Can I Use Lagrangian Equations to Calculate a Car's Response on an Uneven Road?

AI Thread Summary
To calculate a car's response on an uneven road using Lagrangian equations, one must consider the system's dynamics, including the stiffness and mass matrices. The discussion highlights the need to derive an ordinary differential equation (ODE) with a forcing component or a transfer function based on displacement measurements. The concept of a "7DOF Car" is questioned, as traditional cars typically exhibit only 2 degrees of freedom related to suspension and motion. However, the user explains their approach by factoring in additional elements like passengers and luggage, which contribute to the overall degrees of freedom. Understanding these dynamics is essential for accurately modeling the car's behavior over bumps.
alexisonsmith
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So I am trying to calculate the system responsee if a car is driving 30mph over an uneven road with a bumpb of height 0.05 and a length of 20m between each bump. I have the stiffness matrix, mass matrix etc. However I am unclear about the next step, I think possibly by using the Lagrangien equations of motion but I am not sure

Thanks,

Alex
 
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you'll likely calculate an ODE with a forcing component... or the transfer function using displacement at two points (more likely).
But the reason I came to read this is really the "7DOF Car" part... How can you have 7 degrees of freedom? Do you have a DeLorean with a Flux Compensator :)? If it is a "car", I can really only see 2 DOF...
Please explain...
 
The reason is that you take into account the front and read suspension that is 4, after that the engine, 2 passengers on seats and some luggage in the back, at the moments I have the motion of x (in the vertical condition) and the motion around theta...
 

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