Category Archives: Engineering

Cool Robot Locomotion: Transforms from Wheeled to Walking For Stairs and Rough Terrain

This is a very cool engineering solution. Wheeled locomotion is very efficient on the right terrain. This transformation lets the robot switch to climb stairs and handle rough terrain very nicely. A team of mechanical engineers at National Taiwan University built this energy-efficient leg-wheel hybrid mobile robot. From their description:

Compared to most hybrid platforms, which have separate mechanisms and actuators for wheels and legs, our leg-wheel hybrid mobile robot, Quattroped, uses a “transformation mechanism” that deforms a specific portion of the body to act as a wheel or a leg. From a geometrical point of view, a wheel usually has a circular rim and a rotational axis located at the center of the rim. The rim contacts the ground and the rotational axis connects to the robot body at a point hereafter referred to as the “hip joint.” In general, with wheeled locomotion on flat ground, the wheel rotates continuously and the ground-contact point of the wheel is located directly below the hip joint with a fixed distance. In contrast, in legged locomotion the leg moves in a periodic manner and there is no specific geometrical configuration between the hip joint and the ground-contact point; thereby, the relative position of the legs varies frequently and periodically during locomotion.

Based on this observation, shifting the hip joint out of the center of the circular rim and changing the continuous rotation motion to other motion patterns implies the locomotion switches from wheeled mode to legged mode. This motivated us to design a mechanism that directly controls the relative position of the circular rim with respect to the hip joint so it can generate both wheeled and legged motions. Because the circular rim is a 2-dimensional object, the most straightforward method to achieve this goal is to add a second degree of freedom (DOF) that can adjust the relative position of the hip joint to the center of the circular rim along the radial direction. The motions of the two DOFs are also orthogonal to each other. In addition, the same set of actuation power can be efficiently used in both wheeled and legged modes.

Related: Big Dog, The Robotic Dog (2008)Robots That Start as Babies Master Walking Faster Than Those That Start as AdultsSelf Re-assembling RobotsSoft Morphing Robot (soft tissue)

Popular Curious Cat Science and Engineering Blog Posts

Here I include a list of some of the most popular posts from my blog in the last year. I hope you enjoy them. Only one post was written in 2011. Many of my older posts are consistently popular, while some have huge spikes for a day or two when they are popular on some social site (Reddit, Facebook, Twitter, Google+…). For posts that get huge spikes it isn’t uncommon for that pattern to repeat occasionally. I must have been doing something right in 2008 (based on how many of my popular post are from 2008). I’ll try to repeat that in 2012.

Photo of kids intently studying on a Malaysian beach

My mom with a group of Malaysia kids apparently intent on learning something. I am there, but not visible in this photo. Photo by my father.

Remote Presence Robot

Anybots allow remote presence today. They can be rented for just $600 a month. You can purchase your own for just $15,000.

The newest version, just unveiled at a CES has a much bigger screen (which seems very wise to me).

This is another example of robots making it into real use. While I am sure few workplaces are ready for this jump today, 10 or 20 years from now a telepresence robot (that can do much more) is likely I think to be significantly used. Not only will functionality increase, prices will drop dramatically: as the wonderful combination so often happens with technology. There is a great deal of effort going into making commercial viable “personal” robots. I think these efforts will make significant inroads in the next 10-20 years.

My old office wouldn’t have been willing to pay $15,000 but one of our developers looked into creating his own (after he moved and was working remotely). He hasn’t quite gotten it done yet, but may at some point.

Related: Managing By Rolling Around (I like how the robot owner used the robot to have his mother attend his wedding (and dressed up the robot) – Robot Finds Lost Shoppers and Provides DirectionsNew Yorkers Help Robot Find Its Way in the Big CityToyota Partner Robots

Using a Virus to Improve Solar-cell Efficiency Over 30%

Solar and wind energy are making great strides, and are already contributing significantly to providing relatively clean energy.

Researchers at MIT have found a way to make significant improvements to the power-conversion efficiency of solar cells by enlisting the services of tiny viruses to perform detailed assembly work at the microscopic level.

In a solar cell, sunlight hits a light-harvesting material, causing it to release electrons that can be harnessed to produce an electric current. The research, is based on findings that carbon nanotubes — microscopic, hollow cylinders of pure carbon — can enhance the efficiency of electron collection from a solar cell’s surface.

