Jim Kenzie of the Toronto Star tries out the U3-X - Click above for high-res image gallery

If there is one thing humans love, it's personal mobility. After all, what other species regularly harness other creatures for the sole purpose of getting around. The auto industry is all about personal mobility. Since the dawn of the car in the late 19th century, it has been adopted world-wide as one of the preferred means of getting around.

Mobility, of course, is about a lot more than just driving. Just moving around is important and when people find themselves unable to move or having difficulty, it plays havoc with the psyche. A number of automakers are researching ways to expand mobility beyond the automobile and the result is projects like the GM Puma and Toyota Winglet. Honda, too, is studying the problem and while we were in Japan for the Tokyo Motor Show, Honda took us to their R&D center to check out a few recent projects, including the quirky U3-X (shown above). Read on for a first hand account of what we saw and sat on.

Photos Copyright ©2009 Sam Abuelsamid / Weblogs, Inc.

One section of Honda R&D is known as the Fundamental Technology Research Center. Here, engineers, scientists and technicians examine a wide variety of problems and search for solutions. Some seem wacky on the surface and have no relationship to transportation. One of those is Asimo, the bi-pedal robot. We've all seen Asimo at some point and while it might not be directly related, lessons learned from its development can be applied elsewhere.

Other groups at Honda have been looking at mobility at the most fundamental level, that of just moving the body. This can become more difficult as we age or get sick or injured. We got to see and try out two different motion assist devices developed by Honda.

One is known as the stride management assist device. This one looks like a large belt with a pair of braces extending down from the hips that have straps to go around the thighs. The idea here is to help those who have motion issues get a more even and effective stride. A pair of motors at the hips help to get the legs moving. Sensors measure the forces in each leg and help to amplify and even things out from side to side. For example, if someone is shuffling or limping, the device gets the effectiveness of each leg balanced.

Autoblog's Sam Abuelsamid getting some assistance putting on Honda's stride management assist device

In practice, the sensation is quite interesting. At rest no force is applied. However, as soon as you start to walk, you can feel the effort required is reduced. It's a very interesting sensation and could be of significant value to those who need such a device, especially for walking up stairs or up a slope.

The Honda engineers measured what they called walking ratio, the length of stride divided by the pace (number of steps per minute). With the assist device, the ratio improved from 0.0043 to 0.005. Over a three-month test, they found the users stride increased from 0.55 to 0.6 m and the walking speed a little over 4 to nearly 5 km/h while the heart rate and physical load went down by nearly 20 bpm. This is not intended as a device for healthy people, but rather for those who have lost mobility and need help. For that, it certainly seems effective.

The second device to aid movement is the body weight support assist. This odd looking contraption consists of a pair of links tied together by a saddle. At the bottom of the links are shoes with tread force sensors built in. The idea here is to reduce the load on muscles and alleviate fatigue. In action, the device looks like some sort of bionic exo-skeleton for the legs. You sit down, put on the shoes and then turn on the device and raise it up between your legs. Motors in the links are controlled based on the sensors and in effect amplify the forces in your leg muscles.

In use, the effect is again that of reducing the effort to move your legs. If you squat down, and then stand back up, it's much easier with the device on. While the stride management device feels more natural thanks to the relatively unobtrusive mechanism, this one takes a bit more getting used to. The structure of the device means you may walk with a slightly wider than normal stance. However, it does achieve the desired effect.

Honda has been testing it with some workers in its Saitama factory as well as with people in other applications. It has proved to reduce fatigue by over 20 percent when doing activities like knee bends.

At this point, Honda has no immediate plans to commercialize either of these devices but also doesn't rule it out. It's ultimately possible that it could build them in-house just as it does now with solar panels, or it could license the technology to another company like a medical device manufacturer.

In both cases, these devices share some ideas with Asimo. Knowledge gained by Honda engineers in studying the detailed mechanics of how humans actually move was fed into these programs and similar concepts are incorporated. Neither of the programs are directly connected, but there are synergies.

The third and, in many respects, most interesting device is the U3-X. Honda recently unveiled this little self-balancing unicycle. When it was first revealed a few weeks ago, most observers described it as a one-wheeled Segway. However, in several respects this is far more intriguing than a Segway.

First of all, it was designed to fit within the same space used by a walking human when in use, thus the single wheel layout. Unlike the gyroscopically controlled nerd icon, the U3-X only uses an inclinometer for its feedback loop. Assistant chief engineer Shin-ichiro Kobashi described the basic mechanism as similar to what you do when balancing a broom-stick on the palm of your hand. Continuous small back and forth movements are required to keep it upright.

Exactly how this is achieved is the cool part. The team devised what they called the Honda Omni Traction drive system (HOT drive). This mechanism allows the single-wheel device to move in all directions: forward, back and left-right.

To achieve this, they incorporated something close to the same principle as a differential. A series of small wheels with their axis tangential to the big wheel surround what appears to be the circumference of the wheel. In actual fact there is no main wheel. The small wheels are sandwiched between a pair of side gears analogous to the side gears of a differential while the small wheels themselves are comparable to the pinion gears.


Each of the side "gears" is tied to a motor. When the side gears rotate at the same speed and direction, the small wheels don't turn on their own axis and the whole mechanism acts as one big wheel. When the speed of the side gears is varied, the small wheels start to rotate allowing the U3-X to move sideways or diagonally. Honda wouldn't let us take a close look at the wheel or photograph it, but there is definitely some interesting stuff going on there.

Riding the U3-X couldn't be easier. Turn it on and it just stands there making small motions to balance itself (see video above). The two halves of the seat pop out from the upper half and the foot pegs from the lower half. Sit gently on the seat and lean in the direction you want to go. The inclinometer detects very subtle changes in balance and makes immediate adjustments. The motions required are actually very subtle. Lean too far and too fast and it is possible to tip over but it's really very easy to stay upright.

With no controls other than your shifting weight balance, turning requires dipping a toe down to the ground to trigger a bit of rotation on the vertical axis. The whole process is incredibly intuitive and simply works. We were zipping around the room at up to 4 mph in seconds after sitting down.

The current form of the device weighs about 20 lbs and is designed for indoor use on relatively smooth surfaces. The wheel has no suspension and is not currently designed to deal with bumps, curbs or other protuberances. It could well be adapted for outdoor use on more uneven surfaces, but it would probably get much larger.

Unfortunately, Honda has no commercialization plans for the U3-X that it's talking about right now, but they won't rule it out either.

With this small taste of what is going on inside the R&D department at Honda, we can only wonder what other goodies they are cooking up.

Photos Copyright ©2009 Sam Abuelsamid / Weblogs, Inc.

Our travel and lodging for this media event was provided by the manufacturer.

Share This Photo X