Robot Cars

This is the third and final installment of my "robots in transportation" series.  The first one was http://sigma5.blogspot.com/2010/12/space-final-frontier.html.  It argued in favor of shutting down the manned part of the space program and going with robot space probes.  The second installment: http://sigma5.blogspot.com/2011/01/robot-jet-fighters.html discussed unmanned airplanes.  Here I discuss robot cars.   But before I get into replacing drivers with robots I am going to discuss some other aspects of cars of the future.

Does the car have a future?  There are some who would argue that it does not.  There is a small but vocal contingent of people in my town that hate cars.  They walk, bicycle, or take public transportation.  They see cars as evil incarnate.  In the most general sense they are arguing against personal transportation, unless it is people powered.  So, taking things in reverse order, is people powered transportation practical?  People have been walking since there were people.  And animals have been walking for a lot longer.  So in some sense walking is practical.  But during the long period when walking was how most people got around most people never ventured more than 25 miles from where they were born.  I for one, do not want to give up the option of venturing further abroad.

Walking also has another disadvantage.  You can't carry much along with you.  If you intend to walk more than about 10 miles in a day I would estimate that it would be impossible for most people to carry more than about 100 lbs.  Many people couldn't handle even this amount.  And if you want to go further you need to cut down on your load.  If you want to carry more, and the limit would be less than 200 lbs, you would not be able to walk even 10 miles per day.  Domestic animals have been around for about 10,000 years as a way to improve the distance/load calculus. People have also been inventing things like ships and wagons as another solution to the problem.

A more recent invention is the bicycle.  It is another approach to beating the distance/load calculus.  There is an annual "Seattle to Portland" bicycle race in my neck of the woods that demonstrates this.  Most participants travel the roughly 200 mile distance in two days.  Many of them do it in a day.  So a bicycle allows you to travel four to eight times as far as pure foot power would permit.  This is a definite improvement.  But most people, given the option of trading a bicycle for an automobile, opt for the car.  This is most obvious in China.  We all have seen video of hordes of bicycles on the streets of Beijing a few years ago.  But Chinese are deserting their bikes for cars in the millions.  China is now the largest single car market in the world.

Public transportation, typically in the form of buses, but also in the form of light rail, is touted by many as the "correct" alternative to cars when feet or bicycles are not the answer.  Why?  Well, when you strip the argument down it is efficiency.  Public transportation is more efficient and produces less pollution than cars.  There is also the gridlock problem.  Let's take each of these issues separately.

The theory is that public transportation is more efficient.  But is it?  If you take a bus and fill it full of people it will be cheaper per passenger mile than the equivalent number of cars, each with only one person in it.  That's the way the efficiency argument is usually presented.  But are the buses really full?  Currently the answer is pretty much yes.  But this is because the number of buses is far less than the number that would be needed to meet the demand in a car free environment.  Bus systems all lose money and are limited in size to what the taxpayer will support.  Tax payer support falls off rapidly as the load (number of people on the typical bus run) decreases.  So the current subsidy is only enough to provide for a few pretty full buses.  This works because there are lots of cars around to take care of most of the transportation need.

There is also a hidden cost to buses and other mass transportation solutions.  That is lost time.  One of the real benefits to a car is in it I can go long distances whenever I want.  I take a lot of short in-city trips.  Frequently I have some flexibility as to when I go so theoretically I could time the trip to fit the bus schedule.  But much of the time this is not true.  I got my hair cut today.  It took me about 10 minutes each way.  In a bus, if I timed it right, it might have taken me 20 minutes each way.  So right away my travel time doubled.  Next, it was to an appointment.  So I really needed to travel to the appointment at a specific time.  It is possible to go early but whatever time I would have waited between when I arrived and when my appointment started would have been lost time.  Even on the most traveled bus routes an "every 20 minutes" schedule is about as good as it gets.  So I would have lost another ten minutes in synchronizing with the bus schedule.  And all this is true for my trip home too.  So in this semi-ideal situation 20 minutes of travel time has ballooned up to 60 minutes.  And this is for an in-city to in-city trip.

Buses (or light rail) don't go most suburban places.  And they do not go every 20 minutes and they do not run all the time.  Let's say we fixed that.  Buses would now go everywhere and they run all the time on an "every 20 minutes" schedule.  What do things look like now?  First, we need a lot of buses, between 10 and 100 times as many buses as we now have.  We would also have to use some kind of "hub and spoke" system.  It is impractical to have buses running from everywhere to everywhere.  So for a lot of trips you would take a local to a hub, a trip to a second hub, and finally a local to your actual destination.  That means a 10 minute delay at the first hub, a 10 minute delay at your second hub, and arriving at your destination 10 minutes early.  We add an hour to a typical longer round trip.  And, in order to meet our "every 20 minutes" and our "goes everywhere" requirement we are going to be running most buses pretty empty a lot of the time and some buses completely empty some of the time.  This scenario I have outlined may seem unrealistic but it is exactly what cars provide.  I can get in my car whenever I want and go reasonably directly to wherever I want.  My route and schedule is completely independent of anyone else's route and schedule.  What is your time worth?  There is an incredibly large time penalty to shifting most people from traveling by car to traveling by public transportation.

