Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A method for computer-aided design. The method includes the steps of representing a computer-aided design activity as a design cycle and defining a goal of the design activity. The method also includes the steps of defining alternate design steps toward achieving the goal. According to one embodiment, the design activity is represented as a graph containing the alternate design steps. According to this embodiment, a cost metric is assigned for each of the alternate design steps that includes elements representing relative costs of taking each of a plurality of paths in the graph. Element values and bounds on the cost metric are the determined by searching the graph to project costs incurred upon execution of each of the alternate design steps to achieve the goal. The cost of achieving the goal is then optimized by selecting one of the alternate design steps associated with a smallest cost metric.

Abstract: The present invention is a method and apparatus for dynamic optimization of a dynamic physical system having a device under control and a controller along with a modeling system having an estimator and a constrained nonlinear program. The time varying trajectories of the dynamic physical system are parameterized and run through the modeling system in order to produce a set of optimal time varying setpoint trajectories to be used in the dynamic physical system. The optimal time varying setpoint trajectories optimize the physical system to produce the desired end result (or product) of the dynamic physical system.

Abstract: A method for the estimation of the state variables of nonlinear systems with exogenous inputs is based on improved extended Kalman filtering (EKF) type techniques. The method uses a discrete-time model, based on a set of nonlinear differential equations describing the system, that is linearized about the current operating point. The time update for the state estimates is performed using integration methods. Integration, which is accomplished through the use of matrix exponential techniques, avoids the inaccuracies of approximate numerical integration techniques. The updated state estimates and corresponding covariance estimates use a common time-varying system model for ensuring stability of both estimates. Other improvements include the use of QR factorization for both time and measurement updating of square-root covariance and Kalman gain matrices and the use of simulated annealing for ensuring that globally optimal estimates are produced.

Abstract: A method for computing model error bounds for system identification of stochastic systems is disclosed. The model error bounds take the form of additive frequency-weighted singular value bounds such that they are directly used in H∞ and &mgr;-synthesis robust control design methods. The largest singular value of the additive uncertainty bound is determined by performing a high number of simulations for the model uncertainty. Simulated values of the uncertainty are computed for a large data population, such that each candidate entry of simulated value lies on the 3-sigma ellipsoids defined by the covariance functions. For each simulated value of uncertainty, the maximum singular values are then determined. In order to determine the scalar uncertainty function needed for robust control design, the maximum over the population of the maximum singular values of uncertainty simulated values is then computed.

Abstract: 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.

Abstract: 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.

Abstract: A method for computer aided design of a product or process. The method includes the steps of representing a computer-aided design activity as a design cycle. The design cycle is then converted into individual iterations of decisions to be made within the design cycle. The individual iterations of decisions are then mapped into a hierarchical structure of influence diagrams. The decision making process of the influence diagrams are performed and data is collected from the decision process that has been performed. The remaining unexecuted decisions and their posterior probabilities are updated based upon the outcomes of the decision process that was most recently performed.

Abstract: The present invention is a method and apparatus for dynamic optimization of a dynamic physical system having a device under control and a controller along with a modeling system having an estimator and a constrained nonlinear program. The time varying trajectories of the dynamic physical system are parameterized and run through the modeling system in order to produce a set of optimal time varying setpoint trajectories to be used in the dynamic physical system. The optimal time varying setpoint trajectories optimize the physical system to produce the desired end result (or product) of the dynamic physical system.

Abstract: A method for processing signals and controlling a physical system in which measurements are obtained at different time scales and/or different space scales. Signals generated from the physical system are processed by first creating a first dynamic model at a first time/space scale that consists of a first set of parameters, a first set of states and a first set of inputs. A second dynamic model at a second time/space scale is also created and consists of a second set of parameters, a second set of states and a second set of inputs. At least one of the first set of parameters in the first dynamic model are computed from the second set of states in the second dynamic model. A second estimator is then created to produce estimates of the second set of states using the second dynamic model, measurements from the first physical system at the second time scale.

Abstract: A method for the estimation of the state variables of nonlinear systems with exogenous inputs is based on improved extended Kalman filtering (EKF) type techniques. The method uses a discrete-time model, based on a set of nonlinear differential equations describing the system, that is linearized about the current operating point. The time update for the state estimates is performed using integration methods. Integration, which is accomplished through the use of matrix exponential techniques, avoids the inaccuracies of approximate numerical integration techniques. The updated state estimates and corresponding covariance estimates use a common time-varying system model for ensuring stability of both estimates. Other improvements include the use of QR factorization for both time and measurement updating of square-root covariance and Kalman gain matrices and the use of simulated annealing for ensuring that globally optimal estimates are produced.

Abstract: A method for computer-aided design. The method includes the steps of representing a computer-aided design activity as a design cycle and defining a goal of the design activity. The method also includes the steps of defining alternate design steps toward achieving the goal. According to one embodiment, the design activity is represented as a graph containing the alternate design steps. According to this embodiment, a cost metric is assigned for each of the alternate design steps that includes elements representing relative costs of taking each of a plurality of paths in the graph. Element values and bounds on the cost metric are the determined by searching the graph to project costs incurred upon execution of each of the alternate design steps to achieve the goal. The cost of achieving the goal is then optimized by selecting one of the alternate design steps associated with a smallest cost metric.

Abstract: A system for controlling a thermal reactor is disclosed that characterizes the thermal reactor with a reactor model that indicates behavior of the thermal reactor and of a load contained in the thermal reactor and that accounts for interaction among a set of heating zones of the thermal reactor. An online reactor model is then determined that estimates the thermal behavior of the load based upon an online input power to the thermal reactor and upon an online temperature indication from the thermal reactor. A time varying temperature and reactant flow recipe is determined that minimizes end of run parameters on the load. A multi-variable controller is employed to minimize temperature deviations of the load from a predetermined temperature recipe or time varying trajectory.

Abstract: A method is disclosed for operating a real-time multirate and discrete even computer system for simulation and automatic code generation of modelled systems requiring both expert system technology and conventional algorithms. Simulation of a system to be modelled proceeds on data inputs to yield outputs as responses of the simulated system to data inputs for assembling an organized catalog of blocks, both conventional and expert system, based on the operational rates and time skews. These blocks can be assembled for automatic code generation so that all blocks operating with identical rates and time skews can be organized within a single subsystem. Code is then generated for each subsystem, including code for a scheduler to run the entire system thus modelled. Each expert system block generates its own inference engine, and set of parameters representing the knowledge base, and storage allocation for the data base.

Abstract: An automatic computer software code generator for multirate real time control systems uses a functional library to define a multiplicity of functional blocks for building a functional description of a control system. For each functional block there is a software template for generating a set of software statements for performing one or more computations each time the software associated with that functional block is executed. A functional description of the control system software to be generated is provided in the form of a catalog database, and the computational relationships to be implemented by the software generated by the invention are defined by specified combinations of the functional blocks in the functional library. A linking software module organizes the catalog database into a plurality of separate subsystems, each subsystem including all the specified functional blocks with a given repetition rate and skew.