Project

AIM:-To preper a simulation report of an all-terrain vehicle in different condition.

SOFTWARE:-Matlab,Simulink

OBJECTIVE:-

1. To study the baja ATV model with dashboard.
2. To study the baja ATV model without dashboard.
3. To study the baja ATV model using lookup table with dashboard.
4. To study the baja ATV model using lookup table without dashboard.

INTRODUCTION:-Transmission,which transmits the power from engine to the wheels through the shafts.It consists of 4 types mainly,

• Manual transmission
• Continous variable transmission
• semi-automatic transmission
• Automatic transmission

An all-terrain vehicle(ATV) is defined as a motorized off-highway vechicle designed to travel on four low-pressure or non-pneumatic tires,having a seat designed to be straddled by the driver for steering control.CVTs are light weight as compare to traditional automatic transmissions.CVT provides more power, more fuel efficiency and smoot driving comfort rhan the traditional automatic trasmission.It is an automatic, gearless and single speed transmission that can shift through an infinite number of gear ratios.CVT gives quicker acceleration than the traditional autmatic transmission.

COMPONENTS IN THE MODEL:-

• Signal builder block
• CVT block
• Vehicle body
• Engine sensor
• Generic engine
• constant
• Simple gear
• Scope

CASE 1:-study of baja ATV model with dashboard.

In simulink model of CVT consists of signal bulider,generic engine,motion sensors,vehicle transmission,vehicle body,tyres and solver configurations blocks etc.The CVT subsystem includes Transmission block,input and output shaft inertia and motion.The vehicle body subsystem includes vehicle body block,double drum brake and tyres.In this model we have a dashboard which contains knob to control the inputs.In this case, the inputs -'Throttle' & 'Brake' are not provided using signal builder.A knob is provided to control both the parameters in real-time for the user.The main concept of using dash board is study the result by varying yhe input of brake and throttle,which shows that the velocity and speed of the engine.The gear ratio is maintained as 2.3 for 5 secs and linearly decreases to 1.8 and maintained constant for overall simulation .As the brake input varies from 0- 0.5, the velocity and speed decreases accordingly.By increasing the throttle, the velocity and speed of thee engine and shift increases..

OUTPUT:-It can be observed from the graph that the velocity of vehicle increases drastically fro 0 to 50kmph when throttle value is 0.5 & brake input is 0.Once the braking value increases from 0.1 to 0.5,the velocity of the vehicle decreases to 0 at constant throttle value.This explains the direct relation of vehicle velocity with respect to throttle and brake inputs.

CASE 2:-study of baja ATV model without dashboard.

Simulink model of CVT consists of signal bulider of signal bulider,generic engine,motion sensors,vehicle transmission,vehicle body,tyres and solver configurations blocks etc.The CVT subsystem includes Transmission block,input and output shaft inertia and motion.The vehicle body subsystem includes vehicle body block,double drum brake and tyres.The initial engine speed is given as 2100 rpm, mechanical rotation for driven pulley and driver pulley as 0.8 & 0.7 respectively. The mass of the vehicle as 250kg and 2 axles which connects 4 wheel accordingly.The signal builder is used as innput for brake and gear ratio.Brake input is maintained as 0 for overall simulation.The throttle input is given as 0.3 for 20 sec and increases to 1for overall simulation.The throttle value is mainly to control the flow or amount of fuel into the engine.The gear ratio is maintained as 2.3 for 5secs and linearly decreases to 1.8 and maintained constant for overall simulation.

OUTPUT:-It is clear from the graph that the vehicle attains its maximum speed at full throttle=1 after 30 secs and then remains constant.The brake input value is zero,hence it has no effect on velocity.

CASE 3:-Study of the baja ATV model using lookup table with dashboard.

A lookup table is an array of data that maps input values.That leads approximating a mathematical function.In simulink model 'Baja ATV with dashboard' consists throttle meter and brake input in the dash board and indicated as constant block.The CVT subsystem includes look up table,Transmission block,input and output shaft inertia and motion sensors.The vehicle body subsystem includes vehicle body block,double drum brake and tyres.The main concept of using dash board is study the result by varying the input of brake and throttle,which shows that the variation of velocity and speed of the engine.The gear ratio is given by lookup table,simulink get the input value from the lookup table and obtain the result according to the lookup table.As the brake input varies from 0-0.5, the velocity and speed decreases accordingly which inturn the gear ratio also decreasing.The velocity and speed of the engine & shaft increases, by increasing the throttle.The transmission as primary pulley and secondary pulley,in which the radius of primary pulley increses by compacting and the radius of secondary pulley decreases.As the gear ratio varies,the torque aslo varies.Gear ratio is directly proportional to the torque,which increases by increasing the gear ratio.At the max torque,the speed and velocity is decreases.

OUTPUT:- The variation in vehicle velocity can be observed with change in throttle and brake inputs. With increase in braking value,the speed of the vehicle decreases.On the other hand increasing the throttle leads to increased vehicle velocity.

CASE 4:-Study of the baja ATV model using lookup table without dashboard.

In simulink model of CVT consists of the step time,generic engine,motion sensors, vehicle transmission, vehicle body,tyres and solver configuration blocks etc.The CVT subsystem includes look up table,Transmission block,input and output shaft inertia and motion sensors.The vehicle body subsystem includes vehicle body block,double drum brake and tyres.The initial engine speed is given as 2100 rpm,mechanical roration for driven pulley and driver pulley as 0.8 & 0.7 respectively.The mass of the vehicle as 250 kg and 2 axles which connects 4 wheel accordingly.

A lookup table is an array of data that maps input values.That leads approximating a mathematical function.If the lookup table does not explicitly define the input values,simulink can estimate an output value using interpolation,extrapolation, or rounding, where:

• An interpolation is a process for estimating values that lie betwwn known data points.
• An extrapolation is a process for estimating values that lie beyond the range of known data points.
• A roundingg is a process for approximating a value by altering its digits according to a known rule.

OUTPUT:-Both the result are same as the frist case.

CONCLUSION:-Thus we have successfully analysed 4 different models of BAJA ATV WITH CVT and recorded the output with respect to variations in input throttle and brake.