Introduce the Development and Application of Radar for You

With the rapid development of science and technology, lidar technology has been constantly developed and upgraded. With the advent of the era of artificial intelligence, radar has been widely used in high-tech fields such as autonomous driving, robotics, security monitoring, unmanned aerial vehicles, mapping, Internet of things, and smart cities. There are various forms of lidar. With the update of device level and manufacturing level, the technical indexes and methods of radar are constantly upgraded.

Radar technology can be divided into spaceborne, airborne, vehicle-borne and stationary radar systems according to different carriers. The satellite-borne and airborne lidar systems, combined with satellite positioning, inertial navigation, photography and remote sensing technologies, can acquire a large range of digital surface model data. The vehicle-mounted system can be used to acquire 3d data on roads, Bridges, tunnels and large buildings. Stationary lidar system is often used for accurate scanning and measurement of small area and 3d model data acquisition.

First, the development of laser radar sensing technology

The research and development of foreign lidar technology started earlier, as early as the 1960s, people began to carry out laser ranging test; In the 1970s, laser altimeter technology was used in the Apollo moon landing program of the United States. In the 1980s, lidar technology developed rapidly, and a reliable lidar measurement sensor was developed to obtain high-resolution geographic information on the surface of the planet. In short, the emergence of lidar technology provides a new technical means for the acquisition of spatial information, which makes the acquisition of spatial information more automatic and more efficient. The development of this technology also brings a revolutionary challenge to the traditional measurement technology.

Second, the application of laser radar sensing technology

According to the survey, most companies are focusing on unmanned vehicles, robots and laser radar in the field of unmanned vehicles. However, the traditional mechanical lidar has gradually changed to the solid-state lidar. In terms of price, the lidar in the unmanned field is less than tens of thousands of yuan, more than hundreds of thousands of yuan, generally higher than the price of robots and AGV and other fields. In the future, solid state, small, low cost lidar will be the focus of enterprises. With the in-depth study of lidar technology in the international community, the superiority of this new technology is more and more obvious, and has its unique advantages in various industries. The leading technologies in the main application areas are listed below.

1. Autonomous driving

Lidar and cameras have been regarded as the core sensors for autonomous driving due to their excellent imaging capabilities. The advantage of lidar compared to a camera is that it can get accurate three-dimensional information, and it is an active source of light, so it can work day and night without being affected by light. Camera recognition is relatively high granularity, can obtain rich texture color, so it can achieve fine recognition, in this point, lidar is inferior to the camera.

The biggest disadvantage of the camera is that it is greatly affected by the ambient light, and it is difficult to carry out effective and reliable environmental perception of the collected data through algorithms in situations such as strong light irradiation, highlighting anti-white objects, and weak light environment at night.

Lidar is a laser active detection imaging, not affected by ambient light, directly measure the range of the object azimuth, depth information, reflectivity, etc. The algorithm firstly identifies the obstacles and then classifies them. The accuracy and reliability of the algorithm are much higher than that of the camera, but the computational resource consumption is lower than that of the camera. It can be said that the most important part of the application of laser radar in automatic driving is high-precision positioning. Only when the automatic driving vehicle determines its own position can it face the problem of "where to go". So, identifying "where I am" is the first and crucial step. According to conventional understanding, positioning should only be the task of GPS. Indeed, GPS will be used in the positioning of autonomous driving, but the accuracy of GPS positioning is insufficient, and the signal stability is poor in the case of high-rise buildings or entering and leaving tunnels, so it is difficult to ensure the safety of autonomous driving vehicles. Therefore, automatic driving positioning needs to be combined with laser radar, GPS, IMU, etc., in order to complete stable and reliable high-precision positioning.

Radar hardware, combined with AI sensing algorithm developed for autonomous driving, can complete the identification of obstacles around, detect the road edge, high-precision positioning and other tasks, but also to achieve classification labeling, obstacles into trucks, cars, pedestrians, bicycles and so on.

