During normal travel, an electric motor powers the wheels. But when needed, the robot can engage a hopping mechanism and leap over 25 feet in the air to clear an obstacle (as the video posted by Sharon demonstrated earlier this week) . It may look strange, but its unique capability might give the Hopper an important role in urban warfare.
Ground robots have always had problems with curbs, stairs and other obstacles that humans cross with ease. One solution is to build a bipedal robot the size of a human, but it’s much harder for small robots. Researchers at Sandia National Laboratories have been working on hopping robots which, much like grasshoppers or fleas, can leap over obstacles several times taller than themselves. Work started as far back as 1997. But recent advances have finally made it a practical proposition.
According to Mark Peterson of DARPA, the Pentagon’s far-out research arm, the three important developments have been the hybrid rolling/hopping design, miniaturization, and high-precision valves. “With these improved valving technologies, researchers are now able to precisely meter fluid fuels and oxidizers into the piston systems, and accurately provide the needed energy to hop the vehicle to an exact spot,” he told Danger Room.
The hopping mechanism works like an explosive pogo stick. It uses methyl acetylene-propadiene gas as fuel and nitrous oxide as an oxidizer, igniting the combination with a glow plug. Accuracy is the key here: The Hopper is capable of negotiating cluttered environments and can go up stairwells. It can even pop through (open) windows.
The Hopper has a number of advantages over small unmanned air vehicles, in particular persistence and stealth. “Most small UAVs have limited time on station because of limited fuel,” Peterson said. “Hovering is not very fuel efficient, exacerbating the problem of time on station. In some non-electric UAVs, flying and hovering are also very noisy.”
The electric motor is very quiet, and the Hopper can leap on to a roof, balcony or other vantage point and remain in place. High-resolution video will give the option to jump vertically and check the terrain ahead before going forward -– the Hopper will be able to look before it leaps.
Another advantage is that the 6.5 pound Hopper can carry a much larger payload than an equivalent UAV. The payload might consist of ground sensors or bugs; it might even be used to store and transport insect-sized UAVs closer to a target. But it might also have an offensive role. DARPA budget documents suggest that the Hopper could provide “surgical lethality and/or Intelligence, Surveillance, and Reconnaissance (ISR) to any point of the urban jungle while remaining lightweight, small and expendable.” The Hopper is likely to be a cheaper way of getting a warhead to a target than a $70k Javelin missile, and can go around corners or deep inside buildings. It also gives you the option of not blowing up the target when you’ve had a good look at them. Darpa plans to transition the project to Special Operations Command.
The Hopper is now being further developed by Boston Dynamics, makers of the impressive BigDog quadruped robot. Enhancements are likely to include active in-flight mechanisms for a more stable and elegant landing. The next version should be delivered in 2010, and limited user-testing will be carried out to give the military the opportunity to find uses for it. I asked whether there was a “giggle factor” to overcome because the Hopper is so unusual.
“As a future capability, reception has been largely been favorable,” said Peterson. “People appear to be impressed with some of Hopper’s statistics. Seeing it operate adds credibility. How it will ultimately be used, and when will be defined by tests … We are looking forward to these trials.”