What is the hottest topic in today's car circle? The automatic driving station came out to be called the second, but it is really not obvious who would dare to claim to be the first.
Regardless of the driver-assisted system (ADAS) of the traditional car company, or the unmanned car field that Internet giants such as Google expect to share, the principles are basically the same.
Autopilot is like walking on a pedestrian. We first use the eye to observe the route, and then the brain gives us instructions. For the car, various radars, cameras and other sensors are the eyes of the car, the electronic circuit is the central nervous system, and the control system such as chips and algorithms is the brain, which ultimately determines the direction and speed of the car. The "eyes" play a very important role: collecting first-hand data for analysis and judgment.
In these "eyes", the camera is relatively simple. Its advantages are outstanding: high precision, long distance, intuitive and convenient; but the shortcomings are also outstanding: too much impact from the weather. If the smog comes, or if it is rainy, it is estimated that only two eyes will be black.
The on-board radar has outstanding features and advantages. They have higher real-time, accuracy and reliability than ultrasound detectors and computer vision equipment. Among them, the main research focuses on millimeter wave radar and laser radar.
â–Ž Millimeter wave radar - weather-proof, all-weather serviceThe millimeter wave refers to an electromagnetic wave with a wavelength between 1 and 10 mm, and the millimeter wave radar refers to a radar that operates in the millimeter wave band. The wavelength of the millimeter wave is between the centimeter wave and the light wave, so the millimeter wave has the advantages of microwave guidance and photoelectric guidance. When used in a car, it has strong resistance to environmental disturbances and can meet the vehicle's requirements for weatherability throughout the day. And the characteristics of the millimeter wave itself determine the small size and light weight of the millimeter wave radar sensor device, which makes up for the shortcomings of the sensor such as the camera, which makes it have great advantages in the vehicle application.
At present, the mainstream automotive millimeter wave radar frequency band at home and abroad is 24 GHz (for short to medium range radar, 15-30 meters) and 77 GHz (for long range radar, 100-200 meters). Such applications have become popular in Europe, the United States and Japan. At present, almost all cars in these regions are equipped with automotive millimeter-wave radar sensors, including automobile collision avoidance radars and vehicle blind zone detection radars.
The most common of the ordinary radars is the millimeter-wave radar, but even so, there are still features of low precision and short visible range. These two defects are placed in autonomous driving, but the difference is a thousand miles, which is very easy to cause an accident. So in this context, the upgraded version came into being - Lidar.
â–ŽLaser - accurate safety protectionLidar, also called Lidar, is a collection of lasers and radars. In fact, everyone is not unfamiliar with it. When many unmanned cars are driving on the road, there will be a "small jar" on the roof that looks like a camera, but will always rotate within a certain angle. Usually it is a laser radar.
Lidar is generally divided into two types: pulsed and continuous wave. Pulsed lidar uses time interval to calculate relative distance; while continuous wave lidar calculates the target distance by calculating the phase difference between reflected and reflected light. Specifically, the technical point of the laser radar is: TOF (TIme of Flight). When the radar emits laser light, it will turn back when encountering obstacles. The returned beam will be analyzed by the radar internal receiver, and finally processed by the processor through the turn-back time and measurement signal, thus generating accurate 3D maps, surrounding the The environmental characteristics are re-reduced.
For example, millimeter-wave radar can find roadside obstacles, but can only “see†the fuzzy shape, while the centimeter-accurate laser radar can clearly distinguish whether the obstacle is a shoulder or a slope in a very short time, if automatic After driving the car to determine that it is a slope, you can make a safe decision to drive the lane. This accuracy is closer to 100% safer for self-driving cars on the road.
Then maybe a lot of people will ask, why don't we go to develop a full laser radar? In fact, the reason is very simple, a word, expensive! For example, Google uses a laser radar produced by Velodyne, USA. The 64-line is 80,000 US dollars and the 32-line is 40,000 US dollars. It is necessary to know that the price of an Audi TT and BMW Z4 is only more than 40,000 US dollars. A radar can even buy a GTR (of course in the US). If it is to be used in mass production, what is the cost?
Therefore, compared with millimeter-wave radar, lidar has a long and short duration. For the various types of sensors used in cars, the table below gives a more intuitive comparison:
However, it is difficult for thousands of people to withstand the hard-working hands and wisdom of the working people. Since autonomous driving is the trend of the times, and laser radar as a core component of the "eyes", it is imperative to reduce costs. One of the main solutions is "solid state." The explanation of this concept can be compared with the SSD of the mechanical hard disk: the internal mechanism of the mechanical hard disk is based on mechanical rotation to read and write data, which is bulky and cumbersome; while the solid state hard disk has no mechanical rotating parts inside, so the volume is small and stable. Therefore, "solid-state" laser radar can also be understood as a laser radar based on electronic components and without mechanical rotating components.
Founded in 2012, the laser radar start-up Quanergy is one of the pioneers of solid-state laser radar. The company released "the world's first solid-state laser radar for autonomous vehicles" at the CES Consumer Electronics Show in early 16th, and plans to cut the price of lidar products to around $250 in the future; Innoviz from Israel plans to be in the year. The prototype is enhanced, and in 2018 it is expected to begin production of a $100 solid-state laser radar designed for autonomous vehicles.
Many of these laser radar startups have sprung up, and such developments will exist for a long time. In particular, the market's growing demand for low-cost, high-performance products will help accelerate lasers. The radar will soon achieve the goal of commercial mass production. In the future, the market will be full of flowers, and the laser radar and millimeter wave radar will be shorter than each other to better protect the driving safety.
So how far is the automatic driving from us after polishing the "eye of the car"? Maybe there will be an answer soon.
USB 2.0 Printer Cable,USB 2.0 Cable,USB 2.0 Harness,USB Extension Cable
Dong guan Sum Wai Electronic Co,. Ltd. , https://www.sw-cables.com