Copyright Interesting Engineering
Chinese scientists have reportedly developed a new prototype “morphing” hypersonic vehicle that can fly faster than Mach 5 (6,174 kph). According to reports, this new technology can change shape mid-flight. Transforming abilities include retractable wings that can fold in, making the vehicle sleeker and more compact. This benefits the hypersonic vehicle by reducing drag, so it can fly extremely fast. When the wings are extended, they provide extra lift and manoeuvrability, letting it turn or glide more effectively. What#s more, when extended, the wings provide extra lift and manoeuvrability, letting it turn or glide more effectively. According to experts, this flexibility is considered a “holy grail” technology in hypersonics because most hypersonic craft have to pick one good shape either for speed or for control, not both. The new “morphing” hypersonic vehicle was developed by Professor Wang Peng’s team at the National University of Defence Technology (NUDT), which is a major Chinese military-run research institution. Their paper, published in Acta Aeronautica et Astronautica Sinica (China’s top aerospace journal), isn’t just theory either they’ve already done hardware-in-the-loop (HIL) tests. Mighty-morphing hypersonic vehicle HIL tests mean the control system (the “brain” that flies it) is connected to real hardware and sensors running in a simulator that mimics flight conditions. This shows the system actually works in real time with physical components, not just in computer models. This new technology could have some important military implications, too. China has already shown off the CJ-1000 hypersonic cruise missile, which it claims can hit moving targets, even aircraft or ships, from thousands of miles/kilometres away. That’s something most experts previously thought was impossible, because hypersonic flight normally trades manoeuvrability for speed. In theory, this new morphing-wing concept could provide China with some interesting new possibilities regarding its hypersonic capabilities. The first is to provide a vehicle that can fly fast to reach its target zone quickly (wings retracted). Such a vehicle could then extend its wings slightly to turn, dive, or change trajectory, making interception or prediction extremely hard. If claims about the new hypersonic vehicle are true, it gives China a major edge in penetrating defences or engaging mobile, high-value targets like carriers or stealth aircraft. But it is not without its challenges. Flying at Mach 5+ means the vehicle can experience temperatures of over 3,632°F (2,000 °C), which is enough to soften metal and ionize air. It also has to endure enormous aerodynamic forces, meaning that every moving part becomes a potential failure point. The new vehicle also has the added problem of moving wings to the mix. To this end, each movement changes the aerodynamics, which changes the forces on the craft, which in turn affects control. Beyond the mechanical issues the team had to overcome, the vehicle’s onboard flight computer must recalculate lift, drag, and stability every split second. This, the team explains, means that drive actuators (motors) must physically move the wings with no delay or vibration. But onboard computers in missiles are small and rugged, not supercomputers. Applications beyond the military So the control algorithm must be ultra-efficient, able to make instant, stable decisions without needing huge computing power. Wang’s team claims to have solved the control problem using a new algorithm that combines a few new innovations. The first is high-order system modelling, or a very precise mathematical representation of how every part of the aircraft behaves. The second is something called prescribed performance control that sets exact performance targets (like max error, response time, etc.) in advance. Lastly, the new vehicle includes super-twisting sliding-mode control, which is an advanced control method that can handle uncertainty and noise without the “chattering” vibrations that normally destroy actuators. Beyond military applications, this new technology could have other benefits for various industries, from commercial flights to freight transport. For the former, global business flights that be dramatically reduced to 1–2 hours instead of 10–12 hours today. Similarly, it could also open the door for rapid cargo transport across continents. If news about this new technology is true, this would mark one of the biggest leaps in hypersonic technology since the field began. It could also be a sign that China is pushing into territory few other nations have mastered, even in classified programs.
