Project

EV BATCH - 17

Carry out a system-level simulation of an all-terrain vehicle.

Download the model from the given link:

https://www.mathworks.com/matlabcentral/fileexchange/70576-baja-all-terrain-vehicle-atv-model

Prepare a technical report explaining the model properties & comments on the results.

AIM : To study the system-level simulation of an all-terrain vehicle.

SOFTWARE : Matlab, simulink

OBJECTIVES :

• Study the baja ATV model without dashboard.
• Study the baja ATV model with dashboard.
• Study the baja ATV model using lookup table without dashboard.
• Study the baja ATV model using lookup table with 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

1. A continuously variable transmission, or CVT, is a type of automatic transmission that provides more useable power better fuel economy and a smoother driving experience than a traditional automatic transmission.
2. The CVT is a system that makes it possible to vary stepless the transmission ratio without interruption of the torque flow.
3. Therefore an infinite number of ratios (between a minimum and maximum value) are possible, it is an automatic, single speed, and gearless transmission that can shift through an infinite number of gear ratios.
4. This ability to seamlessly shift through these different gears.
5. provides a number of benefits including extremely smooth shifts and exceptional fuel economy A CVT draws top engine power from a small engine which gives drivers quicker acceleration than standard automatic transmissions Bocaiuso of their greator ability to control the engine speed range.
6. CVTs produce lewat emissions CVTs are also Tighter weight than traditional automatic transmissions.

1 . Study the baja ATV model without dashboard.

• By using simulink model of CVT consists of Signal builder, generic engine, motion sensors, vehicle transmission, vehicle body,tyres and solver configuration blocks etc., .
• The CVT subsystem includes 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 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 as shown in the below figure .

INSIDE THE CVT :

INSIDE THE VEHICLE BODY :

SIGNAL BUILDER :

• The signal builder is used as input for brake, throttle and gear ratio. Brake input is maintained as 0 for overall simulation.
• The throttle valve is mainly to control the flow or amount of fuel into the engine, if the throttle value increases the flow of fuel increases to the IC engine which inturn increases the power of the engine.

CVT GEAR RATIO :

OUTPUTS :

CVT SHAFT SPEED :

2 . Study the baja ATV model with dashboard.

• The below figure shows 'Baja ATV with dashboard' model which consists throttle meter and brake input in the dash board instead of giving input through signal builder.
• Rest of the blocks and subsystems are common in the above baja ATV model without dash board
• The main concept of using dash board is study the result by varying the input of brake and throttle, which shows that the velocity and speed of the engine.
• By increasing the throttle, the velocity and speed of the engine & shaft increases.

OUTPUTS :

CVT SHAFT SPEED :

3 . Study the baja ATV model using lookup table without dashboard

• By using simulink model of CVT consists of 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 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.
• A lookup table is an array of data that maps input values to output values, thereby approximating a mathematical function.
• Given a set of input values, a lookup operation retrieves the corresponding output values from the table.

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

BAJA ATV USING LOOK UP CHART :

INSIDE THE CVT :

INSIDE THE VEHICLE BODY :

LOOKUP TABLE VISUALIZATION :

• The brake input and throttle input is given by step time, which depends on the run time and varies accordingly.
• By using Lookup table for gear ratio which takes as input to the CVT and works according to the input gear ratio and obtained the output.
• This method is very effective which can avoid the unusual torque at the certain speed and very easy to achieve greater velocity & engine speed.
• It works as closed loop when the input is given by lookup table.
• The simulink get the input value from lookup table and obtain the result according to the input values of gear ratio.

OUTPUTS :

VEHICLE SPPED :

CVT SHAFT SPEED:

4 . Study the baja ATV model using lookup table with dashboard.

• The above figure shows 'Baja ATV with dashboard' model using lookup table which consists throttle meter and brake input in the dash board and indicated as constant block. Rest of the blocks and subsystems are common in the above baja ATV model without dash board .
• 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 , the velocity and speed decreases accordingly which inturn the gear ratio also decreasing.
• By increasing the throttle, the velocity and speed of the engine & shaft increases.
• 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 also 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 :

VEHICLE SPPED :

CVT SHAFT SPEED :