Cycle to Cycle Manufacturing Process Control

Most manufacturing processes produce parts that can only be correctly measured after the process cycle has been completed. Even if in-process measurement and control is possible, it is often too expensive or complex to practically implement. In this paper, a simple control scheme based on output measurement and input change after each processing cycle is proposed. It is shown to reduce the process dynamics to a simple gain with a delay, and reduce the control problem to a SISO discrete time problem. The goal of the controller is to both reduce mean output errors and reduce their variance. In so doing the process capability (e.g. Cpk) can be increased without additional investment in control hardware or in-process sensors. This control system is analyzed for two types of disturbance processes: independent (uncorrelated) and dependent (correlated). For the former the closed-loop control increased the output variance, whereas for the latter it can decrease it significantly. In both cases, proper controller design can reduce the mean error to zero without introducing poor transient performance. These finding were demonstrated by implementing Cycle to Cycle (CtC) control on a simple bending process (uncorrelated disturbance) and on an injection molding process (correlated disturbance). The results followed closely those predicted by the analysis.Singapore-MIT Alliance (SMA

Designing neural networks for manufacturing process control systems

The design of neural networks for the control of discrete manufacturing processes is addressed. Rather than treating the networks as adaptive black boxes, an architecture that links the weights associated with the nodes and thus allows the relationships and internal structure to be tightly constrained is introduced. The constrained search space gives greater confidence in the internal representations that have been induced by the training set and therefore about the correct behavior of the network between the given limits. The method is illustrated by applying it to the dispensing of adhesive

Investigating UK Biobank blood metrics variation to inform cell therapy manufacturing process control [poster]

Investigating UK Biobank blood metrics variation to inform cell therapy manufacturing process control [poster

The Study Manufacturing Process Control Selected Components

Diplomová práce se zabývá studií řízení výrobního procesu vybrané komponenty v akciové společnosti ŽĎAS. Touto komponentou je odlitek. První část je zaměřena obecně na výrobní proces odlitku, který začíná nabídkou, jejím zpracováním, návrhem výrobního postupu, výrobou odlitku včetně jeho zkoušení, dle požadavků zákazníka strojním opracováním, kdy poslední fází zakázky je přeprava výrobku k zákazníkovi. Druhá část je zaměřena na výrobní úsek formovny, kde jsou popsány vstupy a výstupy formovny, výroba formy a vyhodnocení plnění plánu výroby odlitků ve sledovaném období. V závěrečné části jsou uvedeny návrhy, které by měli vést ke zlepšení výroby, podmínky jejich realizace a možné přínosy.This diploma thesis deals with a study on production process management for a selected component of the joint-stock company ZDAS. This component is cast piece. The first section is paying attention to the production process of a cast piece, starting from the offer, offer processing, proposal of manufacturing process, production of a cast piece inclusive of testing and, according to customer´s requirement, rough machining, where the last phase of order is a transport of product to customer. Another section is focusing on the productional subdivision of the moulding shop, where the moulding shop inputs and outputs, the mould making are described as well as evaluation of the plan fulfilment of castings production in the monitored periond. The closing section contains proposals that should lead to the improvement of production, conditions of their implementation and potential contributions.

Manufacturing Process Control with VLSI-Compatible Sensors

Pressure sensor elements compatible with NMOS and CMOS VLSI fabrication processes, and suitable for on-line process control, are being devEnoped. The techniques employed offer either single Enements or flexible conformable arrays of capacitive or piezoresistive units. By using standard integrated circuit processing, the sensors themsEnves are naturally compatible with further Enectronic processing both on and off chip. Solid state sensors also offer cost effective batch fabrication processes and the ability to have signal conditioning and processing right on the substrate, without bulky interconnects and multiple packages

Data mining algorithm for manufacturing process control

In this paper, a new data mining algorithm based on the rough sets theory is presented for manufacturing process control. The algorithm extracts useful knowledge from large data sets obtained from manufacturing processes and represents this knowledge using “if/then” decision rules. Application of the data mining algorithm developed in this paper is illustrated with an industrial example of rapid tool making (RTM). RTM is a technology that adopts rapid prototyping (RP) techniques, such as spray forming, and applies them to tool and die making. A detailed discussion on how to control the output of the manufacturing process using the results obtained from the data mining algorithm is also presented. Compared to other data mining methods, such decision trees and neural networks, the advantage of the proposed approach is its accuracy, computational efficiency, and ease of use.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45889/1/170_2004_Article_2367.pd

Coherent systems in the terahertz frequency range: Elements, operation, and examples

The topics are presented in viewgraph form and include the following: terahertz coherent systems applications; a brief overview of selected components; radiometry and spectroscopy--astronomy; radiometry--aircraft all weather landing system; radiometry--atmospheric remote sensing; plasma diagnostics; communications; radar systems; and materials measurement and manufacturing process control