Project

AIM:-

To prepare a technical report of simulation of BAJA All-Terrian vehicle (ATV) under different conditions .

Objective:-

Carry out a system -level simulation of an all- terrain vehicle and prepare a technical report a explanining the model properties & comments on the results.

ALL TERRAIN VEHICLE:-

An all -terrain vehicle is defined as a matorized off -highway vehicle designed to travel on four low -prssure or non -pneumatic tires. having a seat designed to be straddled by the operator and handlebare for steering control.

STUDY #1:-

CASE1:-

SIMULINK MODEL FOR BAJA ATV WITH CVT:-

FIGURE :- SYSTEM LEVEL SIMULINK figure .

Major components in the Model:-

Continuously Variable Transmission drive (CVD)

It is batter to have more gears in a transmission ,since it can optimize engine speed in a variety of driving conditions ,that means law gears can pravide better acceleration while higher gears can maximize fuel economy .CVTs differ from traditional automatic transmission in that they don't have gears that provide "steps" between law -and high speed operations .intead ,the majority of them work via a pair of variable -diameter ,cone -shaped pulleys connected by a steel compsite belt.The halves of each pulley are aligned with the pointed ends of the cones touching .these form a V-shaped grove in which the connecting belt rides .One side of the pulley is fixed .and the other side is movable ,actuated by a hydraullic cylinder . the cylinder can increacse or decrease the amount of space between the two sides of the pullley .this allows the belt to ride lower or higher along the wails of the pulley, depending on driving conditions thereby changing the gear ratio.

CVT Block in figure system level simulink 2

VARIABLE TRANSMISSION RATIO:-

Represent a variable ratio gear box such as implemend by mechanical belt .CVT electric or hytraulic transmission the physical signal input defines the ratio of input to output angular shaft velocities . Connections B (base ) and F(follower) are mechanical ratational conserving ports .specify the relations between base and follower relation directions with the output shaft ratats parameter.

ENGINE:-

Represent a system -level model of spark -ignition and disel engines suitable for use at initial stages of modeling when only the basic parameter are available .optional idle speed and red line controllers are included .the throttle input signal T lines between zero and one and specifies the torque demanded from the engine as a fraction of the maximum possible torque .

Connections F and B are mechanical ratational conserving parts associated with the engine crankshift and engine block .respectively .connection P and FC are physical signal output ports through which engine powe and fuel consumption rate are reported.

INPUT SIGNAL :-

A signal builder is used to create signals for brake and throttle in figure system level simulink 3.

CVT Gear Ratio input in figure system level simulink 4.

torque vs Engine Speed input:-

VEHICLE BODY:-

in figure system level simulation 6.

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 second and then remains constant .the brake input value is zero ,hence it has no effect on velocity in figure system level simulink 7.

CVT SHAFT RPM:-

These graphs shows the variation in angular velocities of input shafts of the variable gear transmission system .,these values differ with respect to the gear ratio.

STUDY#1:-

CASE1:-

SIMULINK MODEL FOR BAJA ATV WITH CVT USING DASHBORD:-

In this model we have a dashboard which contains knobs to control the input in this case ,the input .THROTTLE and BROKE are not provided using signal builder .Aknobs is provided to control both the parameter in real -time for the user in figure system level simulink9.

OUTPUT:-

VEHICLE SPEED.:-

It can be abserved from th graph thatthe velocity of the vehicle increase drastically from 0 to 50kmph when throttle value is 0.5 and brake input is 0.Once the braking value increase from 0.1 to0.5, the velocity of the vehicle decreases to 0 at constant throttle value .this explains the direct relation of vehivle velocity with respect to throttle and brake input in figure system level simulink 10.

CVT SHAFT RPM:- figure system level simulink 11.

STUDY#2.

CASE1:-

SIMULINK MODEL FOR BAJA ATV WITH CVT USING LOOKUP TABLE :

figure in system level simulik 12 and 13. The only difference between this model and the first model is that in the model .the gear ratio input to cvt is provided using alookup table the vehicle velocity and shaft rpm output s are same as before .

CVT GEAR RATIO:- figure in system level simuilnk 14.

LOOKUP TABLE VISUALISATION :-

In figure sysytem level simulink 15.

CVT SHAFT RPM:-

In figure system level simulink 17. this graph indicates the variation in rpm of primary and secondry shafts with respect to input parameter .

CONCLUSION :-

Thus we have successfully analysed 4 different models of BAJA ATV WITH CVT and recorded the output with respect to variation in input throttle and broke.

thank you .