Quake Summit 2012
July 9-12, 2012
Development of a Flexible Platform
for Real-time Hybrid Simulation
Oya Mercan, Ph.D
Assistant Professor, University of Toronto
Computational/Control Platform
NI PXI 1042 with a built-in NI PXI 8110 controller
(deterministic, fast, CPU running RT with a built in clock)
Field Programmable Gate Array, FPGA
(high reliability, high determinism, true
Parallelism, & re-configurability)
SCB-68 (Break-Out-Box)
(68 screw terminals for I/O signal conditioning)
NI 5191 expansion chassis
• NI 9237, Load Cell Module
• NI 9239, LVDT Module
• NI 9481, Relay Module
Computational/Control Platform
Experimental Setup
Software Development
PXI- Real time
FPGA
State Machine Based with 7 States
• Safe start-up
• Emergency/ regular shutdown
•Command generation: either
predefined or using an integration
algorithm
FIFO
• Data logging and observation
DMA
• State determination of the
analytical substructure
•Interface with the I/O
modules to receive and
issue analog and
digital signals.
• Limit checks
• Data transfer
• Control law
• Dither injection
NI LabVIEW
synchronization
NI LabVIEW
MATLAB Simulink
NI LabVIEW
Software Development
LabVIEW VI for Tuning the PID Controller for a Single Actuator
(Front Panel)
Software Development
Initialization State
Open up FPGA
Write the
user
defined
values for
calibration ,
constants
PID gains,
limits etc.
on the
FPGA
Enable/Disable buttons on the front panel
Go to “Start up” state
Write “False” to HSM Stop and Next buttons
Software Development
Start-up State
Wait for the
user to turn
HSM on
Disable PID gains and filename
If Next button is hit  go to “Pre Zero” state
If Stop button is hit  go to “Stop” state
Software Development
Pre Zero State
Software Development
Zero State
Impose
user-defined
displacements
Check if the limits, next or stop buttons
have been hit, decide the next state
Software Development
Pre Run State
Clear FIFO Memory
Open up the
predefined
displacement
file
Depending on whether the displacement file
makes sense, decide the next state
Software Development
Run State
Impose predefined displacements within the timed loop
Either finish or abort the test and go to Startup
Write data to file
Software Development
Stop State
Immediately
turn the HSM
high pressure
off
Wait 5 seconds and turn
off the low pressure
and HSM completely
Software Development
FPGA VI
The relay channels in NI 9481 are being turned on/off
depending on the user input
Acquire restoring force data from NI 9237, perform
limit check
measured displacement
Limit check
Dither injection
command displacement
Electrical command
to the servo valve
PID
Write data to the FIFO
Verification Tests
To verify the developed software, hardware configuration, data transfer, as
well as the PID tuning and tracking performance of the proposed system
several predefined displacement histories were applied.
Real-time Hybrid Simulation
Pre Run State
Real-time hybrid simulation
considering one experimental
substructure
Real-time Hybrid Simulation
Pre Run State – 1DOF Hybrid Simulation
Information about the dll file that contains the
Integration algorithm and analytical
substructure is extracted and made available
to the other states
Depending on whether there is an error in the model dll file
decide the next state
Real-time Hybrid Simulation
Simulink model subsystem to be converted to
model dll using Simulation interface toolkit
Real-time Hybrid Simulation
Analytical substructure
Real-time Hybrid Simulation
Analytical substructure
Integration Algorithm
Real-time Hybrid Simulation
Analytical substructure
Integration Algorithm
Real-time Hybrid Simulation
Pre Run State – 1DOF Hybrid Simulation
Information about the dll file that contains the
Integration algorithm and analytical
substructure is extracted and made available
to the other states
model dll file
Depending on whether there is an error in the
decide the next state
Real-time Hybrid Simulation
Error notification, let the user decide what to do next.
Real-time Hybrid Simulation
Run State – 1DOF Hybrid Simulation
Current & Future Work
• Software modification to
control two actuators
simultaneously with and
without physical coupling.
• Replacing PID control
with other control laws.
• Control of larger scale
actuators (with three stage
servo-valves) with the NI
computational/control
platform.
Acknowledgements
• NSERC Discovery (Grant 371627-2009)
• NSERC RTI (Grant 374707-2009 EQPEQ)
• Start-up funds from University of Alberta and University of Toronto
Thank you!
Questions ?
Real-time Hybrid Simulation
Experimental Setup
Mechanical Components
Hydraulic power supply
Hydraulic service manifold
2-Stage electro servo-valves
Hydraulic dynamic actuators
Built-in AC LVDT
Fatigue rated load cell
3000 psi (pressurized oil)
120 gpm (continuous flow)
16.5 gpm (flow capacity)
±7,5 kips (force) & ±5 inch (stroke)
±5 inch (stroke)
±12,500 kips (load capacity)