Research On Dynamic Characteristic Analysis And Evaluation Of Vehicle Steering Control

Vehicle steering control is one of the important performances of vehicle handling and stability. Itis related to whether the car can avoid the obstacles quickly and effectivly when driving in high speedand whether the driver can drive easily.A dynamic characteristic of vehicle steering control is discussed in this paper. From test dataanalysis and processing, changing rull summery and evaluation index exploring these aspects toresearch the dynamic characteristic of vehicle steering control.(1) Using the theories of wavelet transform to denoise the vehicle steering control test dataexploringly. The feature of wavelet basis especially for vehicle steering test data denoising is analyzedbased on the feature of vehicle steering control test data. Choosing the wavelet basis based on thereconfiguration ability of each wavelet basis. Then the optimal threshold and denoising function arechosen by compearing their features. Taking steering wheel angle test data of serpentine test forexample, choosing the wavelet basis especially for steering wheel angle test data of serpentine test.The effection of the chosen wavelet basis is verified by denoising a group of real steering wheel angletest data.(2) A three-degree-freedom closed-loop system for steering angel input vehicle model isestablished. Using an evaluation index which has contains path error, steering wheel angular velocityand lateral acceleration to choose the optimal preview time of each condition. The denoised steeringwheel angle test data is used to verify the closed-loop system. The simulation result is consistent withtest data, it is verified the correctness of the closed-loop system.(3) Using the established driver-vehicle three-degree-freedom closed-loop system to calculate thesteering wheel manipulate information of a model in different lane change conditions. The maximumamplitude of steering wheel angle, maximum steering wheel angle speed, main steering wheel rotationfrequency and the proportion of busy frequency range are chosen as main object of investidation.Then the trends and amplitudes of each manipulate information changing with different lane changepaths and different speeds are obtained. Their changing law are also summaried so that the dynamiccharacteristic of vehicle steering control. Correctness of the summaried changing law of steeringcontrol is verified through real vehicle test.(4) Based on the formal analysis results, the evaluation indexes of dynamic characteristic ofvehicle steering control are proporsed exploringly. The gentle degree of dynamic changing of maximum sreering wheel angle, the gentle degree of dynamic changing of maximum sreering wheelangle speed and the gentle degree of dynamic changing of steering wheel manipulating frequency arechosen out to evaluate the dynamic characteristic of vehicle steering control comprehensively.Cauculating another model’s dynamic characteristic of vehicle steering control and comparing withthe formal model. The result is that the dynamic characteristic of vehicle steering control of thesecond model is better than the first one. The second modle may be driven easier than the first one.The correstness of evaluation results and the feasibility of the proporsed evaluation indexes areverified through contast the manipulating performance of those two models.