Project
Objective : To study the system level simulation of all terrain vehicle. To Study the baja ATV model.
CVT : There are mainly 4 types of transmission.
Manual transmission,Semi- automatic transmission,Automatic transmission and Continious variable transmission(CVT)
A CVT is a type of automatic transmission that provides more useable power,better fuel economy and smoother driving experience than the traditional automatic transmission.The CVT is a system that can change seamlessly through a continious range of gear ratios.This contrasts with other transmission that provide a limited number of gear ratios in fixed step.The flexibility of a CVT with suitable control may allow the engine to operate at constant RPM while the vehicle moving with varying speed. The most common type of CVT uses Two Pulleys connected by a belt, however, several other designs have also been used at times.
we will be looking at the Pulley example.
Simulink Model of CVT :
The simulink model is having Signal Builder, Generic Engine,vehicle transmission,vehicle body, simple gear etc and another subsystem includes Ideal motion sensor and vehicle body which consist of Tyres, Double shoe brakes etc.
Transmission :
Vehicle Body:
MotionSensor:
The signal builder is used as input for brake, throttle and gear ratio.The throttle input is given as 0.3 for 20seconds and then increases to 1. Brake is given as 0.when the trottle value increrases the flow of fuel increase to Engine which increases the Power of Engine.The Gear ratio is maintained as 2.3 for 5 seconds and then decreases to 1.8.
Vehicle Speed:
CVT Gear Ratio:
BAJA ATV Model:
In the Baja ATV dashboard model, brake input and throttle meter blocks are provided as constant block.RPM and Velocity Gauge are provided for display. Rest of the blocks and subsystem are common as mentioned earlier. The idea is to study the result by varying the input of brake and trottle which shows that the variation of velocity and speeed of engine.The gear ratio is 2.3 for 5 seconds then decreases to 1.8. As the brake input varies from 0-0.5 the velocity and speed decreases and by increasing the trottle the velocity and speed increases.
BAJA ATV Model
CVT Subsystem
Vehicle Body Subsystem:
Variation of velocity and speed
In the above figure the brake maintained as constant and increase in throttle which shows increases in velocity.The flow of fuel is increases when the throttle increases from 0.3 to 1 thus the power in engine increases. The gear ratio is given in lookup table as input to simulink which reads the input value and obtain the results accordingly.
