Research On Vehicle Control System Of Intelligent Electric Vehicle Under Follow-up Condition

The environmental awareness,information fusion,intelligent control and other key technologies can be used in intelligent vehicles for achieving autonomous driving.Intelligent vehicle is an important part of intelligent transportation system(ITS).In order to meet the requirements of achieving intelligent and real-time control of the horizontal and vertical movement under intelligent electric vehicle in follow-up driving conditions,based on the intelligent electric vehicle,named QUTEV-1,the information perception and input of the vehicle control system were researched.The upper layer control strategy and the lower control algorithm of the automatic variable speed,braking and steering of the intelligent electric vehicle under the following conditions were studied.On this basis,hardware and software of vehicle control system was designed,and simulation and real vehicle experiments were carried out to verify the performance of the control system.The vehicle distance measurement algorithm based on monocular vision and front vehicle license plate width measurement was designed to provide the basic input parameters such as vehicle distance,vehicle speed,front vehicle speed and front vehicle acceleration for vehicle control system.Measurement algorithm of the vehicle yaw angle,the lateral distance and the curvature of the curves based on the monocular vision was designed.The vehicle posture control strategy is designed for realize the automatic adjustment of the vehicle posture every second,which provides the prerequisite for the autonomous driving.Based on the safety vehicle distance model,the vehicle traffic congestion degree and the vehicle speed forecasting model based on NAR neural network,the automatic variable speed and brake coupling control strategy under the following driving condition were designed.The longitudinal control algorithm of longitudinal motion was designed.And automatic control of wheel motor speed control voltage and brake wheel cylinder pressure was realized.The longitudinal motion automatic control of QUTEV-1under the following conditions was realized by the automatic variable speed and braking coupling control strategy and the longitudinal motion control algorithm.By analyzing the two indexes of skidding and roll-over stability,a safety evaluation model of corners was established.Based on the curve safety evaluation model,therelationship between the safe running speed of the curve and the radius of the curve was established by simulation,and the control strategy of the steering direction was designed.The algorithm of lateral motion control matching control strategy was studied,and the optimal control of lateral motion deviation was realized.The hardware design of the vehicle control system was carried out by using the circuit design software.The software design of the vehicle control system was carried out by ARM single chip language and C language.Simulation and real vehicle experiments showed that the control system possessed good performance in real-time,accuracy and robustness.