Adv Manuf Technol Research Articles

A counterexample to a proposed dynamic programming algorithm for optimal bid construction in an auction-based fully distributed manufacturing system

The paper by Veeramani and Wang (Int J Adv Manuf Technol 28:541–550, 2006) published in this journal offers a general bid construction scheme for minimizing the job flow time in auction-based manufacturing control and claims the optimality of the procedure. The purpose of this note is to provide a small example, in which their proposed new method fails to produce an optimal solution. We also address efficient correct algorithms so as to protect the readers from mistakenly believing that their new procedure is a better way of computing solutions.

Finite Element and Experimental Investigation of the Multipoint Flexible Hydroforming

FINITE ELEMENT AND EXPERIMENTAL INVESTIGATIONS OF THE MULTI-POINT FLEXIBLE HYDOFORMING. N. Selmi*, H. BelHadjSalah* *Mechanical Engineering Laboratory (LGM), National Engineering School of Monastir (ENIM), University of Monastir, Avenue Ibn El Jazzar 5019, Monastir, Tunisia. naselmi2002@yahoo.fr, hedi.belhadjsalah@enim.rnu.tn. ABSTRACT Multi-point flexible forming (MPF) process is relatively recent flexible techniques [1], instead of the conventional fixed shape die sets, the basic idea in this process, consist to form the sheet metal between a pair of opposed matrices of punch elements, by adjusting the height of the punch elements [2]. Production of many parts with different geometry will be possible, just by using one same device and the need to design and manufacturing of various dies will be avoided that lead to great saving in time and manufacturing cost specially in the field of small batch or single production. The hydroforming process is attractive compared with conventional solid die forming processes, the basic idea consist to suppress one tool of two forming tools (punch or die), which is replaced by hydraulic pressure, only one tool is necessary to define the final shape of formed sheet. The multipoint flexible hydroforming, proposed in this paper, is an original process which combines the hydroforming and the multipoint flexible forming [3], to obtain a synergy of the advantages of both processes. The new process, subject of this work, is a combination of the last described processes that keep the whole flexibility of the basic multipoint flexible forming (with two dies), by using, only at one side, a single multipoint die to perform completely the final part shape, the fluid pressure is applied on the other side of the sheet metal part and substitutes advantageously the second die. Firstly, investigations were carried out by numerical simulation, to quantify, the effect of the most influent parameters on the process performances, and to highlight the ability of this new process, in the production of complex forms, as well as its contribution in quality, placed with regards existing flexible processes. Secondly, to prove the feasibility and to carry out a valuable experimental investigation of the multipoint flexible hydroforming, an experimental prototype was designed and realized, and successful doubly curved shell shape parts were obtained by the new process testing set up. The part profiles and the thickness distribution were in agreement with those obtained by numerical investigation furthermore, numerical investigation for efficient methods to suppress the dimpling phenomenon and edge buckling were confirmed by experimental investigation. From investigations it appears that the parameters attached to the discreet character of the multipoint tool, have an important effect on the quality of the final metal sheet product, such as, the punch elements density, the punch elements extremity curvature radius, the blank and the elastomeric interpolator thicknesses. From simulation results, it emerges essentially, that an adequate setting of parameters can upgrade the thickness distribution, reduce the residual stress and attenuate the dimples.

On the scheduling with past-sequence-dependent setup times and learning effects on a single machine

This paper deals with a single-machine scheduling problem with setup time and learning effects. The setup times are proportional to the length of the already processed jobs, i.e., the setup times are job-independent and past-sequence-dependent, and the learning effects are job-independent and position-dependent. The objective is to minimize the sum of earliness penalties subject to no tardy jobs. Wang, Wang, Gao, and Huang [Int J Adv Manuf Technol 48: 739–746, 2010] showed that an optimal sequence for this problem could be obtained by arranging jobs in non-increasing order of processing times. In this paper, we first demonstrate that this result is incorrect, and then introduce new exact solution strategies that polynomially solve problems whose earliness penalties are strictly increasing functions of job earliness. Polynomial time solutions are also presented for some special cases.

