Project

Aim:-

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

Matlab and simulink

Objective:-

1. Study the baja ATV model without dashboard.
2. Study the baja ATV modal with dashboard
3. Study the baja ATV modal using loopup table without dashboard
4. Study the baja ATV modal using loopup table with dashboard

Introduction:-

Transmission with transmit the power form engine to the wheel through the shaft on 4 type of transmit

1. Manual transmission
2. continous variable transmission
3. semi automatic transmission
4. automatic transmission

The CVT is a system that makes it possible to vary stepless the transmission ratio without interruption of the torque flow. 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. This ability to seamlessly shift through these different gears 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. Because of their greater ability to control the engine speed range,

Study1 :-

By using the simulnk modal at CVT consist at signal builder of brake and throttle input generic engine, motion sensors, vehicle transmission, vehicle body,tyres and solver configuration blocks etc., as show an figure1 the CVT subsystem indicate the input and output inertia and variable gear ratio it dues connecting the CVT primary RPM and CVT secendary RPM and figure2 the vehical body subsystem indicate the 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. the signal builder is used as the input for break

BAJA AVT MODAL

CVT SUBSYSTEM

VEHICAL BODY SUBSYSTEM

Increase the gear ratio to simulation block if the throttle value increases the flow of fuel increases to the IC engine which inturn increases the power of the engine.

Output of BAJA AVT MODAL :-

CVT shaft speed

Output of variation at velocity and shaft speed:-

CVT gear ratio

Study 2:-

BAJA AVT WITH DASHBOARD MODAL

In that baja AVT with dashboard madal is nothing but the block diagram of Baja AVT modal and add the initial condition to run the simulation break input = 0 and then throttle input = 0.5 and the step time was infinity if the modal was 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 and then By increasing the throttle, the velocity and speed of the engine & shaft increases.

Output of BAJA AVT with dashboard modal:-

CVT shaft speed

Output of variation at velocity and shaft speed :-

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 and vehical body subsystem is vehicle body block, double drum brake and tyres

• 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.

BAJA AVT MODAL USING LOOPUP CHART

CVT SUBSYSTEM

VEHICAL BODY SUBSYSTEM

Lookup visualization:-

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.

Study 3 output:-

CVT shaft speed

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. The gear ratio is assigned in lookup table and given as input to the simulink which reads every input value and obtain the result according to the input.

Variation at velocity and shaft speed :-

Study 4:-

BAJA AVT MODAL WITH DASHBOARD USING LOOPUP TABLE

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.

Output of study 4:-

Increasing the brake input, the velocity of the vehicle decreasing accordingly which shown in figure18. 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 or any random value within the range by using extrapolation and interpolation by lookup table.

Conclution:-

As the gear ratio increases, torque increases which inturn the velocity decreases.

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