1, positioning navigation technology
Positioning and navigation module includes positioning technology and navigation technology. Positioning technology can be divided into relative positioning (such as gyroscope and odometer), absolute positioning (such as GPS) and combined positioning. Navigation technology can be divided into map-based navigation and non-map-based navigation, among which high-precision map plays a key role in unmanned navigation.
2. Environmental awareness technology
The environmental sensing module senses the environmental information around the vehicle through various sensors. Perceptual information includes not only the vehicle's own state information, such as vehicle speed, front wheel deflection angle and vehicle heading angle, but also the surrounding environment information, such as road position, road direction, obstacle position and speed, traffic signs and so on. Commonly used sensors are cameras, lidar and millimeter-wave radar.
3. Planning decision-making technology
The planning and decision-making module is equivalent to the brain of a smart car. It plans the current vehicle behavior (speed planning, obstacle avoidance local path planning, etc. Through comprehensive analysis of the information provided by the environmental awareness system, corresponding decisions are made (following the car, changing lanes, stopping, etc.). ). The planning technology also needs to consider the mechanical characteristics, dynamic characteristics and kinematic characteristics of the vehicle. Common decision-making techniques include expert control, hidden Markov model, Bayesian network, fuzzy logic and so on.
4. Automatic control technology
The automatic control module mainly includes three systems: steering, driving and braking. The three control systems of driverless cars have their own emphasis on performance requirements such as control accuracy, ride comfort and response delay.
Among them, steering control is mainly the control of steering motor, which is divided into angle closed-loop control and torque closed-loop control according to different control objectives. Drive control realizes the control of vehicle acceleration, uniform speed and deceleration. According to different braking scenarios, braking control can be divided into normal braking control and emergency braking control.
special technology
Driverless car is a smart car that senses the road environment, automatically plans the driving route and controls the vehicle to reach the predetermined target through the on-board sensing system.
It uses on-board sensors to sense the environment around the vehicle, and controls the steering and speed of the vehicle according to the sensed information of the road, vehicle position and obstacles, so that the vehicle can run safely and reliably on the road.
It combines automatic control, architecture, artificial intelligence, visual computing and other technologies. It is the product of highly developed computer science, pattern recognition and intelligent control technology, and it is also an important symbol to measure a country's scientific research strength and industrial level. It has broad application prospects in the fields of national defense and national economy.
Refer to the above? Baidu encyclopedia-driverless car