Research On Vehicle Quality Identification Method Applied To Commercial Vehicle EPB System

With the development of automotive electronic technology,the requirements of commercial vehicles for safety,comfort and driving convenience are increasing gradually,.And the electrical parking brake(EPB)system has become the standard configuration of many advanced commercial vehicles over the world.Vehicle mass plays an important role in effects of the control of the electrical parking brake system.Therefore,vehicle mass estimating method which is applied to the commercial vehicle's EPB system is mainly studied in this paper.Firstly,the commercial vehicle's EPB system is introduced and the demands of the EPB system for the vehicle mass information is analyzed.According to the researching status of vehicle mass estimating methods at home and abroad,a recursive least square method based on the vehicle longitudinal dynamics model is proposed for vehicle mass estimation.Based on the theories of the vehicle longitudinal dynamics model and the recursive form of least square algorithm,a vehicle mass estimating model based on recursive least square method is established.Then the simulation which combines Trucksim and Matlab/Simulink is used to verify the proposed recursive least square method of vehicle mass estimating model.The results of simulation illustrate that the vehicle mass estimating model proposed in this paper can estimate the vehicle mass effectively in several driving conditions.Then,in order to providing the Hill Start Assist(HSA)function of the commercial vehicle's EPB system with the accurate information of vehicle mass,a static vehicle mass detecting device based on the deflection of suspensions is proposed.In this paper,the working principle of the vehicle mass detecting device is illustrated,the system components are designed and its installation location requirements are analyzed-At the same time,a vehicle mass iterative algorithm based on the relationship of the suspension deflection and centroid offset is proposed.Finally,the vehicle mass is off-line estimated by using the vehicle mass estimating model proposed in this paper with the data from vehicle tests.And the static vehicle mass detecting device based on the deflection of suspensions is installed on the testing vehicle.The results of the tests show that the recursive least squares vehicle mass estimating method based on the vehicle longitudinal dynamics model and the static vehicle mass detecting device based on the deflection of suspensions can estimate and detect the vehicle mass efficiently and accurately.