Take the Road Train, Revisited

September 16, 2012

I’ve written here before about some of the work being done to develop “self-driving” cars, including Google’s tests of a fully-autonomous vehicle, and Volvo’s work on developing “road trains”, essentially convoys of semi-autonomous vehicles that follow a lead vehicle with a human driver.  Volvo’s  work is part of the European Union’s Project SARTRE (Safe Road Trains for the Environment).

The New Scientist site has an article reporting on a recent demonstration of the road train technology.  This approach probably has the higher likelihood of practical application in the near term, because it is largely based on technology that is already present, at least in some high-end cars.

Almost all the sensors and actuators that keep me from flying off the road now come as standard in most new Volvos (and other manufacturers for that matter). They are the exact same ones that enable cars to stay in lanes and avoid hitting other cars and pedestrians.

In contrast, completely autonomous cars, like those being tested by Google, require a considerable amount of added equipment to function.

Both approaches have the potential to provide significant improvements in safety.  The autonomous “driver” will not drive while sleepy or intoxicated; nor will it be distracted by sightseeing, fiddling with a cell phone, or turning around to smack the kid in the back seat.  An automatic system can also react more quickly than a human driver.

That faster reaction time means, in practice, that cars, particularly in a road train system, can follow one another much closer than would be safe or legal with a human driver  .  In the test reported in the article, the following distance at a speed of 90 km/hour [56 mph] was about 6 meters [19.7 feet].  By comparison, with a driver reaction time of 500 milliseconds, about 80 feet of additional separation would be needed at the same speed.  Putting vehicles closer together, with fewer speed fluctuations, should help reduce road congestion.  Obviously, all this assumes that the lead driver is highly competent.

The ability to follow other vehicles more  closely also might improve fuel economy, by the phenomenon that cyclists everywhere know as “drafting”.  As speed increases, the amount of power required just to overcome air resistance increases as the third power of the vehicle’s relative air speed (that is, taking into account any head- or tail-wind).   At a speed of 15 mph on level ground, for example, most of a cyclist’s power is used just to make a hole in the air. [Source: Bicycling Science, 2nd Edition, by Frank R. Whitt and David G. Wilson; Cambridge MA: MIT Press, 1997].  The effect is not so pronounced for cars, since they are typically more streamlined (that is, have a lower drag coefficient), but it is still significant.

Vehicles driving in such tight formations with fewer speed fluctuations should dramatically reduce congestion, says Erik Coelingh, Volvo’s senior technical specialist who is heading the research near Gothenburg. The reduction in drag could potentially cut fuel consumption by as much as 20 per cent, he says.

The technology is certainly interesting, and seems to have a good deal of potential.  Whether the legal and cultural obstacles to its adoption can be overcome remains to be seen.

California Will Allow Driverless Cars

August 31, 2012

I first wrote about Google’s project to develop a self-driving car back in October 2010, and I’ve tried to follow its progress here from time to time.  Earlier this year, the state of Nevada approved test operation of the driverless vehicles on public roads, under specified conditions.  (For example, the company is required to post a $1 million insurance bond, and to have human drivers in the vehicle who can take over in an emergency.)

Now, according to a brief article at Ars Technica, Google’s home state of California is getting in on the act.  The state legislature has passed, and sent to the Governor for signature, legislation that would further the move toward self-driving  vehicles.

The new bill requires the state’s Department of Motor Vehicles to adopt new regulations, including safety standards and “performance requirements” for new autonomous vehicles. Once those new rules are put in place, the bill “would permit autonomous vehicles to be operated or tested on the public roads in this state.”

Google has, of course, been conducting tests on roads in California for a while, under various arrrangements, but the new legislation enables testing, and possible future use, to be put on a more formal basis.  The details have been left for the motor vehicle department to sort out, so it remains to be seen what the rules will be.

It seems to me that this technology might potentially improve the safety and efficiency of road transportation, if we can work out a way to solve  not only the technical problems, but the legal and cultural ones also.

Road Train Test

May 29, 2012

Back in January of last year, I posted a note here about some work being done by Volvo to develop the technology for “road trains”.  Using a variety of technologies, including cameras, radar, and laser tracking systems, along with wireless networking, the idea is that a group of specially equipped vehicles can travel together as an ensemble.  One “lead” vehicle, with a skilled driver, will lead the way, and the other will follow along using automated controls.  The motivation is that a road train system could reduce fuel consumption, increase safety, and possibly even relieve congestion, by allowing cars to travel safely in closer proximity.   The work is part of a European Union project, SARTRE (Safe Road Trains for the Environment).

