Research On The Vehicle-Road Coupling Simulation Based On The Automatic Transmission Object-in-the-loop System

The automatic transmission is one of the key components of the automotive powertrain.Its accurate and effective indoor bench control strategy verification and outdoor real vehicle calibration matching test are of great significance for improving vehicle dynamics and economy.At present,the matching calibration of the AT is mainly carried out in the outdoor real vehicle test.However,the actual vehicle test cycle is long,the cost is high,and it is greatly affected by the external environment.The indoor transmission body functionality and trend verification are mainly focused on traditional bench testing.And the control strategy development and verification mainly performs hardware-in-the-loop testing.However,indoor tests are not able to accurately simulate the actual vehicle operating conditions.Based on this,the research group proposed object-in-the-loop test system for AT.It integrated bench testing and hardware-in-the-loop testing,and provided a more realistic indoor vehicle test environment to simulate the actual vehicle operating conditions,and it wil replace the actual vehicle for the transmission matching calibration test.Therefore,the system had high scientific research value and engineering application value for controller verification and vehicle-level performance matching.Vehicle-road coupling simulation is one of the key links in the construction of the "human-vehicle-road" vehicle environmental test system.It can provide a road driving environment for the object-in-the-loop test system.This paper combined the object-in-the-loop principle and architecture to carry out vehicle-road coupling simulation research,the researched focuses on different road characteristics,vehicle dynamics models and PreScan virtual road scenes,etc.The details are as follows:(1)Studied different types of pavement roughness characteristics and pavement parameters modeling methods.Analyzed the effect of pavement roughness on the dynamic load of the wheel.And combined with the pavement characteristics of the virtual test site and the research and development needs of the object-in-the-loop system.Used Matlab/Simulink software to build a different kind of road model.(2)Studied the theory and method of vehicle-road coupling modeling.Built a tire model,vehicle longitudinal and lateral dynamic model,and vehicle auxiliary modules such as vehicle steering model and brake model.Combined with the virtual road parameter module,analyzed the response of vehicle under the different driving conditions and the road environment,provided a more realistic road driving environment for the object-in-the-loop system.(3)Studied PreScan virtual road scene modeling theory and technology.Combined with the object-in-the-loop system test requirements to carry out co-simulation of different virtual road environments and vehicle dynamics models,further verified the validity and stability of the vehicle-road coupling model.(4)Embeded vehicle-road coupling model into object-in-the-loop test system,performed simulating test and verification of the vehicle-road coupling model at the automatic transmission object-in-the-loop system.And established a vehicle-road coupling model for the object-in-the-loop system.