Google, which has just established an independent company, Waymo, has a large number of competitors, and the self-driving cars of various companies are constantly experimenting on the road. After a successful trial run in Pittsburgh, Uber launched its "self-driving car" project in San Francisco on December 14th, and the decision quickly fell into the controversy of the regulations - Uber has not yet got an unmanned car License. But Uber insists that this is unnecessary because every car currently in operation has an alternate driver ready to take over control in times of danger (December 22, Uber's 16 unmanned vehicles in San Francisco are locally managed) The bureau ordered that the operation be stopped.) GM has just announced that they are conducting autonomous car testing in Michigan. One of these things is especially important for these test vehicles: the car handling system needs to have a reliable vision.
At present, no artificial system can compete with human eyes and brain, and developers must find a compromise solution. That's why engineers are using huge struts and drum kits to carry sensors for scanning road conditions. In the presence of multiple sensors, if one sensor does not detect a dangerous situation (such as a moving car or a pedestrian crossing the road), other sensors can detect it and issue an instruction to the vehicle to evade.
Current autonomous vehicles primarily use three sensing systems - cameras, ultrasonic detectors and radar - which are inexpensive and easy to deploy. The fourth way: Lidar, using laser scanning and ranging to establish a detailed three-dimensional model of the surrounding environment of the vehicle. The Lidar image is highly accurate, which makes it comparable to the first three sensor methods. However, the laser sensor is facing an oversized problem (see the roof of Google's self-driving car, Uber is the same). At the same time, its mechanical structure is very complicated, and the cost is comparable to the car body that carries the system.
Currently, some manufacturers are developing smaller, cheaper lidar systems. One of the most promising is a miniaturized design based on silicon chips. Its prototype has been delivered to major auto parts suppliers (such as Delphi He ZF) to start production. If all goes well, the laser radar chip will appear on the production car within three years.
Abandon the old method
Bringing a new generation of miniature laser radar lidar is Infineon, a German chip manufacturer. This company is one of the largest manufacturers of radar detector chips. The radar works by transmitting a radio pulse and accepting the reflected signal, and the time delay between transmitting and receiving the reflection is used to calculate the distance between the detected object and the object being detected. If the object is a moving object, its velocity can also be determined (via the Doppler effect).
15 years ago, radar sensors were a device that needed to be customized, priced at about $3,000 each. Infineon has developed a new approach that uses the silicon manufacturing process common in the semiconductor industry and integrates many of the radar's functions on a single chip to improve performance. This design has caused the price of sensors to drop rapidly to a few hundred dollars. Radar chips are not only an important part of autonomous vehicles, but have also been increasingly used in conventional vehicles to provide safety configurations such as automatic emergency braking.
Lidar has a similar history as traditional laser radar. Lidar was invented after the laser was put into practical use in the 1960s. It measures the distance to an object by scanning a specific area with a laser beam and then receiving light reflection. Since light has a shorter wavelength than radio waves, it is easily reflected by small objects, and the laser radar can detect objects that are missed by the radar. Lidar is being widely used for map mapping, measuring atmospheric conditions, and scanning accidents and crime scenes.
Typically, lidars use a rotating mirror to direct their laser beam, emitting a beam of light in the near-infrared portion of the spectrum that is invisible to humans. Commercial laser radars can cost around $50,000 and are currently the best-selling, but smaller, lower-power versions are priced at about $10,000. Many laser radar manufacturers, such as Velodyne of California, are trying to develop so-called "solid-state" lidars, a more compact version that eliminates all moving parts. Some researchers are trying to use laser scintillation instead of a constant bright beam and capture the reflection using a miniature sensor array on the chip.
Infineon has its own unique ideas, using different types of emitters and using microelectromechanical systems (MEMS). This special MEMS was developed by Innoluce, a Dutch company acquired by Infineon in October 2016. The device consists of an elliptical mirror measuring 3mm & TImes; 4mm, which is integrated on the silicon chip. The mirror is connected to the actuator to change the direction of the laser beam. Infineon said the design allows the laser to use full-power centralized scanning while it uses a scintillation system.
"MEMS lidar can collect 5,000 data points per second and can scan as far as 250 meters," said Ralf Bornefeld, head of Induction's automotive sensing and control division. Although the device still has mirrors, lidar has the same reliability as other silicon chips. In the case of mass production (eg attached to the windshield), MEMS lidar can cost less than $250 at the car manufacturer's end. These small laser radars can also be used in other applications such as robots and drones.
Many engineers, including Bornefeld, believe that future autonomous vehicles will use multiple miniature lidars, ordinary radars, ultrasonic sensors and cameras to form an array. "Every sensor system has its own advantages and disadvantages," says Bornefeld. "Efficiently integrate them to provide safety for autonomous vehicles."
Radar can accurately measure distance and speed, and work in dark or dense fog environment - the camera can not get valid information, but the radar produces images that are not fine enough to be classified by computer systems. On the other hand, some materials (such as rubber) will absorb rather than reflect the radar wave, so that the radar can not detect, causing security risks, then the advantages of the camera will appear. The camera captures high-resolution images for analysis by artificial intelligence software and then applies image recognition technology to identify objects that need to be avoided. Lidar has the ability to detect small objects in the dark and collect high-resolution images, but may not penetrate dense fog. Ultrasonic detectors will still work in future driverless cars, and this inexpensive detection device can be used to make parking sensors.
Google, Uber and most car manufacturers want to apply lidar as soon as possible, so they are very happy to see new developments in these technologies. But not everyone is embracing the lidar, and Elon Musk and his Tesla gave up the technology. Musk believes that the performance of the camera, radar and ultrasonic sensor systems installed on Tesla vehicles is rapidly increasing and there is no need to introduce other equipment.
See more
Elon Musk may soon change his mind. In May of this year, a Tesla owner crashed into a container truck and eventually died while using the automatic driving mode. Although current autonomous driving equipment requires the driver to put his hands on the steering wheel and look at the road with both eyes (this is also the case with the ready drivers on Google Waymo and Uber self-driving cars), but in this accident, Tesla’s Neither the camera nor the radar found the container truck in front of it - it was painted white and almost integrated into the sky at the time. Perhaps the system recognized the container truck as something else, such as a traffic sign across the head. In this case, will lidar get the correct information? No one will ever know. But as more and more driverless cars venture on the road, having more drum kits and probes will always give passengers more peace of mind.
Pickleball is a mix of tennis, table tennis and badminton, usually played on outdoor courts. It can be divided into the following categories:
1. Amateur and Professional competitions: Pickleball has active amateur and professional competitions, including competitions at all levels, from beginners to professionals.
2. Doubles and Singles: Pickleball can play doubles and singles, doubles is the most common form of play, but there are some people who prefer to play singles.
3. Age and Gender Categories: Pickleball competitions are usually grouped according to the age and gender of participants to ensure fair competition.
4. Leisure and fitness activities: In addition to competitions, many people also enjoy playing Pickleball in leisure situations as a fitness activity and social entertainment.
Overall, Pickleball can be categorized according to the level, purpose and age of the participants to meet the needs and interests of different populations.
Nantong Boxin Electronic Technology Co., Ltd. , https://www.ntbosen.com