As I stated recently, humanoid robots aren’t likely to experience the head-spinning progress driverless cars have enjoyed because they’re more complicated machines that need to move in every direction, not just forward and reverse, and they require smart limbs as well as rolling wheels. But having numerous multibillion dollar corporations working on these hard problems is also an incredible force for improvement.

An Economist report of the recent DARPA Robotics Challenge notes the promise but also the frustrations of the field:

Running Man, the Atlas robot with which IHMC won second place, showed what the platform was capable of—though after completing its winning round it did rather let the side down by falling over as it struck a sequence of victorious poses. Jerry Pratt, who led the IHMC team, argues convincingly that, in principle, walking has huge advantages—a human can quite easily make progress along a discontinuous track no wider than a single foot, taking in its stride obstacles big enough to pose a problem to the wheels of anything short of a monster truck. But on the evidence of the DRC, the software and hardware needed to match that ability remain far off. For the time being, a robot designed for responding to DRC-style disasters looks likely to need an alternative to legs.

Getting a handle on how long that time being might be was another of the points of the DRC. Gill Pratt, who ran the programme at DARPA (and is no relation to IHMC’s Mr Pratt, though he did supervise his doctoral research) saw it as a way not just to stimulate progress in the field but also to gauge how quickly such progress could be made. Everyone involved in the DRC remembers the startling improvement between the first of DARPA’s “Grand Challenges” for autonomous vehicles—which, in 2004, saw the winning car travel just 11.8km of a 240km route—and the second, in 2005, in which five teams went the whole distance. That demonstration of rapidly expanding capabilities played a role in convincing people, such as the bosses of Google, that self-driving cars were a practical possibility in the not-too-distant future.

The progress between the first real-world DRC trials, in late 2013, and the finals this month was less spectacular. Humanoid robots are not yet at the ready-for-take-off point autonomous cars were at ten years ago. The teams using the Atlases knew that less than two years of working with their charges gave them time to implement little more than a simple ability to walk—one expert says that developing robust locomotion from the ground up and debugging it is more like a five-year job. There were also limitations with the hardware. Atlas’s arms were not strong enough to lift its 150kg bulk back up if it fell down.•