Most autonomous vehicles test-driving in cities navigate (导航) by using 3-D maps marking every edge of roadside with almost centimeter-level accuracy. But few places have been mapped in such detail, which has left most areas like smaller towns inaccessible to those driverless cars.

Researchers at the Massachusetts Institute of Technology (MIT) now have developed a new navigation system that guides autonomous vehicles without such accurate maps. This technology can help driverless cars travel almost anywhere.

The navigation system maps out a course down unfamiliar roads much as a human driver would by continually scanning its surroundings, with a laser sensor (激光感应器), to measure   how close it is to the edges of the road. Meanwhile, the car also follows a tool like a smart phone map app that provides directions to its destination, as well as information about the rules of the road, such as speed limits and the positions of stoplights. Teddy Ort, a roboticist at MIT, test-drove a car equipped with this navigation system on a one-way road. It slowly traveled one kilometer without any human assistance.

This system assumes that a car has a clear path down the road, but it can be paired with other existing computing technology to discover in-road obstacles (障碍), says Ort. The researchers also plan to build a version of this system which can spot markings painted on streets, so that the car can drive on two-way roads. "Self-driving cars with this navigation system may need other sensors to work in different conditions,” Alexander Wyglinski, and electrical engineer at Worcester Polytechnic Institute. "Since laser sensors don’t work well in rain or snow,   these cars might need additional imaging technologies to drive safely in bad weather. "

Edison and Popular Culture

Whenever we play music or go to the movies, we enjoy the benefits of Thomas Edison’s genius and hard work. Although Edison is perhaps most famous for his light bulb, his inventions in sound recording and motion pictures has contributed to entertainment industry.

After his successful development of the first phonograph in 1877, Edison and his researchers made countless improvements to the phonograph (留声机) striving for the finest sound reproduction possible. 【小题1】 What the public really wanted, however, was a machine to play music. Recognizing the biggest market for the phonograph, Edison began producing musical records in the early 1890s. However scratchy and rough those early records seemed, they were amazing to buyers who were hearing recorded sound for the very first time. The development of records, cassette tapes and finally digital music traces back to Edison’s early experiments with sound recording.

【小题2】 In October 1888, Edison intended to do “for the Eye what the phonograph does for the Ear, which is the recording and reproduction of things in motion.” Thus began Edison’s development of the kinetograph (motion picture camera) and kinetoscope (motion picture viewer).

Over the next years, Edison experimented with the making of motion pictures, constructing the Black Maria, the world’s first structure especially built to be a motion picture studio. The first motion pictures were not projected on a theater screen. 【小题3】 For a 5-cent coin, viewers could look through the peephole (窥孔) to see Blacksmith Scene, or the Barbershop. Although the first films lasted less than a minute, they excited audiences as much as any film seen today.

The first films were silent, but in 1895 Edison attempted to combine sound recording and motion pictures in a device he called the kinetophone. Unfortunately, this early effort at talking motion pictures proved unsuccessful. More than thirty years would pass before sound films would become widespread.

Edison wanted to invent things to improve the lives of all people, whether it was electric light bulbs to light their homes or phonographs and motion pictures to inspire their imagination. Every time we turn on a light switch or watch movie, we enjoy the gift of Edison’s genius. But true genius, said Edison, relies on “hard work, stick-to-initiativeness, and common sense”. 【小题4】

Robots have long been drawing inspiration from animals, with the creation of robot dogs or snake-shaped robots. And yet, the field of robotics is far less enthusiastic about the other kind of living things — plants. Barbara Mazzolai, an Italian roboticist owes this to a misconception about plant behavior: that they cannot move or think. “It’s not true at all,” she says. To challenge this view, Dr Mazzolai and her team recently launched a machine called “FiloBot”, a robot based on a climbing species.

To survive, a climbing plant must switch between several different behaviors. In forest environments, it must first grow out of the soil and travel along the ground in search of a support to hold onto, such as a nearby tree. Once a support is located, though, the plant fixes itself around the object and then growing towards the light. To choose the best angle to grow upwards, a climbing plant uses its shoots (芽) to receive information about light and gravity.

FiloBot has sensors on its main shoot. It can 3D-print its body with plastic and grow at a controllable rate. These functions, researchers found, enabled FiloBot to cross gaps, and find things to attach to. The lack of heavy on-board computing device means that it is light and requires minimal care, while its slow pace means that it doesn’t disturb things around it, making it possible to move through a complex, unseen environment, or monitoring disaster sites.

For now, FiloBot is still being tested. Its tendrils (卷须) have not left the laboratory. Still, it has already been employed in deconstructing plant behaviour. For example, it was long assumed that climbing plants find their supports by growing towards shade, though the exact mechanism was unclear. FiloBot could imitate this behaviour by detecting far-red light, which is typical of shaded areas, providing clues to how plants do it.

Dr Mazzolai hopes that such projects will inspire other roboticists to take their cues from plants and develop completely new technologies.