2, security field

With the rapid development of the security field in China, the security system is becoming more and more integrated, multi-functional and intelligent. The traditional single camera mode has been unable to fully meet the requirements of the increasingly complicated, diversified and multi-functional security environment. Compared with the traditional security monitoring system, the security scheme based on lidar can not only meet the basic protection and alarm function of customers, but also enhance the deep needs of customers, and has greater advantages.

In recent years, the rapid development of laser radar technology, technology from a simple laser ranging technology, gradually developed laser tracking, laser velocimetry, laser scanning imaging, laser Doppler imaging and other technologies. Its working environment also from the initial visible light region (ruby laser), to the near infrared region (Nd: YAG laser), and then the infrared region (CO2 laser), and now many lidar work in the near infrared region (0.76 ~ 1.5 μm) which is harmless to human eyes. As a result, lidar has emerged for many different purposes, such as precision tracking lidar, detection lidar, underwater lidar, etc., so that lidar has become a kind of system with many functions.

3. Smart transportation

As the population of big cities continues to grow, the traffic in cities is becoming more crowded, which requires more "smart" transportation in the future. The rapid development of the Internet of Things, sensors and artificial intelligence has made this a reality. Information technology, sensing technology, communication technology and other technologies are widely used in the field of transportation. Laser radar has place in many places, for example in the millimeter wave radar can accurately detect lanes and ms data, the detection is microcosmic, but also the real-time and accurate, can be used for instant induction signal control machine control, adaptive control and green wave band, is the basis for the future to realize car networking way together.

4. Robotics

As robots go deep into people's lives, such as factories, warehouses, hotels, shopping malls, restaurants and other environments, people pay more attention to the mobility of robots, and the market demand for intelligent equipment is rising. So that obstacle avoidance becomes a critical and necessary function. Obstacle avoidance refers to that mobile robots can effectively avoid obstacles according to certain methods when they perceive static and dynamic objects obstructing their passage through lidar sensors in the process of walking according to the state information of obstacles collected and finally reach the target point. The necessary condition for obstacle avoidance and navigation is environmental perception. In unknown or partially unknown environment, obstacle avoidance needs to obtain the surrounding environment information through lidar sensor, including the size, shape and position of obstacles, so sensor technology plays a very important role in mobile robot obstacle avoidance.

5. VR/AR

VR/AR is also hot in recent years, the market prospect is considerable. VR all-in-one machine, smart glasses and other products have hit the market, and AR glasses and AR head display are also widely used. In the games using AR head display, laser radar and many supporting optical sensors are used in the space sensing positioning technology. Through SLAM technology (real-time positioning and map construction), the precise positioning of oneself in the three-dimensional space can enhance the real experience in the game.

6. 3D printing

In recent years, 3D printing has attracted much attention. It is a technology that builds objects layer by layer using adhesive materials such as powdered metal or plastic, based on digital model files. As a pioneering and pioneering intelligent manufacturing technology, 3D printing will lead the transformation of traditional production methods and production processes, and is expected to become the source power to promote a new round of industrial revolution.

In 3D printing, lidar is also useful. For example, the recently popular PrintopTIcal3D printing technology is essentially a one-stop technology "from CAD design to optical parts", and the printed optical parts do not need post-processing such as polishing, grinding and coloring. Based on mature, wide-format industrial inkjet printing equipment, the technology is sprayed with transparent polymer droplets that are cured by a strong UV lamp integrated into the print head, resulting in a variety of geometric shapes in which lidar is used to measure, monitor and so on.

Third, the prospect of laser radar sensing technology

The development of the laser radar technology to obtain high space-time resolution of earth space information provides a new technical method, make people from the traditional single point data acquisition is a continuous automatic data acquisition, and can quickly get accurate high resolution digital terrain model and the ground three-dimensional coordinates of the object, with features of the image at the same time, enhance the capacity of understanding and recognition of features, It has broad development prospect and application demand in all fields of social construction. Currently, more and more users are taking a keen interest in using lidar technology, indicating a strong market demand for this technology.