| The braking system is very important.It is related to our safety and property. Engineers have been looking for the use of computer aided design for the brake system design aims at designing for the brake system due to the various components of the hydraulic brake system and the complex calculation. At present most of the design and matching is static. Most cases, the simulation analysis is carried out for the one or two components. In order to make up for the deficiency of that, this paper establishes the whole braking system of AMESim model and vehicle 5 degrees of freedom simulation model based on MATLAB. And carry up the co-simulation analysis. Analysis whether brake system parts match for each other. Whether brake system matches the vehicle.The contents of this paper are as follows:1.This paper had analysis the braking system regulations of the passenger car, that is GB21670-2008. Had analysis the braking system regulations of commercial vehicle, that is GB 12676-2014. Put an analysis on the safety requirements of motor vehicle named GB7258-2012. This also have an research on the design requirements of brake system components.2.Build up brake system components model, including brake pedal model, engine model, model of electric vacuum pump, vacuum booster model, model of brake master cylinder, model SABS, cylinder model. The characteristics of some models are analyzed. Build up the whole vehicle longitudinal five degree of freedom model in MATLAB. Analysis relationship between the vacuum degree of the engine intake manifold with the throttle opening and rotational speed of the crank axle. And analysis the necessity of electric vacuum pump for power assist system.3. Build up co-simulation between the brake system model and vehicle model. Analyze the matching of vehicle parameters and the braking system based on laws and design requirement. Include analysis of braking distance and braking deceleration, using adhesion coefficient, braking force distribution coefficient, braking force percentage and braking efficiency analysis. Analyze the characteristics of brake system components such as the characteristics of about brake pedal force and brake pedal stroke, the input and output characteristics of the vacuum booster, the control effect of electric vacuum pump, the characteristics of hydraulic pressure and stroke of master cylinder, the response time of braking system.Make co-simulation analysis on the attenuation of vehicle braking deceleration of naturally aspirated engine when it encounteres urban traffic congestion conditions and the driver repeatedly stepped on the brake pedal.4.Build up a brake test bench based on brake system parts of Pentium B70. The electric vacuum pump is used as a vacuum source to the vacuum booster. Analysis of the characteristics of the braking system components. And compared with the simulation model. |
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