And, once you increase the density of public transportation sufficiently to reduce the time cost to a reasonable amount the efficiency goes out the door.  And the efficiency of public transportation is none too good now.  There is no public transportation system in existence that recovers all of its costs.  If you increase the quality of service of a public transportation system to anything approaching that currently provided by cars it becomes fantastically expensive.  Even in a place like New York City with its subway system that was built 100 years ago and its very high density, public transportation is heavily subsidized and they have lots of automobile traffic.

Next, let's consider pollution.  Cars are a definite improvement over horses.  The release far less pollution per mile.  But is a car inherently a polluter?  The answer is no!  We know this because we can now buy electric cars.  The single problem with electric cars is that the current battery technology sucks.  The motors that turn the propellers of the aircraft carrier Enterprise are electric.  Given this it should be clear that there is absolutely no problem making electric motors that will provide all the performance anyone could want.  But current batteries can't store much power.  So manufacturers put in wimpy motors to make the batteries last longer so people think electric cars are wimpy.  Fix the battery problem and you fix the wimpy problem.  Until the crappy battery problem is fixed electric cars are not for everybody.

Given cheap gas and a lack of powerful cheap batteries we will continue to have gas powered cars that pollute.  The obvious solution, if we want to reduce the pollution problem, is to make gas more expensive.  I drove a big old car while I was in college.  It ran on "super".  One day I bought super for 29.9 cents/gallon.  I said to myself  "I will never buy super cheaper in my life".  I was right.  That was a lot of years ago but it demonstrates what has been happening to gas prices over the last 40 years.  Even with the price increases gas is still cheap.  But let's assume it gets expensive or we decide for other reasons that we need to make cars much more efficient.  What will we do?

The current answer is a hybrid.  This is a combination of gas and electric.  There are a number of ways to do hybrid and it is not clear how most hybrids work now.  In a purely gas car you have an engine, a transmission, some mechanical connections like the differential and this all this spins shafts that turn wheels.  This is a pretty inefficient process.  There is another way to do this, the way aircraft carriers and diesel locomotives do it.  There the primary motor (nuclear or diesel) that is connected to a generator.  The electricity is fed to electric motors that spin the wheels.  For powerful machines like locomotives and aircraft carriers, this is the most efficient way to do it.  It seems to me that this should be the most efficient way to do cars.  You would also throw some batteries and a more complex "control" system in between the generator and the motors on the wheels.  This approach has many advantages.  You can put more or less batteries in.  You can add in the capability of charging the batteries from the electric grid.  More batteries and charging allows you to run the car on electricity more of the time.  The motor generator approach allows you to make the motor more efficient because it doesn't have to run at different speeds and loads.  It is no longer connected to the wheels.  You get rid of the transmission and other mechanical equipment that is inefficient at transferring power along the line to the wheels.  This general approach should result in the most efficient car.  So why don't all cars do it this way?

It turns out that if you do the same thing a lot of times for a long time you get very efficient at it.  Auto makers have been making a lot of traditional cars for a long time.  They have gotten very efficient at it.  Going to the design I recommend means learning how to do a lot of new things very efficiently.  It may be cheaper to do the theoretically less efficient thing (a car with a lot of old technology) because you are so darn good at doing the old thing.  Eventually some auto makers will figure out how to be good at making the new kinds of cars.  They will force the rest to figure it out too.  It might take a while but probably less than 10 years.

Moving from our current "gas" car to hybrid cars is hard but doable.  Most of our infrastructure; most of the manufacturing process, roads, gas stations, etc., will require little or no modification.  Switching to all electric cars would require a much greater change.  Batteries are the critical problem.  I have been following battery technology for 30 years.  The newest batteries are better than the old ones but we have merely moved from appalling to awful.  We need to move all the way to good.  Then there is our electricity grid.  It is not set up to handle the load that moving our transportation system over to a high percentage of electric would require.  Part of it is just more as in more generating capacity and more transmission lines.  We know how to do these things.  The part we don't know how to do is storage.  Our electric grid is real time.  It has a little inertia built into it but mostly it generates and distributes what is needed now.  Any serious imbalance between supply and demand results in outages.  And wind, solar, and some other sources are intermittent.  It would be nice if we could store the excess from some periods to cover the shortages from other periods.  Being able to store large amounts of power for a few days or even a few hours would make a tremendous difference.  This is the wholesale version of the electric car battery problem.  Again, I have been watching this area for over 30 years and not much progress has been made.  Nuff said.  Back to cars.

