Hello,
I've gone through many posts, calculations regarding Jacking Forces on the forum, but could not get a clear answer of what exactly is the effect of jacking force on the net Tire load(both Steady state and Transient).
From my understanding of the concept, the Jacking force depends upon the RC height and the RC Lateral Position(or IC as per some) and also lateral forces. So if during a cornering maneuver the lateral force on the outside wheel is more(assuming RC to be static for simplicity, RC Height above ground), the net jacking force on the chassis would be in the upward direction, thus causing a vertical acc. and lifting the chassis.
Thus net force on 4 wheel = Mass*(gravity-vertical acceleration) ; vertical acc: due to jacking
so the net effect should be a reduction of the net normal load.
What I dont understand is why some of the calculations on the forum:
a) First add up the jacking force on each side of the suspension to the net tire normal load on that side "(Lateral force is perpendicular to normal force(in tire coordinates), so why does it DIRECTLY add to some tire normal force ???)" and then decrease the same force from the spring and keeping the net tire load same ??
or to say:
(No effect of cg movement or roll etc etc.)
Lateral Forces ---> Jacking Forces ---> Vertical CG movement ---> Spring being longer ---> Reduction of net Normal Load. (Did i miss something somewhere?)
If this is true:
Then during constant cornering maneuver, if the lateral force on the outside wheel is always more than on the inside, the net vertical force due to jacking will act to lift the sprung mass and this in effect will decrease the net tire load due to the spring being longer, and this condition is maintained till the exit of the turn when the forces on both side is same. (Which has a large effect on my Dynamic Model
Any help, advice is appreciated.
Varun
PS: I hope to get Unscented Kalman Load observer working one day :/