| Along with the rapid development of the social economy and the improvement of people's living standards,car ownership continues to grow,and people's requirements for safety and comfort are also increasing.As an evolutionary version of the vehicle's cruise control system,the vehicle adaptive cruise system still changes the vehicle's throttle opening and brake pressure to change the longitudinal acceleration of the vehicle during cruise,and thus achieves the vehicle in the no-for-vehicle state.Cruise at a constant speed and with the speed of the car in the front vehicle.The vehicle adaptive cruise system can reduce the driver's driving burden to a certain extent and improve the active safety and comfort during the vehicle cruise.Compared with the vehicle cruise control system,the adaptive cruise system has stronger robustness,higher active safety and comfort,and greater adaptability to the cruise path.In view of some shortcomings in the existing adaptive cruise system technology,this paper is based on the classical PID control theory,taking into account the road environment factors during vehicle cruising and the safety and comfort requirements of drivers and passengers.The control system was studied.This paper focuses on the following work:(1)Perceived environmental conditions during vehicle cruising.Aiming at the general driving conditions that the vehicle will appear in the cruise state,the multi-sensor detection advantages can be complemented by the machine vision technology formed by the vehicle millimeter wave radar and the camera and its image processing,and the driving environment can be similar to the human driver.The perceived effect provides a guarantee for accurately determining the driving environment and assisting driving.(2)Fusion of multi-sensor data.The fusion method selected by this system is divided into two types: spatial and temporal: spatial data fusion is to integrate the data obtained by different sensor coordinate systems into the same world coordinate system through matrix transformation;time data fusion is through Sensors with different sampling frequencies are triggered in an orderly manner and form a loop-by-breaking method.(3)The overall logic of the vehicle adaptive cruise system and its controller design.For the design purpose of the system,analyze and logically judge the overall solution ideas;construct different working conditions and their corresponding safety distance and speed models;at the same time complete the design of the upper and lower controllers in the hierarchical control structure and realize different control layers Smooth transition between.(4)System simulation and analysis of results.Firstly,the overall simulation model of the system is built by the connection between different sub-modules of the system,and the simulation is verified for different working conditions,including: fixed-speed cruise,adaptive follow-up,anti-overspeed and rear-end warning.The simulation results show that the system can realize the cruise control under various working conditions under the premise of satisfying the safety and comfort requirements of the driver and passengers,which can better ensure the stability of the whole system and reduce the driving burden of the driver.And it has a certain significance to improve the overall safety of the vehicle. |
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