A note on “Single-machine scheduling problems with release time of jobs depending on resource allocated”

A result in a recent paper reported by Zhang et al. (Int J Adv Manuf Technol 57:1175–1181) is incorrect because job processing times are variable due to both deteriorating jobs and learning effects, which is not taken into account by the authors. In this note, we show by a counter-example that the published result is incorrect and provide the corrected result.

Comment on “Multiple cycle economic lot and delivery-scheduling problem in a two-echelon supply chain”

This paper revisits the work-in process inventory formulation presented by Torabi and Jenabi which appeared in Int J Adv Manuf Technol (43:785–798, 2009, doi: 10.1007/s00170-008-1752-6).

AIWIN—a fast and jigless inspection technique for machined parts

Precision inspection of manufactured components having multiple complex surfaces and variable tolerance definition is an involved, complex and time-consuming function. In routine practice, a jig is used to present the part in a known reference frame to carry out the inspection process. Jigs involve both time and cost in their development, manufacture and use. This paper describes 'as is where is inspection' (AIWIN), a new automated inspection technique that accelerates the inspection process by carrying out a fast registration procedure and establishing a quick correspondence between the part to inspect and its CAD geometry. The main challenge in doing away with a jig is that the inspection reference frame could be far removed from the CAD frame. Traditional techniques based on iterative closest point (ICP) or Newton methods require either a large number of iterations for convergence or fail in such a situation. A two-step coarse registration process is proposed to provide a good initial guess for a modified ICP algorithm developed earlier (Ravishankar et al., Int J Adv Manuf Technol 46(1-4):227-236, 2010). The first step uses a calibrated sphere for local hard registration and fixing the translation error. This transformation locates the centre for the sphere in the CAD frame. In the second step, the inverse transformation (involving pure rotation about multiple axes) required to align the inspection points measured on the manufactured part with the CAD point dataset of the model is determined and enforced. This completes the coarse registration enabling fast convergence of the modified ICP algorithm. The new technique has been implemented on complex freeform machined components and the inspection results clearly show that the process is precise and reliable with rapid convergence. © 2011 Springer-Verlag London Limited.

A note on “Selection of cutting parameters in side milling operation using graph theory and matrix approach”

Determination of optimal cutting parameters is one of the vital modules in process planning of parts since economy of machining operations plays an important role in increasing productivity and competitiveness. Recently, Gadakh and Shinde (Int J Adv Manuf Technol 2011) presented a graph theory and matrix approach (GTMA) and few other multiple attribute decision making (MADM) methods for selection of cutting parameters in side milling operation in their paper “Selection of cutting parameters in side milling operation using graph theory and matrix approach” Gadakh and Shinde (Int J Adv Manuf Technol DOI 10.1007/S00170-011-3256-Z, 2011). The authors had presented the experimental results of Chiang-Kao and Lu (Int J Adv Manuf Technol 34:440–447, 2007) to demonstrate the proposed methods. However, the systematic procedures of GTMA and the other MADM methods were already reported exhaustively by Rao (2007), and Gadakh and Shinde (Int J Adv Manuf Technol 2011) had reproduced the related contents. Many computational and fundamental mistakes were also present in their work. Furthermore, the authors had presented the incorrect values of metal removal rate (MRR) and these values were different from the values presented by Chiang-Kao and Lu (Int J Adv Manuf Technol 34:440–447, 2007). This note discusses these mistakes and presents the correct approaches and the results.

