A 4-speed AT for a FWD vehicle is shown in the stick diagram. The clutch engagement...

 

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A 4-speed AT for a FWD vehicle is shown in the stick diagram. The clutch engagement schedule is shown in the table. The first gear ratio and the overdrive gear ratio are designed to be 2.96 and 0.68 respectively. The chain ratio and the final drive ratio are 1.0 and 3.11 respectively. 3 a) Determine the planetary train parameters B., B. and B. for the three PGTs. Find the gear ratio for the 2nd, 3rd, and reverse gear respectively. b) Assume the turbine torque is T. Find the reaction torque in the 1st, 2nd, 4th and reverse gear respectively. c) The transmission is in the process of making a 2-3 upshift. The sensors of the control system detect a vehicle speed of 35 mph and a turbine speed of 2300 RPM. Determine the RPM of the front sun (S₁). Determine also the slip rate in clutch C3, defined as the ratio between the speed difference of the two clutch sides and the input side speed. d) The vehicle is being driven in the 1st gear at a speed of 12mph on a 5% slope and the vehicle acceleration is 5 ft/s². Determine the combined reaction torque in clutches B₂ and R3. Front axle weight: 2010 lbs Center of gravity height: 14 inch Air drag coefficient: 0.31 Tire radius: 11.0 in. Powertrain efficiency: 0.96 Vehicle Data Rear axle weight: 1980 lbs Wheel base: 108 in. Frontal projected area: 21 square feet Roll resistance coefficient: 0.02 Road adhesion coefficient: 1.0 44 R₁ B₂ wwwwwww C₂ C3 To left wheel Gear First second Third fourth Reverse S,T Clutch Engagement Table C₁ C₂ C3 C4 C5 B₁ B₂ R R₂ R3 X X XIX X XIXIX XIX B₂ Ji X X X X C4 C R₂ R₂ 3 X X XIX XX Note: 4th gear is overdrive. 1 VAX To right wheel A 4-speed AT for a FWD vehicle is shown in the stick diagram. The clutch engagement schedule is shown in the table. The first gear ratio and the overdrive gear ratio are designed to be 2.96 and 0.68 respectively. The chain ratio and the final drive ratio are 1.0 and 3.11 respectively. 3 a) Determine the planetary train parameters B., B. and B. for the three PGTs. Find the gear ratio for the 2nd, 3rd, and reverse gear respectively. b) Assume the turbine torque is T. Find the reaction torque in the 1st, 2nd, 4th and reverse gear respectively. c) The transmission is in the process of making a 2-3 upshift. The sensors of the control system detect a vehicle speed of 35 mph and a turbine speed of 2300 RPM. Determine the RPM of the front sun (S₁). Determine also the slip rate in clutch C3, defined as the ratio between the speed difference of the two clutch sides and the input side speed. d) The vehicle is being driven in the 1st gear at a speed of 12mph on a 5% slope and the vehicle acceleration is 5 ft/s². Determine the combined reaction torque in clutches B₂ and R3. Front axle weight: 2010 lbs Center of gravity height: 14 inch Air drag coefficient: 0.31 Tire radius: 11.0 in. Powertrain efficiency: 0.96 Vehicle Data Rear axle weight: 1980 lbs Wheel base: 108 in. Frontal projected area: 21 square feet Roll resistance coefficient: 0.02 Road adhesion coefficient: 1.0 44 R₁ B₂ wwwwwww C₂ C3 To left wheel Gear First second Third fourth Reverse S,T Clutch Engagement Table C₁ C₂ C3 C4 C5 B₁ B₂ R R₂ R3 X X XIX X XIXIX XIX B₂ Ji X X X X C4 C R₂ R₂ 3 X X XIX XX Note: 4th gear is overdrive. 1 VAX To right wheel