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Article
Publication date: 1 January 1987

T.C.E. Cheng

An important issue in the design of a flexible manufacturing system (FMS) is the operational control of the materials handling subsystem, through which reparts are…

Abstract

An important issue in the design of a flexible manufacturing system (FMS) is the operational control of the materials handling subsystem, through which reparts are conveyed from one work station to the next. A popular type of materials handling device is the automatic guided vehicle (AGV), which has been widely adopted in FMS because of its versatility and speed. This paper presents a simulation study to investigate the effects of different AGV dispatching rules on the performance of an FMS under various operating conditions. The dispatching rules studied are: FAFS — select the first available AGV; MIT — select the AGV with the most idle time; STT — select the AGV with the shortest travel time; and LTT — select the AGV with the longest travel time. The performance measures adopted are: overall production rate of the system; mean work station utilisation; and mean AGV utilisation. Although the results obtained are related to the specific FMS layout studied in this paper, it is believed that the inferences drawn from them are applicable to any FMS with similar layout structure and can provide useful guidelines for AGV design.

Details

International Journal of Operations & Production Management, vol. 7 no. 1
Type: Research Article
ISSN: 0144-3577

Keywords

Article
Publication date: 7 April 2022

Hua Ding, Yanhong Huang, Jianqi Shi, Qi Shi and Yang Yang

Automatic guided vehicles (AGVs) are widely used in industrial fields. But most control strategies merely take the lateral force into consideration. This will reduce the…

Abstract

Purpose

Automatic guided vehicles (AGVs) are widely used in industrial fields. But most control strategies merely take the lateral force into consideration. This will reduce the accuracy, stability and robustness and will pay additional costs. Therefore, this paper aims to design a control strategy that initially considers lateral force. Thereby, it will improve the accuracy, stability and robustness and reduce the overall cost of AGV.

Design/methodology/approach

To achieve the goal of comprehensively improving AGV operating performance, this paper presents a new scheme, combining the dual-wheeled chassis model (DCM) using proportional–integral–differential (PID) control and a supporting quick response (QR) code navigation technology. DCM is the core, which analyzes the deviation caused by lateral force. Then, DCM with PID control by the control law is combined to suppress the errors. Meanwhile, QR code navigation technology provides effective data support for the control strategy.

Findings

Most AGV experiments are carried out in a standard environment. However, this study prepares unfavorable scenarios and operating conditions for the experiments that generate detailed data to demonstrate this study’s strategy, which can make an accurate, stable and robust operation process of AGV under various adverse environmental and mechanical factors.

Originality/value

This study proposed DCM, fully considering lateral force and converting the force into velocity. Subsequently, PID controls the speed of two wheels to reduce the error. QR code provides an efficient and low – cost way to obtain information. The three are cleverly combined as a novel industrial AGV control strategy, which can comprehensively improve the operating performance while reducing overall costs.

Article
Publication date: 26 June 2021

Hamed Fazlollahtabar, Mohammad Saidi-Mehrabad and Ellips Masehian

The purpose of this study is to investigate the benefits of the turning point layout; a simulation model being applicable for strategic level is designed that compares…

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Abstract

Purpose

The purpose of this study is to investigate the benefits of the turning point layout; a simulation model being applicable for strategic level is designed that compares systems with and without turning points. Specifically, the avoidance of deadlocks and prevention of conflicts is substantial.

Design/methodology/approach

Optimization process for different layouts and configuration of autonomous guided vehicles (AGVs) are worked out using statistical methods for design parameters. Regression analysis is used to find effective design parameters and analysis of variance is applied for adjusting critical factors. Also, the optimal design is then implemented in a manufacturing system for an industrial automation and the results are reported.

Findings

The outputs imply the effectiveness of the proposed approach for real industrial cases. This research will combine both simulation-based method and optimization technique to improve the quality of solutions.

Originality/value

In AGV systems, the begin-end combinations are usually connected by using a fixed layout, which is not the optimal path. The capability of these configurations is limited and often the conflict of multiple AGVs and deadlock are inevitable. By appearing more flexible layouts and advanced technology, the positioning and dispatching of AGVs increased. A new concept would be to determine each path dynamically. This would use the free paths for AGVs leading to overcome the conflicts and deadlocks.

