Getting road-trip ready, and no driver needed | Science News for Students

Getting road-trip ready, and no driver needed

New navigation system for self-driving cars uses laser sensors to ‘see’ its path
Jun 20, 2018 — 6:45 am EST
photo of a road through a car windshield

Laser sensors help a new type of driverless car stay on the road, even without detailed maps.

vvvita/iStockphoto

A new kind of navigation system could help self-driving cars hit the road and get out of town.

Cars that do not need a human driver are called autonomous (Aw-TAAH-nuh-muss). Controlled by computers, they navigate using detailed 3-D maps. Some companies are testing such cars in big cities. They use maps marking every curbside and off-ramp with almost centimeter-level precision. But few places have been mapped in such detail. The places that have not include smaller cities, towns and millions of miles of open road. That has left most areas off-limits to driverless cars. But not for long, if some researchers have their way.

Researchers at the Massachusetts Institute of Technology (MIT) in Cambridge asked: What if self-driving vehicles could get around another way? Intrigued by the challenge, they developed a new navigation system to guide autonomous vehicles without such detailed maps. This tech could help driverless cars drive almost anywhere.

The MIT team described its new system May 22 at the IEEE International Conference on Robotics and Automation in Brisbane, Australia.

The new system charts a course down unfamiliar roads much as a human driver would. It continually scans its surroundings to gauge how close it is to the edges of the road. Instead of human eyes, it uses a laser sensor. At the same time, the car follows GPS directions to its destination from a tool like a mapping app. Along the way, it notes traffic rules. These may include speed limits and the where stoplights exist.

Story continues below image.

autonomous car
A new kind of self-driving car navigation system that “sees” its surroundings with laser sensing can take riders off the beaten path.
MIT CSAIL

The MIT team test-drove a car equipped with this system on a one-lane road. The road wound through a forest in Devens, Mass. This remote location lacks those detailed maps, so other driverless cars would be lost here. The vehicle slowly cruised along a 1 kilometer (roughly half-mile) stretch of road without needing any human assistance. The researchers plan to build a version of this system to also spot lane markings painted on streets. That would allow the car to drive on roads with more lanes, Ort says.

Right now, the new system assumes that a car has a clear path down the road, notes Teddy Ort. He’s a roboticist at MIT who worked on the new system. But the new system could be paired with other computer programs that can sense obstacles. These might use lasers to detect in-road objects such as other vehicles or pedestrians. That should help the car navigate roads with heavier traffic.

The technology might be useful for future self-driving cars on cross-country road trips, says Raghvendra Cowlagi. This mechanical engineer at Worcester Polytechnic Institute, or WPI, in Massachusetts. Still, he warns, for weaving through city traffic even these vehicles would probably still need meticulous 3-D maps.

Alexander Wyglinski is an electrical and computer engineer at WPI. And like Cowlagi, he did not work on the new system. The new system may need other kinds of sensors to work in less than ideal conditions, he suspects. Laser sensors don’t work well in rain or snow, for instance. So these cars might need other technologies to navigate safely in bad weather.

Power Words

(for more about Power Words, click here)

3-D     Short for three-dimensional. This term is an adjective for something that has features that can be described in three dimensions — height, width and length. 

app     Short for application, or a computer program designed for a specific task.

autonomous vehicle     A driverless car, submarine, airplane or other autonomous vehicle. These pilot themselves based on instructions that have been programmed into their computer guidance system, but sometimes subject to reprogramming midway to their destination.

computer program     A set of instructions that a computer uses to perform some analysis or computation. The writing of these instructions is known as computer programming.

engineer     A person who uses science to solve problems. As a verb, to engineer means to design a device, material or process that will solve some problem or unmet need.

gauge     A device to measure the size or volume of something. For instance, tide gauges track the ever-changing height of coastal water levels throughout the day. Or any system or event that can be used to estimate the size or magnitude of something else. (v. to gauge) The act of measuring or estimating the size of something.

GPS     Abbreviation for global positioning system, it uses a device to calculate the position of individuals or things (in terms of latitude, longitude and elevation — or altitude) from any place on the ground or in the air. The device does this by comparing how long it takes signals from different satellites to reach it.

laser     A device that generates an intense beam of coherent light of a single color. Lasers are used in drilling and cutting, alignment and guidance, in data storage and in surgery.

mechanical engineering     A research field in which people use physics to study motion and the properties of materials to design, build and/or test devices.

navigate     To find one’s way through a landscape using visual cues, sensory information (like scents), magnetic information (like an internal compass) or other techniques.

roboticist     Someone who designs or builds robots.

self-driving car     Also known as a driverless car or autonomous vehicle. These cars pilot themselves based on instructions that have been programmed into their computer guidance system.

sensor     A device that picks up information on physical or chemical conditions — such as temperature, barometric pressure, salinity, humidity, pH, light intensity or radiation — and stores or broadcasts that information. Scientists and engineers often rely on sensors to inform them of conditions that may change over time or that exist far from where a researcher can measure them directly. . (in biology) The structure that an organism uses to sense attributes of its environment, such as heat, winds, chemicals, moisture, trauma or an attack by predators.

Citation

Meeting: T. Ort et al. Autonomous vehicle navigation in rural environments without detailed prior maps. IEEE International Conference on Robotics and Automation, Brisbane, Australia, May 22, 2018.