In the field of technology prediction, “twenty years” is a strange Neverland. How many times have you heard an expert confidently predict a brilliant new technology will arrive in about twenty years? And how many times has any two-decades-away tech ever actually materialised?

Fortunately, the cynicism in my tone won’t stop researchers trying to develop brilliant things that will change our lives but are forever just about twenty years over the horizon.

One of those things is the good old domestic robot. An impressive stand at the Future Parc hall here at CeBit in Germany – a hall dedicated to research projects and the like – is showing off some of the state-of-the-art robotics happening in academia.

The centerpiece is a very big, very shiny, very blue robot called – and I apologise for making you cringe here – “Rollin’ Justin” (those crazy Germans!).

The people who built Justin are part of a research collective called DESIRE – which in German stands for the German Service Robot Initiative. The interesting bit is that it’s focused on a new, formal discipline of “service robotics”, in other words robots explicitly designed to help humans in everyday life, not just build cars or run around little artificial mazes in robotics labs. This was explained to me by Ingo Luthesohle, a research graduate from Bielefield University conducting a postgrad project into ways of teaching robots how to recognize and manipulate arbitrary objects.

“But,” I rudely chimed in as he spoke, “people have being saying that we’ll get domestic robots soon for at least fifty years now. Nothing seems to have happened. When are we actually going to get them?”

Ingo’s point was that robotics has been developing, and it’s moving gradually from being tied to completely fixed, predictable environments (usually industrial ones), to being able to cope with more uncertainty. The issue is that service robots sit at the very end of that uncertainty spectrum: there are few indoor environments more uncertain than your house.

“About fifty years ago, it was all about industrial robots doing fixed tasks,” he explained. “Then twenty years or so ago mobile robots [like Honda's Asimo] started appearing. But service robotics, which is what we’re doing, that’s pretty new, maybe the last ten years.” (Read about Asimo and other creations in our feature).

I looked over at Rollin’ Justin and could certainly see he didn’t exactly look like a mature domestic robot. He’s massive and seems more like the kind of robot you see in car factories, but with an added cutesy-pie blue finish, organic curves and a set of wheels.

Basically, Justin gave me the creeps. As part of his demonstration routine he stretched out his multi-jointed arms; a curiously triumphant-looking gesture which showed an arm span of about six feet and looked, frankly, terrifying.

My heebie-jeebies weren’t helped by his human handler watching Justin like a hawk at all times, a small yellow box always in his hand. On the box was a big red button: a remote kill switch, obviously set up to fry Justin’s insides or blow his head up should he get it into his brain to go on a murderous robotic rampage.

Happily though, Justin doesn’t seem quite up to freeing himself from the bonds of robotic slavery just yet. During the demo I watched – in which he showed his impressive mobility by, er, slowly trundling four feet to the left and back again – he happened to stretch out an arm and bump it on the table in front of him (which you can see in the photo). And then he just sort of stopped. A helpful man at the front of the gathered spectators pulled the table a few inches back for clearance, but the damage was done – Justin had clearly become hopelessly confused. All his fail-safes had kicked in simultaneously while in the presence of squishy, easily decapitated humans. Bless.

Just as well though. When you’ve got a robot in your house – especially one the size and weight of Justin (he weighs 120kg) – safety has to be the number one concern. This is my main objection to domestic robots. You can program every domestic scenario you can think of into its little brain but there will still be an unlimited number left over it won’t know about. A robot can’t, for instance, tell that it’s just knocked a burning candle onto the carpet.

“Actually, it can,” says Ingo, looking just a tiny bit smug. “There’s a project going on to give a robot a type of latex skin so it can feel if it knocks anything over.” I looked a bit impressed.

So then I had to ask the much-vexed question – how long, really, truly, before we all actually get personal domestic robots? A pause for thought ensued.

“I’d say about twenty years”.