The real world is inherently multi-disciplinary. In order to accurately understand the behavior of such systems, there is a need to simultaneously combine hitherto separate physical disciplines in a logical manner to generate higher-level mathematical models that can accurately represent natural behavior. Simulation tools have traditionally focused on a single discipline such as controls, fluid dynamics, structures or motion. There is a pressing need to efficiently combine these various representations, solve the resulting model and predict reality. Due to its system level focus, multi-body simulation is a natural environment for integrating the different technologies together. MotionSolve is an Industry proven multi-body simulation tool that provides a logical environment to integrate different technologies and solve the combined problem. This presentation discusses three topics: (a) The need for multi-disciplinary simulations and strategies for combining models (b) Simulating real world phenomena using MotionSolve (c) Case studies illustrating how customers have successfully used MotionSolve to solve multi-physics problems.

1. Multi-Physics with MotionSolve
Rajiv Rampalli & Keshav Sundaresh, Altair
Innovation Intelligence®

2. Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Presentation Outline
• Need for Multi-Physics simulations
• Case Study: Control of a Wind Turbine
• How other customers are doing Multi-Physics simulations
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3. Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Real Models Are Complex
Hydraulics &
H d li Flexible N
Fl ibl & Non-linear
li
Control systems components
Virtual tires & Virtual driver
digitized roads models
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4. Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Industrial Processes Are Complex
TIRE & ROAD
MBD FATIGUE
G POST
DRIVER
FE
DRIVER FE
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5. Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
The Conundrum
Systems Software
Multiple Domains Single Domain
Diverse Phenomena Single Formulation
Many Technologies One Integrator
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6. Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Introducing MotionSolve…
• A natural environment for multi-disciplinary studies
• Open architecture for coupling domains
• Many different choices available for coupling
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7. Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Model Connection Methodologies
Master
System Equations
S-1 S-2 S-2
Sharing Equations Co-Simulation (Sharing signals)
Simulator-1 Simulator-2
Shared
Data
Sharing Linear Models
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8. Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Sharing Linear Models: With Simulink
Matlab
MotionSolve
M ti S l
Simulink
MotionSolve exchanges state matrices with Matlab/Simulink
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9. Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Sharing Linear Models: With FE
HyperMesh MotionView
Radioss MotionSolve
MotionSolve shares data with a variety of FE codes
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10. Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Sharing Equations: via User Subroutines
Object
Code
User MotionSolve
Subroutine Python Script DLL MotionSolve
User subroutines allow users to link their own equations to MS
U b ti ll t li k th i ti t
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11. Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Sharing Equations: via Code Export
Object
Code
Motion
Motion “C”
Solve RTW
Solve Code
DLL
Simulink
Controller
Co-simulation
Co simulation
Native RTW code import from Simulink
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12. Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Sharing Signals: MotionSolve + Simulink
System Model
MotionSolve
model
S-Function (MS ) Controller
Simulink Window
MotionSolve is an S-Function in Simulink
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13. Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Sharing Signals: MotionSolve + DSHplus
System Model
User Block (MS ) Hydraulic System
DSHplus Window
MotionSolve is a user block in DSHplus
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14. Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Sharing Signals: MotionSolve + Driver
System Model
y
Controls & Switching Signals
Speed Controller
Gearbox Controller
Feedback Controller
Signals Outputs
Steering Controller
Vehicle Model Driver Model
(
(MS))
MotionSolve can include complex driver models via co-simulation
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15. Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Presentation Outline
• Need for Multi-Physics simulations
• Case Study: Control of a Wind Turbine
• How other customers are doing Multi-Physics simulations
15

16. Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Co-simulation – Wind Turbine Emergency Stop
“Grid loss” – Sudden drop in generator torque
Grid loss
Reaction: Immediate blade pitching and activation of the brake disk.
E-stop event
•
0-60s Ramp up to full effect, 1MW.
120.0s “Grid loss” 100-0% in 0.1s
120.4s Maximum brake pressure & reversing pitch angle
135.0s Pitching complete
Mechanical system, Wind loads – lift and drag forces v/s pitch angle, Tower shadow - %ge drop of wind forces in front of the tower 16

17. Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Initial Results
• Grid loss and braking generate massive
rotor torque variations
t t i ti
• Large blade vibrations during overshoot
• Blades vibrate during initial braking, causing
high frequency variations of rotor torque.
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18. Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Control Requirements
• Implement a non-linear braking pressure to:
• Reduce blade deflection
• Eliminate overshoot
Brake controller: Blade deflection v/s Brake magnifier
Brake release: Rotational speed v/s release factor
Low pass filter to the braking signal – to avoid rapid vibrations 18

19. Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Control Model in Simulink
Rotor Velocity Flex Sensors
Control Parameter
C t lP t
Plant Outputs Plant Outputs
Flex Sensors Rotor Velocity
Controller
MS Model Sensors
Flex Sensors
1
z
Rotor Velocity
1
z
Blade Deflection
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20. Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Co-Simulation Results
100% Rotor Speed
Simulink Rotor Speed
100% R t S
Rotor Speed
d Simulink Rotor Speed
Si li k R t S d
100% Rotor Speed
Simulink Rotor Speed
Brake controller: Blade deflection v/s Brake magnifier
Brake release: Rotational speed v/s release factor
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21. Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Presentation Outline
• Need for Multi-Physics simulations
• Case Study: Control of a Wind Turbine
• How other customers are doing Multi-Physics simulations
21

22. Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Faurecia – Glass guidance simulation
• Challenge:
• Find the cable positions to meet requirements
on normal f
l forces f different combinations of
for diff t bi ti f
friction.
• Solution:
• Mechanism analysis with MotionSolve to find
the normal forces
• Design optimization with HyperStudy to find the
optimal cable positions.
• Benefits:
• An optimal design that meets all conflicting
requirements.
• A fast & automated design process leading to
fewer errors & better designs.
“Co-simulation of window regulator with MotionSolve and Matlab/Simulink gives a full
mechatronics model of the system, allowing simultaneous design of both mechanism and
actuator” – Dany Desrus, Leader Product Line EE & Mechatronics, Faurecia Interior Systems22

23. Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Summary
• Real systems are complex
• A full understanding of these requires multi-disciplinary
simulation
• MotionSolve has an architecture that facilitates coupling
of different solvers to enable multi-disciplinary simulation
• Many different options for coupling are available
y g
• The simulation requirements and coupling
difficulty dictate which choice should be used.
Thank You!
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24. Rajiv Rampalli
Keshav Sundaresh(keshavs@altair.com)
Innovation Intelligence®