Details

Assembly Automation, vol. 41 no. 4
Type: Research Article
ISSN: 0144-5154

Keywords

Article
Publication date: 26 August 2020

Yi Yang and Wei Pan

This paper aims to examine the potentials of using automated guided vehicle (AGV) technology in modular integrated construction (MiC) to realise logistics automation in…

Abstract

Purpose

This paper aims to examine the potentials of using automated guided vehicle (AGV) technology in modular integrated construction (MiC) to realise logistics automation in module manufacturing and transport.

Design/methodology/approach

This paper adopts a scenario approach through three phases (i.e. scenario preparation, development and transfer), with six steps performed iteratively. The scenarios were systematically developed using a six-aspect socio-technical framework. Data were collected through a comprehensive literature review, site visits and interviews with relevant stakeholders and professionals. Implications regarding strength, weakness, opportunities and challenges and future research directions are provided.

Findings

The developed scenarios of “smart manufacturing” and “last-mile delivery” demonstrated how AGVs could be used to enhance efficiency and productivity in module manufacturing and transport. The synergies between AGVs and emerging information technologies should pave a good foundation for realising logistics automation in MiC. Future research should address: how to define the tasks of AGVs, how will the use of AGVs impact MiC practices, how to design AGV-integrated module manufacturing/transport systems and how to integrate people factors into the use of AGVs in MiC.

Practical implications

This paper reveals the socio-technical benefits and challenges of using AGVs in MiC.

Originality/value

This study extends the understanding of using logistics automation in MiC as emerging research directions, with the intention of directing scholars’ and practitioners’ interest into future exploration. It is the first attempt in its kind. Its findings could be extended to constitute a comprehensive development roadmap and prospects of automation in modular construction.

Details

Construction Innovation , vol. 21 no. 1
Type: Research Article
ISSN: 1471-4175

Keywords

Article
Publication date: 1 October 2006

Sandor Ujvari and Olli‐Pekka Hilmola

This paper aims to highlight the complex nature of automated guided vehicle (AGV) simulation model building, and especially how system modelling details affect the end…

1429

Abstract

Purpose

This paper aims to highlight the complex nature of automated guided vehicle (AGV) simulation model building, and especially how system modelling details affect the end results. This is an important issue in all of the transportation simulation systems, since they are service‐based by their nature, and additional inefficiencies create unanticipated performance downgrading.

Design/methodology/approach

This paper uses a simulation approach, and simulated systems are based on a real‐life case study and on well accepted hypothetical simulation example.

Findings

Simulation system boundaries are often neglected in the model building, and especially interface to inbound (and possibly outbound) material flow should be considered carefully; based on these research results, AGV investments are seen in an entirely different light, as system boundary is enlarged to contain more realistically interacting elements. Similar system boundary issues were found from the case study: interface with overhead gantry did not provide near optimal performance. The case study also revealed that high speed of AGVs is not necessarily worth additional investment; constraints exist in safety, acceleration and ability to turn in corners.

Research limitations/implications

The findings are based on the simulation work and, to see the real implications, real‐life implementations on policy level are needed.

Practical implications

Results of this research provide more insights for manufacturing unit investments, and especially in the scope of automated transportation system use. Also changes in manufacturing flow management issues, after investing in, for example, AGV systems, are different from in less‐automated manufacturing units.

Originality/value

This research work provides more insights to simulation research work, especially from the perspective of transportation systems. Also implications arising from case study are unique as being compared to previous research in the field.

Details

Industrial Management & Data Systems, vol. 106 no. 8
Type: Research Article
ISSN: 0263-5577

Keywords

Article
Publication date: 13 February 2007

Nebil Buyurgan, Lakshmanan Meyyappan, Can Saygin and Cihan H. Dagli

The purpose of this paper is to present the development of an architecture for real‐time routing of automated guided vehicles (AGV) in a random flexible manufacturing system (FMS).

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Abstract

Purpose

The purpose of this paper is to present the development of an architecture for real‐time routing of automated guided vehicles (AGV) in a random flexible manufacturing system (FMS).

