Thales Tests Fly-by-Wire Hardware with PXI and LabVIEW based HIL System
Print
Author(s):
Shahzad Sarwar - Averna Technologies Inc.
Daniel Cox - Averna Technologies, Inc.
Industry:
Aerospace/Avionics
Products:
LabVIEW, PXI/CompactPCI, Real-Time Module, Data Acquisition
The Challenge:
Creating a hardware-in-the-loop (HIL) platform with a deterministic loop rate of 1,000 iterations per second that can manage a high count of 300 I/O channels scalable to 2,000 channels without performance deterioration, integrate more than 10 nodes running device models in real time, and share simulation and I/O data with a timing jitter of a ten millionth of a second – all within a tight delivery schedule and budget.
The Solution:
Using multiple National Instruments PXI-1045 chassis and a wide range of NI analog and digital I/O modules along with custom signal conditioning, and ARINC 429 hardware integrated with efficient software – developed with National Instruments LabVIEW Real-Time on PXI nodes and LabVIEW on Microsoft Windows nodes – and networked through reflective memory boards and TCP/IP to create this platform.
"NI PXI, LabVIEW, and LabVIEW Real-Time were the key factors in making this flexible, high-throughput, low-latency HIL system a remarkable success while saving more than $200K in implementation cost and several months of development time."
HIL Facility Benefits
For many years, aerospace and automotive design engineers have reduced their cycle times using HIL facilities. They can simulate design models for new products at high speeds and interface them with I/O signals from existing hardware in real time, which means they can iterate and validate their designs with unprecedented efficiency. As these systems begin to play a major role in design activities, a new demand for cost-effective implementation of flexible and high-performance HIL facilities is surfacing. Time, cost, and maintenance considerations dictate the opportunity to integrate multi-vendor technology and to use off-the-shelf components. NI PXI hardware and LabVIEW software provide an ideal platform for conceiving such solutions.
Our customer, the Thales Canada, Aerospace Division, which designs fly-by-wire controllers, needed to update its design validation facility using an HIL system. Thales required a system that deterministically integrated hundreds of data channels with a system composed of device models executed on more than 10 computing nodes. Because of node interdependency, Thales needed to transmit computed or acquired data system wide with a very low latency of a fraction of a millisecond. To capture any system transients, Thales required a loop rate of 1 kHz to synchronously acquire all input signals, update all outputs, and step through the model computation.
To ensure compatibility with future products, the HIL facility required a flexible system with dynamic association of hardware resources to physical signals, scalability to 2,000 channels, and rugged system integrity checks during new test setup configuration.
Thales also needed exhaustive data logging and an equally flexible and dynamic real-time graphical and tabular data displays that engineers could view through multiple access controlled computers.
Thales Engineering team elaborated all performance requirements and outsourced the system technical design and implementation to Averna Technologies. Averna’s solution to this challenging set of requirements is presented below.
System Design
A tight delivery schedule and a competitive cost-effectiveness requirement further constrained our system design. We determined that the NI PXI platform offered much of what we needed for our solution – embedded real-time controller availability, a wide range of NI modules for analog and digital I/O, openness to vendors not from NI to take advantage of ARINC 429 hardware, reflective memory, and IRIG-B synchronization boards, along with rapid software development made possible by LabVIEW Real-Time and LabVIEW.
Signal Conditioning and Data Acquisition
Given the varied and custom nature of signals originating from field transducers LVDTs and RVDTs, a custom signal conditioning hardware was designed and implemented to amplify the signals, provide isolation, along with synchronized sample and hold functionality. The conditioned signals were wired to I/O modules from NI housed in multiple PXI chassis. The PXI platform provides the needed modularity and system scalability along with precise timing synchronization and distribution of real-time clock. In the early phases of system development we successfully verified that a fully populated PXI chassis could perform full speed data acquisition at 1kHz without creating any throughput bottlenecks. Throughput and determinism checks were also successful for TCP/IP, reflective memory and even including CPU interrupt times making critical design review of system; a great success.
Application Software
We stored the system configuration in a Windows database that included tag names, hardware channel association, acquisition rates, engineering conversion, and system calibration information. Using LabVIEW, the application created system configurations – targeted for specific device tests – from hardware resources and database information. We then checked these configurations for system integrity and throughput requirements and downloaded them to embedded targets running LabVIEW Real-Time on PXI nodes.
We used LabVIEW Real-Time to initialize the entire system and used PXI timing modules to synchronize all PXI nodes. Then we developed a custom VHDL personality code for the PXI-7831R reconfigurable I/O module, which generated the IRIG-B signal to synchronize ARINC 429 transceiver modules with the PXI 10 MHz backplane clock. By doing this, the time-critical code on PXI real-time controllers handshakes with signal conditioning hardware and deterministically acquires the input signals and updates outputs – all at the same clock edge.
The HIL system allows Simulink® models to interface with I/O’s on PXI system through a reflective memory network that ensures a low node-to-node latency. Using LabVIEW Real-Time, we developed custom software that glues multiple nodes in the system through reflective memory boards.
LabVIEW Real-Time and PXI also interfaced with a number of ARINC 429 transceivers, providing extensive communication, word definition, and ARINC pollution capabilities when combined with other NI virtual instrumentation.
System Monitoring
Using a static reflective memory ring buffer, Thales can transfer all test data in real time to a remote node for disk storage. This system makes transferred data available to multiple monitoring nodes that can view the real-time data as well as logged data for test analysis. With virtual instrumentation based on LabVIEW, engineers can define the graphical and tabular data viewing displays.
Conclusions
The presented solution integrates diverse-technology products while being highly modular and flexible. Whereas the system is currently working with a channel count of 300, its scalability and extension to thousands of channels by adding more PXI chassis has been tested.
PXI, LabVIEW and LabVIEW RT were the key factors of making this dynamically configurable, high-throughput, low-latency hardware-in-the-loop system a remarkable success while providing an open, rapid, and reliable development platform.
Simulink® is a registered trademark of The MathWorks, Inc.
For more information, contact:
Shahzad Sarwar
Director of Industrial and Real-Time Solutions
Averna Technologies Inc.
Tel: (613) 230-0283
Fax: (613) 236-3754
E-mail: shahzad.sarwar@averna.com
Web: www.averna.com
Related Case Studies
Hardware-in-the-Loop Made Easy with NI LabVIEW Real-Time and PXIDeveloping a Hardware-in-the-Loop (HIL) Simulator for Testing Servoassisted Gears
Using LabVIEW Real-Time and Dynamic Signal Acquisition for Propulsion Inlet Flow Distortion Pattern Assessment in Jet Engine Inlets for Lockheed Martin
Lockheed Martin Reduces Costs and Time Testing F-35 Joint Strike Fighter with LabVIEW Real-Time
LabVIEW Real-Time Reduces Development Time of Hydraulic Actuator Test Cells
|
|