Real-time simulation system aids complex system design
Components and subsystems that form large, complex systems such as automobiles and aircraft need testing before the entire system is built. An engine-control unit (ECU) for example, has numerous sensors that must be simulated to test how the ECU responds to normal and abnormal conditions. While hardware-in-the-loop (HIL) systems have been around for years, Bloomy Controls has developed a system that can handle most of the inputs and outputs needed to simulate a system. You add the customization.
Bloomy's real-time simulation system consists of three models: Flight-control test system, environmental test system, and Full Authority Digital Engine Control (FADEC)/electronic engine controller (EEC), the system is built around commercial off-the-shelf (COTS) hardware and provides the inputs and output you need. According to Bloomy president Peter Blume, the system provides 80% of what you need to simulate a system. "The remaining 20% is the part that makes the system unique," he said during my visit to the company on July 12, 2019. Figure 1 shows a demonstration unit at the Bloomy office in Marlborough, Mass.
Figure 1. A demonstration model of the Bloomy hardware-in-the-loop simulation tester.
The system consists of a PXI chassis that provides analog and digital I/O and FPGA capabilities, but it needed some help to provide the source and sink capabilities to simulate a system. That's where Bloomy engineers stepped in to design modules for the National Instruments Switch, Load, and Signal Conditioning chassis ( SLSC). The PXI and SLSC chassis connect through cables and a Virginia Panel mass connector to what Bloomy calls a ThroughPoint Interface panel. The interface panel includes a switching matrix that routes signal to the appropriate terminals. Because the system uses cables and switches rather than point-to-point wiring, all connections are made for you. There are no individual wires to troubleshoot. Figure 2 shows the inside of the system with SLSC chassis (top) connecting to the PXI chassis and to the front panel (not shown).
Figure 2. The Bloomy HIL simulation system is based on an SLSC chassis (top) and PXI chassis. Image: Martin Rowe.
Bloomy's SLSC modules include:
8-channel thermocouple simulation module.
8-channel load module capable of handling 5 W/ch internally or 120 W/ch externally.
Multipurpose module for custom interconnects.
With hardware in place, engineers can add the test parameters using National Instruments' VeriStand, TestStand, LabVIEW, C/C++, or DIADem.
In the video below, Bloomy's director of corporate development Bill Eccles explains how the system works.
>> This article was originally published on our sister site, EDN: "Simulate system hardware before it's built."