Problem set 2 -week 3 challenge : Anti-Characteristics
Formulas in excel:-
1. Throttle acceleration per g = (throttle acc.)/(acc. due to gravity)
2. Load transfer = [(total weight)*(throttle accn)*(CG height)]/[(wheelbase)*g]
3. Front axle weight (after throttle) = (static front axle weight) - (load transfer)
4. Rear axle weight (after throttle) = (static rear axle weight) + (load tansfer)
5. Front wheel rate = (front spring rate)*(front motion ratio)^2
6. Rear wheel rate = (rear spring rate)*(rear motion ratio)^2
A) Without Compensation
1. Front end deflection = (load transfer)*0.5/(front wheel rate)
2. Rear end deflection = (load transfer)*0.5/(rear wheel rate)
3. Pitch angle = arctan{[(front defelction) + (rear deflection)]/wheelbase}*(180/pi)
4. Pitch gradient = (pitch angle)/(throttle acc.(g))
B) With Compensation
1. Front anti-lift angle = arctan{[(FICV) - (tire radius)]/(FICH)}
2. Rear anti-squat angle = arctan{[(RICV) - (tire radius)]/(RICH)}
3. Front swing arm angle = arctan[(CG height)/wheelbase]
4. Rear swing arm angle = arctan[(CG height)/wheelbase]
5. Front anti-lift % = (front anti-lift angle)*(drive ratio)/(front swing arm angle)
6. Rear anti-squat % = (rear anti-squat angle)*[100 - (drive ratio)]/(rear swing arm angle)
C) After compensation
1. Front end deflection = [front end deflection (w/o comp)]*[100 - (front anti-lift %)]/100
2. Rear end deflection = [rear end deflection (w/o comp)]*[100 - (front anti-squat %)]/100
3. Pitch angle = arctan{[(front defelction with comp) + (rear deflection with comp)]/wheelbase}*(180/pi)
4. Pitch gradient = (pitch angle)/(throttle acc.(g))
Excel Calculation:-
The pitch angle is found to be minimised near zero at RICH = 12 in
