Research On Testing Technology Of Electric Propulsion And Braking System For Intelligent Vehicles

The concern for traffic safety and the increasing demand for mobility are promoting the research on intelligent driving technology.However,immature control technology can lead to serious traffic accidents,so series of tests are needed to improve the safety and reliability of intelligent driving systems.Compared to real-vehicle testing,software-in-the-loop and hardware-in-the-loop tests can perform low-cost implementation of complex traffic scenarios more quickly and accurately,which is the development trend of intelligent vehicle test technology.This paper designs a variety of typical test conditions based on domestic and foreign laws and regulations,actual engineering application scenarios,and testing requirements for extreme driving conditions.Three representative longitudinal control systems are designed and tested,including Adaptive Cruise Control(ACC),Autonomous Emergency Braking(AEB)and Anti-lock Braking System(ABS).Software-in-the-loop and hardware-in-the-loop dynamic tests are done on the electric propulsion and braking system of an electric front-axle-driven intelligent vehicle.First of all,this article gives an overview of the existing intelligent vehicle and testing technology,and focuses on the status of the software-in-the-loop and hardware-in-the-loop testing technologies for intelligent vehicles.The advantages and disadvantages of common modeling software are analyzed,and the configuration and functions of intelligent vehicle test benches home and aboard are compared.The research content and technical route of this article are then clarified.Secondly,the scheme design of the software and hardware-in-the-loop testing is carried on.It is clarified that the software-in-the-loop testing uses the co-simulation of CarMaker and MATLAB/Simulink,and the modeling methods for vehicle dynamics and complex traffic scenarios are shown.The setting of automated testing by using CarMaker/Test Manager is demonstrated.At the same time,the composition and signal connection of the hardware-in-the-loop test bench are determined,and the function of the test bench is clarified.After that,an ACC system based on model predictive control,an AEB system based on the safety distance model and an ABS system based on feed-forward PID control are constructed.Subsequently,a variety of targeted and representative test cases are designed and implemented.Based on these control algorithms,a number of targeted and representative software-in-the-loop test cases were designed and implemented,preparing for further research and tests of the electric propulsion and braking system.Moreover,the real-time solution of multi-objective optimization algorithm is realized in dSPACE,based on ACC,AEB and ABS systems,a series of representative hardware-in-the-loop tests are performed.On the basis of the software-in-the-loop test results,the economic analysis of several control strategies has been carried out,taking into account the regeneration of braking energy.Then the HIL tests are performed under low adhesion coefficient driving conditions,and the ABS control results of pure motor,pure hydraulic and electro-hydraulic hybrid braking systems are compared and analyzed.The control technology of the test bench under complicated traffic conditions and extreme conditions are tested,and the test capability of the test bench,which is designed to test electric propulsion and braking s ystem for intelligent vehicles,was demonstrated.