News Center
There are many lidar parameters, what should we pay attention?
Release time:
2021-07-23
① Angle resolution, that is, angle measurement accuracy.
Angular resolution is the ability of the scanner to resolve the target. The smaller the angular resolution, the smaller the target can be resolved, and the finer the measured point cloud data. Generally, the angle measurement accuracy of the obstacle avoidance laser sensor is only about 0.1 °, while the angle resolution of the mapping laser sensor is generally 0.001 ° or even lower.
② Measuring distance
The measurement distance is related to the laser emission frequency and the reflectivity of the actual ground object. The maximum measurement distance is related to the reflectivity, and the reflectivity generally refers to the maximum scanning distance under the condition of ρ≧ 60% (some even reach ρ≧ 90%). At the same time, the measurement distance is inversely proportional to the laser emission frequency. The greater the transmission frequency, the smaller the measurement distance.
Different objects (hillsides, vegetation, cement buildings, metal pipes, soil minerals, coal, etc.) with different reflectivity. The reflectivity of most buildings is about 50%, and the reflectivity of coal asphalt pavement is about 20%. Therefore, in practical applications, we must discount the maximum range of equipment.
③ Measuring speed
It is generally reflected by the maximum emission frequency of the laser pulse. For example, RIEGL's VUX-1 unmanned aerial vehicle has a maximum laser emission frequency of 550,000 points/second, while mini's VUX-1 unmanned aerial vehicle has a maximum laser emission frequency of 100,000 points/second.
④ Measurement accuracy
Refers to the true value obtained after measuring a certain amount, that is, the degree of agreement with the truth. Repeatability, also known as reproducibility or repeatability, is a quantity used to indicate the likelihood of obtaining the same result from multiple measurements. The measurement accuracy of the general surveying and mapping laser sensor is about 1cm.
⑤ Field of view
The field of view angle = the scanning angle of the laser beam refers to the maximum angle range that the laser beam can reach through the scanning device. The effective field of view angle is generally related to the altitude and effective measurement distance in the actual operation. Although the horizontal field of view of many laser sensors is 360 °, we usually only use 90 °-120 ° in practical applications.
Having said so much, what are the disadvantages of lidar?
1. Affected by weather and environment.
No matter which mode of laser radar works, due to the limitation of laser physical characteristics, laser sensors are greatly affected by environmental factors and cannot work stably and reliably in outdoor and smoke, dust, rain, snow, dust, strong light and other environments.
Two: expensive.
The price of industrial products is rational, its R & D cost is very high, and it can only be diluted through mass production. At present, the demand for lidar is not so great, which makes it difficult to reduce costs.
The other is marginal cost. Lidar is a high-precision machine, and the laser head that can be used for mapping is much more expensive than the obstacle avoidance level. It is not easy to make products, and the manufacturing cost itself is very high.
Although the lidar is not perfect at present, it is favored by many customers because it can transmit vegetation, directly measure the surface, and solve the problem of dense forest measurement. In the future, with the progress of technology and the increase of mass production, the problem of high cost can be effectively reduced. Although the laser radar is not perfect at present, the future can be expected!
Related News
Customer Service Hotline
E-mail:swzn@surertech.cn
Official website:http://www.surertech.cn
Address: 13-14 floors, Building 1, Software Valley Headquarters Economic Park, Yuhuatai District, Nanjing City, Jiangsu Province
Sweep the two-dimensional code
