Project
Aim:- To prepare a technical report of simulation on Baja All-terrain vehicle (AVT) under different conditions.
Objectives:- Carry out a system-level simulation of an all-terrain vehicle. Prepare a technical report explaining the model properties & comments on the results
ALL TERRAIN VEHICLE:
An all-terrain vehicle (ATV) is defined as a motorized off-highway vehicle designed to travel on four low-pressure or non-pneumatic tires, having a seat designed to be straddled by the operator and handlebars for steering control.
STUDY #1:
CASE1:
SIMULINK MODEL FOR BAJA ATV WITH CVT:
Major components in the model:
Continuously Variable Transmission drive (CVT):
It is better to have more gears in a transmission, since it can optimize engine speed in a variety of driving conditions. That means low gears can provide better acceleration while higher gears can maximize fuel economy. CVTs differ from traditional automatic transmissions in that they don't have gears that provide "steps" between low- and high-speed operations. Instead, the majority of them work via a pair of variable-diameter, cone-shaped pulleys connected by a steel or composite belt. The halves of each pulley are aligned with the pointed ends of the cones touching. These form a V-shaped groove in which the connecting belt rides. One side of the pulley is fixed, and the other side is movable, actuated by a hydraulic cylinder. The cylinder can increase or decrease the amount of space between the two sides of the pulley. This allows the belt to ride lower or higher along the walls of the pulley, depending on driving conditions, thereby changing the "gear" ratio.
CVT Block:-
VEHICLE BODY BLOCK:-
SIGNAL BUILDER (CVT RATIO):-
SIGNAL BUILDER (BRAKE AND THROTTLE):-
Output For Case 1:
VEHICLE SPEED:-
It is clear from the graph that the vehicle attains its maximum speed (V = 55km/hr) at full throttle = 1 after 30 seconds and then remains constant. The brake input value is zero, hence it has no effect on velocity.
CVT SHAFT SPEED:-
These graphs shows the variation in angular velocities of input and output shafts of the variable gear transmission system. These values differ with respect to the gear ratio.
CASE2:
SIMULINK MODEL FOR BAJA ATV WITH CVT MAPPED:
CVT LOOKUP TABLE BLOCK:-
Output for case 2:-
CVT RATIO
VEHICLE SPEED:-
CVT SHAFT SPEED:-
CASE3:
SIMULINK MODEL FOR BAJA ATV WITH CVT MODEL DASHBOARD MAPPED:
CVT RATIO:-
VEHICLE SPEED:-
CVT SHAFT SPEED:-
CASE4:
SIMULINK MODEL FOR BAJA ATV WITH CVT RATIO RPM:
Output for case 4:-
CVT SHAFT SPEED:-
CONCLUSION:
Thus we have successfully analysed 4 different models of BAJA ATV WITH CVT and recorded the outputs: - (Vehicle velocity & CVT shaft rpm) with respect to variations in input throttle and brake.