Project

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

KEYWORDS :- cvt , look up table, Dashboard, Baja ATV

SOFTWARE :- Matlab, Simulink

Objective :- 1 :- Study the baja ATV Model Without Dashboard

2 :- Study The baja ATV model with Dashboard

3:- Study the baja ATV Model using lookup .

4 :- Study the baja ATV model using lookup table With Dashboard

INTURDUCTION :- Transmission , which transmits the power from Engine to the wheels through the shafts. It consists of 4 type mainly,

• Manual transmission
• Continous Varable transmission
• Semi - Automatic transmission
• Automatic Transmission

A countinuously variable transmission ,or CVT ,is a type of automatic trans mission that Provides more useable power, Better Fuel Economy and a smoother driving Experience than a traditional automatic transmission . The CVT is a system that makes it possible to vary stepless the transmission ratio (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. Thish ability to seamlessly shift through these different gear provides a number of benefits including extrmely 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. Because of their greater ability to control the engine speed range, CVTs produce fewer emissions. CVTs are also lighter weight than traditional automatic transmissions.

STUDY :- 1

By using simulink modelof CVT Consists of Signal builder , generic engine , motion sensors, Vehicle transmission, vehicle body subsystem includes transmission block ,input and output shaft inertia and motion sensors as shown in figure-2. The vehicle body subsystem includes vehicle body block, double drum brake and tyres as shown in figure-3. 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

BAJAATV MODEL

Figure :-1

CVT SUBSYSTEM

FIGURE :- 2

VEHICLE BODY SUBSYS

Figure :- 3

The signal builder is used as input for brake, throttle and gear ratio. Brake input is maintained as 0 for overall simulation. The throttle input is given as 0.3 for20 secs and increases to 1 for overall simulatuion. 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. The gear ratio is maintained as 2.3 for 5 secs and linearly decreases to 1.8 and maintained constant for overall simulation as shown in figure (4 - 5).

FIGURE :-4

FIGURE :-5

STUDY :-2

BAJAATV WITH DASHBOARD MODEL

FIGURE :-6

The above 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 as shown in figure 2 & figure 3. 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. The gear ratio is maintained as 2.3 for 5 secs and linearly decreases to 1.8 and maintained constant for overall simulation as shown in figure 5. As the brake input varies from 0 - 0.5, the velocity and speed decreases accordingly. By increasing the throttle, the velocity and speed of the engine & shaft increases.

STUDY :-3

By using simulink model of CVT consists of step time, generic engine, motion sensors, vehicle transmission, vehicle body,tyres and solver configuration blocks etc., as shown in figure-7. The CVT subsystem includes look up table, Transmission block, input and output shaft inertia and motion sensors as shown in figure-8. The vehicle body subsystem includes vehicle body block, double drum brake and tyres as shown in figure-9. 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 lie between 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.

FIGURE :-7

FIGURE :- 8

FIGURE:-9

The brakke input and throttle input is given by step time, which depends on the run time and varies according ly . 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 and engine speed . It works as closed loop when the is given by lookup table . The simulink get the input value from lookup table and obtain according to the input values of gear ratio. The gear ratio varies from 2.3 to 1.8 as input and output interms of velocity . The maximum velocity reached as 57Kmph approximately.

FIGURE :- 10

STUDY 4:-

BAJA ATV MODEL WITH DASHBOARD USING LOOKUP TABLE

FIGURE :- 11

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 as shown in figure 8 & figure 9. 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. 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 :-

STUDY 1:- variation of velocity and shaft speed

FIGURE :- 12

In the above figure, the brake is maintained as constant and increase in throttle which shows increase in velocity. The flow of fuel is increses when the throttle increases from 0.3 to 1, thus the power in the engine increases. The torque reaches approximately 7N-m at 1.8 gear ratio, which defines that gear ratio is directly proportional to the torque. By this gear ratio, the speed & velocity can achieve maximum.

