Testing to the max

National Instruments (NI) has been a major driver in the development of testing systems – both hardware and software – since its inception in the mid-1970s. Test and measurement, data acquisition, virtual instrumentation software and instrument control are just some of the areas where it expertise is employed.
Demand for its products and services both civil and military is growing all the time but one particular area showing dramatic development is UAVs.

“Our embedded systems use small intelligent systems for the same process of taking measurement and analysing it, but instead of reporting it back to an engineer it involves sending a control signal to do something,” states Ian Matthews NI, business development manager for Europe. “These systems can end up being used in robots or in aerospace applications for UAVs, for example, on the National Oceanic and Atmospheric Administration (NOAA) Global Hawk UAVs for atmospheric monitoring in America.”

Quick thinking

The systems rely heavily on the use of processors known as field programmable gate arrays (FPGAs), high speed semi-automatous microchips that can make fast decisions when linked to various input/output (IO) devices.

NI's expertise in software-defined radio is also heavily employed in testing systems controlling UAV aircraft in flight. Demand for this technology is growing as more and more aerospace companies look into UAV applications both in the military and civil sectors.

Matthews continuous: “UAVs may be the latest thing, but in many ways testing them is the same as with a conventional plane or helicopter. If you have good examples of how you test the components that are on a plane, you can use similar testing systems for UAVs. However, there are more radio systems that replace the role of the pilot and you don't have to include the cockpit display systems that a pilot needs.”

NI has worked with Airbus Military to create a copper bird (a custom made testing simulation system consisting of electrical components for the UAV), so it could be connected to NI's Veristand hardware-in-the-loop software to monitor real world electrical signals and compare them to a simulation to confirm they function correctly.

The next big area of demand in the UAV sector will be on the civil side according to Matthews. Development of smaller flying machines in the 20-100kg range will allow for prolonged and more automated airborne applications such as crop and livestock monitoring or situations where the risks for a pilot might be too great such as the Fukushima Nuclear power plant meltdown in Japan.

The company has been working with VTOL Technologies to help develop a new generation of flying wing designed specifically for long endurance, out of sight operations.

“They use single-board RIO, which is one of our small embedded systems as the heart of the control system. It monitors all the signals from the sensors such as the altimeter and controls the propellers etc. It has helped them to prototype the system while they had Technology Strategy Board funding for the project based on simulation but they will also use the system for the control application when it is built.

“The civil application of UAVs is a very exciting development for NI because there are many areas that need to be tested. For example, if you are flying in civil airspace then there is a need for collision avoidance as there may be other aircraft close by. This creates challenges for video processing and the UAV being able to assess the environment around it. For example, other objects in the sky entering the UAV's airspace. We can use faster chips on an embedded system that can help the UAV and its operators assess the situation quicker. This is also where graphical system design for control systems, aided by NI Test software, can substantially help bring systems to the market more quickly.”

Test engineers can use NI's FlexRIO system to quickly adapt to numerous testing situations to carry out graphical system design. The modular system uses the attachment of different testing modules – sometimes made by NI partner companies. It uses reconfigurable FPGAs and IO hardware modules along with NI's PXI modular platform to make a flexible testing system.

“FlexRIO has a common board that plugs into your computing platform and then you can plug in an adaptor module to do a specific job. That might be to add another instrument or another avionics bus,” Matthews adds.
Combined with NI's LabVIEW software it means test engineers who would normally have to create custom built electronics can adapt the modular system for a specific task and also programme it themselves, without the need to employ experts in hardware description language (HDL).

“This is very helpful for test engineers because they are being asked to do more and more testing but they can do it without large customised electronics. They can ask their engineers to tweak a modular system which is faster, more efficient and saves money.”

Future proof

Matthews argues that with changes in avionics increasing all the time, quicker adaptable testing systems are needed to keep up with the expected ramp ups in production.

“Electronic systems are constantly changing - just look at the recent developments that have been seen in electronics in the mobile phone field. These sorts of advances such as touchscreen displays are also being introduced into aircraft. Avionic systems are becoming more and more complex, which means you have to get the testing right. If you work out problems at the design, testing and simulation stage, it's about a twentieth cheaper than dealing with those problems at the prototype stage.

“We work with aerospace manufacturers to help their test engineers become more efficient and find faults early on. This is a very important technology when it comes to aerospace applications because there are so many different standards and regulations such as ARINC protocols. Using FPGAs allows you to adapt testing requirements when new ones are introduced. You have a core structure that you can adapt quickly for new programmes. It's a bit like getting the latest upgrade automatically downloaded onto your computer.”

Matthews also contends that embedded avionics systems need to be designed to be future proof because of the constant changes in electronics.

“Architecting an avionics system correctly when it's first introduced means it will be easier to adapt and to change if it is going to have a working life of 20 years, which is more common with aircraft these days.
“Five years down the line someone may produce a new technology or system and if you have not designed an architecture that can adapt to that it makes things very difficult. If you can't plug in and test you are stuck with having to use the old technology.”

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