Study On Characteristics Of NEHB System And The Vehicle Performance Based On NEHB

People’s increasingly high requirements in the performance of vehicle brakingsystem is meted by Braking-by-wire system with its excellent braking performance.There are two representative products: EHB and EMB. EHB is more suitable at thisstage than EMB because of it its economic aspect and less change based on thetraditional hydraulic brake system. It is easier to achieve vehicle assembly and massproduction. Electro-hydraulic braking system is a braking system with multiplefunctions which is the transition product from traditional hydraulic brake system toElectronic Mechanic Brake. It is also the target of the brake system at present stage.The study structure of this paper is based on the model of our group’s NEHB, a newform of EHB.AMESim software is used here to do the simulation of the dynamiccharacteristics and vehicle brake performance. The dynamic characteristics make agreat influence in the control of brake pressure in EHB brake system. Study thedynamic characteristic is the basic for the development of NEHB system. Besides, Todemonstrate the NEHB system’s safety and reliability when used in the vehicle, weneed to study the performance of its vehicle braking system on the basis of areasonable match.First, introduced the principle and the control mode, and the principle of the newEHB-NEHB and the difference between NEHB system and the conventional EHBsystem. Also, introduced the development situation and achievements of electronichydraulic braking system at home and abroad.Secondly, established the NEHB system simulation models based on themodeling and controlling platform in AMESim software. Established the mathemati-cal model of main components. Combined with actual parameter chosed forsolenoid valve in NEHB system, get the critical natural frequencies formulas andcalculate the critical natural frequency of valve. What’s more, made the establishmentthe model of vehicle with seven degrees freedoms.third, Made the simulation and analysis of its characteristics. The responsecharacteristics of solenoid valves, the pressure growth characteristics and the pressuredrop characteristics of new electronic hydraulic system are all successfully gained at last. The parameters of main components, such as brake master cylinder, the motor,the fluid properties and brake lines, which make important influence on thecharacteristic of NEHB system are analyzed..Finally, Based on the new electronic hydraulic system AMESim model and thevehicle model with seven degrees freedoms, research and analysis the vehicle brakingperformance in three working conditions: backup brake condition, conventional brakecondition and the anti-lock brake condition. According to some standards, theperformance in different conditions are evaluated and compared. Analyzed andcompared the brake performance on different vehicle.In this paper, through the simulation of the NEHB brake system, and comparisonbetween the theory and the different simulation test, the dynamic characteristics ofsolenoid valve is known. The research on the vehicle braking performance is in orderto ensure the brake safety when NEHB is used in vehicle. These provide solidfoundation for the development of NEHB system in the future work.