Nissan shows evolution of autonomy
Technology rolling out with 2018 Leaf boasts the building blocks for a hands-free future
Truly autonomous cars — where you’ll sit back and let your vehicle do all the work — are still well off in the future, but they won’t suddenly spring up fully-formed. Instead, automakers are using the building blocks that will come together to create them.
Virtually all automakers currently offer some of these technologies, either alone or bundled together. Nissan recently presented its version, called ProPilot Assist, which brings several of these together. It will launch on the 2018 Leaf. Some other manufacturers offer technology bundles that work similarly, including Mercedes-Benz, Tesla and Acura, but Nissan’s is the first for a lower-priced model.
Nissan stresses it’s only a driver assist feature, rather than handsfree. In reality, most of these systems could drive by themselves all day under the right conditions. But because they have their limitations, along with legal restrictions, automakers limit how long they’ll work on their own without the driver’s assist.
Cars are rated on six levels, with Level Zero being no automation at all. Level One provides some assistance, such as adaptive cruise control or a self-parking feature, but the car can’t simultaneously drive and steer. Having that ability takes it to Level Two, or partial automation, which is where most of these currently-available systems sit. Level Three cars will do more but still require driver intervention, while Level Four will drive itself but can still be driven. At the highest Level Five, there might not even be a steering wheel.
Most systems currently available, including ProPilot Assist, primarily use intelligent cruise control and lane-keeping assist. Unlike regular cruise control, which just maintains a set speed, intelligent or active cruise control uses radar to determine the position of the vehicle ahead.
If it gets too close, the system adjusts the throttle or uses the brake to maintain a pre-set gap.
Lane-keeping assist uses cameras to find the lane markings, and guides the electric power steering to keep the vehicle in the middle between them. This differs from the lane departure system found on many cars, which uses the steering or a subtle quick tap of the brakes to nudge the vehicle back over if the driver inadvertently crosses the line. Using that would result in the car bouncing back and forth between the lines, while a self-driving car must keep itself in the centre.
The ProPilot Assist system, like many others, brings the vehicle to a complete stop if the car ahead does, and then starts moving again if the vehicle in front starts moving within three seconds. If the stop is longer, the driver has to tap the throttle or hit the cruise control button to activate the system again. When driving, the system also monitors the steering wheel and the little nudges that indicate that the driver’s holding it. If this isn’t detected after a specific period, the system sends warnings that increase in intensity. Keep your hands off long enough, and the car will eventually slow down and stop.
Nissan’s system will gradually expand its capability, and within two years the company will release a version that can change lanes. Some premium cars can already do this: when the driver hits the turn signal, the vehicle uses its blind spot monitoring to check the adjacent lane and then, if it’s clear, moves over into it and centres itself in that lane.
So if cars can do this, why aren’t they already taking us where we want to go? These current systems are only reactive, watching the vehicles in front and looking at the road lines. They can follow curves but can’t turn corners, and they don’t recognize traffic lights or stop signs. The automakers are already on that — they work about five years ahead — but there are still many obstacles to overcome.
The adaptive cruise control radar sensors can be affected by dirt or snow, and while some automakers are experimenting with LIDAR, which uses laser pulses, it’s still very expensive.
Full autonomy also goes beyond the vehicle’s on-board technology. Cars will need to “talk” to each other, known as vehicle-to-vehicle communication or V2V, to move smoothly through traffic, be aware of collisions or other issues ahead, and to pull over for emergency vehicles. They’ll also need vehicle-to-infrastructure, or V2I, to communicate with their surroundings. That will include traffic signals, speed zones, parking garages, fuelling stations, and information on hazards such as ice or flooding.
But these communication systems also have their own issues that must be overcome, such as determining common platforms and wireless frequencies, privacy issues for drivers, the cost and who pays, equipping farflung communities with infrastructure, and protecting these systems from hackers. There may be cars on the road right now that can follow the lines and change their lanes, but we still have a long way to go before you can finally put the steering wheel away.