Experimental and numerical study of the temperature field during creep feed grinding

Creep feed grinding is a mechanical process that allows for a higher removal rate of material when compared to surface grinding. The risk of thermal damage is also present in creep feed grinding and must be avoided. In this work an experimental process to determine the temperature evolution on the surface of a steel workpiece, during a creep feed grinding operation is described. The workpiece is placed on a piezoelectric dynamometer and one thermocouple is placed on the workpiece, inside a small hole. The force acting on the workpiece, measured by the piezoelectric dynamometer and the temperature measured by the thermocouple are registered simultaneously and continuously during a passage of the grinding wheel. The obtained results are then compared with the numerical results, obtained using the finite element method (Mamalis et al., Int J Adv Manuf Technol 22:761–767, 2003). The authors show that it is possible to use a simplified finite element model to obtain the temperature field during a creep feed grinding operation, while using significantly different grinding wheels. The proposed finite element model is based on the model proposed by Jaeger (Proc R Soc NSW 76:203–224, 1942). The grinding thermal process is simulated using the commercial finite element code ABAQUS (SIMULIA 2007).

Development of a feed rate adaption control system for high-speed rough and finish end-milling of hardened EN24 steel

High-speed machining centers are used for end-milling operations of a variety of parts, dies, and molds needed in power and transport industries. Different approaches are used for rough and finish end-milling, since desired productivity and quality are important in the respective cases. In the present work, a feed rate adaption control system is proposed by integrating different requirements of high-speed end-milling. Hardened EN 24 steel which is being widely used in the production of dies, molds, and other parts is taken as a candidate work material for implementation of the proposed control system. Based on extensive experimentation, investigations have been carried out on high-speed rough and finish end-milling operations, and the details are reported by the authors (Saikumar and Shunmugam, Int J Adv Manuf Technol, under review). In this paper, relevant response surface and artificial neural network models have been used, and suitable reference parameters are obtained for the proposed control system. In the case of rough end-milling, material removal volume is taken as the objective, and the reference values for cutting force and cutting time are used. Only a reference cutting force is used for finish end-milling in which surface roughness is considered as the objective. Implementation details of the proposed PC-based control system are presented. The results obtained for a newly devised H–A–S–H test (short run) along with those for long-run tests are presented and discussed.

Note to: Deteriorating jobs and learning effects on a single-machine scheduling with past-sequence-dependent setup times

Some results in a recent paper (Yin et al., Int J Adv Manuf Technol 46:707–714, 2010) are incorrect. In this note, we show by a counterexample that the results are incorrect.

A note on deteriorating jobs and learning effects on a single-machine scheduling with past-sequence-dependent setup times

A result in a recent paper by Yin et al. (Int J Adv Manuf Technol 46:707–714, (2010) is incorrect because job processing times are variable due to both deteriorating jobs and learning effects, a consideration which was not taken into account by the authors. In this note, we show by a counter-example that the published result is incorrect.

Notes on “Single-machine scheduling with past-sequence-dependent setup times and effects of deterioration and learning”

The aim of this paper is to show by a counterexample that theorem 6 and corollary 5 in Wang et al. (Int J Adv Manuf Technol 41:1221–1226, 2009) are incorrect.

Comments on “Deteriorating jobs and learning effects on a single-machine scheduling with past-sequence-dependent setup times”

The purpose of this paper is to point out that the jobs in the scheduling problem considered in Yin et al. (Int J Adv Manuf Technol 46:707–714, 2010) may not be deteriorating jobs.

Design of a closed-loop supply chain (CLSC) model using an interactive fuzzy goal programming

A closed-loop supply chain (CLSC) network is composed of both forward and reverse flows. An essential issue to be considered in designing any supply chain network is determination of number and locations of facilities in each layer of the network. Such a problem is a challenging job, since it contains sub-problems which are proven to be nondeterministic polynomial time complete. This paper proposes a CLSC distribution network design problem in which reverse flows are imported into forward model proposed by Selim and Ozkarahan (Int J Adv Manuf Technol 36:401–418, 1). Such a model is considered assuming forward covering (model I) and backward covering (model II) objectives, and then results are compared against the model incorporating covering of both forward and backward networks (model III). Our aim is to accentuate on the role of considering backward parameters in design of a CLSC network and to show how results differ from considering sub-problems separately. To model and solve the problem, a fuzzy goal programming approach is developed for network design in an interactive manner between decision maker and the model. To validate the presented model and the proposed solution approach, a test problem is presented and comparison of results is made using this problem. The results show that the proposed model can solve the CLSC problems in a manageable time. Moreover, outputs of the three models differ significantly. Therefore, the role of incorporating backward flows into the network design problem has been shown using our experiments.

