3. Sensor required for Autonomous Driving
There are various sensors required for Autonomous Driving, but here I would like to introduce about the sensors necessary for Autonomous Driving of the car.
3-1 Sensor that grasps the position of the vehicle
Self-location estimation (control to estimate your own position) is important for automobile Autonomous Driving .
There are cameras and 3D-LiDAR that can acquire the distance and shape of the surroundings as a sensor to be used for that purpose.
In addition, GPS sensor may be used in the meaning of acquiring position information.
For this GPS sensor, sensors for outdoor use are common, but localization using GPS sensors is also possible indoors.
The GPS acquires multiple signals from the satellite and calculates the position, but the accuracy of the position information deteriorates in places where the satellite does not reach (inside the building or shade of the high building). Therefore, in indoor, a device that transmits signal information (latitude and longitude) of position information is installed on the ceiling, and a method of grasping indoor position is also used for indoor automation.
3-2 Sensor to monitor the surroundings
After an automobile or machine grasps its own position, what is around your vehicle is important to move autonomously. There are various sensors to monitor the surroundings, but below are representative sensors.
Currently, 3D-LiDAR can be cited as a sensor that is used in Autonomous Driving vehicles. This sensor is a sensor to measure the distance by skipping light. Although there is a difference in distance, if it says in person, is it an image that grasps the shapes and positions of surrounding objects and sees the surroundings by hand and moves it?
At the same time as this sensor is utilized in the above self location estimation, it judges the object recognition and the presence or absence of the object which estimated the shape from the information of the acquired point cloud.
The camera is applied to distance and object recognition using the image information. Because it hits the part of "eyes" that people say, I think that it is a sensor that is easy to image. The camera also has a monocular camera and a stereo camera.
Monocular cameras are used in the form of objects, white lines, and signal recognition. The stereo camera calculates the distance of the object ahead from the difference (disparity information) between the two cameras.
· Millimeter wave sensor
The millimeter wave sensor which is still mounted still transmits ultrasonic waves and detects the existence of objects ahead from the interference. It seems that it is possible to perform tracking by attaching the ID of the object with the algorithm inside the sensor.
Since the output of the car-mounted millimeter wave sensor is made with CAN, the data is light and easy to handle.
Millimeter wave sensor is not affected by bad visibility, so you can detect things even in bad weather such as rain, snow, dense fog.
· Sonar sensor
The sonar sensor which is adopted as a proximity sensor of a vehicle (sound when going closer, etc.) is also utilized as an auxiliary sensor for Autonomous Driving . America's Tesla is a concept to implement Autonomous Driving a camera and sonar sensor configuration, it seems possible to distinguish distant recognition using a camera and using a sonar sensor when approaching. Millimeter wave sensors and sonar sensors have relatively small data volumes, so they have features such as high speed computation because the load at calculation is small.
There are various sensors for monitoring the surroundings, but not all of them can be grasped by any one, but it is required to integrate multiple sensors and to reliably grasp the surrounding environment.
To that end, the existence of the system to be used for Autonomous Driving described next becomes important.