LCS - 06b - Modelling of Quarter Car Suspension System

[@zhenhuawei7939]

I understand the knowledge, thank you professor!

[@anishmanandhar1203]

Nice explanation professor

[@AbhishekSingh-up4rv]

Very nice video, may Allah bless you

[@ashishkumargupta94]

Nice lecture. sir can you plz make a video on 2-dof quarter car model with PZT stack in series or parallel with suspension spring for energy harvesting.

[@umerzamankhan4565]

Firstly very good explanation Sir. Secondly what will be the way of calculating the overall transfer function i.e. if we consider other wheels as well. In a way that they are interconnected by chassis. Will there be any change if we consider all the tires and car body instead of quarter wheel suspension?

[@MAFarooqi]

For modelling of full car model of a vehicle suspension system, each tire can be modelled in a similar way with an addition that a force will be exerted by the vehicle chassis on the tire. The chassis can have roll, pitch and heave motions and each motion can be modelled by writing torque and force balance equations. Torques will be due to the forces exerted by the tires on the chassis. If you want to study more realistic situation, you may also add seat dynamics.

[@briankiprono4580]

But the wheel is not attached to the ground, so why would k2 exert a force downwards given in these cases weight of the wheel is negligible?

[@MAFarooqi]

Please note that the weight of the wheel is not negligible, its mass is m2 and hence its weight is m2*g. Secondly, the spring will always exert a force whenever there is elongation or suppression in the spring. Since the displacements x and y2 are linearly independent from each other, there will be an elongation/suppression in the spring resulting into a force.

[@وائلالمزيني]

Why there are no three equations as we have three displacements? I thought we had to do something for the displacement "r" like you explained in lecture (LCS 6a).

[@MAFarooqi]

In this system, the third displacement 'r' is the road profile, and it is not determined by the system dynamics (whatever is the system, road profile will be the same). Thus, r is taken as an external input to the system.

[@UdoyeTobechukwu]

Please when you did for active suspension was it Y/X or F/Y

[@MAFarooqi]

For active suspension, transfer functions Y/F and Y/X would be useful.

[@UdoyeTobechukwu]

@@MAFarooqi Please could I see the answer to the assignment

[@presannagovindaraju2781]

Hi sir, is this modelling can be applicable for 2-wheeler suspension?

[@MAFarooqi]

This can be extended to two wheel model, called bicycle model, by considering the dynamics of the link between two wheels.

[@TARIQKHAN-my8ou]

Masha Allah Sir Jee ❤❤

[@MAFarooqi]

Thanks.

[@chakrichakri6096]

This is my first video of yours I didn't understand that acceleration acting downwards is denoted by m1s²Y1(s) can you please explain this phrase for me please what exactly s is

[@MAFarooqi]

m1s^2Y1(s) is the force due to inertia of mass m1. Force due to inertia is always opposite to the direction of acceleration. Let me elaborate it with a simple example: If you are sitting on a car and the driver suddenly presses the accelerator and the car accelerates in forward direction. In which direction your body will feel the jerk? In reverse direction. Why? Because the force due to inertia is opposite to the direction of acceleration.

[@chakrichakri6096]

@@MAFarooqi I get what you are saying I want to know that how you are denoting the acceleration as s²Y1(s)

[@MAFarooqi]

This 's' is called the Laplace variable. You may consider it equivalent to the time derivative. Thus, s^2Y(s) is equivalent to the second derivative of Y with respect to time. And you know that the second derivative of position is acceleration.

[@chakrichakri6096]

@@MAFarooqi Acha on sir I got it thank you so much

[@dyourbae4799]

do you have any video that explain the active suspension system?

[@MAFarooqi]

Not yet.

[@bilalsadiq3495]

@@MAFarooqi active suspension system is the main thing ,,you should consider those things to teach instead of these "bookish" material,..

[@MAFarooqi]

@@bilalsadiq3495 If you can model the system underhand, you will definitely be able to model the active suspension system. The assignment at the end of this lecture deals with active suspension system, and believe me, my students had no difficulty in modeling the active suspension system.

[@bilalsadiq3495]

@@MAFarooqi Well Dr Abid,,you are right but my point is only that please try to make videos on those topic which are not available on the internet.To model and design the passive system is extremely an easy and availiabe on internet,but "acitve system " modeling and control design is not available ,so please try to make those stuff if you really want to upload things.I must say appreciate your time and energy and your contribution but upload those things which i mentioned.At the end nice effort overall.

[@cupoftea411]

👍🏼