Previous attempts to use the nanotubes, however, had been thwarted by two problems. First, the making of carbon nanotubes generally produces a mix of two types, some of which act as semiconductors (sometimes allowing an electric current to flow, sometimes not) or metals (which act like wires, allowing current to flow easily). The new research, for the first time, showed that the effects of these two types tend to be different, because the semiconducting nanotubes can enhance the performance of solar cells, but the metallic ones have the opposite effect. Second, nanotubes tend to clump together, which reduces their effectiveness.

And that’s where viruses come to the rescue. Graduate students Xiangnan Dang and Hyunjung Yi — working with Angela Belcher, the W. M. Keck Professor of Energy, and several other researchers — found that a genetically engineered version of a virus called M13, which normally infects bacteria, can be used to control the arrangement of the nanotubes on a surface, keeping the tubes separate so they can’t short out the circuits, and keeping the tubes apart so they don’t clump.

The system the researchers tested used a type of solar cell known as dye-sensitized solar cells, a lightweight and inexpensive type where the active layer is composed of titanium dioxide, rather than the silicon used in conventional solar cells. But the same technique could be applied to other types as well, including quantum-dot and organic solar cells, the researchers say. In their tests, adding the virus-built structures enhanced the power conversion efficiency to 10.6% from 8% — almost a one-third improvement.

Read the full press release

Related: Using Virus to Build BatteriesUsing Viruses to Construct ElectrodesUsing Bacteria to Carry Nanoparticles Into Cells

Toyota Scion iQ: 37 MPG

I posted on the Toyota iQ a few years ago. It has been successful in Europe for several years and is now available in the USA also as the Scion iQ. Sadly it only gets 37 miles per gallon (the same for city and highway, as it is optimized for city driving). The earlier post discussed the Toyota iQ diesel which achieved 59 MPG (now the UK Toyota sites quotes 64 MPG).

The UK gallon (the imperial gallon) is 1.2 USA gallons – why are we not using the metric system yet 🙁 37 MPG would be the highest yield, for a non-hybrid, in the USA, still it is disappointing when compared to the diesel Toyota iQ figures (64 imperial MPG equates to 53 USA mpg).

The base price for the Scion iQ is $15,595. The car is obviously built for city driving: the small size makes it great for finding parking and navigating small streets.

A fully electric Toyota iQ is being planned for 2012 that can be recharged by 4 hours with a normal electric plug. It can be 80% recharged in 15 minutes with a special adapter. It will have a range of about 65 miles.

I really like the management of Toyota and own stock in Toyota.

On another front, sadly, the company behind the aptera concept car (230 MPG) announced they were closing down.

Related: Companies Sharing Engineering Resources Across the GlobeBigger Impact: 15 to 18 mpg or 50 to 100 mpg?Global Installed Wind Power Now Over 1.5% of Global Electricity Demand

Underwater Pedestrian Bridge

photo of a 'bridge' parting the waters to allow pedestrian to pass

The Dutch water line was a series of water based defenses conceived by Maurice of Nassau in the early 17th century, and completed by his half brother Frederick Henry. Combined with natural bodies of water. The line could be used to protect the economic heartland of the Dutch Republic behind difficult to cross water barriers, when in danger.

The Fort de Roovere was part of this defense. In 2010 the fort was renovated and the moat revived with a small extra bit of engineering: a sunken pedestrian “bridge.” Where once engineers used ingenuity to use water to keep people out, now engineers used wood to let people experience the moat while still reaching the fort.

via: Sunken Pedestrian Bridge in the Netherlands Parts Moat Waters Like Moses!

Related: Monitor-Merrimac Memorial Bridge-TunnelMonkey BridgeQuantum Teleportation

Companies Sharing Engineering Resources Across the Globe

Swapping batteries for diesel engines

Car companies, like aircraft manufacturers, are sharing engineering skills across borders to speed up and cut the costs of technological development. It happened with Boeing’s 787 Dreamliner. The American aircraft maker outsourced some of the engineering to Japanese suppliers, admitting that it does not have all the necessary expertise. Likewise, Toyota has agreed to work on hybrid trucks with Ford, and electric vehicles with Tesla, the Silicon Valley sports-car maker. BMW is working on improving the current generation of lithium-ion batteries with France’s Peugeot Citroën. Nissan, as well as joining forces with Renault, has joint projects with Daimler.