There is another "clean car" idea out there.  That's fuel cell/hydrogen.  The idea is to use a fuel cell to turn hydrogen into electricity.  NASA has been doing this since the '60s so its something we know how to do.  The problem is not in the fuel cell it is in the Hydrogen.  If you are NASA sending a space probe to the back side of beyond, the many problems associated with dealing with Hydrogen are worth the hassle.  But this is not true here on Earth.  Hydrogen has two problems:  making it and storing it.  There is no Hydrogen loose around to collect.  You have to make it.  Hydrogen is a constituent of lots of things including water.  But Hydrogen really likes to combine with stuff.  So it does.  To make it into a fuel we have to uncombine it.  That takes lots of energy.  Well, the whole point of Hydrogen is as a source of energy so this whole thing about consuming a lot of energy to create Hydrogen is just wrong.  A simple way to make Hydrogen is to use electricity to separate out the Hydrogen in water.  Other than the fantastic amounts of energy this requires it works pretty well.  And that's the problem with the many alternatives.  You end up having to use a lot of energy to make the Hydrogen.  This is not good.  Then when you have made the Hydrogen you have made something that loves to recombine with other stuff.  The name for this "combine" process, in many cases, is explosion.  So you need to be very careful how you handle things or you get explosions or perhaps just a very large very hot fire.

So Hydrogen is dangerous to store and you have to be very careful.  That sounds like the "storage" problem but it's not.  To store gas in a car you make this thing that is a couple of cubic feet in size out of sheet metal called a gas tank.  It's not very big and it's not very heavy, even full of gas.  But in this not very big not very heavy thing you can put enough gas with enough energy to move a big SUV 300 miles.  To store the same amount of energy as Hydrogen under similar conditions you would need a tank many times the size of the SUV.  So you have to do something.  One thing is to compress it.  But you have to compress it a lot.  So you need a very strong tank and you need to transfer the Hydrogen from the gas station to the car under these very high pressures.  This is dangerous and expensive.  And probably the gas tank is now very heavy in order to be strong enough.

Another approach is a sponge.  It turns out that there are certain materials that wick up Hydrogen.  They do it so well that you can get a lot of cubic feet of Hydrogen into a few cubic feet of tank.  And the pressure is not very high.  It's some kind of chemistry magic but it works.  Effectively you get a lot of compression without a lot of pressure.  You need a kind of sponge material that will store a lot of Hydrogen in each cubic foot of sponge.  There are some materials that do this but not many.  And it's tricky.  You have to get the Hydrogen to go into the sponge material at a reasonable rate at roughly room temperature and pressure.  This is tough.  And the Hydrogen needs to leak out of the sponge material without a lot of encouragement so that you can get the Hydrogen back to use in the fuel cell.  And it has to be cheap enough to be practical to put into millions of car fuel tanks.  So far no one has come up with a magic sponge material that has all these characteristics.  I don't see Hydrogen fuel cell cars in any numbers any time soon.

So what are we going to see on the road in the next 20-40 years?  I don't see anything replacing the car.  So we will see lots of cars.  I see a lot of hybrids, some electrics. And a lot of old style gas cars unless gas gets up to $40/gal.  I also don't see cars looking a lot different than they do now.  One reason to change the shape of cars is aerodynamics.  The first aerodynamic car was introduced in the '30s.  Wind resistance does not make much difference in the 30-60 MPH speed range.  It makes even less difference under 30 MPH.  So if you can make the power train more efficient or the car drastically lighter you will get a lot more bang for the buck.  I'm sure auto designers will find new and different ways to bend the sheet metal but this will be due more to fashion trends than anything else.  We will see more plastic, especially carbon fiber but that won't make much change in the look and feel of cars.

But I do predict a major change in one area.  It gets back to congestion and the title of this piece:  robot cars.  A robot car as anything other than Science Fiction is a pretty recent development.  The idea of a practical robot car that you could imagine sharing a street with regular cars is only about 10 years old.  But the field is now moving rapidly.  The first development to demonstrate this was the DARPA Grand Challenge series of rallies.  DARPA, a DOD agency, issued its first challenge in this area for an event that took place in 2004.  Driverless cars were to navigate on their own over a 150 mile route on regular roads on a closed course (no other traffic).  The best car went 7.3 miles before coming to a stop.  Not a very impressive showing.

But oh what a difference a year makes.  Round two took place in 2005.  The course was similar.  But this time 6 out of 15 vehicles finished including one that was a 30,000 lb military vehicle.  The winning vehicle was put together by a team from Stanford University.  Two years later in 2007 round three was held.  This time the course was only 60 miles long but it was over an "urban" route.  Vehicles had to obey speed limits, stop for traffic signs, and avoid other "moving hazard" vehicles.  Again, 6 teams finished.

