An Interactive Modeling, Simulation, Animation, and Real-Time Control (MoSART) Twin-Lift Helicopter System Environment Chen-I Lim Richard P. Metzger,Jr. Armando A. Rodriguez American Control Conference June 3 rd 1999 Hyatt Regency, San Diego, CA Ack : White House, NSF, WAESO/CIMD, Boeing, Intel, Microsoft, CADSI, Knowledge Revolution, MathWorks, Lego, Xilinx, Honeywell, National Instruments, Integrated Systems, ASU CIEE.

New Technologies Affordable High Performance Computing Hi-fidelity Simulation Capability –Simulink / MATLAB, etc… –Visual C++ PC Animation Creation / Manipulation Technologies –3D Modeling Software (e.g. 3D Studio, RPM D3D toolbox, etc.) –Microsoft DirectX (provides: 3D-animation, sound, video, user-input, etc.) Object Oriented Programming (OOP) Framework –ActiveX / OLE

Key Environment Features Accelerated-time simulation Alter model/controller: –structure –parameters (on-the-fly) Advanced visualization: –real-time graphics –visual indicators/aids –3D animation models Direct user input via joystick, mouse, etc. Integration with MATLAB and Simulink

System-specific interactive MoSART environments High performance: Windows/ C++ Advanced visualization tools: Direct-3D Extensible: integration with MATLAB User friendly Contributions of Work

Aerodynamic Derivatives Near Hover Sikorsky UH-60 Blackhawk

State Space Representation: B lc - Cyclic control Unstable: backflapping mode Open loop poles: …need AFCS to minimize pilot workload  010  0  =0M q M u  +M Blc B lc x-g0X u xx Blc..... Horizontal damping mode Longitudinal Dynamics Near Hover X/ B lc.  / B lc

General System Diagram

Horizontal Speed Controller Horizontal Speed Dynamics (s+b) 2 (2500) ( s + 50 ) 2 b 2 k (s+a) s. Desired speed Speed, x - + Cyclic control, B lc a = 2.5 b = 0.6 k = 0.5e-3

Pentium PC Windows ’95/’98/NT System Requirements: Pentium PC running Windows 95/NT. 32 MB RAM. Direct-3D 3.0. Recommended: Pentium II 266 w/ MMX running Windows NT MB RAM. Direct-3D 3.0. Visual C++/ MFC Direct-3D v3.0 MATLAB Engine v5.0 About the Program

Interactive MoSART Environment Modules Communication Module (COM) Program User Interface (PUI) Simulation Module (SIM) Graphical Animation Module (GAM) Help/Instruct Module (HIM) Physical SystemSimulinkMATLABInternet Other Applications Interactive Environment Application ActiveX

(PUI) User Friendly Windows ’95/NT Interface Menus Multiple windows Program control toolbars Interactive System Diagram Block diagram representation of system Point-and-click access Program User Interface

Program interface

(SIM) Numerical Simulation On-the-Fly Parameter Editing Fast compiled C++: >3000 Hz / 266MHz PII Better than real-time simulation Plant models Controller parameters Reference Commands, Disturbances, Noise, etc. Integration methods: Euler, Runge-Kutta 4, etc. Extensibility Simulation Module

Changing plant parameters on-the-fly Playback of externally generated simulation: e.g. MATLAB/SIMULINK Dynamic linking: MATLAB Engine... (Edit Mode) (Playback Mode) (External-Link Mode) Simulation Module: Extensibility

(GAM) 3D Animation Direct-3D Texture-mapped, light-shaded polygons Wireframe copters from previous simulations Real-Time Variable Display Window 2D Animation Window: pitch indicator Real-time multiple-graph plotting Visualization Tools & Indicators (SMAC) Extensibility Graphical Animation Module

Direct-3D standard file format 3D modeling packages: e.g. 3D Studio Libraries of 3D objects widely available: Internet & commercial vendors. Animation Module: Extensibility

(HIM) On-line Help Instructions on using the environment Program reference HTML / PDF Documents Model documentation/ references Interactive tutorials Help-Instruct Module

Open-loop joystick control Closed-loop user joystick control TLHS: Modal Analysis TLHS: Command Following Utility of Environment

Open-Loop Joystick Control Undesirable level of pitching. Very oscillatory cyclic control Difficult to maintain a desired speed Very difficult to maintain a desired pitch attitude

Closed-Loop Command Following Smooth cyclic control response Acceptable levels of pitching Good acceleration and smooth speed transient

TLHS System Configuration Payload Spreader Bar Master Slave

TLHS open-loop poles Real Axis Imaginary Axis AVM SM ASM TLHS System Poles Backflapping Tethered Helicopter Pendular Horizontal Spring Vertical Spring Average Vertical Damping Anti-Symmetric Damping Symmetric Damping

TLHS: Modal Analysis

TLHS: Command Following Command:5 ft/sec forward speed 5 ft/sec climb

TLHS: Command Following

Future Directions More visual indicators Advanced SIM and GAM (e.g. TLHS) Expanded HIM: web support, multimedia –Develop Model Documentation Feature Enhanced integration with MATLAB / SIMULINK / LABVIEW / Excel….all are ActiveX Compatible Integrated design & analysis environment Develop Additional Environments … development of Facility VISIT:

END OF PRESENTATION Some auxilary slides follow

Controller #1 (proportional only) Controller #2 (Dynamical Feedback) Horizontal Speed Controller

Unstable Backflapping Mode

TLHS: Loop Transfer Function

TLHS: Sensitivity

TLHS: Complementary Sensitivity