Adaptive Cruise Control and Traffic-Jam Assistants

Lock on to cars with radar, but switch to other sensors in traffic

3 min read
Adaptive Cruise Control and Traffic-Jam Assistants
Illustration: mckibillo

On the A-1 highway north of Madrid, Ford Spain’s press fleet manager, Eusebio Ruiz, locks his car’s radar onto another vehicle perhaps 75 meters ahead. An outline of the car appears on the dashboard with a few red bars behind it indicating the target distance. Deep memories of the film Top Gun and years of flight-simulator play kick in, and I reach for the joystick to arm my Sidewinder missiles. But the Ford Kuga is armed with neither Sidewinders nor a joystick. I sigh, click my pen, and continue taking notes as Ruiz fiddles with buttons on the steering wheel.

“If you want to have fun, you bring this in,” he says, until our car, with no footwork on his part, closes the distance to a few, more Madrid-like car lengths and then holds steady. Ruiz was demonstrating a technology Ford calls adaptive cruise control (also known as autonomous cruise control, with the same handy acronym of ACC). Like traditional cruise control, ACC requires drivers to select a target speed and throttles the engine to achieve it. But ACC also uses sensors, once lasers but now mostly radar (See “Keeping Cars From Crashing,” 3 September 2001, and “Long-Distance Car Radar,” 29 September 2011 in IEEE Spectrum), to adapt the target speed to that of slower-moving cars ahead.

Not long after Ruiz got us into formation with the car ahead, that driver changed lanes. Then we hit a hill and the engine revved in response to maintain speed. The latest commercial iterations of ACC could have anticipated that hill, using GPS data and a map, and adjusted the transmission ahead of time. They can also integrate data from cameras to read traffic signs and make smoother transitions ahead of zones with higher or lower speed limits. From a sensor and CPU standpoint, little distinguishes today’s front-runners—offered in Europe by Audi, BMW, and Mercedes-Benz—as the manufacturers share parts suppliers. They do, however, differ in how they program their ACCs and in how the car’s control systems respond to sensor information.

The differences may be more clear when driving at lower speeds, where just idling the engine or adjusting the transmission may not be a fast enough response to changing road conditions. Braking and steering behavior play a large role in how a car feels and may be an area where the carmakers can distinguish themselves, according to Audi spokesman Mark Dahncke. Both functions are crucial to the most-sophisticated driver assistance systems on the market today, called traffic-jam assistants or stop-and-go adaptive cruise control.

Traffic-jam assistants take over below 30 or 40 kilometers per hour (19 to 25 miles per hour), depending on the system. BMW’s X5, 5 Series, and 7 Series can also handle low-speed steering, which is more sophisticated than most so-called lane-keeping aids, which tend to nudge the wheel once before requiring drivers to take over again.

What has made traffic-jam assistants possible is not ACC radar improvement so much as the increasing sophistication of the cameras, image processors, and ultrasonic sensors first installed to aid parking. Most car radars have been tuned to detect relative motion, not stopped obstacles, and are sensitive to large, metallic objects. So carmakers hesitated to rely on them in slower-driving environments, where a pedestrian or other obstacle might appear. Cameras, on the other hand, feed image processors that are getting better and better at detecting pedestrians under a wider range of light and weather, as computer scientist Antonio M. López and colleagues at the Autonomous University of Barcelona are demonstrating.

Another problem carmakers had to overcome was a networking challenge: “It was a matter of how fast we were going to be able to send information between the different control modules, and of reliability,” says BMW spokesman Julian Arguelles. In Top Gun, Maverick said, “If you think, you’re dead,” in a dogfight. But in a traffic jam, a car that thinks for its driver may be just what it takes to escape the danger zone.

The Conversation (0)

Golf Robot Learns To Putt Like A Pro

Watch out Tiger Woods, Golfi has a mean short game

4 min read
Golf Robot Learns To Putt Like A Pro

While being able to drive the ball 300 yards might get the fans excited, a solid putting game is often what separates a golf champion from the journeymen. A robot built by German researchers is quickly becoming a master of this short game using a clever combination of classical control engineering and machine learning.

In golf tournaments, players often scout out the greens the day beforehand to think through how they are going to play their shots, says Annika Junker, a doctoral student at Paderborn University in Germany. So she and her colleagues decided to see if giving a robot similar capabilities could help it to sink a putt from anywhere on the green, without assistance from a human.

Keep Reading ↓Show less

Tickle Pill Bug Toes With These Haptic Microfingers

Balloon actuators and liquid metal sensors enable tactile human-insect interactions

4 min read
A gif showing a live pill bug on its back wiggling its body and feet as a very small robot hand touches it

All things considered, we humans are kind of big, which is very limiting to how we can comfortably interact with the world. The practical effect of this is that we tend to prioritize things that we can see and touch and otherwise directly experience, even if those things are only a small part of the world in which we live. A recent study conservatively estimates that there are 2.5 million ants for every one human on Earth. And that’s just ants. There are probably something like 7 million different species of terrestrial insects, and humans have only even noticed like 10 percent of them. The result of this disconnect is that when (for example) insect populations around the world start to crater, it takes us much longer to first notice, care, and act.

To give the small scale the attention that it deserves, we need a way of interacting with it. In a paper recently published in Scientific Reports, roboticists from Ritsumeikan University in Japan demonstrate a haptic teleoperation system that connects a human hand on one end with microfingers on the other, letting the user feel what it’s like to give a pill bug a tummy rub.

Keep Reading ↓Show less

Solving Automotive Design Challenges With Simulation

Learn about low-frequency electromagnetic simulations and see a live demonstration of COMSOL Multiphysics software

1 min read

The development of new hybrid and battery electric vehicles introduces numerous design challenges. Many of these challenges are static or low-frequency electromagnetic by nature, as the devices involved in such designs are much smaller than the operating wavelength. Examples include sensors (such as MEMS sensors), transformers, and motors. Many of these challenges include multiple physics. For instance, sensors activated by acoustic energy as well as heat transfer in electric motors and power electronics combine low-frequency electromagnetic simulations with acoustic and heat transfer simulations, respectively.

Multiphysics simulation makes it possible to account for such phenomena in designs and can provide design engineers with the tools needed for developing products more effectively and optimizing device performance.

Keep Reading ↓Show less