The Mathworks, Inc.

Pascal Gahinet

Bora Eryilmaz

Rong Chen

Pierre Apkarian

Peter James Maloney

James Gareth Owen

Rajiv Singh

Dominikus Noll

Lawrence F Shampine

Zhiping You

John W Glass

Alec Stothert

Craig Buhr

Baljeet Singh

Anthony Lennon

Embodiments provide techniques, computer-readable media, and devices for allowing users to perform interactive design of controllers, such as PID controllers, in a free-form modeling environment. Users can tune controllers using characteristics familiar to typical users rather than having to specify gain values for the controller, which may be difficult for a user to relate to the performance of a controller.

Automated PID controller design, using parameters that satisfy a merit function

A device receives a control system model that includes a fixed portion that models elements of a control system to be controlled and a tunable portion that models elements of the control system used to control the elements modeled by the fixed portion. The device receives information that identifies a tunable parameter of the tunable portion of the control system model, a hard constraint associated with the control system model, and a soft constraint associated with the control system model. The hard constraint identifies a first constraint that is to be satisfied, and the soft constraint identifies a second constraint that is to be reduced. The device calculates a parameter value for the tunable parameter by applying an optimization algorithm to the control system model, based on the control system model, the tunable parameter, the hard constraint, and the soft constraint. The device provides the parameter value.

Multi-model, multi-objective tuning of control systems

H-infinity optimization techniques may be automated for multiple input multiple output (MIMO) control problems. In one implementation, a model may be received, where the model includes a plant portion that models elements that are to be controlled and a controller portion that models elements used to control the plant portion, the plant and controller portions of the model interacting with each other in a MIMO feedback configuration. Identification of tunable elements of the controller portion of the model may also be received. Requirements, relating to constraints of open or closed loop transfer functions of the model may also be received. Values for the adjustable parameters of the tunable elements may be calculated, where the calculation may be performed using non-smooth H-infinity optimization techniques and the calculation may be based on the model, the identification of the tunable elements, and the one or more requirements.

Automatic H-infinity optimization for multivariable control systems

Exemplary embodiments allow users to interactively formulate and solve multivariable feedback control problems. For example, users can solve problems where a plurality of control elements are distributed over one or more feedback loops and need to be jointly tuned to optimize overall performance and robustness of a control system. Embodiments allow users to specify design requirements and objectives in formats familiar to the user. Embodiments can operate on tunable parameters to solve the control problem in a manner that satisfies the design requirements and/or objectives provided by the user.

Interactive control of multiple input multiple output control structures

A tool for analyzing a sequence of data in an object-oriented environment is disclosed. In an embodiment, the sequence of data may include time-indexed sequence of data ('time series data'). The tool may provide graphical user interfaces that enable a user to analyze the time series data encapsulated in a time series object or time series collection object. The graphical user interfaces may enable a user to create a time series object and manipulate the data in the time series object or time series collection object. The graphical user interfaces may also display the data in the time series object or time series collection object in various types of plots, such as time plots, spectral plots, x-y plots, correlation plots and histograms.

Graphical user interface for analysis of a sequence of data in object-oriented environment

A method and apparatus are provided to model, analyze, and build linear time invariant systems with delays. The method and apparatus model a linear time invariant system as a linear fractional transformation of matrices of a delay free linear time invariant model with a bank of pure delays. The method and apparatus of the present invention can further accommodate input delays and output delays associated with the linear time invariant system with delays.

Method for modeling and analyzing linear time invariant systems with time delays

A method and system allow users to interactively formulate and solve multivariable feedback control problems. Users can solve problems where a plurality of control elements are distributed over one or more feedback loops and need to be jointly tuned to optimize overall performance and robustness of a control system. The method and system allow users to specify design requirements and objectives in formats familiar to the user. The method and system can operate on tunable parameters to solve the control problem in a manner that satisfies the design requirements and/or objectives provided by the user.

Interactive system for controlling multiple input multiple output control (MIMO) structures

A tool for analyzing a sequence of data in an object-oriented environment is disclosed. In an embodiment, the sequence of data may include time-indexed sequence of data ('time series data'). The tool may enable a user to generate a time series object for encapsulating the time series data in the object-oriented environment. The user may construct the time series object from data or mathematical expressions using a command line interface. The time series object may include a sequence of objects implementing APIs that supply an interface for analyzing the times series data in the time series object. The user may analyze the time series data encapsulated in the time series object using the APIs of the time series object.

Analysis of a sequence of data in object-oriented environments

Automated PID controller design

A system may include a memory to store a graphical block diagram model including a graphical block, the graphical block being associated with a lookup table and one or more inputs for receiving input data. The system may further include one or more processors to update data stored in the lookup table based on the received input data, where data stored in the lookup table includes data for simulating an embedded control system.

Adaptive lookup table: a graphical simulation component for recursively updating numeric data storage in table form

A graphical block that defines the functionality of a lookup table and can be used in a block diagram model to capture time-varying characteristics of a system's behavior in the lookup table is presented. The block uses input and output data of the system to dynamically create and update the contents of the underlying lookup table over time. More specifically, the block utilizes an adaptation process that uses the system (or plant) output data to recompute the table values. The adaptation process is implemented as a statistical and signal processing algorithm, such as Recursive Sample Means (RSM), Least Mean Squares (LMS) and Recursive Least-Squares (RLS). The adaptation can be cell-based or point based.

Adaptive look up table: a graphical simulation component for recursively updating numeric data storage in table form

The present invention provides a framework to let users systematically analyze, and design controllers for, complex non-linear dynamic systems modeled in a block diagram environment. By extracting linearized models from non-linear plant models (block diagrams), users can use one or more control design and tuning methodologies available for linear systems. Complex side effects, such as cross-coupling and exogenous disturbances, are viewable and can be dealt with in real-time during a design. The results of a design are automatically implemented in a block diagram.

Method for analysis of control systems

A method and apparatus create a general framework for representing and manipulating control systems having a plurality of SISO feedback loops or, more generally, SISO 'compensators' to be designed or tuned. A graphical user interface (GUI) design tool can include graphical interfaces, such as editors, which users can utilize to modify such variables as gain and other dynamics of each SISO compensator. Changes made to one SISO compensator generate different outputs, which are automatically translated to the other SISO compensators of the DSCS. There is a linking of interfaces and/or editors, such that changes made in one that affect another are automatically displayed accordingly. Such an arrangement provides for performance measuring views that provide real-time visual feedback on the effect of modified parameters on global performance. Different configuration tools can be utilized in conjunction with the present invention to enable a user to experiment with different design scenarios and compare results.

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Hopkinton, MA, United States of America

Pascal Gahinet