our method is very accurate even when there is severe misalignment between the mirror and the camera and that all calibration operations, except the calibration of a standard camera, can be completed in 1 min. The result of the comparison with the traditional calibration method shows that our method is superior to the traditional method in the terms of accuracy and efficiency.Originality/value - The proposed calibration method is scalable to larger fields because it only uses the boundary of the mirror and three feature points on the field, and does not need additional calibration objects. Additionally, an automatic calibration method that can be used during the game can be easily developed based on our method. Moreover, the proposed mirror-pose-selection method and a unique solution to the non-SVP P3P problem are especially useful for a non-SVP catadioptric camera.

Research on Detection of Welding Penetration State during Robotic GTAW Process based on Audible Arc Sound

Fri, 16 Aug 2013 00:00:00 +0100

Abstract

Purpose - With the purpose of identifying and classifying the penetration state and welding quality through the features of arc sound signal during robotic GTAW process, penetration state is one of the most important factors to judge the quality of a gas tungsten arc welding (GTAW) joint.Design/methodology/approach - This paper tries to make a foundation work to achieve on-line monitoring of penetration state to weld pool through arc sound signal. The statistic features of arc sound under different penetration state like partial penetration, full penetration and excessive penetration are extracted and analysed, and wavelet packet analysis was used to extract frequency energy at different frequency band. The prediction models are established by artificial neural networks based on different features combination.Findings - The experiment results demonstrate that each feature in time and frequency domain could react the penetration behaviour, arc sound in different frequency band have different performance at different penetration state and the prediction model established by 23 features in time domain and frequency domain get the best prediction effect to recognize different penetration state and welding quality through arc sound signal.Originality/value - This paper try to make a foundation work to achieve identifying penetration state and welding quality through the features of arc sound signal during robotic GTAW process. 23 features in time domain and frequency domain are extracted at different penetration state. And energy at different frequency band are proved to be effective factors for identifying different penetration state. Finally, a prediction model built by 23 features is proved to having the best prediction effect of welding quality.

Online measurement based tool path generation toward integrated robotic laser cladding

literatinetwork@emeraldinsight.com (Jie Liu) — Fri, 16 Aug 2013 00:00:00 +0100

Abstract

Purpose - Refurbishing may be the most practical approach under the low volume production. This effort aims to achieve robotic laser cladding with the main purpose of achieving maximum processing flexibility, predictably high quality, lower maintenance and operating costs. This study focuses on online measurement and cladding path generation toward automatic laser cladding. Design/methodology/approach - Based on the specific requirements of automatic laser cladding, an approach was proposed toward an automatic laser cladding with powder injection for the refurbishment of components with free-form surfaces. This study assessed the feasibility of integrating a non-contact free-form surface measurement system, an industrial robot, and an algorithm for generating cladding tool paths seamlessly.Findings - 3D laser scanning and laser cladding systems can be embedded into an existing robot motion control system. Online measurement based 3D surface reconstruction is a practical approach toward cladding tool path generation for on-site refurbishment.Practical implications - Robotic laser cladding may be a potential application by integrating other measurement devices, such as temperature sensor based monitoring system. Originality/value - Refurbishing worn-out components could have significant economic benefits. This study indicates that robotic laser cladding may potentially facilitate improved refurbishment of oversized components.

Optimal trajectory planning for industrial robots using harmony search algorithm

Fri, 16 Aug 2013 00:00:00 +0100

Abstract

Purpose - This paper presents a technique for optimal trajectory planning of industrial robots that applies a new harmony search (HS) algorithm.Design/methodology/approach - The new HS optimization algorithm adds one more operation to the original HS algorithm. The objective function to be minimized is the trajectory execution time subject to kinematical and mechanical constraints. The trajectory is built by quintic B-spline curves and cubic B-spline curves.Findings - Simulation experiments have been undertaken using a 6-DOF robot QH165. The results show that the proposed technique is valid and that the trajectory obtained using quintic B-spline curves is smoother than the trajectory using cubic B-spline curves.Originality/value - The proposed new HS algorithm is more efficient than the sequential quadratic programming method (SQP) and the original HS method. The proposed technique is applicable to any industrial robot and yields smooth and time-optimal trajectories.