FIGURE :- 13

In the above figure, the primary shaft reaches high speed and secondary shaft as low rotational speed because the radius of the primary shaft as more than the secondary shaft, the speed is directly proportional to the radius of the shaft. As the radius increases the speed of the shaft also increases.

STUDY 2 :- VARIATION OF VELOCITY AND SHAFT SPEED

FIGURE :- 14

In the above figure , the velocity of the the Vehicle is maintainned as constant for consttsnt throttle value as 0.3 and varying by increase the value of throttle which incrase the velocity of vechicle . By increasing the break input , the velocity of the vechile decreasing accordingly which shown in figure14.

FIGURE:- 15

In the above figure , the primary shaft speed increases by increasing throttle and decreasing by increasing breake input value , which defines that the throttle can flow more amount of fuel which increases the power of the engine and smilar to the secondary shaft . the radius of the primary shaft as more than the secondary shaft , the speed is directly proportional to the radius of the shaft . As the radius increases the speed of the shaft also increases

STUDY 3:- VARIATION OF VELOCITY AND SHAFT SPEED

FIGURE - 16

In the above figure ,the brake is maintained as constant and increase in throttle whic Shows increase in velocity. The flow of fuel is increases when the throttle increases from 0.3 to 1, thus the power in the engine increases. the torque reaches approximately 7N-M at 1.8 gear ratio , which defines that gear ration is proportional to the torque . By thish gear ration , The speed and velocity can achieve maximum. the gear ration is assigned in lookup table and given as input to the simulink which reads every value and obtain the tresult according to the input.

FIGURE :- 17

In the above figure, the primary shaft speed increases by increasing throttle and decreasing by increasing brake input value , which defines that throttle can flow more amount of fuel which increases the power of the engine and similar to the secondary shaft, The radius of the primary shaft as more than the secondary shaft , the speed is directly proportional to the radius of the shaft .As radius increases the speed is directly proportional to the radius increases the speed of the shaft also increases

STUDY 4 : - VARIATION OF VELOCITY AND SHAFT SPEED

FIGURE :- 18

In the above figure ,the velocity of the vehicle is maintained as constant for constant throttle value as 0.3 and varying by increasing the the value of throttle which increases the velocity of vehicle. By increasing the brake input , the velocity of the vechicle decreasing according which show in figure 18 , By using lookup table, it works as closed loop by recording the velocity value and we can get at any particular value of gear ratio which is beyond the range random value within the range by using extrapolation and interpolation by table.

FIGURE :- 19

In the above figure , the primary shaft speed increases by increasing throttle and decreasing by increasing brake input value, which defines that the throttle can flow more amount of fuel which increases the power of the engine and similar to the secondary shaft. The radius of the primary shaft as more than the secondary shaft , the speed is directly proportional to the radius of the shaft . as the radius increases of the shaft also increases. The throttle value and brake input value can be varying dashboard , so we cam get any particular value for input.

CONCLUSION :-

1. As the throttle incfreases, the velocity also increases which inturn the power in engine also increases.

FIGURE :- 20

1. In the above figure , at the beginning the speed reducing because of gear ratio and torque output . when the gear ration increases, the torque increases.

2. As the brake input increases, the velocity decreases and engine power also decreases At a certain brake input value the engine may shut down and there is no power output . The engine power is inversly proportional to the input.

FIGURE :- 21

3. As the gear ration increases, torque increases which inturn the velocity decreases.

FIGURE :-22

In the above figure , the torque is increasing by increase in engine speed. At a particular point the the torque is decreasing when the gear ratio increases to achieve maximum velocity.

FIGURE :- 23

In the above figure , the velocity is varying wrt the gear ratio. For the high gear ration , The torque is more which decrease thevelocity .By changing to high gear , the gear ratio become less paralelly the torque also less which can get high velocity.,

4. With help of lookup table , we can vary any input and also get the output value by using interpolation and extrapolation method which the simulink can solve.