There are many reasons to pursue such efforts (as well as drawbacks). My belief is companies would rather not take on the complications of such partnerships but the advantages overcome those desires. The high cost of research into these efforts is a big part of what pushes such collaboration. Also once a company has success they often can build up quite an advantage. The costs of trying to engineer a different solution (that doesn’t violate someone’s patents) often makes buying that technology or partnering attractive.

I really like this webcast, from 2008, on Toyota’s engineering development program.

Related: Wave Disk Engine Could Increase Efficiency 5 Times59 MPG Toyota iQ Diesel Available in Europe (2008)Toyota Cultivating Engineering Talent

Stand with Science – Late is Better than Never

The USA public has made very bad decisions in who to send to Washington DC to spend our money (and the money of our children and grandchildren). We have wasted hundreds of billions that could have been spent more wisely. I happen to think investing in science and engineering is important for a societies economic health. The problem the USA has is we have chosen to waste lots of money for decades, at some point you run out of money (yes the USA government doesn’t really, as they can print it, but essentially they do – in practical terms).

I would certainly eliminate tax breaks for trust fund babies and trust fund grandchildren (while your grandchildren are going to be left holding the bag for the spending those elected by us, the grandchildren of the rich often get huge trust funds with no taxes being paid at all). But most of the people we have elected want to give trust fund babies huge payoffs. I would cut much spending in government – spending 5% less in 2020 than we did this year would be fine with me. But we don’t elect people that support that. I would support not adding new extensions to tax cuts sold with false claims and again supported by those we continue to elect. I wouldn’t allow the financial industry subverting of markets. But again we elect people that do allow that. And when the bill comes due for letting them take tens and hundreds of millions in individual profits in the good years, we can either let the economy go into a depression (maybe) or spend hundreds of billions to trillions bailing out those institutions our politicians let threaten the economy.

It might not seem fair, but there are consequences to allowing our political system to waste huge amounts of money paying of special interests for decades. And investing in science and engineering has been a casualty and will likely continue to be. Eventually you run out of money, even for the stuff that matters. Trying to fight for politicians that will put the interests of the country ahead of their donors is not something you can do effectively only when your interests are directly threatened. At that point things may already be too bad to be saved.

I have been writing about the failed political system for quite awhile now. I wrote awhile back that Hillary Clinton’s idea to tripple the number of GRFP awards was something I thought was very smart economically. But even then I questioned if we could afford it, if we refused to do anything else different (just adding new spending isn’t what the country needed).

Even in the state the politicians we continue to elect (we elect the same people election after election – there is no confusion about what they will do) we can debate what to cut and for something we spend so little on as investing science and engineering we can even easily increase that spending and not have any real impact on cutting overall spending. But those we have elected don’t show much interest in investing in science and engineering overall.

The USA continues to invest a good deal in science and engineering. But the difference in focus today versus the 1960’s is dramatic. The USA will continue to do well in the realm of science. The advantages gained over decades leave us in a hugely beneficial position – and one that takes other countries decades to catch up to. Now some countries have been working on that for decades now, and are doing very well. China, hasn’t been at it quite as long but has been making amazingly fast progress (similar to the amazing economic story).

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I was Interviewed About Encouraging Kids to Pursue Engineering

Amanda Moreno interviewed me about Encouraging Kids to Pursue Engineering over on the Knovel Blog.

What can parents do to cultivate an interest in science in their kids early on?

John Hunter: Ask questions. Answer questions. Explain how things work. Explain why things are done the way they are. Kids want the attention of their parents, and when they are younger they are constantly trying to get it (dad look, mom look, watch me!). They have similar feelings when they are older, but are not as forthright about saying what they want. If you take a sincere interest in their questions, you’ll motivate them to continue pondering how the world works. Make it fun to learn. Kids have an intrinsic motivation to learn. Keeping their curiosity alive is the first step.

So, on the university level, professors generally aren’t student-centric enough. What other factors are discouraging students in the classroom?

JH: I have one belief that is close to heresy. I don’t see why publication has to be so important for professors (if what we are after is good teachers, not authors). …

Read the rest of the interview.

Related: Backyard Wildlife: Sharpshinned HawkQubits Construction ToyWhat Kids can Learn By PlayingEncouraging Curiosity in Kids