Project

Aim: to prepare a technical report of simulation of baja all terrain vehicle under different conditions

objectives: carryout a system level simulation of an all train vehicle and prepare a technical report explaining the model properties and comments on the results.

All Terrain Vehicle: An all terrain vehicle is defined as motorized off highway vehicle designed to travel on four low pressure or non pneumatic tires having a seat designed to be stradde

led by the operator and handlebars for steering control."C:\Users\yenum\OneDrive\Pictures\atv.jpg"

CASE-1:

simulink model for baja atv with cvt

"C:\Users\yenum\OneDrive\Pictures\simulin model for baja atv with cvt.jpg"

major components in model:

continuously variable transmission drive : it is better to have more gears in a gtransmission 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 donot have geras that provide steps between low and high speed operations. instead the majority of them work via apair of variable diameter cone shaped pulleys connected by 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 pully is fixed, and the other side is movable actuated by a hydrallic cylider. the cylinder can increase or decrease the amount of space between the two sides of the pully this allows the belt to ride lower or higher along the walls of the pully depending on driving conditions there by chnaging the gear ratio.

"C:\Users\yenum\OneDrive\Pictures\low gear and high gear.jpg"

cvt block:"C:\Users\yenum\OneDrive\Pictures\cvt block.jpg"

variable transmissin ratio:

represents a variable ratio gearbox such as implemented by mechanical belt cvt, electric or hydrallic transmissions. the physical signal input devices the ratio of input to output angular shaft velocities.

connections B(base) and F(follower) are mechanical rotational conserving ports specify the relation between base and follower rotation directions with the output shaft rotates parameter.

"C:\Users\yenum\OneDrive\Pictures\variable transmission ratio.jpg"

Engine:

represents a system level model of spark ignition and diesel engines suitable for use at initial stages of modelling when only the basic parameters are available. optional idle speed and red line controllers are included. the throttle input signal T lies between zero and one and specifies the torque demanded from the engine as a fraction of the max possible torque.

connection F and B are mechanical rotational conserving ports associated with the engine crankshaft and engine block, respectivelly connections p and Fc are physical signal output ports through which engine power and fuel consumption rate are reported.

"C:\Users\yenum\OneDrive\Pictures\engine.jpg"

input signal:

a signal builder is used to create signals for brake and throttle.

"C:\Users\yenum\OneDrive\Pictures\input signal.jpg"

cvt gear ratio input:"C:\Users\yenum\OneDrive\Pictures\cvt gear ratio input.jpg"

torque Vs engine speed input: "C:\Users\yenum\OneDrive\Pictures\torque Vs engine speed input.jpg"

vehicle body: "C:\Users\yenum\OneDrive\Pictures\vehicle body.jpg"

OUTPUT for CASE 1:

vehicle speed: "C:\Users\yenum\OneDrive\Pictures\vehicle speed.jpg"

it is clear taht the vehicle attains its maximum speed at full throttle after 30 sec and then remains constant. the brake input value is zero, hence it has no effect on velocity.

CVT shaft rpm: "C:\Users\yenum\OneDrive\Pictures\cvt shaft RPM.jpg"

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.

STUDY 2:

CASE-1:

simulink model for baja atv with cvt using lookup table:"C:\Users\yenum\OneDrive\Pictures\simulink model for baja atv with cvt using lookup table.jpg"

CVT BLOCK:"C:\Users\yenum\OneDrive\Pictures\CVT BLOCK 2.jpg"

CVT GEAR RATIO: "C:\Users\yenum\OneDrive\Pictures\CVT GEAR RATIO 2.jpg"

LOOK UP TABLE VISUALISATION: "C:\Users\yenum\OneDrive\Pictures\LOOKUP TABLE.jpg"

OUTPUT FOR CASE 1:

VEHICLE SPEED:"C:\Users\yenum\OneDrive\Pictures\VEHICLE SPEED 2.jpg"

CVT SHAFT RPM : "C:\Users\yenum\OneDrive\Pictures\CVT SHAFT RPM 2.jpg"

Both results are same as that of the first case since the input parameters are same.

STUDY 2:

CASE-2:

simulink model for baja atv with cvt using lookup table and dashboard: "C:\Users\yenum\OneDrive\Pictures\simulink model lookup and dashboard.jpg"

in this model dashboard is used to controll input throttle and brake with knobs.

output for case 2:

vehicle speed: "C:\Users\yenum\OneDrive\Pictures\vehicle speed dashborad.jpg"

this graph is simillar to that of cvt dashboard case. the variation in vehicle velocity can be observed with change in throttle and brake inputs. eith increasing in braking value the speed of vehicle decreases, on other hand increasing the throttle leads to increased cehicle velocity.

cvt shaft rpm: "C:\Users\yenum\OneDrive\Pictures\cvt shaft rpm 3.jpg"

CONCLUSION: We successfully analysed 4 different models of baja atv with cvt and recorded the outputs with respect to variation in input throttle and brake