Measurex Corporation

Other

Asyst Technologies, Inc.

Ramesh Balakrishnan

Gurcan Aral

Arun Kumar Sharma

Kuoting Mike Tao

Murali D Rangachari

Balaji Pitchaikani

Mathew G Boissevain

Xiaohua George He

Bruce S Taylor

George M Butler

The present invention provides for a method of automating a microelectronic manufacturing process by configuring application objects that implement a domain knowledge for a piece of equipment and implementing a workflow using the application object where the workflow represents a sequence of steps in the microelectronic manufacturing process. The method is embodied in a computer program that is part of a computer system.

Method and apparatus for automating a microelectronic manufacturing process

Method and apparatus for automating a microelectric manufacturing process

The present invention is directed to a method and apparatus for controlling a process which may include long process delays, using an internal model-based control strategy wherein any external disturbances are effectively taken into account in a manner which results in a stable, predictable output. In accordance with exemplary embodiments, rather than using a mismatch signal .epsilon. as a feedback signal to address mismatches due to both modelling errors and to any external disturbance component, exemplary embodiments feedback an adaptive prediction of the mismatch signal. In accordance with exemplary embodiments, the adaptive, predicted mismatch signal possesses a value which takes into account the process time delay, or the process time delay plus some additional delay, to allow time for the control system to respond.

Method and apparatus for controlling a process using adaptive prediction

The present invention is directed to a method and apparatus for filtering a signal of a control and/or signal processing system in a manner which achieves both rapid tracking of signal transients (e.g., step changes in the signal) and heavy filtering of noise during steady-state operation. In accordance with exemplary embodiments, nonlinear features are combined with a conventional exponential filter to achieve both of these objectives. Exemplary embodiments are easy to use in a control and/or signal process system, and perform in a highly accurate manner. For example, in accordance with exemplary embodiments, a filter is configured with a deadband component which constitutes the sole adjustable component of the filter.

Method and apparatus for nonlinear exponential filtering of signals

A time delay compensation control system for use in controlling a sheetmaking process includes a controller operated according to the Smith Predictor control scheme and means to automatically adjust the closed-loop time constant of the controller in inverse relationship to the system error or to the signal-to-noise ratio of the system output signals.

Control system for sheetmaking

A moisture control system including an apparatus for discharging independently variable amounts of working fluid toward selected cross-directional sections of a calendered sheet material after the material has left the calender stack and before it is taken up by a collection device. The apparatus includes a plurality of valves spaced across the width of the calendered material to control the amount of fluid applied to each section. Nozzles provided on the valves direct the fluid from the valves toward a surface of the calenderable material. The system permits cross-directional equalization of the moisture content of the calendered material without affecting other physical properties of the sheet, such as sheet finish.

Cross-directional moisture control system and method

A system and process for controlling the displacement of a thickness regulating member which regulates the basis weight of a sheet being formed from fluid material. The displacement of the thickness regulating member is determined by measuring the forces which slice rods exert on the thickness regulating member.

Process and system for controlling the basis weight of a sheet material

A system for controlling the calendering of sheet materials includes means for receiving measurements of one property of sheet material during production wherein the input to the system represents the setpoints of a calender profile actuator system. In operation, the system first calculates a linear trend line from a pattern of setpoints. Then, the linear trend line is substrated from the pattern of setpoints and used to control an edge loading system. The residual setpoints are provided to a frequency splitter whose low frequency output is used to determine the setpoints of a crown roll system and whose high frequency output is used to determine the setpoints of a calender profile actuator system.

Calender control system for sheetmaking

A system and method for controlling sheetproducing machines includes measurement devices for measuring properties of a sheet at cross-directional locations to provide cross-directional profiles, and spatial-frequency splitting means for separating low spatial-frequency components from high spatial-frequency components for each profile. The separated high and low spatial-frequency components provide operating signals to controllably adjust properties of the sheet.

Cross-directional control of sheetmaking systems

To determine machine-direction variations in measurements of a travelling sheet during production, the sheet is repeatedly traversed with a scanning sensor and, during each traverse, measurements are taken at a plurality of locations. Then, a series of reference slice locations are selected which extend in the true cross-direction. For the reference locations, measurement values are estimated based upon actual measurements. Then, for each scan, the average of the estimated measurement values is calculated. Next, cross-directional variations in values at each slice location along selected scans are calculated by subtracting the average value from the estimated value at each location along the scan. During the next consecutive scans, machine-directional variations in the sheet property at slice locations are calculated by determining the difference between the measured value and the calculated cross-directional variation value for that slice location along the prior scan.

System and process for detecting properties of travelling sheets in the

To determine measurements such as basis weight and caliper of a travelling sheet during production, the sheet is repeatedly traversed with a scanning sensor and, during each traverse, measurements are taken at a plurality of slice locations. Then, a series of reference locations are selected which are spaced apart in the machine direction along the sheet surface. Then, for selected slices, measurement values are estimated based upon actual measurements taken at locations on the selected slices which are not spaced in the machine direction at the same spacing as reference locations.

A process is provided for controlling a thickness regulating member such as a slice lip coupled to slice rods. The process includes determining the desired configuration of the slice lip and determing the required slice rod movements based upon physical characteristics of the slice lip and the slice rods.

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Stanford, CA, United States of America

Ramesh Balakrishnan