A recent article at the Register (a UK-based technology news site) reports that the first tests of the system have now taken place on public roads: 200 km [~ 125 miles] of Spanish motorways.

Three cars have successfully driven themselves by automatically following a lorry [truck] for 125 miles on a public motorway in the presence of other, normal road users.

The average speed during the trip was slightly more than 50 mph.  The three cars stayed in line behind the lead truck, with an average separation of 6 m [~19.6 feet].   Considering that the speed (50 mph) is 70+ feet per second, this spacing would be dangerously close for human drivers; if these results hold up, there would seem to be some validity in the claim of closer proximity travel via this “platooning”.

As with Google’s “self-driving” cars, I think this technology has the potential to make auto travel safer and more efficient.  Both these technologies will also require some changes to traffic laws and people’s attitudes.

Update Tuesday, 29 May, 23:05 EDT

The “Autopia” blog at Wired also has a report on this test, which gives a bit more detail.

Living with Driverless Cars

May 13, 2012

A couple of days ago, I posted a note on Google’s receiving approval to test its driverless cars in Nevada.  If the technology proves successful, and is adopted to any significant extent, it will probably change how we drive, and how we think about driving, possibly in unexpected ways.

The BBC News Magazine has an article on how some of those changes might play out.  Some of the changes would very likely be positive.  An automated driver will not be talking or texting on a cell phone,  sightseeing, or otherwise diverting its attention to something other than driving.  It will not be sleepy or intoxicated, and will have faster reaction times than a human driver.  That should mean fewer crashes.  Automated driving might also allow more traffic to be carried on the same roadway, because cars could travel closer together, particularly if vehicles are able to communicate with each other, as in the “road train” experiments.  The automated driver can also be programmed to avoid human drivers’ dangerous behavior.

When the car is on self-driving mode, it doesn’t speed, it doesn’t cut you off, it doesn’t tailgate.

Some of the changes suggested in the article seem to me a bit more problematic.  It suggests that the technology might make auto use available to people who currently, because of physical infirmities, cannot drive, such as the elderly, or people with epilepsy.  The article also suggests that a self-driving car could, in effect, run errands on its own.

A car could take the children to school early in the morning, then return home on its own to pick up the parents for their commute.

After a late-night carouse, a drinker could find and reserve a hire car on their phone, then have it pick them up and drive them home.

I’m sure that, properly used, the technology could make driving safer, and allow some people to drive who would otherwise be only marginally capable.  But the idea of having the vehicle operate without at least one competent adult along, in case of emergency, strikes me as ill-advised; I hope that we will require a lot of evidence of the technology’s reliability before we begin that experiment.

Google Gets a No-Driver License

May 11, 2012

I’ve written here a few times about some of the developments in automotive technology that are aimed at turning over at least part of the driver’s job to an autonomous computer system.  Specifically, I’ve mentioned experiments, mostly in Europe, with “Road trains” (in essence, car convoys), and Google’s work on a self-driving vehicle.   There are also efforts underway to gradually incorporate some of the more mature results of these experiments into production autos.

According to a report posted on the “Law and Disorder” blog at Ars Technica, Google has now received approval to test drive its autonomous autos in Nevada.  The conditions for the license, established by legislation and regulations earlier this year, are not very different from the rules in the initial Google tests.

The state previously outlined that companies that want to test such vehicles will need an insurance bond of $1 million and must provide detailed outlines of where they plan to test it and under what conditions. Further, the car must have two people in it at all times, with one behind the wheel who can take control of the vehicle if needed.

As I’ve said before, the idea of automatic control is not new.  Aircraft have had autopilots and instrument landing systems for many years; trains have had signaling and switching systems for a very long time, too.  Some rail systems, like BART in the San Francisco Bay area, have centralized control systems.

Considering major transportation systems together, it’s clear that, in some sense at least, automobile transportation is the anomaly, consisting of a large number of vehicles operated more or less independently by more or less independent agents.   We have traffic laws, of course, such as speed limits and STOP signs, but travel by car provides a lot of flexibility and freedom to the individual driver.   That comes at a cost, however; in the US, somewhere between 35 and 40 thousand people die in auto crashes every year.  (For what it’s worth, I think that the most important Driver’s Ed lesson almost never taught is “It’s not a Race”.)

Part of the move to “smarter” autos, of course, is about testing and refining the technology, and that has to  be done.  The bigger part of the problem, though, will involve changing how we think about driving.

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