So the DARPA challenges resulted in autonomous vehicles that could tell road from not-road, identify stop signs, avoid moving vehicles and perform other basic driving tasks.  This was a tremendous accomplishment but could they drive on ordinary roads beside vehicles driven by ordinary people?  Other than the last one, the DARPA challenges represented a more sophisticated version of what people had been experimenting for longer.  Several demonstrations had been done earlier with robot vehicles that could navigate in a closed "toy" system.  The last DARPA challenge introduced a more "real world" environment.

Things have been moving forward rapidly since.  Google has been experimenting with a driverless car.  Most of the testing has been in closed "toy" environments but not all.  The Google car has driven on California freeways.  It has even navigated Lombard Street, the famous twisty road in San Francisco.  The Google car has not been actually driverless.  There has been someone aboard who can take over if necessary.  But it has rarely been necessary.  The Google car has even been involved in an accident.  It was rear ended while stopped at a stop sign.  So I have every confidence that we will crack the "robot car" problem from a technical point of view in the next few years.

But the robot car question is also one of those "how do we get there from here" problems.  If all cars were robot cars then we can imagine all cars being robot cars but they are not.  I think it is idiotic to think that we will have dedicated robot car roads and other non-robot car roads so robot cars need to be able to work in a "real world" environment where there are lots of non-robot cars around.  DARPA, Google, and whoever come next are busy proving that it is possible to build robot cars that can do this.  So technology will not be the impediment.  So we can see the end.  But it is necessary to see the intermediate steps too.

I believe the foundation we can build the intermediate steps on is a Collision Avoidance System (CAS).  Cars have had crude cruise control systems for many years.  These are capable of maintaining a constant speed.  But it was the driver's responsibility to do collision avoidance.  And the systems were so dumb that you can't even lower the target speed.  But we are now seeing much more sophisticate systems coming on line in new cars, especially luxury cars.  A simple version of this ties into the cruise control system.  It will detect that the vehicle in front is getting too close and alert the driver and disconnect the cruise control.  Another improvement is a system that checks what's behind you when you are backing up and alerts you.  Another system will parallel park your car.  I believe the current version of the parallel park system operates blindly but I can see an upgrade that checks for obstacles and stops.  Another possible component is a system that looks for vehicles in your blind spot.

These are the beginning steps.  But sensors are getting cheaper and computing power is getting cheaper.  Adding more sensors and tying them together to give you a smart cruise control, a "blind spot" (to the side and rear) detection system and other features gives the auto manufacturing companies something to build on.  They can market them not only as a differentiator (my CAS has more features than your CAS) but at least some of the features will bring real value to the driver.  If you can use your cruise control in heavier traffic and go faster with greater fuel economy, that's worth something.  The features that warn you of vehicles in your blind spot, save you from backing into things, and do most of the work in parking your car would all be appealing to me. The equipment that enables all this is the equipment that can be enhanced to provide the robot car capability.

There is one feature that I see that is important to moving things along in the proper direction.  GM has an "EN-V" program.  The cars themselves are cute and toys, in my opinion.  But they do have one feature I see as a good idea.  The cars talk to each other.  This allows one EN-V to not run into another EN-V.  But the system is proprietary.  I think it would be a big help if the automakers got together and built a standard for cars talking to each other.  The difference in road knowledge possible when a car is on its own versus even the situation where a only few of the cars are exchanging information is tremendous.  Imagine a simple situation where one car is following another car.  Assume the cars are exchanging information and the rear car is following the front car in "cruise control" mode.  The rear car could easily maintain a constant distance because it knows the speed of the front car.  Now let's say that he front car needed to brake severely to avoid an obstacle.  It could pass the information back to the rear car so that it too could slow and avoid a collision.  And in a more mundane case, say the front car was about to exit the freeway.  It could signal the following car so it could break off station keeping.  There would be fewer situations where the rear car could provide information useful to the front car but there would be some.

Now imagine a situation where most cars were information sharing and had sophisticated robot car capability.  Here you could transition to convoying.  This would let cars stay closer together and go faster safely.  This increases the effective capacity of our current road system thus reducing congestion.  And with many sensors in many vehicles the chances of a surprise that might lead to an accident become very small.  From here it becomes possible to transition to a true robot car environment.  The result would be a cleaner, safer, and more efficient situation than what we have now.  Why more efficient?  As with bicycles, slowing down and then speeding up uses a lot of energy.  If you can save the energy you save the cost of generating the energy.  So we get the benefits the car haters desire without getting rid of the convenience benefit car lovers love.  A win all around.