Journal ArticleDOI
On-line scheduling for adaptive control machine tools in FMS
Tohru Watanabe,Masahiko Sakamoto +1 more
TLDR
In this paper, on-line scheduling which changes the schedule according to the change of operating times is proposed, and their validity is verified by computer simulation that online scheduling using SLACK, EDD, or the Look Ahead heuristic rule is available.Abstract:
Adaptive control is available to adjust the operating speed of machine tools in FMS according to the condition of production, but it changes the time of each operation and disturbs the previously determined schedule. In this paper, on-line scheduling which changes the schedule according to the change of operating times is proposed. It is verified by computer simulation that on-line scheduling using SLACK, EDD, or the Look Ahead heuristic rule is available. The Look Ahead rule is the best for decreasing the lateness of due dates. Algorithms to change the adaptive control mode between optimization for cost performance and that for productivity according to the condition of the schedule are proposed, and their validity is verified by computer simulation.read more
Citations
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Journal ArticleDOI
Job-shop scheduling using neural networks
TL;DR: A method for adding a second neural network for judging thereliability of the estimated margins composed to the first one and for switching to the margins calculated by the SLACK rule when the reliability is low is proposed.
Journal ArticleDOI
Regenerative pull (Kanban) production control policies
TL;DR: Attention is drawn to the qualitative behavior of the optimal pull control policy in certain manufacturing systems with stochastic processing rates.
Journal ArticleDOI
Optimization Aspects of Experimental FMS at the Technical University of Budapest (TUB)
TL;DR: In this article, the authors present a more detailed description of the production scheduling system and some optimization ideas, as one of the way toward the total system performance performance improvement, the secondary optimization is proposed.
Journal ArticleDOI
Intelligent control in the hierarchy of automatic manufacturing systems
TL;DR: The multiple performances of manufacturing systems are given by applying theoretical/heuristic knowledge to hierarchical control loop in various ways by using the knowledge of electromagnetism, dynamics, machining and scheduling, respectively, with sensor signals in the system.
References
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Journal ArticleDOI
Heuristics in Job Shop Scheduling
TL;DR: The approach is simulative in that the operation of the shop is simulated in a Fortran program, but in addition to the straightforward use of priority rules for determining sequences of jobs on the machines, a number of heuristics or rules of thumb are incorporated.
Journal ArticleDOI
A Control System to Improve the Accuracy of Finished Surfaces in Milling
Tohru Watanabe,S. Iwai +1 more
TL;DR: In this paper, a geometric adaptive control system to compensate for errors in the finished surface due to tool deflection generated by milling operations is presented, and the effects of cutting forces upon the shape of the final surface are analyzed.
Journal ArticleDOI
A Model-Based Approach to Adaptive Control Optimization in Milling
TL;DR: In this paper, an adaptive control optimization system using a model to represent actual physical phenomena in milling is discussed, where the model is used for the identification of physical parameters, the calculation of the temperature at the tool edges, and the estimation of the tool wear rate.
Journal ArticleDOI
Adaptive Controller for a Metal Cutting Process
R. M. Centner,J. M. Idelsohn +1 more
TL;DR: The design of an adaptive controller is described which, in conjuction with a numerical control system, extends the process measurement to the actual tool-work interface and adjusts the process input parameters so as to optimize cutting performance.
Journal ArticleDOI
An Adaptive CNC System of a Milling Machine Tool
T. Watanabe,S. Iwai,Y. Nawata +2 more
TL;DR: In this article, an adaptive CNC (computer numerical control) system of a milling machine tool using a precise tool wear rate model is presented, where the bending moments on the spindle are sensed and used for computing the fundamental parameters of cutting conditions such as work material hardness, cutter sharpness, and others.