Unmanned Systems Technology 042 | Mayflower Autonomous Ship | Embedded Computing | ElevonX Sierra VTOL | UUVs insight | Flygas Engineering GAS418S | Ocean Business 2021 report | Electric motors | Priva Kompano

42 D esigning embedded systems for unmanned vehicles involves a balance of reliability and safety. Added to that are the challenges of components currently in short supply and an increasing drive to use interoperable COTS systems. Then there is the software needed to enable a safe, secure and reliable system. Modular processor and sensor boards provide more flexibility for customisation, and standards have emerged over recent years to support the demands of embedded designs. Processor module standards range from PC/104e and COM Express for x86 processors to Qseven and SMARC for ARM-based processors, while larger 3U and 6U boards are standardising on the OpenVPX standard and are being combined via the Sensor Open System Architecture (SOSA). From a software perspective, new tools for model-based design are allowing the automatic generation of code, minimising the verification and testing requirements and allowing the code to be ported quickly and easily to different processors and boards. This is helping to reduce the development cycle for embedded designs. Embedded design With any unmanned product, the key is reliability across the whole system. This has to be balanced against the need to interface with many different products and their multiple configurations. For example, with an ECU for a UAV gasoline engine, there will be a few variations in the hardware depending on the inputs and connectors and the specification of the airframe, using a CAN interface to link to the rest of the system. The key is the customisation. The base design handles the trigger input from a missing tooth wheel on the crank shaft that provides the timing information. The ECU’s function is a matter of getting the crank position signal, determining the position of the cylinder and when the fuel injector needs to be opened and the coil fired. Customers send the engine to the developer to run the system and make sure there are no issues, and customise the hardware and the software. Printed circuit boards made locally provide a quick turnaround with an assurance of reliability, or the software can be ported to run on a controller elsewhere in the system. This highlights the demands of customisation in both hardware and software for embedded systems. One increasingly popular way to provide customisation with COTS is to use a processor module. With this approach, Module-based embedded designs help greatly with customising unmanned systems, and as Nick Flaherty reports, standards have been emerging to support them Custom support February/March 2022 | Unmanned Systems Technology A COM Express Type 6 module on a carrier (Courtesy of WIN Systems)