Design/methodology/approach

AGV routing problem is modeled using an evolutionary algorithm‐based intelligent path planning model, which handles vehicle assignments to material handling requests and makes routing decisions with the objective of maximizing the system throughput. The architecture is implemented on a 3‐layer software environment in order to evaluate the effectiveness of the proposed model.

Findings

The proposed architecture, along with the evolutionary algorithm‐based routing model, is implemented in a simulated FMS environment using hypothetical production data. In order to benchmark the performance of the path planning algorithm, the same FMS model is run by traditional dispatching rules. The analysis shows that the proposed routing model outperforms the traditional dispatching rules for real‐time routing of AGVs in many cases.

Research limitations/implications

Future work includes expanding the scope of the current work by developing and implementing other routing models and benchmarking them against the proposed model on different performance measures.

Originality/value

The implementation of evolutionary algorithms in real‐time routing of AGVs is unique. In addition, due to its modularity, the proposed 3‐layer architecture can allow effective and efficient integration of different real‐time routing algorithms; therefore it can be used as a benchmarking platform.

Details

Journal of Manufacturing Technology Management, vol. 18 no. 2
Type: Research Article
ISSN: 1741-038X

Keywords

Article
Publication date: 9 July 2020

Ting Pan, Jiaqing Yan, Shenyun Zhou, Yingjie Cai and Congda Lu

The purpose of this paper is to propose the situation that the existing parking automated guided vehicle (AGV) has a single walking mode, a spin forward motion mode based…

Abstract

Purpose

The purpose of this paper is to propose the situation that the existing parking automated guided vehicle (AGV) has a single walking mode, a spin forward motion mode based on a dual steering wheel driven parking AGV. In this way, the AGV can complete the 180° spin of the AGV in the process of straight forward.

Design/methodology/approach

A spin forward kinematics model of the dual steering wheel AGV is established, and a motion controller of the dual steering wheel AGV is designed based on the principle of model predictive control to complete the path following the spin forward motion mode.

Findings

Computer simulations and laboratory tests were performed on this movement mode, which showed that the operation mode was feasible. It also verified that the mode can improve the handling efficiency, and also solved the problem that the parking space beside the wall could not be set and the site utilization was improved.

Research limitations/implications

The controller should be further improved to make the operation smoother and more accurate.

Practical implications

This mode has the applicability to the indoor logistics AGVs. In addition, it can improve the handling efficiency and also solved the problem that the storage space for goods beside the wall could not be set and the site utilization was improved.

Social implications

This method can solve the problem due to the increasing number of private cars and parking spaces are hard to find. It increases the number of parking spaces and improves the utilization rate of the site. In addition, it also saves people the time to find a parking space and reduces car exhaust emissions in the process. It follows the requirements of sustainable development.

Originality/value

The studies in this paper provide AGV with more ideas on the issue of improving handling efficiency and site utilization and also solves the problem of being unable to set parking spaces when parking against the wall. In addition, this model has applicability to indoor logistics AGV and plays the same role.

Details

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

Keywords

Article
Publication date: 23 June 2015

Hamed Fazlollahtabar, Mohammad Saidi-Mehrabad and Ellips Masehian

This paper aims to propose and formulate a complicated routing/scheduling problem for multiple automated guided vehicles (AGVs) in a manufacturing system.

Abstract

Purpose

This paper aims to propose and formulate a complicated routing/scheduling problem for multiple automated guided vehicles (AGVs) in a manufacturing system.

Design/methodology/approach

Considering the due date of AGVs requiring for material handling among shops in a jobshop layout, their earliness and tardiness are significant in satisfying the expected cycle time and from an economic view point. Therefore, the authors propose a mathematical program to minimize the penalized earliness and tardiness for a conflict-free and just-in-time production.

Findings

The model considers a new concept of turning point for deadlock resolution. As the mathematical program is difficult to solve with a conventional method, an optimization method in two stages, namely, searching the solution space and finding optimal solutions are proposed. The performance of the proposed mathematical model is tested in a numerical example.

Practical implications

A case study in real industrial environment is conducted. The findings lead the decision-makers to develop a user interface decision support as a simulator to plan the AGVs’ movement through the manufacturing network and help AGVs to prevent deadlock trap or conflicts. The proposed decision support can easily be commercialized.

