Sunil A Shah

6404581, Jun 11, 2002

Oct 4, 2000

09/680128

Sunil C. Shah - Los Altos CA

Voyan Technology - Santa Clara CA

G11B 2102

360 75, 360 7809, 360 61, 700 29

A scheme for management of uncertainty in control systems that require adaptation is described. The scheme removes as much uncertainty as possible at design time and manufacturing time by taking advantage of available compute resources in pre-computing a large set of robustness-performance tradeoff based model controllers at different operating conditions for different values of uncertainty parameters that occur in-use and in manufacturing. A group of control models, and corresponding model controllers with an uncertainty bound larger than the best-tuned controller, are generated. A subset of the model controllers is implemented in the system at manufacturing time based on characterization of the system. The subset of model controllers is switched at run time based on transient information received during operation of the system.

6498694, Dec 24, 2002

Jun 15, 2000

09/596428

Sunil C. Shah - Los Altos CA

Voyan Technology - Santa Clara CA

G11B 509

360 46, 360 53, 360 65, 360 7702, 360 7804

A method and system for servo error integration in read-channel equalization are described. In the present invention servo error is integrated into an equalizer. Also described in the present invention are methods and systems for determining the servo error.

6684114, Jan 27, 2004

Mar 3, 2000

09/517948

Mark A. Erickson - San Bruno CA
Cecilia Galarza - San Francisco CA
Dan Hernandez - Cupertino CA
Sunil C. Shah - Los Altos CA

Tokyo Electron Limited - Tokyo

G05B 1302

700 45, 360 7704

A system and method is given for minimizing periodic disturbances in electronic systems. Given the input-output characteristics of the system, the present method identifies and cancels the periodic disturbance. The periodic disturbance parameters are identified through the use of a residual generator. The output of the residual generator is fed into an identifier that estimates disturbance parameters. The compensation filter combines the output of the identifier with a set of pre-computed parameters to form a cancellation signal. This signal is then added to the input of the plant to cancel the periodic disturbance.

6711598, Mar 23, 2004

Nov 10, 2000

09/710410

Daniel Joseph Hernandez - San Jose CA
Cecilia Gabriela Galarza - San Francisco CA
Mark Alan Erickson - San Bruno CA
Sunil C. Shah - Los Altos CA

Tokyo Electron Limited - Tokyo

G06F 1710

708300

A method and system is disclosed for design and implementation of fixed-point filters from floating-point filters. A design sequence for designing a fixed-point filter for a system is selected. A low-order floating-point filter and a first set of parameters associated with the low-order floating-point filter components are then selected. One or more parameters of the first set of parameters is then iteratively modified to obtain a set of modified parameters, until a plurality of performance characteristics calculated using the first set of parameters meets a performance objective for the fixed-point filter for the system.

6725099, Apr 20, 2004

Jun 27, 2001

09/894061

Mark Erickson - Sunnyvale CA
Thorkell Gudmundsson - San Jose CA
Sunil C. Shah - Los Altos CA

Tokyo Electron Limited - Tokyo

G05B 1302

700 33, 700 44, 700 45, 700121, 700300, 118725, 219391, 392416, 392418, 432 36, 438 5, 438 14

The present invention includes a method and system for limiting the ramp rate of a variable under control in order to control stress in a process or plant under control. The present invention takes a limit curve provided by the user and combines that limit curve with a scale factor curve obtained from a model of the system to produce an allowable limit curve. A ramp rate limiter then uses the allowable limit curve to control the ramp rate of the variable under control such that the ramp rate of the variable under control is able to achieve the maximum allowable limit but no more.

6730885, May 4, 2004

Jul 5, 2001

09/897908

Fujio Suzuki - Tokyo-To, JP
Wenling Wang - Tokyo-To, JP
Koichi Sakamoto - Tokyo-To, JP
Moyuru Yasuhara - Tokyo-To, JP
Sunil Shah - Los Altos CA
Pradeep Pandey - San Jose CA

Tokyo Electron Limited - Tokyo-To

H05B 302

219486, 392416

There is provided a batch type heat treatment system, control method and heat treatment method capable of appropriately coping with a multi-product small-lot production. A reaction tube comprises a plurality of heaters through and a plurality of temperature sensors, and houses therein a wafer boat A control part stores therein many mathematical models for estimating (calculating) the temperature of wafers W in the reaction tube in accordance with the number and arranged position of the wafers W mounted on the wafer boat and many target temperature trajectories. If the wafer boat is loaded in the reaction tube a mathematical model and a target temperature trajectory corresponding to the number and arranged position of the mounted wafers W are read. If a deposition process is started, the output of a temperature sensor S and the model are used for estimating the temperature of the wafers W in the reaction tube and the powers to be supplied to the heaters through are separately controlled so that the estimated temperature approaches the target temperature trajectory.

6741414, May 25, 2004

Jun 15, 2000

09/595455

Stephen Boyd - Stanford CA
Sunil C. Shah - Los Altos CA
Mark Erickson - San Bruno CA
Ioannis Kanellakopoulos - Cupertino CA

Tokyo Electron Limited - Tokyo

G11B 1546

360 7303

A method and system for joint spindle speed and head position control in rotating media storage systems are described. A controller changes the rotation speed of a spindle assembly based upon the position information of a desired data sector. This controller may also control the actuator assembly based upon the position information of the desired data sector.

6745087, Jun 1, 2004

Dec 14, 2000

09/737992

Sunil C. Shah - Los Altos CA

Tokyo Electron Limited - Tokyo

G05B 1302

700 29, 700 30, 700 31, 700 9, 700 65, 703182, 703183, 703188

A scheme for management of uncertainty in control systems that require adaptation is described. The scheme removes as much uncertainty as possible at design time and manufacturing time by taking advantage of available computer resources in pre-computing a large set of robustness-performance tradeoffs. a plant that is controlled by having model controllers and a data evaluator receive monitored signals. The monitored signals are evaluated to determine when sufficient information is received. One of the model controllers generates a control signal based upon the monitored signals received.