4x4 Brake Design and Tolerance Study
I used a Monte Carlo simulation several years ago when I faced with a unique design challenge with multiple constraints and variable inputs. I was responsible for developing the brakes for a new four wheel drive utility vehicle. The challenge was to properly set the height adjustment for the brake pedal. The vehicle uses hydraulic brake system with two semi-independent systems so if one is damaged and inoperable the operator will still be able to stop the vehicle with the second. If one system fails the brake pedal will travel roughly half its stroke before any stopping force is generated. I had a balancing act, I had to position the pedal so that it could generate the pressure to stop the car in any situation before it bottomed out on the floorboard or was uncomfortably close to the driver. Also, each part involved has its normal manufacturing tolerances that must be considered.
Typically most design issues can be resolved using 3D computer aided drafting practice and a quick max and min analysis. In this case, potential failures resulting in a poor design were serious and my constraints were so tight that I was forced to use more advanced models.
The model I created used outputted the location of the pedal in the resting and fully depressed positions along with the potential interference with the floorboard and clearance to the driver's reach called the "zone of comfort". I was able to alter dimensions and tolerances for every part in the system to locate the pedal in the ideal position. The conclusion of the analysis resulted in a few design changes and a pedal that is optimally located for comfort and safety. The Monte Carlo modeling approach took plenty of time to develop but in the long run I was able to cut design time and cost.
As a rookie blogger I'm not sure how to upload the actual file so I clipped pictures of different sections of the analysis for your entertainment. If you'd like to see the actual model email me.
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