Originality/value

The benefits of such commercialization are increase in the quality of material handling, improve the delivery time and prevent delays, decrease the cost of traditional handling, capability of computerized planning and control, intelligent tracking and validation experiments in simulation environment.

Details

Industrial Robot: An International Journal, vol. 42 no. 3
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 26 September 2019

Ruochen Tai, Jingchuan Wang and Weidong Chen

In the running of multiple automated guided vehicles (AGVs) in warehouses, delay problems in motions happen unavoidably as there might exist some disabled components of…

Abstract

Purpose

In the running of multiple automated guided vehicles (AGVs) in warehouses, delay problems in motions happen unavoidably as there might exist some disabled components of robots, the instability of networks and the interference of people walking. Under this case, robots would not follow the designed paths and the coupled relationship between temporal and space domain for paths is broken. And there is no doubt that other robots are disturbed by the ones where delays happen. Finally, this brings about chaos or even breakdown of the whole system. Therefore, taking the delay disturbance into consideration in the path planning of multiple robots is an issue worthy of attention and research.

Design/methodology/approach

This paper proposes a prioritized path planning algorithm based on time windows to solve the delay problems of multiple AGVs. The architecture is a unity consisting of three components which are focused on scheduling AGVs under normal operations, delays of AGVs, and recovery of AGVs. In the components of scheduling AGVs under normal operations and recovery, this paper adopts a dynamic routing method based on time windows to ensure the coordination of multiple AGVs and efficient completion of tasks. In the component for scheduling AGVs under delays, a dynamical prioritized local path planning algorithm based on time windows is designed to solve delay problems. The introduced planning principle of time windows would enable the algorithm to plan new solutions of trajectories for multiple AGVs, which could lower the makespan. At the same time, the real-time performance is acceptable based on the planning principle which stipulates the parameters of local time windows to ensure that the computation of the designed algorithm would not be too large.

Findings

The simulation results demonstrate that the proposed algorithm is more efficient than the state-of-the-art method based on homotopy classes, which aims at solving the delay problems. What is more, it is validated that the proposed algorithm can achieve the acceptable real-time performance for the scheduling in warehousing applications.

Originality/value

By introducing the planning principle and generating delay space and local adjustable paths, the proposed algorithm in this paper can not only solve the delay problems in real time, but also lower the makespan compared with the previous method. The designed algorithm guarantees the scheduling of multiple AGVs with delay disturbance and enhances the robustness of the scheduling algorithm in multi-AGV system.

Details

Assembly Automation, vol. 39 no. 5
Type: Research Article
ISSN: 0144-5154

Keywords

Article
Publication date: 1 August 2016

Hamed Fazlollahtabar

This paper aims to propose a parallel automated assembly line system to produce multiple products in a semi-continuous system.

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Abstract

Purpose

This paper aims to propose a parallel automated assembly line system to produce multiple products in a semi-continuous system.

Design/methodology/approach

The control system developed in this research consists of a manufacturing system for two-level hierarchical dynamic decisions of autonomous/automated/automatic-guided vehicles (AGVs) dispatching/next station selection and machining schedules and a station control scheme for operational control of machines and components. In this proposed problem, the assignment of multiple AGVs to different assembly lines and the semi-continuous stations is a critical objective. AGVs and station scheduling decisions are made at the assembly line level. On the other hand, component and machining resource scheduling are made at the station level.

Findings

The proposed scheduler first decomposes the dynamic scheduling problems into a static AGV and machine assignment during each short-term rolling window. It optimizes weighted completion time of tasks for each short-term window by formulating the task and resource assignment problem as a minimum cost flow problem during each short-term scheduling window. A comprehensive decision making process and heuristics are developed for efficient implementation. A simulation study is worked out for validation.

Originality/value

Several assembly lines are configured to produce multiple products in which the technologies of machines are shared among the assembly lines when required. The sequence of stations is pre-specified in each assembly line and the components of a product are kept in machine magazine. The transportation between the stations in an assembly line (intra assembly line) and among stations in different assembly lines (inter assembly line) are performed using AGVs.

Details

Assembly Automation, vol. 36 no. 3
Type: Research Article
ISSN: 0144-5154

Keywords

1 – 10 of 499