Software Development And Function Realization Of Hardware-in-loop Simulation System For Automobile Chassis Control

Intelligent connected vehicles is the trend of automotive development.It can provide drivers with more intelligent,convenient and safe driving modes,and significantly improve the traffic environment and improve travel efficiency.For intelligent connected vehicles,the high-precision chassis control system is the key to realizing the autopilot function.The intelligent connected vehicle relies on the X-by-wire technology,which mainly includes three parts: steer-by-wire,brake-by-wire and drive-by-wire.For now,hardware-in-loop development is one of the important means of intelligent automobile function development,which is beneficial to improve the public development efficiency and shorten the development cycle.Therefore,it is of great significance to develop a software platform based on chassis hardware-in-loop simulation system and to study the key issues of the intelligent connected vehicle X-by-wire system.This paper is based on the hardware system and electrical system of automobile chassis electronic control hardware-in-loop simulation platform,constructing high precision virtual vehicle model,developing real-time interactive software system and line control chassis function.The main innovation lies in that the hardware-in-loop simulation platform has the vehicle model foundation,the software interaction foundation and the line control chassis function foundation that the intelligent vehicle upper control system development needs.A real-time observation algorithm for cylinder pressure is built,line control chassis program with real car portability.Firstly,this paper uses CarSim software to design a virtual vehicle model based on NL-4 real vehicle parameters.The vehicle model accuracy error is controlled within 10% by comparing and verifying the real vehicle dynamics test data.On the basis of the vehicle model,using CarSim and Labview software,the test platform of with good man-machine interaction interface simulation system is built.Secondly,in view of the problem of line chassis control,using the ESC system,the EPS system and the pseudo throttle system,designed a X-by-wire controller can meet the function of automatic driving line control,which contains steering-by-wire controller,brake-by-wire controller and drive-by-wire controller,results show that wire control chassis system meet the design requirements.Thirdly,the feedback problem of cylinder pressure signal is required for the brake-by-wire controller.Based on the traditional ESC brake system configuration,the simplified hydraulic control unit model is established.The pressure estimation algorithm for four-wheel simultaneous pressurization is designed.The results show that the real-time observation values of cylinder pressure meet the requirements of line control system.Finally,this paper carried out the typical driving conditions in manual mode and automatic mode of verification experiment.Through the closed loop driving conditions,steering,acceleration and braking result prove the design of software system and line control function has high accuracy and reliability.