Flight Control: CONDUIT®

System Overview

CONDUIT represents a significant new capability in flight control design, development, and integration. The system is built on top of the highly flexible MATLAB/Simulink system modeling and analysis environment, which includes a graphical block diagram editor and block-diagram-to-code features.

Supported Platforms

• Microsoft Windows 2000 Professional/XP Professional/Vista
• Red Hat Linux 9.0 and above
• Sun/Solaris 7 and above

Required Software

• MATLAB, Simulink, and Control Systems Toolbox R14SP3 or above
• Simulink Control Design Toolbox is optional

Key Features of CONDUIT

• Graphical User Interface:CONDUIT makes extensive use of the MATLAB graphical user interface (GUI) coding features to create an interactive interface for problem setup and pushbutton program operation.
• Built-in Libraries: The user graphically selects the desired handling qualities and flight control system specifications from libraries of over 160 fixed- and rotary-wing specifications.
• Customizable Specifications: The user can build new specifications from generic time- and frequency-domain specifications using the highly interactive Specmaker tool.
• Easy Problem Set-up: Specifications are wired to the simulation block diagram via a graphical editor, thereby avoiding any manipulation of the extensive MATLAB "m" files used for each specification. The user can bend the specification boundary curves, and the system automatically updates the relevant defining spline data.
• Quick Access to Detailed Information: Compliance with all active specifications is graphically displayed on the criteria with a single pushbutton command, significantly streamlining the system evaluation process. A key feature of CONDUIT is that a single mouse click on any of the specifications brings up an extensive set of supporting plots that present all the relevant analyses associated with the specification.
• Optimization: A multiobjective optimization engine, Feasible Sequential Quadratic Programming (FSQP), is used in CONDUIT to allow the user to tune selected design parameters (e.g., gains, time constants) for compliance with the active design specifications or to update control laws for changes in modeling data and design specifications. If desired, the user can generate a gain schedule for the full flight envelope by optimizing the control system at each of the operating points or can determine a single gain set that satisfies the criteria for multiple flight conditions. An important application of the automated tuning capability is for examining the tradeoffs between control system performance and actuator authority requirements and between competing specifications.
• Results: The CONDUIT problem definition and all results are stored and organized by case name for easy retrieval and comparative studies by the user.
• External Scripts Plug-in: The user can incorporate his/her favorite control design methods/scripts (e.g., LQR, H-Infinity) into the CONDUIT analysis.
• Test Data Analysis: The user can import flight test data for compliance with design specifications (ADS-33, 9490D, 1797), as well as analyze and overlay results with those based on analytical/simulation models, in both frequency and time domains.
• Sensitivity and Robustness Studies: Tools are provided for the user to gain in-sight information about relationships between specifications and design parameters during the optimization process, and allows the user to analyze the designed control system in CONDUIT to see if it can maintain its robustness with the presence of uncertainties within the system.
• Integration with CIFER Database: For users who perform aircraft system identification using CIFER and want to utilize the identified model in a CONDUIT problem, CONDUIT allows direct access to the identified state-space model for a given CIFER case stored in the database via a simple function call in the initialization file.
• Batch Mode Evaluation: An extension to CONDUIT which allows the user to create, analyze, and optimize multiple configurations or flight conditions of an aircraft in one batch session.

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