Vehicle Ride 1

The objective of this challenge is to select springs that satisfy the frequency targets for the given parameters and plot the bump oscillation profile for the same in MATLAB.

First, the spring rates were fixed and the corresponding wheel and ride rates were calculated using the following equations,

• wheel_rate Kw = spring_rate*motion_ratio^2
• ride_rate Krs(sprung mass) = (Kw*Kt)/(Kw+Kt)
• ride_rate Kru = Kw+Kt

where Kt is the tire rate and Ks is the spring rate.

In the next step, the given front frequency target was achieved by choosing the relevant spring rates and the recommended rear frequency was calculated accordingly.

• fs = 1/2*pi*sqrt(Krs/ms)
• fus = 1/2*pi*sqrt(kru/mus)
• time_lag t = wheelbase/speed
• recommended rear frequency fr = 1/ (1/frs) - t

where frs is the rear sprung mas frequency

The above calculations are made for all the 3 load conditions given.

Further, the bump oscillation profile is plotted in MATLAB. the following equation is used to calculate the amplitude,

y = e^(-t) * sin(wt)

where, w = 2*pi*f

The obtained bump profile shows that the calculated frequency values limit the excessive pitching and hence achieving a better flat ride.

https://drive.google.com/drive/folders/1uLTvrnL3IsjG1DyASIDugLfxNxN9-v8D?usp=sharing