Experimental milling moment model in orthogonal cutting condition: to an accurate energy balance

The control of cutting energy parameters is essential to optimize the cutting condition during the milling process. Our previous works (Cahuc et al., Int J Adv Manuf Technol 18(9):648–656, 2001; Darnis et al. 2000) have shown the existence of the six components of the cutting mechanical actions. Thus, the influence of geometric and kinematic parameters on the six components must be quantified. Based on the experimental approach explained in our last works (Albert et al., 2008a, b), this study proposes an energetic criterion characterizing the cutting moment in orthogonal cutting condition. Then, the energy balance has to take into account the cutting moment, highlighting the utility of this criterion. Therefore, the cutting moment model proposed allows an accurate evaluation of the energy balance and the mechanical actions (forces and moments) applied to the workpiece. Consequently, the cutting parameters can be chosen in order to optimize the cutting power consumption.

A note on multivariate non-normal process capability analysis using “mvtnorm” library in R

In this note we examine using Genzbretz and Miwa algorithms to improve estimation of proposition of non-conformance in multivariate normal distributions. This estimation is required in the procedure outlined in Abbasi and Niaki (Int J Adv Manuf Technol 50(5–8):823–830, 2010) to determine process capability index of multivariate non-normal processes.

Comments on “A bicriteria parallel machine scheduling with a learning effect”

The purpose of this paper is to point out that if there are some machines that do not process any job then the mathematical programming model provided by Eren and Guner (Int J Adv Manuf Technol 40:1202–1205, 2009) may not be a valid one.

Metaheuristic based control of a flow rack automated storage retrieval system

This paper presents two metaheuristic algorithms, namely taboo search and simulated annealing, applied to the control of a flow rack automated storage retrieval system (AS/RS). These metaheuristic algorithms are developed to control the retrieval machine of the AS/RS in order to minimize the retrieval cycle time. Results of these metaheuristic algorithms are compared to classical heuristics and analytical models found in literature (Gaouar et al. in MOSIM 2006, Rabat, Maroc, avril 2006; Sari et al. in Int J Adv Manuf Technol 25:979---987, 2005; Ghomri & Sari in Conception et Production Integrees, CPI'2009, Fes, Maroc, 19---21 Octobre 2009). These heuristics were developed to control the storage and retrieval of items in the AS/RS. On the other hand, analytical models were conceived to bring a bottom line for comparison of different control techniques. To carry out this comparative study, simulations were performed on a wide range of system configurations. In order to validate metaheuristics results, a sensitive study on their parameters was achieved, and the best parameters were selected for comparative study.

A note on “A multi-objective genetic algorithm for solving assembly line balancing problem”

Assembly line balancing has a considerable place in industrial importance. Hence, a lot of researchers are interested in this subject and several papers have been published so far. Many exact, heuristic, metaheuristic, and hybrid approaches have been used to solve this type of problems. Recently Ponnanbalam et al. (Int J Adv Manuf Technol 16:341–352, 2000) have considered a multi-objective genetic algorithm utilizing several simple heuristic rules for solving the simple assembly line balancing problems, one of these rules was “rank positional weight (RPW)” originally published in Helgeson and Birnie (J Ind Eng 12(6):394–398, 1961). Through providing two possible justifications, this note suggests that the mentioned rule can be mistakenly utilized and some revisions in Ponnanbalam et al. (Int J Adv Manuf Technol 16:341–352, 2000) seem to be necessary.

Notes on “minimizing the earliness/tardiness costs on parallel machine with learning effects and deteriorating jobs: a mixed nonlinear integer programming approach”

The aim of this paper is to point out that the mixed nonlinear integer programming model proposed by Toksari and Guner (Int J Adv Manuf Technol 38:801–808, 2008) is incorrect. We present a mixed nonlinear 0–1 programming model for the same scheduling problem based on their model.