Dynamic Modeling of a Cars Hydraulic Braking System - No ABS

[mm391]

Hello,

I was wondering if anyone could perhaps direct me to articles or websites in regards to dynamically modelling a car/vehicles braking system? It doesn't need to be to complicated.

Many Thanks

Matt

 

[GregLocock]

If its a dynamic model then it probably will be complicated. Frankly, is google broken on your pc?

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

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[MintJulep]

In the beginning the pads or shoes are not touching the disc or drum.

Then there is a bit of fluid flowing in the system to take up the clearance.

Then pressure builds, more or less linear vs. time if you want to avoid complication.

Then pressure is constant.

Braking force is directly proportional to pressure.

 

[BrianPetersen]

... and since the center of gravity is above ground level, there is a forward weight transfer that increases with increasing deceleration, which means the ideal front-to-rear brake bias isn't constant, and it varies with loading, hence why some vehicles had load-sensing proportioning valves for the rear brakes that limited the maximum pressure to the rear brakes only.

 

[GregLocock]

So which bit are you modelling that is dynamic? The hydraulics, the car, both or what?

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[tbuelna]

Don't forget to include the effect of the tire traction with regards to modelling braking. After all, the brakes only stop the wheels. It's the tires that stop the car.

 

[Tmoose]

I think typical drum brakes have some servo action, so their force might not be linearly proportional to hydraulic pressure.
Maybe the diminutive rear drums typical of the few modern cars that still have them at all are non-servo.

One of our early 200X Mazda MPV had pretty decent sized drums in the back.
I don't recall if it used the most curious, patented mono-shoe, or if that was part of the parking brake on the later MPV with 4 discusses.