The Tech & The Head to Head Test: Autonomous Vehicles Update

Andy_Self Driving Car_Update 2

Autonomous Driving Vehicles Update: Part 2 & 3 

The best articles we found on the topic were this head to head comparison in Car and Driver, and this one on technology and the larger societal issues from First, take a second to let that sink in. Car and Drive makes sense but we’re already looking at a Tech focused media source when talking cars. Will the mechanics of the future have computer science degrees? (Special note: the Wired article is from 2012, but it’s just one of those seminal treatments of the issue that’s not been surpassed in 5 years.)

Both articles are great to read, but we’ll provide a brief, tech-focused, synopsis below.

Tech Being Explored for Use in Car Autonomy

1 Wheel Encoder

Most of us don’t think too hard about how a cruise control decides how fast you’re are going. We assume it looks at the speedometer the same as we do, but that’s sort of like a photocopy of a photocopy. In actuality, speed sensors either monitor the axles or the wheels. The best option for tracking velocity is wheel-mounted sensors.

2 Radar

Oldie but goodie, we’re all familiar with it and it’s already in use in High-end vehicles, accident-prevention systems like Mercedes’ Distronic Plus, which assists lane changes by covering the blind spot.


Light Detection and Ranging, uses lasers, spinning around a thousand rpm, to create a 360-degree awareness that has different weaknesses than radar. The idea is to use LIDAR and RADAR together to eliminate common things that would interfere with either of them separately.

4 Lane-keeping

Some autonomous vehicles use dedicated cameras to watch the contrast between the road surface and the boundary lines. When the lane paint isn’t faded, drivers often comment on how well the cars remain exactly in the center of the lane. On occasions when a large vehicle would make it uncomfortable to remain dead center, most of the systems are able to cheat slightly to one side of the lane.

5 Infrared Camera

Mercedes’ adapted early to using this technology, which has been used by the military for many years. Commonly confused with thermal cameras or twilight vision cameras, which use heat or light-gathering to create types of night-vision, Infrared requires infrared light to project forward and be picked up by infrared cameras. Obviously, that’s not difficult to add to headlamps, but it radically improves the ability to spot nonreflective objects at night. A dashboard display shows the view ahead with hazards illuminated.

6 Stereo Vision

The core of most systems is twin cameras for binocular vision. Much like your own eyes, two cameras are needed to assist with depth perception. It then needs to communicate with a central brain that recognizes and processes what is seen so that drivers or automated systems can respond. Don’t underestimate that brain function. According to IEEE Spectrum, “a premium-class automobile runs 100 million lines of computer code, more than Boeing’s new 787 Dreamliner.”

7 GPS/Inertial Measurement

Obviously, any automated-driver needs a map to follow and it needs to know where it at on that map. Most of us take GPS for granted these days, but really knowing exactly where you are on the planet is a must for a system trying to navigate to a destination.

Tech. Comparison

The list of technology below goes by specific brand names and represents unique approaches to the needs of an autonomous driving system, which in turn creates some variance in capabilities. However, a certain uniformity of function can be observed which we’ll try to list first.

All four cars tested had some form of adaptive cruise control, which responds to objects in its path and allows for an auto-follow function in thick traffic. The technology has been out for a few years and it works like a charm on all four cars.

How the Tech. Differs

We also wanted to note what sets these cars apart from each other, aside from simple effectiveness.

mercedes-1422819_1920The Infiniti Q50 seems to hold the steering wheel straight when steering for you and allows several features to be active, like active lane control, even if the car isn’t in a self-driving mode.

The Mercedes S65 only drives for you for 12 seconds at a time. You can tug the wheel either direction and reset the clock.

The BMW 750i begins warning you to put your hands back on the wheel after 3 seconds and the controls to engage the functions are more easily accessible on the steering wheel than other systems.

We had reports that the Tesla Model S would allow you to drive completely hands-free (with a warning that the law requires you to have your hands on the wheel) but the Model S we test drove light up with warnings every time you took either hand off the wheel. The “stalk” between the steering wheel and the turn signal isn’t the easiest way to engage the functionality and it relies on the driver to learn a few different commands to engage different functions. Adjust cruise control up or down by moving it up or down, engage auto-steer with two quick pulls toward you, maintain interval to a car ahead by twisting the switch on the end of the stalk. Bottom line if you’re not going a distance, it’s not worth doing the hokie pokie to engage it.

Head to Head Comparison

The four production vehicles that currently claim a form of autonomous driving capability are:

Andy_Self driving Car_update_Tesla

Tesla Model S – 1 camera, 1 radar sensor, 12 ultrasonic sensors provide Autopilot, Autosteer, Auto Lane Change, Autopark, Traffic-Aware Cruise Control.

Andy_Self driving Car_Update_BMW

BMW 750i – Uses 1 stereo camera and 5 radar sources to provide what they call Active Driving Assistance Plus & Driver Assistance Plus.

Andy_Self driving Car_Update_infinit

Infiniti Q50S – 1 camera and 1 radar source to provide Intelligent Cruise Control, Predictive Forward Collision Warning, Forward Emergency Braking, Lane Departure Warning/Prevention, Active Lane Control.

Andy_Self driving Car_Update_Mercedes

Mercedes-Benz S65 AMG – 1 camera and 5 radar sources to provide Distronic Plus with Steering Assist, Adaptive Brake Technology, Active Lane-Keeping Assist.

Summary Chart
Tesla Model S 1 camera, 1 radar sensor,12 ultrasonic sensors Autopilot, Autosteer, Auto Lane Change, Autopark, Traffic-Aware Cruise Control
BMW 750i 1 stereo camera and 5 radar sources Active Driving Assistance Plus & Driver Assistance Plus
Infiniti Q50S 1 camera and 1 radar source Intelligent Cruise Control, Predictive Forward Collision Warning, Forward Emergency Braking, Lane Departure Warning/Prevention, Active Lane Control
Mercedes-Benz S65 AMG 1 camera and 5 radar sources Distronic Plus with Steering Assist, Adaptive Brake Technology, Active Lane-Keeping Assist

According to Car and Driver head to head testing over a 50-mile course with a variety of road and weather conditions the “winner” was Tesla Model S, with around half the lane violations of any of the other cars. In order from least to most lane violations Tesla had 29, BMW had 56, Mercedes had 58 and Infiniti had a whopping 96. Perhaps worth noting is the Tesla price tag at $136,000 compared to the Infiniti at a mere $54,000. The Beemer was comparably priced to the Tesla while the Mercedes cost as much as a three bedroom, two bathroom ranch style house. Literally!

Car Lane Violations Price of Car Tested
Tesla 29 $136,000
BMW 56 $129,000
Mercedes 59 $253,000
Infiniti 96 $54,000


Three things we haven’t really mentioned yet:

When an autonomous car does make a mistake, say run a red light, who gets the ticket?
Will car manufacturers actually get these things to market given that they could be sued for mistakes?
The number of disabled people who could become drivers.

If you have any information on those three topics we’d love to hear from you on this site or on our FaceBook page.

For more on Elon Musk the brain behind the Tesla here’s a TED Talk from the man himself.

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