Project
AIM: To study the system level simulation of an all terrain vehicle.
KEYWORDS: CVT, Looup table, Dashboard, bajaATV
SOFTWARE: MATLAB, SIMULINK
OBJECTIVE: carry out a system-level simulation of an all-terrian vehicle and prepare a technical report explaining the model properties & comments on the results.
1. Study the baja ATV model without dashboard.
2. Study the baja Atv model with dashboard.
3. Study the baja ATV model using lookup table without dashboard.
4. Study the baja ATV model using lookuo table with dashboard.
ALL-TERRIAN VEHICLE:
An all-terrian vechile is defined as a motorized off-highway vehicle designed to travel on low-pressure or non-penumatic tries,having a seat designed to be streeing control.
STUDY 1:
SIMULINK MODEL FOR BAJA ATV WITH CVT:
simulink model of CVT consists of Singal builder, generic engine, motion sensors, vehicle transmission, vehicle body, tyres and solver configuration blocks etc., as shown in figure-1.
Continously variable transmission drive(CVT):
CVT does not make use of gears like a basic automatic transmission. Rather, it uses 2 pulleys linked by a belt. It's like snowmobile transmission, one pulley connects to the engine, the other to the transmission. The belt transfer the power between them . As the name suggests the transmission modifes continusly. this helps the vechile engine to run more efficiently.
INPUT SIGNAL:
A Single builder is used to create signals for brake and throttle.
CVT Gear Ratio Input:
Torque vs Engine Speed Input:
OUTPUT
Vehicle Speed:
It is clear from the graph that the value attains ita maximum speed(v=55km/hr) at full throttle=1 after 30 seconds and then remains constant. The brake input value is zero, hence it has no effect on velocity.
CVT Shaft RPM:
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:
SIMULINK MODEL FOR BAJA ATV WITH CVT USING DASHBOARD:
In this model we have a dashboard which contains knobs to control the inputs. in this case, the input's 'Throttle'&'brake' are not provided using signal builder. A knob is provided to control both the prameters in real-time for the user.
Output
vehicle speed:
It can observed from the graph thst the velocity of the vechile increase drastically from 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 trottle value.
STUDY 3:
SIMULINK MODEL FOR BAJA ATV WITH CVT USING LOOKUP TABLE:
The only differnce between this study and the first study, the gear ratio input to CVT is provivded using a lookup table. the vechile velocity and shaft rpm outputs are same as before.
LOOKUP TABLE VISUALISATION:
Output
vehicle speed
CVT sahft RPM:
Both the results are same as that of the first case of SIMULINK MODEL FOR BAJA ATV WITH CVT
since the input parameters are same.
STUDY 4:
SIMULINK MODEL FOR BAJA ATV WITH CVT USING LOOKUP TABLE & DASHBOARD:
This is similar to second study, In this model a dashboard is used to control the inputs-'throttle' &'brake' with knobs.
Output:
vehcile speed:
This graph is similar to that of CVT dashboard case,. The variation in vechile velocity can be observed with change in throttle and brake inputs. with increase in braking value, the speed of vechile decreases. On thev throttle leads to increased vechike velocity.
CVT shaft RPM:
This graph indicates the variation in RPM of primary and secondry shafts with respect to input prameters.
CONCLUSION:
Thus we have successfully analysed 4 different models of BAJA ATV WITH CVT and recoded the outputs
(vechile velocity & CVT shaft rpm) with respect to variations in input throttle and brake.