# 英国论文代写-飞行距离测量时间

在本篇英国论文代写-飞行距离测量时间中，最重要的激光传感器是激光扫描仪和激光探测与测距(LIDAR)。激光传感器是那些工作在发射光波脉冲的电磁波。近红外光谱的波长为800-950nm，紫外光谱的波长为1500 nm (Yenkanchi, 2016)。当汽车运动时，物体之间的距离由飞行时间信息来计算，飞行时间信息负责计算接收到的脉冲和发射出的脉冲之间的差。这些类型的传感器能够检测多个对象。然而，这些传感器也有一些缺点，比如它们对变化的天气很敏感，而且对灰尘也很敏感。如果镜头被灰尘覆盖，它们就不能很好地反射目标物。然而，一些重要的功能，如消除事故，碰撞缓解和自动停车是很少的例子。接下来有关英国论文代写-飞行距离测量时间分析如下：

For the appropriate road safety and guidance, it is very significant that acquisition of all the objects on and around the road should be clear. Therefore, good lighting conditions are very important (Petit et al., 2015).

Laser works as the 2D range scanner for the detection of the obstacle. However, the desired ranges are not received with 2D scanner, so 3D laser scanner is very significant. The stopping distance for an autonomous vehicle to stop before the hit and detecting the object is also called as the look ahead distance. For measuring the distance, the appropriate knowledge of the truck and sensor is important. The stopping distance is measured as:

S = 1.1 · (Vmax · (t1 + t2) + B) + ZM + F

S is the maximum stopping distance and Vmax is the maximum speed of the vehicle that is the reaction time for the sensor, while t2 is the reaction time for the vehicle. B is considered as the maximum braking distance, ZM is the maximum measuring error and F is considered as the foot clearance. The braking distance of the sensor is affected by t1. With the increasing speed of the vehicle, the reaction time becomes more important for the purpose of maximum measuring error. However, in the 3D laser sensors, the range data is obtained through time-of-flight (TOF). The active sensors emit the energy and measure the time that energy takes to reflect. To calculate the distance in this case, velocity is used. Since velocity is called as energy, the distance is calculated as

Z = v . ∆t / 2

Here v is the velocity and ∆t is the elapsed time that is required by the energy to return to the sensor. This time of flight is used with the lidar (Light Detection and Ranging), as well as with radar sensors (Radio Detection and Ranging). One significant advantage of the radar sensor is that the velocity of the object is calculated easily, and directly. It is done with the help of the frequency shift that are created between the emitted signal and the Doppler echo (Meinel, 2014). Therefore, in the driverless cars, the radar sensors can help in detecting the velocity and the range of the object and the obstacles (Luettel, Himmelsbach&Wuensche, 2012).