Project

Aim: To analyse the BAJA ATV vehicle performance and cvt ratios using various types of input and feedback methods.

Blocks used:

Signal builder: the brake and throttle input are given using the signal builder block.

Simulink-PS converter:used to convert simulink signals to physical signals

PS-Simulink converter:used to convert physical signals to simulink signals.

Inertia: simscape block used to give inertia

Mechanical referrance : used to provide the mechanical referrence.

CVT ratio block:build using signal builder to give cvt ratio to the cvt block

Generic engine:It is a model of spark ignition system where F and B are rotational ports.

Engine sensor : Consists of a rotational sensor used to sense the rpm of generic engine.

CVT-cvt block consists of a gear box with variable gear ratio.It also consists of inertia used to give an intertia to the primary and secondary shafts.Rotational sensors are also attatched to the shafts so as to sense the speed.

Gear box:used as gear box of the vehicle.

Vehicle body: used to represent vehicle body consisting of four tyres.

Tyres: Block used for the function of tyres.

Double shoe brake :used as brake.

Case 1:

In this case the gear ratio is indipendent of the velocity since there is no feedback provided.Here the simulation is run for 200 sec.Here brake and throttle is applied through signal builder where throttle is applied for 200 sec and brake is applied for 200 sec but the brake applied is zero till 200 sec.And the acceleration keeps on increasing till 200 sec.when the throttle is applied and the generic engine will provide rotation as output and the output rotation obtained is given to engine sensor to analyse the rotational input.The engine sensor provides its ouput to the cvt gear ratio.The gear ratio is given through a signal builder.Here the cvt ratio doesnot depend on velocity but its applied on a time basis through signal builder.The output of cvt is applied to the wheels through gear box whose output is connected to the vehicle body.The tyre size and the body parameters is given through vehicle body block

The secondary rpm is increasing linearly with primary rpm.

Case 2:

Here the cvt ratio is selected on the basis of velocity. The output from the velocity is fed back and is connected to cvt block inside which is connected to lookup table.The velocity is compared to the velocities inside the lookup table and corresponding gear ratio according to the velocity is selected.The simulation time is 200 sec but the inputs cannot be varied and the simulations will occur till 200 only.Here the ouput is same as before.The output increases linearly then becomes constant.The secondary rpm increases as primary rpm increases.

Case 3:

Here the cvt ratio is predefined using signal builder and doesnot depend on the the velocity.The throttle and brake is adjusted using the knob on the dashboard.Initially throttle input is 0.3. and brake is 0.The throttle will increase and will decrease when brake is applied and will not increase after which the throttle is increased beacuse the cvt ratio is not depending on the velocity. This is because that it doesnot have feedback.Here the simulation is done for infinity

Case 4:

Here the cvt ratio is selected according to the velocity fed back, the velocity fed back is compared with the velocities in the lookup table and corresponding velocity is produced.Here when the throttle and brake is adjusted simultaneously it will show the corresponding velocity changes.Here the simulation is run for infinity so the throttle and brake is adjusted while running the simulation.